Received: by 2002:a25:e7d8:0:0:0:0:0 with SMTP id e207csp4070424ybh; Tue, 17 Mar 2020 11:38:50 -0700 (PDT) X-Google-Smtp-Source: ADFU+vvWI+xYZzXZMcLIJBx4mfUBNrytIQb1CuNOmtUiBeHsOnKoF4Xja5o2CURd8MJh8ZKTQFID X-Received: by 2002:aca:c256:: with SMTP id s83mr205659oif.57.1584470329991; Tue, 17 Mar 2020 11:38:49 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1584470329; cv=none; d=google.com; s=arc-20160816; b=RX2i5464GDoXljBrLs7xrOIu73eFp2j/zu9EosSD9MyHTY78vHltyCmZMTZjGpFZvO Nyyq2/8BGDPsUVcQfm9ZhL+yKferrU1cqEmf+bcxcc3Er8IYwwRFPqmM/uiVAsIFFTsT zOtYzZfwC22+S8txINvg0v8DX+cYa06HBKIwi+Y6I9wYEz8qVINZVVq5cUXx0tQPCwNd BGWbZE+ehEpbIf+EiT02U2V1NR9k3ib4vdagKC6c8CDJagguJj92wx5THcPdeKyfti4q 1Kgx90OpAA816YKdfrQJe3x7XqeBKZ9eTnj4FylryOOCuyqYdxNErqdIboRIPrm+1EUh BQYg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:in-reply-to:content-disposition :mime-version:references:message-id:subject:cc:to:from:date; bh=cdQO825RRa128SGNzB8E5tKBphtXSS9mBnKb2/IvDhY=; b=Xy+B5JcsBJmefYpjoEP02DFinfK/z2Ca/bm0hK2FTBdbBOp9sj2le+gD+EysIaY4nq I7hbfCKadPBmIg+wZTRIEr2gj9Ybpx8ybX4/OxkeIcR3S067vhnKrw6ppem1aZdNP0wp bJY0ZmuRYh86eo+mtbWOuxRg5pr4duY140WXzBHtR89tp8TkE42NYB4mJi3cgHfCSKl0 4jRTQxpZRfsa6QXgyJCgFm+2V7YEecn9XjdDyUJ8IU96dyYDgS4l7CAuv0spHcSSE1fp G1wpiDCCccjeZ1AUvSth7N/uSbETihAjKav7XyBZGRKSIT7nnefCVhmoNvmUb3iYcPL4 Wt1g== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id h23si2192980otk.294.2020.03.17.11.38.26; Tue, 17 Mar 2020 11:38:49 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726733AbgCQSh1 (ORCPT + 99 others); Tue, 17 Mar 2020 14:37:27 -0400 Received: from foss.arm.com ([217.140.110.172]:41442 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726506AbgCQSh1 (ORCPT ); Tue, 17 Mar 2020 14:37:27 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id D608131B; Tue, 17 Mar 2020 11:37:26 -0700 (PDT) Received: from arrakis.emea.arm.com (arrakis.cambridge.arm.com [10.1.196.71]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id D6D383F67D; Tue, 17 Mar 2020 11:37:25 -0700 (PDT) Date: Tue, 17 Mar 2020 18:37:23 +0000 From: Catalin Marinas To: glider@google.com Cc: will.deacon@arm.com, mark.rutland@arm.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, keescook@chromium.org, akpm@linux-foundation.org Subject: Re: [PATCH] arm64: define __alloc_zeroed_user_highpage Message-ID: <20200317183723.GH632169@arrakis.emea.arm.com> References: <20200312155920.50067-1-glider@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200312155920.50067-1-glider@google.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 12, 2020 at 04:59:20PM +0100, glider@google.com wrote: > When running the kernel with init_on_alloc=1, calling the default > implementation of __alloc_zeroed_user_highpage() from include/linux/highmem.h > leads to double-initialization of the allocated page (first by the page > allocator, then by clear_user_page(). > Calling alloc_page_vma() with __GFP_ZERO, similarly to e.g. x86, seems > to be enough to ensure the user page is zeroed only once. > > Signed-off-by: Alexander Potapenko I queued this for 5.7. Thanks. -- Catalin