1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _ASM_X86_PTRACE_H 3 #define _ASM_X86_PTRACE_H 4 5 #include <asm/segment.h> 6 #include <asm/page_types.h> 7 #include <uapi/asm/ptrace.h> 8 9 #ifndef __ASSEMBLY__ 10 #ifdef __i386__ 11 12 struct pt_regs { 13 /* 14 * NB: 32-bit x86 CPUs are inconsistent as what happens in the 15 * following cases (where %seg represents a segment register): 16 * 17 * - pushl %seg: some do a 16-bit write and leave the high 18 * bits alone 19 * - movl %seg, [mem]: some do a 16-bit write despite the movl 20 * - IDT entry: some (e.g. 486) will leave the high bits of CS 21 * and (if applicable) SS undefined. 22 * 23 * Fortunately, x86-32 doesn't read the high bits on POP or IRET, 24 * so we can just treat all of the segment registers as 16-bit 25 * values. 26 */ 27 unsigned long bx; 28 unsigned long cx; 29 unsigned long dx; 30 unsigned long si; 31 unsigned long di; 32 unsigned long bp; 33 unsigned long ax; 34 unsigned short ds; 35 unsigned short __dsh; 36 unsigned short es; 37 unsigned short __esh; 38 unsigned short fs; 39 unsigned short __fsh; 40 unsigned short gs; 41 unsigned short __gsh; 42 unsigned long orig_ax; 43 unsigned long ip; 44 unsigned short cs; 45 unsigned short __csh; 46 unsigned long flags; 47 unsigned long sp; 48 unsigned short ss; 49 unsigned short __ssh; 50 }; 51 52 #else /* __i386__ */ 53 54 struct pt_regs { 55 /* 56 * C ABI says these regs are callee-preserved. They aren't saved on kernel entry 57 * unless syscall needs a complete, fully filled "struct pt_regs". 58 */ 59 unsigned long r15; 60 unsigned long r14; 61 unsigned long r13; 62 unsigned long r12; 63 unsigned long bp; 64 unsigned long bx; 65 /* These regs are callee-clobbered. Always saved on kernel entry. */ 66 unsigned long r11; 67 unsigned long r10; 68 unsigned long r9; 69 unsigned long r8; 70 unsigned long ax; 71 unsigned long cx; 72 unsigned long dx; 73 unsigned long si; 74 unsigned long di; 75 /* 76 * On syscall entry, this is syscall#. On CPU exception, this is error code. 77 * On hw interrupt, it's IRQ number: 78 */ 79 unsigned long orig_ax; 80 /* Return frame for iretq */ 81 unsigned long ip; 82 unsigned long cs; 83 unsigned long flags; 84 unsigned long sp; 85 unsigned long ss; 86 /* top of stack page */ 87 }; 88 89 #endif /* !__i386__ */ 90 91 #ifdef CONFIG_PARAVIRT 92 #include <asm/paravirt_types.h> 93 #endif 94 95 struct cpuinfo_x86; 96 struct task_struct; 97 98 extern unsigned long profile_pc(struct pt_regs *regs); 99 #define profile_pc profile_pc 100 101 extern unsigned long 102 convert_ip_to_linear(struct task_struct *child, struct pt_regs *regs); 103 extern void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs, 104 int error_code, int si_code); 105 106 107 static inline unsigned long regs_return_value(struct pt_regs *regs) 108 { 109 return regs->ax; 110 } 111 112 static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc) 113 { 114 regs->ax = rc; 115 } 116 117 /* 118 * user_mode(regs) determines whether a register set came from user 119 * mode. On x86_32, this is true if V8086 mode was enabled OR if the 120 * register set was from protected mode with RPL-3 CS value. This 121 * tricky test checks that with one comparison. 122 * 123 * On x86_64, vm86 mode is mercifully nonexistent, and we don't need 124 * the extra check. 125 */ 126 static inline int user_mode(struct pt_regs *regs) 127 { 128 #ifdef CONFIG_X86_32 129 return ((regs->cs & SEGMENT_RPL_MASK) | (regs->flags & X86_VM_MASK)) >= USER_RPL; 130 #else 131 return !!(regs->cs & 3); 132 #endif 133 } 134 135 static inline int v8086_mode(struct pt_regs *regs) 136 { 137 #ifdef CONFIG_X86_32 138 return (regs->flags & X86_VM_MASK); 139 #else 140 return 0; /* No V86 mode support in long mode */ 141 #endif 142 } 143 144 static inline bool user_64bit_mode(struct pt_regs *regs) 145 { 146 #ifdef CONFIG_X86_64 147 #ifndef CONFIG_PARAVIRT 148 /* 149 * On non-paravirt systems, this is the only long mode CPL 3 150 * selector. We do not allow long mode selectors in the LDT. 151 */ 152 return regs->cs == __USER_CS; 153 #else 154 /* Headers are too twisted for this to go in paravirt.h. */ 155 return regs->cs == __USER_CS || regs->cs == pv_info.extra_user_64bit_cs; 156 #endif 157 #else /* !CONFIG_X86_64 */ 158 return false; 159 #endif 160 } 161 162 #ifdef CONFIG_X86_64 163 #define current_user_stack_pointer() current_pt_regs()->sp 164 #define compat_user_stack_pointer() current_pt_regs()->sp 165 #endif 166 167 #ifdef CONFIG_X86_32 168 extern unsigned long kernel_stack_pointer(struct pt_regs *regs); 169 #else 170 static inline unsigned long kernel_stack_pointer(struct pt_regs *regs) 171 { 172 return regs->sp; 173 } 174 #endif 175 176 #define GET_IP(regs) ((regs)->ip) 177 #define GET_FP(regs) ((regs)->bp) 178 #define GET_USP(regs) ((regs)->sp) 179 180 #include <asm-generic/ptrace.h> 181 182 /* Query offset/name of register from its name/offset */ 183 extern int regs_query_register_offset(const char *name); 184 extern const char *regs_query_register_name(unsigned int offset); 185 #define MAX_REG_OFFSET (offsetof(struct pt_regs, ss)) 186 187 /** 188 * regs_get_register() - get register value from its offset 189 * @regs: pt_regs from which register value is gotten. 190 * @offset: offset number of the register. 191 * 192 * regs_get_register returns the value of a register. The @offset is the 193 * offset of the register in struct pt_regs address which specified by @regs. 194 * If @offset is bigger than MAX_REG_OFFSET, this returns 0. 195 */ 196 static inline unsigned long regs_get_register(struct pt_regs *regs, 197 unsigned int offset) 198 { 199 if (unlikely(offset > MAX_REG_OFFSET)) 200 return 0; 201 #ifdef CONFIG_X86_32 202 /* 203 * Traps from the kernel do not save sp and ss. 204 * Use the helper function to retrieve sp. 205 */ 206 if (offset == offsetof(struct pt_regs, sp) && 207 regs->cs == __KERNEL_CS) 208 return kernel_stack_pointer(regs); 209 210 /* The selector fields are 16-bit. */ 211 if (offset == offsetof(struct pt_regs, cs) || 212 offset == offsetof(struct pt_regs, ss) || 213 offset == offsetof(struct pt_regs, ds) || 214 offset == offsetof(struct pt_regs, es) || 215 offset == offsetof(struct pt_regs, fs) || 216 offset == offsetof(struct pt_regs, gs)) { 217 return *(u16 *)((unsigned long)regs + offset); 218 219 } 220 #endif 221 return *(unsigned long *)((unsigned long)regs + offset); 222 } 223 224 /** 225 * regs_within_kernel_stack() - check the address in the stack 226 * @regs: pt_regs which contains kernel stack pointer. 227 * @addr: address which is checked. 228 * 229 * regs_within_kernel_stack() checks @addr is within the kernel stack page(s). 230 * If @addr is within the kernel stack, it returns true. If not, returns false. 231 */ 232 static inline int regs_within_kernel_stack(struct pt_regs *regs, 233 unsigned long addr) 234 { 235 return ((addr & ~(THREAD_SIZE - 1)) == 236 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1))); 237 } 238 239 /** 240 * regs_get_kernel_stack_nth() - get Nth entry of the stack 241 * @regs: pt_regs which contains kernel stack pointer. 242 * @n: stack entry number. 243 * 244 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which 245 * is specified by @regs. If the @n th entry is NOT in the kernel stack, 246 * this returns 0. 247 */ 248 static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, 249 unsigned int n) 250 { 251 unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs); 252 addr += n; 253 if (regs_within_kernel_stack(regs, (unsigned long)addr)) 254 return *addr; 255 else 256 return 0; 257 } 258 259 #define arch_has_single_step() (1) 260 #ifdef CONFIG_X86_DEBUGCTLMSR 261 #define arch_has_block_step() (1) 262 #else 263 #define arch_has_block_step() (boot_cpu_data.x86 >= 6) 264 #endif 265 266 #define ARCH_HAS_USER_SINGLE_STEP_INFO 267 268 /* 269 * When hitting ptrace_stop(), we cannot return using SYSRET because 270 * that does not restore the full CPU state, only a minimal set. The 271 * ptracer can change arbitrary register values, which is usually okay 272 * because the usual ptrace stops run off the signal delivery path which 273 * forces IRET; however, ptrace_event() stops happen in arbitrary places 274 * in the kernel and don't force IRET path. 275 * 276 * So force IRET path after a ptrace stop. 277 */ 278 #define arch_ptrace_stop_needed(code, info) \ 279 ({ \ 280 force_iret(); \ 281 false; \ 282 }) 283 284 struct user_desc; 285 extern int do_get_thread_area(struct task_struct *p, int idx, 286 struct user_desc __user *info); 287 extern int do_set_thread_area(struct task_struct *p, int idx, 288 struct user_desc __user *info, int can_allocate); 289 290 #endif /* !__ASSEMBLY__ */ 291 #endif /* _ASM_X86_PTRACE_H */ 292