6.5-stable review patch. If anyone has any objections, please let me know.
------------------
From: Andy Chiu <andy.chiu@xxxxxxxxxx>
commit 9300f00439743c4a34d735e1a27118eb68a1504e upstream.
This patch add back the ptrace support with the following fix:
- Define NT_RISCV_CSR and re-number NT_RISCV_VECTOR to prevent
conflicting with gdb's NT_RISCV_CSR.
- Use struct __riscv_v_regset_state to handle ptrace requests
Since gdb does not directly include the note description header in
Linux and has already defined NT_RISCV_CSR as 0x900, we decide to
sync with gdb and renumber NT_RISCV_VECTOR to solve and prevent future
conflicts.
Fixes: 0c59922c769a ("riscv: Add ptrace vector support")
Signed-off-by: Andy Chiu <andy.chiu@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20230825050248.32681-1-andy.chiu@xxxxxxxxxx
[Palmer: Drop the unused "size" variable in riscv_vr_set().]
Signed-off-by: Palmer Dabbelt <palmer@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/riscv/include/uapi/asm/ptrace.h | 13 +++--
arch/riscv/kernel/ptrace.c | 79 ++++++++++++++++++++++++++++
include/uapi/linux/elf.h | 2 +
3 files changed, 90 insertions(+), 4 deletions(-)
diff --git a/arch/riscv/include/uapi/asm/ptrace.h b/arch/riscv/include/uapi/asm/ptrace.h
index 283800130614..575e95bb1bc3 100644
--- a/arch/riscv/include/uapi/asm/ptrace.h
+++ b/arch/riscv/include/uapi/asm/ptrace.h
@@ -103,13 +103,18 @@ struct __riscv_v_ext_state {
* In signal handler, datap will be set a correct user stack offset
* and vector registers will be copied to the address of datap
* pointer.
- *
- * In ptrace syscall, datap will be set to zero and the vector
- * registers will be copied to the address right after this
- * structure.
*/
};
+struct __riscv_v_regset_state {
+ unsigned long vstart;
+ unsigned long vl;
+ unsigned long vtype;
+ unsigned long vcsr;
+ unsigned long vlenb;
+ char vreg[];
+};
+
/*
* According to spec: The number of bits in a single vector register,
* VLEN >= ELEN, which must be a power of 2, and must be no greater than
diff --git a/arch/riscv/kernel/ptrace.c b/arch/riscv/kernel/ptrace.c
index 487303e3ef22..2afe460de16a 100644
--- a/arch/riscv/kernel/ptrace.c
+++ b/arch/riscv/kernel/ptrace.c
@@ -25,6 +25,9 @@ enum riscv_regset {
#ifdef CONFIG_FPU
REGSET_F,
#endif
+#ifdef CONFIG_RISCV_ISA_V
+ REGSET_V,
+#endif
};
static int riscv_gpr_get(struct task_struct *target,
@@ -81,6 +84,71 @@ static int riscv_fpr_set(struct task_struct *target,
}
#endif
+#ifdef CONFIG_RISCV_ISA_V
+static int riscv_vr_get(struct task_struct *target,
+ const struct user_regset *regset,
+ struct membuf to)
+{
+ struct __riscv_v_ext_state *vstate = &target->thread.vstate;
+ struct __riscv_v_regset_state ptrace_vstate;
+
+ if (!riscv_v_vstate_query(task_pt_regs(target)))
+ return -EINVAL;
+
+ /*
+ * Ensure the vector registers have been saved to the memory before
+ * copying them to membuf.
+ */
+ if (target == current)
+ riscv_v_vstate_save(current, task_pt_regs(current));
+
+ ptrace_vstate.vstart = vstate->vstart;
+ ptrace_vstate.vl = vstate->vl;
+ ptrace_vstate.vtype = vstate->vtype;
+ ptrace_vstate.vcsr = vstate->vcsr;
+ ptrace_vstate.vlenb = vstate->vlenb;
+
+ /* Copy vector header from vstate. */
+ membuf_write(&to, &ptrace_vstate, sizeof(struct __riscv_v_regset_state));
+
+ /* Copy all the vector registers from vstate. */
+ return membuf_write(&to, vstate->datap, riscv_v_vsize);
+}
+
+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_ext_state *vstate = &target->thread.vstate;
+ struct __riscv_v_regset_state ptrace_vstate;
+
+ if (!riscv_v_vstate_query(task_pt_regs(target)))
+ return -EINVAL;
+
+ /* Copy rest of the vstate except datap */
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ptrace_vstate, 0,
+ sizeof(struct __riscv_v_regset_state));
+ if (unlikely(ret))
+ return ret;
+
+ if (vstate->vlenb != ptrace_vstate.vlenb)
+ return -EINVAL;
+
+ vstate->vstart = ptrace_vstate.vstart;
+ vstate->vl = ptrace_vstate.vl;
+ vstate->vtype = ptrace_vstate.vtype;
+ vstate->vcsr = ptrace_vstate.vcsr;
+
+ /* Copy all the vector registers. */
+ pos = 0;
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, vstate->datap,
+ 0, riscv_v_vsize);
+ return ret;
+}
+#endif
+
static const struct user_regset riscv_user_regset[] = {
[REGSET_X] = {
.core_note_type = NT_PRSTATUS,
@@ -100,6 +168,17 @@ static const struct user_regset riscv_user_regset[] = {
.set = riscv_fpr_set,
},
#endif
+#ifdef CONFIG_RISCV_ISA_V
+ [REGSET_V] = {
+ .core_note_type = NT_RISCV_VECTOR,
+ .align = 16,
+ .n = ((32 * RISCV_MAX_VLENB) +
+ sizeof(struct __riscv_v_regset_state)) / sizeof(__u32),
+ .size = sizeof(__u32),
+ .regset_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 e0e159138331..20e285fdbc46 100644
--- a/include/uapi/linux/elf.h
+++ b/include/uapi/linux/elf.h
@@ -443,6 +443,8 @@ 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_CSR 0x900 /* RISC-V Control and Status Registers */
+#define NT_RISCV_VECTOR 0x901 /* RISC-V vector registers */
#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 */
--
2.42.0
