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Diffstat (limited to 'include')
-rw-r--r--include/linux/mm_types.h4
-rw-r--r--include/linux/page-debug-flags.h30
-rw-r--r--include/linux/poison.h3
3 files changed, 37 insertions, 0 deletions
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index d84feb7bdbf0..ddadb4defe00 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -11,6 +11,7 @@
#include <linux/rwsem.h>
#include <linux/completion.h>
#include <linux/cpumask.h>
+#include <linux/page-debug-flags.h>
#include <asm/page.h>
#include <asm/mmu.h>
@@ -174,6 +175,9 @@ struct vm_area_struct {
#ifdef CONFIG_NUMA
struct mempolicy *vm_policy; /* NUMA policy for the VMA */
#endif
+#ifdef CONFIG_WANT_PAGE_DEBUG_FLAGS
+ unsigned long debug_flags; /* Use atomic bitops on this */
+#endif
};
struct core_thread {
diff --git a/include/linux/page-debug-flags.h b/include/linux/page-debug-flags.h
new file mode 100644
index 000000000000..b0638fd91e92
--- /dev/null
+++ b/include/linux/page-debug-flags.h
@@ -0,0 +1,30 @@
+#ifndef LINUX_PAGE_DEBUG_FLAGS_H
+#define LINUX_PAGE_DEBUG_FLAGS_H
+
+/*
+ * page->debug_flags bits:
+ *
+ * PAGE_DEBUG_FLAG_POISON is set for poisoned pages. This is used to
+ * implement generic debug pagealloc feature. The pages are filled with
+ * poison patterns and set this flag after free_pages(). The poisoned
+ * pages are verified whether the patterns are not corrupted and clear
+ * the flag before alloc_pages().
+ */
+
+enum page_debug_flags {
+ PAGE_DEBUG_FLAG_POISON, /* Page is poisoned */
+};
+
+/*
+ * Ensure that CONFIG_WANT_PAGE_DEBUG_FLAGS reliably
+ * gets turned off when no debug features are enabling it!
+ */
+
+#ifdef CONFIG_WANT_PAGE_DEBUG_FLAGS
+#if !defined(CONFIG_PAGE_POISONING) \
+/* && !defined(CONFIG_PAGE_DEBUG_SOMETHING_ELSE) && ... */
+#error WANT_PAGE_DEBUG_FLAGS is turned on with no debug features!
+#endif
+#endif /* CONFIG_WANT_PAGE_DEBUG_FLAGS */
+
+#endif /* LINUX_PAGE_DEBUG_FLAGS_H */
diff --git a/include/linux/poison.h b/include/linux/poison.h
index 9f31683728fd..6729f7dcd60e 100644
--- a/include/linux/poison.h
+++ b/include/linux/poison.h
@@ -17,6 +17,9 @@
*/
#define TIMER_ENTRY_STATIC ((void *) 0x74737461)
+/********** mm/debug-pagealloc.c **********/
+#define PAGE_POISON 0xaa
+
/********** mm/slab.c **********/
/*
* Magic nums for obj red zoning.