glibc/elf/dlclose.c
Roland McGrath f68b86cc7b Tue Jun 4 18:57:57 1996 Roland McGrath <roland@delasyd.gnu.ai.mit.edu>
* elf/dladdr.c: Remove #include <setjmp.h>, we don't use it.

	* shlib-versions: Set libdl=2.

	* elf/dl-deps.c (_dl_map_object_deps): Use a linked list of alloca'd
 	elements and then scan it to fill the single malloc'd array, instead
 	of using realloc to grow the array in the first pass.  _dl_map_object
	may do some mallocs that break our stream of reallocs, and the minimal
	realloc can't handle that.

	* elf/dl-init.c (_dl_init_next): Take argument, link_map whose
 	searchlist describes the piece of the DT_NEEDED graph to be
 	initialized.
	* elf/link.h: Update prototype.
	* sysdeps/i386/dl-machine.h (RTLD_START): Pass _dl_loaded as argument
	to _dl_init_next.
	* sysdeps/m68k/dl-machine.h: Likewise.
	* elf/dl-deps.c (_dl_open): Pass new object as arg to _dl_init_next.

	* elf/link.h (struct link_map): Add `l_reserved' member, soaking up
	extra bits in last byte.
	* elf/dl-deps.c (_dl_map_object_deps): Use that for mark bit to avoid
	putting dup elts in search list.

	* elf/dlclose.c: Use MAP->l_searchlist to find deps to close.

	* elf/dlsym.c: Don't tweak linked list.  Scope array given to
	_dl_lookup_symbol does the right thing.
Tue Jun  4 02:25:44 1996  Roland McGrath  <roland@delasyd.gnu.ai.mit.edu>
1996-06-04 23:06:02 +00:00

102 lines
3.1 KiB
C

/* dlclose -- Close a handle opened by `dlopen'.
Copyright (C) 1995, 1996 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 Library General Public License as
published by the Free Software Foundation; either version 2 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA. */
#include <link.h>
#include <dlfcn.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/mman.h>
#define LOSE(s) _dl_signal_error (0, map->l_name, s)
int
dlclose (void *handle)
{
void doit (void)
{
struct link_map *map = handle;
struct link_map **list;
unsigned int i;
if (map->l_opencount == 0)
LOSE ("shared object not open");
/* Decrement the reference count. */
if (--map->l_opencount > 0 || map->l_type != lt_loaded)
/* There are still references to this object. Do nothing more. */
return;
list = map->l_searchlist;
/* The search list contains a counted reference to each object it
points to, the 0th elt being MAP itself. Decrement the reference
counts on all the objects MAP depends on. */
for (i = 1; i < map->l_nsearchlist; ++i)
--list[i]->l_opencount;
/* Clear the search list so it doesn't get freed while we are still
using it. We have cached it in LIST and will free it when
finished. */
map->l_searchlist = NULL;
/* Check each element of the search list to see if all references to
it are gone. */
for (i = 0; i < map->l_nsearchlist; ++i)
{
struct link_map *map = list[i];
if (map->l_opencount == 0 && map->l_type == lt_loaded)
{
/* That was the last reference, and this was a dlopen-loaded
object. We can unmap it. */
const Elf32_Phdr *ph;
if (map->l_info[DT_FINI])
/* Call its termination function. */
(*(void (*) (void)) ((void *) map->l_addr +
map->l_info[DT_FINI]->d_un.d_ptr)) ();
/* Unmap the segments. */
for (ph = map->l_phdr; ph < &map->l_phdr[map->l_phnum]; ++ph)
if (ph->p_type == PT_LOAD)
{
Elf32_Addr mapstart = ph->p_vaddr & ~(ph->p_align - 1);
Elf32_Addr mapend = ((ph->p_vaddr + ph->p_memsz
+ ph->p_align - 1)
& ~(ph->p_align - 1));
munmap ((caddr_t) mapstart, mapend - mapstart);
}
/* Finally, unlink the data structure and free it. */
map->l_prev->l_next = map->l_next;
if (map->l_next)
map->l_next->l_prev = map->l_prev;
if (map->l_searchlist)
free (map->l_searchlist);
free (map);
}
}
free (list);
}
return _dlerror_run (doit) ? -1 : 0;
}