From: Andy Shevchenko Date: Tue, 2 Apr 2024 19:50:28 +0000 (+0300) Subject: serial: max3100: Lock port->lock when calling uart_handle_cts_change() X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=77ab53371a2066fdf9b895246505f5ef5a4b5d47;p=linux.git serial: max3100: Lock port->lock when calling uart_handle_cts_change() uart_handle_cts_change() has to be called with port lock taken, Since we run it in a separate work, the lock may not be taken at the time of running. Make sure that it's taken by explicitly doing that. Without it we got a splat: WARNING: CPU: 0 PID: 10 at drivers/tty/serial/serial_core.c:3491 uart_handle_cts_change+0xa6/0xb0 ... Workqueue: max3100-0 max3100_work [max3100] RIP: 0010:uart_handle_cts_change+0xa6/0xb0 ... max3100_handlerx+0xc5/0x110 [max3100] max3100_work+0x12a/0x340 [max3100] Fixes: 7831d56b0a35 ("tty: MAX3100") Signed-off-by: Andy Shevchenko Link: https://lore.kernel.org/r/20240402195306.269276-2-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/tty/serial/max3100.c b/drivers/tty/serial/max3100.c index b83eee37c17d4..53dde3391abf4 100644 --- a/drivers/tty/serial/max3100.c +++ b/drivers/tty/serial/max3100.c @@ -213,7 +213,7 @@ static int max3100_sr(struct max3100_port *s, u16 tx, u16 *rx) return 0; } -static int max3100_handlerx(struct max3100_port *s, u16 rx) +static int max3100_handlerx_unlocked(struct max3100_port *s, u16 rx) { unsigned int status = 0; int ret = 0, cts; @@ -254,6 +254,17 @@ static int max3100_handlerx(struct max3100_port *s, u16 rx) return ret; } +static int max3100_handlerx(struct max3100_port *s, u16 rx) +{ + unsigned long flags; + int ret; + + uart_port_lock_irqsave(&s->port, &flags); + ret = max3100_handlerx_unlocked(s, rx); + uart_port_unlock_irqrestore(&s->port, flags); + return ret; +} + static void max3100_work(struct work_struct *w) { struct max3100_port *s = container_of(w, struct max3100_port, work);