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 #ifdef __powerpc64__ 74 75 /* 76 * Size of redzone that userspace is allowed to use below the stack 77 * pointer. This is 288 in the 64-bit big-endian ELF ABI, and 512 in 78 * the new ELFv2 little-endian ABI, so we allow the larger amount. 79 * 80 * For kernel code we allow a 288-byte redzone, in order to conserve 81 * kernel stack space; gcc currently only uses 288 bytes, and will 82 * hopefully allow explicit control of the redzone size in future. 83 */ 84 #define USER_REDZONE_SIZE 512 85 #define KERNEL_REDZONE_SIZE 288 86 87 #define STACK_FRAME_OVERHEAD 112 /* size of minimum stack frame */ 88 #define STACK_FRAME_LR_SAVE 2 /* Location of LR in stack frame */ 89 #define STACK_FRAME_REGS_MARKER ASM_CONST(0x7265677368657265) 90 #define STACK_INT_FRAME_SIZE (sizeof(struct pt_regs) + \ 91 STACK_FRAME_OVERHEAD + KERNEL_REDZONE_SIZE) 92 #define STACK_FRAME_MARKER 12 93 94 #ifdef PPC64_ELF_ABI_v2 95 #define STACK_FRAME_MIN_SIZE 32 96 #else 97 #define STACK_FRAME_MIN_SIZE STACK_FRAME_OVERHEAD 98 #endif 99 100 /* Size of dummy stack frame allocated when calling signal handler. */ 101 #define __SIGNAL_FRAMESIZE 128 102 #define __SIGNAL_FRAMESIZE32 64 103 104 #else /* __powerpc64__ */ 105 106 #define USER_REDZONE_SIZE 0 107 #define KERNEL_REDZONE_SIZE 0 108 #define STACK_FRAME_OVERHEAD 16 /* size of minimum stack frame */ 109 #define STACK_FRAME_LR_SAVE 1 /* Location of LR in stack frame */ 110 #define STACK_FRAME_REGS_MARKER ASM_CONST(0x72656773) 111 #define STACK_INT_FRAME_SIZE (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD) 112 #define STACK_FRAME_MARKER 2 113 #define STACK_FRAME_MIN_SIZE STACK_FRAME_OVERHEAD 114 115 /* Size of stack frame allocated when calling signal handler. */ 116 #define __SIGNAL_FRAMESIZE 64 117 118 #endif /* __powerpc64__ */ 119 120 #ifndef __ASSEMBLY__ 121 122 static inline unsigned long instruction_pointer(struct pt_regs *regs) 123 { 124 return regs->nip; 125 } 126 127 static inline void instruction_pointer_set(struct pt_regs *regs, 128 unsigned long val) 129 { 130 regs->nip = val; 131 } 132 133 static inline unsigned long user_stack_pointer(struct pt_regs *regs) 134 { 135 return regs->gpr[1]; 136 } 137 138 static inline unsigned long frame_pointer(struct pt_regs *regs) 139 { 140 return 0; 141 } 142 143 #ifdef CONFIG_SMP 144 extern unsigned long profile_pc(struct pt_regs *regs); 145 #else 146 #define profile_pc(regs) instruction_pointer(regs) 147 #endif 148 149 long do_syscall_trace_enter(struct pt_regs *regs); 150 void do_syscall_trace_leave(struct pt_regs *regs); 151 152 #define kernel_stack_pointer(regs) ((regs)->gpr[1]) 153 static inline int is_syscall_success(struct pt_regs *regs) 154 { 155 return !(regs->ccr & 0x10000000); 156 } 157 158 static inline long regs_return_value(struct pt_regs *regs) 159 { 160 if (is_syscall_success(regs)) 161 return regs->gpr[3]; 162 else 163 return -regs->gpr[3]; 164 } 165 166 static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc) 167 { 168 regs->gpr[3] = rc; 169 } 170 171 #ifdef __powerpc64__ 172 #define user_mode(regs) ((((regs)->msr) >> MSR_PR_LG) & 0x1) 173 #else 174 #define user_mode(regs) (((regs)->msr & MSR_PR) != 0) 175 #endif 176 177 #define force_successful_syscall_return() \ 178 do { \ 179 set_thread_flag(TIF_NOERROR); \ 180 } while(0) 181 182 #define current_pt_regs() \ 183 ((struct pt_regs *)((unsigned long)task_stack_page(current) + THREAD_SIZE) - 1) 184 185 #ifdef __powerpc64__ 186 #ifdef CONFIG_PPC_BOOK3S 187 #define TRAP_FLAGS_MASK 0x10 188 #define TRAP(regs) ((regs)->trap & ~TRAP_FLAGS_MASK) 189 #define FULL_REGS(regs) true 190 #define SET_FULL_REGS(regs) do { } while (0) 191 #else 192 #define TRAP_FLAGS_MASK 0x11 193 #define TRAP(regs) ((regs)->trap & ~TRAP_FLAGS_MASK) 194 #define FULL_REGS(regs) (((regs)->trap & 1) == 0) 195 #define SET_FULL_REGS(regs) ((regs)->trap |= 1) 196 #endif 197 #define CHECK_FULL_REGS(regs) BUG_ON(!FULL_REGS(regs)) 198 #define NV_REG_POISON 0xdeadbeefdeadbeefUL 199 #else 200 /* 201 * We use the least-significant bit of the trap field to indicate 202 * whether we have saved the full set of registers, or only a 203 * partial set. A 1 there means the partial set. 204 * On 4xx we use the next bit to indicate whether the exception 205 * is a critical exception (1 means it is). 206 */ 207 #define TRAP_FLAGS_MASK 0x1F 208 #define TRAP(regs) ((regs)->trap & ~TRAP_FLAGS_MASK) 209 #define FULL_REGS(regs) (((regs)->trap & 1) == 0) 210 #define SET_FULL_REGS(regs) ((regs)->trap |= 1) 211 #define IS_CRITICAL_EXC(regs) (((regs)->trap & 2) != 0) 212 #define IS_MCHECK_EXC(regs) (((regs)->trap & 4) != 0) 213 #define IS_DEBUG_EXC(regs) (((regs)->trap & 8) != 0) 214 #define NV_REG_POISON 0xdeadbeef 215 #define CHECK_FULL_REGS(regs) \ 216 do { \ 217 if ((regs)->trap & 1) \ 218 printk(KERN_CRIT "%s: partial register set\n", __func__); \ 219 } while (0) 220 #endif /* __powerpc64__ */ 221 222 static inline void set_trap(struct pt_regs *regs, unsigned long val) 223 { 224 regs->trap = (regs->trap & TRAP_FLAGS_MASK) | (val & ~TRAP_FLAGS_MASK); 225 } 226 227 static inline bool trap_is_scv(struct pt_regs *regs) 228 { 229 return (IS_ENABLED(CONFIG_PPC_BOOK3S_64) && TRAP(regs) == 0x3000); 230 } 231 232 static inline bool trap_is_syscall(struct pt_regs *regs) 233 { 234 return (trap_is_scv(regs) || TRAP(regs) == 0xc00); 235 } 236 237 static inline bool trap_norestart(struct pt_regs *regs) 238 { 239 return regs->trap & 0x10; 240 } 241 242 static inline void set_trap_norestart(struct pt_regs *regs) 243 { 244 regs->trap |= 0x10; 245 } 246 247 #define arch_has_single_step() (1) 248 #define arch_has_block_step() (true) 249 #define ARCH_HAS_USER_SINGLE_STEP_REPORT 250 251 /* 252 * kprobe-based event tracer support 253 */ 254 255 #include <linux/stddef.h> 256 #include <linux/thread_info.h> 257 extern int regs_query_register_offset(const char *name); 258 extern const char *regs_query_register_name(unsigned int offset); 259 #define MAX_REG_OFFSET (offsetof(struct pt_regs, dsisr)) 260 261 /** 262 * regs_get_register() - get register value from its offset 263 * @regs: pt_regs from which register value is gotten 264 * @offset: offset number of the register. 265 * 266 * regs_get_register returns the value of a register whose offset from @regs. 267 * The @offset is the offset of the register in struct pt_regs. 268 * If @offset is bigger than MAX_REG_OFFSET, this returns 0. 269 */ 270 static inline unsigned long regs_get_register(struct pt_regs *regs, 271 unsigned int offset) 272 { 273 if (unlikely(offset > MAX_REG_OFFSET)) 274 return 0; 275 return *(unsigned long *)((unsigned long)regs + offset); 276 } 277 278 /** 279 * regs_within_kernel_stack() - check the address in the stack 280 * @regs: pt_regs which contains kernel stack pointer. 281 * @addr: address which is checked. 282 * 283 * regs_within_kernel_stack() checks @addr is within the kernel stack page(s). 284 * If @addr is within the kernel stack, it returns true. If not, returns false. 285 */ 286 287 static inline bool regs_within_kernel_stack(struct pt_regs *regs, 288 unsigned long addr) 289 { 290 return ((addr & ~(THREAD_SIZE - 1)) == 291 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1))); 292 } 293 294 /** 295 * regs_get_kernel_stack_nth() - get Nth entry of the stack 296 * @regs: pt_regs which contains kernel stack pointer. 297 * @n: stack entry number. 298 * 299 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which 300 * is specified by @regs. If the @n th entry is NOT in the kernel stack, 301 * this returns 0. 302 */ 303 static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, 304 unsigned int n) 305 { 306 unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs); 307 addr += n; 308 if (regs_within_kernel_stack(regs, (unsigned long)addr)) 309 return *addr; 310 else 311 return 0; 312 } 313 314 #endif /* __ASSEMBLY__ */ 315 316 #ifndef __powerpc64__ 317 /* We need PT_SOFTE defined at all time to avoid #ifdefs */ 318 #define PT_SOFTE PT_MQ 319 #else /* __powerpc64__ */ 320 #define PT_FPSCR32 (PT_FPR0 + 2*32 + 1) /* each FP reg occupies 2 32-bit userspace slots */ 321 #define PT_VR0_32 164 /* each Vector reg occupies 4 slots in 32-bit */ 322 #define PT_VSCR_32 (PT_VR0 + 32*4 + 3) 323 #define PT_VRSAVE_32 (PT_VR0 + 33*4) 324 #define PT_VSR0_32 300 /* each VSR reg occupies 4 slots in 32-bit */ 325 #endif /* __powerpc64__ */ 326 #endif /* _ASM_POWERPC_PTRACE_H */ 327