From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S941523AbcIZPQa (ORCPT ); Mon, 26 Sep 2016 11:16:30 -0400 Received: from foss.arm.com ([217.140.101.70]:34132 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S941496AbcIZPQ1 (ORCPT ); Mon, 26 Sep 2016 11:16:27 -0400 From: Mark Rutland To: linux-kernel@vger.kernel.org Cc: Mark Rutland , Greg Kroah-Hartman , Ingo Molnar , Jiri Slaby , Josh Poimboeuf Subject: [PATCH 2/3] drivers/tty: Explicitly pass current to show_stack Date: Mon, 26 Sep 2016 16:16:18 +0100 Message-Id: <1474902979-18436-3-git-send-email-mark.rutland@arm.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1474902979-18436-1-git-send-email-mark.rutland@arm.com> References: <1474902979-18436-1-git-send-email-mark.rutland@arm.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org As noted in commit: 81539169f283329f ("x86/dumpstack: Remove NULL task pointer convention") ... having a NULL task parameter imply current leads to subtle bugs in stack walking code (so far seen on both 86 and arm64), makes callsites harder to read, and is unnecessary as all callers have access to current. As a step towards removing the problematic NULL-implies-current idiom entirely, have the sysrq code explicitly pass current to show_stack. Signed-off-by: Mark Rutland Cc: Greg Kroah-Hartman Cc: Ingo Molnar Cc: Jiri Slaby Cc: Josh Poimboeuf Cc: linux-kernel@vger.kernel.org --- drivers/tty/sysrq.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/tty/sysrq.c b/drivers/tty/sysrq.c index 52bbd27..5b1e0ed 100644 --- a/drivers/tty/sysrq.c +++ b/drivers/tty/sysrq.c @@ -224,7 +224,7 @@ static void showacpu(void *dummy) spin_lock_irqsave(&show_lock, flags); pr_info("CPU%d:\n", smp_processor_id()); - show_stack(NULL, NULL); + show_stack(current, NULL); spin_unlock_irqrestore(&show_lock, flags); } -- 2.7.4