gcc/config/i386/linux-unwind.h

   1 /* DWARF2 EH unwinding support for AMD x86-64 and x86.
   2    Copyright (C) 2004, 2005, 2006 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 In addition to the permissions in the GNU General Public License, the
  12 Free Software Foundation gives you unlimited permission to link the
  13 compiled version of this file with other programs, and to distribute
  14 those programs without any restriction coming from the use of this
  15 file.  (The General Public License restrictions do apply in other
  16 respects; for example, they cover modification of the file, and
  17 distribution when not linked into another program.)
  18
  19 GCC is distributed in the hope that it will be useful,
  20 but WITHOUT ANY WARRANTY; without even the implied warranty of
  21 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22 GNU General Public License for more details.
  23
  24 You should have received a copy of the GNU General Public License
  25 along with GCC; see the file COPYING.  If not, write to
  26 the Free Software Foundation, 51 Franklin Street, Fifth Floor,
  27 Boston, MA 02110-1301, USA.  */
  28
  29 /* Do code reading to identify a signal frame, and set the frame
  30    state data appropriately.  See unwind-dw2.c for the structs.
  31    Don't use this at all if inhibit_libc is used.  */
  32
  33 #ifndef inhibit_libc
  34
  35 #ifdef __x86_64__
  36
  37 #include <signal.h>
  38 #include <sys/ucontext.h>
  39
  40 #define MD_FALLBACK_FRAME_STATE_FOR x86_64_fallback_frame_state
  41
  42 static _Unwind_Reason_Code
  43 x86_64_fallback_frame_state (struct _Unwind_Context *context,
  44                              _Unwind_FrameState *fs)
  45 {
  46   unsigned char *pc = context->ra;
  47   struct sigcontext *sc;
  48   long new_cfa;
  49
  50   /* movq __NR_rt_sigreturn, %rax ; syscall  */
  51   if (*(unsigned char *)(pc+0) == 0x48
  52       && *(unsigned long *)(pc+1) == 0x050f0000000fc0c7)
  53     {
  54       struct ucontext *uc_ = context->cfa;
  55       /* The void * cast is necessary to avoid an aliasing warning.
  56          The aliasing warning is correct, but should not be a problem
  57          because it does not alias anything.  */
  58       sc = (struct sigcontext *) (void *) &uc_->uc_mcontext;
  59     }
  60   else
  61     return _URC_END_OF_STACK;
  62
  63   new_cfa = sc->rsp;
  64   fs->regs.cfa_how = CFA_REG_OFFSET;
  65   /* Register 7 is rsp  */
  66   fs->regs.cfa_reg = 7;
  67   fs->regs.cfa_offset = new_cfa - (long) context->cfa;
  68
  69   /* The SVR4 register numbering macros aren't usable in libgcc.  */
  70   fs->regs.reg[0].how = REG_SAVED_OFFSET;
  71   fs->regs.reg[0].loc.offset = (long)&sc->rax - new_cfa;
  72   fs->regs.reg[1].how = REG_SAVED_OFFSET;
  73   fs->regs.reg[1].loc.offset = (long)&sc->rdx - new_cfa;
  74   fs->regs.reg[2].how = REG_SAVED_OFFSET;
  75   fs->regs.reg[2].loc.offset = (long)&sc->rcx - new_cfa;
  76   fs->regs.reg[3].how = REG_SAVED_OFFSET;
  77   fs->regs.reg[3].loc.offset = (long)&sc->rbx - new_cfa;
  78   fs->regs.reg[4].how = REG_SAVED_OFFSET;
  79   fs->regs.reg[4].loc.offset = (long)&sc->rsi - new_cfa;
  80   fs->regs.reg[5].how = REG_SAVED_OFFSET;
  81   fs->regs.reg[5].loc.offset = (long)&sc->rdi - new_cfa;
  82   fs->regs.reg[6].how = REG_SAVED_OFFSET;
  83   fs->regs.reg[6].loc.offset = (long)&sc->rbp - new_cfa;
  84   fs->regs.reg[8].how = REG_SAVED_OFFSET;
  85   fs->regs.reg[8].loc.offset = (long)&sc->r8 - new_cfa;
  86   fs->regs.reg[9].how = REG_SAVED_OFFSET;
  87   fs->regs.reg[9].loc.offset = (long)&sc->r9 - new_cfa;
  88   fs->regs.reg[10].how = REG_SAVED_OFFSET;
  89   fs->regs.reg[10].loc.offset = (long)&sc->r10 - new_cfa;
  90   fs->regs.reg[11].how = REG_SAVED_OFFSET;
  91   fs->regs.reg[11].loc.offset = (long)&sc->r11 - new_cfa;
  92   fs->regs.reg[12].how = REG_SAVED_OFFSET;
  93   fs->regs.reg[12].loc.offset = (long)&sc->r12 - new_cfa;
  94   fs->regs.reg[13].how = REG_SAVED_OFFSET;
  95   fs->regs.reg[13].loc.offset = (long)&sc->r13 - new_cfa;
  96   fs->regs.reg[14].how = REG_SAVED_OFFSET;
  97   fs->regs.reg[14].loc.offset = (long)&sc->r14 - new_cfa;
  98   fs->regs.reg[15].how = REG_SAVED_OFFSET;
  99   fs->regs.reg[15].loc.offset = (long)&sc->r15 - new_cfa;
 100   fs->regs.reg[16].how = REG_SAVED_OFFSET;
 101   fs->regs.reg[16].loc.offset = (long)&sc->rip - new_cfa;
 102   fs->retaddr_column = 16;
 103   fs->signal_frame = 1;
 104   return _URC_NO_REASON;
 105 }
 106
 107 #else /* ifdef __x86_64__  */
 108
 109 /* There's no sys/ucontext.h for glibc 2.0, so no
 110    signal-turned-exceptions for them.  There's also no configure-run for
 111    the target, so we can't check on (e.g.) HAVE_SYS_UCONTEXT_H.  Using the
 112    target libc version macro should be enough.  */
 113 #if !(__GLIBC__ == 2 && __GLIBC_MINOR__ == 0)
 114
 115 #include <signal.h>
 116 #include <sys/ucontext.h>
 117
 118 #define MD_FALLBACK_FRAME_STATE_FOR x86_fallback_frame_state
 119
 120 static _Unwind_Reason_Code
 121 x86_fallback_frame_state (struct _Unwind_Context *context,
 122                           _Unwind_FrameState *fs)
 123 {
 124   unsigned char *pc = context->ra;
 125   struct sigcontext *sc;
 126   long new_cfa;
 127
 128   /* popl %eax ; movl $__NR_sigreturn,%eax ; int $0x80  */
 129   if (*(unsigned short *)(pc+0) == 0xb858
 130       && *(unsigned int *)(pc+2) == 119
 131       && *(unsigned short *)(pc+6) == 0x80cd)
 132     sc = context->cfa + 4;
 133   /* movl $__NR_rt_sigreturn,%eax ; int $0x80  */
 134   else if (*(unsigned char *)(pc+0) == 0xb8
 135            && *(unsigned int *)(pc+1) == 173
 136            && *(unsigned short *)(pc+5) == 0x80cd)
 137     {
 138       struct rt_sigframe {
 139         int sig;
 140         struct siginfo *pinfo;
 141         void *puc;
 142         struct siginfo info;
 143         struct ucontext uc;
 144       } *rt_ = context->cfa;
 145       /* The void * cast is necessary to avoid an aliasing warning.
 146          The aliasing warning is correct, but should not be a problem
 147          because it does not alias anything.  */
 148       sc = (struct sigcontext *) (void *) &rt_->uc.uc_mcontext;
 149     }
 150   else
 151     return _URC_END_OF_STACK;
 152
 153   new_cfa = sc->REG_NAME(esp);
 154   fs->regs.cfa_how = CFA_REG_OFFSET;
 155   fs->regs.cfa_reg = 4;
 156   fs->regs.cfa_offset = new_cfa - (long) context->cfa;
 157
 158   /* The SVR4 register numbering macros aren't usable in libgcc.  */
 159   fs->regs.reg[0].how = REG_SAVED_OFFSET;
 160   fs->regs.reg[0].loc.offset = (long)&sc->REG_NAME(eax) - new_cfa;
 161   fs->regs.reg[3].how = REG_SAVED_OFFSET;
 162   fs->regs.reg[3].loc.offset = (long)&sc->REG_NAME(ebx) - new_cfa;
 163   fs->regs.reg[1].how = REG_SAVED_OFFSET;
 164   fs->regs.reg[1].loc.offset = (long)&sc->REG_NAME(ecx) - new_cfa;
 165   fs->regs.reg[2].how = REG_SAVED_OFFSET;
 166   fs->regs.reg[2].loc.offset = (long)&sc->REG_NAME(edx) - new_cfa;
 167   fs->regs.reg[6].how = REG_SAVED_OFFSET;
 168   fs->regs.reg[6].loc.offset = (long)&sc->REG_NAME(esi) - new_cfa;
 169   fs->regs.reg[7].how = REG_SAVED_OFFSET;
 170   fs->regs.reg[7].loc.offset = (long)&sc->REG_NAME(edi) - new_cfa;
 171   fs->regs.reg[5].how = REG_SAVED_OFFSET;
 172   fs->regs.reg[5].loc.offset = (long)&sc->REG_NAME(ebp) - new_cfa;
 173   fs->regs.reg[8].how = REG_SAVED_OFFSET;
 174   fs->regs.reg[8].loc.offset = (long)&sc->REG_NAME(eip) - new_cfa;
 175   fs->retaddr_column = 8;
 176   fs->signal_frame = 1;
 177   return _URC_NO_REASON;
 178 }
 179 #endif /* not glibc 2.0 */
 180 #endif /* ifdef __x86_64__  */
 181 #endif /* ifdef inhibit_libc  */