On Thu, Jul 16, 2020 at 05:19:52PM -0700, Dexuan-Linux Cui wrote: > On Thu, Jul 16, 2020 at 7:47 AM Naresh Kamboju > <naresh.kamboju@xxxxxxxxxx> wrote: > > > > On Sun, 12 Jul 2020 at 21:39, Paul E. McKenney <paulmck@xxxxxxxxxx> wrote: > > > > > > On Sun, Jul 12, 2020 at 06:40:03PM +0530, madhuparnabhowmik10@xxxxxxxxx wrote: > > > > From: Madhuparna Bhowmik <madhuparnabhowmik10@xxxxxxxxx> > > > > > > > > Use hlist_for_each_entry_srcu() instead of hlist_for_each_entry_rcu() > > > > as it also checkes if the right lock is held. > > > > Using hlist_for_each_entry_rcu() with a condition argument will not > > > > report the cases where a SRCU protected list is traversed using > > > > rcu_read_lock(). Hence, use hlist_for_each_entry_srcu(). > > > > > > > > Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@xxxxxxxxx> > > > > > > I queued both for testing and review, thank you! > > > > > > In particular, this one needs an ack by the maintainer. > > > > > > Thanx, Paul > > > > > > > arch/x86/kvm/mmu/page_track.c | 6 ++++-- > > > > 1 file changed, 4 insertions(+), 2 deletions(-) > > > > > > > > diff --git a/arch/x86/kvm/mmu/page_track.c b/arch/x86/kvm/mmu/page_track.c > > > > index a7bcde34d1f2..a9cd17625950 100644 > > > > --- a/arch/x86/kvm/mmu/page_track.c > > > > +++ b/arch/x86/kvm/mmu/page_track.c > > > > @@ -229,7 +229,8 @@ void kvm_page_track_write(struct kvm_vcpu *vcpu, gpa_t gpa, const u8 *new, > > > > return; > > > > > > > > idx = srcu_read_lock(&head->track_srcu); > > > > - hlist_for_each_entry_rcu(n, &head->track_notifier_list, node) > > > > + hlist_for_each_entry_srcu(n, &head->track_notifier_list, node, > > > > + srcu_read_lock_held(&head->track_srcu)) > > > > x86 build failed on linux -next 20200716. > > > > arch/x86/kvm/mmu/page_track.c: In function 'kvm_page_track_write': > > include/linux/rculist.h:727:30: error: left-hand operand of comma > > expression has no effect [-Werror=unused-value] > > for (__list_check_srcu(cond), \ > > ^ > > arch/x86/kvm/mmu/page_track.c:232:2: note: in expansion of macro > > 'hlist_for_each_entry_srcu' > > hlist_for_each_entry_srcu(n, &head->track_notifier_list, node, > > ^~~~~~~~~~~~~~~~~~~~~~~~~ > > arch/x86/kvm/mmu/page_track.c: In function 'kvm_page_track_flush_slot': > > include/linux/rculist.h:727:30: error: left-hand operand of comma > > expression has no effect [-Werror=unused-value] > > for (__list_check_srcu(cond), \ > > ^ > > arch/x86/kvm/mmu/page_track.c:258:2: note: in expansion of macro > > 'hlist_for_each_entry_srcu' > > hlist_for_each_entry_srcu(n, &head->track_notifier_list, node, > > ^~~~~~~~~~~~~~~~~~~~~~~~~ > > cc1: all warnings being treated as errors > > make[3]: *** [arch/x86/kvm/mmu/page_track.o] Error 1 > > > > build link, > > https://ci.linaro.org/view/lkft/job/openembedded-lkft-linux-next/DISTRO=lkft,MACHINE=intel-corei7-64,label=docker-lkft/815/consoleText > > > > -- > > Linaro LKFT > > https://lkft.linaro.org > > Hi, we're seeing the same building failure with the latest linux-next tree. I am not seeing this here. Could you please let us know what compiler and command-line options you are using to generate this? Thanx, Paul