[{"id":1794844,"web_url":"http://patchwork.ozlabs.org/comment/1794844/","msgid":"<20171027130411.qc2ee2z5ywocnvnw@armageddon.cambridge.arm.com>","list_archive_url":null,"date":"2017-10-27T13:04:11","subject":"Re: [PATCH v4 19/28] arm64/sve: ptrace and ELF coredump 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 11:51:01AM +0100, Dave P Martin wrote:\n> This patch defines and implements a new regset NT_ARM_SVE, which\n> describes a thread's SVE register state. This allows a debugger to\n> manipulate the SVE state, as well as being included in ELF\n> coredumps for post-mortem debugging.\n> \n> Because the regset size and layout are dependent on the thread's\n> current vector length, it is not possible to define a C struct to\n> describe the regset contents as is done for existing regsets.\n> Instead, and for the same reasons, NT_ARM_SVE is based on the\n> freeform variable-layout approach used for the SVE signal frame.\n> \n> Additionally, to reduce debug overhead when debugging threads that\n> might or might not have live SVE register state, NT_ARM_SVE may be\n> presented in one of two different formats: the old struct\n> user_fpsimd_state format is embedded for describing the state of a\n> thread with no live SVE state, whereas a new variable-layout\n> structure is embedded for describing live SVE state. This avoids a\n> debugger needing to poll NT_PRFPREG in addition to NT_ARM_SVE, and\n> allows existing userspace code to handle the non-SVE case without\n> too much modification.\n> \n> For this to work, NT_ARM_SVE is defined with a fixed-format header\n> of type struct user_sve_header, which the recipient can use to\n> figure out the content, size and layout of the reset of the regset.\n> Accessor macros are defined to allow the vector-length-dependent\n> parts of the regset to be manipulated.\n> \n> Signed-off-by: Alan Hayward \n> Signed-off-by: Dave Martin \n> Cc: Alex Bennée \n> Cc: Okamoto Takayuki \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; 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Fri, 27 Oct 2017 06:04:14 -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=PqEYUAEppLAH8voUENpFJUzNFvI5BQ2Mb7jhjAc8+NY=;\n\tb=AAs9nj6LB2IY7B\n\th6UMk2MDsWPl+OGYsqRU87mGd5ralGmxoT+aaBgxDjuR5Zifk6UMfAFoL0j1IrHx+uOeraepuccd4\n\t/8qpifkRnCrjfqtrQWUyYZcGp2w7kfbtDcGA4aLeucdgR3l0SGKJQnTdmazqBNKH+zTvF5K/8w7M1\n\tgeKJ+4rTJs0ZCrRz9/smtIX0LRu774RJVBc/qVCOvaMU2Nm3Ui36JkhhewvHEejAiKHDnG95837gQ\n\thzQjMKEQJ3yyOT8ReCXyss+y6O+lvDELyxNyOXdm3FNPmzeZBUWBmQNcaW/fO6r9sBZ9KT6vzwe0u\n\tNEUYIdU5GEzVcsjL0Lgg==;","Date":"Fri, 27 Oct 2017 14:04:11 +0100","From":"Catalin Marinas ","To":"Dave Martin ","Subject":"Re: [PATCH v4 19/28] arm64/sve: ptrace and ELF coredump support","Message-ID":"<20171027130411.qc2ee2z5ywocnvnw@armageddon.cambridge.arm.com>","References":"<1509101470-7881-1-git-send-email-Dave.Martin@arm.com>\n\t<1509101470-7881-20-git-send-email-Dave.Martin@arm.com>","MIME-Version":"1.0","Content-Disposition":"inline","In-Reply-To":"<1509101470-7881-20-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_060438_170884_8A93C5E7 ","X-CRM114-Status":"GOOD ( 12.99 )","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\n\t, Will Deacon , Alan Hayward\n\t, Alex =?iso-8859-1?q?Benn=E9e?=\n\t, kvmarm@lists.cs.columbia.edu,\n\tlinux-arm-kernel@lists.infradead.org","Content-Type":"text/plain; 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