From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 30A71C432C0 for ; Tue, 3 Dec 2019 22:41:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 038BD20862 for ; Tue, 3 Dec 2019 22:41:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575412877; bh=EaplAfuheF1sBF4x0lD26ZSodyHdeqvGBmEQkvmT834=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=GDHSZjYBBgT3C4q+yKlOyGRpxcRW6IWdv3MEbq9uXKBNGMYaqHWpkjlCrBoxYi9Em zS+PF6M2P+5TxRRLSbvFBCAYbyC8dJJ+oElil7Ai5phNYcLNub7dMPO3uV9LVfMG7L PbF9+0dd4BBinrQHGvwaTOdwun0Heizy6jKm982E= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728515AbfLCWlQ (ORCPT ); Tue, 3 Dec 2019 17:41:16 -0500 Received: from mail.kernel.org ([198.145.29.99]:55544 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727731AbfLCWlN (ORCPT ); Tue, 3 Dec 2019 17:41:13 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 2DC212080A; Tue, 3 Dec 2019 22:41:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575412872; bh=EaplAfuheF1sBF4x0lD26ZSodyHdeqvGBmEQkvmT834=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gSmvNfosgqxixKjFTIsIglyJTlBDnVM6oXOLblal5oM/N1IgbqupWtjdTLky1Wumh T9t07g8SDyGFBtPCDNF9YIhkaYUBBBTtchoiBvWNzZqmOLsqqnGvy8NK4e/2D87U2n nwi6QCQf9VksbzCSdk0yJtMKAHi6d4di3Y3PS8e0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jiri Slaby , Thomas Gleixner , Michal Suchanek , Josh Poimboeuf , Sasha Levin Subject: [PATCH 5.3 050/135] stacktrace: Dont skip first entry on noncurrent tasks Date: Tue, 3 Dec 2019 23:34:50 +0100 Message-Id: <20191203213019.500970064@linuxfoundation.org> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191203213005.828543156@linuxfoundation.org> References: <20191203213005.828543156@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jiri Slaby [ Upstream commit b0c51f158455e31d5024100cf3580fcd88214b0e ] When doing cat /proc//stack, the output is missing the first entry. When the current code walks the stack starting in stack_trace_save_tsk, it skips all scheduler functions (that's OK) plus one more function. But this one function should be skipped only for the 'current' task as it is stack_trace_save_tsk proper. The original code (before the common infrastructure) skipped one function only for the 'current' task -- see save_stack_trace_tsk before 3599fe12a125. So do so also in the new infrastructure now. Fixes: 214d8ca6ee85 ("stacktrace: Provide common infrastructure") Signed-off-by: Jiri Slaby Signed-off-by: Thomas Gleixner Tested-by: Michal Suchanek Acked-by: Josh Poimboeuf Link: https://lkml.kernel.org/r/20191030072545.19462-1-jslaby@suse.cz Signed-off-by: Sasha Levin --- kernel/stacktrace.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/kernel/stacktrace.c b/kernel/stacktrace.c index f5440abb75329..9bbfbdb96ae51 100644 --- a/kernel/stacktrace.c +++ b/kernel/stacktrace.c @@ -141,7 +141,8 @@ unsigned int stack_trace_save_tsk(struct task_struct *tsk, unsigned long *store, struct stacktrace_cookie c = { .store = store, .size = size, - .skip = skipnr + 1, + /* skip this function if they are tracing us */ + .skip = skipnr + !!(current == tsk), }; if (!try_get_task_stack(tsk)) @@ -298,7 +299,8 @@ unsigned int stack_trace_save_tsk(struct task_struct *task, struct stack_trace trace = { .entries = store, .max_entries = size, - .skip = skipnr + 1, + /* skip this function if they are tracing us */ + .skip = skipnr + !!(current == task), }; save_stack_trace_tsk(task, &trace); -- 2.20.1