123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137 |
- // SPDX-License-Identifier: GPL-2.0-only
- /*
- * Copyright 2021 Google LLC
- *
- * This file can optionally be built into fips140.ko in order to support certain
- * types of testing that the FIPS lab has to do to evaluate the module. It
- * should not be included in production builds of the module.
- */
- /*
- * We have to redefine inline to mean always_inline, so that _copy_to_user()
- * gets inlined. This is needed for it to be placed into the correct section.
- * See fips140_copy_to_user().
- *
- * We also need to undefine BUILD_FIPS140_KO to allow the use of the code
- * patching which copy_to_user() requires.
- */
- #undef inline
- #define inline inline __attribute__((__always_inline__)) __gnu_inline \
- __inline_maybe_unused notrace
- #undef BUILD_FIPS140_KO
- /*
- * Since this .c file contains real module parameters for fips140.ko, it needs
- * to be compiled normally, so undo the hacks that were done in fips140-defs.h.
- */
- #define MODULE
- #undef KBUILD_MODFILE
- #undef __DISABLE_EXPORTS
- #include <linux/cdev.h>
- #include <linux/fs.h>
- #include <linux/module.h>
- #include <linux/slab.h>
- #include "fips140-module.h"
- #include "fips140-eval-testing-uapi.h"
- /*
- * This option allows deliberately failing the self-tests for a particular
- * algorithm.
- */
- static char *fips140_fail_selftest;
- module_param_named(fail_selftest, fips140_fail_selftest, charp, 0);
- /* This option allows deliberately failing the integrity check. */
- static bool fips140_fail_integrity_check;
- module_param_named(fail_integrity_check, fips140_fail_integrity_check, bool, 0);
- static dev_t fips140_devnum;
- static struct cdev fips140_cdev;
- /* Inject a self-test failure (via corrupting the result) if requested. */
- void fips140_inject_selftest_failure(const char *impl, u8 *result)
- {
- if (fips140_fail_selftest && strcmp(impl, fips140_fail_selftest) == 0)
- result[0] ^= 0xff;
- }
- /* Inject an integrity check failure (via corrupting the text) if requested. */
- void fips140_inject_integrity_failure(u8 *textcopy)
- {
- if (fips140_fail_integrity_check)
- textcopy[0] ^= 0xff;
- }
- static long fips140_ioctl_is_approved_service(unsigned long arg)
- {
- const char *service_name = strndup_user((const char __user *)arg, 256);
- long ret;
- if (IS_ERR(service_name))
- return PTR_ERR(service_name);
- ret = fips140_is_approved_service(service_name);
- kfree(service_name);
- return ret;
- }
- /*
- * Code in fips140.ko is covered by an integrity check by default, and this
- * check breaks if copy_to_user() is called. This is because copy_to_user() is
- * an inline function that relies on code patching. However, since this is
- * "evaluation testing" code which isn't included in the production builds of
- * fips140.ko, it's acceptable to just exclude it from the integrity check.
- */
- static noinline unsigned long __section("text.._fips140_unchecked")
- fips140_copy_to_user(void __user *to, const void *from, unsigned long n)
- {
- return copy_to_user(to, from, n);
- }
- static long fips140_ioctl_module_version(unsigned long arg)
- {
- const char *version = fips140_module_version();
- size_t len = strlen(version) + 1;
- if (len > 256)
- return -EOVERFLOW;
- if (fips140_copy_to_user((void __user *)arg, version, len))
- return -EFAULT;
- return 0;
- }
- static long fips140_ioctl(struct file *file, unsigned int cmd,
- unsigned long arg)
- {
- switch (cmd) {
- case FIPS140_IOCTL_IS_APPROVED_SERVICE:
- return fips140_ioctl_is_approved_service(arg);
- case FIPS140_IOCTL_MODULE_VERSION:
- return fips140_ioctl_module_version(arg);
- default:
- return -ENOTTY;
- }
- }
- static const struct file_operations fips140_fops = {
- .unlocked_ioctl = fips140_ioctl,
- };
- bool fips140_eval_testing_init(void)
- {
- if (alloc_chrdev_region(&fips140_devnum, 1, 1, "fips140") != 0) {
- pr_err("failed to allocate device number\n");
- return false;
- }
- cdev_init(&fips140_cdev, &fips140_fops);
- if (cdev_add(&fips140_cdev, fips140_devnum, 1) != 0) {
- pr_err("failed to add fips140 character device\n");
- return false;
- }
- return true;
- }
|