commit 94784872e7a57bbf47059c969128af401227e1a3
author Linux Build Service Account <lnxbuild@quicinc.com> Wed May 10 10:48:03 2017 -0700
committer Gerrit - the friendly Code Review server <code-review@localhost> Wed May 10 10:48:03 2017 -0700
tree 7ccd308b87b408ee0cb1e22c4ffa622eaac8075a
parent 8f2f68463c6fa0a332510921283eb43efa4afd72
parent dcbca175daec552b75ba03f696575d397ee1fb11

Merge "kasan: improve double-free report format" into msm-4.9

mm/kasan/kasan.c

diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c
index 0e9505f..1258b16 100644
--- a/mm/kasan/kasan.c
+++ b/mm/kasan/kasan.c
@@ -559,7 +559,8 @@ bool kasan_slab_free(struct kmem_cache *cache, void *object)
 
 	shadow_byte = READ_ONCE(*(s8 *)kasan_mem_to_shadow(object));
 	if (shadow_byte < 0 || shadow_byte >= KASAN_SHADOW_SCALE_SIZE) {
-		kasan_report_double_free(cache, object, shadow_byte);
+		kasan_report_double_free(cache, object,
+				__builtin_return_address(1));
 		return true;
 	}
 

mm/kasan/kasan.h

diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
index 1c260e6..7572917 100644
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h
@@ -104,7 +104,7 @@ static inline bool kasan_report_enabled(void)
 void kasan_report(unsigned long addr, size_t size,
 		bool is_write, unsigned long ip);
 void kasan_report_double_free(struct kmem_cache *cache, void *object,
-			s8 shadow);
+					void *ip);
 
 #if defined(CONFIG_SLAB) || defined(CONFIG_SLUB)
 void quarantine_put(struct kasan_free_meta *info, struct kmem_cache *cache);

mm/kasan/report.c

diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index 44166a6..ca3e926 100644
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -238,22 +238,8 @@ static void describe_object(struct kmem_cache *cache, void *object,
 	describe_object_addr(cache, object, addr);
 }
 
-void kasan_report_double_free(struct kmem_cache *cache, void *object,
-			s8 shadow)
+static void print_address_description(void *addr)
 {
-	unsigned long flags;
-
-	kasan_start_report(&flags);
-	pr_err("BUG: Double free or freeing an invalid pointer\n");
-	pr_err("Unexpected shadow byte: 0x%hhX\n", shadow);
-	dump_stack();
-	describe_object(cache, object, NULL);
-	kasan_end_report(&flags);
-}
-
-static void print_address_description(struct kasan_access_info *info)
-{
-	void *addr = (void *)info->access_addr;
 	struct page *page = addr_to_page(addr);
 
 	dump_stack();
@@ -328,6 +314,18 @@ static void print_shadow_for_address(const void *addr)
 	}
 }
 
+void kasan_report_double_free(struct kmem_cache *cache, void *object,
+				void *ip)
+{
+	unsigned long flags;
+
+	kasan_start_report(&flags);
+	pr_err("BUG: KASAN: double-free or invalid-free in %pS\n", ip);
+	print_address_description(object);
+	print_shadow_for_address(object);
+	kasan_end_report(&flags);
+}
+
 static void kasan_report_error(struct kasan_access_info *info)
 {
 	unsigned long flags;
@@ -339,7 +337,7 @@ static void kasan_report_error(struct kasan_access_info *info)
 	if (!addr_has_shadow(info)) {
 		dump_stack();
 	} else {
-		print_address_description(info);
+		print_address_description((void *)info->access_addr);
 		print_shadow_for_address(info->first_bad_addr);
 	}