summaryrefslogtreecommitdiffstats
path: root/arch/riscv/kernel/ptrace.c
blob: 2d6395f5ad54f0c93cc162671fd97e6acfe72771 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright 2010 Tilera Corporation. All Rights Reserved.
 * Copyright 2015 Regents of the University of California
 * Copyright 2017 SiFive
 *
 * Copied from arch/tile/kernel/ptrace.c
 */

#include <asm/ptrace.h>
#include <asm/syscall.h>
#include <asm/thread_info.h>
#include <linux/audit.h>
#include <linux/ptrace.h>
#include <linux/elf.h>
#include <linux/regset.h>
#include <linux/sched.h>
#include <linux/sched/task_stack.h>
#include <linux/tracehook.h>

#define CREATE_TRACE_POINTS
#include <trace/events/syscalls.h>

enum riscv_regset {
	REGSET_X,
#ifdef CONFIG_FPU
	REGSET_F,
#endif
};

static int riscv_gpr_get(struct task_struct *target,
			 const struct user_regset *regset,
			 struct membuf to)
{
	return membuf_write(&to, task_pt_regs(target),
			    sizeof(struct user_regs_struct));
}

static int riscv_gpr_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 pt_regs *regs;

	regs = task_pt_regs(target);
	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, regs, 0, -1);
	return ret;
}

#ifdef CONFIG_FPU
static int riscv_fpr_get(struct task_struct *target,
			 const struct user_regset *regset,
			 struct membuf to)
{
	struct __riscv_d_ext_state *fstate = &target->thread.fstate;

	membuf_write(&to, fstate, offsetof(struct __riscv_d_ext_state, fcsr));
	membuf_store(&to, fstate->fcsr);
	return membuf_zero(&to, 4);	// explicitly pad
}

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] = {
		.core_note_type = NT_PRSTATUS,
		.n = ELF_NGREG,
		.size = sizeof(elf_greg_t),
		.align = sizeof(elf_greg_t),
		.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),
		.regset_get = riscv_fpr_get,
		.set = riscv_fpr_set,
	},
#endif
};

static const struct user_regset_view riscv_user_native_view = {
	.name = "riscv",
	.e_machine = EM_RISCV,
	.regsets = riscv_user_regset,
	.n = ARRAY_SIZE(riscv_user_regset),
};

const struct user_regset_view *task_user_regset_view(struct task_struct *task)
{
	return &riscv_user_native_view;
}

void ptrace_disable(struct task_struct *child)
{
	clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
}

long arch_ptrace(struct task_struct *child, long request,
		 unsigned long addr, unsigned long data)
{
	long ret = -EIO;

	switch (request) {
	default:
		ret = ptrace_request(child, request, addr, data);
		break;
	}

	return ret;
}

/*
 * Allows PTRACE_SYSCALL to work.  These are called from entry.S in
 * {handle,ret_from}_syscall.
 */
__visible int do_syscall_trace_enter(struct pt_regs *regs)
{
	if (test_thread_flag(TIF_SYSCALL_TRACE))
		if (tracehook_report_syscall_entry(regs))
			return -1;

	/*
	 * Do the secure computing after ptrace; failures should be fast.
	 * If this fails we might have return value in a0 from seccomp
	 * (via SECCOMP_RET_ERRNO/TRACE).
	 */
	if (secure_computing() == -1)
		return -1;

#ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
	if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
		trace_sys_enter(regs, syscall_get_nr(current, regs));
#endif

	audit_syscall_entry(regs->a7, regs->a0, regs->a1, regs->a2, regs->a3);
	return 0;
}

__visible void do_syscall_trace_exit(struct pt_regs *regs)
{
	audit_syscall_exit(regs);

	if (test_thread_flag(TIF_SYSCALL_TRACE))
		tracehook_report_syscall_exit(regs, 0);

#ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
	if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
		trace_sys_exit(regs, regs_return_value(regs));
#endif
}