Merge tag 'for-linus-2022100501' of git://git.kernel.org/pub/scm/linux/kernel/git...
[platform/kernel/linux-starfive.git] / lib / fortify_kunit.c
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Runtime test cases for CONFIG_FORTIFY_SOURCE that aren't expected to
4  * Oops the kernel on success. (For those, see drivers/misc/lkdtm/fortify.c)
5  *
6  * For corner cases with UBSAN, try testing with:
7  *
8  * ./tools/testing/kunit/kunit.py run --arch=x86_64 \
9  *      --kconfig_add CONFIG_FORTIFY_SOURCE=y \
10  *      --kconfig_add CONFIG_UBSAN=y \
11  *      --kconfig_add CONFIG_UBSAN_TRAP=y \
12  *      --kconfig_add CONFIG_UBSAN_BOUNDS=y \
13  *      --kconfig_add CONFIG_UBSAN_LOCAL_BOUNDS=y \
14  *      --make_options LLVM=1 fortify
15  */
16 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
17
18 #include <kunit/test.h>
19 #include <linux/string.h>
20
21 static const char array_of_10[] = "this is 10";
22 static const char *ptr_of_11 = "this is 11!";
23 static char array_unknown[] = "compiler thinks I might change";
24
25 static void known_sizes_test(struct kunit *test)
26 {
27         KUNIT_EXPECT_EQ(test, __compiletime_strlen("88888888"), 8);
28         KUNIT_EXPECT_EQ(test, __compiletime_strlen(array_of_10), 10);
29         KUNIT_EXPECT_EQ(test, __compiletime_strlen(ptr_of_11), 11);
30
31         KUNIT_EXPECT_EQ(test, __compiletime_strlen(array_unknown), SIZE_MAX);
32         /* Externally defined and dynamically sized string pointer: */
33         KUNIT_EXPECT_EQ(test, __compiletime_strlen(test->name), SIZE_MAX);
34 }
35
36 /* This is volatile so the optimizer can't perform DCE below. */
37 static volatile int pick;
38
39 /* Not inline to keep optimizer from figuring out which string we want. */
40 static noinline size_t want_minus_one(int pick)
41 {
42         const char *str;
43
44         switch (pick) {
45         case 1:
46                 str = "4444";
47                 break;
48         case 2:
49                 str = "333";
50                 break;
51         default:
52                 str = "1";
53                 break;
54         }
55         return __compiletime_strlen(str);
56 }
57
58 static void control_flow_split_test(struct kunit *test)
59 {
60         KUNIT_EXPECT_EQ(test, want_minus_one(pick), SIZE_MAX);
61 }
62
63 static struct kunit_case fortify_test_cases[] = {
64         KUNIT_CASE(known_sizes_test),
65         KUNIT_CASE(control_flow_split_test),
66         {}
67 };
68
69 static struct kunit_suite fortify_test_suite = {
70         .name = "fortify",
71         .test_cases = fortify_test_cases,
72 };
73
74 kunit_test_suite(fortify_test_suite);
75
76 MODULE_LICENSE("GPL");