[{"id":1794834,"web_url":"http://patchwork.ozlabs.org/comment/1794834/","msgid":"<20171027125450.zvksms255zs5oqtj@armageddon.cambridge.arm.com>","list_archive_url":null,"date":"2017-10-27T12:54:51","subject":"Re: [PATCH v4 13/28] arm64/sve: Signal handling support","submitter":{"id":938,"url":"http://patchwork.ozlabs.org/api/people/938/","name":"Catalin Marinas","email":"catalin.marinas@arm.com"},"content":"On Fri, Oct 27, 2017 at 11:50:55AM +0100, Dave P Martin wrote:\n> This patch implements support for saving and restoring the SVE\n> registers around signals.\n> \n> A fixed-size header struct sve_context is always included in the\n> signal frame encoding the thread's vector length at the time of\n> signal delivery, optionally followed by a variable-layout structure\n> encoding the SVE registers.\n> \n> Because of the need to preserve backwards compatibility, the FPSIMD\n> view of the SVE registers is always dumped as a struct\n> fpsimd_context in the usual way, in addition to any sve_context.\n> \n> The SVE vector registers are dumped in full, including bits 127:0\n> of each register which alias the corresponding FPSIMD vector\n> registers in the hardware. To avoid any ambiguity about which\n> alias to restore during sigreturn, the kernel always restores bits\n> 127:0 of each SVE vector register from the fpsimd_context in the\n> signal frame (which must be present): userspace needs to take this\n> into account if it wants to modify the SVE vector register contents\n> on return from a signal.\n> \n> FPSR and FPCR, which are used by both FPSIMD and SVE, are not\n> included in sve_context because they are always present in\n> fpsimd_context anyway.\n> \n> For signal delivery, a new helper\n> fpsimd_signal_preserve_current_state() is added to update _both_\n> the FPSIMD and SVE views in the task struct, to make it easier to\n> populate this information into the signal frame. Because of the\n> redundancy between the two views of the state, only one is updated\n> otherwise.\n> \n> Signed-off-by: Dave Martin \n> Cc: Alex Bennée \n> Cc: Ard Biesheuvel \n\nReviewed-by: Catalin Marinas ","headers":{"Return-Path":"","X-Original-To":"incoming-imx@patchwork.ozlabs.org","Delivered-To":"patchwork-incoming-imx@bilbo.ozlabs.org","Authentication-Results":["ozlabs.org;\n\tspf=none (mailfrom) smtp.mailfrom=lists.infradead.org\n\t(client-ip=65.50.211.133; helo=bombadil.infradead.org;\n\tenvelope-from=linux-arm-kernel-bounces+incoming-imx=patchwork.ozlabs.org@lists.infradead.org;\n\treceiver=)","ozlabs.org; dkim=pass (2048-bit key;\n\tunprotected) header.d=lists.infradead.org\n\theader.i=@lists.infradead.org\n\theader.b=\"XIPDWf0a\"; dkim-atps=neutral"],"Received":["from bombadil.infradead.org (bombadil.infradead.org\n\t[65.50.211.133])\n\t(using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256\n\tbits)) (No client certificate requested)\n\tby ozlabs.org (Postfix) with ESMTPS id 3yNkPr69f9z9t2x\n\tfor ;\n\tFri, 27 Oct 2017 23:55:44 +1100 (AEDT)","from localhost ([127.0.0.1] helo=bombadil.infradead.org)\n\tby bombadil.infradead.org with esmtp (Exim 4.87 #1 (Red Hat Linux))\n\tid 1e84Ak-0004q4-Bf; Fri, 27 Oct 2017 12:55:38 +0000","from foss.arm.com ([217.140.101.70])\n\tby bombadil.infradead.org with esmtp (Exim 4.87 #1 (Red Hat Linux))\n\tid 1e84AQ-0003am-2D for linux-arm-kernel@lists.infradead.org;\n\tFri, 27 Oct 2017 12:55:20 +0000","from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249])\n\tby usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id BAA861529;\n\tFri, 27 Oct 2017 05:54:55 -0700 (PDT)","from armageddon.cambridge.arm.com (armageddon.cambridge.arm.com\n\t[10.1.206.84])\n\tby usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id\n\tC1C513F246; Fri, 27 Oct 2017 05:54:53 -0700 (PDT)"],"DKIM-Signature":"v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed;\n\td=lists.infradead.org; s=bombadil.20170209; h=Sender:\n\tContent-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post:\n\tList-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:\n\tMessage-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description:\n\tResent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:\n\tList-Owner; bh=idcIBdTLLOXeI8wle1yYTeXQiapMGLfauEwQBW0DCdE=;\n\tb=XIPDWf0a7QdKE4\n\t9iv3NPGsWmp86+/vzwPZ6gUxI1DsQ4QTi7uXBmcp27fHprBLKfrs2pQNF1VIDcc4v3sCvX1JmfrGU\n\tfYOAmofBD78jRNnB1T2lmMMBBKL8FQhlA1n7l++STcBb1Gu2PFBS+ehoal9CkRyGICsww/by8P8sK\n\t0Bx2aZ1dXUbL7C3NSZr7v0SzYQv7yL87Mu/06r4IRpZv+h0j3GdzPCg3BpvdxFpqISS8YyU2UqjJo\n\tAVLbQZorjS+QZgxHR/I3AB8RIO9/qQLGhGZak9F4o0vUKK1X5e5DmoocZK7yEHQYyjfxUgJKM74yx\n\tOLCzK2Wqzi0ohMBfFFZA==;","Date":"Fri, 27 Oct 2017 13:54:51 +0100","From":"Catalin Marinas ","To":"Dave Martin ","Subject":"Re: [PATCH v4 13/28] arm64/sve: Signal handling support","Message-ID":"<20171027125450.zvksms255zs5oqtj@armageddon.cambridge.arm.com>","References":"<1509101470-7881-1-git-send-email-Dave.Martin@arm.com>\n\t<1509101470-7881-14-git-send-email-Dave.Martin@arm.com>","MIME-Version":"1.0","Content-Disposition":"inline","In-Reply-To":"<1509101470-7881-14-git-send-email-Dave.Martin@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-20171027_055518_121356_13F24799 ","X-CRM114-Status":"GOOD ( 14.47 )","X-Spam-Score":"-6.9 (------)","X-Spam-Report":"SpamAssassin version 3.4.1 on bombadil.infradead.org summary:\n\tContent analysis details: (-6.9 points)\n\tpts rule name description\n\t---- ----------------------\n\t--------------------------------------------------\n\t-5.0 RCVD_IN_DNSWL_HI RBL: Sender listed at http://www.dnswl.org/,\n\thigh trust [217.140.101.70 listed in list.dnswl.org]\n\t-0.0 SPF_PASS SPF: sender matches SPF record\n\t-0.0 RP_MATCHES_RCVD Envelope sender domain matches handover relay\n\tdomain\n\t-1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1%\n\t[score: 0.0000]","X-BeenThere":"linux-arm-kernel@lists.infradead.org","X-Mailman-Version":"2.1.21","Precedence":"list","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Cc":"linux-arch@vger.kernel.org, Okamoto Takayuki ,\n\tlibc-alpha@sourceware.org, Ard Biesheuvel , \n\tSzabolcs Nagy , Will Deacon ,\n\tAlex =?iso-8859-1?q?Benn=E9e?= ,\n\tkvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org","Content-Type":"text/plain; charset=\"iso-8859-1\"","Content-Transfer-Encoding":"quoted-printable","Sender":"\"linux-arm-kernel\" ","Errors-To":"linux-arm-kernel-bounces+incoming-imx=patchwork.ozlabs.org@lists.infradead.org","List-Id":"linux-imx-kernel.lists.patchwork.ozlabs.org"}}]