@@ -1,4 +1,4 @@
-/*	$NetBSD: asan.c,v 1.3 2018/08/22 12:07:42 maxv Exp $	*/
+/*	$NetBSD: asan.c,v 1.4 2018/08/22 17:04:36 maxv Exp $	*/
 
 /*
  * Copyright (c) 2018 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: asan.c,v 1.3 2018/08/22 12:07:42 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: asan.c,v 1.4 2018/08/22 17:04:36 maxv Exp $");
 
 #include <sys/param.h>
 #include <sys/device.h>
@@ -59,6 +59,7 @@
 
 #define __RET_ADDR	(unsigned long)__builtin_return_address(0)
 
+void kasan_softint(struct lwp *);
 void kasan_shadow_map(void *, size_t);
 void kasan_early_init(void);
 void kasan_init(void);
@@ -320,6 +321,14 @@
 		KASSERT(size % KASAN_SHADOW_SCALE_SIZE == 0);
 		kasan_shadow_fill(addr, size, KASAN_MEMORY_REDZONE);
 	}
+}
+
+void
+kasan_softint(struct lwp *l)
+{
+	const void *stk = (const void *)uvm_lwp_getuarea(l);
+
+	kasan_shadow_fill(stk, USPACE, 0);
 }
 
 void

@@ -1,4 +1,4 @@
-/*	$NetBSD: spl.S,v 1.35 2018/07/14 14:29:40 maxv Exp $	*/
+/*	$NetBSD: spl.S,v 1.36 2018/08/22 17:04:36 maxv Exp $	*/
 
 /*
  * Copyright (c) 2003 Wasabi Systems, Inc.
@@ -65,6 +65,7 @@
  */
 
 #include "opt_ddb.h"
+#include "opt_kasan.h"
 
 #define ALIGN_TEXT	.align 16,0x90
 
@@ -104,6 +105,17 @@
 	movq	L_PCB(%rdi),%rdx
 	movq	L_PCB(%r15),%rcx
 	movq	%rdi,CPUVAR(CURLWP)
+
+#ifdef KASAN
+	/* clear the new stack */
+	pushq	%rax
+	pushq	%rdx
+	pushq	%rcx
+	callq	_C_LABEL(kasan_softint)
+	popq	%rcx
+	popq	%rdx
+	popq	%rax
+#endif
 
 	/* save old context */
 	movq	%rsp,PCB_RSP(%rcx)