On Mon, 2018-12-10 at 12:17 +0100, Christoph Hellwig wrote: > On Sun, Dec 09, 2018 at 07:08:14PM -0800, Bart Van Assche wrote: > > According to what I found in > > https://bugzilla.kernel.org/show_bug.cgi?id=201935 patch "block: > > Clear > > kernel memory before copying to user" broke tape access. Hence > > revert > > that patch. > > This looks wrong. The patch from Keith is obviously correct for > normal usage of bio_copy_user_iov. The SCSI tape drivers use the > somewhat odd null_mapped case, so we probably need to refine the > checks > for that a bit. I am going to look into that, just connected a tape device so I can reproduce and then see what we need to make it more specific in the st driver. I may need help from folks who understand the bio stuff better than I do. Back when I have more. Regards Laurence
