diff options
Diffstat (limited to 'elf/dl-close.c')
| -rw-r--r-- | elf/dl-close.c | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/elf/dl-close.c b/elf/dl-close.c new file mode 100644 index 0000000..69fdefa --- /dev/null +++ b/elf/dl-close.c @@ -0,0 +1,107 @@ +/* _dl_close -- Close a shared object opened by `_dl_open'. +Copyright (C) 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) + +void +_dl_close (struct link_map *map) +{ + 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 ElfW(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)) (); + + if (map->l_global) + { + /* This object is in the global scope list. Remove it. */ + struct link_map **tail = _dl_global_scope_end; + do + --tail; + while (*tail != map); + --_dl_global_scope_end; + memcpy (tail, tail + 1, _dl_global_scope_end - tail); + _dl_global_scope_end[0] = NULL; + _dl_global_scope_end[1] = NULL; + } + + /* Unmap the segments. */ + for (ph = map->l_phdr; ph < &map->l_phdr[map->l_phnum]; ++ph) + if (ph->p_type == PT_LOAD) + { + ElfW(Addr) mapstart = ph->p_vaddr & ~(ph->p_align - 1); + ElfW(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); +} |