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__ 27struct 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#ifdef CONFIG_PPC_KUAP 58 unsigned long kuap; 59#endif 60 }; 61 unsigned long __pad[2]; /* Maintain 16 byte interrupt stack alignment */ 62 }; 63}; 64#endif 65 66 67#define STACK_FRAME_WITH_PT_REGS (STACK_FRAME_OVERHEAD + sizeof(struct pt_regs)) 68 69#ifdef __powerpc64__ 70 71/* 72 * Size of redzone that userspace is allowed to use below the stack 73 * pointer. This is 288 in the 64-bit big-endian ELF ABI, and 512 in 74 * the new ELFv2 little-endian ABI, so we allow the larger amount. 75 * 76 * For kernel code we allow a 288-byte redzone, in order to conserve 77 * kernel stack space; gcc currently only uses 288 bytes, and will 78 * hopefully allow explicit control of the redzone size in future. 79 */ 80#define USER_REDZONE_SIZE 512 81#define KERNEL_REDZONE_SIZE 288 82 83#define STACK_FRAME_OVERHEAD 112 /* size of minimum stack frame */ 84#define STACK_FRAME_LR_SAVE 2 /* Location of LR in stack frame */ 85#define STACK_FRAME_REGS_MARKER ASM_CONST(0x7265677368657265) 86#define STACK_INT_FRAME_SIZE (sizeof(struct pt_regs) + \ 87 STACK_FRAME_OVERHEAD + KERNEL_REDZONE_SIZE) 88#define STACK_FRAME_MARKER 12 89 90#ifdef PPC64_ELF_ABI_v2 91#define STACK_FRAME_MIN_SIZE 32 92#else 93#define STACK_FRAME_MIN_SIZE STACK_FRAME_OVERHEAD 94#endif 95 96/* Size of dummy stack frame allocated when calling signal handler. */ 97#define __SIGNAL_FRAMESIZE 128 98#define __SIGNAL_FRAMESIZE32 64 99 100#else /* __powerpc64__ */ 101 102#define USER_REDZONE_SIZE 0 103#define KERNEL_REDZONE_SIZE 0 104#define STACK_FRAME_OVERHEAD 16 /* size of minimum stack frame */ 105#define STACK_FRAME_LR_SAVE 1 /* Location of LR in stack frame */ 106#define STACK_FRAME_REGS_MARKER ASM_CONST(0x72656773) 107#define STACK_INT_FRAME_SIZE (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD) 108#define STACK_FRAME_MARKER 2 109#define STACK_FRAME_MIN_SIZE STACK_FRAME_OVERHEAD 110 111/* Size of stack frame allocated when calling signal handler. */ 112#define __SIGNAL_FRAMESIZE 64 113 114#endif /* __powerpc64__ */ 115 116#ifndef __ASSEMBLY__ 117 118static inline unsigned long instruction_pointer(struct pt_regs *regs) 119{ 120 return regs->nip; 121} 122 123static inline void instruction_pointer_set(struct pt_regs *regs, 124 unsigned long val) 125{ 126 regs->nip = val; 127} 128 129static inline unsigned long user_stack_pointer(struct pt_regs *regs) 130{ 131 return regs->gpr[1]; 132} 133 134static inline unsigned long frame_pointer(struct pt_regs *regs) 135{ 136 return 0; 137} 138 139#ifdef CONFIG_SMP 140extern unsigned long profile_pc(struct pt_regs *regs); 141#else 142#define profile_pc(regs) instruction_pointer(regs) 143#endif 144 145long do_syscall_trace_enter(struct pt_regs *regs); 146void do_syscall_trace_leave(struct pt_regs *regs); 147 148#ifdef __powerpc64__ 149#define user_mode(regs) ((((regs)->msr) >> MSR_PR_LG) & 0x1) 150#else 151#define user_mode(regs) (((regs)->msr & MSR_PR) != 0) 152#endif 153 154#define force_successful_syscall_return() \ 155 do { \ 156 set_thread_flag(TIF_NOERROR); \ 157 } while(0) 158 159struct task_struct; 160extern int ptrace_get_reg(struct task_struct *task, int regno, 161 unsigned long *data); 162extern int ptrace_put_reg(struct task_struct *task, int regno, 163 unsigned long data); 164 165#define current_pt_regs() \ 166 ((struct pt_regs *)((unsigned long)task_stack_page(current) + THREAD_SIZE) - 1) 167 168#ifdef __powerpc64__ 169#ifdef CONFIG_PPC_BOOK3S 170#define TRAP_FLAGS_MASK 0x10 171#define TRAP(regs) ((regs)->trap & ~TRAP_FLAGS_MASK) 172#define FULL_REGS(regs) true 173#define SET_FULL_REGS(regs) do { } while (0) 174#else 175#define TRAP_FLAGS_MASK 0x11 176#define TRAP(regs) ((regs)->trap & ~TRAP_FLAGS_MASK) 177#define FULL_REGS(regs) (((regs)->trap & 1) == 0) 178#define SET_FULL_REGS(regs) ((regs)->trap &= ~1) 179#endif 180#define CHECK_FULL_REGS(regs) BUG_ON(!FULL_REGS(regs)) 181#define NV_REG_POISON 0xdeadbeefdeadbeefUL 182#else 183/* 184 * We use the least-significant bit of the trap field to indicate 185 * whether we have saved the full set of registers, or only a 186 * partial set. A 1 there means the partial set. 187 * On 4xx we use the next bit to indicate whether the exception 188 * is a critical exception (1 means it is). 189 */ 190#define TRAP_FLAGS_MASK 0x1F 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#define IS_CRITICAL_EXC(regs) (((regs)->trap & 2) != 0) 195#define IS_MCHECK_EXC(regs) (((regs)->trap & 4) != 0) 196#define IS_DEBUG_EXC(regs) (((regs)->trap & 8) != 0) 197#define NV_REG_POISON 0xdeadbeef 198#define CHECK_FULL_REGS(regs) \ 199do { \ 200 if ((regs)->trap & 1) \ 201 printk(KERN_CRIT "%s: partial register set\n", __func__); \ 202} while (0) 203#endif /* __powerpc64__ */ 204 205static inline void set_trap(struct pt_regs *regs, unsigned long val) 206{ 207 regs->trap = (regs->trap & TRAP_FLAGS_MASK) | (val & ~TRAP_FLAGS_MASK); 208} 209 210static inline bool trap_is_scv(struct pt_regs *regs) 211{ 212 return (IS_ENABLED(CONFIG_PPC_BOOK3S_64) && TRAP(regs) == 0x3000); 213} 214 215static inline bool trap_is_syscall(struct pt_regs *regs) 216{ 217 return (trap_is_scv(regs) || TRAP(regs) == 0xc00); 218} 219 220static inline bool trap_norestart(struct pt_regs *regs) 221{ 222 return regs->trap & 0x10; 223} 224 225static inline void set_trap_norestart(struct pt_regs *regs) 226{ 227 regs->trap |= 0x10; 228} 229 230#define kernel_stack_pointer(regs) ((regs)->gpr[1]) 231static inline int is_syscall_success(struct pt_regs *regs) 232{ 233 if (trap_is_scv(regs)) 234 return !IS_ERR_VALUE((unsigned long)regs->gpr[3]); 235 else 236 return !(regs->ccr & 0x10000000); 237} 238 239static inline long regs_return_value(struct pt_regs *regs) 240{ 241 if (trap_is_scv(regs)) 242 return regs->gpr[3]; 243 244 if (is_syscall_success(regs)) 245 return regs->gpr[3]; 246 else 247 return -regs->gpr[3]; 248} 249 250static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc) 251{ 252 regs->gpr[3] = rc; 253} 254 255#define arch_has_single_step() (1) 256#define arch_has_block_step() (true) 257#define ARCH_HAS_USER_SINGLE_STEP_REPORT 258 259/* 260 * kprobe-based event tracer support 261 */ 262 263#include <linux/stddef.h> 264#include <linux/thread_info.h> 265extern int regs_query_register_offset(const char *name); 266extern const char *regs_query_register_name(unsigned int offset); 267#define MAX_REG_OFFSET (offsetof(struct pt_regs, dsisr)) 268 269/** 270 * regs_get_register() - get register value from its offset 271 * @regs: pt_regs from which register value is gotten 272 * @offset: offset number of the register. 273 * 274 * regs_get_register returns the value of a register whose offset from @regs. 275 * The @offset is the offset of the register in struct pt_regs. 276 * If @offset is bigger than MAX_REG_OFFSET, this returns 0. 277 */ 278static inline unsigned long regs_get_register(struct pt_regs *regs, 279 unsigned int offset) 280{ 281 if (unlikely(offset > MAX_REG_OFFSET)) 282 return 0; 283 return *(unsigned long *)((unsigned long)regs + offset); 284} 285 286/** 287 * regs_within_kernel_stack() - check the address in the stack 288 * @regs: pt_regs which contains kernel stack pointer. 289 * @addr: address which is checked. 290 * 291 * regs_within_kernel_stack() checks @addr is within the kernel stack page(s). 292 * If @addr is within the kernel stack, it returns true. If not, returns false. 293 */ 294 295static inline bool regs_within_kernel_stack(struct pt_regs *regs, 296 unsigned long addr) 297{ 298 return ((addr & ~(THREAD_SIZE - 1)) == 299 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1))); 300} 301 302/** 303 * regs_get_kernel_stack_nth() - get Nth entry of the stack 304 * @regs: pt_regs which contains kernel stack pointer. 305 * @n: stack entry number. 306 * 307 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which 308 * is specified by @regs. If the @n th entry is NOT in the kernel stack, 309 * this returns 0. 310 */ 311static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, 312 unsigned int n) 313{ 314 unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs); 315 addr += n; 316 if (regs_within_kernel_stack(regs, (unsigned long)addr)) 317 return *addr; 318 else 319 return 0; 320} 321 322#endif /* __ASSEMBLY__ */ 323 324#ifndef __powerpc64__ 325/* We need PT_SOFTE defined at all time to avoid #ifdefs */ 326#define PT_SOFTE PT_MQ 327#else /* __powerpc64__ */ 328#define PT_FPSCR32 (PT_FPR0 + 2*32 + 1) /* each FP reg occupies 2 32-bit userspace slots */ 329#define PT_VR0_32 164 /* each Vector reg occupies 4 slots in 32-bit */ 330#define PT_VSCR_32 (PT_VR0 + 32*4 + 3) 331#define PT_VRSAVE_32 (PT_VR0 + 33*4) 332#define PT_VSR0_32 300 /* each VSR reg occupies 4 slots in 32-bit */ 333#endif /* __powerpc64__ */ 334#endif /* _ASM_POWERPC_PTRACE_H */ 335