Commit 3ad6f93e authored by Al Viro's avatar Al Viro
Browse files

annotate poll-related wait keys 



__poll_t is also used as wait key in some waitqueues.
Verify that wait_..._poll() gets __poll_t as key and
provide a helper for wakeup functions to get back to
that __poll_t value.

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent e6c8adca

drivers/vfio/virqfd.c

+1 −1
Original line number Diff line number Diff line
@@ -46,7 +46,7 @@ static void virqfd_deactivate(struct virqfd *virqfd) 
static int virqfd_wakeup(wait_queue_entry_t *wait, unsigned mode, int sync, void *key)

{

	struct virqfd *virqfd = container_of(wait, struct virqfd, wait);

	unsigned long flags = (unsigned long)key;

	__poll_t flags = key_to_poll(key);



	if (flags & POLLIN) {

		/* An event has been signaled, call function */

drivers/vhost/vhost.c

+2 −2
Original line number Diff line number Diff line
@@ -170,7 +170,7 @@ static int vhost_poll_wakeup(wait_queue_entry_t *wait, unsigned mode, int sync, 
{

	struct vhost_poll *poll = container_of(wait, struct vhost_poll, wait);



	if (!((unsigned long)key & poll->mask))

	if (!(key_to_poll(key) & poll->mask))

		return 0;



	vhost_poll_queue(poll);
@@ -211,7 +211,7 @@ int vhost_poll_start(struct vhost_poll *poll, struct file *file) 


	mask = file->f_op->poll(file, &poll->table);

	if (mask)

		vhost_poll_wakeup(&poll->wait, 0, 0, (void *)(uintptr_t)mask);

		vhost_poll_wakeup(&poll->wait, 0, 0, poll_to_key(mask));

	if (mask & POLLERR) {

		if (poll->wqh)

			remove_wait_queue(poll->wqh, &poll->wait);

fs/eventpoll.c

+5 −4
Original line number Diff line number Diff line
@@ -1117,6 +1117,7 @@ static int ep_poll_callback(wait_queue_entry_t *wait, unsigned mode, int sync, v 
	unsigned long flags;

	struct epitem *epi = ep_item_from_wait(wait);

	struct eventpoll *ep = epi->ep;

	__poll_t pollflags = key_to_poll(key);

	int ewake = 0;



	spin_lock_irqsave(&ep->lock, flags);
@@ -1138,7 +1139,7 @@ static int ep_poll_callback(wait_queue_entry_t *wait, unsigned mode, int sync, v 
	 * callback. We need to be able to handle both cases here, hence the

	 * test for "key" != NULL before the event match test.

	 */

	if (key && !((unsigned long) key & epi->event.events))

	if (pollflags && !(pollflags & epi->event.events))

		goto out_unlock;



	/*
@@ -1175,8 +1176,8 @@ static int ep_poll_callback(wait_queue_entry_t *wait, unsigned mode, int sync, v 
	 */

	if (waitqueue_active(&ep->wq)) {

		if ((epi->event.events & EPOLLEXCLUSIVE) &&

					!((unsigned long)key & POLLFREE)) {

			switch ((unsigned long)key & EPOLLINOUT_BITS) {

					!(pollflags & POLLFREE)) {

			switch (pollflags & EPOLLINOUT_BITS) {

			case POLLIN:

				if (epi->event.events & POLLIN)

					ewake = 1;
@@ -1205,7 +1206,7 @@ static int ep_poll_callback(wait_queue_entry_t *wait, unsigned mode, int sync, v 
	if (!(epi->event.events & EPOLLEXCLUSIVE))

		ewake = 1;



	if ((unsigned long)key & POLLFREE) {

	if (pollflags & POLLFREE) {

		/*

		 * If we race with ep_remove_wait_queue() it can miss

		 * ->whead = NULL and do another remove_wait_queue() after

fs/select.c

+1 −1
Original line number Diff line number Diff line
@@ -212,7 +212,7 @@ static int pollwake(wait_queue_entry_t *wait, unsigned mode, int sync, void *key 
	struct poll_table_entry *entry;



	entry = container_of(wait, struct poll_table_entry, wait);

	if (key && !((unsigned long)key & entry->key))

	if (key && !(key_to_poll(key) & entry->key))

		return 0;

	return __pollwake(wait, mode, sync, key);

}

include/linux/wait.h

+6 −4
Original line number Diff line number Diff line
@@ -206,14 +206,16 @@ void __wake_up_sync(struct wait_queue_head *wq_head, unsigned int mode, int nr); 
/*

 * Wakeup macros to be used to report events to the targets.

 */

#define poll_to_key(m) ((void *)(__force uintptr_t)(__poll_t)(m))

#define key_to_poll(m) ((__force __poll_t)(uintptr_t)(void *)(m))

#define wake_up_poll(x, m)							\

	__wake_up(x, TASK_NORMAL, 1, (void *) (m))

	__wake_up(x, TASK_NORMAL, 1, poll_to_key(m))

#define wake_up_locked_poll(x, m)						\

	__wake_up_locked_key((x), TASK_NORMAL, (void *) (m))

	__wake_up_locked_key((x), TASK_NORMAL, poll_to_key(m))

#define wake_up_interruptible_poll(x, m)					\

	__wake_up(x, TASK_INTERRUPTIBLE, 1, (void *) (m))

	__wake_up(x, TASK_INTERRUPTIBLE, 1, poll_to_key(m))

#define wake_up_interruptible_sync_poll(x, m)					\

	__wake_up_sync_key((x), TASK_INTERRUPTIBLE, 1, (void *) (m))

	__wake_up_sync_key((x), TASK_INTERRUPTIBLE, 1, poll_to_key(m))



#define ___wait_cond_timeout(condition)						\

({										\