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 X-Spam-Level: X-Spam-Status: No, score=-3.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, URIBL_BLOCKED,USER_AGENT_NEOMUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B35E5C4360F for ; Tue, 2 Apr 2019 10:07:11 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 7DE1B20856 for ; Tue, 2 Apr 2019 10:07:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="fetRrCAs" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7DE1B20856 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=4GFCqdGCze+T4E18QIT357vFUZ+gaKodAkdrO1DvTAM=; b=fetRrCAsuTrltA RyItVL/WWskdU4fRQSudoImqECNjZm5fHs9BERf68YFkE2L/dswwJupc+q6SO0BefFl3E7baWiry+ WTR1wtfFh0d3CCIayMEoSwwN2LKMimK65svV5BwwYvhNv7JZRCQZjx788gnEbEwGPuT2xYInx8Dq4 7J4wLCNq0XhyTXRiizung/owBhK5qft2X9a/yRYs7ps1w4BZIM+VrMqLOlgZx5t5J00yogTjrNwkf sYdHTHU13Rjh8AOND9GajIa+oPoA0AqmjTRZRe1NiIUn0iPKmxY3+nv2DjmuEbYGW6Cct2gh7ppxH 7knEW0vHQ527D6C0tDHQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hBGJt-0007XW-1y; Tue, 02 Apr 2019 10:07:05 +0000 Received: from foss.arm.com ([217.140.101.70]) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hBGJq-0007Wk-7V for linux-arm-kernel@lists.infradead.org; Tue, 02 Apr 2019 10:07:03 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id ECE8315AD; Tue, 2 Apr 2019 03:07:01 -0700 (PDT) Received: from mbp (usa-sjc-mx-foss1.foss.arm.com [217.140.101.70]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id C2C743F59C; Tue, 2 Apr 2019 03:07:00 -0700 (PDT) Date: Tue, 2 Apr 2019 11:06:57 +0100 From: Catalin Marinas To: Vincenzo Frascino Subject: Re: [PATCH 1/4] arm64: compat: Alloc separate pages for vectors and sigpage Message-ID: <20190402100657.tkvdkqtx2xjjixma@mbp> References: <20190401112025.40807-1-vincenzo.frascino@arm.com> <20190401112025.40807-2-vincenzo.frascino@arm.com> <20190401142754.GF14874@arrakis.emea.arm.com> <6c43e9f9-3500-b828-3cf9-1917b9de256a@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <6c43e9f9-3500-b828-3cf9-1917b9de256a@arm.com> User-Agent: NeoMutt/20170113 (1.7.2) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190402_030702_269819_8600DAA7 X-CRM114-Status: GOOD ( 13.45 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-arch@vger.kernel.org, Mark Rutland , Will Deacon , linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, Apr 02, 2019 at 11:01:04AM +0100, Vincenzo Frascino wrote: > On 01/04/2019 15:27, Catalin Marinas wrote: > > On Mon, Apr 01, 2019 at 12:20:22PM +0100, Vincenzo Frascino wrote: > >> +static int aarch32_sigreturn_setup(struct mm_struct *mm) > >> +{ > >> + unsigned long addr; > >> void *ret; > >> > >> - if (down_write_killable(&mm->mmap_sem)) > >> - return -EINTR; > >> - current->mm->context.vdso = (void *)addr; > >> + addr = get_unmapped_area(NULL, 0, PAGE_SIZE, 0, 0); > >> + if (IS_ERR_VALUE(addr)) { > >> + ret = ERR_PTR(addr); > >> + goto out; > >> + } > >> > >> - /* Map vectors page at the high address. */ > >> ret = _install_special_mapping(mm, addr, PAGE_SIZE, > >> - VM_READ|VM_EXEC|VM_MAYREAD|VM_MAYEXEC, > >> - &spec); > >> + VM_READ | VM_EXEC | VM_MAYREAD | > >> + VM_MAYWRITE | VM_MAYEXEC, > >> + &aarch32_vdso_spec[1]); > > > > Any reason for setting VM_MAYWRITE here? > > VM_MAYWRITE is required to allow gdb to Copy-on-Write and set breakpoints. Thanks. Please add a comment to the code so I don't ask again ;). -- Catalin _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel