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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 874EBC433DF for ; Thu, 9 Jul 2020 14:36:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 645B6207FF for ; Thu, 9 Jul 2020 14:36:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1594305392; bh=ICGlWFp9oftqMqwcCIzBqthg+wZlKlhq+++ODcMFf9U=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:List-ID: From; b=tpMxv2rs7A1uZJUnXbj/yo5YUV7WYTQfG14L00UDUeXO3MCvcmWVYEKuNl5ol3V6I 56K7DWFv16K8lg0+C/uM8+TKyUHaX1A5tL30gu5f72yGaSWX07XAMYyHqDpXIwS78y r9CbqABICtYuuEBZ/uunwqxlthq5u6Zf4eg+/zHg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727856AbgGIOgb (ORCPT ); Thu, 9 Jul 2020 10:36:31 -0400 Received: from mail.kernel.org ([198.145.29.99]:45832 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726410AbgGIOga (ORCPT ); Thu, 9 Jul 2020 10:36:30 -0400 Received: from paulmck-ThinkPad-P72.home (50-39-111-31.bvtn.or.frontiernet.net [50.39.111.31]) (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 7276A2073A; Thu, 9 Jul 2020 14:36:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1594305390; bh=ICGlWFp9oftqMqwcCIzBqthg+wZlKlhq+++ODcMFf9U=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:From; b=PLhS8zQ6yuuyiPOemZn9nzEARXmDfH0cui/vCHHUbCt6oAMMDDGLqM8r042TdbrRV f6KzlyJNdje4zlHVhNNieW4DM+RC0StPgLhVF2j5Ruv42o0NZf1RISQa8qrpBThACT BVB852+PMhZZnSfqajnZYwu6hTeZ5D0v7qkBT0U8= Received: by paulmck-ThinkPad-P72.home (Postfix, from userid 1000) id 5C1993522B7F; Thu, 9 Jul 2020 07:36:30 -0700 (PDT) Date: Thu, 9 Jul 2020 07:36:30 -0700 From: "Paul E. McKenney" To: Sebastian Andrzej Siewior Cc: Peter Zijlstra , Dan Carpenter , Ingo Molnar , Thomas Gleixner , Kaitao Cheng , linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: Re: [PATCH] kernel/smp: Fix an off by one in csd_lock_wait_toolong() Message-ID: <20200709143630.GY9247@paulmck-ThinkPad-P72> Reply-To: paulmck@kernel.org References: <20200709104818.GC20875@mwanda> <20200709105906.GR597537@hirez.programming.kicks-ass.net> <20200709114900.b475kfqz3447zgfg@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200709114900.b475kfqz3447zgfg@linutronix.de> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jul 09, 2020 at 01:49:00PM +0200, Sebastian Andrzej Siewior wrote: > On 2020-07-09 12:59:06 [+0200], Peter Zijlstra wrote: > > On Thu, Jul 09, 2020 at 01:48:18PM +0300, Dan Carpenter wrote: > > > The __per_cpu_offset[] array has "nr_cpu_ids" elements so change the > > > > >= to prevent a read one element beyond the end of the array. > > > > > > Fixes: 0504bc41a62c ("kernel/smp: Provide CSD lock timeout diagnostics") > > > > I don't have a copy of that patch in my inbox, even though it says Cc: > > me. > > > > Paul, where do you expect that patch to go? The version I see from my > > next tree needs a _lot_ of work. > > There is also > > https://lkml.kernel.org/r/20200705082603.GX3874@shao2-debian > https://lkml.kernel.org/r/00000000000042f21905a991ecea@google.com > > it might be the same thing. Same commit, different bug, but the fix should be in -next by now. For these two reports, the problem was that I had debug-recording code on the wrong side of a csd_unlock(). Thanx, Paul