patch "staging: comedi: comedi_fops: do not call blocking ops when" added to staging-linus

This is a note to let you know that I've just added the patch titled

staging: comedi: comedi_fops: do not call blocking ops when

to my staging git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git
in the staging-linus branch.

The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.

If you have any questions about this process, please let me know.

From: Ian Abbott <[email protected]>
Date: Fri, 28 Jul 2017 16:22:31 +0100
Subject: staging: comedi: comedi_fops: do not call blocking ops when
!TASK_RUNNING

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.

---
 drivers/staging/comedi/comedi_fops.c | 3 +++
 1 file changed, 3 insertions(+)

index ca11be21f64b..34ca7823255d 100644
@@ -2396,6 +2396,7 @@ 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;

@@ -2528,6 +2529,8 @@ 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;

2.13.3