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-rw-r--r--kernel/Makefile1
-rw-r--r--kernel/exit.c10
-rw-r--r--kernel/fork.c3
-rw-r--r--kernel/kthread.c5
-rw-r--r--kernel/marker.c36
-rw-r--r--kernel/module.c81
-rw-r--r--kernel/notifier.c2
-rw-r--r--kernel/sched.c17
-rw-r--r--kernel/signal.c3
-rw-r--r--kernel/trace/Kconfig64
-rw-r--r--kernel/trace/Makefile4
-rw-r--r--kernel/trace/ftrace.c275
-rw-r--r--kernel/trace/ring_buffer.c2014
-rw-r--r--kernel/trace/trace.c1845
-rw-r--r--kernel/trace/trace.h211
-rw-r--r--kernel/trace/trace_boot.c126
-rw-r--r--kernel/trace/trace_functions.c2
-rw-r--r--kernel/trace/trace_irqsoff.c19
-rw-r--r--kernel/trace/trace_mmiotrace.c116
-rw-r--r--kernel/trace/trace_nop.c64
-rw-r--r--kernel/trace/trace_sched_switch.c137
-rw-r--r--kernel/trace/trace_sched_wakeup.c148
-rw-r--r--kernel/trace/trace_selftest.c83
-rw-r--r--kernel/trace/trace_stack.c310
-rw-r--r--kernel/trace/trace_sysprof.c2
-rw-r--r--kernel/tracepoint.c477
26 files changed, 4711 insertions, 1344 deletions
diff --git a/kernel/Makefile b/kernel/Makefile
index 066550a..305f11d 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -85,6 +85,7 @@ obj-$(CONFIG_SYSCTL) += utsname_sysctl.o
obj-$(CONFIG_TASK_DELAY_ACCT) += delayacct.o
obj-$(CONFIG_TASKSTATS) += taskstats.o tsacct.o
obj-$(CONFIG_MARKERS) += marker.o
+obj-$(CONFIG_TRACEPOINTS) += tracepoint.o
obj-$(CONFIG_LATENCYTOP) += latencytop.o
obj-$(CONFIG_HAVE_GENERIC_DMA_COHERENT) += dma-coherent.o
obj-$(CONFIG_FTRACE) += trace/
diff --git a/kernel/exit.c b/kernel/exit.c
index 059b38c..80137a5 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -47,6 +47,7 @@
#include <linux/blkdev.h>
#include <linux/task_io_accounting_ops.h>
#include <linux/tracehook.h>
+#include <trace/sched.h>
#include <asm/uaccess.h>
#include <asm/unistd.h>
@@ -146,7 +147,10 @@ static void __exit_signal(struct task_struct *tsk)
static void delayed_put_task_struct(struct rcu_head *rhp)
{
- put_task_struct(container_of(rhp, struct task_struct, rcu));
+ struct task_struct *tsk = container_of(rhp, struct task_struct, rcu);
+
+ trace_sched_process_free(tsk);
+ put_task_struct(tsk);
}
@@ -1070,6 +1074,8 @@ NORET_TYPE void do_exit(long code)
if (group_dead)
acct_process();
+ trace_sched_process_exit(tsk);
+
exit_sem(tsk);
exit_files(tsk);
exit_fs(tsk);
@@ -1675,6 +1681,8 @@ static long do_wait(enum pid_type type, struct pid *pid, int options,
struct task_struct *tsk;
int retval;
+ trace_sched_process_wait(pid);
+
add_wait_queue(&current->signal->wait_chldexit,&wait);
repeat:
/*
diff --git a/kernel/fork.c b/kernel/fork.c
index 44e64d7..4d09355 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -58,6 +58,7 @@
#include <linux/tty.h>
#include <linux/proc_fs.h>
#include <linux/blkdev.h>
+#include <trace/sched.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
@@ -1372,6 +1373,8 @@ long do_fork(unsigned long clone_flags,
if (!IS_ERR(p)) {
struct completion vfork;
+ trace_sched_process_fork(current, p);
+
nr = task_pid_vnr(p);
if (clone_flags & CLONE_PARENT_SETTID)
diff --git a/kernel/kthread.c b/kernel/kthread.c
index 14ec64f..8e7a7ce 100644
--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -13,6 +13,7 @@
#include <linux/file.h>
#include <linux/module.h>
#include <linux/mutex.h>
+#include <trace/sched.h>
#define KTHREAD_NICE_LEVEL (-5)
@@ -205,6 +206,8 @@ int kthread_stop(struct task_struct *k)
/* It could exit after stop_info.k set, but before wake_up_process. */
get_task_struct(k);
+ trace_sched_kthread_stop(k);
+
/* Must init completion *before* thread sees kthread_stop_info.k */
init_completion(&kthread_stop_info.done);
smp_wmb();
@@ -220,6 +223,8 @@ int kthread_stop(struct task_struct *k)
ret = kthread_stop_info.err;
mutex_unlock(&kthread_stop_lock);
+ trace_sched_kthread_stop_ret(ret);
+
return ret;
}
EXPORT_SYMBOL(kthread_stop);
diff --git a/kernel/marker.c b/kernel/marker.c
index 7d1faec..e9c6b2b 100644
--- a/kernel/marker.c
+++ b/kernel/marker.c
@@ -62,7 +62,7 @@ struct marker_entry {
int refcount; /* Number of times armed. 0 if disarmed. */
struct rcu_head rcu;
void *oldptr;
- unsigned char rcu_pending:1;
+ int rcu_pending;
unsigned char ptype:1;
char name[0]; /* Contains name'\0'format'\0' */
};
@@ -103,11 +103,11 @@ void marker_probe_cb(const struct marker *mdata, void *call_private, ...)
char ptype;
/*
- * preempt_disable does two things : disabling preemption to make sure
- * the teardown of the callbacks can be done correctly when they are in
- * modules and they insure RCU read coherency.
+ * rcu_read_lock_sched does two things : disabling preemption to make
+ * sure the teardown of the callbacks can be done correctly when they
+ * are in modules and they insure RCU read coherency.
*/
- preempt_disable();
+ rcu_read_lock_sched();
ptype = mdata->ptype;
if (likely(!ptype)) {
marker_probe_func *func;
@@ -145,7 +145,7 @@ void marker_probe_cb(const struct marker *mdata, void *call_private, ...)
va_end(args);
}
}
- preempt_enable();
+ rcu_read_unlock_sched();
}
EXPORT_SYMBOL_GPL(marker_probe_cb);
@@ -162,7 +162,7 @@ void marker_probe_cb_noarg(const struct marker *mdata, void *call_private, ...)
va_list args; /* not initialized */
char ptype;
- preempt_disable();
+ rcu_read_lock_sched();
ptype = mdata->ptype;
if (likely(!ptype)) {
marker_probe_func *func;
@@ -195,7 +195,7 @@ void marker_probe_cb_noarg(const struct marker *mdata, void *call_private, ...)
multi[i].func(multi[i].probe_private, call_private,
mdata->format, &args);
}
- preempt_enable();
+ rcu_read_unlock_sched();
}
EXPORT_SYMBOL_GPL(marker_probe_cb_noarg);
@@ -560,7 +560,7 @@ static int set_marker(struct marker_entry **entry, struct marker *elem,
* Disable a marker and its probe callback.
* Note: only waiting an RCU period after setting elem->call to the empty
* function insures that the original callback is not used anymore. This insured
- * by preempt_disable around the call site.
+ * by rcu_read_lock_sched around the call site.
*/
static void disable_marker(struct marker *elem)
{
@@ -653,11 +653,17 @@ int marker_probe_register(const char *name, const char *format,
entry = get_marker(name);
if (!entry) {
entry = add_marker(name, format);
- if (IS_ERR(entry)) {
+ if (IS_ERR(entry))
ret = PTR_ERR(entry);
- goto end;
- }
+ } else if (format) {
+ if (!entry->format)
+ ret = marker_set_format(&entry, format);
+ else if (strcmp(entry->format, format))
+ ret = -EPERM;
}
+ if (ret)
+ goto end;
+
/*
* If we detect that a call_rcu is pending for this marker,
* make sure it's executed now.
@@ -674,6 +680,8 @@ int marker_probe_register(const char *name, const char *format,
mutex_lock(&markers_mutex);
entry = get_marker(name);
WARN_ON(!entry);
+ if (entry->rcu_pending)
+ rcu_barrier_sched();
entry->oldptr = old;
entry->rcu_pending = 1;
/* write rcu_pending before calling the RCU callback */
@@ -717,6 +725,8 @@ int marker_probe_unregister(const char *name,
entry = get_marker(name);
if (!entry)
goto end;
+ if (entry->rcu_pending)
+ rcu_barrier_sched();
entry->oldptr = old;
entry->rcu_pending = 1;
/* write rcu_pending before calling the RCU callback */
@@ -795,6 +805,8 @@ int marker_probe_unregister_private_data(marker_probe_func *probe,
mutex_lock(&markers_mutex);
entry = get_marker_from_private_data(probe, probe_private);
WARN_ON(!entry);
+ if (entry->rcu_pending)
+ rcu_barrier_sched();
entry->oldptr = old;
entry->rcu_pending = 1;
/* write rcu_pending before calling the RCU callback */
diff --git a/kernel/module.c b/kernel/module.c
index 25bc9ac..0d8d21e 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -46,6 +46,8 @@
#include <asm/cacheflush.h>
#include <linux/license.h>
#include <asm/sections.h>
+#include <linux/tracepoint.h>
+#include <linux/ftrace.h>
#if 0
#define DEBUGP printk
@@ -1430,6 +1432,9 @@ static void free_module(struct module *mod)
/* Module unload stuff */
module_unload_free(mod);
+ /* release any pointers to mcount in this module */
+ ftrace_release(mod->module_core, mod->core_size);
+
/* This may be NULL, but that's OK */
module_free(mod, mod->module_init);
kfree(mod->args);
@@ -1861,9 +1866,13 @@ static noinline struct module *load_module(void __user *umod,
unsigned int markersindex;
unsigned int markersstringsindex;
unsigned int verboseindex;
+ unsigned int tracepointsindex;
+ unsigned int tracepointsstringsindex;
+ unsigned int mcountindex;
struct module *mod;
long err = 0;
void *percpu = NULL, *ptr = NULL; /* Stops spurious gcc warning */
+ void *mseg;
struct exception_table_entry *extable;
mm_segment_t old_fs;
@@ -2156,6 +2165,12 @@ static noinline struct module *load_module(void __user *umod,
markersstringsindex = find_sec(hdr, sechdrs, secstrings,
"__markers_strings");
verboseindex = find_sec(hdr, sechdrs, secstrings, "__verbose");
+ tracepointsindex = find_sec(hdr, sechdrs, secstrings, "__tracepoints");
+ tracepointsstringsindex = find_sec(hdr, sechdrs, secstrings,
+ "__tracepoints_strings");
+
+ mcountindex = find_sec(hdr, sechdrs, secstrings,
+ "__mcount_loc");
/* Now do relocations. */
for (i = 1; i < hdr->e_shnum; i++) {
@@ -2183,6 +2198,12 @@ static noinline struct module *load_module(void __user *umod,
mod->num_markers =
sechdrs[markersindex].sh_size / sizeof(*mod->markers);
#endif
+#ifdef CONFIG_TRACEPOINTS
+ mod->tracepoints = (void *)sechdrs[tracepointsindex].sh_addr;
+ mod->num_tracepoints =
+ sechdrs[tracepointsindex].sh_size / sizeof(*mod->tracepoints);
+#endif
+
/* Find duplicate symbols */
err = verify_export_symbols(mod);
@@ -2201,12 +2222,22 @@ static noinline struct module *load_module(void __user *umod,
add_kallsyms(mod, sechdrs, symindex, strindex, secstrings);
+ if (!mod->taints) {
#ifdef CONFIG_MARKERS
- if (!mod->taints)
marker_update_probe_range(mod->markers,
mod->markers + mod->num_markers);
#endif
dynamic_printk_setup(sechdrs, verboseindex);
+#ifdef CONFIG_TRACEPOINTS
+ tracepoint_update_probe_range(mod->tracepoints,
+ mod->tracepoints + mod->num_tracepoints);
+#endif
+ }
+
+ /* sechdrs[0].sh_size is always zero */
+ mseg = (void *)sechdrs[mcountindex].sh_addr;
+ ftrace_init_module(mseg, mseg + sechdrs[mcountindex].sh_size);
+
err = module_finalize(hdr, sechdrs, mod);
if (err < 0)
goto cleanup;
@@ -2276,6 +2307,7 @@ static noinline struct module *load_module(void __user *umod,
cleanup:
kobject_del(&mod->mkobj.kobj);
kobject_put(&mod->mkobj.kobj);
+ ftrace_release(mod->module_core, mod->core_size);
free_unload:
module_unload_free(mod);
module_free(mod, mod->module_init);
@@ -2759,3 +2791,50 @@ void module_update_markers(void)
mutex_unlock(&module_mutex);
}
#endif
+
+#ifdef CONFIG_TRACEPOINTS
+void module_update_tracepoints(void)
+{
+ struct module *mod;
+
+ mutex_lock(&module_mutex);
+ list_for_each_entry(mod, &modules, list)
+ if (!mod->taints)
+ tracepoint_update_probe_range(mod->tracepoints,
+ mod->tracepoints + mod->num_tracepoints);
+ mutex_unlock(&module_mutex);
+}
+
+/*
+ * Returns 0 if current not found.
+ * Returns 1 if current found.
+ */
+int module_get_iter_tracepoints(struct tracepoint_iter *iter)
+{
+ struct module *iter_mod;
+ int found = 0;
+
+ mutex_lock(&module_mutex);
+ list_for_each_entry(iter_mod, &modules, list) {
+ if (!iter_mod->taints) {
+ /*
+ * Sorted module list
+ */
+ if (iter_mod < iter->module)
+ continue;
+ else if (iter_mod > iter->module)
+ iter->tracepoint = NULL;
+ found = tracepoint_get_iter_range(&iter->tracepoint,
+ iter_mod->tracepoints,
+ iter_mod->tracepoints
+ + iter_mod->num_tracepoints);
+ if (found) {
+ iter->module = iter_mod;
+ break;
+ }
+ }
+ }
+ mutex_unlock(&module_mutex);
+ return found;
+}
+#endif
diff --git a/kernel/notifier.c b/kernel/notifier.c
index 823be115..4282c0a 100644
--- a/kernel/notifier.c
+++ b/kernel/notifier.c
@@ -550,7 +550,7 @@ EXPORT_SYMBOL(unregister_reboot_notifier);
static ATOMIC_NOTIFIER_HEAD(die_chain);
-int notify_die(enum die_val val, const char *str,
+int notrace notify_die(enum die_val val, const char *str,
struct pt_regs *regs, long err, int trap, int sig)
{
struct die_args args = {
diff --git a/kernel/sched.c b/kernel/sched.c
index 09a8c15..d906f72 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -71,6 +71,7 @@
#include <linux/debugfs.h>
#include <linux/ctype.h>
#include <linux/ftrace.h>
+#include <trace/sched.h>
#include <asm/tlb.h>
#include <asm/irq_regs.h>
@@ -1936,6 +1937,7 @@ unsigned long wait_task_inactive(struct task_struct *p, long match_state)
* just go back and repeat.
*/
rq = task_rq_lock(p, &flags);
+ trace_sched_wait_task(rq, p);
running = task_running(rq, p);
on_rq = p->se.on_rq;
ncsw = 0;
@@ -2297,9 +2299,7 @@ out_activate:
success = 1;
out_running:
- trace_mark(kernel_sched_wakeup,
- "pid %d state %ld ## rq %p task %p rq->curr %p",
- p->pid, p->state, rq, p, rq->curr);
+ trace_sched_wakeup(rq, p);
check_preempt_curr(rq, p, sync);
p->state = TASK_RUNNING;
@@ -2432,9 +2432,7 @@ void wake_up_new_task(struct task_struct *p, unsigned long clone_flags)
p->sched_class->task_new(rq, p);
inc_nr_running(rq);
}
- trace_mark(kernel_sched_wakeup_new,
- "pid %d state %ld ## rq %p task %p rq->curr %p",
- p->pid, p->state, rq, p, rq->curr);
+ trace_sched_wakeup_new(rq, p);
check_preempt_curr(rq, p, 0);
#ifdef CONFIG_SMP
if (p->sched_class->task_wake_up)
@@ -2607,11 +2605,7 @@ context_switch(struct rq *rq, struct task_struct *prev,
struct mm_struct *mm, *oldmm;
prepare_task_switch(rq, prev, next);
- trace_mark(kernel_sched_schedule,
- "prev_pid %d next_pid %d prev_state %ld "
- "## rq %p prev %p next %p",
- prev->pid, next->pid, prev->state,
- rq, prev, next);
+ trace_sched_switch(rq, prev, next);
mm = next->mm;
oldmm = prev->active_mm;
/*
@@ -2851,6 +2845,7 @@ static void sched_migrate_task(struct task_struct *p, int dest_cpu)
|| unlikely(!cpu_active(dest_cpu)))
goto out;
+ trace_sched_migrate_task(rq, p, dest_cpu);
/* force the process onto the specified CPU */
if (migrate_task(p, dest_cpu, &req)) {
/* Need to wait for migration thread (might exit: take ref). */
diff --git a/kernel/signal.c b/kernel/signal.c
index 6eea582..105217d 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -27,6 +27,7 @@
#include <linux/freezer.h>
#include <linux/pid_namespace.h>
#include <linux/nsproxy.h>
+#include <trace/sched.h>
#include <asm/param.h>
#include <asm/uaccess.h>
@@ -803,6 +804,8 @@ static int send_signal(int sig, struct siginfo *info, struct task_struct *t,
struct sigpending *pending;
struct sigqueue *q;
+ trace_sched_signal_send(sig, t);
+
assert_spin_locked(&t->sighand->siglock);
if (!prepare_signal(sig, t))
return 0;
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 263e9e6..1cb3e1f 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -1,23 +1,37 @@
#
# Architectures that offer an FTRACE implementation should select HAVE_FTRACE:
#
+
+config NOP_TRACER
+ bool
+
config HAVE_FTRACE
bool
+ select NOP_TRACER
config HAVE_DYNAMIC_FTRACE
bool
+config HAVE_FTRACE_MCOUNT_RECORD
+ bool
+
config TRACER_MAX_TRACE
bool
+config RING_BUFFER
+ bool
+
config TRACING
bool
select DEBUG_FS
+ select RING_BUFFER
select STACKTRACE
+ select TRACEPOINTS
config FTRACE
bool "Kernel Function Tracer"
depends on HAVE_FTRACE
+ depends on DEBUG_KERNEL
select FRAME_POINTER
select TRACING
select CONTEXT_SWITCH_TRACER
@@ -36,6 +50,7 @@ config IRQSOFF_TRACER
depends on TRACE_IRQFLAGS_SUPPORT
depends on GENERIC_TIME
depends on HAVE_FTRACE
+ depends on DEBUG_KERNEL
select TRACE_IRQFLAGS
select TRACING
select TRACER_MAX_TRACE
@@ -59,6 +74,7 @@ config PREEMPT_TRACER
depends on GENERIC_TIME
depends on PREEMPT
depends on HAVE_FTRACE
+ depends on DEBUG_KERNEL
select TRACING
select TRACER_MAX_TRACE
help
@@ -86,6 +102,7 @@ config SYSPROF_TRACER
config SCHED_TRACER
bool "Scheduling Latency Tracer"
depends on HAVE_FTRACE
+ depends on DEBUG_KERNEL
select TRACING
select CONTEXT_SWITCH_TRACER
select TRACER_MAX_TRACE
@@ -96,16 +113,56 @@ config SCHED_TRACER
config CONTEXT_SWITCH_TRACER
bool "Trace process context switches"
depends on HAVE_FTRACE
+ depends on DEBUG_KERNEL
select TRACING
select MARKERS
help
This tracer gets called from the context switch and records
all switching of tasks.
+config BOOT_TRACER
+ bool "Trace boot initcalls"
+ depends on HAVE_FTRACE
+ depends on DEBUG_KERNEL
+ select TRACING
+ help
+ This tracer helps developers to optimize boot times: it records
+ the timings of the initcalls and traces key events and the identity
+ of tasks that can cause boot delays, such as context-switches.
+
+ Its aim is to be parsed by the /scripts/bootgraph.pl tool to
+ produce pretty graphics about boot inefficiencies, giving a visual
+ representation of the delays during initcalls - but the raw
+ /debug/tracing/trace text output is readable too.
+
+ ( Note that tracing self tests can't be enabled if this tracer is
+ selected, because the self-tests are an initcall as well and that
+ would invalidate the boot trace. )
+
+config STACK_TRACER
+ bool "Trace max stack"
+ depends on HAVE_FTRACE
+ depends on DEBUG_KERNEL
+ select FTRACE
+ select STACKTRACE
+ help
+ This special tracer records the maximum stack footprint of the
+ kernel and displays it in debugfs/tracing/stack_trace.
+
+ This tracer works by hooking into every function call that the
+ kernel executes, and keeping a maximum stack depth value and
+ stack-trace saved. Because this logic has to execute in every
+ kernel function, all the time, this option can slow down the
+ kernel measurably and is generally intended for kernel
+ developers only.
+
+ Say N if unsure.
+
config DYNAMIC_FTRACE
bool "enable/disable ftrace tracepoints dynamically"
depends on FTRACE
depends on HAVE_DYNAMIC_FTRACE
+ depends on DEBUG_KERNEL
default y
help
This option will modify all the calls to ftrace dynamically
@@ -121,12 +178,17 @@ config DYNAMIC_FTRACE
were made. If so, it runs stop_machine (stops all CPUS)
and modifies the code to jump over the call to ftrace.
+config FTRACE_MCOUNT_RECORD
+ def_bool y
+ depends on DYNAMIC_FTRACE
+ depends on HAVE_FTRACE_MCOUNT_RECORD
+
config FTRACE_SELFTEST
bool
config FTRACE_STARTUP_TEST
bool "Perform a startup test on ftrace"
- depends on TRACING
+ depends on TRACING && DEBUG_KERNEL && !BOOT_TRACER
select FTRACE_SELFTEST
help
This option performs a series of startup tests on ftrace. On bootup
diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile
index 71d17de..a85dfba 100644
--- a/kernel/trace/Makefile
+++ b/kernel/trace/Makefile
@@ -11,6 +11,7 @@ obj-y += trace_selftest_dynamic.o
endif
obj-$(CONFIG_FTRACE) += libftrace.o
+obj-$(CONFIG_RING_BUFFER) += ring_buffer.o
obj-$(CONFIG_TRACING) += trace.o
obj-$(CONFIG_CONTEXT_SWITCH_TRACER) += trace_sched_switch.o
@@ -19,6 +20,9 @@ obj-$(CONFIG_FTRACE) += trace_functions.o
obj-$(CONFIG_IRQSOFF_TRACER) += trace_irqsoff.o
obj-$(CONFIG_PREEMPT_TRACER) += trace_irqsoff.o
obj-$(CONFIG_SCHED_TRACER) += trace_sched_wakeup.o
+obj-$(CONFIG_NOP_TRACER) += trace_nop.o
+obj-$(CONFIG_STACK_TRACER) += trace_stack.o
obj-$(CONFIG_MMIOTRACE) += trace_mmiotrace.o
+obj-$(CONFIG_BOOT_TRACER) += trace_boot.o
libftrace-y := ftrace.o
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index f6e3af3..4dda4f6 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -81,7 +81,7 @@ void clear_ftrace_function(void)
static int __register_ftrace_function(struct ftrace_ops *ops)
{
- /* Should never be called by interrupts */
+ /* should not be called from interrupt context */
spin_lock(&ftrace_lock);
ops->next = ftrace_list;
@@ -115,6 +115,7 @@ static int __unregister_ftrace_function(struct ftrace_ops *ops)
struct ftrace_ops **p;
int ret = 0;
+ /* should not be called from interrupt context */
spin_lock(&ftrace_lock);
/*
@@ -153,6 +154,30 @@ static int __unregister_ftrace_function(struct ftrace_ops *ops)
#ifdef CONFIG_DYNAMIC_FTRACE
+#ifndef CONFIG_FTRACE_MCOUNT_RECORD
+/*
+ * The hash lock is only needed when the recording of the mcount
+ * callers are dynamic. That is, by the caller themselves and
+ * not recorded via the compilation.
+ */
+static DEFINE_SPINLOCK(ftrace_hash_lock);
+#define ftrace_hash_lock(flags) spin_lock_irqsave(&ftrace_hash_lock, flags)
+#define ftrace_hash_unlock(flags) \
+ spin_unlock_irqrestore(&ftrace_hash_lock, flags)
+#else
+/* This is protected via the ftrace_lock with MCOUNT_RECORD. */
+#define ftrace_hash_lock(flags) do { (void)(flags); } while (0)
+#define ftrace_hash_unlock(flags) do { } while(0)
+#endif
+
+/*
+ * Since MCOUNT_ADDR may point to mcount itself, we do not want
+ * to get it confused by reading a reference in the code as we
+ * are parsing on objcopy output of text. Use a variable for
+ * it instead.
+ */
+static unsigned long mcount_addr = MCOUNT_ADDR;
+
static struct task_struct *ftraced_task;
enum {
@@ -171,7 +196,6 @@ static struct hlist_head ftrace_hash[FTRACE_HASHSIZE];
static DEFINE_PER_CPU(int, ftrace_shutdown_disable_cpu);
-static DEFINE_SPINLOCK(ftrace_shutdown_lock);
static DEFINE_MUTEX(ftraced_lock);
static DEFINE_MUTEX(ftrace_regex_lock);
@@ -294,13 +318,37 @@ static inline void ftrace_del_hash(struct dyn_ftrace *node)
static void ftrace_free_rec(struct dyn_ftrace *rec)
{
- /* no locking, only called from kstop_machine */
-
rec->ip = (unsigned long)ftrace_free_records;
ftrace_free_records = rec;
rec->flags |= FTRACE_FL_FREE;
}
+void ftrace_release(void *start, unsigned long size)
+{
+ struct dyn_ftrace *rec;
+ struct ftrace_page *pg;
+ unsigned long s = (unsigned long)start;
+ unsigned long e = s + size;
+ int i;
+
+ if (ftrace_disabled || !start)
+ return;
+
+ /* should not be called from interrupt context */
+ spin_lock(&ftrace_lock);
+
+ for (pg = ftrace_pages_start; pg; pg = pg->next) {
+ for (i = 0; i < pg->index; i++) {
+ rec = &pg->records[i];
+
+ if ((rec->ip >= s) && (rec->ip < e))
+ ftrace_free_rec(rec);
+ }
+ }
+ spin_unlock(&ftrace_lock);
+
+}
+
static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip)
{
struct dyn_ftrace *rec;
@@ -338,7 +386,6 @@ ftrace_record_ip(unsigned long ip)
unsigned long flags;
unsigned long key;
int resched;
- int atomic;
int cpu;
if (!ftrace_enabled || ftrace_disabled)
@@ -368,9 +415,7 @@ ftrace_record_ip(unsigned long ip)
if (ftrace_ip_in_hash(ip, key))
goto out;
- atomic = irqs_disabled();
-
- spin_lock_irqsave(&ftrace_shutdown_lock, flags);
+ ftrace_hash_lock(flags);
/* This ip may have hit the hash before the lock */
if (ftrace_ip_in_hash(ip, key))
@@ -387,7 +432,7 @@ ftrace_record_ip(unsigned long ip)
ftraced_trigger = 1;
out_unlock:
- spin_unlock_irqrestore(&ftrace_shutdown_lock, flags);
+ ftrace_hash_unlock(flags);
out:
per_cpu(ftrace_shutdown_disable_cpu, cpu)--;
@@ -531,6 +576,16 @@ static void ftrace_shutdown_replenish(void)
ftrace_pages->next = (void *)get_zeroed_page(GFP_KERNEL);
}
+static void print_ip_ins(const char *fmt, unsigned char *p)
+{
+ int i;
+
+ printk(KERN_CONT "%s", fmt);
+
+ for (i = 0; i < MCOUNT_INSN_SIZE; i++)
+ printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]);
+}
+
static int
ftrace_code_disable(struct dyn_ftrace *rec)
{
@@ -541,10 +596,27 @@ ftrace_code_disable(struct dyn_ftrace *rec)
ip = rec->ip;
nop = ftrace_nop_replace();
- call = ftrace_call_replace(ip, MCOUNT_ADDR);
+ call = ftrace_call_replace(ip, mcount_addr);
failed = ftrace_modify_code(ip, call, nop);
if (failed) {
+ switch (failed) {
+ case 1:
+ WARN_ON_ONCE(1);
+ pr_info("ftrace faulted on modifying ");
+ print_ip_sym(ip);
+ break;
+ case 2:
+ WARN_ON_ONCE(1);
+ pr_info("ftrace failed to modify ");
+ print_ip_sym(ip);
+ print_ip_ins(" expected: ", call);
+ print_ip_ins(" actual: ", (unsigned char *)ip);
+ print_ip_ins(" replace: ", nop);
+ printk(KERN_CONT "\n");
+ break;
+ }
+
rec->flags |= FTRACE_FL_FAILED;
return 0;
}
@@ -792,47 +864,7 @@ static int ftrace_update_code(void)
return 1;
}
-static int ftraced(void *ignore)
-{
- unsigned long usecs;
-
- while (!kthread_should_stop()) {
-
- set_current_state(TASK_INTERRUPTIBLE);
-
- /* check once a second */
- schedule_timeout(HZ);
-
- if (unlikely(ftrace_disabled))
- continue;
-
- mutex_lock(&ftrace_sysctl_lock);
- mutex_lock(&ftraced_lock);
- if (!ftraced_suspend && !ftraced_stop &&
- ftrace_update_code()) {
- usecs = nsecs_to_usecs(ftrace_update_time);
- if (ftrace_update_tot_cnt > 100000) {
- ftrace_update_tot_cnt = 0;
- pr_info("hm, dftrace overflow: %lu change%s"
- " (%lu total) in %lu usec%s\n",
- ftrace_update_cnt,
- ftrace_update_cnt != 1 ? "s" : "",
- ftrace_update_tot_cnt,
- usecs, usecs != 1 ? "s" : "");
- ftrace_disabled = 1;
- WARN_ON_ONCE(1);
- }
- }
- mutex_unlock(&ftraced_lock);
- mutex_unlock(&ftrace_sysctl_lock);
-
- ftrace_shutdown_replenish();
- }
- __set_current_state(TASK_RUNNING);
- return 0;
-}
-
-static int __init ftrace_dyn_table_alloc(void)
+static int __init ftrace_dyn_table_alloc(unsigned long num_to_init)
{
struct ftrace_page *pg;
int cnt;
@@ -859,7 +891,9 @@ static int __init ftrace_dyn_table_alloc(void)
pg = ftrace_pages = ftrace_pages_start;
- cnt = NR_TO_INIT / ENTRIES_PER_PAGE;
+ cnt = num_to_init / ENTRIES_PER_PAGE;
+ pr_info("ftrace: allocating %ld hash entries in %d pages\n",
+ num_to_init, cnt);
for (i = 0; i < cnt; i++) {
pg->next = (void *)get_zeroed_page(GFP_KERNEL);
@@ -901,6 +935,8 @@ t_next(struct seq_file *m, void *v, loff_t *pos)
(*pos)++;
+ /* should not be called from interrupt context */
+ spin_lock(&ftrace_lock);
retry:
if (iter->idx >= iter->pg->index) {
if (iter->pg->next) {
@@ -910,15 +946,13 @@ t_next(struct seq_file *m, void *v, loff_t *pos)
}
} else {
rec = &iter->pg->records[iter->idx++];
- if ((!(iter->flags & FTRACE_ITER_FAILURES) &&
+ if ((rec->flags & FTRACE_FL_FREE) ||
+
+ (!(iter->flags & FTRACE_ITER_FAILURES) &&
(rec->flags & FTRACE_FL_FAILED)) ||
((iter->flags & FTRACE_ITER_FAILURES) &&
- (!(rec->flags & FTRACE_FL_FAILED) ||
- (rec->flags & FTRACE_FL_FREE))) ||
-
- ((iter->flags & FTRACE_ITER_FILTER) &&
- !(rec->flags & FTRACE_FL_FILTER)) ||
+ !(rec->flags & FTRACE_FL_FAILED)) ||
((iter->flags & FTRACE_ITER_NOTRACE) &&
!(rec->flags & FTRACE_FL_NOTRACE))) {
@@ -926,6 +960,7 @@ t_next(struct seq_file *m, void *v, loff_t *pos)
goto retry;
}
}
+ spin_unlock(&ftrace_lock);
iter->pos = *pos;
@@ -1039,8 +1074,8 @@ static void ftrace_filter_reset(int enable)
unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE;
unsigned i;
- /* keep kstop machine from running */
- preempt_disable();
+ /* should not be called from interrupt context */
+ spin_lock(&ftrace_lock);
if (enable)
ftrace_filtered = 0;
pg = ftrace_pages_start;
@@ -1053,7 +1088,7 @@ static void ftrace_filter_reset(int enable)
}
pg = pg->next;
}
- preempt_enable();
+ spin_unlock(&ftrace_lock);
}
static int
@@ -1165,8 +1200,8 @@ ftrace_match(unsigned char *buff, int len, int enable)
}
}
- /* keep kstop machine from running */
- preempt_disable();
+ /* should not be called from interrupt context */
+ spin_lock(&ftrace_lock);
if (enable)
ftrace_filtered = 1;
pg = ftrace_pages_start;
@@ -1203,7 +1238,7 @@ ftrace_match(unsigned char *buff, int len, int enable)
}
pg = pg->next;
}
- preempt_enable();
+ spin_unlock(&ftrace_lock);
}
static ssize_t
@@ -1556,6 +1591,114 @@ static __init int ftrace_init_debugfs(void)
fs_initcall(ftrace_init_debugfs);
+#ifdef CONFIG_FTRACE_MCOUNT_RECORD
+static int ftrace_convert_nops(unsigned long *start,
+ unsigned long *end)
+{
+ unsigned long *p;
+ unsigned long addr;
+ unsigned long flags;
+
+ p = start;
+ while (p < end) {
+ addr = ftrace_call_adjust(*p++);
+ /* should not be called from interrupt context */
+ spin_lock(&ftrace_lock);
+ ftrace_record_ip(addr);
+ spin_unlock(&ftrace_lock);
+ ftrace_shutdown_replenish();
+ }
+
+ /* p is ignored */
+ local_irq_save(flags);
+ __ftrace_update_code(p);
+ local_irq_restore(flags);
+
+ return 0;
+}
+
+void ftrace_init_module(unsigned long *start, unsigned long *end)
+{
+ if (ftrace_disabled || start == end)
+ return;
+ ftrace_convert_nops(start, end);
+}
+
+extern unsigned long __start_mcount_loc[];
+extern unsigned long __stop_mcount_loc[];
+
+void __init ftrace_init(void)
+{
+ unsigned long count, addr, flags;
+ int ret;
+
+ /* Keep the ftrace pointer to the stub */
+ addr = (unsigned long)ftrace_stub;
+
+ local_irq_save(flags);
+ ftrace_dyn_arch_init(&addr);
+ local_irq_restore(flags);
+
+ /* ftrace_dyn_arch_init places the return code in addr */
+ if (addr)
+ goto failed;
+
+ count = __stop_mcount_loc - __start_mcount_loc;
+
+ ret = ftrace_dyn_table_alloc(count);
+ if (ret)
+ goto failed;
+
+ last_ftrace_enabled = ftrace_enabled = 1;
+
+ ret = ftrace_convert_nops(__start_mcount_loc,
+ __stop_mcount_loc);
+
+ return;
+ failed:
+ ftrace_disabled = 1;
+}
+#else /* CONFIG_FTRACE_MCOUNT_RECORD */
+static int ftraced(void *ignore)
+{
+ unsigned long usecs;
+
+ while (!kthread_should_stop()) {
+
+ set_current_state(TASK_INTERRUPTIBLE);
+
+ /* check once a second */
+ schedule_timeout(HZ);
+
+ if (unlikely(ftrace_disabled))
+ continue;
+
+ mutex_lock(&ftrace_sysctl_lock);
+ mutex_lock(&ftraced_lock);
+ if (!ftraced_suspend && !ftraced_stop &&
+ ftrace_update_code()) {
+ usecs = nsecs_to_usecs(ftrace_update_time);
+ if (ftrace_update_tot_cnt > 100000) {
+ ftrace_update_tot_cnt = 0;
+ pr_info("hm, dftrace overflow: %lu change%s"
+ " (%lu total) in %lu usec%s\n",
+ ftrace_update_cnt,
+ ftrace_update_cnt != 1 ? "s" : "",
+ ftrace_update_tot_cnt,
+ usecs, usecs != 1 ? "s" : "");
+ ftrace_disabled = 1;
+ WARN_ON_ONCE(1);
+ }
+ }
+ mutex_unlock(&ftraced_lock);
+ mutex_unlock(&ftrace_sysctl_lock);
+
+ ftrace_shutdown_replenish();
+ }
+ __set_current_state(TASK_RUNNING);
+ return 0;
+}
+
static int __init ftrace_dynamic_init(void)
{
struct task_struct *p;
@@ -1572,7 +1715,7 @@ static int __init ftrace_dynamic_init(void)
goto failed;
}
- ret = ftrace_dyn_table_alloc();
+ ret = ftrace_dyn_table_alloc(NR_TO_INIT);
if (ret)
goto failed;
@@ -1593,6 +1736,8 @@ static int __init ftrace_dynamic_init(void)
}
core_initcall(ftrace_dynamic_init);
+#endif /* CONFIG_FTRACE_MCOUNT_RECORD */
+
#else
# define ftrace_startup() do { } while (0)
# define ftrace_shutdown() do { } while (0)
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
new file mode 100644
index 0000000..94af1fe
--- /dev/null
+++ b/kernel/trace/ring_buffer.c
@@ -0,0 +1,2014 @@
+/*
+ * Generic ring buffer
+ *
+ * Copyright (C) 2008 Steven Rostedt <srostedt@redhat.com>
+ */
+#include <linux/ring_buffer.h>
+#include <linux/spinlock.h>
+#include <linux/debugfs.h>
+#include <linux/uaccess.h>
+#include <linux/module.h>
+#include <linux/percpu.h>
+#include <linux/mutex.h>
+#include <linux/sched.h> /* used for sched_clock() (for now) */
+#include <linux/init.h>
+#include <linux/hash.h>
+#include <linux/list.h>
+#include <linux/fs.h>
+
+/* Up this if you want to test the TIME_EXTENTS and normalization */
+#define DEBUG_SHIFT 0
+
+/* FIXME!!! */
+u64 ring_buffer_time_stamp(int cpu)
+{
+ /* shift to debug/test normalization and TIME_EXTENTS */
+ return sched_clock() << DEBUG_SHIFT;
+}
+
+void ring_buffer_normalize_time_stamp(int cpu, u64 *ts)
+{
+ /* Just stupid testing the normalize function and deltas */
+ *ts >>= DEBUG_SHIFT;
+}
+
+#define RB_EVNT_HDR_SIZE (sizeof(struct ring_buffer_event))
+#define RB_ALIGNMENT_SHIFT 2
+#define RB_ALIGNMENT (1 << RB_ALIGNMENT_SHIFT)
+#define RB_MAX_SMALL_DATA 28
+
+enum {
+ RB_LEN_TIME_EXTEND = 8,
+ RB_LEN_TIME_STAMP = 16,
+};
+
+/* inline for ring buffer fast paths */
+static inline unsigned
+rb_event_length(struct ring_buffer_event *event)
+{
+ unsigned length;
+
+ switch (event->type) {
+ case RINGBUF_TYPE_PADDING:
+ /* undefined */
+ return -1;
+
+ case RINGBUF_TYPE_TIME_EXTEND:
+ return RB_LEN_TIME_EXTEND;
+
+ case RINGBUF_TYPE_TIME_STAMP:
+ return RB_LEN_TIME_STAMP;
+
+ case RINGBUF_TYPE_DATA:
+ if (event->len)
+ length = event->len << RB_ALIGNMENT_SHIFT;
+ else
+ length = event->array[0];
+ return length + RB_EVNT_HDR_SIZE;
+ default:
+ BUG();
+ }
+ /* not hit */
+ return 0;
+}
+
+/**
+ * ring_buffer_event_length - return the length of the event
+ * @event: the event to get the length of
+ */
+unsigned ring_buffer_event_length(struct ring_buffer_event *event)
+{
+ return rb_event_length(event);
+}
+
+/* inline for ring buffer fast paths */
+static inline void *
+rb_event_data(struct ring_buffer_event *event)
+{
+ BUG_ON(event->type != RINGBUF_TYPE_DATA);
+ /* If length is in len field, then array[0] has the data */
+ if (event->len)
+ return (void *)&event->array[0];
+ /* Otherwise length is in array[0] and array[1] has the data */
+ return (void *)&event->array[1];
+}
+
+/**
+ * ring_buffer_event_data - return the data of the event
+ * @event: the event to get the data from
+ */
+void *ring_buffer_event_data(struct ring_buffer_event *event)
+{
+ return rb_event_data(event);
+}
+
+#define for_each_buffer_cpu(buffer, cpu) \
+ for_each_cpu_mask(cpu, buffer->cpumask)
+
+#define TS_SHIFT 27
+#define TS_MASK ((1ULL << TS_SHIFT) - 1)
+#define TS_DELTA_TEST (~TS_MASK)
+
+/*
+ * This hack stolen from mm/slob.c.
+ * We can store per page timing information in the page frame of the page.
+ * Thanks to Peter Zijlstra for suggesting this idea.
+ */
+struct buffer_page {
+ u64 time_stamp; /* page time stamp */
+ local_t write; /* index for next write */
+ local_t commit; /* write commited index */
+ unsigned read; /* index for next read */
+ struct list_head list; /* list of free pages */
+ void *page; /* Actual data page */
+};
+
+/*
+ * Also stolen from mm/slob.c. Thanks to Mathieu Desnoyers for pointing
+ * this issue out.
+ */
+static inline void free_buffer_page(struct buffer_page *bpage)
+{
+ if (bpage->page)
+ __free_page(bpage->page);
+ kfree(bpage);
+}
+
+/*
+ * We need to fit the time_stamp delta into 27 bits.
+ */
+static inline int test_time_stamp(u64 delta)
+{
+ if (delta & TS_DELTA_TEST)
+ return 1;
+ return 0;
+}
+
+#define BUF_PAGE_SIZE PAGE_SIZE
+
+/*
+ * head_page == tail_page && head == tail then buffer is empty.
+ */
+struct ring_buffer_per_cpu {
+ int cpu;
+ struct ring_buffer *buffer;
+ spinlock_t lock;
+ struct lock_class_key lock_key;
+ struct list_head pages;
+ struct buffer_page *head_page; /* read from head */
+ struct buffer_page *tail_page; /* write to tail */
+ struct buffer_page *commit_page; /* commited pages */
+ struct buffer_page *reader_page;
+ unsigned long overrun;
+ unsigned long entries;
+ u64 write_stamp;
+ u64 read_stamp;
+ atomic_t record_disabled;
+};
+
+struct ring_buffer {
+ unsigned long size;
+ unsigned pages;
+ unsigned flags;
+ int cpus;
+ cpumask_t cpumask;
+ atomic_t record_disabled;
+
+ struct mutex mutex;
+
+ struct ring_buffer_per_cpu **buffers;
+};
+
+struct ring_buffer_iter {
+ struct ring_buffer_per_cpu *cpu_buffer;
+ unsigned long head;
+ struct buffer_page *head_page;
+ u64 read_stamp;
+};
+
+#define RB_WARN_ON(buffer, cond) \
+ do { \
+ if (unlikely(cond)) { \
+ atomic_inc(&buffer->record_disabled); \
+ WARN_ON(1); \
+ } \
+ } while (0)
+
+#define RB_WARN_ON_RET(buffer, cond) \
+ do { \
+ if (unlikely(cond)) { \
+ atomic_inc(&buffer->record_disabled); \
+ WARN_ON(1); \
+ return -1; \
+ } \
+ } while (0)
+
+#define RB_WARN_ON_ONCE(buffer, cond) \
+ do { \
+ static int once; \
+ if (unlikely(cond) && !once) { \
+ once++; \
+ atomic_inc(&buffer->record_disabled); \
+ WARN_ON(1); \
+ } \
+ } while (0)
+
+/**
+ * check_pages - integrity check of buffer pages
+ * @cpu_buffer: CPU buffer with pages to test
+ *
+ * As a safty measure we check to make sure the data pages have not
+ * been corrupted.
+ */
+static int rb_check_pages(struct ring_buffer_per_cpu *cpu_buffer)
+{
+ struct list_head *head = &cpu_buffer->pages;
+ struct buffer_page *page, *tmp;
+
+ RB_WARN_ON_RET(cpu_buffer, head->next->prev != head);
+ RB_WARN_ON_RET(cpu_buffer, head->prev->next != head);
+
+ list_for_each_entry_safe(page, tmp, head, list) {
+ RB_WARN_ON_RET(cpu_buffer,
+ page->list.next->prev != &page->list);
+ RB_WARN_ON_RET(cpu_buffer,
+ page->list.prev->next != &page->list);
+ }
+
+ return 0;
+}
+
+static int rb_allocate_pages(struct ring_buffer_per_cpu *cpu_buffer,
+ unsigned nr_pages)
+{
+ struct list_head *head = &cpu_buffer->pages;
+ struct buffer_page *page, *tmp;
+ unsigned long addr;
+ LIST_HEAD(pages);
+ unsigned i;
+
+ for (i = 0; i < nr_pages; i++) {
+ page = kzalloc_node(ALIGN(sizeof(*page), cache_line_size()),
+ GFP_KERNEL, cpu_to_node(cpu_buffer->cpu));
+ if (!page)
+ goto free_pages;
+ list_add(&page->list, &pages);
+
+ addr = __get_free_page(GFP_KERNEL);
+ if (!addr)
+ goto free_pages;
+ page->page = (void *)addr;
+ }
+
+ list_splice(&pages, head);
+
+ rb_check_pages(cpu_buffer);
+
+ return 0;
+
+ free_pages:
+ list_for_each_entry_safe(page, tmp, &pages, list) {
+ list_del_init(&page->list);
+ free_buffer_page(page);
+ }
+ return -ENOMEM;
+}
+
+static struct ring_buffer_per_cpu *
+rb_allocate_cpu_buffer(struct ring_buffer *buffer, int cpu)
+{
+ struct ring_buffer_per_cpu *cpu_buffer;
+ struct buffer_page *page;
+ unsigned long addr;
+ int ret;
+
+ cpu_buffer = kzalloc_node(ALIGN(sizeof(*cpu_buffer), cache_line_size()),
+ GFP_KERNEL, cpu_to_node(cpu));
+ if (!cpu_buffer)
+ return NULL;
+
+ cpu_buffer->cpu = cpu;
+ cpu_buffer->buffer = buffer;
+ spin_lock_init(&cpu_buffer->lock);
+ INIT_LIST_HEAD(&cpu_buffer->pages);
+
+ page = kzalloc_node(ALIGN(sizeof(*page), cache_line_size()),
+ GFP_KERNEL, cpu_to_node(cpu));
+ if (!page)
+ goto fail_free_buffer;
+
+ cpu_buffer->reader_page = page;
+ addr = __get_free_page(GFP_KERNEL);
+ if (!addr)
+ goto fail_free_reader;
+ page->page = (void *)addr;
+
+ INIT_LIST_HEAD(&cpu_buffer->reader_page->list);
+
+ ret = rb_allocate_pages(cpu_buffer, buffer->pages);
+ if (ret < 0)
+ goto fail_free_reader;
+
+ cpu_buffer->head_page
+ = list_entry(cpu_buffer->pages.next, struct buffer_page, list);
+ cpu_buffer->tail_page = cpu_buffer->commit_page = cpu_buffer->head_page;
+
+ return cpu_buffer;
+
+ fail_free_reader:
+ free_buffer_page(cpu_buffer->reader_page);
+
+ fail_free_buffer:
+ kfree(cpu_buffer);
+ return NULL;
+}
+
+static void rb_free_cpu_buffer(struct ring_buffer_per_cpu *cpu_buffer)
+{
+ struct list_head *head = &cpu_buffer->pages;
+ struct buffer_page *page, *tmp;
+
+ list_del_init(&cpu_buffer->reader_page->list);
+ free_buffer_page(cpu_buffer->reader_page);
+
+ list_for_each_entry_safe(page, tmp, head, list) {
+ list_del_init(&page->list);
+ free_buffer_page(page);
+ }
+ kfree(cpu_buffer);
+}
+
+/*
+ * Causes compile errors if the struct buffer_page gets bigger
+ * than the struct page.
+ */
+extern int ring_buffer_page_too_big(void);
+
+/**
+ * ring_buffer_alloc - allocate a new ring_buffer
+ * @size: the size in bytes that is needed.
+ * @flags: attributes to set for the ring buffer.
+ *
+ * Currently the only flag that is available is the RB_FL_OVERWRITE
+ * flag. This flag means that the buffer will overwrite old data
+ * when the buffer wraps. If this flag is not set, the buffer will
+ * drop data when the tail hits the head.
+ */
+struct ring_buffer *ring_buffer_alloc(unsigned long size, unsigned flags)
+{
+ struct ring_buffer *buffer;
+ int bsize;
+ int cpu;
+
+ /* Paranoid! Optimizes out when all is well */
+ if (sizeof(struct buffer_page) > sizeof(struct page))
+ ring_buffer_page_too_big();
+
+
+ /* keep it in its own cache line */
+ buffer = kzalloc(ALIGN(sizeof(*buffer), cache_line_size()),
+ GFP_KERNEL);
+ if (!buffer)
+ return NULL;
+
+ buffer->pages = DIV_ROUND_UP(size, BUF_PAGE_SIZE);
+ buffer->flags = flags;
+
+ /* need at least two pages */
+ if (buffer->pages == 1)
+ buffer->pages++;
+
+ buffer->cpumask = cpu_possible_map;
+ buffer->cpus = nr_cpu_ids;
+
+ bsize = sizeof(void *) * nr_cpu_ids;
+ buffer->buffers = kzalloc(ALIGN(bsize, cache_line_size()),
+ GFP_KERNEL);
+ if (!buffer->buffers)
+ goto fail_free_buffer;
+
+ for_each_buffer_cpu(buffer, cpu) {
+ buffer->buffers[cpu] =
+ rb_allocate_cpu_buffer(buffer, cpu);
+ if (!buffer->buffers[cpu])
+ goto fail_free_buffers;
+ }
+
+ mutex_init(&buffer->mutex);
+
+ return buffer;
+
+ fail_free_buffers:
+ for_each_buffer_cpu(buffer, cpu) {
+ if (buffer->buffers[cpu])
+ rb_free_cpu_buffer(buffer->buffers[cpu]);
+ }
+ kfree(buffer->buffers);
+
+ fail_free_buffer:
+ kfree(buffer);
+ return NULL;
+}
+
+/**
+ * ring_buffer_free - free a ring buffer.
+ * @buffer: the buffer to free.
+ */
+void
+ring_buffer_free(struct ring_buffer *buffer)
+{
+ int cpu;
+
+ for_each_buffer_cpu(buffer, cpu)
+ rb_free_cpu_buffer(buffer->buffers[cpu]);
+
+ kfree(buffer);
+}
+
+static void rb_reset_cpu(struct ring_buffer_per_cpu *cpu_buffer);
+
+static void
+rb_remove_pages(struct ring_buffer_per_cpu *cpu_buffer, unsigned nr_pages)
+{
+ struct buffer_page *page;
+ struct list_head *p;
+ unsigned i;
+
+ atomic_inc(&cpu_buffer->record_disabled);
+ synchronize_sched();
+
+ for (i = 0; i < nr_pages; i++) {
+ BUG_ON(list_empty(&cpu_buffer->pages));
+ p = cpu_buffer->pages.next;
+ page = list_entry(p, struct buffer_page, list);
+ list_del_init(&page->list);
+ free_buffer_page(page);
+ }
+ BUG_ON(list_empty(&cpu_buffer->pages));
+
+ rb_reset_cpu(cpu_buffer);
+
+ rb_check_pages(cpu_buffer);
+
+ atomic_dec(&cpu_buffer->record_disabled);
+
+}
+
+static void
+rb_insert_pages(struct ring_buffer_per_cpu *cpu_buffer,
+ struct list_head *pages, unsigned nr_pages)
+{
+ struct buffer_page *page;
+ struct list_head *p;
+ unsigned i;
+
+ atomic_inc(&cpu_buffer->record_disabled);
+ synchronize_sched();
+
+ for (i = 0; i < nr_pages; i++) {
+ BUG_ON(list_empty(pages));
+ p = pages->next;
+ page = list_entry(p, struct buffer_page, list);
+ list_del_init(&page->list);
+ list_add_tail(&page->list, &cpu_buffer->pages);
+ }
+ rb_reset_cpu(cpu_buffer);
+
+ rb_check_pages(cpu_buffer);
+
+ atomic_dec(&cpu_buffer->record_disabled);
+}
+
+/**
+ * ring_buffer_resize - resize the ring buffer
+ * @buffer: the buffer to resize.
+ * @size: the new size.
+ *
+ * The tracer is responsible for making sure that the buffer is
+ * not being used while changing the size.
+ * Note: We may be able to change the above requirement by using
+ * RCU synchronizations.
+ *
+ * Minimum size is 2 * BUF_PAGE_SIZE.
+ *
+ * Returns -1 on failure.
+ */
+int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size)
+{
+ struct ring_buffer_per_cpu *cpu_buffer;
+ unsigned nr_pages, rm_pages, new_pages;
+ struct buffer_page *page, *tmp;
+ unsigned long buffer_size;
+ unsigned long addr;
+ LIST_HEAD(pages);
+ int i, cpu;
+
+ size = DIV_ROUND_UP(size, BUF_PAGE_SIZE);
+ size *= BUF_PAGE_SIZE;
+ buffer_size = buffer->pages * BUF_PAGE_SIZE;
+
+ /* we need a minimum of two pages */
+ if (size < BUF_PAGE_SIZE * 2)
+ size = BUF_PAGE_SIZE * 2;
+
+ if (size == buffer_size)
+ return size;
+
+ mutex_lock(&buffer->mutex);
+
+ nr_pages = DIV_ROUND_UP(size, BUF_PAGE_SIZE);
+
+ if (size < buffer_size) {
+
+ /* easy case, just free pages */
+ BUG_ON(nr_pages >= buffer->pages);
+
+ rm_pages = buffer->pages - nr_pages;
+
+ for_each_buffer_cpu(buffer, cpu) {
+ cpu_buffer = buffer->buffers[cpu];
+ rb_remove_pages(cpu_buffer, rm_pages);
+ }
+ goto out;
+ }
+
+ /*
+ * This is a bit more difficult. We only want to add pages
+ * when we can allocate enough for all CPUs. We do this
+ * by allocating all the pages and storing them on a local
+ * link list. If we succeed in our allocation, then we
+ * add these pages to the cpu_buffers. Otherwise we just free
+ * them all and return -ENOMEM;
+ */
+ BUG_ON(nr_pages <= buffer->pages);
+ new_pages = nr_pages - buffer->pages;
+
+ for_each_buffer_cpu(buffer, cpu) {
+ for (i = 0; i < new_pages; i++) {
+ page = kzalloc_node(ALIGN(sizeof(*page),
+ cache_line_size()),
+ GFP_KERNEL, cpu_to_node(cpu));
+ if (!page)
+ goto free_pages;
+ list_add(&page->list, &pages);
+ addr = __get_free_page(GFP_KERNEL);
+ if (!addr)
+ goto free_pages;
+ page->page = (void *)addr;
+ }
+ }
+
+ for_each_buffer_cpu(buffer, cpu) {
+ cpu_buffer = buffer->buffers[cpu];
+ rb_insert_pages(cpu_buffer, &pages, new_pages);
+ }
+
+ BUG_ON(!list_empty(&pages));
+
+ out:
+ buffer->pages = nr_pages;
+ mutex_unlock(&buffer->mutex);
+
+ return size;
+
+ free_pages:
+ list_for_each_entry_safe(page, tmp, &pages, list) {
+ list_del_init(&page->list);
+ free_buffer_page(page);
+ }
+ return -ENOMEM;
+}
+
+static inline int rb_null_event(struct ring_buffer_event *event)
+{
+ return event->type == RINGBUF_TYPE_PADDING;
+}
+
+static inline void *__rb_page_index(struct buffer_page *page, unsigned index)
+{
+ return page->page + index;
+}
+
+static inline struct ring_buffer_event *
+rb_reader_event(struct ring_buffer_per_cpu *cpu_buffer)
+{
+ return __rb_page_index(cpu_buffer->reader_page,
+ cpu_buffer->reader_page->read);
+}
+
+static inline struct ring_buffer_event *
+rb_head_event(struct ring_buffer_per_cpu *cpu_buffer)
+{
+ return __rb_page_index(cpu_buffer->head_page,
+ cpu_buffer->head_page->read);
+}
+
+static inline struct ring_buffer_event *
+rb_iter_head_event(struct ring_buffer_iter *iter)
+{
+ return __rb_page_index(iter->head_page, iter->head);
+}
+
+static inline unsigned rb_page_write(struct buffer_page *bpage)
+{
+ return local_read(&bpage->write);
+}
+
+static inline unsigned rb_page_commit(struct buffer_page *bpage)
+{
+ return local_read(&bpage->commit);
+}
+
+/* Size is determined by what has been commited */
+static inline unsigned rb_page_size(struct buffer_page *bpage)
+{
+ return rb_page_commit(bpage);
+}
+
+static inline unsigned
+rb_commit_index(struct ring_buffer_per_cpu *cpu_buffer)
+{
+ return rb_page_commit(cpu_buffer->commit_page);
+}
+
+static inline unsigned rb_head_size(struct ring_buffer_per_cpu *cpu_buffer)
+{
+ return rb_page_commit(cpu_buffer->head_page);
+}
+
+/*
+ * When the tail hits the head and the buffer is in overwrite mode,
+ * the head jumps to the next page and all content on the previous
+ * page is discarded. But before doing so, we update the overrun
+ * variable of the buffer.
+ */
+static void rb_update_overflow(struct ring_buffer_per_cpu *cpu_buffer)
+{
+ struct ring_buffer_event *event;
+ unsigned long head;
+
+ for (head = 0; head < rb_head_size(cpu_buffer);
+ head += rb_event_length(event)) {
+
+ event = __rb_page_index(cpu_buffer->head_page, head);
+ BUG_ON(rb_null_event(event));
+ /* Only count data entries */
+ if (event->type != RINGBUF_TYPE_DATA)
+ continue;
+ cpu_buffer->overrun++;
+ cpu_buffer->entries--;
+ }
+}
+
+static inline void rb_inc_page(struct ring_buffer_per_cpu *cpu_buffer,
+ struct buffer_page **page)
+{
+ struct list_head *p = (*page)->list.next;
+
+ if (p == &cpu_buffer->pages)
+ p = p->next;
+
+ *page = list_entry(p, struct buffer_page, list);
+}
+
+static inline unsigned
+rb_event_index(struct ring_buffer_event *event)
+{
+ unsigned long addr = (unsigned long)event;
+
+ return (addr & ~PAGE_MASK) - (PAGE_SIZE - BUF_PAGE_SIZE);
+}
+
+static inline int
+rb_is_commit(struct ring_buffer_per_cpu *cpu_buffer,
+ struct ring_buffer_event *event)
+{
+ unsigned long addr = (unsigned long)event;
+ unsigned long index;
+
+ index = rb_event_index(event);
+ addr &= PAGE_MASK;
+
+ return cpu_buffer->commit_page->page == (void *)addr &&
+ rb_commit_index(cpu_buffer) == index;
+}
+
+static inline void
+rb_set_commit_event(struct ring_buffer_per_cpu *cpu_buffer,
+ struct ring_buffer_event *event)
+{
+ unsigned long addr = (unsigned long)event;
+ unsigned long index;
+
+ index = rb_event_index(event);
+ addr &= PAGE_MASK;
+
+ while (cpu_buffer->commit_page->page != (void *)addr) {
+ RB_WARN_ON(cpu_buffer,
+ cpu_buffer->commit_page == cpu_buffer->tail_page);
+ cpu_buffer->commit_page->commit =
+ cpu_buffer->commit_page->write;
+ rb_inc_page(cpu_buffer, &cpu_buffer->commit_page);
+ cpu_buffer->write_stamp = cpu_buffer->commit_page->time_stamp;
+ }
+
+ /* Now set the commit to the event's index */
+ local_set(&cpu_buffer->commit_page->commit, index);
+}
+
+static inline void
+rb_set_commit_to_write(struct ring_buffer_per_cpu *cpu_buffer)
+{
+ /*
+ * We only race with interrupts and NMIs on this CPU.
+ * If we own the commit event, then we can commit
+ * all others that interrupted us, since the interruptions
+ * are in stack format (they finish before they come
+ * back to us). This allows us to do a simple loop to
+ * assign the commit to the tail.
+ */
+ while (cpu_buffer->commit_page != cpu_buffer->tail_page) {
+ cpu_buffer->commit_page->commit =
+ cpu_buffer->commit_page->write;
+ rb_inc_page(cpu_buffer, &cpu_buffer->commit_page);
+ cpu_buffer->write_stamp = cpu_buffer->commit_page->time_stamp;
+ /* add barrier to keep gcc from optimizing too much */
+ barrier();
+ }
+ while (rb_commit_index(cpu_buffer) !=
+ rb_page_write(cpu_buffer->commit_page)) {
+ cpu_buffer->commit_page->commit =
+ cpu_buffer->commit_page->write;
+ barrier();
+ }
+}
+
+static void rb_reset_reader_page(struct ring_buffer_per_cpu *cpu_buffer)
+{
+ cpu_buffer->read_stamp = cpu_buffer->reader_page->time_stamp;
+ cpu_buffer->reader_page->read = 0;
+}
+
+static inline void rb_inc_iter(struct ring_buffer_iter *iter)
+{
+ struct ring_buffer_per_cpu *cpu_buffer = iter->cpu_buffer;
+
+ /*
+ * The iterator could be on the reader page (it starts there).
+ * But the head could have moved, since the reader was
+ * found. Check for this case and assign the iterator
+ * to the head page instead of next.
+ */
+ if (iter->head_page == cpu_buffer->reader_page)
+ iter->head_page = cpu_buffer->head_page;
+ else
+ rb_inc_page(cpu_buffer, &iter->head_page);
+
+ iter->read_stamp = iter->head_page->time_stamp;
+ iter->head = 0;
+}
+
+/**
+ * ring_buffer_update_event - update event type and data
+ * @event: the even to update
+ * @type: the type of event
+ * @length: the size of the event field in the ring buffer
+ *
+ * Update the type and data fields of the event. The length
+ * is the actual size that is written to the ring buffer,
+ * and with this, we can determine what to place into the
+ * data field.
+ */
+static inline void
+rb_update_event(struct ring_buffer_event *event,
+ unsigned type, unsigned length)
+{
+ event->type = type;
+
+ switch (type) {
+
+ case RINGBUF_TYPE_PADDING:
+ break;
+
+ case RINGBUF_TYPE_TIME_EXTEND:
+ event->len =
+ (RB_LEN_TIME_EXTEND + (RB_ALIGNMENT-1))
+ >> RB_ALIGNMENT_SHIFT;
+ break;
+
+ case RINGBUF_TYPE_TIME_STAMP:
+ event->len =
+ (RB_LEN_TIME_STAMP + (RB_ALIGNMENT-1))
+ >> RB_ALIGNMENT_SHIFT;
+ break;
+
+ case RINGBUF_TYPE_DATA:
+ length -= RB_EVNT_HDR_SIZE;
+ if (length > RB_MAX_SMALL_DATA) {
+ event->len = 0;
+ event->array[0] = length;
+ } else
+ event->len =
+ (length + (RB_ALIGNMENT-1))
+ >> RB_ALIGNMENT_SHIFT;
+ break;
+ default:
+ BUG();
+ }
+}
+
+static inline unsigned rb_calculate_event_length(unsigned length)
+{
+ struct ring_buffer_event event; /* Used only for sizeof array */
+
+ /* zero length can cause confusions */
+ if (!length)
+ length = 1;
+
+ if (length > RB_MAX_SMALL_DATA)
+ length += sizeof(event.array[0]);
+
+ length += RB_EVNT_HDR_SIZE;
+ length = ALIGN(length, RB_ALIGNMENT);
+
+ return length;
+}
+
+static struct ring_buffer_event *
+__rb_reserve_next(struct ring_buffer_per_cpu *cpu_buffer,
+ unsigned type, unsigned long length, u64 *ts)
+{
+ struct buffer_page *tail_page, *head_page, *reader_page;
+ unsigned long tail, write;
+ struct ring_buffer *buffer = cpu_buffer->buffer;
+ struct ring_buffer_event *event;
+ unsigned long flags;
+
+ tail_page = cpu_buffer->tail_page;
+ write = local_add_return(length, &tail_page->write);
+ tail = write - length;
+
+ /* See if we shot pass the end of this buffer page */
+ if (write > BUF_PAGE_SIZE) {
+ struct buffer_page *next_page = tail_page;
+
+ spin_lock_irqsave(&cpu_buffer->lock, flags);
+
+ rb_inc_page(cpu_buffer, &next_page);
+
+ head_page = cpu_buffer->head_page;
+ reader_page = cpu_buffer->reader_page;
+
+ /* we grabbed the lock before incrementing */
+ RB_WARN_ON(cpu_buffer, next_page == reader_page);
+
+ /*
+ * If for some reason, we had an interrupt storm that made
+ * it all the way around the buffer, bail, and warn
+ * about it.
+ */
+ if (unlikely(next_page == cpu_buffer->commit_page)) {
+ WARN_ON_ONCE(1);
+ goto out_unlock;
+ }
+
+ if (next_page == head_page) {
+ if (!(buffer->flags & RB_FL_OVERWRITE)) {
+ /* reset write */
+ if (tail <= BUF_PAGE_SIZE)
+ local_set(&tail_page->write, tail);
+ goto out_unlock;
+ }
+
+ /* tail_page has not moved yet? */
+ if (tail_page == cpu_buffer->tail_page) {
+ /* count overflows */
+ rb_update_overflow(cpu_buffer);
+
+ rb_inc_page(cpu_buffer, &head_page);
+ cpu_buffer->head_page = head_page;
+ cpu_buffer->head_page->read = 0;
+ }
+ }
+
+ /*
+ * If the tail page is still the same as what we think
+ * it is, then it is up to us to update the tail
+ * pointer.
+ */
+ if (tail_page == cpu_buffer->tail_page) {
+ local_set(&next_page->write, 0);
+ local_set(&next_page->commit, 0);
+ cpu_buffer->tail_page = next_page;
+
+ /* reread the time stamp */
+ *ts = ring_buffer_time_stamp(cpu_buffer->cpu);
+ cpu_buffer->tail_page->time_stamp = *ts;
+ }
+
+ /*
+ * The actual tail page has moved forward.
+ */
+ if (tail < BUF_PAGE_SIZE) {
+ /* Mark the rest of the page with padding */
+ event = __rb_page_index(tail_page, tail);
+ event->type = RINGBUF_TYPE_PADDING;
+ }
+
+ if (tail <= BUF_PAGE_SIZE)
+ /* Set the write back to the previous setting */
+ local_set(&tail_page->write, tail);
+
+ /*
+ * If this was a commit entry that failed,
+ * increment that too
+ */
+ if (tail_page == cpu_buffer->commit_page &&
+ tail == rb_commit_index(cpu_buffer)) {
+ rb_set_commit_to_write(cpu_buffer);
+ }
+
+ spin_unlock_irqrestore(&cpu_buffer->lock, flags);
+
+ /* fail and let the caller try again */
+ return ERR_PTR(-EAGAIN);
+ }
+
+ /* We reserved something on the buffer */
+
+ BUG_ON(write > BUF_PAGE_SIZE);
+
+ event = __rb_page_index(tail_page, tail);
+ rb_update_event(event, type, length);
+
+ /*
+ * If this is a commit and the tail is zero, then update
+ * this page's time stamp.
+ */
+ if (!tail && rb_is_commit(cpu_buffer, event))
+ cpu_buffer->commit_page->time_stamp = *ts;
+
+ return event;
+
+ out_unlock:
+ spin_unlock_irqrestore(&cpu_buffer->lock, flags);
+ return NULL;
+}
+
+static int
+rb_add_time_stamp(struct ring_buffer_per_cpu *cpu_buffer,
+ u64 *ts, u64 *delta)
+{
+ struct ring_buffer_event *event;
+ static int once;
+ int ret;
+
+ if (unlikely(*delta > (1ULL << 59) && !once++)) {
+ printk(KERN_WARNING "Delta way too big! %llu"
+ " ts=%llu write stamp = %llu\n",
+ *delta, *ts, cpu_buffer->write_stamp);
+ WARN_ON(1);
+ }
+
+ /*
+ * The delta is too big, we to add a
+ * new timestamp.
+ */
+ event = __rb_reserve_next(cpu_buffer,
+ RINGBUF_TYPE_TIME_EXTEND,
+ RB_LEN_TIME_EXTEND,
+ ts);
+ if (!event)
+ return -EBUSY;
+
+ if (PTR_ERR(event) == -EAGAIN)
+ return -EAGAIN;
+
+ /* Only a commited time event can update the write stamp */
+ if (rb_is_commit(cpu_buffer, event)) {
+ /*
+ * If this is the first on the page, then we need to
+ * update the page itself, and just put in a zero.
+ */
+ if (rb_event_index(event)) {
+ event->time_delta = *delta & TS_MASK;
+ event->array[0] = *delta >> TS_SHIFT;
+ } else {
+ cpu_buffer->commit_page->time_stamp = *ts;
+ event->time_delta = 0;
+ event->array[0] = 0;
+ }
+ cpu_buffer->write_stamp = *ts;
+ /* let the caller know this was the commit */
+ ret = 1;
+ } else {
+ /* Darn, this is just wasted space */
+ event->time_delta = 0;
+ event->array[0] = 0;
+ ret = 0;
+ }
+
+ *delta = 0;
+
+ return ret;
+}
+
+static struct ring_buffer_event *
+rb_reserve_next_event(struct ring_buffer_per_cpu *cpu_buffer,
+ unsigned type, unsigned long length)
+{
+ struct ring_buffer_event *event;
+ u64 ts, delta;
+ int commit = 0;
+
+ again:
+ ts = ring_buffer_time_stamp(cpu_buffer->cpu);
+
+ /*
+ * Only the first commit can update the timestamp.
+ * Yes there is a race here. If an interrupt comes in
+ * just after the conditional and it traces too, then it
+ * will also check the deltas. More than one timestamp may
+ * also be made. But only the entry that did the actual
+ * commit will be something other than zero.
+ */
+ if (cpu_buffer->tail_page == cpu_buffer->commit_page &&
+ rb_page_write(cpu_buffer->tail_page) ==
+ rb_commit_index(cpu_buffer)) {
+
+ delta = ts - cpu_buffer->write_stamp;
+
+ /* make sure this delta is calculated here */
+ barrier();
+
+ /* Did the write stamp get updated already? */
+ if (unlikely(ts < cpu_buffer->write_stamp))
+ goto again;
+
+ if (test_time_stamp(delta)) {
+
+ commit = rb_add_time_stamp(cpu_buffer, &ts, &delta);
+
+ if (commit == -EBUSY)
+ return NULL;
+
+ if (commit == -EAGAIN)
+ goto again;
+
+ RB_WARN_ON(cpu_buffer, commit < 0);
+ }
+ } else
+ /* Non commits have zero deltas */
+ delta = 0;
+
+ event = __rb_reserve_next(cpu_buffer, type, length, &ts);
+ if (PTR_ERR(event) == -EAGAIN)
+ goto again;
+
+ if (!event) {
+ if (unlikely(commit))
+ /*
+ * Ouch! We needed a timestamp and it was commited. But
+ * we didn't get our event reserved.
+ */
+ rb_set_commit_to_write(cpu_buffer);
+ return NULL;
+ }
+
+ /*
+ * If the timestamp was commited, make the commit our entry
+ * now so that we will update it when needed.
+ */
+ if (commit)
+ rb_set_commit_event(cpu_buffer, event);
+ else if (!rb_is_commit(cpu_buffer, event))
+ delta = 0;
+
+ event->time_delta = delta;
+
+ return event;
+}
+
+static DEFINE_PER_CPU(int, rb_need_resched);
+
+/**
+ * ring_buffer_lock_reserve - reserve a part of the buffer
+ * @buffer: the ring buffer to reserve from
+ * @length: the length of the data to reserve (excluding event header)
+ * @flags: a pointer to save the interrupt flags
+ *
+ * Returns a reseverd event on the ring buffer to copy directly to.
+ * The user of this interface will need to get the body to write into
+ * and can use the ring_buffer_event_data() interface.
+ *
+ * The length is the length of the data needed, not the event length
+ * which also includes the event header.
+ *
+ * Must be paired with ring_buffer_unlock_commit, unless NULL is returned.
+ * If NULL is returned, then nothing has been allocated or locked.
+ */
+struct ring_buffer_event *
+ring_buffer_lock_reserve(struct ring_buffer *buffer,
+ unsigned long length,
+ unsigned long *flags)
+{
+ struct ring_buffer_per_cpu *cpu_buffer;
+ struct ring_buffer_event *event;
+ int cpu, resched;
+
+ if (atomic_read(&buffer->record_disabled))
+ return NULL;
+
+ /* If we are tracing schedule, we don't want to recurse */
+ resched = need_resched();
+ preempt_disable_notrace();
+
+ cpu = raw_smp_processor_id();
+
+ if (!cpu_isset(cpu, buffer->cpumask))
+ goto out;
+
+ cpu_buffer = buffer->buffers[cpu];
+
+ if (atomic_read(&cpu_buffer->record_disabled))
+ goto out;
+
+ length = rb_calculate_event_length(length);
+ if (length > BUF_PAGE_SIZE)
+ goto out;
+
+ event = rb_reserve_next_event(cpu_buffer, RINGBUF_TYPE_DATA, length);
+ if (!event)
+ goto out;
+
+ /*
+ * Need to store resched state on this cpu.
+ * Only the first needs to.
+ */
+
+ if (preempt_count() == 1)
+ per_cpu(rb_need_resched, cpu) = resched;
+
+ return event;
+
+ out:
+ if (resched)
+ preempt_enable_notrace();
+ else
+ preempt_enable_notrace();
+ return NULL;
+}
+
+static void rb_commit(struct ring_buffer_per_cpu *cpu_buffer,
+ struct ring_buffer_event *event)
+{
+ cpu_buffer->entries++;
+
+ /* Only process further if we own the commit */
+ if (!rb_is_commit(cpu_buffer, event))
+ return;
+
+ cpu_buffer->write_stamp += event->time_delta;
+
+ rb_set_commit_to_write(cpu_buffer);
+}
+
+/**
+ * ring_buffer_unlock_commit - commit a reserved
+ * @buffer: The buffer to commit to
+ * @event: The event pointer to commit.
+ * @flags: the interrupt flags received from ring_buffer_lock_reserve.
+ *
+ * This commits the data to the ring buffer, and releases any locks held.
+ *
+ * Must be paired with ring_buffer_lock_reserve.
+ */
+int ring_buffer_unlock_commit(struct ring_buffer *buffer,
+ struct ring_buffer_event *event,
+ unsigned long flags)
+{
+ struct ring_buffer_per_cpu *cpu_buffer;
+ int cpu = raw_smp_processor_id();
+
+ cpu_buffer = buffer->buffers[cpu];
+
+ rb_commit(cpu_buffer, event);
+
+ /*
+ * Only the last preempt count needs to restore preemption.
+ */
+ if (preempt_count() == 1) {
+ if (per_cpu(rb_need_resched, cpu))
+ preempt_enable_no_resched_notrace();
+ else
+ preempt_enable_notrace();
+ } else
+ preempt_enable_no_resched_notrace();
+
+ return 0;
+}
+
+/**
+ * ring_buffer_write - write data to the buffer without reserving
+ * @buffer: The ring buffer to write to.
+ * @length: The length of the data being written (excluding the event header)
+ * @data: The data to write to the buffer.
+ *
+ * This is like ring_buffer_lock_reserve and ring_buffer_unlock_commit as
+ * one function. If you already have the data to write to the buffer, it
+ * may be easier to simply call this function.
+ *
+ * Note, like ring_buffer_lock_reserve, the length is the length of the data
+ * and not the length of the event which would hold the header.
+ */
+int ring_buffer_write(struct ring_buffer *buffer,
+ unsigned long length,
+ void *data)
+{
+ struct ring_buffer_per_cpu *cpu_buffer;
+ struct ring_buffer_event *event;
+ unsigned long event_length;
+ void *body;
+ int ret = -EBUSY;
+ int cpu, resched;
+
+ if (atomic_read(&buffer->record_disabled))
+ return -EBUSY;
+
+ resched = need_resched();
+ preempt_disable_notrace();
+
+ cpu = raw_smp_processor_id();
+
+ if (!cpu_isset(cpu, buffer->cpumask))
+ goto out;
+
+ cpu_buffer = buffer->buffers[cpu];
+
+ if (atomic_read(&cpu_buffer->record_disabled))
+ goto out;
+
+ event_length = rb_calculate_event_length(length);
+ event = rb_reserve_next_event(cpu_buffer,
+ RINGBUF_TYPE_DATA, event_length);
+ if (!event)
+ goto out;
+
+ body = rb_event_data(event);
+
+ memcpy(body, data, length);
+
+ rb_commit(cpu_buffer, event);
+
+ ret = 0;
+ out:
+ if (resched)
+ preempt_enable_no_resched_notrace();
+ else
+ preempt_enable_notrace();
+
+ return ret;
+}
+
+static inline int rb_per_cpu_empty(struct ring_buffer_per_cpu *cpu_buffer)
+{
+ struct buffer_page *reader = cpu_buffer->reader_page;
+ struct buffer_page *head = cpu_buffer->head_page;
+ struct buffer_page *commit = cpu_buffer->commit_page;
+
+ return reader->read == rb_page_commit(reader) &&
+ (commit == reader ||
+ (commit == head &&
+ head->read == rb_page_commit(commit)));
+}
+
+/**
+ * ring_buffer_record_disable - stop all writes into the buffer
+ * @buffer: The ring buffer to stop writes to.
+ *
+ * This prevents all writes to the buffer. Any attempt to write
+ * to the buffer after this will fail and return NULL.
+ *
+ * The caller should call synchronize_sched() after this.
+ */
+void ring_buffer_record_disable(struct ring_buffer *buffer)
+{
+ atomic_inc(&buffer->record_disabled);
+}
+
+/**
+ * ring_buffer_record_enable - enable writes to the buffer
+ * @buffer: The ring buffer to enable writes
+ *
+ * Note, multiple disables will need the same number of enables
+ * to truely enable the writing (much like preempt_disable).
+ */
+void ring_buffer_record_enable(struct ring_buffer *buffer)
+{
+ atomic_dec(&buffer->record_disabled);
+}
+
+/**
+ * ring_buffer_record_disable_cpu - stop all writes into the cpu_buffer
+ * @buffer: The ring buffer to stop writes to.
+ * @cpu: The CPU buffer to stop
+ *
+ * This prevents all writes to the buffer. Any attempt to write
+ * to the buffer after this will fail and return NULL.
+ *
+ * The caller should call synchronize_sched() after this.
+ */
+void ring_buffer_record_disable_cpu(struct ring_buffer *buffer, int cpu)
+{
+ struct ring_buffer_per_cpu *cpu_buffer;
+
+ if (!cpu_isset(cpu, buffer->cpumask))
+ return;
+
+ cpu_buffer = buffer->buffers[cpu];
+ atomic_inc(&cpu_buffer->record_disabled);
+}
+
+/**
+ * ring_buffer_record_enable_cpu - enable writes to the buffer
+ * @buffer: The ring buffer to enable writes
+ * @cpu: The CPU to enable.
+ *
+ * Note, multiple disables will need the same number of enables
+ * to truely enable the writing (much like preempt_disable).
+ */
+void ring_buffer_record_enable_cpu(struct ring_buffer *buffer, int cpu)
+{
+ struct ring_buffer_per_cpu *cpu_buffer;
+
+ if (!cpu_isset(cpu, buffer->cpumask))
+ return;
+
+ cpu_buffer = buffer->buffers[cpu];
+ atomic_dec(&cpu_buffer->record_disabled);
+}
+
+/**
+ * ring_buffer_entries_cpu - get the number of entries in a cpu buffer
+ * @buffer: The ring buffer
+ * @cpu: The per CPU buffer to get the entries from.
+ */
+unsigned long ring_buffer_entries_cpu(struct ring_buffer *buffer, int cpu)
+{
+ struct ring_buffer_per_cpu *cpu_buffer;
+
+ if (!cpu_isset(cpu, buffer->cpumask))
+ return 0;
+
+ cpu_buffer = buffer->buffers[cpu];
+ return cpu_buffer->entries;
+}
+
+/**
+ * ring_buffer_overrun_cpu - get the number of overruns in a cpu_buffer
+ * @buffer: The ring buffer
+ * @cpu: The per CPU buffer to get the number of overruns from
+ */
+unsigned long ring_buffer_overrun_cpu(struct ring_buffer *buffer, int cpu)
+{
+ struct ring_buffer_per_cpu *cpu_buffer;
+
+ if (!cpu_isset(cpu, buffer->cpumask))
+ return 0;
+
+ cpu_buffer = buffer->buffers[cpu];
+ return cpu_buffer->overrun;
+}
+
+/**
+ * ring_buffer_entries - get the number of entries in a buffer
+ * @buffer: The ring buffer
+ *
+ * Returns the total number of entries in the ring buffer
+ * (all CPU entries)
+ */
+unsigned long ring_buffer_entries(struct ring_buffer *buffer)
+{
+ struct ring_buffer_per_cpu *cpu_buffer;
+ unsigned long entries = 0;
+ int cpu;
+
+ /* if you care about this being correct, lock the buffer */
+ for_each_buffer_cpu(buffer, cpu) {
+ cpu_buffer = buffer->buffers[cpu];
+ entries += cpu_buffer->entries;
+ }
+
+ return entries;
+}
+
+/**
+ * ring_buffer_overrun_cpu - get the number of overruns in buffer
+ * @buffer: The ring buffer
+ *
+ * Returns the total number of overruns in the ring buffer
+ * (all CPU entries)
+ */
+unsigned long ring_buffer_overruns(struct ring_buffer *buffer)
+{
+ struct ring_buffer_per_cpu *cpu_buffer;
+ unsigned long overruns = 0;
+ int cpu;
+
+ /* if you care about this being correct, lock the buffer */
+ for_each_buffer_cpu(buffer, cpu) {
+ cpu_buffer = buffer->buffers[cpu];
+ overruns += cpu_buffer->overrun;
+ }
+
+ return overruns;
+}
+
+/**
+ * ring_buffer_iter_reset - reset an iterator
+ * @iter: The iterator to reset
+ *
+ * Resets the iterator, so that it will start from the beginning
+ * again.
+ */
+void ring_buffer_iter_reset(struct ring_buffer_iter *iter)
+{
+ struct ring_buffer_per_cpu *cpu_buffer = iter->cpu_buffer;
+
+ /* Iterator usage is expected to have record disabled */
+ if (list_empty(&cpu_buffer->reader_page->list)) {
+ iter->head_page = cpu_buffer->head_page;
+ iter->head = cpu_buffer->head_page->read;
+ } else {
+ iter->head_page = cpu_buffer->reader_page;
+ iter->head = cpu_buffer->reader_page->read;
+ }
+ if (iter->head)
+ iter->read_stamp = cpu_buffer->read_stamp;
+ else
+ iter->read_stamp = iter->head_page->time_stamp;
+}
+
+/**
+ * ring_buffer_iter_empty - check if an iterator has no more to read
+ * @iter: The iterator to check
+ */
+int ring_buffer_iter_empty(struct ring_buffer_iter *iter)
+{
+ struct ring_buffer_per_cpu *cpu_buffer;
+
+ cpu_buffer = iter->cpu_buffer;
+
+ return iter->head_page == cpu_buffer->commit_page &&
+ iter->head == rb_commit_index(cpu_buffer);
+}
+
+static void
+rb_update_read_stamp(struct ring_buffer_per_cpu *cpu_buffer,
+ struct ring_buffer_event *event)
+{
+ u64 delta;
+
+ switch (event->type) {
+ case RINGBUF_TYPE_PADDING:
+ return;
+
+ case RINGBUF_TYPE_TIME_EXTEND:
+ delta = event->array[0];
+ delta <<= TS_SHIFT;
+ delta += event->time_delta;
+ cpu_buffer->read_stamp += delta;
+ return;
+
+ case RINGBUF_TYPE_TIME_STAMP:
+ /* FIXME: not implemented */
+ return;
+
+ case RINGBUF_TYPE_DATA:
+ cpu_buffer->read_stamp += event->time_delta;
+ return;
+
+ default:
+ BUG();
+ }
+ return;
+}
+
+static void
+rb_update_iter_read_stamp(struct ring_buffer_iter *iter,
+ struct ring_buffer_event *event)
+{
+ u64 delta;
+
+ switch (event->type) {
+ case RINGBUF_TYPE_PADDING:
+ return;
+
+ case RINGBUF_TYPE_TIME_EXTEND:
+ delta = event->array[0];
+ delta <<= TS_SHIFT;
+ delta += event->time_delta;
+ iter->read_stamp += delta;
+ return;
+
+ case RINGBUF_TYPE_TIME_STAMP:
+ /* FIXME: not implemented */
+ return;
+
+ case RINGBUF_TYPE_DATA:
+ iter->read_stamp += event->time_delta;
+ return;
+
+ default:
+ BUG();
+ }
+ return;
+}
+
+static struct buffer_page *
+rb_get_reader_page(struct ring_buffer_per_cpu *cpu_buffer)
+{
+ struct buffer_page *reader = NULL;
+ unsigned long flags;
+
+ spin_lock_irqsave(&cpu_buffer->lock, flags);
+
+ again:
+ reader = cpu_buffer->reader_page;
+
+ /* If there's more to read, return this page */
+ if (cpu_buffer->reader_page->read < rb_page_size(reader))
+ goto out;
+
+ /* Never should we have an index greater than the size */
+ RB_WARN_ON(cpu_buffer,
+ cpu_buffer->reader_page->read > rb_page_size(reader));
+
+ /* check if we caught up to the tail */
+ reader = NULL;
+ if (cpu_buffer->commit_page == cpu_buffer->reader_page)
+ goto out;
+
+ /*
+ * Splice the empty reader page into the list around the head.
+ * Reset the reader page to size zero.
+ */
+
+ reader = cpu_buffer->head_page;
+ cpu_buffer->reader_page->list.next = reader->list.next;
+ cpu_buffer->reader_page->list.prev = reader->list.prev;
+
+ local_set(&cpu_buffer->reader_page->write, 0);
+ local_set(&cpu_buffer->reader_page->commit, 0);
+
+ /* Make the reader page now replace the head */
+ reader->list.prev->next = &cpu_buffer->reader_page->list;
+ reader->list.next->prev = &cpu_buffer->reader_page->list;
+
+ /*
+ * If the tail is on the reader, then we must set the head
+ * to the inserted page, otherwise we set it one before.
+ */
+ cpu_buffer->head_page = cpu_buffer->reader_page;
+
+ if (cpu_buffer->commit_page != reader)
+ rb_inc_page(cpu_buffer, &cpu_buffer->head_page);
+
+ /* Finally update the reader page to the new head */
+ cpu_buffer->reader_page = reader;
+ rb_reset_reader_page(cpu_buffer);
+
+ goto again;
+
+ out:
+ spin_unlock_irqrestore(&cpu_buffer->lock, flags);
+
+ return reader;
+}
+
+static void rb_advance_reader(struct ring_buffer_per_cpu *cpu_buffer)
+{
+ struct ring_buffer_event *event;
+ struct buffer_page *reader;
+ unsigned length;
+
+ reader = rb_get_reader_page(cpu_buffer);
+
+ /* This function should not be called when buffer is empty */
+ BUG_ON(!reader);
+
+ event = rb_reader_event(cpu_buffer);
+
+ if (event->type == RINGBUF_TYPE_DATA)
+ cpu_buffer->entries--;
+
+ rb_update_read_stamp(cpu_buffer, event);
+
+ length = rb_event_length(event);
+ cpu_buffer->reader_page->read += length;
+}
+
+static void rb_advance_iter(struct ring_buffer_iter *iter)
+{
+ struct ring_buffer *buffer;
+ struct ring_buffer_per_cpu *cpu_buffer;
+ struct ring_buffer_event *event;
+ unsigned length;
+
+ cpu_buffer = iter->cpu_buffer;
+ buffer = cpu_buffer->buffer;
+
+ /*
+ * Check if we are at the end of the buffer.
+ */
+ if (iter->head >= rb_page_size(iter->head_page)) {
+ BUG_ON(iter->head_page == cpu_buffer->commit_page);
+ rb_inc_iter(iter);
+ return;
+ }
+
+ event = rb_iter_head_event(iter);
+
+ length = rb_event_length(event);
+
+ /*
+ * This should not be called to advance the header if we are
+ * at the tail of the buffer.
+ */
+ BUG_ON((iter->head_page == cpu_buffer->commit_page) &&
+ (iter->head + length > rb_commit_index(cpu_buffer)));
+
+ rb_update_iter_read_stamp(iter, event);
+
+ iter->head += length;
+
+ /* check for end of page padding */
+ if ((iter->head >= rb_page_size(iter->head_page)) &&
+ (iter->head_page != cpu_buffer->commit_page))
+ rb_advance_iter(iter);
+}
+
+/**
+ * ring_buffer_peek - peek at the next event to be read
+ * @buffer: The ring buffer to read
+ * @cpu: The cpu to peak at
+ * @ts: The timestamp counter of this event.
+ *
+ * This will return the event that will be read next, but does
+ * not consume the data.
+ */
+struct ring_buffer_event *
+ring_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts)
+{
+ struct ring_buffer_per_cpu *cpu_buffer;
+ struct ring_buffer_event *event;
+ struct buffer_page *reader;
+
+ if (!cpu_isset(cpu, buffer->cpumask))
+ return NULL;
+
+ cpu_buffer = buffer->buffers[cpu];
+
+ again:
+ reader = rb_get_reader_page(cpu_buffer);
+ if (!reader)
+ return NULL;
+
+ event = rb_reader_event(cpu_buffer);
+
+ switch (event->type) {
+ case RINGBUF_TYPE_PADDING:
+ RB_WARN_ON(cpu_buffer, 1);
+ rb_advance_reader(cpu_buffer);
+ return NULL;
+
+ case RINGBUF_TYPE_TIME_EXTEND:
+ /* Internal data, OK to advance */
+ rb_advance_reader(cpu_buffer);
+ goto again;
+
+ case RINGBUF_TYPE_TIME_STAMP:
+ /* FIXME: not implemented */
+ rb_advance_reader(cpu_buffer);
+ goto again;
+
+ case RINGBUF_TYPE_DATA:
+ if (ts) {
+ *ts = cpu_buffer->read_stamp + event->time_delta;
+ ring_buffer_normalize_time_stamp(cpu_buffer->cpu, ts);
+ }
+ return event;
+
+ default:
+ BUG();
+ }
+
+ return NULL;
+}
+
+/**
+ * ring_buffer_iter_peek - peek at the next event to be read
+ * @iter: The ring buffer iterator
+ * @ts: The timestamp counter of this event.
+ *
+ * This will return the event that will be read next, but does
+ * not increment the iterator.
+ */
+struct ring_buffer_event *
+ring_buffer_iter_peek(struct ring_buffer_iter *iter, u64 *ts)
+{
+ struct ring_buffer *buffer;
+ struct ring_buffer_per_cpu *cpu_buffer;
+ struct ring_buffer_event *event;
+
+ if (ring_buffer_iter_empty(iter))
+ return NULL;
+
+ cpu_buffer = iter->cpu_buffer;
+ buffer = cpu_buffer->buffer;
+
+ again:
+ if (rb_per_cpu_empty(cpu_buffer))
+ return NULL;
+
+ event = rb_iter_head_event(iter);
+
+ switch (event->type) {
+ case RINGBUF_TYPE_PADDING:
+ rb_inc_iter(iter);
+ goto again;
+
+ case RINGBUF_TYPE_TIME_EXTEND:
+ /* Internal data, OK to advance */
+ rb_advance_iter(iter);
+ goto again;
+
+ case RINGBUF_TYPE_TIME_STAMP:
+ /* FIXME: not implemented */
+ rb_advance_iter(iter);
+ goto again;
+
+ case RINGBUF_TYPE_DATA:
+ if (ts) {
+ *ts = iter->read_stamp + event->time_delta;
+ ring_buffer_normalize_time_stamp(cpu_buffer->cpu, ts);
+ }
+ return event;
+
+ default:
+ BUG();
+ }
+
+ return NULL;
+}
+
+/**
+ * ring_buffer_consume - return an event and consume it
+ * @buffer: The ring buffer to get the next event from
+ *
+ * Returns the next event in the ring buffer, and that event is consumed.
+ * Meaning, that sequential reads will keep returning a different event,
+ * and eventually empty the ring buffer if the producer is slower.
+ */
+struct ring_buffer_event *
+ring_buffer_consume(struct ring_buffer *buffer, int cpu, u64 *ts)
+{
+ struct ring_buffer_per_cpu *cpu_buffer;
+ struct ring_buffer_event *event;
+
+ if (!cpu_isset(cpu, buffer->cpumask))
+ return NULL;
+
+ event = ring_buffer_peek(buffer, cpu, ts);
+ if (!event)
+ return NULL;
+
+ cpu_buffer = buffer->buffers[cpu];
+ rb_advance_reader(cpu_buffer);
+
+ return event;
+}
+
+/**
+ * ring_buffer_read_start - start a non consuming read of the buffer
+ * @buffer: The ring buffer to read from
+ * @cpu: The cpu buffer to iterate over
+ *
+ * This starts up an iteration through the buffer. It also disables
+ * the recording to the buffer until the reading is finished.
+ * This prevents the reading from being corrupted. This is not
+ * a consuming read, so a producer is not expected.
+ *
+ * Must be paired with ring_buffer_finish.
+ */
+struct ring_buffer_iter *
+ring_buffer_read_start(struct ring_buffer *buffer, int cpu)
+{
+ struct ring_buffer_per_cpu *cpu_buffer;
+ struct ring_buffer_iter *iter;
+ unsigned long flags;
+
+ if (!cpu_isset(cpu, buffer->cpumask))
+ return NULL;
+
+ iter = kmalloc(sizeof(*iter), GFP_KERNEL);
+ if (!iter)
+ return NULL;
+
+ cpu_buffer = buffer->buffers[cpu];
+
+ iter->cpu_buffer = cpu_buffer;
+
+ atomic_inc(&cpu_buffer->record_disabled);
+ synchronize_sched();
+
+ spin_lock_irqsave(&cpu_buffer->lock, flags);
+ ring_buffer_iter_reset(iter);
+ spin_unlock_irqrestore(&cpu_buffer->lock, flags);
+
+ return iter;
+}
+
+/**
+ * ring_buffer_finish - finish reading the iterator of the buffer
+ * @iter: The iterator retrieved by ring_buffer_start
+ *
+ * This re-enables the recording to the buffer, and frees the
+ * iterator.
+ */
+void
+ring_buffer_read_finish(struct ring_buffer_iter *iter)
+{
+ struct ring_buffer_per_cpu *cpu_buffer = iter->cpu_buffer;
+
+ atomic_dec(&cpu_buffer->record_disabled);
+ kfree(iter);
+}
+
+/**
+ * ring_buffer_read - read the next item in the ring buffer by the iterator
+ * @iter: The ring buffer iterator
+ * @ts: The time stamp of the event read.
+ *
+ * This reads the next event in the ring buffer and increments the iterator.
+ */
+struct ring_buffer_event *
+ring_buffer_read(struct ring_buffer_iter *iter, u64 *ts)
+{
+ struct ring_buffer_event *event;
+
+ event = ring_buffer_iter_peek(iter, ts);
+ if (!event)
+ return NULL;
+
+ rb_advance_iter(iter);
+
+ return event;
+}
+
+/**
+ * ring_buffer_size - return the size of the ring buffer (in bytes)
+ * @buffer: The ring buffer.
+ */
+unsigned long ring_buffer_size(struct ring_buffer *buffer)
+{
+ return BUF_PAGE_SIZE * buffer->pages;
+}
+
+static void
+rb_reset_cpu(struct ring_buffer_per_cpu *cpu_buffer)
+{
+ cpu_buffer->head_page
+ = list_entry(cpu_buffer->pages.next, struct buffer_page, list);
+ local_set(&cpu_buffer->head_page->write, 0);
+ local_set(&cpu_buffer->head_page->commit, 0);
+
+ cpu_buffer->head_page->read = 0;
+
+ cpu_buffer->tail_page = cpu_buffer->head_page;
+ cpu_buffer->commit_page = cpu_buffer->head_page;
+
+ INIT_LIST_HEAD(&cpu_buffer->reader_page->list);
+ local_set(&cpu_buffer->reader_page->write, 0);
+ local_set(&cpu_buffer->reader_page->commit, 0);
+ cpu_buffer->reader_page->read = 0;
+
+ cpu_buffer->overrun = 0;
+ cpu_buffer->entries = 0;
+}
+
+/**
+ * ring_buffer_reset_cpu - reset a ring buffer per CPU buffer
+ * @buffer: The ring buffer to reset a per cpu buffer of
+ * @cpu: The CPU buffer to be reset
+ */
+void ring_buffer_reset_cpu(struct ring_buffer *buffer, int cpu)
+{
+ struct ring_buffer_per_cpu *cpu_buffer = buffer->buffers[cpu];
+ unsigned long flags;
+
+ if (!cpu_isset(cpu, buffer->cpumask))
+ return;
+
+ spin_lock_irqsave(&cpu_buffer->lock, flags);
+
+ rb_reset_cpu(cpu_buffer);
+
+ spin_unlock_irqrestore(&cpu_buffer->lock, flags);
+}
+
+/**
+ * ring_buffer_reset - reset a ring buffer
+ * @buffer: The ring buffer to reset all cpu buffers
+ */
+void ring_buffer_reset(struct ring_buffer *buffer)
+{
+ int cpu;
+
+ for_each_buffer_cpu(buffer, cpu)
+ ring_buffer_reset_cpu(buffer, cpu);
+}
+
+/**
+ * rind_buffer_empty - is the ring buffer empty?
+ * @buffer: The ring buffer to test
+ */
+int ring_buffer_empty(struct ring_buffer *buffer)
+{
+ struct ring_buffer_per_cpu *cpu_buffer;
+ int cpu;
+
+ /* yes this is racy, but if you don't like the race, lock the buffer */
+ for_each_buffer_cpu(buffer, cpu) {
+ cpu_buffer = buffer->buffers[cpu];
+ if (!rb_per_cpu_empty(cpu_buffer))
+ return 0;
+ }
+ return 1;
+}
+
+/**
+ * ring_buffer_empty_cpu - is a cpu buffer of a ring buffer empty?
+ * @buffer: The ring buffer
+ * @cpu: The CPU buffer to test
+ */
+int ring_buffer_empty_cpu(struct ring_buffer *buffer, int cpu)
+{
+ struct ring_buffer_per_cpu *cpu_buffer;
+
+ if (!cpu_isset(cpu, buffer->cpumask))
+ return 1;
+
+ cpu_buffer = buffer->buffers[cpu];
+ return rb_per_cpu_empty(cpu_buffer);
+}
+
+/**
+ * ring_buffer_swap_cpu - swap a CPU buffer between two ring buffers
+ * @buffer_a: One buffer to swap with
+ * @buffer_b: The other buffer to swap with
+ *
+ * This function is useful for tracers that want to take a "snapshot"
+ * of a CPU buffer and has another back up buffer lying around.
+ * it is expected that the tracer handles the cpu buffer not being
+ * used at the moment.
+ */
+int ring_buffer_swap_cpu(struct ring_buffer *buffer_a,
+ struct ring_buffer *buffer_b, int cpu)
+{
+ struct ring_buffer_per_cpu *cpu_buffer_a;
+ struct ring_buffer_per_cpu *cpu_buffer_b;
+
+ if (!cpu_isset(cpu, buffer_a->cpumask) ||
+ !cpu_isset(cpu, buffer_b->cpumask))
+ return -EINVAL;
+
+ /* At least make sure the two buffers are somewhat the same */
+ if (buffer_a->size != buffer_b->size ||
+ buffer_a->pages != buffer_b->pages)
+ return -EINVAL;
+
+ cpu_buffer_a = buffer_a->buffers[cpu];
+ cpu_buffer_b = buffer_b->buffers[cpu];
+
+ /*
+ * We can't do a synchronize_sched here because this
+ * function can be called in atomic context.
+ * Normally this will be called from the same CPU as cpu.
+ * If not it's up to the caller to protect this.
+ */
+ atomic_inc(&cpu_buffer_a->record_disabled);
+ atomic_inc(&cpu_buffer_b->record_disabled);
+
+ buffer_a->buffers[cpu] = cpu_buffer_b;
+ buffer_b->buffers[cpu] = cpu_buffer_a;
+
+ cpu_buffer_b->buffer = buffer_a;
+ cpu_buffer_a->buffer = buffer_b;
+
+ atomic_dec(&cpu_buffer_a->record_disabled);
+ atomic_dec(&cpu_buffer_b->record_disabled);
+
+ return 0;
+}
+
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 8f3fb3d..d345d64 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -14,6 +14,7 @@
#include <linux/utsrelease.h>
#include <linux/kallsyms.h>
#include <linux/seq_file.h>
+#include <linux/notifier.h>
#include <linux/debugfs.h>
#include <linux/pagemap.h>
#include <linux/hardirq.h>
@@ -22,6 +23,7 @@
#include <linux/ftrace.h>
#include <linux/module.h>
#include <linux/percpu.h>
+#include <linux/kdebug.h>
#include <linux/ctype.h>
#include <linux/init.h>
#include <linux/poll.h>
@@ -31,25 +33,36 @@
#include <linux/writeback.h>
#include <linux/stacktrace.h>
+#include <linux/ring_buffer.h>
#include "trace.h"
+#define TRACE_BUFFER_FLAGS (RB_FL_OVERWRITE)
+
unsigned long __read_mostly tracing_max_latency = (cycle_t)ULONG_MAX;
unsigned long __read_mostly tracing_thresh;
-static unsigned long __read_mostly tracing_nr_buffers;
+static DEFINE_PER_CPU(local_t, ftrace_cpu_disabled);
+
+static inline void ftrace_disable_cpu(void)
+{
+ preempt_disable();
+ local_inc(&__get_cpu_var(ftrace_cpu_disabled));
+}
+
+static inline void ftrace_enable_cpu(void)
+{
+ local_dec(&__get_cpu_var(ftrace_cpu_disabled));
+ preempt_enable();
+}
+
static cpumask_t __read_mostly tracing_buffer_mask;
#define for_each_tracing_cpu(cpu) \
for_each_cpu_mask(cpu, tracing_buffer_mask)
-static int trace_alloc_page(void);
-static int trace_free_page(void);
-
static int tracing_disabled = 1;
-static unsigned long tracing_pages_allocated;
-
long
ns2usecs(cycle_t nsec)
{
@@ -60,7 +73,9 @@ ns2usecs(cycle_t nsec)
cycle_t ftrace_now(int cpu)
{
- return cpu_clock(cpu);
+ u64 ts = ring_buffer_time_stamp(cpu);
+ ring_buffer_normalize_time_stamp(cpu, &ts);
+ return ts;
}
/*
@@ -100,11 +115,18 @@ static int tracer_enabled = 1;
int ftrace_function_enabled;
/*
- * trace_nr_entries is the number of entries that is allocated
- * for a buffer. Note, the number of entries is always rounded
- * to ENTRIES_PER_PAGE.
+ * trace_buf_size is the size in bytes that is allocated
+ * for a buffer. Note, the number of bytes is always rounded
+ * to page size.
+ *
+ * This number is purposely set to a low number of 16384.
+ * If the dump on oops happens, it will be much appreciated
+ * to not have to wait for all that output. Anyway this can be
+ * boot time and run time configurable.
*/
-static unsigned long trace_nr_entries = 65536UL;
+#define TRACE_BUF_SIZE_DEFAULT 1441792UL /* 16384 * 88 (sizeof(entry)) */
+
+static unsigned long trace_buf_size = TRACE_BUF_SIZE_DEFAULT;
/* trace_types holds a link list of available tracers. */
static struct tracer *trace_types __read_mostly;
@@ -133,24 +155,6 @@ static DECLARE_WAIT_QUEUE_HEAD(trace_wait);
/* trace_flags holds iter_ctrl options */
unsigned long trace_flags = TRACE_ITER_PRINT_PARENT;
-static notrace void no_trace_init(struct trace_array *tr)
-{
- int cpu;
-
- ftrace_function_enabled = 0;
- if(tr->ctrl)
- for_each_online_cpu(cpu)
- tracing_reset(tr->data[cpu]);
- tracer_enabled = 0;
-}
-
-/* dummy trace to disable tracing */
-static struct tracer no_tracer __read_mostly = {
- .name = "none",
- .init = no_trace_init
-};
-
-
/**
* trace_wake_up - wake up tasks waiting for trace input
*
@@ -167,23 +171,21 @@ void trace_wake_up(void)
wake_up(&trace_wait);
}
-#define ENTRIES_PER_PAGE (PAGE_SIZE / sizeof(struct trace_entry))
-
-static int __init set_nr_entries(char *str)
+static int __init set_buf_size(char *str)
{
- unsigned long nr_entries;
+ unsigned long buf_size;
int ret;
if (!str)
return 0;
- ret = strict_strtoul(str, 0, &nr_entries);
+ ret = strict_strtoul(str, 0, &buf_size);
/* nr_entries can not be zero */
- if (ret < 0 || nr_entries == 0)
+ if (ret < 0 || buf_size == 0)
return 0;
- trace_nr_entries = nr_entries;
+ trace_buf_size = buf_size;
return 1;
}
-__setup("trace_entries=", set_nr_entries);
+__setup("trace_buf_size=", set_buf_size);
unsigned long nsecs_to_usecs(unsigned long nsecs)
{
@@ -191,21 +193,6 @@ unsigned long nsecs_to_usecs(unsigned long nsecs)
}
/*
- * trace_flag_type is an enumeration that holds different
- * states when a trace occurs. These are:
- * IRQS_OFF - interrupts were disabled
- * NEED_RESCED - reschedule is requested
- * HARDIRQ - inside an interrupt handler
- * SOFTIRQ - inside a softirq handler
- */
-enum trace_flag_type {
- TRACE_FLAG_IRQS_OFF = 0x01,
- TRACE_FLAG_NEED_RESCHED = 0x02,
- TRACE_FLAG_HARDIRQ = 0x04,
- TRACE_FLAG_SOFTIRQ = 0x08,
-};
-
-/*
* TRACE_ITER_SYM_MASK masks the options in trace_flags that
* control the output of kernel symbols.
*/
@@ -224,6 +211,7 @@ static const char *trace_options[] = {
"block",
"stacktrace",
"sched-tree",
+ "ftrace_printk",
NULL
};
@@ -266,54 +254,6 @@ __update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
tracing_record_cmdline(current);
}
-#define CHECK_COND(cond) \
- if (unlikely(cond)) { \
- tracing_disabled = 1; \
- WARN_ON(1); \
- return -1; \
- }
-
-/**
- * check_pages - integrity check of trace buffers
- *
- * As a safty measure we check to make sure the data pages have not
- * been corrupted.
- */
-int check_pages(struct trace_array_cpu *data)
-{
- struct page *page, *tmp;
-
- CHECK_COND(data->trace_pages.next->prev != &data->trace_pages);
- CHECK_COND(data->trace_pages.prev->next != &data->trace_pages);
-
- list_for_each_entry_safe(page, tmp, &data->trace_pages, lru) {
- CHECK_COND(page->lru.next->prev != &page->lru);
- CHECK_COND(page->lru.prev->next != &page->lru);
- }
-
- return 0;
-}
-
-/**
- * head_page - page address of the first page in per_cpu buffer.
- *
- * head_page returns the page address of the first page in
- * a per_cpu buffer. This also preforms various consistency
- * checks to make sure the buffer has not been corrupted.
- */
-void *head_page(struct trace_array_cpu *data)
-{
- struct page *page;
-
- if (list_empty(&data->trace_pages))
- return NULL;
-
- page = list_entry(data->trace_pages.next, struct page, lru);
- BUG_ON(&page->lru == &data->trace_pages);
-
- return page_address(page);
-}
-
/**
* trace_seq_printf - sequence printing of trace information
* @s: trace sequence descriptor
@@ -395,28 +335,23 @@ trace_seq_putmem(struct trace_seq *s, void *mem, size_t len)
return len;
}
-#define HEX_CHARS 17
-static const char hex2asc[] = "0123456789abcdef";
+#define MAX_MEMHEX_BYTES 8
+#define HEX_CHARS (MAX_MEMHEX_BYTES*2 + 1)
static int
trace_seq_putmem_hex(struct trace_seq *s, void *mem, size_t len)
{
unsigned char hex[HEX_CHARS];
unsigned char *data = mem;
- unsigned char byte;
int i, j;
- BUG_ON(len >= HEX_CHARS);
-
#ifdef __BIG_ENDIAN
for (i = 0, j = 0; i < len; i++) {
#else
for (i = len-1, j = 0; i >= 0; i--) {
#endif
- byte = data[i];
-
- hex[j++] = hex2asc[byte & 0x0f];
- hex[j++] = hex2asc[byte >> 4];
+ hex[j++] = hex_asc_hi(data[i]);
+ hex[j++] = hex_asc_lo(data[i]);
}
hex[j++] = ' ';
@@ -460,34 +395,6 @@ trace_print_seq(struct seq_file *m, struct trace_seq *s)
trace_seq_reset(s);
}
-/*
- * flip the trace buffers between two trace descriptors.
- * This usually is the buffers between the global_trace and
- * the max_tr to record a snapshot of a current trace.
- *
- * The ftrace_max_lock must be held.
- */
-static void
-flip_trace(struct trace_array_cpu *tr1, struct trace_array_cpu *tr2)
-{
- struct list_head flip_pages;
-
- INIT_LIST_HEAD(&flip_pages);
-
- memcpy(&tr1->trace_head_idx, &tr2->trace_head_idx,
- sizeof(struct trace_array_cpu) -
- offsetof(struct trace_array_cpu, trace_head_idx));
-
- check_pages(tr1);
- check_pages(tr2);
- list_splice_init(&tr1->trace_pages, &flip_pages);
- list_splice_init(&tr2->trace_pages, &tr1->trace_pages);
- list_splice_init(&flip_pages, &tr2->trace_pages);
- BUG_ON(!list_empty(&flip_pages));
- check_pages(tr1);
- check_pages(tr2);
-}
-
/**
* update_max_tr - snapshot all trace buffers from global_trace to max_tr
* @tr: tracer
@@ -500,17 +407,17 @@ flip_trace(struct trace_array_cpu *tr1, struct trace_array_cpu *tr2)
void
update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
{
- struct trace_array_cpu *data;
- int i;
+ struct ring_buffer *buf = tr->buffer;
WARN_ON_ONCE(!irqs_disabled());
__raw_spin_lock(&ftrace_max_lock);
- /* clear out all the previous traces */
- for_each_tracing_cpu(i) {
- data = tr->data[i];
- flip_trace(max_tr.data[i], data);
- tracing_reset(data);
- }
+
+ tr->buffer = max_tr.buffer;
+ max_tr.buffer = buf;
+
+ ftrace_disable_cpu();
+ ring_buffer_reset(tr->buffer);
+ ftrace_enable_cpu();
__update_max_tr(tr, tsk, cpu);
__raw_spin_unlock(&ftrace_max_lock);
@@ -527,16 +434,19 @@ update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
void
update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu)
{
- struct trace_array_cpu *data = tr->data[cpu];
- int i;
+ int ret;
WARN_ON_ONCE(!irqs_disabled());
__raw_spin_lock(&ftrace_max_lock);
- for_each_tracing_cpu(i)
- tracing_reset(max_tr.data[i]);
- flip_trace(max_tr.data[cpu], data);
- tracing_reset(data);
+ ftrace_disable_cpu();
+
+ ring_buffer_reset(max_tr.buffer);
+ ret = ring_buffer_swap_cpu(max_tr.buffer, tr->buffer, cpu);
+
+ ftrace_enable_cpu();
+
+ WARN_ON_ONCE(ret);
__update_max_tr(tr, tsk, cpu);
__raw_spin_unlock(&ftrace_max_lock);
@@ -573,7 +483,6 @@ int register_tracer(struct tracer *type)
#ifdef CONFIG_FTRACE_STARTUP_TEST
if (type->selftest) {
struct tracer *saved_tracer = current_trace;
- struct trace_array_cpu *data;
struct trace_array *tr = &global_trace;
int saved_ctrl = tr->ctrl;
int i;
@@ -585,10 +494,7 @@ int register_tracer(struct tracer *type)
* If we fail, we do not register this tracer.
*/
for_each_tracing_cpu(i) {
- data = tr->data[i];
- if (!head_page(data))
- continue;
- tracing_reset(data);
+ tracing_reset(tr, i);
}
current_trace = type;
tr->ctrl = 0;
@@ -604,10 +510,7 @@ int register_tracer(struct tracer *type)
}
/* Only reset on passing, to avoid touching corrupted buffers */
for_each_tracing_cpu(i) {
- data = tr->data[i];
- if (!head_page(data))
- continue;
- tracing_reset(data);
+ tracing_reset(tr, i);
}
printk(KERN_CONT "PASSED\n");
}
@@ -653,13 +556,11 @@ void unregister_tracer(struct tracer *type)
mutex_unlock(&trace_types_lock);
}
-void tracing_reset(struct trace_array_cpu *data)
+void tracing_reset(struct trace_array *tr, int cpu)
{
- data->trace_idx = 0;
- data->overrun = 0;
- data->trace_head = data->trace_tail = head_page(data);
- data->trace_head_idx = 0;
- data->trace_tail_idx = 0;
+ ftrace_disable_cpu();
+ ring_buffer_reset_cpu(tr->buffer, cpu);
+ ftrace_enable_cpu();
}
#define SAVED_CMDLINES 128
@@ -745,82 +646,16 @@ void tracing_record_cmdline(struct task_struct *tsk)
trace_save_cmdline(tsk);
}
-static inline struct list_head *
-trace_next_list(struct trace_array_cpu *data, struct list_head *next)
-{
- /*
- * Roundrobin - but skip the head (which is not a real page):
- */
- next = next->next;
- if (unlikely(next == &data->trace_pages))
- next = next->next;
- BUG_ON(next == &data->trace_pages);
-
- return next;
-}
-
-static inline void *
-trace_next_page(struct trace_array_cpu *data, void *addr)
-{
- struct list_head *next;
- struct page *page;
-
- page = virt_to_page(addr);
-
- next = trace_next_list(data, &page->lru);
- page = list_entry(next, struct page, lru);
-
- return page_address(page);
-}
-
-static inline struct trace_entry *
-tracing_get_trace_entry(struct trace_array *tr, struct trace_array_cpu *data)
-{
- unsigned long idx, idx_next;
- struct trace_entry *entry;
-
- data->trace_idx++;
- idx = data->trace_head_idx;
- idx_next = idx + 1;
-
- BUG_ON(idx * TRACE_ENTRY_SIZE >= PAGE_SIZE);
-
- entry = data->trace_head + idx * TRACE_ENTRY_SIZE;
-
- if (unlikely(idx_next >= ENTRIES_PER_PAGE)) {
- data->trace_head = trace_next_page(data, data->trace_head);
- idx_next = 0;
- }
-
- if (data->trace_head == data->trace_tail &&
- idx_next == data->trace_tail_idx) {
- /* overrun */
- data->overrun++;
- data->trace_tail_idx++;
- if (data->trace_tail_idx >= ENTRIES_PER_PAGE) {
- data->trace_tail =
- trace_next_page(data, data->trace_tail);
- data->trace_tail_idx = 0;
- }
- }
-
- data->trace_head_idx = idx_next;
-
- return entry;
-}
-
-static inline void
-tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags)
+void
+tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags,
+ int pc)
{
struct task_struct *tsk = current;
- unsigned long pc;
-
- pc = preempt_count();
- entry->preempt_count = pc & 0xff;
- entry->pid = (tsk) ? tsk->pid : 0;
- entry->t = ftrace_now(raw_smp_processor_id());
- entry->flags = (irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) |
+ entry->preempt_count = pc & 0xff;
+ entry->pid = (tsk) ? tsk->pid : 0;
+ entry->flags =
+ (irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) |
((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) |
((pc & SOFTIRQ_MASK) ? TRACE_FLAG_SOFTIRQ : 0) |
(need_resched() ? TRACE_FLAG_NEED_RESCHED : 0);
@@ -828,145 +663,139 @@ tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags)
void
trace_function(struct trace_array *tr, struct trace_array_cpu *data,
- unsigned long ip, unsigned long parent_ip, unsigned long flags)
+ unsigned long ip, unsigned long parent_ip, unsigned long flags,
+ int pc)
{
- struct trace_entry *entry;
+ struct ring_buffer_event *event;
+ struct ftrace_entry *entry;
unsigned long irq_flags;
- raw_local_irq_save(irq_flags);
- __raw_spin_lock(&data->lock);
- entry = tracing_get_trace_entry(tr, data);
- tracing_generic_entry_update(entry, flags);
- entry->type = TRACE_FN;
- entry->fn.ip = ip;
- entry->fn.parent_ip = parent_ip;
- __raw_spin_unlock(&data->lock);
- raw_local_irq_restore(irq_flags);
+ /* If we are reading the ring buffer, don't trace */
+ if (unlikely(local_read(&__get_cpu_var(ftrace_cpu_disabled))))
+ return;
+
+ event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
+ &irq_flags);
+ if (!event)
+ return;
+ entry = ring_buffer_event_data(event);
+ tracing_generic_entry_update(&entry->ent, flags, pc);
+ entry->ent.type = TRACE_FN;
+ entry->ip = ip;
+ entry->parent_ip = parent_ip;
+ ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
}
void
ftrace(struct trace_array *tr, struct trace_array_cpu *data,
- unsigned long ip, unsigned long parent_ip, unsigned long flags)
+ unsigned long ip, unsigned long parent_ip, unsigned long flags,
+ int pc)
{
if (likely(!atomic_read(&data->disabled)))
- trace_function(tr, data, ip, parent_ip, flags);
+ trace_function(tr, data, ip, parent_ip, flags, pc);
}
-#ifdef CONFIG_MMIOTRACE
-void __trace_mmiotrace_rw(struct trace_array *tr, struct trace_array_cpu *data,
- struct mmiotrace_rw *rw)
+static void ftrace_trace_stack(struct trace_array *tr,
+ struct trace_array_cpu *data,
+ unsigned long flags,
+ int skip, int pc)
{
- struct trace_entry *entry;
+ struct ring_buffer_event *event;
+ struct stack_entry *entry;
+ struct stack_trace trace;
unsigned long irq_flags;
- raw_local_irq_save(irq_flags);
- __raw_spin_lock(&data->lock);
-
- entry = tracing_get_trace_entry(tr, data);
- tracing_generic_entry_update(entry, 0);
- entry->type = TRACE_MMIO_RW;
- entry->mmiorw = *rw;
-
- __raw_spin_unlock(&data->lock);
- raw_local_irq_restore(irq_flags);
-
- trace_wake_up();
-}
-
-void __trace_mmiotrace_map(struct trace_array *tr, struct trace_array_cpu *data,
- struct mmiotrace_map *map)
-{
- struct trace_entry *entry;
- unsigned long irq_flags;
+ if (!(trace_flags & TRACE_ITER_STACKTRACE))
+ return;
- raw_local_irq_save(irq_flags);
- __raw_spin_lock(&data->lock);
+ event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
+ &irq_flags);
+ if (!event)
+ return;
+ entry = ring_buffer_event_data(event);
+ tracing_generic_entry_update(&entry->ent, flags, pc);
+ entry->ent.type = TRACE_STACK;
- entry = tracing_get_trace_entry(tr, data);
- tracing_generic_entry_update(entry, 0);
- entry->type = TRACE_MMIO_MAP;
- entry->mmiomap = *map;
+ memset(&entry->caller, 0, sizeof(entry->caller));
- __raw_spin_unlock(&data->lock);
- raw_local_irq_restore(irq_flags);
+ trace.nr_entries = 0;
+ trace.max_entries = FTRACE_STACK_ENTRIES;
+ trace.skip = skip;
+ trace.entries = entry->caller;
- trace_wake_up();
+ save_stack_trace(&trace);
+ ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
}
-#endif
void __trace_stack(struct trace_array *tr,
struct trace_array_cpu *data,
unsigned long flags,
int skip)
{
- struct trace_entry *entry;
- struct stack_trace trace;
-
- if (!(trace_flags & TRACE_ITER_STACKTRACE))
- return;
-
- entry = tracing_get_trace_entry(tr, data);
- tracing_generic_entry_update(entry, flags);
- entry->type = TRACE_STACK;
-
- memset(&entry->stack, 0, sizeof(entry->stack));
-
- trace.nr_entries = 0;
- trace.max_entries = FTRACE_STACK_ENTRIES;
- trace.skip = skip;
- trace.entries = entry->stack.caller;
-
- save_stack_trace(&trace);
+ ftrace_trace_stack(tr, data, flags, skip, preempt_count());
}
-void
-__trace_special(void *__tr, void *__data,
- unsigned long arg1, unsigned long arg2, unsigned long arg3)
+static void
+ftrace_trace_special(void *__tr, void *__data,
+ unsigned long arg1, unsigned long arg2, unsigned long arg3,
+ int pc)
{
+ struct ring_buffer_event *event;
struct trace_array_cpu *data = __data;
struct trace_array *tr = __tr;
- struct trace_entry *entry;
+ struct special_entry *entry;
unsigned long irq_flags;
- raw_local_irq_save(irq_flags);
- __raw_spin_lock(&data->lock);
- entry = tracing_get_trace_entry(tr, data);
- tracing_generic_entry_update(entry, 0);
- entry->type = TRACE_SPECIAL;
- entry->special.arg1 = arg1;
- entry->special.arg2 = arg2;
- entry->special.arg3 = arg3;
- __trace_stack(tr, data, irq_flags, 4);
- __raw_spin_unlock(&data->lock);
- raw_local_irq_restore(irq_flags);
+ event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
+ &irq_flags);
+ if (!event)
+ return;
+ entry = ring_buffer_event_data(event);
+ tracing_generic_entry_update(&entry->ent, 0, pc);
+ entry->ent.type = TRACE_SPECIAL;
+ entry->arg1 = arg1;
+ entry->arg2 = arg2;
+ entry->arg3 = arg3;
+ ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
+ ftrace_trace_stack(tr, data, irq_flags, 4, pc);
trace_wake_up();
}
void
+__trace_special(void *__tr, void *__data,
+ unsigned long arg1, unsigned long arg2, unsigned long arg3)
+{
+ ftrace_trace_special(__tr, __data, arg1, arg2, arg3, preempt_count());
+}
+
+void
tracing_sched_switch_trace(struct trace_array *tr,
struct trace_array_cpu *data,
struct task_struct *prev,
struct task_struct *next,
- unsigned long flags)
+ unsigned long flags, int pc)
{
- struct trace_entry *entry;
+ struct ring_buffer_event *event;
+ struct ctx_switch_entry *entry;
unsigned long irq_flags;
- raw_local_irq_save(irq_flags);
- __raw_spin_lock(&data->lock);
- entry = tracing_get_trace_entry(tr, data);
- tracing_generic_entry_update(entry, flags);
- entry->type = TRACE_CTX;
- entry->ctx.prev_pid = prev->pid;
- entry->ctx.prev_prio = prev->prio;
- entry->ctx.prev_state = prev->state;
- entry->ctx.next_pid = next->pid;
- entry->ctx.next_prio = next->prio;
- entry->ctx.next_state = next->state;
- __trace_stack(tr, data, flags, 5);
- __raw_spin_unlock(&data->lock);
- raw_local_irq_restore(irq_flags);
+ event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
+ &irq_flags);
+ if (!event)
+ return;
+ entry = ring_buffer_event_data(event);
+ tracing_generic_entry_update(&entry->ent, flags, pc);
+ entry->ent.type = TRACE_CTX;
+ entry->prev_pid = prev->pid;
+ entry->prev_prio = prev->prio;
+ entry->prev_state = prev->state;
+ entry->next_pid = next->pid;
+ entry->next_prio = next->prio;
+ entry->next_state = next->state;
+ entry->next_cpu = task_cpu(next);
+ ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
+ ftrace_trace_stack(tr, data, flags, 5, pc);
}
void
@@ -974,25 +803,28 @@ tracing_sched_wakeup_trace(struct trace_array *tr,
struct trace_array_cpu *data,
struct task_struct *wakee,
struct task_struct *curr,
- unsigned long flags)
+ unsigned long flags, int pc)
{
- struct trace_entry *entry;
+ struct ring_buffer_event *event;
+ struct ctx_switch_entry *entry;
unsigned long irq_flags;
- raw_local_irq_save(irq_flags);
- __raw_spin_lock(&data->lock);
- entry = tracing_get_trace_entry(tr, data);
- tracing_generic_entry_update(entry, flags);
- entry->type = TRACE_WAKE;
- entry->ctx.prev_pid = curr->pid;
- entry->ctx.prev_prio = curr->prio;
- entry->ctx.prev_state = curr->state;
- entry->ctx.next_pid = wakee->pid;
- entry->ctx.next_prio = wakee->prio;
- entry->ctx.next_state = wakee->state;
- __trace_stack(tr, data, flags, 6);
- __raw_spin_unlock(&data->lock);
- raw_local_irq_restore(irq_flags);
+ event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
+ &irq_flags);
+ if (!event)
+ return;
+ entry = ring_buffer_event_data(event);
+ tracing_generic_entry_update(&entry->ent, flags, pc);
+ entry->ent.type = TRACE_WAKE;
+ entry->prev_pid = curr->pid;
+ entry->prev_prio = curr->prio;
+ entry->prev_state = curr->state;
+ entry->next_pid = wakee->pid;
+ entry->next_prio = wakee->prio;
+ entry->next_state = wakee->state;
+ entry->next_cpu = task_cpu(wakee);
+ ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
+ ftrace_trace_stack(tr, data, flags, 6, pc);
trace_wake_up();
}
@@ -1002,23 +834,21 @@ ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3)
{
struct trace_array *tr = &global_trace;
struct trace_array_cpu *data;
- unsigned long flags;
- long disabled;
int cpu;
+ int pc;
- if (tracing_disabled || current_trace == &no_tracer || !tr->ctrl)
+ if (tracing_disabled || !tr->ctrl)
return;
- local_irq_save(flags);
+ pc = preempt_count();
+ preempt_disable_notrace();
cpu = raw_smp_processor_id();
data = tr->data[cpu];
- disabled = atomic_inc_return(&data->disabled);
- if (likely(disabled == 1))
- __trace_special(tr, data, arg1, arg2, arg3);
+ if (likely(!atomic_read(&data->disabled)))
+ ftrace_trace_special(tr, data, arg1, arg2, arg3, pc);
- atomic_dec(&data->disabled);
- local_irq_restore(flags);
+ preempt_enable_notrace();
}
#ifdef CONFIG_FTRACE
@@ -1029,7 +859,8 @@ function_trace_call(unsigned long ip, unsigned long parent_ip)
struct trace_array_cpu *data;
unsigned long flags;
long disabled;
- int cpu;
+ int cpu, resched;
+ int pc;
if (unlikely(!ftrace_function_enabled))
return;
@@ -1037,16 +868,22 @@ function_trace_call(unsigned long ip, unsigned long parent_ip)
if (skip_trace(ip))
return;
- local_irq_save(flags);
+ pc = preempt_count();
+ resched = need_resched();
+ preempt_disable_notrace();
+ local_save_flags(flags);
cpu = raw_smp_processor_id();
data = tr->data[cpu];
disabled = atomic_inc_return(&data->disabled);
if (likely(disabled == 1))
- trace_function(tr, data, ip, parent_ip, flags);
+ trace_function(tr, data, ip, parent_ip, flags, pc);
atomic_dec(&data->disabled);
- local_irq_restore(flags);
+ if (resched)
+ preempt_enable_no_resched_notrace();
+ else
+ preempt_enable_notrace();
}
static struct ftrace_ops trace_ops __read_mostly =
@@ -1073,111 +910,96 @@ enum trace_file_type {
TRACE_FILE_LAT_FMT = 1,
};
-static struct trace_entry *
-trace_entry_idx(struct trace_array *tr, struct trace_array_cpu *data,
- struct trace_iterator *iter, int cpu)
+static void trace_iterator_increment(struct trace_iterator *iter, int cpu)
{
- struct page *page;
- struct trace_entry *array;
+ /* Don't allow ftrace to trace into the ring buffers */
+ ftrace_disable_cpu();
- if (iter->next_idx[cpu] >= tr->entries ||
- iter->next_idx[cpu] >= data->trace_idx ||
- (data->trace_head == data->trace_tail &&
- data->trace_head_idx == data->trace_tail_idx))
- return NULL;
+ iter->idx++;
+ if (iter->buffer_iter[iter->cpu])
+ ring_buffer_read(iter->buffer_iter[iter->cpu], NULL);
- if (!iter->next_page[cpu]) {
- /* Initialize the iterator for this cpu trace buffer */
- WARN_ON(!data->trace_tail);
- page = virt_to_page(data->trace_tail);
- iter->next_page[cpu] = &page->lru;
- iter->next_page_idx[cpu] = data->trace_tail_idx;
- }
+ ftrace_enable_cpu();
+}
+
+static struct trace_entry *
+peek_next_entry(struct trace_iterator *iter, int cpu, u64 *ts)
+{
+ struct ring_buffer_event *event;
+ struct ring_buffer_iter *buf_iter = iter->buffer_iter[cpu];
- page = list_entry(iter->next_page[cpu], struct page, lru);
- BUG_ON(&data->trace_pages == &page->lru);
+ /* Don't allow ftrace to trace into the ring buffers */
+ ftrace_disable_cpu();
+
+ if (buf_iter)
+ event = ring_buffer_iter_peek(buf_iter, ts);
+ else
+ event = ring_buffer_peek(iter->tr->buffer, cpu, ts);
- array = page_address(page);
+ ftrace_enable_cpu();
- WARN_ON(iter->next_page_idx[cpu] >= ENTRIES_PER_PAGE);
- return &array[iter->next_page_idx[cpu]];
+ return event ? ring_buffer_event_data(event) : NULL;
}
static struct trace_entry *
-find_next_entry(struct trace_iterator *iter, int *ent_cpu)
+__find_next_entry(struct trace_iterator *iter, int *ent_cpu, u64 *ent_ts)
{
- struct trace_array *tr = iter->tr;
+ struct ring_buffer *buffer = iter->tr->buffer;
struct trace_entry *ent, *next = NULL;
+ u64 next_ts = 0, ts;
int next_cpu = -1;
int cpu;
for_each_tracing_cpu(cpu) {
- if (!head_page(tr->data[cpu]))
+
+ if (ring_buffer_empty_cpu(buffer, cpu))
continue;
- ent = trace_entry_idx(tr, tr->data[cpu], iter, cpu);
+
+ ent = peek_next_entry(iter, cpu, &ts);
+
/*
* Pick the entry with the smallest timestamp:
*/
- if (ent && (!next || ent->t < next->t)) {
+ if (ent && (!next || ts < next_ts)) {
next = ent;
next_cpu = cpu;
+ next_ts = ts;
}
}
if (ent_cpu)
*ent_cpu = next_cpu;
+ if (ent_ts)
+ *ent_ts = next_ts;
+
return next;
}
-static void trace_iterator_increment(struct trace_iterator *iter)
+/* Find the next real entry, without updating the iterator itself */
+static struct trace_entry *
+find_next_entry(struct trace_iterator *iter, int *ent_cpu, u64 *ent_ts)
{
- iter->idx++;
- iter->next_idx[iter->cpu]++;
- iter->next_page_idx[iter->cpu]++;
-
- if (iter->next_page_idx[iter->cpu] >= ENTRIES_PER_PAGE) {
- struct trace_array_cpu *data = iter->tr->data[iter->cpu];
-
- iter->next_page_idx[iter->cpu] = 0;
- iter->next_page[iter->cpu] =
- trace_next_list(data, iter->next_page[iter->cpu]);
- }
+ return __find_next_entry(iter, ent_cpu, ent_ts);
}
-static void trace_consume(struct trace_iterator *iter)
+/* Find the next real entry, and increment the iterator to the next entry */
+static void *find_next_entry_inc(struct trace_iterator *iter)
{
- struct trace_array_cpu *data = iter->tr->data[iter->cpu];
+ iter->ent = __find_next_entry(iter, &iter->cpu, &iter->ts);
- data->trace_tail_idx++;
- if (data->trace_tail_idx >= ENTRIES_PER_PAGE) {
- data->trace_tail = trace_next_page(data, data->trace_tail);
- data->trace_tail_idx = 0;
- }
+ if (iter->ent)
+ trace_iterator_increment(iter, iter->cpu);
- /* Check if we empty it, then reset the index */
- if (data->trace_head == data->trace_tail &&
- data->trace_head_idx == data->trace_tail_idx)
- data->trace_idx = 0;
+ return iter->ent ? iter : NULL;
}
-static void *find_next_entry_inc(struct trace_iterator *iter)
+static void trace_consume(struct trace_iterator *iter)
{
- struct trace_entry *next;
- int next_cpu = -1;
-
- next = find_next_entry(iter, &next_cpu);
-
- iter->prev_ent = iter->ent;
- iter->prev_cpu = iter->cpu;
-
- iter->ent = next;
- iter->cpu = next_cpu;
-
- if (next)
- trace_iterator_increment(iter);
-
- return next ? iter : NULL;
+ /* Don't allow ftrace to trace into the ring buffers */
+ ftrace_disable_cpu();
+ ring_buffer_consume(iter->tr->buffer, iter->cpu, &iter->ts);
+ ftrace_enable_cpu();
}
static void *s_next(struct seq_file *m, void *v, loff_t *pos)
@@ -1210,7 +1032,7 @@ static void *s_start(struct seq_file *m, loff_t *pos)
struct trace_iterator *iter = m->private;
void *p = NULL;
loff_t l = 0;
- int i;
+ int cpu;
mutex_lock(&trace_types_lock);
@@ -1229,14 +1051,15 @@ static void *s_start(struct seq_file *m, loff_t *pos)
iter->ent = NULL;
iter->cpu = 0;
iter->idx = -1;
- iter->prev_ent = NULL;
- iter->prev_cpu = -1;
- for_each_tracing_cpu(i) {
- iter->next_idx[i] = 0;
- iter->next_page[i] = NULL;
+ ftrace_disable_cpu();
+
+ for_each_tracing_cpu(cpu) {
+ ring_buffer_iter_reset(iter->buffer_iter[cpu]);
}
+ ftrace_enable_cpu();
+
for (p = iter; p && l < *pos; p = s_next(m, p, &l))
;
@@ -1330,21 +1153,21 @@ seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
static void print_lat_help_header(struct seq_file *m)
{
- seq_puts(m, "# _------=> CPU# \n");
- seq_puts(m, "# / _-----=> irqs-off \n");
- seq_puts(m, "# | / _----=> need-resched \n");
- seq_puts(m, "# || / _---=> hardirq/softirq \n");
- seq_puts(m, "# ||| / _--=> preempt-depth \n");
- seq_puts(m, "# |||| / \n");
- seq_puts(m, "# ||||| delay \n");
- seq_puts(m, "# cmd pid ||||| time | caller \n");
- seq_puts(m, "# \\ / ||||| \\ | / \n");
+ seq_puts(m, "# _------=> CPU# \n");
+ seq_puts(m, "# / _-----=> irqs-off \n");
+ seq_puts(m, "# | / _----=> need-resched \n");
+ seq_puts(m, "# || / _---=> hardirq/softirq \n");
+ seq_puts(m, "# ||| / _--=> preempt-depth \n");
+ seq_puts(m, "# |||| / \n");
+ seq_puts(m, "# ||||| delay \n");
+ seq_puts(m, "# cmd pid ||||| time | caller \n");
+ seq_puts(m, "# \\ / ||||| \\ | / \n");
}
static void print_func_help_header(struct seq_file *m)
{
- seq_puts(m, "# TASK-PID CPU# TIMESTAMP FUNCTION\n");
- seq_puts(m, "# | | | | |\n");
+ seq_puts(m, "# TASK-PID CPU# TIMESTAMP FUNCTION\n");
+ seq_puts(m, "# | | | | |\n");
}
@@ -1355,23 +1178,16 @@ print_trace_header(struct seq_file *m, struct trace_iterator *iter)
struct trace_array *tr = iter->tr;
struct trace_array_cpu *data = tr->data[tr->cpu];
struct tracer *type = current_trace;
- unsigned long total = 0;
- unsigned long entries = 0;
- int cpu;
+ unsigned long total;
+ unsigned long entries;
const char *name = "preemption";
if (type)
name = type->name;
- for_each_tracing_cpu(cpu) {
- if (head_page(tr->data[cpu])) {
- total += tr->data[cpu]->trace_idx;
- if (tr->data[cpu]->trace_idx > tr->entries)
- entries += tr->entries;
- else
- entries += tr->data[cpu]->trace_idx;
- }
- }
+ entries = ring_buffer_entries(iter->tr->buffer);
+ total = entries +
+ ring_buffer_overruns(iter->tr->buffer);
seq_printf(m, "%s latency trace v1.1.5 on %s\n",
name, UTS_RELEASE);
@@ -1428,7 +1244,7 @@ lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
comm = trace_find_cmdline(entry->pid);
trace_seq_printf(s, "%8.8s-%-5d ", comm, entry->pid);
- trace_seq_printf(s, "%d", cpu);
+ trace_seq_printf(s, "%3d", cpu);
trace_seq_printf(s, "%c%c",
(entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' : '.',
((entry->flags & TRACE_FLAG_NEED_RESCHED) ? 'N' : '.'));
@@ -1457,7 +1273,7 @@ lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
unsigned long preempt_mark_thresh = 100;
static void
-lat_print_timestamp(struct trace_seq *s, unsigned long long abs_usecs,
+lat_print_timestamp(struct trace_seq *s, u64 abs_usecs,
unsigned long rel_usecs)
{
trace_seq_printf(s, " %4lldus", abs_usecs);
@@ -1471,34 +1287,76 @@ lat_print_timestamp(struct trace_seq *s, unsigned long long abs_usecs,
static const char state_to_char[] = TASK_STATE_TO_CHAR_STR;
-static int
+/*
+ * The message is supposed to contain an ending newline.
+ * If the printing stops prematurely, try to add a newline of our own.
+ */
+void trace_seq_print_cont(struct trace_seq *s, struct trace_iterator *iter)
+{
+ struct trace_entry *ent;
+ struct trace_field_cont *cont;
+ bool ok = true;
+
+ ent = peek_next_entry(iter, iter->cpu, NULL);
+ if (!ent || ent->type != TRACE_CONT) {
+ trace_seq_putc(s, '\n');
+ return;
+ }
+
+ do {
+ cont = (struct trace_field_cont *)ent;
+ if (ok)
+ ok = (trace_seq_printf(s, "%s", cont->buf) > 0);
+
+ ftrace_disable_cpu();
+
+ if (iter->buffer_iter[iter->cpu])
+ ring_buffer_read(iter->buffer_iter[iter->cpu], NULL);
+ else
+ ring_buffer_consume(iter->tr->buffer, iter->cpu, NULL);
+
+ ftrace_enable_cpu();
+
+ ent = peek_next_entry(iter, iter->cpu, NULL);
+ } while (ent && ent->type == TRACE_CONT);
+
+ if (!ok)
+ trace_seq_putc(s, '\n');
+}
+
+static enum print_line_t
print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu)
{
struct trace_seq *s = &iter->seq;
unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
- struct trace_entry *next_entry = find_next_entry(iter, NULL);
+ struct trace_entry *next_entry;
unsigned long verbose = (trace_flags & TRACE_ITER_VERBOSE);
struct trace_entry *entry = iter->ent;
unsigned long abs_usecs;
unsigned long rel_usecs;
+ u64 next_ts;
char *comm;
int S, T;
int i;
unsigned state;
+ if (entry->type == TRACE_CONT)
+ return TRACE_TYPE_HANDLED;
+
+ next_entry = find_next_entry(iter, NULL, &next_ts);
if (!next_entry)
- next_entry = entry;
- rel_usecs = ns2usecs(next_entry->t - entry->t);
- abs_usecs = ns2usecs(entry->t - iter->tr->time_start);
+ next_ts = iter->ts;
+ rel_usecs = ns2usecs(next_ts - iter->ts);
+ abs_usecs = ns2usecs(iter->ts - iter->tr->time_start);
if (verbose) {
comm = trace_find_cmdline(entry->pid);
- trace_seq_printf(s, "%16s %5d %d %d %08x %08x [%08lx]"
+ trace_seq_printf(s, "%16s %5d %3d %d %08x %08x [%08lx]"
" %ld.%03ldms (+%ld.%03ldms): ",
comm,
entry->pid, cpu, entry->flags,
entry->preempt_count, trace_idx,
- ns2usecs(entry->t),
+ ns2usecs(iter->ts),
abs_usecs/1000,
abs_usecs % 1000, rel_usecs/1000,
rel_usecs % 1000);
@@ -1507,52 +1365,85 @@ print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu)
lat_print_timestamp(s, abs_usecs, rel_usecs);
}
switch (entry->type) {
- case TRACE_FN:
- seq_print_ip_sym(s, entry->fn.ip, sym_flags);
+ case TRACE_FN: {
+ struct ftrace_entry *field;
+
+ trace_assign_type(field, entry);
+
+ seq_print_ip_sym(s, field->ip, sym_flags);
trace_seq_puts(s, " (");
- if (kretprobed(entry->fn.parent_ip))
+ if (kretprobed(field->parent_ip))
trace_seq_puts(s, KRETPROBE_MSG);
else
- seq_print_ip_sym(s, entry->fn.parent_ip, sym_flags);
+ seq_print_ip_sym(s, field->parent_ip, sym_flags);
trace_seq_puts(s, ")\n");
break;
+ }
case TRACE_CTX:
- case TRACE_WAKE:
- T = entry->ctx.next_state < sizeof(state_to_char) ?
- state_to_char[entry->ctx.next_state] : 'X';
+ case TRACE_WAKE: {
+ struct ctx_switch_entry *field;
+
+ trace_assign_type(field, entry);
+
+ T = field->next_state < sizeof(state_to_char) ?
+ state_to_char[field->next_state] : 'X';
- state = entry->ctx.prev_state ? __ffs(entry->ctx.prev_state) + 1 : 0;
+ state = field->prev_state ?
+ __ffs(field->prev_state) + 1 : 0;
S = state < sizeof(state_to_char) - 1 ? state_to_char[state] : 'X';
- comm = trace_find_cmdline(entry->ctx.next_pid);
- trace_seq_printf(s, " %5d:%3d:%c %s %5d:%3d:%c %s\n",
- entry->ctx.prev_pid,
- entry->ctx.prev_prio,
+ comm = trace_find_cmdline(field->next_pid);
+ trace_seq_printf(s, " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",
+ field->prev_pid,
+ field->prev_prio,
S, entry->type == TRACE_CTX ? "==>" : " +",
- entry->ctx.next_pid,
- entry->ctx.next_prio,
+ field->next_cpu,
+ field->next_pid,
+ field->next_prio,
T, comm);
break;
- case TRACE_SPECIAL:
+ }
+ case TRACE_SPECIAL: {
+ struct special_entry *field;
+
+ trace_assign_type(field, entry);
+
trace_seq_printf(s, "# %ld %ld %ld\n",
- entry->special.arg1,
- entry->special.arg2,
- entry->special.arg3);
+ field->arg1,
+ field->arg2,
+ field->arg3);
break;
- case TRACE_STACK:
+ }
+ case TRACE_STACK: {
+ struct stack_entry *field;
+
+ trace_assign_type(field, entry);
+
for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
if (i)
trace_seq_puts(s, " <= ");
- seq_print_ip_sym(s, entry->stack.caller[i], sym_flags);
+ seq_print_ip_sym(s, field->caller[i], sym_flags);
}
trace_seq_puts(s, "\n");
break;
+ }
+ case TRACE_PRINT: {
+ struct print_entry *field;
+
+ trace_assign_type(field, entry);
+
+ seq_print_ip_sym(s, field->ip, sym_flags);
+ trace_seq_printf(s, ": %s", field->buf);
+ if (entry->flags & TRACE_FLAG_CONT)
+ trace_seq_print_cont(s, iter);
+ break;
+ }
default:
trace_seq_printf(s, "Unknown type %d\n", entry->type);
}
- return 1;
+ return TRACE_TYPE_HANDLED;
}
-static int print_trace_fmt(struct trace_iterator *iter)
+static enum print_line_t print_trace_fmt(struct trace_iterator *iter)
{
struct trace_seq *s = &iter->seq;
unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
@@ -1567,90 +1458,126 @@ static int print_trace_fmt(struct trace_iterator *iter)
entry = iter->ent;
+ if (entry->type == TRACE_CONT)
+ return TRACE_TYPE_HANDLED;
+
comm = trace_find_cmdline(iter->ent->pid);
- t = ns2usecs(entry->t);
+ t = ns2usecs(iter->ts);
usec_rem = do_div(t, 1000000ULL);
secs = (unsigned long)t;
ret = trace_seq_printf(s, "%16s-%-5d ", comm, entry->pid);
if (!ret)
- return 0;
- ret = trace_seq_printf(s, "[%02d] ", iter->cpu);
+ return TRACE_TYPE_PARTIAL_LINE;
+ ret = trace_seq_printf(s, "[%03d] ", iter->cpu);
if (!ret)
- return 0;
+ return TRACE_TYPE_PARTIAL_LINE;
ret = trace_seq_printf(s, "%5lu.%06lu: ", secs, usec_rem);
if (!ret)
- return 0;
+ return TRACE_TYPE_PARTIAL_LINE;
switch (entry->type) {
- case TRACE_FN:
- ret = seq_print_ip_sym(s, entry->fn.ip, sym_flags);
+ case TRACE_FN: {
+ struct ftrace_entry *field;
+
+ trace_assign_type(field, entry);
+
+ ret = seq_print_ip_sym(s, field->ip, sym_flags);
if (!ret)
- return 0;
+ return TRACE_TYPE_PARTIAL_LINE;
if ((sym_flags & TRACE_ITER_PRINT_PARENT) &&
- entry->fn.parent_ip) {
+ field->parent_ip) {
ret = trace_seq_printf(s, " <-");
if (!ret)
- return 0;
- if (kretprobed(entry->fn.parent_ip))
+ return TRACE_TYPE_PARTIAL_LINE;
+ if (kretprobed(field->parent_ip))
ret = trace_seq_puts(s, KRETPROBE_MSG);
else
- ret = seq_print_ip_sym(s, entry->fn.parent_ip,
+ ret = seq_print_ip_sym(s,
+ field->parent_ip,
sym_flags);
if (!ret)
- return 0;
+ return TRACE_TYPE_PARTIAL_LINE;
}
ret = trace_seq_printf(s, "\n");
if (!ret)
- return 0;
+ return TRACE_TYPE_PARTIAL_LINE;
break;
+ }
case TRACE_CTX:
- case TRACE_WAKE:
- S = entry->ctx.prev_state < sizeof(state_to_char) ?
- state_to_char[entry->ctx.prev_state] : 'X';
- T = entry->ctx.next_state < sizeof(state_to_char) ?
- state_to_char[entry->ctx.next_state] : 'X';
- ret = trace_seq_printf(s, " %5d:%3d:%c %s %5d:%3d:%c\n",
- entry->ctx.prev_pid,
- entry->ctx.prev_prio,
+ case TRACE_WAKE: {
+ struct ctx_switch_entry *field;
+
+ trace_assign_type(field, entry);
+
+ S = field->prev_state < sizeof(state_to_char) ?
+ state_to_char[field->prev_state] : 'X';
+ T = field->next_state < sizeof(state_to_char) ?
+ state_to_char[field->next_state] : 'X';
+ ret = trace_seq_printf(s, " %5d:%3d:%c %s [%03d] %5d:%3d:%c\n",
+ field->prev_pid,
+ field->prev_prio,
S,
entry->type == TRACE_CTX ? "==>" : " +",
- entry->ctx.next_pid,
- entry->ctx.next_prio,
+ field->next_cpu,
+ field->next_pid,
+ field->next_prio,
T);
if (!ret)
- return 0;
+ return TRACE_TYPE_PARTIAL_LINE;
break;
- case TRACE_SPECIAL:
+ }
+ case TRACE_SPECIAL: {
+ struct special_entry *field;
+
+ trace_assign_type(field, entry);
+
ret = trace_seq_printf(s, "# %ld %ld %ld\n",
- entry->special.arg1,
- entry->special.arg2,
- entry->special.arg3);
+ field->arg1,
+ field->arg2,
+ field->arg3);
if (!ret)
- return 0;
+ return TRACE_TYPE_PARTIAL_LINE;
break;
- case TRACE_STACK:
+ }
+ case TRACE_STACK: {
+ struct stack_entry *field;
+
+ trace_assign_type(field, entry);
+
for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
if (i) {
ret = trace_seq_puts(s, " <= ");
if (!ret)
- return 0;
+ return TRACE_TYPE_PARTIAL_LINE;
}
- ret = seq_print_ip_sym(s, entry->stack.caller[i],
+ ret = seq_print_ip_sym(s, field->caller[i],
sym_flags);
if (!ret)
- return 0;
+ return TRACE_TYPE_PARTIAL_LINE;
}
ret = trace_seq_puts(s, "\n");
if (!ret)
- return 0;
+ return TRACE_TYPE_PARTIAL_LINE;
break;
}
- return 1;
+ case TRACE_PRINT: {
+ struct print_entry *field;
+
+ trace_assign_type(field, entry);
+
+ seq_print_ip_sym(s, field->ip, sym_flags);
+ trace_seq_printf(s, ": %s", field->buf);
+ if (entry->flags & TRACE_FLAG_CONT)
+ trace_seq_print_cont(s, iter);
+ break;
+ }
+ }
+ return TRACE_TYPE_HANDLED;
}
-static int print_raw_fmt(struct trace_iterator *iter)
+static enum print_line_t print_raw_fmt(struct trace_iterator *iter)
{
struct trace_seq *s = &iter->seq;
struct trace_entry *entry;
@@ -1659,47 +1586,77 @@ static int print_raw_fmt(struct trace_iterator *iter)
entry = iter->ent;
+ if (entry->type == TRACE_CONT)
+ return TRACE_TYPE_HANDLED;
+
ret = trace_seq_printf(s, "%d %d %llu ",
- entry->pid, iter->cpu, entry->t);
+ entry->pid, iter->cpu, iter->ts);
if (!ret)
- return 0;
+ return TRACE_TYPE_PARTIAL_LINE;
switch (entry->type) {
- case TRACE_FN:
+ case TRACE_FN: {
+ struct ftrace_entry *field;
+
+ trace_assign_type(field, entry);
+
ret = trace_seq_printf(s, "%x %x\n",
- entry->fn.ip, entry->fn.parent_ip);
+ field->ip,
+ field->parent_ip);
if (!ret)
- return 0;
+ return TRACE_TYPE_PARTIAL_LINE;
break;
+ }
case TRACE_CTX:
- case TRACE_WAKE:
- S = entry->ctx.prev_state < sizeof(state_to_char) ?
- state_to_char[entry->ctx.prev_state] : 'X';
- T = entry->ctx.next_state < sizeof(state_to_char) ?
- state_to_char[entry->ctx.next_state] : 'X';
+ case TRACE_WAKE: {
+ struct ctx_switch_entry *field;
+
+ trace_assign_type(field, entry);
+
+ S = field->prev_state < sizeof(state_to_char) ?
+ state_to_char[field->prev_state] : 'X';
+ T = field->next_state < sizeof(state_to_char) ?
+ state_to_char[field->next_state] : 'X';
if (entry->type == TRACE_WAKE)
S = '+';
- ret = trace_seq_printf(s, "%d %d %c %d %d %c\n",
- entry->ctx.prev_pid,
- entry->ctx.prev_prio,
+ ret = trace_seq_printf(s, "%d %d %c %d %d %d %c\n",
+ field->prev_pid,
+ field->prev_prio,
S,
- entry->ctx.next_pid,
- entry->ctx.next_prio,
+ field->next_cpu,
+ field->next_pid,
+ field->next_prio,
T);
if (!ret)
- return 0;
+ return TRACE_TYPE_PARTIAL_LINE;
break;
+ }
case TRACE_SPECIAL:
- case TRACE_STACK:
+ case TRACE_STACK: {
+ struct special_entry *field;
+
+ trace_assign_type(field, entry);
+
ret = trace_seq_printf(s, "# %ld %ld %ld\n",
- entry->special.arg1,
- entry->special.arg2,
- entry->special.arg3);
+ field->arg1,
+ field->arg2,
+ field->arg3);
if (!ret)
- return 0;
+ return TRACE_TYPE_PARTIAL_LINE;
break;
}
- return 1;
+ case TRACE_PRINT: {
+ struct print_entry *field;
+
+ trace_assign_type(field, entry);
+
+ trace_seq_printf(s, "# %lx %s", field->ip, field->buf);
+ if (entry->flags & TRACE_FLAG_CONT)
+ trace_seq_print_cont(s, iter);
+ break;
+ }
+ }
+ return TRACE_TYPE_HANDLED;
}
#define SEQ_PUT_FIELD_RET(s, x) \
@@ -1710,11 +1667,12 @@ do { \
#define SEQ_PUT_HEX_FIELD_RET(s, x) \
do { \
+ BUILD_BUG_ON(sizeof(x) > MAX_MEMHEX_BYTES); \
if (!trace_seq_putmem_hex(s, &(x), sizeof(x))) \
return 0; \
} while (0)
-static int print_hex_fmt(struct trace_iterator *iter)
+static enum print_line_t print_hex_fmt(struct trace_iterator *iter)
{
struct trace_seq *s = &iter->seq;
unsigned char newline = '\n';
@@ -1723,97 +1681,139 @@ static int print_hex_fmt(struct trace_iterator *iter)
entry = iter->ent;
+ if (entry->type == TRACE_CONT)
+ return TRACE_TYPE_HANDLED;
+
SEQ_PUT_HEX_FIELD_RET(s, entry->pid);
SEQ_PUT_HEX_FIELD_RET(s, iter->cpu);
- SEQ_PUT_HEX_FIELD_RET(s, entry->t);
+ SEQ_PUT_HEX_FIELD_RET(s, iter->ts);
switch (entry->type) {
- case TRACE_FN:
- SEQ_PUT_HEX_FIELD_RET(s, entry->fn.ip);
- SEQ_PUT_HEX_FIELD_RET(s, entry->fn.parent_ip);
+ case TRACE_FN: {
+ struct ftrace_entry *field;
+
+ trace_assign_type(field, entry);
+
+ SEQ_PUT_HEX_FIELD_RET(s, field->ip);
+ SEQ_PUT_HEX_FIELD_RET(s, field->parent_ip);
break;
+ }
case TRACE_CTX:
- case TRACE_WAKE:
- S = entry->ctx.prev_state < sizeof(state_to_char) ?
- state_to_char[entry->ctx.prev_state] : 'X';
- T = entry->ctx.next_state < sizeof(state_to_char) ?
- state_to_char[entry->ctx.next_state] : 'X';
+ case TRACE_WAKE: {
+ struct ctx_switch_entry *field;
+
+ trace_assign_type(field, entry);
+
+ S = field->prev_state < sizeof(state_to_char) ?
+ state_to_char[field->prev_state] : 'X';
+ T = field->next_state < sizeof(state_to_char) ?
+ state_to_char[field->next_state] : 'X';
if (entry->type == TRACE_WAKE)
S = '+';
- SEQ_PUT_HEX_FIELD_RET(s, entry->ctx.prev_pid);
- SEQ_PUT_HEX_FIELD_RET(s, entry->ctx.prev_prio);
+ SEQ_PUT_HEX_FIELD_RET(s, field->prev_pid);
+ SEQ_PUT_HEX_FIELD_RET(s, field->prev_prio);
SEQ_PUT_HEX_FIELD_RET(s, S);
- SEQ_PUT_HEX_FIELD_RET(s, entry->ctx.next_pid);
- SEQ_PUT_HEX_FIELD_RET(s, entry->ctx.next_prio);
- SEQ_PUT_HEX_FIELD_RET(s, entry->fn.parent_ip);
+ SEQ_PUT_HEX_FIELD_RET(s, field->next_cpu);
+ SEQ_PUT_HEX_FIELD_RET(s, field->next_pid);
+ SEQ_PUT_HEX_FIELD_RET(s, field->next_prio);
SEQ_PUT_HEX_FIELD_RET(s, T);
break;
+ }
case TRACE_SPECIAL:
- case TRACE_STACK:
- SEQ_PUT_HEX_FIELD_RET(s, entry->special.arg1);
- SEQ_PUT_HEX_FIELD_RET(s, entry->special.arg2);
- SEQ_PUT_HEX_FIELD_RET(s, entry->special.arg3);
+ case TRACE_STACK: {
+ struct special_entry *field;
+
+ trace_assign_type(field, entry);
+
+ SEQ_PUT_HEX_FIELD_RET(s, field->arg1);
+ SEQ_PUT_HEX_FIELD_RET(s, field->arg2);
+ SEQ_PUT_HEX_FIELD_RET(s, field->arg3);
break;
}
+ }
SEQ_PUT_FIELD_RET(s, newline);
- return 1;
+ return TRACE_TYPE_HANDLED;
}
-static int print_bin_fmt(struct trace_iterator *iter)
+static enum print_line_t print_bin_fmt(struct trace_iterator *iter)
{
struct trace_seq *s = &iter->seq;
struct trace_entry *entry;
entry = iter->ent;
+ if (entry->type == TRACE_CONT)
+ return TRACE_TYPE_HANDLED;
+
SEQ_PUT_FIELD_RET(s, entry->pid);
- SEQ_PUT_FIELD_RET(s, entry->cpu);
- SEQ_PUT_FIELD_RET(s, entry->t);
+ SEQ_PUT_FIELD_RET(s, iter->cpu);
+ SEQ_PUT_FIELD_RET(s, iter->ts);
switch (entry->type) {
- case TRACE_FN:
- SEQ_PUT_FIELD_RET(s, entry->fn.ip);
- SEQ_PUT_FIELD_RET(s, entry->fn.parent_ip);
+ case TRACE_FN: {
+ struct ftrace_entry *field;
+
+ trace_assign_type(field, entry);
+
+ SEQ_PUT_FIELD_RET(s, field->ip);
+ SEQ_PUT_FIELD_RET(s, field->parent_ip);
break;
- case TRACE_CTX:
- SEQ_PUT_FIELD_RET(s, entry->ctx.prev_pid);
- SEQ_PUT_FIELD_RET(s, entry->ctx.prev_prio);
- SEQ_PUT_FIELD_RET(s, entry->ctx.prev_state);
- SEQ_PUT_FIELD_RET(s, entry->ctx.next_pid);
- SEQ_PUT_FIELD_RET(s, entry->ctx.next_prio);
- SEQ_PUT_FIELD_RET(s, entry->ctx.next_state);
+ }
+ case TRACE_CTX: {
+ struct ctx_switch_entry *field;
+
+ trace_assign_type(field, entry);
+
+ SEQ_PUT_FIELD_RET(s, field->prev_pid);
+ SEQ_PUT_FIELD_RET(s, field->prev_prio);
+ SEQ_PUT_FIELD_RET(s, field->prev_state);
+ SEQ_PUT_FIELD_RET(s, field->next_pid);
+ SEQ_PUT_FIELD_RET(s, field->next_prio);
+ SEQ_PUT_FIELD_RET(s, field->next_state);
break;
+ }
case TRACE_SPECIAL:
- case TRACE_STACK:
- SEQ_PUT_FIELD_RET(s, entry->special.arg1);
- SEQ_PUT_FIELD_RET(s, entry->special.arg2);
- SEQ_PUT_FIELD_RET(s, entry->special.arg3);
+ case TRACE_STACK: {
+ struct special_entry *field;
+
+ trace_assign_type(field, entry);
+
+ SEQ_PUT_FIELD_RET(s, field->arg1);
+ SEQ_PUT_FIELD_RET(s, field->arg2);
+ SEQ_PUT_FIELD_RET(s, field->arg3);
break;
}
+ }
return 1;
}
static int trace_empty(struct trace_iterator *iter)
{
- struct trace_array_cpu *data;
int cpu;
for_each_tracing_cpu(cpu) {
- data = iter->tr->data[cpu];
-
- if (head_page(data) && data->trace_idx &&
- (data->trace_tail != data->trace_head ||
- data->trace_tail_idx != data->trace_head_idx))
- return 0;
+ if (iter->buffer_iter[cpu]) {
+ if (!ring_buffer_iter_empty(iter->buffer_iter[cpu]))
+ return 0;
+ } else {
+ if (!ring_buffer_empty_cpu(iter->tr->buffer, cpu))
+ return 0;
+ }
}
+
return 1;
}
-static int print_trace_line(struct trace_iterator *iter)
+static enum print_line_t print_trace_line(struct trace_iterator *iter)
{
- if (iter->trace && iter->trace->print_line)
- return iter->trace->print_line(iter);
+ enum print_line_t ret;
+
+ if (iter->trace && iter->trace->print_line) {
+ ret = iter->trace->print_line(iter);
+ if (ret != TRACE_TYPE_UNHANDLED)
+ return ret;
+ }
if (trace_flags & TRACE_ITER_BIN)
return print_bin_fmt(iter);
@@ -1869,6 +1869,8 @@ static struct trace_iterator *
__tracing_open(struct inode *inode, struct file *file, int *ret)
{
struct trace_iterator *iter;
+ struct seq_file *m;
+ int cpu;
if (tracing_disabled) {
*ret = -ENODEV;
@@ -1889,28 +1891,45 @@ __tracing_open(struct inode *inode, struct file *file, int *ret)
iter->trace = current_trace;
iter->pos = -1;
+ for_each_tracing_cpu(cpu) {
+
+ iter->buffer_iter[cpu] =
+ ring_buffer_read_start(iter->tr->buffer, cpu);
+
+ if (!iter->buffer_iter[cpu])
+ goto fail_buffer;
+ }
+
/* TODO stop tracer */
*ret = seq_open(file, &tracer_seq_ops);
- if (!*ret) {
- struct seq_file *m = file->private_data;
- m->private = iter;
+ if (*ret)
+ goto fail_buffer;
- /* stop the trace while dumping */
- if (iter->tr->ctrl) {
- tracer_enabled = 0;
- ftrace_function_enabled = 0;
- }
+ m = file->private_data;
+ m->private = iter;
- if (iter->trace && iter->trace->open)
- iter->trace->open(iter);
- } else {
- kfree(iter);
- iter = NULL;
+ /* stop the trace while dumping */
+ if (iter->tr->ctrl) {
+ tracer_enabled = 0;
+ ftrace_function_enabled = 0;
}
+
+ if (iter->trace && iter->trace->open)
+ iter->trace->open(iter);
+
mutex_unlock(&trace_types_lock);
out:
return iter;
+
+ fail_buffer:
+ for_each_tracing_cpu(cpu) {
+ if (iter->buffer_iter[cpu])
+ ring_buffer_read_finish(iter->buffer_iter[cpu]);
+ }
+ mutex_unlock(&trace_types_lock);
+
+ return ERR_PTR(-ENOMEM);
}
int tracing_open_generic(struct inode *inode, struct file *filp)
@@ -1926,8 +1945,14 @@ int tracing_release(struct inode *inode, struct file *file)
{
struct seq_file *m = (struct seq_file *)file->private_data;
struct trace_iterator *iter = m->private;
+ int cpu;
mutex_lock(&trace_types_lock);
+ for_each_tracing_cpu(cpu) {
+ if (iter->buffer_iter[cpu])
+ ring_buffer_read_finish(iter->buffer_iter[cpu]);
+ }
+
if (iter->trace && iter->trace->close)
iter->trace->close(iter);
@@ -2352,9 +2377,11 @@ tracing_set_trace_write(struct file *filp, const char __user *ubuf,
struct tracer *t;
char buf[max_tracer_type_len+1];
int i;
+ size_t ret;
if (cnt > max_tracer_type_len)
cnt = max_tracer_type_len;
+ ret = cnt;
if (copy_from_user(&buf, ubuf, cnt))
return -EFAULT;
@@ -2370,7 +2397,11 @@ tracing_set_trace_write(struct file *filp, const char __user *ubuf,
if (strcmp(t->name, buf) == 0)
break;
}
- if (!t || t == current_trace)
+ if (!t) {
+ ret = -EINVAL;
+ goto out;
+ }
+ if (t == current_trace)
goto out;
if (current_trace && current_trace->reset)
@@ -2383,9 +2414,10 @@ tracing_set_trace_write(struct file *filp, const char __user *ubuf,
out:
mutex_unlock(&trace_types_lock);
- filp->f_pos += cnt;
+ if (ret == cnt)
+ filp->f_pos += cnt;
- return cnt;
+ return ret;
}
static ssize_t
@@ -2500,20 +2532,12 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
size_t cnt, loff_t *ppos)
{
struct trace_iterator *iter = filp->private_data;
- struct trace_array_cpu *data;
- static cpumask_t mask;
- unsigned long flags;
-#ifdef CONFIG_FTRACE
- int ftrace_save;
-#endif
- int cpu;
ssize_t sret;
/* return any leftover data */
sret = trace_seq_to_user(&iter->seq, ubuf, cnt);
if (sret != -EBUSY)
return sret;
- sret = 0;
trace_seq_reset(&iter->seq);
@@ -2524,6 +2548,8 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
goto out;
}
+waitagain:
+ sret = 0;
while (trace_empty(iter)) {
if ((filp->f_flags & O_NONBLOCK)) {
@@ -2588,46 +2614,12 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
offsetof(struct trace_iterator, seq));
iter->pos = -1;
- /*
- * We need to stop all tracing on all CPUS to read the
- * the next buffer. This is a bit expensive, but is
- * not done often. We fill all what we can read,
- * and then release the locks again.
- */
-
- cpus_clear(mask);
- local_irq_save(flags);
-#ifdef CONFIG_FTRACE
- ftrace_save = ftrace_enabled;
- ftrace_enabled = 0;
-#endif
- smp_wmb();
- for_each_tracing_cpu(cpu) {
- data = iter->tr->data[cpu];
-
- if (!head_page(data) || !data->trace_idx)
- continue;
-
- atomic_inc(&data->disabled);
- cpu_set(cpu, mask);
- }
-
- for_each_cpu_mask(cpu, mask) {
- data = iter->tr->data[cpu];
- __raw_spin_lock(&data->lock);
-
- if (data->overrun > iter->last_overrun[cpu])
- iter->overrun[cpu] +=
- data->overrun - iter->last_overrun[cpu];
- iter->last_overrun[cpu] = data->overrun;
- }
-
while (find_next_entry_inc(iter) != NULL) {
- int ret;
+ enum print_line_t ret;
int len = iter->seq.len;
ret = print_trace_line(iter);
- if (!ret) {
+ if (ret == TRACE_TYPE_PARTIAL_LINE) {
/* don't print partial lines */
iter->seq.len = len;
break;
@@ -2639,26 +2631,17 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
break;
}
- for_each_cpu_mask(cpu, mask) {
- data = iter->tr->data[cpu];
- __raw_spin_unlock(&data->lock);
- }
-
- for_each_cpu_mask(cpu, mask) {
- data = iter->tr->data[cpu];
- atomic_dec(&data->disabled);
- }
-#ifdef CONFIG_FTRACE
- ftrace_enabled = ftrace_save;
-#endif
- local_irq_restore(flags);
-
/* Now copy what we have to the user */
sret = trace_seq_to_user(&iter->seq, ubuf, cnt);
if (iter->seq.readpos >= iter->seq.len)
trace_seq_reset(&iter->seq);
+
+ /*
+ * If there was nothing to send to user, inspite of consuming trace
+ * entries, go back to wait for more entries.
+ */
if (sret == -EBUSY)
- sret = 0;
+ goto waitagain;
out:
mutex_unlock(&trace_types_lock);
@@ -2684,7 +2667,8 @@ tracing_entries_write(struct file *filp, const char __user *ubuf,
{
unsigned long val;
char buf[64];
- int i, ret;
+ int ret;
+ struct trace_array *tr = filp->private_data;
if (cnt >= sizeof(buf))
return -EINVAL;
@@ -2704,59 +2688,38 @@ tracing_entries_write(struct file *filp, const char __user *ubuf,
mutex_lock(&trace_types_lock);
- if (current_trace != &no_tracer) {
+ if (tr->ctrl) {
cnt = -EBUSY;
- pr_info("ftrace: set current_tracer to none"
+ pr_info("ftrace: please disable tracing"
" before modifying buffer size\n");
goto out;
}
- if (val > global_trace.entries) {
- long pages_requested;
- unsigned long freeable_pages;
-
- /* make sure we have enough memory before mapping */
- pages_requested =
- (val + (ENTRIES_PER_PAGE-1)) / ENTRIES_PER_PAGE;
-
- /* account for each buffer (and max_tr) */
- pages_requested *= tracing_nr_buffers * 2;
-
- /* Check for overflow */
- if (pages_requested < 0) {
- cnt = -ENOMEM;
- goto out;
- }
-
- freeable_pages = determine_dirtyable_memory();
-
- /* we only allow to request 1/4 of useable memory */
- if (pages_requested >
- ((freeable_pages + tracing_pages_allocated) / 4)) {
- cnt = -ENOMEM;
+ if (val != global_trace.entries) {
+ ret = ring_buffer_resize(global_trace.buffer, val);
+ if (ret < 0) {
+ cnt = ret;
goto out;
}
- while (global_trace.entries < val) {
- if (trace_alloc_page()) {
- cnt = -ENOMEM;
- goto out;
+ ret = ring_buffer_resize(max_tr.buffer, val);
+ if (ret < 0) {
+ int r;
+ cnt = ret;
+ r = ring_buffer_resize(global_trace.buffer,
+ global_trace.entries);
+ if (r < 0) {
+ /* AARGH! We are left with different
+ * size max buffer!!!! */
+ WARN_ON(1);
+ tracing_disabled = 1;
}
- /* double check that we don't go over the known pages */
- if (tracing_pages_allocated > pages_requested)
- break;
+ goto out;
}
- } else {
- /* include the number of entries in val (inc of page entries) */
- while (global_trace.entries > val + (ENTRIES_PER_PAGE - 1))
- trace_free_page();
+ global_trace.entries = val;
}
- /* check integrity */
- for_each_tracing_cpu(i)
- check_pages(global_trace.data[i]);
-
filp->f_pos += cnt;
/* If check pages failed, return ENOMEM */
@@ -2769,6 +2732,52 @@ tracing_entries_write(struct file *filp, const char __user *ubuf,
return cnt;
}
+static int mark_printk(const char *fmt, ...)
+{
+ int ret;
+ va_list args;
+ va_start(args, fmt);
+ ret = trace_vprintk(0, fmt, args);
+ va_end(args);
+ return ret;
+}
+
+static ssize_t
+tracing_mark_write(struct file *filp, const char __user *ubuf,
+ size_t cnt, loff_t *fpos)
+{
+ char *buf;
+ char *end;
+ struct trace_array *tr = &global_trace;
+
+ if (!tr->ctrl || tracing_disabled)
+ return -EINVAL;
+
+ if (cnt > TRACE_BUF_SIZE)
+ cnt = TRACE_BUF_SIZE;
+
+ buf = kmalloc(cnt + 1, GFP_KERNEL);
+ if (buf == NULL)
+ return -ENOMEM;
+
+ if (copy_from_user(buf, ubuf, cnt)) {
+ kfree(buf);
+ return -EFAULT;
+ }
+
+ /* Cut from the first nil or newline. */
+ buf[cnt] = '\0';
+ end = strchr(buf, '\n');
+ if (end)
+ *end = '\0';
+
+ cnt = mark_printk("%s\n", buf);
+ kfree(buf);
+ *fpos += cnt;
+
+ return cnt;
+}
+
static struct file_operations tracing_max_lat_fops = {
.open = tracing_open_generic,
.read = tracing_max_lat_read,
@@ -2800,6 +2809,11 @@ static struct file_operations tracing_entries_fops = {
.write = tracing_entries_write,
};
+static struct file_operations tracing_mark_fops = {
+ .open = tracing_open_generic,
+ .write = tracing_mark_write,
+};
+
#ifdef CONFIG_DYNAMIC_FTRACE
static ssize_t
@@ -2846,7 +2860,7 @@ struct dentry *tracing_init_dentry(void)
#include "trace_selftest.c"
#endif
-static __init void tracer_init_debugfs(void)
+static __init int tracer_init_debugfs(void)
{
struct dentry *d_tracer;
struct dentry *entry;
@@ -2881,12 +2895,12 @@ static __init void tracer_init_debugfs(void)
entry = debugfs_create_file("available_tracers", 0444, d_tracer,
&global_trace, &show_traces_fops);
if (!entry)
- pr_warning("Could not create debugfs 'trace' entry\n");
+ pr_warning("Could not create debugfs 'available_tracers' entry\n");
entry = debugfs_create_file("current_tracer", 0444, d_tracer,
&global_trace, &set_tracer_fops);
if (!entry)
- pr_warning("Could not create debugfs 'trace' entry\n");
+ pr_warning("Could not create debugfs 'current_tracer' entry\n");
entry = debugfs_create_file("tracing_max_latency", 0644, d_tracer,
&tracing_max_latency,
@@ -2899,7 +2913,7 @@ static __init void tracer_init_debugfs(void)
&tracing_thresh, &tracing_max_lat_fops);
if (!entry)
pr_warning("Could not create debugfs "
- "'tracing_threash' entry\n");
+ "'tracing_thresh' entry\n");
entry = debugfs_create_file("README", 0644, d_tracer,
NULL, &tracing_readme_fops);
if (!entry)
@@ -2909,13 +2923,19 @@ static __init void tracer_init_debugfs(void)
NULL, &tracing_pipe_fops);
if (!entry)
pr_warning("Could not create debugfs "
- "'tracing_threash' entry\n");
+ "'trace_pipe' entry\n");
entry = debugfs_create_file("trace_entries", 0644, d_tracer,
&global_trace, &tracing_entries_fops);
if (!entry)
pr_warning("Could not create debugfs "
- "'tracing_threash' entry\n");
+ "'trace_entries' entry\n");
+
+ entry = debugfs_create_file("trace_marker", 0220, d_tracer,
+ NULL, &tracing_mark_fops);
+ if (!entry)
+ pr_warning("Could not create debugfs "
+ "'trace_marker' entry\n");
#ifdef CONFIG_DYNAMIC_FTRACE
entry = debugfs_create_file("dyn_ftrace_total_info", 0444, d_tracer,
@@ -2928,230 +2948,263 @@ static __init void tracer_init_debugfs(void)
#ifdef CONFIG_SYSPROF_TRACER
init_tracer_sysprof_debugfs(d_tracer);
#endif
+ return 0;
}
-static int trace_alloc_page(void)
+int trace_vprintk(unsigned long ip, const char *fmt, va_list args)
{
+ static DEFINE_SPINLOCK(trace_buf_lock);
+ static char trace_buf[TRACE_BUF_SIZE];
+
+ struct ring_buffer_event *event;
+ struct trace_array *tr = &global_trace;
struct trace_array_cpu *data;
- struct page *page, *tmp;
- LIST_HEAD(pages);
- void *array;
- unsigned pages_allocated = 0;
- int i;
+ struct print_entry *entry;
+ unsigned long flags, irq_flags;
+ int cpu, len = 0, size, pc;
- /* first allocate a page for each CPU */
- for_each_tracing_cpu(i) {
- array = (void *)__get_free_page(GFP_KERNEL);
- if (array == NULL) {
- printk(KERN_ERR "tracer: failed to allocate page"
- "for trace buffer!\n");
- goto free_pages;
- }
+ if (!tr->ctrl || tracing_disabled)
+ return 0;
- pages_allocated++;
- page = virt_to_page(array);
- list_add(&page->lru, &pages);
+ pc = preempt_count();
+ preempt_disable_notrace();
+ cpu = raw_smp_processor_id();
+ data = tr->data[cpu];
-/* Only allocate if we are actually using the max trace */
-#ifdef CONFIG_TRACER_MAX_TRACE
- array = (void *)__get_free_page(GFP_KERNEL);
- if (array == NULL) {
- printk(KERN_ERR "tracer: failed to allocate page"
- "for trace buffer!\n");
- goto free_pages;
- }
- pages_allocated++;
- page = virt_to_page(array);
- list_add(&page->lru, &pages);
-#endif
- }
+ if (unlikely(atomic_read(&data->disabled)))
+ goto out;
- /* Now that we successfully allocate a page per CPU, add them */
- for_each_tracing_cpu(i) {
- data = global_trace.data[i];
- page = list_entry(pages.next, struct page, lru);
- list_del_init(&page->lru);
- list_add_tail(&page->lru, &data->trace_pages);
- ClearPageLRU(page);
+ spin_lock_irqsave(&trace_buf_lock, flags);
+ len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args);
-#ifdef CONFIG_TRACER_MAX_TRACE
- data = max_tr.data[i];
- page = list_entry(pages.next, struct page, lru);
- list_del_init(&page->lru);
- list_add_tail(&page->lru, &data->trace_pages);
- SetPageLRU(page);
-#endif
- }
- tracing_pages_allocated += pages_allocated;
- global_trace.entries += ENTRIES_PER_PAGE;
+ len = min(len, TRACE_BUF_SIZE-1);
+ trace_buf[len] = 0;
- return 0;
+ size = sizeof(*entry) + len + 1;
+ event = ring_buffer_lock_reserve(tr->buffer, size, &irq_flags);
+ if (!event)
+ goto out_unlock;
+ entry = ring_buffer_event_data(event);
+ tracing_generic_entry_update(&entry->ent, flags, pc);
+ entry->ent.type = TRACE_PRINT;
+ entry->ip = ip;
- free_pages:
- list_for_each_entry_safe(page, tmp, &pages, lru) {
- list_del_init(&page->lru);
- __free_page(page);
- }
- return -ENOMEM;
+ memcpy(&entry->buf, trace_buf, len);
+ entry->buf[len] = 0;
+ ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
+
+ out_unlock:
+ spin_unlock_irqrestore(&trace_buf_lock, flags);
+
+ out:
+ preempt_enable_notrace();
+
+ return len;
}
+EXPORT_SYMBOL_GPL(trace_vprintk);
-static int trace_free_page(void)
+int __ftrace_printk(unsigned long ip, const char *fmt, ...)
{
- struct trace_array_cpu *data;
- struct page *page;
- struct list_head *p;
- int i;
- int ret = 0;
+ int ret;
+ va_list ap;
- /* free one page from each buffer */
- for_each_tracing_cpu(i) {
- data = global_trace.data[i];
- p = data->trace_pages.next;
- if (p == &data->trace_pages) {
- /* should never happen */
- WARN_ON(1);
- tracing_disabled = 1;
- ret = -1;
- break;
- }
- page = list_entry(p, struct page, lru);
- ClearPageLRU(page);
- list_del(&page->lru);
- tracing_pages_allocated--;
- tracing_pages_allocated--;
- __free_page(page);
+ if (!(trace_flags & TRACE_ITER_PRINTK))
+ return 0;
- tracing_reset(data);
+ va_start(ap, fmt);
+ ret = trace_vprintk(ip, fmt, ap);
+ va_end(ap);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(__ftrace_printk);
-#ifdef CONFIG_TRACER_MAX_TRACE
- data = max_tr.data[i];
- p = data->trace_pages.next;
- if (p == &data->trace_pages) {
- /* should never happen */
- WARN_ON(1);
- tracing_disabled = 1;
- ret = -1;
- break;
- }
- page = list_entry(p, struct page, lru);
- ClearPageLRU(page);
- list_del(&page->lru);
- __free_page(page);
+static int trace_panic_handler(struct notifier_block *this,
+ unsigned long event, void *unused)
+{
+ ftrace_dump();
+ return NOTIFY_OK;
+}
- tracing_reset(data);
-#endif
- }
- global_trace.entries -= ENTRIES_PER_PAGE;
+static struct notifier_block trace_panic_notifier = {
+ .notifier_call = trace_panic_handler,
+ .next = NULL,
+ .priority = 150 /* priority: INT_MAX >= x >= 0 */
+};
- return ret;
+static int trace_die_handler(struct notifier_block *self,
+ unsigned long val,
+ void *data)
+{
+ switch (val) {
+ case DIE_OOPS:
+ ftrace_dump();
+ break;
+ default:
+ break;
+ }
+ return NOTIFY_OK;
}
-__init static int tracer_alloc_buffers(void)
+static struct notifier_block trace_die_notifier = {
+ .notifier_call = trace_die_handler,
+ .priority = 200
+};
+
+/*
+ * printk is set to max of 1024, we really don't need it that big.
+ * Nothing should be printing 1000 characters anyway.
+ */
+#define TRACE_MAX_PRINT 1000
+
+/*
+ * Define here KERN_TRACE so that we have one place to modify
+ * it if we decide to change what log level the ftrace dump
+ * should be at.
+ */
+#define KERN_TRACE KERN_INFO
+
+static void
+trace_printk_seq(struct trace_seq *s)
{
- struct trace_array_cpu *data;
- void *array;
- struct page *page;
- int pages = 0;
- int ret = -ENOMEM;
- int i;
+ /* Probably should print a warning here. */
+ if (s->len >= 1000)
+ s->len = 1000;
- /* TODO: make the number of buffers hot pluggable with CPUS */
- tracing_nr_buffers = num_possible_cpus();
- tracing_buffer_mask = cpu_possible_map;
+ /* should be zero ended, but we are paranoid. */
+ s->buffer[s->len] = 0;
- /* Allocate the first page for all buffers */
- for_each_tracing_cpu(i) {
- data = global_trace.data[i] = &per_cpu(global_trace_cpu, i);
- max_tr.data[i] = &per_cpu(max_data, i);
+ printk(KERN_TRACE "%s", s->buffer);
- array = (void *)__get_free_page(GFP_KERNEL);
- if (array == NULL) {
- printk(KERN_ERR "tracer: failed to allocate page"
- "for trace buffer!\n");
- goto free_buffers;
- }
+ trace_seq_reset(s);
+}
+
+
+void ftrace_dump(void)
+{
+ static DEFINE_SPINLOCK(ftrace_dump_lock);
+ /* use static because iter can be a bit big for the stack */
+ static struct trace_iterator iter;
+ static cpumask_t mask;
+ static int dump_ran;
+ unsigned long flags;
+ int cnt = 0, cpu;
- /* set the array to the list */
- INIT_LIST_HEAD(&data->trace_pages);
- page = virt_to_page(array);
- list_add(&page->lru, &data->trace_pages);
- /* use the LRU flag to differentiate the two buffers */
- ClearPageLRU(page);
+ /* only one dump */
+ spin_lock_irqsave(&ftrace_dump_lock, flags);
+ if (dump_ran)
+ goto out;
- data->lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
- max_tr.data[i]->lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
+ dump_ran = 1;
-/* Only allocate if we are actually using the max trace */
-#ifdef CONFIG_TRACER_MAX_TRACE
- array = (void *)__get_free_page(GFP_KERNEL);
- if (array == NULL) {
- printk(KERN_ERR "tracer: failed to allocate page"
- "for trace buffer!\n");
- goto free_buffers;
- }
+ /* No turning back! */
+ ftrace_kill_atomic();
- INIT_LIST_HEAD(&max_tr.data[i]->trace_pages);
- page = virt_to_page(array);
- list_add(&page->lru, &max_tr.data[i]->trace_pages);
- SetPageLRU(page);
-#endif
+ for_each_tracing_cpu(cpu) {
+ atomic_inc(&global_trace.data[cpu]->disabled);
}
+ printk(KERN_TRACE "Dumping ftrace buffer:\n");
+
+ iter.tr = &global_trace;
+ iter.trace = current_trace;
+
/*
- * Since we allocate by orders of pages, we may be able to
- * round up a bit.
+ * We need to stop all tracing on all CPUS to read the
+ * the next buffer. This is a bit expensive, but is
+ * not done often. We fill all what we can read,
+ * and then release the locks again.
*/
- global_trace.entries = ENTRIES_PER_PAGE;
- pages++;
- while (global_trace.entries < trace_nr_entries) {
- if (trace_alloc_page())
- break;
- pages++;
+ cpus_clear(mask);
+
+ while (!trace_empty(&iter)) {
+
+ if (!cnt)
+ printk(KERN_TRACE "---------------------------------\n");
+
+ cnt++;
+
+ /* reset all but tr, trace, and overruns */
+ memset(&iter.seq, 0,
+ sizeof(struct trace_iterator) -
+ offsetof(struct trace_iterator, seq));
+ iter.iter_flags |= TRACE_FILE_LAT_FMT;
+ iter.pos = -1;
+
+ if (find_next_entry_inc(&iter) != NULL) {
+ print_trace_line(&iter);
+ trace_consume(&iter);
+ }
+
+ trace_printk_seq(&iter.seq);
}
- max_tr.entries = global_trace.entries;
- pr_info("tracer: %d pages allocated for %ld entries of %ld bytes\n",
- pages, trace_nr_entries, (long)TRACE_ENTRY_SIZE);
- pr_info(" actual entries %ld\n", global_trace.entries);
+ if (!cnt)
+ printk(KERN_TRACE " (ftrace buffer empty)\n");
+ else
+ printk(KERN_TRACE "---------------------------------\n");
+
+ out:
+ spin_unlock_irqrestore(&ftrace_dump_lock, flags);
+}
+
+__init static int tracer_alloc_buffers(void)
+{
+ struct trace_array_cpu *data;
+ int i;
+
+ /* TODO: make the number of buffers hot pluggable with CPUS */
+ tracing_buffer_mask = cpu_possible_map;
+
+ global_trace.buffer = ring_buffer_alloc(trace_buf_size,
+ TRACE_BUFFER_FLAGS);
+ if (!global_trace.buffer) {
+ printk(KERN_ERR "tracer: failed to allocate ring buffer!\n");
+ WARN_ON(1);
+ return 0;
+ }
+ global_trace.entries = ring_buffer_size(global_trace.buffer);
- tracer_init_debugfs();
+#ifdef CONFIG_TRACER_MAX_TRACE
+ max_tr.buffer = ring_buffer_alloc(trace_buf_size,
+ TRACE_BUFFER_FLAGS);
+ if (!max_tr.buffer) {
+ printk(KERN_ERR "tracer: failed to allocate max ring buffer!\n");
+ WARN_ON(1);
+ ring_buffer_free(global_trace.buffer);
+ return 0;
+ }
+ max_tr.entries = ring_buffer_size(max_tr.buffer);
+ WARN_ON(max_tr.entries != global_trace.entries);
+#endif
+
+ /* Allocate the first page for all buffers */
+ for_each_tracing_cpu(i) {
+ data = global_trace.data[i] = &per_cpu(global_trace_cpu, i);
+ max_tr.data[i] = &per_cpu(max_data, i);
+ }
trace_init_cmdlines();
- register_tracer(&no_tracer);
- current_trace = &no_tracer;
+ register_tracer(&nop_trace);
+#ifdef CONFIG_BOOT_TRACER
+ register_tracer(&boot_tracer);
+ current_trace = &boot_tracer;
+ current_trace->init(&global_trace);
+#else
+ current_trace = &nop_trace;
+#endif
/* All seems OK, enable tracing */
global_trace.ctrl = tracer_enabled;
tracing_disabled = 0;
- return 0;
+ atomic_notifier_chain_register(&panic_notifier_list,
+ &trace_panic_notifier);
- free_buffers:
- for (i-- ; i >= 0; i--) {
- struct page *page, *tmp;
- struct trace_array_cpu *data = global_trace.data[i];
+ register_die_notifier(&trace_die_notifier);
- if (data) {
- list_for_each_entry_safe(page, tmp,
- &data->trace_pages, lru) {
- list_del_init(&page->lru);
- __free_page(page);
- }
- }
-
-#ifdef CONFIG_TRACER_MAX_TRACE
- data = max_tr.data[i];
- if (data) {
- list_for_each_entry_safe(page, tmp,
- &data->trace_pages, lru) {
- list_del_init(&page->lru);
- __free_page(page);
- }
- }
-#endif
- }
- return ret;
+ return 0;
}
-fs_initcall(tracer_alloc_buffers);
+early_initcall(tracer_alloc_buffers);
+fs_initcall(tracer_init_debugfs);
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index f69f867..f1f9957 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -5,7 +5,9 @@
#include <asm/atomic.h>
#include <linux/sched.h>
#include <linux/clocksource.h>
+#include <linux/ring_buffer.h>
#include <linux/mmiotrace.h>
+#include <linux/ftrace.h>
enum trace_type {
__TRACE_FIRST_TYPE = 0,
@@ -13,38 +15,60 @@ enum trace_type {
TRACE_FN,
TRACE_CTX,
TRACE_WAKE,
+ TRACE_CONT,
TRACE_STACK,
+ TRACE_PRINT,
TRACE_SPECIAL,
TRACE_MMIO_RW,
TRACE_MMIO_MAP,
+ TRACE_BOOT,
__TRACE_LAST_TYPE
};
/*
+ * The trace entry - the most basic unit of tracing. This is what
+ * is printed in the end as a single line in the trace output, such as:
+ *
+ * bash-15816 [01] 235.197585: idle_cpu <- irq_enter
+ */
+struct trace_entry {
+ unsigned char type;
+ unsigned char cpu;
+ unsigned char flags;
+ unsigned char preempt_count;
+ int pid;
+};
+
+/*
* Function trace entry - function address and parent function addres:
*/
struct ftrace_entry {
+ struct trace_entry ent;
unsigned long ip;
unsigned long parent_ip;
};
+extern struct tracer boot_tracer;
/*
* Context switch trace entry - which task (and prio) we switched from/to:
*/
struct ctx_switch_entry {
+ struct trace_entry ent;
unsigned int prev_pid;
unsigned char prev_prio;
unsigned char prev_state;
unsigned int next_pid;
unsigned char next_prio;
unsigned char next_state;
+ unsigned int next_cpu;
};
/*
* Special (free-form) trace entry:
*/
struct special_entry {
+ struct trace_entry ent;
unsigned long arg1;
unsigned long arg2;
unsigned long arg3;
@@ -57,33 +81,60 @@ struct special_entry {
#define FTRACE_STACK_ENTRIES 8
struct stack_entry {
+ struct trace_entry ent;
unsigned long caller[FTRACE_STACK_ENTRIES];
};
/*
- * The trace entry - the most basic unit of tracing. This is what
- * is printed in the end as a single line in the trace output, such as:
- *
- * bash-15816 [01] 235.197585: idle_cpu <- irq_enter
+ * ftrace_printk entry:
*/
-struct trace_entry {
- char type;
- char cpu;
- char flags;
- char preempt_count;
- int pid;
- cycle_t t;
- union {
- struct ftrace_entry fn;
- struct ctx_switch_entry ctx;
- struct special_entry special;
- struct stack_entry stack;
- struct mmiotrace_rw mmiorw;
- struct mmiotrace_map mmiomap;
- };
+struct print_entry {
+ struct trace_entry ent;
+ unsigned long ip;
+ char buf[];
+};
+
+#define TRACE_OLD_SIZE 88
+
+struct trace_field_cont {
+ unsigned char type;
+ /* Temporary till we get rid of this completely */
+ char buf[TRACE_OLD_SIZE - 1];
+};
+
+struct trace_mmiotrace_rw {
+ struct trace_entry ent;
+ struct mmiotrace_rw rw;
};
-#define TRACE_ENTRY_SIZE sizeof(struct trace_entry)
+struct trace_mmiotrace_map {
+ struct trace_entry ent;
+ struct mmiotrace_map map;
+};
+
+struct trace_boot {
+ struct trace_entry ent;
+ struct boot_trace initcall;
+};
+
+/*
+ * trace_flag_type is an enumeration that holds different
+ * states when a trace occurs. These are:
+ * IRQS_OFF - interrupts were disabled
+ * NEED_RESCED - reschedule is requested
+ * HARDIRQ - inside an interrupt handler
+ * SOFTIRQ - inside a softirq handler
+ * CONT - multiple entries hold the trace item
+ */
+enum trace_flag_type {
+ TRACE_FLAG_IRQS_OFF = 0x01,
+ TRACE_FLAG_NEED_RESCHED = 0x02,
+ TRACE_FLAG_HARDIRQ = 0x04,
+ TRACE_FLAG_SOFTIRQ = 0x08,
+ TRACE_FLAG_CONT = 0x10,
+};
+
+#define TRACE_BUF_SIZE 1024
/*
* The CPU trace array - it consists of thousands of trace entries
@@ -91,16 +142,9 @@ struct trace_entry {
* the trace, etc.)
*/
struct trace_array_cpu {
- struct list_head trace_pages;
atomic_t disabled;
- raw_spinlock_t lock;
- struct lock_class_key lock_key;
/* these fields get copied into max-trace: */
- unsigned trace_head_idx;
- unsigned trace_tail_idx;
- void *trace_head; /* producer */
- void *trace_tail; /* consumer */
unsigned long trace_idx;
unsigned long overrun;
unsigned long saved_latency;
@@ -124,6 +168,7 @@ struct trace_iterator;
* They have on/off state as well:
*/
struct trace_array {
+ struct ring_buffer *buffer;
unsigned long entries;
long ctrl;
int cpu;
@@ -132,6 +177,56 @@ struct trace_array {
struct trace_array_cpu *data[NR_CPUS];
};
+#define FTRACE_CMP_TYPE(var, type) \
+ __builtin_types_compatible_p(typeof(var), type *)
+
+#undef IF_ASSIGN
+#define IF_ASSIGN(var, entry, etype, id) \
+ if (FTRACE_CMP_TYPE(var, etype)) { \
+ var = (typeof(var))(entry); \
+ WARN_ON(id && (entry)->type != id); \
+ break; \
+ }
+
+/* Will cause compile errors if type is not found. */
+extern void __ftrace_bad_type(void);
+
+/*
+ * The trace_assign_type is a verifier that the entry type is
+ * the same as the type being assigned. To add new types simply
+ * add a line with the following format:
+ *
+ * IF_ASSIGN(var, ent, type, id);
+ *
+ * Where "type" is the trace type that includes the trace_entry
+ * as the "ent" item. And "id" is the trace identifier that is
+ * used in the trace_type enum.
+ *
+ * If the type can have more than one id, then use zero.
+ */
+#define trace_assign_type(var, ent) \
+ do { \
+ IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN); \
+ IF_ASSIGN(var, ent, struct ctx_switch_entry, 0); \
+ IF_ASSIGN(var, ent, struct trace_field_cont, TRACE_CONT); \
+ IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK); \
+ IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT); \
+ IF_ASSIGN(var, ent, struct special_entry, 0); \
+ IF_ASSIGN(var, ent, struct trace_mmiotrace_rw, \
+ TRACE_MMIO_RW); \
+ IF_ASSIGN(var, ent, struct trace_mmiotrace_map, \
+ TRACE_MMIO_MAP); \
+ IF_ASSIGN(var, ent, struct trace_boot, TRACE_BOOT); \
+ __ftrace_bad_type(); \
+ } while (0)
+
+/* Return values for print_line callback */
+enum print_line_t {
+ TRACE_TYPE_PARTIAL_LINE = 0, /* Retry after flushing the seq */
+ TRACE_TYPE_HANDLED = 1,
+ TRACE_TYPE_UNHANDLED = 2 /* Relay to other output functions */
+};
+
/*
* A specific tracer, represented by methods that operate on a trace array:
*/
@@ -152,7 +247,7 @@ struct tracer {
int (*selftest)(struct tracer *trace,
struct trace_array *tr);
#endif
- int (*print_line)(struct trace_iterator *iter);
+ enum print_line_t (*print_line)(struct trace_iterator *iter);
struct tracer *next;
int print_max;
};
@@ -171,57 +266,58 @@ struct trace_iterator {
struct trace_array *tr;
struct tracer *trace;
void *private;
- long last_overrun[NR_CPUS];
- long overrun[NR_CPUS];
+ struct ring_buffer_iter *buffer_iter[NR_CPUS];
/* The below is zeroed out in pipe_read */
struct trace_seq seq;
struct trace_entry *ent;
int cpu;
-
- struct trace_entry *prev_ent;
- int prev_cpu;
+ u64 ts;
unsigned long iter_flags;
loff_t pos;
- unsigned long next_idx[NR_CPUS];
- struct list_head *next_page[NR_CPUS];
- unsigned next_page_idx[NR_CPUS];
long idx;
};
-void tracing_reset(struct trace_array_cpu *data);
+void trace_wake_up(void);
+void tracing_reset(struct trace_array *tr, int cpu);
int tracing_open_generic(struct inode *inode, struct file *filp);
struct dentry *tracing_init_dentry(void);
void init_tracer_sysprof_debugfs(struct dentry *d_tracer);
+struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
+ struct trace_array_cpu *data);
+void tracing_generic_entry_update(struct trace_entry *entry,
+ unsigned long flags,
+ int pc);
+
void ftrace(struct trace_array *tr,
struct trace_array_cpu *data,
unsigned long ip,
unsigned long parent_ip,
- unsigned long flags);
+ unsigned long flags, int pc);
void tracing_sched_switch_trace(struct trace_array *tr,
struct trace_array_cpu *data,
struct task_struct *prev,
struct task_struct *next,
- unsigned long flags);
+ unsigned long flags, int pc);
void tracing_record_cmdline(struct task_struct *tsk);
void tracing_sched_wakeup_trace(struct trace_array *tr,
struct trace_array_cpu *data,
struct task_struct *wakee,
struct task_struct *cur,
- unsigned long flags);
+ unsigned long flags, int pc);
void trace_special(struct trace_array *tr,
struct trace_array_cpu *data,
unsigned long arg1,
unsigned long arg2,
- unsigned long arg3);
+ unsigned long arg3, int pc);
void trace_function(struct trace_array *tr,
struct trace_array_cpu *data,
unsigned long ip,
unsigned long parent_ip,
- unsigned long flags);
+ unsigned long flags, int pc);
void tracing_start_cmdline_record(void);
void tracing_stop_cmdline_record(void);
@@ -268,51 +364,33 @@ extern unsigned long ftrace_update_tot_cnt;
extern int DYN_FTRACE_TEST_NAME(void);
#endif
-#ifdef CONFIG_MMIOTRACE
-extern void __trace_mmiotrace_rw(struct trace_array *tr,
- struct trace_array_cpu *data,
- struct mmiotrace_rw *rw);
-extern void __trace_mmiotrace_map(struct trace_array *tr,
- struct trace_array_cpu *data,
- struct mmiotrace_map *map);
-#endif
-
#ifdef CONFIG_FTRACE_STARTUP_TEST
-#ifdef CONFIG_FTRACE
extern int trace_selftest_startup_function(struct tracer *trace,
struct trace_array *tr);
-#endif
-#ifdef CONFIG_IRQSOFF_TRACER
extern int trace_selftest_startup_irqsoff(struct tracer *trace,
struct trace_array *tr);
-#endif
-#ifdef CONFIG_PREEMPT_TRACER
extern int trace_selftest_startup_preemptoff(struct tracer *trace,
struct trace_array *tr);
-#endif
-#if defined(CONFIG_IRQSOFF_TRACER) && defined(CONFIG_PREEMPT_TRACER)
extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
struct trace_array *tr);
-#endif
-#ifdef CONFIG_SCHED_TRACER
extern int trace_selftest_startup_wakeup(struct tracer *trace,
struct trace_array *tr);
-#endif
-#ifdef CONFIG_CONTEXT_SWITCH_TRACER
+extern int trace_selftest_startup_nop(struct tracer *trace,
+ struct trace_array *tr);
extern int trace_selftest_startup_sched_switch(struct tracer *trace,
struct trace_array *tr);
-#endif
-#ifdef CONFIG_SYSPROF_TRACER
extern int trace_selftest_startup_sysprof(struct tracer *trace,
struct trace_array *tr);
-#endif
#endif /* CONFIG_FTRACE_STARTUP_TEST */
extern void *head_page(struct trace_array_cpu *data);
extern int trace_seq_printf(struct trace_seq *s, const char *fmt, ...);
+extern void trace_seq_print_cont(struct trace_seq *s,
+ struct trace_iterator *iter);
extern ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf,
size_t cnt);
extern long ns2usecs(cycle_t nsec);
+extern int trace_vprintk(unsigned long ip, const char *fmt, va_list args);
extern unsigned long trace_flags;
@@ -334,6 +412,9 @@ enum trace_iterator_flags {
TRACE_ITER_BLOCK = 0x80,
TRACE_ITER_STACKTRACE = 0x100,
TRACE_ITER_SCHED_TREE = 0x200,
+ TRACE_ITER_PRINTK = 0x400,
};
+extern struct tracer nop_trace;
+
#endif /* _LINUX_KERNEL_TRACE_H */
diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c
new file mode 100644
index 0000000..d0a5e50
--- /dev/null
+++ b/kernel/trace/trace_boot.c
@@ -0,0 +1,126 @@
+/*
+ * ring buffer based initcalls tracer
+ *
+ * Copyright (C) 2008 Frederic Weisbecker <fweisbec@gmail.com>
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/debugfs.h>
+#include <linux/ftrace.h>
+#include <linux/kallsyms.h>
+
+#include "trace.h"
+
+static struct trace_array *boot_trace;
+static int trace_boot_enabled;
+
+
+/* Should be started after do_pre_smp_initcalls() in init/main.c */
+void start_boot_trace(void)
+{
+ trace_boot_enabled = 1;
+}
+
+void stop_boot_trace(void)
+{
+ trace_boot_enabled = 0;
+}
+
+void reset_boot_trace(struct trace_array *tr)
+{
+ stop_boot_trace();
+}
+
+static void boot_trace_init(struct trace_array *tr)
+{
+ int cpu;
+ boot_trace = tr;
+
+ trace_boot_enabled = 0;
+
+ for_each_cpu_mask(cpu, cpu_possible_map)
+ tracing_reset(tr, cpu);
+}
+
+static void boot_trace_ctrl_update(struct trace_array *tr)
+{
+ if (tr->ctrl)
+ start_boot_trace();
+ else
+ stop_boot_trace();
+}
+
+static enum print_line_t initcall_print_line(struct trace_iterator *iter)
+{
+ int ret;
+ struct trace_entry *entry = iter->ent;
+ struct trace_boot *field = (struct trace_boot *)entry;
+ struct boot_trace *it = &field->initcall;
+ struct trace_seq *s = &iter->seq;
+ struct timespec calltime = ktime_to_timespec(it->calltime);
+ struct timespec rettime = ktime_to_timespec(it->rettime);
+
+ if (entry->type == TRACE_BOOT) {
+ ret = trace_seq_printf(s, "[%5ld.%09ld] calling %s @ %i\n",
+ calltime.tv_sec,
+ calltime.tv_nsec,
+ it->func, it->caller);
+ if (!ret)
+ return TRACE_TYPE_PARTIAL_LINE;
+
+ ret = trace_seq_printf(s, "[%5ld.%09ld] initcall %s "
+ "returned %d after %lld msecs\n",
+ rettime.tv_sec,
+ rettime.tv_nsec,
+ it->func, it->result, it->duration);
+
+ if (!ret)
+ return TRACE_TYPE_PARTIAL_LINE;
+ return TRACE_TYPE_HANDLED;
+ }
+ return TRACE_TYPE_UNHANDLED;
+}
+
+struct tracer boot_tracer __read_mostly =
+{
+ .name = "initcall",
+ .init = boot_trace_init,
+ .reset = reset_boot_trace,
+ .ctrl_update = boot_trace_ctrl_update,
+ .print_line = initcall_print_line,
+};
+
+void trace_boot(struct boot_trace *it, initcall_t fn)
+{
+ struct ring_buffer_event *event;
+ struct trace_boot *entry;
+ struct trace_array_cpu *data;
+ unsigned long irq_flags;
+ struct trace_array *tr = boot_trace;
+
+ if (!trace_boot_enabled)
+ return;
+
+ /* Get its name now since this function could
+ * disappear because it is in the .init section.
+ */
+ sprint_symbol(it->func, (unsigned long)fn);
+ preempt_disable();
+ data = tr->data[smp_processor_id()];
+
+ event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
+ &irq_flags);
+ if (!event)
+ goto out;
+ entry = ring_buffer_event_data(event);
+ tracing_generic_entry_update(&entry->ent, 0, 0);
+ entry->ent.type = TRACE_BOOT;
+ entry->initcall = *it;
+ ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
+
+ trace_wake_up();
+
+ out:
+ preempt_enable();
+}
diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c
index 3121448..e90eb0c 100644
--- a/kernel/trace/trace_functions.c
+++ b/kernel/trace/trace_functions.c
@@ -23,7 +23,7 @@ static void function_reset(struct trace_array *tr)
tr->time_start = ftrace_now(tr->cpu);
for_each_online_cpu(cpu)
- tracing_reset(tr->data[cpu]);
+ tracing_reset(tr, cpu);
}
static void start_function_trace(struct trace_array *tr)
diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c
index ece6cfb..a7db7f0 100644
--- a/kernel/trace/trace_irqsoff.c
+++ b/kernel/trace/trace_irqsoff.c
@@ -95,7 +95,7 @@ irqsoff_tracer_call(unsigned long ip, unsigned long parent_ip)
disabled = atomic_inc_return(&data->disabled);
if (likely(disabled == 1))
- trace_function(tr, data, ip, parent_ip, flags);
+ trace_function(tr, data, ip, parent_ip, flags, preempt_count());
atomic_dec(&data->disabled);
}
@@ -130,6 +130,7 @@ check_critical_timing(struct trace_array *tr,
unsigned long latency, t0, t1;
cycle_t T0, T1, delta;
unsigned long flags;
+ int pc;
/*
* usecs conversion is slow so we try to delay the conversion
@@ -141,6 +142,8 @@ check_critical_timing(struct trace_array *tr,
local_save_flags(flags);
+ pc = preempt_count();
+
if (!report_latency(delta))
goto out;
@@ -150,7 +153,7 @@ check_critical_timing(struct trace_array *tr,
if (!report_latency(delta))
goto out_unlock;
- trace_function(tr, data, CALLER_ADDR0, parent_ip, flags);
+ trace_function(tr, data, CALLER_ADDR0, parent_ip, flags, pc);
latency = nsecs_to_usecs(delta);
@@ -173,8 +176,8 @@ out_unlock:
out:
data->critical_sequence = max_sequence;
data->preempt_timestamp = ftrace_now(cpu);
- tracing_reset(data);
- trace_function(tr, data, CALLER_ADDR0, parent_ip, flags);
+ tracing_reset(tr, cpu);
+ trace_function(tr, data, CALLER_ADDR0, parent_ip, flags, pc);
}
static inline void
@@ -203,11 +206,11 @@ start_critical_timing(unsigned long ip, unsigned long parent_ip)
data->critical_sequence = max_sequence;
data->preempt_timestamp = ftrace_now(cpu);
data->critical_start = parent_ip ? : ip;
- tracing_reset(data);
+ tracing_reset(tr, cpu);
local_save_flags(flags);
- trace_function(tr, data, ip, parent_ip, flags);
+ trace_function(tr, data, ip, parent_ip, flags, preempt_count());
per_cpu(tracing_cpu, cpu) = 1;
@@ -234,14 +237,14 @@ stop_critical_timing(unsigned long ip, unsigned long parent_ip)
data = tr->data[cpu];
- if (unlikely(!data) || unlikely(!head_page(data)) ||
+ if (unlikely(!data) ||
!data->critical_start || atomic_read(&data->disabled))
return;
atomic_inc(&data->disabled);
local_save_flags(flags);
- trace_function(tr, data, ip, parent_ip, flags);
+ trace_function(tr, data, ip, parent_ip, flags, preempt_count());
check_critical_timing(tr, data, parent_ip ? : ip, cpu);
data->critical_start = 0;
atomic_dec(&data->disabled);
diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c
index b13dc19..f284846 100644
--- a/kernel/trace/trace_mmiotrace.c
+++ b/kernel/trace/trace_mmiotrace.c
@@ -27,7 +27,7 @@ static void mmio_reset_data(struct trace_array *tr)
tr->time_start = ftrace_now(tr->cpu);
for_each_online_cpu(cpu)
- tracing_reset(tr->data[cpu]);
+ tracing_reset(tr, cpu);
}
static void mmio_trace_init(struct trace_array *tr)
@@ -130,10 +130,14 @@ static unsigned long count_overruns(struct trace_iterator *iter)
{
int cpu;
unsigned long cnt = 0;
+/* FIXME: */
+#if 0
for_each_online_cpu(cpu) {
cnt += iter->overrun[cpu];
iter->overrun[cpu] = 0;
}
+#endif
+ (void)cpu;
return cnt;
}
@@ -171,17 +175,21 @@ print_out:
return (ret == -EBUSY) ? 0 : ret;
}
-static int mmio_print_rw(struct trace_iterator *iter)
+static enum print_line_t mmio_print_rw(struct trace_iterator *iter)
{
struct trace_entry *entry = iter->ent;
- struct mmiotrace_rw *rw = &entry->mmiorw;
+ struct trace_mmiotrace_rw *field;
+ struct mmiotrace_rw *rw;
struct trace_seq *s = &iter->seq;
- unsigned long long t = ns2usecs(entry->t);
+ unsigned long long t = ns2usecs(iter->ts);
unsigned long usec_rem = do_div(t, 1000000ULL);
unsigned secs = (unsigned long)t;
int ret = 1;
- switch (entry->mmiorw.opcode) {
+ trace_assign_type(field, entry);
+ rw = &field->rw;
+
+ switch (rw->opcode) {
case MMIO_READ:
ret = trace_seq_printf(s,
"R %d %lu.%06lu %d 0x%llx 0x%lx 0x%lx %d\n",
@@ -209,21 +217,25 @@ static int mmio_print_rw(struct trace_iterator *iter)
break;
}
if (ret)
- return 1;
- return 0;
+ return TRACE_TYPE_HANDLED;
+ return TRACE_TYPE_PARTIAL_LINE;
}
-static int mmio_print_map(struct trace_iterator *iter)
+static enum print_line_t mmio_print_map(struct trace_iterator *iter)
{
struct trace_entry *entry = iter->ent;
- struct mmiotrace_map *m = &entry->mmiomap;
+ struct trace_mmiotrace_map *field;
+ struct mmiotrace_map *m;
struct trace_seq *s = &iter->seq;
- unsigned long long t = ns2usecs(entry->t);
+ unsigned long long t = ns2usecs(iter->ts);
unsigned long usec_rem = do_div(t, 1000000ULL);
unsigned secs = (unsigned long)t;
- int ret = 1;
+ int ret;
- switch (entry->mmiorw.opcode) {
+ trace_assign_type(field, entry);
+ m = &field->map;
+
+ switch (m->opcode) {
case MMIO_PROBE:
ret = trace_seq_printf(s,
"MAP %lu.%06lu %d 0x%llx 0x%lx 0x%lx 0x%lx %d\n",
@@ -241,20 +253,43 @@ static int mmio_print_map(struct trace_iterator *iter)
break;
}
if (ret)
- return 1;
- return 0;
+ return TRACE_TYPE_HANDLED;
+ return TRACE_TYPE_PARTIAL_LINE;
+}
+
+static enum print_line_t mmio_print_mark(struct trace_iterator *iter)
+{
+ struct trace_entry *entry = iter->ent;
+ struct print_entry *print = (struct print_entry *)entry;
+ const char *msg = print->buf;
+ struct trace_seq *s = &iter->seq;
+ unsigned long long t = ns2usecs(iter->ts);
+ unsigned long usec_rem = do_div(t, 1000000ULL);
+ unsigned secs = (unsigned long)t;
+ int ret;
+
+ /* The trailing newline must be in the message. */
+ ret = trace_seq_printf(s, "MARK %lu.%06lu %s", secs, usec_rem, msg);
+ if (!ret)
+ return TRACE_TYPE_PARTIAL_LINE;
+
+ if (entry->flags & TRACE_FLAG_CONT)
+ trace_seq_print_cont(s, iter);
+
+ return TRACE_TYPE_HANDLED;
}
-/* return 0 to abort printing without consuming current entry in pipe mode */
-static int mmio_print_line(struct trace_iterator *iter)
+static enum print_line_t mmio_print_line(struct trace_iterator *iter)
{
switch (iter->ent->type) {
case TRACE_MMIO_RW:
return mmio_print_rw(iter);
case TRACE_MMIO_MAP:
return mmio_print_map(iter);
+ case TRACE_PRINT:
+ return mmio_print_mark(iter);
default:
- return 1; /* ignore unknown entries */
+ return TRACE_TYPE_HANDLED; /* ignore unknown entries */
}
}
@@ -276,6 +311,27 @@ __init static int init_mmio_trace(void)
}
device_initcall(init_mmio_trace);
+static void __trace_mmiotrace_rw(struct trace_array *tr,
+ struct trace_array_cpu *data,
+ struct mmiotrace_rw *rw)
+{
+ struct ring_buffer_event *event;
+ struct trace_mmiotrace_rw *entry;
+ unsigned long irq_flags;
+
+ event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
+ &irq_flags);
+ if (!event)
+ return;
+ entry = ring_buffer_event_data(event);
+ tracing_generic_entry_update(&entry->ent, 0, preempt_count());
+ entry->ent.type = TRACE_MMIO_RW;
+ entry->rw = *rw;
+ ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
+
+ trace_wake_up();
+}
+
void mmio_trace_rw(struct mmiotrace_rw *rw)
{
struct trace_array *tr = mmio_trace_array;
@@ -283,6 +339,27 @@ void mmio_trace_rw(struct mmiotrace_rw *rw)
__trace_mmiotrace_rw(tr, data, rw);
}
+static void __trace_mmiotrace_map(struct trace_array *tr,
+ struct trace_array_cpu *data,
+ struct mmiotrace_map *map)
+{
+ struct ring_buffer_event *event;
+ struct trace_mmiotrace_map *entry;
+ unsigned long irq_flags;
+
+ event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
+ &irq_flags);
+ if (!event)
+ return;
+ entry = ring_buffer_event_data(event);
+ tracing_generic_entry_update(&entry->ent, 0, preempt_count());
+ entry->ent.type = TRACE_MMIO_MAP;
+ entry->map = *map;
+ ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
+
+ trace_wake_up();
+}
+
void mmio_trace_mapping(struct mmiotrace_map *map)
{
struct trace_array *tr = mmio_trace_array;
@@ -293,3 +370,8 @@ void mmio_trace_mapping(struct mmiotrace_map *map)
__trace_mmiotrace_map(tr, data, map);
preempt_enable();
}
+
+int mmio_trace_printk(const char *fmt, va_list args)
+{
+ return trace_vprintk(0, fmt, args);
+}
diff --git a/kernel/trace/trace_nop.c b/kernel/trace/trace_nop.c
new file mode 100644
index 0000000..4592b48
--- /dev/null
+++ b/kernel/trace/trace_nop.c
@@ -0,0 +1,64 @@
+/*
+ * nop tracer
+ *
+ * Copyright (C) 2008 Steven Noonan <steven@uplinklabs.net>
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/debugfs.h>
+#include <linux/ftrace.h>
+
+#include "trace.h"
+
+static struct trace_array *ctx_trace;
+
+static void start_nop_trace(struct trace_array *tr)
+{
+ /* Nothing to do! */
+}
+
+static void stop_nop_trace(struct trace_array *tr)
+{
+ /* Nothing to do! */
+}
+
+static void nop_trace_init(struct trace_array *tr)
+{
+ int cpu;
+ ctx_trace = tr;
+
+ for_each_online_cpu(cpu)
+ tracing_reset(tr, cpu);
+
+ if (tr->ctrl)
+ start_nop_trace(tr);
+}
+
+static void nop_trace_reset(struct trace_array *tr)
+{
+ if (tr->ctrl)
+ stop_nop_trace(tr);
+}
+
+static void nop_trace_ctrl_update(struct trace_array *tr)
+{
+ /* When starting a new trace, reset the buffers */
+ if (tr->ctrl)
+ start_nop_trace(tr);
+ else
+ stop_nop_trace(tr);
+}
+
+struct tracer nop_trace __read_mostly =
+{
+ .name = "nop",
+ .init = nop_trace_init,
+ .reset = nop_trace_reset,
+ .ctrl_update = nop_trace_ctrl_update,
+#ifdef CONFIG_FTRACE_SELFTEST
+ .selftest = trace_selftest_startup_nop,
+#endif
+};
+
diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c
index cb817a2..b8f56be 100644
--- a/kernel/trace/trace_sched_switch.c
+++ b/kernel/trace/trace_sched_switch.c
@@ -9,8 +9,8 @@
#include <linux/debugfs.h>
#include <linux/kallsyms.h>
#include <linux/uaccess.h>
-#include <linux/marker.h>
#include <linux/ftrace.h>
+#include <trace/sched.h>
#include "trace.h"
@@ -19,15 +19,16 @@ static int __read_mostly tracer_enabled;
static atomic_t sched_ref;
static void
-sched_switch_func(void *private, void *__rq, struct task_struct *prev,
+probe_sched_switch(struct rq *__rq, struct task_struct *prev,
struct task_struct *next)
{
- struct trace_array **ptr = private;
- struct trace_array *tr = *ptr;
struct trace_array_cpu *data;
unsigned long flags;
- long disabled;
int cpu;
+ int pc;
+
+ if (!atomic_read(&sched_ref))
+ return;
tracing_record_cmdline(prev);
tracing_record_cmdline(next);
@@ -35,97 +36,41 @@ sched_switch_func(void *private, void *__rq, struct task_struct *prev,
if (!tracer_enabled)
return;
+ pc = preempt_count();
local_irq_save(flags);
cpu = raw_smp_processor_id();
- data = tr->data[cpu];
- disabled = atomic_inc_return(&data->disabled);
+ data = ctx_trace->data[cpu];
- if (likely(disabled == 1))
- tracing_sched_switch_trace(tr, data, prev, next, flags);
+ if (likely(!atomic_read(&data->disabled)))
+ tracing_sched_switch_trace(ctx_trace, data, prev, next, flags, pc);
- atomic_dec(&data->disabled);
local_irq_restore(flags);
}
-static notrace void
-sched_switch_callback(void *probe_data, void *call_data,
- const char *format, va_list *args)
-{
- struct task_struct *prev;
- struct task_struct *next;
- struct rq *__rq;
-
- if (!atomic_read(&sched_ref))
- return;
-
- /* skip prev_pid %d next_pid %d prev_state %ld */
- (void)va_arg(*args, int);
- (void)va_arg(*args, int);
- (void)va_arg(*args, long);
- __rq = va_arg(*args, typeof(__rq));
- prev = va_arg(*args, typeof(prev));
- next = va_arg(*args, typeof(next));
-
- /*
- * If tracer_switch_func only points to the local
- * switch func, it still needs the ptr passed to it.
- */
- sched_switch_func(probe_data, __rq, prev, next);
-}
-
static void
-wakeup_func(void *private, void *__rq, struct task_struct *wakee, struct
- task_struct *curr)
+probe_sched_wakeup(struct rq *__rq, struct task_struct *wakee)
{
- struct trace_array **ptr = private;
- struct trace_array *tr = *ptr;
struct trace_array_cpu *data;
unsigned long flags;
- long disabled;
- int cpu;
+ int cpu, pc;
- if (!tracer_enabled)
+ if (!likely(tracer_enabled))
return;
- tracing_record_cmdline(curr);
+ pc = preempt_count();
+ tracing_record_cmdline(current);
local_irq_save(flags);
cpu = raw_smp_processor_id();
- data = tr->data[cpu];
- disabled = atomic_inc_return(&data->disabled);
+ data = ctx_trace->data[cpu];
- if (likely(disabled == 1))
- tracing_sched_wakeup_trace(tr, data, wakee, curr, flags);
+ if (likely(!atomic_read(&data->disabled)))
+ tracing_sched_wakeup_trace(ctx_trace, data, wakee, current,
+ flags, pc);
- atomic_dec(&data->disabled);
local_irq_restore(flags);
}
-static notrace void
-wake_up_callback(void *probe_data, void *call_data,
- const char *format, va_list *args)
-{
- struct task_struct *curr;
- struct task_struct *task;
- struct rq *__rq;
-
- if (likely(!tracer_enabled))
- return;
-
- /* Skip pid %d state %ld */
- (void)va_arg(*args, int);
- (void)va_arg(*args, long);
- /* now get the meat: "rq %p task %p rq->curr %p" */
- __rq = va_arg(*args, typeof(__rq));
- task = va_arg(*args, typeof(task));
- curr = va_arg(*args, typeof(curr));
-
- tracing_record_cmdline(task);
- tracing_record_cmdline(curr);
-
- wakeup_func(probe_data, __rq, task, curr);
-}
-
static void sched_switch_reset(struct trace_array *tr)
{
int cpu;
@@ -133,67 +78,47 @@ static void sched_switch_reset(struct trace_array *tr)
tr->time_start = ftrace_now(tr->cpu);
for_each_online_cpu(cpu)
- tracing_reset(tr->data[cpu]);
+ tracing_reset(tr, cpu);
}
static int tracing_sched_register(void)
{
int ret;
- ret = marker_probe_register("kernel_sched_wakeup",
- "pid %d state %ld ## rq %p task %p rq->curr %p",
- wake_up_callback,
- &ctx_trace);
+ ret = register_trace_sched_wakeup(probe_sched_wakeup);
if (ret) {
- pr_info("wakeup trace: Couldn't add marker"
+ pr_info("wakeup trace: Couldn't activate tracepoint"
" probe to kernel_sched_wakeup\n");
return ret;
}
- ret = marker_probe_register("kernel_sched_wakeup_new",
- "pid %d state %ld ## rq %p task %p rq->curr %p",
- wake_up_callback,
- &ctx_trace);
+ ret = register_trace_sched_wakeup_new(probe_sched_wakeup);
if (ret) {
- pr_info("wakeup trace: Couldn't add marker"
+ pr_info("wakeup trace: Couldn't activate tracepoint"
" probe to kernel_sched_wakeup_new\n");
goto fail_deprobe;
}
- ret = marker_probe_register("kernel_sched_schedule",
- "prev_pid %d next_pid %d prev_state %ld "
- "## rq %p prev %p next %p",
- sched_switch_callback,
- &ctx_trace);
+ ret = register_trace_sched_switch(probe_sched_switch);
if (ret) {
- pr_info("sched trace: Couldn't add marker"
+ pr_info("sched trace: Couldn't activate tracepoint"
" probe to kernel_sched_schedule\n");
goto fail_deprobe_wake_new;
}
return ret;
fail_deprobe_wake_new:
- marker_probe_unregister("kernel_sched_wakeup_new",
- wake_up_callback,
- &ctx_trace);
+ unregister_trace_sched_wakeup_new(probe_sched_wakeup);
fail_deprobe:
- marker_probe_unregister("kernel_sched_wakeup",
- wake_up_callback,
- &ctx_trace);
+ unregister_trace_sched_wakeup(probe_sched_wakeup);
return ret;
}
static void tracing_sched_unregister(void)
{
- marker_probe_unregister("kernel_sched_schedule",
- sched_switch_callback,
- &ctx_trace);
- marker_probe_unregister("kernel_sched_wakeup_new",
- wake_up_callback,
- &ctx_trace);
- marker_probe_unregister("kernel_sched_wakeup",
- wake_up_callback,
- &ctx_trace);
+ unregister_trace_sched_switch(probe_sched_switch);
+ unregister_trace_sched_wakeup_new(probe_sched_wakeup);
+ unregister_trace_sched_wakeup(probe_sched_wakeup);
}
static void tracing_start_sched_switch(void)
diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c
index e303ccb..fe4a252 100644
--- a/kernel/trace/trace_sched_wakeup.c
+++ b/kernel/trace/trace_sched_wakeup.c
@@ -15,7 +15,7 @@
#include <linux/kallsyms.h>
#include <linux/uaccess.h>
#include <linux/ftrace.h>
-#include <linux/marker.h>
+#include <trace/sched.h>
#include "trace.h"
@@ -44,10 +44,12 @@ wakeup_tracer_call(unsigned long ip, unsigned long parent_ip)
long disabled;
int resched;
int cpu;
+ int pc;
if (likely(!wakeup_task))
return;
+ pc = preempt_count();
resched = need_resched();
preempt_disable_notrace();
@@ -70,7 +72,7 @@ wakeup_tracer_call(unsigned long ip, unsigned long parent_ip)
if (task_cpu(wakeup_task) != cpu)
goto unlock;
- trace_function(tr, data, ip, parent_ip, flags);
+ trace_function(tr, data, ip, parent_ip, flags, pc);
unlock:
__raw_spin_unlock(&wakeup_lock);
@@ -112,17 +114,18 @@ static int report_latency(cycle_t delta)
}
static void notrace
-wakeup_sched_switch(void *private, void *rq, struct task_struct *prev,
+probe_wakeup_sched_switch(struct rq *rq, struct task_struct *prev,
struct task_struct *next)
{
unsigned long latency = 0, t0 = 0, t1 = 0;
- struct trace_array **ptr = private;
- struct trace_array *tr = *ptr;
struct trace_array_cpu *data;
cycle_t T0, T1, delta;
unsigned long flags;
long disabled;
int cpu;
+ int pc;
+
+ tracing_record_cmdline(prev);
if (unlikely(!tracer_enabled))
return;
@@ -139,12 +142,14 @@ wakeup_sched_switch(void *private, void *rq, struct task_struct *prev,
if (next != wakeup_task)
return;
+ pc = preempt_count();
+
/* The task we are waiting for is waking up */
- data = tr->data[wakeup_cpu];
+ data = wakeup_trace->data[wakeup_cpu];
/* disable local data, not wakeup_cpu data */
cpu = raw_smp_processor_id();
- disabled = atomic_inc_return(&tr->data[cpu]->disabled);
+ disabled = atomic_inc_return(&wakeup_trace->data[cpu]->disabled);
if (likely(disabled != 1))
goto out;
@@ -155,7 +160,7 @@ wakeup_sched_switch(void *private, void *rq, struct task_struct *prev,
if (unlikely(!tracer_enabled || next != wakeup_task))
goto out_unlock;
- trace_function(tr, data, CALLER_ADDR1, CALLER_ADDR2, flags);
+ trace_function(wakeup_trace, data, CALLER_ADDR1, CALLER_ADDR2, flags, pc);
/*
* usecs conversion is slow so we try to delay the conversion
@@ -174,39 +179,14 @@ wakeup_sched_switch(void *private, void *rq, struct task_struct *prev,
t0 = nsecs_to_usecs(T0);
t1 = nsecs_to_usecs(T1);
- update_max_tr(tr, wakeup_task, wakeup_cpu);
+ update_max_tr(wakeup_trace, wakeup_task, wakeup_cpu);
out_unlock:
- __wakeup_reset(tr);
+ __wakeup_reset(wakeup_trace);
__raw_spin_unlock(&wakeup_lock);
local_irq_restore(flags);
out:
- atomic_dec(&tr->data[cpu]->disabled);
-}
-
-static notrace void
-sched_switch_callback(void *probe_data, void *call_data,
- const char *format, va_list *args)
-{
- struct task_struct *prev;
- struct task_struct *next;
- struct rq *__rq;
-
- /* skip prev_pid %d next_pid %d prev_state %ld */
- (void)va_arg(*args, int);
- (void)va_arg(*args, int);
- (void)va_arg(*args, long);
- __rq = va_arg(*args, typeof(__rq));
- prev = va_arg(*args, typeof(prev));
- next = va_arg(*args, typeof(next));
-
- tracing_record_cmdline(prev);
-
- /*
- * If tracer_switch_func only points to the local
- * switch func, it still needs the ptr passed to it.
- */
- wakeup_sched_switch(probe_data, __rq, prev, next);
+ atomic_dec(&wakeup_trace->data[cpu]->disabled);
}
static void __wakeup_reset(struct trace_array *tr)
@@ -216,7 +196,7 @@ static void __wakeup_reset(struct trace_array *tr)
for_each_possible_cpu(cpu) {
data = tr->data[cpu];
- tracing_reset(data);
+ tracing_reset(tr, cpu);
}
wakeup_cpu = -1;
@@ -240,19 +220,26 @@ static void wakeup_reset(struct trace_array *tr)
}
static void
-wakeup_check_start(struct trace_array *tr, struct task_struct *p,
- struct task_struct *curr)
+probe_wakeup(struct rq *rq, struct task_struct *p)
{
int cpu = smp_processor_id();
unsigned long flags;
long disabled;
+ int pc;
+
+ if (likely(!tracer_enabled))
+ return;
+
+ tracing_record_cmdline(p);
+ tracing_record_cmdline(current);
if (likely(!rt_task(p)) ||
p->prio >= wakeup_prio ||
- p->prio >= curr->prio)
+ p->prio >= current->prio)
return;
- disabled = atomic_inc_return(&tr->data[cpu]->disabled);
+ pc = preempt_count();
+ disabled = atomic_inc_return(&wakeup_trace->data[cpu]->disabled);
if (unlikely(disabled != 1))
goto out;
@@ -264,7 +251,7 @@ wakeup_check_start(struct trace_array *tr, struct task_struct *p,
goto out_locked;
/* reset the trace */
- __wakeup_reset(tr);
+ __wakeup_reset(wakeup_trace);
wakeup_cpu = task_cpu(p);
wakeup_prio = p->prio;
@@ -274,74 +261,37 @@ wakeup_check_start(struct trace_array *tr, struct task_struct *p,
local_save_flags(flags);
- tr->data[wakeup_cpu]->preempt_timestamp = ftrace_now(cpu);
- trace_function(tr, tr->data[wakeup_cpu],
- CALLER_ADDR1, CALLER_ADDR2, flags);
+ wakeup_trace->data[wakeup_cpu]->preempt_timestamp = ftrace_now(cpu);
+ trace_function(wakeup_trace, wakeup_trace->data[wakeup_cpu],
+ CALLER_ADDR1, CALLER_ADDR2, flags, pc);
out_locked:
__raw_spin_unlock(&wakeup_lock);
out:
- atomic_dec(&tr->data[cpu]->disabled);
-}
-
-static notrace void
-wake_up_callback(void *probe_data, void *call_data,
- const char *format, va_list *args)
-{
- struct trace_array **ptr = probe_data;
- struct trace_array *tr = *ptr;
- struct task_struct *curr;
- struct task_struct *task;
- struct rq *__rq;
-
- if (likely(!tracer_enabled))
- return;
-
- /* Skip pid %d state %ld */
- (void)va_arg(*args, int);
- (void)va_arg(*args, long);
- /* now get the meat: "rq %p task %p rq->curr %p" */
- __rq = va_arg(*args, typeof(__rq));
- task = va_arg(*args, typeof(task));
- curr = va_arg(*args, typeof(curr));
-
- tracing_record_cmdline(task);
- tracing_record_cmdline(curr);
-
- wakeup_check_start(tr, task, curr);
+ atomic_dec(&wakeup_trace->data[cpu]->disabled);
}
static void start_wakeup_tracer(struct trace_array *tr)
{
int ret;
- ret = marker_probe_register("kernel_sched_wakeup",
- "pid %d state %ld ## rq %p task %p rq->curr %p",
- wake_up_callback,
- &wakeup_trace);
+ ret = register_trace_sched_wakeup(probe_wakeup);
if (ret) {
- pr_info("wakeup trace: Couldn't add marker"
+ pr_info("wakeup trace: Couldn't activate tracepoint"
" probe to kernel_sched_wakeup\n");
return;
}
- ret = marker_probe_register("kernel_sched_wakeup_new",
- "pid %d state %ld ## rq %p task %p rq->curr %p",
- wake_up_callback,
- &wakeup_trace);
+ ret = register_trace_sched_wakeup_new(probe_wakeup);
if (ret) {
- pr_info("wakeup trace: Couldn't add marker"
+ pr_info("wakeup trace: Couldn't activate tracepoint"
" probe to kernel_sched_wakeup_new\n");
goto fail_deprobe;
}
- ret = marker_probe_register("kernel_sched_schedule",
- "prev_pid %d next_pid %d prev_state %ld "
- "## rq %p prev %p next %p",
- sched_switch_callback,
- &wakeup_trace);
+ ret = register_trace_sched_switch(probe_wakeup_sched_switch);
if (ret) {
- pr_info("sched trace: Couldn't add marker"
+ pr_info("sched trace: Couldn't activate tracepoint"
" probe to kernel_sched_schedule\n");
goto fail_deprobe_wake_new;
}
@@ -363,28 +313,18 @@ static void start_wakeup_tracer(struct trace_array *tr)
return;
fail_deprobe_wake_new:
- marker_probe_unregister("kernel_sched_wakeup_new",
- wake_up_callback,
- &wakeup_trace);
+ unregister_trace_sched_wakeup_new(probe_wakeup);
fail_deprobe:
- marker_probe_unregister("kernel_sched_wakeup",
- wake_up_callback,
- &wakeup_trace);
+ unregister_trace_sched_wakeup(probe_wakeup);
}
static void stop_wakeup_tracer(struct trace_array *tr)
{
tracer_enabled = 0;
unregister_ftrace_function(&trace_ops);
- marker_probe_unregister("kernel_sched_schedule",
- sched_switch_callback,
- &wakeup_trace);
- marker_probe_unregister("kernel_sched_wakeup_new",
- wake_up_callback,
- &wakeup_trace);
- marker_probe_unregister("kernel_sched_wakeup",
- wake_up_callback,
- &wakeup_trace);
+ unregister_trace_sched_switch(probe_wakeup_sched_switch);
+ unregister_trace_sched_wakeup_new(probe_wakeup);
+ unregister_trace_sched_wakeup(probe_wakeup);
}
static void wakeup_tracer_init(struct trace_array *tr)
diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c
index 0911b7e..09cf230 100644
--- a/kernel/trace/trace_selftest.c
+++ b/kernel/trace/trace_selftest.c
@@ -9,65 +9,29 @@ static inline int trace_valid_entry(struct trace_entry *entry)
case TRACE_FN:
case TRACE_CTX:
case TRACE_WAKE:
+ case TRACE_CONT:
case TRACE_STACK:
+ case TRACE_PRINT:
case TRACE_SPECIAL:
return 1;
}
return 0;
}
-static int
-trace_test_buffer_cpu(struct trace_array *tr, struct trace_array_cpu *data)
+static int trace_test_buffer_cpu(struct trace_array *tr, int cpu)
{
- struct trace_entry *entries;
- struct page *page;
- int idx = 0;
- int i;
+ struct ring_buffer_event *event;
+ struct trace_entry *entry;
- BUG_ON(list_empty(&data->trace_pages));
- page = list_entry(data->trace_pages.next, struct page, lru);
- entries = page_address(page);
+ while ((event = ring_buffer_consume(tr->buffer, cpu, NULL))) {
+ entry = ring_buffer_event_data(event);
- check_pages(data);
- if (head_page(data) != entries)
- goto failed;
-
- /*
- * The starting trace buffer always has valid elements,
- * if any element exists.
- */
- entries = head_page(data);
-
- for (i = 0; i < tr->entries; i++) {
-
- if (i < data->trace_idx && !trace_valid_entry(&entries[idx])) {
+ if (!trace_valid_entry(entry)) {
printk(KERN_CONT ".. invalid entry %d ",
- entries[idx].type);
+ entry->type);
goto failed;
}
-
- idx++;
- if (idx >= ENTRIES_PER_PAGE) {
- page = virt_to_page(entries);
- if (page->lru.next == &data->trace_pages) {
- if (i != tr->entries - 1) {
- printk(KERN_CONT ".. entries buffer mismatch");
- goto failed;
- }
- } else {
- page = list_entry(page->lru.next, struct page, lru);
- entries = page_address(page);
- }
- idx = 0;
- }
}
-
- page = virt_to_page(entries);
- if (page->lru.next != &data->trace_pages) {
- printk(KERN_CONT ".. too many entries");
- goto failed;
- }
-
return 0;
failed:
@@ -89,13 +53,11 @@ static int trace_test_buffer(struct trace_array *tr, unsigned long *count)
/* Don't allow flipping of max traces now */
raw_local_irq_save(flags);
__raw_spin_lock(&ftrace_max_lock);
- for_each_possible_cpu(cpu) {
- if (!head_page(tr->data[cpu]))
- continue;
- cnt += tr->data[cpu]->trace_idx;
+ cnt = ring_buffer_entries(tr->buffer);
- ret = trace_test_buffer_cpu(tr, tr->data[cpu]);
+ for_each_possible_cpu(cpu) {
+ ret = trace_test_buffer_cpu(tr, cpu);
if (ret)
break;
}
@@ -120,11 +82,11 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace,
struct trace_array *tr,
int (*func)(void))
{
- unsigned long count;
- int ret;
int save_ftrace_enabled = ftrace_enabled;
int save_tracer_enabled = tracer_enabled;
+ unsigned long count;
char *func_name;
+ int ret;
/* The ftrace test PASSED */
printk(KERN_CONT "PASSED\n");
@@ -157,6 +119,7 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace,
/* enable tracing */
tr->ctrl = 1;
trace->init(tr);
+
/* Sleep for a 1/10 of a second */
msleep(100);
@@ -212,10 +175,10 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace,
int
trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr)
{
- unsigned long count;
- int ret;
int save_ftrace_enabled = ftrace_enabled;
int save_tracer_enabled = tracer_enabled;
+ unsigned long count;
+ int ret;
/* make sure msleep has been recorded */
msleep(1);
@@ -415,6 +378,15 @@ trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array *
}
#endif /* CONFIG_IRQSOFF_TRACER && CONFIG_PREEMPT_TRACER */
+#ifdef CONFIG_NOP_TRACER
+int
+trace_selftest_startup_nop(struct tracer *trace, struct trace_array *tr)
+{
+ /* What could possibly go wrong? */
+ return 0;
+}
+#endif
+
#ifdef CONFIG_SCHED_TRACER
static int trace_wakeup_test_thread(void *data)
{
@@ -486,6 +458,9 @@ trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr)
wake_up_process(p);
+ /* give a little time to let the thread wake up */
+ msleep(100);
+
/* stop the tracing. */
tr->ctrl = 0;
trace->ctrl_update(tr);
diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
new file mode 100644
index 0000000..74c5d9a
--- /dev/null
+++ b/kernel/trace/trace_stack.c
@@ -0,0 +1,310 @@
+/*
+ * Copyright (C) 2008 Steven Rostedt <srostedt@redhat.com>
+ *
+ */
+#include <linux/stacktrace.h>
+#include <linux/kallsyms.h>
+#include <linux/seq_file.h>
+#include <linux/spinlock.h>
+#include <linux/uaccess.h>
+#include <linux/debugfs.h>
+#include <linux/ftrace.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/fs.h>
+#include "trace.h"
+
+#define STACK_TRACE_ENTRIES 500
+
+static unsigned long stack_dump_trace[STACK_TRACE_ENTRIES+1] =
+ { [0 ... (STACK_TRACE_ENTRIES)] = ULONG_MAX };
+static unsigned stack_dump_index[STACK_TRACE_ENTRIES];
+
+static struct stack_trace max_stack_trace = {
+ .max_entries = STACK_TRACE_ENTRIES,
+ .entries = stack_dump_trace,
+};
+
+static unsigned long max_stack_size;
+static raw_spinlock_t max_stack_lock =
+ (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
+
+static int stack_trace_disabled __read_mostly;
+static DEFINE_PER_CPU(int, trace_active);
+
+static inline void check_stack(void)
+{
+ unsigned long this_size, flags;
+ unsigned long *p, *top, *start;
+ int i;
+
+ this_size = ((unsigned long)&this_size) & (THREAD_SIZE-1);
+ this_size = THREAD_SIZE - this_size;
+
+ if (this_size <= max_stack_size)
+ return;
+
+ raw_local_irq_save(flags);
+ __raw_spin_lock(&max_stack_lock);
+
+ /* a race could have already updated it */
+ if (this_size <= max_stack_size)
+ goto out;
+
+ max_stack_size = this_size;
+
+ max_stack_trace.nr_entries = 0;
+ max_stack_trace.skip = 3;
+
+ save_stack_trace(&max_stack_trace);
+
+ /*
+ * Now find where in the stack these are.
+ */
+ i = 0;
+ start = &this_size;
+ top = (unsigned long *)
+ (((unsigned long)start & ~(THREAD_SIZE-1)) + THREAD_SIZE);
+
+ /*
+ * Loop through all the entries. One of the entries may
+ * for some reason be missed on the stack, so we may
+ * have to account for them. If they are all there, this
+ * loop will only happen once. This code only takes place
+ * on a new max, so it is far from a fast path.
+ */
+ while (i < max_stack_trace.nr_entries) {
+
+ stack_dump_index[i] = this_size;
+ p = start;
+
+ for (; p < top && i < max_stack_trace.nr_entries; p++) {
+ if (*p == stack_dump_trace[i]) {
+ this_size = stack_dump_index[i++] =
+ (top - p) * sizeof(unsigned long);
+ /* Start the search from here */
+ start = p + 1;
+ }
+ }
+
+ i++;
+ }
+
+ out:
+ __raw_spin_unlock(&max_stack_lock);
+ raw_local_irq_restore(flags);
+}
+
+static void
+stack_trace_call(unsigned long ip, unsigned long parent_ip)
+{
+ int cpu, resched;
+
+ if (unlikely(!ftrace_enabled || stack_trace_disabled))
+ return;
+
+ resched = need_resched();
+ preempt_disable_notrace();
+
+ cpu = raw_smp_processor_id();
+ /* no atomic needed, we only modify this variable by this cpu */
+ if (per_cpu(trace_active, cpu)++ != 0)
+ goto out;
+
+ check_stack();
+
+ out:
+ per_cpu(trace_active, cpu)--;
+ /* prevent recursion in schedule */
+ if (resched)
+ preempt_enable_no_resched_notrace();
+ else
+ preempt_enable_notrace();
+}
+
+static struct ftrace_ops trace_ops __read_mostly =
+{
+ .func = stack_trace_call,
+};
+
+static ssize_t
+stack_max_size_read(struct file *filp, char __user *ubuf,
+ size_t count, loff_t *ppos)
+{
+ unsigned long *ptr = filp->private_data;
+ char buf[64];
+ int r;
+
+ r = snprintf(buf, sizeof(buf), "%ld\n", *ptr);
+ if (r > sizeof(buf))
+ r = sizeof(buf);
+ return simple_read_from_buffer(ubuf, count, ppos, buf, r);
+}
+
+static ssize_t
+stack_max_size_write(struct file *filp, const char __user *ubuf,
+ size_t count, loff_t *ppos)
+{
+ long *ptr = filp->private_data;
+ unsigned long val, flags;
+ char buf[64];
+ int ret;
+
+ if (count >= sizeof(buf))
+ return -EINVAL;
+
+ if (copy_from_user(&buf, ubuf, count))
+ return -EFAULT;
+
+ buf[count] = 0;
+
+ ret = strict_strtoul(buf, 10, &val);
+ if (ret < 0)
+ return ret;
+
+ raw_local_irq_save(flags);
+ __raw_spin_lock(&max_stack_lock);
+ *ptr = val;
+ __raw_spin_unlock(&max_stack_lock);
+ raw_local_irq_restore(flags);
+
+ return count;
+}
+
+static struct file_operations stack_max_size_fops = {
+ .open = tracing_open_generic,
+ .read = stack_max_size_read,
+ .write = stack_max_size_write,
+};
+
+static void *
+t_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ long i = (long)m->private;
+
+ (*pos)++;
+
+ i++;
+
+ if (i >= max_stack_trace.nr_entries ||
+ stack_dump_trace[i] == ULONG_MAX)
+ return NULL;
+
+ m->private = (void *)i;
+
+ return &m->private;
+}
+
+static void *t_start(struct seq_file *m, loff_t *pos)
+{
+ void *t = &m->private;
+ loff_t l = 0;
+
+ local_irq_disable();
+ __raw_spin_lock(&max_stack_lock);
+
+ for (; t && l < *pos; t = t_next(m, t, &l))
+ ;
+
+ return t;
+}
+
+static void t_stop(struct seq_file *m, void *p)
+{
+ __raw_spin_unlock(&max_stack_lock);
+ local_irq_enable();
+}
+
+static int trace_lookup_stack(struct seq_file *m, long i)
+{
+ unsigned long addr = stack_dump_trace[i];
+#ifdef CONFIG_KALLSYMS
+ char str[KSYM_SYMBOL_LEN];
+
+ sprint_symbol(str, addr);
+
+ return seq_printf(m, "%s\n", str);
+#else
+ return seq_printf(m, "%p\n", (void*)addr);
+#endif
+}
+
+static int t_show(struct seq_file *m, void *v)
+{
+ long i = *(long *)v;
+ int size;
+
+ if (i < 0) {
+ seq_printf(m, " Depth Size Location"
+ " (%d entries)\n"
+ " ----- ---- --------\n",
+ max_stack_trace.nr_entries);
+ return 0;
+ }
+
+ if (i >= max_stack_trace.nr_entries ||
+ stack_dump_trace[i] == ULONG_MAX)
+ return 0;
+
+ if (i+1 == max_stack_trace.nr_entries ||
+ stack_dump_trace[i+1] == ULONG_MAX)
+ size = stack_dump_index[i];
+ else
+ size = stack_dump_index[i] - stack_dump_index[i+1];
+
+ seq_printf(m, "%3ld) %8d %5d ", i, stack_dump_index[i], size);
+
+ trace_lookup_stack(m, i);
+
+ return 0;
+}
+
+static struct seq_operations stack_trace_seq_ops = {
+ .start = t_start,
+ .next = t_next,
+ .stop = t_stop,
+ .show = t_show,
+};
+
+static int stack_trace_open(struct inode *inode, struct file *file)
+{
+ int ret;
+
+ ret = seq_open(file, &stack_trace_seq_ops);
+ if (!ret) {
+ struct seq_file *m = file->private_data;
+ m->private = (void *)-1;
+ }
+
+ return ret;
+}
+
+static struct file_operations stack_trace_fops = {
+ .open = stack_trace_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+};
+
+static __init int stack_trace_init(void)
+{
+ struct dentry *d_tracer;
+ struct dentry *entry;
+
+ d_tracer = tracing_init_dentry();
+
+ entry = debugfs_create_file("stack_max_size", 0644, d_tracer,
+ &max_stack_size, &stack_max_size_fops);
+ if (!entry)
+ pr_warning("Could not create debugfs 'stack_max_size' entry\n");
+
+ entry = debugfs_create_file("stack_trace", 0444, d_tracer,
+ NULL, &stack_trace_fops);
+ if (!entry)
+ pr_warning("Could not create debugfs 'stack_trace' entry\n");
+
+ register_ftrace_function(&trace_ops);
+
+ return 0;
+}
+
+device_initcall(stack_trace_init);
diff --git a/kernel/trace/trace_sysprof.c b/kernel/trace/trace_sysprof.c
index db58fb6..9587d3b 100644
--- a/kernel/trace/trace_sysprof.c
+++ b/kernel/trace/trace_sysprof.c
@@ -241,7 +241,7 @@ static void stack_reset(struct trace_array *tr)
tr->time_start = ftrace_now(tr->cpu);
for_each_online_cpu(cpu)
- tracing_reset(tr->data[cpu]);
+ tracing_reset(tr, cpu);
}
static void start_stack_trace(struct trace_array *tr)
diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c
new file mode 100644
index 0000000..f2b7c28
--- /dev/null
+++ b/kernel/tracepoint.c
@@ -0,0 +1,477 @@
+/*
+ * Copyright (C) 2008 Mathieu Desnoyers
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/types.h>
+#include <linux/jhash.h>
+#include <linux/list.h>
+#include <linux/rcupdate.h>
+#include <linux/tracepoint.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+
+extern struct tracepoint __start___tracepoints[];
+extern struct tracepoint __stop___tracepoints[];
+
+/* Set to 1 to enable tracepoint debug output */
+static const int tracepoint_debug;
+
+/*
+ * tracepoints_mutex nests inside module_mutex. Tracepoints mutex protects the
+ * builtin and module tracepoints and the hash table.
+ */
+static DEFINE_MUTEX(tracepoints_mutex);
+
+/*
+ * Tracepoint hash table, containing the active tracepoints.
+ * Protected by tracepoints_mutex.
+ */
+#define TRACEPOINT_HASH_BITS 6
+#define TRACEPOINT_TABLE_SIZE (1 << TRACEPOINT_HASH_BITS)
+
+/*
+ * Note about RCU :
+ * It is used to to delay the free of multiple probes array until a quiescent
+ * state is reached.
+ * Tracepoint entries modifications are protected by the tracepoints_mutex.
+ */
+struct tracepoint_entry {
+ struct hlist_node hlist;
+ void **funcs;
+ int refcount; /* Number of times armed. 0 if disarmed. */
+ struct rcu_head rcu;
+ void *oldptr;
+ unsigned char rcu_pending:1;
+ char name[0];
+};
+
+static struct hlist_head tracepoint_table[TRACEPOINT_TABLE_SIZE];
+
+static void free_old_closure(struct rcu_head *head)
+{
+ struct tracepoint_entry *entry = container_of(head,
+ struct tracepoint_entry, rcu);
+ kfree(entry->oldptr);
+ /* Make sure we free the data before setting the pending flag to 0 */
+ smp_wmb();
+ entry->rcu_pending = 0;
+}
+
+static void tracepoint_entry_free_old(struct tracepoint_entry *entry, void *old)
+{
+ if (!old)
+ return;
+ entry->oldptr = old;
+ entry->rcu_pending = 1;
+ /* write rcu_pending before calling the RCU callback */
+ smp_wmb();
+ call_rcu_sched(&entry->rcu, free_old_closure);
+}
+
+static void debug_print_probes(struct tracepoint_entry *entry)
+{
+ int i;
+
+ if (!tracepoint_debug)
+ return;
+
+ for (i = 0; entry->funcs[i]; i++)
+ printk(KERN_DEBUG "Probe %d : %p\n", i, entry->funcs[i]);
+}
+
+static void *
+tracepoint_entry_add_probe(struct tracepoint_entry *entry, void *probe)
+{
+ int nr_probes = 0;
+ void **old, **new;
+
+ WARN_ON(!probe);
+
+ debug_print_probes(entry);
+ old = entry->funcs;
+ if (old) {
+ /* (N -> N+1), (N != 0, 1) probes */
+ for (nr_probes = 0; old[nr_probes]; nr_probes++)
+ if (old[nr_probes] == probe)
+ return ERR_PTR(-EEXIST);
+ }
+ /* + 2 : one for new probe, one for NULL func */
+ new = kzalloc((nr_probes + 2) * sizeof(void *), GFP_KERNEL);
+ if (new == NULL)
+ return ERR_PTR(-ENOMEM);
+ if (old)
+ memcpy(new, old, nr_probes * sizeof(void *));
+ new[nr_probes] = probe;
+ entry->refcount = nr_probes + 1;
+ entry->funcs = new;
+ debug_print_probes(entry);
+ return old;
+}
+
+static void *
+tracepoint_entry_remove_probe(struct tracepoint_entry *entry, void *probe)
+{
+ int nr_probes = 0, nr_del = 0, i;
+ void **old, **new;
+
+ old = entry->funcs;
+
+ debug_print_probes(entry);
+ /* (N -> M), (N > 1, M >= 0) probes */
+ for (nr_probes = 0; old[nr_probes]; nr_probes++) {
+ if ((!probe || old[nr_probes] == probe))
+ nr_del++;
+ }
+
+ if (nr_probes - nr_del == 0) {
+ /* N -> 0, (N > 1) */
+ entry->funcs = NULL;
+ entry->refcount = 0;
+ debug_print_probes(entry);
+ return old;
+ } else {
+ int j = 0;
+ /* N -> M, (N > 1, M > 0) */
+ /* + 1 for NULL */
+ new = kzalloc((nr_probes - nr_del + 1)
+ * sizeof(void *), GFP_KERNEL);
+ if (new == NULL)
+ return ERR_PTR(-ENOMEM);
+ for (i = 0; old[i]; i++)
+ if ((probe && old[i] != probe))
+ new[j++] = old[i];
+ entry->refcount = nr_probes - nr_del;
+ entry->funcs = new;
+ }
+ debug_print_probes(entry);
+ return old;
+}
+
+/*
+ * Get tracepoint if the tracepoint is present in the tracepoint hash table.
+ * Must be called with tracepoints_mutex held.
+ * Returns NULL if not present.
+ */
+static struct tracepoint_entry *get_tracepoint(const char *name)
+{
+ struct hlist_head *head;
+ struct hlist_node *node;
+ struct tracepoint_entry *e;
+ u32 hash = jhash(name, strlen(name), 0);
+
+ head = &tracepoint_table[hash & (TRACEPOINT_TABLE_SIZE - 1)];
+ hlist_for_each_entry(e, node, head, hlist) {
+ if (!strcmp(name, e->name))
+ return e;
+ }
+ return NULL;
+}
+
+/*
+ * Add the tracepoint to the tracepoint hash table. Must be called with
+ * tracepoints_mutex held.
+ */
+static struct tracepoint_entry *add_tracepoint(const char *name)
+{
+ struct hlist_head *head;
+ struct hlist_node *node;
+ struct tracepoint_entry *e;
+ size_t name_len = strlen(name) + 1;
+ u32 hash = jhash(name, name_len-1, 0);
+
+ head = &tracepoint_table[hash & (TRACEPOINT_TABLE_SIZE - 1)];
+ hlist_for_each_entry(e, node, head, hlist) {
+ if (!strcmp(name, e->name)) {
+ printk(KERN_NOTICE
+ "tracepoint %s busy\n", name);
+ return ERR_PTR(-EEXIST); /* Already there */
+ }
+ }
+ /*
+ * Using kmalloc here to allocate a variable length element. Could
+ * cause some memory fragmentation if overused.
+ */
+ e = kmalloc(sizeof(struct tracepoint_entry) + name_len, GFP_KERNEL);
+ if (!e)
+ return ERR_PTR(-ENOMEM);
+ memcpy(&e->name[0], name, name_len);
+ e->funcs = NULL;
+ e->refcount = 0;
+ e->rcu_pending = 0;
+ hlist_add_head(&e->hlist, head);
+ return e;
+}
+
+/*
+ * Remove the tracepoint from the tracepoint hash table. Must be called with
+ * mutex_lock held.
+ */
+static int remove_tracepoint(const char *name)
+{
+ struct hlist_head *head;
+ struct hlist_node *node;
+ struct tracepoint_entry *e;
+ int found = 0;
+ size_t len = strlen(name) + 1;
+ u32 hash = jhash(name, len-1, 0);
+
+ head = &tracepoint_table[hash & (TRACEPOINT_TABLE_SIZE - 1)];
+ hlist_for_each_entry(e, node, head, hlist) {
+ if (!strcmp(name, e->name)) {
+ found = 1;
+ break;
+ }
+ }
+ if (!found)
+ return -ENOENT;
+ if (e->refcount)
+ return -EBUSY;
+ hlist_del(&e->hlist);
+ /* Make sure the call_rcu_sched has been executed */
+ if (e->rcu_pending)
+ rcu_barrier_sched();
+ kfree(e);
+ return 0;
+}
+
+/*
+ * Sets the probe callback corresponding to one tracepoint.
+ */
+static void set_tracepoint(struct tracepoint_entry **entry,
+ struct tracepoint *elem, int active)
+{
+ WARN_ON(strcmp((*entry)->name, elem->name) != 0);
+
+ /*
+ * rcu_assign_pointer has a smp_wmb() which makes sure that the new
+ * probe callbacks array is consistent before setting a pointer to it.
+ * This array is referenced by __DO_TRACE from
+ * include/linux/tracepoints.h. A matching smp_read_barrier_depends()
+ * is used.
+ */
+ rcu_assign_pointer(elem->funcs, (*entry)->funcs);
+ elem->state = active;
+}
+
+/*
+ * Disable a tracepoint and its probe callback.
+ * Note: only waiting an RCU period after setting elem->call to the empty
+ * function insures that the original callback is not used anymore. This insured
+ * by preempt_disable around the call site.
+ */
+static void disable_tracepoint(struct tracepoint *elem)
+{
+ elem->state = 0;
+}
+
+/**
+ * tracepoint_update_probe_range - Update a probe range
+ * @begin: beginning of the range
+ * @end: end of the range
+ *
+ * Updates the probe callback corresponding to a range of tracepoints.
+ */
+void tracepoint_update_probe_range(struct tracepoint *begin,
+ struct tracepoint *end)
+{
+ struct tracepoint *iter;
+ struct tracepoint_entry *mark_entry;
+
+ mutex_lock(&tracepoints_mutex);
+ for (iter = begin; iter < end; iter++) {
+ mark_entry = get_tracepoint(iter->name);
+ if (mark_entry) {
+ set_tracepoint(&mark_entry, iter,
+ !!mark_entry->refcount);
+ } else {
+ disable_tracepoint(iter);
+ }
+ }
+ mutex_unlock(&tracepoints_mutex);
+}
+
+/*
+ * Update probes, removing the faulty probes.
+ */
+static void tracepoint_update_probes(void)
+{
+ /* Core kernel tracepoints */
+ tracepoint_update_probe_range(__start___tracepoints,
+ __stop___tracepoints);
+ /* tracepoints in modules. */
+ module_update_tracepoints();
+}
+
+/**
+ * tracepoint_probe_register - Connect a probe to a tracepoint
+ * @name: tracepoint name
+ * @probe: probe handler
+ *
+ * Returns 0 if ok, error value on error.
+ * The probe address must at least be aligned on the architecture pointer size.
+ */
+int tracepoint_probe_register(const char *name, void *probe)
+{
+ struct tracepoint_entry *entry;
+ int ret = 0;
+ void *old;
+
+ mutex_lock(&tracepoints_mutex);
+ entry = get_tracepoint(name);
+ if (!entry) {
+ entry = add_tracepoint(name);
+ if (IS_ERR(entry)) {
+ ret = PTR_ERR(entry);
+ goto end;
+ }
+ }
+ /*
+ * If we detect that a call_rcu_sched is pending for this tracepoint,
+ * make sure it's executed now.
+ */
+ if (entry->rcu_pending)
+ rcu_barrier_sched();
+ old = tracepoint_entry_add_probe(entry, probe);
+ if (IS_ERR(old)) {
+ ret = PTR_ERR(old);
+ goto end;
+ }
+ mutex_unlock(&tracepoints_mutex);
+ tracepoint_update_probes(); /* may update entry */
+ mutex_lock(&tracepoints_mutex);
+ entry = get_tracepoint(name);
+ WARN_ON(!entry);
+ if (entry->rcu_pending)
+ rcu_barrier_sched();
+ tracepoint_entry_free_old(entry, old);
+end:
+ mutex_unlock(&tracepoints_mutex);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(tracepoint_probe_register);
+
+/**
+ * tracepoint_probe_unregister - Disconnect a probe from a tracepoint
+ * @name: tracepoint name
+ * @probe: probe function pointer
+ *
+ * We do not need to call a synchronize_sched to make sure the probes have
+ * finished running before doing a module unload, because the module unload
+ * itself uses stop_machine(), which insures that every preempt disabled section
+ * have finished.
+ */
+int tracepoint_probe_unregister(const char *name, void *probe)
+{
+ struct tracepoint_entry *entry;
+ void *old;
+ int ret = -ENOENT;
+
+ mutex_lock(&tracepoints_mutex);
+ entry = get_tracepoint(name);
+ if (!entry)
+ goto end;
+ if (entry->rcu_pending)
+ rcu_barrier_sched();
+ old = tracepoint_entry_remove_probe(entry, probe);
+ mutex_unlock(&tracepoints_mutex);
+ tracepoint_update_probes(); /* may update entry */
+ mutex_lock(&tracepoints_mutex);
+ entry = get_tracepoint(name);
+ if (!entry)
+ goto end;
+ if (entry->rcu_pending)
+ rcu_barrier_sched();
+ tracepoint_entry_free_old(entry, old);
+ remove_tracepoint(name); /* Ignore busy error message */
+ ret = 0;
+end:
+ mutex_unlock(&tracepoints_mutex);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(tracepoint_probe_unregister);
+
+/**
+ * tracepoint_get_iter_range - Get a next tracepoint iterator given a range.
+ * @tracepoint: current tracepoints (in), next tracepoint (out)
+ * @begin: beginning of the range
+ * @end: end of the range
+ *
+ * Returns whether a next tracepoint has been found (1) or not (0).
+ * Will return the first tracepoint in the range if the input tracepoint is
+ * NULL.
+ */
+int tracepoint_get_iter_range(struct tracepoint **tracepoint,
+ struct tracepoint *begin, struct tracepoint *end)
+{
+ if (!*tracepoint && begin != end) {
+ *tracepoint = begin;
+ return 1;
+ }
+ if (*tracepoint >= begin && *tracepoint < end)
+ return 1;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(tracepoint_get_iter_range);
+
+static void tracepoint_get_iter(struct tracepoint_iter *iter)
+{
+ int found = 0;
+
+ /* Core kernel tracepoints */
+ if (!iter->module) {
+ found = tracepoint_get_iter_range(&iter->tracepoint,
+ __start___tracepoints, __stop___tracepoints);
+ if (found)
+ goto end;
+ }
+ /* tracepoints in modules. */
+ found = module_get_iter_tracepoints(iter);
+end:
+ if (!found)
+ tracepoint_iter_reset(iter);
+}
+
+void tracepoint_iter_start(struct tracepoint_iter *iter)
+{
+ tracepoint_get_iter(iter);
+}
+EXPORT_SYMBOL_GPL(tracepoint_iter_start);
+
+void tracepoint_iter_next(struct tracepoint_iter *iter)
+{
+ iter->tracepoint++;
+ /*
+ * iter->tracepoint may be invalid because we blindly incremented it.
+ * Make sure it is valid by marshalling on the tracepoints, getting the
+ * tracepoints from following modules if necessary.
+ */
+ tracepoint_get_iter(iter);
+}
+EXPORT_SYMBOL_GPL(tracepoint_iter_next);
+
+void tracepoint_iter_stop(struct tracepoint_iter *iter)
+{
+}
+EXPORT_SYMBOL_GPL(tracepoint_iter_stop);
+
+void tracepoint_iter_reset(struct tracepoint_iter *iter)
+{
+ iter->module = NULL;
+ iter->tracepoint = NULL;
+}
+EXPORT_SYMBOL_GPL(tracepoint_iter_reset);
generated by cgit v0.10.2 at 2024-11-16 08:35:28 (GMT)