Function report

Linux Kernel

v5.5.9

Brick Technologies Co., Ltd

Source Code:fs\userfaultfd.c Create Date:2022-07-28 20:20:34
Last Modify:2020-03-12 14:18:49 Copyright©Brick
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Annotation kernel can get tool activityDownload SCCTChinese

Name:userfaultfd_poll

Proto:static __poll_t userfaultfd_poll(struct file *file, poll_table *wait)

Type:__poll_t

Parameter:

TypeParameterName
struct file *file
poll_table *wait
978  ctx = needed for tty driver, and maybe others
981  poll_wait(file, & waitqueue head for the pseudo fd to wakeup poll/read , wait)
984  Case state machine == UFFD_STATE_WAIT_API
985  Return EPOLLERR
986  Case state machine == UFFD_STATE_RUNNING
991  If Value for the false possibility is greater at compile time(!(f_flags & O_NONBLOCK)) Then Return EPOLLERR
1003  ret = 0
1004  smp_mb()
1005  If waitqueue_active -- locklessly test for waiters on the queue*@wq_head: the waitqueue to test for waiters* returns true if the wait list is not empty* NOTE: this function is lockless and requires care, incorrect usage _will_ Then ret = Epoll event masks
1007  Else if waitqueue_active -- locklessly test for waiters on the queue*@wq_head: the waitqueue to test for waiters* returns true if the wait list is not empty* NOTE: this function is lockless and requires care, incorrect usage _will_ Then ret = Epoll event masks
1010  Return ret
1011  Default
1012  WARN_ON_ONCE(1)
1013  Return EPOLLERR