Merge pull request torvalds#125 from pscollins/return-pthread-tid

lkl: Return thread id from thread_create host op

arch/lkl/include/uapi/asm/host_ops.h

@@ -4,6 +4,7 @@
 /* Defined in {posix,nt}-host.c */
 struct lkl_mutex_t;
 struct lkl_sem_t;
+typedef unsigned long lkl_thread_t;
 
 /**
  * lkl_host_operations - host operations used by the Linux kernel
@@ -31,7 +32,7 @@ struct lkl_sem_t;
  * @mutex_unlock - release the mutex
  *
  * @thread_create - create a new thread and run f(arg) in its context; returns a
- * thread handle or NULL if the thread could not be created
+ * thread handle or 0 if the thread could not be created
  * @thread_exit - terminates the current thread
  *
  * @tls_alloc - allocate a thread local storage key; returns 0 if succesful
@@ -74,7 +75,7 @@ struct lkl_host_operations {
 	void (*mutex_lock)(struct lkl_mutex_t *mutex);
 	void (*mutex_unlock)(struct lkl_mutex_t *mutex);
 
-	int (*thread_create)(void (*f)(void *), void *arg);
+	lkl_thread_t (*thread_create)(void (*f)(void *), void *arg);
 	void (*thread_exit)(void);
 
 	int (*tls_alloc)(unsigned int *key);

arch/lkl/kernel/setup.c

@@ -81,7 +81,7 @@ int __init lkl_start_kernel(struct lkl_host_operations *ops,
 	}
 
 	ret = lkl_ops->thread_create(lkl_run_kernel, NULL);
-	if (ret) {
+	if (!ret) {
 		ret = -ENOMEM;
 		goto out_free_idle_sem;
 	}

arch/lkl/kernel/threads.c

@@ -144,7 +144,7 @@ int copy_thread(unsigned long clone_flags, unsigned long esp,
 	tba->ti = ti;
 
 	ret = lkl_ops->thread_create(thread_bootstrap, tba);
-	if (ret) {
+	if (!ret) {
 		kfree(tba);
 		return -ENOMEM;
 	}

tools/lkl/lib/nt-host.c

@@ -63,11 +63,11 @@ static void mutex_free(struct lkl_mutex_t *_mutex)
 	free(_mutex);
 }
 
-static int thread_create(void (*fn)(void *), void *arg)
+static lkl_thread_t thread_create(void (*fn)(void *), void *arg)
 {
 	DWORD WINAPI (*win_fn)(LPVOID arg) = (DWORD WINAPI (*)(LPVOID))fn;
 
-	return CreateThread(NULL, 0, win_fn, arg, 0, NULL) ? 0 : -1;
+	return CreateThread(NULL, 0, win_fn, arg, 0, NULL);
 }
 
 static void thread_exit(void)

tools/lkl/lib/posix-host.c

@@ -53,13 +53,17 @@ struct lkl_sem_t {
 			lkl_printf("%s: %s\n", #exp, strerror(errno));	\
 	} while (0)
 
-/* pthread_* functions use the reverse convention */
-#define WARN_PTHREAD(exp) do {						\
-		int __ret = exp;					\
-		if (__ret > 0)						\
-			lkl_printf("%s: %s\n", #exp, strerror(__ret));	\
-	} while (0)
+static int _warn_pthread(int ret, char *str_exp)
+{
+	if (ret > 0)
+		lkl_printf("%s: %s\n", str_exp, strerror(ret));
 
+	return ret;
+}
+
+
+/* pthread_* functions use the reverse convention */
+#define WARN_PTHREAD(exp) _warn_pthread(exp, #exp)
 
 static struct lkl_sem_t *sem_alloc(int count)
 {
@@ -176,11 +180,13 @@ static void mutex_free(struct lkl_mutex_t *_mutex)
 	free(_mutex);
 }
 
-static int thread_create(void (*fn)(void *), void *arg)
+static lkl_thread_t thread_create(void (*fn)(void *), void *arg)
 {
 	pthread_t thread;
-
-	return pthread_create(&thread, NULL, (void* (*)(void *))fn, arg);
+	if (WARN_PTHREAD(pthread_create(&thread, NULL, (void* (*)(void *))fn, arg)))
+		return 0;
+	else
+		return (lkl_thread_t) thread;
 }
 
 static void thread_exit(void)

tools/lkl/lib/virtio_net.c

@@ -198,10 +198,10 @@ int lkl_netdev_add(struct lkl_netdev *nd, void *mac)
 	if (ret)
 		goto out_free;
 
-	if (lkl_host_ops.thread_create(poll_thread, &dev->rx_poll) < 0)
+	if (lkl_host_ops.thread_create(poll_thread, &dev->rx_poll) == 0)
 		goto out_cleanup_dev;
 
-	if (lkl_host_ops.thread_create(poll_thread, &dev->tx_poll) < 0)
+	if (lkl_host_ops.thread_create(poll_thread, &dev->tx_poll) == 0)
 		goto out_cleanup_dev;
 
 	/* RX/TX thread polls will exit when the host netdev handle is closed */

tools/lkl/tests/boot.c

@@ -667,7 +667,7 @@ static int test_syscall_thread(char *str, int len)
 	}
 
 	ret = lkl_host_ops.thread_create(test_thread, pipe_fds);
-	if (ret) {
+	if (!ret) {
 		snprintf(str, len, "failed to create thread");
 		return TEST_FAILURE;
 	}