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