diff options
Diffstat (limited to 'libgcc/config/s390/linux-unwind.h')
| -rw-r--r-- | libgcc/config/s390/linux-unwind.h | 130 |
1 files changed, 130 insertions, 0 deletions
diff --git a/libgcc/config/s390/linux-unwind.h b/libgcc/config/s390/linux-unwind.h new file mode 100644 index 00000000000..558087fad94 --- /dev/null +++ b/libgcc/config/s390/linux-unwind.h @@ -0,0 +1,130 @@ +/* DWARF2 EH unwinding support for S/390 Linux. + Copyright (C) 2004, 2005, 2006, 2009 Free Software Foundation, Inc. + +This file is part of GCC. + +GCC is free software; you can redistribute it and/or modify it under +the terms of the GNU General Public License as published by the Free +Software Foundation; either version 3, or (at your option) any later +version. + +GCC is distributed in the hope that it will be useful, but WITHOUT ANY +WARRANTY; without even the implied warranty of MERCHANTABILITY or +FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License +for more details. + +Under Section 7 of GPL version 3, you are granted additional +permissions described in the GCC Runtime Library Exception, version +3.1, as published by the Free Software Foundation. + +You should have received a copy of the GNU General Public License and +a copy of the GCC Runtime Library Exception along with this program; +see the files COPYING3 and COPYING.RUNTIME respectively. If not, see +<http://www.gnu.org/licenses/>. */ + +/* Do code reading to identify a signal frame, and set the frame + state data appropriately. See unwind-dw2.c for the structs. */ + +#define MD_FALLBACK_FRAME_STATE_FOR s390_fallback_frame_state + +static _Unwind_Reason_Code +s390_fallback_frame_state (struct _Unwind_Context *context, + _Unwind_FrameState *fs) +{ + unsigned char *pc = context->ra; + long new_cfa; + int i; + + typedef struct + { + unsigned long psw_mask; + unsigned long psw_addr; + unsigned long gprs[16]; + unsigned int acrs[16]; + unsigned int fpc; + unsigned int __pad; + double fprs[16]; + } __attribute__ ((__aligned__ (8))) sigregs_; + + sigregs_ *regs; + int *signo; + + /* svc $__NR_sigreturn or svc $__NR_rt_sigreturn */ + if (pc[0] != 0x0a || (pc[1] != 119 && pc[1] != 173)) + return _URC_END_OF_STACK; + + /* Legacy frames: + old signal mask (8 bytes) + pointer to sigregs (8 bytes) - points always to next location + sigregs + retcode + This frame layout was used on kernels < 2.6.9 for non-RT frames, + and on kernels < 2.4.13 for RT frames as well. Note that we need + to look at RA to detect this layout -- this means that if you use + sa_restorer to install a different signal restorer on a legacy + kernel, unwinding from signal frames will not work. */ + if (context->ra == context->cfa + 16 + sizeof (sigregs_)) + { + regs = (sigregs_ *)(context->cfa + 16); + signo = NULL; + } + + /* New-style RT frame: + retcode + alignment (8 bytes) + siginfo (128 bytes) + ucontext (contains sigregs) */ + else if (pc[1] == 173 /* __NR_rt_sigreturn */) + { + struct ucontext_ + { + unsigned long uc_flags; + struct ucontext_ *uc_link; + unsigned long uc_stack[3]; + sigregs_ uc_mcontext; + } *uc = context->cfa + 8 + 128; + + regs = &uc->uc_mcontext; + signo = context->cfa + sizeof(long); + } + + /* New-style non-RT frame: + old signal mask (8 bytes) + pointer to sigregs (followed by signal number) */ + else + { + regs = *(sigregs_ **)(context->cfa + 8); + signo = (int *)(regs + 1); + } + + new_cfa = regs->gprs[15] + 16*sizeof(long) + 32; + fs->regs.cfa_how = CFA_REG_OFFSET; + fs->regs.cfa_reg = 15; + fs->regs.cfa_offset = + new_cfa - (long) context->cfa + 16*sizeof(long) + 32; + + for (i = 0; i < 16; i++) + { + fs->regs.reg[i].how = REG_SAVED_OFFSET; + fs->regs.reg[i].loc.offset = + (long)®s->gprs[i] - new_cfa; + } + for (i = 0; i < 16; i++) + { + fs->regs.reg[16+i].how = REG_SAVED_OFFSET; + fs->regs.reg[16+i].loc.offset = + (long)®s->fprs[i] - new_cfa; + } + + /* Load return addr from PSW into dummy register 32. */ + + fs->regs.reg[32].how = REG_SAVED_OFFSET; + fs->regs.reg[32].loc.offset = (long)®s->psw_addr - new_cfa; + fs->retaddr_column = 32; + /* SIGILL, SIGFPE and SIGTRAP are delivered with psw_addr + after the faulting instruction rather than before it. + Don't set FS->signal_frame in that case. */ + if (!signo || (*signo != 4 && *signo != 5 && *signo != 8)) + fs->signal_frame = 1; + + return _URC_NO_REASON; +} |