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| author | Konstantin Belousov <kib@FreeBSD.org> | 2021-05-13 01:35:06 +0000 |
|---|---|---|
| committer | Konstantin Belousov <kib@FreeBSD.org> | 2021-05-18 17:52:03 +0000 |
| commit | 8cf912b017a04a2eec01fbaa1f7b9ef556403ede (patch) | |
| tree | 2ad527afd7aa1f91a5856fa51c34f813fc2c3bfe | |
| parent | cc6f46ac2fd5d910e632fced3f21d0b0f53030d8 (diff) | |
| download | src-8cf912b017a04a2eec01fbaa1f7b9ef556403ede.tar.gz src-8cf912b017a04a2eec01fbaa1f7b9ef556403ede.zip | |
ttydev_write: prevent stops while terminal is busied
Since busy state is checked by all blocked writes, stopping a process
which waits in ttydisc_write() causes cascade. Utilize sigdeferstop()
to avoid the issue.
Submitted by: Jakub Piecuch <j.piecuch96@gmail.com>
PR: 255816
MFC after: 1 week
| -rw-r--r-- | sys/kern/tty.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/sys/kern/tty.c b/sys/kern/tty.c index 00b4df675311..8700eb8f9ef1 100644 --- a/sys/kern/tty.c +++ b/sys/kern/tty.c @@ -525,7 +525,7 @@ static int ttydev_write(struct cdev *dev, struct uio *uio, int ioflag) { struct tty *tp = dev->si_drv1; - int error; + int defer, error; error = ttydev_enter(tp); if (error) @@ -549,7 +549,9 @@ ttydev_write(struct cdev *dev, struct uio *uio, int ioflag) } tp->t_flags |= TF_BUSY_OUT; + defer = sigdeferstop(SIGDEFERSTOP_ERESTART); error = ttydisc_write(tp, uio, ioflag); + sigallowstop(defer); tp->t_flags &= ~TF_BUSY_OUT; cv_signal(&tp->t_outserwait); } |