1 /* 2 * Copyright (C) 2001 PPC64 Team, IBM Corp 3 * 4 * This struct defines the way the registers are stored on the 5 * kernel stack during a system call or other kernel entry. 6 * 7 * this should only contain volatile regs 8 * since we can keep non-volatile in the thread_struct 9 * should set this up when only volatiles are saved 10 * by intr code. 11 * 12 * Since this is going on the stack, *CARE MUST BE TAKEN* to insure 13 * that the overall structure is a multiple of 16 bytes in length. 14 * 15 * Note that the offsets of the fields in this struct correspond with 16 * the PT_* values below. This simplifies arch/powerpc/kernel/ptrace.c. 17 * 18 * This program is free software; you can redistribute it and/or 19 * modify it under the terms of the GNU General Public License 20 * as published by the Free Software Foundation; either version 21 * 2 of the License, or (at your option) any later version. 22 */ 23 #ifndef _ASM_POWERPC_PTRACE_H 24 #define _ASM_POWERPC_PTRACE_H 25 26 #include <uapi/asm/ptrace.h> 27 28 29 #ifdef __powerpc64__ 30 31 /* 32 * Size of redzone that userspace is allowed to use below the stack 33 * pointer. This is 288 in the 64-bit big-endian ELF ABI, and 512 in 34 * the new ELFv2 little-endian ABI, so we allow the larger amount. 35 * 36 * For kernel code we allow a 288-byte redzone, in order to conserve 37 * kernel stack space; gcc currently only uses 288 bytes, and will 38 * hopefully allow explicit control of the redzone size in future. 39 */ 40 #define USER_REDZONE_SIZE 512 41 #define KERNEL_REDZONE_SIZE 288 42 43 #define STACK_FRAME_OVERHEAD 112 /* size of minimum stack frame */ 44 #define STACK_FRAME_LR_SAVE 2 /* Location of LR in stack frame */ 45 #define STACK_FRAME_REGS_MARKER ASM_CONST(0x7265677368657265) 46 #define STACK_INT_FRAME_SIZE (sizeof(struct pt_regs) + \ 47 STACK_FRAME_OVERHEAD + KERNEL_REDZONE_SIZE) 48 #define STACK_FRAME_MARKER 12 49 50 #if defined(_CALL_ELF) && _CALL_ELF == 2 51 #define STACK_FRAME_MIN_SIZE 32 52 #else 53 #define STACK_FRAME_MIN_SIZE STACK_FRAME_OVERHEAD 54 #endif 55 56 /* Size of dummy stack frame allocated when calling signal handler. */ 57 #define __SIGNAL_FRAMESIZE 128 58 #define __SIGNAL_FRAMESIZE32 64 59 60 #else /* __powerpc64__ */ 61 62 #define USER_REDZONE_SIZE 0 63 #define KERNEL_REDZONE_SIZE 0 64 #define STACK_FRAME_OVERHEAD 16 /* size of minimum stack frame */ 65 #define STACK_FRAME_LR_SAVE 1 /* Location of LR in stack frame */ 66 #define STACK_FRAME_REGS_MARKER ASM_CONST(0x72656773) 67 #define STACK_INT_FRAME_SIZE (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD) 68 #define STACK_FRAME_MARKER 2 69 #define STACK_FRAME_MIN_SIZE STACK_FRAME_OVERHEAD 70 71 /* Size of stack frame allocated when calling signal handler. */ 72 #define __SIGNAL_FRAMESIZE 64 73 74 #endif /* __powerpc64__ */ 75 76 #ifndef __ASSEMBLY__ 77 78 #define GET_IP(regs) ((regs)->nip) 79 #define GET_USP(regs) ((regs)->gpr[1]) 80 #define GET_FP(regs) (0) 81 #define SET_FP(regs, val) 82 83 #ifdef CONFIG_SMP 84 extern unsigned long profile_pc(struct pt_regs *regs); 85 #define profile_pc profile_pc 86 #endif 87 88 #include <asm-generic/ptrace.h> 89 90 #define kernel_stack_pointer(regs) ((regs)->gpr[1]) 91 static inline int is_syscall_success(struct pt_regs *regs) 92 { 93 return !(regs->ccr & 0x10000000); 94 } 95 96 static inline long regs_return_value(struct pt_regs *regs) 97 { 98 if (is_syscall_success(regs)) 99 return regs->gpr[3]; 100 else 101 return -regs->gpr[3]; 102 } 103 104 #ifdef __powerpc64__ 105 #define user_mode(regs) ((((regs)->msr) >> MSR_PR_LG) & 0x1) 106 #else 107 #define user_mode(regs) (((regs)->msr & MSR_PR) != 0) 108 #endif 109 110 #define force_successful_syscall_return() \ 111 do { \ 112 set_thread_flag(TIF_NOERROR); \ 113 } while(0) 114 115 struct task_struct; 116 extern int ptrace_get_reg(struct task_struct *task, int regno, 117 unsigned long *data); 118 extern int ptrace_put_reg(struct task_struct *task, int regno, 119 unsigned long data); 120 121 #define current_pt_regs() \ 122 ((struct pt_regs *)((unsigned long)current_thread_info() + THREAD_SIZE) - 1) 123 /* 124 * We use the least-significant bit of the trap field to indicate 125 * whether we have saved the full set of registers, or only a 126 * partial set. A 1 there means the partial set. 127 * On 4xx we use the next bit to indicate whether the exception 128 * is a critical exception (1 means it is). 129 */ 130 #define FULL_REGS(regs) (((regs)->trap & 1) == 0) 131 #ifndef __powerpc64__ 132 #define IS_CRITICAL_EXC(regs) (((regs)->trap & 2) != 0) 133 #define IS_MCHECK_EXC(regs) (((regs)->trap & 4) != 0) 134 #define IS_DEBUG_EXC(regs) (((regs)->trap & 8) != 0) 135 #endif /* ! __powerpc64__ */ 136 #define TRAP(regs) ((regs)->trap & ~0xF) 137 #ifdef __powerpc64__ 138 #define NV_REG_POISON 0xdeadbeefdeadbeefUL 139 #define CHECK_FULL_REGS(regs) BUG_ON(regs->trap & 1) 140 #else 141 #define NV_REG_POISON 0xdeadbeef 142 #define CHECK_FULL_REGS(regs) \ 143 do { \ 144 if ((regs)->trap & 1) \ 145 printk(KERN_CRIT "%s: partial register set\n", __func__); \ 146 } while (0) 147 #endif /* __powerpc64__ */ 148 149 #define arch_has_single_step() (1) 150 #define arch_has_block_step() (!cpu_has_feature(CPU_FTR_601)) 151 #define ARCH_HAS_USER_SINGLE_STEP_INFO 152 153 /* 154 * kprobe-based event tracer support 155 */ 156 157 #include <linux/stddef.h> 158 #include <linux/thread_info.h> 159 extern int regs_query_register_offset(const char *name); 160 extern const char *regs_query_register_name(unsigned int offset); 161 #define MAX_REG_OFFSET (offsetof(struct pt_regs, dsisr)) 162 163 /** 164 * regs_get_register() - get register value from its offset 165 * @regs: pt_regs from which register value is gotten 166 * @offset: offset number of the register. 167 * 168 * regs_get_register returns the value of a register whose offset from @regs. 169 * The @offset is the offset of the register in struct pt_regs. 170 * If @offset is bigger than MAX_REG_OFFSET, this returns 0. 171 */ 172 static inline unsigned long regs_get_register(struct pt_regs *regs, 173 unsigned int offset) 174 { 175 if (unlikely(offset > MAX_REG_OFFSET)) 176 return 0; 177 return *(unsigned long *)((unsigned long)regs + offset); 178 } 179 180 /** 181 * regs_within_kernel_stack() - check the address in the stack 182 * @regs: pt_regs which contains kernel stack pointer. 183 * @addr: address which is checked. 184 * 185 * regs_within_kernel_stack() checks @addr is within the kernel stack page(s). 186 * If @addr is within the kernel stack, it returns true. If not, returns false. 187 */ 188 189 static inline bool regs_within_kernel_stack(struct pt_regs *regs, 190 unsigned long addr) 191 { 192 return ((addr & ~(THREAD_SIZE - 1)) == 193 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1))); 194 } 195 196 /** 197 * regs_get_kernel_stack_nth() - get Nth entry of the stack 198 * @regs: pt_regs which contains kernel stack pointer. 199 * @n: stack entry number. 200 * 201 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which 202 * is specified by @regs. If the @n th entry is NOT in the kernel stack, 203 * this returns 0. 204 */ 205 static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, 206 unsigned int n) 207 { 208 unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs); 209 addr += n; 210 if (regs_within_kernel_stack(regs, (unsigned long)addr)) 211 return *addr; 212 else 213 return 0; 214 } 215 216 #endif /* __ASSEMBLY__ */ 217 218 #ifndef __powerpc64__ 219 #else /* __powerpc64__ */ 220 #define PT_FPSCR32 (PT_FPR0 + 2*32 + 1) /* each FP reg occupies 2 32-bit userspace slots */ 221 #define PT_VR0_32 164 /* each Vector reg occupies 4 slots in 32-bit */ 222 #define PT_VSCR_32 (PT_VR0 + 32*4 + 3) 223 #define PT_VRSAVE_32 (PT_VR0 + 33*4) 224 #define PT_VSR0_32 300 /* each VSR reg occupies 4 slots in 32-bit */ 225 #endif /* __powerpc64__ */ 226 #endif /* _ASM_POWERPC_PTRACE_H */ 227