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| author | Frederic Weisbecker <fweisbec@gmail.com> | 2008-11-15 02:37:44 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-11-16 07:57:37 +0100 |
| commit | b01c746617da5e260803eb10ed64ca043e9a1241 (patch) | |
| tree | 7b835904f337778b604048169dd064a87149aa99 /arch/x86 | |
| parent | 985809608f758a8d3ddda4ce5a53ed0e57fb9e1b (diff) | |
| download | blackbird-op-linux-b01c746617da5e260803eb10ed64ca043e9a1241.tar.gz blackbird-op-linux-b01c746617da5e260803eb10ed64ca043e9a1241.zip | |
tracing/function-return-tracer: add a barrier to ensure return stack index is incremented in memory
Impact: fix possible race condition in ftrace function return tracer
This fixes a possible race condition if index incrementation
is not immediately flushed in memory.
Thanks for Andi Kleen and Steven Rostedt for pointing out this issue
and give me this solution.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/kernel/ftrace.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index 762222ad1387..d98b5a8ecf4c 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -56,6 +56,7 @@ static int push_return_trace(unsigned long ret, unsigned long long time, return -EBUSY; index = ++ti->curr_ret_stack; + barrier(); ti->ret_stack[index].ret = ret; ti->ret_stack[index].func = func; ti->ret_stack[index].calltime = time; |
