glibc/dlfcn/dlopen.c
Florian Weimer 9e78f6f6e7 Implement _dl_catch_error, _dl_signal_error in libc.so [BZ #16628]
This change moves the main implementation of _dl_catch_error,
_dl_signal_error to libc.so, where TLS variables can be used
directly.  This removes a writable function pointer from the
rtld_global variable.

For use during initial relocation, minimal implementations of these
functions are provided in ld.so.  These are eventually interposed
by the libc.so implementations.  This is implemented by compiling
elf/dl-error-skeleton.c twice, via elf/dl-error.c and
elf/dl-error-minimal.c.

As a side effect of this change, the static version of dl-error.c
no longer includes support for the
_dl_signal_cerror/_dl_receive_error mechanism because it is only
used in ld.so.
2016-11-30 15:59:57 +01:00

104 lines
2.6 KiB
C

/* Load a shared object at run time.
Copyright (C) 1995-2016 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 <dlfcn.h>
#include <libintl.h>
#include <stddef.h>
#include <unistd.h>
#include <ldsodefs.h>
#if !defined SHARED && IS_IN (libdl)
void *
dlopen (const char *file, int mode)
{
return __dlopen (file, mode, RETURN_ADDRESS (0));
}
static_link_warning (dlopen)
#else
struct dlopen_args
{
/* The arguments for dlopen_doit. */
const char *file;
int mode;
/* The return value of dlopen_doit. */
void *new;
/* Address of the caller. */
const void *caller;
};
/* Non-shared code has no support for multiple namespaces. */
# ifdef SHARED
# define NS __LM_ID_CALLER
# else
# define NS LM_ID_BASE
# endif
static void
dlopen_doit (void *a)
{
struct dlopen_args *args = (struct dlopen_args *) a;
if (args->mode & ~(RTLD_BINDING_MASK | RTLD_NOLOAD | RTLD_DEEPBIND
| RTLD_GLOBAL | RTLD_LOCAL | RTLD_NODELETE
| __RTLD_SPROF))
_dl_signal_error (0, NULL, NULL, _("invalid mode parameter"));
args->new = GLRO(dl_open) (args->file ?: "", args->mode | __RTLD_DLOPEN,
args->caller,
args->file == NULL ? LM_ID_BASE : NS,
__dlfcn_argc, __dlfcn_argv, __environ);
}
void *
__dlopen (const char *file, int mode DL_CALLER_DECL)
{
# ifdef SHARED
if (__glibc_unlikely (_dlfcn_hook != NULL))
return _dlfcn_hook->dlopen (file, mode, DL_CALLER);
# endif
struct dlopen_args args;
args.file = file;
args.mode = mode;
args.caller = DL_CALLER;
# ifdef SHARED
return _dlerror_run (dlopen_doit, &args) ? NULL : args.new;
# else
if (_dlerror_run (dlopen_doit, &args))
return NULL;
__libc_register_dl_open_hook ((struct link_map *) args.new);
__libc_register_dlfcn_hook ((struct link_map *) args.new);
return args.new;
# endif
}
# ifdef SHARED
# include <shlib-compat.h>
strong_alias (__dlopen, __dlopen_check)
versioned_symbol (libdl, __dlopen_check, dlopen, GLIBC_2_1);
# endif
#endif