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 union { 57 #ifdef CONFIG_PPC_KUAP 58 unsigned long kuap; 59 #endif 60 #ifdef CONFIG_PPC_PKEY 61 unsigned long amr; 62 #endif 63 }; 64 }; 65 unsigned long __pad[2]; /* Maintain 16 byte interrupt stack alignment */ 66 }; 67 }; 68 #endif 69 70 #ifdef __powerpc64__ 71 72 /* 73 * Size of redzone that userspace is allowed to use below the stack 74 * pointer. This is 288 in the 64-bit big-endian ELF ABI, and 512 in 75 * the new ELFv2 little-endian ABI, so we allow the larger amount. 76 * 77 * For kernel code we allow a 288-byte redzone, in order to conserve 78 * kernel stack space; gcc currently only uses 288 bytes, and will 79 * hopefully allow explicit control of the redzone size in future. 80 */ 81 #define USER_REDZONE_SIZE 512 82 #define KERNEL_REDZONE_SIZE 288 83 84 #define STACK_FRAME_OVERHEAD 112 /* size of minimum stack frame */ 85 #define STACK_FRAME_LR_SAVE 2 /* Location of LR in stack frame */ 86 #define STACK_FRAME_REGS_MARKER ASM_CONST(0x7265677368657265) 87 #define STACK_INT_FRAME_SIZE (sizeof(struct pt_regs) + \ 88 STACK_FRAME_OVERHEAD + KERNEL_REDZONE_SIZE) 89 #define STACK_FRAME_MARKER 12 90 91 #ifdef PPC64_ELF_ABI_v2 92 #define STACK_FRAME_MIN_SIZE 32 93 #else 94 #define STACK_FRAME_MIN_SIZE STACK_FRAME_OVERHEAD 95 #endif 96 97 /* Size of dummy stack frame allocated when calling signal handler. */ 98 #define __SIGNAL_FRAMESIZE 128 99 #define __SIGNAL_FRAMESIZE32 64 100 101 #else /* __powerpc64__ */ 102 103 #define USER_REDZONE_SIZE 0 104 #define KERNEL_REDZONE_SIZE 0 105 #define STACK_FRAME_OVERHEAD 16 /* size of minimum stack frame */ 106 #define STACK_FRAME_LR_SAVE 1 /* Location of LR in stack frame */ 107 #define STACK_FRAME_REGS_MARKER ASM_CONST(0x72656773) 108 #define STACK_INT_FRAME_SIZE (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD) 109 #define STACK_FRAME_MARKER 2 110 #define STACK_FRAME_MIN_SIZE STACK_FRAME_OVERHEAD 111 112 /* Size of stack frame allocated when calling signal handler. */ 113 #define __SIGNAL_FRAMESIZE 64 114 115 #endif /* __powerpc64__ */ 116 117 #ifndef __ASSEMBLY__ 118 119 static inline unsigned long instruction_pointer(struct pt_regs *regs) 120 { 121 return regs->nip; 122 } 123 124 static inline void instruction_pointer_set(struct pt_regs *regs, 125 unsigned long val) 126 { 127 regs->nip = val; 128 } 129 130 static inline unsigned long user_stack_pointer(struct pt_regs *regs) 131 { 132 return regs->gpr[1]; 133 } 134 135 static inline unsigned long frame_pointer(struct pt_regs *regs) 136 { 137 return 0; 138 } 139 140 #ifdef CONFIG_SMP 141 extern unsigned long profile_pc(struct pt_regs *regs); 142 #else 143 #define profile_pc(regs) instruction_pointer(regs) 144 #endif 145 146 long do_syscall_trace_enter(struct pt_regs *regs); 147 void do_syscall_trace_leave(struct pt_regs *regs); 148 149 #define kernel_stack_pointer(regs) ((regs)->gpr[1]) 150 static inline int is_syscall_success(struct pt_regs *regs) 151 { 152 return !(regs->ccr & 0x10000000); 153 } 154 155 static inline long regs_return_value(struct pt_regs *regs) 156 { 157 if (is_syscall_success(regs)) 158 return regs->gpr[3]; 159 else 160 return -regs->gpr[3]; 161 } 162 163 static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc) 164 { 165 regs->gpr[3] = rc; 166 } 167 168 #ifdef __powerpc64__ 169 #define user_mode(regs) ((((regs)->msr) >> MSR_PR_LG) & 0x1) 170 #else 171 #define user_mode(regs) (((regs)->msr & MSR_PR) != 0) 172 #endif 173 174 #define force_successful_syscall_return() \ 175 do { \ 176 set_thread_flag(TIF_NOERROR); \ 177 } while(0) 178 179 #define current_pt_regs() \ 180 ((struct pt_regs *)((unsigned long)task_stack_page(current) + THREAD_SIZE) - 1) 181 182 #ifdef __powerpc64__ 183 #ifdef CONFIG_PPC_BOOK3S 184 #define TRAP_FLAGS_MASK 0x10 185 #define TRAP(regs) ((regs)->trap & ~TRAP_FLAGS_MASK) 186 #define FULL_REGS(regs) true 187 #define SET_FULL_REGS(regs) do { } while (0) 188 #else 189 #define TRAP_FLAGS_MASK 0x11 190 #define TRAP(regs) ((regs)->trap & ~TRAP_FLAGS_MASK) 191 #define FULL_REGS(regs) (((regs)->trap & 1) == 0) 192 #define SET_FULL_REGS(regs) ((regs)->trap |= 1) 193 #endif 194 #define CHECK_FULL_REGS(regs) BUG_ON(!FULL_REGS(regs)) 195 #define NV_REG_POISON 0xdeadbeefdeadbeefUL 196 #else 197 /* 198 * We use the least-significant bit of the trap field to indicate 199 * whether we have saved the full set of registers, or only a 200 * partial set. A 1 there means the partial set. 201 * On 4xx we use the next bit to indicate whether the exception 202 * is a critical exception (1 means it is). 203 */ 204 #define TRAP_FLAGS_MASK 0x1F 205 #define TRAP(regs) ((regs)->trap & ~TRAP_FLAGS_MASK) 206 #define FULL_REGS(regs) (((regs)->trap & 1) == 0) 207 #define SET_FULL_REGS(regs) ((regs)->trap |= 1) 208 #define IS_CRITICAL_EXC(regs) (((regs)->trap & 2) != 0) 209 #define IS_MCHECK_EXC(regs) (((regs)->trap & 4) != 0) 210 #define IS_DEBUG_EXC(regs) (((regs)->trap & 8) != 0) 211 #define NV_REG_POISON 0xdeadbeef 212 #define CHECK_FULL_REGS(regs) \ 213 do { \ 214 if ((regs)->trap & 1) \ 215 printk(KERN_CRIT "%s: partial register set\n", __func__); \ 216 } while (0) 217 #endif /* __powerpc64__ */ 218 219 static inline void set_trap(struct pt_regs *regs, unsigned long val) 220 { 221 regs->trap = (regs->trap & TRAP_FLAGS_MASK) | (val & ~TRAP_FLAGS_MASK); 222 } 223 224 static inline bool trap_is_scv(struct pt_regs *regs) 225 { 226 return (IS_ENABLED(CONFIG_PPC_BOOK3S_64) && TRAP(regs) == 0x3000); 227 } 228 229 static inline bool trap_is_syscall(struct pt_regs *regs) 230 { 231 return (trap_is_scv(regs) || TRAP(regs) == 0xc00); 232 } 233 234 static inline bool trap_norestart(struct pt_regs *regs) 235 { 236 return regs->trap & 0x10; 237 } 238 239 static inline void set_trap_norestart(struct pt_regs *regs) 240 { 241 regs->trap |= 0x10; 242 } 243 244 #define arch_has_single_step() (1) 245 #define arch_has_block_step() (true) 246 #define ARCH_HAS_USER_SINGLE_STEP_REPORT 247 248 /* 249 * kprobe-based event tracer support 250 */ 251 252 #include <linux/stddef.h> 253 #include <linux/thread_info.h> 254 extern int regs_query_register_offset(const char *name); 255 extern const char *regs_query_register_name(unsigned int offset); 256 #define MAX_REG_OFFSET (offsetof(struct pt_regs, dsisr)) 257 258 /** 259 * regs_get_register() - get register value from its offset 260 * @regs: pt_regs from which register value is gotten 261 * @offset: offset number of the register. 262 * 263 * regs_get_register returns the value of a register whose offset from @regs. 264 * The @offset is the offset of the register in struct pt_regs. 265 * If @offset is bigger than MAX_REG_OFFSET, this returns 0. 266 */ 267 static inline unsigned long regs_get_register(struct pt_regs *regs, 268 unsigned int offset) 269 { 270 if (unlikely(offset > MAX_REG_OFFSET)) 271 return 0; 272 return *(unsigned long *)((unsigned long)regs + offset); 273 } 274 275 /** 276 * regs_within_kernel_stack() - check the address in the stack 277 * @regs: pt_regs which contains kernel stack pointer. 278 * @addr: address which is checked. 279 * 280 * regs_within_kernel_stack() checks @addr is within the kernel stack page(s). 281 * If @addr is within the kernel stack, it returns true. If not, returns false. 282 */ 283 284 static inline bool regs_within_kernel_stack(struct pt_regs *regs, 285 unsigned long addr) 286 { 287 return ((addr & ~(THREAD_SIZE - 1)) == 288 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1))); 289 } 290 291 /** 292 * regs_get_kernel_stack_nth() - get Nth entry of the stack 293 * @regs: pt_regs which contains kernel stack pointer. 294 * @n: stack entry number. 295 * 296 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which 297 * is specified by @regs. If the @n th entry is NOT in the kernel stack, 298 * this returns 0. 299 */ 300 static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, 301 unsigned int n) 302 { 303 unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs); 304 addr += n; 305 if (regs_within_kernel_stack(regs, (unsigned long)addr)) 306 return *addr; 307 else 308 return 0; 309 } 310 311 #endif /* __ASSEMBLY__ */ 312 313 #ifndef __powerpc64__ 314 /* We need PT_SOFTE defined at all time to avoid #ifdefs */ 315 #define PT_SOFTE PT_MQ 316 #else /* __powerpc64__ */ 317 #define PT_FPSCR32 (PT_FPR0 + 2*32 + 1) /* each FP reg occupies 2 32-bit userspace slots */ 318 #define PT_VR0_32 164 /* each Vector reg occupies 4 slots in 32-bit */ 319 #define PT_VSCR_32 (PT_VR0 + 32*4 + 3) 320 #define PT_VRSAVE_32 (PT_VR0 + 33*4) 321 #define PT_VSR0_32 300 /* each VSR reg occupies 4 slots in 32-bit */ 322 #endif /* __powerpc64__ */ 323 #endif /* _ASM_POWERPC_PTRACE_H */ 324