kern/thread: make thread_create slightly more convenient

Don't require the caller to pass a pointer to the newly created thread.

2 files changed, 6 insertions, 1 deletions

diff --git a/kern/thread.c b/kern/thread.c
index 85e557d3..e79ef311 100644
--- a/kern/thread.c
+++ b/kern/thread.c
@@ -2367,7 +2367,9 @@ thread_create(struct thread **threadp, const struct thread_attr *attr,
      * The new thread address must be written before the thread is started
      * in case it's passed to it.
      */
-    *threadp = thread;
+    if (threadp) {
+        *threadp = thread;
+    }
 
     thread_wakeup(thread);
 
diff --git a/kern/thread.h b/kern/thread.h
index 4bead755..6e696fc7 100644
--- a/kern/thread.h
+++ b/kern/thread.h
@@ -182,6 +182,9 @@ void thread_ap_setup(void);
  * Creation attributes must be passed, but some of them may be NULL, in which
  * case the value is inherited from the caller. The name attribute must not be
  * NULL.
+ *
+ * If successful, and if the caller passed a non-NULL thread pointer, it is
+ * filled with the address of the newly created thread.
  */
 int thread_create(struct thread **threadp, const struct thread_attr *attr,
                   void (*fn)(void *), void *arg);