From 7de31c3e1c7d8c876eb8490a93e2583b1554600a Mon Sep 17 00:00:00 2001 From: obrien Date: Sat, 6 Jan 2001 06:07:52 +0000 Subject: 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 --- lib/libpthread/thread/thr_init.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) (limited to 'lib/libpthread/thread') diff --git a/lib/libpthread/thread/thr_init.c b/lib/libpthread/thread/thr_init.c index be671a1..93d7849 100644 --- a/lib/libpthread/thread/thr_init.c +++ b/lib/libpthread/thread/thr_init.c @@ -54,6 +54,31 @@ #include #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: */ -- cgit v1.1