svn commit: r220004 - head/libexec/rtld-elf

[Andriy Gapon]

Author: avg
Date: Fri Mar 25 18:23:10 2011
New Revision: 220004
URL: http://svn.freebsd.org/changeset/base/220004

Log:
  rtld: eliminate double call to close(2) that may occur in load_object
  
  The second close(2) call resulted in heisenbugs in some multi-threaded
  applications where e.g. dlopen(3) call in one thread could close a file
  descriptor for a file having been opened in other thread concurrently.
  
  My litmus test for this issue was an openoffice.org build.
  
  Reviewed by:	jhb
  MFC after:	2 weeks

Modified:
  head/libexec/rtld-elf/rtld.c

Modified: head/libexec/rtld-elf/rtld.c
==============================================================================
--- head/libexec/rtld-elf/rtld.c	Fri Mar 25 18:16:49 2011	(r220003)
+++ head/libexec/rtld-elf/rtld.c	Fri Mar 25 18:23:10 2011	(r220004)
@@ -1633,12 +1633,9 @@ load_object(const char *name, const Obj_
 	free(path);
 	return NULL;
     }
-    for (obj = obj_list->next;  obj != NULL;  obj = obj->next) {
-	if (obj->ino == sb.st_ino && obj->dev == sb.st_dev) {
-	    close(fd);
+    for (obj = obj_list->next;  obj != NULL;  obj = obj->next)
+	if (obj->ino == sb.st_ino && obj->dev == sb.st_dev)
 	    break;
-	}
-    }
     if (obj != NULL) {
 	object_add_name(obj, name);
 	free(path);