1 /* DWARF2 EH unwinding support for Alpha Linux. 2 Copyright (C) 2004-2018 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 3, or (at your option) 9 any later version. 10 11 GCC is distributed in the hope that it will be useful, 12 but WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 GNU General Public 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 #ifndef inhibit_libc 26 /* Do code reading to identify a signal frame, and set the frame 27 state data appropriately. See unwind-dw2.c for the structs. */ 28 29 #include <signal.h> 30 #include <sys/ucontext.h> 31 32 #define MD_FALLBACK_FRAME_STATE_FOR alpha_fallback_frame_state 33 34 static _Unwind_Reason_Code 35 alpha_fallback_frame_state (struct _Unwind_Context *context, 36 _Unwind_FrameState *fs) 37 { 38 unsigned int *pc = context->ra; 39 struct sigcontext *sc; 40 long new_cfa; 41 int i; 42 43 if (pc[0] != 0x47fe0410 /* mov $30,$16 */ 44 || pc[2] != 0x00000083) /* callsys */ 45 return _URC_END_OF_STACK; 46 if (context->cfa == 0) 47 return _URC_END_OF_STACK; 48 if (pc[1] == 0x201f0067) /* lda $0,NR_sigreturn */ 49 sc = context->cfa; 50 else if (pc[1] == 0x201f015f) /* lda $0,NR_rt_sigreturn */ 51 { 52 struct rt_sigframe { 53 siginfo_t info; 54 ucontext_t uc; 55 } *rt_ = context->cfa; 56 sc = &rt_->uc.uc_mcontext; 57 } 58 else 59 return _URC_END_OF_STACK; 60 61 new_cfa = sc->sc_regs[30]; 62 fs->regs.cfa_how = CFA_REG_OFFSET; 63 fs->regs.cfa_reg = 30; 64 fs->regs.cfa_offset = new_cfa - (long) context->cfa; 65 for (i = 0; i < 30; ++i) 66 { 67 fs->regs.reg[i].how = REG_SAVED_OFFSET; 68 fs->regs.reg[i].loc.offset 69 = (long) &sc->sc_regs[i] - new_cfa; 70 } 71 for (i = 0; i < 31; ++i) 72 { 73 fs->regs.reg[i+32].how = REG_SAVED_OFFSET; 74 fs->regs.reg[i+32].loc.offset 75 = (long) &sc->sc_fpregs[i] - new_cfa; 76 } 77 fs->regs.reg[64].how = REG_SAVED_OFFSET; 78 fs->regs.reg[64].loc.offset = (long)&sc->sc_pc - new_cfa; 79 fs->retaddr_column = 64; 80 fs->signal_frame = 1; 81 82 return _URC_NO_REASON; 83 } 84 85 #define MD_FROB_UPDATE_CONTEXT alpha_frob_update_context 86 87 /* Fix up for signal handlers that don't have S flag set. */ 88 89 static void 90 alpha_frob_update_context (struct _Unwind_Context *context, 91 _Unwind_FrameState *fs ATTRIBUTE_UNUSED) 92 { 93 unsigned int *pc = context->ra; 94 95 if (pc[0] == 0x47fe0410 /* mov $30,$16 */ 96 && pc[2] == 0x00000083 /* callsys */ 97 && (pc[1] == 0x201f0067 /* lda $0,NR_sigreturn */ 98 || pc[1] == 0x201f015f)) /* lda $0,NR_rt_sigreturn */ 99 _Unwind_SetSignalFrame (context, 1); 100 } 101 #endif 102