On Tue, May 10, 2016 at 10:49 AM, Cyrill Gorcunov <gorcunov@xxxxxxxxx> wrote: > On Tue, May 10, 2016 at 10:26:05AM -0700, Andy Lutomirski wrote: > ... >> >> >> >> It's annoying and ugly. It also makes the idea of doing 32-bit CRIU >> >> restore by starting in 64-bit mode and switching to 32-bit more >> >> complicated because it requires switching TASK_SIZE. >> > >> > Well, you know I'm not sure it's that annoying. It serves as it should >> > for task limit. Sure we can add one more parameter into get-unmapped-addr >> > but same time the task-size will be present in say page faulting code >> > (the helper might be renamed but it will be here still). >> >> Why should the page faulting code care at all what type of task it is? >> If there's a vma there, fault it in. If there isn't, then don't. > > __bad_area_nosemaphore > ... > /* Kernel addresses are always protection faults: */ > if (address >= TASK_SIZE) > error_code |= PF_PROT; > > For sure page faulting must consider what kind of fault is it. > Or we gonna drop such code at all? That code was bogus. (Well, it was correct unless user code had a way to create a funny high mapping in an otherwise 32-bit task, but it still should have been TASK_SIZE_MAX.) Fix sent. --Andy -- 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>