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 42DA0C433EF for ; Fri, 17 Dec 2021 21:52:21 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id CEE0B6B0073; Fri, 17 Dec 2021 16:52:10 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id C9CD06B0074; Fri, 17 Dec 2021 16:52:10 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B64F86B0075; Fri, 17 Dec 2021 16:52:10 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0237.hostedemail.com [216.40.44.237]) by kanga.kvack.org (Postfix) with ESMTP id AA76C6B0073 for ; Fri, 17 Dec 2021 16:52:10 -0500 (EST) Received: from smtpin07.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 546FA8249980 for ; Fri, 17 Dec 2021 21:52:00 +0000 (UTC) X-FDA: 78928634400.07.A2C6378 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by imf06.hostedemail.com (Postfix) with ESMTP id 0ED1A18002E for ; Fri, 17 Dec 2021 21:51:58 +0000 (UTC) From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1639777918; 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=AT2D4l2B7gM1XeRgIpRAp9+Ku96ZpvKzPu5JSMbwNS0=; b=ZKVZHy79OUfLqeNlY9BPm+IvQJe2D/rq0NPmuXGTrAdH2NuBVX3cp0XeXpgNjpAhLFtf1Q azRrW/FLt5o8aRZhLfVTVcXhk+OYYTSpWP6MO6LLiEQ5eYlq/ZoMcPZ4/njjSgv/ihUALI XK0Tv4HliXC9VVuGFg9ouO7bjtA8ty63t5A/Owsq2rrigd/zwmMfRinDtX8fsyk1AzqEBk hFVkeoqDJEbDjygS8i97ohoTbxMn/PKKngPeHYLo8B1wbrrjDrVT4mlKD9niijSkc1pkT+ 2VRtsefqu+Lpk3i/9dWUorDuihvUE2+AjE3hQR7rDoTxz0xU8QjbV7UelGD/+Q== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1639777918; 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=AT2D4l2B7gM1XeRgIpRAp9+Ku96ZpvKzPu5JSMbwNS0=; b=h6Nbh3aDlpBkkO5FE3mZMJIvZzB5kYR0sUKQn8VSX+/j1dQO8KrxZq3IrXhnx140ZkPHM8 1FKGLyqknjKHxpAg== To: Alexander Potapenko , glider@google.com 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-mm@kvack.org, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 39/43] x86: kmsan: handle register passing from uninstrumented code In-Reply-To: <20211214162050.660953-40-glider@google.com> References: <20211214162050.660953-1-glider@google.com> <20211214162050.660953-40-glider@google.com> Date: Fri, 17 Dec 2021 22:51:57 +0100 Message-ID: <87bl1ec32a.ffs@tglx> MIME-Version: 1.0 Content-Type: text/plain Authentication-Results: imf06.hostedemail.com; dkim=pass header.d=linutronix.de header.s=2020 header.b=ZKVZHy79; dkim=pass header.d=linutronix.de header.s=2020e header.b=h6Nbh3aD; spf=pass (imf06.hostedemail.com: domain of tglx@linutronix.de designates 193.142.43.55 as permitted sender) smtp.mailfrom=tglx@linutronix.de; dmarc=pass (policy=none) header.from=linutronix.de X-Rspamd-Queue-Id: 0ED1A18002E X-Stat-Signature: ba8djxmmiu4t1964fusscodnokfmusa9 X-Rspamd-Server: rspam04 X-HE-Tag: 1639777918-947362 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: 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 when > 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 +++ > @@ -76,6 +77,7 @@ __visible noinstr void do_syscall_64(struct pt_regs *regs, int nr) > nr = 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); or some other sensible name which hides that kmsan gunk and avoids to touch all of this again when KFOOSAN comes around? Thanks, tglx