Hi Ben, If my understanding is correct, the writer could not be a rcu thread because it does not need report holding or not holding pointers. So old memory will be freed after all rcu thread report quiesce.
Best Regards, Wei Yanqin > -----Original Message----- > From: Ben Pfaff <[email protected]> > Sent: Wednesday, June 3, 2020 1:28 AM > To: Linhaifeng <[email protected]> > Cc: Yanqin Wei <[email protected]>; [email protected]; nd > <[email protected]>; Lilijun (Jerry) <[email protected]>; chenchanghu > <[email protected]>; Lichunhe <[email protected]> > Subject: Re: [ovs-dev] [PATCH v2] ovs rcu: update rcu pointer first > > On Tue, Jun 02, 2020 at 07:27:59AM +0000, Linhaifeng wrote: > > We should update rcu pointer first then use ovsrcu_postpone to free > > otherwise maybe cause use-after-free. > > e.g.,reader indicates momentary quiescent and access old pointer after > > writer postpone free old pointer and before setting new pointer. > > > > Signed-off-by: Linhaifeng <[email protected]> > > I don't see how that's possible, since the writer hasn't quiesced. _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
