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/* DWARF2 EH unwinding support for AMD x86-64 and x86.
Copyright (C) 2009-2022 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. */
#include <ucontext.h>
#include <sys/frame.h>
#ifdef __x86_64__
#define MD_FALLBACK_FRAME_STATE_FOR x86_64_fallback_frame_state
static _Unwind_Reason_Code
x86_64_fallback_frame_state (struct _Unwind_Context *context,
_Unwind_FrameState *fs)
{
unsigned char *pc = context->ra;
mcontext_t *mctx;
long new_cfa;
if (/* Solaris 10+
------------
<__sighndlr+0>: push %rbp
<__sighndlr+1>: mov %rsp,%rbp
<__sighndlr+4>: callq *%rcx
<__sighndlr+6>: leaveq <--- PC
<__sighndlr+7>: retq */
*(unsigned long *)(pc - 6) == 0xc3c9d1ffe5894855)
/* We need to move up three frames:
<signal handler> <-- context->cfa
__sighndlr
call_user_handler
sigacthandler
<kernel>
context->cfa points into the frame after the saved frame pointer and
saved pc (struct frame).
The ucontext_t structure is in the kernel frame after the signal
number and a siginfo_t *. Since the frame sizes vary even within
Solaris 10 updates, we need to walk the stack to get there. */
{
struct frame *fp = (struct frame *) context->cfa - 1;
struct handler_args {
int signo;
siginfo_t *sip;
ucontext_t ucontext;
} *handler_args;
ucontext_t *ucp;
/* Next frame: __sighndlr frame pointer. */
fp = (struct frame *) fp->fr_savfp;
/* call_user_handler frame pointer. */
fp = (struct frame *) fp->fr_savfp;
/* sigacthandler frame pointer. */
fp = (struct frame *) fp->fr_savfp;
/* The argument area precedes the struct frame. */
handler_args = (struct handler_args *) (fp + 1);
ucp = &handler_args->ucontext;
mctx = &ucp->uc_mcontext;
}
else
return _URC_END_OF_STACK;
new_cfa = mctx->gregs[REG_RSP];
fs->regs.cfa_how = CFA_REG_OFFSET;
fs->regs.cfa_reg = 7;
fs->regs.cfa_offset = new_cfa - (long) context->cfa;
/* The SVR4 register numbering macros aren't usable in libgcc. */
fs->regs.reg[0].how = REG_SAVED_OFFSET;
fs->regs.reg[0].loc.offset = (long)&mctx->gregs[REG_RAX] - new_cfa;
fs->regs.reg[1].how = REG_SAVED_OFFSET;
fs->regs.reg[1].loc.offset = (long)&mctx->gregs[REG_RDX] - new_cfa;
fs->regs.reg[2].how = REG_SAVED_OFFSET;
fs->regs.reg[2].loc.offset = (long)&mctx->gregs[REG_RCX] - new_cfa;
fs->regs.reg[3].how = REG_SAVED_OFFSET;
fs->regs.reg[3].loc.offset = (long)&mctx->gregs[REG_RBX] - new_cfa;
fs->regs.reg[4].how = REG_SAVED_OFFSET;
fs->regs.reg[4].loc.offset = (long)&mctx->gregs[REG_RSI] - new_cfa;
fs->regs.reg[5].how = REG_SAVED_OFFSET;
fs->regs.reg[5].loc.offset = (long)&mctx->gregs[REG_RDI] - new_cfa;
fs->regs.reg[6].how = REG_SAVED_OFFSET;
fs->regs.reg[6].loc.offset = (long)&mctx->gregs[REG_RBP] - new_cfa;
fs->regs.reg[8].how = REG_SAVED_OFFSET;
fs->regs.reg[8].loc.offset = (long)&mctx->gregs[REG_R8] - new_cfa;
fs->regs.reg[9].how = REG_SAVED_OFFSET;
fs->regs.reg[9].loc.offset = (long)&mctx->gregs[REG_R9] - new_cfa;
fs->regs.reg[10].how = REG_SAVED_OFFSET;
fs->regs.reg[10].loc.offset = (long)&mctx->gregs[REG_R10] - new_cfa;
fs->regs.reg[11].how = REG_SAVED_OFFSET;
fs->regs.reg[11].loc.offset = (long)&mctx->gregs[REG_R11] - new_cfa;
fs->regs.reg[12].how = REG_SAVED_OFFSET;
fs->regs.reg[12].loc.offset = (long)&mctx->gregs[REG_R12] - new_cfa;
fs->regs.reg[13].how = REG_SAVED_OFFSET;
fs->regs.reg[13].loc.offset = (long)&mctx->gregs[REG_R13] - new_cfa;
fs->regs.reg[14].how = REG_SAVED_OFFSET;
fs->regs.reg[14].loc.offset = (long)&mctx->gregs[REG_R14] - new_cfa;
fs->regs.reg[15].how = REG_SAVED_OFFSET;
fs->regs.reg[15].loc.offset = (long)&mctx->gregs[REG_R15] - new_cfa;
fs->regs.reg[16].how = REG_SAVED_OFFSET;
fs->regs.reg[16].loc.offset = (long)&mctx->gregs[REG_RIP] - new_cfa;
fs->retaddr_column = 16;
fs->signal_frame = 1;
return _URC_NO_REASON;
}
#else
#define MD_FALLBACK_FRAME_STATE_FOR x86_fallback_frame_state
static _Unwind_Reason_Code
x86_fallback_frame_state (struct _Unwind_Context *context,
_Unwind_FrameState *fs)
{
unsigned char *pc = context->ra;
mcontext_t *mctx;
long new_cfa;
if (/* Solaris 11 since snv_125
-------------------------
<__sighndlr+0> push %ebp
<__sighndlr+1> mov %esp,%ebp
<__sighndlr+3> and $0xfffffff0,%esp
<__sighndlr+6> sub $0x4,%esp
<__sighndlr+9> pushl 0x10(%ebp)
<__sighndlr+12> pushl 0xc(%ebp)
<__sighndlr+15> pushl 0x8(%ebp)
<__sighndlr+18> call *0x14(%ebp)
<__sighndlr+21> leave <--- PC
<__sighndlr+22> ret */
(*(unsigned long *)(pc - 21) == 0x83ec8b55
&& *(unsigned long *)(pc - 17) == 0xec83f0e4
&& *(unsigned long *)(pc - 13) == 0x1075ff04
&& *(unsigned long *)(pc - 9) == 0xff0c75ff
&& *(unsigned long *)(pc - 5) == 0x55ff0875
&& (*(unsigned long *)(pc - 1) & 0x00ffffff) == 0x00c3c914))
{
struct handler_args {
int signo;
siginfo_t *sip;
ucontext_t *ucontext;
} *handler_args = context->cfa;
mctx = &handler_args->ucontext->uc_mcontext;
}
else
return _URC_END_OF_STACK;
new_cfa = mctx->gregs[UESP];
fs->regs.cfa_how = CFA_REG_OFFSET;
fs->regs.cfa_reg = 4;
fs->regs.cfa_offset = new_cfa - (long) context->cfa;
/* The SVR4 register numbering macros aren't usable in libgcc. */
fs->regs.reg[0].how = REG_SAVED_OFFSET;
fs->regs.reg[0].loc.offset = (long)&mctx->gregs[EAX] - new_cfa;
fs->regs.reg[3].how = REG_SAVED_OFFSET;
fs->regs.reg[3].loc.offset = (long)&mctx->gregs[EBX] - new_cfa;
fs->regs.reg[1].how = REG_SAVED_OFFSET;
fs->regs.reg[1].loc.offset = (long)&mctx->gregs[ECX] - new_cfa;
fs->regs.reg[2].how = REG_SAVED_OFFSET;
fs->regs.reg[2].loc.offset = (long)&mctx->gregs[EDX] - new_cfa;
fs->regs.reg[6].how = REG_SAVED_OFFSET;
fs->regs.reg[6].loc.offset = (long)&mctx->gregs[ESI] - new_cfa;
fs->regs.reg[7].how = REG_SAVED_OFFSET;
fs->regs.reg[7].loc.offset = (long)&mctx->gregs[EDI] - new_cfa;
fs->regs.reg[5].how = REG_SAVED_OFFSET;
fs->regs.reg[5].loc.offset = (long)&mctx->gregs[EBP] - new_cfa;
fs->regs.reg[8].how = REG_SAVED_OFFSET;
fs->regs.reg[8].loc.offset = (long)&mctx->gregs[EIP] - new_cfa;
fs->retaddr_column = 8;
/* SIGFPE for IEEE-754 exceptions is delivered after the faulting insn
rather than before it, so don't set fs->signal_frame in that case.
We test whether the ES field of the Status Register is zero. */
if ((mctx->fpregs.fp_reg_set.fpchip_state.status & 0x80) == 0)
fs->signal_frame = 1;
return _URC_NO_REASON;
}
#endif