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| author | Frederic Weisbecker <fweisbec@gmail.com> | 2008-11-16 05:59:52 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-11-16 07:55:59 +0100 |
| commit | 072b40a15616fe6bea68466e6bffcfcbf5c8f26f (patch) | |
| tree | 0efdcf29a712e8f381a56e57f6a89cb7ca7be901 | |
| parent | c91add5fa68ea9b1f2923b3788c5dae0e60e1f6b (diff) | |
| download | blackbird-op-linux-072b40a15616fe6bea68466e6bffcfcbf5c8f26f.tar.gz blackbird-op-linux-072b40a15616fe6bea68466e6bffcfcbf5c8f26f.zip | |
tracing/branch-tracer: fix a trace recursion on branch tracer
Impact: fix crash when enabling the branch-tracer
When the branch tracer inserts an event through
probe_likely_condition(), it calls local_irq_save() and then results
in a trace recursion.
local_irq_save() -> trace_hardirqs_off() -> trace_hardirqs_off_caller()
-> unlikely()
The trace_branch.c file is protected by DISABLE_BRANCH_PROFILING but
that doesn't prevent from external call to functions that use
unlikely().
My box crashed each time I tried to set this tracer (sudden and hard
reboot).
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
| -rw-r--r-- | kernel/trace/trace_branch.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/trace/trace_branch.c b/kernel/trace/trace_branch.c index 85265553918f..2511e32572ca 100644 --- a/kernel/trace/trace_branch.c +++ b/kernel/trace/trace_branch.c @@ -41,7 +41,7 @@ probe_likely_condition(struct ftrace_branch_data *f, int val, int expect) if (unlikely(!tr)) return; - local_irq_save(flags); + raw_local_irq_save(flags); cpu = raw_smp_processor_id(); if (atomic_inc_return(&tr->data[cpu]->disabled) != 1) goto out; @@ -73,7 +73,7 @@ probe_likely_condition(struct ftrace_branch_data *f, int val, int expect) out: atomic_dec(&tr->data[cpu]->disabled); - local_irq_restore(flags); + raw_local_irq_restore(flags); } static inline |
