glibc/elf/dl-debug.c

79 lines
2.8 KiB
C

/* Communicate dynamic linker state to the debugger at runtime.
Copyright (C) 1996, 1998,2000,2002,2004,2005,2006
Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <ldsodefs.h>
/* These are the members in the public `struct link_map' type.
Sanity check that the internal type and the public type match. */
#define VERIFY_MEMBER(name) \
(offsetof (struct link_map_public, name) == offsetof (struct link_map, name))
extern const int verify_link_map_members[(VERIFY_MEMBER (l_addr)
&& VERIFY_MEMBER (l_name)
&& VERIFY_MEMBER (l_ld)
&& VERIFY_MEMBER (l_next)
&& VERIFY_MEMBER (l_prev))
? 1 : -1];
/* This structure communicates dl state to the debugger. The debugger
normally finds it via the DT_DEBUG entry in the dynamic section, but in
a statically-linked program there is no dynamic section for the debugger
to examine and it looks for this particular symbol name. */
struct r_debug _r_debug;
/* Initialize _r_debug if it has not already been done. The argument is
the run-time load address of the dynamic linker, to be put in
_r_debug.r_ldbase. Returns the address of _r_debug. */
struct r_debug *
internal_function
_dl_debug_initialize (ElfW(Addr) ldbase, Lmid_t ns)
{
struct r_debug *r;
if (ns == LM_ID_BASE)
r = &_r_debug;
else
r = &GL(dl_ns)[ns]._ns_debug;
if (r->r_map == NULL || ldbase != 0)
{
/* Tell the debugger where to find the map of loaded objects. */
r->r_version = 1 /* R_DEBUG_VERSION XXX */;
r->r_ldbase = ldbase ?: _r_debug.r_ldbase;
r->r_map = (void *) GL(dl_ns)[ns]._ns_loaded;
r->r_brk = (ElfW(Addr)) &_dl_debug_state;
}
return r;
}
/* This function exists solely to have a breakpoint set on it by the
debugger. The debugger is supposed to find this function's address by
examining the r_brk member of struct r_debug, but GDB 4.15 in fact looks
for this particular symbol name in the PT_INTERP file. */
void
_dl_debug_state (void)
{
}
rtld_hidden_def (_dl_debug_state)