Messages in this thread | | | Date | Fri, 25 Sep 2015 11:01:13 -0400 | From | Tejun Heo <> | Subject | Re: netlink: Add barrier to netlink_connect for theoretical case |
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Hello, Herbert.
On Fri, Sep 25, 2015 at 09:43:27AM +0800, Herbert Xu wrote: > Well had you said this in the first place I would've fixed it a > long time ago. There aren't any in-kernel users right now and > even if there were they'd have to do a connect/bind/sendmsg on > the same socket in two threads at the same time. But let's close > this theoretical hole:
I'm not even sure we guarantee memory barrier on kernel/user crossings. In practice, we probably have enough barriers (e.g. some syscall traps imply barrier) but I can't think of a reason why we'd guarantee the existence of barrier there. As an extreme example, imagine UML on an architecture with relaxed memory model.
Thanks.
-- tejun
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