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Unverified Commit b8c8a959 authored by Jim Wilson's avatar Jim Wilson Committed by Palmer Dabbelt
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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: default avatarJim Wilson <jimw@sifive.com>
Signed-off-by: default avatarPalmer Dabbelt <palmer@sifive.com>
parent 86e581e3

arch/riscv/include/uapi/asm/elf.h

+3 −0
Original line number Diff line number Diff line
@@ -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)

arch/riscv/kernel/ptrace.c

+52 −0
Original line number Diff line number Diff line
@@ -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 = {