@@ -324,6 +324,14 @@ struct user_za_header {
#define ZA_PT_SIZE(vq) \
(ZA_PT_ZA_OFFSET + ZA_PT_ZA_SIZE(vq))
+/* GCS state (NT_ARM_GCS) */
+
+struct user_gcs {
+ __u64 features_enabled;
+ __u64 features_locked;
+ __u64 gcspr_el0;
+};
+
#endif /* __ASSEMBLY__ */
#endif /* _UAPI__ASM_PTRACE_H */
@@ -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>
@@ -1440,6 +1441,51 @@ static int tagged_addr_ctrl_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 (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;
+
+ 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;
+
+ /* Do not allow enable via ptrace */
+ if ((user_gcs.features_enabled & PR_SHADOW_STACK_ENABLE) &&
+ !(target->thread.gcs_el0_mode & PR_SHADOW_STACK_ENABLE))
+ return -EBUSY;
+
+ 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,
@@ -1469,6 +1515,9 @@ enum aarch64_regset {
#ifdef CONFIG_ARM64_TAGGED_ADDR_ABI
REGSET_TAGGED_ADDR_CTRL,
#endif
+#ifdef CONFIG_ARM64_GCS
+ REGSET_GCS,
+#endif
};
static const struct user_regset aarch64_regsets[] = {
@@ -1628,6 +1677,16 @@ static const struct user_regset aarch64_regsets[] = {
.set = tagged_addr_ctrl_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 = {
@@ -441,6 +441,7 @@ typedef struct elf64_shdr {
#define NT_ARM_ZA 0x40c /* ARM SME ZA registers */
#define NT_ARM_ZT 0x40d /* ARM SME ZT registers */
#define NT_ARM_FPMR 0x40e /* ARM floating point mode register */
+#define NT_ARM_GCS 0x40f /* ARM GCS state */
#define NT_ARC_V2 0x600 /* ARCv2 accumulator/extra registers */
#define NT_VMCOREDD 0x700 /* Vmcore Device Dump Note */
#define NT_MIPS_DSP 0x800 /* MIPS DSP ASE registers */