From: Mark Brown <broonie@kernel.org>
To: Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>, Jonathan Corbet <corbet@lwn.net>,
Andrew Morton <akpm@linux-foundation.org>,
Marc Zyngier <maz@kernel.org>,
Oliver Upton <oliver.upton@linux.dev>,
James Morse <james.morse@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Arnd Bergmann <arnd@arndb.de>, Oleg Nesterov <oleg@redhat.com>,
Eric Biederman <ebiederm@xmission.com>,
Kees Cook <keescook@chromium.org>, Shuah Khan <shuah@kernel.org>,
"Rick P. Edgecombe" <rick.p.edgecombe@intel.com>,
Deepak Gupta <debug@rivosinc.com>,
Ard Biesheuvel <ardb@kernel.org>,
Szabolcs Nagy <Szabolcs.Nagy@arm.com>
Cc: "H.J. Lu" <hjl.tools@gmail.com>,
Paul Walmsley <paul.walmsley@sifive.com>,
Palmer Dabbelt <palmer@dabbelt.com>,
Albert Ou <aou@eecs.berkeley.edu>,
Florian Weimer <fweimer@redhat.com>,
Christian Brauner <brauner@kernel.org>,
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 <broonie@kernel.org>
Subject: [PATCH v6 10/38] arm64/cpufeature: Runtime detection of Guarded Control Stack (GCS)
Date: Mon, 09 Oct 2023 13:08:44 +0100 [thread overview]
Message-ID: <20231009-arm64-gcs-v6-10-78e55deaa4dd@kernel.org> (raw)
In-Reply-To: <20231009-arm64-gcs-v6-0-78e55deaa4dd@kernel.org>
Add a cpufeature for GCS, allowing other code to conditionally support it
at runtime.
Signed-off-by: Mark Brown <broonie@kernel.org>
---
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 5bba39376055..4a5eea41f8ed 100644
--- a/arch/arm64/include/asm/cpufeature.h
+++ b/arch/arm64/include/asm/cpufeature.h
@@ -831,6 +831,12 @@ static inline bool system_supports_tlb_range(void)
cpus_have_const_cap(ARM64_HAS_TLB_RANGE);
}
+static inline bool system_supports_gcs(void)
+{
+ return IS_ENABLED(CONFIG_ARM64_GCS) &&
+ cpus_have_const_cap(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 444a73c2e638..e247dce1759c 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -255,6 +255,8 @@ 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),
@@ -2220,6 +2222,12 @@ 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)
@@ -2719,6 +2727,14 @@ static const struct arm64_cpu_capabilities arm64_features[] = {
.matches = has_cpuid_feature,
ARM64_CPUID_FIELDS(ID_AA64MMFR2_EL1, EVT, IMP)
},
+ {
+ .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 c3f06fdef609..9b470b311f29 100644
--- a/arch/arm64/tools/cpucaps
+++ b/arch/arm64/tools/cpucaps
@@ -27,6 +27,7 @@ HAS_ECV_CNTPOFF
HAS_EPAN
HAS_EVT
HAS_FGT
+HAS_GCS
HAS_GENERIC_AUTH
HAS_GENERIC_AUTH_ARCH_QARMA3
HAS_GENERIC_AUTH_ARCH_QARMA5
--
2.30.2
next prev parent reply other threads:[~2023-10-09 12:12 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-09 12:08 [PATCH v6 00/38] arm64/gcs: Provide support for GCS in userspace Mark Brown
2023-10-09 12:08 ` [PATCH v6 01/38] arm64/mm: Restructure arch_validate_flags() for extensibility Mark Brown
2023-10-09 12:08 ` [PATCH v6 02/38] prctl: arch-agnostic prctl for shadow stack Mark Brown
2023-10-09 12:08 ` [PATCH v6 03/38] mman: Add map_shadow_stack() flags Mark Brown
2023-10-09 12:08 ` [PATCH v6 04/38] arm64: Document boot requirements for Guarded Control Stacks Mark Brown
2023-10-09 12:08 ` [PATCH v6 05/38] arm64/gcs: Document the ABI " Mark Brown
2023-10-09 12:08 ` [PATCH v6 06/38] arm64/sysreg: Add new system registers for GCS Mark Brown
2023-10-09 12:08 ` [PATCH v6 07/38] arm64/sysreg: Add definitions for architected GCS caps Mark Brown
2023-10-09 12:08 ` [PATCH v6 08/38] arm64/gcs: Add manual encodings of GCS instructions Mark Brown
2023-10-09 12:08 ` [PATCH v6 09/38] arm64/gcs: Provide copy_to_user_gcs() Mark Brown
2023-10-09 12:08 ` Mark Brown [this message]
2023-10-09 12:08 ` [PATCH v6 11/38] arm64/mm: Allocate PIE slots for EL0 guarded control stack Mark Brown
2023-10-09 12:08 ` [PATCH v6 12/38] mm: Define VM_SHADOW_STACK for arm64 when we support GCS Mark Brown
2023-10-09 12:08 ` [PATCH v6 13/38] arm64/mm: Map pages for guarded control stack Mark Brown
2023-10-09 12:08 ` [PATCH v6 14/38] KVM: arm64: Manage GCS registers for guests Mark Brown
2023-10-09 12:08 ` [PATCH v6 15/38] arm64/gcs: Allow GCS usage at EL0 and EL1 Mark Brown
2023-10-09 12:08 ` [PATCH v6 16/38] arm64/idreg: Add overrride for GCS Mark Brown
2023-10-09 12:08 ` [PATCH v6 17/38] arm64/hwcap: Add hwcap " Mark Brown
2023-10-09 12:08 ` [PATCH v6 18/38] arm64/traps: Handle GCS exceptions Mark Brown
2023-10-09 12:08 ` [PATCH v6 19/38] arm64/mm: Handle GCS data aborts Mark Brown
2023-10-09 12:08 ` [PATCH v6 20/38] arm64/gcs: Context switch GCS state for EL0 Mark Brown
2023-10-09 12:08 ` [PATCH v6 21/38] arm64/gcs: Allocate a new GCS for threads with GCS enabled Mark Brown
2023-10-09 12:08 ` [PATCH v6 22/38] arm64/gcs: Implement shadow stack prctl() interface Mark Brown
2023-10-09 12:08 ` [PATCH v6 23/38] arm64/mm: Implement map_shadow_stack() Mark Brown
2023-10-09 12:08 ` [PATCH v6 24/38] arm64/signal: Set up and restore the GCS context for signal handlers Mark Brown
2023-10-09 12:08 ` [PATCH v6 25/38] arm64/signal: Expose GCS state in signal frames Mark Brown
2023-10-09 12:09 ` [PATCH v6 26/38] arm64/ptrace: Expose GCS via ptrace and core files Mark Brown
2023-10-09 12:09 ` [PATCH v6 27/38] arm64: Add Kconfig for Guarded Control Stack (GCS) Mark Brown
2023-10-09 12:09 ` [PATCH v6 28/38] kselftest/arm64: Verify the GCS hwcap Mark Brown
2023-10-09 12:09 ` [PATCH v6 29/38] kselftest/arm64: Add GCS as a detected feature in the signal tests Mark Brown
2023-10-09 12:09 ` [PATCH v6 30/38] kselftest/arm64: Add framework support for GCS to signal handling tests Mark Brown
2023-10-09 12:09 ` [PATCH v6 31/38] kselftest/arm64: Allow signals tests to specify an expected si_code Mark Brown
2023-10-09 12:09 ` [PATCH v6 32/38] kselftest/arm64: Always run signals tests with GCS enabled Mark Brown
2023-10-09 12:09 ` [PATCH v6 33/38] kselftest/arm64: Add very basic GCS test program Mark Brown
2023-10-09 12:09 ` [PATCH v6 34/38] kselftest/arm64: Add a GCS test program built with the system libc Mark Brown
2023-10-09 12:09 ` [PATCH v6 35/38] kselftest/arm64: Add test coverage for GCS mode locking Mark Brown
2023-10-09 12:09 ` [PATCH v6 36/38] selftests/arm64: Add GCS signal tests Mark Brown
2023-10-09 12:09 ` [PATCH v6 37/38] kselftest/arm64: Add a GCS stress test Mark Brown
2023-10-09 12:09 ` [PATCH v6 38/38] kselftest/arm64: Enable GCS for the FP stress tests Mark Brown
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