From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-244123.protonmail.ch (mail-244123.protonmail.ch [109.224.244.123]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C777434A3C4; Tue, 10 Mar 2026 19:18:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=109.224.244.123 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773170282; cv=none; b=I0QCu4uc/smpYpfC2Nxm7V0N9uPJ2GwjcslmfP9R4KVAJMuwanxJtjjaXNA6VK4+Um7kP9cB2q8XxsRuD7gqubCPePz7X6Ro37D/Wr4Tq0lfU1GFB4IYZISdrGn7qJrpryGXaMY7kYnOMUBkaSzUPIxNuMoprTKeU5pwjWpsJ3Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773170282; c=relaxed/simple; bh=yNkjvj8zK3UszVO/pQmPPu8PEirskW7YGxcg6RWvrOA=; h=Date:To:From:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=ms4eR5YGALMf0XFAUavJGGfHMQYHKI1T8imNNYwyDDlZV79K6TrVz7CV7/KSXBfWF5QTabU8GK4JJK1EzDpybv1NM4xriSJoIf98nFcQqLNSFtIDGmbUF5amAtqGTvXM/sLsw9IcYD2DIDUydTINBTCqUzN1+1ytW8dUTyu3LBg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=pm.me; spf=pass smtp.mailfrom=pm.me; dkim=pass (2048-bit key) header.d=pm.me header.i=@pm.me header.b=rR9gSYkh; arc=none smtp.client-ip=109.224.244.123 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=pm.me Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=pm.me Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=pm.me header.i=@pm.me header.b="rR9gSYkh" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=pm.me; s=protonmail3; t=1773170277; x=1773429477; bh=qoHZk/OhrSl6MrxG5Mj/wzOQ+Ag6/K1R4s+ErDzpvw0=; h=Date:To:From:Cc:Subject:Message-ID:In-Reply-To:References: Feedback-ID:From:To:Cc:Date:Subject:Reply-To:Feedback-ID: Message-ID:BIMI-Selector; b=rR9gSYkhvunRslGRTcO93zUtjG4S9QPohyc7ONkvqctlqRe5PAr6eHvbGcQDs36n3 33yQN5T+ps4YqoZEpt+gLyhdwBysz/a2OO5acn6s5y8CxSR9RWbUEH0PIVT6p2UtCC +uztI4Plu+Gmk2sFw6yDf1p441e0Y4cmuh6BD8HOGwl+MQRtA42Sm5SodKs90+7Td2 wlE34NSb2zzCAQpxCfImaeT7NnWInHxaoALO26ADLN7txCDcMhSVsLhxaqpIcUfY1l 2ik5c5wMsrTJTnUVu9RSRaIDQtui9rXEXNSCN8Gl9GupewNhLmIv1OHtkTl1zTwqU0 2OvHHg0vin3Mw== Date: Tue, 10 Mar 2026 19:17:43 +0000 To: Andrew Morton From: Maciej Wieczor-Retman Cc: urezki@gmail.com, ryan.roberts@arm.com, kevin.brodsky@arm.com, samuel.holland@sifive.com, dave.hansen@linux.intel.com, jeremy.linton@arm.com, peterz@infradead.org, weixugc@google.com, ljs@kernel.org, ryabinin.a.a@gmail.com, rppt@kernel.org, bp@alien8.de, luto@kernel.org, jan.kiszka@siemens.com, mingo@redhat.com, david@kernel.org, mhocko@suse.com, andreas@gaisler.com, kas@kernel.org, Liam.Howlett@oracle.com, morbo@google.com, thuth@redhat.com, catalin.marinas@arm.com, ankur.a.arora@oracle.com, kbingham@kernel.org, nick.desaulniers+lkml@gmail.com, andreyknvl@gmail.com, dvyukov@google.com, corbet@lwn.net, leitao@debian.org, hpa@zytor.com, tglx@kernel.org, yuanchu@google.com, ardb@kernel.org, vincenzo.frascino@arm.com, tabba@google.com, joey.gouly@arm.com, nsc@kernel.org, will@kernel.org, yeoreum.yun@arm.com, nathan@kernel.org, maciej.wieczor-retman@intel.com, skhan@linuxfoundation.org, axelrasmussen@google.com, osandov@fb.com, surenb@google.com, justinstitt@google.com, kees@kernel.org, vbabka@kernel.org, hsj0512@snu.ac.kr, trintaeoitogc@gmail.com, jackmanb@google.com, maz@kernel.org, glider@google.com, linux-doc@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, workflows@vger.kernel.org, llvm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kbuild@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH v11 00/15] kasan: x86: arm64: KASAN tag-based mode for x86 Message-ID: In-Reply-To: <20260310112421.8ceb7415e14b49cbd86db715@linux-foundation.org> References: <20260310112421.8ceb7415e14b49cbd86db715@linux-foundation.org> Feedback-ID: 164464600:user:proton X-Pm-Message-ID: 0e6fddfcfa9693d70ed9e03b42a5ca69edab13d7 Precedence: bulk X-Mailing-List: workflows@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On 2026-03-10 at 11:24:21 -0700, Andrew Morton wrote: >On Tue, 10 Mar 2026 17:51:19 +0000 Maciej Wieczor-Retman wrote: > >> >> [1] Currently inline mode doesn't work on x86 due to things missing in >> the compiler. I have written a patch for clang that seems to fix the >> inline mode and I was able to boot and check that all patches regarding >> the inline mode work as expected. My hope is to post the patch to LLVM >> once this series is completed, and then make inline mode available in >> the kernel config. >> >> [2] While I was able to boot the inline tag-based kernel with my >> compiler changes in a simulated environment, due to toolchain >> difficulties I couldn't get it to boot on the machine I had access to. >> Also boot time results from the simulation seem too good to be true, and >> they're much too worse for the generic case to be believable. Therefore >> I'm posting only results from the physical server platform. >> >> =3D=3D=3D=3D=3D=3D=3D Compilation >> Clang was used to compile the series (make LLVM=3D1) since gcc doesn't >> seem to have support for KASAN tag-based compiler instrumentation on >> x86. Patchset does seem to compile with gcc without an issue but doesn't >> boot afterwards. > >So LLVM works partially and gcc doesn't work at all? The non-working options are disabled in Kconfig so right now only outline K= ASAN with LLVM works fully. >Do we know which compiler people are using? Google tells me that >Android, ChromeOS, and OpenMandriva use LLVM. That's pretty thin. I don't have any numbers on this matter, from working on this I only got th= at there is much more KASAN traffic around clang. So I thought that most KASAN users prefer LLVM. >This is all rather problematic and it isn't clear (to me) how to >proceed at this time. Do we have any projections on when all this will >be fixed up? My understanding is that there is something off in gcc support. I recall An= drey Konovalov mentioning that gcc also doesn't work well with arm64's KASAN tag-based mode. As for LLVM inline support I do know the codebase a bit so = I got some WIP patches there. But I wanted to see where this review process goes before posting to LLVM. >> The series is based on mm-new. > >I actually carry kexec patches in the mm-nonmm-[un]stable branches. >But the series applies OK anyway. Should I base this patchset on top of mm-nonmm-stable in the future? I was = after one patch by Andrey Ryabinin that was in mm-new and I needed to rebase on t= op of it. --=20 Kind regards Maciej Wiecz=C3=B3r-Retman