The patch below does not apply to the 5.10-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From a8c5b8255f8a9acd58a4b15ff1c14cd6effd114b Mon Sep 17 00:00:00 2001
From: Daniel Starke <daniel.starke(a)siemens.com>
Date: Fri, 22 Apr 2022 00:10:23 -0700
Subject: [PATCH] tty: n_gsm: fix broken virtual tty handling
Dynamic virtual tty registration was introduced to allow the user to handle
these cases with uevent rules. The following commits relate to this:
Commit 5b87686e3203 ("tty: n_gsm: Modify gsmtty driver register method when config requester")
Commit 0b91b5332368 ("tty: n_gsm: Save dlci address open status when config requester")
Commit 46292622ad73 ("tty: n_gsm: clean up indenting in gsm_queue()")
However, the following behavior can be seen with this implementation:
- n_gsm ldisc is activated via ioctl
- all configuration parameters are set to their default value (initiator=0)
- the mux gets activated and attached and gsmtty0 is being registered in
in gsm_dlci_open() after DLCI 0 was established (DLCI 0 is the control
channel)
- the user configures n_gsm via ioctl GSMIOC_SETCONF as initiator
- this re-attaches the n_gsm mux
- no new gsmtty devices are registered in gsmld_attach_gsm() because the
mux is already active
- the initiator side registered only the control channel as gsmtty0
(which should never happen) and no user channel tty
The commits above make it impossible to operate the initiator side as no
user channel tty is or will be available.
On the other hand, this behavior will make it also impossible to allow DLCI
parameter negotiation on responder side in the future. The responder side
first needs to provide a device for the application before the application
can set its parameters of the associated DLCI via ioctl.
Note that the user application is still able to detect a link establishment
without relaying to uevent by waiting for DTR open on responder side. This
is the same behavior as on a physical serial interface. And on initiator
side a tty hangup can be detected if a link establishment request failed.
Revert the commits above completely to always register all user channels
and no control channel after mux attachment. No other changes are made.
Fixes: 5b87686e3203 ("tty: n_gsm: Modify gsmtty driver register method when config requester")
Cc: stable(a)vger.kernel.org
Signed-off-by: Daniel Starke <daniel.starke(a)siemens.com>
Link: https://lore.kernel.org/r/20220422071025.5490-1-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 979dc9151383..99fe54247a87 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -272,10 +272,6 @@ static DEFINE_SPINLOCK(gsm_mux_lock);
static struct tty_driver *gsm_tty_driver;
-/* Save dlci open address */
-static int addr_open[256] = { 0 };
-/* Save dlci open count */
-static int addr_cnt;
/*
* This section of the driver logic implements the GSM encodings
* both the basic and the 'advanced'. Reliable transport is not
@@ -1185,7 +1181,6 @@ static void gsm_control_rls(struct gsm_mux *gsm, const u8 *data, int clen)
}
static void gsm_dlci_begin_close(struct gsm_dlci *dlci);
-static void gsm_dlci_close(struct gsm_dlci *dlci);
/**
* gsm_control_message - DLCI 0 control processing
@@ -1204,28 +1199,15 @@ static void gsm_control_message(struct gsm_mux *gsm, unsigned int command,
{
u8 buf[1];
unsigned long flags;
- struct gsm_dlci *dlci;
- int i;
- int address;
switch (command) {
case CMD_CLD: {
- if (addr_cnt > 0) {
- for (i = 0; i < addr_cnt; i++) {
- address = addr_open[i];
- dlci = gsm->dlci[address];
- gsm_dlci_close(dlci);
- addr_open[i] = 0;
- }
- }
+ struct gsm_dlci *dlci = gsm->dlci[0];
/* Modem wishes to close down */
- dlci = gsm->dlci[0];
if (dlci) {
dlci->dead = true;
gsm->dead = true;
- gsm_dlci_close(dlci);
- addr_cnt = 0;
- gsm_response(gsm, 0, UA|PF);
+ gsm_dlci_begin_close(dlci);
}
}
break;
@@ -1459,8 +1441,6 @@ static void gsm_dlci_close(struct gsm_dlci *dlci)
wake_up_interruptible(&dlci->port.open_wait);
} else
dlci->gsm->dead = true;
- /* Unregister gsmtty driver,report gsmtty dev remove uevent for user */
- tty_unregister_device(gsm_tty_driver, dlci->addr);
wake_up(&dlci->gsm->event);
/* A DLCI 0 close is a MUX termination so we need to kick that
back to userspace somehow */
@@ -1482,8 +1462,6 @@ static void gsm_dlci_open(struct gsm_dlci *dlci)
dlci->state = DLCI_OPEN;
if (debug & 8)
pr_debug("DLCI %d goes open.\n", dlci->addr);
- /* Register gsmtty driver,report gsmtty dev add uevent for user */
- tty_register_device(gsm_tty_driver, dlci->addr, NULL);
/* Send current modem state */
if (dlci->addr)
gsmtty_modem_update(dlci, 0);
@@ -1794,7 +1772,6 @@ static void gsm_queue(struct gsm_mux *gsm)
struct gsm_dlci *dlci;
u8 cr;
int address;
- int i, j, k, address_tmp;
if (gsm->fcs != GOOD_FCS) {
gsm->bad_fcs++;
@@ -1826,11 +1803,6 @@ static void gsm_queue(struct gsm_mux *gsm)
else {
gsm_response(gsm, address, UA|PF);
gsm_dlci_open(dlci);
- /* Save dlci open address */
- if (address) {
- addr_open[addr_cnt] = address;
- addr_cnt++;
- }
}
break;
case DISC|PF:
@@ -1841,33 +1813,8 @@ static void gsm_queue(struct gsm_mux *gsm)
return;
}
/* Real close complete */
- if (!address) {
- if (addr_cnt > 0) {
- for (i = 0; i < addr_cnt; i++) {
- address = addr_open[i];
- dlci = gsm->dlci[address];
- gsm_dlci_close(dlci);
- addr_open[i] = 0;
- }
- }
- dlci = gsm->dlci[0];
- gsm_dlci_close(dlci);
- addr_cnt = 0;
- gsm_response(gsm, 0, UA|PF);
- } else {
- gsm_response(gsm, address, UA|PF);
- gsm_dlci_close(dlci);
- /* clear dlci address */
- for (j = 0; j < addr_cnt; j++) {
- address_tmp = addr_open[j];
- if (address_tmp == address) {
- for (k = j; k < addr_cnt; k++)
- addr_open[k] = addr_open[k+1];
- addr_cnt--;
- break;
- }
- }
- }
+ gsm_response(gsm, address, UA|PF);
+ gsm_dlci_close(dlci);
break;
case UA|PF:
if (cr == 0 || dlci == NULL)
@@ -2451,19 +2398,17 @@ static int gsmld_attach_gsm(struct tty_struct *tty, struct gsm_mux *gsm)
else {
/* Don't register device 0 - this is the control channel and not
a usable tty interface */
- if (gsm->initiator) {
- base = mux_num_to_base(gsm); /* Base for this MUX */
- for (i = 1; i < NUM_DLCI; i++) {
- struct device *dev;
+ base = mux_num_to_base(gsm); /* Base for this MUX */
+ for (i = 1; i < NUM_DLCI; i++) {
+ struct device *dev;
- dev = tty_register_device(gsm_tty_driver,
+ dev = tty_register_device(gsm_tty_driver,
base + i, NULL);
- if (IS_ERR(dev)) {
- for (i--; i >= 1; i--)
- tty_unregister_device(gsm_tty_driver,
- base + i);
- return PTR_ERR(dev);
- }
+ if (IS_ERR(dev)) {
+ for (i--; i >= 1; i--)
+ tty_unregister_device(gsm_tty_driver,
+ base + i);
+ return PTR_ERR(dev);
}
}
}
@@ -2485,10 +2430,8 @@ static void gsmld_detach_gsm(struct tty_struct *tty, struct gsm_mux *gsm)
int i;
WARN_ON(tty != gsm->tty);
- if (gsm->initiator) {
- for (i = 1; i < NUM_DLCI; i++)
- tty_unregister_device(gsm_tty_driver, base + i);
- }
+ for (i = 1; i < NUM_DLCI; i++)
+ tty_unregister_device(gsm_tty_driver, base + i);
tty_kref_put(gsm->tty);
gsm->tty = NULL;
}
The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From a8c5b8255f8a9acd58a4b15ff1c14cd6effd114b Mon Sep 17 00:00:00 2001
From: Daniel Starke <daniel.starke(a)siemens.com>
Date: Fri, 22 Apr 2022 00:10:23 -0700
Subject: [PATCH] tty: n_gsm: fix broken virtual tty handling
Dynamic virtual tty registration was introduced to allow the user to handle
these cases with uevent rules. The following commits relate to this:
Commit 5b87686e3203 ("tty: n_gsm: Modify gsmtty driver register method when config requester")
Commit 0b91b5332368 ("tty: n_gsm: Save dlci address open status when config requester")
Commit 46292622ad73 ("tty: n_gsm: clean up indenting in gsm_queue()")
However, the following behavior can be seen with this implementation:
- n_gsm ldisc is activated via ioctl
- all configuration parameters are set to their default value (initiator=0)
- the mux gets activated and attached and gsmtty0 is being registered in
in gsm_dlci_open() after DLCI 0 was established (DLCI 0 is the control
channel)
- the user configures n_gsm via ioctl GSMIOC_SETCONF as initiator
- this re-attaches the n_gsm mux
- no new gsmtty devices are registered in gsmld_attach_gsm() because the
mux is already active
- the initiator side registered only the control channel as gsmtty0
(which should never happen) and no user channel tty
The commits above make it impossible to operate the initiator side as no
user channel tty is or will be available.
On the other hand, this behavior will make it also impossible to allow DLCI
parameter negotiation on responder side in the future. The responder side
first needs to provide a device for the application before the application
can set its parameters of the associated DLCI via ioctl.
Note that the user application is still able to detect a link establishment
without relaying to uevent by waiting for DTR open on responder side. This
is the same behavior as on a physical serial interface. And on initiator
side a tty hangup can be detected if a link establishment request failed.
Revert the commits above completely to always register all user channels
and no control channel after mux attachment. No other changes are made.
Fixes: 5b87686e3203 ("tty: n_gsm: Modify gsmtty driver register method when config requester")
Cc: stable(a)vger.kernel.org
Signed-off-by: Daniel Starke <daniel.starke(a)siemens.com>
Link: https://lore.kernel.org/r/20220422071025.5490-1-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 979dc9151383..99fe54247a87 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -272,10 +272,6 @@ static DEFINE_SPINLOCK(gsm_mux_lock);
static struct tty_driver *gsm_tty_driver;
-/* Save dlci open address */
-static int addr_open[256] = { 0 };
-/* Save dlci open count */
-static int addr_cnt;
/*
* This section of the driver logic implements the GSM encodings
* both the basic and the 'advanced'. Reliable transport is not
@@ -1185,7 +1181,6 @@ static void gsm_control_rls(struct gsm_mux *gsm, const u8 *data, int clen)
}
static void gsm_dlci_begin_close(struct gsm_dlci *dlci);
-static void gsm_dlci_close(struct gsm_dlci *dlci);
/**
* gsm_control_message - DLCI 0 control processing
@@ -1204,28 +1199,15 @@ static void gsm_control_message(struct gsm_mux *gsm, unsigned int command,
{
u8 buf[1];
unsigned long flags;
- struct gsm_dlci *dlci;
- int i;
- int address;
switch (command) {
case CMD_CLD: {
- if (addr_cnt > 0) {
- for (i = 0; i < addr_cnt; i++) {
- address = addr_open[i];
- dlci = gsm->dlci[address];
- gsm_dlci_close(dlci);
- addr_open[i] = 0;
- }
- }
+ struct gsm_dlci *dlci = gsm->dlci[0];
/* Modem wishes to close down */
- dlci = gsm->dlci[0];
if (dlci) {
dlci->dead = true;
gsm->dead = true;
- gsm_dlci_close(dlci);
- addr_cnt = 0;
- gsm_response(gsm, 0, UA|PF);
+ gsm_dlci_begin_close(dlci);
}
}
break;
@@ -1459,8 +1441,6 @@ static void gsm_dlci_close(struct gsm_dlci *dlci)
wake_up_interruptible(&dlci->port.open_wait);
} else
dlci->gsm->dead = true;
- /* Unregister gsmtty driver,report gsmtty dev remove uevent for user */
- tty_unregister_device(gsm_tty_driver, dlci->addr);
wake_up(&dlci->gsm->event);
/* A DLCI 0 close is a MUX termination so we need to kick that
back to userspace somehow */
@@ -1482,8 +1462,6 @@ static void gsm_dlci_open(struct gsm_dlci *dlci)
dlci->state = DLCI_OPEN;
if (debug & 8)
pr_debug("DLCI %d goes open.\n", dlci->addr);
- /* Register gsmtty driver,report gsmtty dev add uevent for user */
- tty_register_device(gsm_tty_driver, dlci->addr, NULL);
/* Send current modem state */
if (dlci->addr)
gsmtty_modem_update(dlci, 0);
@@ -1794,7 +1772,6 @@ static void gsm_queue(struct gsm_mux *gsm)
struct gsm_dlci *dlci;
u8 cr;
int address;
- int i, j, k, address_tmp;
if (gsm->fcs != GOOD_FCS) {
gsm->bad_fcs++;
@@ -1826,11 +1803,6 @@ static void gsm_queue(struct gsm_mux *gsm)
else {
gsm_response(gsm, address, UA|PF);
gsm_dlci_open(dlci);
- /* Save dlci open address */
- if (address) {
- addr_open[addr_cnt] = address;
- addr_cnt++;
- }
}
break;
case DISC|PF:
@@ -1841,33 +1813,8 @@ static void gsm_queue(struct gsm_mux *gsm)
return;
}
/* Real close complete */
- if (!address) {
- if (addr_cnt > 0) {
- for (i = 0; i < addr_cnt; i++) {
- address = addr_open[i];
- dlci = gsm->dlci[address];
- gsm_dlci_close(dlci);
- addr_open[i] = 0;
- }
- }
- dlci = gsm->dlci[0];
- gsm_dlci_close(dlci);
- addr_cnt = 0;
- gsm_response(gsm, 0, UA|PF);
- } else {
- gsm_response(gsm, address, UA|PF);
- gsm_dlci_close(dlci);
- /* clear dlci address */
- for (j = 0; j < addr_cnt; j++) {
- address_tmp = addr_open[j];
- if (address_tmp == address) {
- for (k = j; k < addr_cnt; k++)
- addr_open[k] = addr_open[k+1];
- addr_cnt--;
- break;
- }
- }
- }
+ gsm_response(gsm, address, UA|PF);
+ gsm_dlci_close(dlci);
break;
case UA|PF:
if (cr == 0 || dlci == NULL)
@@ -2451,19 +2398,17 @@ static int gsmld_attach_gsm(struct tty_struct *tty, struct gsm_mux *gsm)
else {
/* Don't register device 0 - this is the control channel and not
a usable tty interface */
- if (gsm->initiator) {
- base = mux_num_to_base(gsm); /* Base for this MUX */
- for (i = 1; i < NUM_DLCI; i++) {
- struct device *dev;
+ base = mux_num_to_base(gsm); /* Base for this MUX */
+ for (i = 1; i < NUM_DLCI; i++) {
+ struct device *dev;
- dev = tty_register_device(gsm_tty_driver,
+ dev = tty_register_device(gsm_tty_driver,
base + i, NULL);
- if (IS_ERR(dev)) {
- for (i--; i >= 1; i--)
- tty_unregister_device(gsm_tty_driver,
- base + i);
- return PTR_ERR(dev);
- }
+ if (IS_ERR(dev)) {
+ for (i--; i >= 1; i--)
+ tty_unregister_device(gsm_tty_driver,
+ base + i);
+ return PTR_ERR(dev);
}
}
}
@@ -2485,10 +2430,8 @@ static void gsmld_detach_gsm(struct tty_struct *tty, struct gsm_mux *gsm)
int i;
WARN_ON(tty != gsm->tty);
- if (gsm->initiator) {
- for (i = 1; i < NUM_DLCI; i++)
- tty_unregister_device(gsm_tty_driver, base + i);
- }
+ for (i = 1; i < NUM_DLCI; i++)
+ tty_unregister_device(gsm_tty_driver, base + i);
tty_kref_put(gsm->tty);
gsm->tty = NULL;
}
The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 48473802506d2d6151f59e0e764932b33b53cb3b Mon Sep 17 00:00:00 2001
From: Daniel Starke <daniel.starke(a)siemens.com>
Date: Wed, 20 Apr 2022 03:13:44 -0700
Subject: [PATCH] tty: n_gsm: fix missing update of modem controls after DLCI
open
Currently the peer is not informed about the initial state of the modem
control lines after a new DLCI has been opened.
Fix this by sending the initial modem control line states after DLCI open.
Fixes: e1eaea46bb40 ("tty: n_gsm line discipline")
Cc: stable(a)vger.kernel.org
Signed-off-by: Daniel Starke <daniel.starke(a)siemens.com>
Link: https://lore.kernel.org/r/20220420101346.3315-1-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index e440c7f6d20e..979dc9151383 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -370,6 +370,7 @@ static const u8 gsm_fcs8[256] = {
#define GOOD_FCS 0xCF
static int gsmld_output(struct gsm_mux *gsm, u8 *data, int len);
+static int gsmtty_modem_update(struct gsm_dlci *dlci, u8 brk);
/**
* gsm_fcs_add - update FCS
@@ -1483,6 +1484,9 @@ static void gsm_dlci_open(struct gsm_dlci *dlci)
pr_debug("DLCI %d goes open.\n", dlci->addr);
/* Register gsmtty driver,report gsmtty dev add uevent for user */
tty_register_device(gsm_tty_driver, dlci->addr, NULL);
+ /* Send current modem state */
+ if (dlci->addr)
+ gsmtty_modem_update(dlci, 0);
wake_up(&dlci->gsm->event);
}
The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 48473802506d2d6151f59e0e764932b33b53cb3b Mon Sep 17 00:00:00 2001
From: Daniel Starke <daniel.starke(a)siemens.com>
Date: Wed, 20 Apr 2022 03:13:44 -0700
Subject: [PATCH] tty: n_gsm: fix missing update of modem controls after DLCI
open
Currently the peer is not informed about the initial state of the modem
control lines after a new DLCI has been opened.
Fix this by sending the initial modem control line states after DLCI open.
Fixes: e1eaea46bb40 ("tty: n_gsm line discipline")
Cc: stable(a)vger.kernel.org
Signed-off-by: Daniel Starke <daniel.starke(a)siemens.com>
Link: https://lore.kernel.org/r/20220420101346.3315-1-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index e440c7f6d20e..979dc9151383 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -370,6 +370,7 @@ static const u8 gsm_fcs8[256] = {
#define GOOD_FCS 0xCF
static int gsmld_output(struct gsm_mux *gsm, u8 *data, int len);
+static int gsmtty_modem_update(struct gsm_dlci *dlci, u8 brk);
/**
* gsm_fcs_add - update FCS
@@ -1483,6 +1484,9 @@ static void gsm_dlci_open(struct gsm_dlci *dlci)
pr_debug("DLCI %d goes open.\n", dlci->addr);
/* Register gsmtty driver,report gsmtty dev add uevent for user */
tty_register_device(gsm_tty_driver, dlci->addr, NULL);
+ /* Send current modem state */
+ if (dlci->addr)
+ gsmtty_modem_update(dlci, 0);
wake_up(&dlci->gsm->event);
}
The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 48473802506d2d6151f59e0e764932b33b53cb3b Mon Sep 17 00:00:00 2001
From: Daniel Starke <daniel.starke(a)siemens.com>
Date: Wed, 20 Apr 2022 03:13:44 -0700
Subject: [PATCH] tty: n_gsm: fix missing update of modem controls after DLCI
open
Currently the peer is not informed about the initial state of the modem
control lines after a new DLCI has been opened.
Fix this by sending the initial modem control line states after DLCI open.
Fixes: e1eaea46bb40 ("tty: n_gsm line discipline")
Cc: stable(a)vger.kernel.org
Signed-off-by: Daniel Starke <daniel.starke(a)siemens.com>
Link: https://lore.kernel.org/r/20220420101346.3315-1-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index e440c7f6d20e..979dc9151383 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -370,6 +370,7 @@ static const u8 gsm_fcs8[256] = {
#define GOOD_FCS 0xCF
static int gsmld_output(struct gsm_mux *gsm, u8 *data, int len);
+static int gsmtty_modem_update(struct gsm_dlci *dlci, u8 brk);
/**
* gsm_fcs_add - update FCS
@@ -1483,6 +1484,9 @@ static void gsm_dlci_open(struct gsm_dlci *dlci)
pr_debug("DLCI %d goes open.\n", dlci->addr);
/* Register gsmtty driver,report gsmtty dev add uevent for user */
tty_register_device(gsm_tty_driver, dlci->addr, NULL);
+ /* Send current modem state */
+ if (dlci->addr)
+ gsmtty_modem_update(dlci, 0);
wake_up(&dlci->gsm->event);
}
The patch below does not apply to the 5.10-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 48473802506d2d6151f59e0e764932b33b53cb3b Mon Sep 17 00:00:00 2001
From: Daniel Starke <daniel.starke(a)siemens.com>
Date: Wed, 20 Apr 2022 03:13:44 -0700
Subject: [PATCH] tty: n_gsm: fix missing update of modem controls after DLCI
open
Currently the peer is not informed about the initial state of the modem
control lines after a new DLCI has been opened.
Fix this by sending the initial modem control line states after DLCI open.
Fixes: e1eaea46bb40 ("tty: n_gsm line discipline")
Cc: stable(a)vger.kernel.org
Signed-off-by: Daniel Starke <daniel.starke(a)siemens.com>
Link: https://lore.kernel.org/r/20220420101346.3315-1-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index e440c7f6d20e..979dc9151383 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -370,6 +370,7 @@ static const u8 gsm_fcs8[256] = {
#define GOOD_FCS 0xCF
static int gsmld_output(struct gsm_mux *gsm, u8 *data, int len);
+static int gsmtty_modem_update(struct gsm_dlci *dlci, u8 brk);
/**
* gsm_fcs_add - update FCS
@@ -1483,6 +1484,9 @@ static void gsm_dlci_open(struct gsm_dlci *dlci)
pr_debug("DLCI %d goes open.\n", dlci->addr);
/* Register gsmtty driver,report gsmtty dev add uevent for user */
tty_register_device(gsm_tty_driver, dlci->addr, NULL);
+ /* Send current modem state */
+ if (dlci->addr)
+ gsmtty_modem_update(dlci, 0);
wake_up(&dlci->gsm->event);
}
The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 48473802506d2d6151f59e0e764932b33b53cb3b Mon Sep 17 00:00:00 2001
From: Daniel Starke <daniel.starke(a)siemens.com>
Date: Wed, 20 Apr 2022 03:13:44 -0700
Subject: [PATCH] tty: n_gsm: fix missing update of modem controls after DLCI
open
Currently the peer is not informed about the initial state of the modem
control lines after a new DLCI has been opened.
Fix this by sending the initial modem control line states after DLCI open.
Fixes: e1eaea46bb40 ("tty: n_gsm line discipline")
Cc: stable(a)vger.kernel.org
Signed-off-by: Daniel Starke <daniel.starke(a)siemens.com>
Link: https://lore.kernel.org/r/20220420101346.3315-1-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index e440c7f6d20e..979dc9151383 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -370,6 +370,7 @@ static const u8 gsm_fcs8[256] = {
#define GOOD_FCS 0xCF
static int gsmld_output(struct gsm_mux *gsm, u8 *data, int len);
+static int gsmtty_modem_update(struct gsm_dlci *dlci, u8 brk);
/**
* gsm_fcs_add - update FCS
@@ -1483,6 +1484,9 @@ static void gsm_dlci_open(struct gsm_dlci *dlci)
pr_debug("DLCI %d goes open.\n", dlci->addr);
/* Register gsmtty driver,report gsmtty dev add uevent for user */
tty_register_device(gsm_tty_driver, dlci->addr, NULL);
+ /* Send current modem state */
+ if (dlci->addr)
+ gsmtty_modem_update(dlci, 0);
wake_up(&dlci->gsm->event);
}
The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 48473802506d2d6151f59e0e764932b33b53cb3b Mon Sep 17 00:00:00 2001
From: Daniel Starke <daniel.starke(a)siemens.com>
Date: Wed, 20 Apr 2022 03:13:44 -0700
Subject: [PATCH] tty: n_gsm: fix missing update of modem controls after DLCI
open
Currently the peer is not informed about the initial state of the modem
control lines after a new DLCI has been opened.
Fix this by sending the initial modem control line states after DLCI open.
Fixes: e1eaea46bb40 ("tty: n_gsm line discipline")
Cc: stable(a)vger.kernel.org
Signed-off-by: Daniel Starke <daniel.starke(a)siemens.com>
Link: https://lore.kernel.org/r/20220420101346.3315-1-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index e440c7f6d20e..979dc9151383 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -370,6 +370,7 @@ static const u8 gsm_fcs8[256] = {
#define GOOD_FCS 0xCF
static int gsmld_output(struct gsm_mux *gsm, u8 *data, int len);
+static int gsmtty_modem_update(struct gsm_dlci *dlci, u8 brk);
/**
* gsm_fcs_add - update FCS
@@ -1483,6 +1484,9 @@ static void gsm_dlci_open(struct gsm_dlci *dlci)
pr_debug("DLCI %d goes open.\n", dlci->addr);
/* Register gsmtty driver,report gsmtty dev add uevent for user */
tty_register_device(gsm_tty_driver, dlci->addr, NULL);
+ /* Send current modem state */
+ if (dlci->addr)
+ gsmtty_modem_update(dlci, 0);
wake_up(&dlci->gsm->event);
}
The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 73029a4d7161f8b6c0934553145ef574d2d0c645 Mon Sep 17 00:00:00 2001
From: Daniel Starke <daniel.starke(a)siemens.com>
Date: Thu, 14 Apr 2022 02:42:22 -0700
Subject: [PATCH] tty: n_gsm: fix reset fifo race condition
gsmtty_write() and gsm_dlci_data_output() properly guard the fifo access.
However, gsm_dlci_close() and gsmtty_flush_buffer() modifies the fifo but
do not guard this.
Add a guard here to prevent race conditions on parallel writes to the fifo.
Fixes: e1eaea46bb40 ("tty: n_gsm line discipline")
Cc: stable(a)vger.kernel.org
Signed-off-by: Daniel Starke <daniel.starke(a)siemens.com>
Link: https://lore.kernel.org/r/20220414094225.4527-17-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index f3fb66be8513..15be4a235783 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -1442,13 +1442,17 @@ static int gsm_control_wait(struct gsm_mux *gsm, struct gsm_control *control)
static void gsm_dlci_close(struct gsm_dlci *dlci)
{
+ unsigned long flags;
+
del_timer(&dlci->t1);
if (debug & 8)
pr_debug("DLCI %d goes closed.\n", dlci->addr);
dlci->state = DLCI_CLOSED;
if (dlci->addr != 0) {
tty_port_tty_hangup(&dlci->port, false);
+ spin_lock_irqsave(&dlci->lock, flags);
kfifo_reset(&dlci->fifo);
+ spin_unlock_irqrestore(&dlci->lock, flags);
/* Ensure that gsmtty_open() can return. */
tty_port_set_initialized(&dlci->port, 0);
wake_up_interruptible(&dlci->port.open_wait);
@@ -3148,13 +3152,17 @@ static unsigned int gsmtty_chars_in_buffer(struct tty_struct *tty)
static void gsmtty_flush_buffer(struct tty_struct *tty)
{
struct gsm_dlci *dlci = tty->driver_data;
+ unsigned long flags;
+
if (dlci->state == DLCI_CLOSED)
return;
/* Caution needed: If we implement reliable transport classes
then the data being transmitted can't simply be junked once
it has first hit the stack. Until then we can just blow it
away */
+ spin_lock_irqsave(&dlci->lock, flags);
kfifo_reset(&dlci->fifo);
+ spin_unlock_irqrestore(&dlci->lock, flags);
/* Need to unhook this DLCI from the transmit queue logic */
}
The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 73029a4d7161f8b6c0934553145ef574d2d0c645 Mon Sep 17 00:00:00 2001
From: Daniel Starke <daniel.starke(a)siemens.com>
Date: Thu, 14 Apr 2022 02:42:22 -0700
Subject: [PATCH] tty: n_gsm: fix reset fifo race condition
gsmtty_write() and gsm_dlci_data_output() properly guard the fifo access.
However, gsm_dlci_close() and gsmtty_flush_buffer() modifies the fifo but
do not guard this.
Add a guard here to prevent race conditions on parallel writes to the fifo.
Fixes: e1eaea46bb40 ("tty: n_gsm line discipline")
Cc: stable(a)vger.kernel.org
Signed-off-by: Daniel Starke <daniel.starke(a)siemens.com>
Link: https://lore.kernel.org/r/20220414094225.4527-17-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index f3fb66be8513..15be4a235783 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -1442,13 +1442,17 @@ static int gsm_control_wait(struct gsm_mux *gsm, struct gsm_control *control)
static void gsm_dlci_close(struct gsm_dlci *dlci)
{
+ unsigned long flags;
+
del_timer(&dlci->t1);
if (debug & 8)
pr_debug("DLCI %d goes closed.\n", dlci->addr);
dlci->state = DLCI_CLOSED;
if (dlci->addr != 0) {
tty_port_tty_hangup(&dlci->port, false);
+ spin_lock_irqsave(&dlci->lock, flags);
kfifo_reset(&dlci->fifo);
+ spin_unlock_irqrestore(&dlci->lock, flags);
/* Ensure that gsmtty_open() can return. */
tty_port_set_initialized(&dlci->port, 0);
wake_up_interruptible(&dlci->port.open_wait);
@@ -3148,13 +3152,17 @@ static unsigned int gsmtty_chars_in_buffer(struct tty_struct *tty)
static void gsmtty_flush_buffer(struct tty_struct *tty)
{
struct gsm_dlci *dlci = tty->driver_data;
+ unsigned long flags;
+
if (dlci->state == DLCI_CLOSED)
return;
/* Caution needed: If we implement reliable transport classes
then the data being transmitted can't simply be junked once
it has first hit the stack. Until then we can just blow it
away */
+ spin_lock_irqsave(&dlci->lock, flags);
kfifo_reset(&dlci->fifo);
+ spin_unlock_irqrestore(&dlci->lock, flags);
/* Need to unhook this DLCI from the transmit queue logic */
}