1 /* SPDX-License-Identifier: GPL-2.0-or-later */ 2 /* 3 * Copyright (C) 2001 PPC64 Team, IBM Corp 4 * 5 * This struct defines the way the registers are stored on the 6 * kernel stack during a system call or other kernel entry. 7 * 8 * this should only contain volatile regs 9 * since we can keep non-volatile in the thread_struct 10 * should set this up when only volatiles are saved 11 * by intr code. 12 * 13 * Since this is going on the stack, *CARE MUST BE TAKEN* to insure 14 * that the overall structure is a multiple of 16 bytes in length. 15 * 16 * Note that the offsets of the fields in this struct correspond with 17 * the PT_* values below. This simplifies arch/powerpc/kernel/ptrace.c. 18 */ 19 #ifndef _ASM_POWERPC_PTRACE_H 20 #define _ASM_POWERPC_PTRACE_H 21 22 #include <uapi/asm/ptrace.h> 23 #include <asm/asm-const.h> 24 25 #ifndef __ASSEMBLY__ 26 struct pt_regs 27 { 28 union { 29 struct user_pt_regs user_regs; 30 struct { 31 unsigned long gpr[32]; 32 unsigned long nip; 33 unsigned long msr; 34 unsigned long orig_gpr3; 35 unsigned long ctr; 36 unsigned long link; 37 unsigned long xer; 38 unsigned long ccr; 39 #ifdef CONFIG_PPC64 40 unsigned long softe; 41 #else 42 unsigned long mq; 43 #endif 44 unsigned long trap; 45 unsigned long dar; 46 unsigned long dsisr; 47 unsigned long result; 48 }; 49 }; 50 51 union { 52 struct { 53 #ifdef CONFIG_PPC64 54 unsigned long ppr; 55 #endif 56 #ifdef CONFIG_PPC_KUAP 57 unsigned long kuap; 58 #endif 59 }; 60 unsigned long __pad[2]; /* Maintain 16 byte interrupt stack alignment */ 61 }; 62 }; 63 #endif 64 65 #ifdef __powerpc64__ 66 67 /* 68 * Size of redzone that userspace is allowed to use below the stack 69 * pointer. This is 288 in the 64-bit big-endian ELF ABI, and 512 in 70 * the new ELFv2 little-endian ABI, so we allow the larger amount. 71 * 72 * For kernel code we allow a 288-byte redzone, in order to conserve 73 * kernel stack space; gcc currently only uses 288 bytes, and will 74 * hopefully allow explicit control of the redzone size in future. 75 */ 76 #define USER_REDZONE_SIZE 512 77 #define KERNEL_REDZONE_SIZE 288 78 79 #define STACK_FRAME_OVERHEAD 112 /* size of minimum stack frame */ 80 #define STACK_FRAME_LR_SAVE 2 /* Location of LR in stack frame */ 81 #define STACK_FRAME_REGS_MARKER ASM_CONST(0x7265677368657265) 82 #define STACK_INT_FRAME_SIZE (sizeof(struct pt_regs) + \ 83 STACK_FRAME_OVERHEAD + KERNEL_REDZONE_SIZE) 84 #define STACK_FRAME_MARKER 12 85 86 #ifdef PPC64_ELF_ABI_v2 87 #define STACK_FRAME_MIN_SIZE 32 88 #else 89 #define STACK_FRAME_MIN_SIZE STACK_FRAME_OVERHEAD 90 #endif 91 92 /* Size of dummy stack frame allocated when calling signal handler. */ 93 #define __SIGNAL_FRAMESIZE 128 94 #define __SIGNAL_FRAMESIZE32 64 95 96 #else /* __powerpc64__ */ 97 98 #define USER_REDZONE_SIZE 0 99 #define KERNEL_REDZONE_SIZE 0 100 #define STACK_FRAME_OVERHEAD 16 /* size of minimum stack frame */ 101 #define STACK_FRAME_LR_SAVE 1 /* Location of LR in stack frame */ 102 #define STACK_FRAME_REGS_MARKER ASM_CONST(0x72656773) 103 #define STACK_INT_FRAME_SIZE (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD) 104 #define STACK_FRAME_MARKER 2 105 #define STACK_FRAME_MIN_SIZE STACK_FRAME_OVERHEAD 106 107 /* Size of stack frame allocated when calling signal handler. */ 108 #define __SIGNAL_FRAMESIZE 64 109 110 #endif /* __powerpc64__ */ 111 112 #ifndef __ASSEMBLY__ 113 114 static inline unsigned long instruction_pointer(struct pt_regs *regs) 115 { 116 return regs->nip; 117 } 118 119 static inline void instruction_pointer_set(struct pt_regs *regs, 120 unsigned long val) 121 { 122 regs->nip = val; 123 } 124 125 static inline unsigned long user_stack_pointer(struct pt_regs *regs) 126 { 127 return regs->gpr[1]; 128 } 129 130 static inline unsigned long frame_pointer(struct pt_regs *regs) 131 { 132 return 0; 133 } 134 135 #ifdef CONFIG_SMP 136 extern unsigned long profile_pc(struct pt_regs *regs); 137 #else 138 #define profile_pc(regs) instruction_pointer(regs) 139 #endif 140 141 #define kernel_stack_pointer(regs) ((regs)->gpr[1]) 142 static inline int is_syscall_success(struct pt_regs *regs) 143 { 144 return !(regs->ccr & 0x10000000); 145 } 146 147 static inline long regs_return_value(struct pt_regs *regs) 148 { 149 if (is_syscall_success(regs)) 150 return regs->gpr[3]; 151 else 152 return -regs->gpr[3]; 153 } 154 155 static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc) 156 { 157 regs->gpr[3] = rc; 158 } 159 160 #ifdef __powerpc64__ 161 #define user_mode(regs) ((((regs)->msr) >> MSR_PR_LG) & 0x1) 162 #else 163 #define user_mode(regs) (((regs)->msr & MSR_PR) != 0) 164 #endif 165 166 #define force_successful_syscall_return() \ 167 do { \ 168 set_thread_flag(TIF_NOERROR); \ 169 } while(0) 170 171 struct task_struct; 172 extern int ptrace_get_reg(struct task_struct *task, int regno, 173 unsigned long *data); 174 extern int ptrace_put_reg(struct task_struct *task, int regno, 175 unsigned long data); 176 177 #define current_pt_regs() \ 178 ((struct pt_regs *)((unsigned long)task_stack_page(current) + THREAD_SIZE) - 1) 179 /* 180 * We use the least-significant bit of the trap field to indicate 181 * whether we have saved the full set of registers, or only a 182 * partial set. A 1 there means the partial set. 183 * On 4xx we use the next bit to indicate whether the exception 184 * is a critical exception (1 means it is). 185 */ 186 #define FULL_REGS(regs) (((regs)->trap & 1) == 0) 187 #ifndef __powerpc64__ 188 #define IS_CRITICAL_EXC(regs) (((regs)->trap & 2) != 0) 189 #define IS_MCHECK_EXC(regs) (((regs)->trap & 4) != 0) 190 #define IS_DEBUG_EXC(regs) (((regs)->trap & 8) != 0) 191 #endif /* ! __powerpc64__ */ 192 #define TRAP(regs) ((regs)->trap & ~0xF) 193 #ifdef __powerpc64__ 194 #define NV_REG_POISON 0xdeadbeefdeadbeefUL 195 #define CHECK_FULL_REGS(regs) BUG_ON(regs->trap & 1) 196 #else 197 #define NV_REG_POISON 0xdeadbeef 198 #define CHECK_FULL_REGS(regs) \ 199 do { \ 200 if ((regs)->trap & 1) \ 201 printk(KERN_CRIT "%s: partial register set\n", __func__); \ 202 } while (0) 203 #endif /* __powerpc64__ */ 204 205 #define arch_has_single_step() (1) 206 #define arch_has_block_step() (!cpu_has_feature(CPU_FTR_601)) 207 #define ARCH_HAS_USER_SINGLE_STEP_REPORT 208 209 /* 210 * kprobe-based event tracer support 211 */ 212 213 #include <linux/stddef.h> 214 #include <linux/thread_info.h> 215 extern int regs_query_register_offset(const char *name); 216 extern const char *regs_query_register_name(unsigned int offset); 217 #define MAX_REG_OFFSET (offsetof(struct pt_regs, dsisr)) 218 219 /** 220 * regs_get_register() - get register value from its offset 221 * @regs: pt_regs from which register value is gotten 222 * @offset: offset number of the register. 223 * 224 * regs_get_register returns the value of a register whose offset from @regs. 225 * The @offset is the offset of the register in struct pt_regs. 226 * If @offset is bigger than MAX_REG_OFFSET, this returns 0. 227 */ 228 static inline unsigned long regs_get_register(struct pt_regs *regs, 229 unsigned int offset) 230 { 231 if (unlikely(offset > MAX_REG_OFFSET)) 232 return 0; 233 return *(unsigned long *)((unsigned long)regs + offset); 234 } 235 236 /** 237 * regs_within_kernel_stack() - check the address in the stack 238 * @regs: pt_regs which contains kernel stack pointer. 239 * @addr: address which is checked. 240 * 241 * regs_within_kernel_stack() checks @addr is within the kernel stack page(s). 242 * If @addr is within the kernel stack, it returns true. If not, returns false. 243 */ 244 245 static inline bool regs_within_kernel_stack(struct pt_regs *regs, 246 unsigned long addr) 247 { 248 return ((addr & ~(THREAD_SIZE - 1)) == 249 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1))); 250 } 251 252 /** 253 * regs_get_kernel_stack_nth() - get Nth entry of the stack 254 * @regs: pt_regs which contains kernel stack pointer. 255 * @n: stack entry number. 256 * 257 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which 258 * is specified by @regs. If the @n th entry is NOT in the kernel stack, 259 * this returns 0. 260 */ 261 static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, 262 unsigned int n) 263 { 264 unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs); 265 addr += n; 266 if (regs_within_kernel_stack(regs, (unsigned long)addr)) 267 return *addr; 268 else 269 return 0; 270 } 271 272 #endif /* __ASSEMBLY__ */ 273 274 #ifndef __powerpc64__ 275 #else /* __powerpc64__ */ 276 #define PT_FPSCR32 (PT_FPR0 + 2*32 + 1) /* each FP reg occupies 2 32-bit userspace slots */ 277 #define PT_VR0_32 164 /* each Vector reg occupies 4 slots in 32-bit */ 278 #define PT_VSCR_32 (PT_VR0 + 32*4 + 3) 279 #define PT_VRSAVE_32 (PT_VR0 + 33*4) 280 #define PT_VSR0_32 300 /* each VSR reg occupies 4 slots in 32-bit */ 281 #endif /* __powerpc64__ */ 282 #endif /* _ASM_POWERPC_PTRACE_H */ 283