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 #ifdef CONFIG_PPC_KUAP 57 unsigned long kuap; 58 #endif 59 }; 60 unsigned long __pad[2]; /* Maintain 16 byte interrupt stack alignment */ 61 }; 62 }; 63 #endif 64 65 #ifdef __powerpc64__ 66 67 /* 68 * Size of redzone that userspace is allowed to use below the stack 69 * pointer. This is 288 in the 64-bit big-endian ELF ABI, and 512 in 70 * the new ELFv2 little-endian ABI, so we allow the larger amount. 71 * 72 * For kernel code we allow a 288-byte redzone, in order to conserve 73 * kernel stack space; gcc currently only uses 288 bytes, and will 74 * hopefully allow explicit control of the redzone size in future. 75 */ 76 #define USER_REDZONE_SIZE 512 77 #define KERNEL_REDZONE_SIZE 288 78 79 #define STACK_FRAME_OVERHEAD 112 /* size of minimum stack frame */ 80 #define STACK_FRAME_LR_SAVE 2 /* Location of LR in stack frame */ 81 #define STACK_FRAME_REGS_MARKER ASM_CONST(0x7265677368657265) 82 #define STACK_INT_FRAME_SIZE (sizeof(struct pt_regs) + \ 83 STACK_FRAME_OVERHEAD + KERNEL_REDZONE_SIZE) 84 #define STACK_FRAME_MARKER 12 85 86 #ifdef PPC64_ELF_ABI_v2 87 #define STACK_FRAME_MIN_SIZE 32 88 #else 89 #define STACK_FRAME_MIN_SIZE STACK_FRAME_OVERHEAD 90 #endif 91 92 /* Size of dummy stack frame allocated when calling signal handler. */ 93 #define __SIGNAL_FRAMESIZE 128 94 #define __SIGNAL_FRAMESIZE32 64 95 96 #else /* __powerpc64__ */ 97 98 #define USER_REDZONE_SIZE 0 99 #define KERNEL_REDZONE_SIZE 0 100 #define STACK_FRAME_OVERHEAD 16 /* size of minimum stack frame */ 101 #define STACK_FRAME_LR_SAVE 1 /* Location of LR in stack frame */ 102 #define STACK_FRAME_REGS_MARKER ASM_CONST(0x72656773) 103 #define STACK_INT_FRAME_SIZE (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD) 104 #define STACK_FRAME_MARKER 2 105 #define STACK_FRAME_MIN_SIZE STACK_FRAME_OVERHEAD 106 107 /* Size of stack frame allocated when calling signal handler. */ 108 #define __SIGNAL_FRAMESIZE 64 109 110 #endif /* __powerpc64__ */ 111 112 #ifndef __ASSEMBLY__ 113 114 static inline unsigned long instruction_pointer(struct pt_regs *regs) 115 { 116 return regs->nip; 117 } 118 119 static inline void instruction_pointer_set(struct pt_regs *regs, 120 unsigned long val) 121 { 122 regs->nip = val; 123 } 124 125 static inline unsigned long user_stack_pointer(struct pt_regs *regs) 126 { 127 return regs->gpr[1]; 128 } 129 130 static inline unsigned long frame_pointer(struct pt_regs *regs) 131 { 132 return 0; 133 } 134 135 #ifdef CONFIG_SMP 136 extern unsigned long profile_pc(struct pt_regs *regs); 137 #else 138 #define profile_pc(regs) instruction_pointer(regs) 139 #endif 140 141 long do_syscall_trace_enter(struct pt_regs *regs); 142 void do_syscall_trace_leave(struct pt_regs *regs); 143 144 #define kernel_stack_pointer(regs) ((regs)->gpr[1]) 145 static inline int is_syscall_success(struct pt_regs *regs) 146 { 147 return !(regs->ccr & 0x10000000); 148 } 149 150 static inline long regs_return_value(struct pt_regs *regs) 151 { 152 if (is_syscall_success(regs)) 153 return regs->gpr[3]; 154 else 155 return -regs->gpr[3]; 156 } 157 158 static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc) 159 { 160 regs->gpr[3] = rc; 161 } 162 163 #ifdef __powerpc64__ 164 #define user_mode(regs) ((((regs)->msr) >> MSR_PR_LG) & 0x1) 165 #else 166 #define user_mode(regs) (((regs)->msr & MSR_PR) != 0) 167 #endif 168 169 #define force_successful_syscall_return() \ 170 do { \ 171 set_thread_flag(TIF_NOERROR); \ 172 } while(0) 173 174 struct task_struct; 175 extern int ptrace_get_reg(struct task_struct *task, int regno, 176 unsigned long *data); 177 extern int ptrace_put_reg(struct task_struct *task, int regno, 178 unsigned long data); 179 180 #define current_pt_regs() \ 181 ((struct pt_regs *)((unsigned long)task_stack_page(current) + THREAD_SIZE) - 1) 182 183 #ifdef __powerpc64__ 184 #ifdef CONFIG_PPC_BOOK3S 185 #define TRAP_FLAGS_MASK 0x10 186 #define TRAP(regs) ((regs)->trap & ~TRAP_FLAGS_MASK) 187 #define FULL_REGS(regs) true 188 #define SET_FULL_REGS(regs) do { } while (0) 189 #else 190 #define TRAP_FLAGS_MASK 0x11 191 #define TRAP(regs) ((regs)->trap & ~TRAP_FLAGS_MASK) 192 #define FULL_REGS(regs) (((regs)->trap & 1) == 0) 193 #define SET_FULL_REGS(regs) ((regs)->trap |= 1) 194 #endif 195 #define CHECK_FULL_REGS(regs) BUG_ON(!FULL_REGS(regs)) 196 #define NV_REG_POISON 0xdeadbeefdeadbeefUL 197 #else 198 /* 199 * We use the least-significant bit of the trap field to indicate 200 * whether we have saved the full set of registers, or only a 201 * partial set. A 1 there means the partial set. 202 * On 4xx we use the next bit to indicate whether the exception 203 * is a critical exception (1 means it is). 204 */ 205 #define TRAP_FLAGS_MASK 0x1F 206 #define TRAP(regs) ((regs)->trap & ~TRAP_FLAGS_MASK) 207 #define FULL_REGS(regs) (((regs)->trap & 1) == 0) 208 #define SET_FULL_REGS(regs) ((regs)->trap |= 1) 209 #define IS_CRITICAL_EXC(regs) (((regs)->trap & 2) != 0) 210 #define IS_MCHECK_EXC(regs) (((regs)->trap & 4) != 0) 211 #define IS_DEBUG_EXC(regs) (((regs)->trap & 8) != 0) 212 #define NV_REG_POISON 0xdeadbeef 213 #define CHECK_FULL_REGS(regs) \ 214 do { \ 215 if ((regs)->trap & 1) \ 216 printk(KERN_CRIT "%s: partial register set\n", __func__); \ 217 } while (0) 218 #endif /* __powerpc64__ */ 219 220 static inline void set_trap(struct pt_regs *regs, unsigned long val) 221 { 222 regs->trap = (regs->trap & TRAP_FLAGS_MASK) | (val & ~TRAP_FLAGS_MASK); 223 } 224 225 static inline bool trap_is_scv(struct pt_regs *regs) 226 { 227 return (IS_ENABLED(CONFIG_PPC_BOOK3S_64) && TRAP(regs) == 0x3000); 228 } 229 230 static inline bool trap_is_syscall(struct pt_regs *regs) 231 { 232 return (trap_is_scv(regs) || TRAP(regs) == 0xc00); 233 } 234 235 static inline bool trap_norestart(struct pt_regs *regs) 236 { 237 return regs->trap & 0x10; 238 } 239 240 static inline void set_trap_norestart(struct pt_regs *regs) 241 { 242 regs->trap |= 0x10; 243 } 244 245 #define arch_has_single_step() (1) 246 #ifndef CONFIG_PPC_BOOK3S_601 247 #define arch_has_block_step() (true) 248 #else 249 #define arch_has_block_step() (false) 250 #endif 251 #define ARCH_HAS_USER_SINGLE_STEP_REPORT 252 253 /* 254 * kprobe-based event tracer support 255 */ 256 257 #include <linux/stddef.h> 258 #include <linux/thread_info.h> 259 extern int regs_query_register_offset(const char *name); 260 extern const char *regs_query_register_name(unsigned int offset); 261 #define MAX_REG_OFFSET (offsetof(struct pt_regs, dsisr)) 262 263 /** 264 * regs_get_register() - get register value from its offset 265 * @regs: pt_regs from which register value is gotten 266 * @offset: offset number of the register. 267 * 268 * regs_get_register returns the value of a register whose offset from @regs. 269 * The @offset is the offset of the register in struct pt_regs. 270 * If @offset is bigger than MAX_REG_OFFSET, this returns 0. 271 */ 272 static inline unsigned long regs_get_register(struct pt_regs *regs, 273 unsigned int offset) 274 { 275 if (unlikely(offset > MAX_REG_OFFSET)) 276 return 0; 277 return *(unsigned long *)((unsigned long)regs + offset); 278 } 279 280 /** 281 * regs_within_kernel_stack() - check the address in the stack 282 * @regs: pt_regs which contains kernel stack pointer. 283 * @addr: address which is checked. 284 * 285 * regs_within_kernel_stack() checks @addr is within the kernel stack page(s). 286 * If @addr is within the kernel stack, it returns true. If not, returns false. 287 */ 288 289 static inline bool regs_within_kernel_stack(struct pt_regs *regs, 290 unsigned long addr) 291 { 292 return ((addr & ~(THREAD_SIZE - 1)) == 293 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1))); 294 } 295 296 /** 297 * regs_get_kernel_stack_nth() - get Nth entry of the stack 298 * @regs: pt_regs which contains kernel stack pointer. 299 * @n: stack entry number. 300 * 301 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which 302 * is specified by @regs. If the @n th entry is NOT in the kernel stack, 303 * this returns 0. 304 */ 305 static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, 306 unsigned int n) 307 { 308 unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs); 309 addr += n; 310 if (regs_within_kernel_stack(regs, (unsigned long)addr)) 311 return *addr; 312 else 313 return 0; 314 } 315 316 #endif /* __ASSEMBLY__ */ 317 318 #ifndef __powerpc64__ 319 /* We need PT_SOFTE defined at all time to avoid #ifdefs */ 320 #define PT_SOFTE PT_MQ 321 #else /* __powerpc64__ */ 322 #define PT_FPSCR32 (PT_FPR0 + 2*32 + 1) /* each FP reg occupies 2 32-bit userspace slots */ 323 #define PT_VR0_32 164 /* each Vector reg occupies 4 slots in 32-bit */ 324 #define PT_VSCR_32 (PT_VR0 + 32*4 + 3) 325 #define PT_VRSAVE_32 (PT_VR0 + 33*4) 326 #define PT_VSR0_32 300 /* each VSR reg occupies 4 slots in 32-bit */ 327 #endif /* __powerpc64__ */ 328 #endif /* _ASM_POWERPC_PTRACE_H */ 329