[RFC PATCH V3 10/11] riscv: Add ptrace support

[guoren@kernel.org]

From: Guo Ren <guoren@linux.alibaba.com>

Add new regset for vector and the implementation is similar to
fpu.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
---
 arch/riscv/include/uapi/asm/elf.h |  1 +
 arch/riscv/kernel/ptrace.c        | 41 +++++++++++++++++++++++++++++++
 include/uapi/linux/elf.h          |  1 +
 3 files changed, 43 insertions(+)

diff --git a/arch/riscv/include/uapi/asm/elf.h b/arch/riscv/include/uapi/asm/elf.h
index d696d6610231..099434d075a7 100644
--- a/arch/riscv/include/uapi/asm/elf.h
+++ b/arch/riscv/include/uapi/asm/elf.h
@@ -23,6 +23,7 @@ typedef struct user_regs_struct elf_gregset_t;
 typedef __u64 elf_fpreg_t;
 typedef union __riscv_fp_state elf_fpregset_t;
 #define ELF_NFPREG (sizeof(struct __riscv_d_ext_state) / sizeof(elf_fpreg_t))
+#define ELF_NVREG  (sizeof(struct __riscv_v_state) / sizeof(elf_greg_t))
 
 #if __riscv_xlen == 64
 #define ELF_RISCV_R_SYM(r_info)		ELF64_R_SYM(r_info)
diff --git a/arch/riscv/kernel/ptrace.c b/arch/riscv/kernel/ptrace.c
index 407464201b91..0e3c3543476c 100644
--- a/arch/riscv/kernel/ptrace.c
+++ b/arch/riscv/kernel/ptrace.c
@@ -26,6 +26,9 @@ enum riscv_regset {
 #ifdef CONFIG_FPU
 	REGSET_F,
 #endif
+#ifdef CONFIG_VECTOR
+	REGSET_V,
+#endif
 };
 
 static int riscv_gpr_get(struct task_struct *target,
@@ -92,6 +95,34 @@ static int riscv_fpr_set(struct task_struct *target,
 }
 #endif
 
+#ifdef CONFIG_VECTOR
+static int riscv_vr_get(struct task_struct *target,
+			 const struct user_regset *regset,
+			 unsigned int pos, unsigned int count,
+			 void *kbuf, void __user *ubuf)
+{
+	int ret;
+	struct __riscv_v_state *vstate = &target->thread.vstate;
+
+	ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, vstate, 0,
+				  offsetof(struct __riscv_v_state, vtype));
+	return ret;
+}
+
+static int riscv_vr_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 __riscv_v_state *vstate = &target->thread.vstate;
+
+	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, vstate, 0,
+				 offsetof(struct __riscv_v_state, vtype));
+	return ret;
+}
+#endif
+
 static const struct user_regset riscv_user_regset[] = {
 	[REGSET_X] = {
 		.core_note_type = NT_PRSTATUS,
@@ -111,6 +142,16 @@ static const struct user_regset riscv_user_regset[] = {
 		.set = &riscv_fpr_set,
 	},
 #endif
+#ifdef CONFIG_VECTOR
+	[REGSET_V] = {
+		.core_note_type = NT_RISCV_VECTOR,
+		.n = ELF_NVREG,
+		.size = sizeof(elf_greg_t),
+		.align = sizeof(elf_greg_t),
+		.get = &riscv_vr_get,
+		.set = &riscv_vr_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 34c02e4290fe..e428f9e8710a 100644
--- a/include/uapi/linux/elf.h
+++ b/include/uapi/linux/elf.h
@@ -428,6 +428,7 @@ typedef struct elf64_shdr {
 #define NT_MIPS_DSP	0x800		/* MIPS DSP ASE registers */
 #define NT_MIPS_FP_MODE	0x801		/* MIPS floating-point mode */
 #define NT_MIPS_MSA	0x802		/* MIPS SIMD registers */
+#define NT_RISCV_VECTOR	0x900		/* RISC-V vector registers */
 
 /* Note header in a PT_NOTE section */
 typedef struct elf32_note {
-- 
2.17.0