blob: 1f7f95e8ceedadfc11c9e1c84d04dadfcfdc005d [file] [log] [blame]
/* DWARF2 EH unwinding support for Alpha Linux.
Copyright (C) 2004-2022 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/>. */
#ifndef inhibit_libc
/* Do code reading to identify a signal frame, and set the frame
state data appropriately. See unwind-dw2.c for the structs. */
#include <signal.h>
#include <sys/ucontext.h>
#define MD_FALLBACK_FRAME_STATE_FOR alpha_fallback_frame_state
static _Unwind_Reason_Code
alpha_fallback_frame_state (struct _Unwind_Context *context,
_Unwind_FrameState *fs)
{
unsigned int *pc = context->ra;
struct sigcontext *sc;
long new_cfa;
int i;
if (pc[0] != 0x47fe0410 /* mov $30,$16 */
|| pc[2] != 0x00000083) /* callsys */
return _URC_END_OF_STACK;
if (context->cfa == 0)
return _URC_END_OF_STACK;
if (pc[1] == 0x201f0067) /* lda $0,NR_sigreturn */
sc = context->cfa;
else if (pc[1] == 0x201f015f) /* lda $0,NR_rt_sigreturn */
{
struct rt_sigframe {
siginfo_t info;
ucontext_t uc;
} *rt_ = context->cfa;
/* The void * cast is necessary to avoid an aliasing warning.
The aliasing warning is correct, but should not be a problem
because it does not alias anything. */
sc = (struct sigcontext *) (void *) &rt_->uc.uc_mcontext;
}
else
return _URC_END_OF_STACK;
new_cfa = sc->sc_regs[30];
fs->regs.cfa_how = CFA_REG_OFFSET;
fs->regs.cfa_reg = 30;
fs->regs.cfa_offset = new_cfa - (long) context->cfa;
for (i = 0; i < 30; ++i)
{
fs->regs.reg[i].how = REG_SAVED_OFFSET;
fs->regs.reg[i].loc.offset
= (long) &sc->sc_regs[i] - new_cfa;
}
for (i = 0; i < 31; ++i)
{
fs->regs.reg[i+32].how = REG_SAVED_OFFSET;
fs->regs.reg[i+32].loc.offset
= (long) &sc->sc_fpregs[i] - new_cfa;
}
fs->regs.reg[64].how = REG_SAVED_OFFSET;
fs->regs.reg[64].loc.offset = (long)&sc->sc_pc - new_cfa;
fs->retaddr_column = 64;
fs->signal_frame = 1;
return _URC_NO_REASON;
}
#define MD_FROB_UPDATE_CONTEXT alpha_frob_update_context
/* Fix up for signal handlers that don't have S flag set. */
static void
alpha_frob_update_context (struct _Unwind_Context *context,
_Unwind_FrameState *fs ATTRIBUTE_UNUSED)
{
unsigned int *pc = context->ra;
if (pc[0] == 0x47fe0410 /* mov $30,$16 */
&& pc[2] == 0x00000083 /* callsys */
&& (pc[1] == 0x201f0067 /* lda $0,NR_sigreturn */
|| pc[1] == 0x201f015f)) /* lda $0,NR_rt_sigreturn */
_Unwind_SetSignalFrame (context, 1);
}
#endif