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