On Mon, Apr 02, 2012 at 04:48:21PM +0200, Oleg Nesterov wrote: > On 04/02, Konstantin Khlebnikov wrote: > > > > In this patch I leave mm->exe_file lockless. > > After exec/fork we can change it only for current task and only if mm->mm_users == 1. > > > > something like this: > > > > task_lock(current); > > OK, this protects against the race with get_task_mm() > > > if (atomic_read(¤t->mm->mm_users) == 1) > > this means PR_SET_MM_EXE_FILE can fail simply because someone did > get_task_mm(). Or the caller is multithreaded. So it leads to the same question -- do we *really* need the PR_SET_MM_EXE_FILE to be one-shot action? Yeah, I know, we agreed that one-shot is better than anything else from sysadmin perspective and such, but maybe I could introduce a special capability bit for c/r and allow a program which has such cap to modify exe-file without checkin mm_users? /me hides > > > set_mm_exe_file(current->mm, new_file); > > No, fput() can sleep. Sure, it was just "something like" as Konstantin stated, thanks anyway ;) Cyrill -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>