1 files changed, 45 insertions, 0 deletions
diff --git a/kernel/bpf/sysfs_btf.c b/kernel/bpf/sysfs_btf.c
new file mode 100644
index 000000000..ef6911aee
--- /dev/null
+++ b/kernel/bpf/sysfs_btf.c
@@ -0,0 +1,45 @@
+// 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 __start_BTF[];
+extern char __weak __stop_BTF[];
+
+static ssize_t
+btf_vmlinux_read(struct file *file, struct kobject *kobj,
+		 struct bin_attribute *bin_attr,
+		 char *buf, loff_t off, size_t len)
+{
+	memcpy(buf, __start_BTF + off, len);
+	return len;
+}
+
+static struct bin_attribute bin_attr_btf_vmlinux __ro_after_init = {
+	.attr = { .name = "vmlinux", .mode = 0444, },
+	.read = btf_vmlinux_read,
+};
+
+struct kobject *btf_kobj;
+
+static int __init btf_vmlinux_init(void)
+{
+	bin_attr_btf_vmlinux.size = __stop_BTF - __start_BTF;
+
+	if (!__start_BTF || bin_attr_btf_vmlinux.size == 0)
+		return 0;
+
+	btf_kobj = kobject_create_and_add("btf", kernel_kobj);
+	if (!btf_kobj)
+		return -ENOMEM;
+
+	return sysfs_create_bin_file(btf_kobj, &bin_attr_btf_vmlinux);
+}
+
+subsys_initcall(btf_vmlinux_init);