On Fri, Dec 14, 2012 at 03:14:50AM -0800, Andy Lutomirski wrote: > > Wait a minute. get_user_pages() relies on ->mmap_sem being held. Unless > > I'm seriously misreading your patch it removes that protection. And yes, > > I'm aware of execve-related exception; it's in special circumstances - > > bprm->mm is guaranteed to be not shared (and we need to rearchitect that > > area anyway, but that's a separate story). > > Unless I completely screwed up the patch, ->mmap_sem is still held for > read (it's downgraded from write). It's just not held for write > anymore. Huh? I'm talking about the call of get_user_pages() in aio_setup_ring(). With your patch it's done completely outside of ->mmap_sem, isn't it? -- 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>