On 3/10/20 5:43 PM, Andy Shevchenko wrote:
> Refactor uart_unlock_and_check_sysrq() to:
>
> - explicitly show that we release a port lock which makes
> static analyzers happy:
>
> CHECK drivers/tty/serial/serial_core.c
> .../serial_core.c:3290:17: warning: context imbalance in 'uart_unlock_and_check_sysrq' - unexpected unlock
>
> - use flags instead of irqflags to avoid confusion with IRQ flags
>
> - provide one return point
>
> - be more compact
>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Thanks!
Reviewed-by: Dmitry Safonov <0x7f454c46@xxxxxxxxx>
> ---
> v2: move sysrq_ch declaration inside branch (Dmitry)
> drivers/tty/serial/serial_core.c | 23 ++++++++++-------------
> include/linux/serial_core.h | 3 +--
> 2 files changed, 11 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
> index e3f8e641e3a7..203697465afc 100644
> --- a/drivers/tty/serial/serial_core.c
> +++ b/drivers/tty/serial/serial_core.c
> @@ -3286,22 +3286,19 @@ int uart_prepare_sysrq_char(struct uart_port *port, unsigned int ch)
> }
> EXPORT_SYMBOL_GPL(uart_prepare_sysrq_char);
>
> -void uart_unlock_and_check_sysrq(struct uart_port *port, unsigned long irqflags)
> +void uart_unlock_and_check_sysrq(struct uart_port *port, unsigned long flags)
> +__releases(&port->lock)
> {
> - int sysrq_ch;
> + if (port->has_sysrq) {
> + int sysrq_ch = port->sysrq_ch;
>
> - if (!port->has_sysrq) {
> - spin_unlock_irqrestore(&port->lock, irqflags);
> - return;
> + port->sysrq_ch = 0;
> + spin_unlock_irqrestore(&port->lock, flags);
> + if (sysrq_ch)
> + handle_sysrq(sysrq_ch);
> + } else {
> + spin_unlock_irqrestore(&port->lock, flags);
> }
> -
> - sysrq_ch = port->sysrq_ch;
> - port->sysrq_ch = 0;
> -
> - spin_unlock_irqrestore(&port->lock, irqflags);
> -
> - if (sysrq_ch)
> - handle_sysrq(sysrq_ch);
> }
> EXPORT_SYMBOL_GPL(uart_unlock_and_check_sysrq);
>
> diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
> index 7a025042e0bb..cab896c60e35 100644
> --- a/include/linux/serial_core.h
> +++ b/include/linux/serial_core.h
> @@ -447,8 +447,7 @@ extern void uart_insert_char(struct uart_port *port, unsigned int status,
>
> extern int uart_handle_sysrq_char(struct uart_port *port, unsigned int ch);
> extern int uart_prepare_sysrq_char(struct uart_port *port, unsigned int ch);
> -extern void uart_unlock_and_check_sysrq(struct uart_port *port,
> - unsigned long irqflags);
> +extern void uart_unlock_and_check_sysrq(struct uart_port *port, unsigned long flags);
> extern int uart_handle_break(struct uart_port *port);
>
> /*
>
--
Dima
