1// SPDX-License-Identifier: GPL-2.0-only
2
3#include <linux/sched.h>
4#include <linux/wait.h>
5
6#define SYS_TPIDR2 "S3_3_C13_C0_5"
7
8#define EXPECTED_TESTS 5
9
10static void putstr(const char *str)
11{
12 write(1, str, strlen(str));
13}
14
15static void putnum(unsigned int num)
16{
17 char c;
18
19 if (num / 10)
20 putnum(num: num / 10);
21
22 c = '0' + (num % 10);
23 write(1, &c, 1);
24}
25
26static int tests_run;
27static int tests_passed;
28static int tests_failed;
29static int tests_skipped;
30
31static void set_tpidr2(uint64_t val)
32{
33 asm volatile (
34 "msr " SYS_TPIDR2 ", %0\n"
35 :
36 : "r"(val)
37 : "cc");
38}
39
40static uint64_t get_tpidr2(void)
41{
42 uint64_t val;
43
44 asm volatile (
45 "mrs %0, " SYS_TPIDR2 "\n"
46 : "=r"(val)
47 :
48 : "cc");
49
50 return val;
51}
52
53static void print_summary(void)
54{
55 if (tests_passed + tests_failed + tests_skipped != EXPECTED_TESTS)
56 putstr(str: "# UNEXPECTED TEST COUNT: ");
57
58 putstr(str: "# Totals: pass:");
59 putnum(num: tests_passed);
60 putstr(str: " fail:");
61 putnum(num: tests_failed);
62 putstr(str: " xfail:0 xpass:0 skip:");
63 putnum(num: tests_skipped);
64 putstr(str: " error:0\n");
65}
66
67/* Processes should start with TPIDR2 == 0 */
68static int default_value(void)
69{
70 return get_tpidr2() == 0;
71}
72
73/* If we set TPIDR2 we should read that value */
74static int write_read(void)
75{
76 set_tpidr2(getpid());
77
78 return getpid() == get_tpidr2();
79}
80
81/* If we set a value we should read the same value after scheduling out */
82static int write_sleep_read(void)
83{
84 set_tpidr2(getpid());
85
86 msleep(100);
87
88 return getpid() == get_tpidr2();
89}
90
91/*
92 * If we fork the value in the parent should be unchanged and the
93 * child should start with the same value and be able to set its own
94 * value.
95 */
96static int write_fork_read(void)
97{
98 pid_t newpid, waiting, oldpid;
99 int status;
100
101 set_tpidr2(getpid());
102
103 oldpid = getpid();
104 newpid = fork();
105 if (newpid == 0) {
106 /* In child */
107 if (get_tpidr2() != oldpid) {
108 putstr(str: "# TPIDR2 changed in child: ");
109 putnum(num: get_tpidr2());
110 putstr(str: "\n");
111 exit(0);
112 }
113
114 set_tpidr2(getpid());
115 if (get_tpidr2() == getpid()) {
116 exit(1);
117 } else {
118 putstr(str: "# Failed to set TPIDR2 in child\n");
119 exit(0);
120 }
121 }
122 if (newpid < 0) {
123 putstr(str: "# fork() failed: -");
124 putnum(num: -newpid);
125 putstr(str: "\n");
126 return 0;
127 }
128
129 for (;;) {
130 waiting = waitpid(newpid, &status, 0);
131
132 if (waiting < 0) {
133 if (errno == EINTR)
134 continue;
135 putstr(str: "# waitpid() failed: ");
136 putnum(num: errno);
137 putstr(str: "\n");
138 return 0;
139 }
140 if (waiting != newpid) {
141 putstr(str: "# waitpid() returned wrong PID\n");
142 return 0;
143 }
144
145 if (!WIFEXITED(status)) {
146 putstr(str: "# child did not exit\n");
147 return 0;
148 }
149
150 if (getpid() != get_tpidr2()) {
151 putstr(str: "# TPIDR2 corrupted in parent\n");
152 return 0;
153 }
154
155 return WEXITSTATUS(status);
156 }
157}
158
159/*
160 * sys_clone() has a lot of per architecture variation so just define
161 * it here rather than adding it to nolibc, plus the raw API is a
162 * little more convenient for this test.
163 */
164static int sys_clone(unsigned long clone_flags, unsigned long newsp,
165 int *parent_tidptr, unsigned long tls,
166 int *child_tidptr)
167{
168 return my_syscall5(__NR_clone, clone_flags, newsp, parent_tidptr, tls,
169 child_tidptr);
170}
171
172#define __STACK_SIZE (8 * 1024 * 1024)
173
174/*
175 * If we clone with CLONE_VM then the value in the parent should
176 * be unchanged and the child should start with zero and be able to
177 * set its own value.
178 */
179static int write_clone_read(void)
180{
181 int parent_tid, child_tid;
182 pid_t parent, waiting;
183 int ret, status;
184 void *stack;
185
186 parent = getpid();
187 set_tpidr2(parent);
188
189 stack = malloc(__STACK_SIZE);
190 if (!stack) {
191 putstr(str: "# malloc() failed\n");
192 return 0;
193 }
194
195 ret = sys_clone(CLONE_VM, newsp: (unsigned long)stack + __STACK_SIZE,
196 parent_tidptr: &parent_tid, tls: 0, child_tidptr: &child_tid);
197 if (ret == -1) {
198 putstr(str: "# clone() failed\n");
199 putnum(num: errno);
200 putstr(str: "\n");
201 return 0;
202 }
203
204 if (ret == 0) {
205 /* In child */
206 if (get_tpidr2() != 0) {
207 putstr(str: "# TPIDR2 non-zero in child: ");
208 putnum(num: get_tpidr2());
209 putstr(str: "\n");
210 exit(0);
211 }
212
213 if (gettid() == 0)
214 putstr(str: "# Child TID==0\n");
215 set_tpidr2(gettid());
216 if (get_tpidr2() == gettid()) {
217 exit(1);
218 } else {
219 putstr(str: "# Failed to set TPIDR2 in child\n");
220 exit(0);
221 }
222 }
223
224 for (;;) {
225 waiting = wait4(ret, &status, __WCLONE, NULL);
226
227 if (waiting < 0) {
228 if (errno == EINTR)
229 continue;
230 putstr(str: "# wait4() failed: ");
231 putnum(num: errno);
232 putstr(str: "\n");
233 return 0;
234 }
235 if (waiting != ret) {
236 putstr(str: "# wait4() returned wrong PID ");
237 putnum(num: waiting);
238 putstr(str: "\n");
239 return 0;
240 }
241
242 if (!WIFEXITED(status)) {
243 putstr(str: "# child did not exit\n");
244 return 0;
245 }
246
247 if (parent != get_tpidr2()) {
248 putstr(str: "# TPIDR2 corrupted in parent\n");
249 return 0;
250 }
251
252 return WEXITSTATUS(status);
253 }
254}
255
256#define run_test(name) \
257 if (name()) { \
258 tests_passed++; \
259 } else { \
260 tests_failed++; \
261 putstr("not "); \
262 } \
263 putstr("ok "); \
264 putnum(++tests_run); \
265 putstr(" " #name "\n");
266
267#define skip_test(name) \
268 tests_skipped++; \
269 putstr("ok "); \
270 putnum(++tests_run); \
271 putstr(" # SKIP " #name "\n");
272
273int main(int argc, char **argv)
274{
275 int ret;
276
277 putstr(str: "TAP version 13\n");
278 putstr(str: "1..");
279 putnum(EXPECTED_TESTS);
280 putstr(str: "\n");
281
282 putstr(str: "# PID: ");
283 putnum(num: getpid());
284 putstr(str: "\n");
285
286 /*
287 * This test is run with nolibc which doesn't support hwcap and
288 * it's probably disproportionate to implement so instead check
289 * for the default vector length configuration in /proc.
290 */
291 ret = open("/proc/sys/abi/sme_default_vector_length", O_RDONLY, 0);
292 if (ret >= 0) {
293 run_test(default_value);
294 run_test(write_read);
295 run_test(write_sleep_read);
296 run_test(write_fork_read);
297 run_test(write_clone_read);
298
299 } else {
300 putstr(str: "# SME support not present\n");
301
302 skip_test(default_value);
303 skip_test(write_read);
304 skip_test(write_sleep_read);
305 skip_test(write_fork_read);
306 skip_test(write_clone_read);
307 }
308
309 print_summary();
310
311 return 0;
312}
313

source code of linux/tools/testing/selftests/arm64/abi/tpidr2.c