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c=relaxed/simple; d=kernel.org; s=k20201202; t=1688391151; bh=7qlSX9Nell5J7ysbWiOfRWUhTOykTgPNeRvu7kTYWFI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Z+7keICwZsDZYvzIbUYbAjua4wVC7WpRTZjY+p0UqCOPQWrv55HZV17LbtFu8q55z w7+nnoVSS94ACBMalD0MKTnRFPFU8Lo8gOJYLxh/7fFg8lK8+z+7ucOmuceABT2LbP OXt0TLl2OgWesEtsAtwwdogHYkJAqX6uxcjqLNOnN4FJ/q4GQ94xo2jHCEL0RlmBjG 3HH9mfElWZu57e7nhMbgJKjDoRJ7NCGaeytE3WK+/Oau36Zx6m+PH6EyMFWK9dN/+P O5o5DDMYh20KrcIyUUvLmMh9lCta8zIFQh0t07Nl5P0Z5JSBTdsqs9+tHNT3DtqWGF BFhK3s1ZBvHeQ== Date: Mon, 3 Jul 2023 14:32:19 +0100 From: Mark Brown To: "Edgecombe, Rick P" Cc: "szabolcs.nagy@arm.com" , "Lutomirski, Andy" , "Xu, Pengfei" , "tglx@linutronix.de" , "linux-arch@vger.kernel.org" , "kcc@google.com" , "nadav.amit@gmail.com" , "kirill.shutemov@linux.intel.com" , "david@redhat.com" , "Schimpe, Christina" , "akpm@linux-foundation.org" , "peterz@infradead.org" , "corbet@lwn.net" , "nd@arm.com" , "jannh@google.com" , "linux-kernel@vger.kernel.org" , "x86@kernel.org" , "debug@rivosinc.com" , "bp@alien8.de" , "rdunlap@infradead.org" , "linux-api@vger.kernel.org" , "rppt@kernel.org" , "jamorris@linux.microsoft.com" , "pavel@ucw.cz" , "john.allen@amd.com" , "bsingharora@gmail.com" , "mike.kravetz@oracle.com" , "dethoma@microsoft.com" , "andrew.cooper3@citrix.com" , "oleg@redhat.com" , "keescook@chromium.org" , "gorcunov@gmail.com" , "arnd@arndb.de" , "Yu, Yu-cheng" , "fweimer@redhat.com" , "hpa@zytor.com" , "mingo@redhat.com" , "hjl.tools@gmail.com" , "linux-mm@kvack.org" , "Syromiatnikov, Eugene" , "Yang, Weijiang" , "linux-doc@vger.kernel.org" , "dave.hansen@linux.intel.com" , "Torvalds, Linus" , "Eranian, Stephane" Subject: Re: [PATCH v9 23/42] Documentation/x86: Add CET shadow stack description Message-ID: References: <1cd67ae45fc379fd82d2745190e4caf74e67499e.camel@intel.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="3loSgCLP1vFHrOSe" Content-Disposition: inline In-Reply-To: X-Cookie: Please go away. X-Rspam-User: X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 45F21C0010 X-Stat-Signature: awu1hqxg714nb1pgj5f1ggepy6yqkgom X-HE-Tag: 1688391153-472856 X-HE-Meta: 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 b4HshZ7M bgtbIAnUlfUJNxVGwo2KFWOv9vRRW///u6pMAGYbTWMPBSoQlQMVuh5c5ex1IB08Obo/GY4ft3clxUbtHrRq1SL1QcYt3RUcqk/X2OldyfGZC32OduUD7NDrRRuH62B3CY8Ojvh7fQZeVOKFThhlUo8y+MSKMgolzEkA3uViHmSF6gopX0jqjBTjZEWkTLEJFMGd2D6ptRcUM3JdUhcQrpS+IuCWSQmZKIkneF7RBLHldzIccSX1ToF1EiwWw59jnjVWcxG8ZVWt2UgmDLAG8qL320VJ+6jGe2CbS5Xb1XeoJ+C6+M4E1+tTCmCsrRTN/ewMDuiKq0PbaItMNIrKoJ0L8rhzRN7JLXqmFDXL7JVkEhdbhdyn7/T/ULJa/KUdSByrixZQ7Z8EYcxVcvk4OrmqGSBHXRF5jY3RfRMDL3K9UuRCY8S67lq3V/ICbnqpPUPnxMMQJawBENclcybnwS6klJ+uYpw+JIrut0mdpwZneKvKrRiZBdv6uxKVddJoMfnabnVdNOEqCMohqA6h7iqGbSJvdTmGijwA7 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: --3loSgCLP1vFHrOSe Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Sun, Jul 02, 2023 at 06:03:42PM +0000, Edgecombe, Rick P wrote: > On Thu, 2023-06-29 at 17:07 +0100, szabolcs.nagy@arm.com wrote: > > which means x86 linux will likely end up maintaining two incompatible > > abis and the future one will need user code and build system changes, > > not just runtime changes. it is not a small incremental change to add > > alt shadow stack support for example. > > i don't think the maintenance burden of two shadow stack abis is the > > right path for arm64 to follow, so the shadow stack semantics will > > likely become divergent not common across targets. > Unfortunately we are at a bit of an information asymmetry here because > the ARM spec and patches are not public. It may be part of the cause of > the confusion. While the descriptive text bit of the spec is not yet integrated into the ARM the architecture XML describing the instructions and system registers is there, the document is numbered DDI0601: https://developer.arm.com/documentation/ddi0601/ The GCS specific instructions and system registers are all named beginning with GCS, it's aarch64 only. Hopefully I should have something out next week for the kernel. --3loSgCLP1vFHrOSe Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAmSizeIACgkQJNaLcl1U h9D3Wwf/baVnu4r+oxpjrck31M4SQYopy428bSNBHaGoVHcoFSNJEIBylX2Zcrp+ c+z0gkJRAjSvAfpT1mqWkw96gSlqLrDzUS6VClhMu0JZwkfmoNiqXwO2iK1jV5w9 9ZMxbCYtfA6pSN8DHwhVkEJO1+9sI6iUJrWsXXcQBRFEeWwkeKpR8CeYL4F8hpdl 4sOC1f2UeEJ82Rm6WPJ/ZNY/pTaGF3CWRP2WfoewkBwzMw9TevsYXdQAIOooFCOT 5ukjmiLiGw2IuYux8Y0Gb1ZaOiOI/W95yow0cPBDS9YGj7y6ZbZqIa5PVfK1Smwf 1QRf+xHUlAz6eiCCxHK2lZZqEP4vOw== =6QcV -----END PGP SIGNATURE----- --3loSgCLP1vFHrOSe--