From f79f520dc86a49487b124f17347cbb17a98abbf9 Mon Sep 17 00:00:00 2001
From: Tao Zeng <tao.zeng@amlogic.com>
Date: Tue, 25 Dec 2018 17:43:02 +0800
Subject: [PATCH] mm: fix too many wrong kasan report [1/1]

PD#SWPL-3583

Problem:
After merge change:
http://scgit.amlogic.com:8080/#/c/55018/
Too many wrong kasan report occur when booting kernel

Solution:
Fix kasan poison address range when free wasted memory.

Verify:
P212

Change-Id: I576a7edb7b4e70f9c6c782639f433ad45bafba1d
Signed-off-by: Tao Zeng <tao.zeng@amlogic.com>
---
 include/linux/kasan.h |  9 +++++++++
 mm/kasan/kasan.c      | 25 +++++++++++++++++++++++++
 mm/slab_common.c      | 16 ++++++++++++++--
 mm/slub.c             |  8 ++++++--
 4 files changed, 54 insertions(+), 4 deletions(-)

diff --git a/include/linux/kasan.h b/include/linux/kasan.h
index b37afd1..ecd57cf 100644
--- a/include/linux/kasan.h
+++ b/include/linux/kasan.h
@@ -54,6 +54,9 @@ void kasan_poison_object_data(struct kmem_cache *cache, void *object);
 void kasan_init_slab_obj(struct kmem_cache *cache, const void *object);
 
 void kasan_kmalloc_large(const void *ptr, size_t size, gfp_t flags);
+#ifdef CONFIG_AMLOGIC_MEMORY_EXTEND
+void kasan_kmalloc_save(const void *ptr, size_t size, gfp_t flags);
+#endif
 void kasan_kfree_large(const void *ptr);
 void kasan_poison_kfree(void *ptr);
 void kasan_kmalloc(struct kmem_cache *s, const void *object, size_t size,
@@ -106,6 +109,12 @@ static inline void kasan_init_slab_obj(struct kmem_cache *cache,
 				const void *object) {}
 
 static inline void kasan_kmalloc_large(void *ptr, size_t size, gfp_t flags) {}
+#ifdef CONFIG_AMLOGIC_MEMORY_EXTEND
+static inline void kasan_kmalloc_save(const void *ptr, size_t size,
+				      gfp_t flags)
+{
+}
+#endif
 static inline void kasan_kfree_large(const void *ptr) {}
 static inline void kasan_poison_kfree(void *ptr) {}
 static inline void kasan_kmalloc(struct kmem_cache *s, const void *object,
diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c
index 7d78b5f..8622541 100644
--- a/mm/kasan/kasan.c
+++ b/mm/kasan/kasan.c
@@ -632,6 +632,31 @@ void kasan_kmalloc_large(const void *ptr, size_t size, gfp_t flags)
 		KASAN_PAGE_REDZONE);
 }
 
+#ifdef CONFIG_AMLOGIC_MEMORY_EXTEND
+void kasan_kmalloc_save(const void *ptr, size_t size, gfp_t flags)
+{
+	struct page *page;
+	unsigned long redzone_start;
+	unsigned long redzone_end;
+
+	if (gfpflags_allow_blocking(flags))
+		quarantine_reduce();
+
+	if (unlikely(ptr == NULL))
+		return;
+
+	page = virt_to_page(ptr);
+	redzone_start = round_up((unsigned long)(ptr + size),
+				KASAN_SHADOW_SCALE_SIZE);
+	redzone_end = (unsigned long)ptr + PAGE_ALIGN(size);
+
+	kasan_unpoison_shadow(ptr, size);
+	kasan_poison_shadow((void *)redzone_start, redzone_end - redzone_start,
+		KASAN_PAGE_REDZONE);
+}
+
+#endif
+
 void kasan_krealloc(const void *object, size_t size, gfp_t flags)
 {
 	struct page *page;
diff --git a/mm/slab_common.c b/mm/slab_common.c
index 07b8fc8..45b23eb 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -1091,19 +1091,31 @@ void *kmalloc_order(size_t size, gfp_t flags, unsigned int order)
 {
 	void *ret;
 	struct page *page;
+#ifdef CONFIG_AMLOGIC_MEMORY_EXTEND
+	int saved = 0;
+#endif
 
 	flags |= __GFP_COMP;
 #ifdef CONFIG_AMLOGIC_MEMORY_EXTEND
-	if (size < (PAGE_SIZE * (1 << order)))
+	if (size < (PAGE_SIZE * (1 << order))) {
 		page = aml_slub_alloc_large(size, flags, order);
-	else
+		saved = 1;
+	} else
 		page = alloc_pages(flags, order);
 #else
 	page = alloc_pages(flags, order);
 #endif
 	ret = page ? page_address(page) : NULL;
 	kmemleak_alloc(ret, size, 1, flags);
+#ifdef CONFIG_AMLOGIC_MEMORY_EXTEND
+	/* only need poison used pages */
+	if (saved && ret)
+		kasan_kmalloc_save(ret, size, flags);
+	else
+		kasan_kmalloc_large(ret, size, flags);
+#else
 	kasan_kmalloc_large(ret, size, flags);
+#endif
 	return ret;
 }
 EXPORT_SYMBOL(kmalloc_order);
diff --git a/mm/slub.c b/mm/slub.c
index 71ae980..59ec527 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -3734,6 +3734,7 @@ static void aml_slub_free_large(struct page *page, const void *obj)
 			__func__, page_address(page), nr_pages, obj);
 		for (i = 0; i < nr_pages; i++)  {
 			__free_pages(page, 0);
+			kasan_free_pages(page, 0);
 			page++;
 		}
 	}
@@ -3900,14 +3901,17 @@ void kfree(const void *x)
 	page = virt_to_head_page(x);
 	if (unlikely(!PageSlab(page))) {
 		BUG_ON(!PageCompound(page));
-		kfree_hook(x);
 	#ifdef CONFIG_AMLOGIC_MEMORY_EXTEND
+		kmemleak_free(x);
 		if (unlikely(PageOwnerPriv1(page)))
 			aml_slub_free_large(page, x);
-		else
+		else {
 			__free_pages(page, compound_order(page));
+			kasan_kfree_large(x);
+		}
 		return;
 	#else
+		kfree_hook(x);
 		__free_pages(page, compound_order(page));
 		return;
 	#endif /* CONFIG_AMLOGIC_MEMORY_EXTEND */
-- 
2.7.4