On Thu, 2015-01-15 at 09:58 +0100, Christian Borntraeger wrote: > ACCESS_ONCE does not work reliably on non-scalar types. For > example gcc 4.6 and 4.7 might remove the volatile tag for such > accesses during the SRA (scalar replacement of aggregates) step > (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58145) > > Change the ppc/kvm code to replace ACCESS_ONCE with READ_ONCE. > > Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx> > --- > arch/powerpc/kvm/book3s_hv_rm_xics.c | 8 ++++---- > arch/powerpc/kvm/book3s_xics.c | 16 ++++++++-------- > 2 files changed, 12 insertions(+), 12 deletions(-) > > diff --git a/arch/powerpc/kvm/book3s_hv_rm_xics.c b/arch/powerpc/kvm/book3s_hv_rm_xics.c > index 7b066f6..7c22997 100644 > --- a/arch/powerpc/kvm/book3s_hv_rm_xics.c > +++ b/arch/powerpc/kvm/book3s_hv_rm_xics.c > @@ -152,7 +152,7 @@ static void icp_rm_down_cppr(struct kvmppc_xics *xics, struct kvmppc_icp *icp, > * in virtual mode. > */ > do { > - old_state = new_state = ACCESS_ONCE(icp->state); > + old_state = new_state = READ_ONCE(icp->state); These are all icp->state. Which is a union, but it's only the size of unsigned long. So in practice there shouldn't be a bug here right? cheers -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>