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 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 \ 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 */ 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 */ 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 */ 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) 144 145 static inline int is_syscall_success(struct pt_regs *regs) 146 { 147 return !regs->regs[7]; 148 } 149 150 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; 167 168 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 */ 181 182 static inline unsigned long user_stack_pointer(struct pt_regs *regs) 183 { 184 return regs->regs[29]; 185 } 186 187 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