RISC-V: Remove ptrace support for vectors

We've found two bugs here: NT_RISCV_VECTOR steps on NT_RISCV_CSR (which
is only for embedded), and we don't have vlenb in the core dumps.  Given
that we've have a pair of bugs croup up as part of the GDB review we've
probably got other issues, so let's just cut this for 6.5 and get it
right.

Fixes: 0c59922c769a ("riscv: Add ptrace vector support")
Reviewed-by: Maciej W. Rozycki <macro@orcam.me.uk>
Signed-off-by: Andy Chiu <andy.chiu@sifive.com>
Link: https://lore.kernel.org/r/20230816155450.26200-2-andy.chiu@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

diff --git a/arch/riscv/kernel/ptrace.c b/arch/riscv/kernel/ptrace.c
index 1d572cf3140f0bf2a731ed7b88aebe0018830a2f..487303e3ef229346c6cf5515add1e3b998ac982c 100644 (file)
--- a/arch/riscv/kernel/ptrace.c
+++ b/arch/riscv/kernel/ptrace.c
@@ -25,9 +25,6 @@ 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,
@@ -84,61 +81,6 @@ 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;
-
-       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));
-
-       /* Copy vector header from vstate. */
-       membuf_write(&to, vstate, offsetof(struct __riscv_v_ext_state, datap));
-       membuf_zero(&to, sizeof(vstate->datap));
-
-       /* 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, size;
-       struct __riscv_v_ext_state *vstate = &target->thread.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, vstate, 0,
-                                offsetof(struct __riscv_v_ext_state, datap));
-       if (unlikely(ret))
-               return ret;
-
-       /* Skip copy datap. */
-       size = sizeof(vstate->datap);
-       count -= size;
-       ubuf += size;
-
-       /* 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,
@@ -158,17 +100,6 @@ 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_ext_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 0c8cf359ea5b4c622423ecae0ac7decebdc4102c..e0e15913833123b9f02e301b6e7a6de3969238a1 100644 (file)
--- a/include/uapi/linux/elf.h
+++ b/include/uapi/linux/elf.h
@@ -443,7 +443,6 @@ 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 */
 #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 */