Merge branch 'misc.poll' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull poll annotations from Al Viro:
 "This introduces a __bitwise type for POLL### bitmap, and propagates
  the annotations through the tree. Most of that stuff is as simple as
  'make ->poll() instances return __poll_t and do the same to local
  variables used to hold the future return value'.

  Some of the obvious brainos found in process are fixed (e.g. POLLIN
  misspelled as POLL_IN). At that point the amount of sparse warnings is
  low and most of them are for genuine bugs - e.g. ->poll() instance
  deciding to return -EINVAL instead of a bitmap. I hadn't touched those
  in this series - it's large enough as it is.

  Another problem it has caught was eventpoll() ABI mess; select.c and
  eventpoll.c assumed that corresponding POLL### and EPOLL### were
  equal. That's true for some, but not all of them - EPOLL### are
  arch-independent, but POLL### are not.

  The last commit in this series separates userland POLL### values from
  the (now arch-independent) kernel-side ones, converting between them
  in the few places where they are copied to/from userland. AFAICS, this
  is the least disruptive fix preserving poll(2) ABI and making epoll()
  work on all architectures.

  As it is, it's simply broken on sparc - try to give it EPOLLWRNORM and
  it will trigger only on what would've triggered EPOLLWRBAND on other
  architectures. EPOLLWRBAND and EPOLLRDHUP, OTOH, are never triggered
  at all on sparc. With this patch they should work consistently on all
  architectures"

* 'misc.poll' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (37 commits)
  make kernel-side POLL... arch-independent
  eventpoll: no need to mask the result of epi_item_poll() again
  eventpoll: constify struct epoll_event pointers
  debugging printk in sg_poll() uses %x to print POLL... bitmap
  annotate poll(2) guts
  9p: untangle ->poll() mess
  ->si_band gets POLL... bitmap stored into a user-visible long field
  ring_buffer_poll_wait() return value used as return value of ->poll()
  the rest of drivers/*: annotate ->poll() instances
  media: annotate ->poll() instances
  fs: annotate ->poll() instances
  ipc, kernel, mm: annotate ->poll() instances
  net: annotate ->poll() instances
  apparmor: annotate ->poll() instances
  tomoyo: annotate ->poll() instances
  sound: annotate ->poll() instances
  acpi: annotate ->poll() instances
  crypto: annotate ->poll() instances
  block: annotate ->poll() instances
  x86: annotate ->poll() instances
  ...

1 files changed, 16 insertions, 11 deletions

diff --git a/fs/select.c b/fs/select.c
index 6de493bb42a4..ec14171dd78a 100644
--- 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);
 }
@@ -438,7 +438,7 @@ get_max:
 
 static inline void wait_key_set(poll_table *wait, unsigned long in,
 				unsigned long out, unsigned long bit,
-				unsigned int ll_flag)
+				__poll_t ll_flag)
 {
 	wait->_key = POLLEX_SET | ll_flag;
 	if (in & bit)
@@ -454,7 +454,7 @@ static int do_select(int n, fd_set_bits *fds, struct timespec64 *end_time)
 	poll_table *wait;
 	int retval, i, timed_out = 0;
 	u64 slack = 0;
-	unsigned int busy_flag = net_busy_loop_on() ? POLL_BUSY_LOOP : 0;
+	__poll_t busy_flag = net_busy_loop_on() ? POLL_BUSY_LOOP : 0;
 	unsigned long busy_start = 0;
 
 	rcu_read_lock();
@@ -484,8 +484,9 @@ static int do_select(int n, fd_set_bits *fds, struct timespec64 *end_time)
 		rinp = fds->res_in; routp = fds->res_out; rexp = fds->res_ex;
 
 		for (i = 0; i < n; ++rinp, ++routp, ++rexp) {
-			unsigned long in, out, ex, all_bits, bit = 1, mask, j;
+			unsigned long in, out, ex, all_bits, bit = 1, j;
 			unsigned long res_in = 0, res_out = 0, res_ex = 0;
+			__poll_t mask;
 
 			in = *inp++; out = *outp++; ex = *exp++;
 			all_bits = in | out | ex;
@@ -802,11 +803,11 @@ struct poll_list {
  * pwait poll_table will be used by the fd-provided poll handler for waiting,
  * if pwait->_qproc is non-NULL.
  */
-static inline unsigned int do_pollfd(struct pollfd *pollfd, poll_table *pwait,
+static inline __poll_t do_pollfd(struct pollfd *pollfd, poll_table *pwait,
 				     bool *can_busy_poll,
-				     unsigned int busy_flag)
+				     __poll_t busy_flag)
 {
-	unsigned int mask;
+	__poll_t mask;
 	int fd;
 
 	mask = 0;
@@ -815,20 +816,24 @@ static inline unsigned int do_pollfd(struct pollfd *pollfd, poll_table *pwait,
 		struct fd f = fdget(fd);
 		mask = POLLNVAL;
 		if (f.file) {
+			/* userland u16 ->events contains POLL... bitmap */
+			__poll_t filter = demangle_poll(pollfd->events) |
+						POLLERR | POLLHUP;
 			mask = DEFAULT_POLLMASK;
 			if (f.file->f_op->poll) {
-				pwait->_key = pollfd->events|POLLERR|POLLHUP;
+				pwait->_key = filter;
 				pwait->_key |= busy_flag;
 				mask = f.file->f_op->poll(f.file, pwait);
 				if (mask & busy_flag)
 					*can_busy_poll = true;
 			}
 			/* Mask out unneeded events. */
-			mask &= pollfd->events | POLLERR | POLLHUP;
+			mask &= filter;
 			fdput(f);
 		}
 	}
-	pollfd->revents = mask;
+	/* ... and so does ->revents */
+	pollfd->revents = mangle_poll(mask);
 
 	return mask;
 }
@@ -840,7 +845,7 @@ static int do_poll(struct poll_list *list, struct poll_wqueues *wait,
 	ktime_t expire, *to = NULL;
 	int timed_out = 0, count = 0;
 	u64 slack = 0;
-	unsigned int busy_flag = net_busy_loop_on() ? POLL_BUSY_LOOP : 0;
+	__poll_t busy_flag = net_busy_loop_on() ? POLL_BUSY_LOOP : 0;
 	unsigned long busy_start = 0;
 
 	/* Optimise the no-wait case */