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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 , Cyrill Gorcunov , Dave Hansen , Eugene Syromiatnikov , Florian Weimer , "H . J . Lu" , Jann Horn , Jonathan Corbet , Kees Cook , Mike Kravetz , Nadav Amit , Oleg Nesterov , Pavel Machek , Peter Zijlstra , Randy Dunlap , Weijiang Yang , "Kirill A . Shutemov" , John Allen , kcc@google.com, eranian@google.com, rppt@kernel.org, jamorris@linux.microsoft.com, dethoma@microsoft.com, akpm@linux-foundation.org, Andrew.Cooper3@citrix.com, christina.schimpe@intel.com, david@redhat.com, debug@rivosinc.com Subject: Re: [PATCH v7 20/41] x86/mm: Teach pte_mkwrite() about stack memory Message-ID: References: <20230227222957.24501-1-rick.p.edgecombe@intel.com> <20230227222957.24501-21-rick.p.edgecombe@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20230227222957.24501-21-rick.p.edgecombe@intel.com> X-Rspam-User: X-Rspamd-Server: rspam03 X-Stat-Signature: srykc1y8pjrhdkgdfgj4p44szcg9yuhu X-Rspamd-Queue-Id: 5CFE4160013 X-HE-Tag: 1677857851-522914 X-HE-Meta: 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 QUjc8mAh hC9bOU5dmKyw+x22UO/7Nge62rNHvHzAIO9MffCu7Ya1F4akL5tE3RkcjRn+ifYUrgPpqYLmZ+u2HJDFTyr3f+Vgu5vTz5RlbXN/sNSG+dR3BIUHYW7ngmCHu2/+DJo7Se7rBzyDPWQAum4RSl862SBNlN6YDDWMnlT2ddH/MXdH+f6U7xAxYHIPyTD/LhJ3Jyi73J1xzGHoTeJhmUOD4dKCdVHzZdcUBieJc2slt2Lib6jARNq5RJDXrWL0EEy2aSGLOTst2MR0bSbJ4KEv/SUnD86TBaxhvc/UHiIUbfioZPu0CrMjno4OgG0NmaYAPtku0a6iWJbCanb6Ow3Ffu6X5+JTq/+0vcwKEHccHl6qrxxsEPhx+0ueN7Yef8OgVjPJ69IlwOHydUFYCnvdnz1yQfHsOyQFhLqv2Ya7oE3fkYDeRFdh6aWIXUNO5WZZzTUbs 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, Feb 27, 2023 at 02:29:36PM -0800, Rick Edgecombe wrote: > If a VMA has the VM_SHADOW_STACK flag, it is shadow stack memory. So > when it is made writable with pte_mkwrite(), it should create shadow > stack memory, not conventionally writable memory. Now that pte_mkwrite() > takes a VMA, and places where shadow stack memory might be created pass > one, pte_mkwrite() can know when it should do this. ^^^^ This sentence needs rewriting. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette