xref: /linux/kernel/crash_core_test.c (revision e406d57be7bd2a4e73ea512c1ae36a40a44e499e)
1 // SPDX-License-Identifier: GPL-2.0-only
2 #include <kunit/test.h>
3 #include <linux/crash_core.h> // For struct crash_mem and struct range if defined there
4 
5 // Helper to create and initialize crash_mem
create_crash_mem(struct kunit * test,unsigned int max_ranges,unsigned int nr_initial_ranges,const struct range * initial_ranges)6 static struct crash_mem *create_crash_mem(struct kunit *test, unsigned int max_ranges,
7 					  unsigned int nr_initial_ranges,
8 					  const struct range *initial_ranges)
9 {
10 	struct crash_mem *mem;
11 	size_t alloc_size;
12 
13 	// Check if max_ranges can even hold initial_ranges
14 	if (max_ranges < nr_initial_ranges) {
15 		kunit_err(test, "max_ranges (%u) < nr_initial_ranges (%u)\n",
16 			  max_ranges, nr_initial_ranges);
17 		return NULL;
18 	}
19 
20 	alloc_size = sizeof(struct crash_mem) + (size_t)max_ranges * sizeof(struct range);
21 	mem = kunit_kzalloc(test, alloc_size, GFP_KERNEL);
22 	if (!mem) {
23 		kunit_err(test, "Failed to allocate crash_mem\n");
24 		return NULL;
25 	}
26 
27 	mem->max_nr_ranges = max_ranges;
28 	mem->nr_ranges = nr_initial_ranges;
29 	if (initial_ranges && nr_initial_ranges > 0) {
30 		memcpy(mem->ranges, initial_ranges,
31 		       nr_initial_ranges * sizeof(struct range));
32 	}
33 
34 	return mem;
35 }
36 
37 // Helper to compare ranges for assertions
assert_ranges_equal(struct kunit * test,const struct range * actual_ranges,unsigned int actual_nr_ranges,const struct range * expected_ranges,unsigned int expected_nr_ranges,const char * case_name)38 static void assert_ranges_equal(struct kunit *test,
39 				const struct range *actual_ranges,
40 				unsigned int actual_nr_ranges,
41 				const struct range *expected_ranges,
42 				unsigned int expected_nr_ranges,
43 				const char *case_name)
44 {
45 	unsigned int i;
46 
47 	KUNIT_ASSERT_EQ_MSG(test, expected_nr_ranges, actual_nr_ranges,
48 			    "%s: Number of ranges mismatch.", case_name);
49 
50 	for (i = 0; i < expected_nr_ranges; i++) {
51 		KUNIT_ASSERT_EQ_MSG(test, expected_ranges[i].start, actual_ranges[i].start,
52 				    "%s: Range %u start mismatch.", case_name, i);
53 		KUNIT_ASSERT_EQ_MSG(test, expected_ranges[i].end, actual_ranges[i].end,
54 				    "%s: Range %u end mismatch.", case_name, i);
55 	}
56 }
57 
58 // Structure for test parameters
59 struct exclude_test_param {
60 	const char *description;
61 	unsigned long long exclude_start;
62 	unsigned long long exclude_end;
63 	unsigned int initial_max_ranges;
64 	const struct range *initial_ranges;
65 	unsigned int initial_nr_ranges;
66 	const struct range *expected_ranges;
67 	unsigned int expected_nr_ranges;
68 	int expected_ret;
69 };
70 
run_exclude_test_case(struct kunit * test,const struct exclude_test_param * params)71 static void run_exclude_test_case(struct kunit *test, const struct exclude_test_param *params)
72 {
73 	struct crash_mem *mem;
74 	int ret;
75 
76 	kunit_info(test, "%s", params->description);
77 
78 	mem = create_crash_mem(test, params->initial_max_ranges,
79 			       params->initial_nr_ranges, params->initial_ranges);
80 	if (!mem)
81 		return; // Error already logged by create_crash_mem or kunit_kzalloc
82 
83 	ret = crash_exclude_mem_range(mem, params->exclude_start, params->exclude_end);
84 
85 	KUNIT_ASSERT_EQ_MSG(test, params->expected_ret, ret,
86 			    "%s: Return value mismatch.", params->description);
87 
88 	if (params->expected_ret == 0) {
89 		assert_ranges_equal(test, mem->ranges, mem->nr_ranges,
90 				    params->expected_ranges, params->expected_nr_ranges,
91 				    params->description);
92 	} else {
93 		// If an error is expected, nr_ranges might still be relevant to check
94 		// depending on the exact point of failure. For ENOMEM on split,
95 		// nr_ranges shouldn't have changed.
96 		KUNIT_ASSERT_EQ_MSG(test, params->initial_nr_ranges,
97 				    mem->nr_ranges,
98 				    "%s: Number of ranges mismatch on error.",
99 				    params->description);
100 	}
101 }
102 
103 /*
104  * Test Strategy 1: One to-be-excluded range A and one existing range B.
105  *
106  * Exhaust all possibilities of the position of A regarding B.
107  */
108 
109 static const struct range single_range_b = { .start = 100, .end = 199 };
110 
111 static const struct exclude_test_param exclude_single_range_test_data[] = {
112 	{
113 		.description = "1.1: A is left of B, no overlap",
114 		.exclude_start = 10, .exclude_end = 50,
115 		.initial_max_ranges = 1,
116 		.initial_ranges = &single_range_b, .initial_nr_ranges = 1,
117 		.expected_ranges = &single_range_b, .expected_nr_ranges = 1,
118 		.expected_ret = 0,
119 	},
120 	{
121 		.description = "1.2: A's right boundary touches B's left boundary",
122 		.exclude_start = 10, .exclude_end = 99,
123 		.initial_max_ranges = 1,
124 		.initial_ranges = &single_range_b, .initial_nr_ranges = 1,
125 		.expected_ranges = &single_range_b, .expected_nr_ranges = 1,
126 		.expected_ret = 0,
127 	},
128 	{
129 		.description = "1.3: A overlaps B's left part",
130 		.exclude_start = 50, .exclude_end = 149,
131 		.initial_max_ranges = 1,
132 		.initial_ranges = &single_range_b, .initial_nr_ranges = 1,
133 		.expected_ranges = (const struct range[]){{ .start = 150, .end = 199 }},
134 		.expected_nr_ranges = 1,
135 		.expected_ret = 0,
136 	},
137 	{
138 		.description = "1.4: A is completely inside B",
139 		.exclude_start = 120, .exclude_end = 179,
140 		.initial_max_ranges = 2, // Needs space for split
141 		.initial_ranges = &single_range_b, .initial_nr_ranges = 1,
142 		.expected_ranges = (const struct range[]){
143 			{ .start = 100, .end = 119 },
144 			{ .start = 180, .end = 199 }
145 		},
146 		.expected_nr_ranges = 2,
147 		.expected_ret = 0,
148 	},
149 	{
150 		.description = "1.5: A overlaps B's right part",
151 		.exclude_start = 150, .exclude_end = 249,
152 		.initial_max_ranges = 1,
153 		.initial_ranges = &single_range_b, .initial_nr_ranges = 1,
154 		.expected_ranges = (const struct range[]){{ .start = 100, .end = 149 }},
155 		.expected_nr_ranges = 1,
156 		.expected_ret = 0,
157 	},
158 	{
159 		.description = "1.6: A's left boundary touches B's right boundary",
160 		.exclude_start = 200, .exclude_end = 250,
161 		.initial_max_ranges = 1,
162 		.initial_ranges = &single_range_b, .initial_nr_ranges = 1,
163 		.expected_ranges = &single_range_b, .expected_nr_ranges = 1,
164 		.expected_ret = 0,
165 	},
166 	{
167 		.description = "1.7: A is right of B, no overlap",
168 		.exclude_start = 250, .exclude_end = 300,
169 		.initial_max_ranges = 1,
170 		.initial_ranges = &single_range_b, .initial_nr_ranges = 1,
171 		.expected_ranges = &single_range_b, .expected_nr_ranges = 1,
172 		.expected_ret = 0,
173 	},
174 	{
175 		.description = "1.8: A completely covers B and extends beyond",
176 		.exclude_start = 50, .exclude_end = 250,
177 		.initial_max_ranges = 1,
178 		.initial_ranges = &single_range_b, .initial_nr_ranges = 1,
179 		.expected_ranges = NULL, .expected_nr_ranges = 0,
180 		.expected_ret = 0,
181 	},
182 	{
183 		.description = "1.9: A covers B and extends to the left",
184 		.exclude_start = 50, .exclude_end = 199, // A ends exactly where B ends
185 		.initial_max_ranges = 1,
186 		.initial_ranges = &single_range_b, .initial_nr_ranges = 1,
187 		.expected_ranges = NULL, .expected_nr_ranges = 0,
188 		.expected_ret = 0,
189 	},
190 	{
191 		.description = "1.10: A covers B and extends to the right",
192 		.exclude_start = 100, .exclude_end = 250, // A starts exactly where B starts
193 		.initial_max_ranges = 1,
194 		.initial_ranges = &single_range_b, .initial_nr_ranges = 1,
195 		.expected_ranges = NULL, .expected_nr_ranges = 0,
196 		.expected_ret = 0,
197 	},
198 	{
199 		.description = "1.11: A is identical to B",
200 		.exclude_start = 100, .exclude_end = 199,
201 		.initial_max_ranges = 1,
202 		.initial_ranges = &single_range_b, .initial_nr_ranges = 1,
203 		.expected_ranges = NULL, .expected_nr_ranges = 0,
204 		.expected_ret = 0,
205 	},
206 	{
207 		.description = "1.12: A is a point, left of B, no overlap",
208 		.exclude_start = 10, .exclude_end = 10,
209 		.initial_max_ranges = 1,
210 		.initial_ranges = &single_range_b, .initial_nr_ranges = 1,
211 		.expected_ranges = &single_range_b, .expected_nr_ranges = 1,
212 		.expected_ret = 0,
213 	},
214 	{
215 		.description = "1.13: A is a point, at start of B",
216 		.exclude_start = 100, .exclude_end = 100,
217 		.initial_max_ranges = 1,
218 		.initial_ranges = &single_range_b, .initial_nr_ranges = 1,
219 		.expected_ranges = (const struct range[]){{ .start = 101, .end = 199 }},
220 		.expected_nr_ranges = 1,
221 		.expected_ret = 0,
222 	},
223 	{
224 		.description = "1.14: A is a point, in middle of B (causes split)",
225 		.exclude_start = 150, .exclude_end = 150,
226 		.initial_max_ranges = 2, // Needs space for split
227 		.initial_ranges = &single_range_b, .initial_nr_ranges = 1,
228 		.expected_ranges = (const struct range[]){
229 			{ .start = 100, .end = 149 },
230 			{ .start = 151, .end = 199 }
231 		},
232 		.expected_nr_ranges = 2,
233 		.expected_ret = 0,
234 	},
235 	{
236 		.description = "1.15: A is a point, at end of B",
237 		.exclude_start = 199, .exclude_end = 199,
238 		.initial_max_ranges = 1,
239 		.initial_ranges = &single_range_b, .initial_nr_ranges = 1,
240 		.expected_ranges = (const struct range[]){{ .start = 100, .end = 198 }},
241 		.expected_nr_ranges = 1,
242 		.expected_ret = 0,
243 	},
244 	{
245 		.description = "1.16: A is a point, right of B, no overlap",
246 		.exclude_start = 250, .exclude_end = 250,
247 		.initial_max_ranges = 1,
248 		.initial_ranges = &single_range_b, .initial_nr_ranges = 1,
249 		.expected_ranges = &single_range_b, .expected_nr_ranges = 1,
250 		.expected_ret = 0,
251 	},
252 	// ENOMEM case for single range split
253 	{
254 		.description = "1.17: A completely inside B (split), no space (ENOMEM)",
255 		.exclude_start = 120, .exclude_end = 179,
256 		.initial_max_ranges = 1, // Not enough for split
257 		.initial_ranges = &single_range_b, .initial_nr_ranges = 1,
258 		.expected_ranges = NULL, // Not checked on error by assert_ranges_equal for content
259 		.expected_nr_ranges = 1, // Should remain unchanged
260 		.expected_ret = -ENOMEM,
261 	},
262 };
263 
264 
exclude_single_range_test(struct kunit * test)265 static void exclude_single_range_test(struct kunit *test)
266 {
267 	size_t i;
268 
269 	for (i = 0; i < ARRAY_SIZE(exclude_single_range_test_data); i++) {
270 		kunit_log(KERN_INFO, test, "Running: %s", exclude_single_range_test_data[i].description);
271 		run_exclude_test_case(test, &exclude_single_range_test_data[i]);
272 		// KUnit will stop on first KUNIT_ASSERT failure within run_exclude_test_case
273 	}
274 }
275 
276 /*
277  * Test Strategy 2: Regression test.
278  */
279 
280 static const struct exclude_test_param exclude_range_regression_test_data[] = {
281 	// Test data from commit a2e9a95d2190
282 	{
283 		.description = "2.1: exclude low 1M",
284 		.exclude_start = 0, .exclude_end = (1 << 20) - 1,
285 		.initial_max_ranges = 3,
286 		.initial_ranges = (const struct range[]){
287 			{ .start = 0, .end = 0x3efff },
288 			{ .start = 0x3f000, .end = 0x3ffff },
289 			{ .start = 0x40000, .end = 0x9ffff }
290 		},
291 		.initial_nr_ranges = 3,
292 		.expected_nr_ranges = 0,
293 		.expected_ret = 0,
294 	},
295 	// Test data from https://lore.kernel.org/all/ZXrY7QbXAlxydsSC@MiWiFi-R3L-srv/T/#u
296 	{
297 		.description = "2.2: when range out of bound",
298 		.exclude_start = 100, .exclude_end = 200,
299 		.initial_max_ranges = 3,
300 		.initial_ranges = (const struct range[]){
301 			{ .start = 1, .end = 299 },
302 			{ .start = 401, .end = 1000 },
303 			{ .start = 1001, .end = 2000 }
304 		},
305 		.initial_nr_ranges = 3,
306 		.expected_ranges = NULL, // Not checked on error by assert_ranges_equal for content
307 		.expected_nr_ranges = 3, // Should remain unchanged
308 		.expected_ret = -ENOMEM
309 	},
310 
311 };
312 
313 
exclude_range_regression_test(struct kunit * test)314 static void exclude_range_regression_test(struct kunit *test)
315 {
316 	size_t i;
317 
318 	for (i = 0; i < ARRAY_SIZE(exclude_range_regression_test_data); i++) {
319 		kunit_log(KERN_INFO, test, "Running: %s", exclude_range_regression_test_data[i].description);
320 		run_exclude_test_case(test, &exclude_range_regression_test_data[i]);
321 		// KUnit will stop on first KUNIT_ASSERT failure within run_exclude_test_case
322 	}
323 }
324 
325 /*
326  * KUnit Test Suite
327  */
328 static struct kunit_case crash_exclude_mem_range_test_cases[] = {
329 	KUNIT_CASE(exclude_single_range_test),
330 	KUNIT_CASE(exclude_range_regression_test),
331 	{}
332 };
333 
334 static struct kunit_suite crash_exclude_mem_range_suite = {
335 	.name = "crash_exclude_mem_range_tests",
336 	.test_cases = crash_exclude_mem_range_test_cases,
337 	// .init and .exit can be NULL if not needed globally for the suite
338 };
339 
340 kunit_test_suite(crash_exclude_mem_range_suite);
341 
342 MODULE_DESCRIPTION("crash dump KUnit test suite");
343 MODULE_LICENSE("GPL");
344