Messages in this thread | | | Date | Mon, 14 Dec 2009 22:30:04 +0100 | From | Frederic Weisbecker <> | Subject | Re: packet_sendmsg_spkt sleeping from invalid context |
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On Mon, Dec 14, 2009 at 10:25:57PM +0100, Eric Dumazet wrote: > Le 14/12/2009 21:52, Frederic Weisbecker a écrit : > > > > I also wonder. Are you using PREEMPT_RCU ? > > Not at all :) > > But yes, this is illegal to do the memcpy_fromiovec() in rcu_read_lock() context.
I've just tested, and with rcu preempt it is mute, no warning :)
> > That may explain why you haven't seen this issue because > > might_sleep() doesn't see you are in a rcu read locked > > section as preemption is not disabled, but it is illegal to > > voluntarily sleep in such area (although it's fine with > > preempt rcu) as doing so with non-prempt RCU config would barf. > > > > I'm trying a patch to handle that. > > As you want, I also have a patch testing right now :)
But mine is to teach might_sleep() to handle rcu preempt case, not to fix this net dev thing.
But I'll happily test the fix you have :)
Thanks.
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