diff options
| author | Mark Brown <broonie@kernel.org> | 2024-10-01 23:59:06 +0100 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2024-10-04 12:04:41 +0100 |
| commit | 7ec3b57cb29f8371bf12a725b6e8f75831a03f27 (patch) | |
| tree | 44ffff9e205c8d372cd1c38d81fca334dfde0be3 /arch/arm64/kernel/ptrace.c | |
| parent | 16f47bb9ac8afe09e7ca14cc53748f779b2a12e0 (diff) | |
arm64/ptrace: Expose GCS via ptrace and core files
Provide a new register type NT_ARM_GCS reporting the current GCS mode
and pointer for EL0. Due to the interactions with allocation and
deallocation of Guarded Control Stacks we do not permit any changes to
the GCS mode via ptrace, only GCSPR_EL0 may be changed.
Reviewed-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20241001-arm64-gcs-v13-27-222b78d87eee@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/kernel/ptrace.c')
| -rw-r--r-- | arch/arm64/kernel/ptrace.c | 62 |
1 files changed, 61 insertions, 1 deletions
diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c index b756578aeaee..6c1dcfe6d25a 100644 --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -34,6 +34,7 @@ #include <asm/cpufeature.h> #include <asm/debug-monitors.h> #include <asm/fpsimd.h> +#include <asm/gcs.h> #include <asm/mte.h> #include <asm/pointer_auth.h> #include <asm/stacktrace.h> @@ -1473,6 +1474,52 @@ static int poe_set(struct task_struct *target, const struct } #endif +#ifdef CONFIG_ARM64_GCS +static int gcs_get(struct task_struct *target, + const struct user_regset *regset, + struct membuf to) +{ + struct user_gcs user_gcs; + + if (!system_supports_gcs()) + return -EINVAL; + + if (target == current) + gcs_preserve_current_state(); + + user_gcs.features_enabled = target->thread.gcs_el0_mode; + user_gcs.features_locked = target->thread.gcs_el0_locked; + user_gcs.gcspr_el0 = target->thread.gcspr_el0; + + return membuf_write(&to, &user_gcs, sizeof(user_gcs)); +} + +static int gcs_set(struct task_struct *target, const struct + user_regset *regset, unsigned int pos, + unsigned int count, const void *kbuf, const + void __user *ubuf) +{ + int ret; + struct user_gcs user_gcs; + + if (!system_supports_gcs()) + return -EINVAL; + + ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &user_gcs, 0, -1); + if (ret) + return ret; + + if (user_gcs.features_enabled & ~PR_SHADOW_STACK_SUPPORTED_STATUS_MASK) + return -EINVAL; + + target->thread.gcs_el0_mode = user_gcs.features_enabled; + target->thread.gcs_el0_locked = user_gcs.features_locked; + target->thread.gcspr_el0 = user_gcs.gcspr_el0; + + return 0; +} +#endif + enum aarch64_regset { REGSET_GPR, REGSET_FPR, @@ -1503,7 +1550,10 @@ enum aarch64_regset { REGSET_TAGGED_ADDR_CTRL, #endif #ifdef CONFIG_ARM64_POE - REGSET_POE + REGSET_POE, +#endif +#ifdef CONFIG_ARM64_GCS + REGSET_GCS, #endif }; @@ -1674,6 +1724,16 @@ static const struct user_regset aarch64_regsets[] = { .set = poe_set, }, #endif +#ifdef CONFIG_ARM64_GCS + [REGSET_GCS] = { + .core_note_type = NT_ARM_GCS, + .n = sizeof(struct user_gcs) / sizeof(u64), + .size = sizeof(u64), + .align = sizeof(u64), + .regset_get = gcs_get, + .set = gcs_set, + }, +#endif }; static const struct user_regset_view user_aarch64_view = { |