From d66e34cd423425c348bcc83df127dd19711b0b9a Mon Sep 17 00:00:00 2001
From: Roland McGrath <roland@gnu.org>
Date: Tue, 2 May 1995 06:35:55 +0000
Subject: * 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.
---
 elf/dlclose.c | 97 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 97 insertions(+)
 create mode 100644 elf/dlclose.c

(limited to 'elf/dlclose.c')

diff --git a/elf/dlclose.c b/elf/dlclose.c
new file mode 100644
index 0000000000..4aa4085f66
--- /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;
+}
+
-- 
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