// 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/kobject.h>

  #include <linux/init.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\"		
  "
  "	.global kernel_headers_data		
  "
  "kernel_headers_data:				
  "
  "	.incbin \"kernel/kheaders_data.tar.xz\"	
  "
  "	.global kernel_headers_data_end		
  "
  "kernel_headers_data_end:			
  "
  "	.popsection				
  "
  );
  
  extern char kernel_headers_data;
  extern char kernel_headers_data_end;
  
  static ssize_t

  ikheaders_read(struct file *file,  struct kobject *kobj,
  	       struct bin_attribute *bin_attr,
  	       char *buf, loff_t off, size_t len)

  {

  	memcpy(buf, &kernel_headers_data + off, len);
  	return len;

  }

  static struct bin_attribute kheaders_attr __ro_after_init = {
  	.attr = {
  		.name = "kheaders.tar.xz",
  		.mode = 0444,
  	},
  	.read = &ikheaders_read,

  };
  
  static int __init ikheaders_init(void)
  {

  	kheaders_attr.size = (&kernel_headers_data_end -
  			      &kernel_headers_data);
  	return sysfs_create_bin_file(kernel_kobj, &kheaders_attr);

  }
  
  static void __exit ikheaders_cleanup(void)
  {

  	sysfs_remove_bin_file(kernel_kobj, &kheaders_attr);

  }
  
  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");