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a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1688409496; bh=PbN14/Dkbpb3I7UfEf+MueR7WvA16x243pRvsQ4xVeo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=IP9Zm1Vo4XMFzACthKdt1xgOwg0m9L9tlji7BKPeJcis8lKBigCHCRtnjD95b4fHx nGGMrg9l2I85k1vWsK4aGYArlT9ir15Au9ef6D+a8NxdOiEYRyZvWeGhqpASDcRTU+ YieQ/Q1Oy4EVXg543ID0BT5aubS371dhCIjsUdH1woiQr0g6BSp7CdhhHjbr/PHiNN GuW2eD9li2WNGp8z1rEAjfbIiBrVpeRAedUejWTBcxmBs+IMfWGYxsjkyW5lAk6+jL 2hkwwIocL+upa2WIaiqFCWhvtyVZMPR91PFU67VVZbFBsgCS0IbtjYp0lJdZ34HT29 cP6GAaCvm974g== Date: Mon, 3 Jul 2023 19:38:04 +0100 From: Mark Brown To: "szabolcs.nagy@arm.com" Cc: "Edgecombe, Rick P" , "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: <16147d5c-3f4c-4be0-8af1-9cd34d010363@sirena.org.uk> References: <1cd67ae45fc379fd82d2745190e4caf74e67499e.camel@intel.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="D5fPsWucXka/TR0l" Content-Disposition: inline In-Reply-To: X-Cookie: Please go away. X-Rspamd-Queue-Id: 3F3E414000E X-Rspam-User: X-Rspamd-Server: rspam11 X-Stat-Signature: dxi1bi4gsg134fg7wubox9gmd1zn9nfh X-HE-Tag: 1688409497-18264 X-HE-Meta: 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 aEnC2E4U 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 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: --D5fPsWucXka/TR0l Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Mon, Jul 03, 2023 at 07:19:00PM +0100, szabolcs.nagy@arm.com wrote: > The 07/02/2023 18:03, Edgecombe, Rick P wrote: > > 3. Support more options for shadow stack sizing. (I think you are > > referring to this conversation: > > https://lore.kernel.org/lkml/ZAIgrXQ4670gxlE4@arm.com/). I don't see > > why this is needed for the base implementation. If ARM wants to add a > > new rlimit or clone variant, I don't see why x86 can't support it > > later. > i think it can be added later. > but it may be important for deployment on some platforms, since a > libc (or other language runtime) may want to set the shadow stack > size differently than the kernel default, because I agree that this can be deferred to later, so long as we err on the side of large stacks now we can provide an additional limit without confusing things. --D5fPsWucXka/TR0l Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAmSjFYsACgkQJNaLcl1U h9BYQwgAhRm5MgFMw8EWJtEyiQ4CP2w9dpB5HKwcEwXRO4LTusw+Rm1ZD+UHy/od nFrB/LuHxH11pDwa/T80iFHemMyEV8OyoTKsxX8VaQKp+9n2H6lq7J4+rujJFoMV uPrq7opwtLLgu8L8JXUC9SCTXETmiKzEK+YXfN1PvS2BzMKN0RFrzIh8LQ+E20Q8 JBRT4vsKJpQN63kUHGHl/2WgP/f6H+qeEapyXuaNa49uRsr0j2BE26xUOGB+K39U zoPbUSo27naEGpLCHPRDDPQxz3PowV3hXvLoVHa0nBgBlfEbMGzaJxtiqrwAYKvy i6I+y/Thvht3Bain7j8d4Pw/bQhawQ== =xDQQ -----END PGP SIGNATURE----- --D5fPsWucXka/TR0l--