From: John Ogness <john.ogness@xxxxxxxxxxxxx> [ Upstream commit aabdbb1b7a5819e18c403334a31fb0cc2c06ad41 ] __msm_console_write() assumes that interrupts are disabled, but with threaded console printers it is possible that the write() callback of the console is called with interrupts enabled. Explicitly disable interrupts using local_irq_save() to preserve the assumed context. Reported-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx> Reviewed-by: Petr Mladek <pmladek@xxxxxxxx> Signed-off-by: John Ogness <john.ogness@xxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20220506213324.470461-1-john.ogness@xxxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/tty/serial/msm_serial.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/tty/serial/msm_serial.c b/drivers/tty/serial/msm_serial.c index a40827956bd1..d248c43db36a 100644 --- a/drivers/tty/serial/msm_serial.c +++ b/drivers/tty/serial/msm_serial.c @@ -1579,6 +1579,7 @@ static inline struct uart_port *msm_get_port_from_line(unsigned int line) static void __msm_console_write(struct uart_port *port, const char *s, unsigned int count, bool is_uartdm) { + unsigned long flags; int i; int num_newlines = 0; bool replaced = false; @@ -1596,6 +1597,8 @@ static void __msm_console_write(struct uart_port *port, const char *s, num_newlines++; count += num_newlines; + local_irq_save(flags); + if (port->sysrq) locked = 0; else if (oops_in_progress) @@ -1641,6 +1644,8 @@ static void __msm_console_write(struct uart_port *port, const char *s, if (locked) spin_unlock(&port->lock); + + local_irq_restore(flags); } static void msm_console_write(struct console *co, const char *s, -- 2.35.1
