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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/device.h>
19#include <kunit/test.h>
20#include <linux/device.h>
21#include <linux/slab.h>
22#include <linux/string.h>
23#include <linux/vmalloc.h>
24
25static const char array_of_10[] = "this is 10";
26static const char *ptr_of_11 = "this is 11!";
27static char array_unknown[] = "compiler thinks I might change";
28
29static void known_sizes_test(struct kunit *test)
30{
31 KUNIT_EXPECT_EQ(test, __compiletime_strlen("88888888"), 8);
32 KUNIT_EXPECT_EQ(test, __compiletime_strlen(array_of_10), 10);
33 KUNIT_EXPECT_EQ(test, __compiletime_strlen(ptr_of_11), 11);
34
35 KUNIT_EXPECT_EQ(test, __compiletime_strlen(array_unknown), SIZE_MAX);
36 /* Externally defined and dynamically sized string pointer: */
37 KUNIT_EXPECT_EQ(test, __compiletime_strlen(test->name), SIZE_MAX);
38}
39
40/* This is volatile so the optimizer can't perform DCE below. */
41static volatile int pick;
42
43/* Not inline to keep optimizer from figuring out which string we want. */
44static noinline size_t want_minus_one(int pick)
45{
46 const char *str;
47
48 switch (pick) {
49 case 1:
50 str = "4444";
51 break;
52 case 2:
53 str = "333";
54 break;
55 default:
56 str = "1";
57 break;
58 }
59 return __compiletime_strlen(str);
60}
61
62static void control_flow_split_test(struct kunit *test)
63{
64 KUNIT_EXPECT_EQ(test, want_minus_one(pick), SIZE_MAX);
65}
66
67#define KUNIT_EXPECT_BOS(test, p, expected, name) \
68 KUNIT_EXPECT_EQ_MSG(test, __builtin_object_size(p, 1), \
69 expected, \
70 "__alloc_size() not working with __bos on " name "\n")
71
72#if !__has_builtin(__builtin_dynamic_object_size)
73#define KUNIT_EXPECT_BDOS(test, p, expected, name) \
74 /* Silence "unused variable 'expected'" warning. */ \
75 KUNIT_EXPECT_EQ(test, expected, expected)
76#else
77#define KUNIT_EXPECT_BDOS(test, p, expected, name) \
78 KUNIT_EXPECT_EQ_MSG(test, __builtin_dynamic_object_size(p, 1), \
79 expected, \
80 "__alloc_size() not working with __bdos on " name "\n")
81#endif
82
83/* If the execpted size is a constant value, __bos can see it. */
84#define check_const(_expected, alloc, free) do { \
85 size_t expected = (_expected); \
86 void *p = alloc; \
87 KUNIT_EXPECT_TRUE_MSG(test, p != NULL, #alloc " failed?!\n"); \
88 KUNIT_EXPECT_BOS(test, p, expected, #alloc); \
89 KUNIT_EXPECT_BDOS(test, p, expected, #alloc); \
90 free; \
91} while (0)
92
93/* If the execpted size is NOT a constant value, __bos CANNOT see it. */
94#define check_dynamic(_expected, alloc, free) do { \
95 size_t expected = (_expected); \
96 void *p = alloc; \
97 KUNIT_EXPECT_TRUE_MSG(test, p != NULL, #alloc " failed?!\n"); \
98 KUNIT_EXPECT_BOS(test, p, SIZE_MAX, #alloc); \
99 KUNIT_EXPECT_BDOS(test, p, expected, #alloc); \
100 free; \
101} while (0)
102
103/* Assortment of constant-value kinda-edge cases. */
104#define CONST_TEST_BODY(TEST_alloc) do { \
105 /* Special-case vmalloc()-family to skip 0-sized allocs. */ \
106 if (strcmp(#TEST_alloc, "TEST_vmalloc") != 0) \
107 TEST_alloc(check_const, 0, 0); \
108 TEST_alloc(check_const, 1, 1); \
109 TEST_alloc(check_const, 128, 128); \
110 TEST_alloc(check_const, 1023, 1023); \
111 TEST_alloc(check_const, 1025, 1025); \
112 TEST_alloc(check_const, 4096, 4096); \
113 TEST_alloc(check_const, 4097, 4097); \
114} while (0)
115
116static volatile size_t zero_size;
117static volatile size_t unknown_size = 50;
118
119#if !__has_builtin(__builtin_dynamic_object_size)
120#define DYNAMIC_TEST_BODY(TEST_alloc) \
121 kunit_skip(test, "Compiler is missing __builtin_dynamic_object_size() support\n")
122#else
123#define DYNAMIC_TEST_BODY(TEST_alloc) do { \
124 size_t size = unknown_size; \
125 \
126 /* \
127 * Expected size is "size" in each test, before it is then \
128 * internally incremented in each test. Requires we disable \
129 * -Wunsequenced. \
130 */ \
131 TEST_alloc(check_dynamic, size, size++); \
132 /* Make sure incrementing actually happened. */ \
133 KUNIT_EXPECT_NE(test, size, unknown_size); \
134} while (0)
135#endif
136
137#define DEFINE_ALLOC_SIZE_TEST_PAIR(allocator) \
138static void alloc_size_##allocator##_const_test(struct kunit *test) \
139{ \
140 CONST_TEST_BODY(TEST_##allocator); \
141} \
142static void alloc_size_##allocator##_dynamic_test(struct kunit *test) \
143{ \
144 DYNAMIC_TEST_BODY(TEST_##allocator); \
145}
146
147#define TEST_kmalloc(checker, expected_size, alloc_size) do { \
148 gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; \
149 void *orig; \
150 size_t len; \
151 \
152 checker(expected_size, kmalloc(alloc_size, gfp), \
153 kfree(p)); \
154 checker(expected_size, \
155 kmalloc_node(alloc_size, gfp, NUMA_NO_NODE), \
156 kfree(p)); \
157 checker(expected_size, kzalloc(alloc_size, gfp), \
158 kfree(p)); \
159 checker(expected_size, \
160 kzalloc_node(alloc_size, gfp, NUMA_NO_NODE), \
161 kfree(p)); \
162 checker(expected_size, kcalloc(1, alloc_size, gfp), \
163 kfree(p)); \
164 checker(expected_size, kcalloc(alloc_size, 1, gfp), \
165 kfree(p)); \
166 checker(expected_size, \
167 kcalloc_node(1, alloc_size, gfp, NUMA_NO_NODE), \
168 kfree(p)); \
169 checker(expected_size, \
170 kcalloc_node(alloc_size, 1, gfp, NUMA_NO_NODE), \
171 kfree(p)); \
172 checker(expected_size, kmalloc_array(1, alloc_size, gfp), \
173 kfree(p)); \
174 checker(expected_size, kmalloc_array(alloc_size, 1, gfp), \
175 kfree(p)); \
176 checker(expected_size, \
177 kmalloc_array_node(1, alloc_size, gfp, NUMA_NO_NODE), \
178 kfree(p)); \
179 checker(expected_size, \
180 kmalloc_array_node(alloc_size, 1, gfp, NUMA_NO_NODE), \
181 kfree(p)); \
182 checker(expected_size, __kmalloc(alloc_size, gfp), \
183 kfree(p)); \
184 checker(expected_size, \
185 __kmalloc_node(alloc_size, gfp, NUMA_NO_NODE), \
186 kfree(p)); \
187 \
188 orig = kmalloc(alloc_size, gfp); \
189 KUNIT_EXPECT_TRUE(test, orig != NULL); \
190 checker((expected_size) * 2, \
191 krealloc(orig, (alloc_size) * 2, gfp), \
192 kfree(p)); \
193 orig = kmalloc(alloc_size, gfp); \
194 KUNIT_EXPECT_TRUE(test, orig != NULL); \
195 checker((expected_size) * 2, \
196 krealloc_array(orig, 1, (alloc_size) * 2, gfp), \
197 kfree(p)); \
198 orig = kmalloc(alloc_size, gfp); \
199 KUNIT_EXPECT_TRUE(test, orig != NULL); \
200 checker((expected_size) * 2, \
201 krealloc_array(orig, (alloc_size) * 2, 1, gfp), \
202 kfree(p)); \
203 \
204 len = 11; \
205 /* Using memdup() with fixed size, so force unknown length. */ \
206 if (!__builtin_constant_p(expected_size)) \
207 len += zero_size; \
208 checker(len, kmemdup("hello there", len, gfp), kfree(p)); \
209} while (0)
210DEFINE_ALLOC_SIZE_TEST_PAIR(kmalloc)
211
212/* Sizes are in pages, not bytes. */
213#define TEST_vmalloc(checker, expected_pages, alloc_pages) do { \
214 gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; \
215 checker((expected_pages) * PAGE_SIZE, \
216 vmalloc((alloc_pages) * PAGE_SIZE), vfree(p)); \
217 checker((expected_pages) * PAGE_SIZE, \
218 vzalloc((alloc_pages) * PAGE_SIZE), vfree(p)); \
219 checker((expected_pages) * PAGE_SIZE, \
220 __vmalloc((alloc_pages) * PAGE_SIZE, gfp), vfree(p)); \
221} while (0)
222DEFINE_ALLOC_SIZE_TEST_PAIR(vmalloc)
223
224/* Sizes are in pages (and open-coded for side-effects), not bytes. */
225#define TEST_kvmalloc(checker, expected_pages, alloc_pages) do { \
226 gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; \
227 size_t prev_size; \
228 void *orig; \
229 \
230 checker((expected_pages) * PAGE_SIZE, \
231 kvmalloc((alloc_pages) * PAGE_SIZE, gfp), \
232 vfree(p)); \
233 checker((expected_pages) * PAGE_SIZE, \
234 kvmalloc_node((alloc_pages) * PAGE_SIZE, gfp, NUMA_NO_NODE), \
235 vfree(p)); \
236 checker((expected_pages) * PAGE_SIZE, \
237 kvzalloc((alloc_pages) * PAGE_SIZE, gfp), \
238 vfree(p)); \
239 checker((expected_pages) * PAGE_SIZE, \
240 kvzalloc_node((alloc_pages) * PAGE_SIZE, gfp, NUMA_NO_NODE), \
241 vfree(p)); \
242 checker((expected_pages) * PAGE_SIZE, \
243 kvcalloc(1, (alloc_pages) * PAGE_SIZE, gfp), \
244 vfree(p)); \
245 checker((expected_pages) * PAGE_SIZE, \
246 kvcalloc((alloc_pages) * PAGE_SIZE, 1, gfp), \
247 vfree(p)); \
248 checker((expected_pages) * PAGE_SIZE, \
249 kvmalloc_array(1, (alloc_pages) * PAGE_SIZE, gfp), \
250 vfree(p)); \
251 checker((expected_pages) * PAGE_SIZE, \
252 kvmalloc_array((alloc_pages) * PAGE_SIZE, 1, gfp), \
253 vfree(p)); \
254 \
255 prev_size = (expected_pages) * PAGE_SIZE; \
256 orig = kvmalloc(prev_size, gfp); \
257 KUNIT_EXPECT_TRUE(test, orig != NULL); \
258 checker(((expected_pages) * PAGE_SIZE) * 2, \
259 kvrealloc(orig, prev_size, \
260 ((alloc_pages) * PAGE_SIZE) * 2, gfp), \
261 kvfree(p)); \
262} while (0)
263DEFINE_ALLOC_SIZE_TEST_PAIR(kvmalloc)
264
265#define TEST_devm_kmalloc(checker, expected_size, alloc_size) do { \
266 gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; \
267 const char dev_name[] = "fortify-test"; \
268 struct device *dev; \
269 void *orig; \
270 size_t len; \
271 \
272 /* Create dummy device for devm_kmalloc()-family tests. */ \
273 dev = kunit_device_register(test, dev_name); \
274 KUNIT_ASSERT_FALSE_MSG(test, IS_ERR(dev), \
275 "Cannot register test device\n"); \
276 \
277 checker(expected_size, devm_kmalloc(dev, alloc_size, gfp), \
278 devm_kfree(dev, p)); \
279 checker(expected_size, devm_kzalloc(dev, alloc_size, gfp), \
280 devm_kfree(dev, p)); \
281 checker(expected_size, \
282 devm_kmalloc_array(dev, 1, alloc_size, gfp), \
283 devm_kfree(dev, p)); \
284 checker(expected_size, \
285 devm_kmalloc_array(dev, alloc_size, 1, gfp), \
286 devm_kfree(dev, p)); \
287 checker(expected_size, \
288 devm_kcalloc(dev, 1, alloc_size, gfp), \
289 devm_kfree(dev, p)); \
290 checker(expected_size, \
291 devm_kcalloc(dev, alloc_size, 1, gfp), \
292 devm_kfree(dev, p)); \
293 \
294 orig = devm_kmalloc(dev, alloc_size, gfp); \
295 KUNIT_EXPECT_TRUE(test, orig != NULL); \
296 checker((expected_size) * 2, \
297 devm_krealloc(dev, orig, (alloc_size) * 2, gfp), \
298 devm_kfree(dev, p)); \
299 \
300 len = 4; \
301 /* Using memdup() with fixed size, so force unknown length. */ \
302 if (!__builtin_constant_p(expected_size)) \
303 len += zero_size; \
304 checker(len, devm_kmemdup(dev, "Ohai", len, gfp), \
305 devm_kfree(dev, p)); \
306 \
307 kunit_device_unregister(test, dev); \
308} while (0)
309DEFINE_ALLOC_SIZE_TEST_PAIR(devm_kmalloc)
310
311static struct kunit_case fortify_test_cases[] = {
312 KUNIT_CASE(known_sizes_test),
313 KUNIT_CASE(control_flow_split_test),
314 KUNIT_CASE(alloc_size_kmalloc_const_test),
315 KUNIT_CASE(alloc_size_kmalloc_dynamic_test),
316 KUNIT_CASE(alloc_size_vmalloc_const_test),
317 KUNIT_CASE(alloc_size_vmalloc_dynamic_test),
318 KUNIT_CASE(alloc_size_kvmalloc_const_test),
319 KUNIT_CASE(alloc_size_kvmalloc_dynamic_test),
320 KUNIT_CASE(alloc_size_devm_kmalloc_const_test),
321 KUNIT_CASE(alloc_size_devm_kmalloc_dynamic_test),
322 {}
323};
324
325static struct kunit_suite fortify_test_suite = {
326 .name = "fortify",
327 .test_cases = fortify_test_cases,
328};
329
330kunit_test_suite(fortify_test_suite);
331
332MODULE_LICENSE("GPL");