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 26 #ifndef __ASSEMBLY__ 27 struct pt_regs 28 { 29 union { 30 struct user_pt_regs user_regs; 31 struct { 32 unsigned long gpr[32]; 33 unsigned long nip; 34 unsigned long msr; 35 unsigned long orig_gpr3; 36 unsigned long ctr; 37 unsigned long link; 38 unsigned long xer; 39 unsigned long ccr; 40 #ifdef CONFIG_PPC64 41 unsigned long softe; 42 #else 43 unsigned long mq; 44 #endif 45 unsigned long trap; 46 unsigned long dar; 47 unsigned long dsisr; 48 unsigned long result; 49 }; 50 }; 51 #if defined(CONFIG_PPC64) || defined(CONFIG_PPC_KUAP) 52 union { 53 struct { 54 #ifdef CONFIG_PPC64 55 unsigned long ppr; 56 unsigned long exit_result; 57 #endif 58 union { 59 #ifdef CONFIG_PPC_KUAP 60 unsigned long kuap; 61 #endif 62 #ifdef CONFIG_PPC_PKEY 63 unsigned long amr; 64 #endif 65 }; 66 #ifdef CONFIG_PPC_PKEY 67 unsigned long iamr; 68 #endif 69 }; 70 unsigned long __pad[4]; /* Maintain 16 byte interrupt stack alignment */ 71 }; 72 #endif 73 #if defined(CONFIG_PPC32) && defined(CONFIG_BOOKE) 74 struct { /* Must be a multiple of 16 bytes */ 75 unsigned long mas0; 76 unsigned long mas1; 77 unsigned long mas2; 78 unsigned long mas3; 79 unsigned long mas6; 80 unsigned long mas7; 81 unsigned long srr0; 82 unsigned long srr1; 83 unsigned long csrr0; 84 unsigned long csrr1; 85 unsigned long dsrr0; 86 unsigned long dsrr1; 87 }; 88 #endif 89 }; 90 #endif 91 92 93 #define STACK_FRAME_WITH_PT_REGS (STACK_FRAME_OVERHEAD + sizeof(struct pt_regs)) 94 95 #ifdef __powerpc64__ 96 97 /* 98 * Size of redzone that userspace is allowed to use below the stack 99 * pointer. This is 288 in the 64-bit big-endian ELF ABI, and 512 in 100 * the new ELFv2 little-endian ABI, so we allow the larger amount. 101 * 102 * For kernel code we allow a 288-byte redzone, in order to conserve 103 * kernel stack space; gcc currently only uses 288 bytes, and will 104 * hopefully allow explicit control of the redzone size in future. 105 */ 106 #define USER_REDZONE_SIZE 512 107 #define KERNEL_REDZONE_SIZE 288 108 109 #define STACK_FRAME_OVERHEAD 112 /* size of minimum stack frame */ 110 #define STACK_FRAME_LR_SAVE 2 /* Location of LR in stack frame */ 111 #define STACK_FRAME_REGS_MARKER ASM_CONST(0x7265677368657265) 112 #define STACK_INT_FRAME_SIZE (sizeof(struct pt_regs) + \ 113 STACK_FRAME_OVERHEAD + KERNEL_REDZONE_SIZE) 114 #define STACK_FRAME_MARKER 12 115 116 #ifdef PPC64_ELF_ABI_v2 117 #define STACK_FRAME_MIN_SIZE 32 118 #else 119 #define STACK_FRAME_MIN_SIZE STACK_FRAME_OVERHEAD 120 #endif 121 122 /* Size of dummy stack frame allocated when calling signal handler. */ 123 #define __SIGNAL_FRAMESIZE 128 124 #define __SIGNAL_FRAMESIZE32 64 125 126 #else /* __powerpc64__ */ 127 128 #define USER_REDZONE_SIZE 0 129 #define KERNEL_REDZONE_SIZE 0 130 #define STACK_FRAME_OVERHEAD 16 /* size of minimum stack frame */ 131 #define STACK_FRAME_LR_SAVE 1 /* Location of LR in stack frame */ 132 #define STACK_FRAME_REGS_MARKER ASM_CONST(0x72656773) 133 #define STACK_INT_FRAME_SIZE (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD) 134 #define STACK_FRAME_MARKER 2 135 #define STACK_FRAME_MIN_SIZE STACK_FRAME_OVERHEAD 136 137 /* Size of stack frame allocated when calling signal handler. */ 138 #define __SIGNAL_FRAMESIZE 64 139 140 #endif /* __powerpc64__ */ 141 142 #ifndef __ASSEMBLY__ 143 #include <asm/paca.h> 144 145 #ifdef CONFIG_SMP 146 extern unsigned long profile_pc(struct pt_regs *regs); 147 #else 148 #define profile_pc(regs) instruction_pointer(regs) 149 #endif 150 151 long do_syscall_trace_enter(struct pt_regs *regs); 152 void do_syscall_trace_leave(struct pt_regs *regs); 153 154 static inline void set_return_regs_changed(void) 155 { 156 #ifdef CONFIG_PPC_BOOK3S_64 157 local_paca->hsrr_valid = 0; 158 local_paca->srr_valid = 0; 159 #endif 160 } 161 162 static inline void regs_set_return_ip(struct pt_regs *regs, unsigned long ip) 163 { 164 regs->nip = ip; 165 set_return_regs_changed(); 166 } 167 168 static inline void regs_set_return_msr(struct pt_regs *regs, unsigned long msr) 169 { 170 regs->msr = msr; 171 set_return_regs_changed(); 172 } 173 174 static inline void regs_add_return_ip(struct pt_regs *regs, long offset) 175 { 176 regs_set_return_ip(regs, regs->nip + offset); 177 } 178 179 static inline unsigned long instruction_pointer(struct pt_regs *regs) 180 { 181 return regs->nip; 182 } 183 184 static inline void instruction_pointer_set(struct pt_regs *regs, 185 unsigned long val) 186 { 187 regs_set_return_ip(regs, val); 188 } 189 190 static inline unsigned long user_stack_pointer(struct pt_regs *regs) 191 { 192 return regs->gpr[1]; 193 } 194 195 static inline unsigned long frame_pointer(struct pt_regs *regs) 196 { 197 return 0; 198 } 199 200 #ifdef __powerpc64__ 201 #define user_mode(regs) ((((regs)->msr) >> MSR_PR_LG) & 0x1) 202 #else 203 #define user_mode(regs) (((regs)->msr & MSR_PR) != 0) 204 #endif 205 206 #define force_successful_syscall_return() \ 207 do { \ 208 set_thread_flag(TIF_NOERROR); \ 209 } while(0) 210 211 #define current_pt_regs() \ 212 ((struct pt_regs *)((unsigned long)task_stack_page(current) + THREAD_SIZE) - 1) 213 214 /* 215 * The 4 low bits (0xf) are available as flags to overload the trap word, 216 * because interrupt vectors have minimum alignment of 0x10. TRAP_FLAGS_MASK 217 * must cover the bits used as flags, including bit 0 which is used as the 218 * "norestart" bit. 219 */ 220 #ifdef __powerpc64__ 221 #define TRAP_FLAGS_MASK 0x1 222 #else 223 /* 224 * On 4xx we use bit 1 in the trap word to indicate whether the exception 225 * is a critical exception (1 means it is). 226 */ 227 #define TRAP_FLAGS_MASK 0xf 228 #define IS_CRITICAL_EXC(regs) (((regs)->trap & 2) != 0) 229 #define IS_MCHECK_EXC(regs) (((regs)->trap & 4) != 0) 230 #define IS_DEBUG_EXC(regs) (((regs)->trap & 8) != 0) 231 #endif /* __powerpc64__ */ 232 #define TRAP(regs) ((regs)->trap & ~TRAP_FLAGS_MASK) 233 234 static __always_inline void set_trap(struct pt_regs *regs, unsigned long val) 235 { 236 regs->trap = (regs->trap & TRAP_FLAGS_MASK) | (val & ~TRAP_FLAGS_MASK); 237 } 238 239 static inline bool trap_is_scv(struct pt_regs *regs) 240 { 241 return (IS_ENABLED(CONFIG_PPC_BOOK3S_64) && TRAP(regs) == 0x3000); 242 } 243 244 static inline bool trap_is_unsupported_scv(struct pt_regs *regs) 245 { 246 return IS_ENABLED(CONFIG_PPC_BOOK3S_64) && TRAP(regs) == 0x7ff0; 247 } 248 249 static inline bool trap_is_syscall(struct pt_regs *regs) 250 { 251 return (trap_is_scv(regs) || TRAP(regs) == 0xc00); 252 } 253 254 static inline bool trap_norestart(struct pt_regs *regs) 255 { 256 return regs->trap & 0x1; 257 } 258 259 static __always_inline void set_trap_norestart(struct pt_regs *regs) 260 { 261 regs->trap |= 0x1; 262 } 263 264 #define kernel_stack_pointer(regs) ((regs)->gpr[1]) 265 static inline int is_syscall_success(struct pt_regs *regs) 266 { 267 if (trap_is_scv(regs)) 268 return !IS_ERR_VALUE((unsigned long)regs->gpr[3]); 269 else 270 return !(regs->ccr & 0x10000000); 271 } 272 273 static inline long regs_return_value(struct pt_regs *regs) 274 { 275 if (trap_is_scv(regs)) 276 return regs->gpr[3]; 277 278 if (is_syscall_success(regs)) 279 return regs->gpr[3]; 280 else 281 return -regs->gpr[3]; 282 } 283 284 static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc) 285 { 286 regs->gpr[3] = rc; 287 } 288 289 #define arch_has_single_step() (1) 290 #define arch_has_block_step() (true) 291 #define ARCH_HAS_USER_SINGLE_STEP_REPORT 292 293 /* 294 * kprobe-based event tracer support 295 */ 296 297 #include <linux/stddef.h> 298 #include <linux/thread_info.h> 299 extern int regs_query_register_offset(const char *name); 300 extern const char *regs_query_register_name(unsigned int offset); 301 #define MAX_REG_OFFSET (offsetof(struct pt_regs, dsisr)) 302 303 /** 304 * regs_get_register() - get register value from its offset 305 * @regs: pt_regs from which register value is gotten 306 * @offset: offset number of the register. 307 * 308 * regs_get_register returns the value of a register whose offset from @regs. 309 * The @offset is the offset of the register in struct pt_regs. 310 * If @offset is bigger than MAX_REG_OFFSET, this returns 0. 311 */ 312 static inline unsigned long regs_get_register(struct pt_regs *regs, 313 unsigned int offset) 314 { 315 if (unlikely(offset > MAX_REG_OFFSET)) 316 return 0; 317 return *(unsigned long *)((unsigned long)regs + offset); 318 } 319 320 /** 321 * regs_within_kernel_stack() - check the address in the stack 322 * @regs: pt_regs which contains kernel stack pointer. 323 * @addr: address which is checked. 324 * 325 * regs_within_kernel_stack() checks @addr is within the kernel stack page(s). 326 * If @addr is within the kernel stack, it returns true. If not, returns false. 327 */ 328 329 static inline bool regs_within_kernel_stack(struct pt_regs *regs, 330 unsigned long addr) 331 { 332 return ((addr & ~(THREAD_SIZE - 1)) == 333 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1))); 334 } 335 336 /** 337 * regs_get_kernel_stack_nth() - get Nth entry of the stack 338 * @regs: pt_regs which contains kernel stack pointer. 339 * @n: stack entry number. 340 * 341 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which 342 * is specified by @regs. If the @n th entry is NOT in the kernel stack, 343 * this returns 0. 344 */ 345 static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, 346 unsigned int n) 347 { 348 unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs); 349 addr += n; 350 if (regs_within_kernel_stack(regs, (unsigned long)addr)) 351 return *addr; 352 else 353 return 0; 354 } 355 356 #endif /* __ASSEMBLY__ */ 357 358 #ifndef __powerpc64__ 359 /* We need PT_SOFTE defined at all time to avoid #ifdefs */ 360 #define PT_SOFTE PT_MQ 361 #else /* __powerpc64__ */ 362 #define PT_FPSCR32 (PT_FPR0 + 2*32 + 1) /* each FP reg occupies 2 32-bit userspace slots */ 363 #define PT_VR0_32 164 /* each Vector reg occupies 4 slots in 32-bit */ 364 #define PT_VSCR_32 (PT_VR0 + 32*4 + 3) 365 #define PT_VRSAVE_32 (PT_VR0 + 33*4) 366 #define PT_VSR0_32 300 /* each VSR reg occupies 4 slots in 32-bit */ 367 #endif /* __powerpc64__ */ 368 #endif /* _ASM_POWERPC_PTRACE_H */ 369