| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.19 159/287] tty: n_gsm: fix missing corner cases in gsmld_poll() | Date | Tue, 23 Aug 2022 10:25:28 +0200 |
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From: Daniel Starke <daniel.starke@siemens.com>
[ Upstream commit 7e5b4322cde067e1d0f1bf8f490e93f664a7c843 ]
gsmld_poll() currently fails to handle the following corner cases correctly: - remote party closed the associated tty
Add the missing checks and map those to EPOLLHUP. Reorder the checks to group them by their reaction.
Fixes: e1eaea46bb40 ("tty: n_gsm line discipline") Signed-off-by: Daniel Starke <daniel.starke@siemens.com> Link: https://lore.kernel.org/r/20220707113223.3685-4-daniel.starke@siemens.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> --- drivers/tty/n_gsm.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c index 727707e02551..f6d2be13b32e 100644 --- a/drivers/tty/n_gsm.c +++ b/drivers/tty/n_gsm.c @@ -2561,12 +2561,15 @@ static __poll_t gsmld_poll(struct tty_struct *tty, struct file *file, poll_wait(file, &tty->read_wait, wait); poll_wait(file, &tty->write_wait, wait); + + if (gsm->dead) + mask |= EPOLLHUP; if (tty_hung_up_p(file)) mask |= EPOLLHUP; + if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) + mask |= EPOLLHUP; if (!tty_is_writelocked(tty) && tty_write_room(tty) > 0) mask |= EPOLLOUT | EPOLLWRNORM; - if (gsm->dead) - mask |= EPOLLHUP; return mask; } -- 2.35.1
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