1 #ifndef LINUX_PAGE_DEBUG_FLAGS_H
2 #define  LINUX_PAGE_DEBUG_FLAGS_H
3 
4 /*
5  * page->debug_flags bits:
6  *
7  * PAGE_DEBUG_FLAG_POISON is set for poisoned pages. This is used to
8  * implement generic debug pagealloc feature. The pages are filled with
9  * poison patterns and set this flag after free_pages(). The poisoned
10  * pages are verified whether the patterns are not corrupted and clear
11  * the flag before alloc_pages().
12  */
13 
14 enum page_debug_flags {
15 	PAGE_DEBUG_FLAG_POISON,		/* Page is poisoned */
16 	PAGE_DEBUG_FLAG_GUARD,
17 };
18 
19 /*
20  * Ensure that CONFIG_WANT_PAGE_DEBUG_FLAGS reliably
21  * gets turned off when no debug features are enabling it!
22  */
23 
24 #ifdef CONFIG_WANT_PAGE_DEBUG_FLAGS
25 #if !defined(CONFIG_PAGE_POISONING) && \
26     !defined(CONFIG_PAGE_GUARD) \
27 /* && !defined(CONFIG_PAGE_DEBUG_SOMETHING_ELSE) && ... */
28 #error WANT_PAGE_DEBUG_FLAGS is turned on with no debug features!
29 #endif
30 #endif /* CONFIG_WANT_PAGE_DEBUG_FLAGS */
31 
32 #endif /* LINUX_PAGE_DEBUG_FLAGS_H */
33