startup()/shutdown() callbacks access SIFIVE_SERIAL_IE_OFFS. The register is also accessed from write() callback.
If console were printing and startup()/shutdown() callback gets called, its access to the register could be overwritten.
Add port->lock to startup()/shutdown() callbacks to make sure their access to SIFIVE_SERIAL_IE_OFFS is synchronized against write() callback.
Signed-off-by: Ryo Takakura ryotkkr98@gmail.com --- drivers/tty/serial/sifive.c | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/drivers/tty/serial/sifive.c b/drivers/tty/serial/sifive.c index 5904a2d4c..054a8e630 100644 --- a/drivers/tty/serial/sifive.c +++ b/drivers/tty/serial/sifive.c @@ -563,8 +563,11 @@ static void sifive_serial_break_ctl(struct uart_port *port, int break_state) static int sifive_serial_startup(struct uart_port *port) { struct sifive_serial_port *ssp = port_to_sifive_serial_port(port); + unsigned long flags;
+ uart_port_lock_irqsave(&ssp->port, &flags); __ssp_enable_rxwm(ssp); + uart_port_unlock_irqrestore(&ssp->port, flags);
return 0; } @@ -572,9 +575,12 @@ static int sifive_serial_startup(struct uart_port *port) static void sifive_serial_shutdown(struct uart_port *port) { struct sifive_serial_port *ssp = port_to_sifive_serial_port(port); + unsigned long flags;
+ uart_port_lock_irqsave(&ssp->port, &flags); __ssp_disable_rxwm(ssp); __ssp_disable_txwm(ssp); + uart_port_unlock_irqrestore(&ssp->port, flags); }
/**
Hi,
Thanks for your patch.
FYI: kernel test robot notices the stable kernel rule is not satisfied.
The check is based on https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html#opti...
Rule: add the tag "Cc: stable@vger.kernel.org" in the sign-off area to have the patch automatically included in the stable tree. Subject: [PATCH v2 1/2] serial: sifive: lock port in startup()/shutdown() callbacks Link: https://lore.kernel.org/stable/20250330003522.386632-1-ryotkkr98%40gmail.com
startup()/shutdown() callbacks access SIFIVE_SERIAL_IE_OFFS. The register is also accessed from write() callback.
If console were printing and startup()/shutdown() callback gets called, its access to the register could be overwritten.
Add port->lock to startup()/shutdown() callbacks to make sure their access to SIFIVE_SERIAL_IE_OFFS is synchronized against write() callback.
Signed-off-by: Ryo Takakura ryotkkr98@gmail.com Cc: stable@vger.kernel.org ---
Hi,
I'm sorry that I wasn't aware of how Cc stable should be done.
I added Cc for stable but please tell me if this patch should be resent or if there is any that is missing.
Sincerely, Ryo Takakura
--- drivers/tty/serial/sifive.c | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/drivers/tty/serial/sifive.c b/drivers/tty/serial/sifive.c index 5904a2d4c..054a8e630 100644 --- a/drivers/tty/serial/sifive.c +++ b/drivers/tty/serial/sifive.c @@ -563,8 +563,11 @@ static void sifive_serial_break_ctl(struct uart_port *port, int break_state) static int sifive_serial_startup(struct uart_port *port) { struct sifive_serial_port *ssp = port_to_sifive_serial_port(port); + unsigned long flags;
+ uart_port_lock_irqsave(&ssp->port, &flags); __ssp_enable_rxwm(ssp); + uart_port_unlock_irqrestore(&ssp->port, flags);
return 0; } @@ -572,9 +575,12 @@ static int sifive_serial_startup(struct uart_port *port) static void sifive_serial_shutdown(struct uart_port *port) { struct sifive_serial_port *ssp = port_to_sifive_serial_port(port); + unsigned long flags;
+ uart_port_lock_irqsave(&ssp->port, &flags); __ssp_disable_rxwm(ssp); __ssp_disable_txwm(ssp); + uart_port_unlock_irqrestore(&ssp->port, flags); }
/**
On Sun, Mar 30, 2025 at 10:16:10AM +0900, Ryo Takakura wrote:
startup()/shutdown() callbacks access SIFIVE_SERIAL_IE_OFFS. The register is also accessed from write() callback.
If console were printing and startup()/shutdown() callback gets called, its access to the register could be overwritten.
Add port->lock to startup()/shutdown() callbacks to make sure their access to SIFIVE_SERIAL_IE_OFFS is synchronized against write() callback.
Signed-off-by: Ryo Takakura ryotkkr98@gmail.com Cc: stable@vger.kernel.org
Hi,
I'm sorry that I wasn't aware of how Cc stable should be done.
I added Cc for stable but please tell me if this patch should be resent or if there is any that is missing.
Please resend a v3.
thanks,
greg k-h
Hi Greg,
On Sun, 30 Mar 2025 09:30:27 +0200, Greg KH wrote:
On Sun, Mar 30, 2025 at 10:16:10AM +0900, Ryo Takakura wrote:
startup()/shutdown() callbacks access SIFIVE_SERIAL_IE_OFFS. The register is also accessed from write() callback.
If console were printing and startup()/shutdown() callback gets called, its access to the register could be overwritten.
Add port->lock to startup()/shutdown() callbacks to make sure their access to SIFIVE_SERIAL_IE_OFFS is synchronized against write() callback.
Signed-off-by: Ryo Takakura ryotkkr98@gmail.com Cc: stable@vger.kernel.org
Hi,
I'm sorry that I wasn't aware of how Cc stable should be done.
I added Cc for stable but please tell me if this patch should be resent or if there is any that is missing.
Please resend a v3.
Ok. I'll send v3 shortly ;)
Sincerely, Ryo Takakura
thanks,
greg k-h
linux-stable-mirror@lists.linaro.org
-
Greg KH -
kernel test robot -
Ryo Takakura