Reported the cleared bytes in case of a partial clear_user instead
of -EFAULT, and remove a pointless conditional, as cleared must be
non-zero by the time we hit the signal_pending check.
Reported-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20200907082700.2057137-1-hch@lst.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
while (count) {
size_t chunk = min_t(size_t, count, PAGE_SIZE);
+ size_t left;
- if (clear_user(buf + cleared, chunk))
- return cleared ? cleared : -EFAULT;
+ left = clear_user(buf + cleared, chunk);
+ if (unlikely(left)) {
+ cleared += (chunk - left);
+ if (!cleared)
+ return -EFAULT;
+ break;
+ }
cleared += chunk;
count -= chunk;
if (signal_pending(current))
- return cleared ? cleared : -ERESTARTSYS;
+ break;
cond_resched();
}