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 2BA9FC4167B for ; Fri, 8 Dec 2023 13:56:36 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 756956B0075; Fri, 8 Dec 2023 08:56:35 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 6DEFB6B0082; Fri, 8 Dec 2023 08:56:35 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5A6B96B0083; Fri, 8 Dec 2023 08:56:35 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 461DC6B0075 for ; Fri, 8 Dec 2023 08:56:35 -0500 (EST) Received: from smtpin11.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 0FFD4C020C for ; Fri, 8 Dec 2023 13:56:35 +0000 (UTC) X-FDA: 81543801150.11.C10FF3C Received: from mail-qv1-f43.google.com (mail-qv1-f43.google.com [209.85.219.43]) by imf13.hostedemail.com (Postfix) with ESMTP id 4F29F20023 for ; Fri, 8 Dec 2023 13:56:33 +0000 (UTC) Authentication-Results: imf13.hostedemail.com; dkim=pass header.d=google.com header.s=20230601 header.b=MKcwWVqA; spf=pass (imf13.hostedemail.com: domain of glider@google.com designates 209.85.219.43 as permitted sender) smtp.mailfrom=glider@google.com; dmarc=pass (policy=reject) header.from=google.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1702043793; 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:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=SlUqBCSJE7b+NOWHxQNrRwEhp2gTAvY03mAPrdADOdo=; b=pp5xV2d8D10RQUTqm7yrWVCtPXv5evl/84eg01rxVBXcoSLkSQdDEC2sDTJhpwkSmoxye3 JyXS2bKfs8WzvLPQbgUUTIbcPyEiUUjhuB8Tx5kWIrRkjnViaUkR1ihdTCMjIM/FNwCGNc 1ypKp/rjIBeZGSG2lO8R7qN3GmsM3x8= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1702043793; a=rsa-sha256; cv=none; b=tYUU72jodSOa+BzTsKEDVj7ges39cHOh8hdn4edaiGZpGxl4plRH9gXB3+72qGSM74WDOz YwsqNf/AQgjizlYy6oOn1j0rgRICHhJR4RnYRzhTWeLH+2VSRutON0V1kRitFJrbnnUDxK 82cTk12Tl7ATXtJamoScG2tiJHQyGTQ= ARC-Authentication-Results: i=1; imf13.hostedemail.com; dkim=pass header.d=google.com header.s=20230601 header.b=MKcwWVqA; spf=pass (imf13.hostedemail.com: domain of glider@google.com designates 209.85.219.43 as permitted sender) smtp.mailfrom=glider@google.com; dmarc=pass (policy=reject) header.from=google.com Received: by mail-qv1-f43.google.com with SMTP id 6a1803df08f44-67a894ccb4eso11808736d6.3 for ; Fri, 08 Dec 2023 05:56:33 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1702043792; x=1702648592; darn=kvack.org; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=SlUqBCSJE7b+NOWHxQNrRwEhp2gTAvY03mAPrdADOdo=; b=MKcwWVqAQ0RtaLiPDRBEozSrOEBPfSNSTF9rGbuUeMah6WeaVF8St0tkgMYFcoFd3I 3Rv1+Ppjt6i+r5kgc6m8TtaRUqU1kWqIFLNdCW7cJaAEj42v+Psdv4WOZJBTra/qbEe8 VPPZQGM0hP/elUOCZgRJ1MwC20Np0ayTQobLWOFz3/vQc+Epx63eKR8LbapJBLjDLzkR fRlUW0XYQY2s2XYjvKJHzhREDOSIqUnaT3AkK0rZuPb/ucuTPPKXVRhpQQfzO4Ay2gcV yaq864bw+h209ynI4ULVLttO2gjpmUPE+4vY+p8J6SGhMzme+iWWdBQnx08obf2YEyN1 aWaw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1702043792; x=1702648592; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=SlUqBCSJE7b+NOWHxQNrRwEhp2gTAvY03mAPrdADOdo=; b=TfxsF8m+SltL6JSpN5JmV7RtCgpbuFDpCiePtwQyW87DW59xOMUK0OiAASW9XXUj/M 76oz5clt2RDyOUbH1eVcbxlwj7YQvR2uVc2UOS1mB5YvhKJV3e8ZiNdYAd7s6LnKNi5Y k3fZAVgV6wDfWEbmjA5i7AA0MTLXcminB98DNmQl2Fjru+ywGaDKjBIKRz1IT/EWDdeR XqIcki2HGDiUxt+14/Ljxzi/4t0QHIyKjaoehlFzY/4qyX13RdHD9D5i0lfCCPGOkwaW GiwE8FTbbdBXdxN9gl9X/A6fdYXqqqji5oh95yY+XUJy+Id0nuNu8N46gq3Wl8/8Tan0 UBjA== X-Gm-Message-State: AOJu0YxSXd5nVEMOKFoMSYMjWz8dY/t4ME0mukwiDPZB4j6yOP5jr53T iEA+93jMn58rFmJOcZ3UpCbeGp1RzWZXlINc9+Hr8w== X-Google-Smtp-Source: AGHT+IH23iVUpBsOBONYMPHwppBBTzpfL3Q8/bvfC4kzRpEJUfOAA07YjvKi0Z4sAx0eXzRBOWPNA1eAjy4CZz3bJdM= X-Received: by 2002:a05:6214:5802:b0:67a:a951:7fc2 with SMTP id mk2-20020a056214580200b0067aa9517fc2mr4258051qvb.119.1702043792410; Fri, 08 Dec 2023 05:56:32 -0800 (PST) MIME-Version: 1.0 References: <20231121220155.1217090-1-iii@linux.ibm.com> <20231121220155.1217090-18-iii@linux.ibm.com> In-Reply-To: From: Alexander Potapenko Date: Fri, 8 Dec 2023 14:55:56 +0100 Message-ID: Subject: Re: [PATCH v2 17/33] mm: kfence: Disable KMSAN when checking the canary To: Ilya Leoshkevich Cc: Alexander Gordeev , Andrew Morton , Christoph Lameter , David Rientjes , Heiko Carstens , Joonsoo Kim , Marco Elver , Masami Hiramatsu , Pekka Enberg , Steven Rostedt , Vasily Gorbik , Vlastimil Babka , Christian Borntraeger , Dmitry Vyukov , Hyeonggon Yoo <42.hyeyoo@gmail.com>, kasan-dev@googlegroups.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-s390@vger.kernel.org, linux-trace-kernel@vger.kernel.org, Mark Rutland , Roman Gushchin , Sven Schnelle Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspamd-Queue-Id: 4F29F20023 X-Rspam-User: X-Rspamd-Server: rspam11 X-Stat-Signature: hm81g8ix6zixta8d91k1h9ebrzpsndf9 X-HE-Tag: 1702043793-35322 X-HE-Meta: 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 6Vck+oY3 mZA0/T4pERQbVf3OKpLy/YgdXkiagZmEcUEWkyqRGCJ03digntCnrKApLS/MQ5taBri2z/5xyKDIsV44101fU2exI3Q2Abk1YMC2pAq6ar9Us+KVE6lYdNJz0C7wPHOxN2i1q6B4dDjnkPKzo25omWreekLJLG0Atqm+54bYfpgSAR2ms9Xsez3urQjPNBq9oTKlWDCqYhZgg4PdhyVsodcEVMHWkmxQJHrq1RrcPlZuR38o4f5YVnoTsBZl+W+ny7y8XdUiPGD0LcrxBgp9U2JMgsOvMjzQcXK88+kebmCaxmIn1S8u/j0mluOsAgzrymXpWwdHw0NaJmY+lc82dePAuMk/h34xgW5Ps X-Bogosity: Ham, tests=bogofilter, spamicity=0.162606, 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 Fri, Dec 8, 2023 at 1:53=E2=80=AFPM Alexander Potapenko wrote: > > On Tue, Nov 21, 2023 at 11:02=E2=80=AFPM Ilya Leoshkevich wrote: > > > > KMSAN warns about check_canary() accessing the canary. > > > > The reason is that, even though set_canary() is properly instrumented > > and sets shadow, slub explicitly poisons the canary's address range > > afterwards. > > > > Unpoisoning the canary is not the right thing to do: only > > check_canary() is supposed to ever touch it. Instead, disable KMSAN > > checks around canary read accesses. > > > > Signed-off-by: Ilya Leoshkevich > Reviewed-by: Alexander Potapenko and even Tested-by: Alexander Potapenko