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Commit 19f4b51b authored by John Ogness's avatar John Ogness Committed by Greg Kroah-Hartman
Browse files

serial: msm_serial: disable interrupts in __msm_console_write() 



[ 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: default avatarMarek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: default avatarPetr Mladek <pmladek@suse.com>
Signed-off-by: default avatarJohn Ogness <john.ogness@linutronix.de>
Link: https://lore.kernel.org/r/20220506213324.470461-1-john.ogness@linutronix.de


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent 52a0d88c

drivers/tty/serial/msm_serial.c

+5 −0
Original line number Original line Diff line number Diff line
@@ -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,

static void __msm_console_write(struct uart_port *port, const char *s,

				unsigned int count, bool is_uartdm)

				unsigned int count, bool is_uartdm)

{

{

	unsigned long flags;

	int i;

	int i;

	int num_newlines = 0;

	int num_newlines = 0;

	bool replaced = false;

	bool replaced = false;
@@ -1596,6 +1597,8 @@ static void __msm_console_write(struct uart_port *port, const char *s, 
			num_newlines++;

			num_newlines++;

	count += num_newlines;

	count += num_newlines;





	local_irq_save(flags);



	if (port->sysrq)

	if (port->sysrq)

		locked = 0;

		locked = 0;

	else if (oops_in_progress)

	else if (oops_in_progress)
@@ -1641,6 +1644,8 @@ static void __msm_console_write(struct uart_port *port, const char *s, 




	if (locked)

	if (locked)

		spin_unlock(&port->lock);

		spin_unlock(&port->lock);



	local_irq_restore(flags);

}

}





static void msm_console_write(struct console *co, const char *s,

static void msm_console_write(struct console *co, const char *s,