linux-kernel - [PATCH] kcov: disable tracing and branch profiling in kcov

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <1461234772-31832-1-git-send-email-aryabinin@virtuozzo.com>
Date:	Thu, 21 Apr 2016 13:32:52 +0300
From:	Andrey Ryabinin <aryabinin@...tuozzo.com>
To:	Dmitry Vyukov <dvyukov@...gle.com>,
	Andrew Morton <akpm@...ux-foundation.org>
CC:	<linux-kernel@...r.kernel.org>, <syzkaller@...glegroups.com>,
	Andrey Ryabinin <aryabinin@...tuozzo.com>
Subject: [PATCH] kcov: disable tracing and branch profiling in kcov

Tracing of __sanitizer_cov_trace_pc() causes unbound recursion and crash,
because __sanitizer_cov_trace_pc() is also called from tracer code.
For the same reason we need to disable profiling of 'if' branches.

Signed-off-by: Andrey Ryabinin <aryabinin@...tuozzo.com>
---
 kernel/kcov.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/kcov.c b/kernel/kcov.c
index 3efbee0..7919253 100644
--- a/kernel/kcov.c
+++ b/kernel/kcov.c
@@ -1,5 +1,6 @@
 #define pr_fmt(fmt) "kcov: " fmt
 
+#define DISABLE_BRANCH_PROFILING
 #include <linux/compiler.h>
 #include <linux/types.h>
 #include <linux/file.h>
@@ -43,7 +44,7 @@ struct kcov {
  * Entry point from instrumented code.
  * This is called once per basic-block/edge.
  */
-void __sanitizer_cov_trace_pc(void)
+notrace void __sanitizer_cov_trace_pc(void)
 {
 	struct task_struct *t;
 	enum kcov_mode mode;
-- 
2.7.3