linux_old1/kernel/bpf/sysfs_btf.c

52 lines
1.2 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Provide kernel BTF information for introspection and use by eBPF tools.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/kobject.h>
#include <linux/init.h>
#include <linux/sysfs.h>
/* See scripts/link-vmlinux.sh, gen_btf() func for details */
extern char __weak _binary__btf_kernel_bin_start[];
extern char __weak _binary__btf_kernel_bin_end[];
static ssize_t
btf_kernel_read(struct file *file, struct kobject *kobj,
struct bin_attribute *bin_attr,
char *buf, loff_t off, size_t len)
{
memcpy(buf, _binary__btf_kernel_bin_start + off, len);
return len;
}
static struct bin_attribute bin_attr_btf_kernel __ro_after_init = {
.attr = { .name = "kernel", .mode = 0444, },
.read = btf_kernel_read,
};
static struct kobject *btf_kobj;
static int __init btf_kernel_init(void)
{
int err;
if (!_binary__btf_kernel_bin_start)
return 0;
btf_kobj = kobject_create_and_add("btf", kernel_kobj);
if (IS_ERR(btf_kobj)) {
err = PTR_ERR(btf_kobj);
btf_kobj = NULL;
return err;
}
bin_attr_btf_kernel.size = _binary__btf_kernel_bin_end -
_binary__btf_kernel_bin_start;
return sysfs_create_bin_file(btf_kobj, &bin_attr_btf_kernel);
}
subsys_initcall(btf_kernel_init);