summaryrefslogtreecommitdiff
path: root/arch/mips/include/asm/ptrace.h
blob: b6578611dddbfc37e9a7bea36886affe93d87411 (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
/*
 * 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.
 *
 * Copyright (C) 1994, 95, 96, 97, 98, 99, 2000 by Ralf Baechle
 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
 */
#ifndef _ASM_PTRACE_H
#define _ASM_PTRACE_H


#include <linux/compiler.h>
#include <linux/linkage.h>
#include <linux/types.h>
#include <asm/isadep.h>
#include <asm/page.h>
#include <asm/thread_info.h>
#include <uapi/asm/ptrace.h>

/*
 * This struct defines the way the registers are stored on the stack during a
 * system call/exception. As usual the registers k0/k1 aren't being saved.
 *
 * If you add a register here, also add it to regoffset_table[] in
 * arch/mips/kernel/ptrace.c.
 */
struct pt_regs {
#ifdef CONFIG_32BIT
	/* Pad bytes for argument save space on the stack. */
	unsigned long pad0[8];
#endif

	/* Saved main processor registers. */
	unsigned long regs[32];

	/* Saved special registers. */
	unsigned long cp0_status;
	unsigned long hi;
	unsigned long lo;
#ifdef CONFIG_CPU_HAS_SMARTMIPS
	unsigned long acx;
#endif
	unsigned long cp0_badvaddr;
	unsigned long cp0_cause;
	unsigned long cp0_epc;
#ifdef CONFIG_CPU_CAVIUM_OCTEON
	unsigned long long mpl[6];        /* MTM{0-5} */
	unsigned long long mtp[6];        /* MTP{0-5} */
#endif
	unsigned long __last[0];
} __aligned(8);

static inline unsigned long kernel_stack_pointer(struct pt_regs *regs)
{
	return regs->regs[31];
}

/*
 * Don't use asm-generic/ptrace.h it defines FP accessors that don't make
 * sense on MIPS.  We rather want an error if they get invoked.
 */

static inline void instruction_pointer_set(struct pt_regs *regs,
                                           unsigned long val)
{
	regs->cp0_epc = val;
}

/* Query offset/name of register from its name/offset */
extern int regs_query_register_offset(const char *name);
#define MAX_REG_OFFSET (offsetof(struct pt_regs, __last))

/**
 * regs_get_register() - get register value from its offset
 * @regs:       pt_regs from which register value is gotten.
 * @offset:     offset number of the register.
 *
 * regs_get_register returns the value of a register. The @offset is the
 * offset of the register in struct pt_regs address which specified by @regs.
 * If @offset is bigger than MAX_REG_OFFSET, this returns 0.
 */
static inline unsigned long regs_get_register(struct pt_regs *regs,
                                              unsigned int offset)
{
	if (unlikely(offset > MAX_REG_OFFSET))
		return 0;

	return *(unsigned long *)((unsigned long)regs + offset);
}

/**
 * regs_within_kernel_stack() - check the address in the stack
 * @regs:       pt_regs which contains kernel stack pointer.
 * @addr:       address which is checked.
 *
 * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
 * If @addr is within the kernel stack, it returns true. If not, returns false.
 */
static inline int regs_within_kernel_stack(struct pt_regs *regs,
                                           unsigned long addr)
{
	return ((addr & ~(THREAD_SIZE - 1))  ==
		(kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)));
}

/**
 * regs_get_kernel_stack_nth() - get Nth entry of the stack
 * @regs:       pt_regs which contains kernel stack pointer.
 * @n:          stack entry number.
 *
 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
 * is specified by @regs. If the @n th entry is NOT in the kernel stack,
 * this returns 0.
 */
static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
                                                      unsigned int n)
{
	unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);

	addr += n;
	if (regs_within_kernel_stack(regs, (unsigned long)addr))
		return *addr;
	else
		return 0;
}

struct task_struct;

extern int ptrace_getregs(struct task_struct *child,
	struct user_pt_regs __user *data);
extern int ptrace_setregs(struct task_struct *child,
	struct user_pt_regs __user *data);

extern int ptrace_getfpregs(struct task_struct *child, __u32 __user *data);
extern int ptrace_setfpregs(struct task_struct *child, __u32 __user *data);

extern int ptrace_get_watch_regs(struct task_struct *child,
	struct pt_watch_regs __user *addr);
extern int ptrace_set_watch_regs(struct task_struct *child,
	struct pt_watch_regs __user *addr);

/*
 * Does the process account for user or for system time?
 */
#define user_mode(regs) (((regs)->cp0_status & KU_MASK) == KU_USER)

static inline int is_syscall_success(struct pt_regs *regs)
{
	return !regs->regs[7];
}

static inline long regs_return_value(struct pt_regs *regs)
{
	if (is_syscall_success(regs) || !user_mode(regs))
		return regs->regs[2];
	else
		return -regs->regs[2];
}

#define instruction_pointer(regs) ((regs)->cp0_epc)
#define profile_pc(regs) instruction_pointer(regs)

extern asmlinkage long syscall_trace_enter(struct pt_regs *regs, long syscall);
extern asmlinkage void syscall_trace_leave(struct pt_regs *regs);

extern void die(const char *, struct pt_regs *) __noreturn;

static inline void die_if_kernel(const char *str, struct pt_regs *regs)
{
	if (unlikely(!user_mode(regs)))
		die(str, regs);
}

#define current_pt_regs()						\
({									\
	unsigned long sp = (unsigned long)__builtin_frame_address(0);	\
	(struct pt_regs *)((sp | (THREAD_SIZE - 1)) + 1 - 32) - 1;	\
})

/* Helpers for working with the user stack pointer */

static inline unsigned long user_stack_pointer(struct pt_regs *regs)
{
	return regs->regs[29];
}

static inline void user_stack_pointer_set(struct pt_regs *regs,
	unsigned long val)
{
	regs->regs[29] = val;
}

#endif /* _ASM_PTRACE_H */