Messages in this thread | | | Date | Wed, 14 Aug 2019 14:50:12 +0200 | From | Oleg Nesterov <> | Subject | Re: [PATCH v1 1/1] waitid: Add support for waiting for the current process group |
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On 08/14, Christian Brauner wrote: > > On Wed, Aug 14, 2019 at 02:29:10PM +0200, Oleg Nesterov wrote: > > On 08/14, christian.brauner@ubuntu.com wrote: > > > > > > case P_PGID: > > > type = PIDTYPE_PGID; > > > - if (upid <= 0) > > > + if (upid < 0) > > > return -EINVAL; > > > + > > > + if (upid == 0) > > > + pid = get_pid(task_pgrp(current)); > > > > this needs rcu lock or tasklist_lock, this can race with another thread > > doing sys_setpgid/setsid (see change_pid(PIDTYPE_PGID)). > > Oh, I naively assumed task_pgrp() would take an rcu lock...
but it would not help ;)
> though I think we should be fine with just rcu_read_lock().
Yes,
Oleg.
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