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 __ASSEMBLER__ 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 // Always displays as "REGS" in memory dumps 101 #ifdef CONFIG_CPU_BIG_ENDIAN 102 #define STACK_FRAME_REGS_MARKER ASM_CONST(0x52454753) 103 #else 104 #define STACK_FRAME_REGS_MARKER ASM_CONST(0x53474552) 105 #endif 106 107 #ifdef __powerpc64__ 108 109 /* 110 * Size of redzone that userspace is allowed to use below the stack 111 * pointer. This is 288 in the 64-bit big-endian ELF ABI, and 512 in 112 * the new ELFv2 little-endian ABI, so we allow the larger amount. 113 * 114 * For kernel code we allow a 288-byte redzone, in order to conserve 115 * kernel stack space; gcc currently only uses 288 bytes, and will 116 * hopefully allow explicit control of the redzone size in future. 117 */ 118 #define USER_REDZONE_SIZE 512 119 #define KERNEL_REDZONE_SIZE 288 120 121 #define STACK_FRAME_LR_SAVE 2 /* Location of LR in stack frame */ 122 123 #ifdef CONFIG_PPC64_ELF_ABI_V2 124 #define STACK_FRAME_MIN_SIZE 32 125 #define STACK_USER_INT_FRAME_SIZE (sizeof(struct pt_regs) + STACK_FRAME_MIN_SIZE + 16) 126 #define STACK_INT_FRAME_REGS (STACK_FRAME_MIN_SIZE + 16) 127 #define STACK_INT_FRAME_MARKER STACK_FRAME_MIN_SIZE 128 #define STACK_SWITCH_FRAME_SIZE (sizeof(struct pt_regs) + STACK_FRAME_MIN_SIZE + 16) 129 #define STACK_SWITCH_FRAME_REGS (STACK_FRAME_MIN_SIZE + 16) 130 #else 131 /* 132 * The ELFv1 ABI specifies 48 bytes plus a minimum 64 byte parameter save 133 * area. This parameter area is not used by calls to C from interrupt entry, 134 * so the second from last one of those is used for the frame marker. 135 */ 136 #define STACK_FRAME_MIN_SIZE 112 137 #define STACK_USER_INT_FRAME_SIZE (sizeof(struct pt_regs) + STACK_FRAME_MIN_SIZE) 138 #define STACK_INT_FRAME_REGS STACK_FRAME_MIN_SIZE 139 #define STACK_INT_FRAME_MARKER (STACK_FRAME_MIN_SIZE - 16) 140 #define STACK_SWITCH_FRAME_SIZE (sizeof(struct pt_regs) + STACK_FRAME_MIN_SIZE) 141 #define STACK_SWITCH_FRAME_REGS STACK_FRAME_MIN_SIZE 142 #endif 143 144 /* Size of dummy stack frame allocated when calling signal handler. */ 145 #define __SIGNAL_FRAMESIZE 128 146 #define __SIGNAL_FRAMESIZE32 64 147 148 #else /* __powerpc64__ */ 149 150 #define USER_REDZONE_SIZE 0 151 #define KERNEL_REDZONE_SIZE 0 152 #define STACK_FRAME_MIN_SIZE 16 153 #define STACK_FRAME_LR_SAVE 1 /* Location of LR in stack frame */ 154 #define STACK_USER_INT_FRAME_SIZE (sizeof(struct pt_regs) + STACK_FRAME_MIN_SIZE) 155 #define STACK_INT_FRAME_REGS STACK_FRAME_MIN_SIZE 156 #define STACK_INT_FRAME_MARKER (STACK_FRAME_MIN_SIZE - 8) 157 #define STACK_SWITCH_FRAME_SIZE (sizeof(struct pt_regs) + STACK_FRAME_MIN_SIZE) 158 #define STACK_SWITCH_FRAME_REGS STACK_FRAME_MIN_SIZE 159 160 /* Size of stack frame allocated when calling signal handler. */ 161 #define __SIGNAL_FRAMESIZE 64 162 163 #endif /* __powerpc64__ */ 164 165 #define STACK_INT_FRAME_SIZE (KERNEL_REDZONE_SIZE + STACK_USER_INT_FRAME_SIZE) 166 #define STACK_INT_FRAME_MARKER_LONGS (STACK_INT_FRAME_MARKER/sizeof(long)) 167 168 #ifndef __ASSEMBLER__ 169 #include <asm/paca.h> 170 171 #ifdef CONFIG_SMP 172 extern unsigned long profile_pc(struct pt_regs *regs); 173 #else 174 #define profile_pc(regs) instruction_pointer(regs) 175 #endif 176 177 static inline void set_return_regs_changed(void) 178 { 179 #ifdef CONFIG_PPC_BOOK3S_64 180 WRITE_ONCE(local_paca->hsrr_valid, 0); 181 WRITE_ONCE(local_paca->srr_valid, 0); 182 #endif 183 } 184 185 static inline void regs_set_return_ip(struct pt_regs *regs, unsigned long ip) 186 { 187 regs->nip = ip; 188 set_return_regs_changed(); 189 } 190 191 static inline void regs_set_return_msr(struct pt_regs *regs, unsigned long msr) 192 { 193 regs->msr = msr; 194 set_return_regs_changed(); 195 } 196 197 static inline void regs_add_return_ip(struct pt_regs *regs, long offset) 198 { 199 regs_set_return_ip(regs, regs->nip + offset); 200 } 201 202 static inline unsigned long instruction_pointer(struct pt_regs *regs) 203 { 204 return regs->nip; 205 } 206 207 static inline void instruction_pointer_set(struct pt_regs *regs, 208 unsigned long val) 209 { 210 regs_set_return_ip(regs, val); 211 } 212 213 static inline unsigned long user_stack_pointer(struct pt_regs *regs) 214 { 215 return regs->gpr[1]; 216 } 217 218 static inline unsigned long frame_pointer(struct pt_regs *regs) 219 { 220 return 0; 221 } 222 223 #define user_mode(regs) (((regs)->msr & MSR_PR) != 0) 224 225 #define force_successful_syscall_return() \ 226 do { \ 227 set_thread_flag(TIF_NOERROR); \ 228 } while(0) 229 230 #define current_pt_regs() \ 231 ((struct pt_regs *)((unsigned long)task_stack_page(current) + THREAD_SIZE) - 1) 232 233 /* 234 * The 4 low bits (0xf) are available as flags to overload the trap word, 235 * because interrupt vectors have minimum alignment of 0x10. TRAP_FLAGS_MASK 236 * must cover the bits used as flags, including bit 0 which is used as the 237 * "norestart" bit. 238 */ 239 #ifdef __powerpc64__ 240 #define TRAP_FLAGS_MASK 0x1 241 #else 242 /* 243 * On 4xx we use bit 1 in the trap word to indicate whether the exception 244 * is a critical exception (1 means it is). 245 */ 246 #define TRAP_FLAGS_MASK 0xf 247 #define IS_CRITICAL_EXC(regs) (((regs)->trap & 2) != 0) 248 #define IS_MCHECK_EXC(regs) (((regs)->trap & 4) != 0) 249 #define IS_DEBUG_EXC(regs) (((regs)->trap & 8) != 0) 250 #endif /* __powerpc64__ */ 251 #define TRAP(regs) ((regs)->trap & ~TRAP_FLAGS_MASK) 252 253 static __always_inline void set_trap(struct pt_regs *regs, unsigned long val) 254 { 255 regs->trap = (regs->trap & TRAP_FLAGS_MASK) | (val & ~TRAP_FLAGS_MASK); 256 } 257 258 static inline bool trap_is_scv(struct pt_regs *regs) 259 { 260 return (IS_ENABLED(CONFIG_PPC_BOOK3S_64) && TRAP(regs) == 0x3000); 261 } 262 263 static inline bool trap_is_unsupported_scv(struct pt_regs *regs) 264 { 265 return IS_ENABLED(CONFIG_PPC_BOOK3S_64) && TRAP(regs) == 0x7ff0; 266 } 267 268 static inline bool trap_is_syscall(struct pt_regs *regs) 269 { 270 return (trap_is_scv(regs) || TRAP(regs) == 0xc00); 271 } 272 273 static inline bool trap_norestart(struct pt_regs *regs) 274 { 275 return regs->trap & 0x1; 276 } 277 278 static __always_inline void set_trap_norestart(struct pt_regs *regs) 279 { 280 regs->trap |= 0x1; 281 } 282 283 #define kernel_stack_pointer(regs) ((regs)->gpr[1]) 284 static inline int is_syscall_success(struct pt_regs *regs) 285 { 286 if (trap_is_scv(regs)) 287 return !IS_ERR_VALUE((unsigned long)regs->gpr[3]); 288 else 289 return !(regs->ccr & 0x10000000); 290 } 291 292 static inline long regs_return_value(struct pt_regs *regs) 293 { 294 if (trap_is_scv(regs)) 295 return regs->gpr[3]; 296 297 if (is_syscall_success(regs)) 298 return regs->gpr[3]; 299 else 300 return -regs->gpr[3]; 301 } 302 303 static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc) 304 { 305 regs->gpr[3] = rc; 306 } 307 308 static inline bool cpu_has_msr_ri(void) 309 { 310 return !IS_ENABLED(CONFIG_BOOKE); 311 } 312 313 static inline bool regs_is_unrecoverable(struct pt_regs *regs) 314 { 315 return unlikely(cpu_has_msr_ri() && !(regs->msr & MSR_RI)); 316 } 317 318 static inline void regs_set_recoverable(struct pt_regs *regs) 319 { 320 if (cpu_has_msr_ri()) 321 regs_set_return_msr(regs, regs->msr | MSR_RI); 322 } 323 324 static inline void regs_set_unrecoverable(struct pt_regs *regs) 325 { 326 if (cpu_has_msr_ri()) 327 regs_set_return_msr(regs, regs->msr & ~MSR_RI); 328 } 329 330 #define arch_has_single_step() (1) 331 #define arch_has_block_step() (true) 332 #define ARCH_HAS_USER_SINGLE_STEP_REPORT 333 334 /* 335 * kprobe-based event tracer support 336 */ 337 338 #include <linux/stddef.h> 339 #include <linux/thread_info.h> 340 extern int regs_query_register_offset(const char *name); 341 extern const char *regs_query_register_name(unsigned int offset); 342 #define MAX_REG_OFFSET (offsetof(struct pt_regs, dsisr)) 343 344 /** 345 * regs_get_register() - get register value from its offset 346 * @regs: pt_regs from which register value is gotten 347 * @offset: offset number of the register. 348 * 349 * regs_get_register returns the value of a register whose offset from @regs. 350 * The @offset is the offset of the register in struct pt_regs. 351 * If @offset is bigger than MAX_REG_OFFSET, this returns 0. 352 */ 353 static inline unsigned long regs_get_register(struct pt_regs *regs, 354 unsigned int offset) 355 { 356 if (unlikely(offset > MAX_REG_OFFSET)) 357 return 0; 358 return *(unsigned long *)((unsigned long)regs + offset); 359 } 360 361 /** 362 * regs_within_kernel_stack() - check the address in the stack 363 * @regs: pt_regs which contains kernel stack pointer. 364 * @addr: address which is checked. 365 * 366 * regs_within_kernel_stack() checks @addr is within the kernel stack page(s). 367 * If @addr is within the kernel stack, it returns true. If not, returns false. 368 */ 369 370 static inline bool regs_within_kernel_stack(struct pt_regs *regs, 371 unsigned long addr) 372 { 373 return ((addr & ~(THREAD_SIZE - 1)) == 374 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1))); 375 } 376 377 /** 378 * regs_get_kernel_stack_nth() - get Nth entry of the stack 379 * @regs: pt_regs which contains kernel stack pointer. 380 * @n: stack entry number. 381 * 382 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which 383 * is specified by @regs. If the @n th entry is NOT in the kernel stack, 384 * this returns 0. 385 */ 386 static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, 387 unsigned int n) 388 { 389 unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs); 390 addr += n; 391 if (regs_within_kernel_stack(regs, (unsigned long)addr)) 392 return *addr; 393 else 394 return 0; 395 } 396 397 /** 398 * regs_get_kernel_argument() - get Nth function argument in kernel 399 * @regs: pt_regs of that context 400 * @n: function argument number (start from 0) 401 * 402 * We support up to 8 arguments and assume they are sent in through the GPRs. 403 * This will fail for fp/vector arguments, but those aren't usually found in 404 * kernel code. This is expected to be called from kprobes or ftrace with regs. 405 */ 406 static inline unsigned long regs_get_kernel_argument(struct pt_regs *regs, unsigned int n) 407 { 408 #define NR_REG_ARGUMENTS 8 409 if (n < NR_REG_ARGUMENTS) 410 return regs_get_register(regs, offsetof(struct pt_regs, gpr[3 + n])); 411 return 0; 412 } 413 414 #endif /* __ASSEMBLER__ */ 415 416 #ifndef __powerpc64__ 417 /* We need PT_SOFTE defined at all time to avoid #ifdefs */ 418 #define PT_SOFTE PT_MQ 419 #else /* __powerpc64__ */ 420 #define PT_FPSCR32 (PT_FPR0 + 2*32 + 1) /* each FP reg occupies 2 32-bit userspace slots */ 421 #define PT_VR0_32 164 /* each Vector reg occupies 4 slots in 32-bit */ 422 #define PT_VSCR_32 (PT_VR0 + 32*4 + 3) 423 #define PT_VRSAVE_32 (PT_VR0 + 33*4) 424 #define PT_VSR0_32 300 /* each VSR reg occupies 4 slots in 32-bit */ 425 #endif /* __powerpc64__ */ 426 #endif /* _ASM_POWERPC_PTRACE_H */ 427