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-rw-r--r--kernel/kheaders.c66
1 files changed, 66 insertions, 0 deletions
diff --git a/kernel/kheaders.c b/kernel/kheaders.c
new file mode 100644
index 0000000000..42163c9e94
--- /dev/null
+++ b/kernel/kheaders.c
@@ -0,0 +1,66 @@
+// 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\" \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(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");