gcc/config/ia64/linux-unwind.h

   1 /* DWARF2 EH unwinding support for IA64 Linux.
   2    Copyright (C) 2004, 2005 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    In addition to the permissions in the GNU General Public License,
  12    the Free Software Foundation gives you unlimited permission to link
  13    the compiled version of this file with other programs, and to
  14    distribute those programs without any restriction coming from the
  15    use of this file.  (The General Public License restrictions do
  16    apply in other respects; for example, they cover modification of
  17    the file, and distribution when not linked into another program.)
  18
  19    GCC is distributed in the hope that it will be useful, but WITHOUT
  20    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  21    or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
  22    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 the
  26    Free Software Foundation, 59 Temple Place - Suite 330, Boston,
  27    MA 02111-1307, 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
  32 /* This works only for glibc-2.3 and later, because sigcontext is different
  33    in glibc-2.2.4.  */
  34
  35 #if __GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 3)
  36 #include <signal.h>
  37 #include <sys/ucontext.h>
  38
  39 #define IA64_GATE_AREA_START 0xa000000000000100LL
  40 #define IA64_GATE_AREA_END   0xa000000000030000LL
  41
  42 #define MD_FALLBACK_FRAME_STATE_FOR ia64_fallback_frame_state
  43
  44 static _Unwind_Reason_Code
  45 ia64_fallback_frame_state (struct _Unwind_Context *context,
  46                            _Unwind_FrameState *fs)
  47 {
  48   if (context->rp >= IA64_GATE_AREA_START
  49       && context->rp < IA64_GATE_AREA_END)
  50     {
  51       struct sigframe {
  52         char scratch[16];
  53         unsigned long sig_number;
  54         struct siginfo *info;
  55         struct sigcontext *sc;
  56       } *frame_ = (struct sigframe *)context->psp;
  57       struct sigcontext *sc = frame_->sc;
  58
  59       /* Restore scratch registers in case the unwinder needs to
  60          refer to a value stored in one of them.  */
  61       {
  62         int i;
  63
  64         for (i = 2; i < 4; i++)
  65           context->ireg[i - 2].loc = &sc->sc_gr[i];
  66         for (i = 8; i < 12; i++)
  67           context->ireg[i - 2].loc = &sc->sc_gr[i];
  68         for (i = 14; i < 32; i++)
  69           context->ireg[i - 2].loc = &sc->sc_gr[i];
  70       }
  71
  72       context->fpsr_loc = &(sc->sc_ar_fpsr);
  73       context->pfs_loc = &(sc->sc_ar_pfs);
  74       context->lc_loc = &(sc->sc_ar_lc);
  75       context->unat_loc = &(sc->sc_ar_unat);
  76       context->br_loc[0] = &(sc->sc_br[0]);
  77       context->br_loc[6] = &(sc->sc_br[6]);
  78       context->br_loc[7] = &(sc->sc_br[7]);
  79       context->pr = sc->sc_pr;
  80       context->psp = sc->sc_gr[12];
  81       context->gp = sc->sc_gr[1];
  82       /* Signal frame doesn't have an associated reg. stack frame
  83          other than what we adjust for below.     */
  84       fs -> no_reg_stack_frame = 1;
  85
  86       if (sc->sc_rbs_base)
  87         {
  88           /* Need to switch from alternate register backing store.  */
  89           long ndirty, loadrs = sc->sc_loadrs >> 16;
  90           unsigned long alt_bspstore = context->bsp - loadrs;
  91           unsigned long bspstore;
  92           unsigned long *ar_bsp = (unsigned long *)(sc->sc_ar_bsp);
  93
  94           ndirty = ia64_rse_num_regs ((unsigned long *) alt_bspstore,
  95                                       (unsigned long *) context->bsp);
  96           bspstore = (unsigned long)
  97             ia64_rse_skip_regs (ar_bsp, -ndirty);
  98           ia64_copy_rbs (context, bspstore, alt_bspstore, loadrs,
  99                          sc->sc_ar_rnat);
 100         }
 101
 102       /* Don't touch the branch registers o.t. b0, b6 and b7.
 103          The kernel doesn't pass the preserved branch registers
 104          in the sigcontext but leaves them intact, so there's no
 105          need to do anything with them here.  */
 106       {
 107         unsigned long sof = sc->sc_cfm & 0x7f;
 108         context->bsp = (unsigned long)
 109           ia64_rse_skip_regs ((unsigned long *)(sc->sc_ar_bsp), -sof);
 110       }
 111
 112       fs->curr.reg[UNW_REG_RP].where = UNW_WHERE_SPREL;
 113       fs->curr.reg[UNW_REG_RP].val
 114         = (unsigned long)&(sc->sc_ip) - context->psp;
 115       fs->curr.reg[UNW_REG_RP].when = -1;
 116
 117       return _URC_NO_REASON;
 118     }
 119   return _URC_END_OF_STACK;
 120 }
 121
 122 #define MD_HANDLE_UNWABI ia64_handle_unwabi
 123
 124 static void
 125 ia64_handle_unwabi (struct _Unwind_Context *context, _Unwind_FrameState *fs)
 126 {
 127   if (fs->unwabi == ((3 << 8) | 's')
 128       || fs->unwabi == ((0 << 8) | 's'))
 129     {
 130       struct sigframe {
 131         char scratch[16];
 132         unsigned long sig_number;
 133         struct siginfo *info;
 134         struct sigcontext *sc;
 135       } *frame = (struct sigframe *)context->psp;
 136       struct sigcontext *sc = frame->sc;
 137
 138       /* Restore scratch registers in case the unwinder needs to
 139          refer to a value stored in one of them.  */
 140       {
 141         int i;
 142
 143         for (i = 2; i < 4; i++)
 144           context->ireg[i - 2].loc = &sc->sc_gr[i];
 145         for (i = 8; i < 12; i++)
 146           context->ireg[i - 2].loc = &sc->sc_gr[i];
 147         for (i = 14; i < 32; i++)
 148           context->ireg[i - 2].loc = &sc->sc_gr[i];
 149       }
 150
 151       context->pfs_loc = &(sc->sc_ar_pfs);
 152       context->lc_loc = &(sc->sc_ar_lc);
 153       context->unat_loc = &(sc->sc_ar_unat);
 154       context->br_loc[0] = &(sc->sc_br[0]);
 155       context->br_loc[6] = &(sc->sc_br[6]);
 156       context->br_loc[7] = &(sc->sc_br[7]);
 157       context->pr = sc->sc_pr;
 158       context->gp = sc->sc_gr[1];
 159       /* Signal frame doesn't have an associated reg. stack frame
 160          other than what we adjust for below.     */
 161       fs -> no_reg_stack_frame = 1;
 162
 163       if (sc->sc_rbs_base)
 164         {
 165           /* Need to switch from alternate register backing store.  */
 166           long ndirty, loadrs = sc->sc_loadrs >> 16;
 167           unsigned long alt_bspstore = context->bsp - loadrs;
 168           unsigned long bspstore;
 169           unsigned long *ar_bsp = (unsigned long *)(sc->sc_ar_bsp);
 170
 171           ndirty = ia64_rse_num_regs ((unsigned long *) alt_bspstore,
 172                                       (unsigned long *) context->bsp);
 173           bspstore = (unsigned long) ia64_rse_skip_regs (ar_bsp, -ndirty);
 174           ia64_copy_rbs (context, bspstore, alt_bspstore, loadrs,
 175                          sc->sc_ar_rnat);
 176         }
 177
 178       /* Don't touch the branch registers o.t. b0, b6 and b7.
 179          The kernel doesn't pass the preserved branch registers
 180          in the sigcontext but leaves them intact, so there's no
 181          need to do anything with them here.  */
 182       {
 183         unsigned long sof = sc->sc_cfm & 0x7f;
 184         context->bsp = (unsigned long)
 185           ia64_rse_skip_regs ((unsigned long *)(sc->sc_ar_bsp), -sof);
 186       }
 187
 188       /* pfs_loc already set above.  Without this pfs_loc would point
 189          incorrectly to sc_cfm instead of sc_ar_pfs.  */
 190       fs->curr.reg[UNW_REG_PFS].where = UNW_WHERE_NONE;
 191     }
 192 }
 193 #endif /* glibc-2.3 or better */