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: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/drivers/vfio/virqfd.c b/drivers/vfio/virqfd.c
index d18b10f..8cc4b48 100644 (file)
--- a/drivers/vfio/virqfd.c
+++ b/drivers/vfio/virqfd.c
@@ -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 */

diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index c18e70b..7aad77b 100644 (file)
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -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);

diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index afd548e..21e6fee 100644 (file)
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -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 @@ out_unlock:
        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

diff --git a/fs/select.c b/fs/select.c
index b2bf84b..ffc16fd 100644 (file)
--- a/fs/select.c
+++ b/fs/select.c
@@ -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);
 }

diff --git a/include/linux/wait.h b/include/linux/wait.h
index 1587154..55a6114 100644 (file)
--- a/include/linux/wait.h
+++ b/include/linux/wait.h
@@ -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)                                                \
 ({                                                                             \

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 50e6906..006aa27 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3777,7 +3777,7 @@ static int memcg_event_wake(wait_queue_entry_t *wait, unsigned mode,
        struct mem_cgroup_event *event =
                container_of(wait, struct mem_cgroup_event, wait);
        struct mem_cgroup *memcg = event->memcg;
-       unsigned long flags = (unsigned long)key;
+       __poll_t flags = key_to_poll(key);
 
        if (flags & POLLHUP) {
                /*

diff --git a/net/core/datagram.c b/net/core/datagram.c
index 522873e..000da13 100644 (file)
--- a/net/core/datagram.c
+++ b/net/core/datagram.c
@@ -72,12 +72,10 @@ static inline int connection_based(struct sock *sk)
 static int receiver_wake_function(wait_queue_entry_t *wait, unsigned int mode, int sync,
                                  void *key)
 {
-       unsigned long bits = (unsigned long)key;
-
        /*
         * Avoid a wakeup if event not interesting for us
         */
-       if (bits && !(bits & (POLLIN | POLLERR)))
+       if (key && !(key_to_poll(key) & (POLLIN | POLLERR)))
                return 0;
        return autoremove_wake_function(wait, mode, sync, key);
 }

diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index a9ee634..7295796 100644 (file)
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -367,7 +367,7 @@ static int unix_dgram_peer_wake_relay(wait_queue_entry_t *q, unsigned mode, int
        /* relaying can only happen while the wq still exists */
        u_sleep = sk_sleep(&u->sk);
        if (u_sleep)
-               wake_up_interruptible_poll(u_sleep, key);
+               wake_up_interruptible_poll(u_sleep, key_to_poll(key));
 
        return 0;
 }

diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c
index a1f68ed..a334399 100644 (file)
--- a/virt/kvm/eventfd.c
+++ b/virt/kvm/eventfd.c
@@ -188,7 +188,7 @@ irqfd_wakeup(wait_queue_entry_t *wait, unsigned mode, int sync, void *key)
 {
        struct kvm_kernel_irqfd *irqfd =
                container_of(wait, struct kvm_kernel_irqfd, wait);
-       unsigned long flags = (unsigned long)key;
+       __poll_t flags = key_to_poll(key);
        struct kvm_kernel_irq_routing_entry irq;
        struct kvm *kvm = irqfd->kvm;
        unsigned seq;