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 93D4AC433EF for ; Tue, 14 Dec 2021 22:09:22 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id DD7F46B0071; Tue, 14 Dec 2021 17:09:11 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id D87276B0073; Tue, 14 Dec 2021 17:09:11 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C28206B0074; Tue, 14 Dec 2021 17:09:11 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0143.hostedemail.com [216.40.44.143]) by kanga.kvack.org (Postfix) with ESMTP id B0EE46B0071 for ; Tue, 14 Dec 2021 17:09:11 -0500 (EST) Received: from smtpin06.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 68446181AC9C6 for ; Tue, 14 Dec 2021 22:09:01 +0000 (UTC) X-FDA: 78917790882.06.1455155 Received: from mail-io1-f42.google.com (mail-io1-f42.google.com [209.85.166.42]) by imf28.hostedemail.com (Postfix) with ESMTP id 5CBF4C0014 for ; Tue, 14 Dec 2021 22:09:00 +0000 (UTC) Received: by mail-io1-f42.google.com with SMTP id k21so26802552ioh.4 for ; Tue, 14 Dec 2021 14:09:00 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=tP6csCLv+Ba35Rqxl/QI5p1YOyxnicuG22GVHFYUF1U=; b=Cc38oMKWk2brJxZDGoC8suov16Oq0YtG58O6cq6oiQTqRNg/SL4mIz90EmLVAnObiB T7MdVO+WibnifiPKGbqd2HGhMmcWOMEn2wfqt1mhmUPmVvzMluNpItXKYi7r4obpZ14+ vEFYVpcIlu/68azAW/1nmUbUNTCpl7nYCIhSlSC4KANXjv8kfbJKMVYOKmujbfqthcLf W4/BnybqvyIUBWy+8dQwZfyl/Sc2sVvnLpTESUfTCtXCnh6Hl6KPPW8y2+aFdxUu66nf odPDm2tHTZN8EIG9pVT3cmkNAjRykGS+FWUaUZ2ew7iGjYi7CuY5sHtqr1yl4RqnBTd8 mLbA== 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; bh=tP6csCLv+Ba35Rqxl/QI5p1YOyxnicuG22GVHFYUF1U=; b=1Dfx8I6CdlYs9tibeSbUtJmrslCy5rWcF5EGN4u108U+aXwyc4MrGUj2tqfTUGGE9/ 1uoWZF6PyI0zndKLPvio8em5WdnlEkMxZfLPUeAGaof+7++2y/KenlktwYg+h6oCOr83 CEyYfCxvtwtZempA8kkED3SviqbVd2EFNlmiSmm7l1vhd7NGRlk4NThPHbEzdWGwrEgo LvfPZCXeB8RAkC9XhWmpkbeStBXzUEEBbWr635bx9ZYyuvkxc7q5AIfYoVjUFpbRe0q8 wvAsQeQ57rxMNYMl1TXqUAJoOZpck+O89gUi5MpncfribFADbZbYLuA5BSqCXmX9icSJ Q3rw== X-Gm-Message-State: AOAM533Q/9XvO+wW1XpofLUyv0DNnOxINj6hLwK792XpK7cLYMplZqVc Ypi9nHRAToyXbPfDoIOPGUKwPnzxav/5dCPRxNQ= X-Google-Smtp-Source: ABdhPJwZpEx7lKlhd9sQu94o+KABcOC4exIObwhJKgQluloyoysImPofu+FfrETOdJsyEK7m/4nW5u+WBFq9eHEUhNw= X-Received: by 2002:a5e:d502:: with SMTP id e2mr5381245iom.118.1639519739580; Tue, 14 Dec 2021 14:08:59 -0800 (PST) MIME-Version: 1.0 References: In-Reply-To: From: Andrey Konovalov Date: Tue, 14 Dec 2021 23:08:49 +0100 Message-ID: Subject: Re: [PATCH mm v3 29/38] kasan, vmalloc: add vmalloc tagging for HW_TAGS To: Marco Elver Cc: andrey.konovalov@linux.dev, Alexander Potapenko , Andrew Morton , Dmitry Vyukov , Andrey Ryabinin , kasan-dev , Linux Memory Management List , Vincenzo Frascino , Catalin Marinas , Will Deacon , Mark Rutland , Linux ARM , Peter Collingbourne , Evgenii Stepanov , LKML , Andrey Konovalov Content-Type: text/plain; charset="UTF-8" Authentication-Results: imf28.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=Cc38oMKW; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf28.hostedemail.com: domain of andreyknvl@gmail.com designates 209.85.166.42 as permitted sender) smtp.mailfrom=andreyknvl@gmail.com X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: 5CBF4C0014 X-Stat-Signature: atrcgse6c34s5fjfzkdokb5yekd3b34k X-HE-Tag: 1639519740-504288 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 Tue, Dec 14, 2021 at 8:56 PM Marco Elver wrote: > > On Mon, Dec 13, 2021 at 10:54PM +0100, andrey.konovalov@linux.dev wrote: > [...] > > > > + /* > > + * Skip page_alloc poisoning and zeroing for pages backing VM_ALLOC > > + * mappings. Only effective in HW_TAGS mode. > > + */ > > + gfp &= __GFP_SKIP_KASAN_UNPOISON & __GFP_SKIP_ZERO; > > This will turn gfp == 0 always. Should it have been > > gfp |= __GFP_SKIP_KASAN_UNPOISON | __GFP_SKIP_ZERO Oh, this is bad. Thanks for noticing! Will fix in v4. > Also, not sure it matters, but on non-KASAN builds, this will now always > generate an extra instruction. You could conditionally define GFP_SKIP* > only in the KASAN modes that need them, otherwise they become 0, so the > compiler optimizes this out. (Although I think it does does complicate > GFP_SHIFT a little?) I can implement this, but I don't think a single extra instruction per vmalloc() matters.