From 6f60a2b0a27a742690aa6acd5df1912ccb5fc8d3 Mon Sep 17 00:00:00 2001
From: Etienne Perot <eperot@google.com>
Date: Thu, 3 Dec 2020 06:18:03 -0800
Subject: 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
---
pkg/sentry/fsimpl/overlay/regular_file.go | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
(limited to 'pkg/sentry/fsimpl/overlay')
diff --git a/pkg/sentry/fsimpl/overlay/regular_file.go b/pkg/sentry/fsimpl/overlay/regular_file.go
index 2b89a7a6d..25c785fd4 100644
--- a/pkg/sentry/fsimpl/overlay/regular_file.go
+++ b/pkg/sentry/fsimpl/overlay/regular_file.go
@@ -103,8 +103,8 @@ func (fd *regularFileFD) currentFDLocked(ctx context.Context) (*vfs.FileDescript
for e, mask := range fd.lowerWaiters {
fd.cachedFD.EventUnregister(e)
upperFD.EventRegister(e, mask)
- if ready&mask != 0 {
- e.Callback.Callback(e)
+ if m := ready & mask; m != 0 {
+ e.Callback.Callback(e, m)
}
}
}
--
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