summaryrefslogtreecommitdiff
path: root/kernel/trace
diff options
context:
space:
mode:
authorJason Jin <Jason.Jin@freescale.com>2015-03-19 05:40:14 (GMT)
committerJason Jin <Jason.Jin@freescale.com>2015-03-19 05:40:14 (GMT)
commitb2d58e506b33b18574807e63007e87ebca0f9c07 (patch)
treefc2afd772ba5cdac0dd091f65c492695b27d9a17 /kernel/trace
parent2bbe09ef71ce8446ba0b3e29df2099150e9e6fdf (diff)
parenteb985cb9b5e02d470870617b41fa51a1d9360c7f (diff)
downloadlinux-fsl-qoriq-b2d58e506b33b18574807e63007e87ebca0f9c07.tar.xz
Merge branch 'qoriq-sdk' into LS1-SDK
Diffstat (limited to 'kernel/trace')
-rw-r--r--kernel/trace/blktrace.c20
-rw-r--r--kernel/trace/ftrace.c31
-rw-r--r--kernel/trace/ring_buffer.c56
-rw-r--r--kernel/trace/trace.c66
-rw-r--r--kernel/trace/trace.h4
-rw-r--r--kernel/trace/trace_clock.c9
-rw-r--r--kernel/trace/trace_events.c2
-rw-r--r--kernel/trace/trace_syscalls.c8
8 files changed, 107 insertions, 89 deletions
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 7f727b3..e0e5f73 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -703,6 +703,7 @@ void blk_trace_shutdown(struct request_queue *q)
* blk_add_trace_rq - Add a trace for a request oriented action
* @q: queue the io is for
* @rq: the source request
+ * @nr_bytes: number of completed bytes
* @what: the action
*
* Description:
@@ -710,7 +711,7 @@ void blk_trace_shutdown(struct request_queue *q)
*
**/
static void blk_add_trace_rq(struct request_queue *q, struct request *rq,
- u32 what)
+ unsigned int nr_bytes, u32 what)
{
struct blk_trace *bt = q->blk_trace;
@@ -719,11 +720,11 @@ static void blk_add_trace_rq(struct request_queue *q, struct request *rq,
if (rq->cmd_type == REQ_TYPE_BLOCK_PC) {
what |= BLK_TC_ACT(BLK_TC_PC);
- __blk_add_trace(bt, 0, blk_rq_bytes(rq), rq->cmd_flags,
+ __blk_add_trace(bt, 0, nr_bytes, rq->cmd_flags,
what, rq->errors, rq->cmd_len, rq->cmd);
} else {
what |= BLK_TC_ACT(BLK_TC_FS);
- __blk_add_trace(bt, blk_rq_pos(rq), blk_rq_bytes(rq),
+ __blk_add_trace(bt, blk_rq_pos(rq), nr_bytes,
rq->cmd_flags, what, rq->errors, 0, NULL);
}
}
@@ -731,33 +732,34 @@ static void blk_add_trace_rq(struct request_queue *q, struct request *rq,
static void blk_add_trace_rq_abort(void *ignore,
struct request_queue *q, struct request *rq)
{
- blk_add_trace_rq(q, rq, BLK_TA_ABORT);
+ blk_add_trace_rq(q, rq, blk_rq_bytes(rq), BLK_TA_ABORT);
}
static void blk_add_trace_rq_insert(void *ignore,
struct request_queue *q, struct request *rq)
{
- blk_add_trace_rq(q, rq, BLK_TA_INSERT);
+ blk_add_trace_rq(q, rq, blk_rq_bytes(rq), BLK_TA_INSERT);
}
static void blk_add_trace_rq_issue(void *ignore,
struct request_queue *q, struct request *rq)
{
- blk_add_trace_rq(q, rq, BLK_TA_ISSUE);
+ blk_add_trace_rq(q, rq, blk_rq_bytes(rq), BLK_TA_ISSUE);
}
static void blk_add_trace_rq_requeue(void *ignore,
struct request_queue *q,
struct request *rq)
{
- blk_add_trace_rq(q, rq, BLK_TA_REQUEUE);
+ blk_add_trace_rq(q, rq, blk_rq_bytes(rq), BLK_TA_REQUEUE);
}
static void blk_add_trace_rq_complete(void *ignore,
struct request_queue *q,
- struct request *rq)
+ struct request *rq,
+ unsigned int nr_bytes)
{
- blk_add_trace_rq(q, rq, BLK_TA_COMPLETE);
+ blk_add_trace_rq(q, rq, nr_bytes, BLK_TA_COMPLETE);
}
/**
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index e66411f..d2ab10b 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -331,12 +331,12 @@ static void update_ftrace_function(void)
func = ftrace_ops_list_func;
}
+ update_function_graph_func();
+
/* If there's no change, then do nothing more here */
if (ftrace_trace_function == func)
return;
- update_function_graph_func();
-
/*
* If we are using the list function, it doesn't care
* about the function_trace_ops.
@@ -4252,16 +4252,11 @@ static void ftrace_init_module(struct module *mod,
ftrace_process_locs(mod, start, end);
}
-static int ftrace_module_notify_enter(struct notifier_block *self,
- unsigned long val, void *data)
+void ftrace_module_init(struct module *mod)
{
- struct module *mod = data;
-
- if (val == MODULE_STATE_COMING)
- ftrace_init_module(mod, mod->ftrace_callsites,
- mod->ftrace_callsites +
- mod->num_ftrace_callsites);
- return 0;
+ ftrace_init_module(mod, mod->ftrace_callsites,
+ mod->ftrace_callsites +
+ mod->num_ftrace_callsites);
}
static int ftrace_module_notify_exit(struct notifier_block *self,
@@ -4275,11 +4270,6 @@ static int ftrace_module_notify_exit(struct notifier_block *self,
return 0;
}
#else
-static int ftrace_module_notify_enter(struct notifier_block *self,
- unsigned long val, void *data)
-{
- return 0;
-}
static int ftrace_module_notify_exit(struct notifier_block *self,
unsigned long val, void *data)
{
@@ -4287,11 +4277,6 @@ static int ftrace_module_notify_exit(struct notifier_block *self,
}
#endif /* CONFIG_MODULES */
-struct notifier_block ftrace_module_enter_nb = {
- .notifier_call = ftrace_module_notify_enter,
- .priority = INT_MAX, /* Run before anything that can use kprobes */
-};
-
struct notifier_block ftrace_module_exit_nb = {
.notifier_call = ftrace_module_notify_exit,
.priority = INT_MIN, /* Run after anything that can remove kprobes */
@@ -4328,10 +4313,6 @@ void __init ftrace_init(void)
__start_mcount_loc,
__stop_mcount_loc);
- ret = register_module_notifier(&ftrace_module_enter_nb);
- if (ret)
- pr_warning("Failed to register trace ftrace module enter notifier\n");
-
ret = register_module_notifier(&ftrace_module_exit_nb);
if (ret)
pr_warning("Failed to register trace ftrace module exit notifier\n");
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 0e337ee..21ee379 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -543,7 +543,7 @@ static void rb_wake_up_waiters(struct irq_work *work)
* as data is added to any of the @buffer's cpu buffers. Otherwise
* it will wait for data to be added to a specific cpu buffer.
*/
-void ring_buffer_wait(struct ring_buffer *buffer, int cpu)
+int ring_buffer_wait(struct ring_buffer *buffer, int cpu)
{
struct ring_buffer_per_cpu *cpu_buffer;
DEFINE_WAIT(wait);
@@ -557,6 +557,8 @@ void ring_buffer_wait(struct ring_buffer *buffer, int cpu)
if (cpu == RING_BUFFER_ALL_CPUS)
work = &buffer->irq_work;
else {
+ if (!cpumask_test_cpu(cpu, buffer->cpumask))
+ return -ENODEV;
cpu_buffer = buffer->buffers[cpu];
work = &cpu_buffer->irq_work;
}
@@ -591,6 +593,7 @@ void ring_buffer_wait(struct ring_buffer *buffer, int cpu)
schedule();
finish_wait(&work->waiters, &wait);
+ return 0;
}
/**
@@ -613,10 +616,6 @@ int ring_buffer_poll_wait(struct ring_buffer *buffer, int cpu,
struct ring_buffer_per_cpu *cpu_buffer;
struct rb_irq_work *work;
- if ((cpu == RING_BUFFER_ALL_CPUS && !ring_buffer_empty(buffer)) ||
- (cpu != RING_BUFFER_ALL_CPUS && !ring_buffer_empty_cpu(buffer, cpu)))
- return POLLIN | POLLRDNORM;
-
if (cpu == RING_BUFFER_ALL_CPUS)
work = &buffer->irq_work;
else {
@@ -627,8 +626,22 @@ int ring_buffer_poll_wait(struct ring_buffer *buffer, int cpu,
work = &cpu_buffer->irq_work;
}
- work->waiters_pending = true;
poll_wait(filp, &work->waiters, poll_table);
+ work->waiters_pending = true;
+ /*
+ * There's a tight race between setting the waiters_pending and
+ * checking if the ring buffer is empty. Once the waiters_pending bit
+ * is set, the next event will wake the task up, but we can get stuck
+ * if there's only a single event in.
+ *
+ * FIXME: Ideally, we need a memory barrier on the writer side as well,
+ * but adding a memory barrier to all events will cause too much of a
+ * performance hit in the fast path. We only need a memory barrier when
+ * the buffer goes from empty to having content. But as this race is
+ * extremely small, and it's not a problem if another event comes in, we
+ * will fix it later.
+ */
+ smp_mb();
if ((cpu == RING_BUFFER_ALL_CPUS && !ring_buffer_empty(buffer)) ||
(cpu != RING_BUFFER_ALL_CPUS && !ring_buffer_empty_cpu(buffer, cpu)))
@@ -1982,7 +1995,7 @@ rb_add_time_stamp(struct ring_buffer_event *event, u64 delta)
/**
* rb_update_event - update event type and data
- * @event: the even to update
+ * @event: the event to update
* @type: the type of event
* @length: the size of the event field in the ring buffer
*
@@ -3355,21 +3368,16 @@ static void rb_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 = rb_set_head_page(cpu_buffer);
- if (unlikely(!iter->head_page))
- return;
- iter->head = iter->head_page->read;
- } else {
- iter->head_page = cpu_buffer->reader_page;
- iter->head = cpu_buffer->reader_page->read;
- }
+ iter->head_page = cpu_buffer->reader_page;
+ iter->head = cpu_buffer->reader_page->read;
+
+ iter->cache_reader_page = iter->head_page;
+ iter->cache_read = cpu_buffer->read;
+
if (iter->head)
iter->read_stamp = cpu_buffer->read_stamp;
else
iter->read_stamp = iter->head_page->page->time_stamp;
- iter->cache_reader_page = cpu_buffer->reader_page;
- iter->cache_read = cpu_buffer->read;
}
/**
@@ -3762,12 +3770,14 @@ rb_iter_peek(struct ring_buffer_iter *iter, u64 *ts)
return NULL;
/*
- * We repeat when a time extend is encountered.
- * Since the time extend is always attached to a data event,
- * we should never loop more than once.
- * (We never hit the following condition more than twice).
+ * We repeat when a time extend is encountered or we hit
+ * the end of the page. Since the time extend is always attached
+ * to a data event, we should never loop more than three times.
+ * Once for going to next page, once on time extend, and
+ * finally once to get the event.
+ * (We never hit the following condition more than thrice).
*/
- if (RB_WARN_ON(cpu_buffer, ++nr_loops > 2))
+ if (RB_WARN_ON(cpu_buffer, ++nr_loops > 3))
return NULL;
if (rb_per_cpu_empty(cpu_buffer))
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index f9401ed..9f79237 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -434,6 +434,12 @@ int __trace_puts(unsigned long ip, const char *str, int size)
struct print_entry *entry;
unsigned long irq_flags;
int alloc;
+ int pc;
+
+ if (!(trace_flags & TRACE_ITER_PRINTK))
+ return 0;
+
+ pc = preempt_count();
if (unlikely(tracing_selftest_running || tracing_disabled))
return 0;
@@ -442,8 +448,8 @@ int __trace_puts(unsigned long ip, const char *str, int size)
local_save_flags(irq_flags);
buffer = global_trace.trace_buffer.buffer;
- event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, alloc,
- irq_flags, preempt_count());
+ event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, alloc,
+ irq_flags, pc);
if (!event)
return 0;
@@ -460,6 +466,7 @@ int __trace_puts(unsigned long ip, const char *str, int size)
entry->buf[size] = '\0';
__buffer_unlock_commit(buffer, event);
+ ftrace_trace_stack(buffer, irq_flags, 4, pc);
return size;
}
@@ -477,6 +484,12 @@ int __trace_bputs(unsigned long ip, const char *str)
struct bputs_entry *entry;
unsigned long irq_flags;
int size = sizeof(struct bputs_entry);
+ int pc;
+
+ if (!(trace_flags & TRACE_ITER_PRINTK))
+ return 0;
+
+ pc = preempt_count();
if (unlikely(tracing_selftest_running || tracing_disabled))
return 0;
@@ -484,7 +497,7 @@ int __trace_bputs(unsigned long ip, const char *str)
local_save_flags(irq_flags);
buffer = global_trace.trace_buffer.buffer;
event = trace_buffer_lock_reserve(buffer, TRACE_BPUTS, size,
- irq_flags, preempt_count());
+ irq_flags, pc);
if (!event)
return 0;
@@ -493,6 +506,7 @@ int __trace_bputs(unsigned long ip, const char *str)
entry->str = str;
__buffer_unlock_commit(buffer, event);
+ ftrace_trace_stack(buffer, irq_flags, 4, pc);
return 1;
}
@@ -750,7 +764,7 @@ static struct {
{ trace_clock_local, "local", 1 },
{ trace_clock_global, "global", 1 },
{ trace_clock_counter, "counter", 0 },
- { trace_clock_jiffies, "uptime", 1 },
+ { trace_clock_jiffies, "uptime", 0 },
{ trace_clock, "perf", 1 },
ARCH_TRACE_CLOCKS
};
@@ -1044,13 +1058,13 @@ update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu)
}
#endif /* CONFIG_TRACER_MAX_TRACE */
-static void default_wait_pipe(struct trace_iterator *iter)
+static int default_wait_pipe(struct trace_iterator *iter)
{
/* Iterators are static, they should be filled or empty */
if (trace_buffer_iter(iter, iter->cpu_file))
- return;
+ return 0;
- ring_buffer_wait(iter->trace_buffer->buffer, iter->cpu_file);
+ return ring_buffer_wait(iter->trace_buffer->buffer, iter->cpu_file);
}
#ifdef CONFIG_FTRACE_STARTUP_TEST
@@ -1323,7 +1337,6 @@ void tracing_start(void)
arch_spin_unlock(&ftrace_max_lock);
- ftrace_start();
out:
raw_spin_unlock_irqrestore(&global_trace.start_lock, flags);
}
@@ -1370,7 +1383,6 @@ void tracing_stop(void)
struct ring_buffer *buffer;
unsigned long flags;
- ftrace_stop();
raw_spin_lock_irqsave(&global_trace.start_lock, flags);
if (global_trace.stop_count++)
goto out;
@@ -1417,12 +1429,12 @@ static void tracing_stop_tr(struct trace_array *tr)
void trace_stop_cmdline_recording(void);
-static void trace_save_cmdline(struct task_struct *tsk)
+static int trace_save_cmdline(struct task_struct *tsk)
{
unsigned pid, idx;
if (!tsk->pid || unlikely(tsk->pid > PID_MAX_DEFAULT))
- return;
+ return 0;
/*
* It's not the end of the world if we don't get
@@ -1431,7 +1443,7 @@ static void trace_save_cmdline(struct task_struct *tsk)
* so if we miss here, then better luck next time.
*/
if (!arch_spin_trylock(&trace_cmdline_lock))
- return;
+ return 0;
idx = map_pid_to_cmdline[tsk->pid];
if (idx == NO_CMDLINE_MAP) {
@@ -1456,6 +1468,8 @@ static void trace_save_cmdline(struct task_struct *tsk)
memcpy(&saved_cmdlines[idx], tsk->comm, TASK_COMM_LEN);
arch_spin_unlock(&trace_cmdline_lock);
+
+ return 1;
}
void trace_find_cmdline(int pid, char comm[])
@@ -1497,9 +1511,8 @@ void tracing_record_cmdline(struct task_struct *tsk)
if (!__this_cpu_read(trace_cmdline_save))
return;
- __this_cpu_write(trace_cmdline_save, false);
-
- trace_save_cmdline(tsk);
+ if (trace_save_cmdline(tsk))
+ __this_cpu_write(trace_cmdline_save, false);
}
void
@@ -4070,17 +4083,19 @@ tracing_poll_pipe(struct file *filp, poll_table *poll_table)
*
* Anyway, this is really very primitive wakeup.
*/
-void poll_wait_pipe(struct trace_iterator *iter)
+int poll_wait_pipe(struct trace_iterator *iter)
{
set_current_state(TASK_INTERRUPTIBLE);
/* sleep for 100 msecs, and try again. */
schedule_timeout(HZ / 10);
+ return 0;
}
/* Must be called with trace_types_lock mutex held. */
static int tracing_wait_pipe(struct file *filp)
{
struct trace_iterator *iter = filp->private_data;
+ int ret;
while (trace_empty(iter)) {
@@ -4090,10 +4105,13 @@ static int tracing_wait_pipe(struct file *filp)
mutex_unlock(&iter->mutex);
- iter->trace->wait_pipe(iter);
+ ret = iter->trace->wait_pipe(iter);
mutex_lock(&iter->mutex);
+ if (ret)
+ return ret;
+
if (signal_pending(current))
return -EINTR;
@@ -5027,8 +5045,12 @@ tracing_buffers_read(struct file *filp, char __user *ubuf,
goto out_unlock;
}
mutex_unlock(&trace_types_lock);
- iter->trace->wait_pipe(iter);
+ ret = iter->trace->wait_pipe(iter);
mutex_lock(&trace_types_lock);
+ if (ret) {
+ size = ret;
+ goto out_unlock;
+ }
if (signal_pending(current)) {
size = -EINTR;
goto out_unlock;
@@ -5240,8 +5262,10 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
goto out;
}
mutex_unlock(&trace_types_lock);
- iter->trace->wait_pipe(iter);
+ ret = iter->trace->wait_pipe(iter);
mutex_lock(&trace_types_lock);
+ if (ret)
+ goto out;
if (signal_pending(current)) {
ret = -EINTR;
goto out;
@@ -6049,7 +6073,7 @@ static int instance_mkdir (struct inode *inode, struct dentry *dentry, umode_t m
int ret;
/* Paranoid: Make sure the parent is the "instances" directory */
- parent = hlist_entry(inode->i_dentry.first, struct dentry, d_alias);
+ parent = hlist_entry(inode->i_dentry.first, struct dentry, d_u.d_alias);
if (WARN_ON_ONCE(parent != trace_instance_dir))
return -ENOENT;
@@ -6076,7 +6100,7 @@ static int instance_rmdir(struct inode *inode, struct dentry *dentry)
int ret;
/* Paranoid: Make sure the parent is the "instances" directory */
- parent = hlist_entry(inode->i_dentry.first, struct dentry, d_alias);
+ parent = hlist_entry(inode->i_dentry.first, struct dentry, d_u.d_alias);
if (WARN_ON_ONCE(parent != trace_instance_dir))
return -ENOENT;
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 109291a..90584b5 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -336,7 +336,7 @@ struct tracer {
void (*stop)(struct trace_array *tr);
void (*open)(struct trace_iterator *iter);
void (*pipe_open)(struct trace_iterator *iter);
- void (*wait_pipe)(struct trace_iterator *iter);
+ int (*wait_pipe)(struct trace_iterator *iter);
void (*close)(struct trace_iterator *iter);
void (*pipe_close)(struct trace_iterator *iter);
ssize_t (*read)(struct trace_iterator *iter,
@@ -551,7 +551,7 @@ void trace_init_global_iter(struct trace_iterator *iter);
void tracing_iter_reset(struct trace_iterator *iter, int cpu);
-void poll_wait_pipe(struct trace_iterator *iter);
+int poll_wait_pipe(struct trace_iterator *iter);
void tracing_sched_switch_trace(struct trace_array *tr,
struct task_struct *prev,
diff --git a/kernel/trace/trace_clock.c b/kernel/trace/trace_clock.c
index 26dc348..57b67b1 100644
--- a/kernel/trace/trace_clock.c
+++ b/kernel/trace/trace_clock.c
@@ -59,13 +59,14 @@ u64 notrace trace_clock(void)
/*
* trace_jiffy_clock(): Simply use jiffies as a clock counter.
+ * Note that this use of jiffies_64 is not completely safe on
+ * 32-bit systems. But the window is tiny, and the effect if
+ * we are affected is that we will have an obviously bogus
+ * timestamp on a trace event - i.e. not life threatening.
*/
u64 notrace trace_clock_jiffies(void)
{
- u64 jiffy = jiffies - INITIAL_JIFFIES;
-
- /* Return nsecs */
- return (u64)jiffies_to_usecs(jiffy) * 1000ULL;
+ return jiffies_64_to_clock_t(jiffies_64 - INITIAL_JIFFIES);
}
/*
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 9e49f3f..6574925 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -429,7 +429,7 @@ static void remove_event_file_dir(struct ftrace_event_file *file)
if (dir) {
spin_lock(&dir->d_lock); /* probably unneeded */
- list_for_each_entry(child, &dir->d_subdirs, d_u.d_child) {
+ list_for_each_entry(child, &dir->d_subdirs, d_child) {
if (child->d_inode) /* probably unneeded */
child->d_inode->i_private = NULL;
}
diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index 559329d..d8ce71b 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -312,7 +312,7 @@ static void ftrace_syscall_enter(void *data, struct pt_regs *regs, long id)
int size;
syscall_nr = trace_get_syscall_nr(current, regs);
- if (syscall_nr < 0)
+ if (syscall_nr < 0 || syscall_nr >= NR_syscalls)
return;
if (!test_bit(syscall_nr, tr->enabled_enter_syscalls))
return;
@@ -354,7 +354,7 @@ static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret)
int syscall_nr;
syscall_nr = trace_get_syscall_nr(current, regs);
- if (syscall_nr < 0)
+ if (syscall_nr < 0 || syscall_nr >= NR_syscalls)
return;
if (!test_bit(syscall_nr, tr->enabled_exit_syscalls))
return;
@@ -557,7 +557,7 @@ static void perf_syscall_enter(void *ignore, struct pt_regs *regs, long id)
int size;
syscall_nr = trace_get_syscall_nr(current, regs);
- if (syscall_nr < 0)
+ if (syscall_nr < 0 || syscall_nr >= NR_syscalls)
return;
if (!test_bit(syscall_nr, enabled_perf_enter_syscalls))
return;
@@ -631,7 +631,7 @@ static void perf_syscall_exit(void *ignore, struct pt_regs *regs, long ret)
int size;
syscall_nr = trace_get_syscall_nr(current, regs);
- if (syscall_nr < 0)
+ if (syscall_nr < 0 || syscall_nr >= NR_syscalls)
return;
if (!test_bit(syscall_nr, enabled_perf_exit_syscalls))
return;