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 // 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 __ASSEMBLY__ 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 long do_syscall_trace_enter(struct pt_regs *regs); 178 void do_syscall_trace_leave(struct pt_regs *regs); 179 180 static inline void set_return_regs_changed(void) 181 { 182 #ifdef CONFIG_PPC_BOOK3S_64 183 WRITE_ONCE(local_paca->hsrr_valid, 0); 184 WRITE_ONCE(local_paca->srr_valid, 0); 185 #endif 186 } 187 188 static inline void regs_set_return_ip(struct pt_regs *regs, unsigned long ip) 189 { 190 regs->nip = ip; 191 set_return_regs_changed(); 192 } 193 194 static inline void regs_set_return_msr(struct pt_regs *regs, unsigned long msr) 195 { 196 regs->msr = msr; 197 set_return_regs_changed(); 198 } 199 200 static inline void regs_add_return_ip(struct pt_regs *regs, long offset) 201 { 202 regs_set_return_ip(regs, regs->nip + offset); 203 } 204 205 static inline unsigned long instruction_pointer(struct pt_regs *regs) 206 { 207 return regs->nip; 208 } 209 210 static inline void instruction_pointer_set(struct pt_regs *regs, 211 unsigned long val) 212 { 213 regs_set_return_ip(regs, val); 214 } 215 216 static inline unsigned long user_stack_pointer(struct pt_regs *regs) 217 { 218 return regs->gpr[1]; 219 } 220 221 static inline unsigned long frame_pointer(struct pt_regs *regs) 222 { 223 return 0; 224 } 225 226 #define user_mode(regs) (((regs)->msr & MSR_PR) != 0) 227 228 #define force_successful_syscall_return() \ 229 do { \ 230 set_thread_flag(TIF_NOERROR); \ 231 } while(0) 232 233 #define current_pt_regs() \ 234 ((struct pt_regs *)((unsigned long)task_stack_page(current) + THREAD_SIZE) - 1) 235 236 /* 237 * The 4 low bits (0xf) are available as flags to overload the trap word, 238 * because interrupt vectors have minimum alignment of 0x10. TRAP_FLAGS_MASK 239 * must cover the bits used as flags, including bit 0 which is used as the 240 * "norestart" bit. 241 */ 242 #ifdef __powerpc64__ 243 #define TRAP_FLAGS_MASK 0x1 244 #else 245 /* 246 * On 4xx we use bit 1 in the trap word to indicate whether the exception 247 * is a critical exception (1 means it is). 248 */ 249 #define TRAP_FLAGS_MASK 0xf 250 #define IS_CRITICAL_EXC(regs) (((regs)->trap & 2) != 0) 251 #define IS_MCHECK_EXC(regs) (((regs)->trap & 4) != 0) 252 #define IS_DEBUG_EXC(regs) (((regs)->trap & 8) != 0) 253 #endif /* __powerpc64__ */ 254 #define TRAP(regs) ((regs)->trap & ~TRAP_FLAGS_MASK) 255 256 static __always_inline void set_trap(struct pt_regs *regs, unsigned long val) 257 { 258 regs->trap = (regs->trap & TRAP_FLAGS_MASK) | (val & ~TRAP_FLAGS_MASK); 259 } 260 261 static inline bool trap_is_scv(struct pt_regs *regs) 262 { 263 return (IS_ENABLED(CONFIG_PPC_BOOK3S_64) && TRAP(regs) == 0x3000); 264 } 265 266 static inline bool trap_is_unsupported_scv(struct pt_regs *regs) 267 { 268 return IS_ENABLED(CONFIG_PPC_BOOK3S_64) && TRAP(regs) == 0x7ff0; 269 } 270 271 static inline bool trap_is_syscall(struct pt_regs *regs) 272 { 273 return (trap_is_scv(regs) || TRAP(regs) == 0xc00); 274 } 275 276 static inline bool trap_norestart(struct pt_regs *regs) 277 { 278 return regs->trap & 0x1; 279 } 280 281 static __always_inline void set_trap_norestart(struct pt_regs *regs) 282 { 283 regs->trap |= 0x1; 284 } 285 286 #define kernel_stack_pointer(regs) ((regs)->gpr[1]) 287 static inline int is_syscall_success(struct pt_regs *regs) 288 { 289 if (trap_is_scv(regs)) 290 return !IS_ERR_VALUE((unsigned long)regs->gpr[3]); 291 else 292 return !(regs->ccr & 0x10000000); 293 } 294 295 static inline long regs_return_value(struct pt_regs *regs) 296 { 297 if (trap_is_scv(regs)) 298 return regs->gpr[3]; 299 300 if (is_syscall_success(regs)) 301 return regs->gpr[3]; 302 else 303 return -regs->gpr[3]; 304 } 305 306 static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc) 307 { 308 regs->gpr[3] = rc; 309 } 310 311 static inline bool cpu_has_msr_ri(void) 312 { 313 return !IS_ENABLED(CONFIG_BOOKE_OR_40x); 314 } 315 316 static inline bool regs_is_unrecoverable(struct pt_regs *regs) 317 { 318 return unlikely(cpu_has_msr_ri() && !(regs->msr & MSR_RI)); 319 } 320 321 static inline void regs_set_recoverable(struct pt_regs *regs) 322 { 323 if (cpu_has_msr_ri()) 324 regs_set_return_msr(regs, regs->msr | MSR_RI); 325 } 326 327 static inline void regs_set_unrecoverable(struct pt_regs *regs) 328 { 329 if (cpu_has_msr_ri()) 330 regs_set_return_msr(regs, regs->msr & ~MSR_RI); 331 } 332 333 #define arch_has_single_step() (1) 334 #define arch_has_block_step() (true) 335 #define ARCH_HAS_USER_SINGLE_STEP_REPORT 336 337 /* 338 * kprobe-based event tracer support 339 */ 340 341 #include <linux/stddef.h> 342 #include <linux/thread_info.h> 343 extern int regs_query_register_offset(const char *name); 344 extern const char *regs_query_register_name(unsigned int offset); 345 #define MAX_REG_OFFSET (offsetof(struct pt_regs, dsisr)) 346 347 /** 348 * regs_get_register() - get register value from its offset 349 * @regs: pt_regs from which register value is gotten 350 * @offset: offset number of the register. 351 * 352 * regs_get_register returns the value of a register whose offset from @regs. 353 * The @offset is the offset of the register in struct pt_regs. 354 * If @offset is bigger than MAX_REG_OFFSET, this returns 0. 355 */ 356 static inline unsigned long regs_get_register(struct pt_regs *regs, 357 unsigned int offset) 358 { 359 if (unlikely(offset > MAX_REG_OFFSET)) 360 return 0; 361 return *(unsigned long *)((unsigned long)regs + offset); 362 } 363 364 /** 365 * regs_within_kernel_stack() - check the address in the stack 366 * @regs: pt_regs which contains kernel stack pointer. 367 * @addr: address which is checked. 368 * 369 * regs_within_kernel_stack() checks @addr is within the kernel stack page(s). 370 * If @addr is within the kernel stack, it returns true. If not, returns false. 371 */ 372 373 static inline bool regs_within_kernel_stack(struct pt_regs *regs, 374 unsigned long addr) 375 { 376 return ((addr & ~(THREAD_SIZE - 1)) == 377 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1))); 378 } 379 380 /** 381 * regs_get_kernel_stack_nth() - get Nth entry of the stack 382 * @regs: pt_regs which contains kernel stack pointer. 383 * @n: stack entry number. 384 * 385 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which 386 * is specified by @regs. If the @n th entry is NOT in the kernel stack, 387 * this returns 0. 388 */ 389 static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, 390 unsigned int n) 391 { 392 unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs); 393 addr += n; 394 if (regs_within_kernel_stack(regs, (unsigned long)addr)) 395 return *addr; 396 else 397 return 0; 398 } 399 400 /** 401 * regs_get_kernel_argument() - get Nth function argument in kernel 402 * @regs: pt_regs of that context 403 * @n: function argument number (start from 0) 404 * 405 * We support up to 8 arguments and assume they are sent in through the GPRs. 406 * This will fail for fp/vector arguments, but those aren't usually found in 407 * kernel code. This is expected to be called from kprobes or ftrace with regs. 408 */ 409 static inline unsigned long regs_get_kernel_argument(struct pt_regs *regs, unsigned int n) 410 { 411 #define NR_REG_ARGUMENTS 8 412 if (n < NR_REG_ARGUMENTS) 413 return regs_get_register(regs, offsetof(struct pt_regs, gpr[3 + n])); 414 return 0; 415 } 416 417 #endif /* __ASSEMBLY__ */ 418 419 #ifndef __powerpc64__ 420 /* We need PT_SOFTE defined at all time to avoid #ifdefs */ 421 #define PT_SOFTE PT_MQ 422 #else /* __powerpc64__ */ 423 #define PT_FPSCR32 (PT_FPR0 + 2*32 + 1) /* each FP reg occupies 2 32-bit userspace slots */ 424 #define PT_VR0_32 164 /* each Vector reg occupies 4 slots in 32-bit */ 425 #define PT_VSCR_32 (PT_VR0 + 32*4 + 3) 426 #define PT_VRSAVE_32 (PT_VR0 + 33*4) 427 #define PT_VSR0_32 300 /* each VSR reg occupies 4 slots in 32-bit */ 428 #endif /* __powerpc64__ */ 429 #endif /* _ASM_POWERPC_PTRACE_H */ 430