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authorVlastimil Babka <vbabka@suse.cz>2020-12-15 06:13:38 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2020-12-15 23:13:46 +0300
commit03b6c9a3e8805606c0bb4ad41855fac3bf85c3b9 (patch)
treeb9b875e274c934c792e9b5b2b40aa6fe7607ecc6 /kernel/power
parent8db26a3d47354ce7271a8cab03cd65b9d3d610b9 (diff)
downloadlinux-03b6c9a3e8805606c0bb4ad41855fac3bf85c3b9.tar.xz
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 <vbabka@suse.cz> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> [hibernation] Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Mike Rapoport <rppt@linux.ibm.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>
Diffstat (limited to 'kernel/power')
-rw-r--r--kernel/power/hibernate.c2
-rw-r--r--kernel/power/power.h2
-rw-r--r--kernel/power/snapshot.c14
3 files changed, 13 insertions, 5 deletions
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);
diff --git a/kernel/power/power.h b/kernel/power/power.h
index 24f12d534515..778bf431ec02 100644
--- a/kernel/power/power.h
+++ b/kernel/power/power.h
@@ -106,7 +106,7 @@ extern int create_basic_memory_bitmaps(void);
extern void free_basic_memory_bitmaps(void);
extern int hibernate_preallocate_memory(void);
-extern void clear_free_pages(void);
+extern void clear_or_poison_free_pages(void);
/**
* Auxiliary structure used for reading the snapshot image data and
diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
index d848377dd8dc..d63560e1cf87 100644
--- a/kernel/power/snapshot.c
+++ b/kernel/power/snapshot.c
@@ -1178,7 +1178,15 @@ void free_basic_memory_bitmaps(void)
pr_debug("Basic memory bitmaps freed\n");
}
-void clear_free_pages(void)
+static void clear_or_poison_free_page(struct page *page)
+{
+ if (page_poisoning_enabled_static())
+ __kernel_poison_pages(page, 1);
+ else if (want_init_on_free())
+ clear_highpage(page);
+}
+
+void clear_or_poison_free_pages(void)
{
struct memory_bitmap *bm = free_pages_map;
unsigned long pfn;
@@ -1186,12 +1194,12 @@ void clear_free_pages(void)
if (WARN_ON(!(free_pages_map)))
return;
- if (IS_ENABLED(CONFIG_PAGE_POISONING_ZERO) || want_init_on_free()) {
+ if (page_poisoning_enabled() || want_init_on_free()) {
memory_bm_position_reset(bm);
pfn = memory_bm_next_pfn(bm);
while (pfn != BM_END_OF_MAP) {
if (pfn_valid(pfn))
- clear_highpage(pfn_to_page(pfn));
+ clear_or_poison_free_page(pfn_to_page(pfn));
pfn = memory_bm_next_pfn(bm);
}