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[31]; 57 } 58 59 /* 60 * Don't use asm-generic/ptrace.h it defines FP accessors that don't make 61 * sense on MIPS. We rather want an error if they get invoked. 62 */ 63 64 static inline void instruction_pointer_set(struct pt_regs *regs, 65 unsigned long val) 66 { 67 regs->cp0_epc = val; 68 } 69 70 /* Query offset/name of register from its name/offset */ 71 extern int regs_query_register_offset(const char *name); 72 #define MAX_REG_OFFSET (offsetof(struct pt_regs, __last)) 73 74 /** 75 * regs_get_register() - get register value from its offset 76 * @regs: pt_regs from which register value is gotten. 77 * @offset: offset number of the register. 78 * 79 * regs_get_register returns the value of a register. The @offset is the 80 * offset of the register in struct pt_regs address which specified by @regs. 81 * If @offset is bigger than MAX_REG_OFFSET, this returns 0. 82 */ 83 static inline unsigned long regs_get_register(struct pt_regs *regs, 84 unsigned int offset) 85 { 86 if (unlikely(offset > MAX_REG_OFFSET)) 87 return 0; 88 89 return *(unsigned long *)((unsigned long)regs + offset); 90 } 91 92 /** 93 * regs_within_kernel_stack() - check the address in the stack 94 * @regs: pt_regs which contains kernel stack pointer. 95 * @addr: address which is checked. 96 * 97 * regs_within_kernel_stack() checks @addr is within the kernel stack page(s). 98 * If @addr is within the kernel stack, it returns true. If not, returns false. 99 */ 100 static inline int regs_within_kernel_stack(struct pt_regs *regs, 101 unsigned long addr) 102 { 103 return ((addr & ~(THREAD_SIZE - 1)) == 104 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1))); 105 } 106 107 /** 108 * regs_get_kernel_stack_nth() - get Nth entry of the stack 109 * @regs: pt_regs which contains kernel stack pointer. 110 * @n: stack entry number. 111 * 112 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which 113 * is specified by @regs. If the @n th entry is NOT in the kernel stack, 114 * this returns 0. 115 */ 116 static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, 117 unsigned int n) 118 { 119 unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs); 120 121 addr += n; 122 if (regs_within_kernel_stack(regs, (unsigned long)addr)) 123 return *addr; 124 else 125 return 0; 126 } 127 128 struct task_struct; 129 130 extern int ptrace_getregs(struct task_struct *child, 131 struct user_pt_regs __user *data); 132 extern int ptrace_setregs(struct task_struct *child, 133 struct user_pt_regs __user *data); 134 135 extern int ptrace_getfpregs(struct task_struct *child, __u32 __user *data); 136 extern int ptrace_setfpregs(struct task_struct *child, __u32 __user *data); 137 138 extern int ptrace_get_watch_regs(struct task_struct *child, 139 struct pt_watch_regs __user *addr); 140 extern int ptrace_set_watch_regs(struct task_struct *child, 141 struct pt_watch_regs __user *addr); 142 143 /* 144 * Does the process account for user or for system time? 145 */ 146 #define user_mode(regs) (((regs)->cp0_status & KU_MASK) == KU_USER) 147 148 static inline int is_syscall_success(struct pt_regs *regs) 149 { 150 return !regs->regs[7]; 151 } 152 153 static inline long regs_return_value(struct pt_regs *regs) 154 { 155 if (is_syscall_success(regs) || !user_mode(regs)) 156 return regs->regs[2]; 157 else 158 return -regs->regs[2]; 159 } 160 161 #define instruction_pointer(regs) ((regs)->cp0_epc) 162 #define profile_pc(regs) instruction_pointer(regs) 163 164 extern asmlinkage long syscall_trace_enter(struct pt_regs *regs, long syscall); 165 extern asmlinkage void syscall_trace_leave(struct pt_regs *regs); 166 167 extern void die(const char *, struct pt_regs *) __noreturn; 168 169 static inline void die_if_kernel(const char *str, struct pt_regs *regs) 170 { 171 if (unlikely(!user_mode(regs))) 172 die(str, regs); 173 } 174 175 #define current_pt_regs() \ 176 ({ \ 177 unsigned long sp = (unsigned long)__builtin_frame_address(0); \ 178 (struct pt_regs *)((sp | (THREAD_SIZE - 1)) + 1 - 32) - 1; \ 179 }) 180 181 /* Helpers for working with the user stack pointer */ 182 183 static inline unsigned long user_stack_pointer(struct pt_regs *regs) 184 { 185 return regs->regs[29]; 186 } 187 188 static inline void user_stack_pointer_set(struct pt_regs *regs, 189 unsigned long val) 190 { 191 regs->regs[29] = val; 192 } 193 194 #endif /* _ASM_PTRACE_H */ 195