On 12/13/2017 04:57 AM, Kirill A. Shutemov wrote: > Dave, what is effect of this on protection keys? The goal was to make pkeys-protected userspace memory access _consistent_ with normal access. Specifically, we want a kernel to disallow access (or writes) to memory where userspace mapping has a pkey whose permissions are in conflict with the access. For instance: This will fault writing a byte to 'addr': char *addr = malloc(PAGE_SIZE); pkey_mprotect(addr, PAGE_SIZE, 13); pkey_deny_access(13); *addr[0] = 'f'; But this will write one byte to addr successfully (if it uses the kernel mapping of the physical page backing 'addr'): char *addr = malloc(PAGE_SIZE); pkey_mprotect(addr, PAGE_SIZE, 13); pkey_deny_access(13); read(fd, addr, 1); -- 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>
