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authorSteven Rostedt <srostedt@redhat.com>2012-07-20 11:04:44 -0400
committerSteven Rostedt <rostedt@goodmis.org>2012-07-31 10:29:52 -0400
commit4740974a6844156c14d741b0080b59d275679a23 (patch)
tree7272f577c74a185d9fe037a424d0401e4ec7c126 /kernel/trace/trace_stack.c
parent5767cfeaa9ec7b67c802143394f3ad9f8b174eb8 (diff)
downloadop-kernel-dev-4740974a6844156c14d741b0080b59d275679a23.zip
op-kernel-dev-4740974a6844156c14d741b0080b59d275679a23.tar.gz
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.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
index 2fa5328..0c1b1657 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
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