1 /* DWARF2 EH unwinding support for Alpha 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 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 32 #include <signal.h> 33 #include <sys/ucontext.h> 34 35 #define MD_FALLBACK_FRAME_STATE_FOR alpha_fallback_frame_state 36 37 static _Unwind_Reason_Code 38 alpha_fallback_frame_state (struct _Unwind_Context *context, 39 _Unwind_FrameState *fs) 40 { 41 unsigned int *pc = context->ra; 42 struct sigcontext *sc; 43 long new_cfa, i; 44 45 if (pc[0] != 0x47fe0410 /* mov $30,$16 */ 46 || pc[2] != 0x00000083 /* callsys */) 47 return _URC_END_OF_STACK; 48 if (context->cfa == 0) 49 return _URC_END_OF_STACK; 50 if (pc[1] == 0x201f0067) /* lda $0,NR_sigreturn */ 51 sc = context->cfa; 52 else if (pc[1] == 0x201f015f) /* lda $0,NR_rt_sigreturn */ 53 { 54 struct rt_sigframe { 55 struct siginfo info; 56 struct ucontext uc; 57 } *rt_ = context->cfa; 58 sc = &rt_->uc.uc_mcontext; 59 } 60 else 61 return _URC_END_OF_STACK; 62 new_cfa = sc->sc_regs[30]; 63 fs->cfa_how = CFA_REG_OFFSET; 64 fs->cfa_reg = 30; 65 fs->cfa_offset = new_cfa - (long) context->cfa; 66 for (i = 0; i < 30; ++i) 67 { 68 fs->regs.reg[i].how = REG_SAVED_OFFSET; 69 fs->regs.reg[i].loc.offset 70 = (long)&sc->sc_regs[i] - new_cfa; 71 } 72 for (i = 0; i < 31; ++i) 73 { 74 fs->regs.reg[i+32].how = REG_SAVED_OFFSET; 75 fs->regs.reg[i+32].loc.offset 76 = (long)&sc->sc_fpregs[i] - new_cfa; 77 } 78 fs->regs.reg[64].how = REG_SAVED_OFFSET; 79 fs->regs.reg[64].loc.offset = (long)&sc->sc_pc - new_cfa; 80 fs->retaddr_column = 64; 81 return _URC_NO_REASON; 82 } 83