From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-3.7 required=5.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED,RCVD_IN_MSPIKE_H4, RCVD_IN_MSPIKE_WL,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.4 Received: from second.openwall.net (second.openwall.net [193.110.157.125]) by inbox.vuxu.org (Postfix) with SMTP id 1DC742AE41 for ; Thu, 14 Mar 2024 15:07:09 +0100 (CET) Received: (qmail 24444 invoked by uid 550); 14 Mar 2024 14:02:52 -0000 Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Reply-To: musl@lists.openwall.com Received: (qmail 18191 invoked from network); 14 Mar 2024 13:59:36 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1710425019; bh=ocgVFU/TLLicKSAOp5e6Jw1mceRESxNPxDSwgKLBNEA=; h=Date:From:To:Subject:References:In-Reply-To:From; b=D/9GI0MNs8JWQAPf5Z1G4ogPOnDtQG33rHgiHHxOa92Emq5WYrPE2KautM9N9cX+a WbAAwO3Wj6eGQhlBVLL1NOWBqJbIlFLWdPaqBN/vgFeUiLRGt27X/853VR56NhzJPM bhGT0rC8lV23Q2AvhaQZDdo1vP+n3SNU5ZK6A1oMZc/AgCrrdI/vToA98gaZ6j16XQ 410z3sbYFy+9A6BbGCT/624NNsQU9AsUlIbj4QVgBsD7FAG1GJ9BPAnQ5tp06sJY54 ZxTk2LafU3ZP/TjsguM9rT43oB0GzuUw09qEcfHP28AKHoMaGH0kFo3KBKE2b2YYZk 0oMCxcfNdjKUg== Date: Thu, 14 Mar 2024 14:03:30 +0000 From: Mark Brown To: "dalias@libc.org" , "Edgecombe, Rick P" , "linux-arch@vger.kernel.org" , "suzuki.poulose@arm.com" , "Szabolcs.Nagy@arm.com" , "musl@lists.openwall.com" , "linux-fsdevel@vger.kernel.org" , "linux-riscv@lists.infradead.org" , "kvmarm@lists.linux.dev" , "corbet@lwn.net" , "linux-kernel@vger.kernel.org" , "catalin.marinas@arm.com" , "oliver.upton@linux.dev" , "palmer@dabbelt.com" , "debug@rivosinc.com" , "aou@eecs.berkeley.edu" , "shuah@kernel.org" , "arnd@arndb.de" , "maz@kernel.org" , "oleg@redhat.com" , "fweimer@redhat.com" , "keescook@chromium.org" , "james.morse@arm.com" , "ebiederm@xmission.com" , "will@kernel.org" , "brauner@kernel.org" , "hjl.tools@gmail.com" , "linux-kselftest@vger.kernel.org" , "paul.walmsley@sifive.com" , "ardb@kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-mm@kvack.org" , "thiago.bauermann@linaro.org" , "akpm@linux-foundation.org" , "sorear@fastmail.com" , "linux-doc@vger.kernel.org" Message-ID: References: <4c7bdf8fde9cc45174f10b9221fa58ffb450b755.camel@intel.com> <20240220185714.GO4163@brightrain.aerifal.cx> <9fc9c45ff6e14df80ad023e66ff7a978bd4ec91c.camel@intel.com> <20240220235415.GP4163@brightrain.aerifal.cx> <20240221012736.GQ4163@brightrain.aerifal.cx> <20240221145800.GR4163@brightrain.aerifal.cx> <4a3809e8-61b2-4341-a868-292ba6e64e8a@sirena.org.uk> <20240302145702.GD1884416@port70.net> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="pT4wHotY8cx/YSEA" Content-Disposition: inline In-Reply-To: <20240302145702.GD1884416@port70.net> X-Cookie: WYSIWYG: Subject: Re: [musl] Re: [PATCH v8 00/38] arm64/gcs: Provide support for GCS in userspace --pT4wHotY8cx/YSEA Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Sat, Mar 02, 2024 at 03:57:02PM +0100, Szabolcs Nagy wrote: > * Mark Brown [2024-02-21 17:36:12 +0000]: > > > I said NOP but there's no reason it strictly needs to be a NOP. It > > > could instead do something reasonable to convey the state of racing > > > with shadow stack being disabled. > > This feels like it's getting complicated and I fear it may be an uphill > > struggle to get such code merged, at least for arm64. My instinct is > the aarch64 behaviour is already nop > for gcs instructions when gcs is disabled. > the isa was designed so async disable is > possible. Yeah, we'd need to handle GCSPR_EL0 somehow (currently it's inaccessible when GCS is disabled) and userspace would need to take care it's not doing something that could get stuck if for example a pop didn't actually *do* anything. --pT4wHotY8cx/YSEA Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAmXzA7EACgkQJNaLcl1U h9DtMwf+JnNjwm9DjgfaCHDp+cP7YhhFhwS5JiqPHng947Eq2YICGNh1KUf/HVq8 VjnGVfZYycl6Q5XcsKtiIge6fzgb0z/vDrjYKaCVLhu7sC03mGroef90nO0gvw2K OvMgE+0BzMA7XrMHBWIQlu7p5Wm6rF6U/pVowEHQNunK3uQEyFUzjJUyTYewV/YV vuEPBmX2VzqLAzACX142ClcYwHzODx0SQPdvnzrSpXnpw7440+JMYNK/x7QKwPV+ kWJg2tTuYGo37YLUmSXzk/EQLoQ2mMtcC423i+XHC3W1ATJC6lioyhuPFrec4rmw f6AuUBTWAwPFswxpCAmg1ZfUVZGWZg== =Oz06 -----END PGP SIGNATURE----- --pT4wHotY8cx/YSEA--