diff options
| author | Ian Abbott <abbotti@mev.co.uk> | 2017-07-28 16:22:31 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-08-16 13:43:20 -0700 |
| commit | b189f8eb27153daaaa464d7bfec9c5a8ed2989a0 (patch) | |
| tree | ea58022cbf85f895e12f8e7cc649cd278551bffa | |
| parent | bbae08213e6e9811a2d3ece7ba95b1ac0e21f47c (diff) | |
staging: comedi: comedi_fops: do not call blocking ops when !TASK_RUNNING
commit cef988642cdac44e910a27cb6e8166c96f86a0df upstream.
Comedi's read and write file operation handlers (`comedi_read()` and
`comedi_write()`) currently call `copy_to_user()` or `copy_from_user()`
whilst in the `TASK_INTERRUPTIBLE` state, which falls foul of the
`might_fault()` checks when enabled. Fix it by setting the current task
state back to `TASK_RUNNING` a bit earlier before calling these
functions.
Reported-by: Piotr Gregor <piotrgregor@rsyncme.org>
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/staging/comedi/comedi_fops.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c index ec9979070479..7458df4b6854 100644 --- a/drivers/staging/comedi/comedi_fops.c +++ b/drivers/staging/comedi/comedi_fops.c @@ -2385,6 +2385,7 @@ static ssize_t comedi_write(struct file *file, const char __user *buf, continue; } + set_current_state(TASK_RUNNING); wp = async->buf_write_ptr; n1 = min(n, async->prealloc_bufsz - wp); n2 = n - n1; @@ -2517,6 +2518,8 @@ static ssize_t comedi_read(struct file *file, char __user *buf, size_t nbytes, } continue; } + + set_current_state(TASK_RUNNING); rp = async->buf_read_ptr; n1 = min(n, async->prealloc_bufsz - rp); n2 = n - n1; |