Commit 1b999eb8 authored by Jiri Slaby's avatar Jiri Slaby Committed by Zheng Zengkai
Browse files

tty: drop tty_schedule_flip() 

stable inclusion
from stable-v5.10.134
commit c84986d097451203bb79a8bff8d37e56488fbf1d
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I5A5Y1
CVE: CVE-2022-1462

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=c84986d097451203bb79a8bff8d37e56488fbf1d



--------------------------------

commit 5db96ef2 upstream.

Since commit a9c3f68f (tty: Fix low_latency BUG) in 2014,
tty_flip_buffer_push() is only a wrapper to tty_schedule_flip(). All
users were converted in the previous patches, so remove
tty_schedule_flip() completely while inlining its body into
tty_flip_buffer_push().

One less exported function.

Reviewed-by: default avatarJohan Hovold <johan@kernel.org>
Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20211122111648.30379-4-jslaby@suse.cz


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarYi Yang <yiyang13@huawei.com>
Reviewed-by: default avatarWang Weiyang <wangweiyang2@huawei.com>
Signed-off-by: default avatarZheng Zengkai <zhengzengkai@huawei.com>
parent c92bf054

drivers/tty/tty_buffer.c

+8 −22
Original line number Diff line number Diff line
@@ -395,27 +395,6 @@ int __tty_insert_flip_char(struct tty_port *port, unsigned char ch, char flag) 
}

EXPORT_SYMBOL(__tty_insert_flip_char);



/**

 *	tty_schedule_flip	-	push characters to ldisc

 *	@port: tty port to push from

 *

 *	Takes any pending buffers and transfers their ownership to the

 *	ldisc side of the queue. It then schedules those characters for

 *	processing by the line discipline.

 */



void tty_schedule_flip(struct tty_port *port)

{

	struct tty_bufhead *buf = &port->buf;



	/* paired w/ acquire in flush_to_ldisc(); ensures

	 * flush_to_ldisc() sees buffer data.

	 */

	smp_store_release(&buf->tail->commit, buf->tail->used);

	queue_work(system_unbound_wq, &buf->work);

}

EXPORT_SYMBOL(tty_schedule_flip);



/**

 *	tty_prepare_flip_string		-	make room for characters

 *	@port: tty port
@@ -558,7 +537,14 @@ static void flush_to_ldisc(struct work_struct *work) 


void tty_flip_buffer_push(struct tty_port *port)

{

	tty_schedule_flip(port);

	struct tty_bufhead *buf = &port->buf;



	/*

	 * Paired w/ acquire in flush_to_ldisc(); ensures flush_to_ldisc() sees

	 * buffer data.

	 */

	smp_store_release(&buf->tail->commit, buf->tail->used);

	queue_work(system_unbound_wq, &buf->work);

}

EXPORT_SYMBOL(tty_flip_buffer_push);

include/linux/tty_flip.h

+0 −1
Original line number Diff line number Diff line
@@ -12,7 +12,6 @@ extern int tty_insert_flip_string_fixed_flag(struct tty_port *port, 
extern int tty_prepare_flip_string(struct tty_port *port,

		unsigned char **chars, size_t size);

extern void tty_flip_buffer_push(struct tty_port *port);

void tty_schedule_flip(struct tty_port *port);

int __tty_insert_flip_char(struct tty_port *port, unsigned char ch, char flag);



static inline int tty_insert_flip_char(struct tty_port *port,