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 #include <asm/asm-const.h> 28 29 #ifndef __ASSEMBLY__ 30 struct pt_regs 31 { 32 union { 33 struct user_pt_regs user_regs; 34 struct { 35 unsigned long gpr[32]; 36 unsigned long nip; 37 unsigned long msr; 38 unsigned long orig_gpr3; 39 unsigned long ctr; 40 unsigned long link; 41 unsigned long xer; 42 unsigned long ccr; 43 #ifdef CONFIG_PPC64 44 unsigned long softe; 45 #else 46 unsigned long mq; 47 #endif 48 unsigned long trap; 49 unsigned long dar; 50 unsigned long dsisr; 51 unsigned long result; 52 }; 53 }; 54 55 #ifdef CONFIG_PPC64 56 unsigned long ppr; 57 unsigned long __pad; /* Maintain 16 byte interrupt stack alignment */ 58 #endif 59 }; 60 #endif 61 62 #ifdef __powerpc64__ 63 64 /* 65 * Size of redzone that userspace is allowed to use below the stack 66 * pointer. This is 288 in the 64-bit big-endian ELF ABI, and 512 in 67 * the new ELFv2 little-endian ABI, so we allow the larger amount. 68 * 69 * For kernel code we allow a 288-byte redzone, in order to conserve 70 * kernel stack space; gcc currently only uses 288 bytes, and will 71 * hopefully allow explicit control of the redzone size in future. 72 */ 73 #define USER_REDZONE_SIZE 512 74 #define KERNEL_REDZONE_SIZE 288 75 76 #define STACK_FRAME_OVERHEAD 112 /* size of minimum stack frame */ 77 #define STACK_FRAME_LR_SAVE 2 /* Location of LR in stack frame */ 78 #define STACK_FRAME_REGS_MARKER ASM_CONST(0x7265677368657265) 79 #define STACK_INT_FRAME_SIZE (sizeof(struct pt_regs) + \ 80 STACK_FRAME_OVERHEAD + KERNEL_REDZONE_SIZE) 81 #define STACK_FRAME_MARKER 12 82 83 #ifdef PPC64_ELF_ABI_v2 84 #define STACK_FRAME_MIN_SIZE 32 85 #else 86 #define STACK_FRAME_MIN_SIZE STACK_FRAME_OVERHEAD 87 #endif 88 89 /* Size of dummy stack frame allocated when calling signal handler. */ 90 #define __SIGNAL_FRAMESIZE 128 91 #define __SIGNAL_FRAMESIZE32 64 92 93 #else /* __powerpc64__ */ 94 95 #define USER_REDZONE_SIZE 0 96 #define KERNEL_REDZONE_SIZE 0 97 #define STACK_FRAME_OVERHEAD 16 /* size of minimum stack frame */ 98 #define STACK_FRAME_LR_SAVE 1 /* Location of LR in stack frame */ 99 #define STACK_FRAME_REGS_MARKER ASM_CONST(0x72656773) 100 #define STACK_INT_FRAME_SIZE (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD) 101 #define STACK_FRAME_MARKER 2 102 #define STACK_FRAME_MIN_SIZE STACK_FRAME_OVERHEAD 103 104 /* Size of stack frame allocated when calling signal handler. */ 105 #define __SIGNAL_FRAMESIZE 64 106 107 #endif /* __powerpc64__ */ 108 109 #ifndef __ASSEMBLY__ 110 111 #define GET_IP(regs) ((regs)->nip) 112 #define GET_USP(regs) ((regs)->gpr[1]) 113 #define GET_FP(regs) (0) 114 #define SET_FP(regs, val) 115 116 #ifdef CONFIG_SMP 117 extern unsigned long profile_pc(struct pt_regs *regs); 118 #define profile_pc profile_pc 119 #endif 120 121 #include <asm-generic/ptrace.h> 122 123 #define kernel_stack_pointer(regs) ((regs)->gpr[1]) 124 static inline int is_syscall_success(struct pt_regs *regs) 125 { 126 return !(regs->ccr & 0x10000000); 127 } 128 129 static inline long regs_return_value(struct pt_regs *regs) 130 { 131 if (is_syscall_success(regs)) 132 return regs->gpr[3]; 133 else 134 return -regs->gpr[3]; 135 } 136 137 static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc) 138 { 139 regs->gpr[3] = rc; 140 } 141 142 #ifdef __powerpc64__ 143 #define user_mode(regs) ((((regs)->msr) >> MSR_PR_LG) & 0x1) 144 #else 145 #define user_mode(regs) (((regs)->msr & MSR_PR) != 0) 146 #endif 147 148 #define force_successful_syscall_return() \ 149 do { \ 150 set_thread_flag(TIF_NOERROR); \ 151 } while(0) 152 153 struct task_struct; 154 extern int ptrace_get_reg(struct task_struct *task, int regno, 155 unsigned long *data); 156 extern int ptrace_put_reg(struct task_struct *task, int regno, 157 unsigned long data); 158 159 #define current_pt_regs() \ 160 ((struct pt_regs *)((unsigned long)current_thread_info() + THREAD_SIZE) - 1) 161 /* 162 * We use the least-significant bit of the trap field to indicate 163 * whether we have saved the full set of registers, or only a 164 * partial set. A 1 there means the partial set. 165 * On 4xx we use the next bit to indicate whether the exception 166 * is a critical exception (1 means it is). 167 */ 168 #define FULL_REGS(regs) (((regs)->trap & 1) == 0) 169 #ifndef __powerpc64__ 170 #define IS_CRITICAL_EXC(regs) (((regs)->trap & 2) != 0) 171 #define IS_MCHECK_EXC(regs) (((regs)->trap & 4) != 0) 172 #define IS_DEBUG_EXC(regs) (((regs)->trap & 8) != 0) 173 #endif /* ! __powerpc64__ */ 174 #define TRAP(regs) ((regs)->trap & ~0xF) 175 #ifdef __powerpc64__ 176 #define NV_REG_POISON 0xdeadbeefdeadbeefUL 177 #define CHECK_FULL_REGS(regs) BUG_ON(regs->trap & 1) 178 #else 179 #define NV_REG_POISON 0xdeadbeef 180 #define CHECK_FULL_REGS(regs) \ 181 do { \ 182 if ((regs)->trap & 1) \ 183 printk(KERN_CRIT "%s: partial register set\n", __func__); \ 184 } while (0) 185 #endif /* __powerpc64__ */ 186 187 #define arch_has_single_step() (1) 188 #define arch_has_block_step() (!cpu_has_feature(CPU_FTR_601)) 189 #define ARCH_HAS_USER_SINGLE_STEP_REPORT 190 191 /* 192 * kprobe-based event tracer support 193 */ 194 195 #include <linux/stddef.h> 196 #include <linux/thread_info.h> 197 extern int regs_query_register_offset(const char *name); 198 extern const char *regs_query_register_name(unsigned int offset); 199 #define MAX_REG_OFFSET (offsetof(struct pt_regs, dsisr)) 200 201 /** 202 * regs_get_register() - get register value from its offset 203 * @regs: pt_regs from which register value is gotten 204 * @offset: offset number of the register. 205 * 206 * regs_get_register returns the value of a register whose offset from @regs. 207 * The @offset is the offset of the register in struct pt_regs. 208 * If @offset is bigger than MAX_REG_OFFSET, this returns 0. 209 */ 210 static inline unsigned long regs_get_register(struct pt_regs *regs, 211 unsigned int offset) 212 { 213 if (unlikely(offset > MAX_REG_OFFSET)) 214 return 0; 215 return *(unsigned long *)((unsigned long)regs + offset); 216 } 217 218 /** 219 * regs_within_kernel_stack() - check the address in the stack 220 * @regs: pt_regs which contains kernel stack pointer. 221 * @addr: address which is checked. 222 * 223 * regs_within_kernel_stack() checks @addr is within the kernel stack page(s). 224 * If @addr is within the kernel stack, it returns true. If not, returns false. 225 */ 226 227 static inline bool regs_within_kernel_stack(struct pt_regs *regs, 228 unsigned long addr) 229 { 230 return ((addr & ~(THREAD_SIZE - 1)) == 231 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1))); 232 } 233 234 /** 235 * regs_get_kernel_stack_nth() - get Nth entry of the stack 236 * @regs: pt_regs which contains kernel stack pointer. 237 * @n: stack entry number. 238 * 239 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which 240 * is specified by @regs. If the @n th entry is NOT in the kernel stack, 241 * this returns 0. 242 */ 243 static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, 244 unsigned int n) 245 { 246 unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs); 247 addr += n; 248 if (regs_within_kernel_stack(regs, (unsigned long)addr)) 249 return *addr; 250 else 251 return 0; 252 } 253 254 #endif /* __ASSEMBLY__ */ 255 256 #ifndef __powerpc64__ 257 #else /* __powerpc64__ */ 258 #define PT_FPSCR32 (PT_FPR0 + 2*32 + 1) /* each FP reg occupies 2 32-bit userspace slots */ 259 #define PT_VR0_32 164 /* each Vector reg occupies 4 slots in 32-bit */ 260 #define PT_VSCR_32 (PT_VR0 + 32*4 + 3) 261 #define PT_VRSAVE_32 (PT_VR0 + 33*4) 262 #define PT_VSR0_32 300 /* each VSR reg occupies 4 slots in 32-bit */ 263 #endif /* __powerpc64__ */ 264 #endif /* _ASM_POWERPC_PTRACE_H */ 265