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