On 07/20/2016 03:24 AM, Balbir Singh wrote:
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.
I caught it while looking at the code and then wrote a test case to confirm I was correct because I wasn't sure how to easily find an in tree user. Thanks, Laura -- To unsubscribe from this list: send the line "unsubscribe linux-ia64" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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