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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 528F5C43331 for ; Sun, 10 Nov 2019 22:01:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 26BF8206C3 for ; Sun, 10 Nov 2019 22:01:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727180AbfKJWBD (ORCPT ); Sun, 10 Nov 2019 17:01:03 -0500 Received: from smtprelay0014.hostedemail.com ([216.40.44.14]:55209 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727080AbfKJWBC (ORCPT ); Sun, 10 Nov 2019 17:01:02 -0500 Received: from filter.hostedemail.com (clb03-v110.bra.tucows.net [216.40.38.60]) by smtprelay01.hostedemail.com (Postfix) with ESMTP id 310B9100E7B40; Sun, 10 Nov 2019 22:01:01 +0000 (UTC) X-Session-Marker: 6A6F6540706572636865732E636F6D X-HE-Tag: river90_25ddd2f9e5c25 X-Filterd-Recvd-Size: 2113 Received: from XPS-9350.home (unknown [47.151.135.224]) (Authenticated sender: joe@perches.com) by omf08.hostedemail.com (Postfix) with ESMTPA; Sun, 10 Nov 2019 22:01:00 +0000 (UTC) Message-ID: <698b03300532f80dfbd30fa35446a33e58ae0c89.camel@perches.com> Subject: Re: [GIT pull] core/urgent for v5.4-rc7 From: Joe Perches To: Thomas Gleixner , Linus Torvalds , Jiri Slaby Cc: linux-kernel@vger.kernel.org, x86@kernel.org Date: Sun, 10 Nov 2019 14:00:44 -0800 In-Reply-To: <157338131323.14789.2179255265964358886.tglx@nanos.tec.linutronix.de> References: <157338131323.14789.2179255265964358886.tglx@nanos.tec.linutronix.de> Content-Type: text/plain; charset="ISO-8859-1" User-Agent: Evolution 3.34.1-2 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 2019-11-10 at 10:21 +0000, Thomas Gleixner wrote: > A small fix for a stacktrace regression. Saving a stacktrace for a foreign > task skipped an extra entry which makes e.g. the output of /proc/$PID/stack > incomplete. [] > ------------------> > Jiri Slaby (1): > stacktrace: Don't skip first entry on noncurrent tasks [] > diff --git 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), trivia: This idiom '!!(logical test)' is odd and redundant. Logical test result is already 0 or 1, no !! is unnecessary. > }; > > 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); > >