kernel/tools/testing/selftests/seccomp/seccomp_bpf.c

   1 /*
   2  * Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
   3  * Use of this source code is governed by the GPLv2 license.
   4  *
   5  * Test code for seccomp bpf.
   6  */
   7
   8 #include <asm/siginfo.h>
   9 #define __have_siginfo_t 1
  10 #define __have_sigval_t 1
  11 #define __have_sigevent_t 1
  12
  13 #include <errno.h>
  14 #include <linux/filter.h>
  15 #include <sys/prctl.h>
  16 #include <sys/ptrace.h>
  17 #include <sys/types.h>
  18 #include <sys/user.h>
  19 #include <linux/prctl.h>
  20 #include <linux/ptrace.h>
  21 #include <linux/seccomp.h>
  22 #include <pthread.h>
  23 #include <semaphore.h>
  24 #include <signal.h>
  25 #include <stddef.h>
  26 #include <stdbool.h>
  27 #include <string.h>
  28 #include <time.h>
  29 #include <linux/elf.h>
  30 #include <sys/uio.h>
  31 #include <sys/utsname.h>
  32 #include <sys/fcntl.h>
  33 #include <sys/mman.h>
  34 #include <sys/times.h>
  35
  36 #define _GNU_SOURCE
  37 #include <unistd.h>
  38 #include <sys/syscall.h>
  39
  40 #include "test_harness.h"
  41
  42 #ifndef PR_SET_PTRACER
  43 # define PR_SET_PTRACER 0x59616d61
  44 #endif
  45
  46 #ifndef PR_SET_NO_NEW_PRIVS
  47 #define PR_SET_NO_NEW_PRIVS 38
  48 #define PR_GET_NO_NEW_PRIVS 39
  49 #endif
  50
  51 #ifndef PR_SECCOMP_EXT
  52 #define PR_SECCOMP_EXT 43
  53 #endif
  54
  55 #ifndef SECCOMP_EXT_ACT
  56 #define SECCOMP_EXT_ACT 1
  57 #endif
  58
  59 #ifndef SECCOMP_EXT_ACT_TSYNC
  60 #define SECCOMP_EXT_ACT_TSYNC 1
  61 #endif
  62
  63 #ifndef SECCOMP_MODE_STRICT
  64 #define SECCOMP_MODE_STRICT 1
  65 #endif
  66
  67 #ifndef SECCOMP_MODE_FILTER
  68 #define SECCOMP_MODE_FILTER 2
  69 #endif
  70
  71 #ifndef SECCOMP_RET_KILL
  72 #define SECCOMP_RET_KILL        0x00000000U /* kill the task immediately */
  73 #define SECCOMP_RET_TRAP        0x00030000U /* disallow and force a SIGSYS */
  74 #define SECCOMP_RET_ERRNO       0x00050000U /* returns an errno */
  75 #define SECCOMP_RET_TRACE       0x7ff00000U /* pass to a tracer or disallow */
  76 #define SECCOMP_RET_ALLOW       0x7fff0000U /* allow */
  77
  78 /* Masks for the return value sections. */
  79 #define SECCOMP_RET_ACTION      0x7fff0000U
  80 #define SECCOMP_RET_DATA        0x0000ffffU
  81
  82 struct seccomp_data {
  83         int nr;
  84         __u32 arch;
  85         __u64 instruction_pointer;
  86         __u64 args[6];
  87 };
  88 #endif
  89
  90 #if __BYTE_ORDER == __LITTLE_ENDIAN
  91 #define syscall_arg(_n) (offsetof(struct seccomp_data, args[_n]))
  92 #elif __BYTE_ORDER == __BIG_ENDIAN
  93 #define syscall_arg(_n) (offsetof(struct seccomp_data, args[_n]) + sizeof(__u32))
  94 #else
  95 #error "wut? Unknown __BYTE_ORDER?!"
  96 #endif
  97
  98 #define SIBLING_EXIT_UNKILLED   0xbadbeef
  99 #define SIBLING_EXIT_FAILURE    0xbadface
 100 #define SIBLING_EXIT_NEWPRIVS   0xbadfeed
 101
 102 TEST(mode_strict_support)
 103 {
 104         long ret;
 105
 106         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, NULL, NULL);
 107         ASSERT_EQ(0, ret) {
 108                 TH_LOG("Kernel does not support CONFIG_SECCOMP");
 109         }
 110         syscall(__NR_exit, 1);
 111 }
 112
 113 TEST_SIGNAL(mode_strict_cannot_call_prctl, SIGKILL)
 114 {
 115         long ret;
 116
 117         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, NULL, NULL);
 118         ASSERT_EQ(0, ret) {
 119                 TH_LOG("Kernel does not support CONFIG_SECCOMP");
 120         }
 121         syscall(__NR_prctl, PR_SET_SECCOMP, SECCOMP_MODE_FILTER,
 122                 NULL, NULL, NULL);
 123         EXPECT_FALSE(true) {
 124                 TH_LOG("Unreachable!");
 125         }
 126 }
 127
 128 /* Note! This doesn't test no new privs behavior */
 129 TEST(no_new_privs_support)
 130 {
 131         long ret;
 132
 133         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
 134         EXPECT_EQ(0, ret) {
 135                 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
 136         }
 137 }
 138
 139 /* Tests kernel support by checking for a copy_from_user() fault on * NULL. */
 140 TEST(mode_filter_support)
 141 {
 142         long ret;
 143
 144         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
 145         ASSERT_EQ(0, ret) {
 146                 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
 147         }
 148         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, NULL, NULL, NULL);
 149         EXPECT_EQ(-1, ret);
 150         EXPECT_EQ(EFAULT, errno) {
 151                 TH_LOG("Kernel does not support CONFIG_SECCOMP_FILTER!");
 152         }
 153 }
 154
 155 TEST(mode_filter_without_nnp)
 156 {
 157         struct sock_filter filter[] = {
 158                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
 159         };
 160         struct sock_fprog prog = {
 161                 .len = (unsigned short)ARRAY_SIZE(filter),
 162                 .filter = filter,
 163         };
 164         long ret;
 165
 166         ret = prctl(PR_GET_NO_NEW_PRIVS, 0, NULL, 0, 0);
 167         ASSERT_LE(0, ret) {
 168                 TH_LOG("Expected 0 or unsupported for NO_NEW_PRIVS");
 169         }
 170         errno = 0;
 171         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
 172         /* Succeeds with CAP_SYS_ADMIN, fails without */
 173         /* TODO(wad) check caps not euid */
 174         if (geteuid()) {
 175                 EXPECT_EQ(-1, ret);
 176                 EXPECT_EQ(EACCES, errno);
 177         } else {
 178                 EXPECT_EQ(0, ret);
 179         }
 180 }
 181
 182 #define MAX_INSNS_PER_PATH 32768
 183
 184 TEST(filter_size_limits)
 185 {
 186         int i;
 187         int count = BPF_MAXINSNS + 1;
 188         struct sock_filter allow[] = {
 189                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
 190         };
 191         struct sock_filter *filter;
 192         struct sock_fprog prog = { };
 193         long ret;
 194
 195         filter = calloc(count, sizeof(*filter));
 196         ASSERT_NE(NULL, filter);
 197
 198         for (i = 0; i < count; i++)
 199                 filter[i] = allow[0];
 200
 201         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
 202         ASSERT_EQ(0, ret);
 203
 204         prog.filter = filter;
 205         prog.len = count;
 206
 207         /* Too many filter instructions in a single filter. */
 208         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
 209         ASSERT_NE(0, ret) {
 210                 TH_LOG("Installing %d insn filter was allowed", prog.len);
 211         }
 212
 213         /* One less is okay, though. */
 214         prog.len -= 1;
 215         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
 216         ASSERT_EQ(0, ret) {
 217                 TH_LOG("Installing %d insn filter wasn't allowed", prog.len);
 218         }
 219 }
 220
 221 TEST(filter_chain_limits)
 222 {
 223         int i;
 224         int count = BPF_MAXINSNS;
 225         struct sock_filter allow[] = {
 226                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
 227         };
 228         struct sock_filter *filter;
 229         struct sock_fprog prog = { };
 230         long ret;
 231
 232         filter = calloc(count, sizeof(*filter));
 233         ASSERT_NE(NULL, filter);
 234
 235         for (i = 0; i < count; i++)
 236                 filter[i] = allow[0];
 237
 238         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
 239         ASSERT_EQ(0, ret);
 240
 241         prog.filter = filter;
 242         prog.len = 1;
 243
 244         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
 245         ASSERT_EQ(0, ret);
 246
 247         prog.len = count;
 248
 249         /* Too many total filter instructions. */
 250         for (i = 0; i < MAX_INSNS_PER_PATH; i++) {
 251                 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
 252                 if (ret != 0)
 253                         break;
 254         }
 255         ASSERT_NE(0, ret) {
 256                 TH_LOG("Allowed %d %d-insn filters (total with penalties:%d)",
 257                        i, count, i * (count + 4));
 258         }
 259 }
 260
 261 TEST(mode_filter_cannot_move_to_strict)
 262 {
 263         struct sock_filter filter[] = {
 264                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
 265         };
 266         struct sock_fprog prog = {
 267                 .len = (unsigned short)ARRAY_SIZE(filter),
 268                 .filter = filter,
 269         };
 270         long ret;
 271
 272         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
 273         ASSERT_EQ(0, ret);
 274
 275         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
 276         ASSERT_EQ(0, ret);
 277
 278         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, 0, 0);
 279         EXPECT_EQ(-1, ret);
 280         EXPECT_EQ(EINVAL, errno);
 281 }
 282
 283
 284 TEST(mode_filter_get_seccomp)
 285 {
 286         struct sock_filter filter[] = {
 287                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
 288         };
 289         struct sock_fprog prog = {
 290                 .len = (unsigned short)ARRAY_SIZE(filter),
 291                 .filter = filter,
 292         };
 293         long ret;
 294
 295         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
 296         ASSERT_EQ(0, ret);
 297
 298         ret = prctl(PR_GET_SECCOMP, 0, 0, 0, 0);
 299         EXPECT_EQ(0, ret);
 300
 301         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
 302         ASSERT_EQ(0, ret);
 303
 304         ret = prctl(PR_GET_SECCOMP, 0, 0, 0, 0);
 305         EXPECT_EQ(2, ret);
 306 }
 307
 308
 309 TEST(ALLOW_all)
 310 {
 311         struct sock_filter filter[] = {
 312                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
 313         };
 314         struct sock_fprog prog = {
 315                 .len = (unsigned short)ARRAY_SIZE(filter),
 316                 .filter = filter,
 317         };
 318         long ret;
 319
 320         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
 321         ASSERT_EQ(0, ret);
 322
 323         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
 324         ASSERT_EQ(0, ret);
 325 }
 326
 327 TEST(empty_prog)
 328 {
 329         struct sock_filter filter[] = {
 330         };
 331         struct sock_fprog prog = {
 332                 .len = (unsigned short)ARRAY_SIZE(filter),
 333                 .filter = filter,
 334         };
 335         long ret;
 336
 337         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
 338         ASSERT_EQ(0, ret);
 339
 340         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
 341         EXPECT_EQ(-1, ret);
 342         EXPECT_EQ(EINVAL, errno);
 343 }
 344
 345 TEST_SIGNAL(unknown_ret_is_kill_inside, SIGSYS)
 346 {
 347         struct sock_filter filter[] = {
 348                 BPF_STMT(BPF_RET|BPF_K, 0x10000000U),
 349         };
 350         struct sock_fprog prog = {
 351                 .len = (unsigned short)ARRAY_SIZE(filter),
 352                 .filter = filter,
 353         };
 354         long ret;
 355
 356         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
 357         ASSERT_EQ(0, ret);
 358
 359         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
 360         ASSERT_EQ(0, ret);
 361         EXPECT_EQ(0, syscall(__NR_getpid)) {
 362                 TH_LOG("getpid() shouldn't ever return");
 363         }
 364 }
 365
 366 /* return code >= 0x80000000 is unused. */
 367 TEST_SIGNAL(unknown_ret_is_kill_above_allow, SIGSYS)
 368 {
 369         struct sock_filter filter[] = {
 370                 BPF_STMT(BPF_RET|BPF_K, 0x90000000U),
 371         };
 372         struct sock_fprog prog = {
 373                 .len = (unsigned short)ARRAY_SIZE(filter),
 374                 .filter = filter,
 375         };
 376         long ret;
 377
 378         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
 379         ASSERT_EQ(0, ret);
 380
 381         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
 382         ASSERT_EQ(0, ret);
 383         EXPECT_EQ(0, syscall(__NR_getpid)) {
 384                 TH_LOG("getpid() shouldn't ever return");
 385         }
 386 }
 387
 388 TEST_SIGNAL(KILL_all, SIGSYS)
 389 {
 390         struct sock_filter filter[] = {
 391                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
 392         };
 393         struct sock_fprog prog = {
 394                 .len = (unsigned short)ARRAY_SIZE(filter),
 395                 .filter = filter,
 396         };
 397         long ret;
 398
 399         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
 400         ASSERT_EQ(0, ret);
 401
 402         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
 403         ASSERT_EQ(0, ret);
 404 }
 405
 406 TEST_SIGNAL(KILL_one, SIGSYS)
 407 {
 408         struct sock_filter filter[] = {
 409                 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
 410                         offsetof(struct seccomp_data, nr)),
 411                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
 412                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
 413                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
 414         };
 415         struct sock_fprog prog = {
 416                 .len = (unsigned short)ARRAY_SIZE(filter),
 417                 .filter = filter,
 418         };
 419         long ret;
 420         pid_t parent = getppid();
 421
 422         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
 423         ASSERT_EQ(0, ret);
 424
 425         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
 426         ASSERT_EQ(0, ret);
 427
 428         EXPECT_EQ(parent, syscall(__NR_getppid));
 429         /* getpid() should never return. */
 430         EXPECT_EQ(0, syscall(__NR_getpid));
 431 }
 432
 433 TEST_SIGNAL(KILL_one_arg_one, SIGSYS)
 434 {
 435         void *fatal_address;
 436         struct sock_filter filter[] = {
 437                 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
 438                         offsetof(struct seccomp_data, nr)),
 439                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_times, 1, 0),
 440                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
 441                 /* Only both with lower 32-bit for now. */
 442                 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(0)),
 443                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K,
 444                         (unsigned long)&fatal_address, 0, 1),
 445                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
 446                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
 447         };
 448         struct sock_fprog prog = {
 449                 .len = (unsigned short)ARRAY_SIZE(filter),
 450                 .filter = filter,
 451         };
 452         long ret;
 453         pid_t parent = getppid();
 454         struct tms timebuf;
 455         clock_t clock = times(&timebuf);
 456
 457         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
 458         ASSERT_EQ(0, ret);
 459
 460         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
 461         ASSERT_EQ(0, ret);
 462
 463         EXPECT_EQ(parent, syscall(__NR_getppid));
 464         EXPECT_LE(clock, syscall(__NR_times, &timebuf));
 465         /* times() should never return. */
 466         EXPECT_EQ(0, syscall(__NR_times, &fatal_address));
 467 }
 468
 469 TEST_SIGNAL(KILL_one_arg_six, SIGSYS)
 470 {
 471 #ifndef __NR_mmap2
 472         int sysno = __NR_mmap;
 473 #else
 474         int sysno = __NR_mmap2;
 475 #endif
 476         struct sock_filter filter[] = {
 477                 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
 478                         offsetof(struct seccomp_data, nr)),
 479                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, sysno, 1, 0),
 480                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
 481                 /* Only both with lower 32-bit for now. */
 482                 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(5)),
 483                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 0x0C0FFEE, 0, 1),
 484                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
 485                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
 486         };
 487         struct sock_fprog prog = {
 488                 .len = (unsigned short)ARRAY_SIZE(filter),
 489                 .filter = filter,
 490         };
 491         long ret;
 492         pid_t parent = getppid();
 493         int fd;
 494         void *map1, *map2;
 495         int page_size = sysconf(_SC_PAGESIZE);
 496
 497         ASSERT_LT(0, page_size);
 498
 499         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
 500         ASSERT_EQ(0, ret);
 501
 502         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
 503         ASSERT_EQ(0, ret);
 504
 505         fd = open("/dev/zero", O_RDONLY);
 506         ASSERT_NE(-1, fd);
 507
 508         EXPECT_EQ(parent, syscall(__NR_getppid));
 509         map1 = (void *)syscall(sysno,
 510                 NULL, page_size, PROT_READ, MAP_PRIVATE, fd, page_size);
 511         EXPECT_NE(MAP_FAILED, map1);
 512         /* mmap2() should never return. */
 513         map2 = (void *)syscall(sysno,
 514                  NULL, page_size, PROT_READ, MAP_PRIVATE, fd, 0x0C0FFEE);
 515         EXPECT_EQ(MAP_FAILED, map2);
 516
 517         /* The test failed, so clean up the resources. */
 518         munmap(map1, page_size);
 519         munmap(map2, page_size);
 520         close(fd);
 521 }
 522
 523 /* TODO(wad) add 64-bit versus 32-bit arg tests. */
 524 TEST(arg_out_of_range)
 525 {
 526         struct sock_filter filter[] = {
 527                 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(6)),
 528                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
 529         };
 530         struct sock_fprog prog = {
 531                 .len = (unsigned short)ARRAY_SIZE(filter),
 532                 .filter = filter,
 533         };
 534         long ret;
 535
 536         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
 537         ASSERT_EQ(0, ret);
 538
 539         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
 540         EXPECT_EQ(-1, ret);
 541         EXPECT_EQ(EINVAL, errno);
 542 }
 543
 544 TEST(ERRNO_valid)
 545 {
 546         struct sock_filter filter[] = {
 547                 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
 548                         offsetof(struct seccomp_data, nr)),
 549                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1),
 550                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | E2BIG),
 551                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
 552         };
 553         struct sock_fprog prog = {
 554                 .len = (unsigned short)ARRAY_SIZE(filter),
 555                 .filter = filter,
 556         };
 557         long ret;
 558         pid_t parent = getppid();
 559
 560         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
 561         ASSERT_EQ(0, ret);
 562
 563         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
 564         ASSERT_EQ(0, ret);
 565
 566         EXPECT_EQ(parent, syscall(__NR_getppid));
 567         EXPECT_EQ(-1, read(0, NULL, 0));
 568         EXPECT_EQ(E2BIG, errno);
 569 }
 570
 571 TEST(ERRNO_zero)
 572 {
 573         struct sock_filter filter[] = {
 574                 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
 575                         offsetof(struct seccomp_data, nr)),
 576                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1),
 577                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | 0),
 578                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
 579         };
 580         struct sock_fprog prog = {
 581                 .len = (unsigned short)ARRAY_SIZE(filter),
 582                 .filter = filter,
 583         };
 584         long ret;
 585         pid_t parent = getppid();
 586
 587         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
 588         ASSERT_EQ(0, ret);
 589
 590         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
 591         ASSERT_EQ(0, ret);
 592
 593         EXPECT_EQ(parent, syscall(__NR_getppid));
 594         /* "errno" of 0 is ok. */
 595         EXPECT_EQ(0, read(0, NULL, 0));
 596 }
 597
 598 TEST(ERRNO_capped)
 599 {
 600         struct sock_filter filter[] = {
 601                 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
 602                         offsetof(struct seccomp_data, nr)),
 603                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1),
 604                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | 4096),
 605                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
 606         };
 607         struct sock_fprog prog = {
 608                 .len = (unsigned short)ARRAY_SIZE(filter),
 609                 .filter = filter,
 610         };
 611         long ret;
 612         pid_t parent = getppid();
 613
 614         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
 615         ASSERT_EQ(0, ret);
 616
 617         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
 618         ASSERT_EQ(0, ret);
 619
 620         EXPECT_EQ(parent, syscall(__NR_getppid));
 621         EXPECT_EQ(-1, read(0, NULL, 0));
 622         EXPECT_EQ(4095, errno);
 623 }
 624
 625 FIXTURE_DATA(TRAP) {
 626         struct sock_fprog prog;
 627 };
 628
 629 FIXTURE_SETUP(TRAP)
 630 {
 631         struct sock_filter filter[] = {
 632                 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
 633                         offsetof(struct seccomp_data, nr)),
 634                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
 635                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRAP),
 636                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
 637         };
 638
 639         memset(&self->prog, 0, sizeof(self->prog));
 640         self->prog.filter = malloc(sizeof(filter));
 641         ASSERT_NE(NULL, self->prog.filter);
 642         memcpy(self->prog.filter, filter, sizeof(filter));
 643         self->prog.len = (unsigned short)ARRAY_SIZE(filter);
 644 }
 645
 646 FIXTURE_TEARDOWN(TRAP)
 647 {
 648         if (self->prog.filter)
 649                 free(self->prog.filter);
 650 }
 651
 652 TEST_F_SIGNAL(TRAP, dfl, SIGSYS)
 653 {
 654         long ret;
 655
 656         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
 657         ASSERT_EQ(0, ret);
 658
 659         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog);
 660         ASSERT_EQ(0, ret);
 661         syscall(__NR_getpid);
 662 }
 663
 664 /* Ensure that SIGSYS overrides SIG_IGN */
 665 TEST_F_SIGNAL(TRAP, ign, SIGSYS)
 666 {
 667         long ret;
 668
 669         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
 670         ASSERT_EQ(0, ret);
 671
 672         signal(SIGSYS, SIG_IGN);
 673
 674         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog);
 675         ASSERT_EQ(0, ret);
 676         syscall(__NR_getpid);
 677 }
 678
 679 static struct siginfo TRAP_info;
 680 static volatile int TRAP_nr;
 681 static void TRAP_action(int nr, siginfo_t *info, void *void_context)
 682 {
 683         memcpy(&TRAP_info, info, sizeof(TRAP_info));
 684         TRAP_nr = nr;
 685 }
 686
 687 TEST_F(TRAP, handler)
 688 {
 689         int ret, test;
 690         struct sigaction act;
 691         sigset_t mask;
 692
 693         memset(&act, 0, sizeof(act));
 694         sigemptyset(&mask);
 695         sigaddset(&mask, SIGSYS);
 696
 697         act.sa_sigaction = &TRAP_action;
 698         act.sa_flags = SA_SIGINFO;
 699         ret = sigaction(SIGSYS, &act, NULL);
 700         ASSERT_EQ(0, ret) {
 701                 TH_LOG("sigaction failed");
 702         }
 703         ret = sigprocmask(SIG_UNBLOCK, &mask, NULL);
 704         ASSERT_EQ(0, ret) {
 705                 TH_LOG("sigprocmask failed");
 706         }
 707
 708         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
 709         ASSERT_EQ(0, ret);
 710         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog);
 711         ASSERT_EQ(0, ret);
 712         TRAP_nr = 0;
 713         memset(&TRAP_info, 0, sizeof(TRAP_info));
 714         /* Expect the registers to be rolled back. (nr = error) may vary
 715          * based on arch. */
 716         ret = syscall(__NR_getpid);
 717         /* Silence gcc warning about volatile. */
 718         test = TRAP_nr;
 719         EXPECT_EQ(SIGSYS, test);
 720         struct local_sigsys {
 721                 void *_call_addr;       /* calling user insn */
 722                 int _syscall;           /* triggering system call number */
 723                 unsigned int _arch;     /* AUDIT_ARCH_* of syscall */
 724         } *sigsys = (struct local_sigsys *)
 725 #ifdef si_syscall
 726                 &(TRAP_info.si_call_addr);
 727 #else
 728                 &TRAP_info.si_pid;
 729 #endif
 730         EXPECT_EQ(__NR_getpid, sigsys->_syscall);
 731         /* Make sure arch is non-zero. */
 732         EXPECT_NE(0, sigsys->_arch);
 733         EXPECT_NE(0, (unsigned long)sigsys->_call_addr);
 734 }
 735
 736 FIXTURE_DATA(precedence) {
 737         struct sock_fprog allow;
 738         struct sock_fprog trace;
 739         struct sock_fprog error;
 740         struct sock_fprog trap;
 741         struct sock_fprog kill;
 742 };
 743
 744 FIXTURE_SETUP(precedence)
 745 {
 746         struct sock_filter allow_insns[] = {
 747                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
 748         };
 749         struct sock_filter trace_insns[] = {
 750                 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
 751                         offsetof(struct seccomp_data, nr)),
 752                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
 753                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
 754                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE),
 755         };
 756         struct sock_filter error_insns[] = {
 757                 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
 758                         offsetof(struct seccomp_data, nr)),
 759                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
 760                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
 761                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO),
 762         };
 763         struct sock_filter trap_insns[] = {
 764                 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
 765                         offsetof(struct seccomp_data, nr)),
 766                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
 767                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
 768                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRAP),
 769         };
 770         struct sock_filter kill_insns[] = {
 771                 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
 772                         offsetof(struct seccomp_data, nr)),
 773                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
 774                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
 775                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
 776         };
 777
 778         memset(self, 0, sizeof(*self));
 779 #define FILTER_ALLOC(_x) \
 780         self->_x.filter = malloc(sizeof(_x##_insns)); \
 781         ASSERT_NE(NULL, self->_x.filter); \
 782         memcpy(self->_x.filter, &_x##_insns, sizeof(_x##_insns)); \
 783         self->_x.len = (unsigned short)ARRAY_SIZE(_x##_insns)
 784         FILTER_ALLOC(allow);
 785         FILTER_ALLOC(trace);
 786         FILTER_ALLOC(error);
 787         FILTER_ALLOC(trap);
 788         FILTER_ALLOC(kill);
 789 }
 790
 791 FIXTURE_TEARDOWN(precedence)
 792 {
 793 #define FILTER_FREE(_x) if (self->_x.filter) free(self->_x.filter)
 794         FILTER_FREE(allow);
 795         FILTER_FREE(trace);
 796         FILTER_FREE(error);
 797         FILTER_FREE(trap);
 798         FILTER_FREE(kill);
 799 }
 800
 801 TEST_F(precedence, allow_ok)
 802 {
 803         pid_t parent, res = 0;
 804         long ret;
 805
 806         parent = getppid();
 807         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
 808         ASSERT_EQ(0, ret);
 809
 810         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
 811         ASSERT_EQ(0, ret);
 812         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
 813         ASSERT_EQ(0, ret);
 814         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
 815         ASSERT_EQ(0, ret);
 816         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
 817         ASSERT_EQ(0, ret);
 818         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill);
 819         ASSERT_EQ(0, ret);
 820         /* Should work just fine. */
 821         res = syscall(__NR_getppid);
 822         EXPECT_EQ(parent, res);
 823 }
 824
 825 TEST_F_SIGNAL(precedence, kill_is_highest, SIGSYS)
 826 {
 827         pid_t parent, res = 0;
 828         long ret;
 829
 830         parent = getppid();
 831         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
 832         ASSERT_EQ(0, ret);
 833
 834         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
 835         ASSERT_EQ(0, ret);
 836         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
 837         ASSERT_EQ(0, ret);
 838         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
 839         ASSERT_EQ(0, ret);
 840         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
 841         ASSERT_EQ(0, ret);
 842         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill);
 843         ASSERT_EQ(0, ret);
 844         /* Should work just fine. */
 845         res = syscall(__NR_getppid);
 846         EXPECT_EQ(parent, res);
 847         /* getpid() should never return. */
 848         res = syscall(__NR_getpid);
 849         EXPECT_EQ(0, res);
 850 }
 851
 852 TEST_F_SIGNAL(precedence, kill_is_highest_in_any_order, SIGSYS)
 853 {
 854         pid_t parent;
 855         long ret;
 856
 857         parent = getppid();
 858         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
 859         ASSERT_EQ(0, ret);
 860
 861         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
 862         ASSERT_EQ(0, ret);
 863         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill);
 864         ASSERT_EQ(0, ret);
 865         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
 866         ASSERT_EQ(0, ret);
 867         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
 868         ASSERT_EQ(0, ret);
 869         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
 870         ASSERT_EQ(0, ret);
 871         /* Should work just fine. */
 872         EXPECT_EQ(parent, syscall(__NR_getppid));
 873         /* getpid() should never return. */
 874         EXPECT_EQ(0, syscall(__NR_getpid));
 875 }
 876
 877 TEST_F_SIGNAL(precedence, trap_is_second, SIGSYS)
 878 {
 879         pid_t parent;
 880         long ret;
 881
 882         parent = getppid();
 883         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
 884         ASSERT_EQ(0, ret);
 885
 886         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
 887         ASSERT_EQ(0, ret);
 888         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
 889         ASSERT_EQ(0, ret);
 890         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
 891         ASSERT_EQ(0, ret);
 892         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
 893         ASSERT_EQ(0, ret);
 894         /* Should work just fine. */
 895         EXPECT_EQ(parent, syscall(__NR_getppid));
 896         /* getpid() should never return. */
 897         EXPECT_EQ(0, syscall(__NR_getpid));
 898 }
 899
 900 TEST_F_SIGNAL(precedence, trap_is_second_in_any_order, SIGSYS)
 901 {
 902         pid_t parent;
 903         long ret;
 904
 905         parent = getppid();
 906         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
 907         ASSERT_EQ(0, ret);
 908
 909         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
 910         ASSERT_EQ(0, ret);
 911         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
 912         ASSERT_EQ(0, ret);
 913         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
 914         ASSERT_EQ(0, ret);
 915         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
 916         ASSERT_EQ(0, ret);
 917         /* Should work just fine. */
 918         EXPECT_EQ(parent, syscall(__NR_getppid));
 919         /* getpid() should never return. */
 920         EXPECT_EQ(0, syscall(__NR_getpid));
 921 }
 922
 923 TEST_F(precedence, errno_is_third)
 924 {
 925         pid_t parent;
 926         long ret;
 927
 928         parent = getppid();
 929         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
 930         ASSERT_EQ(0, ret);
 931
 932         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
 933         ASSERT_EQ(0, ret);
 934         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
 935         ASSERT_EQ(0, ret);
 936         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
 937         ASSERT_EQ(0, ret);
 938         /* Should work just fine. */
 939         EXPECT_EQ(parent, syscall(__NR_getppid));
 940         EXPECT_EQ(0, syscall(__NR_getpid));
 941 }
 942
 943 TEST_F(precedence, errno_is_third_in_any_order)
 944 {
 945         pid_t parent;
 946         long ret;
 947
 948         parent = getppid();
 949         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
 950         ASSERT_EQ(0, ret);
 951
 952         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
 953         ASSERT_EQ(0, ret);
 954         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
 955         ASSERT_EQ(0, ret);
 956         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
 957         ASSERT_EQ(0, ret);
 958         /* Should work just fine. */
 959         EXPECT_EQ(parent, syscall(__NR_getppid));
 960         EXPECT_EQ(0, syscall(__NR_getpid));
 961 }
 962
 963 TEST_F(precedence, trace_is_fourth)
 964 {
 965         pid_t parent;
 966         long ret;
 967
 968         parent = getppid();
 969         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
 970         ASSERT_EQ(0, ret);
 971
 972         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
 973         ASSERT_EQ(0, ret);
 974         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
 975         ASSERT_EQ(0, ret);
 976         /* Should work just fine. */
 977         EXPECT_EQ(parent, syscall(__NR_getppid));
 978         /* No ptracer */
 979         EXPECT_EQ(-1, syscall(__NR_getpid));
 980 }
 981
 982 TEST_F(precedence, trace_is_fourth_in_any_order)
 983 {
 984         pid_t parent;
 985         long ret;
 986
 987         parent = getppid();
 988         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
 989         ASSERT_EQ(0, ret);
 990
 991         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
 992         ASSERT_EQ(0, ret);
 993         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
 994         ASSERT_EQ(0, ret);
 995         /* Should work just fine. */
 996         EXPECT_EQ(parent, syscall(__NR_getppid));
 997         /* No ptracer */
 998         EXPECT_EQ(-1, syscall(__NR_getpid));
 999 }
1000
1001 #ifndef PTRACE_O_TRACESECCOMP
1002 #define PTRACE_O_TRACESECCOMP   0x00000080
1003 #endif
1004
1005 /* Catch the Ubuntu 12.04 value error. */
1006 #if PTRACE_EVENT_SECCOMP != 7
1007 #undef PTRACE_EVENT_SECCOMP
1008 #endif
1009
1010 #ifndef PTRACE_EVENT_SECCOMP
1011 #define PTRACE_EVENT_SECCOMP 7
1012 #endif
1013
1014 #define IS_SECCOMP_EVENT(status) ((status >> 16) == PTRACE_EVENT_SECCOMP)
1015 bool tracer_running;
1016 void tracer_stop(int sig)
1017 {
1018         tracer_running = false;
1019 }
1020
1021 typedef void tracer_func_t(struct __test_metadata *_metadata,
1022                            pid_t tracee, int status, void *args);
1023
1024 void tracer(struct __test_metadata *_metadata, int fd, pid_t tracee,
1025             tracer_func_t tracer_func, void *args)
1026 {
1027         int ret = -1;
1028         struct sigaction action = {
1029                 .sa_handler = tracer_stop,
1030         };
1031
1032         /* Allow external shutdown. */
1033         tracer_running = true;
1034         ASSERT_EQ(0, sigaction(SIGUSR1, &action, NULL));
1035
1036         errno = 0;
1037         while (ret == -1 && errno != EINVAL)
1038                 ret = ptrace(PTRACE_ATTACH, tracee, NULL, 0);
1039         ASSERT_EQ(0, ret) {
1040                 kill(tracee, SIGKILL);
1041         }
1042         /* Wait for attach stop */
1043         wait(NULL);
1044
1045         ret = ptrace(PTRACE_SETOPTIONS, tracee, NULL, PTRACE_O_TRACESECCOMP);
1046         ASSERT_EQ(0, ret) {
1047                 TH_LOG("Failed to set PTRACE_O_TRACESECCOMP");
1048                 kill(tracee, SIGKILL);
1049         }
1050         ptrace(PTRACE_CONT, tracee, NULL, 0);
1051
1052         /* Unblock the tracee */
1053         ASSERT_EQ(1, write(fd, "A", 1));
1054         ASSERT_EQ(0, close(fd));
1055
1056         /* Run until we're shut down. Must assert to stop execution. */
1057         while (tracer_running) {
1058                 int status;
1059
1060                 if (wait(&status) != tracee)
1061                         continue;
1062                 if (WIFSIGNALED(status) || WIFEXITED(status))
1063                         /* Child is dead. Time to go. */
1064                         return;
1065
1066                 /* Make sure this is a seccomp event. */
1067                 ASSERT_EQ(true, IS_SECCOMP_EVENT(status));
1068
1069                 tracer_func(_metadata, tracee, status, args);
1070
1071                 ret = ptrace(PTRACE_CONT, tracee, NULL, NULL);
1072                 ASSERT_EQ(0, ret);
1073         }
1074         /* Directly report the status of our test harness results. */
1075         syscall(__NR_exit, _metadata->passed ? EXIT_SUCCESS : EXIT_FAILURE);
1076 }
1077
1078 /* Common tracer setup/teardown functions. */
1079 void cont_handler(int num)
1080 { }
1081 pid_t setup_trace_fixture(struct __test_metadata *_metadata,
1082                           tracer_func_t func, void *args)
1083 {
1084         char sync;
1085         int pipefd[2];
1086         pid_t tracer_pid;
1087         pid_t tracee = getpid();
1088
1089         /* Setup a pipe for clean synchronization. */
1090         ASSERT_EQ(0, pipe(pipefd));
1091
1092         /* Fork a child which we'll promote to tracer */
1093         tracer_pid = fork();
1094         ASSERT_LE(0, tracer_pid);
1095         signal(SIGALRM, cont_handler);
1096         if (tracer_pid == 0) {
1097                 close(pipefd[0]);
1098                 tracer(_metadata, pipefd[1], tracee, func, args);
1099                 syscall(__NR_exit, 0);
1100         }
1101         close(pipefd[1]);
1102         prctl(PR_SET_PTRACER, tracer_pid, 0, 0, 0);
1103         read(pipefd[0], &sync, 1);
1104         close(pipefd[0]);
1105
1106         return tracer_pid;
1107 }
1108 void teardown_trace_fixture(struct __test_metadata *_metadata,
1109                             pid_t tracer)
1110 {
1111         if (tracer) {
1112                 int status;
1113                 /*
1114                  * Extract the exit code from the other process and
1115                  * adopt it for ourselves in case its asserts failed.
1116                  */
1117                 ASSERT_EQ(0, kill(tracer, SIGUSR1));
1118                 ASSERT_EQ(tracer, waitpid(tracer, &status, 0));
1119                 if (WEXITSTATUS(status))
1120                         _metadata->passed = 0;
1121         }
1122 }
1123
1124 /* "poke" tracer arguments and function. */
1125 struct tracer_args_poke_t {
1126         unsigned long poke_addr;
1127 };
1128
1129 void tracer_poke(struct __test_metadata *_metadata, pid_t tracee, int status,
1130                  void *args)
1131 {
1132         int ret;
1133         unsigned long msg;
1134         struct tracer_args_poke_t *info = (struct tracer_args_poke_t *)args;
1135
1136         ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg);
1137         EXPECT_EQ(0, ret);
1138         /* If this fails, don't try to recover. */
1139         ASSERT_EQ(0x1001, msg) {
1140                 kill(tracee, SIGKILL);
1141         }
1142         /*
1143          * Poke in the message.
1144          * Registers are not touched to try to keep this relatively arch
1145          * agnostic.
1146          */
1147         ret = ptrace(PTRACE_POKEDATA, tracee, info->poke_addr, 0x1001);
1148         EXPECT_EQ(0, ret);
1149 }
1150
1151 FIXTURE_DATA(TRACE_poke) {
1152         struct sock_fprog prog;
1153         pid_t tracer;
1154         long poked;
1155         struct tracer_args_poke_t tracer_args;
1156 };
1157
1158 FIXTURE_SETUP(TRACE_poke)
1159 {
1160         struct sock_filter filter[] = {
1161                 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1162                         offsetof(struct seccomp_data, nr)),
1163                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1),
1164                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1001),
1165                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1166         };
1167
1168         self->poked = 0;
1169         memset(&self->prog, 0, sizeof(self->prog));
1170         self->prog.filter = malloc(sizeof(filter));
1171         ASSERT_NE(NULL, self->prog.filter);
1172         memcpy(self->prog.filter, filter, sizeof(filter));
1173         self->prog.len = (unsigned short)ARRAY_SIZE(filter);
1174
1175         /* Set up tracer args. */
1176         self->tracer_args.poke_addr = (unsigned long)&self->poked;
1177
1178         /* Launch tracer. */
1179         self->tracer = setup_trace_fixture(_metadata, tracer_poke,
1180                                            &self->tracer_args);
1181 }
1182
1183 FIXTURE_TEARDOWN(TRACE_poke)
1184 {
1185         teardown_trace_fixture(_metadata, self->tracer);
1186         if (self->prog.filter)
1187                 free(self->prog.filter);
1188 }
1189
1190 TEST_F(TRACE_poke, read_has_side_effects)
1191 {
1192         ssize_t ret;
1193
1194         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1195         ASSERT_EQ(0, ret);
1196
1197         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1198         ASSERT_EQ(0, ret);
1199
1200         EXPECT_EQ(0, self->poked);
1201         ret = read(-1, NULL, 0);
1202         EXPECT_EQ(-1, ret);
1203         EXPECT_EQ(0x1001, self->poked);
1204 }
1205
1206 TEST_F(TRACE_poke, getpid_runs_normally)
1207 {
1208         long ret;
1209
1210         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1211         ASSERT_EQ(0, ret);
1212
1213         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1214         ASSERT_EQ(0, ret);
1215
1216         EXPECT_EQ(0, self->poked);
1217         EXPECT_NE(0, syscall(__NR_getpid));
1218         EXPECT_EQ(0, self->poked);
1219 }
1220
1221 #if defined(__x86_64__)
1222 # define ARCH_REGS      struct user_regs_struct
1223 # define SYSCALL_NUM    orig_rax
1224 # define SYSCALL_RET    rax
1225 #elif defined(__i386__)
1226 # define ARCH_REGS      struct user_regs_struct
1227 # define SYSCALL_NUM    orig_eax
1228 # define SYSCALL_RET    eax
1229 #elif defined(__arm__)
1230 # define ARCH_REGS      struct pt_regs
1231 # define SYSCALL_NUM    ARM_r7
1232 # define SYSCALL_RET    ARM_r0
1233 #elif defined(__aarch64__)
1234 # define ARCH_REGS      struct user_pt_regs
1235 # define SYSCALL_NUM    regs[8]
1236 # define SYSCALL_RET    regs[0]
1237 #elif defined(__powerpc__)
1238 # define ARCH_REGS      struct pt_regs
1239 # define SYSCALL_NUM    gpr[0]
1240 # define SYSCALL_RET    gpr[3]
1241 #elif defined(__s390__)
1242 # define ARCH_REGS     s390_regs
1243 # define SYSCALL_NUM   gprs[2]
1244 # define SYSCALL_RET   gprs[2]
1245 #else
1246 # error "Do not know how to find your architecture's registers and syscalls"
1247 #endif
1248
1249 /* Architecture-specific syscall fetching routine. */
1250 int get_syscall(struct __test_metadata *_metadata, pid_t tracee)
1251 {
1252         struct iovec iov;
1253         ARCH_REGS regs;
1254
1255         iov.iov_base = &regs;
1256         iov.iov_len = sizeof(regs);
1257         EXPECT_EQ(0, ptrace(PTRACE_GETREGSET, tracee, NT_PRSTATUS, &iov)) {
1258                 TH_LOG("PTRACE_GETREGSET failed");
1259                 return -1;
1260         }
1261
1262         return regs.SYSCALL_NUM;
1263 }
1264
1265 /* Architecture-specific syscall changing routine. */
1266 void change_syscall(struct __test_metadata *_metadata,
1267                     pid_t tracee, int syscall)
1268 {
1269         struct iovec iov;
1270         int ret;
1271         ARCH_REGS regs;
1272
1273         iov.iov_base = &regs;
1274         iov.iov_len = sizeof(regs);
1275         ret = ptrace(PTRACE_GETREGSET, tracee, NT_PRSTATUS, &iov);
1276         EXPECT_EQ(0, ret);
1277
1278 #if defined(__x86_64__) || defined(__i386__) || defined(__powerpc__) || \
1279     defined(__s390__)
1280         {
1281                 regs.SYSCALL_NUM = syscall;
1282         }
1283
1284 #elif defined(__arm__)
1285 # ifndef PTRACE_SET_SYSCALL
1286 #  define PTRACE_SET_SYSCALL   23
1287 # endif
1288         {
1289                 ret = ptrace(PTRACE_SET_SYSCALL, tracee, NULL, syscall);
1290                 EXPECT_EQ(0, ret);
1291         }
1292
1293 #elif defined(__aarch64__)
1294 # ifndef NT_ARM_SYSTEM_CALL
1295 #  define NT_ARM_SYSTEM_CALL 0x404
1296 # endif
1297         {
1298                 iov.iov_base = &syscall;
1299                 iov.iov_len = sizeof(syscall);
1300                 ret = ptrace(PTRACE_SETREGSET, tracee, NT_ARM_SYSTEM_CALL,
1301                              &iov);
1302                 EXPECT_EQ(0, ret);
1303         }
1304
1305 #else
1306         ASSERT_EQ(1, 0) {
1307                 TH_LOG("How is the syscall changed on this architecture?");
1308         }
1309 #endif
1310
1311         /* If syscall is skipped, change return value. */
1312         if (syscall == -1)
1313                 regs.SYSCALL_RET = 1;
1314
1315         iov.iov_base = &regs;
1316         iov.iov_len = sizeof(regs);
1317         ret = ptrace(PTRACE_SETREGSET, tracee, NT_PRSTATUS, &iov);
1318         EXPECT_EQ(0, ret);
1319 }
1320
1321 void tracer_syscall(struct __test_metadata *_metadata, pid_t tracee,
1322                     int status, void *args)
1323 {
1324         int ret;
1325         unsigned long msg;
1326
1327         /* Make sure we got the right message. */
1328         ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg);
1329         EXPECT_EQ(0, ret);
1330
1331         /* Validate and take action on expected syscalls. */
1332         switch (msg) {
1333         case 0x1002:
1334                 /* change getpid to getppid. */
1335                 EXPECT_EQ(__NR_getpid, get_syscall(_metadata, tracee));
1336                 change_syscall(_metadata, tracee, __NR_getppid);
1337                 break;
1338         case 0x1003:
1339                 /* skip gettid. */
1340                 EXPECT_EQ(__NR_gettid, get_syscall(_metadata, tracee));
1341                 change_syscall(_metadata, tracee, -1);
1342                 break;
1343         case 0x1004:
1344                 /* do nothing (allow getppid) */
1345                 EXPECT_EQ(__NR_getppid, get_syscall(_metadata, tracee));
1346                 break;
1347         default:
1348                 EXPECT_EQ(0, msg) {
1349                         TH_LOG("Unknown PTRACE_GETEVENTMSG: 0x%lx", msg);
1350                         kill(tracee, SIGKILL);
1351                 }
1352         }
1353
1354 }
1355
1356 FIXTURE_DATA(TRACE_syscall) {
1357         struct sock_fprog prog;
1358         pid_t tracer, mytid, mypid, parent;
1359 };
1360
1361 FIXTURE_SETUP(TRACE_syscall)
1362 {
1363         struct sock_filter filter[] = {
1364                 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1365                         offsetof(struct seccomp_data, nr)),
1366                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
1367                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1002),
1368                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_gettid, 0, 1),
1369                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1003),
1370                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
1371                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1004),
1372                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1373         };
1374
1375         memset(&self->prog, 0, sizeof(self->prog));
1376         self->prog.filter = malloc(sizeof(filter));
1377         ASSERT_NE(NULL, self->prog.filter);
1378         memcpy(self->prog.filter, filter, sizeof(filter));
1379         self->prog.len = (unsigned short)ARRAY_SIZE(filter);
1380
1381         /* Prepare some testable syscall results. */
1382         self->mytid = syscall(__NR_gettid);
1383         ASSERT_GT(self->mytid, 0);
1384         ASSERT_NE(self->mytid, 1) {
1385                 TH_LOG("Running this test as init is not supported. :)");
1386         }
1387
1388         self->mypid = getpid();
1389         ASSERT_GT(self->mypid, 0);
1390         ASSERT_EQ(self->mytid, self->mypid);
1391
1392         self->parent = getppid();
1393         ASSERT_GT(self->parent, 0);
1394         ASSERT_NE(self->parent, self->mypid);
1395
1396         /* Launch tracer. */
1397         self->tracer = setup_trace_fixture(_metadata, tracer_syscall, NULL);
1398 }
1399
1400 FIXTURE_TEARDOWN(TRACE_syscall)
1401 {
1402         teardown_trace_fixture(_metadata, self->tracer);
1403         if (self->prog.filter)
1404                 free(self->prog.filter);
1405 }
1406
1407 TEST_F(TRACE_syscall, syscall_allowed)
1408 {
1409         long ret;
1410
1411         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1412         ASSERT_EQ(0, ret);
1413
1414         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1415         ASSERT_EQ(0, ret);
1416
1417         /* getppid works as expected (no changes). */
1418         EXPECT_EQ(self->parent, syscall(__NR_getppid));
1419         EXPECT_NE(self->mypid, syscall(__NR_getppid));
1420 }
1421
1422 TEST_F(TRACE_syscall, syscall_redirected)
1423 {
1424         long ret;
1425
1426         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1427         ASSERT_EQ(0, ret);
1428
1429         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1430         ASSERT_EQ(0, ret);
1431
1432         /* getpid has been redirected to getppid as expected. */
1433         EXPECT_EQ(self->parent, syscall(__NR_getpid));
1434         EXPECT_NE(self->mypid, syscall(__NR_getpid));
1435 }
1436
1437 TEST_F(TRACE_syscall, syscall_dropped)
1438 {
1439         long ret;
1440
1441         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1442         ASSERT_EQ(0, ret);
1443
1444         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1445         ASSERT_EQ(0, ret);
1446
1447         /* gettid has been skipped and an altered return value stored. */
1448         EXPECT_EQ(1, syscall(__NR_gettid));
1449         EXPECT_NE(self->mytid, syscall(__NR_gettid));
1450 }
1451
1452 #ifndef __NR_seccomp
1453 # if defined(__i386__)
1454 #  define __NR_seccomp 354
1455 # elif defined(__x86_64__)
1456 #  define __NR_seccomp 317
1457 # elif defined(__arm__)
1458 #  define __NR_seccomp 383
1459 # elif defined(__aarch64__)
1460 #  define __NR_seccomp 277
1461 # elif defined(__powerpc__)
1462 #  define __NR_seccomp 358
1463 # elif defined(__s390__)
1464 #  define __NR_seccomp 348
1465 # else
1466 #  warning "seccomp syscall number unknown for this architecture"
1467 #  define __NR_seccomp 0xffff
1468 # endif
1469 #endif
1470
1471 #ifndef SECCOMP_SET_MODE_STRICT
1472 #define SECCOMP_SET_MODE_STRICT 0
1473 #endif
1474
1475 #ifndef SECCOMP_SET_MODE_FILTER
1476 #define SECCOMP_SET_MODE_FILTER 1
1477 #endif
1478
1479 #ifndef SECCOMP_FLAG_FILTER_TSYNC
1480 #define SECCOMP_FLAG_FILTER_TSYNC 1
1481 #endif
1482
1483 #ifndef seccomp
1484 int seccomp(unsigned int op, unsigned int flags, struct sock_fprog *filter)
1485 {
1486         errno = 0;
1487         return syscall(__NR_seccomp, op, flags, filter);
1488 }
1489 #endif
1490
1491 TEST(seccomp_syscall)
1492 {
1493         struct sock_filter filter[] = {
1494                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1495         };
1496         struct sock_fprog prog = {
1497                 .len = (unsigned short)ARRAY_SIZE(filter),
1498                 .filter = filter,
1499         };
1500         long ret;
1501
1502         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1503         ASSERT_EQ(0, ret) {
1504                 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
1505         }
1506
1507         /* Reject insane operation. */
1508         ret = seccomp(-1, 0, &prog);
1509         ASSERT_NE(ENOSYS, errno) {
1510                 TH_LOG("Kernel does not support seccomp syscall!");
1511         }
1512         EXPECT_EQ(EINVAL, errno) {
1513                 TH_LOG("Did not reject crazy op value!");
1514         }
1515
1516         /* Reject strict with flags or pointer. */
1517         ret = seccomp(SECCOMP_SET_MODE_STRICT, -1, NULL);
1518         EXPECT_EQ(EINVAL, errno) {
1519                 TH_LOG("Did not reject mode strict with flags!");
1520         }
1521         ret = seccomp(SECCOMP_SET_MODE_STRICT, 0, &prog);
1522         EXPECT_EQ(EINVAL, errno) {
1523                 TH_LOG("Did not reject mode strict with uargs!");
1524         }
1525
1526         /* Reject insane args for filter. */
1527         ret = seccomp(SECCOMP_SET_MODE_FILTER, -1, &prog);
1528         EXPECT_EQ(EINVAL, errno) {
1529                 TH_LOG("Did not reject crazy filter flags!");
1530         }
1531         ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, NULL);
1532         EXPECT_EQ(EFAULT, errno) {
1533                 TH_LOG("Did not reject NULL filter!");
1534         }
1535
1536         ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
1537         EXPECT_EQ(0, errno) {
1538                 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER: %s",
1539                         strerror(errno));
1540         }
1541 }
1542
1543 TEST(seccomp_syscall_mode_lock)
1544 {
1545         struct sock_filter filter[] = {
1546                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1547         };
1548         struct sock_fprog prog = {
1549                 .len = (unsigned short)ARRAY_SIZE(filter),
1550                 .filter = filter,
1551         };
1552         long ret;
1553
1554         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
1555         ASSERT_EQ(0, ret) {
1556                 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
1557         }
1558
1559         ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
1560         ASSERT_NE(ENOSYS, errno) {
1561                 TH_LOG("Kernel does not support seccomp syscall!");
1562         }
1563         EXPECT_EQ(0, ret) {
1564                 TH_LOG("Could not install filter!");
1565         }
1566
1567         /* Make sure neither entry point will switch to strict. */
1568         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, 0, 0, 0);
1569         EXPECT_EQ(EINVAL, errno) {
1570                 TH_LOG("Switched to mode strict!");
1571         }
1572
1573         ret = seccomp(SECCOMP_SET_MODE_STRICT, 0, NULL);
1574         EXPECT_EQ(EINVAL, errno) {
1575                 TH_LOG("Switched to mode strict!");
1576         }
1577 }
1578
1579 TEST(TSYNC_first)
1580 {
1581         struct sock_filter filter[] = {
1582                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1583         };
1584         struct sock_fprog prog = {
1585                 .len = (unsigned short)ARRAY_SIZE(filter),
1586                 .filter = filter,
1587         };
1588         long ret;
1589
1590         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
1591         ASSERT_EQ(0, ret) {
1592                 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
1593         }
1594
1595         ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FLAG_FILTER_TSYNC,
1596                       &prog);
1597         ASSERT_NE(ENOSYS, errno) {
1598                 TH_LOG("Kernel does not support seccomp syscall!");
1599         }
1600         EXPECT_EQ(0, ret) {
1601                 TH_LOG("Could not install initial filter with TSYNC!");
1602         }
1603 }
1604
1605 #define TSYNC_SIBLINGS 2
1606 struct tsync_sibling {
1607         pthread_t tid;
1608         pid_t system_tid;
1609         sem_t *started;
1610         pthread_cond_t *cond;
1611         pthread_mutex_t *mutex;
1612         int diverge;
1613         int num_waits;
1614         struct sock_fprog *prog;
1615         struct __test_metadata *metadata;
1616 };
1617
1618 FIXTURE_DATA(TSYNC) {
1619         struct sock_fprog root_prog, apply_prog;
1620         struct tsync_sibling sibling[TSYNC_SIBLINGS];
1621         sem_t started;
1622         pthread_cond_t cond;
1623         pthread_mutex_t mutex;
1624         int sibling_count;
1625 };
1626
1627 FIXTURE_SETUP(TSYNC)
1628 {
1629         struct sock_filter root_filter[] = {
1630                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1631         };
1632         struct sock_filter apply_filter[] = {
1633                 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1634                         offsetof(struct seccomp_data, nr)),
1635                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1),
1636                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
1637                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1638         };
1639
1640         memset(&self->root_prog, 0, sizeof(self->root_prog));
1641         memset(&self->apply_prog, 0, sizeof(self->apply_prog));
1642         memset(&self->sibling, 0, sizeof(self->sibling));
1643         self->root_prog.filter = malloc(sizeof(root_filter));
1644         ASSERT_NE(NULL, self->root_prog.filter);
1645         memcpy(self->root_prog.filter, &root_filter, sizeof(root_filter));
1646         self->root_prog.len = (unsigned short)ARRAY_SIZE(root_filter);
1647
1648         self->apply_prog.filter = malloc(sizeof(apply_filter));
1649         ASSERT_NE(NULL, self->apply_prog.filter);
1650         memcpy(self->apply_prog.filter, &apply_filter, sizeof(apply_filter));
1651         self->apply_prog.len = (unsigned short)ARRAY_SIZE(apply_filter);
1652
1653         self->sibling_count = 0;
1654         pthread_mutex_init(&self->mutex, NULL);
1655         pthread_cond_init(&self->cond, NULL);
1656         sem_init(&self->started, 0, 0);
1657         self->sibling[0].tid = 0;
1658         self->sibling[0].cond = &self->cond;
1659         self->sibling[0].started = &self->started;
1660         self->sibling[0].mutex = &self->mutex;
1661         self->sibling[0].diverge = 0;
1662         self->sibling[0].num_waits = 1;
1663         self->sibling[0].prog = &self->root_prog;
1664         self->sibling[0].metadata = _metadata;
1665         self->sibling[1].tid = 0;
1666         self->sibling[1].cond = &self->cond;
1667         self->sibling[1].started = &self->started;
1668         self->sibling[1].mutex = &self->mutex;
1669         self->sibling[1].diverge = 0;
1670         self->sibling[1].prog = &self->root_prog;
1671         self->sibling[1].num_waits = 1;
1672         self->sibling[1].metadata = _metadata;
1673 }
1674
1675 FIXTURE_TEARDOWN(TSYNC)
1676 {
1677         int sib = 0;
1678
1679         if (self->root_prog.filter)
1680                 free(self->root_prog.filter);
1681         if (self->apply_prog.filter)
1682                 free(self->apply_prog.filter);
1683
1684         for ( ; sib < self->sibling_count; ++sib) {
1685                 struct tsync_sibling *s = &self->sibling[sib];
1686                 void *status;
1687
1688                 if (!s->tid)
1689                         continue;
1690                 if (pthread_kill(s->tid, 0)) {
1691                         pthread_cancel(s->tid);
1692                         pthread_join(s->tid, &status);
1693                 }
1694         }
1695         pthread_mutex_destroy(&self->mutex);
1696         pthread_cond_destroy(&self->cond);
1697         sem_destroy(&self->started);
1698 }
1699
1700 void *tsync_sibling(void *data)
1701 {
1702         long ret = 0;
1703         struct tsync_sibling *me = data;
1704
1705         me->system_tid = syscall(__NR_gettid);
1706
1707         pthread_mutex_lock(me->mutex);
1708         if (me->diverge) {
1709                 /* Just re-apply the root prog to fork the tree */
1710                 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER,
1711                                 me->prog, 0, 0);
1712         }
1713         sem_post(me->started);
1714         /* Return outside of started so parent notices failures. */
1715         if (ret) {
1716                 pthread_mutex_unlock(me->mutex);
1717                 return (void *)SIBLING_EXIT_FAILURE;
1718         }
1719         do {
1720                 pthread_cond_wait(me->cond, me->mutex);
1721                 me->num_waits = me->num_waits - 1;
1722         } while (me->num_waits);
1723         pthread_mutex_unlock(me->mutex);
1724
1725         ret = prctl(PR_GET_NO_NEW_PRIVS, 0, 0, 0, 0);
1726         if (!ret)
1727                 return (void *)SIBLING_EXIT_NEWPRIVS;
1728         read(0, NULL, 0);
1729         return (void *)SIBLING_EXIT_UNKILLED;
1730 }
1731
1732 void tsync_start_sibling(struct tsync_sibling *sibling)
1733 {
1734         pthread_create(&sibling->tid, NULL, tsync_sibling, (void *)sibling);
1735 }
1736
1737 TEST_F(TSYNC, siblings_fail_prctl)
1738 {
1739         long ret;
1740         void *status;
1741         struct sock_filter filter[] = {
1742                 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1743                         offsetof(struct seccomp_data, nr)),
1744                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1),
1745                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EINVAL),
1746                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1747         };
1748         struct sock_fprog prog = {
1749                 .len = (unsigned short)ARRAY_SIZE(filter),
1750                 .filter = filter,
1751         };
1752
1753         ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
1754                 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
1755         }
1756
1757         /* Check prctl failure detection by requesting sib 0 diverge. */
1758         ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
1759         ASSERT_NE(ENOSYS, errno) {
1760                 TH_LOG("Kernel does not support seccomp syscall!");
1761         }
1762         ASSERT_EQ(0, ret) {
1763                 TH_LOG("setting filter failed");
1764         }
1765
1766         self->sibling[0].diverge = 1;
1767         tsync_start_sibling(&self->sibling[0]);
1768         tsync_start_sibling(&self->sibling[1]);
1769
1770         while (self->sibling_count < TSYNC_SIBLINGS) {
1771                 sem_wait(&self->started);
1772                 self->sibling_count++;
1773         }
1774
1775         /* Signal the threads to clean up*/
1776         pthread_mutex_lock(&self->mutex);
1777         ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
1778                 TH_LOG("cond broadcast non-zero");
1779         }
1780         pthread_mutex_unlock(&self->mutex);
1781
1782         /* Ensure diverging sibling failed to call prctl. */
1783         pthread_join(self->sibling[0].tid, &status);
1784         EXPECT_EQ(SIBLING_EXIT_FAILURE, (long)status);
1785         pthread_join(self->sibling[1].tid, &status);
1786         EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
1787 }
1788
1789 TEST_F(TSYNC, two_siblings_with_ancestor)
1790 {
1791         long ret;
1792         void *status;
1793
1794         ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
1795                 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
1796         }
1797
1798         ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
1799         ASSERT_NE(ENOSYS, errno) {
1800                 TH_LOG("Kernel does not support seccomp syscall!");
1801         }
1802         ASSERT_EQ(0, ret) {
1803                 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
1804         }
1805         tsync_start_sibling(&self->sibling[0]);
1806         tsync_start_sibling(&self->sibling[1]);
1807
1808         while (self->sibling_count < TSYNC_SIBLINGS) {
1809                 sem_wait(&self->started);
1810                 self->sibling_count++;
1811         }
1812
1813         ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FLAG_FILTER_TSYNC,
1814                       &self->apply_prog);
1815         ASSERT_EQ(0, ret) {
1816                 TH_LOG("Could install filter on all threads!");
1817         }
1818         /* Tell the siblings to test the policy */
1819         pthread_mutex_lock(&self->mutex);
1820         ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
1821                 TH_LOG("cond broadcast non-zero");
1822         }
1823         pthread_mutex_unlock(&self->mutex);
1824         /* Ensure they are both killed and don't exit cleanly. */
1825         pthread_join(self->sibling[0].tid, &status);
1826         EXPECT_EQ(0x0, (long)status);
1827         pthread_join(self->sibling[1].tid, &status);
1828         EXPECT_EQ(0x0, (long)status);
1829 }
1830
1831 TEST_F(TSYNC, two_sibling_want_nnp)
1832 {
1833         void *status;
1834
1835         /* start siblings before any prctl() operations */
1836         tsync_start_sibling(&self->sibling[0]);
1837         tsync_start_sibling(&self->sibling[1]);
1838         while (self->sibling_count < TSYNC_SIBLINGS) {
1839                 sem_wait(&self->started);
1840                 self->sibling_count++;
1841         }
1842
1843         /* Tell the siblings to test no policy */
1844         pthread_mutex_lock(&self->mutex);
1845         ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
1846                 TH_LOG("cond broadcast non-zero");
1847         }
1848         pthread_mutex_unlock(&self->mutex);
1849
1850         /* Ensure they are both upset about lacking nnp. */
1851         pthread_join(self->sibling[0].tid, &status);
1852         EXPECT_EQ(SIBLING_EXIT_NEWPRIVS, (long)status);
1853         pthread_join(self->sibling[1].tid, &status);
1854         EXPECT_EQ(SIBLING_EXIT_NEWPRIVS, (long)status);
1855 }
1856
1857 TEST_F(TSYNC, two_siblings_with_no_filter)
1858 {
1859         long ret;
1860         void *status;
1861
1862         /* start siblings before any prctl() operations */
1863         tsync_start_sibling(&self->sibling[0]);
1864         tsync_start_sibling(&self->sibling[1]);
1865         while (self->sibling_count < TSYNC_SIBLINGS) {
1866                 sem_wait(&self->started);
1867                 self->sibling_count++;
1868         }
1869
1870         ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
1871                 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
1872         }
1873
1874         ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FLAG_FILTER_TSYNC,
1875                       &self->apply_prog);
1876         ASSERT_NE(ENOSYS, errno) {
1877                 TH_LOG("Kernel does not support seccomp syscall!");
1878         }
1879         ASSERT_EQ(0, ret) {
1880                 TH_LOG("Could install filter on all threads!");
1881         }
1882
1883         /* Tell the siblings to test the policy */
1884         pthread_mutex_lock(&self->mutex);
1885         ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
1886                 TH_LOG("cond broadcast non-zero");
1887         }
1888         pthread_mutex_unlock(&self->mutex);
1889
1890         /* Ensure they are both killed and don't exit cleanly. */
1891         pthread_join(self->sibling[0].tid, &status);
1892         EXPECT_EQ(0x0, (long)status);
1893         pthread_join(self->sibling[1].tid, &status);
1894         EXPECT_EQ(0x0, (long)status);
1895 }
1896
1897 TEST_F(TSYNC, two_siblings_with_one_divergence)
1898 {
1899         long ret;
1900         void *status;
1901
1902         ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
1903                 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
1904         }
1905
1906         ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
1907         ASSERT_NE(ENOSYS, errno) {
1908                 TH_LOG("Kernel does not support seccomp syscall!");
1909         }
1910         ASSERT_EQ(0, ret) {
1911                 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
1912         }
1913         self->sibling[0].diverge = 1;
1914         tsync_start_sibling(&self->sibling[0]);
1915         tsync_start_sibling(&self->sibling[1]);
1916
1917         while (self->sibling_count < TSYNC_SIBLINGS) {
1918                 sem_wait(&self->started);
1919                 self->sibling_count++;
1920         }
1921
1922         ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FLAG_FILTER_TSYNC,
1923                       &self->apply_prog);
1924         ASSERT_EQ(self->sibling[0].system_tid, ret) {
1925                 TH_LOG("Did not fail on diverged sibling.");
1926         }
1927
1928         /* Wake the threads */
1929         pthread_mutex_lock(&self->mutex);
1930         ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
1931                 TH_LOG("cond broadcast non-zero");
1932         }
1933         pthread_mutex_unlock(&self->mutex);
1934
1935         /* Ensure they are both unkilled. */
1936         pthread_join(self->sibling[0].tid, &status);
1937         EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
1938         pthread_join(self->sibling[1].tid, &status);
1939         EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
1940 }
1941
1942 TEST_F(TSYNC, two_siblings_not_under_filter)
1943 {
1944         long ret, sib;
1945         void *status;
1946
1947         ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
1948                 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
1949         }
1950
1951         /*
1952          * Sibling 0 will have its own seccomp policy
1953          * and Sibling 1 will not be under seccomp at
1954          * all. Sibling 1 will enter seccomp and 0
1955          * will cause failure.
1956          */
1957         self->sibling[0].diverge = 1;
1958         tsync_start_sibling(&self->sibling[0]);
1959         tsync_start_sibling(&self->sibling[1]);
1960
1961         while (self->sibling_count < TSYNC_SIBLINGS) {
1962                 sem_wait(&self->started);
1963                 self->sibling_count++;
1964         }
1965
1966         ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
1967         ASSERT_NE(ENOSYS, errno) {
1968                 TH_LOG("Kernel does not support seccomp syscall!");
1969         }
1970         ASSERT_EQ(0, ret) {
1971                 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
1972         }
1973
1974         ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FLAG_FILTER_TSYNC,
1975                       &self->apply_prog);
1976         ASSERT_EQ(ret, self->sibling[0].system_tid) {
1977                 TH_LOG("Did not fail on diverged sibling.");
1978         }
1979         sib = 1;
1980         if (ret == self->sibling[0].system_tid)
1981                 sib = 0;
1982
1983         pthread_mutex_lock(&self->mutex);
1984
1985         /* Increment the other siblings num_waits so we can clean up
1986          * the one we just saw.
1987          */
1988         self->sibling[!sib].num_waits += 1;
1989
1990         /* Signal the thread to clean up*/
1991         ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
1992                 TH_LOG("cond broadcast non-zero");
1993         }
1994         pthread_mutex_unlock(&self->mutex);
1995         pthread_join(self->sibling[sib].tid, &status);
1996         EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
1997         /* Poll for actual task death. pthread_join doesn't guarantee it. */
1998         while (!kill(self->sibling[sib].system_tid, 0))
1999                 sleep(0.1);
2000         /* Switch to the remaining sibling */
2001         sib = !sib;
2002
2003         ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FLAG_FILTER_TSYNC,
2004                       &self->apply_prog);
2005         ASSERT_EQ(0, ret) {
2006                 TH_LOG("Expected the remaining sibling to sync");
2007         };
2008
2009         pthread_mutex_lock(&self->mutex);
2010
2011         /* If remaining sibling didn't have a chance to wake up during
2012          * the first broadcast, manually reduce the num_waits now.
2013          */
2014         if (self->sibling[sib].num_waits > 1)
2015                 self->sibling[sib].num_waits = 1;
2016         ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2017                 TH_LOG("cond broadcast non-zero");
2018         }
2019         pthread_mutex_unlock(&self->mutex);
2020         pthread_join(self->sibling[sib].tid, &status);
2021         EXPECT_EQ(0, (long)status);
2022         /* Poll for actual task death. pthread_join doesn't guarantee it. */
2023         while (!kill(self->sibling[sib].system_tid, 0))
2024                 sleep(0.1);
2025
2026         ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FLAG_FILTER_TSYNC,
2027                       &self->apply_prog);
2028         ASSERT_EQ(0, ret);  /* just us chickens */
2029 }
2030
2031 /* Make sure restarted syscalls are seen directly as "restart_syscall". */
2032 TEST(syscall_restart)
2033 {
2034         long ret;
2035         unsigned long msg;
2036         pid_t child_pid;
2037         int pipefd[2];
2038         int status;
2039         siginfo_t info = { };
2040         struct sock_filter filter[] = {
2041                 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2042                          offsetof(struct seccomp_data, nr)),
2043
2044 #ifdef __NR_sigreturn
2045                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_sigreturn, 6, 0),
2046 #endif
2047                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 5, 0),
2048                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_exit, 4, 0),
2049                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_rt_sigreturn, 3, 0),
2050                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_nanosleep, 4, 0),
2051                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_restart_syscall, 4, 0),
2052
2053                 /* Allow __NR_write for easy logging. */
2054                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_write, 0, 1),
2055                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2056                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
2057                 /* The nanosleep jump target. */
2058                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x100),
2059                 /* The restart_syscall jump target. */
2060                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x200),
2061         };
2062         struct sock_fprog prog = {
2063                 .len = (unsigned short)ARRAY_SIZE(filter),
2064                 .filter = filter,
2065         };
2066 #if defined(__arm__)
2067         struct utsname utsbuf;
2068 #endif
2069
2070         ASSERT_EQ(0, pipe(pipefd));
2071
2072         child_pid = fork();
2073         ASSERT_LE(0, child_pid);
2074         if (child_pid == 0) {
2075                 /* Child uses EXPECT not ASSERT to deliver status correctly. */
2076                 char buf = ' ';
2077                 struct timespec timeout = { };
2078
2079                 /* Attach parent as tracer and stop. */
2080                 EXPECT_EQ(0, ptrace(PTRACE_TRACEME));
2081                 EXPECT_EQ(0, raise(SIGSTOP));
2082
2083                 EXPECT_EQ(0, close(pipefd[1]));
2084
2085                 EXPECT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2086                         TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2087                 }
2088
2089                 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
2090                 EXPECT_EQ(0, ret) {
2091                         TH_LOG("Failed to install filter!");
2092                 }
2093
2094                 EXPECT_EQ(1, read(pipefd[0], &buf, 1)) {
2095                         TH_LOG("Failed to read() sync from parent");
2096                 }
2097                 EXPECT_EQ('.', buf) {
2098                         TH_LOG("Failed to get sync data from read()");
2099                 }
2100
2101                 /* Start nanosleep to be interrupted. */
2102                 timeout.tv_sec = 1;
2103                 errno = 0;
2104                 EXPECT_EQ(0, nanosleep(&timeout, NULL)) {
2105                         TH_LOG("Call to nanosleep() failed (errno %d)", errno);
2106                 }
2107
2108                 /* Read final sync from parent. */
2109                 EXPECT_EQ(1, read(pipefd[0], &buf, 1)) {
2110                         TH_LOG("Failed final read() from parent");
2111                 }
2112                 EXPECT_EQ('!', buf) {
2113                         TH_LOG("Failed to get final data from read()");
2114                 }
2115
2116                 /* Directly report the status of our test harness results. */
2117                 syscall(__NR_exit, _metadata->passed ? EXIT_SUCCESS
2118                                                      : EXIT_FAILURE);
2119         }
2120         EXPECT_EQ(0, close(pipefd[0]));
2121
2122         /* Attach to child, setup options, and release. */
2123         ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2124         ASSERT_EQ(true, WIFSTOPPED(status));
2125         ASSERT_EQ(0, ptrace(PTRACE_SETOPTIONS, child_pid, NULL,
2126                             PTRACE_O_TRACESECCOMP));
2127         ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2128         ASSERT_EQ(1, write(pipefd[1], ".", 1));
2129
2130         /* Wait for nanosleep() to start. */
2131         ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2132         ASSERT_EQ(true, WIFSTOPPED(status));
2133         ASSERT_EQ(SIGTRAP, WSTOPSIG(status));
2134         ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16));
2135         ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg));
2136         ASSERT_EQ(0x100, msg);
2137         EXPECT_EQ(__NR_nanosleep, get_syscall(_metadata, child_pid));
2138
2139         /* Might as well check siginfo for sanity while we're here. */
2140         ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info));
2141         ASSERT_EQ(SIGTRAP, info.si_signo);
2142         ASSERT_EQ(SIGTRAP | (PTRACE_EVENT_SECCOMP << 8), info.si_code);
2143         EXPECT_EQ(0, info.si_errno);
2144         EXPECT_EQ(getuid(), info.si_uid);
2145         /* Verify signal delivery came from child (seccomp-triggered). */
2146         EXPECT_EQ(child_pid, info.si_pid);
2147
2148         /* Interrupt nanosleep with SIGSTOP (which we'll need to handle). */
2149         ASSERT_EQ(0, kill(child_pid, SIGSTOP));
2150         ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2151         ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2152         ASSERT_EQ(true, WIFSTOPPED(status));
2153         ASSERT_EQ(SIGSTOP, WSTOPSIG(status));
2154         /* Verify signal delivery came from parent now. */
2155         ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info));
2156         EXPECT_EQ(getpid(), info.si_pid);
2157
2158         /* Restart nanosleep with SIGCONT, which triggers restart_syscall. */
2159         ASSERT_EQ(0, kill(child_pid, SIGCONT));
2160         ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2161         ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2162         ASSERT_EQ(true, WIFSTOPPED(status));
2163         ASSERT_EQ(SIGCONT, WSTOPSIG(status));
2164         ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2165
2166         /* Wait for restart_syscall() to start. */
2167         ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2168         ASSERT_EQ(true, WIFSTOPPED(status));
2169         ASSERT_EQ(SIGTRAP, WSTOPSIG(status));
2170         ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16));
2171         ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg));
2172
2173         ASSERT_EQ(0x200, msg);
2174         ret = get_syscall(_metadata, child_pid);
2175 #if defined(__arm__)
2176         /*
2177          * FIXME:
2178          * - native ARM registers do NOT expose true syscall.
2179          * - compat ARM registers on ARM64 DO expose true syscall.
2180          */
2181         ASSERT_EQ(0, uname(&utsbuf));
2182         if (strncmp(utsbuf.machine, "arm", 3) == 0) {
2183                 EXPECT_EQ(__NR_nanosleep, ret);
2184         } else
2185 #endif
2186         {
2187                 EXPECT_EQ(__NR_restart_syscall, ret);
2188         }
2189
2190         /* Write again to end test. */
2191         ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2192         ASSERT_EQ(1, write(pipefd[1], "!", 1));
2193         EXPECT_EQ(0, close(pipefd[1]));
2194
2195         ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2196         if (WIFSIGNALED(status) || WEXITSTATUS(status))
2197                 _metadata->passed = 0;
2198 }
2199
2200 /*
2201  * TODO:
2202  * - add microbenchmarks
2203  * - expand NNP testing
2204  * - better arch-specific TRACE and TRAP handlers.
2205  * - endianness checking when appropriate
2206  * - 64-bit arg prodding
2207  * - arch value testing (x86 modes especially)
2208  * - ...
2209  */
2210
2211 TEST_HARNESS_MAIN