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 } 64 65 /* Query offset/name of register from its name/offset */ 66 extern int regs_query_register_offset(const char *name); 67 #define MAX_REG_OFFSET (offsetof(struct pt_regs, __last)) 68 69 /** 70 * regs_get_register() - get register value from its offset 71 * @regs: pt_regs from which register value is gotten. 72 * @offset: offset number of the register. 73 * 74 * regs_get_register returns the value of a register. The @offset is the 75 * offset of the register in struct pt_regs address which specified by @regs. 76 * If @offset is bigger than MAX_REG_OFFSET, this returns 0. 77 */ 78 static inline unsigned long regs_get_register(struct pt_regs *regs, 79 unsigned int offset) 80 { 81 if (unlikely(offset > MAX_REG_OFFSET)) 82 return 0; 83 84 return *(unsigned long *)((unsigned long)regs + offset); 85 } 86 87 /** 88 * regs_within_kernel_stack() - check the address in the stack 89 * @regs: pt_regs which contains kernel stack pointer. 90 * @addr: address which is checked. 91 * 92 * regs_within_kernel_stack() checks @addr is within the kernel stack page(s). 93 * If @addr is within the kernel stack, it returns true. If not, returns false. 94 */ 95 static inline int regs_within_kernel_stack(struct pt_regs *regs, 96 unsigned long addr) 97 { 98 return ((addr & ~(THREAD_SIZE - 1)) == 99 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1))); 100 } 101 102 /** 103 * regs_get_kernel_stack_nth() - get Nth entry of the stack 104 * @regs: pt_regs which contains kernel stack pointer. 105 * @n: stack entry number. 106 * 107 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which 108 * is specified by @regs. If the @n th entry is NOT in the kernel stack, 109 * this returns 0. 110 */ 111 static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, 112 unsigned int n) 113 { 114 unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs); 115 116 addr += n; 117 if (regs_within_kernel_stack(regs, (unsigned long)addr)) 118 return *addr; 119 else 120 return 0; 121 } 122 123 struct task_struct; 124 125 extern int ptrace_getregs(struct task_struct *child, 126 struct user_pt_regs __user *data); 127 extern int ptrace_setregs(struct task_struct *child, 128 struct user_pt_regs __user *data); 129 130 extern int ptrace_getfpregs(struct task_struct *child, __u32 __user *data); 131 extern int ptrace_setfpregs(struct task_struct *child, __u32 __user *data); 132 133 extern int ptrace_get_watch_regs(struct task_struct *child, 134 struct pt_watch_regs __user *addr); 135 extern int ptrace_set_watch_regs(struct task_struct *child, 136 struct pt_watch_regs __user *addr); 137 138 /* 139 * Does the process account for user or for system time? 140 */ 141 #define user_mode(regs) (((regs)->cp0_status & KU_MASK) == KU_USER) 142 143 static inline int is_syscall_success(struct pt_regs *regs) 144 { 145 return !regs->regs[7]; 146 } 147 148 static inline long regs_return_value(struct pt_regs *regs) 149 { 150 if (is_syscall_success(regs) || !user_mode(regs)) 151 return regs->regs[2]; 152 else 153 return -regs->regs[2]; 154 } 155 156 #define instruction_pointer(regs) ((regs)->cp0_epc) 157 #define profile_pc(regs) instruction_pointer(regs) 158 159 extern asmlinkage long syscall_trace_enter(struct pt_regs *regs, long syscall); 160 extern asmlinkage void syscall_trace_leave(struct pt_regs *regs); 161 162 extern void die(const char *, struct pt_regs *) __noreturn; 163 164 static inline void die_if_kernel(const char *str, struct pt_regs *regs) 165 { 166 if (unlikely(!user_mode(regs))) 167 die(str, regs); 168 } 169 170 #define current_pt_regs() \ 171 ({ \ 172 unsigned long sp = (unsigned long)__builtin_frame_address(0); \ 173 (struct pt_regs *)((sp | (THREAD_SIZE - 1)) + 1 - 32) - 1; \ 174 }) 175 176 /* Helpers for working with the user stack pointer */ 177 178 static inline unsigned long user_stack_pointer(struct pt_regs *regs) 179 { 180 return regs->regs[29]; 181 } 182 183 static inline void user_stack_pointer_set(struct pt_regs *regs, 184 unsigned long val) 185 { 186 regs->regs[29] = val; 187 } 188 189 #endif /* _ASM_PTRACE_H */ 190