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 <uapi/asm/ptrace.h> 23 #include <asm/asm-const.h> 24 25 #ifndef __ASSEMBLY__ 26 struct pt_regs 27 { 28 union { 29 struct user_pt_regs user_regs; 30 struct { 31 unsigned long gpr[32]; 32 unsigned long nip; 33 unsigned long msr; 34 unsigned long orig_gpr3; 35 unsigned long ctr; 36 unsigned long link; 37 unsigned long xer; 38 unsigned long ccr; 39 #ifdef CONFIG_PPC64 40 unsigned long softe; 41 #else 42 unsigned long mq; 43 #endif 44 unsigned long trap; 45 unsigned long dar; 46 unsigned long dsisr; 47 unsigned long result; 48 }; 49 }; 50 51 union { 52 struct { 53 #ifdef CONFIG_PPC64 54 unsigned long ppr; 55 #endif 56 union { 57 #ifdef CONFIG_PPC_KUAP 58 unsigned long kuap; 59 #endif 60 #ifdef CONFIG_PPC_PKEY 61 unsigned long amr; 62 #endif 63 }; 64 #ifdef CONFIG_PPC_PKEY 65 unsigned long iamr; 66 #endif 67 }; 68 unsigned long __pad[4]; /* Maintain 16 byte interrupt stack alignment */ 69 }; 70 }; 71 #endif 72 73 74 #define STACK_FRAME_WITH_PT_REGS (STACK_FRAME_OVERHEAD + sizeof(struct pt_regs)) 75 76 #ifdef __powerpc64__ 77 78 /* 79 * Size of redzone that userspace is allowed to use below the stack 80 * pointer. This is 288 in the 64-bit big-endian ELF ABI, and 512 in 81 * the new ELFv2 little-endian ABI, so we allow the larger amount. 82 * 83 * For kernel code we allow a 288-byte redzone, in order to conserve 84 * kernel stack space; gcc currently only uses 288 bytes, and will 85 * hopefully allow explicit control of the redzone size in future. 86 */ 87 #define USER_REDZONE_SIZE 512 88 #define KERNEL_REDZONE_SIZE 288 89 90 #define STACK_FRAME_OVERHEAD 112 /* size of minimum stack frame */ 91 #define STACK_FRAME_LR_SAVE 2 /* Location of LR in stack frame */ 92 #define STACK_FRAME_REGS_MARKER ASM_CONST(0x7265677368657265) 93 #define STACK_INT_FRAME_SIZE (sizeof(struct pt_regs) + \ 94 STACK_FRAME_OVERHEAD + KERNEL_REDZONE_SIZE) 95 #define STACK_FRAME_MARKER 12 96 97 #ifdef PPC64_ELF_ABI_v2 98 #define STACK_FRAME_MIN_SIZE 32 99 #else 100 #define STACK_FRAME_MIN_SIZE STACK_FRAME_OVERHEAD 101 #endif 102 103 /* Size of dummy stack frame allocated when calling signal handler. */ 104 #define __SIGNAL_FRAMESIZE 128 105 #define __SIGNAL_FRAMESIZE32 64 106 107 #else /* __powerpc64__ */ 108 109 #define USER_REDZONE_SIZE 0 110 #define KERNEL_REDZONE_SIZE 0 111 #define STACK_FRAME_OVERHEAD 16 /* size of minimum stack frame */ 112 #define STACK_FRAME_LR_SAVE 1 /* Location of LR in stack frame */ 113 #define STACK_FRAME_REGS_MARKER ASM_CONST(0x72656773) 114 #define STACK_INT_FRAME_SIZE (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD) 115 #define STACK_FRAME_MARKER 2 116 #define STACK_FRAME_MIN_SIZE STACK_FRAME_OVERHEAD 117 118 /* Size of stack frame allocated when calling signal handler. */ 119 #define __SIGNAL_FRAMESIZE 64 120 121 #endif /* __powerpc64__ */ 122 123 #ifndef __ASSEMBLY__ 124 125 static inline unsigned long instruction_pointer(struct pt_regs *regs) 126 { 127 return regs->nip; 128 } 129 130 static inline void instruction_pointer_set(struct pt_regs *regs, 131 unsigned long val) 132 { 133 regs->nip = val; 134 } 135 136 static inline unsigned long user_stack_pointer(struct pt_regs *regs) 137 { 138 return regs->gpr[1]; 139 } 140 141 static inline unsigned long frame_pointer(struct pt_regs *regs) 142 { 143 return 0; 144 } 145 146 #ifdef CONFIG_SMP 147 extern unsigned long profile_pc(struct pt_regs *regs); 148 #else 149 #define profile_pc(regs) instruction_pointer(regs) 150 #endif 151 152 long do_syscall_trace_enter(struct pt_regs *regs); 153 void do_syscall_trace_leave(struct pt_regs *regs); 154 155 #define kernel_stack_pointer(regs) ((regs)->gpr[1]) 156 static inline int is_syscall_success(struct pt_regs *regs) 157 { 158 return !(regs->ccr & 0x10000000); 159 } 160 161 static inline long regs_return_value(struct pt_regs *regs) 162 { 163 if (is_syscall_success(regs)) 164 return regs->gpr[3]; 165 else 166 return -regs->gpr[3]; 167 } 168 169 static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc) 170 { 171 regs->gpr[3] = rc; 172 } 173 174 #ifdef __powerpc64__ 175 #define user_mode(regs) ((((regs)->msr) >> MSR_PR_LG) & 0x1) 176 #else 177 #define user_mode(regs) (((regs)->msr & MSR_PR) != 0) 178 #endif 179 180 #define force_successful_syscall_return() \ 181 do { \ 182 set_thread_flag(TIF_NOERROR); \ 183 } while(0) 184 185 #define current_pt_regs() \ 186 ((struct pt_regs *)((unsigned long)task_stack_page(current) + THREAD_SIZE) - 1) 187 188 /* 189 * The 4 low bits (0xf) are available as flags to overload the trap word, 190 * because interrupt vectors have minimum alignment of 0x10. TRAP_FLAGS_MASK 191 * must cover the bits used as flags, including bit 0 which is used as the 192 * "norestart" bit. 193 */ 194 #ifdef __powerpc64__ 195 #define TRAP_FLAGS_MASK 0x1 196 #else 197 /* 198 * On 4xx we use bit 1 in the trap word to indicate whether the exception 199 * is a critical exception (1 means it is). 200 */ 201 #define TRAP_FLAGS_MASK 0xf 202 #define IS_CRITICAL_EXC(regs) (((regs)->trap & 2) != 0) 203 #define IS_MCHECK_EXC(regs) (((regs)->trap & 4) != 0) 204 #define IS_DEBUG_EXC(regs) (((regs)->trap & 8) != 0) 205 #endif /* __powerpc64__ */ 206 #define TRAP(regs) ((regs)->trap & ~TRAP_FLAGS_MASK) 207 208 static __always_inline void set_trap(struct pt_regs *regs, unsigned long val) 209 { 210 regs->trap = (regs->trap & TRAP_FLAGS_MASK) | (val & ~TRAP_FLAGS_MASK); 211 } 212 213 static inline bool trap_is_scv(struct pt_regs *regs) 214 { 215 return (IS_ENABLED(CONFIG_PPC_BOOK3S_64) && TRAP(regs) == 0x3000); 216 } 217 218 static inline bool trap_is_unsupported_scv(struct pt_regs *regs) 219 { 220 return IS_ENABLED(CONFIG_PPC_BOOK3S_64) && TRAP(regs) == 0x7ff0; 221 } 222 223 static inline bool trap_is_syscall(struct pt_regs *regs) 224 { 225 return (trap_is_scv(regs) || TRAP(regs) == 0xc00); 226 } 227 228 static inline bool trap_norestart(struct pt_regs *regs) 229 { 230 return regs->trap & 0x1; 231 } 232 233 static __always_inline void set_trap_norestart(struct pt_regs *regs) 234 { 235 regs->trap |= 0x1; 236 } 237 238 #define arch_has_single_step() (1) 239 #define arch_has_block_step() (true) 240 #define ARCH_HAS_USER_SINGLE_STEP_REPORT 241 242 /* 243 * kprobe-based event tracer support 244 */ 245 246 #include <linux/stddef.h> 247 #include <linux/thread_info.h> 248 extern int regs_query_register_offset(const char *name); 249 extern const char *regs_query_register_name(unsigned int offset); 250 #define MAX_REG_OFFSET (offsetof(struct pt_regs, dsisr)) 251 252 /** 253 * regs_get_register() - get register value from its offset 254 * @regs: pt_regs from which register value is gotten 255 * @offset: offset number of the register. 256 * 257 * regs_get_register returns the value of a register whose offset from @regs. 258 * The @offset is the offset of the register in struct pt_regs. 259 * If @offset is bigger than MAX_REG_OFFSET, this returns 0. 260 */ 261 static inline unsigned long regs_get_register(struct pt_regs *regs, 262 unsigned int offset) 263 { 264 if (unlikely(offset > MAX_REG_OFFSET)) 265 return 0; 266 return *(unsigned long *)((unsigned long)regs + offset); 267 } 268 269 /** 270 * regs_within_kernel_stack() - check the address in the stack 271 * @regs: pt_regs which contains kernel stack pointer. 272 * @addr: address which is checked. 273 * 274 * regs_within_kernel_stack() checks @addr is within the kernel stack page(s). 275 * If @addr is within the kernel stack, it returns true. If not, returns false. 276 */ 277 278 static inline bool regs_within_kernel_stack(struct pt_regs *regs, 279 unsigned long addr) 280 { 281 return ((addr & ~(THREAD_SIZE - 1)) == 282 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1))); 283 } 284 285 /** 286 * regs_get_kernel_stack_nth() - get Nth entry of the stack 287 * @regs: pt_regs which contains kernel stack pointer. 288 * @n: stack entry number. 289 * 290 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which 291 * is specified by @regs. If the @n th entry is NOT in the kernel stack, 292 * this returns 0. 293 */ 294 static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, 295 unsigned int n) 296 { 297 unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs); 298 addr += n; 299 if (regs_within_kernel_stack(regs, (unsigned long)addr)) 300 return *addr; 301 else 302 return 0; 303 } 304 305 #endif /* __ASSEMBLY__ */ 306 307 #ifndef __powerpc64__ 308 /* We need PT_SOFTE defined at all time to avoid #ifdefs */ 309 #define PT_SOFTE PT_MQ 310 #else /* __powerpc64__ */ 311 #define PT_FPSCR32 (PT_FPR0 + 2*32 + 1) /* each FP reg occupies 2 32-bit userspace slots */ 312 #define PT_VR0_32 164 /* each Vector reg occupies 4 slots in 32-bit */ 313 #define PT_VSCR_32 (PT_VR0 + 32*4 + 3) 314 #define PT_VRSAVE_32 (PT_VR0 + 33*4) 315 #define PT_VSR0_32 300 /* each VSR reg occupies 4 slots in 32-bit */ 316 #endif /* __powerpc64__ */ 317 #endif /* _ASM_POWERPC_PTRACE_H */ 318