From: Fedor Pchelkin <[email protected]>
[ Upstream commit acdab4cb4ba7e5f94d2b422ebd7bf4bf68178fb2 ]
This reverts commit eb75efdec8dd0f01ac85c88feafa6e63b34a2521.
The above commit is reverted as the usage of tx_mutex seems not to solve
the problem described in eb75efdec8dd ("tty: n_gsm: avoid call of sleeping
functions from atomic context") and just moves the bug to another place.
Signed-off-by: Fedor Pchelkin <[email protected]>
Signed-off-by: Alexey Khoroshilov <[email protected]>
Reviewed-by: Daniel Starke <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
---
drivers/tty/n_gsm.c | 39 +++++++++++++++++++++------------------
1 file changed, 21 insertions(+), 18 deletions(-)
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index c91a3004931f..c2212f52a603 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -235,7 +235,7 @@ struct gsm_mux {
int old_c_iflag; /* termios c_iflag value before attach */
bool constipated; /* Asked by remote to shut up */
- struct mutex tx_mutex;
+ spinlock_t tx_lock;
unsigned int tx_bytes; /* TX data outstanding */
#define TX_THRESH_HI 8192
#define TX_THRESH_LO 2048
@@ -820,14 +820,15 @@ static void __gsm_data_queue(struct gsm_dlci *dlci, struct gsm_msg *msg)
*
* Add data to the transmit queue and try and get stuff moving
* out of the mux tty if not already doing so. Take the
- * the gsm tx mutex and dlci lock.
+ * the gsm tx lock and dlci lock.
*/
static void gsm_data_queue(struct gsm_dlci *dlci, struct gsm_msg *msg)
{
- mutex_lock(&dlci->gsm->tx_mutex);
+ unsigned long flags;
+ spin_lock_irqsave(&dlci->gsm->tx_lock, flags);
__gsm_data_queue(dlci, msg);
- mutex_unlock(&dlci->gsm->tx_mutex);
+ spin_unlock_irqrestore(&dlci->gsm->tx_lock, flags);
}
/**
@@ -839,7 +840,7 @@ static void gsm_data_queue(struct gsm_dlci *dlci, struct gsm_msg *msg)
* is data. Keep to the MRU of the mux. This path handles the usual tty
* interface which is a byte stream with optional modem data.
*
- * Caller must hold the tx_mutex of the mux.
+ * Caller must hold the tx_lock of the mux.
*/
static int gsm_dlci_data_output(struct gsm_mux *gsm, struct gsm_dlci *dlci)
@@ -902,7 +903,7 @@ static int gsm_dlci_data_output(struct gsm_mux *gsm, struct gsm_dlci *dlci)
* is data. Keep to the MRU of the mux. This path handles framed data
* queued as skbuffs to the DLCI.
*
- * Caller must hold the tx_mutex of the mux.
+ * Caller must hold the tx_lock of the mux.
*/
static int gsm_dlci_data_output_framed(struct gsm_mux *gsm,
@@ -918,7 +919,7 @@ static int gsm_dlci_data_output_framed(struct gsm_mux *gsm,
if (dlci->adaption == 4)
overhead = 1;
- /* dlci->skb is locked by tx_mutex */
+ /* dlci->skb is locked by tx_lock */
if (dlci->skb == NULL) {
dlci->skb = skb_dequeue_tail(&dlci->skb_list);
if (dlci->skb == NULL)
@@ -1018,12 +1019,13 @@ static void gsm_dlci_data_sweep(struct gsm_mux *gsm)
static void gsm_dlci_data_kick(struct gsm_dlci *dlci)
{
+ unsigned long flags;
int sweep;
if (dlci->constipated)
return;
- mutex_lock(&dlci->gsm->tx_mutex);
+ spin_lock_irqsave(&dlci->gsm->tx_lock, flags);
/* If we have nothing running then we need to fire up */
sweep = (dlci->gsm->tx_bytes < TX_THRESH_LO);
if (dlci->gsm->tx_bytes == 0) {
@@ -1034,7 +1036,7 @@ static void gsm_dlci_data_kick(struct gsm_dlci *dlci)
}
if (sweep)
gsm_dlci_data_sweep(dlci->gsm);
- mutex_unlock(&dlci->gsm->tx_mutex);
+ spin_unlock_irqrestore(&dlci->gsm->tx_lock, flags);
}
/*
@@ -1256,6 +1258,7 @@ static void gsm_control_message(struct gsm_mux *gsm, unsigned int command,
const u8 *data, int clen)
{
u8 buf[1];
+ unsigned long flags;
switch (command) {
case CMD_CLD: {
@@ -1277,9 +1280,9 @@ static void gsm_control_message(struct gsm_mux *gsm, unsigned int command,
gsm->constipated = false;
gsm_control_reply(gsm, CMD_FCON, NULL, 0);
/* Kick the link in case it is idling */
- mutex_lock(&gsm->tx_mutex);
+ spin_lock_irqsave(&gsm->tx_lock, flags);
gsm_data_kick(gsm, NULL);
- mutex_unlock(&gsm->tx_mutex);
+ spin_unlock_irqrestore(&gsm->tx_lock, flags);
break;
case CMD_FCOFF:
/* Modem wants us to STFU */
@@ -2225,7 +2228,6 @@ static void gsm_free_mux(struct gsm_mux *gsm)
break;
}
}
- mutex_destroy(&gsm->tx_mutex);
mutex_destroy(&gsm->mutex);
kfree(gsm->txframe);
kfree(gsm->buf);
@@ -2297,12 +2299,12 @@ static struct gsm_mux *gsm_alloc_mux(void)
}
spin_lock_init(&gsm->lock);
mutex_init(&gsm->mutex);
- mutex_init(&gsm->tx_mutex);
kref_init(&gsm->ref);
INIT_LIST_HEAD(&gsm->tx_list);
timer_setup(&gsm->t2_timer, gsm_control_retransmit, 0);
init_waitqueue_head(&gsm->event);
spin_lock_init(&gsm->control_lock);
+ spin_lock_init(&gsm->tx_lock);
gsm->t1 = T1;
gsm->t2 = T2;
@@ -2327,7 +2329,6 @@ static struct gsm_mux *gsm_alloc_mux(void)
}
spin_unlock(&gsm_mux_lock);
if (i == MAX_MUX) {
- mutex_destroy(&gsm->tx_mutex);
mutex_destroy(&gsm->mutex);
kfree(gsm->txframe);
kfree(gsm->buf);
@@ -2652,15 +2653,16 @@ static int gsmld_open(struct tty_struct *tty)
static void gsmld_write_wakeup(struct tty_struct *tty)
{
struct gsm_mux *gsm = tty->disc_data;
+ unsigned long flags;
/* Queue poll */
clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
- mutex_lock(&gsm->tx_mutex);
+ spin_lock_irqsave(&gsm->tx_lock, flags);
gsm_data_kick(gsm, NULL);
if (gsm->tx_bytes < TX_THRESH_LO) {
gsm_dlci_data_sweep(gsm);
}
- mutex_unlock(&gsm->tx_mutex);
+ spin_unlock_irqrestore(&gsm->tx_lock, flags);
}
/**
@@ -2703,6 +2705,7 @@ static ssize_t gsmld_write(struct tty_struct *tty, struct file *file,
const unsigned char *buf, size_t nr)
{
struct gsm_mux *gsm = tty->disc_data;
+ unsigned long flags;
int space;
int ret;
@@ -2710,13 +2713,13 @@ static ssize_t gsmld_write(struct tty_struct *tty, struct file *file,
return -ENODEV;
ret = -ENOBUFS;
- mutex_lock(&gsm->tx_mutex);
+ spin_lock_irqsave(&gsm->tx_lock, flags);
space = tty_write_room(tty);
if (space >= nr)
ret = tty->ops->write(tty, buf, nr);
else
set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
- mutex_unlock(&gsm->tx_mutex);
+ spin_unlock_irqrestore(&gsm->tx_lock, flags);
return ret;
}
--
2.38.1
On Wed 2022-11-23 21:19:16, Fedor Pchelkin wrote:
> From: Fedor Pchelkin <[email protected]>
>
> [ Upstream commit acdab4cb4ba7e5f94d2b422ebd7bf4bf68178fb2 ]
>
> This reverts commit eb75efdec8dd0f01ac85c88feafa6e63b34a2521.
>
> The above commit is reverted as the usage of tx_mutex seems not to solve
> the problem described in eb75efdec8dd ("tty: n_gsm: avoid call of sleeping
> functions from atomic context") and just moves the bug to another place.
>
> Signed-off-by: Fedor Pchelkin <[email protected]>
> Signed-off-by: Alexey Khoroshilov <[email protected]>
> Reviewed-by: Daniel Starke <[email protected]>
> Link:
https://lore.kernel.org/r/[email protected]
Reviewed-by: Pavel Machek <[email protected]>
--
People of Russia, stop Putin before his war on Ukraine escalates.
On Wed, Nov 23, 2022 at 09:19:16PM +0300, Fedor Pchelkin wrote:
> From: Fedor Pchelkin <[email protected]>
>
> [ Upstream commit acdab4cb4ba7e5f94d2b422ebd7bf4bf68178fb2 ]
>
> This reverts commit eb75efdec8dd0f01ac85c88feafa6e63b34a2521.
>
> The above commit is reverted as the usage of tx_mutex seems not to solve
> the problem described in eb75efdec8dd ("tty: n_gsm: avoid call of sleeping
> functions from atomic context") and just moves the bug to another place.
>
> Signed-off-by: Fedor Pchelkin <[email protected]>
> Signed-off-by: Alexey Khoroshilov <[email protected]>
> Reviewed-by: Daniel Starke <[email protected]>
> Link: https://lore.kernel.org/r/[email protected]
> ---
> drivers/tty/n_gsm.c | 39 +++++++++++++++++++++------------------
> 1 file changed, 21 insertions(+), 18 deletions(-)
Also, what happened to my original signed-off-by here?
thanks,
greg k-h
On Wed, Nov 23, 2022 at 09:19:16PM +0300, Fedor Pchelkin wrote:
> From: Fedor Pchelkin <[email protected]>
>
> [ Upstream commit acdab4cb4ba7e5f94d2b422ebd7bf4bf68178fb2 ]
>
> This reverts commit eb75efdec8dd0f01ac85c88feafa6e63b34a2521.
What about for 5.15? This should also be needed there, right?
thanks,
greg k-h
From: Fedor Pchelkin <[email protected]>
[ Upstream commit acdab4cb4ba7e5f94d2b422ebd7bf4bf68178fb2 ]
This reverts commit eb75efdec8dd0f01ac85c88feafa6e63b34a2521.
The above commit is reverted as the usage of tx_mutex seems not to solve
the problem described in eb75efdec8dd ("tty: n_gsm: avoid call of sleeping
functions from atomic context") and just moves the bug to another place.
Signed-off-by: Fedor Pchelkin <[email protected]>
Signed-off-by: Alexey Khoroshilov <[email protected]>
Reviewed-by: Daniel Starke <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Reviewed-by: Pavel Machek <[email protected]>
---
v1->v2: added signed-off-by and reviewed-by
drivers/tty/n_gsm.c | 39 +++++++++++++++++++++------------------
1 file changed, 21 insertions(+), 18 deletions(-)
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index c91a3004931f..c2212f52a603 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -235,7 +235,7 @@ struct gsm_mux {
int old_c_iflag; /* termios c_iflag value before attach */
bool constipated; /* Asked by remote to shut up */
- struct mutex tx_mutex;
+ spinlock_t tx_lock;
unsigned int tx_bytes; /* TX data outstanding */
#define TX_THRESH_HI 8192
#define TX_THRESH_LO 2048
@@ -820,14 +820,15 @@ static void __gsm_data_queue(struct gsm_dlci *dlci, struct gsm_msg *msg)
*
* Add data to the transmit queue and try and get stuff moving
* out of the mux tty if not already doing so. Take the
- * the gsm tx mutex and dlci lock.
+ * the gsm tx lock and dlci lock.
*/
static void gsm_data_queue(struct gsm_dlci *dlci, struct gsm_msg *msg)
{
- mutex_lock(&dlci->gsm->tx_mutex);
+ unsigned long flags;
+ spin_lock_irqsave(&dlci->gsm->tx_lock, flags);
__gsm_data_queue(dlci, msg);
- mutex_unlock(&dlci->gsm->tx_mutex);
+ spin_unlock_irqrestore(&dlci->gsm->tx_lock, flags);
}
/**
@@ -839,7 +840,7 @@ static void gsm_data_queue(struct gsm_dlci *dlci, struct gsm_msg *msg)
* is data. Keep to the MRU of the mux. This path handles the usual tty
* interface which is a byte stream with optional modem data.
*
- * Caller must hold the tx_mutex of the mux.
+ * Caller must hold the tx_lock of the mux.
*/
static int gsm_dlci_data_output(struct gsm_mux *gsm, struct gsm_dlci *dlci)
@@ -902,7 +903,7 @@ static int gsm_dlci_data_output(struct gsm_mux *gsm, struct gsm_dlci *dlci)
* is data. Keep to the MRU of the mux. This path handles framed data
* queued as skbuffs to the DLCI.
*
- * Caller must hold the tx_mutex of the mux.
+ * Caller must hold the tx_lock of the mux.
*/
static int gsm_dlci_data_output_framed(struct gsm_mux *gsm,
@@ -918,7 +919,7 @@ static int gsm_dlci_data_output_framed(struct gsm_mux *gsm,
if (dlci->adaption == 4)
overhead = 1;
- /* dlci->skb is locked by tx_mutex */
+ /* dlci->skb is locked by tx_lock */
if (dlci->skb == NULL) {
dlci->skb = skb_dequeue_tail(&dlci->skb_list);
if (dlci->skb == NULL)
@@ -1018,12 +1019,13 @@ static void gsm_dlci_data_sweep(struct gsm_mux *gsm)
static void gsm_dlci_data_kick(struct gsm_dlci *dlci)
{
+ unsigned long flags;
int sweep;
if (dlci->constipated)
return;
- mutex_lock(&dlci->gsm->tx_mutex);
+ spin_lock_irqsave(&dlci->gsm->tx_lock, flags);
/* If we have nothing running then we need to fire up */
sweep = (dlci->gsm->tx_bytes < TX_THRESH_LO);
if (dlci->gsm->tx_bytes == 0) {
@@ -1034,7 +1036,7 @@ static void gsm_dlci_data_kick(struct gsm_dlci *dlci)
}
if (sweep)
gsm_dlci_data_sweep(dlci->gsm);
- mutex_unlock(&dlci->gsm->tx_mutex);
+ spin_unlock_irqrestore(&dlci->gsm->tx_lock, flags);
}
/*
@@ -1256,6 +1258,7 @@ static void gsm_control_message(struct gsm_mux *gsm, unsigned int command,
const u8 *data, int clen)
{
u8 buf[1];
+ unsigned long flags;
switch (command) {
case CMD_CLD: {
@@ -1277,9 +1280,9 @@ static void gsm_control_message(struct gsm_mux *gsm, unsigned int command,
gsm->constipated = false;
gsm_control_reply(gsm, CMD_FCON, NULL, 0);
/* Kick the link in case it is idling */
- mutex_lock(&gsm->tx_mutex);
+ spin_lock_irqsave(&gsm->tx_lock, flags);
gsm_data_kick(gsm, NULL);
- mutex_unlock(&gsm->tx_mutex);
+ spin_unlock_irqrestore(&gsm->tx_lock, flags);
break;
case CMD_FCOFF:
/* Modem wants us to STFU */
@@ -2225,7 +2228,6 @@ static void gsm_free_mux(struct gsm_mux *gsm)
break;
}
}
- mutex_destroy(&gsm->tx_mutex);
mutex_destroy(&gsm->mutex);
kfree(gsm->txframe);
kfree(gsm->buf);
@@ -2297,12 +2299,12 @@ static struct gsm_mux *gsm_alloc_mux(void)
}
spin_lock_init(&gsm->lock);
mutex_init(&gsm->mutex);
- mutex_init(&gsm->tx_mutex);
kref_init(&gsm->ref);
INIT_LIST_HEAD(&gsm->tx_list);
timer_setup(&gsm->t2_timer, gsm_control_retransmit, 0);
init_waitqueue_head(&gsm->event);
spin_lock_init(&gsm->control_lock);
+ spin_lock_init(&gsm->tx_lock);
gsm->t1 = T1;
gsm->t2 = T2;
@@ -2327,7 +2329,6 @@ static struct gsm_mux *gsm_alloc_mux(void)
}
spin_unlock(&gsm_mux_lock);
if (i == MAX_MUX) {
- mutex_destroy(&gsm->tx_mutex);
mutex_destroy(&gsm->mutex);
kfree(gsm->txframe);
kfree(gsm->buf);
@@ -2652,15 +2653,16 @@ static int gsmld_open(struct tty_struct *tty)
static void gsmld_write_wakeup(struct tty_struct *tty)
{
struct gsm_mux *gsm = tty->disc_data;
+ unsigned long flags;
/* Queue poll */
clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
- mutex_lock(&gsm->tx_mutex);
+ spin_lock_irqsave(&gsm->tx_lock, flags);
gsm_data_kick(gsm, NULL);
if (gsm->tx_bytes < TX_THRESH_LO) {
gsm_dlci_data_sweep(gsm);
}
- mutex_unlock(&gsm->tx_mutex);
+ spin_unlock_irqrestore(&gsm->tx_lock, flags);
}
/**
@@ -2703,6 +2705,7 @@ static ssize_t gsmld_write(struct tty_struct *tty, struct file *file,
const unsigned char *buf, size_t nr)
{
struct gsm_mux *gsm = tty->disc_data;
+ unsigned long flags;
int space;
int ret;
@@ -2710,13 +2713,13 @@ static ssize_t gsmld_write(struct tty_struct *tty, struct file *file,
return -ENODEV;
ret = -ENOBUFS;
- mutex_lock(&gsm->tx_mutex);
+ spin_lock_irqsave(&gsm->tx_lock, flags);
space = tty_write_room(tty);
if (space >= nr)
ret = tty->ops->write(tty, buf, nr);
else
set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
- mutex_unlock(&gsm->tx_mutex);
+ spin_unlock_irqrestore(&gsm->tx_lock, flags);
return ret;
}
--
2.38.1
Thanks for notice, n_gsm tx_mutex patches just were added to 5.19, not
5.15, so we need to revert them.
I'm sorry for the inconvenience with 5.10 revert patch, fixed that in
the corresponding thread.
From: Fedor Pchelkin <[email protected]>
[ Upstream commit acdab4cb4ba7e5f94d2b422ebd7bf4bf68178fb2 ]
This reverts commit 132331c1f605eb5911795a6b9115114575594d0a.
The above commit is reverted as the usage of tx_mutex seems not to solve
the problem described in 132331c1f605 ("tty: n_gsm: avoid call of sleeping
functions from atomic context") and just moves the bug to another place.
Signed-off-by: Fedor Pchelkin <[email protected]>
Signed-off-by: Alexey Khoroshilov <[email protected]>
Reviewed-by: Daniel Starke <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/tty/n_gsm.c | 53 +++++++++++++++++++++++++--------------------
1 file changed, 29 insertions(+), 24 deletions(-)
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 01c112e2e214..e23225aff5d9 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -248,7 +248,7 @@ struct gsm_mux {
bool constipated; /* Asked by remote to shut up */
bool has_devices; /* Devices were registered */
- struct mutex tx_mutex;
+ spinlock_t tx_lock;
unsigned int tx_bytes; /* TX data outstanding */
#define TX_THRESH_HI 8192
#define TX_THRESH_LO 2048
@@ -680,6 +680,7 @@ static int gsm_send(struct gsm_mux *gsm, int addr, int cr, int control)
struct gsm_msg *msg;
u8 *dp;
int ocr;
+ unsigned long flags;
msg = gsm_data_alloc(gsm, addr, 0, control);
if (!msg)
@@ -701,10 +702,10 @@ static int gsm_send(struct gsm_mux *gsm, int addr, int cr, int control)
gsm_print_packet("Q->", addr, cr, control, NULL, 0);
- mutex_lock(&gsm->tx_mutex);
+ spin_lock_irqsave(&gsm->tx_lock, flags);
list_add_tail(&msg->list, &gsm->tx_ctrl_list);
gsm->tx_bytes += msg->len;
- mutex_unlock(&gsm->tx_mutex);
+ spin_unlock_irqrestore(&gsm->tx_lock, flags);
gsmld_write_trigger(gsm);
return 0;
@@ -729,7 +730,7 @@ static void gsm_dlci_clear_queues(struct gsm_mux *gsm, struct gsm_dlci *dlci)
spin_unlock_irqrestore(&dlci->lock, flags);
/* Clear data packets in MUX write queue */
- mutex_lock(&gsm->tx_mutex);
+ spin_lock_irqsave(&gsm->tx_lock, flags);
list_for_each_entry_safe(msg, nmsg, &gsm->tx_data_list, list) {
if (msg->addr != addr)
continue;
@@ -737,7 +738,7 @@ static void gsm_dlci_clear_queues(struct gsm_mux *gsm, struct gsm_dlci *dlci)
list_del(&msg->list);
kfree(msg);
}
- mutex_unlock(&gsm->tx_mutex);
+ spin_unlock_irqrestore(&gsm->tx_lock, flags);
}
/**
@@ -1023,9 +1024,10 @@ static void __gsm_data_queue(struct gsm_dlci *dlci, struct gsm_msg *msg)
static void gsm_data_queue(struct gsm_dlci *dlci, struct gsm_msg *msg)
{
- mutex_lock(&dlci->gsm->tx_mutex);
+ unsigned long flags;
+ spin_lock_irqsave(&dlci->gsm->tx_lock, flags);
__gsm_data_queue(dlci, msg);
- mutex_unlock(&dlci->gsm->tx_mutex);
+ spin_unlock_irqrestore(&dlci->gsm->tx_lock, flags);
}
/**
@@ -1037,7 +1039,7 @@ static void gsm_data_queue(struct gsm_dlci *dlci, struct gsm_msg *msg)
* is data. Keep to the MRU of the mux. This path handles the usual tty
* interface which is a byte stream with optional modem data.
*
- * Caller must hold the tx_mutex of the mux.
+ * Caller must hold the tx_lock of the mux.
*/
static int gsm_dlci_data_output(struct gsm_mux *gsm, struct gsm_dlci *dlci)
@@ -1097,7 +1099,7 @@ static int gsm_dlci_data_output(struct gsm_mux *gsm, struct gsm_dlci *dlci)
* is data. Keep to the MRU of the mux. This path handles framed data
* queued as skbuffs to the DLCI.
*
- * Caller must hold the tx_mutex of the mux.
+ * Caller must hold the tx_lock of the mux.
*/
static int gsm_dlci_data_output_framed(struct gsm_mux *gsm,
@@ -1113,7 +1115,7 @@ static int gsm_dlci_data_output_framed(struct gsm_mux *gsm,
if (dlci->adaption == 4)
overhead = 1;
- /* dlci->skb is locked by tx_mutex */
+ /* dlci->skb is locked by tx_lock */
if (dlci->skb == NULL) {
dlci->skb = skb_dequeue_tail(&dlci->skb_list);
if (dlci->skb == NULL)
@@ -1167,7 +1169,7 @@ static int gsm_dlci_data_output_framed(struct gsm_mux *gsm,
* Push an empty frame in to the transmit queue to update the modem status
* bits and to transmit an optional break.
*
- * Caller must hold the tx_mutex of the mux.
+ * Caller must hold the tx_lock of the mux.
*/
static int gsm_dlci_modem_output(struct gsm_mux *gsm, struct gsm_dlci *dlci,
@@ -1281,12 +1283,13 @@ static int gsm_dlci_data_sweep(struct gsm_mux *gsm)
static void gsm_dlci_data_kick(struct gsm_dlci *dlci)
{
+ unsigned long flags;
int sweep;
if (dlci->constipated)
return;
- mutex_lock(&dlci->gsm->tx_mutex);
+ spin_lock_irqsave(&dlci->gsm->tx_lock, flags);
/* If we have nothing running then we need to fire up */
sweep = (dlci->gsm->tx_bytes < TX_THRESH_LO);
if (dlci->gsm->tx_bytes == 0) {
@@ -1297,7 +1300,7 @@ static void gsm_dlci_data_kick(struct gsm_dlci *dlci)
}
if (sweep)
gsm_dlci_data_sweep(dlci->gsm);
- mutex_unlock(&dlci->gsm->tx_mutex);
+ spin_unlock_irqrestore(&dlci->gsm->tx_lock, flags);
}
/*
@@ -1991,13 +1994,14 @@ static void gsm_dlci_command(struct gsm_dlci *dlci, const u8 *data, int len)
static void gsm_kick_timeout(struct work_struct *work)
{
struct gsm_mux *gsm = container_of(work, struct gsm_mux, kick_timeout.work);
+ unsigned long flags;
int sent = 0;
- mutex_lock(&gsm->tx_mutex);
+ spin_lock_irqsave(&gsm->tx_lock, flags);
/* If we have nothing running then we need to fire up */
if (gsm->tx_bytes < TX_THRESH_LO)
sent = gsm_dlci_data_sweep(gsm);
- mutex_unlock(&gsm->tx_mutex);
+ spin_unlock_irqrestore(&gsm->tx_lock, flags);
if (sent && debug & 4)
pr_info("%s TX queue stalled\n", __func__);
@@ -2527,7 +2531,6 @@ static void gsm_free_mux(struct gsm_mux *gsm)
break;
}
}
- mutex_destroy(&gsm->tx_mutex);
mutex_destroy(&gsm->mutex);
kfree(gsm->txframe);
kfree(gsm->buf);
@@ -2599,7 +2602,6 @@ static struct gsm_mux *gsm_alloc_mux(void)
}
spin_lock_init(&gsm->lock);
mutex_init(&gsm->mutex);
- mutex_init(&gsm->tx_mutex);
kref_init(&gsm->ref);
INIT_LIST_HEAD(&gsm->tx_ctrl_list);
INIT_LIST_HEAD(&gsm->tx_data_list);
@@ -2608,6 +2610,7 @@ static struct gsm_mux *gsm_alloc_mux(void)
INIT_WORK(&gsm->tx_work, gsmld_write_task);
init_waitqueue_head(&gsm->event);
spin_lock_init(&gsm->control_lock);
+ spin_lock_init(&gsm->tx_lock);
gsm->t1 = T1;
gsm->t2 = T2;
@@ -2632,7 +2635,6 @@ static struct gsm_mux *gsm_alloc_mux(void)
}
spin_unlock(&gsm_mux_lock);
if (i == MAX_MUX) {
- mutex_destroy(&gsm->tx_mutex);
mutex_destroy(&gsm->mutex);
kfree(gsm->txframe);
kfree(gsm->buf);
@@ -2788,16 +2790,17 @@ static void gsmld_write_trigger(struct gsm_mux *gsm)
static void gsmld_write_task(struct work_struct *work)
{
struct gsm_mux *gsm = container_of(work, struct gsm_mux, tx_work);
+ unsigned long flags;
int i, ret;
/* All outstanding control channel and control messages and one data
* frame is sent.
*/
ret = -ENODEV;
- mutex_lock(&gsm->tx_mutex);
+ spin_lock_irqsave(&gsm->tx_lock, flags);
if (gsm->tty)
ret = gsm_data_kick(gsm);
- mutex_unlock(&gsm->tx_mutex);
+ spin_unlock_irqrestore(&gsm->tx_lock, flags);
if (ret >= 0)
for (i = 0; i < NUM_DLCI; i++)
@@ -3005,6 +3008,7 @@ static ssize_t gsmld_write(struct tty_struct *tty, struct file *file,
const unsigned char *buf, size_t nr)
{
struct gsm_mux *gsm = tty->disc_data;
+ unsigned long flags;
int space;
int ret;
@@ -3012,13 +3016,13 @@ static ssize_t gsmld_write(struct tty_struct *tty, struct file *file,
return -ENODEV;
ret = -ENOBUFS;
- mutex_lock(&gsm->tx_mutex);
+ spin_lock_irqsave(&gsm->tx_lock, flags);
space = tty_write_room(tty);
if (space >= nr)
ret = tty->ops->write(tty, buf, nr);
else
set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
- mutex_unlock(&gsm->tx_mutex);
+ spin_unlock_irqrestore(&gsm->tx_lock, flags);
return ret;
}
@@ -3315,13 +3319,14 @@ static struct tty_ldisc_ops tty_ldisc_packet = {
static void gsm_modem_upd_via_data(struct gsm_dlci *dlci, u8 brk)
{
struct gsm_mux *gsm = dlci->gsm;
+ unsigned long flags;
if (dlci->state != DLCI_OPEN || dlci->adaption != 2)
return;
- mutex_lock(&gsm->tx_mutex);
+ spin_lock_irqsave(&gsm->tx_lock, flags);
gsm_dlci_modem_output(gsm, dlci, brk);
- mutex_unlock(&gsm->tx_mutex);
+ spin_unlock_irqrestore(&gsm->tx_lock, flags);
}
/**
--
2.38.1
From: Fedor Pchelkin <[email protected]>
[ Upstream commit 15743ae50e04aa907131e3ae8d66e9a2964ea232 ]
This reverts commit 2af54fe4f713d5f29e1520d7780112ff9b6121be.
The above commit is reverted as it was a prerequisite for tx_mutex
introduction and tx_mutex has been removed as it does not correctly
work in order to protect tx data.
Signed-off-by: Fedor Pchelkin <[email protected]>
Signed-off-by: Alexey Khoroshilov <[email protected]>
Reviewed-by: Daniel Starke <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/tty/n_gsm.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index e23225aff5d9..d6598ca3640f 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -256,7 +256,7 @@ struct gsm_mux {
struct list_head tx_data_list; /* Pending data packets */
/* Control messages */
- struct delayed_work kick_timeout; /* Kick TX queuing on timeout */
+ struct timer_list kick_timer; /* Kick TX queuing on timeout */
struct timer_list t2_timer; /* Retransmit timer for commands */
int cretries; /* Command retry counter */
struct gsm_control *pending_cmd;/* Our current pending command */
@@ -1009,7 +1009,7 @@ static void __gsm_data_queue(struct gsm_dlci *dlci, struct gsm_msg *msg)
gsm->tx_bytes += msg->len;
gsmld_write_trigger(gsm);
- schedule_delayed_work(&gsm->kick_timeout, 10 * gsm->t1 * HZ / 100);
+ mod_timer(&gsm->kick_timer, jiffies + 10 * gsm->t1 * HZ / 100);
}
/**
@@ -1984,16 +1984,16 @@ static void gsm_dlci_command(struct gsm_dlci *dlci, const u8 *data, int len)
}
/**
- * gsm_kick_timeout - transmit if possible
- * @work: work contained in our gsm object
+ * gsm_kick_timer - transmit if possible
+ * @t: timer contained in our gsm object
*
* Transmit data from DLCIs if the queue is empty. We can't rely on
* a tty wakeup except when we filled the pipe so we need to fire off
* new data ourselves in other cases.
*/
-static void gsm_kick_timeout(struct work_struct *work)
+static void gsm_kick_timer(struct timer_list *t)
{
- struct gsm_mux *gsm = container_of(work, struct gsm_mux, kick_timeout.work);
+ struct gsm_mux *gsm = from_timer(gsm, t, kick_timer);
unsigned long flags;
int sent = 0;
@@ -2458,7 +2458,7 @@ static void gsm_cleanup_mux(struct gsm_mux *gsm, bool disc)
}
/* Finish outstanding timers, making sure they are done */
- cancel_delayed_work_sync(&gsm->kick_timeout);
+ del_timer_sync(&gsm->kick_timer);
del_timer_sync(&gsm->t2_timer);
/* Finish writing to ldisc */
@@ -2605,7 +2605,7 @@ static struct gsm_mux *gsm_alloc_mux(void)
kref_init(&gsm->ref);
INIT_LIST_HEAD(&gsm->tx_ctrl_list);
INIT_LIST_HEAD(&gsm->tx_data_list);
- INIT_DELAYED_WORK(&gsm->kick_timeout, gsm_kick_timeout);
+ timer_setup(&gsm->kick_timer, gsm_kick_timer, 0);
timer_setup(&gsm->t2_timer, gsm_control_retransmit, 0);
INIT_WORK(&gsm->tx_work, gsmld_write_task);
init_waitqueue_head(&gsm->event);
--
2.38.1
On Sun, Dec 04, 2022 at 01:35:24AM +0300, Fedor Pchelkin wrote:
> Thanks for notice, n_gsm tx_mutex patches just were added to 5.19, not
> 5.15, so we need to revert them.
5.19 is long end-of-life, there is nothing that we can do about that at
all.
greg k-h
On Sat, Dec 03, 2022 at 02:35:09PM +0100, Greg Kroah-Hartman wrote:
> On Wed, Nov 23, 2022 at 09:19:16PM +0300, Fedor Pchelkin wrote:
> > From: Fedor Pchelkin <[email protected]>
> >
> > [ Upstream commit acdab4cb4ba7e5f94d2b422ebd7bf4bf68178fb2 ]
> >
> > This reverts commit eb75efdec8dd0f01ac85c88feafa6e63b34a2521.
>
> What about for 5.15? This should also be needed there, right?
Odd, it never got applied to 5.15, so nevermind about that, sorry for
the noise.
greg k-h
On Sun, Dec 04, 2022 at 12:55:18AM +0300, Fedor Pchelkin wrote:
> From: Fedor Pchelkin <[email protected]>
>
> [ Upstream commit acdab4cb4ba7e5f94d2b422ebd7bf4bf68178fb2 ]
>
> This reverts commit eb75efdec8dd0f01ac85c88feafa6e63b34a2521.
>
> The above commit is reverted as the usage of tx_mutex seems not to solve
> the problem described in eb75efdec8dd ("tty: n_gsm: avoid call of sleeping
> functions from atomic context") and just moves the bug to another place.
>
> Signed-off-by: Fedor Pchelkin <[email protected]>
> Signed-off-by: Alexey Khoroshilov <[email protected]>
> Reviewed-by: Daniel Starke <[email protected]>
> Link: https://lore.kernel.org/r/[email protected]
> Signed-off-by: Greg Kroah-Hartman <[email protected]>
> Reviewed-by: Pavel Machek <[email protected]>
Now queued up, thanks.
greg k-h