diff options
| author | Gaurav Kohli <gkohli@codeaurora.org> | 2018-01-23 13:16:34 +0530 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-02-03 17:05:41 +0100 |
| commit | 55eaecffe3d663d02084023b9fc06d5f39b97389 (patch) | |
| tree | 22de3c04e0e672a4943fa2723633d70c4f3a46af /include | |
| parent | 383e0620b70bc654619c12faf3fd3b2384a42a4c (diff) | |
tty: fix data race between tty_init_dev and flush of buf
commit b027e2298bd588d6fa36ed2eda97447fb3eac078 upstream.
There can be a race, if receive_buf call comes before
tty initialization completes in n_tty_open and tty->disc_data
may be NULL.
CPU0 CPU1
---- ----
000|n_tty_receive_buf_common() n_tty_open()
-001|n_tty_receive_buf2() tty_ldisc_open.isra.3()
-002|tty_ldisc_receive_buf(inline) tty_ldisc_setup()
Using ldisc semaphore lock in tty_init_dev till disc_data
initializes completely.
Signed-off-by: Gaurav Kohli <gkohli@codeaurora.org>
Reviewed-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/tty.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/tty.h b/include/linux/tty.h index 40144f382516..a41244fe58d0 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -394,6 +394,8 @@ extern struct tty_struct *get_current_tty(void); /* tty_io.c */ extern int __init tty_init(void); extern const char *tty_name(const struct tty_struct *tty); +extern int tty_ldisc_lock(struct tty_struct *tty, unsigned long timeout); +extern void tty_ldisc_unlock(struct tty_struct *tty); #else static inline void console_init(void) { } |