On Fri, Jun 21, 2013 at 02:33:19PM -0600, Alex Williamson wrote: > If we use a large mapping, the expectation is that only unmaps from > the first pte in the superpage are supported. Unmaps from offsets > into the superpage should fail (ie. return zero sized unmap). In the > current code, unmapping from an offset clears the size of the full > mapping starting from an offset. For instance, if we map a 16k > physically contiguous range at IOVA 0x0 with a large page, then > attempt to unmap 4k at offset 12k, 4 ptes are cleared (12k - 28k) and > the unmap returns 16k unmapped. This potentially incorrectly clears > valid mappings and confuses drivers like VFIO that use the unmap size > to release pinned pages. > > Fix by refusing to unmap from offsets into the page. > > Signed-off-by: Alex Williamson <[email protected]> > Cc: [email protected]
Applied, thanks for fixing this. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
