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| author |   Al Viro <viro@zeniv.linux.org.uk> | 2017-07-16 23:51:03 -0400 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2017-11-28 11:07:13 -0500 |
| commit | fb3679372bd7967f39ea48e701fcd1e8f55e75cd (patch) | |
| tree | 371c4e45a7ef3cd7e280cb51712d9cda82b49a9d /fs/select.c | |
| parent | 9p: untangle ->poll() mess (diff) | |
| download | linux-dev-fb3679372bd7967f39ea48e701fcd1e8f55e75cd.tar.xz linux-dev-fb3679372bd7967f39ea48e701fcd1e8f55e75cd.zip | |
annotate poll(2) guts
struct pollfd contains two 16bit fields (mask and result) that encode
the POLL... bitmaps.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/select.c')
| -rw-r--r-- | fs/select.c | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/fs/select.c b/fs/select.c index 8d6d47912134..b2deeb215dbe 100644 --- a/fs/select.c +++ b/fs/select.c @@ -803,9 +803,9 @@ 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) { __poll_t mask; int fd; @@ -816,20 +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 = (__force __poll_t)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 = (__force u16)mask; return mask; } @@ -841,7 +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 */ |