Force strong references to several pthread_* functions which are weakly

referenced to by libgcc.a.

This is needed when linking statically as SVR4 (ie, ELF) behavior is to only
link in a module if it satisfies an undefined strong reference from somewhere.
(this surprises a lot of people) Things are different when using shared libs,
the entire library and its modules and their symbols are available at run-time
(when the weak reference is seen to still be unsatisfied and is satisfied on
the spot), this is not the case with static libs.

Thus one can have a static binary with unresolved week references, and at
run-time dereference a NULL pointer.

Submitted by:	eischen

1 files changed, 32 insertions, 0 deletions

diff --git a/lib/libkse/thread/thr_init.c b/lib/libkse/thread/thr_init.c
index be671a1..93d7849 100644
--- a/lib/libkse/thread/thr_init.c
+++ b/lib/libkse/thread/thr_init.c
@@ -54,6 +54,31 @@
 #include <pthread.h>
 #include "pthread_private.h"
 
+/*
+ * These are needed when linking statically.  All references within
+ * libgcc (and in the future libc) to these routines are weak, but
+ * if they are not (strongly) referenced by the application or other
+ * libraries, then the actual functions will not be loaded.
+ */
+static void *thread_references[] = {
+	&pthread_once,
+	&pthread_key_create,
+	&pthread_key_delete,
+	&pthread_getspecific,
+	&pthread_setspecific,
+	&pthread_mutex_init,
+	&pthread_mutex_destroy,
+	&pthread_mutex_lock,
+	&pthread_mutex_trylock,
+	&pthread_mutex_unlock,
+	&pthread_cond_init,
+	&pthread_cond_destroy,
+	&pthread_cond_wait,
+	&pthread_cond_timedwait,
+	&pthread_cond_signal,
+	&pthread_cond_broadcast
+};
+
 #ifdef GCC_2_8_MADE_THREAD_AWARE
 typedef void *** (*dynamic_handler_allocator)();
 extern void __set_dynamic_handler_allocator(dynamic_handler_allocator);
@@ -99,6 +124,13 @@ _thread_init(void)
 		return;
 
 	/*
+	 * Make gcc quiescent about thread_references not being
+	 * referenced:
+	 */
+	if (thread_references[0] == NULL)
+		PANIC("Mandatory pthread_* functions not loaded");
+
+	/*
 	 * Check for the special case of this process running as
 	 * or in place of init as pid = 1:
 	 */