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authorRoland McGrath <roland@gnu.org>1995-05-02 06:35:55 +0000
committerRoland McGrath <roland@gnu.org>1995-05-02 06:35:55 +0000
commitd66e34cd423425c348bcc83df127dd19711b0b9a (patch)
tree97058e776d3b4fe06ef54bc4951596991652183f /elf/dlclose.c
parent08162fa888913a5153d2fcdc4e1a816b57b1fe56 (diff)
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* sysdeps/mach/i386/sysdep.h (SNARF_ARGS, CALL_WITH_SP): Rewritten.
* sysdeps/i386/dl-machine.h: New file. * sysdeps/stub/dl-machine.h: New file. * sysdeps/i386/dl-runtime.c: New file. * sysdeps/stub/dl-runtime.c: New file. * sysdeps/i386/elf/start.S: New file. * sysdeps/generic/dl-sysdep.c: New file. * sysdeps/mach/hurd/dl-sysdep.c: New file.
Diffstat (limited to 'elf/dlclose.c')
-rw-r--r--elf/dlclose.c97
1 files changed, 97 insertions, 0 deletions
diff --git a/elf/dlclose.c b/elf/dlclose.c
new file mode 100644
index 0000000..4aa4085
--- /dev/null
+++ b/elf/dlclose.c
@@ -0,0 +1,97 @@
+/* dlclose -- Close a handle opened by `dlopen'.
+Copyright (C) 1995 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, s)
+
+int
+dlclose (void *handle)
+{
+ void doit (void)
+ {
+ struct link_map *map = handle;
+
+ if (map->l_opencount == 0)
+ LOSE ("shared object not open");
+
+ /* Decrement the reference count. */
+ --map->l_opencount;
+
+ 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)) ();
+
+ if (map->l_info[DT_NEEDED])
+ {
+ /* Also close all the dependencies. */
+ const char *strtab
+ = (void *) map->l_addr + map->l_info[DT_STRTAB]->d_un.d_ptr;
+ const Elf32_Dyn *d;
+ for (d = map->l_ld; d->d_tag != DT_NULL; ++d)
+ if (d->d_tag == DT_NEEDED)
+ {
+ /* It must already be open, since this one needed it;
+ so dlopen will just find us its `struct link_map'
+ and bump its reference count. */
+ struct link_map *o, *dep
+ = dlopen (strtab + d->d_un.d_val, RTLD_LAZY);
+ --dep->l_opencount; /* Lose the ref from that dlopen. */
+ /* Now we have the handle; we can close it for real. */
+ o = map;
+ map = dep;
+ doit ();
+ map = o;
+ }
+ }
+
+ /* 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;
+ free (map);
+ }
+ }
+
+ return _dlerror_run (doit) ? -1 : 0;
+}
+