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-rw-r--r--include/linux/mm.h29
-rw-r--r--include/linux/page-flags-layout.h10
2 files changed, 39 insertions, 0 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 5411de93a363..b4d01969e700 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -804,6 +804,7 @@ vm_fault_t finish_mkwrite_fault(struct vm_fault *vmf);
#define NODES_PGOFF (SECTIONS_PGOFF - NODES_WIDTH)
#define ZONES_PGOFF (NODES_PGOFF - ZONES_WIDTH)
#define LAST_CPUPID_PGOFF (ZONES_PGOFF - LAST_CPUPID_WIDTH)
+#define KASAN_TAG_PGOFF (LAST_CPUPID_PGOFF - KASAN_TAG_WIDTH)
/*
* Define the bit shifts to access each section. For non-existent
@@ -814,6 +815,7 @@ vm_fault_t finish_mkwrite_fault(struct vm_fault *vmf);
#define NODES_PGSHIFT (NODES_PGOFF * (NODES_WIDTH != 0))
#define ZONES_PGSHIFT (ZONES_PGOFF * (ZONES_WIDTH != 0))
#define LAST_CPUPID_PGSHIFT (LAST_CPUPID_PGOFF * (LAST_CPUPID_WIDTH != 0))
+#define KASAN_TAG_PGSHIFT (KASAN_TAG_PGOFF * (KASAN_TAG_WIDTH != 0))
/* NODE:ZONE or SECTION:ZONE is used to ID a zone for the buddy allocator */
#ifdef NODE_NOT_IN_PAGE_FLAGS
@@ -836,6 +838,7 @@ vm_fault_t finish_mkwrite_fault(struct vm_fault *vmf);
#define NODES_MASK ((1UL << NODES_WIDTH) - 1)
#define SECTIONS_MASK ((1UL << SECTIONS_WIDTH) - 1)
#define LAST_CPUPID_MASK ((1UL << LAST_CPUPID_SHIFT) - 1)
+#define KASAN_TAG_MASK ((1UL << KASAN_TAG_WIDTH) - 1)
#define ZONEID_MASK ((1UL << ZONEID_SHIFT) - 1)
static inline enum zone_type page_zonenum(const struct page *page)
@@ -1101,6 +1104,32 @@ static inline bool cpupid_match_pid(struct task_struct *task, int cpupid)
}
#endif /* CONFIG_NUMA_BALANCING */
+#ifdef CONFIG_KASAN_SW_TAGS
+static inline u8 page_kasan_tag(const struct page *page)
+{
+ return (page->flags >> KASAN_TAG_PGSHIFT) & KASAN_TAG_MASK;
+}
+
+static inline void page_kasan_tag_set(struct page *page, u8 tag)
+{
+ page->flags &= ~(KASAN_TAG_MASK << KASAN_TAG_PGSHIFT);
+ page->flags |= (tag & KASAN_TAG_MASK) << KASAN_TAG_PGSHIFT;
+}
+
+static inline void page_kasan_tag_reset(struct page *page)
+{
+ page_kasan_tag_set(page, 0xff);
+}
+#else
+static inline u8 page_kasan_tag(const struct page *page)
+{
+ return 0xff;
+}
+
+static inline void page_kasan_tag_set(struct page *page, u8 tag) { }
+static inline void page_kasan_tag_reset(struct page *page) { }
+#endif
+
static inline struct zone *page_zone(const struct page *page)
{
return &NODE_DATA(page_to_nid(page))->node_zones[page_zonenum(page)];
diff --git a/include/linux/page-flags-layout.h b/include/linux/page-flags-layout.h
index 7ec86bf31ce4..1dda31825ec4 100644
--- a/include/linux/page-flags-layout.h
+++ b/include/linux/page-flags-layout.h
@@ -82,6 +82,16 @@
#define LAST_CPUPID_WIDTH 0
#endif
+#ifdef CONFIG_KASAN_SW_TAGS
+#define KASAN_TAG_WIDTH 8
+#if SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH+LAST_CPUPID_WIDTH+KASAN_TAG_WIDTH \
+ > BITS_PER_LONG - NR_PAGEFLAGS
+#error "KASAN: not enough bits in page flags for tag"
+#endif
+#else
+#define KASAN_TAG_WIDTH 0
+#endif
+
/*
* We are going to use the flags for the page to node mapping if its in
* there. This includes the case where there is no node, so it is implicit.