From: Peter Zijlstra <peterz@infradead.org>
Date: Wed, 24 May 2017 01:53:57 +0000 (-0400)
Subject: kasan: respect /proc/sys/kernel/traceoff_on_warning
X-Git-Tag: release-20171130_firefly~4^2~100^2~1^2~3^2~28
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=55d0f89a1a0cc6a38a078d69f6a1b1c294aa039e;p=firefly-linux-kernel-4.4.55.git

kasan: respect /proc/sys/kernel/traceoff_on_warning


[ Upstream commit 4f40c6e5627ea73b4e7c615c59631f38cc880885 ]

After much waiting I finally reproduced a KASAN issue, only to find my
trace-buffer empty of useful information because it got spooled out :/

Make kasan_report honour the /proc/sys/kernel/traceoff_on_warning
interface.

Link: http://lkml.kernel.org/r/20170125164106.3514-1-aryabinin@virtuozzo.com
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Acked-by: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index 12f222d0224b..b4e31f78ae69 100644
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -13,6 +13,7 @@
  *
  */
 
+#include <linux/ftrace.h>
 #include <linux/kernel.h>
 #include <linux/mm.h>
 #include <linux/printk.h>
@@ -251,6 +252,8 @@ void kasan_report(unsigned long addr, size_t size,
 	if (likely(!kasan_report_enabled()))
 		return;
 
+	disable_trace_on_warning();
+
 	info.access_addr = (void *)addr;
 	info.access_size = size;
 	info.is_write = is_write;