On Mon, May 20, 2019 at 12:52 AM Jan Kara <jack@xxxxxxx> wrote: > > On Sat 18-05-19 21:46:03, Dan Williams wrote: > > On Fri, May 17, 2019 at 12:25 PM Kees Cook <keescook@xxxxxxxxxxxx> wrote: > > > On Fri, May 17, 2019 at 10:28:48AM -0700, Dan Williams wrote: > > > > It seems dax_iomap_actor() is not a path where we'd be worried about > > > > needing hardened user copy checks. > > > > > > I would agree: I think the proposed patch makes sense. :) > > > > Sounds like an acked-by to me. > > Yeah, if Kees agrees, I'm fine with skipping the checks as well. I just > wanted that to be clarified. Also it helped me that you wrote: > > That routine (dax_iomap_actor()) validates that the logical file offset is > within bounds of the file, then it does a sector-to-pfn translation which > validates that the physical mapping is within bounds of the block device. > > That is more specific than "dax_iomap_actor() takes care of necessary > checks" which was in the changelog. And the above paragraph helped me > clarify which checks in dax_iomap_actor() you think replace those usercopy > checks. So I think it would be good to add that paragraph to those > copy_from_pmem() functions as a comment just in case we are wondering in > the future why we are skipping the checks... Also feel free to add: > > Acked-by: Jan Kara <jack@xxxxxxx> Will do, thanks Jan.
