Add poisoning to page struct to catch corruption at either the beginning or
the end of the struct.
Signed-off-by: Sasha Levin <sasha.le...@oracle.com>
---
include/linux/mm.h | 9 +++++++++
include/linux/mm_types.h | 6 ++++++
include/linux/mmdebug.h | 6 ++++++
include/linux/page-flags.h | 24 ++++++++++++++++--------
4 files changed, 37 insertions(+), 8 deletions(-)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 0c13412..c48c4e2 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -524,6 +524,10 @@ static inline struct page *virt_to_head_page(const void *x)
*/
static inline void init_page_count(struct page *page)
{
+#ifdef CONFIG_DEBUG_VM_POISON
+ page->poison_start = MM_POISON_BEGIN;
+ page->poison_end = MM_POISON_END;
+#endif
atomic_set(&page->_count, 1);
}
@@ -1482,12 +1486,17 @@ static inline void pgtable_init(void)
static inline bool pgtable_page_ctor(struct page *page)
{
+#ifdef CONFIG_DEBUG_VM_POISON
+ page->poison_start = MM_POISON_BEGIN;
+ page->poison_end = MM_POISON_END;
+#endif
inc_zone_page_state(page, NR_PAGETABLE);
return ptlock_init(page);
}
static inline void pgtable_page_dtor(struct page *page)
{
+ VM_CHECK_POISON_PAGE(page);
pte_lock_deinit(page);
dec_zone_page_state(page, NR_PAGETABLE);
}
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index 4e2cf93..7cab56a 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -42,6 +42,9 @@ struct address_space;
* and lru list pointers also.
*/
struct page {
+#ifdef CONFIG_DEBUG_VM_POISON
+ u32 poison_start;
+#endif
/* First double word block */
unsigned long flags; /* Atomic flags, some possibly
* updated asynchronously */
@@ -196,6 +199,9 @@ struct page {
#ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS
int _last_cpupid;
#endif
+#ifdef CONFIG_DEBUG_VM_POISON
+ u32 poison_end;
+#endif
}
/*
* The struct page can be forced to be double word aligned so that atomic ops
diff --git a/include/linux/mmdebug.h b/include/linux/mmdebug.h
index 75bc69d..461c452 100644
--- a/include/linux/mmdebug.h
+++ b/include/linux/mmdebug.h
@@ -50,6 +50,11 @@ void dump_mm(const struct mm_struct *mm);
VM_BUG_ON_VMA((vma)->poison_start != MM_POISON_BEGIN, (vma));\
VM_BUG_ON_VMA((vma)->poison_end != MM_POISON_END, (vma));\
} while (0)
+#define VM_CHECK_POISON_PAGE(page) \
+ do { \
+ VM_BUG_ON_PAGE((page)->poison_start != MM_POISON_BEGIN,
(page));\
+ VM_BUG_ON_PAGE((page)->poison_end != MM_POISON_END, (page));\
+ } while (0)
#endif
#else
#define VM_BUG_ON(cond) BUILD_BUG_ON_INVALID(cond)
@@ -61,6 +66,7 @@ void dump_mm(const struct mm_struct *mm);
#define VM_WARN_ONCE(cond, format...) BUILD_BUG_ON_INVALID(cond)
#define VM_CHECK_POISON_MM(mm) do { } while(0)
#define VM_CHECK_POISON_VMA(vma) do { } while(0)
+#define VM_CHECK_POISON_PAGE(page) do { } while(0)
#endif
#ifdef CONFIG_DEBUG_VIRTUAL
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index e1f5fcd..688f72c 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -135,35 +135,43 @@ enum pageflags {
*/
#define TESTPAGEFLAG(uname, lname) \
static inline int Page##uname(const struct page *page) \
- { return test_bit(PG_##lname, &page->flags); }
+ { VM_CHECK_POISON_PAGE(page); \
+ return test_bit(PG_##lname, &page->flags); }
#define SETPAGEFLAG(uname, lname) \
static inline void SetPage##uname(struct page *page) \
- { set_bit(PG_##lname, &page->flags); }
+ { VM_CHECK_POISON_PAGE(page); \
+ set_bit(PG_##lname, &page->flags); }
#define CLEARPAGEFLAG(uname, lname) \
static inline void ClearPage##uname(struct page *page) \
- { clear_bit(PG_##lname, &page->flags); }
+ { VM_CHECK_POISON_PAGE(page); \
+ clear_bit(PG_##lname, &page->flags); }
#define __SETPAGEFLAG(uname, lname) \
static inline void __SetPage##uname(struct page *page) \
- { __set_bit(PG_##lname, &page->flags); }
+ { VM_CHECK_POISON_PAGE(page); \
+ __set_bit(PG_##lname, &page->flags); }
#define __CLEARPAGEFLAG(uname, lname) \
static inline void __ClearPage##uname(struct page *page) \
- { __clear_bit(PG_##lname, &page->flags); }
+ { VM_CHECK_POISON_PAGE(page); \
+ __clear_bit(PG_##lname, &page->flags); }
#define TESTSETFLAG(uname, lname) \
static inline int TestSetPage##uname(struct page *page)
\
- { return test_and_set_bit(PG_##lname, &page->flags); }
+ { VM_CHECK_POISON_PAGE(page); \
+ return test_and_set_bit(PG_##lname, &page->flags); }
#define TESTCLEARFLAG(uname, lname) \
static inline int TestClearPage##uname(struct page *page) \
- { return test_and_clear_bit(PG_##lname, &page->flags); }
+ { VM_CHECK_POISON_PAGE(page); \
+ return test_and_clear_bit(PG_##lname, &page->flags); }
#define __TESTCLEARFLAG(uname, lname) \
static inline int __TestClearPage##uname(struct page *page) \
- { return __test_and_clear_bit(PG_##lname, &page->flags); }
+ { VM_CHECK_POISON_PAGE(page); \
+ return __test_and_clear_bit(PG_##lname, &page->flags); }
#define PAGEFLAG(uname, lname) TESTPAGEFLAG(uname, lname) \
SETPAGEFLAG(uname, lname) CLEARPAGEFLAG(uname, lname)
--
1.9.1
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
