From patchwork Thu Aug 22 01:15:14 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Brown X-Patchwork-Id: 13772304 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 96FA02C190; Thu, 22 Aug 2024 01:18:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724289501; cv=none; b=BgZHQI9la8uaFeojCtYtUdcIRehqYvlsMcqGJ12rvyeVA3aovbPNT81cxSikRVfzMFtGBL3KG0cdu44juyqX5a6QvnF0ecwph8PxVl0b7QohVhQT44+A4la02PvwkJJYaOOdTmHoala13J/2ZXK15Vb1KwCoilVO6gvgJENbGFQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724289501; c=relaxed/simple; bh=sqQ+QKkmK52Q/49cSzsvA/P7PZLEWrgUxaLRjQV/ejo=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=knBJ1kXYbxWjtmxgmr/IooHkxZaG0tuh4acDHaF/YchdHxfeee98iio/M6Ni8X4i14LXAMGuMu+td8lrdpP1VU7JcaNJqgpGLQNu02cPl4nJ0OAd13u8wri8IGRXYcCf3XotlMw85Eg9Gf8J44t5Vs2MUYDSVHNTBHe/9RGQ8W8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=CjJdvIq4; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="CjJdvIq4" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 61B98C4AF18; Thu, 22 Aug 2024 01:18:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1724289501; bh=sqQ+QKkmK52Q/49cSzsvA/P7PZLEWrgUxaLRjQV/ejo=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=CjJdvIq43wLukfmjToKRyHHeVQIojg0WuXILAiXT0/HpQVb+xgWlpUqmMICHCRvt1 poJ59L1QGGcL6MxMWyqKzSmlLrYwEkfmuY3llMWVch9iNGSdYe39j+QPzyESNevFD9 ewMH9HAFaQ4xQHeF7XSVDq//Ae27f60g7oETV5/TNmxiVNYu6ahUQh0nI9vAA/7PSo Nj2wk7CrHbn+/UFUd4i6EMY+0cEkpAGId3U0FgC5EEJq14N+a5naLb7QyqzIaoK4ko HgU381MB7Pi0YycD95LUxpcgbPVnWy5iVmrFOpAd21RvOr/LF/keOzZyJPLLgIHUg+ 3UrPtTfJp16Dw== From: Mark Brown Date: Thu, 22 Aug 2024 02:15:14 +0100 Subject: [PATCH v11 11/39] arm64/cpufeature: Runtime detection of Guarded Control Stack (GCS) Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20240822-arm64-gcs-v11-11-41b81947ecb5@kernel.org> References: <20240822-arm64-gcs-v11-0-41b81947ecb5@kernel.org> In-Reply-To: <20240822-arm64-gcs-v11-0-41b81947ecb5@kernel.org> To: Catalin Marinas , Will Deacon , Jonathan Corbet , Andrew Morton , Marc Zyngier , Oliver Upton , James Morse , Suzuki K Poulose , Arnd Bergmann , Oleg Nesterov , Eric Biederman , Shuah Khan , "Rick P. Edgecombe" , Deepak Gupta , Ard Biesheuvel , Szabolcs Nagy , Kees Cook Cc: "H.J. Lu" , Paul Walmsley , Palmer Dabbelt , Albert Ou , Florian Weimer , Christian Brauner , Thiago Jung Bauermann , Ross Burton , Yury Khrustalev , Wilco Dijkstra , linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, kvmarm@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, Mark Brown X-Mailer: b4 0.15-dev-37811 X-Developer-Signature: v=1; a=openpgp-sha256; l=2509; i=broonie@kernel.org; h=from:subject:message-id; bh=sqQ+QKkmK52Q/49cSzsvA/P7PZLEWrgUxaLRjQV/ejo=; b=owEBbQGS/pANAwAKASTWi3JdVIfQAcsmYgBmxpEssm61j0572jagQn51jVrKg0sQmM+kpfxtQyMu q2YtYBmJATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCZsaRLAAKCRAk1otyXVSH0HenB/ 9SaBGUP0WgFMNDS/6ZR0f8D4eoA6DGU5iVT+BfZQrizL/iBEle0/DIkVgRcO1R30x2kxo4FfClzkc8 aI5PSj4d5AABqhPGa7Le2lPuu5hKBDz2Ta5aBGB1c994qpPa3F0q0HQ4cKEgHLTW8eBqYjyKMIgN/1 gavDgSQOL0Qox4HtTk5FLiatlutI7Slz7KtRR/awNPukoFlsXqXV5BbLivqOsVJX0HlC9t6YC9O1Rb vdN6j0pK3/SsY+CGIoWUWn3h6ykmoKhpwH+Q+59peF12FvFCbD9ZCNADQ9MZLNDNX8dNex7edvJAT8 LBKKQujdtKbLssSgzxABrstFIs4d2s X-Developer-Key: i=broonie@kernel.org; a=openpgp; fpr=3F2568AAC26998F9E813A1C5C3F436CA30F5D8EB Add a cpufeature for GCS, allowing other code to conditionally support it at runtime. Reviewed-by: Thiago Jung Bauermann Reviewed-by: Catalin Marinas Signed-off-by: Mark Brown --- arch/arm64/include/asm/cpufeature.h | 6 ++++++ arch/arm64/kernel/cpufeature.c | 9 +++++++++ arch/arm64/tools/cpucaps | 1 + 3 files changed, 16 insertions(+) diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index 558434267271..e0f0e4c24544 100644 --- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h @@ -832,6 +832,12 @@ static inline bool system_supports_lpa2(void) return cpus_have_final_cap(ARM64_HAS_LPA2); } +static inline bool system_supports_gcs(void) +{ + return IS_ENABLED(CONFIG_ARM64_GCS) && + alternative_has_cap_unlikely(ARM64_HAS_GCS); +} + int do_emulate_mrs(struct pt_regs *regs, u32 sys_reg, u32 rt); bool try_emulate_mrs(struct pt_regs *regs, u32 isn); diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 646ecd3069fd..315bd7be1106 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -291,6 +291,8 @@ static const struct arm64_ftr_bits ftr_id_aa64pfr0[] = { }; static const struct arm64_ftr_bits ftr_id_aa64pfr1[] = { + ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_GCS), + FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_EL1_GCS_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SME), FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_EL1_SME_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_EL1_MPAM_frac_SHIFT, 4, 0), @@ -2870,6 +2872,13 @@ static const struct arm64_cpu_capabilities arm64_features[] = { .matches = has_nv1, ARM64_CPUID_FIELDS_NEG(ID_AA64MMFR4_EL1, E2H0, NI_NV1) }, + { + .desc = "Guarded Control Stack (GCS)", + .capability = ARM64_HAS_GCS, + .type = ARM64_CPUCAP_SYSTEM_FEATURE, + .matches = has_cpuid_feature, + ARM64_CPUID_FIELDS(ID_AA64PFR1_EL1, GCS, IMP) + }, {}, }; diff --git a/arch/arm64/tools/cpucaps b/arch/arm64/tools/cpucaps index ac3429d892b9..66eff95c0824 100644 --- a/arch/arm64/tools/cpucaps +++ b/arch/arm64/tools/cpucaps @@ -29,6 +29,7 @@ HAS_EVT HAS_FPMR HAS_FGT HAS_FPSIMD +HAS_GCS HAS_GENERIC_AUTH HAS_GENERIC_AUTH_ARCH_QARMA3 HAS_GENERIC_AUTH_ARCH_QARMA5