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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8DC77C71157 for ; Wed, 18 Jun 2025 17:48:08 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 2FF106B00AC; Wed, 18 Jun 2025 13:48:08 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 2D6B86B00BA; Wed, 18 Jun 2025 13:48:08 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 214346B00C9; Wed, 18 Jun 2025 13:48:08 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id 081ED6B00BA for ; Wed, 18 Jun 2025 13:48:08 -0400 (EDT) Received: from smtpin25.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 8A2D480868 for ; Wed, 18 Jun 2025 17:48:07 +0000 (UTC) X-FDA: 83569255014.25.747E564 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf18.hostedemail.com (Postfix) with ESMTP id 017711C0008 for ; Wed, 18 Jun 2025 17:48:04 +0000 (UTC) Authentication-Results: imf18.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=vMGmelr0; spf=none (imf18.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1750268885; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=ew1dpRymIrpCtOvaZCR24duIHWaEHbEIruCa80ZhE3k=; b=djphvaCxR9yi2W+6tH8H4KLxAZjoVJcIaI8UaHqIrhecAodIbEUbiBmAUYTHoO2wJ1vuaW OBJCg1lnITNkIdrqY6zLZEXxJzDR0fxlrXCJm87+FVO7tGbVdApC7OORxHdZPdCz5jvJoK sUOn6KRpKDCVezY3NoMIYNsWIkDEryU= ARC-Authentication-Results: i=1; imf18.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=vMGmelr0; spf=none (imf18.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1750268885; a=rsa-sha256; cv=none; b=Ipy98M1MiHRyVCVDLFKp7vdwkL27rC/W/P4BhdjTTsY2Z1cYPSRMPYkEjApbMp3BKhzkrG 4x+pDEP0sH0zUxIIwsBO8TA+vHM9v6LWRGQOGUSV5Tlsba9MGOzYCOH9kSVJqgqZ4LhdXo ezwkE5/fcjgE71Ipl+irYuiMauGv3q0= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=ew1dpRymIrpCtOvaZCR24duIHWaEHbEIruCa80ZhE3k=; b=vMGmelr0jg3aw13ho5UqH0BXyX cpSmEtNVjBTeDgcazw/ac3a/CmQoMTBWQBW/yNMwVpuvL/g2P01QhaksiVFUCsCaYpmygDKlRZ6eG t9yvx0LlBQ7Dyo+r9JmcGzki8UTJtO8bFa9MR2ajFVfYwNYQFvaEIkjur6XHyLKqb00Kgm7DALKr8 qJMCuX+stDMyxPjmNYGmvG7r6fFodeQAOIq1s9bvWYbwQC+NwqI0bCvRel4a3jGGyu/KcnTBdb3qm ApN6r7Ulculi8qSCLxyQ175LSrRvYaQTe1Y7VVPrWyP/6wmUn8peqcpgBdzEa8bwWj2sa9TnfnEM9 xuZCEJrg==; Received: from willy by casper.infradead.org with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1uRwtB-00000004Ryp-15ao; Wed, 18 Jun 2025 17:47:57 +0000 Date: Wed, 18 Jun 2025 18:47:57 +0100 From: Matthew Wilcox To: Dan Carpenter Cc: oe-kbuild@lists.linux.dev, Zi Yan , lkp@intel.com, oe-kbuild-all@lists.linux.dev, linux-kernel@vger.kernel.org, Andrew Morton , Linux Memory Management List , Baolin Wang Subject: Re: mm/shmem.c:2223 shmem_split_large_entry() error: uninitialized symbol 'entry_order'. Message-ID: References: <428fa0fe-8960-4566-9054-5bfd967c18c8@suswa.mountain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <428fa0fe-8960-4566-9054-5bfd967c18c8@suswa.mountain> X-Rspamd-Queue-Id: 017711C0008 X-Rspam-User: X-Rspamd-Server: rspam07 X-Stat-Signature: 6eune8qc5ho7rthfm4dozxdcpns54izx X-HE-Tag: 1750268884-240040 X-HE-Meta: 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 Zyx8Kkl3 xgXtRyNAknuTCFd6RyUWqDk2ZqMuKi8b1cYQ6C+vT5xAKTdTUxW4ic1lWlV8HtGLdgfLO+Gs4tm89ainUKDZBVV63iPaSkiCMGz3lufhDRgAyejnJa0ONnR3jooN562TrHg6k47rLap5dMPe9f7Pqc6Q061DpOCjlzgBL0Hs1+/Z+c0UrbToocSmQqoe3kjSflGjLh7dbgHwPVGXIcp6OtBT4ldE08rbn8SG8j0w2D1ViAsBsRuty5ZUI/H+LbBcWsYv8xNOV9YC5F4LcVqA8XRKVhw== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Wed, Jun 18, 2025 at 08:42:17PM +0300, Dan Carpenter wrote: > smatch warnings: > mm/shmem.c:2223 shmem_split_large_entry() error: uninitialized symbol 'entry_order'. ... > 12885cbe88ddf6 Baolin Wang 2024-08-12 2169 if (!xa_is_value(old) || swp_to_radix_entry(swap) != old) { > 12885cbe88ddf6 Baolin Wang 2024-08-12 2170 xas_set_err(&xas, -EEXIST); > 12885cbe88ddf6 Baolin Wang 2024-08-12 2171 goto unlock; > > Imagine we hit this goto on the first iteration That can happen (but if it does, we set -EEXIST in the xa_state). > 12885cbe88ddf6 Baolin Wang 2024-08-12 2213 unlock: > 12885cbe88ddf6 Baolin Wang 2024-08-12 2214 xas_unlock_irq(&xas); > 12885cbe88ddf6 Baolin Wang 2024-08-12 2215 > 12885cbe88ddf6 Baolin Wang 2024-08-12 2216 if (!xas_nomem(&xas, gfp)) > 12885cbe88ddf6 Baolin Wang 2024-08-12 2217 break; > > And we hit this break. That's guaranteed. If there's an errno in the xa_state that isn't -ENOMEM, xas_nomem() will fail. > 12885cbe88ddf6 Baolin Wang 2024-08-12 2218 } > 12885cbe88ddf6 Baolin Wang 2024-08-12 2219 > 12885cbe88ddf6 Baolin Wang 2024-08-12 2220 if (xas_error(&xas)) > 12885cbe88ddf6 Baolin Wang 2024-08-12 2221 return xas_error(&xas); > 12885cbe88ddf6 Baolin Wang 2024-08-12 2222 > d53c78fffe7ad3 Zi Yan 2025-03-14 @2223 return entry_order; but if this does happen, then xas_error() will be true and we'll return -EEXIST here instead of returning entry_order.