1 /* DWARF2 EH unwinding support for Linux/m68k. 2 Copyright (C) 2006-2013 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 /* Do code reading to identify a signal frame, and set the frame 26 state data appropriately. See unwind-dw2.c for the structs. 27 Don't use this at all if inhibit_libc is used. */ 28 29 #ifndef inhibit_libc 30 31 #include <signal.h> 32 33 /* <sys/ucontext.h> is unfortunately broken right now. */ 34 struct uw_ucontext { 35 unsigned long uc_flags; 36 struct ucontext *uc_link; 37 stack_t uc_stack; 38 mcontext_t uc_mcontext; 39 unsigned long uc_filler[80]; 40 __sigset_t uc_sigmask; 41 }; 42 43 #define MD_FALLBACK_FRAME_STATE_FOR m68k_fallback_frame_state 44 45 #ifdef __mcoldfire__ 46 #define M68K_FP_SIZE 8 47 #else 48 #define M68K_FP_SIZE 12 49 #endif 50 51 static _Unwind_Reason_Code 52 m68k_fallback_frame_state (struct _Unwind_Context *context, 53 _Unwind_FrameState *fs) 54 { 55 unsigned short *pc = context->ra; 56 long cfa; 57 58 /* moveq #__NR_sigreturn,%d0; trap #0 */ 59 if (pc[0] == 0x7077 && pc[1] == 0x4e40) 60 { 61 struct sigcontext *sc; 62 63 /* Context is passed as the 3rd argument. */ 64 sc = *(struct sigcontext **) (context->cfa + 8); 65 66 cfa = sc->sc_usp; 67 fs->regs.cfa_how = CFA_REG_OFFSET; 68 fs->regs.cfa_reg = 15; 69 fs->regs.cfa_offset = cfa - (long) context->cfa; 70 71 fs->regs.reg[0].how = REG_SAVED_OFFSET; 72 fs->regs.reg[0].loc.offset = (long) &sc->sc_d0 - cfa; 73 fs->regs.reg[1].how = REG_SAVED_OFFSET; 74 fs->regs.reg[1].loc.offset = (long) &sc->sc_d1 - cfa; 75 fs->regs.reg[8].how = REG_SAVED_OFFSET; 76 fs->regs.reg[8].loc.offset = (long) &sc->sc_a0 - cfa; 77 fs->regs.reg[9].how = REG_SAVED_OFFSET; 78 fs->regs.reg[9].loc.offset = (long) &sc->sc_a1 - cfa; 79 80 #ifdef __uClinux__ 81 fs->regs.reg[13].how = REG_SAVED_OFFSET; 82 fs->regs.reg[13].loc.offset = (long) &sc->sc_a5 - cfa; 83 #endif 84 85 fs->regs.reg[24].how = REG_SAVED_OFFSET; 86 fs->regs.reg[24].loc.offset = (long) &sc->sc_pc - cfa; 87 88 #ifndef __uClinux__ 89 if (*(int *) sc->sc_fpstate) 90 { 91 int *fpregs = (int *) sc->sc_fpregs; 92 93 fs->regs.reg[16].how = REG_SAVED_OFFSET; 94 fs->regs.reg[16].loc.offset = (long) &fpregs[0] - cfa; 95 fs->regs.reg[17].how = REG_SAVED_OFFSET; 96 fs->regs.reg[17].loc.offset = (long) &fpregs[M68K_FP_SIZE/4] - cfa; 97 } 98 #elif defined __mcffpu__ 99 # error Implement this when uClinux kernel is ported to an FPU architecture 100 #endif 101 } 102 #ifdef __mcoldfire__ 103 /* move.l #__NR_rt_sigreturn,%d0; trap #0 */ 104 else if (pc[0] == 0x203c && pc[1] == 0x0000 && 105 pc[2] == 0x00ad && pc[3] == 0x4e40) 106 #else 107 /* moveq #~__NR_rt_sigreturn,%d0; not.b %d0; trap #0 */ 108 else if (pc[0] == 0x7052 && pc[1] == 0x4600 && pc[2] == 0x4e40) 109 #endif 110 { 111 struct uw_ucontext *uc; 112 greg_t *gregs; 113 int i; 114 115 /* Context is passed as the 3rd argument. */ 116 uc = *(struct uw_ucontext **) (context->cfa + 8); 117 118 gregs = uc->uc_mcontext.gregs; 119 cfa = gregs[15]; 120 fs->regs.cfa_how = CFA_REG_OFFSET; 121 fs->regs.cfa_reg = 15; 122 fs->regs.cfa_offset = cfa - (long) context->cfa; 123 124 /* register %d0-%d7/%a0-%a6 */ 125 for (i = 0; i <= 14; i++) 126 { 127 fs->regs.reg[i].how = REG_SAVED_OFFSET; 128 fs->regs.reg[i].loc.offset = (long) &gregs[i] - cfa; 129 } 130 131 /* return address */ 132 fs->regs.reg[24].how = REG_SAVED_OFFSET; 133 fs->regs.reg[24].loc.offset = (long) &gregs[16] - cfa; 134 135 #define uc_fpstate uc_filler[0] 136 137 if (uc->uc_fpstate) 138 { 139 long fpregs = (long) uc->uc_mcontext.fpregs.f_fpregs; 140 141 /* register %fp0-%fp7 */ 142 for (i = 16; i <= 23; i++) 143 { 144 fs->regs.reg[i].how = REG_SAVED_OFFSET; 145 fs->regs.reg[i].loc.offset = fpregs - cfa; 146 fpregs += M68K_FP_SIZE; 147 } 148 } 149 } 150 else 151 return _URC_END_OF_STACK; 152 153 fs->retaddr_column = 24; 154 fs->signal_frame = 1; 155 156 return _URC_NO_REASON; 157 } 158 #endif /* ifdef inhibit_libc */ 159