Messages in this thread | | | Subject | Re: RT scheduling and a way to make a process hang, unkillable | From | Peter Zijlstra <> | Date | Mon, 16 Feb 2009 15:23:24 +0100 |
| |
On Mon, 2009-02-16 at 14:19 +0100, Peter Zijlstra wrote: > On Mon, 2009-02-16 at 18:44 +0530, Dhaval Giani wrote: > > (This is not a good day!) > > Monday strikes again ;-) > > > @@ -572,6 +572,9 @@ static int set_user(struct cred *new) > > if (!new_user) > > return -EAGAIN; > > So here we just allocated new_user and made sure we didn't fail that > allocation. > > > + if (!task_can_switch_user(new->uid, current)) > > + return -EAGAIN; > > And here you bail, without freeing new_user. The idea was to do this > check before alloc_uid(). > > > if (atomic_read(&new_user->processes) >= > > current->signal->rlim[RLIMIT_NPROC].rlim_cur && > > new_user != INIT_USER) {
Ah, I now see I send you down a hole here,.. your find_user() in task_can_switch_user() relies on that alloc_uid(). So you have to do it after, and just free the new_user thingy when the test fails.
| |