fix missing synchronization of pthread TSD keys with MT-fork

[musl] / src / thread / pthread_key_create.c

diff --git a/src/thread/pthread_key_create.c b/src/thread/pthread_key_create.c
index dc20cc3..39770c7 100644 (file)
--- a/src/thread/pthread_key_create.c
+++ b/src/thread/pthread_key_create.c
@@ -1,4 +1,5 @@
 #include "pthread_impl.h"
+#include "fork_impl.h"
 
 volatile size_t __pthread_tsd_size = sizeof(void *) * PTHREAD_KEYS_MAX;
 void *__pthread_tsd_main[PTHREAD_KEYS_MAX] = { 0 };
@@ -20,9 +21,15 @@ static void dummy_0(void)
 weak_alias(dummy_0, __tl_lock);
 weak_alias(dummy_0, __tl_unlock);
 
+void __pthread_key_atfork(int who)
+{
+       if (who<0) __pthread_rwlock_rdlock(&key_lock);
+       else if (!who) __pthread_rwlock_unlock(&key_lock);
+       else key_lock = (pthread_rwlock_t)PTHREAD_RWLOCK_INITIALIZER;
+}
+
 int __pthread_key_create(pthread_key_t *k, void (*dtor)(void *))
 {
-       pthread_key_t j = next_key;
        pthread_t self = __pthread_self();
 
        /* This can only happen in the main thread before
@@ -33,6 +40,7 @@ int __pthread_key_create(pthread_key_t *k, void (*dtor)(void *))
        if (!dtor) dtor = nodtor;
 
        __pthread_rwlock_wrlock(&key_lock);
+       pthread_key_t j = next_key;
        do {
                if (!keys[j]) {
                        keys[next_key = *k = j] = dtor;
@@ -51,15 +59,17 @@ int __pthread_key_delete(pthread_key_t k)
        pthread_t self = __pthread_self(), td=self;
 
        __block_app_sigs(&set);
+       __pthread_rwlock_wrlock(&key_lock);
+
        __tl_lock();
        do td->tsd[k] = 0;
        while ((td=td->next)!=self);
        __tl_unlock();
-       __restore_sigs(&set);
 
-       __pthread_rwlock_wrlock(&key_lock);
        keys[k] = 0;
+
        __pthread_rwlock_unlock(&key_lock);
+       __restore_sigs(&set);
 
        return 0;
 }