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/* Check whether caller comes from the right place.
Copyright (C) 2004-2017 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, see
<http://www.gnu.org/licenses/>. */
#include <assert.h>
#include <ldsodefs.h>
#include <stddef.h>
#include <caller.h>
#include <gnu/lib-names.h>
int
attribute_hidden
_dl_check_caller (const void *caller, enum allowmask mask)
{
static const char expected1[] = LIBC_SO;
static const char expected2[] = LIBDL_SO;
#ifdef LIBPTHREAD_SO
static const char expected3[] = LIBPTHREAD_SO;
#endif
static const char expected4[] = LD_SO;
for (Lmid_t ns = 0; ns < GL(dl_nns); ++ns)
for (struct link_map *l = GL(dl_ns)[ns]._ns_loaded; l != NULL;
l = l->l_next)
if (caller >= (const void *) l->l_map_start
&& caller < (const void *) l->l_text_end)
{
/* The address falls into this DSO's address range. Check the
name. */
if ((mask & allow_libc) && strcmp (expected1, l->l_name) == 0)
return 0;
if ((mask & allow_libdl) && strcmp (expected2, l->l_name) == 0)
return 0;
#ifdef LIBPTHREAD_SO
if ((mask & allow_libpthread) && strcmp (expected3, l->l_name) == 0)
return 0;
#endif
if ((mask & allow_ldso) && strcmp (expected4, l->l_name) == 0)
return 0;
struct libname_list *runp = l->l_libname;
while (runp != NULL)
{
if ((mask & allow_libc) && strcmp (expected1, runp->name) == 0)
return 0;
if ((mask & allow_libdl) && strcmp (expected2, runp->name) == 0)
return 0;
#ifdef LIBPTHREAD_SO
if ((mask & allow_libpthread)
&& strcmp (expected3, runp->name) == 0)
return 0;
#endif
if ((mask & allow_ldso) && strcmp (expected4, runp->name) == 0)
return 0;
runp = runp->next;
}
break;
}
/* Maybe the dynamic linker is not yet on the list. */
if ((mask & allow_ldso) != 0
&& caller >= (const void *) GL(dl_rtld_map).l_map_start
&& caller < (const void *) GL(dl_rtld_map).l_text_end)
return 0;
/* No valid caller. */
return 1;
}
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