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[/] [openrisc/] [trunk/] [gnu-src/] [gcc-4.5.1/] [gcc/] [config/] [pa/] [linux-unwind.h] - Rev 282
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/* DWARF2 EH unwinding support for PA Linux. Copyright (C) 2004, 2005, 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. */ /* 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 { struct siginfo 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 */