arch/x86/include/asm/ptrace.h

   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         unsigned long bx;
  13         unsigned long cx;
  14         unsigned long dx;
  15         unsigned long si;
  16         unsigned long di;
  17         unsigned long bp;
  18         unsigned long ax;
  19         unsigned long ds;
  20         unsigned long es;
  21         unsigned long fs;
  22         unsigned long gs;
  23         unsigned long orig_ax;
  24         unsigned long ip;
  25         unsigned long cs;
  26         unsigned long flags;
  27         unsigned long sp;
  28         unsigned long ss;
  29 };
  30
  31 #else /* __i386__ */
  32
  33 struct pt_regs {
  34 /*
  35  * C ABI says these regs are callee-preserved. They aren't saved on kernel entry
  36  * unless syscall needs a complete, fully filled "struct pt_regs".
  37  */
  38         unsigned long r15;
  39         unsigned long r14;
  40         unsigned long r13;
  41         unsigned long r12;
  42         unsigned long bp;
  43         unsigned long bx;
  44 /* These regs are callee-clobbered. Always saved on kernel entry. */
  45         unsigned long r11;
  46         unsigned long r10;
  47         unsigned long r9;
  48         unsigned long r8;
  49         unsigned long ax;
  50         unsigned long cx;
  51         unsigned long dx;
  52         unsigned long si;
  53         unsigned long di;
  54 /*
  55  * On syscall entry, this is syscall#. On CPU exception, this is error code.
  56  * On hw interrupt, it's IRQ number:
  57  */
  58         unsigned long orig_ax;
  59 /* Return frame for iretq */
  60         unsigned long ip;
  61         unsigned long cs;
  62         unsigned long flags;
  63         unsigned long sp;
  64         unsigned long ss;
  65 /* top of stack page */
  66 };
  67
  68 #endif /* !__i386__ */
  69
  70 #ifdef CONFIG_PARAVIRT
  71 #include <asm/paravirt_types.h>
  72 #endif
  73
  74 struct cpuinfo_x86;
  75 struct task_struct;
  76
  77 extern unsigned long profile_pc(struct pt_regs *regs);
  78 #define profile_pc profile_pc
  79
  80 extern unsigned long
  81 convert_ip_to_linear(struct task_struct *child, struct pt_regs *regs);
  82 extern void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs,
  83                          int error_code, int si_code);
  84
  85
  86 extern unsigned long syscall_trace_enter_phase1(struct pt_regs *, u32 arch);
  87 extern long syscall_trace_enter_phase2(struct pt_regs *, u32 arch,
  88                                        unsigned long phase1_result);
  89
  90 extern long syscall_trace_enter(struct pt_regs *);
  91
  92 static inline unsigned long regs_return_value(struct pt_regs *regs)
  93 {
  94         return regs->ax;
  95 }
  96
  97 /*
  98  * user_mode(regs) determines whether a register set came from user
  99  * mode.  On x86_32, this is true if V8086 mode was enabled OR if the
 100  * register set was from protected mode with RPL-3 CS value.  This
 101  * tricky test checks that with one comparison.
 102  *
 103  * On x86_64, vm86 mode is mercifully nonexistent, and we don't need
 104  * the extra check.
 105  */
 106 static inline int user_mode(struct pt_regs *regs)
 107 {
 108 #ifdef CONFIG_X86_32
 109         return ((regs->cs & SEGMENT_RPL_MASK) | (regs->flags & X86_VM_MASK)) >= USER_RPL;
 110 #else
 111         return !!(regs->cs & 3);
 112 #endif
 113 }
 114
 115 static inline int v8086_mode(struct pt_regs *regs)
 116 {
 117 #ifdef CONFIG_X86_32
 118         return (regs->flags & X86_VM_MASK);
 119 #else
 120         return 0;       /* No V86 mode support in long mode */
 121 #endif
 122 }
 123
 124 #ifdef CONFIG_X86_64
 125 static inline bool user_64bit_mode(struct pt_regs *regs)
 126 {
 127 #ifndef CONFIG_PARAVIRT
 128         /*
 129          * On non-paravirt systems, this is the only long mode CPL 3
 130          * selector.  We do not allow long mode selectors in the LDT.
 131          */
 132         return regs->cs == __USER_CS;
 133 #else
 134         /* Headers are too twisted for this to go in paravirt.h. */
 135         return regs->cs == __USER_CS || regs->cs == pv_info.extra_user_64bit_cs;
 136 #endif
 137 }
 138
 139 #define current_user_stack_pointer()    current_pt_regs()->sp
 140 #define compat_user_stack_pointer()     current_pt_regs()->sp
 141 #endif
 142
 143 #ifdef CONFIG_X86_32
 144 extern unsigned long kernel_stack_pointer(struct pt_regs *regs);
 145 #else
 146 static inline unsigned long kernel_stack_pointer(struct pt_regs *regs)
 147 {
 148         return regs->sp;
 149 }
 150 #endif
 151
 152 #define GET_IP(regs) ((regs)->ip)
 153 #define GET_FP(regs) ((regs)->bp)
 154 #define GET_USP(regs) ((regs)->sp)
 155
 156 #include <asm-generic/ptrace.h>
 157
 158 /* Query offset/name of register from its name/offset */
 159 extern int regs_query_register_offset(const char *name);
 160 extern const char *regs_query_register_name(unsigned int offset);
 161 #define MAX_REG_OFFSET (offsetof(struct pt_regs, ss))
 162
 163 /**
 164  * regs_get_register() - get register value from its offset
 165  * @regs:       pt_regs from which register value is gotten.
 166  * @offset:     offset number of the register.
 167  *
 168  * regs_get_register returns the value of a register. The @offset is the
 169  * offset of the register in struct pt_regs address which specified by @regs.
 170  * If @offset is bigger than MAX_REG_OFFSET, this returns 0.
 171  */
 172 static inline unsigned long regs_get_register(struct pt_regs *regs,
 173                                               unsigned int offset)
 174 {
 175         if (unlikely(offset > MAX_REG_OFFSET))
 176                 return 0;
 177 #ifdef CONFIG_X86_32
 178         /*
 179          * Traps from the kernel do not save sp and ss.
 180          * Use the helper function to retrieve sp.
 181          */
 182         if (offset == offsetof(struct pt_regs, sp) &&
 183             regs->cs == __KERNEL_CS)
 184                 return kernel_stack_pointer(regs);
 185 #endif
 186         return *(unsigned long *)((unsigned long)regs + offset);
 187 }
 188
 189 /**
 190  * regs_within_kernel_stack() - check the address in the stack
 191  * @regs:       pt_regs which contains kernel stack pointer.
 192  * @addr:       address which is checked.
 193  *
 194  * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
 195  * If @addr is within the kernel stack, it returns true. If not, returns false.
 196  */
 197 static inline int regs_within_kernel_stack(struct pt_regs *regs,
 198                                            unsigned long addr)
 199 {
 200         return ((addr & ~(THREAD_SIZE - 1))  ==
 201                 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)));
 202 }
 203
 204 /**
 205  * regs_get_kernel_stack_nth() - get Nth entry of the stack
 206  * @regs:       pt_regs which contains kernel stack pointer.
 207  * @n:          stack entry number.
 208  *
 209  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
 210  * is specified by @regs. If the @n th entry is NOT in the kernel stack,
 211  * this returns 0.
 212  */
 213 static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
 214                                                       unsigned int n)
 215 {
 216         unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
 217         addr += n;
 218         if (regs_within_kernel_stack(regs, (unsigned long)addr))
 219                 return *addr;
 220         else
 221                 return 0;
 222 }
 223
 224 #define arch_has_single_step()  (1)
 225 #ifdef CONFIG_X86_DEBUGCTLMSR
 226 #define arch_has_block_step()   (1)
 227 #else
 228 #define arch_has_block_step()   (boot_cpu_data.x86 >= 6)
 229 #endif
 230
 231 #define ARCH_HAS_USER_SINGLE_STEP_INFO
 232
 233 /*
 234  * When hitting ptrace_stop(), we cannot return using SYSRET because
 235  * that does not restore the full CPU state, only a minimal set.  The
 236  * ptracer can change arbitrary register values, which is usually okay
 237  * because the usual ptrace stops run off the signal delivery path which
 238  * forces IRET; however, ptrace_event() stops happen in arbitrary places
 239  * in the kernel and don't force IRET path.
 240  *
 241  * So force IRET path after a ptrace stop.
 242  */
 243 #define arch_ptrace_stop_needed(code, info)                             \
 244 ({                                                                      \
 245         force_iret();                                                   \
 246         false;                                                          \
 247 })
 248
 249 struct user_desc;
 250 extern int do_get_thread_area(struct task_struct *p, int idx,
 251                               struct user_desc __user *info);
 252 extern int do_set_thread_area(struct task_struct *p, int idx,
 253                               struct user_desc __user *info, int can_allocate);
 254
 255 #endif /* !__ASSEMBLY__ */
 256 #endif /* _ASM_X86_PTRACE_H */