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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7A3C6C433F5 for ; Mon, 28 Mar 2022 17:03:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244132AbiC1RFO (ORCPT ); Mon, 28 Mar 2022 13:05:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41424 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244065AbiC1RFE (ORCPT ); Mon, 28 Mar 2022 13:05:04 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A0CEF1CB0C for ; Mon, 28 Mar 2022 10:03:23 -0700 (PDT) Date: Mon, 28 Mar 2022 19:03:20 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1648487002; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=srXDUoBEUUPdcjFobaF0lZd9YYmN1yFN4+ozvIVJW9Q=; b=Pmt3+lGNfGL4U0YTB/9h9aYv99clc3rYiHA7ZabaYMzkuWJKFFx3ylcw6dOEPiGFOCtrQi DlXL9WUM7LwG44LngFDeryV4XVBXS0+x9yMQ2pvQ9uusbYiNSS1r7XIgVuGrQDFiCkFl1y ZyvbbX9LHUpei8qjczmufT2LlIRQIJ3kpLIWzzhYG1yj8myub0e0aFNA9GLQuE6r1AR0yb 2V84DiMctksoJZCOf9dA7QXm5UHA9b30EGe8vrh0UTYQI2zmD1oJoUKVo2phd99PYCdmNi ghYt2ElrRwAWIaTpqd1iqfAWYizmIiVIqjVaug/+wOC40Yr8r6kJ8xfZSFRq/g== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1648487002; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=srXDUoBEUUPdcjFobaF0lZd9YYmN1yFN4+ozvIVJW9Q=; b=SJa/ZKaR8ZxqMtI21QJW2n2ad3znC9T4KW9AInZr/BVGtIWn58oR30ZuTRv8gjHUeFt/aI +vFojVL6CUdQSODA== From: Sebastian Andrzej Siewior To: andrey.konovalov@linux.dev Cc: Andrew Morton , Andrey Konovalov , Marco Elver , Alexander Potapenko , Dmitry Vyukov , Andrey Ryabinin , kasan-dev@googlegroups.com, linux-mm@kvack.org, Vlastimil Babka , Matthew Wilcox , linux-kernel@vger.kernel.org, Andrey Konovalov Subject: Re: [PATCH] mm, kasan: fix __GFP_BITS_SHIFT definition breaking LOCKDEP Message-ID: References: <462ff52742a1fcc95a69778685737f723ee4dfb3.1648400273.git.andreyknvl@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <462ff52742a1fcc95a69778685737f723ee4dfb3.1648400273.git.andreyknvl@google.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2022-03-27 19:00:23 [+0200], andrey.konovalov@linux.dev wrote: > From: Andrey Konovalov > > KASAN changes that added new GFP flags mistakenly updated __GFP_BITS_SHIFT > as the total number of GFP bits instead of as a shift used to define > __GFP_BITS_MASK. > > This broke LOCKDEP, as __GFP_BITS_MASK now gets the 25th bit enabled > instead of the 28th for __GFP_NOLOCKDEP. > > Update __GFP_BITS_SHIFT to always count KASAN GFP bits. > > In the future, we could handle all combinations of KASAN and LOCKDEP to > occupy as few bits as possible. For now, we have enough GFP bits to be > inefficient in this quick fix. > > Fixes: 9353ffa6e9e9 ("kasan, page_alloc: allow skipping memory init for HW_TAGS") > Fixes: 53ae233c30a6 ("kasan, page_alloc: allow skipping unpoisoning for HW_TAGS") > Fixes: f49d9c5bb15c ("kasan, mm: only define ___GFP_SKIP_KASAN_POISON with HW_TAGS") > Reported-by: Sebastian Andrzej Siewior > Signed-off-by: Andrey Konovalov Tested-by: Sebastian Andrzej Siewior Sebastian