[Devel] [PATCH 21/39] kmemleak: disable kasan instrumentation for kmemleak

[Andrey Ryabinin]

From: Andrey Ryabinin <a.ryabinin at samsung.com>

commit e79ed2f13faab8fc9d4ad76d5f5a241724e45836 upstream.

kmalloc internally round up allocation size, and kmemleak uses rounded up
size as object's size.  This makes kasan to complain while kmemleak scans
memory or calculates of object's checksum.  The simplest solution here is
to disable kasan.

Signed-off-by: Andrey Ryabinin <a.ryabinin at samsung.com>
Acked-by: Catalin Marinas <catalin.marinas at arm.com>
Cc: Dmitry Vyukov <dvyukov at google.com>
Cc: Konstantin Serebryany <kcc at google.com>
Cc: Dmitry Chernenkov <dmitryc at google.com>
Signed-off-by: Andrey Konovalov <adech.fo at gmail.com>
Cc: Yuri Gribov <tetra2005 at gmail.com>
Cc: Konstantin Khlebnikov <koct9i at gmail.com>
Cc: Sasha Levin <sasha.levin at oracle.com>
Cc: Christoph Lameter <cl at linux.com>
Cc: Joonsoo Kim <iamjoonsoo.kim at lge.com>
Cc: Dave Hansen <dave.hansen at intel.com>
Cc: Andi Kleen <andi at firstfloor.org>
Cc: Ingo Molnar <mingo at elte.hu>
Cc: Thomas Gleixner <tglx at linutronix.de>
Cc: "H. Peter Anvin" <hpa at zytor.com>
Cc: Christoph Lameter <cl at linux.com>
Cc: Pekka Enberg <penberg at kernel.org>
Cc: David Rientjes <rientjes at google.com>
Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
Signed-off-by: Andrey Ryabinin <aryabinin at odin.com>
---
 mm/kmemleak.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/mm/kmemleak.c b/mm/kmemleak.c
index 98e1b34..5fe0a34 100644
--- a/mm/kmemleak.c
+++ b/mm/kmemleak.c
@@ -98,6 +98,7 @@
 #include <asm/processor.h>
 #include <linux/atomic.h>
 
+#include <linux/kasan.h>
 #include <linux/kmemcheck.h>
 #include <linux/kmemleak.h>
 #include <linux/memory_hotplug.h>
@@ -1077,7 +1078,10 @@ static bool update_checksum(struct kmemleak_object *object)
 	if (!kmemcheck_is_obj_initialized(object->pointer, object->size))
 		return false;
 
+	kasan_disable_current();
 	object->checksum = crc32(0, (void *)object->pointer, object->size);
+	kasan_enable_current();
+
 	return object->checksum != old_csum;
 }
 
@@ -1128,7 +1132,9 @@ static void scan_block(void *_start, void *_end,
 						  BYTES_PER_POINTER))
 			continue;
 
+		kasan_disable_current();
 		pointer = *ptr;
+		kasan_enable_current();
 
 		object = find_and_get_object(pointer, 1);
 		if (!object)
-- 
2.4.6