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 8EF47C4332F for ; Thu, 13 Oct 2022 14:01:15 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 922556B0071; Thu, 13 Oct 2022 10:01:14 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 8AA7F6B0073; Thu, 13 Oct 2022 10:01:14 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6FD548E0001; Thu, 13 Oct 2022 10:01:14 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 5885F6B0071 for ; Thu, 13 Oct 2022 10:01:14 -0400 (EDT) Received: from smtpin03.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 1AA12813F5 for ; Thu, 13 Oct 2022 14:01:14 +0000 (UTC) X-FDA: 80016088068.03.7DAF3C0 Received: from mail-qt1-f175.google.com (mail-qt1-f175.google.com [209.85.160.175]) by imf23.hostedemail.com (Postfix) with ESMTP id AF2F4140052 for ; Thu, 13 Oct 2022 14:01:09 +0000 (UTC) Received: by mail-qt1-f175.google.com with SMTP id h15so1141954qtu.2 for ; Thu, 13 Oct 2022 07:01:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=/q9HFSGdoaZv7OXKTbYpwwK8nkInj5DxOSaXWkZAU+U=; b=Kcak6tm0SuGgWwsrDMBLqrQ7qRQe4J5N/ixufaeWu9b7IROIEG9bpyA+ivJFEVwpxG T0gNt1R0XXbdDGaG68MG4F8hw6552zAxTWwLSJBBHuoXjnSz3QgZ2+C8QRlsyQh+ABh1 kH+H+ZP3GETqrOkXvrlj8ex2hrx2CuGIvnl/jtK3VJhEJE7PQ7oIOdb8f04BA7kP+Xbm A6Q56vX3vrMO3qIYJ5OMCh53vbypeXwa4jGVX4S6zJciJUIg+vgZYn9k36oENl1O6oD5 vP1i/ZxKWYAYIemsNBySzufQ6bUFSjb9r5Lph0iDp+fkReHzBUonwShArPPNQURBgy0i g6yQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=/q9HFSGdoaZv7OXKTbYpwwK8nkInj5DxOSaXWkZAU+U=; b=BjYDR3yynT9PWJOapMWkpVlwuO4EDPDK0KblcOCyTaUJBSDIDwD2e7wlSXzfXmSn6j KhXMydRybUUQQ6UXVG3gvkejT1jG0XUzvvyCViCxyyn604f/Wf+CTerMam2+kIFohR5+ E7XwdlBDziQN9dQnQb86BxAdNlGKKszfrLTtUzl3jsrwKoD4hzy0XdGcOt15RmvPIQCk fdjO/yjP1C0LuXTRBLZ1/XcyP9QxRAWh6tp8x6Vm3v4rhHjjfuhXLFrxhCicEPhbnkZ3 aMJt5DprUal67N2tU5GhXsZnO1buWXVW9GoBbUE2bAS+hdBOCkbE4E6OEveRjj071YnI 70XA== X-Gm-Message-State: ACrzQf1oM4KwGiElWiTUm6E5kOHDNxbPnYz9Hc2NXcsvdHEyFLaLwSbo p1dl0T5WeYt/dFsS7sWKLjaBISgM8AQEDk0Pav4= X-Google-Smtp-Source: AMsMyM64yFZ8mtXWRw8gK7FV/429jX/QlN/bnSB3WDi3V83jXcuf1B3cPY45R4wDJLmpzgZuDYW+KxzjfLg+JYj00P8= X-Received: by 2002:a05:620a:d94:b0:6bc:5a8c:3168 with SMTP id q20-20020a05620a0d9400b006bc5a8c3168mr38151qkl.56.1665669668750; Thu, 13 Oct 2022 07:01:08 -0700 (PDT) MIME-Version: 1.0 References: <20220913065423.520159-1-feng.tang@intel.com> <20220913065423.520159-3-feng.tang@intel.com> In-Reply-To: From: Andrey Konovalov Date: Thu, 13 Oct 2022 16:00:57 +0200 Message-ID: Subject: Re: [PATCH v6 2/4] mm/slub: only zero the requested size of buffer for kzalloc To: Feng Tang Cc: Andrew Morton , Vlastimil Babka , Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Roman Gushchin , Hyeonggon Yoo <42.hyeyoo@gmail.com>, Dmitry Vyukov , Jonathan Corbet , "Hansen, Dave" , Linux Memory Management List , LKML , kasan-dev , Kees Cook Content-Type: text/plain; charset="UTF-8" ARC-Authentication-Results: i=1; imf23.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=Kcak6tm0; spf=pass (imf23.hostedemail.com: domain of andreyknvl@gmail.com designates 209.85.160.175 as permitted sender) smtp.mailfrom=andreyknvl@gmail.com; dmarc=pass (policy=none) header.from=gmail.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1665669669; a=rsa-sha256; cv=none; b=kMnCQ8dUJBK5ROEZdvOAjKkS+CoRqk264BecXFVhA2ZAPmuaNo/OgbxprdQGxgBkuGsf8y PaLWAG22DXsxlVlKnXl6si29ar4qQJk3BUec128LpZ9e5WR33UBQtHCa8TKVDr+XdKeakw n9RwXSC0T5eGkwf89qPXtyj4YMiLB10= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1665669669; 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=/q9HFSGdoaZv7OXKTbYpwwK8nkInj5DxOSaXWkZAU+U=; b=ynFtTPMzANuuB7RvHoYoA7a9VxABpENgPJCCzdsjfaZr7o0tKdk311anNrgsycjmZpaRVr /J0ipgYpaUtEGPomdg1fs/RBqIMLVrHacfHdJ5YdCSORJog8/pkUpbKkeEXj9zBW2d5ILu F54593IxD8sorQL4In0YKOdTBjOLlMI= X-Rspam-User: Authentication-Results: imf23.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=Kcak6tm0; spf=pass (imf23.hostedemail.com: domain of andreyknvl@gmail.com designates 209.85.160.175 as permitted sender) smtp.mailfrom=andreyknvl@gmail.com; dmarc=pass (policy=none) header.from=gmail.com X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: AF2F4140052 X-Stat-Signature: 1wt7pd9ag4kf8u4wktjzxbnf816r9ocy X-HE-Tag: 1665669669-15045 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, Sep 27, 2022 at 4:42 AM Feng Tang wrote: > > > > @@ -746,7 +747,7 @@ static inline void slab_post_alloc_hook(struct kmem_cache *s, > > > for (i = 0; i < size; i++) { > > > p[i] = kasan_slab_alloc(s, p[i], flags, init); > > > if (p[i] && init && !kasan_has_integrated_init()) > > > - memset(p[i], 0, s->object_size); > > > + memset(p[i], 0, orig_size); > > > > Note that when KASAN is enabled and has integrated init, it will > > initialize the whole object, which leads to an inconsistency with this > > change. > > Do you mean for kzalloc() only? or there is some kasan check newly added? Hi Feng, I mean that when init is true and kasan_has_integrated_init() is true (with HW_TAGS mode), kasan_slab_alloc() initializes the whole object. Which is inconsistent with the memset() of only orig_size when !kasan_has_integrated_init(). But I think this is fine assuming SLAB poisoning happens later. But please add a comment. Thanks!