Messages in this thread | | | Date | Mon, 28 Jan 2008 12:57:37 +0300 | From | Pavel Emelyanov <> | Subject | Re: [RFC] Per-thread getrusage |
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Andrew Morton wrote: > On Mon, 28 Jan 2008 12:38:17 +0300 Pavel Emelyanov <xemul@openvz.org> wrote: > >>> If the code was using find_task_by_vpid() then OK (I guess). But it is >> Yup, find_task_by_vpid() will find the proper (i.e. in your namespace) task. >> >>> looking the tids up in the init_pid_ns. Which I assume means that if it's >>> in a new namespace and is looking up a sibling thread it will simply fail? >> If it looks in the init_pid_ns, then it can either fail or obtain a task >> from different namespace. The find_task_by_pid_ns() was intended to be used >> in proc mainly, to get tasks from the namespace pointed by the super-block >> being explored. >> >> Please excuse my lamentable ignorance, but which code does such things with >> init_pid_ns? I followed the 'per-thread rusage' thread and didn't find any. > > From: Vinay Sridhar <vinay@linux.vnet.ibm.com> > To: linux-kernel@vger.kernel.org, libc-alpha@sourceware.org > Cc: drepper@redhat.com, wli@holomorphy.com, akpm@linux-foundation.org, sripathik@in.ibm.com > Subject: [RFC] Per-thread getrusage
Ouch. Thanks, I've missed that and looked just at the Roland's patch :(
> ... > +asmlinkage long sys_thread_getrusage(int tid, struct rusage __user *ru) > +{ > + struct task_struct *tsk; > + tsk = find_task_by_pid(tid); > + return getrusage(tsk, RUSAGE_THREAD, ru); > +}
Well, the find_task_by_pid() is really wrong here.
Besides (just in case this system call is going to be developed further), the tsk == NULL case is not checked inside the getrusage and may OOPS even if the proper namespace is used.
Thanks, Pavel
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