gcc/config/ia64/linux-unwind.h

   1 /* DWARF2 EH unwinding support for IA64 Linux.
   2    Copyright (C) 2004 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 it
   7    under the terms of the GNU General Public License as published
   8    by the Free Software Foundation; either version 2, or (at your
   9    option) any later version.
  10
  11    GCC is distributed in the hope that it will be useful, but WITHOUT
  12    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  13    or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
  14    License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with GCC; see the file COPYING.  If not, write to the
  18    Free Software Foundation, 59 Temple Place - Suite 330, Boston,
  19    MA 02111-1307, USA.  */
  20
  21 /* Do code reading to identify a signal frame, and set the frame
  22    state data appropriately.  See unwind-dw2.c for the structs.  */
  23
  24 /* This works only for glibc-2.3 and later, because sigcontext is different
  25    in glibc-2.2.4.  */
  26
  27 #if __GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 3)
  28 #include <signal.h>
  29 #include <sys/ucontext.h>
  30
  31 #define IA64_GATE_AREA_START 0xa000000000000100LL
  32 #define IA64_GATE_AREA_END   0xa000000000030000LL
  33
  34 #define MD_FALLBACK_FRAME_STATE_FOR ia64_fallback_frame_state
  35
  36 static _Unwind_Reason_Code
  37 ia64_fallback_frame_state (struct _Unwind_Context *context,
  38                            _Unwind_FrameState *fs)
  39 {
  40   if (context->rp >= IA64_GATE_AREA_START
  41       && context->rp < IA64_GATE_AREA_END)
  42     {
  43       struct sigframe {
  44         char scratch[16];
  45         unsigned long sig_number;
  46         struct siginfo *info;
  47         struct sigcontext *sc;
  48       } *frame_ = (struct sigframe *)context->psp;
  49       struct sigcontext *sc = frame_->sc;
  50
  51       /* Restore scratch registers in case the unwinder needs to
  52          refer to a value stored in one of them.  */
  53       {
  54         int i;
  55
  56         for (i = 2; i < 4; i++)
  57           context->ireg[i - 2].loc = &sc->sc_gr[i];
  58         for (i = 8; i < 12; i++)
  59           context->ireg[i - 2].loc = &sc->sc_gr[i];
  60         for (i = 14; i < 32; i++)
  61           context->ireg[i - 2].loc = &sc->sc_gr[i];
  62       }
  63
  64       context->fpsr_loc = &(sc->sc_ar_fpsr);
  65       context->pfs_loc = &(sc->sc_ar_pfs);
  66       context->lc_loc = &(sc->sc_ar_lc);
  67       context->unat_loc = &(sc->sc_ar_unat);
  68       context->br_loc[0] = &(sc->sc_br[0]);
  69       context->br_loc[6] = &(sc->sc_br[6]);
  70       context->br_loc[7] = &(sc->sc_br[7]);
  71       context->pr = sc->sc_pr;
  72       context->psp = sc->sc_gr[12];
  73       context->gp = sc->sc_gr[1];
  74       /* Signal frame doesn't have an associated reg. stack frame
  75          other than what we adjust for below.     */
  76       fs -> no_reg_stack_frame = 1;
  77
  78       if (sc->sc_rbs_base)
  79         {
  80           /* Need to switch from alternate register backing store.  */
  81           long ndirty, loadrs = sc->sc_loadrs >> 16;
  82           unsigned long alt_bspstore = context->bsp - loadrs;
  83           unsigned long bspstore;
  84           unsigned long *ar_bsp = (unsigned long *)(sc->sc_ar_bsp);
  85
  86           ndirty = ia64_rse_num_regs ((unsigned long *) alt_bspstore,
  87                                       (unsigned long *) context->bsp);
  88           bspstore = (unsigned long)
  89             ia64_rse_skip_regs (ar_bsp, -ndirty);
  90           ia64_copy_rbs (context, bspstore, alt_bspstore, loadrs,
  91                          sc->sc_ar_rnat);
  92         }
  93
  94       /* Don't touch the branch registers o.t. b0, b6 and b7.
  95          The kernel doesn't pass the preserved branch registers
  96          in the sigcontext but leaves them intact, so there's no
  97          need to do anything with them here.  */
  98       {
  99         unsigned long sof = sc->sc_cfm & 0x7f;
 100         context->bsp = (unsigned long)
 101           ia64_rse_skip_regs ((unsigned long *)(sc->sc_ar_bsp), -sof);
 102       }
 103
 104       fs->curr.reg[UNW_REG_RP].where = UNW_WHERE_SPREL;
 105       fs->curr.reg[UNW_REG_RP].val
 106         = (unsigned long)&(sc->sc_ip) - context->psp;
 107       fs->curr.reg[UNW_REG_RP].when = -1;
 108
 109       return _URC_NO_REASON;
 110     }
 111   return _URC_END_OF_STACK;
 112 }
 113
 114 #define MD_HANDLE_UNWABI ia64_handle_unwabi
 115
 116 static void
 117 ia64_handle_unwabi (struct _Unwind_Context *context, _Unwind_FrameState *fs)
 118 {
 119   if (fs->unwabi == ((3 << 8) | 's')
 120       || fs->unwabi == ((0 << 8) | 's'))
 121     {
 122       struct sigframe {
 123         char scratch[16];
 124         unsigned long sig_number;
 125         struct siginfo *info;
 126         struct sigcontext *sc;
 127       } *frame = (struct sigframe *)context->psp;
 128       struct sigcontext *sc = frame->sc;
 129
 130       /* Restore scratch registers in case the unwinder needs to
 131          refer to a value stored in one of them.  */
 132       {
 133         int i;
 134
 135         for (i = 2; i < 4; i++)
 136           context->ireg[i - 2].loc = &sc->sc_gr[i];
 137         for (i = 8; i < 12; i++)
 138           context->ireg[i - 2].loc = &sc->sc_gr[i];
 139         for (i = 14; i < 32; i++)
 140           context->ireg[i - 2].loc = &sc->sc_gr[i];
 141       }
 142
 143       context->pfs_loc = &(sc->sc_ar_pfs);
 144       context->lc_loc = &(sc->sc_ar_lc);
 145       context->unat_loc = &(sc->sc_ar_unat);
 146       context->br_loc[0] = &(sc->sc_br[0]);
 147       context->br_loc[6] = &(sc->sc_br[6]);
 148       context->br_loc[7] = &(sc->sc_br[7]);
 149       context->pr = sc->sc_pr;
 150       context->gp = sc->sc_gr[1];
 151       /* Signal frame doesn't have an associated reg. stack frame
 152          other than what we adjust for below.     */
 153       fs -> no_reg_stack_frame = 1;
 154
 155       if (sc->sc_rbs_base)
 156         {
 157           /* Need to switch from alternate register backing store.  */
 158           long ndirty, loadrs = sc->sc_loadrs >> 16;
 159           unsigned long alt_bspstore = context->bsp - loadrs;
 160           unsigned long bspstore;
 161           unsigned long *ar_bsp = (unsigned long *)(sc->sc_ar_bsp);
 162
 163           ndirty = ia64_rse_num_regs ((unsigned long *) alt_bspstore,
 164                                       (unsigned long *) context->bsp);
 165           bspstore = (unsigned long) ia64_rse_skip_regs (ar_bsp, -ndirty);
 166           ia64_copy_rbs (context, bspstore, alt_bspstore, loadrs,
 167                          sc->sc_ar_rnat);
 168         }
 169
 170       /* Don't touch the branch registers o.t. b0, b6 and b7.
 171          The kernel doesn't pass the preserved branch registers
 172          in the sigcontext but leaves them intact, so there's no
 173          need to do anything with them here.  */
 174       {
 175         unsigned long sof = sc->sc_cfm & 0x7f;
 176         context->bsp = (unsigned long)
 177           ia64_rse_skip_regs ((unsigned long *)(sc->sc_ar_bsp), -sof);
 178       }
 179
 180       /* pfs_loc already set above.  Without this pfs_loc would point
 181          incorrectly to sc_cfm instead of sc_ar_pfs.  */
 182       fs->curr.reg[UNW_REG_PFS].where = UNW_WHERE_NONE;
 183     }
 184 }
 185 #endif /* glibc-2.3 or better */