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| author |   Steven Rostedt <srostedt@redhat.com> | 2012-07-20 11:04:44 -0400 |
|---|---|---|
| committer |   Steven Rostedt <rostedt@goodmis.org> | 2012-07-31 10:29:52 -0400 |
| commit | 4740974a6844156c14d741b0080b59d275679a23 (patch) | |
| tree | 7272f577c74a185d9fe037a424d0401e4ec7c126 /kernel/trace/trace_stack.c | |
| parent | ftrace/x86: Remove function_trace_stop check from graph caller (diff) | |
| download | linux-dev-4740974a6844156c14d741b0080b59d275679a23.tar.xz linux-dev-4740974a6844156c14d741b0080b59d275679a23.zip | |
ftrace: Add default recursion protection for function tracing
As more users of the function tracer utility are being added, they do
not always add the necessary recursion protection. To protect from
function recursion due to tracing, if the callback ftrace_ops does not
specifically specify that it protects against recursion (by setting
the FTRACE_OPS_FL_RECURSION_SAFE flag), the list operation will be
called by the mcount trampoline which adds recursion protection.
If the flag is set, then the function will be called directly with no
extra protection.
Note, the list operation is called if more than one function callback
is registered, or if the arch does not support all of the function
tracer features.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/trace_stack.c')
| -rw-r--r-- | kernel/trace/trace_stack.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c index 2fa5328e8893..0c1b165778e5 100644 --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c @@ -137,6 +137,7 @@ stack_trace_call(unsigned long ip, unsigned long parent_ip, static struct ftrace_ops trace_ops __read_mostly = { .func = stack_trace_call, + .flags = FTRACE_OPS_FL_RECURSION_SAFE, }; static ssize_t |