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