107 lines
3.3 KiB
C
107 lines
3.3 KiB
C
/* DWARF2 EH unwinding support for Nios II Linux.
|
|
Copyright (C) 2008-2014 Free Software Foundation, Inc.
|
|
|
|
This file 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.
|
|
|
|
This file 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.
|
|
The corresponding bits in the Linux kernel are in
|
|
arch/nios2/kernel/signal.c. */
|
|
|
|
#include <signal.h>
|
|
#include <asm/unistd.h>
|
|
|
|
/* Exactly the same layout as the kernel structures, unique names. */
|
|
struct nios2_mcontext {
|
|
int version;
|
|
int gregs[32];
|
|
};
|
|
|
|
struct nios2_ucontext {
|
|
unsigned long uc_flags;
|
|
struct ucontext *uc_link;
|
|
stack_t uc_stack;
|
|
struct nios2_mcontext uc_mcontext;
|
|
sigset_t uc_sigmask; /* mask last for extensibility */
|
|
};
|
|
|
|
#define MD_FALLBACK_FRAME_STATE_FOR nios2_fallback_frame_state
|
|
|
|
static _Unwind_Reason_Code
|
|
nios2_fallback_frame_state (struct _Unwind_Context *context,
|
|
_Unwind_FrameState *fs)
|
|
{
|
|
u_int32_t *pc = (u_int32_t *) context->ra;
|
|
_Unwind_Ptr new_cfa;
|
|
|
|
/* The expected sequence of instructions is:
|
|
movi r2,(rt_sigreturn)
|
|
trap
|
|
Check for the trap first. */
|
|
if (pc[1] != 0x003b683a)
|
|
return _URC_END_OF_STACK;
|
|
|
|
#define NIOS2_REG(NUM,NAME) \
|
|
(fs->regs.reg[NUM].how = REG_SAVED_OFFSET, \
|
|
fs->regs.reg[NUM].loc.offset = (_Unwind_Ptr)&(regs->NAME) - new_cfa)
|
|
|
|
if (pc[0] == (0x00800004 | (__NR_rt_sigreturn << 6)))
|
|
{
|
|
struct rt_sigframe {
|
|
char retcode[12];
|
|
siginfo_t info;
|
|
struct nios2_ucontext uc;
|
|
} *rt_ = context->ra;
|
|
struct nios2_mcontext *regs = &rt_->uc.uc_mcontext;
|
|
int i;
|
|
|
|
/* MCONTEXT_VERSION is defined to 2 in the kernel. */
|
|
if (regs->version != 2)
|
|
return _URC_END_OF_STACK;
|
|
|
|
/* The CFA is the user's incoming stack pointer value. */
|
|
new_cfa = (_Unwind_Ptr)regs->gregs[28];
|
|
fs->regs.cfa_how = CFA_REG_OFFSET;
|
|
fs->regs.cfa_reg = STACK_POINTER_REGNUM;
|
|
fs->regs.cfa_offset = new_cfa - (_Unwind_Ptr) context->cfa;
|
|
|
|
/* The sequential registers. */
|
|
for (i = 1; i < 24; i++)
|
|
NIOS2_REG (i, gregs[i-1]);
|
|
|
|
/* The random registers. The kernel stores these in a funny order
|
|
in the gregs array. */
|
|
NIOS2_REG (RA_REGNO, gregs[23]);
|
|
NIOS2_REG (FP_REGNO, gregs[24]);
|
|
NIOS2_REG (GP_REGNO, gregs[25]);
|
|
NIOS2_REG (EA_REGNO, gregs[27]);
|
|
|
|
fs->retaddr_column = EA_REGNO;
|
|
fs->signal_frame = 1;
|
|
|
|
return _URC_NO_REASON;
|
|
}
|
|
#undef NIOS2_REG
|
|
return _URC_END_OF_STACK;
|
|
}
|
|
#endif
|