/* DWARF2 EH unwinding support for Xtensa.
|
/* DWARF2 EH unwinding support for Xtensa.
|
Copyright (C) 2008, 2009 Free Software Foundation, Inc.
|
Copyright (C) 2008, 2009 Free Software Foundation, Inc.
|
|
|
This file is part of GCC.
|
This file is part of GCC.
|
|
|
GCC is free software; you can redistribute it and/or modify
|
GCC is free software; you can redistribute it and/or modify
|
it under the terms of the GNU General Public License as published by
|
it under the terms of the GNU General Public License as published by
|
the Free Software Foundation; either version 3, or (at your option)
|
the Free Software Foundation; either version 3, or (at your option)
|
any later version.
|
any later version.
|
|
|
GCC is distributed in the hope that it will be useful,
|
GCC is distributed in the hope that it will be useful,
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
GNU General Public License for more details.
|
GNU General Public License for more details.
|
|
|
Under Section 7 of GPL version 3, you are granted additional
|
Under Section 7 of GPL version 3, you are granted additional
|
permissions described in the GCC Runtime Library Exception, version
|
permissions described in the GCC Runtime Library Exception, version
|
3.1, as published by the Free Software Foundation.
|
3.1, as published by the Free Software Foundation.
|
|
|
You should have received a copy of the GNU General Public License and
|
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;
|
a copy of the GCC Runtime Library Exception along with this program;
|
see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
|
see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
|
<http://www.gnu.org/licenses/>. */
|
<http://www.gnu.org/licenses/>. */
|
|
|
/* Do code reading to identify a signal frame, and set the frame
|
/* Do code reading to identify a signal frame, and set the frame
|
state data appropriately. See unwind-dw2-xtensa.c for the structs.
|
state data appropriately. See unwind-dw2-xtensa.c for the structs.
|
Don't use this at all if inhibit_libc is used. */
|
Don't use this at all if inhibit_libc is used. */
|
|
|
#ifndef inhibit_libc
|
#ifndef inhibit_libc
|
|
|
#include <signal.h>
|
#include <signal.h>
|
#include <sys/ucontext.h>
|
#include <sys/ucontext.h>
|
|
|
/* Encoded bytes for Xtensa instructions:
|
/* Encoded bytes for Xtensa instructions:
|
movi a2, __NR_rt_sigreturn
|
movi a2, __NR_rt_sigreturn
|
syscall
|
syscall
|
entry (first byte only)
|
entry (first byte only)
|
Some of the bytes are endian-dependent. */
|
Some of the bytes are endian-dependent. */
|
|
|
#define MOVI_BYTE0 0x22
|
#define MOVI_BYTE0 0x22
|
#define MOVI_BYTE2 225 /* __NR_rt_sigreturn */
|
#define MOVI_BYTE2 225 /* __NR_rt_sigreturn */
|
#define SYSC_BYTE0 0
|
#define SYSC_BYTE0 0
|
#define SYSC_BYTE2 0
|
#define SYSC_BYTE2 0
|
|
|
#ifdef __XTENSA_EB__
|
#ifdef __XTENSA_EB__
|
#define MOVI_BYTE1 0x0a
|
#define MOVI_BYTE1 0x0a
|
#define SYSC_BYTE1 0x05
|
#define SYSC_BYTE1 0x05
|
#define ENTRY_BYTE 0x6c
|
#define ENTRY_BYTE 0x6c
|
#else
|
#else
|
#define MOVI_BYTE1 0xa0
|
#define MOVI_BYTE1 0xa0
|
#define SYSC_BYTE1 0x50
|
#define SYSC_BYTE1 0x50
|
#define ENTRY_BYTE 0x36
|
#define ENTRY_BYTE 0x36
|
#endif
|
#endif
|
|
|
#define MD_FALLBACK_FRAME_STATE_FOR xtensa_fallback_frame_state
|
#define MD_FALLBACK_FRAME_STATE_FOR xtensa_fallback_frame_state
|
|
|
static _Unwind_Reason_Code
|
static _Unwind_Reason_Code
|
xtensa_fallback_frame_state (struct _Unwind_Context *context,
|
xtensa_fallback_frame_state (struct _Unwind_Context *context,
|
_Unwind_FrameState *fs)
|
_Unwind_FrameState *fs)
|
{
|
{
|
unsigned char *pc = context->ra;
|
unsigned char *pc = context->ra;
|
struct sigcontext *sc;
|
struct sigcontext *sc;
|
|
|
struct rt_sigframe {
|
struct rt_sigframe {
|
struct siginfo info;
|
struct siginfo info;
|
struct ucontext uc;
|
struct ucontext uc;
|
} *rt_;
|
} *rt_;
|
|
|
/* movi a2, __NR_rt_sigreturn; syscall */
|
/* movi a2, __NR_rt_sigreturn; syscall */
|
if (pc[0] != MOVI_BYTE0
|
if (pc[0] != MOVI_BYTE0
|
|| pc[1] != MOVI_BYTE1
|
|| pc[1] != MOVI_BYTE1
|
|| pc[2] != MOVI_BYTE2
|
|| pc[2] != MOVI_BYTE2
|
|| pc[3] != SYSC_BYTE0
|
|| pc[3] != SYSC_BYTE0
|
|| pc[4] != SYSC_BYTE1
|
|| pc[4] != SYSC_BYTE1
|
|| pc[5] != SYSC_BYTE2)
|
|| pc[5] != SYSC_BYTE2)
|
return _URC_END_OF_STACK;
|
return _URC_END_OF_STACK;
|
|
|
rt_ = context->sp;
|
rt_ = context->sp;
|
sc = &rt_->uc.uc_mcontext;
|
sc = &rt_->uc.uc_mcontext;
|
fs->signal_regs = (_Unwind_Word *) sc->sc_a;
|
fs->signal_regs = (_Unwind_Word *) sc->sc_a;
|
|
|
/* If the signal arrived just before an ENTRY instruction, find the return
|
/* If the signal arrived just before an ENTRY instruction, find the return
|
address and pretend the signal arrived before executing the CALL. */
|
address and pretend the signal arrived before executing the CALL. */
|
if (*(unsigned char *) sc->sc_pc == ENTRY_BYTE)
|
if (*(unsigned char *) sc->sc_pc == ENTRY_BYTE)
|
{
|
{
|
unsigned callinc = (sc->sc_ps >> 16) & 3;
|
unsigned callinc = (sc->sc_ps >> 16) & 3;
|
fs->signal_ra = ((sc->sc_a[callinc << 2] & XTENSA_RA_FIELD_MASK)
|
fs->signal_ra = ((sc->sc_a[callinc << 2] & XTENSA_RA_FIELD_MASK)
|
| context->ra_high_bits) - 3;
|
| context->ra_high_bits) - 3;
|
}
|
}
|
else
|
else
|
fs->signal_ra = sc->sc_pc;
|
fs->signal_ra = sc->sc_pc;
|
|
|
fs->signal_frame = 1;
|
fs->signal_frame = 1;
|
return _URC_NO_REASON;
|
return _URC_NO_REASON;
|
}
|
}
|
|
|
#endif /* ifdef inhibit_libc */
|
#endif /* ifdef inhibit_libc */
|
|
|
