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Diffstat (limited to 'include/linux/page-flags.h')
-rw-r--r--include/linux/page-flags.h22
1 files changed, 17 insertions, 5 deletions
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index 50c2b8786831..e34a27727b9a 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -156,9 +156,18 @@ static __always_inline int PageCompound(struct page *page)
return test_bit(PG_head, &page->flags) || PageTail(page);
}
+#define PAGE_POISON_PATTERN -1l
+static inline int PagePoisoned(const struct page *page)
+{
+ return page->flags == PAGE_POISON_PATTERN;
+}
+
/*
* Page flags policies wrt compound pages
*
+ * PF_POISONED_CHECK
+ * check if this struct page poisoned/uninitialized
+ *
* PF_ANY:
* the page flag is relevant for small, head and tail pages.
*
@@ -176,17 +185,20 @@ static __always_inline int PageCompound(struct page *page)
* PF_NO_COMPOUND:
* the page flag is not relevant for compound pages.
*/
-#define PF_ANY(page, enforce) page
-#define PF_HEAD(page, enforce) compound_head(page)
+#define PF_POISONED_CHECK(page) ({ \
+ VM_BUG_ON_PGFLAGS(PagePoisoned(page), page); \
+ page; })
+#define PF_ANY(page, enforce) PF_POISONED_CHECK(page)
+#define PF_HEAD(page, enforce) PF_POISONED_CHECK(compound_head(page))
#define PF_ONLY_HEAD(page, enforce) ({ \
VM_BUG_ON_PGFLAGS(PageTail(page), page); \
- page;})
+ PF_POISONED_CHECK(page); })
#define PF_NO_TAIL(page, enforce) ({ \
VM_BUG_ON_PGFLAGS(enforce && PageTail(page), page); \
- compound_head(page);})
+ PF_POISONED_CHECK(compound_head(page)); })
#define PF_NO_COMPOUND(page, enforce) ({ \
VM_BUG_ON_PGFLAGS(enforce && PageCompound(page), page); \
- page;})
+ PF_POISONED_CHECK(page); })
/*
* Macros to create function definitions for page flags