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 10 static void putstr(const char *str) 11 { 12 write(1, str, strlen(str)); 13 } 14 15 static void putnum(unsigned int num) 16 { 17 char c; 18 19 if (num / 10) 20 putnum(num / 10); 21 22 c = '0' + (num % 10); 23 write(1, &c, 1); 24 } 25 26 static int tests_run; 27 static int tests_passed; 28 static int tests_failed; 29 static int tests_skipped; 30 31 static void set_tpidr2(uint64_t val) 32 { 33 asm volatile ( 34 "msr " SYS_TPIDR2 ", %0\n" 35 : 36 : "r"(val) 37 : "cc"); 38 } 39 40 static 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 53 static void print_summary(void) 54 { 55 if (tests_passed + tests_failed + tests_skipped != EXPECTED_TESTS) 56 putstr("# UNEXPECTED TEST COUNT: "); 57 58 putstr("# Totals: pass:"); 59 putnum(tests_passed); 60 putstr(" fail:"); 61 putnum(tests_failed); 62 putstr(" xfail:0 xpass:0 skip:"); 63 putnum(tests_skipped); 64 putstr(" error:0\n"); 65 } 66 67 /* Processes should start with TPIDR2 == 0 */ 68 static int default_value(void) 69 { 70 return get_tpidr2() == 0; 71 } 72 73 /* If we set TPIDR2 we should read that value */ 74 static 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 */ 82 static 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 */ 96 static 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("# TPIDR2 changed in child: "); 109 putnum(get_tpidr2()); 110 putstr("\n"); 111 exit(0); 112 } 113 114 set_tpidr2(getpid()); 115 if (get_tpidr2() == getpid()) { 116 exit(1); 117 } else { 118 putstr("# Failed to set TPIDR2 in child\n"); 119 exit(0); 120 } 121 } 122 if (newpid < 0) { 123 putstr("# fork() failed: -"); 124 putnum(-newpid); 125 putstr("\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("# waitpid() failed: "); 136 putnum(errno); 137 putstr("\n"); 138 return 0; 139 } 140 if (waiting != newpid) { 141 putstr("# waitpid() returned wrong PID\n"); 142 return 0; 143 } 144 145 if (!WIFEXITED(status)) { 146 putstr("# child did not exit\n"); 147 return 0; 148 } 149 150 if (getpid() != get_tpidr2()) { 151 putstr("# 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 */ 164 static 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 /* 173 * If we clone with CLONE_SETTLS then the value in the parent should 174 * be unchanged and the child should start with zero and be able to 175 * set its own value. 176 */ 177 static int write_clone_read(void) 178 { 179 int parent_tid, child_tid; 180 pid_t parent, waiting; 181 int ret, status; 182 183 parent = getpid(); 184 set_tpidr2(parent); 185 186 ret = sys_clone(CLONE_SETTLS, 0, &parent_tid, 0, &child_tid); 187 if (ret == -1) { 188 putstr("# clone() failed\n"); 189 putnum(errno); 190 putstr("\n"); 191 return 0; 192 } 193 194 if (ret == 0) { 195 /* In child */ 196 if (get_tpidr2() != 0) { 197 putstr("# TPIDR2 non-zero in child: "); 198 putnum(get_tpidr2()); 199 putstr("\n"); 200 exit(0); 201 } 202 203 if (gettid() == 0) 204 putstr("# Child TID==0\n"); 205 set_tpidr2(gettid()); 206 if (get_tpidr2() == gettid()) { 207 exit(1); 208 } else { 209 putstr("# Failed to set TPIDR2 in child\n"); 210 exit(0); 211 } 212 } 213 214 for (;;) { 215 waiting = wait4(ret, &status, __WCLONE, NULL); 216 217 if (waiting < 0) { 218 if (errno == EINTR) 219 continue; 220 putstr("# wait4() failed: "); 221 putnum(errno); 222 putstr("\n"); 223 return 0; 224 } 225 if (waiting != ret) { 226 putstr("# wait4() returned wrong PID "); 227 putnum(waiting); 228 putstr("\n"); 229 return 0; 230 } 231 232 if (!WIFEXITED(status)) { 233 putstr("# child did not exit\n"); 234 return 0; 235 } 236 237 if (parent != get_tpidr2()) { 238 putstr("# TPIDR2 corrupted in parent\n"); 239 return 0; 240 } 241 242 return WEXITSTATUS(status); 243 } 244 } 245 246 #define run_test(name) \ 247 if (name()) { \ 248 tests_passed++; \ 249 } else { \ 250 tests_failed++; \ 251 putstr("not "); \ 252 } \ 253 putstr("ok "); \ 254 putnum(++tests_run); \ 255 putstr(" " #name "\n"); 256 257 #define skip_test(name) \ 258 tests_skipped++; \ 259 putstr("ok "); \ 260 putnum(++tests_run); \ 261 putstr(" # SKIP " #name "\n"); 262 263 int main(int argc, char **argv) 264 { 265 int ret, i; 266 267 putstr("TAP version 13\n"); 268 putstr("1.."); 269 putnum(EXPECTED_TESTS); 270 putstr("\n"); 271 272 putstr("# PID: "); 273 putnum(getpid()); 274 putstr("\n"); 275 276 /* 277 * This test is run with nolibc which doesn't support hwcap and 278 * it's probably disproportionate to implement so instead check 279 * for the default vector length configuration in /proc. 280 */ 281 ret = open("/proc/sys/abi/sme_default_vector_length", O_RDONLY, 0); 282 if (ret >= 0) { 283 run_test(default_value); 284 run_test(write_read); 285 run_test(write_sleep_read); 286 run_test(write_fork_read); 287 run_test(write_clone_read); 288 289 } else { 290 putstr("# SME support not present\n"); 291 292 skip_test(default_value); 293 skip_test(write_read); 294 skip_test(write_sleep_read); 295 skip_test(write_fork_read); 296 skip_test(write_clone_read); 297 } 298 299 print_summary(); 300 301 return 0; 302 } 303