| 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/kobject.h>
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| 12 | #include <linux/init.h>
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| 13 |
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| 14 | |
| 15 | * Define kernel_headers_data and kernel_headers_data_end, within which the
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| 16 | * compressed kernel headers are stored. The file is first compressed with xz.
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| 17 |
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| 18 |
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| 19 | asm (
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| 20 | " .pushsection .rodata, \"a\" \n"
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| 21 | " .global kernel_headers_data \n"
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| 22 | "kernel_headers_data: \n"
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| 23 | " .incbin \"kernel/kheaders_data.tar.xz\" \n"
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| 24 | " .global kernel_headers_data_end \n"
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| 25 | "kernel_headers_data_end: \n"
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| 26 | " .popsection \n"
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| 27 | );
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| 28 |
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| 29 | extern char kernel_headers_data;
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| 30 | extern char kernel_headers_data_end;
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| 31 |
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| 32 | static ssize_t
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| 33 | ikheaders_read(struct file *file, struct kobject *kobj,
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| 34 | struct bin_attribute *bin_attr,
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| 35 | char *buf, loff_t off, size_t len)
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| 36 | {
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| 37 | memcpy(buf, &kernel_headers_data + off, len);
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| 38 | return len;
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| 39 | }
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| 40 |
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| 41 | static struct bin_attribute kheaders_attr __ro_after_init = {
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| 42 | .attr = {
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| 43 | .name = "kheaders.tar.xz",
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| 44 | .mode = 0444,
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| 45 | },
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| 46 | .read = &ikheaders_read,
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| 47 | };
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| 48 |
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| 49 | static int __init ikheaders_init(void)
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| 50 | {
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| 51 | kheaders_attr.size = (&kernel_headers_data_end -
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| 52 | &kernel_headers_data);
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| 53 | return sysfs_create_bin_file(kernel_kobj, &kheaders_attr);
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| 54 | }
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| 55 |
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| 56 | static void __exit ikheaders_cleanup(void)
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| 57 | {
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| 58 | sysfs_remove_bin_file(kernel_kobj, &kheaders_attr);
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| 59 | }
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| 60 |
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| 61 | module_init(ikheaders_init);
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| 62 | module_exit(ikheaders_cleanup);
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| 63 |
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| 64 | MODULE_LICENSE("GPL v2");
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| 65 | MODULE_AUTHOR("Joel Fernandes");
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| 66 | MODULE_DESCRIPTION("Echo the kernel header artifacts used to build the kernel");
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