mirror of
https://github.com/tobast/libunwind-eh_elf.git
synced 2024-11-06 01:34:29 +01:00
130 lines
4.5 KiB
C
130 lines
4.5 KiB
C
/* libunwind - a platform-independent unwind library
|
|
Copyright (C) 2002-2003 Hewlett-Packard Co
|
|
Contributed by David Mosberger-Tang <davidm@hpl.hp.com>
|
|
|
|
This file is part of libunwind.
|
|
|
|
Permission is hereby granted, free of charge, to any person obtaining
|
|
a copy of this software and associated documentation files (the
|
|
"Software"), to deal in the Software without restriction, including
|
|
without limitation the rights to use, copy, modify, merge, publish,
|
|
distribute, sublicense, and/or sell copies of the Software, and to
|
|
permit persons to whom the Software is furnished to do so, subject to
|
|
the following conditions:
|
|
|
|
The above copyright notice and this permission notice shall be
|
|
included in all copies or substantial portions of the Software.
|
|
|
|
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
|
|
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
|
|
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
|
|
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
|
|
LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
|
|
OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
|
|
WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
|
|
|
|
#include "unwind_i.h"
|
|
#include "offsets.h"
|
|
|
|
PROTECTED int
|
|
unw_step (unw_cursor_t *cursor)
|
|
{
|
|
struct cursor *c = (struct cursor *) cursor;
|
|
int ret, i;
|
|
|
|
Debug (2, "(cursor=%p)\n", c);
|
|
|
|
/* Try DWARF-based unwinding... */
|
|
ret = dwarf_step (&c->dwarf);
|
|
|
|
if (unlikely (ret == -UNW_ESTOPUNWIND))
|
|
return ret;
|
|
|
|
if (unlikely (ret < 0))
|
|
{
|
|
/* DWARF failed, let's see if we can follow the frame-chain
|
|
or skip over the signal trampoline. */
|
|
struct dwarf_loc ebp_loc, eip_loc;
|
|
|
|
Debug (13, "dwarf_step() failed (ret=%d), trying frame-chain\n", ret);
|
|
|
|
if (unw_is_signal_frame (cursor))
|
|
{
|
|
/* XXX This code is Linux-specific! */
|
|
|
|
/* c->esp points at the arguments to the handler. Without
|
|
SA_SIGINFO, the arguments consist of a signal number
|
|
followed by a struct sigcontext. With SA_SIGINFO, the
|
|
arguments consist a signal number, a siginfo *, and a
|
|
ucontext *. */
|
|
unw_word_t sigcontext_addr;
|
|
unw_word_t siginfo_ptr_addr = c->dwarf.cfa + 4;
|
|
unw_word_t sigcontext_ptr_addr = c->dwarf.cfa + 8;
|
|
unw_word_t siginfo_ptr, sigcontext_ptr;
|
|
struct dwarf_loc esp_loc, siginfo_ptr_loc, sigcontext_ptr_loc;
|
|
|
|
siginfo_ptr_loc = DWARF_LOC (siginfo_ptr_addr, 0);
|
|
sigcontext_ptr_loc = DWARF_LOC (sigcontext_ptr_addr, 0);
|
|
ret = (dwarf_get (&c->dwarf, siginfo_ptr_loc, &siginfo_ptr)
|
|
| dwarf_get (&c->dwarf, sigcontext_ptr_loc, &sigcontext_ptr));
|
|
if (ret < 0)
|
|
return 0;
|
|
if (siginfo_ptr < c->dwarf.cfa
|
|
|| siginfo_ptr > c->dwarf.cfa + 256
|
|
|| sigcontext_ptr < c->dwarf.cfa
|
|
|| sigcontext_ptr > c->dwarf.cfa + 256)
|
|
{
|
|
/* Not plausible for SA_SIGINFO signal */
|
|
c->sigcontext_format = X86_SCF_LINUX_SIGFRAME;
|
|
c->sigcontext_addr = sigcontext_addr = c->dwarf.cfa + 4;
|
|
}
|
|
else
|
|
{
|
|
/* If SA_SIGINFO were not specified, we actually read
|
|
various segment pointers instead. We believe that at
|
|
least fs and _fsh are always zero for linux, so it is
|
|
not just unlikely, but impossible that we would end
|
|
up here. */
|
|
c->sigcontext_format = X86_SCF_LINUX_RT_SIGFRAME;
|
|
c->sigcontext_addr = sigcontext_ptr;
|
|
sigcontext_addr = sigcontext_ptr + LINUX_UC_MCONTEXT_OFF;
|
|
}
|
|
esp_loc = DWARF_LOC (sigcontext_addr + LINUX_SC_ESP_OFF, 0);
|
|
ebp_loc = DWARF_LOC (sigcontext_addr + LINUX_SC_EBP_OFF, 0);
|
|
eip_loc = DWARF_LOC (sigcontext_addr + LINUX_SC_EIP_OFF, 0);
|
|
ret = dwarf_get (&c->dwarf, esp_loc, &c->dwarf.cfa);
|
|
if (ret < 0)
|
|
return 0;
|
|
}
|
|
else
|
|
{
|
|
ret = dwarf_get (&c->dwarf, c->dwarf.loc[EBP], &c->dwarf.cfa);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
Debug (13, "[EBP=0x%x] = 0x%xx\n", DWARF_GET_LOC (c->dwarf.loc[EBP]),
|
|
c->dwarf.cfa);
|
|
|
|
ebp_loc = DWARF_LOC (c->dwarf.cfa, 0);
|
|
eip_loc = DWARF_LOC (c->dwarf.cfa + 4, 0);
|
|
c->dwarf.cfa += 8;
|
|
}
|
|
/* Mark all registers unsaved, since we don't know where they
|
|
are saved (if at all), except for the EBP and EIP. */
|
|
for (i = 0; i < DWARF_NUM_PRESERVED_REGS; ++i)
|
|
c->dwarf.loc[i] = DWARF_NULL_LOC;
|
|
c->dwarf.loc[EBP] = ebp_loc;
|
|
c->dwarf.loc[EIP] = eip_loc;
|
|
c->dwarf.ret_addr_column = EIP;
|
|
|
|
if (!DWARF_IS_NULL_LOC (c->dwarf.loc[EBP]))
|
|
{
|
|
ret = dwarf_get (&c->dwarf, c->dwarf.loc[EIP], &c->dwarf.ip);
|
|
if (ret < 0)
|
|
return ret;
|
|
}
|
|
else
|
|
c->dwarf.ip = 0;
|
|
}
|
|
return (c->dwarf.ip == 0) ? 0 : 1;
|
|
}
|