e871c7feeb
Commit11c9c7edae("mm/page_poison.c: replace bool variable with static key") changed page_poisoning_enabled() to a static key check. However, the function is not inlined, so each check still involves a function call with overhead not eliminated when page poisoning is disabled. Analogically to how debug_pagealloc is handled, this patch converts page_poisoning_enabled() back to boolean check, and introduces page_poisoning_enabled_static() for fast paths. Both functions are inlined. The function kernel_poison_pages() is also called unconditionally and does the static key check inside. Remove it from there and put it to callers. Also split it to two functions kernel_poison_pages() and kernel_unpoison_pages() instead of the confusing bool parameter. Also optimize the check that enables page poisoning instead of debug_pagealloc for architectures without proper debug_pagealloc support. Move the check to init_mem_debugging_and_hardening() to enable a single static key instead of having two static branches in page_poisoning_enabled_static(). Link: https://lkml.kernel.org/r/20201113104033.22907-3-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Alexander Potapenko <glider@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: Laura Abbott <labbott@kernel.org> Cc: Mateusz Nosek <mateusznosek0@gmail.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> (cherry picked from commit8db26a3d47https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git akpm) Bug: 182930667 Signed-off-by: Alexander Potapenko <glider@google.com> Change-Id: Ifc3fdf5cd58f3b8346bf81480df3836811e7458b