BUG/MEDIUM: threads: Disable the workaround to load libgcc_s on macOS

Don't use the workaround to load libgcc_s on macOS. It is not needed
there, and it causes issues, as recent macOS dislike processes that fork
after threads where created (and the workaround creates a temporary
thread). This fixes crashes on macOS at least when using master-worker,
and using the system resolver.

This should fix Github issue #3035

This should be backported up to 2.8.

diff --git a/src/thread.c b/src/thread.c
index 16d087b839c184bafe2e41f67f27fc3b0b4cf401..4fc7402ea18b99bb7785bedd1b9720152815a174 100644 (file)
--- a/src/thread.c
+++ b/src/thread.c
@@ -1213,6 +1213,7 @@ int pthread_rwlock_unlock(pthread_rwlock_t *rwlock)
 }
 #endif // defined(USE_PTHREAD_EMULATION)
 
+#ifndef __APPLE__
 /* Depending on the platform and how libpthread was built, pthread_exit() may
  * involve some code in libgcc_s that would be loaded on exit for the first
  * time, causing aborts if the process is chrooted. It's harmless bit very
@@ -1233,12 +1234,15 @@ static inline void preload_libgcc_s(void)
        if (pthread_create(&dummy_thread, NULL, dummy_thread_function, NULL) == 0)
                pthread_join(dummy_thread, NULL);
 }
+#endif
 
 static void __thread_init(void)
 {
        char *ptr = NULL;
 
+#ifndef __APPLE__
        preload_libgcc_s();
+#endif
 
        thread_cpus_enabled_at_boot = thread_cpus_enabled();
        thread_cpus_enabled_at_boot = MIN(thread_cpus_enabled_at_boot, MAX_THREADS);