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bh=mxv9hEC3xowLTmvmFVJurKfIxwFTtqwG2eF4dqYJzWc=; b=SK49obZgItT4Z5F3IIn6l60sHQMPZCT+du0YhfY9UfATb/zpIqFvtvH+kn+QPGjKeW7vHm OMnvXPq8cXcj1VFAvaOS04ntDNUniOpg3bqjvWg+IjDikuPn2mi/I3mooKSXKwKxsamuD5 CyiyC/avKhASdDT2vhJNEDITZCO5Yis= Date: Thu, 9 Mar 2023 18:22:16 +0100 From: Borislav Petkov To: "Edgecombe, Rick P" Cc: "david@redhat.com" , "bsingharora@gmail.com" , "hpa@zytor.com" , "Syromiatnikov, Eugene" , "peterz@infradead.org" , "rdunlap@infradead.org" , "keescook@chromium.org" , "Yu, Yu-cheng" , "dave.hansen@linux.intel.com" , "kirill.shutemov@linux.intel.com" , "Eranian, Stephane" , "linux-mm@kvack.org" , "fweimer@redhat.com" , "nadav.amit@gmail.com" , "jannh@google.com" , "dethoma@microsoft.com" , "kcc@google.com" , "linux-arch@vger.kernel.org" , "pavel@ucw.cz" , "oleg@redhat.com" , "hjl.tools@gmail.com" , "Yang, Weijiang" , "Lutomirski, Andy" , "linux-doc@vger.kernel.org" , "arnd@arndb.de" , "tglx@linutronix.de" , "Schimpe, Christina" , "mike.kravetz@oracle.com" , "x86@kernel.org" , "akpm@linux-foundation.org" , "debug@rivosinc.com" , "jamorris@linux.microsoft.com" , "john.allen@amd.com" , "rppt@kernel.org" , "andrew.cooper3@citrix.com" , "mingo@redhat.com" , "corbet@lwn.net" , "linux-kernel@vger.kernel.org" , "linux-api@vger.kernel.org" , "gorcunov@gmail.com" Subject: Re: [PATCH v7 31/41] x86/shstk: Introduce routines modifying shstk Message-ID: <20230309172216.GHZAoVyHoTqLG+YKB4@fat_crate.local> References: <20230227222957.24501-1-rick.p.edgecombe@intel.com> <20230227222957.24501-32-rick.p.edgecombe@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: X-Stat-Signature: xp9k6sy3gdg1qmsbwzhc56jqmw5dcckh X-Rspam-User: X-Rspamd-Queue-Id: A6D59C0014 X-Rspamd-Server: rspam06 X-HE-Tag: 1678382542-862847 X-HE-Meta: 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 Ud1LOvmr WyJDSszssod5BKKhD4L+/nJRB7asI9DnMJXPUUZ1AdfjEuc2hpi1ohJtfTWDCLvFcLBgYmu1LnhoPnAnrgAFBqMLgSZ5ZMDWItABPATYv8griz/OS1DcFnyWHRsVtE1qUzA3E7OHHz/QE7fCprvJf+QaVOx4y4hKvr/9Pldcaz5jRn3QMWROa0eA4o4x1W2s/j0Ci6rupsEeN9B9o2SrBDxHeqlwjWg2PxWZYBbvW/TB0Lhgd2zABMUFJpeOuXMLg4t+kUhl/e6qPne0FwVf5BBK2y1CeRGt3w1gQtHyeGtZVNtzSLm2x7pl/KWad7sVNUhg6mo19fIvc2GYyqL02G24tpQ== 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, Mar 09, 2023 at 05:03:26PM +0000, Edgecombe, Rick P wrote: > On Thu, 2023-03-09 at 17:48 +0100, Borislav Petkov wrote: > > On Mon, Feb 27, 2023 at 02:29:47PM -0800, Rick Edgecombe wrote: > > > From: Yu-cheng Yu > > > > > > Shadow stacks are normally written to via CALL/RET or specific CET > > > > ^ > > indirectly. > > Dunno here, RSTORSSP/SAVEPREVSSP are kind of direct. > > > > > > instructions like RSTORSSP/SAVEPREVSSP. However during some Linux > > > operations the kernel will need to write to directly using the ^^^^^^^^^ Yes, I was trying to make the contrast more obvious because you say "directly" here. But not too important. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette