diff options
| author | Etienne Perot <eperot@google.com> | 2020-12-03 06:18:03 -0800 |
|---|---|---|
| committer | gVisor bot <gvisor-bot@google.com> | 2020-12-03 06:20:29 -0800 |
| commit | 6f60a2b0a27a742690aa6acd5df1912ccb5fc8d3 (patch) | |
| tree | b706a5e534592d9aaa7fb4dc6237b4ab3686af13 /pkg/sentry/vfs/epoll.go | |
| parent | 80552b936d06e43ea77df09a6b6c5ce2600a6f6a (diff) | |
Implement `fcntl` options `F_GETSIG` and `F_SETSIG`.
These options allow overriding the signal that gets sent to the process when
I/O operations are available on the file descriptor, rather than the default
`SIGIO` signal. Doing so also populates `siginfo` to contain extra information
about which file descriptor caused the event (`si_fd`) and what events happened
on it (`si_band`). The logic around which FD is populated within `si_fd`
matches Linux's, which means it has some weird edge cases where that value may
not actually refer to a file descriptor that is still valid.
This CL also ports extra S/R logic regarding async handler in VFS2.
Without this, async I/O handlers aren't properly re-registered after S/R.
PiperOrigin-RevId: 345436598
Diffstat (limited to 'pkg/sentry/vfs/epoll.go')
| -rw-r--r-- | pkg/sentry/vfs/epoll.go | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/pkg/sentry/vfs/epoll.go b/pkg/sentry/vfs/epoll.go index a98aac52b..072655fe8 100644 --- a/pkg/sentry/vfs/epoll.go +++ b/pkg/sentry/vfs/epoll.go @@ -204,8 +204,8 @@ func (ep *EpollInstance) AddInterest(file *FileDescription, num int32, event lin file.EventRegister(&epi.waiter, wmask) // Check if the file is already ready. - if file.Readiness(wmask)&wmask != 0 { - epi.Callback(nil) + if m := file.Readiness(wmask) & wmask; m != 0 { + epi.Callback(nil, m) } // Add epi to file.epolls so that it is removed when the last @@ -274,8 +274,8 @@ func (ep *EpollInstance) ModifyInterest(file *FileDescription, num int32, event file.EventRegister(&epi.waiter, wmask) // Check if the file is already ready with the new mask. - if file.Readiness(wmask)&wmask != 0 { - epi.Callback(nil) + if m := file.Readiness(wmask) & wmask; m != 0 { + epi.Callback(nil, m) } return nil @@ -311,7 +311,7 @@ func (ep *EpollInstance) DeleteInterest(file *FileDescription, num int32) error } // Callback implements waiter.EntryCallback.Callback. -func (epi *epollInterest) Callback(*waiter.Entry) { +func (epi *epollInterest) Callback(*waiter.Entry, waiter.EventMask) { newReady := false epi.epoll.mu.Lock() if !epi.ready { |