98 lines
2.9 KiB
C
98 lines
2.9 KiB
C
/* dlclose -- Close a handle opened by `dlopen'.
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Copyright (C) 1995 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Library General Public License as
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published by the Free Software Foundation; either version 2 of the
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License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Library General Public License for more details.
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You should have received a copy of the GNU Library General Public
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License along with the GNU C Library; see the file COPYING.LIB. If
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not, write to the Free Software Foundation, Inc., 675 Mass Ave,
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Cambridge, MA 02139, USA. */
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#include <link.h>
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#include <dlfcn.h>
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#include <stdlib.h>
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#include <sys/types.h>
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#include <sys/mman.h>
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#define LOSE(s) _dl_signal_error (0, map->l_name, s)
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int
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dlclose (void *handle)
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{
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void doit (void)
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{
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struct link_map *map = handle;
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if (map->l_opencount == 0)
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LOSE ("shared object not open");
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/* Decrement the reference count. */
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--map->l_opencount;
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if (map->l_opencount == 0 && map->l_type == lt_loaded)
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{
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/* That was the last reference, and this was a dlopen-loaded
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object. We can unmap it. */
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const Elf32_Phdr *ph;
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if (map->l_info[DT_FINI])
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/* Call its termination function. */
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(*(void (*) (void)) ((void *) map->l_addr +
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map->l_info[DT_FINI]->d_un.d_ptr)) ();
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if (map->l_info[DT_NEEDED])
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{
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/* Also close all the dependencies. */
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const char *strtab
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= (void *) map->l_addr + map->l_info[DT_STRTAB]->d_un.d_ptr;
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const Elf32_Dyn *d;
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for (d = map->l_ld; d->d_tag != DT_NULL; ++d)
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if (d->d_tag == DT_NEEDED)
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{
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/* It must already be open, since this one needed it;
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so dlopen will just find us its `struct link_map'
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and bump its reference count. */
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struct link_map *o, *dep
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= dlopen (strtab + d->d_un.d_val, RTLD_LAZY);
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--dep->l_opencount; /* Lose the ref from that dlopen. */
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/* Now we have the handle; we can close it for real. */
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o = map;
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map = dep;
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doit ();
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map = o;
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}
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}
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/* Unmap the segments. */
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for (ph = map->l_phdr; ph < &map->l_phdr[map->l_phnum]; ++ph)
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if (ph->p_type == PT_LOAD)
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{
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Elf32_Addr mapstart = ph->p_vaddr & ~(ph->p_align - 1);
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Elf32_Addr mapend = ((ph->p_vaddr + ph->p_memsz
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+ ph->p_align - 1)
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& ~(ph->p_align - 1));
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munmap ((caddr_t) mapstart, mapend - mapstart);
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}
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/* Finally, unlink the data structure and free it. */
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map->l_prev->l_next = map->l_next;
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if (map->l_next)
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map->l_next->l_prev = map->l_prev;
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free (map);
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}
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}
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return _dlerror_run (doit) ? -1 : 0;
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}
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