From: Daniel Starke <[email protected]>
n_gsm is based on the 3GPP 07.010 and its newer version is the 3GPP 27.010.
See https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=1516
The changes from 07.010 to 27.010 are non-functional. Therefore, I refer to
the newer 27.010 here. Chapter 5.7.3 states that the valid range for the
maximum number of retransmissions (N2) is from 0 to 255 (both including).
gsm_dlci_t1() handles this number incorrectly by performing N2 - 1
retransmission attempts. Setting N2 to zero results in more than 255
retransmission attempts.
Fix gsm_dlci_t1() to comply with 3GPP 27.010.
Fixes: e1eaea46bb40 ("tty: n_gsm line discipline")
Signed-off-by: Daniel Starke <[email protected]>
---
drivers/tty/n_gsm.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
No changes have been applied compared to v1.
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index ba399a660573..1a70e7ae90cc 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -1805,8 +1805,8 @@ static void gsm_dlci_t1(struct timer_list *t)
switch (dlci->state) {
case DLCI_OPENING:
- dlci->retries--;
if (dlci->retries) {
+ dlci->retries--;
gsm_command(dlci->gsm, dlci->addr, SABM|PF);
mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100);
} else if (!dlci->addr && gsm->control == (DM | PF)) {
@@ -1821,8 +1821,8 @@ static void gsm_dlci_t1(struct timer_list *t)
break;
case DLCI_CLOSING:
- dlci->retries--;
if (dlci->retries) {
+ dlci->retries--;
gsm_command(dlci->gsm, dlci->addr, DISC|PF);
mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100);
} else
--
2.34.1
From: Daniel Starke <[email protected]>
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 <[email protected]>
---
drivers/tty/n_gsm.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
Check for valid pointer in tty->disc_data has been removed compared to v1.
Link: https://lore.kernel.org/all/[email protected]/
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 51447ccccbab..caa5c14ed57f 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -3053,12 +3053,15 @@ 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;
}
--
2.34.1