1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Copyright 2010 Tilera Corporation. All Rights Reserved.
  4 * Copyright 2015 Regents of the University of California
  5 * Copyright 2017 SiFive
  6 *
  7 * Copied from arch/tile/kernel/ptrace.c
  8 */
  9
 10#include <asm/ptrace.h>
 11#include <asm/syscall.h>
 12#include <asm/thread_info.h>
 13#include <linux/audit.h>
 14#include <linux/ptrace.h>
 15#include <linux/elf.h>
 16#include <linux/regset.h>
 17#include <linux/sched.h>
 18#include <linux/sched/task_stack.h>
 19#include <linux/tracehook.h>
 20
 21#define CREATE_TRACE_POINTS
 22#include <trace/events/syscalls.h>
 23
 24enum riscv_regset {
 25	REGSET_X,
 26#ifdef CONFIG_FPU
 27	REGSET_F,
 28#endif
 29};
 30
 31static int riscv_gpr_get(struct task_struct *target,
 32			 const struct user_regset *regset,
 33			 unsigned int pos, unsigned int count,
 34			 void *kbuf, void __user *ubuf)
 35{
 36	struct pt_regs *regs;
 37
 38	regs = task_pt_regs(target);
 39	return user_regset_copyout(&pos, &count, &kbuf, &ubuf, regs, 0, -1);
 40}
 41
 42static int riscv_gpr_set(struct task_struct *target,
 43			 const struct user_regset *regset,
 44			 unsigned int pos, unsigned int count,
 45			 const void *kbuf, const void __user *ubuf)
 46{
 47	int ret;
 48	struct pt_regs *regs;
 49
 50	regs = task_pt_regs(target);
 51	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, regs, 0, -1);
 52	return ret;
 53}
 54
 55#ifdef CONFIG_FPU
 56static int riscv_fpr_get(struct task_struct *target,
 57			 const struct user_regset *regset,
 58			 unsigned int pos, unsigned int count,
 59			 void *kbuf, void __user *ubuf)
 60{
 61	int ret;
 62	struct __riscv_d_ext_state *fstate = &target->thread.fstate;
 63
 64	ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, fstate, 0,
 65				  offsetof(struct __riscv_d_ext_state, fcsr));
 66	if (!ret) {
 67		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, fstate, 0,
 68					  offsetof(struct __riscv_d_ext_state, fcsr) +
 69					  sizeof(fstate->fcsr));
 70	}
 71
 72	return ret;
 73}
 74
 75static int riscv_fpr_set(struct task_struct *target,
 76			 const struct user_regset *regset,
 77			 unsigned int pos, unsigned int count,
 78			 const void *kbuf, const void __user *ubuf)
 79{
 80	int ret;
 81	struct __riscv_d_ext_state *fstate = &target->thread.fstate;
 82
 83	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, fstate, 0,
 84				 offsetof(struct __riscv_d_ext_state, fcsr));
 85	if (!ret) {
 86		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, fstate, 0,
 87					 offsetof(struct __riscv_d_ext_state, fcsr) +
 88					 sizeof(fstate->fcsr));
 89	}
 90
 91	return ret;
 92}
 93#endif
 94
 95static const struct user_regset riscv_user_regset[] = {
 96	[REGSET_X] = {
 97		.core_note_type = NT_PRSTATUS,
 98		.n = ELF_NGREG,
 99		.size = sizeof(elf_greg_t),
100		.align = sizeof(elf_greg_t),
101		.get = &riscv_gpr_get,
102		.set = &riscv_gpr_set,
103	},
104#ifdef CONFIG_FPU
105	[REGSET_F] = {
106		.core_note_type = NT_PRFPREG,
107		.n = ELF_NFPREG,
108		.size = sizeof(elf_fpreg_t),
109		.align = sizeof(elf_fpreg_t),
110		.get = &riscv_fpr_get,
111		.set = &riscv_fpr_set,
112	},
113#endif
114};
115
116static const struct user_regset_view riscv_user_native_view = {
117	.name = "riscv",
118	.e_machine = EM_RISCV,
119	.regsets = riscv_user_regset,
120	.n = ARRAY_SIZE(riscv_user_regset),
121};
122
123const struct user_regset_view *task_user_regset_view(struct task_struct *task)
124{
125	return &riscv_user_native_view;
126}
127
128void ptrace_disable(struct task_struct *child)
129{
130	clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
131}
132
133long arch_ptrace(struct task_struct *child, long request,
134		 unsigned long addr, unsigned long data)
135{
136	long ret = -EIO;
137
138	switch (request) {
139	default:
140		ret = ptrace_request(child, request, addr, data);
141		break;
142	}
143
144	return ret;
145}
146
147/*
148 * Allows PTRACE_SYSCALL to work.  These are called from entry.S in
149 * {handle,ret_from}_syscall.
150 */
151__visible void do_syscall_trace_enter(struct pt_regs *regs)
152{
153	if (test_thread_flag(TIF_SYSCALL_TRACE))
154		if (tracehook_report_syscall_entry(regs))
155			syscall_set_nr(current, regs, -1);
156
157#ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
158	if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
159		trace_sys_enter(regs, syscall_get_nr(current, regs));
160#endif
161
162	audit_syscall_entry(regs->a7, regs->a0, regs->a1, regs->a2, regs->a3);
163}
164
165__visible void do_syscall_trace_exit(struct pt_regs *regs)
166{
167	audit_syscall_exit(regs);
168
169	if (test_thread_flag(TIF_SYSCALL_TRACE))
170		tracehook_report_syscall_exit(regs, 0);
171
172#ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
173	if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
174		trace_sys_exit(regs, regs_return_value(regs));
175#endif
176}