[PATCH][GIT PULL] tracing: Fix double free when function profileinit failed

[Steven Rostedt]

Linus,

Namhyung Kim fixed a long standing bug that can cause a kernel panic.
If the function profiler fails to allocate memory for everything,
it will do a double free on the same pointer which can cause a panic.

Please pull the latest trace-fixes-3.9-rc-v2 tree, which can be found at:

  git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git
trace-fixes-3.9-rc-v2

Head SHA1: 19d9c3b1c660a157c6c8b352793497cc67f7321e


Namhyung Kim (1):
      tracing: Fix double free when function profile init failed

----
 kernel/trace/ftrace.c |    1 -
 1 file changed, 1 deletion(-)
---------------------------
commit 83e03b3fe4daffdebbb42151d5410d730ae50bd1
Author: Namhyung Kim <namhyung.kim@xxxxxxx>
Date:   Mon Apr 1 21:46:23 2013 +0900

    tracing: Fix double free when function profile init failed
    
    On the failure path, stat->start and stat->pages will refer same page.
    So it'll attempt to free the same page again and get kernel panic.
    
    Link: http://lkml.kernel.org/r/1364820385-32027-1-git-send-email-namhyung@xxxxxxxxxx
    
    Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
    Cc: Namhyung Kim <namhyung.kim@xxxxxxx>
    Cc: stable@xxxxxxxxxxxxxxx
    Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
    Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 7e89710..926ebfb 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -694,7 +694,6 @@ int ftrace_profile_pages_init(struct ftrace_profile_stat *stat)
 		free_page(tmp);
 	}
 
-	free_page((unsigned long)stat->pages);
 	stat->pages = NULL;
 	stat->start = NULL;
 


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