Power management fix for 5.5-rc8

Prevent the kernel from crashing during resume from hibernation
 if free pages contain leftover data from the restore kernel and
 init_on_free is set (Alexander Potapenko).
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Merge tag 'pm-5.5-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management fix from Rafael Wysocki:
 "Prevent the kernel from crashing during resume from hibernation if
  free pages contain leftover data from the restore kernel and
  init_on_free is set (Alexander Potapenko)"

* tag 'pm-5.5-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  PM: hibernate: fix crashes with init_on_free=1

kernel/power/snapshot.c

@@ -1147,24 +1147,24 @@ void free_basic_memory_bitmaps(void)
 
 void clear_free_pages(void)
 {
-#ifdef CONFIG_PAGE_POISONING_ZERO
 	struct memory_bitmap *bm = free_pages_map;
 	unsigned long pfn;
 
 	if (WARN_ON(!(free_pages_map)))
 		return;
 
-	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));
-
+	if (IS_ENABLED(CONFIG_PAGE_POISONING_ZERO) || 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));
+
+			pfn = memory_bm_next_pfn(bm);
+		}
+		memory_bm_position_reset(bm);
+		pr_info("free pages cleared after restore\n");
 	}
-	memory_bm_position_reset(bm);
-	pr_info("free pages cleared after restore\n");
-#endif /* PAGE_POISONING_ZERO */
 }
 
 /**