On Fri, Jun 21, 2024 at 02:12:22PM -0400, Audra Mitchell wrote: > Currently if we request a feature that is not set in the Kernel > config we fail silently and return all the available features. However, > the man page indicates we should return an EINVAL. > > We need to fix this issue since we can end up with a Kernel warning > should a program request the feature UFFD_FEATURE_WP_UNPOPULATED on > a kernel with the config not set with this feature. > > [ 200.812896] WARNING: CPU: 91 PID: 13634 at mm/memory.c:1660 zap_pte_range+0x43d/0x660 > [ 200.820738] Modules linked in: > [ 200.869387] CPU: 91 PID: 13634 Comm: userfaultfd Kdump: loaded Not tainted 6.9.0-rc5+ #8 > [ 200.877477] Hardware name: Dell Inc. PowerEdge R6525/0N7YGH, BIOS 2.7.3 03/30/2022 > [ 200.885052] RIP: 0010:zap_pte_range+0x43d/0x660 > > Fixes: e06f1e1dd499 ("userfaultfd: wp: enabled write protection in userfaultfd API") > Signed-off-by: Audra Mitchell <audra@xxxxxxxxxx> Please prefix the subject with "mm/uffd:" or "mm/userfault:" if there's a repost. Acked-by: Peter Xu <peterx@xxxxxxxxxx> Thanks, -- Peter Xu