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Shutemov" , joao.moreira@intel.com, John Allen , kcc@google.com, eranian@google.com, jamorris@linux.microsoft.com, dethoma@microsoft.com, Yu-cheng Yu Subject: Re: [OPTIONAL/RFC v2 37/39] x86/cet: Add PTRACE interface for CET Message-ID: References: <20220929222936.14584-1-rick.p.edgecombe@intel.com> <20220929222936.14584-38-rick.p.edgecombe@intel.com> <202210031658.EEC88324FD@keescook> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <202210031658.EEC88324FD@keescook> ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1664873082; 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=P+c6FrpS3cQo9DkmDCMCljzpzKLrzlcC/bdm4divP7U=; b=NcVtUXkdI/BUzmIJfJndXBrTLpoQb90Bze3mnr42omk9W6FIQLXaH/coca6z8ZllSRLEyu ZpMucXS5kihmE17fQcYRGKYe8yszevKgUHagpIfKlHtz3FGUP/TsoLeSiQM5BTuJiTBsQX 3ci9bP62czNUL0DUBChpBJ8QEvlpZ3k= ARC-Authentication-Results: i=1; imf25.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=MNzz79AB; spf=pass (imf25.hostedemail.com: domain of rppt@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=rppt@kernel.org; dmarc=pass (policy=none) header.from=kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1664873082; a=rsa-sha256; cv=none; b=t2saNsOeEsmu1PVOJsNgpbxzdVbxCs2i51UD7JTlAxjqbKCJUBDdAx5Xo4BfzMyzCUPRlp 61NXB1g1eHd3mBnTnAg5ZD7g72qbs6lmgbUIan5tHjttFCX4o0HZwu8hGyTbZNuINd29zR bSt+BzN8aSOP9k2qcKwMnQcHZm4ub7M= X-Stat-Signature: kaiwdbwpcsjgypfnybyrsw96pkjmzyj3 X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 22CC2A0004 Authentication-Results: imf25.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=MNzz79AB; spf=pass (imf25.hostedemail.com: domain of rppt@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=rppt@kernel.org; dmarc=pass (policy=none) header.from=kernel.org X-Rspam-User: X-HE-Tag: 1664873081-823920 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 Mon, Oct 03, 2022 at 04:59:43PM -0700, Kees Cook wrote: > On Thu, Sep 29, 2022 at 03:29:34PM -0700, Rick Edgecombe wrote: > > From: Yu-cheng Yu > > > > Some applications (like GDB and CRIU) would like to tweak CET state via > > Eee. Does GDB really need this? Can we make this whole thing > CONFIG-depend on CRIU? GDB, at least its Intel fork uses this. I don't see how they can jump between frames without an ability to modify shadow stack contents. Last I looked they used NT_X86_CET to update SSP and ptrace(POKEDATA) to write to the shadow stack. > -- > Kees Cook -- Sincerely yours, Mike.