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2cb80dbb IZ |
1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* | |
3 | * KUnit test of proc sysctl. | |
4 | */ | |
5 | ||
6 | #include <kunit/test.h> | |
7 | #include <linux/sysctl.h> | |
8 | ||
9 | #define KUNIT_PROC_READ 0 | |
10 | #define KUNIT_PROC_WRITE 1 | |
11 | ||
12 | static int i_zero; | |
13 | static int i_one_hundred = 100; | |
14 | ||
15 | /* | |
16 | * Test that proc_dointvec will not try to use a NULL .data field even when the | |
17 | * length is non-zero. | |
18 | */ | |
19 | static void sysctl_test_api_dointvec_null_tbl_data(struct kunit *test) | |
20 | { | |
21 | struct ctl_table null_data_table = { | |
22 | .procname = "foo", | |
23 | /* | |
24 | * Here we are testing that proc_dointvec behaves correctly when | |
25 | * we give it a NULL .data field. Normally this would point to a | |
26 | * piece of memory where the value would be stored. | |
27 | */ | |
28 | .data = NULL, | |
29 | .maxlen = sizeof(int), | |
30 | .mode = 0644, | |
31 | .proc_handler = proc_dointvec, | |
32 | .extra1 = &i_zero, | |
33 | .extra2 = &i_one_hundred, | |
34 | }; | |
35 | /* | |
36 | * proc_dointvec expects a buffer in user space, so we allocate one. We | |
37 | * also need to cast it to __user so sparse doesn't get mad. | |
38 | */ | |
39 | void __user *buffer = (void __user *)kunit_kzalloc(test, sizeof(int), | |
40 | GFP_USER); | |
41 | size_t len; | |
42 | loff_t pos; | |
43 | ||
44 | /* | |
45 | * We don't care what the starting length is since proc_dointvec should | |
46 | * not try to read because .data is NULL. | |
47 | */ | |
48 | len = 1234; | |
49 | KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&null_data_table, | |
50 | KUNIT_PROC_READ, buffer, &len, | |
51 | &pos)); | |
388ca2e0 | 52 | KUNIT_EXPECT_EQ(test, 0, len); |
2cb80dbb IZ |
53 | |
54 | /* | |
55 | * See above. | |
56 | */ | |
57 | len = 1234; | |
58 | KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&null_data_table, | |
59 | KUNIT_PROC_WRITE, buffer, &len, | |
60 | &pos)); | |
388ca2e0 | 61 | KUNIT_EXPECT_EQ(test, 0, len); |
2cb80dbb IZ |
62 | } |
63 | ||
64 | /* | |
65 | * Similar to the previous test, we create a struct ctrl_table that has a .data | |
66 | * field that proc_dointvec cannot do anything with; however, this time it is | |
67 | * because we tell proc_dointvec that the size is 0. | |
68 | */ | |
69 | static void sysctl_test_api_dointvec_table_maxlen_unset(struct kunit *test) | |
70 | { | |
71 | int data = 0; | |
72 | struct ctl_table data_maxlen_unset_table = { | |
73 | .procname = "foo", | |
74 | .data = &data, | |
75 | /* | |
76 | * So .data is no longer NULL, but we tell proc_dointvec its | |
77 | * length is 0, so it still shouldn't try to use it. | |
78 | */ | |
79 | .maxlen = 0, | |
80 | .mode = 0644, | |
81 | .proc_handler = proc_dointvec, | |
82 | .extra1 = &i_zero, | |
83 | .extra2 = &i_one_hundred, | |
84 | }; | |
85 | void __user *buffer = (void __user *)kunit_kzalloc(test, sizeof(int), | |
86 | GFP_USER); | |
87 | size_t len; | |
88 | loff_t pos; | |
89 | ||
90 | /* | |
91 | * As before, we don't care what buffer length is because proc_dointvec | |
92 | * cannot do anything because its internal .data buffer has zero length. | |
93 | */ | |
94 | len = 1234; | |
95 | KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&data_maxlen_unset_table, | |
96 | KUNIT_PROC_READ, buffer, &len, | |
97 | &pos)); | |
388ca2e0 | 98 | KUNIT_EXPECT_EQ(test, 0, len); |
2cb80dbb IZ |
99 | |
100 | /* | |
101 | * See previous comment. | |
102 | */ | |
103 | len = 1234; | |
104 | KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&data_maxlen_unset_table, | |
105 | KUNIT_PROC_WRITE, buffer, &len, | |
106 | &pos)); | |
388ca2e0 | 107 | KUNIT_EXPECT_EQ(test, 0, len); |
2cb80dbb IZ |
108 | } |
109 | ||
110 | /* | |
111 | * Here we provide a valid struct ctl_table, but we try to read and write from | |
112 | * it using a buffer of zero length, so it should still fail in a similar way as | |
113 | * before. | |
114 | */ | |
115 | static void sysctl_test_api_dointvec_table_len_is_zero(struct kunit *test) | |
116 | { | |
117 | int data = 0; | |
118 | /* Good table. */ | |
119 | struct ctl_table table = { | |
120 | .procname = "foo", | |
121 | .data = &data, | |
122 | .maxlen = sizeof(int), | |
123 | .mode = 0644, | |
124 | .proc_handler = proc_dointvec, | |
125 | .extra1 = &i_zero, | |
126 | .extra2 = &i_one_hundred, | |
127 | }; | |
128 | void __user *buffer = (void __user *)kunit_kzalloc(test, sizeof(int), | |
129 | GFP_USER); | |
130 | /* | |
131 | * However, now our read/write buffer has zero length. | |
132 | */ | |
133 | size_t len = 0; | |
134 | loff_t pos; | |
135 | ||
136 | KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&table, KUNIT_PROC_READ, buffer, | |
137 | &len, &pos)); | |
388ca2e0 | 138 | KUNIT_EXPECT_EQ(test, 0, len); |
2cb80dbb IZ |
139 | |
140 | KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&table, KUNIT_PROC_WRITE, buffer, | |
141 | &len, &pos)); | |
388ca2e0 | 142 | KUNIT_EXPECT_EQ(test, 0, len); |
2cb80dbb IZ |
143 | } |
144 | ||
145 | /* | |
146 | * Test that proc_dointvec refuses to read when the file position is non-zero. | |
147 | */ | |
148 | static void sysctl_test_api_dointvec_table_read_but_position_set( | |
149 | struct kunit *test) | |
150 | { | |
151 | int data = 0; | |
152 | /* Good table. */ | |
153 | struct ctl_table table = { | |
154 | .procname = "foo", | |
155 | .data = &data, | |
156 | .maxlen = sizeof(int), | |
157 | .mode = 0644, | |
158 | .proc_handler = proc_dointvec, | |
159 | .extra1 = &i_zero, | |
160 | .extra2 = &i_one_hundred, | |
161 | }; | |
162 | void __user *buffer = (void __user *)kunit_kzalloc(test, sizeof(int), | |
163 | GFP_USER); | |
164 | /* | |
165 | * We don't care about our buffer length because we start off with a | |
166 | * non-zero file position. | |
167 | */ | |
168 | size_t len = 1234; | |
169 | /* | |
170 | * proc_dointvec should refuse to read into the buffer since the file | |
171 | * pos is non-zero. | |
172 | */ | |
173 | loff_t pos = 1; | |
174 | ||
175 | KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&table, KUNIT_PROC_READ, buffer, | |
176 | &len, &pos)); | |
388ca2e0 | 177 | KUNIT_EXPECT_EQ(test, 0, len); |
2cb80dbb IZ |
178 | } |
179 | ||
180 | /* | |
181 | * Test that we can read a two digit number in a sufficiently size buffer. | |
182 | * Nothing fancy. | |
183 | */ | |
184 | static void sysctl_test_dointvec_read_happy_single_positive(struct kunit *test) | |
185 | { | |
186 | int data = 0; | |
187 | /* Good table. */ | |
188 | struct ctl_table table = { | |
189 | .procname = "foo", | |
190 | .data = &data, | |
191 | .maxlen = sizeof(int), | |
192 | .mode = 0644, | |
193 | .proc_handler = proc_dointvec, | |
194 | .extra1 = &i_zero, | |
195 | .extra2 = &i_one_hundred, | |
196 | }; | |
197 | size_t len = 4; | |
198 | loff_t pos = 0; | |
199 | char *buffer = kunit_kzalloc(test, len, GFP_USER); | |
200 | char __user *user_buffer = (char __user *)buffer; | |
201 | /* Store 13 in the data field. */ | |
202 | *((int *)table.data) = 13; | |
203 | ||
204 | KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&table, KUNIT_PROC_READ, | |
205 | user_buffer, &len, &pos)); | |
388ca2e0 | 206 | KUNIT_ASSERT_EQ(test, 3, len); |
2cb80dbb IZ |
207 | buffer[len] = '\0'; |
208 | /* And we read 13 back out. */ | |
209 | KUNIT_EXPECT_STREQ(test, "13\n", buffer); | |
210 | } | |
211 | ||
212 | /* | |
213 | * Same as previous test, just now with negative numbers. | |
214 | */ | |
215 | static void sysctl_test_dointvec_read_happy_single_negative(struct kunit *test) | |
216 | { | |
217 | int data = 0; | |
218 | /* Good table. */ | |
219 | struct ctl_table table = { | |
220 | .procname = "foo", | |
221 | .data = &data, | |
222 | .maxlen = sizeof(int), | |
223 | .mode = 0644, | |
224 | .proc_handler = proc_dointvec, | |
225 | .extra1 = &i_zero, | |
226 | .extra2 = &i_one_hundred, | |
227 | }; | |
228 | size_t len = 5; | |
229 | loff_t pos = 0; | |
230 | char *buffer = kunit_kzalloc(test, len, GFP_USER); | |
231 | char __user *user_buffer = (char __user *)buffer; | |
232 | *((int *)table.data) = -16; | |
233 | ||
234 | KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&table, KUNIT_PROC_READ, | |
235 | user_buffer, &len, &pos)); | |
388ca2e0 | 236 | KUNIT_ASSERT_EQ(test, 4, len); |
2cb80dbb | 237 | buffer[len] = '\0'; |
388ca2e0 | 238 | KUNIT_EXPECT_STREQ(test, "-16\n", buffer); |
2cb80dbb IZ |
239 | } |
240 | ||
241 | /* | |
242 | * Test that a simple positive write works. | |
243 | */ | |
244 | static void sysctl_test_dointvec_write_happy_single_positive(struct kunit *test) | |
245 | { | |
246 | int data = 0; | |
247 | /* Good table. */ | |
248 | struct ctl_table table = { | |
249 | .procname = "foo", | |
250 | .data = &data, | |
251 | .maxlen = sizeof(int), | |
252 | .mode = 0644, | |
253 | .proc_handler = proc_dointvec, | |
254 | .extra1 = &i_zero, | |
255 | .extra2 = &i_one_hundred, | |
256 | }; | |
257 | char input[] = "9"; | |
258 | size_t len = sizeof(input) - 1; | |
259 | loff_t pos = 0; | |
260 | char *buffer = kunit_kzalloc(test, len, GFP_USER); | |
261 | char __user *user_buffer = (char __user *)buffer; | |
262 | ||
263 | memcpy(buffer, input, len); | |
264 | ||
265 | KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&table, KUNIT_PROC_WRITE, | |
266 | user_buffer, &len, &pos)); | |
267 | KUNIT_EXPECT_EQ(test, sizeof(input) - 1, len); | |
388ca2e0 | 268 | KUNIT_EXPECT_EQ(test, sizeof(input) - 1, pos); |
2cb80dbb IZ |
269 | KUNIT_EXPECT_EQ(test, 9, *((int *)table.data)); |
270 | } | |
271 | ||
272 | /* | |
273 | * Same as previous test, but now with negative numbers. | |
274 | */ | |
275 | static void sysctl_test_dointvec_write_happy_single_negative(struct kunit *test) | |
276 | { | |
277 | int data = 0; | |
278 | struct ctl_table table = { | |
279 | .procname = "foo", | |
280 | .data = &data, | |
281 | .maxlen = sizeof(int), | |
282 | .mode = 0644, | |
283 | .proc_handler = proc_dointvec, | |
284 | .extra1 = &i_zero, | |
285 | .extra2 = &i_one_hundred, | |
286 | }; | |
287 | char input[] = "-9"; | |
288 | size_t len = sizeof(input) - 1; | |
289 | loff_t pos = 0; | |
290 | char *buffer = kunit_kzalloc(test, len, GFP_USER); | |
291 | char __user *user_buffer = (char __user *)buffer; | |
292 | ||
293 | memcpy(buffer, input, len); | |
294 | ||
295 | KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&table, KUNIT_PROC_WRITE, | |
296 | user_buffer, &len, &pos)); | |
297 | KUNIT_EXPECT_EQ(test, sizeof(input) - 1, len); | |
388ca2e0 | 298 | KUNIT_EXPECT_EQ(test, sizeof(input) - 1, pos); |
2cb80dbb IZ |
299 | KUNIT_EXPECT_EQ(test, -9, *((int *)table.data)); |
300 | } | |
301 | ||
302 | /* | |
303 | * Test that writing a value smaller than the minimum possible value is not | |
304 | * allowed. | |
305 | */ | |
306 | static void sysctl_test_api_dointvec_write_single_less_int_min( | |
307 | struct kunit *test) | |
308 | { | |
309 | int data = 0; | |
310 | struct ctl_table table = { | |
311 | .procname = "foo", | |
312 | .data = &data, | |
313 | .maxlen = sizeof(int), | |
314 | .mode = 0644, | |
315 | .proc_handler = proc_dointvec, | |
316 | .extra1 = &i_zero, | |
317 | .extra2 = &i_one_hundred, | |
318 | }; | |
319 | size_t max_len = 32, len = max_len; | |
320 | loff_t pos = 0; | |
321 | char *buffer = kunit_kzalloc(test, max_len, GFP_USER); | |
322 | char __user *user_buffer = (char __user *)buffer; | |
323 | unsigned long abs_of_less_than_min = (unsigned long)INT_MAX | |
324 | - (INT_MAX + INT_MIN) + 1; | |
325 | ||
326 | /* | |
327 | * We use this rigmarole to create a string that contains a value one | |
328 | * less than the minimum accepted value. | |
329 | */ | |
330 | KUNIT_ASSERT_LT(test, | |
331 | (size_t)snprintf(buffer, max_len, "-%lu", | |
332 | abs_of_less_than_min), | |
333 | max_len); | |
334 | ||
335 | KUNIT_EXPECT_EQ(test, -EINVAL, proc_dointvec(&table, KUNIT_PROC_WRITE, | |
336 | user_buffer, &len, &pos)); | |
337 | KUNIT_EXPECT_EQ(test, max_len, len); | |
338 | KUNIT_EXPECT_EQ(test, 0, *((int *)table.data)); | |
339 | } | |
340 | ||
341 | /* | |
342 | * Test that writing the maximum possible value works. | |
343 | */ | |
344 | static void sysctl_test_api_dointvec_write_single_greater_int_max( | |
345 | struct kunit *test) | |
346 | { | |
347 | int data = 0; | |
348 | struct ctl_table table = { | |
349 | .procname = "foo", | |
350 | .data = &data, | |
351 | .maxlen = sizeof(int), | |
352 | .mode = 0644, | |
353 | .proc_handler = proc_dointvec, | |
354 | .extra1 = &i_zero, | |
355 | .extra2 = &i_one_hundred, | |
356 | }; | |
357 | size_t max_len = 32, len = max_len; | |
358 | loff_t pos = 0; | |
359 | char *buffer = kunit_kzalloc(test, max_len, GFP_USER); | |
360 | char __user *user_buffer = (char __user *)buffer; | |
361 | unsigned long greater_than_max = (unsigned long)INT_MAX + 1; | |
362 | ||
363 | KUNIT_ASSERT_GT(test, greater_than_max, (unsigned long)INT_MAX); | |
364 | KUNIT_ASSERT_LT(test, (size_t)snprintf(buffer, max_len, "%lu", | |
365 | greater_than_max), | |
366 | max_len); | |
367 | KUNIT_EXPECT_EQ(test, -EINVAL, proc_dointvec(&table, KUNIT_PROC_WRITE, | |
368 | user_buffer, &len, &pos)); | |
369 | KUNIT_ASSERT_EQ(test, max_len, len); | |
370 | KUNIT_EXPECT_EQ(test, 0, *((int *)table.data)); | |
371 | } | |
372 | ||
373 | static struct kunit_case sysctl_test_cases[] = { | |
374 | KUNIT_CASE(sysctl_test_api_dointvec_null_tbl_data), | |
375 | KUNIT_CASE(sysctl_test_api_dointvec_table_maxlen_unset), | |
376 | KUNIT_CASE(sysctl_test_api_dointvec_table_len_is_zero), | |
377 | KUNIT_CASE(sysctl_test_api_dointvec_table_read_but_position_set), | |
378 | KUNIT_CASE(sysctl_test_dointvec_read_happy_single_positive), | |
379 | KUNIT_CASE(sysctl_test_dointvec_read_happy_single_negative), | |
380 | KUNIT_CASE(sysctl_test_dointvec_write_happy_single_positive), | |
381 | KUNIT_CASE(sysctl_test_dointvec_write_happy_single_negative), | |
382 | KUNIT_CASE(sysctl_test_api_dointvec_write_single_less_int_min), | |
383 | KUNIT_CASE(sysctl_test_api_dointvec_write_single_greater_int_max), | |
384 | {} | |
385 | }; | |
386 | ||
387 | static struct kunit_suite sysctl_test_suite = { | |
388 | .name = "sysctl_test", | |
389 | .test_cases = sysctl_test_cases, | |
390 | }; | |
391 | ||
c475c77d AM |
392 | kunit_test_suites(&sysctl_test_suite); |
393 | ||
394 | MODULE_LICENSE("GPL v2"); |