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