diff options
| author |   Gaurav Kohli <gkohli@codeaurora.org> | 2018-01-23 13:16:34 +0530 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-01-23 08:57:37 +0100 |
| commit | b027e2298bd588d6fa36ed2eda97447fb3eac078 (patch) | |
| tree | 3b90cee88ac74c2828b90b67d67cf7adf6e9e310 /drivers/tty/tty_ldisc.c | |
| parent | serial: imx: fix endless loop during suspend (diff) | |
| download | linux-dev-b027e2298bd588d6fa36ed2eda97447fb3eac078.tar.xz linux-dev-b027e2298bd588d6fa36ed2eda97447fb3eac078.zip | |
tty: fix data race between tty_init_dev and flush of buf
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>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/tty_ldisc.c')
| -rw-r--r-- | drivers/tty/tty_ldisc.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/tty/tty_ldisc.c b/drivers/tty/tty_ldisc.c index 24ec5c7e6b20..4e7946c0484b 100644 --- a/drivers/tty/tty_ldisc.c +++ b/drivers/tty/tty_ldisc.c @@ -337,7 +337,7 @@ static inline void __tty_ldisc_unlock(struct tty_struct *tty) ldsem_up_write(&tty->ldisc_sem); } -static int tty_ldisc_lock(struct tty_struct *tty, unsigned long timeout) +int tty_ldisc_lock(struct tty_struct *tty, unsigned long timeout) { int ret; @@ -348,7 +348,7 @@ static int tty_ldisc_lock(struct tty_struct *tty, unsigned long timeout) return 0; } -static void tty_ldisc_unlock(struct tty_struct *tty) +void tty_ldisc_unlock(struct tty_struct *tty) { clear_bit(TTY_LDISC_HALTED, &tty->flags); __tty_ldisc_unlock(tty); |