This allows a tracer to control the ABI of the tracee, as on arm64.
Signed-off-by: Samuel Holland <samuel.holland@xxxxxxxxxx>
---
arch/riscv/kernel/ptrace.c | 42 ++++++++++++++++++++++++++++++++++++++
include/uapi/linux/elf.h | 1 +
2 files changed, 43 insertions(+)
diff --git a/arch/riscv/kernel/ptrace.c b/arch/riscv/kernel/ptrace.c
index e8515aa9d80b..3d414db2118b 100644
--- a/arch/riscv/kernel/ptrace.c
+++ b/arch/riscv/kernel/ptrace.c
@@ -28,6 +28,9 @@ enum riscv_regset {
#ifdef CONFIG_RISCV_ISA_V
REGSET_V,
#endif
+#ifdef CONFIG_RISCV_ISA_POINTER_MASKING
+ REGSET_TAGGED_ADDR_CTRL,
+#endif
};
static int riscv_gpr_get(struct task_struct *target,
@@ -152,6 +155,35 @@ static int riscv_vr_set(struct task_struct *target,
}
#endif
+#ifdef CONFIG_RISCV_ISA_POINTER_MASKING
+static int tagged_addr_ctrl_get(struct task_struct *target,
+ const struct user_regset *regset,
+ struct membuf to)
+{
+ long ctrl = get_tagged_addr_ctrl(target);
+
+ if (IS_ERR_VALUE(ctrl))
+ return ctrl;
+
+ return membuf_write(&to, &ctrl, sizeof(ctrl));
+}
+
+static int tagged_addr_ctrl_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;
+ long ctrl;
+
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ctrl, 0, -1);
+ if (ret)
+ return ret;
+
+ return set_tagged_addr_ctrl(target, ctrl);
+}
+#endif
+
static const struct user_regset riscv_user_regset[] = {
[REGSET_X] = {
.core_note_type = NT_PRSTATUS,
@@ -182,6 +214,16 @@ static const struct user_regset riscv_user_regset[] = {
.set = riscv_vr_set,
},
#endif
+#ifdef CONFIG_RISCV_ISA_POINTER_MASKING
+ [REGSET_TAGGED_ADDR_CTRL] = {
+ .core_note_type = NT_RISCV_TAGGED_ADDR_CTRL,
+ .n = 1,
+ .size = sizeof(long),
+ .align = sizeof(long),
+ .regset_get = tagged_addr_ctrl_get,
+ .set = tagged_addr_ctrl_set,
+ },
+#endif
};
static const struct user_regset_view riscv_user_native_view = {
diff --git a/include/uapi/linux/elf.h b/include/uapi/linux/elf.h
index 9417309b7230..90806024fed6 100644
--- a/include/uapi/linux/elf.h
+++ b/include/uapi/linux/elf.h
@@ -447,6 +447,7 @@ typedef struct elf64_shdr {
#define NT_MIPS_MSA 0x802 /* MIPS SIMD registers */
#define NT_RISCV_CSR 0x900 /* RISC-V Control and Status Registers */
#define NT_RISCV_VECTOR 0x901 /* RISC-V vector registers */
+#define NT_RISCV_TAGGED_ADDR_CTRL 0x902 /* RISC-V tagged address control (prctl()) */
#define NT_LOONGARCH_CPUCFG 0xa00 /* LoongArch CPU config registers */
#define NT_LOONGARCH_CSR 0xa01 /* LoongArch control and status registers */
#define NT_LOONGARCH_LSX 0xa02 /* LoongArch Loongson SIMD Extension registers */
--
2.43.1
