linux-user: Fix mmap_lock ordering
mmap_lock() can be called while tb_lock() is being held. To
avoid deadlock when one thread is holding mmap_lock and another
tb_lock, _always_ lock first tb_lock().
Signed-off-by: Riku Voipio <riku.voipio@nokia.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
diff --git a/linux-user/main.c b/linux-user/main.c
index e51539e..12502ad 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -99,13 +99,14 @@
/* Make sure everything is in a consistent state for calling fork(). */
void fork_start(void)
{
- mmap_fork_start();
pthread_mutex_lock(&tb_lock);
pthread_mutex_lock(&exclusive_lock);
+ mmap_fork_start();
}
void fork_end(int child)
{
+ mmap_fork_end(child);
if (child) {
/* Child processes created by fork() only have a single thread.
Discard information about the parent threads. */
@@ -122,7 +123,6 @@
pthread_mutex_unlock(&exclusive_lock);
pthread_mutex_unlock(&tb_lock);
}
- mmap_fork_end(child);
}
/* Wait for pending exclusive operations to complete. The exclusive lock
