Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * test_fprobe.c - simple sanity test for fprobe
4 */
5
6#include <linux/kernel.h>
7#include <linux/fprobe.h>
8#include <linux/random.h>
9#include <kunit/test.h>
10
11#define div_factor 3
12
13static struct kunit *current_test;
14
15static u32 rand1, entry_val, exit_val;
16
17/* Use indirect calls to avoid inlining the target functions */
18static u32 (*target)(u32 value);
19static u32 (*target2)(u32 value);
20static u32 (*target_nest)(u32 value, u32 (*nest)(u32));
21static unsigned long target_ip;
22static unsigned long target2_ip;
23static unsigned long target_nest_ip;
24static int entry_return_value;
25
26static noinline u32 fprobe_selftest_target(u32 value)
27{
28 return (value / div_factor);
29}
30
31static noinline u32 fprobe_selftest_target2(u32 value)
32{
33 return (value / div_factor) + 1;
34}
35
36static noinline u32 fprobe_selftest_nest_target(u32 value, u32 (*nest)(u32))
37{
38 return nest(value + 2);
39}
40
41static notrace int fp_entry_handler(struct fprobe *fp, unsigned long ip,
42 struct pt_regs *regs, void *data)
43{
44 KUNIT_EXPECT_FALSE(current_test, preemptible());
45 /* This can be called on the fprobe_selftest_target and the fprobe_selftest_target2 */
46 if (ip != target_ip)
47 KUNIT_EXPECT_EQ(current_test, ip, target2_ip);
48 entry_val = (rand1 / div_factor);
49 if (fp->entry_data_size) {
50 KUNIT_EXPECT_NOT_NULL(current_test, data);
51 if (data)
52 *(u32 *)data = entry_val;
53 } else
54 KUNIT_EXPECT_NULL(current_test, data);
55
56 return entry_return_value;
57}
58
59static notrace void fp_exit_handler(struct fprobe *fp, unsigned long ip,
60 struct pt_regs *regs, void *data)
61{
62 unsigned long ret = regs_return_value(regs);
63
64 KUNIT_EXPECT_FALSE(current_test, preemptible());
65 if (ip != target_ip) {
66 KUNIT_EXPECT_EQ(current_test, ip, target2_ip);
67 KUNIT_EXPECT_EQ(current_test, ret, (rand1 / div_factor) + 1);
68 } else
69 KUNIT_EXPECT_EQ(current_test, ret, (rand1 / div_factor));
70 KUNIT_EXPECT_EQ(current_test, entry_val, (rand1 / div_factor));
71 exit_val = entry_val + div_factor;
72 if (fp->entry_data_size) {
73 KUNIT_EXPECT_NOT_NULL(current_test, data);
74 if (data)
75 KUNIT_EXPECT_EQ(current_test, *(u32 *)data, entry_val);
76 } else
77 KUNIT_EXPECT_NULL(current_test, data);
78}
79
80static notrace int nest_entry_handler(struct fprobe *fp, unsigned long ip,
81 struct pt_regs *regs, void *data)
82{
83 KUNIT_EXPECT_FALSE(current_test, preemptible());
84 return 0;
85}
86
87static notrace void nest_exit_handler(struct fprobe *fp, unsigned long ip,
88 struct pt_regs *regs, void *data)
89{
90 KUNIT_EXPECT_FALSE(current_test, preemptible());
91 KUNIT_EXPECT_EQ(current_test, ip, target_nest_ip);
92}
93
94/* Test entry only (no rethook) */
95static void test_fprobe_entry(struct kunit *test)
96{
97 struct fprobe fp_entry = {
98 .entry_handler = fp_entry_handler,
99 };
100
101 current_test = test;
102
103 /* Before register, unregister should be failed. */
104 KUNIT_EXPECT_NE(test, 0, unregister_fprobe(&fp_entry));
105 KUNIT_EXPECT_EQ(test, 0, register_fprobe(&fp_entry, "fprobe_selftest_target*", NULL));
106
107 entry_val = 0;
108 exit_val = 0;
109 target(rand1);
110 KUNIT_EXPECT_NE(test, 0, entry_val);
111 KUNIT_EXPECT_EQ(test, 0, exit_val);
112
113 entry_val = 0;
114 exit_val = 0;
115 target2(rand1);
116 KUNIT_EXPECT_NE(test, 0, entry_val);
117 KUNIT_EXPECT_EQ(test, 0, exit_val);
118
119 KUNIT_EXPECT_EQ(test, 0, unregister_fprobe(&fp_entry));
120}
121
122static void test_fprobe(struct kunit *test)
123{
124 struct fprobe fp = {
125 .entry_handler = fp_entry_handler,
126 .exit_handler = fp_exit_handler,
127 };
128
129 current_test = test;
130 KUNIT_EXPECT_EQ(test, 0, register_fprobe(&fp, "fprobe_selftest_target*", NULL));
131
132 entry_val = 0;
133 exit_val = 0;
134 target(rand1);
135 KUNIT_EXPECT_NE(test, 0, entry_val);
136 KUNIT_EXPECT_EQ(test, entry_val + div_factor, exit_val);
137
138 entry_val = 0;
139 exit_val = 0;
140 target2(rand1);
141 KUNIT_EXPECT_NE(test, 0, entry_val);
142 KUNIT_EXPECT_EQ(test, entry_val + div_factor, exit_val);
143
144 KUNIT_EXPECT_EQ(test, 0, unregister_fprobe(&fp));
145}
146
147static void test_fprobe_syms(struct kunit *test)
148{
149 static const char *syms[] = {"fprobe_selftest_target", "fprobe_selftest_target2"};
150 struct fprobe fp = {
151 .entry_handler = fp_entry_handler,
152 .exit_handler = fp_exit_handler,
153 };
154
155 current_test = test;
156 KUNIT_EXPECT_EQ(test, 0, register_fprobe_syms(&fp, syms, 2));
157
158 entry_val = 0;
159 exit_val = 0;
160 target(rand1);
161 KUNIT_EXPECT_NE(test, 0, entry_val);
162 KUNIT_EXPECT_EQ(test, entry_val + div_factor, exit_val);
163
164 entry_val = 0;
165 exit_val = 0;
166 target2(rand1);
167 KUNIT_EXPECT_NE(test, 0, entry_val);
168 KUNIT_EXPECT_EQ(test, entry_val + div_factor, exit_val);
169
170 KUNIT_EXPECT_EQ(test, 0, unregister_fprobe(&fp));
171}
172
173/* Test private entry_data */
174static void test_fprobe_data(struct kunit *test)
175{
176 struct fprobe fp = {
177 .entry_handler = fp_entry_handler,
178 .exit_handler = fp_exit_handler,
179 .entry_data_size = sizeof(u32),
180 };
181
182 current_test = test;
183 KUNIT_EXPECT_EQ(test, 0, register_fprobe(&fp, "fprobe_selftest_target", NULL));
184
185 target(rand1);
186
187 KUNIT_EXPECT_EQ(test, 0, unregister_fprobe(&fp));
188}
189
190/* Test nr_maxactive */
191static void test_fprobe_nest(struct kunit *test)
192{
193 static const char *syms[] = {"fprobe_selftest_target", "fprobe_selftest_nest_target"};
194 struct fprobe fp = {
195 .entry_handler = nest_entry_handler,
196 .exit_handler = nest_exit_handler,
197 .nr_maxactive = 1,
198 };
199
200 current_test = test;
201 KUNIT_EXPECT_EQ(test, 0, register_fprobe_syms(&fp, syms, 2));
202
203 target_nest(rand1, target);
204 KUNIT_EXPECT_EQ(test, 1, fp.nmissed);
205
206 KUNIT_EXPECT_EQ(test, 0, unregister_fprobe(&fp));
207}
208
209static void test_fprobe_skip(struct kunit *test)
210{
211 struct fprobe fp = {
212 .entry_handler = fp_entry_handler,
213 .exit_handler = fp_exit_handler,
214 };
215
216 current_test = test;
217 KUNIT_EXPECT_EQ(test, 0, register_fprobe(&fp, "fprobe_selftest_target", NULL));
218
219 entry_return_value = 1;
220 entry_val = 0;
221 exit_val = 0;
222 target(rand1);
223 KUNIT_EXPECT_NE(test, 0, entry_val);
224 KUNIT_EXPECT_EQ(test, 0, exit_val);
225 KUNIT_EXPECT_EQ(test, 0, fp.nmissed);
226 entry_return_value = 0;
227
228 KUNIT_EXPECT_EQ(test, 0, unregister_fprobe(&fp));
229}
230
231static unsigned long get_ftrace_location(void *func)
232{
233 unsigned long size, addr = (unsigned long)func;
234
235 if (!kallsyms_lookup_size_offset(addr, &size, NULL) || !size)
236 return 0;
237
238 return ftrace_location_range(addr, addr + size - 1);
239}
240
241static int fprobe_test_init(struct kunit *test)
242{
243 rand1 = get_random_u32_above(div_factor);
244 target = fprobe_selftest_target;
245 target2 = fprobe_selftest_target2;
246 target_nest = fprobe_selftest_nest_target;
247 target_ip = get_ftrace_location(target);
248 target2_ip = get_ftrace_location(target2);
249 target_nest_ip = get_ftrace_location(target_nest);
250
251 return 0;
252}
253
254static struct kunit_case fprobe_testcases[] = {
255 KUNIT_CASE(test_fprobe_entry),
256 KUNIT_CASE(test_fprobe),
257 KUNIT_CASE(test_fprobe_syms),
258 KUNIT_CASE(test_fprobe_data),
259 KUNIT_CASE(test_fprobe_nest),
260 KUNIT_CASE(test_fprobe_skip),
261 {}
262};
263
264static struct kunit_suite fprobe_test_suite = {
265 .name = "fprobe_test",
266 .init = fprobe_test_init,
267 .test_cases = fprobe_testcases,
268};
269
270kunit_test_suites(&fprobe_test_suite);
271