svn commit: r259042 - head/lib/libc/stdlib

[Konstantin Belousov]

Author: kib
Date: Fri Dec  6 21:26:57 2013
New Revision: 259042
URL: http://svnweb.freebsd.org/changeset/base/259042

Log:
  Do not force to run atexit handlers, which text comes from a dso
  owning the handle passed to __cxa_finalize() but which are registered
  by other dso, when the process is inside exit(3).
  
  Running them makes the destruction order wrong, and there is hope that
  such destructors would not call dlclose(3), since it is pointless at
  this stage of the process existence.
  
  The change effectively disables the r211706 after the exit(3) is
  called.
  
  Reported and tested by:	Michael Gmelin <freebsd at grem.de>
  Analyzed by:	dim
  Sponsored by:	The FreeBSD Foundation
  MFC after:	1 week

Modified:
  head/lib/libc/stdlib/atexit.c

Modified: head/lib/libc/stdlib/atexit.c
==============================================================================
--- head/lib/libc/stdlib/atexit.c	Fri Dec  6 21:22:33 2013	(r259041)
+++ head/lib/libc/stdlib/atexit.c	Fri Dec  6 21:26:57 2013	(r259042)
@@ -151,6 +151,8 @@ __cxa_atexit(void (*func)(void *), void 
 #pragma weak __pthread_cxa_finalize
 void __pthread_cxa_finalize(const struct dl_phdr_info *);
 
+static int global_exit;
+
 /*
  * Call all handlers registered with __cxa_atexit for the shared
  * object owning 'dso'.  Note: if 'dso' is NULL, then all remaining
@@ -164,10 +166,12 @@ __cxa_finalize(void *dso)
 	struct atexit_fn fn;
 	int n, has_phdr;
 
-	if (dso != NULL)
+	if (dso != NULL) {
 		has_phdr = _rtld_addr_phdr(dso, &phdr_info);
-	else
+	} else {
 		has_phdr = 0;
+		global_exit = 1;
+	}
 
 	_MUTEX_LOCK(&atexit_mutex);
 	for (p = __atexit; p; p = p->next) {
@@ -177,8 +181,9 @@ __cxa_finalize(void *dso)
 			fn = p->fns[n];
 			if (dso != NULL && dso != fn.fn_dso) {
 				/* wrong DSO ? */
-				if (!has_phdr || !__elf_phdr_match_addr(
-				    &phdr_info, fn.fn_ptr.cxa_func))
+				if (!has_phdr || global_exit ||
+				    !__elf_phdr_match_addr(&phdr_info,
+				    fn.fn_ptr.cxa_func))
 					continue;
 			}
 			/*
@@ -200,6 +205,6 @@ __cxa_finalize(void *dso)
 	if (dso == NULL)
 		_MUTEX_DESTROY(&atexit_mutex);
 
-	if (has_phdr && &__pthread_cxa_finalize != NULL)
+	if (has_phdr && !global_exit && &__pthread_cxa_finalize != NULL)
 		__pthread_cxa_finalize(&phdr_info);
 }