| 1 | |
| 2 | |
| 3 | * Provide kernel headers useful to build tracing programs
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| 4 | * such as for running eBPF tracing tools.
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| 5 | *
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| 6 | * (Borrowed code from kernel/configs.c)
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| 7 |
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| 8 |
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| 9 | #include <linux/kernel.h>
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| 10 | #include <linux/module.h>
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| 11 | #include <linux/proc_fs.h>
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| 12 | #include <linux/init.h>
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| 13 | #include <linux/uaccess.h>
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| 14 |
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| 15 | |
| 16 | * Define kernel_headers_data and kernel_headers_data_end, within which the
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| 17 | * compressed kernel headers are stored. The file is first compressed with xz.
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| 18 |
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| 19 |
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| 20 | asm (
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| 21 | " .pushsection .rodata, \"a\" \n"
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| 22 | " .global kernel_headers_data \n"
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| 23 | "kernel_headers_data: \n"
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| 24 | " .incbin \"kernel/kheaders_data.tar.xz\" \n"
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| 25 | " .global kernel_headers_data_end \n"
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| 26 | "kernel_headers_data_end: \n"
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| 27 | " .popsection \n"
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| 28 | );
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| 29 |
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| 30 | extern char kernel_headers_data;
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| 31 | extern char kernel_headers_data_end;
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| 32 |
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| 33 | static ssize_t
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| 34 | ikheaders_read_current(struct file *file, char __user *buf,
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| 35 | size_t len, loff_t *offset)
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| 36 | {
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| 37 | return simple_read_from_buffer(buf, len, offset,
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| 38 | &kernel_headers_data,
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| 39 | &kernel_headers_data_end -
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| 40 | &kernel_headers_data);
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| 41 | }
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| 42 |
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| 43 | static const struct file_operations ikheaders_file_ops = {
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| 44 | .read = ikheaders_read_current,
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| 45 | .llseek = default_llseek,
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| 46 | };
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| 47 |
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| 48 | static int __init ikheaders_init(void)
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| 49 | {
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| 50 | struct proc_dir_entry *entry;
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| 51 |
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| 52 |
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| 53 | entry = proc_create("kheaders.tar.xz", S_IRUGO, NULL,
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| 54 | &ikheaders_file_ops);
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| 55 | if (!entry)
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| 56 | return -ENOMEM;
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| 57 |
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| 58 | proc_set_size(entry,
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| 59 | &kernel_headers_data_end -
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| 60 | &kernel_headers_data);
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| 61 | return 0;
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| 62 | }
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| 63 |
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| 64 | static void __exit ikheaders_cleanup(void)
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| 65 | {
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| 66 | remove_proc_entry("kheaders.tar.xz", NULL);
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| 67 | }
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| 68 |
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| 69 | module_init(ikheaders_init);
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| 70 | module_exit(ikheaders_cleanup);
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| 71 |
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| 72 | MODULE_LICENSE("GPL v2");
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| 73 | MODULE_AUTHOR("Joel Fernandes");
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| 74 | MODULE_DESCRIPTION("Echo the kernel header artifacts used to build the kernel");
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