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[198.145.64.163]) by smtp.gmail.com with ESMTPSA id k14-20020a6555ce000000b0043057fe66c0sm7263780pgs.48.2022.10.03.16.57.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 03 Oct 2022 16:57:31 -0700 (PDT) Date: Mon, 3 Oct 2022 16:57:30 -0700 From: Kees Cook To: Rick Edgecombe Cc: x86@kernel.org, "H . Peter Anvin" , Thomas Gleixner , Ingo Molnar , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-api@vger.kernel.org, Arnd Bergmann , Andy Lutomirski , Balbir Singh , Borislav Petkov , Cyrill Gorcunov , Dave Hansen , Eugene Syromiatnikov , Florian Weimer , "H . J . Lu" , Jann Horn , Jonathan Corbet , Mike Kravetz , Nadav Amit , Oleg Nesterov , Pavel Machek , Peter Zijlstra , Randy Dunlap , "Ravi V . Shankar" , Weijiang Yang , "Kirill A . Shutemov" , joao.moreira@intel.com, John Allen , kcc@google.com, eranian@google.com, rppt@kernel.org, jamorris@linux.microsoft.com, dethoma@microsoft.com Subject: Re: [PATCH v2 33/39] x86/cpufeatures: Limit shadow stack to Intel CPUs Message-ID: <202210031656.23FAA3195@keescook> References: <20220929222936.14584-1-rick.p.edgecombe@intel.com> <20220929222936.14584-34-rick.p.edgecombe@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220929222936.14584-34-rick.p.edgecombe@intel.com> ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1664841452; 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=UHb21iKAOr0dixbnKvFOpyl+rdeQazDsJI0KUTcj5+g=; b=LC9HzMPmBFJgeQFxpcY6WFIAo2MUtdpru/UDv+Tzukwm/Vh5okAQ2PVX3Hkx3pd1Fuzz3J 5tF+vkIza9gjQD+1UQy+muRnUO6Oz9tB9DrHNvPXeYzZZXftqanZO5aLYQ/WbW4h074wOD 4SgtdYdBkptWrFrmJ1CRIXKGMtl8NUQ= ARC-Authentication-Results: i=1; imf26.hostedemail.com; dkim=pass header.d=chromium.org header.s=google header.b=KpStkDnn; spf=pass (imf26.hostedemail.com: domain of keescook@chromium.org designates 209.85.210.170 as permitted sender) smtp.mailfrom=keescook@chromium.org; dmarc=pass (policy=none) header.from=chromium.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1664841452; a=rsa-sha256; cv=none; b=sFfNO25OBNiIp1x0DyM32BxnOTTM+aavnQCGAWQkGBbXqUlglOdrfhDx8w0OiuwGZ7F+g5 pXeCrul0KnKw2HxE30mrtGgjltnu0CmMZ27O+DgOAu/2uheNH9LgK/nJqJXdfImIbpa+Ev 1xm835U4qMyqf/+RuRsNCUFIZmax4Lk= Authentication-Results: imf26.hostedemail.com; dkim=pass header.d=chromium.org header.s=google header.b=KpStkDnn; spf=pass (imf26.hostedemail.com: domain of keescook@chromium.org designates 209.85.210.170 as permitted sender) smtp.mailfrom=keescook@chromium.org; dmarc=pass (policy=none) header.from=chromium.org X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: B3A30140016 X-Rspam-User: X-Stat-Signature: wzemkjeh6i648ubhxmabwkop8byqweou X-HE-Tag: 1664841452-607171 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 Thu, Sep 29, 2022 at 03:29:30PM -0700, Rick Edgecombe wrote: > Shadow stack is supported on newer AMD processors, but the kernel > implementation has not been tested on them. Prevent basic issues from > showing up for normal users by disabling shadow stack on all CPUs except > Intel until it has been tested. At which point the limitation should be > removed. > > Signed-off-by: Rick Edgecombe So running the selftests on an AMD system is sufficient to drop this patch? -- Kees Cook