[PATCH] lib/stackdeopt: use original shadow

[Joonsoo Kim]

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
---
 lib/stackdepot.c |  7 ++++++-
 mm/kasan/kasan.c | 12 ++++++++++++
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/lib/stackdepot.c b/lib/stackdepot.c
index f87d138..cc98ce2 100644
--- a/lib/stackdepot.c
+++ b/lib/stackdepot.c
@@ -80,6 +80,8 @@ static int next_slab_inited;
 static size_t depot_offset;
 static DEFINE_SPINLOCK(depot_lock);
 
+extern void kasan_map_shadow_private(const void *addr, size_t size, gfp_t flags);
+
 static bool init_stack_slab(void **prealloc)
 {
 	if (!*prealloc)
@@ -245,8 +247,11 @@ depot_stack_handle_t depot_save_stack(struct stack_trace *trace,
 		alloc_flags &= (GFP_ATOMIC | GFP_KERNEL);
 		alloc_flags |= __GFP_NOWARN;
 		page = alloc_pages(alloc_flags, STACK_ALLOC_ORDER);
-		if (page)
+		if (page) {
 			prealloc = page_address(page);
+			kasan_map_shadow_private(prealloc,
+				PAGE_SIZE << STACK_ALLOC_ORDER, alloc_flags);
+		}
 	}
 
 	spin_lock_irqsave(&depot_lock, flags);
diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c
index fd6b7d4..3c18d18 100644
--- a/mm/kasan/kasan.c
+++ b/mm/kasan/kasan.c
@@ -247,6 +247,18 @@ static int kasan_map_shadow(const void *addr, size_t size, gfp_t flags)
 	return err;
 }
 
+void kasan_map_shadow_private(const void *addr, size_t size, gfp_t flags)
+{
+	int err;
+
+	err = kasan_map_shadow(addr, size, flags);
+	if (err)
+		return;
+
+	kasan_unpoison_shadow(addr, size);
+	kasan_poison_pshadow(addr, size);
+}
+
 static int kasan_unmap_shadow_pte(pte_t *ptep, pgtable_t token,
 			unsigned long addr, void *data)
 {
-- 
2.7.4