| Message ID | 20250412001847.183221-1-ryotkkr98@gmail.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v3] serial: sifive: lock port in startup()/shutdown() callbacks | expand |
| Context | Check | Description |
|---|---|---|
| bjorn/pre-ci_am | success | Success |
| bjorn/build-rv32-defconfig | success | build-rv32-defconfig |
| bjorn/build-rv64-clang-allmodconfig | success | build-rv64-clang-allmodconfig |
| bjorn/build-rv64-gcc-allmodconfig | success | build-rv64-gcc-allmodconfig |
| bjorn/build-rv64-nommu-k210-defconfig | success | build-rv64-nommu-k210-defconfig |
| bjorn/build-rv64-nommu-k210-virt | success | build-rv64-nommu-k210-virt |
| bjorn/checkpatch | success | checkpatch |
| bjorn/dtb-warn-rv64 | success | dtb-warn-rv64 |
| bjorn/header-inline | success | header-inline |
| bjorn/kdoc | success | kdoc |
| bjorn/module-param | success | module-param |
| bjorn/verify-fixes | success | verify-fixes |
| bjorn/verify-signedoff | success | verify-signedoff |
On 2025-04-12, Ryo Takakura <ryotkkr98@gmail.com> 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. > > Fixes: 45c054d0815b ("tty: serial: add driver for the SiFive UART") > Signed-off-by: Ryo Takakura <ryotkkr98@gmail.com> > Reviewed-by: Petr Mladek <pmladek@suse.com> Reviewed-by: John Ogness <john.ogness@linutronix.de>
On Tue, 15 Apr 2025 09:48:06 +0206, John Ogness wrote: >On 2025-04-12, Ryo Takakura <ryotkkr98@gmail.com> 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. >> >> Fixes: 45c054d0815b ("tty: serial: add driver for the SiFive UART") >> Signed-off-by: Ryo Takakura <ryotkkr98@gmail.com> >> Reviewed-by: Petr Mladek <pmladek@suse.com> > >Reviewed-by: John Ogness <john.ogness@linutronix.de> I'll add for v4, Thank you John! Sincerely, Ryo Takakura
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); } /**
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. Fixes: 45c054d0815b ("tty: serial: add driver for the SiFive UART") Signed-off-by: Ryo Takakura <ryotkkr98@gmail.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Cc: stable@vger.kernel.org --- Changes since v1: https://lore.kernel.org/all/20250405043833.397020-1-ryotkkr98@gmail.com/ - It was sent as part of series but resent as a single patch. Changes since v2: https://lore.kernel.org/linux-serial/20250405145354.492947-1-ryotkkr98@gmail.com/ - Add Reviewed-by by Petr. Thanks Petr for the review! --- drivers/tty/serial/sifive.c | 6 ++++++ 1 file changed, 6 insertions(+)