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 38DBCC4332F for ; Mon, 20 Dec 2021 14:35:53 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 7757A6B0071; Mon, 20 Dec 2021 09:35:52 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 725346B0073; Mon, 20 Dec 2021 09:35:52 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5EC836B0074; Mon, 20 Dec 2021 09:35:52 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0064.hostedemail.com [216.40.44.64]) by kanga.kvack.org (Postfix) with ESMTP id 4D2706B0071 for ; Mon, 20 Dec 2021 09:35:52 -0500 (EST) Received: from smtpin25.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id EA0DE8249980 for ; Mon, 20 Dec 2021 14:35:51 +0000 (UTC) X-FDA: 78938421702.25.53CE4E7 Received: from mail-qv1-f45.google.com (mail-qv1-f45.google.com [209.85.219.45]) by imf26.hostedemail.com (Postfix) with ESMTP id 6388E140042 for ; Mon, 20 Dec 2021 14:35:50 +0000 (UTC) Received: by mail-qv1-f45.google.com with SMTP id kc16so9502479qvb.3 for ; Mon, 20 Dec 2021 06:35:50 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=KIUzswcAUaRAOTc8qof1lu1zKeUeUmXtr9MrXGORaeI=; b=DiEjH6My8Ez1IQhVc6pvDrx8DdYBf5P9Q+clTviqtdAcGoyrz8O3Mm0QM1wUFrNkY0 erUGHvnkQdBzOobPRhQhMUs2tWFe8BqPjTGLGO7iDNYJjnvifWvJK0CZAwohnr/jSIgz QpKt+Ew79In897TuLR2zRLivKaLe3tEQEONG8JVkG6PU0InE460sA5jq4dymMlHT8XSX zg2DC/LWEyYpH62+sfMqlCvUH8ljGrMJB9GT5NpPjnlC3IZ7ST16PWtT0L8tFOZmLFjb TIGp0qdZPmp5QBN5QRqIC1GTcIzUBcUI8b5RNxMVY+8vGRJeuba9qlq6VNmEPxlzglI1 v4Rw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=KIUzswcAUaRAOTc8qof1lu1zKeUeUmXtr9MrXGORaeI=; b=4fNkfUoljv0cUEQsRtyLK7rIBPvkyYR/f9ql9obWTKo6fMtg5s/K8diKVE/gBPOq8S uipheiyp5q9w89pvRsR9h73Ber7zsP/mawEpzdDB8kg+W3FO40KDesEB9j+Fc2vuw0/c HI+EuiwG6sYklmbyE1ddH2u7bcEn2XlXw4Z2+yqSzuwbC29TsHllPuMnjWhQIFTpIhjt dz6sunNp6pP/LRZxG6hmSUoUa82VbkHes8sWxfNkFXH3Emu43uRvuiwXrIel6175QtqL AEge3zPKE+t8YYo7/uvbxtmSkKc1so7cD6So1CcPNXEW67FwVJpPQ9tcavbGq1+tK6Pj WfWg== X-Gm-Message-State: AOAM532we77N3/2h5rj2tHdhbCvwvVFjpUa8dzpqqjqqA9jOXzpudJW5 uF78kLr2KnLVuDfph2wbZFxT7WrF/aeJbxqNZ+z2lg== X-Google-Smtp-Source: ABdhPJzaFRZE2AdeTnoG9pfGf1WQwZj1GmAFj8sa8rSd0l4vITphwUpgRq+6SCv0VHaU8fAW9eiqASykEX99MrCy/vM= X-Received: by 2002:a0c:8031:: with SMTP id 46mr13207207qva.126.1640010949396; Mon, 20 Dec 2021 06:35:49 -0800 (PST) MIME-Version: 1.0 References: <20211214162050.660953-1-glider@google.com> <20211214162050.660953-40-glider@google.com> <87bl1ec32a.ffs@tglx> In-Reply-To: <87bl1ec32a.ffs@tglx> From: Alexander Potapenko Date: Mon, 20 Dec 2021 15:35:13 +0100 Message-ID: Subject: Re: [PATCH 39/43] x86: kmsan: handle register passing from uninstrumented code To: Thomas Gleixner Cc: Alexander Viro , Andrew Morton , Andrey Konovalov , Andy Lutomirski , Ard Biesheuvel , Arnd Bergmann , Borislav Petkov , Christoph Hellwig , Christoph Lameter , David Rientjes , Dmitry Vyukov , Eric Dumazet , Greg Kroah-Hartman , Herbert Xu , Ilya Leoshkevich , Ingo Molnar , Jens Axboe , Joonsoo Kim , Kees Cook , Marco Elver , Matthew Wilcox , "Michael S. Tsirkin" , Pekka Enberg , Peter Zijlstra , Petr Mladek , Steven Rostedt , Vasily Gorbik , Vegard Nossum , Vlastimil Babka , Linux Memory Management List , Linux-Arch , LKML Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspamd-Queue-Id: 6388E140042 X-Stat-Signature: 8mdttg4ftd6oyte5geasgpbiirc9mxtj Authentication-Results: imf26.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=DiEjH6My; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf26.hostedemail.com: domain of glider@google.com designates 209.85.219.45 as permitted sender) smtp.mailfrom=glider@google.com X-Rspamd-Server: rspam02 X-HE-Tag: 1640010950-156993 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: On Fri, Dec 17, 2021 at 10:51 PM Thomas Gleixner wrote= : > > Alexander, > > On Tue, Dec 14 2021 at 17:20, Alexander Potapenko wrote: > > When calling KMSAN-instrumented functions from non-instrumented > > functions, function parameters may not be initialized properly, leading > > to false positive reports. In particular, this happens all the time whe= n > > calling interrupt handlers from `noinstr` IDT entries. > > > > Fortunately, x86 code has instrumentation_begin() and > > It's not only x86 code: > > kernel/entry/common.c | 3 +++ Shall this bit go into a separate patch? > > @@ -76,6 +77,7 @@ __visible noinstr void do_syscall_64(struct pt_regs *= regs, int nr) > > nr =3D syscall_enter_from_user_mode(regs, nr); > > > > instrumentation_begin(); > > + kmsan_instrumentation_begin(regs); > > Can we please make this something like: > > instrumentation_begin_at_entry(regs); Fine, will do. Do you think it would make sense to hide it inside instrumentation_begin(), or is it ok to have both macros follow each other? > or some other sensible name which hides that kmsan gunk and avoids to > touch all of this again when KFOOSAN comes around? > > Thanks, > > tglx > > > --=20 Alexander Potapenko Software Engineer Google Germany GmbH Erika-Mann-Stra=C3=9Fe, 33 80636 M=C3=BCnchen Gesch=C3=A4ftsf=C3=BChrer: Paul Manicle, Halimah DeLaine Prado Registergericht und -nummer: Hamburg, HRB 86891 Sitz der Gesellschaft: Hamburg