Merge tag 'trace-3.8-rc4-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
d26d4525 · Linus Torvalds <[email protected]> · 2013-01-22 10:30:49 -08:00
Pull ftrace fix from Steven Rostedt:
"Kprobes now uses the function tracer if it can. That is, if a probe
is placed on a function mcount/nop location, and the arch supports it,
instead of adding a breakpoint, kprobes will register a function
callback as that is much more efficient.
The function tracer requires to update modules before they run, and
uses the module notifier to do so. But if something else in the
module notifiers registers a kprobe at one of these locations, before
ftrace can get to it, then the system could fail.
The function tracer must be initialized early, otherwise module
notifiers that probe will only work by chance."
* tag 'trace-3.8-rc4-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
ftrace: Be first to run code modification on modules
- Commit
- d26d45253b78ec0a67003eea25bd08fceaa5b78c
- Parents
- 0944c0a0 · c1bf08ac
Merge commit. Changes below are compared with the first parent: 0944c0a0.
Changes
1 files changed · +1 −1
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 3ffe4c5..41473b4 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -3998,7 +3998,7 @@ static int ftrace_module_notify(struct notifier_block *self,
struct notifier_block ftrace_module_nb = {
.notifier_call = ftrace_module_notify,
- .priority = 0,
+ .priority = INT_MAX, /* Run before anything that can use kprobes */
};
extern unsigned long __start_mcount_loc[];