From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754529AbcDMQYn (ORCPT ); Wed, 13 Apr 2016 12:24:43 -0400 Received: from foss.arm.com ([217.140.101.70]:36093 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751061AbcDMQYm (ORCPT ); Wed, 13 Apr 2016 12:24:42 -0400 From: James Morse To: linux-kernel@vger.kernel.org Cc: Dmitry Vyukov , Andrew Morton , Alexander Potapenko , James Morse Subject: [PATCH] kcov: Don't trace the code coverage code Date: Wed, 13 Apr 2016 17:22:37 +0100 Message-Id: <1460564557-2817-1-git-send-email-james.morse@arm.com> X-Mailer: git-send-email 2.8.0.rc3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Kcov causes the compiler to add a call to __sanitizer_cov_trace_pc() in every basic block. Ftrace patches in a call to _mcount() to each function it has annotated. Letting these mechanisms annotate each other is a bad thing. Break the loop by adding 'notrace' to __sanitizer_cov_trace_pc() so that ftrace won't try to patch this code. Signed-off-by: James Morse --- This patch lets arm64 with KCOV and STACK_TRACER boot. kernel/kcov.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/kcov.c b/kernel/kcov.c index 3efbee0834a8..78bed7125515 100644 --- a/kernel/kcov.c +++ b/kernel/kcov.c @@ -43,7 +43,7 @@ struct kcov { * Entry point from instrumented code. * This is called once per basic-block/edge. */ -void __sanitizer_cov_trace_pc(void) +void notrace __sanitizer_cov_trace_pc(void) { struct task_struct *t; enum kcov_mode mode; -- 2.8.0.rc3