Merge branch 'work.poll2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull more poll annotation updates from Al Viro:
"This is preparation to solving the problems you've mentioned in the
original poll series.

After this series, the kernel is ready for running

for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do
L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'`
for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done
done

as a for bulk search-and-replace.

After that, the kernel is ready to apply the patch to unify
{de,}mangle_poll(), and then get rid of kernel-side POLL... uses
entirely, and we should be all done with that stuff.

Basically, that's what you suggested wrt KPOLL..., except that we can
use EPOLL... instead - they already are arch-independent (and equal to
what is currently kernel-side POLL...).

After the preparations (in this series) switch to returning EPOLL...
from ->poll() instances is completely mechanical and kernel-side
POLL... can go away. The last step (killing kernel-side POLL... and
unifying {de,}mangle_poll() has to be done after the
search-and-replace job, since we need userland-side POLL... for
unified {de,}mangle_poll(), thus the cherry-pick at the last step.

After that we will have:

- POLL{IN,OUT,...} *not* in __poll_t, so any stray instances of
->poll() still using those will be caught by sparse.

- eventpoll.c and select.c warning-free wrt __poll_t

- no more kernel-side definitions of POLL... - userland ones are
visible through the entire kernel (and used pretty much only for
mangle/demangle)

- same behavior as after the first series (i.e. sparc et.al. epoll(2)
working correctly)"

* 'work.poll2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
annotate ep_scan_ready_list()
ep_send_events_proc(): return result via esed->res
preparation to switching ->poll() to returning EPOLL...
add EPOLLNVAL, annotate EPOLL... and event_poll->event
use linux/poll.h instead of asm/poll.h
xen: fix poll misannotation
smc: missing poll annotations

drivers/xen/pvcalls-front.h

···
 			  struct msghdr *msg,
 			  size_t len,
 			  int flags);
-unsigned int pvcalls_front_poll(struct file *file,
+__poll_t pvcalls_front_poll(struct file *file,
 				struct socket *sock,
 				poll_table *wait);
 int pvcalls_front_release(struct socket *sock);

fs/coda/psdev.c

···
 #include <linux/device.h>
 #include <linux/pid_namespace.h>
 #include <asm/io.h>
-#include <asm/poll.h>
+#include <linux/poll.h>
 #include <linux/uaccess.h>
 
 #include <linux/coda.h>

fs/debugfs/file.c

···
 #include <linux/slab.h>
 #include <linux/atomic.h>
 #include <linux/device.h>
-#include <asm/poll.h>
+#include <linux/poll.h>
 
 #include "internal.h"
 

fs/eventpoll.c

···
 struct ep_send_events_data {
 	int maxevents;
 	struct epoll_event __user *events;
+	int res;
 };
 
 /*
···
  *
  * Returns: The same integer error code returned by the @sproc callback.
  */
-static int ep_scan_ready_list(struct eventpoll *ep,
-			      int (*sproc)(struct eventpoll *,
+static __poll_t ep_scan_ready_list(struct eventpoll *ep,
+			      __poll_t (*sproc)(struct eventpoll *,
 					   struct list_head *, void *),
 			      void *priv, int depth, bool ep_locked)
 {
-	int error, pwake = 0;
+	__poll_t res;
+	int pwake = 0;
 	unsigned long flags;
 	struct epitem *epi, *nepi;
 	LIST_HEAD(txlist);
···
 	/*
 	 * Now call the callback function.
 	 */
-	error = (*sproc)(ep, &txlist, priv);
+	res = (*sproc)(ep, &txlist, priv);
 
 	spin_lock_irqsave(&ep->lock, flags);
 	/*
···
 	if (pwake)
 		ep_poll_safewake(&ep->poll_wait);
 
-	return error;
+	return res;
 }
 
 static void epi_rcu_free(struct rcu_head *head)
···
 	return 0;
 }
 
-static int ep_read_events_proc(struct eventpoll *ep, struct list_head *head,
+static __poll_t ep_read_events_proc(struct eventpoll *ep, struct list_head *head,
 			       void *priv);
 static void ep_ptable_queue_proc(struct file *file, wait_queue_head_t *whead,
 				 poll_table *pt);
···
  * the ep->mtx so we need to start from depth=1, such that mutex_lock_nested()
  * is correctly annotated.
  */
-static unsigned int ep_item_poll(const struct epitem *epi, poll_table *pt,
+static __poll_t ep_item_poll(const struct epitem *epi, poll_table *pt,
 				 int depth)
 {
 	struct eventpoll *ep;
···
 				  locked) & epi->event.events;
 }
 
-static int ep_read_events_proc(struct eventpoll *ep, struct list_head *head,
+static __poll_t ep_read_events_proc(struct eventpoll *ep, struct list_head *head,
 			       void *priv)
 {
 	struct epitem *epi, *tmp;
···
 static int ep_insert(struct eventpoll *ep, const struct epoll_event *event,
 		     struct file *tfile, int fd, int full_check)
 {
-	int error, revents, pwake = 0;
+	int error, pwake = 0;
+	__poll_t revents;
 	unsigned long flags;
 	long user_watches;
 	struct epitem *epi;
···
 	return 0;
 }
 
-static int ep_send_events_proc(struct eventpoll *ep, struct list_head *head,
+static __poll_t ep_send_events_proc(struct eventpoll *ep, struct list_head *head,
 			       void *priv)
 {
 	struct ep_send_events_data *esed = priv;
-	int eventcnt;
-	unsigned int revents;
+	__poll_t revents;
 	struct epitem *epi;
 	struct epoll_event __user *uevent;
 	struct wakeup_source *ws;
···
 	 * Items cannot vanish during the loop because ep_scan_ready_list() is
 	 * holding "mtx" during this call.
 	 */
-	for (eventcnt = 0, uevent = esed->events;
-	     !list_empty(head) && eventcnt < esed->maxevents;) {
+	for (esed->res = 0, uevent = esed->events;
+	     !list_empty(head) && esed->res < esed->maxevents;) {
 		epi = list_first_entry(head, struct epitem, rdllink);
 
 		/*
···
 			    __put_user(epi->event.data, &uevent->data)) {
 				list_add(&epi->rdllink, head);
 				ep_pm_stay_awake(epi);
-				return eventcnt ? eventcnt : -EFAULT;
+				if (!esed->res)
+					esed->res = -EFAULT;
+				return 0;
 			}
-			eventcnt++;
+			esed->res++;
 			uevent++;
 			if (epi->event.events & EPOLLONESHOT)
 				epi->event.events &= EP_PRIVATE_BITS;
···
 		}
 	}
 
-	return eventcnt;
+	return 0;
 }
 
 static int ep_send_events(struct eventpoll *ep,
···
 	esed.maxevents = maxevents;
 	esed.events = events;
 
-	return ep_scan_ready_list(ep, ep_send_events_proc, &esed, 0, false);
+	ep_scan_ready_list(ep, ep_send_events_proc, &esed, 0, false);
+	return esed.res;
 }
 
 static inline struct timespec64 ep_set_mstimeout(long ms)

fs/fcntl.c

···
 #include <linux/shmem_fs.h>
 #include <linux/compat.h>
 
-#include <asm/poll.h>
+#include <linux/poll.h>
 #include <asm/siginfo.h>
 #include <linux/uaccess.h>
 

include/linux/poll.h

···
 #include <linux/sysctl.h>
 #include <linux/uaccess.h>
 #include <uapi/linux/poll.h>
+#include <uapi/linux/eventpoll.h>
 
 extern struct ctl_table epoll_table[]; /* for sysctl */
 /* ~832 bytes of stack space used max in sys_select/sys_poll before allocating
···
 #define WQUEUES_STACK_ALLOC	(MAX_STACK_ALLOC - FRONTEND_STACK_ALLOC)
 #define N_INLINE_POLL_ENTRIES	(WQUEUES_STACK_ALLOC / sizeof(struct poll_table_entry))
 
-#define DEFAULT_POLLMASK (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)
+#define DEFAULT_POLLMASK (EPOLLIN | EPOLLOUT | EPOLLRDNORM | EPOLLWRNORM)
 
 struct poll_table_struct;
 

include/uapi/linux/eventpoll.h

···
 #define EPOLL_CTL_MOD 3
 
 /* Epoll event masks */
-#define EPOLLIN		0x00000001
-#define EPOLLPRI	0x00000002
-#define EPOLLOUT	0x00000004
-#define EPOLLERR	0x00000008
-#define EPOLLHUP	0x00000010
-#define EPOLLRDNORM	0x00000040
-#define EPOLLRDBAND	0x00000080
-#define EPOLLWRNORM	0x00000100
-#define EPOLLWRBAND	0x00000200
-#define EPOLLMSG	0x00000400
-#define EPOLLRDHUP	0x00002000
+#define EPOLLIN		(__force __poll_t)0x00000001
+#define EPOLLPRI	(__force __poll_t)0x00000002
+#define EPOLLOUT	(__force __poll_t)0x00000004
+#define EPOLLERR	(__force __poll_t)0x00000008
+#define EPOLLHUP	(__force __poll_t)0x00000010
+#define EPOLLNVAL	(__force __poll_t)0x00000020
+#define EPOLLRDNORM	(__force __poll_t)0x00000040
+#define EPOLLRDBAND	(__force __poll_t)0x00000080
+#define EPOLLWRNORM	(__force __poll_t)0x00000100
+#define EPOLLWRBAND	(__force __poll_t)0x00000200
+#define EPOLLMSG	(__force __poll_t)0x00000400
+#define EPOLLRDHUP	(__force __poll_t)0x00002000
 
 /* Set exclusive wakeup mode for the target file descriptor */
-#define EPOLLEXCLUSIVE (1U << 28)
+#define EPOLLEXCLUSIVE (__force __poll_t)(1U << 28)
 
 /*
  * Request the handling of system wakeup events so as to prevent system suspends
···
  *
  * Requires CAP_BLOCK_SUSPEND
  */
-#define EPOLLWAKEUP (1U << 29)
+#define EPOLLWAKEUP (__force __poll_t)(1U << 29)
 
 /* Set the One Shot behaviour for the target file descriptor */
-#define EPOLLONESHOT (1U << 30)
+#define EPOLLONESHOT (__force __poll_t)(1U << 30)
 
 /* Set the Edge Triggered behaviour for the target file descriptor */
-#define EPOLLET (1U << 31)
+#define EPOLLET (__force __poll_t)(1U << 31)
 
 /* 
  * On x86-64 make the 64bit structure have the same alignment as the
···
 #endif
 
 struct epoll_event {
-	__u32 events;
+	__poll_t events;
 	__u64 data;
 } EPOLL_PACKED;
 

net/smc/af_smc.c

···
 static __poll_t smc_accept_poll(struct sock *parent)
 {
 	struct smc_sock *isk = smc_sk(parent);
-	int mask = 0;
+	__poll_t mask = 0;
 
 	spin_lock(&isk->accept_q_lock);
 	if (!list_empty(&isk->accept_q))