75 lines
2.7 KiB
C
75 lines
2.7 KiB
C
/* Target-dependent code for the GNU C Library (glibc).
|
|
|
|
Copyright (C) 2002-2015 Free Software Foundation, Inc.
|
|
|
|
This file is part of GDB.
|
|
|
|
This program 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 of the License, or
|
|
(at your option) any later version.
|
|
|
|
This program 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.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program. If not, see <http://www.gnu.org/licenses/>. */
|
|
|
|
#include "defs.h"
|
|
#include "frame.h"
|
|
#include "symtab.h"
|
|
#include "symfile.h"
|
|
#include "objfiles.h"
|
|
|
|
#include "glibc-tdep.h"
|
|
|
|
/* Calling functions in shared libraries. */
|
|
|
|
/* See the comments for SKIP_SOLIB_RESOLVER at the top of infrun.c.
|
|
This function:
|
|
1) decides whether a PLT has sent us into the linker to resolve
|
|
a function reference, and
|
|
2) if so, tells us where to set a temporary breakpoint that will
|
|
trigger when the dynamic linker is done. */
|
|
|
|
CORE_ADDR
|
|
glibc_skip_solib_resolver (struct gdbarch *gdbarch, CORE_ADDR pc)
|
|
{
|
|
/* The GNU dynamic linker is part of the GNU C library, and is used
|
|
by all GNU systems (GNU/Hurd, GNU/Linux). An unresolved PLT
|
|
entry points to "_dl_runtime_resolve", which calls "fixup" to
|
|
patch the PLT, and then passes control to the function.
|
|
|
|
We look for the symbol `_dl_runtime_resolve', and find `fixup' in
|
|
the same objfile. If we are at the entry point of `fixup', then
|
|
we set a breakpoint at the return address (at the top of the
|
|
stack), and continue.
|
|
|
|
It's kind of gross to do all these checks every time we're
|
|
called, since they don't change once the executable has gotten
|
|
started. But this is only a temporary hack --- upcoming versions
|
|
of GNU/Linux will provide a portable, efficient interface for
|
|
debugging programs that use shared libraries. */
|
|
|
|
struct bound_minimal_symbol resolver
|
|
= lookup_minimal_symbol_and_objfile ("_dl_runtime_resolve");
|
|
|
|
if (resolver.minsym)
|
|
{
|
|
/* The dynamic linker began using this name in early 2005. */
|
|
struct bound_minimal_symbol fixup
|
|
= lookup_minimal_symbol ("_dl_fixup", NULL, resolver.objfile);
|
|
|
|
/* This is the name used in older versions. */
|
|
if (! fixup.minsym)
|
|
fixup = lookup_minimal_symbol ("fixup", NULL, resolver.objfile);
|
|
|
|
if (fixup.minsym && BMSYMBOL_VALUE_ADDRESS (fixup) == pc)
|
|
return frame_unwind_caller_pc (get_current_frame ());
|
|
}
|
|
|
|
return 0;
|
|
}
|