xref: /linux/kernel/kheaders.c (revision 2ab002c755bfa88777e3f2db884d531f3010736c)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Provide kernel headers useful to build tracing programs
4  * such as for running eBPF tracing tools.
5  *
6  * (Borrowed code from kernel/configs.c)
7  */
8 
9 #include <linux/kernel.h>
10 #include <linux/module.h>
11 #include <linux/kobject.h>
12 #include <linux/init.h>
13 
14 /*
15  * Define kernel_headers_data and kernel_headers_data_end, within which the
16  * compressed kernel headers are stored. The file is first compressed with xz.
17  */
18 
19 asm (
20 "	.pushsection .rodata, \"a\"		\n"
21 "	.global kernel_headers_data		\n"
22 "kernel_headers_data:				\n"
23 "	.incbin \"kernel/kheaders_data.tar.xz\"	\n"
24 "	.global kernel_headers_data_end		\n"
25 "kernel_headers_data_end:			\n"
26 "	.popsection				\n"
27 );
28 
29 extern char kernel_headers_data[];
30 extern char kernel_headers_data_end[];
31 
32 static struct bin_attribute kheaders_attr __ro_after_init =
33 	__BIN_ATTR_SIMPLE_RO(kheaders.tar.xz, 0444);
34 
35 static int __init ikheaders_init(void)
36 {
37 	kheaders_attr.private = kernel_headers_data;
38 	kheaders_attr.size = (kernel_headers_data_end -
39 			      kernel_headers_data);
40 	return sysfs_create_bin_file(kernel_kobj, &kheaders_attr);
41 }
42 
43 static void __exit ikheaders_cleanup(void)
44 {
45 	sysfs_remove_bin_file(kernel_kobj, &kheaders_attr);
46 }
47 
48 module_init(ikheaders_init);
49 module_exit(ikheaders_cleanup);
50 
51 MODULE_LICENSE("GPL v2");
52 MODULE_AUTHOR("Joel Fernandes");
53 MODULE_DESCRIPTION("Echo the kernel header artifacts used to build the kernel");
54