From 03b6c9a3e8805606c0bb4ad41855fac3bf85c3b9 Mon Sep 17 00:00:00 2001 From: Vlastimil Babka Date: Mon, 14 Dec 2020 19:13:38 -0800 Subject: kernel/power: allow hibernation with page_poison sanity checking Page poisoning used to be incompatible with hibernation, as the state of poisoned pages was lost after resume, thus enabling CONFIG_HIBERNATION forces CONFIG_PAGE_POISONING_NO_SANITY. For the same reason, the poisoning with zeroes variant CONFIG_PAGE_POISONING_ZERO used to disable hibernation. The latter restriction was removed by commit 1ad1410f632d ("PM / Hibernate: allow hibernation with PAGE_POISONING_ZERO") and similarly for init_on_free by commit 18451f9f9e58 ("PM: hibernate: fix crashes with init_on_free=1") by making sure free pages are cleared after resume. We can use the same mechanism to instead poison free pages with PAGE_POISON after resume. This covers both zero and 0xAA patterns. Thus we can remove the Kconfig restriction that disables page poison sanity checking when hibernation is enabled. Link: https://lkml.kernel.org/r/20201113104033.22907-4-vbabka@suse.cz Signed-off-by: Vlastimil Babka Acked-by: Rafael J. Wysocki [hibernation] Reviewed-by: David Hildenbrand Cc: Mike Rapoport Cc: Alexander Potapenko Cc: Kees Cook Cc: Laura Abbott Cc: Mateusz Nosek Cc: Michal Hocko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/power/hibernate.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/power/hibernate.c') diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index 2fc7d509a34f..da0b41914177 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -326,7 +326,7 @@ static int create_image(int platform_mode) if (!in_suspend) { events_check_enabled = false; - clear_free_pages(); + clear_or_poison_free_pages(); } platform_leave(platform_mode); -- cgit v1.2.3-70-g09d2