From patchwork Tue Jun 25 14:57:37 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Brown X-Patchwork-Id: 807384 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 16F1116F859; Tue, 25 Jun 2024 15:01:45 +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=1719327705; cv=none; b=L2FYVyHfnUdgDmZLO9ZWyM0Xh5jWmJEU1ihI9pOPPUyp+ipUGntBFoPJhdElY655rVu6l5sq32NFhQT+LfO7IMEn2ipXklZvjD+N/d2fyLblmiw++fItJohm0WnMXUHHvwXx6BL7hndTOEhqVQ77s2W7o3cwDVfL3BubG630xkc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719327705; c=relaxed/simple; bh=HBYukUfWWcYFaZwVBzBm0FRifOIeZ7AM+OQsOqT0FkM=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=iCODGhaohBtJIJ2+immqnkM+Qti1xzQXHS/W4sGMAHu8/E1otwe35KosLxOI6B9BsPgvYWqkp/055Qw3z62BGLaolfo8UlvRDaWpJoNSK4Gve9y1BlJzRmt/DTg9L7+01cV43ycb8RjQ+hGAeJr+DYCIawkjuNSYCBVqX1kZjvs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=guFLMlnM; 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="guFLMlnM" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 71FBFC32782; Tue, 25 Jun 2024 15:01:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1719327704; bh=HBYukUfWWcYFaZwVBzBm0FRifOIeZ7AM+OQsOqT0FkM=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=guFLMlnM1QO43GlmvCb+/U/FOOQAUKPCWEgOqJfY5M5MDV6SRmAQOa8q7C9lTPBvJ bCTwBCFm1G71kP5NwfiymCRgWuFdfK88BlX2BsEf4OZvoHlBG33AubZ3oA/ri9TwuR x3h6i4zE6icz8GEnRzzvzKVrK4BJFmIoHUDgx/cYgO94TdAqy3duoeOcMTWTqqkl83 XJYk7MlKz+mCHz9ly6aD2LU/yOz2Xsh7xy2ZOaj10LsQ7cSw/hkg7Hoa8xWvYO8fgZ 5F+4lZS184nGsTwjJsweeg8rH9zsi87ornpjkfw9+/ddJndjUetLK/mVuxfPCyrGG0 cmGd+vmSRllcQ== From: Mark Brown Date: Tue, 25 Jun 2024 15:57:37 +0100 Subject: [PATCH v9 09/39] arm64/cpufeature: Runtime detection of Guarded Control Stack (GCS) Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20240625-arm64-gcs-v9-9-0f634469b8f0@kernel.org> References: <20240625-arm64-gcs-v9-0-0f634469b8f0@kernel.org> In-Reply-To: <20240625-arm64-gcs-v9-0-0f634469b8f0@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 , 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 0.14-dev-d4707 X-Developer-Signature: v=1; a=openpgp-sha256; l=2967; i=broonie@kernel.org; h=from:subject:message-id; bh=HBYukUfWWcYFaZwVBzBm0FRifOIeZ7AM+OQsOqT0FkM=; b=owEBbQGS/pANAwAKASTWi3JdVIfQAcsmYgBmett5TPImNiJ8QKbVQxAR+IKRHbeiwzvOwBa7FcIp VCtDJlSJATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCZnrbeQAKCRAk1otyXVSH0C0wB/ 9NlpCrbN55O/ocWyGWdcitxqcYlV5HNiRlaj/HXg3uyfnTgowjv1GnR10+pBR8qw6i05h/sCLgJkcW 89w0l/rOivkbV/LHTpoMWradc1lhtcePGc8r2oqea9dHPtD1nKD632CWNTiByENihEmHnufFbWzCdD n/kuevX+t5HPce0qds2YCgqByhWei+20Tq3fTtGrBTDK+9DFEpFfKxnT2fuZx1e/20QT/gQaFeXkCQ yrzSLi6gdBWy9fG6Xpuh2j2YiYF7yaiS6DhtFjSLzwS/lGdnk3onXV/WMYzqbgrefN54gTj2hKQG03 WFocfLobkJrHHUhGnQ39ToAgXyrPXO 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 Signed-off-by: Mark Brown --- arch/arm64/include/asm/cpufeature.h | 6 ++++++ arch/arm64/kernel/cpufeature.c | 16 ++++++++++++++++ arch/arm64/tools/cpucaps | 1 + 3 files changed, 23 insertions(+) diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index 8b904a757bd3..0ebed5dfe55f 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 48e7029f1054..056d394920f9 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), @@ -2347,6 +2349,12 @@ static void cpu_enable_mops(const struct arm64_cpu_capabilities *__unused) sysreg_clear_set(sctlr_el1, 0, SCTLR_EL1_MSCEn); } +static void cpu_enable_gcs(const struct arm64_cpu_capabilities *__unused) +{ + /* GCS is not currently used at EL1 */ + write_sysreg_s(0, SYS_GCSCR_EL1); +} + /* Internal helper functions to match cpu capability type */ static bool cpucap_late_cpu_optional(const struct arm64_cpu_capabilities *cap) @@ -2869,6 +2877,14 @@ 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, + .cpu_enable = cpu_enable_gcs, + .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