Messages in this thread | | | From | KOSAKI Motohiro <> | Date | Sat, 14 May 2011 20:12:10 +0900 | Subject | Re: [PATCH 1/3] comm: Introduce comm_lock seqlock to protect task->comm access |
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>> Can you please explain why we should use seqlock? That said, >> we didn't use seqlock for /proc items. because, plenty seqlock >> write may makes readers busy wait. Then, if we don't have another >> protection, we give the local DoS attack way to attackers. > > So you're saying that heavy write contention can cause reader > starvation?
Yes.
>> task->comm is used for very fundamentally. then, I doubt we can >> assume write is enough rare. Why can't we use normal spinlock? > > I think writes are likely to be fairly rare. Tasks can only name > themselves or sibling threads, so I'm not sure I see the risk here.
reader starvation may cause another task's starvation if reader have an another lock. And, "only sibling" don't make any security gurantee as I said past.
Thanks.
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