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 <linux/err.h> 23 #include <uapi/asm/ptrace.h> 24 #include <asm/asm-const.h> 25 #include <asm/reg.h> 26 27 #ifndef __ASSEMBLY__ 28 struct pt_regs 29 { 30 union { 31 struct user_pt_regs user_regs; 32 struct { 33 unsigned long gpr[32]; 34 unsigned long nip; 35 unsigned long msr; 36 unsigned long orig_gpr3; 37 unsigned long ctr; 38 unsigned long link; 39 unsigned long xer; 40 unsigned long ccr; 41 #ifdef CONFIG_PPC64 42 unsigned long softe; 43 #else 44 unsigned long mq; 45 #endif 46 unsigned long trap; 47 union { 48 unsigned long dar; 49 unsigned long dear; 50 }; 51 union { 52 unsigned long dsisr; 53 unsigned long esr; 54 }; 55 unsigned long result; 56 }; 57 }; 58 #if defined(CONFIG_PPC64) || defined(CONFIG_PPC_KUAP) 59 union { 60 struct { 61 #ifdef CONFIG_PPC64 62 unsigned long ppr; 63 unsigned long exit_result; 64 #endif 65 union { 66 #ifdef CONFIG_PPC_KUAP 67 unsigned long kuap; 68 #endif 69 #ifdef CONFIG_PPC_PKEY 70 unsigned long amr; 71 #endif 72 }; 73 #ifdef CONFIG_PPC_PKEY 74 unsigned long iamr; 75 #endif 76 }; 77 unsigned long __pad[4]; /* Maintain 16 byte interrupt stack alignment */ 78 }; 79 #endif 80 #if defined(CONFIG_PPC32) && defined(CONFIG_BOOKE) 81 struct { /* Must be a multiple of 16 bytes */ 82 unsigned long mas0; 83 unsigned long mas1; 84 unsigned long mas2; 85 unsigned long mas3; 86 unsigned long mas6; 87 unsigned long mas7; 88 unsigned long srr0; 89 unsigned long srr1; 90 unsigned long csrr0; 91 unsigned long csrr1; 92 unsigned long dsrr0; 93 unsigned long dsrr1; 94 }; 95 #endif 96 }; 97 #endif 98 99 100 #define STACK_FRAME_WITH_PT_REGS (STACK_FRAME_OVERHEAD + sizeof(struct pt_regs)) 101 102 #ifdef __powerpc64__ 103 104 /* 105 * Size of redzone that userspace is allowed to use below the stack 106 * pointer. This is 288 in the 64-bit big-endian ELF ABI, and 512 in 107 * the new ELFv2 little-endian ABI, so we allow the larger amount. 108 * 109 * For kernel code we allow a 288-byte redzone, in order to conserve 110 * kernel stack space; gcc currently only uses 288 bytes, and will 111 * hopefully allow explicit control of the redzone size in future. 112 */ 113 #define USER_REDZONE_SIZE 512 114 #define KERNEL_REDZONE_SIZE 288 115 116 #define STACK_FRAME_OVERHEAD 112 /* size of minimum stack frame */ 117 #define STACK_FRAME_LR_SAVE 2 /* Location of LR in stack frame */ 118 #define STACK_FRAME_REGS_MARKER ASM_CONST(0x7265677368657265) 119 #define STACK_INT_FRAME_SIZE (sizeof(struct pt_regs) + \ 120 STACK_FRAME_OVERHEAD + KERNEL_REDZONE_SIZE) 121 #define STACK_FRAME_MARKER 12 122 123 #ifdef CONFIG_PPC64_ELF_ABI_V2 124 #define STACK_FRAME_MIN_SIZE 32 125 #else 126 #define STACK_FRAME_MIN_SIZE STACK_FRAME_OVERHEAD 127 #endif 128 129 /* Size of dummy stack frame allocated when calling signal handler. */ 130 #define __SIGNAL_FRAMESIZE 128 131 #define __SIGNAL_FRAMESIZE32 64 132 133 #else /* __powerpc64__ */ 134 135 #define USER_REDZONE_SIZE 0 136 #define KERNEL_REDZONE_SIZE 0 137 #define STACK_FRAME_OVERHEAD 16 /* size of minimum stack frame */ 138 #define STACK_FRAME_LR_SAVE 1 /* Location of LR in stack frame */ 139 #define STACK_FRAME_REGS_MARKER ASM_CONST(0x72656773) 140 #define STACK_INT_FRAME_SIZE (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD) 141 #define STACK_FRAME_MARKER 2 142 #define STACK_FRAME_MIN_SIZE STACK_FRAME_OVERHEAD 143 144 /* Size of stack frame allocated when calling signal handler. */ 145 #define __SIGNAL_FRAMESIZE 64 146 147 #endif /* __powerpc64__ */ 148 149 #ifndef __ASSEMBLY__ 150 #include <asm/paca.h> 151 152 #ifdef CONFIG_SMP 153 extern unsigned long profile_pc(struct pt_regs *regs); 154 #else 155 #define profile_pc(regs) instruction_pointer(regs) 156 #endif 157 158 long do_syscall_trace_enter(struct pt_regs *regs); 159 void do_syscall_trace_leave(struct pt_regs *regs); 160 161 static inline void set_return_regs_changed(void) 162 { 163 #ifdef CONFIG_PPC_BOOK3S_64 164 local_paca->hsrr_valid = 0; 165 local_paca->srr_valid = 0; 166 #endif 167 } 168 169 static inline void regs_set_return_ip(struct pt_regs *regs, unsigned long ip) 170 { 171 regs->nip = ip; 172 set_return_regs_changed(); 173 } 174 175 static inline void regs_set_return_msr(struct pt_regs *regs, unsigned long msr) 176 { 177 regs->msr = msr; 178 set_return_regs_changed(); 179 } 180 181 static inline void regs_add_return_ip(struct pt_regs *regs, long offset) 182 { 183 regs_set_return_ip(regs, regs->nip + offset); 184 } 185 186 static inline unsigned long instruction_pointer(struct pt_regs *regs) 187 { 188 return regs->nip; 189 } 190 191 static inline void instruction_pointer_set(struct pt_regs *regs, 192 unsigned long val) 193 { 194 regs_set_return_ip(regs, val); 195 } 196 197 static inline unsigned long user_stack_pointer(struct pt_regs *regs) 198 { 199 return regs->gpr[1]; 200 } 201 202 static inline unsigned long frame_pointer(struct pt_regs *regs) 203 { 204 return 0; 205 } 206 207 #define user_mode(regs) (((regs)->msr & MSR_PR) != 0) 208 209 #define force_successful_syscall_return() \ 210 do { \ 211 set_thread_flag(TIF_NOERROR); \ 212 } while(0) 213 214 #define current_pt_regs() \ 215 ((struct pt_regs *)((unsigned long)task_stack_page(current) + THREAD_SIZE) - 1) 216 217 /* 218 * The 4 low bits (0xf) are available as flags to overload the trap word, 219 * because interrupt vectors have minimum alignment of 0x10. TRAP_FLAGS_MASK 220 * must cover the bits used as flags, including bit 0 which is used as the 221 * "norestart" bit. 222 */ 223 #ifdef __powerpc64__ 224 #define TRAP_FLAGS_MASK 0x1 225 #else 226 /* 227 * On 4xx we use bit 1 in the trap word to indicate whether the exception 228 * is a critical exception (1 means it is). 229 */ 230 #define TRAP_FLAGS_MASK 0xf 231 #define IS_CRITICAL_EXC(regs) (((regs)->trap & 2) != 0) 232 #define IS_MCHECK_EXC(regs) (((regs)->trap & 4) != 0) 233 #define IS_DEBUG_EXC(regs) (((regs)->trap & 8) != 0) 234 #endif /* __powerpc64__ */ 235 #define TRAP(regs) ((regs)->trap & ~TRAP_FLAGS_MASK) 236 237 static __always_inline void set_trap(struct pt_regs *regs, unsigned long val) 238 { 239 regs->trap = (regs->trap & TRAP_FLAGS_MASK) | (val & ~TRAP_FLAGS_MASK); 240 } 241 242 static inline bool trap_is_scv(struct pt_regs *regs) 243 { 244 return (IS_ENABLED(CONFIG_PPC_BOOK3S_64) && TRAP(regs) == 0x3000); 245 } 246 247 static inline bool trap_is_unsupported_scv(struct pt_regs *regs) 248 { 249 return IS_ENABLED(CONFIG_PPC_BOOK3S_64) && TRAP(regs) == 0x7ff0; 250 } 251 252 static inline bool trap_is_syscall(struct pt_regs *regs) 253 { 254 return (trap_is_scv(regs) || TRAP(regs) == 0xc00); 255 } 256 257 static inline bool trap_norestart(struct pt_regs *regs) 258 { 259 return regs->trap & 0x1; 260 } 261 262 static __always_inline void set_trap_norestart(struct pt_regs *regs) 263 { 264 regs->trap |= 0x1; 265 } 266 267 #define kernel_stack_pointer(regs) ((regs)->gpr[1]) 268 static inline int is_syscall_success(struct pt_regs *regs) 269 { 270 if (trap_is_scv(regs)) 271 return !IS_ERR_VALUE((unsigned long)regs->gpr[3]); 272 else 273 return !(regs->ccr & 0x10000000); 274 } 275 276 static inline long regs_return_value(struct pt_regs *regs) 277 { 278 if (trap_is_scv(regs)) 279 return regs->gpr[3]; 280 281 if (is_syscall_success(regs)) 282 return regs->gpr[3]; 283 else 284 return -regs->gpr[3]; 285 } 286 287 static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc) 288 { 289 regs->gpr[3] = rc; 290 } 291 292 static inline bool cpu_has_msr_ri(void) 293 { 294 return !IS_ENABLED(CONFIG_BOOKE_OR_40x); 295 } 296 297 static inline bool regs_is_unrecoverable(struct pt_regs *regs) 298 { 299 return unlikely(cpu_has_msr_ri() && !(regs->msr & MSR_RI)); 300 } 301 302 static inline void regs_set_recoverable(struct pt_regs *regs) 303 { 304 if (cpu_has_msr_ri()) 305 regs_set_return_msr(regs, regs->msr | MSR_RI); 306 } 307 308 static inline void regs_set_unrecoverable(struct pt_regs *regs) 309 { 310 if (cpu_has_msr_ri()) 311 regs_set_return_msr(regs, regs->msr & ~MSR_RI); 312 } 313 314 #define arch_has_single_step() (1) 315 #define arch_has_block_step() (true) 316 #define ARCH_HAS_USER_SINGLE_STEP_REPORT 317 318 /* 319 * kprobe-based event tracer support 320 */ 321 322 #include <linux/stddef.h> 323 #include <linux/thread_info.h> 324 extern int regs_query_register_offset(const char *name); 325 extern const char *regs_query_register_name(unsigned int offset); 326 #define MAX_REG_OFFSET (offsetof(struct pt_regs, dsisr)) 327 328 /** 329 * regs_get_register() - get register value from its offset 330 * @regs: pt_regs from which register value is gotten 331 * @offset: offset number of the register. 332 * 333 * regs_get_register returns the value of a register whose offset from @regs. 334 * The @offset is the offset of the register in struct pt_regs. 335 * If @offset is bigger than MAX_REG_OFFSET, this returns 0. 336 */ 337 static inline unsigned long regs_get_register(struct pt_regs *regs, 338 unsigned int offset) 339 { 340 if (unlikely(offset > MAX_REG_OFFSET)) 341 return 0; 342 return *(unsigned long *)((unsigned long)regs + offset); 343 } 344 345 /** 346 * regs_within_kernel_stack() - check the address in the stack 347 * @regs: pt_regs which contains kernel stack pointer. 348 * @addr: address which is checked. 349 * 350 * regs_within_kernel_stack() checks @addr is within the kernel stack page(s). 351 * If @addr is within the kernel stack, it returns true. If not, returns false. 352 */ 353 354 static inline bool regs_within_kernel_stack(struct pt_regs *regs, 355 unsigned long addr) 356 { 357 return ((addr & ~(THREAD_SIZE - 1)) == 358 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1))); 359 } 360 361 /** 362 * regs_get_kernel_stack_nth() - get Nth entry of the stack 363 * @regs: pt_regs which contains kernel stack pointer. 364 * @n: stack entry number. 365 * 366 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which 367 * is specified by @regs. If the @n th entry is NOT in the kernel stack, 368 * this returns 0. 369 */ 370 static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, 371 unsigned int n) 372 { 373 unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs); 374 addr += n; 375 if (regs_within_kernel_stack(regs, (unsigned long)addr)) 376 return *addr; 377 else 378 return 0; 379 } 380 381 #endif /* __ASSEMBLY__ */ 382 383 #ifndef __powerpc64__ 384 /* We need PT_SOFTE defined at all time to avoid #ifdefs */ 385 #define PT_SOFTE PT_MQ 386 #else /* __powerpc64__ */ 387 #define PT_FPSCR32 (PT_FPR0 + 2*32 + 1) /* each FP reg occupies 2 32-bit userspace slots */ 388 #define PT_VR0_32 164 /* each Vector reg occupies 4 slots in 32-bit */ 389 #define PT_VSCR_32 (PT_VR0 + 32*4 + 3) 390 #define PT_VRSAVE_32 (PT_VR0 + 33*4) 391 #define PT_VSR0_32 300 /* each VSR reg occupies 4 slots in 32-bit */ 392 #endif /* __powerpc64__ */ 393 #endif /* _ASM_POWERPC_PTRACE_H */ 394