From: Hugh Dickins <hughd@google.com>
Date: Sat, 15 May 2010 02:44:10 +0000 (-0700)
Subject: profile: fix stats and data leakage
X-Git-Tag: v2.6.34~10
X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?p=pandora-kernel.git;a=commitdiff_plain;h=16a2164bb03612efe79a76c73da6da44445b9287

profile: fix stats and data leakage

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>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/kernel/profile.c b/kernel/profile.c
index a55d3a367ae8..dfadc5b729f1 100644
--- 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;