Commits
Jia-Ju Bai committed fe8e7acea24
tty/isicom: Fix a possible sleep-in-atomic bug in WaitTillCardIsFree
The driver may sleep under a spinlock.
The function call paths are:
isicom_activate (acquire the spinlock)
isicom_setup_board
drop_dtr_rts
WaitTillCardIsFree
msleep --> may sleep
isicom_set_termios
isicom_config_port
drop_dtr
WaitTillCardIsFree
msleep --> may sleep
isicom_tiocmset
drop_dtr
WaitTillCardIsFree
msleep --> may sleep
Though "in_atomic" is used to check atomic context,
but it is not recommended to use in driver code (see include/linux/preempt.h).
To fix it, only using mdelay instead.
This bug is found by my static analysis tool(DSAC) and checked by my code review.
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>