RISC-V: Add FP register ptrace support for gdb.

Add a variable and a macro to describe FP registers, assuming only D is
supported.  FP code is conditional on CONFIG_FPU.  The FP regs and FCSR
are copied separately to avoid copying struct padding.  Tested by hand and
with the gdb testsuite.

Signed-off-by: Jim Wilson <jimw@sifive.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
This commit is contained in:
Jim Wilson 2018-10-17 17:59:05 -07:00 committed by Palmer Dabbelt
parent 86e581e310
commit b8c8a9590e
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2 changed files with 55 additions and 0 deletions

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@ -19,7 +19,10 @@ typedef unsigned long elf_greg_t;
typedef struct user_regs_struct elf_gregset_t;
#define ELF_NGREG (sizeof(elf_gregset_t) / sizeof(elf_greg_t))
/* We don't support f without d, or q. */
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))
#if __riscv_xlen == 64
#define ELF_RISCV_R_SYM(r_info) ELF64_R_SYM(r_info)

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@ -28,6 +28,9 @@
enum riscv_regset {
REGSET_X,
#ifdef CONFIG_FPU
REGSET_F,
#endif
};
static int riscv_gpr_get(struct task_struct *target,
@ -54,6 +57,45 @@ static int riscv_gpr_set(struct task_struct *target,
return ret;
}
#ifdef CONFIG_FPU
static int riscv_fpr_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_d_ext_state *fstate = &target->thread.fstate;
ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, fstate, 0,
offsetof(struct __riscv_d_ext_state, fcsr));
if (!ret) {
ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, fstate, 0,
offsetof(struct __riscv_d_ext_state, fcsr) +
sizeof(fstate->fcsr));
}
return ret;
}
static int riscv_fpr_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_d_ext_state *fstate = &target->thread.fstate;
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, fstate, 0,
offsetof(struct __riscv_d_ext_state, fcsr));
if (!ret) {
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, fstate, 0,
offsetof(struct __riscv_d_ext_state, fcsr) +
sizeof(fstate->fcsr));
}
return ret;
}
#endif
static const struct user_regset riscv_user_regset[] = {
[REGSET_X] = {
@ -64,6 +106,16 @@ static const struct user_regset riscv_user_regset[] = {
.get = &riscv_gpr_get,
.set = &riscv_gpr_set,
},
#ifdef CONFIG_FPU
[REGSET_F] = {
.core_note_type = NT_PRFPREG,
.n = ELF_NFPREG,
.size = sizeof(elf_fpreg_t),
.align = sizeof(elf_fpreg_t),
.get = &riscv_fpr_get,
.set = &riscv_fpr_set,
},
#endif
};
static const struct user_regset_view riscv_user_native_view = {