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"); 77