On Tue, 2016-07-19 at 11:48 -0700, Kees Cook wrote: > On Mon, Jul 18, 2016 at 6:06 PM, Laura Abbott <labbott@xxxxxxxxxx> wrote: > > > > On 07/15/2016 02:44 PM, Kees Cook wrote: > > > > This doesn't work when copying CMA allocated memory since CMA purposely > > allocates larger than a page block size without setting head pages. > > Given CMA may be used with drivers doing zero copy buffers, I think it > > should be permitted. > > > > Something like the following lets it pass (I can clean up and submit > > the is_migrate_cma_page APIs as a separate patch for review) > Yeah, this would be great. I'd rather use an accessor to check this > than a direct check for MIGRATE_CMA. > > > */ > > for (; ptr <= end ; ptr += PAGE_SIZE, page = virt_to_head_page(ptr)) > > { > > - if (!PageReserved(page)) > > + if (!PageReserved(page) && !is_migrate_cma_page(page)) > > return "<spans multiple pages>"; > > } > Yeah, I'll modify this a bit so that which type it starts as is > maintained for all pages (rather than allowing to flip back and forth > -- even though that is likely impossible). > Sorry, I completely missed the MIGRATE_CMA bits. Could you clarify if you caught this in testing/review? Balbir Singh. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>