diff options
author | Steven Rostedt <srostedt@redhat.com> | 2008-12-04 05:26:40 (GMT) |
---|---|---|
committer | Ingo Molnar <mingo@elte.hu> | 2008-12-04 08:09:37 (GMT) |
commit | 978f3a45d9499c7a447ca7615455cefb63d44165 (patch) | |
tree | 13a59046c8fe7ae3a095444515cd50c0a57727b3 /kernel/trace | |
parent | 5ef6476190d24419a9a537baa0b5641845136989 (diff) | |
download | linux-fsl-qoriq-978f3a45d9499c7a447ca7615455cefb63d44165.tar.xz |
ftrace: use struct pid
Impact: clean up, extend PID filtering to PID namespaces
Eric Biederman suggested using the struct pid for filtering on
pids in the kernel. This patch is based off of a demonstration
of an implementation that Eric sent me in an email.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/trace')
-rw-r--r-- | kernel/trace/ftrace.c | 76 | ||||
-rw-r--r-- | kernel/trace/trace.h | 4 |
2 files changed, 46 insertions, 34 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 57592a9..10b1d7c 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -48,7 +48,7 @@ int ftrace_enabled __read_mostly; static int last_ftrace_enabled; /* set when tracing only a pid */ -int ftrace_pid_trace = -1; +struct pid *ftrace_pid_trace; /* Quick disabling of function tracer. */ int function_trace_stop; @@ -153,7 +153,7 @@ static int __register_ftrace_function(struct ftrace_ops *ops) else func = ftrace_list_func; - if (ftrace_pid_trace >= 0) { + if (ftrace_pid_trace) { set_ftrace_pid_function(func); func = ftrace_pid_func; } @@ -209,7 +209,7 @@ static int __unregister_ftrace_function(struct ftrace_ops *ops) if (ftrace_list->next == &ftrace_list_end) { ftrace_func_t func = ftrace_list->func; - if (ftrace_pid_trace >= 0) { + if (ftrace_pid_trace) { set_ftrace_pid_function(func); func = ftrace_pid_func; } @@ -239,7 +239,7 @@ static void ftrace_update_pid_func(void) func = ftrace_trace_function; - if (ftrace_pid_trace >= 0) { + if (ftrace_pid_trace) { set_ftrace_pid_function(func); func = ftrace_pid_func; } else { @@ -1678,18 +1678,40 @@ ftrace_pid_read(struct file *file, char __user *ubuf, char buf[64]; int r; - if (ftrace_pid_trace >= 0) - r = sprintf(buf, "%u\n", ftrace_pid_trace); + if (ftrace_pid_trace) + r = sprintf(buf, "%u\n", pid_nr(ftrace_pid_trace)); else r = sprintf(buf, "no pid\n"); return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); } +static void clear_ftrace_pid_task(struct pid **pid) +{ + struct task_struct *p; + + do_each_pid_task(*pid, PIDTYPE_PID, p) { + clear_tsk_trace_trace(p); + } while_each_pid_task(*pid, PIDTYPE_PID, p); + put_pid(*pid); + + *pid = NULL; +} + +static void set_ftrace_pid_task(struct pid *pid) +{ + struct task_struct *p; + + do_each_pid_task(pid, PIDTYPE_PID, p) { + set_tsk_trace_trace(p); + } while_each_pid_task(pid, PIDTYPE_PID, p); +} + static ssize_t ftrace_pid_write(struct file *filp, const char __user *ubuf, size_t cnt, loff_t *ppos) { + struct pid *pid; char buf[64]; long val; int ret; @@ -1707,40 +1729,30 @@ ftrace_pid_write(struct file *filp, const char __user *ubuf, return ret; mutex_lock(&ftrace_start_lock); - if (ret < 0) { + if (val < 0) { /* disable pid tracing */ - if (ftrace_pid_trace < 0) + if (!ftrace_pid_trace) goto out; - ftrace_pid_trace = -1; + + clear_ftrace_pid_task(&ftrace_pid_trace); } else { - struct task_struct *p; - int found = 0; + pid = find_get_pid(val); - if (ftrace_pid_trace == val) + if (pid == ftrace_pid_trace) { + put_pid(pid); goto out; - - /* - * Find the task that matches this pid. - * TODO: use pid namespaces instead. - */ - rcu_read_lock(); - for_each_process(p) { - if (p->pid == val) { - found = 1; - set_tsk_trace_trace(p); - } else if (test_tsk_trace_trace(p)) - clear_tsk_trace_trace(p); } - rcu_read_unlock(); - if (found) - ftrace_pid_trace = val; - else { - if (ftrace_pid_trace < 0) - goto out; - ftrace_pid_trace = -1; - } + if (ftrace_pid_trace) + clear_ftrace_pid_task(&ftrace_pid_trace); + + if (!pid) + goto out; + + ftrace_pid_trace = pid; + + set_ftrace_pid_task(ftrace_pid_trace); } /* update the function call */ diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 95fff37..8b81b4d 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -541,11 +541,11 @@ print_graph_function(struct trace_iterator *iter) } #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ -extern int ftrace_pid_trace; +extern struct pid *ftrace_pid_trace; static inline int ftrace_trace_task(struct task_struct *task) { - if (ftrace_pid_trace < 0) + if (ftrace_pid_trace) return 1; return test_tsk_trace_trace(task); |