From: Ryo Takakura Date: Sat, 12 Apr 2025 00:18:47 +0000 (+0900) Subject: serial: sifive: lock port in startup()/shutdown() callbacks X-Git-Tag: v6.15-rc4~22^2 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e1ca3ff28ab1e2c1e70713ef3fa7943c725742c3;p=thirdparty%2Flinux.git serial: sifive: lock port in startup()/shutdown() callbacks 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 Reviewed-by: Petr Mladek Cc: stable@vger.kernel.org Reviewed-by: John Ogness Rule: add Link: https://lore.kernel.org/stable/20250330003522.386632-1-ryotkkr98%40gmail.com Link: https://lore.kernel.org/r/20250412001847.183221-1-ryotkkr98@gmail.com Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/tty/serial/sifive.c b/drivers/tty/serial/sifive.c index 5904a2d4cefa7..054a8e630acea 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); } /**