We want to check that the dynamic linker is available at run-time, so

we should actually check for _DYNAMIC at run-time rather than checking
for __PIC__ at compile time, since the two are actually independent.

Problem and solution identified by guenther; minor tweaks by me.
ok guenther

3 files changed, 42 insertions, 26 deletions

diff --git a/lib/librthread/rthread.c b/lib/librthread/rthread.c
index 17b7aed61fa..f19fc926d49 100644
--- a/lib/librthread/rthread.c
+++ b/lib/librthread/rthread.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: rthread.c,v 1.65 2012/08/22 22:34:57 matthew Exp $ */
+/*	$OpenBSD: rthread.c,v 1.66 2012/08/22 23:43:32 matthew Exp $ */
 /*
  * Copyright (c) 2004,2005 Ted Unangst <tedu@openbsd.org>
  * All Rights Reserved.
@@ -26,6 +26,10 @@
 #include <sys/socket.h>
 #include <sys/mman.h>
 #include <sys/msg.h>
+#if defined(__ELF__)
+#include <sys/exec_elf.h>
+#pragma weak _DYNAMIC
+#endif
 
 #include <stdlib.h>
 #include <unistd.h>
@@ -174,19 +178,21 @@ _rthread_init(void)
 
 	_rthread_debug(1, "rthread init\n");
 
-#if defined(__ELF__) && defined(__PIC__)
-	/*
-	 * To avoid recursion problems in ld.so, we need to trigger the
-	 * functions once to fully bind them before registering them
-	 * for use.
-	 */
-	_rthread_dl_lock(0);
-	_rthread_dl_lock(1);
-	_rthread_bind_lock(0);
-	_rthread_bind_lock(1);
-	sched_yield();
-	dlctl(NULL, DL_SETTHREADLCK, _rthread_dl_lock);
-	dlctl(NULL, DL_SETBINDLCK, _rthread_bind_lock);
+#if defined(__ELF__)
+	if (_DYNAMIC) {
+		/*
+		 * To avoid recursion problems in ld.so, we need to trigger the
+		 * functions once to fully bind them before registering them
+		 * for use.
+		 */
+		_rthread_dl_lock(0);
+		_rthread_dl_lock(1);
+		_rthread_bind_lock(0);
+		_rthread_bind_lock(1);
+		sched_yield();
+		dlctl(NULL, DL_SETTHREADLCK, _rthread_dl_lock);
+		dlctl(NULL, DL_SETBINDLCK, _rthread_bind_lock);
+	}
 #endif
 
 	/*
@@ -582,7 +588,7 @@ _thread_dump_info(void)
 	_spinunlock(&_thread_lock);
 }
 
-#if defined(__ELF__) && defined(__PIC__)
+#if defined(__ELF__)
 /*
  * _rthread_dl_lock() provides the locking for dlopen(), dlclose(), and
  * the function called via atexit() to invoke all destructors.  The latter
diff --git a/lib/librthread/rthread.h b/lib/librthread/rthread.h
index 4cb86446491..76271cea022 100644
--- a/lib/librthread/rthread.h
+++ b/lib/librthread/rthread.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: rthread.h,v 1.39 2012/05/03 09:07:17 pirofti Exp $ */
+/*	$OpenBSD: rthread.h,v 1.40 2012/08/22 23:43:32 matthew Exp $ */
 /*
  * Copyright (c) 2004,2005 Ted Unangst <tedu@openbsd.org>
  * All Rights Reserved.
@@ -204,7 +204,7 @@ void	_rthread_tls_destructors(pthread_t);
 void	_rthread_debug(int, const char *, ...)
 		__attribute__((__format__ (printf, 2, 3)));
 void	_rthread_debug_init(void);
-#if defined(__ELF__) && defined(PIC)
+#if defined(__ELF__)
 void	_rthread_dl_lock(int what);
 void	_rthread_bind_lock(int);
 #endif
diff --git a/lib/librthread/rthread_fork.c b/lib/librthread/rthread_fork.c
index d5786ed5449..c5847363929 100644
--- a/lib/librthread/rthread_fork.c
+++ b/lib/librthread/rthread_fork.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: rthread_fork.c,v 1.5 2012/08/22 22:34:57 matthew Exp $ */
+/*	$OpenBSD: rthread_fork.c,v 1.6 2012/08/22 23:43:32 matthew Exp $ */
 
 /*
  * Copyright (c) 2008 Kurt Miller <kurt@openbsd.org>
@@ -30,6 +30,12 @@
  * $FreeBSD: /repoman/r/ncvs/src/lib/libc_r/uthread/uthread_atfork.c,v 1.1 2004/12/10 03:36:45 grog Exp $
  */
 
+#if defined(__ELF__)
+#include <sys/types.h>
+#include <sys/exec_elf.h>
+#pragma weak _DYNAMIC
+#endif
+
 #include <errno.h>
 #include <pthread.h>
 #include <stdlib.h>
@@ -77,30 +83,34 @@ _dofork(int is_vfork)
 	 * binding in the other locking functions can succeed.
 	 */
 
-#if defined(__ELF__) && defined(__PIC__)
-	_rthread_dl_lock(0);
+#if defined(__ELF__)
+	if (_DYNAMIC)
+		_rthread_dl_lock(0);
 #endif
 
 	_thread_atexit_lock();
 	_thread_malloc_lock();
 	_thread_arc4_lock();
 
-#if defined(__ELF__) && defined(__PIC__)
-	_rthread_bind_lock(0);
+#if defined(__ELF__)
+	if (_DYNAMIC)
+		_rthread_bind_lock(0);
 #endif
 
 	newid = sys_fork();
 
-#if defined(__ELF__) && defined(__PIC__)
-	_rthread_bind_lock(1);
+#if defined(__ELF__)
+	if (_DYNAMIC)
+		_rthread_bind_lock(1);
 #endif
 
 	_thread_arc4_unlock();
 	_thread_malloc_unlock();
 	_thread_atexit_unlock();
 
-#if defined(__ELF__) && defined(__PIC__)
-	_rthread_dl_lock(1);
+#if defined(__ELF__)
+	if (_DYNAMIC)
+		_rthread_dl_lock(1);
 #endif
 
 	if (newid == 0) {