1 /*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Copyright (C) 1994, 95, 96, 97, 98, 99, 2000 by Ralf Baechle
7 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
8 */
9 #ifndef _ASM_PTRACE_H
10 #define _ASM_PTRACE_H
11
12
13 #include <linux/compiler.h>
14 #include <linux/linkage.h>
15 #include <linux/types.h>
16 #include <asm/isadep.h>
17 #include <asm/page.h>
18 #include <asm/thread_info.h>
19 #include <uapi/asm/ptrace.h>
20
21 /*
22 * This struct defines the way the registers are stored on the stack during a
23 * system call/exception. As usual the registers k0/k1 aren't being saved.
24 *
25 * If you add a register here, also add it to regoffset_table[] in
26 * arch/mips/kernel/ptrace.c.
27 */
28 struct pt_regs {
29 #ifdef CONFIG_32BIT
30 /* Pad bytes for argument save space on the stack. */
31 unsigned long pad0[8];
32 #endif
33
34 /* Saved main processor registers. */
35 unsigned long regs[32];
36
37 /* Saved special registers. */
38 unsigned long cp0_status;
39 unsigned long hi;
40 unsigned long lo;
41 #ifdef CONFIG_CPU_HAS_SMARTMIPS
42 unsigned long acx;
43 #endif
44 unsigned long cp0_badvaddr;
45 unsigned long cp0_cause;
46 unsigned long cp0_epc;
47 #ifdef CONFIG_CPU_CAVIUM_OCTEON
48 unsigned long long mpl[6]; /* MTM{0-5} */
49 unsigned long long mtp[6]; /* MTP{0-5} */
50 #endif
51 unsigned long __last[0];
52 } __aligned(8);
53
54 static inline unsigned long kernel_stack_pointer(struct pt_regs *regs)
55 {
56 return regs->regs[29];
57 }
58
59 static inline void instruction_pointer_set(struct pt_regs *regs,
60 unsigned long val)
61 {
62 regs->cp0_epc = val;
63 regs->cp0_cause &= ~CAUSEF_BD;
64 }
65
66 /* Query offset/name of register from its name/offset */
67 extern int regs_query_register_offset(const char *name);
68 #define MAX_REG_OFFSET (offsetof(struct pt_regs, __last))
69
70 /**
71 * regs_get_register() - get register value from its offset
72 * @regs: pt_regs from which register value is gotten.
73 * @offset: offset number of the register.
74 *
75 * regs_get_register returns the value of a register. The @offset is the
76 * offset of the register in struct pt_regs address which specified by @regs.
77 * If @offset is bigger than MAX_REG_OFFSET, this returns 0.
78 */
79 static inline unsigned long regs_get_register(struct pt_regs *regs,
80 unsigned int offset)
81 {
82 if (unlikely(offset > MAX_REG_OFFSET))
83 return 0;
84
85 return *(unsigned long *)((unsigned long)regs + offset);
86 }
87
88 /**
89 * regs_within_kernel_stack() - check the address in the stack
90 * @regs: pt_regs which contains kernel stack pointer.
91 * @addr: address which is checked.
92 *
93 * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
94 * If @addr is within the kernel stack, it returns true. If not, returns false.
95 */
96 static inline int regs_within_kernel_stack(struct pt_regs *regs,
97 unsigned long addr)
98 {
99 return ((addr & ~(THREAD_SIZE - 1)) ==
100 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)));
101 }
102
103 /**
104 * regs_get_kernel_stack_nth() - get Nth entry of the stack
105 * @regs: pt_regs which contains kernel stack pointer.
106 * @n: stack entry number.
107 *
108 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
109 * is specified by @regs. If the @n th entry is NOT in the kernel stack,
110 * this returns 0.
111 */
112 static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
113 unsigned int n)
114 {
115 unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
116
117 addr += n;
118 if (regs_within_kernel_stack(regs, (unsigned long)addr))
119 return *addr;
120 else
121 return 0;
122 }
123
124 struct task_struct;
125
126 extern int ptrace_getregs(struct task_struct *child,
127 struct user_pt_regs __user *data);
128 extern int ptrace_setregs(struct task_struct *child,
129 struct user_pt_regs __user *data);
130
131 extern int ptrace_getfpregs(struct task_struct *child, __u32 __user *data);
132 extern int ptrace_setfpregs(struct task_struct *child, __u32 __user *data);
133
134 extern int ptrace_get_watch_regs(struct task_struct *child,
135 struct pt_watch_regs __user *addr);
136 extern int ptrace_set_watch_regs(struct task_struct *child,
137 struct pt_watch_regs __user *addr);
138
139 /*
140 * Does the process account for user or for system time?
141 */
142 #define user_mode(regs) (((regs)->cp0_status & KU_MASK) == KU_USER)
143
144 static inline int is_syscall_success(struct pt_regs *regs)
145 {
146 return !regs->regs[7];
147 }
148
149 static inline long regs_return_value(struct pt_regs *regs)
150 {
151 if (is_syscall_success(regs) || !user_mode(regs))
152 return regs->regs[2];
153 else
154 return -regs->regs[2];
155 }
156
157 #define instruction_pointer(regs) ((regs)->cp0_epc)
158 extern unsigned long exception_ip(struct pt_regs *regs);
159 #define exception_ip(regs) exception_ip(regs)
160 #define profile_pc(regs) instruction_pointer(regs)
161
162 extern asmlinkage long syscall_trace_enter(struct pt_regs *regs);
163 extern asmlinkage void syscall_trace_leave(struct pt_regs *regs);
164
165 extern void die(const char *, struct pt_regs *) __noreturn;
166
167 static inline void die_if_kernel(const char *str, struct pt_regs *regs)
168 {
169 if (unlikely(!user_mode(regs)))
170 die(str, regs);
171 }
172
173 #define current_pt_regs() \
174 ({ \
175 unsigned long sp = (unsigned long)__builtin_frame_address(0); \
176 (struct pt_regs *)((sp | (THREAD_SIZE - 1)) + 1 - 32) - 1; \
177 })
178
179 /* Helpers for working with the user stack pointer */
180
181 static inline unsigned long user_stack_pointer(struct pt_regs *regs)
182 {
183 return regs->regs[29];
184 }
185
186 static inline void user_stack_pointer_set(struct pt_regs *regs,
187 unsigned long val)
188 {
189 regs->regs[29] = val;
190 }
191
192 #endif /* _ASM_PTRACE_H */
193
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