diff options
Diffstat (limited to 'gcc-4.9/libgcc/config/pa/linux-unwind.h')
| -rw-r--r-- | gcc-4.9/libgcc/config/pa/linux-unwind.h | 141 |
1 files changed, 141 insertions, 0 deletions
diff --git a/gcc-4.9/libgcc/config/pa/linux-unwind.h b/gcc-4.9/libgcc/config/pa/linux-unwind.h new file mode 100644 index 000000000..485f2d98e --- /dev/null +++ b/gcc-4.9/libgcc/config/pa/linux-unwind.h @@ -0,0 +1,141 @@ +/* DWARF2 EH unwinding support for PA Linux. + Copyright (C) 2004-2014 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. */ + +/* Don't use this if inhibit_libc is set. + The build for this target will fail trying to include missing headers. */ +#ifndef inhibit_libc +#include <signal.h> +#include <sys/ucontext.h> + +/* Unfortunately, because of various bugs and changes to the kernel, + we have several cases to deal with. + + In 2.4, the signal trampoline is 4 words, and (CONTEXT)->ra should + point directly at the beginning of the trampoline and struct rt_sigframe. + + In <= 2.6.5-rc2-pa3, the signal trampoline is 9 words, and + (CONTEXT)->ra points at the 4th word in the trampoline structure. This + is wrong, it should point at the 5th word. This is fixed in 2.6.5-rc2-pa4. + + To detect these cases, we first take (CONTEXT)->ra, align it to 64-bytes + to get the beginning of the signal frame, and then check offsets 0, 4 + and 5 to see if we found the beginning of the trampoline. This will + tell us how to locate the sigcontext structure. + + Note that with a 2.4 64-bit kernel, the signal context is not properly + passed back to userspace so the unwind will not work correctly. */ + +#define MD_FALLBACK_FRAME_STATE_FOR pa32_fallback_frame_state + +static _Unwind_Reason_Code +pa32_fallback_frame_state (struct _Unwind_Context *context, + _Unwind_FrameState *fs) +{ + unsigned long sp = (unsigned long)context->ra & ~63; + unsigned int *pc = (unsigned int *)sp; + unsigned long off; + _Unwind_Ptr new_cfa; + int i; + struct sigcontext *sc; + struct rt_sigframe { + siginfo_t info; + struct ucontext uc; + } *frame; + + /* rt_sigreturn trampoline: + 3419000x ldi 0, %r25 or ldi 1, %r25 (x = 0 or 2) + 3414015a ldi __NR_rt_sigreturn, %r20 + e4008200 be,l 0x100(%sr2, %r0), %sr0, %r31 + 08000240 nop */ + + if (pc[0] == 0x34190000 || pc[0] == 0x34190002) + off = 4*4; + else if (pc[4] == 0x34190000 || pc[4] == 0x34190002) + { + pc += 4; + off = 10 * 4; + } + else if (pc[5] == 0x34190000 || pc[5] == 0x34190002) + { + pc += 5; + off = 10 * 4; + } + else + { + /* We may have to unwind through an alternate signal stack. + We assume that the alignment of the alternate signal stack + is BIGGEST_ALIGNMENT (i.e., that it has been allocated using + malloc). As a result, we can't distinguish trampolines + used prior to 2.6.5-rc2-pa4. However after 2.6.5-rc2-pa4, + the return address of a signal trampoline will be on an odd + word boundary and we can then determine the frame offset. */ + sp = (unsigned long)context->ra; + pc = (unsigned int *)sp; + if ((pc[0] == 0x34190000 || pc[0] == 0x34190002) && (sp & 4)) + off = 5 * 4; + else + return _URC_END_OF_STACK; + } + + if (pc[1] != 0x3414015a + || pc[2] != 0xe4008200 + || pc[3] != 0x08000240) + return _URC_END_OF_STACK; + + frame = (struct rt_sigframe *)(sp + off); + sc = &frame->uc.uc_mcontext; + + new_cfa = sc->sc_gr[30]; + fs->regs.cfa_how = CFA_REG_OFFSET; + fs->regs.cfa_reg = 30; + fs->regs.cfa_offset = new_cfa - (long) context->cfa; + for (i = 1; i <= 31; i++) + { + fs->regs.reg[i].how = REG_SAVED_OFFSET; + fs->regs.reg[i].loc.offset = (long)&sc->sc_gr[i] - new_cfa; + } + for (i = 4; i <= 31; i++) + { + /* FP regs have left and right halves */ + fs->regs.reg[2*i+24].how = REG_SAVED_OFFSET; + fs->regs.reg[2*i+24].loc.offset + = (long)&sc->sc_fr[i] - new_cfa; + fs->regs.reg[2*i+24+1].how = REG_SAVED_OFFSET; + fs->regs.reg[2*i+24+1].loc.offset + = (long)&sc->sc_fr[i] + 4 - new_cfa; + } + fs->regs.reg[88].how = REG_SAVED_OFFSET; + fs->regs.reg[88].loc.offset = (long) &sc->sc_sar - new_cfa; + fs->regs.reg[DWARF_ALT_FRAME_RETURN_COLUMN].how = REG_SAVED_OFFSET; + fs->regs.reg[DWARF_ALT_FRAME_RETURN_COLUMN].loc.offset + = (long) &sc->sc_iaoq[0] - new_cfa; + fs->retaddr_column = DWARF_ALT_FRAME_RETURN_COLUMN; + fs->signal_frame = 1; + return _URC_NO_REASON; +} +#endif /* inhibit_libc */ |