From: Jiri Slaby jslaby@suse.cz
stable inclusion from stable-v4.19.254 commit 3ca62328d9bfaa597397099cb7f5a485a9bebacc category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I5A5Y1 CVE: CVE-2022-1462
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commit 5db96ef23bda6c2a61a51693c85b78b52d03f654 upstream.
Since commit a9c3f68f3cd8d (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: Johan Hovold johan@kernel.org Signed-off-by: Jiri Slaby jslaby@suse.cz Link: https://lore.kernel.org/r/20211122111648.30379-4-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Yi Yang yiyang13@huawei.com Reviewed-by: Xiu Jianfeng xiujianfeng@huawei.com Reviewed-by: Wang Weiyang wangweiyang2@huawei.com Signed-off-by: Yongqiang Liu liuyongqiang13@huawei.com --- drivers/tty/tty_buffer.c | 30 ++++++++---------------------- include/linux/tty_flip.h | 1 - 2 files changed, 8 insertions(+), 23 deletions(-)
diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c index b19047012770..8728342c6482 100644 --- a/drivers/tty/tty_buffer.c +++ b/drivers/tty/tty_buffer.c @@ -390,27 +390,6 @@ 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 @@ -553,7 +532,14 @@ 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);
diff --git a/include/linux/tty_flip.h b/include/linux/tty_flip.h index 767f62086bd9..e183f74b19a0 100644 --- a/include/linux/tty_flip.h +++ b/include/linux/tty_flip.h @@ -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,