libgcc/config/ia64/linux-unwind.h

   1 /* DWARF2 EH unwinding support for IA64 Linux.
   2    Copyright (C) 2004-2017 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 3, 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    Under Section 7 of GPL version 3, you are granted additional
  17    permissions described in the GCC Runtime Library Exception, version
  18    3.1, as published by the Free Software Foundation.
  19
  20    You should have received a copy of the GNU General Public License and
  21    a copy of the GCC Runtime Library Exception along with this program;
  22    see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  23    <http://www.gnu.org/licenses/>.  */
  24
  25 /* Do code reading to identify a signal frame, and set the frame
  26    state data appropriately.  See unwind-ia64.c for the structs.  */
  27
  28 /* This works only for glibc-2.3 and later, because sigcontext is different
  29    in glibc-2.2.4.  */
  30
  31 #if __GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 3)
  32 #include <signal.h>
  33 #include <sys/ucontext.h>
  34
  35 #define IA64_GATE_AREA_START 0xa000000000000100LL
  36 #define IA64_GATE_AREA_END   0xa000000000030000LL
  37
  38 #define MD_FALLBACK_FRAME_STATE_FOR ia64_fallback_frame_state
  39
  40 static _Unwind_Reason_Code
  41 ia64_fallback_frame_state (struct _Unwind_Context *context,
  42                            _Unwind_FrameState *fs)
  43 {
  44   if (context->rp >= IA64_GATE_AREA_START
  45       && context->rp < IA64_GATE_AREA_END)
  46     {
  47       struct sigframe {
  48         char scratch[16];
  49         unsigned long sig_number;
  50         siginfo_t *info;
  51         struct sigcontext *sc;
  52       } *frame_ = (struct sigframe *)context->psp;
  53       struct sigcontext *sc = frame_->sc;
  54
  55       /* Restore scratch registers in case the unwinder needs to
  56          refer to a value stored in one of them.  */
  57       {
  58         int i;
  59
  60         for (i = 2; i < 4; i++)
  61           context->ireg[i - 2].loc = &sc->sc_gr[i];
  62         for (i = 8; i < 12; i++)
  63           context->ireg[i - 2].loc = &sc->sc_gr[i];
  64         for (i = 14; i < 32; i++)
  65           context->ireg[i - 2].loc = &sc->sc_gr[i];
  66       }
  67
  68       context->fpsr_loc = &(sc->sc_ar_fpsr);
  69       context->signal_pfs_loc = &(sc->sc_ar_pfs);
  70       context->lc_loc = &(sc->sc_ar_lc);
  71       context->unat_loc = &(sc->sc_ar_unat);
  72       context->br_loc[0] = &(sc->sc_br[0]);
  73       context->br_loc[6] = &(sc->sc_br[6]);
  74       context->br_loc[7] = &(sc->sc_br[7]);
  75       context->pr = sc->sc_pr;
  76       context->psp = sc->sc_gr[12];
  77       context->gp = sc->sc_gr[1];
  78       /* Signal frame doesn't have an associated reg. stack frame
  79          other than what we adjust for below.     */
  80       fs -> no_reg_stack_frame = 1;
  81
  82       if (sc->sc_rbs_base)
  83         {
  84           /* Need to switch from alternate register backing store.  */
  85           long ndirty, loadrs = sc->sc_loadrs >> 16;
  86           unsigned long alt_bspstore = context->bsp - loadrs;
  87           unsigned long bspstore;
  88           unsigned long *ar_bsp = (unsigned long *)(sc->sc_ar_bsp);
  89
  90           ndirty = ia64_rse_num_regs ((unsigned long *) alt_bspstore,
  91                                       (unsigned long *) context->bsp);
  92           bspstore = (unsigned long)
  93             ia64_rse_skip_regs (ar_bsp, -ndirty);
  94           ia64_copy_rbs (context, bspstore, alt_bspstore, loadrs,
  95                          sc->sc_ar_rnat);
  96         }
  97
  98       /* Don't touch the branch registers o.t. b0, b6 and b7.
  99          The kernel doesn't pass the preserved branch registers
 100          in the sigcontext but leaves them intact, so there's no
 101          need to do anything with them here.  */
 102       {
 103         unsigned long sof = sc->sc_cfm & 0x7f;
 104         context->bsp = (unsigned long)
 105           ia64_rse_skip_regs ((unsigned long *)(sc->sc_ar_bsp), -sof);
 106       }
 107
 108       /* Account for use of br.ret to resume execution of user code.  */
 109       fs->curr.reg[UNW_REG_RP].where = UNW_WHERE_SPREL;
 110       fs->curr.reg[UNW_REG_RP].val
 111         = (unsigned long)&(sc->sc_ip) - context->psp;
 112       fs->curr.reg[UNW_REG_RP].when = -1;
 113
 114       fs->curr.reg[UNW_REG_PFS].where = UNW_WHERE_SPREL;
 115       fs->curr.reg[UNW_REG_PFS].val
 116         = (unsigned long)&(sc->sc_cfm) - context->psp;
 117       fs ->curr.reg[UNW_REG_PFS].when = -1;
 118
 119       return _URC_NO_REASON;
 120     }
 121   return _URC_END_OF_STACK;
 122 }
 123
 124 #define MD_HANDLE_UNWABI ia64_handle_unwabi
 125
 126 #define ABI_MARKER_OLD_LINUX_SIGTRAMP   ((0 << 8) | 's')
 127 #define ABI_MARKER_OLD_LINUX_INTERRUPT  ((0 << 8) | 'i')
 128 #define ABI_MARKER_LINUX_SIGTRAMP       ((3 << 8) | 's')
 129 #define ABI_MARKER_LINUX_INTERRUPT      ((3 << 8) | 'i')
 130
 131 static void
 132 ia64_handle_unwabi (struct _Unwind_Context *context, _Unwind_FrameState *fs)
 133 {
 134   if (fs->unwabi == ABI_MARKER_LINUX_SIGTRAMP
 135       || fs->unwabi == ABI_MARKER_OLD_LINUX_SIGTRAMP)
 136     {
 137       struct sigframe {
 138         char scratch[16];
 139         unsigned long sig_number;
 140         siginfo_t *info;
 141         struct sigcontext *sc;
 142       } *frame = (struct sigframe *)context->psp;
 143       struct sigcontext *sc = frame->sc;
 144
 145       /* Restore scratch registers in case the unwinder needs to
 146          refer to a value stored in one of them.  */
 147       {
 148         int i;
 149
 150         for (i = 2; i < 4; i++)
 151           context->ireg[i - 2].loc = &sc->sc_gr[i];
 152         for (i = 8; i < 12; i++)
 153           context->ireg[i - 2].loc = &sc->sc_gr[i];
 154         for (i = 14; i < 32; i++)
 155           context->ireg[i - 2].loc = &sc->sc_gr[i];
 156       }
 157
 158       context->signal_pfs_loc = &(sc->sc_ar_pfs);
 159       context->lc_loc = &(sc->sc_ar_lc);
 160       context->unat_loc = &(sc->sc_ar_unat);
 161       context->br_loc[0] = &(sc->sc_br[0]);
 162       context->br_loc[6] = &(sc->sc_br[6]);
 163       context->br_loc[7] = &(sc->sc_br[7]);
 164       context->pr = sc->sc_pr;
 165       context->gp = sc->sc_gr[1];
 166       /* Signal frame doesn't have an associated reg. stack frame
 167          other than what we adjust for below.     */
 168       fs -> no_reg_stack_frame = 1;
 169
 170       if (sc->sc_rbs_base)
 171         {
 172           /* Need to switch from alternate register backing store.  */
 173           long ndirty, loadrs = sc->sc_loadrs >> 16;
 174           unsigned long alt_bspstore = context->bsp - loadrs;
 175           unsigned long bspstore;
 176           unsigned long *ar_bsp = (unsigned long *)(sc->sc_ar_bsp);
 177
 178           ndirty = ia64_rse_num_regs ((unsigned long *) alt_bspstore,
 179                                       (unsigned long *) context->bsp);
 180           bspstore = (unsigned long) ia64_rse_skip_regs (ar_bsp, -ndirty);
 181           ia64_copy_rbs (context, bspstore, alt_bspstore, loadrs,
 182                          sc->sc_ar_rnat);
 183         }
 184
 185       /* Don't touch the branch registers o.t. b0, b6 and b7.
 186          The kernel doesn't pass the preserved branch registers
 187          in the sigcontext but leaves them intact, so there's no
 188          need to do anything with them here.  */
 189       {
 190         unsigned long sof = sc->sc_cfm & 0x7f;
 191         context->bsp = (unsigned long)
 192           ia64_rse_skip_regs ((unsigned long *)(sc->sc_ar_bsp), -sof);
 193       }
 194
 195       /* The use of br.ret to resume execution of user code is already
 196          accounted for in the unwind ABI.  */
 197     }
 198 }
 199 #endif /* glibc-2.3 or better */