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author | Soeren Sandmann <sandmann@daimi.au.dk> | 2008-05-12 05:28:50 +0200 |
---|---|---|
committer | Thomas Gleixner <tglx@linutronix.de> | 2008-05-23 23:59:12 +0200 |
commit | cf3271a73b612a03da00681ecd9bfefab37c74c9 (patch) | |
tree | fa4423bf262449aedea54a1145e6b10deefc3bf7 /kernel/trace/trace_sysprof.c | |
parent | 8a9e94c1fbfdac45a3b6811b880777c4116aa309 (diff) | |
download | linux-cf3271a73b612a03da00681ecd9bfefab37c74c9.tar.gz linux-cf3271a73b612a03da00681ecd9bfefab37c74c9.tar.bz2 linux-cf3271a73b612a03da00681ecd9bfefab37c74c9.zip |
ftrace/sysprof: don't trace the user stack if we are a kernel thread.
Check that current->mm is non-NULL before attempting to trace the user
stack.
Also take depth of the kernel stack into account when comparing
against sample_max_depth.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel/trace/trace_sysprof.c')
-rw-r--r-- | kernel/trace/trace_sysprof.c | 50 |
1 files changed, 29 insertions, 21 deletions
diff --git a/kernel/trace/trace_sysprof.c b/kernel/trace/trace_sysprof.c index fe23d6dba7f1..2301e1e7c606 100644 --- a/kernel/trace/trace_sysprof.c +++ b/kernel/trace/trace_sysprof.c @@ -95,13 +95,12 @@ const static struct stacktrace_ops backtrace_ops = { .address = backtrace_address, }; -static struct pt_regs * +static int trace_kernel(struct pt_regs *regs, struct trace_array *tr, struct trace_array_cpu *data) { struct backtrace_info info; unsigned long bp; - char *user_stack; char *stack; info.tr = tr; @@ -119,10 +118,7 @@ trace_kernel(struct pt_regs *regs, struct trace_array *tr, dump_trace(NULL, regs, (void *)stack, bp, &backtrace_ops, &info); - /* Now trace the user stack */ - user_stack = ((char *)current->thread.sp0 - sizeof(struct pt_regs)); - - return (struct pt_regs *)user_stack; + return info.pos; } static void timer_notify(struct pt_regs *regs, int cpu) @@ -150,32 +146,44 @@ static void timer_notify(struct pt_regs *regs, int cpu) __trace_special(tr, data, 0, 0, current->pid); if (!is_user) - regs = trace_kernel(regs, tr, data); + i = trace_kernel(regs, tr, data); + else + i = 0; - fp = (void __user *)regs->bp; + /* + * Trace user stack if we are not a kernel thread + */ + if (current->mm && i < sample_max_depth) { + regs = (struct pt_regs *)current->thread.sp0 - 1; - __trace_special(tr, data, 2, regs->ip, 0); + fp = (void __user *)regs->bp; - for (i = 0; i < sample_max_depth; i++) { - frame.next_fp = 0; - frame.return_address = 0; - if (!copy_stack_frame(fp, &frame)) - break; - if ((unsigned long)fp < regs->sp) - break; + __trace_special(tr, data, 2, regs->ip, 0); - __trace_special(tr, data, 2, frame.return_address, - (unsigned long)fp); - fp = frame.next_fp; - } + while (i < sample_max_depth) { + frame.next_fp = 0; + frame.return_address = 0; + if (!copy_stack_frame(fp, &frame)) + break; + if ((unsigned long)fp < regs->sp) + break; - __trace_special(tr, data, 3, current->pid, i); + __trace_special(tr, data, 2, frame.return_address, + (unsigned long)fp); + fp = frame.next_fp; + + i++; + } + + } /* * Special trace entry if we overflow the max depth: */ if (i == sample_max_depth) __trace_special(tr, data, -1, -1, -1); + + __trace_special(tr, data, 3, current->pid, i); } static enum hrtimer_restart stack_trace_timer_fn(struct hrtimer *hrtimer) |