gcc/libgcc/config/m68k/linux-unwind.h
2022-01-03 10:42:10 +01:00

159 lines
4.6 KiB
C

/* DWARF2 EH unwinding support for Linux/m68k.
Copyright (C) 2006-2022 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/>. */
/* 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 at all if inhibit_libc is used. */
#ifndef inhibit_libc
#include <signal.h>
/* <sys/ucontext.h> is unfortunately broken right now. */
struct uw_ucontext {
unsigned long uc_flags;
ucontext_t *uc_link;
stack_t uc_stack;
mcontext_t uc_mcontext;
unsigned long uc_filler[80];
sigset_t uc_sigmask;
};
#define MD_FALLBACK_FRAME_STATE_FOR m68k_fallback_frame_state
#ifdef __mcoldfire__
#define M68K_FP_SIZE 8
#else
#define M68K_FP_SIZE 12
#endif
static _Unwind_Reason_Code
m68k_fallback_frame_state (struct _Unwind_Context *context,
_Unwind_FrameState *fs)
{
unsigned short *pc = context->ra;
long cfa;
/* moveq #__NR_sigreturn,%d0; trap #0 */
if (pc[0] == 0x7077 && pc[1] == 0x4e40)
{
struct sigcontext *sc;
/* Context is passed as the 3rd argument. */
sc = *(struct sigcontext **) (context->cfa + 8);
cfa = sc->sc_usp;
fs->regs.cfa_how = CFA_REG_OFFSET;
fs->regs.cfa_reg = 15;
fs->regs.cfa_offset = cfa - (long) context->cfa;
fs->regs.reg[0].how = REG_SAVED_OFFSET;
fs->regs.reg[0].loc.offset = (long) &sc->sc_d0 - cfa;
fs->regs.reg[1].how = REG_SAVED_OFFSET;
fs->regs.reg[1].loc.offset = (long) &sc->sc_d1 - cfa;
fs->regs.reg[8].how = REG_SAVED_OFFSET;
fs->regs.reg[8].loc.offset = (long) &sc->sc_a0 - cfa;
fs->regs.reg[9].how = REG_SAVED_OFFSET;
fs->regs.reg[9].loc.offset = (long) &sc->sc_a1 - cfa;
#ifdef __uClinux__
fs->regs.reg[13].how = REG_SAVED_OFFSET;
fs->regs.reg[13].loc.offset = (long) &sc->sc_a5 - cfa;
#endif
fs->regs.reg[24].how = REG_SAVED_OFFSET;
fs->regs.reg[24].loc.offset = (long) &sc->sc_pc - cfa;
#ifndef __uClinux__
if (*(int *) sc->sc_fpstate)
{
int *fpregs = (int *) sc->sc_fpregs;
fs->regs.reg[16].how = REG_SAVED_OFFSET;
fs->regs.reg[16].loc.offset = (long) &fpregs[0] - cfa;
fs->regs.reg[17].how = REG_SAVED_OFFSET;
fs->regs.reg[17].loc.offset = (long) &fpregs[M68K_FP_SIZE/4] - cfa;
}
#elif defined __mcffpu__
# error Implement this when uClinux kernel is ported to an FPU architecture
#endif
}
#ifdef __mcoldfire__
/* move.l #__NR_rt_sigreturn,%d0; trap #0 */
else if (pc[0] == 0x203c && pc[1] == 0x0000 &&
pc[2] == 0x00ad && pc[3] == 0x4e40)
#else
/* moveq #~__NR_rt_sigreturn,%d0; not.b %d0; trap #0 */
else if (pc[0] == 0x7052 && pc[1] == 0x4600 && pc[2] == 0x4e40)
#endif
{
struct uw_ucontext *uc;
greg_t *gregs;
int i;
/* Context is passed as the 3rd argument. */
uc = *(struct uw_ucontext **) (context->cfa + 8);
gregs = uc->uc_mcontext.gregs;
cfa = gregs[15];
fs->regs.cfa_how = CFA_REG_OFFSET;
fs->regs.cfa_reg = 15;
fs->regs.cfa_offset = cfa - (long) context->cfa;
/* register %d0-%d7/%a0-%a6 */
for (i = 0; i <= 14; i++)
{
fs->regs.reg[i].how = REG_SAVED_OFFSET;
fs->regs.reg[i].loc.offset = (long) &gregs[i] - cfa;
}
/* return address */
fs->regs.reg[24].how = REG_SAVED_OFFSET;
fs->regs.reg[24].loc.offset = (long) &gregs[16] - cfa;
#define uc_fpstate uc_filler[0]
if (uc->uc_fpstate)
{
long fpregs = (long) uc->uc_mcontext.fpregs.f_fpregs;
/* register %fp0-%fp7 */
for (i = 16; i <= 23; i++)
{
fs->regs.reg[i].how = REG_SAVED_OFFSET;
fs->regs.reg[i].loc.offset = fpregs - cfa;
fpregs += M68K_FP_SIZE;
}
}
}
else
return _URC_END_OF_STACK;
fs->retaddr_column = 24;
fs->signal_frame = 1;
return _URC_NO_REASON;
}
#endif /* ifdef inhibit_libc */