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 A5B27C54E5D for ; Tue, 12 Mar 2024 15:35:01 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 2113E8D0053; Tue, 12 Mar 2024 11:35:01 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 1C0F28D0036; Tue, 12 Mar 2024 11:35:01 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0895E8D0053; Tue, 12 Mar 2024 11:35:01 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id EF15F8D0036 for ; Tue, 12 Mar 2024 11:35:00 -0400 (EDT) Received: from smtpin22.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 62395160E4C for ; Tue, 12 Mar 2024 15:35:00 +0000 (UTC) X-FDA: 81888785160.22.64B9D39 Received: from mail-yw1-f202.google.com (mail-yw1-f202.google.com [209.85.128.202]) by imf17.hostedemail.com (Postfix) with ESMTP id BD0AF4000D for ; Tue, 12 Mar 2024 15:34:58 +0000 (UTC) Authentication-Results: imf17.hostedemail.com; dkim=pass header.d=google.com header.s=20230601 header.b=yM8KWfz2; spf=pass (imf17.hostedemail.com: domain of 3IXbwZQoKCAY4uyx4gnskjmuumrk.iusrot03-ssq1giq.uxm@flex--yosryahmed.bounces.google.com designates 209.85.128.202 as permitted sender) smtp.mailfrom=3IXbwZQoKCAY4uyx4gnskjmuumrk.iusrot03-ssq1giq.uxm@flex--yosryahmed.bounces.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=1710257698; 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: in-reply-to:in-reply-to:references:references:dkim-signature; bh=KzR+McFxR/OTQhr4rH9hfsDERCQOrw3TFBf8AroZgQI=; b=sBmXK4JrCzQJ+CIp/1NHue4cM0vSI7zahdMLf/OMK55AMyYY5xQXxcJmPGuvYY/dj4gpQV P1NUf8U2aLKuJhJiEfp1n+AkOW7bmcrcPTr3QH6gjwWGtRcFXhvZxuU4oavzx7zK4V98Hx EskMMfSTJLrirAlhmcrlTIWXxNkTzPQ= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1710257698; a=rsa-sha256; cv=none; b=GF9jRjDLdiodDtNBjqr5i2AbK4CC9SzalftGZ8ts4IB30kcUgFSMtE1CsPJcbsyAy+00Po g4WGjMSnubmKhct437GbVEzl3XZ3/5iSglTz3woh9Uju6c6gi5VPBFnFUUq5JOow7CKD+/ nx8v8sGcBMDmsIAYna1VeZne9DDms0k= ARC-Authentication-Results: i=1; imf17.hostedemail.com; dkim=pass header.d=google.com header.s=20230601 header.b=yM8KWfz2; spf=pass (imf17.hostedemail.com: domain of 3IXbwZQoKCAY4uyx4gnskjmuumrk.iusrot03-ssq1giq.uxm@flex--yosryahmed.bounces.google.com designates 209.85.128.202 as permitted sender) smtp.mailfrom=3IXbwZQoKCAY4uyx4gnskjmuumrk.iusrot03-ssq1giq.uxm@flex--yosryahmed.bounces.google.com; dmarc=pass (policy=reject) header.from=google.com Received: by mail-yw1-f202.google.com with SMTP id 00721157ae682-608ad239f8fso91560147b3.0 for ; Tue, 12 Mar 2024 08:34:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1710257697; x=1710862497; darn=kvack.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=KzR+McFxR/OTQhr4rH9hfsDERCQOrw3TFBf8AroZgQI=; b=yM8KWfz2hQeri4MmqzoiuwM+JyxJlCw3+kEY/AmmMLX79NTIme1yWc9ZluFTw3mS05 qdi892P3N6csB3VgDtvNfH177y8c3IVRuKAlsmSWdO5NvDTkoqtC67+aUX30A2R9LY7R kmwo5XmRkuSwNaikR09OUALc62oYs3M8h4roOOh15y12cEXtPD2ZET5K+TeIgeCtYUOA gQuM6YSonsFm03oMiDziqe7vMkZgL1dGt5D87O4JrEBgEWLDyVjsuEYmSrIAZyXY9coR 3K2OGdHg7POt9vZRBfewg94cvmC9vz64+NFBz9QIAGD1JwPHhSKVlX/fKBjJQ0hdOj5L zrsg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1710257697; x=1710862497; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=KzR+McFxR/OTQhr4rH9hfsDERCQOrw3TFBf8AroZgQI=; b=bY/k5CsIJwTFHMDF3+XK4q93qyAxn6Wdku+ExypLDGyxkfmmG9AcF7zNpJr9NTrv4L k55JeHC/5GQvorZHHWDCUb/jwHUnuNREa1/4VJ3Krni3D0gUqZcIXnUGkdTdQF19mrRy 8Cjbyi7HmrXvyJDy1fNEf+toTzwUNsT5rjch54HFeF8aaB0Ptds9/4QsfzEYIFr+05xr Y1OZXr4ok7HV/yEich5/GquaY6aReQsnm/GsbzrZNVS3cZgcDFZZKgMJwiGi4zht9OrM S7/dZOEw7YavZa27pAk9QdLoc7ehoGLV0J3rUxqEmVVI85E8sv3wKztQhVVhuonH5S08 3DHQ== X-Forwarded-Encrypted: i=1; AJvYcCU7mhO5feyq10MU23HdYGknExaou0HkhY6G+bOQLRyvIqi1aICbmZ6mwtF5n+RXBaWrTOtyHhW1o50hlrZqI5yqV68= X-Gm-Message-State: AOJu0Yxi/FZSqgUDAW4dl0Jz3mQ5rD4cGP6JkOsCLo9l9TkmsFlUgt/c 25Lk8uP4uUu7upqrU0clLd7JHoEu3W3qxR7/CvAdSqOdubpoOikxMYUzMhuwwysep6YTDoWIqut iJEgvj8utxk+fo0rKgg== X-Google-Smtp-Source: AGHT+IGl5KiWLmiWgIlSDFPn08YN7J4pt2F+TALRpg5GfylVc4h+AleiTegFVKsV3qZe49owjtCjrvUMMLzVVAZO X-Received: from yosry.c.googlers.com ([fda3:e722:ac3:cc00:20:ed76:c0a8:29b4]) (user=yosryahmed job=sendgmr) by 2002:a05:6902:98a:b0:dc9:5ef8:2b2d with SMTP id bv10-20020a056902098a00b00dc95ef82b2dmr2524948ybb.4.1710257697643; Tue, 12 Mar 2024 08:34:57 -0700 (PDT) Date: Tue, 12 Mar 2024 15:34:55 +0000 In-Reply-To: <3a56vovcqy7ju5og76nqlekfruq42i56wmp4oek3jgkffvzjby@q5guufebkpzr> Mime-Version: 1.0 References: <20240312035951.3535980-1-yosryahmed@google.com> <20240312035951.3535980-2-yosryahmed@google.com> <3a56vovcqy7ju5og76nqlekfruq42i56wmp4oek3jgkffvzjby@q5guufebkpzr> Message-ID: Subject: Re: [PATCH 2/3] x86/mm: Fix LAM inconsistency during context switch From: Yosry Ahmed To: "Kirill A. Shutemov" Cc: x86@kernel.org, Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , Andy Lutomirski , Peter Zijlstra , Rick Edgecombe , Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="us-ascii" X-Stat-Signature: t8xjnzzr9dmxhy8ccdhx6cs5e1qndx3u X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: BD0AF4000D X-Rspam-User: X-HE-Tag: 1710257698-994993 X-HE-Meta: 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 xbo/iPos xigtyqXlg9fIL3YSaRaJVSrxzLoAI5NMPaPqK8vs7HK3Ra7ujf62rb1Yg9vdNIm+fvf5MA2gB3DlZwtLF3qmyOGm/kuDZietl/RoHqIoGklpcH5CVudE27RxhWp7S9+MP2SYTxkiU0kbA2Ap5VDm5lW5xw/QfZicz/xKENcGzRLlG8SJPC6WrZ/eoThSpkbB+8aik2U89D3Qen7hVASsEE5wXzu2gRUqjLxJumj2cqKhFxNCMiEK0/BXvieBrZO1TGsTVD/9qkuICI7SsmlPt4JR7n+pcjvovY/pe3vkiCeD7JhcWat7DQwDKE0t0VX4+vq+xBdrUpZTpGlY+hPnM5yf0A4OAPdeO9kR3K94TVOpKBv46F4zJ1PNRnoyqj4lp0ZHl 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: List-Subscribe: List-Unsubscribe: On Tue, Mar 12, 2024 at 02:35:46PM +0200, Kirill A. Shutemov wrote: > On Tue, Mar 12, 2024 at 03:59:50AM +0000, Yosry Ahmed wrote: > > diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c > > index 76e91fc68c5f3..748d2b3bdb985 100644 > > --- a/arch/x86/kernel/process_64.c > > +++ b/arch/x86/kernel/process_64.c > > @@ -753,10 +753,12 @@ static long prctl_map_vdso(const struct vdso_image *image, unsigned long addr) > > static void enable_lam_func(void *__mm) > > { > > struct mm_struct *mm = __mm; > > + unsigned long lam = mm_lam_cr3_mask(mm); > > + u64 untag_mask = mm_untag_mask(mm); > > > > Maybe push these mm dereferences inside the if block below? > I am not sure if compiler can re-order operations past this_cpu_read(). I am not sure either, so I will push them inside. Better safe than sorry. Will send a v2 shortly, thanks for the reviews! > > > if (this_cpu_read(cpu_tlbstate.loaded_mm) == mm) { > > - write_cr3(__read_cr3() | mm->context.lam_cr3_mask); > > - set_tlbstate_lam_mode(mm); > > + write_cr3(__read_cr3() | lam); > > + cpu_tlbstate_update_lam(lam, untag_mask); > > } > > } > > > > -- > Kiryl Shutsemau / Kirill A. Shutemov