[26/39] profile: fix stats and data leakage

[Greg KH <gregkh@suse.de>]

2.6.33-stable review patch.  If anyone has any objections, please let us know.

------------------
From: Hugh Dickins <hughd@google.com>

commit 16a2164bb03612efe79a76c73da6da44445b9287 upstream.

If the kernel is large or the profiling step small, /proc/profile
leaks data and readprofile shows silly stats, until readprofile -r
has reset the buffer: clear the prof_buffer when it is vmalloc()ed.

Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
 kernel/profile.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/kernel/profile.c
+++ b/kernel/profile.c
@@ -127,8 +127,10 @@ int __ref profile_init(void)
 		return 0;
 
 	prof_buffer = vmalloc(buffer_bytes);
-	if (prof_buffer)
+	if (prof_buffer) {
+		memset(prof_buffer, 0, buffer_bytes);
 		return 0;
+	}
 
 	free_cpumask_var(prof_cpu_mask);
 	return -ENOMEM;