1 // SPDX-License-Identifier: GPL-2.0 2 /* Copyright (C) 2019 ARM Limited */ 3 4 #include <stdio.h> 5 #include <stdlib.h> 6 #include <signal.h> 7 #include <string.h> 8 #include <unistd.h> 9 #include <assert.h> 10 #include <sys/auxv.h> 11 #include <linux/auxvec.h> 12 #include <ucontext.h> 13 14 #include <asm/unistd.h> 15 16 #include <kselftest.h> 17 18 #include "test_signals.h" 19 #include "test_signals_utils.h" 20 #include "testcases/testcases.h" 21 22 23 extern struct tdescr *current; 24 25 static int sig_copyctx = SIGTRAP; 26 27 static char const *const feats_names[FMAX_END] = { 28 " SSBS ", 29 }; 30 31 #define MAX_FEATS_SZ 128 32 static char feats_string[MAX_FEATS_SZ]; 33 34 static inline char *feats_to_string(unsigned long feats) 35 { 36 size_t flen = MAX_FEATS_SZ - 1; 37 38 for (int i = 0; i < FMAX_END; i++) { 39 if (feats & (1UL << i)) { 40 size_t tlen = strlen(feats_names[i]); 41 42 assert(flen > tlen); 43 flen -= tlen; 44 strncat(feats_string, feats_names[i], flen); 45 } 46 } 47 48 return feats_string; 49 } 50 51 static void unblock_signal(int signum) 52 { 53 sigset_t sset; 54 55 sigemptyset(&sset); 56 sigaddset(&sset, signum); 57 sigprocmask(SIG_UNBLOCK, &sset, NULL); 58 } 59 60 static void default_result(struct tdescr *td, bool force_exit) 61 { 62 if (td->result == KSFT_SKIP) { 63 fprintf(stderr, "==>> completed. SKIP.\n"); 64 } else if (td->pass) { 65 fprintf(stderr, "==>> completed. PASS(1)\n"); 66 td->result = KSFT_PASS; 67 } else { 68 fprintf(stdout, "==>> completed. FAIL(0)\n"); 69 td->result = KSFT_FAIL; 70 } 71 72 if (force_exit) 73 exit(td->result); 74 } 75 76 /* 77 * The following handle_signal_* helpers are used by main default_handler 78 * and are meant to return true when signal is handled successfully: 79 * when false is returned instead, it means that the signal was somehow 80 * unexpected in that context and it was NOT handled; default_handler will 81 * take care of such unexpected situations. 82 */ 83 84 static bool handle_signal_unsupported(struct tdescr *td, 85 siginfo_t *si, void *uc) 86 { 87 if (feats_ok(td)) 88 return false; 89 90 /* Mangling PC to avoid loops on original SIGILL */ 91 ((ucontext_t *)uc)->uc_mcontext.pc += 4; 92 93 if (!td->initialized) { 94 fprintf(stderr, 95 "Got SIG_UNSUPP @test_init. Ignore.\n"); 96 } else { 97 fprintf(stderr, 98 "-- RX SIG_UNSUPP on unsupported feat...OK\n"); 99 td->pass = 1; 100 default_result(current, 1); 101 } 102 103 return true; 104 } 105 106 static bool handle_signal_trigger(struct tdescr *td, 107 siginfo_t *si, void *uc) 108 { 109 td->triggered = 1; 110 /* ->run was asserted NON-NULL in test_setup() already */ 111 td->run(td, si, uc); 112 113 return true; 114 } 115 116 static bool handle_signal_ok(struct tdescr *td, 117 siginfo_t *si, void *uc) 118 { 119 /* 120 * it's a bug in the test code when this assert fail: 121 * if sig_trig was defined, it must have been used before getting here. 122 */ 123 assert(!td->sig_trig || td->triggered); 124 fprintf(stderr, 125 "SIG_OK -- SP:0x%llX si_addr@:%p si_code:%d token@:%p offset:%ld\n", 126 ((ucontext_t *)uc)->uc_mcontext.sp, 127 si->si_addr, si->si_code, td->token, td->token - si->si_addr); 128 /* 129 * fake_sigreturn tests, which have sanity_enabled=1, set, at the very 130 * last time, the token field to the SP address used to place the fake 131 * sigframe: so token==0 means we never made it to the end, 132 * segfaulting well-before, and the test is possibly broken. 133 */ 134 if (!td->sanity_disabled && !td->token) { 135 fprintf(stdout, 136 "current->token ZEROED...test is probably broken!\n"); 137 abort(); 138 } 139 /* 140 * Trying to narrow down the SEGV to the ones generated by Kernel itself 141 * via arm64_notify_segfault(). This is a best-effort check anyway, and 142 * the si_code check may need to change if this aspect of the kernel 143 * ABI changes. 144 */ 145 if (td->sig_ok == SIGSEGV && si->si_code != SEGV_ACCERR) { 146 fprintf(stdout, 147 "si_code != SEGV_ACCERR...test is probably broken!\n"); 148 abort(); 149 } 150 td->pass = 1; 151 /* 152 * Some tests can lead to SEGV loops: in such a case we want to 153 * terminate immediately exiting straight away; some others are not 154 * supposed to outlive the signal handler code, due to the content of 155 * the fake sigframe which caused the signal itself. 156 */ 157 default_result(current, 1); 158 159 return true; 160 } 161 162 static bool handle_signal_copyctx(struct tdescr *td, 163 siginfo_t *si, void *uc) 164 { 165 /* Mangling PC to avoid loops on original BRK instr */ 166 ((ucontext_t *)uc)->uc_mcontext.pc += 4; 167 memcpy(td->live_uc, uc, td->live_sz); 168 ASSERT_GOOD_CONTEXT(td->live_uc); 169 td->live_uc_valid = 1; 170 fprintf(stderr, 171 "GOOD CONTEXT grabbed from sig_copyctx handler\n"); 172 173 return true; 174 } 175 176 static void default_handler(int signum, siginfo_t *si, void *uc) 177 { 178 if (current->sig_unsupp && signum == current->sig_unsupp && 179 handle_signal_unsupported(current, si, uc)) { 180 fprintf(stderr, "Handled SIG_UNSUPP\n"); 181 } else if (current->sig_trig && signum == current->sig_trig && 182 handle_signal_trigger(current, si, uc)) { 183 fprintf(stderr, "Handled SIG_TRIG\n"); 184 } else if (current->sig_ok && signum == current->sig_ok && 185 handle_signal_ok(current, si, uc)) { 186 fprintf(stderr, "Handled SIG_OK\n"); 187 } else if (signum == sig_copyctx && current->live_uc && 188 handle_signal_copyctx(current, si, uc)) { 189 fprintf(stderr, "Handled SIG_COPYCTX\n"); 190 } else { 191 if (signum == SIGALRM && current->timeout) { 192 fprintf(stderr, "-- Timeout !\n"); 193 } else { 194 fprintf(stderr, 195 "-- RX UNEXPECTED SIGNAL: %d\n", signum); 196 } 197 default_result(current, 1); 198 } 199 } 200 201 static int default_setup(struct tdescr *td) 202 { 203 struct sigaction sa; 204 205 sa.sa_sigaction = default_handler; 206 sa.sa_flags = SA_SIGINFO | SA_RESTART; 207 sa.sa_flags |= td->sa_flags; 208 sigemptyset(&sa.sa_mask); 209 /* uncatchable signals naturally skipped ... */ 210 for (int sig = 1; sig < 32; sig++) 211 sigaction(sig, &sa, NULL); 212 /* 213 * RT Signals default disposition is Term but they cannot be 214 * generated by the Kernel in response to our tests; so just catch 215 * them all and report them as UNEXPECTED signals. 216 */ 217 for (int sig = SIGRTMIN; sig <= SIGRTMAX; sig++) 218 sigaction(sig, &sa, NULL); 219 220 /* just in case...unblock explicitly all we need */ 221 if (td->sig_trig) 222 unblock_signal(td->sig_trig); 223 if (td->sig_ok) 224 unblock_signal(td->sig_ok); 225 if (td->sig_unsupp) 226 unblock_signal(td->sig_unsupp); 227 228 if (td->timeout) { 229 unblock_signal(SIGALRM); 230 alarm(td->timeout); 231 } 232 fprintf(stderr, "Registered handlers for all signals.\n"); 233 234 return 1; 235 } 236 237 static inline int default_trigger(struct tdescr *td) 238 { 239 return !raise(td->sig_trig); 240 } 241 242 int test_init(struct tdescr *td) 243 { 244 if (td->sig_trig == sig_copyctx) { 245 fprintf(stdout, 246 "Signal %d is RESERVED, cannot be used as a trigger. Aborting\n", 247 sig_copyctx); 248 return 0; 249 } 250 /* just in case */ 251 unblock_signal(sig_copyctx); 252 253 td->minsigstksz = getauxval(AT_MINSIGSTKSZ); 254 if (!td->minsigstksz) 255 td->minsigstksz = MINSIGSTKSZ; 256 fprintf(stderr, "Detected MINSTKSIGSZ:%d\n", td->minsigstksz); 257 258 if (td->feats_required) { 259 td->feats_supported = 0; 260 /* 261 * Checking for CPU required features using both the 262 * auxval and the arm64 MRS Emulation to read sysregs. 263 */ 264 if (getauxval(AT_HWCAP) & HWCAP_SSBS) 265 td->feats_supported |= FEAT_SSBS; 266 if (feats_ok(td)) 267 fprintf(stderr, 268 "Required Features: [%s] supported\n", 269 feats_to_string(td->feats_required & 270 td->feats_supported)); 271 else 272 fprintf(stderr, 273 "Required Features: [%s] NOT supported\n", 274 feats_to_string(td->feats_required & 275 ~td->feats_supported)); 276 } 277 278 /* Perform test specific additional initialization */ 279 if (td->init && !td->init(td)) { 280 fprintf(stderr, "FAILED Testcase initialization.\n"); 281 return 0; 282 } 283 td->initialized = 1; 284 fprintf(stderr, "Testcase initialized.\n"); 285 286 return 1; 287 } 288 289 int test_setup(struct tdescr *td) 290 { 291 /* assert core invariants symptom of a rotten testcase */ 292 assert(current); 293 assert(td); 294 assert(td->name); 295 assert(td->run); 296 297 /* Default result is FAIL if test setup fails */ 298 td->result = KSFT_FAIL; 299 if (td->setup) 300 return td->setup(td); 301 else 302 return default_setup(td); 303 } 304 305 int test_run(struct tdescr *td) 306 { 307 if (td->sig_trig) { 308 if (td->trigger) 309 return td->trigger(td); 310 else 311 return default_trigger(td); 312 } else { 313 return td->run(td, NULL, NULL); 314 } 315 } 316 317 void test_result(struct tdescr *td) 318 { 319 if (td->initialized && td->result != KSFT_SKIP && td->check_result) 320 td->check_result(td); 321 default_result(td, 0); 322 } 323 324 void test_cleanup(struct tdescr *td) 325 { 326 if (td->cleanup) 327 td->cleanup(td); 328 } 329