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 /* Saved syscall stack arguments; entries 0-3 unused. */
31 unsigned long args[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
kernel_stack_pointer(struct pt_regs * regs)54 static inline unsigned long kernel_stack_pointer(struct pt_regs *regs)
55 {
56 return regs->regs[29];
57 }
58
instruction_pointer_set(struct pt_regs * regs,unsigned long val)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 \
69 (offsetof(struct pt_regs, __last) - sizeof(unsigned long))
70
71 /**
72 * regs_get_register() - get register value from its offset
73 * @regs: pt_regs from which register value is gotten.
74 * @offset: offset number of the register.
75 *
76 * regs_get_register returns the value of a register. The @offset is the
77 * offset of the register in struct pt_regs address which specified by @regs.
78 * If @offset is bigger than MAX_REG_OFFSET, this returns 0.
79 */
regs_get_register(struct pt_regs * regs,unsigned int offset)80 static inline unsigned long regs_get_register(struct pt_regs *regs,
81 unsigned int offset)
82 {
83 if (unlikely(offset > MAX_REG_OFFSET))
84 return 0;
85
86 return *(unsigned long *)((unsigned long)regs + offset);
87 }
88
89 /**
90 * regs_within_kernel_stack() - check the address in the stack
91 * @regs: pt_regs which contains kernel stack pointer.
92 * @addr: address which is checked.
93 *
94 * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
95 * If @addr is within the kernel stack, it returns true. If not, returns false.
96 */
regs_within_kernel_stack(struct pt_regs * regs,unsigned long addr)97 static inline int regs_within_kernel_stack(struct pt_regs *regs,
98 unsigned long addr)
99 {
100 return ((addr & ~(THREAD_SIZE - 1)) ==
101 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)));
102 }
103
104 /**
105 * regs_get_kernel_stack_nth() - get Nth entry of the stack
106 * @regs: pt_regs which contains kernel stack pointer.
107 * @n: stack entry number.
108 *
109 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
110 * is specified by @regs. If the @n th entry is NOT in the kernel stack,
111 * this returns 0.
112 */
regs_get_kernel_stack_nth(struct pt_regs * regs,unsigned int n)113 static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
114 unsigned int n)
115 {
116 unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
117
118 addr += n;
119 if (regs_within_kernel_stack(regs, (unsigned long)addr))
120 return *addr;
121 else
122 return 0;
123 }
124
125 struct task_struct;
126
127 extern int ptrace_getregs(struct task_struct *child,
128 struct user_pt_regs __user *data);
129 extern int ptrace_setregs(struct task_struct *child,
130 struct user_pt_regs __user *data);
131
132 extern int ptrace_getfpregs(struct task_struct *child, __u32 __user *data);
133 extern int ptrace_setfpregs(struct task_struct *child, __u32 __user *data);
134
135 extern int ptrace_get_watch_regs(struct task_struct *child,
136 struct pt_watch_regs __user *addr);
137 extern int ptrace_set_watch_regs(struct task_struct *child,
138 struct pt_watch_regs __user *addr);
139
140 /*
141 * Does the process account for user or for system time?
142 */
143 #define user_mode(regs) (((regs)->cp0_status & KU_MASK) == KU_USER)
144
is_syscall_success(struct pt_regs * regs)145 static inline int is_syscall_success(struct pt_regs *regs)
146 {
147 return !regs->regs[7];
148 }
149
regs_return_value(struct pt_regs * regs)150 static inline long regs_return_value(struct pt_regs *regs)
151 {
152 if (is_syscall_success(regs) || !user_mode(regs))
153 return regs->regs[2];
154 else
155 return -regs->regs[2];
156 }
157
158 #define instruction_pointer(regs) ((regs)->cp0_epc)
159 extern unsigned long exception_ip(struct pt_regs *regs);
160 #define exception_ip(regs) exception_ip(regs)
161 #define profile_pc(regs) instruction_pointer(regs)
162
163 extern asmlinkage long syscall_trace_enter(struct pt_regs *regs);
164 extern asmlinkage void syscall_trace_leave(struct pt_regs *regs);
165
166 extern void die(const char *, struct pt_regs *) __noreturn;
167
die_if_kernel(const char * str,struct pt_regs * regs)168 static inline void die_if_kernel(const char *str, struct pt_regs *regs)
169 {
170 if (unlikely(!user_mode(regs)))
171 die(str, regs);
172 }
173
174 #define current_pt_regs() \
175 ({ \
176 unsigned long sp = (unsigned long)__builtin_frame_address(0); \
177 (struct pt_regs *)((sp | (THREAD_SIZE - 1)) + 1 - 32) - 1; \
178 })
179
180 /* Helpers for working with the user stack pointer */
181
user_stack_pointer(struct pt_regs * regs)182 static inline unsigned long user_stack_pointer(struct pt_regs *regs)
183 {
184 return regs->regs[29];
185 }
186
user_stack_pointer_set(struct pt_regs * regs,unsigned long val)187 static inline void user_stack_pointer_set(struct pt_regs *regs,
188 unsigned long val)
189 {
190 regs->regs[29] = val;
191 }
192
193 #endif /* _ASM_PTRACE_H */
194