summaryrefslogtreecommitdiffstats
path: root/arch/h8300/kernel/ptrace.c
blob: 0dc1c8f622bc3fda818d5703896e99be485762ea (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
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
/*
 *  linux/arch/h8300/kernel/ptrace.c
 *
 *  Copyright 2015 Yoshinori Sato <ysato@users.sourceforge.jp>
 *
 * This file is subject to the terms and conditions of the GNU General
 * Public License.  See the file COPYING in the main directory of
 * this archive for more details.
 */

#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/ptrace.h>
#include <linux/audit.h>
#include <linux/tracehook.h>
#include <linux/regset.h>
#include <linux/elf.h>

#define CCR_MASK 0x6f    /* mode/imask not set */
#define EXR_MASK 0x80    /* modify only T */

#define PT_REG(r) offsetof(struct pt_regs, r)

extern void user_disable_single_step(struct task_struct *child);

/* Mapping from PT_xxx to the stack offset at which the register is
   saved.  Notice that usp has no stack-slot and needs to be treated
   specially (see get_reg/put_reg below). */
static const int register_offset[] = {
	PT_REG(er1), PT_REG(er2), PT_REG(er3), PT_REG(er4),
	PT_REG(er5), PT_REG(er6), PT_REG(er0), -1,
	PT_REG(orig_er0), PT_REG(ccr), PT_REG(pc),
#if defined(CONFIG_CPU_H8S)
	PT_REG(exr),
#endif
};

/* read register */
long h8300_get_reg(struct task_struct *task, int regno)
{
	switch (regno) {
	case PT_USP:
		return task->thread.usp + sizeof(long)*2;
	case PT_CCR:
	case PT_EXR:
	    return *(unsigned short *)(task->thread.esp0 +
				       register_offset[regno]);
	default:
	    return *(unsigned long *)(task->thread.esp0 +
				      register_offset[regno]);
	}
}

int h8300_put_reg(struct task_struct *task, int regno, unsigned long data)
{
	unsigned short oldccr;
	unsigned short oldexr;

	switch (regno) {
	case PT_USP:
		task->thread.usp = data - sizeof(long)*2;
	case PT_CCR:
		oldccr = *(unsigned short *)(task->thread.esp0 +
					     register_offset[regno]);
		oldccr &= ~CCR_MASK;
		data &= CCR_MASK;
		data |= oldccr;
		*(unsigned short *)(task->thread.esp0 +
				    register_offset[regno]) = data;
		break;
	case PT_EXR:
		oldexr = *(unsigned short *)(task->thread.esp0 +
					     register_offset[regno]);
		oldccr &= ~EXR_MASK;
		data &= EXR_MASK;
		data |= oldexr;
		*(unsigned short *)(task->thread.esp0 +
				    register_offset[regno]) = data;
		break;
	default:
		*(unsigned long *)(task->thread.esp0 +
				   register_offset[regno]) = data;
		break;
	}
	return 0;
}

static int regs_get(struct task_struct *target,
		    const struct user_regset *regset,
		    unsigned int pos, unsigned int count,
		    void *kbuf, void __user *ubuf)
{
	int r;
	struct user_regs_struct regs;
	long *reg = (long *)&regs;

	/* build user regs in buffer */
	BUILD_BUG_ON(sizeof(regs) % sizeof(long) != 0);
	for (r = 0; r < sizeof(regs) / sizeof(long); r++)
		*reg++ = h8300_get_reg(target, r);

	return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
				   &regs, 0, sizeof(regs));
}

static int regs_set(struct task_struct *target,
		    const struct user_regset *regset,
		    unsigned int pos, unsigned int count,
		    const void *kbuf, const void __user *ubuf)
{
	int r;
	int ret;
	struct user_regs_struct regs;
	long *reg;

	/* build user regs in buffer */
	BUILD_BUG_ON(sizeof(regs) % sizeof(long) != 0);
	for (reg = (long *)&regs, r = 0; r < sizeof(regs) / sizeof(long); r++)
		*reg++ = h8300_get_reg(target, r);

	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
				 &regs, 0, sizeof(regs));
	if (ret)
		return ret;

	/* write back to pt_regs */
	for (reg = (long *)&regs, r = 0; r < sizeof(regs) / sizeof(long); r++)
		h8300_put_reg(target, r, *reg++);
	return 0;
}

enum h8300_regset {
	REGSET_GENERAL,
};

static const struct user_regset h8300_regsets[] = {
	[REGSET_GENERAL] = {
		.core_note_type	= NT_PRSTATUS,
		.n		= ELF_NGREG,
		.size		= sizeof(long),
		.align		= sizeof(long),
		.get		= regs_get,
		.set		= regs_set,
	},
};

static const struct user_regset_view user_h8300_native_view = {
	.name = "h8300",
	.e_machine = EM_H8_300,
	.regsets = h8300_regsets,
	.n = ARRAY_SIZE(h8300_regsets),
};

const struct user_regset_view *task_user_regset_view(struct task_struct *task)
{
	return &user_h8300_native_view;
}

void ptrace_disable(struct task_struct *child)
{
	user_disable_single_step(child);
}

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

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

asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
{
	long ret = 0;

	if (test_thread_flag(TIF_SYSCALL_TRACE) &&
	    tracehook_report_syscall_entry(regs))
		/*
		 * Tracing decided this syscall should not happen.
		 * We'll return a bogus call number to get an ENOSYS
		 * error, but leave the original number in regs->regs[0].
		 */
		ret = -1L;

	audit_syscall_entry(regs->er1, regs->er2, regs->er3,
			    regs->er4, regs->er5);

	return ret ?: regs->er0;
}

asmlinkage void do_syscall_trace_leave(struct pt_regs *regs)
{
	int step;

	audit_syscall_exit(regs);

	step = test_thread_flag(TIF_SINGLESTEP);
	if (step || test_thread_flag(TIF_SYSCALL_TRACE))
		tracehook_report_syscall_exit(regs, step);
}