[PATCH 5.10 095/102] tty: fix up hung_up_tty_read() conversion
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2021-03-05 12:33:24
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From: Linus Torvalds <torvalds@linux-foundation.org> commit ddc5fda7456178e2cbc87675b370920d98360daf upstream. In commit "tty: implement read_iter", I left the read_iter conversion of the hung up tty case alone, because I incorrectly thought it didn't matter. Jiri showed me the errors of my ways, and pointed out the problems with that incomplete conversion. Fix it all up. Reported-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Link: https://lore.kernel.org/r/CAHk-=wh+-rGsa=xruEWdg_fJViFG8rN9bpLrfLz=_yBYh2tBhA@mail.gmail.com (local) Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- drivers/tty/tty_io.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-)
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c@@ -429,8 +429,7 @@ struct tty_driver *tty_find_polling_driv EXPORT_SYMBOL_GPL(tty_find_polling_driver); #endif -static ssize_t hung_up_tty_read(struct file *file, char __user *buf, - size_t count, loff_t *ppos) +static ssize_t hung_up_tty_read(struct kiocb *iocb, struct iov_iter *to) { return 0; }
@@ -502,7 +501,7 @@ static const struct file_operations cons static const struct file_operations hung_up_tty_fops = { .llseek = no_llseek, - .read = hung_up_tty_read, + .read_iter = hung_up_tty_read, .write_iter = hung_up_tty_write, .poll = hung_up_tty_poll, .unlocked_ioctl = hung_up_tty_ioctl,
@@ -929,8 +928,10 @@ static ssize_t tty_read(struct kiocb *io /* We want to wait for the line discipline to sort out in this situation */ ld = tty_ldisc_ref_wait(tty); + if (!ld) + return hung_up_tty_read(iocb, to); i = -EIO; - if (ld && ld->ops->read) + if (ld->ops->read) i = iterate_tty_read(ld, tty, file, to); tty_ldisc_deref(ld);