xref: /freebsd/sys/contrib/openzfs/module/os/linux/zfs/kasan_compat.c (revision 546d3d08e5993cbe2d6141b256e8c2ebad5aa102)
1 // SPDX-License-Identifier: CDDL-1.0
2 /*
3  * CDDL HEADER START
4  *
5  * The contents of this file are subject to the terms of the
6  * Common Development and Distribution License (the "License").
7  * You may not use this file except in compliance with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or https://opensource.org/licenses/CDDL-1.0.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 
23 /*
24  * Copyright (c) 2025, Rob Norris <robn@despairlabs.com>
25  */
26 
27 #ifndef _ZFS_LINUX_KASAN_ENABLED_H
28 #define	_ZFS_LINUX_KASAN_ENABLED_H
29 
30 #ifdef HAVE_KASAN_ENABLED_GPL_ONLY
31 /*
32  * The kernel supports a runtime setting to enable/disable KASAN. The control
33  * flag kasan_flag_enabled is a GPL-only symbol, which prevents us from
34  * accessing it. Unfortunately, this is called by the header function
35  * kasan_enabled(), which in turn is used to call or skip instrumentation
36  * functions in various header-based kernel facilities. If we inadvertently
37  * call one, the build breaks.
38  *
39  * To work around this, we define our own `kasan_flag_enabled` set to "false",
40  * disabling use of KASAN inside our code. The linker will resolve this symbol
41  * at build time, and so never need to reach out to the off-limits kernel
42  * symbol.
43  */
44 #include <linux/static_key.h>
45 struct static_key_false kasan_flag_enabled = STATIC_KEY_FALSE_INIT;
46 #endif
47 
48 #endif
49