1/* DWARF2 EH unwinding support for Alpha Linux. 2 Copyright (C) 2004-2015 Free Software Foundation, Inc. 3 4This file is part of GCC. 5 6GCC is free software; you can redistribute it and/or modify 7it under the terms of the GNU General Public License as published by 8the Free Software Foundation; either version 3, or (at your option) 9any later version. 10 11GCC is distributed in the hope that it will be useful, 12but WITHOUT ANY WARRANTY; without even the implied warranty of 13MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14GNU General Public License for more details. 15 16Under Section 7 of GPL version 3, you are granted additional 17permissions described in the GCC Runtime Library Exception, version 183.1, as published by the Free Software Foundation. 19 20You should have received a copy of the GNU General Public License and 21a copy of the GCC Runtime Library Exception along with this program; 22see 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 34static _Unwind_Reason_Code 35alpha_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 struct ucontext 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 89static void 90alpha_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