From aabdbb1b7a5819e18c403334a31fb0cc2c06ad41 Mon Sep 17 00:00:00 2001

From: John Ogness <john.ogness@linutronix.de>

Date: Fri, 6 May 2022 23:39:24 +0206

Subject: [PATCH] serial: msm_serial: disable interrupts in __msm_console_write()

Git-commit: aabdbb1b7a5819e18c403334a31fb0cc2c06ad41

Patch-mainline: v5.19-rc1

References: git-fixes

__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@samsung.com>

Reviewed-by: Petr Mladek <pmladek@suse.com>

Signed-off-by: John Ogness <john.ogness@linutronix.de>

Link: https://lore.kernel.org/r/20220506213324.470461-1-john.ogness@linutronix.de

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Acked-by: Takashi Iwai <tiwai@suse.de>

---

 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 23c94b927776..e676ec761f18 100644

--- a/drivers/tty/serial/msm_serial.c

+++ b/drivers/tty/serial/msm_serial.c

@@ -1599,6 +1599,7 @@ 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;

@@ -1616,6 +1617,8 @@ 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)

@@ -1661,6 +1664,8 @@ 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,

-- 

2.35.3