rlimits: allow setrlimit to non-current tasks
Add locking to allow setrlimit accept task parameter other than
current.
Namely, lock tasklist_lock for read and check whether the task
structure has sighand non-null. Do all the signal processing under
that lock still held.
There are some points:
1) security_task_setrlimit is now called with that lock held. This is
not new, many security_* functions are called with this lock held
already so it doesn't harm (all this security_* stuff does almost
the same).
2) task->sighand->siglock (in update_rlimit_cpu) is nested in
tasklist_lock. This dependence is already existing.
3) tsk->alloc_lock is nested in tasklist_lock. This is OK too, already
existing dependence.
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
1 file changed