linux/kernel/kheaders.c

75 lines
1.8 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Provide kernel headers useful to build tracing programs
* such as for running eBPF tracing tools.
*
* (Borrowed code from kernel/configs.c)
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/proc_fs.h>
#include <linux/init.h>
#include <linux/uaccess.h>
/*
* Define kernel_headers_data and kernel_headers_data_end, within which the
* compressed kernel headers are stored. The file is first compressed with xz.
*/
asm (
" .pushsection .rodata, \"a\" \n"
" .global kernel_headers_data \n"
"kernel_headers_data: \n"
" .incbin \"kernel/kheaders_data.tar.xz\" \n"
" .global kernel_headers_data_end \n"
"kernel_headers_data_end: \n"
" .popsection \n"
);
extern char kernel_headers_data;
extern char kernel_headers_data_end;
static ssize_t
ikheaders_read_current(struct file *file, char __user *buf,
size_t len, loff_t *offset)
{
return simple_read_from_buffer(buf, len, offset,
&kernel_headers_data,
&kernel_headers_data_end -
&kernel_headers_data);
}
static const struct file_operations ikheaders_file_ops = {
.read = ikheaders_read_current,
.llseek = default_llseek,
};
static int __init ikheaders_init(void)
{
struct proc_dir_entry *entry;
/* create the current headers file */
entry = proc_create("kheaders.tar.xz", S_IRUGO, NULL,
&ikheaders_file_ops);
if (!entry)
return -ENOMEM;
proc_set_size(entry,
&kernel_headers_data_end -
&kernel_headers_data);
return 0;
}
static void __exit ikheaders_cleanup(void)
{
remove_proc_entry("kheaders.tar.xz", NULL);
}
module_init(ikheaders_init);
module_exit(ikheaders_cleanup);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Joel Fernandes");
MODULE_DESCRIPTION("Echo the kernel header artifacts used to build the kernel");