Hi, Le jeudi 02 avril 2015 à 10:52 +0000, Shachar Raindel a écrit : > > -----Original Message----- > > From: Yann Droneaud [mailto:ydroneaud@xxxxxxxxxx] > > Sent: Thursday, April 02, 2015 1:05 PM > > Le mercredi 18 mars 2015 à 17:39 +0000, Shachar Raindel a écrit : > > > + /* > > > + * If the combination of the addr and size requested for this > > memory > > > + * region causes an integer overflow, return error. > > > + */ > > > + if ((PAGE_ALIGN(addr + size) <= size) || > > > + (PAGE_ALIGN(addr + size) <= addr)) > > > + return ERR_PTR(-EINVAL); > > > + > > > > Can access_ok() be used here ? > > > > if (!access_ok(writable ? VERIFY_WRITE : VERIFY_READ, > > addr, size)) > > return ERR_PTR(-EINVAL); > > > > No, this will break the current ODP semantics. > > ODP allows the user to register memory that is not accessible yet. > This is a critical design feature, as it allows avoiding holding > a registration cache. Adding this check will break the behavior, > forcing memory to be all accessible when registering an ODP MR. > Where's the check for the range being in userspace memory space, especially for the ODP case ? For non ODP case (eg. plain old behavior), does get_user_pages() ensure the requested pages fit in userspace region on all architectures ? I think so. In ODP case, I'm not sure such check is ever done ? (Aside, does it take special mesure to protect shared mapping from being read and/or *written* ?) Regards. -- Yann Droneaud OPTEYA -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html