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