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TOMOYO Linux Cross Reference
Linux/tools/testing/selftests/seccomp/seccomp_bpf.c

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  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 <sys/types.h>
  9 
 10 /*
 11  * glibc 2.26 and later have SIGSYS in siginfo_t. Before that,
 12  * we need to use the kernel's siginfo.h file and trick glibc
 13  * into accepting it.
 14  */
 15 #if !__GLIBC_PREREQ(2, 26)
 16 # include <asm/siginfo.h>
 17 # define __have_siginfo_t 1
 18 # define __have_sigval_t 1
 19 # define __have_sigevent_t 1
 20 #endif
 21 
 22 #include <errno.h>
 23 #include <linux/filter.h>
 24 #include <sys/prctl.h>
 25 #include <sys/ptrace.h>
 26 #include <sys/user.h>
 27 #include <linux/prctl.h>
 28 #include <linux/ptrace.h>
 29 #include <linux/seccomp.h>
 30 #include <pthread.h>
 31 #include <semaphore.h>
 32 #include <signal.h>
 33 #include <stddef.h>
 34 #include <stdbool.h>
 35 #include <string.h>
 36 #include <time.h>
 37 #include <linux/elf.h>
 38 #include <sys/uio.h>
 39 #include <sys/utsname.h>
 40 #include <sys/fcntl.h>
 41 #include <sys/mman.h>
 42 #include <sys/times.h>
 43 
 44 #define _GNU_SOURCE
 45 #include <unistd.h>
 46 #include <sys/syscall.h>
 47 
 48 #include "../kselftest_harness.h"
 49 
 50 #ifndef PR_SET_PTRACER
 51 # define PR_SET_PTRACER 0x59616d61
 52 #endif
 53 
 54 #ifndef PR_SET_NO_NEW_PRIVS
 55 #define PR_SET_NO_NEW_PRIVS 38
 56 #define PR_GET_NO_NEW_PRIVS 39
 57 #endif
 58 
 59 #ifndef PR_SECCOMP_EXT
 60 #define PR_SECCOMP_EXT 43
 61 #endif
 62 
 63 #ifndef SECCOMP_EXT_ACT
 64 #define SECCOMP_EXT_ACT 1
 65 #endif
 66 
 67 #ifndef SECCOMP_EXT_ACT_TSYNC
 68 #define SECCOMP_EXT_ACT_TSYNC 1
 69 #endif
 70 
 71 #ifndef SECCOMP_MODE_STRICT
 72 #define SECCOMP_MODE_STRICT 1
 73 #endif
 74 
 75 #ifndef SECCOMP_MODE_FILTER
 76 #define SECCOMP_MODE_FILTER 2
 77 #endif
 78 
 79 #ifndef SECCOMP_RET_ALLOW
 80 struct seccomp_data {
 81         int nr;
 82         __u32 arch;
 83         __u64 instruction_pointer;
 84         __u64 args[6];
 85 };
 86 #endif
 87 
 88 #ifndef SECCOMP_RET_KILL_PROCESS
 89 #define SECCOMP_RET_KILL_PROCESS 0x80000000U /* kill the process */
 90 #define SECCOMP_RET_KILL_THREAD  0x00000000U /* kill the thread */
 91 #endif
 92 #ifndef SECCOMP_RET_KILL
 93 #define SECCOMP_RET_KILL         SECCOMP_RET_KILL_THREAD
 94 #define SECCOMP_RET_TRAP         0x00030000U /* disallow and force a SIGSYS */
 95 #define SECCOMP_RET_ERRNO        0x00050000U /* returns an errno */
 96 #define SECCOMP_RET_TRACE        0x7ff00000U /* pass to a tracer or disallow */
 97 #define SECCOMP_RET_ALLOW        0x7fff0000U /* allow */
 98 #endif
 99 #ifndef SECCOMP_RET_LOG
100 #define SECCOMP_RET_LOG          0x7ffc0000U /* allow after logging */
101 #endif
102 
103 #ifndef __NR_seccomp
104 # if defined(__i386__)
105 #  define __NR_seccomp 354
106 # elif defined(__x86_64__)
107 #  define __NR_seccomp 317
108 # elif defined(__arm__)
109 #  define __NR_seccomp 383
110 # elif defined(__aarch64__)
111 #  define __NR_seccomp 277
112 # elif defined(__hppa__)
113 #  define __NR_seccomp 338
114 # elif defined(__powerpc__)
115 #  define __NR_seccomp 358
116 # elif defined(__s390__)
117 #  define __NR_seccomp 348
118 # else
119 #  warning "seccomp syscall number unknown for this architecture"
120 #  define __NR_seccomp 0xffff
121 # endif
122 #endif
123 
124 #ifndef SECCOMP_SET_MODE_STRICT
125 #define SECCOMP_SET_MODE_STRICT 0
126 #endif
127 
128 #ifndef SECCOMP_SET_MODE_FILTER
129 #define SECCOMP_SET_MODE_FILTER 1
130 #endif
131 
132 #ifndef SECCOMP_GET_ACTION_AVAIL
133 #define SECCOMP_GET_ACTION_AVAIL 2
134 #endif
135 
136 #ifndef SECCOMP_FILTER_FLAG_TSYNC
137 #define SECCOMP_FILTER_FLAG_TSYNC (1UL << 0)
138 #endif
139 
140 #ifndef SECCOMP_FILTER_FLAG_LOG
141 #define SECCOMP_FILTER_FLAG_LOG (1UL << 1)
142 #endif
143 
144 #ifndef SECCOMP_FILTER_FLAG_SPEC_ALLOW
145 #define SECCOMP_FILTER_FLAG_SPEC_ALLOW (1UL << 2)
146 #endif
147 
148 #ifndef PTRACE_SECCOMP_GET_METADATA
149 #define PTRACE_SECCOMP_GET_METADATA     0x420d
150 
151 struct seccomp_metadata {
152         __u64 filter_off;       /* Input: which filter */
153         __u64 flags;             /* Output: filter's flags */
154 };
155 #endif
156 
157 #ifndef seccomp
158 int seccomp(unsigned int op, unsigned int flags, void *args)
159 {
160         errno = 0;
161         return syscall(__NR_seccomp, op, flags, args);
162 }
163 #endif
164 
165 #if __BYTE_ORDER == __LITTLE_ENDIAN
166 #define syscall_arg(_n) (offsetof(struct seccomp_data, args[_n]))
167 #elif __BYTE_ORDER == __BIG_ENDIAN
168 #define syscall_arg(_n) (offsetof(struct seccomp_data, args[_n]) + sizeof(__u32))
169 #else
170 #error "wut? Unknown __BYTE_ORDER?!"
171 #endif
172 
173 #define SIBLING_EXIT_UNKILLED   0xbadbeef
174 #define SIBLING_EXIT_FAILURE    0xbadface
175 #define SIBLING_EXIT_NEWPRIVS   0xbadfeed
176 
177 TEST(mode_strict_support)
178 {
179         long ret;
180 
181         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, NULL, NULL);
182         ASSERT_EQ(0, ret) {
183                 TH_LOG("Kernel does not support CONFIG_SECCOMP");
184         }
185         syscall(__NR_exit, 0);
186 }
187 
188 TEST_SIGNAL(mode_strict_cannot_call_prctl, SIGKILL)
189 {
190         long ret;
191 
192         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, NULL, NULL);
193         ASSERT_EQ(0, ret) {
194                 TH_LOG("Kernel does not support CONFIG_SECCOMP");
195         }
196         syscall(__NR_prctl, PR_SET_SECCOMP, SECCOMP_MODE_FILTER,
197                 NULL, NULL, NULL);
198         EXPECT_FALSE(true) {
199                 TH_LOG("Unreachable!");
200         }
201 }
202 
203 /* Note! This doesn't test no new privs behavior */
204 TEST(no_new_privs_support)
205 {
206         long ret;
207 
208         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
209         EXPECT_EQ(0, ret) {
210                 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
211         }
212 }
213 
214 /* Tests kernel support by checking for a copy_from_user() fault on NULL. */
215 TEST(mode_filter_support)
216 {
217         long ret;
218 
219         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
220         ASSERT_EQ(0, ret) {
221                 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
222         }
223         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, NULL, NULL, NULL);
224         EXPECT_EQ(-1, ret);
225         EXPECT_EQ(EFAULT, errno) {
226                 TH_LOG("Kernel does not support CONFIG_SECCOMP_FILTER!");
227         }
228 }
229 
230 TEST(mode_filter_without_nnp)
231 {
232         struct sock_filter filter[] = {
233                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
234         };
235         struct sock_fprog prog = {
236                 .len = (unsigned short)ARRAY_SIZE(filter),
237                 .filter = filter,
238         };
239         long ret;
240 
241         ret = prctl(PR_GET_NO_NEW_PRIVS, 0, NULL, 0, 0);
242         ASSERT_LE(0, ret) {
243                 TH_LOG("Expected 0 or unsupported for NO_NEW_PRIVS");
244         }
245         errno = 0;
246         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
247         /* Succeeds with CAP_SYS_ADMIN, fails without */
248         /* TODO(wad) check caps not euid */
249         if (geteuid()) {
250                 EXPECT_EQ(-1, ret);
251                 EXPECT_EQ(EACCES, errno);
252         } else {
253                 EXPECT_EQ(0, ret);
254         }
255 }
256 
257 #define MAX_INSNS_PER_PATH 32768
258 
259 TEST(filter_size_limits)
260 {
261         int i;
262         int count = BPF_MAXINSNS + 1;
263         struct sock_filter allow[] = {
264                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
265         };
266         struct sock_filter *filter;
267         struct sock_fprog prog = { };
268         long ret;
269 
270         filter = calloc(count, sizeof(*filter));
271         ASSERT_NE(NULL, filter);
272 
273         for (i = 0; i < count; i++)
274                 filter[i] = allow[0];
275 
276         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
277         ASSERT_EQ(0, ret);
278 
279         prog.filter = filter;
280         prog.len = count;
281 
282         /* Too many filter instructions in a single filter. */
283         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
284         ASSERT_NE(0, ret) {
285                 TH_LOG("Installing %d insn filter was allowed", prog.len);
286         }
287 
288         /* One less is okay, though. */
289         prog.len -= 1;
290         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
291         ASSERT_EQ(0, ret) {
292                 TH_LOG("Installing %d insn filter wasn't allowed", prog.len);
293         }
294 }
295 
296 TEST(filter_chain_limits)
297 {
298         int i;
299         int count = BPF_MAXINSNS;
300         struct sock_filter allow[] = {
301                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
302         };
303         struct sock_filter *filter;
304         struct sock_fprog prog = { };
305         long ret;
306 
307         filter = calloc(count, sizeof(*filter));
308         ASSERT_NE(NULL, filter);
309 
310         for (i = 0; i < count; i++)
311                 filter[i] = allow[0];
312 
313         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
314         ASSERT_EQ(0, ret);
315 
316         prog.filter = filter;
317         prog.len = 1;
318 
319         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
320         ASSERT_EQ(0, ret);
321 
322         prog.len = count;
323 
324         /* Too many total filter instructions. */
325         for (i = 0; i < MAX_INSNS_PER_PATH; i++) {
326                 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
327                 if (ret != 0)
328                         break;
329         }
330         ASSERT_NE(0, ret) {
331                 TH_LOG("Allowed %d %d-insn filters (total with penalties:%d)",
332                        i, count, i * (count + 4));
333         }
334 }
335 
336 TEST(mode_filter_cannot_move_to_strict)
337 {
338         struct sock_filter filter[] = {
339                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
340         };
341         struct sock_fprog prog = {
342                 .len = (unsigned short)ARRAY_SIZE(filter),
343                 .filter = filter,
344         };
345         long ret;
346 
347         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
348         ASSERT_EQ(0, ret);
349 
350         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
351         ASSERT_EQ(0, ret);
352 
353         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, 0, 0);
354         EXPECT_EQ(-1, ret);
355         EXPECT_EQ(EINVAL, errno);
356 }
357 
358 
359 TEST(mode_filter_get_seccomp)
360 {
361         struct sock_filter filter[] = {
362                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
363         };
364         struct sock_fprog prog = {
365                 .len = (unsigned short)ARRAY_SIZE(filter),
366                 .filter = filter,
367         };
368         long ret;
369 
370         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
371         ASSERT_EQ(0, ret);
372 
373         ret = prctl(PR_GET_SECCOMP, 0, 0, 0, 0);
374         EXPECT_EQ(0, ret);
375 
376         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
377         ASSERT_EQ(0, ret);
378 
379         ret = prctl(PR_GET_SECCOMP, 0, 0, 0, 0);
380         EXPECT_EQ(2, ret);
381 }
382 
383 
384 TEST(ALLOW_all)
385 {
386         struct sock_filter filter[] = {
387                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
388         };
389         struct sock_fprog prog = {
390                 .len = (unsigned short)ARRAY_SIZE(filter),
391                 .filter = filter,
392         };
393         long ret;
394 
395         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
396         ASSERT_EQ(0, ret);
397 
398         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
399         ASSERT_EQ(0, ret);
400 }
401 
402 TEST(empty_prog)
403 {
404         struct sock_filter filter[] = {
405         };
406         struct sock_fprog prog = {
407                 .len = (unsigned short)ARRAY_SIZE(filter),
408                 .filter = filter,
409         };
410         long ret;
411 
412         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
413         ASSERT_EQ(0, ret);
414 
415         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
416         EXPECT_EQ(-1, ret);
417         EXPECT_EQ(EINVAL, errno);
418 }
419 
420 TEST(log_all)
421 {
422         struct sock_filter filter[] = {
423                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_LOG),
424         };
425         struct sock_fprog prog = {
426                 .len = (unsigned short)ARRAY_SIZE(filter),
427                 .filter = filter,
428         };
429         long ret;
430         pid_t parent = getppid();
431 
432         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
433         ASSERT_EQ(0, ret);
434 
435         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
436         ASSERT_EQ(0, ret);
437 
438         /* getppid() should succeed and be logged (no check for logging) */
439         EXPECT_EQ(parent, syscall(__NR_getppid));
440 }
441 
442 TEST_SIGNAL(unknown_ret_is_kill_inside, SIGSYS)
443 {
444         struct sock_filter filter[] = {
445                 BPF_STMT(BPF_RET|BPF_K, 0x10000000U),
446         };
447         struct sock_fprog prog = {
448                 .len = (unsigned short)ARRAY_SIZE(filter),
449                 .filter = filter,
450         };
451         long ret;
452 
453         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
454         ASSERT_EQ(0, ret);
455 
456         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
457         ASSERT_EQ(0, ret);
458         EXPECT_EQ(0, syscall(__NR_getpid)) {
459                 TH_LOG("getpid() shouldn't ever return");
460         }
461 }
462 
463 /* return code >= 0x80000000 is unused. */
464 TEST_SIGNAL(unknown_ret_is_kill_above_allow, SIGSYS)
465 {
466         struct sock_filter filter[] = {
467                 BPF_STMT(BPF_RET|BPF_K, 0x90000000U),
468         };
469         struct sock_fprog prog = {
470                 .len = (unsigned short)ARRAY_SIZE(filter),
471                 .filter = filter,
472         };
473         long ret;
474 
475         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
476         ASSERT_EQ(0, ret);
477 
478         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
479         ASSERT_EQ(0, ret);
480         EXPECT_EQ(0, syscall(__NR_getpid)) {
481                 TH_LOG("getpid() shouldn't ever return");
482         }
483 }
484 
485 TEST_SIGNAL(KILL_all, SIGSYS)
486 {
487         struct sock_filter filter[] = {
488                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
489         };
490         struct sock_fprog prog = {
491                 .len = (unsigned short)ARRAY_SIZE(filter),
492                 .filter = filter,
493         };
494         long ret;
495 
496         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
497         ASSERT_EQ(0, ret);
498 
499         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
500         ASSERT_EQ(0, ret);
501 }
502 
503 TEST_SIGNAL(KILL_one, SIGSYS)
504 {
505         struct sock_filter filter[] = {
506                 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
507                         offsetof(struct seccomp_data, nr)),
508                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
509                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
510                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
511         };
512         struct sock_fprog prog = {
513                 .len = (unsigned short)ARRAY_SIZE(filter),
514                 .filter = filter,
515         };
516         long ret;
517         pid_t parent = getppid();
518 
519         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
520         ASSERT_EQ(0, ret);
521 
522         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
523         ASSERT_EQ(0, ret);
524 
525         EXPECT_EQ(parent, syscall(__NR_getppid));
526         /* getpid() should never return. */
527         EXPECT_EQ(0, syscall(__NR_getpid));
528 }
529 
530 TEST_SIGNAL(KILL_one_arg_one, SIGSYS)
531 {
532         void *fatal_address;
533         struct sock_filter filter[] = {
534                 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
535                         offsetof(struct seccomp_data, nr)),
536                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_times, 1, 0),
537                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
538                 /* Only both with lower 32-bit for now. */
539                 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(0)),
540                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K,
541                         (unsigned long)&fatal_address, 0, 1),
542                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
543                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
544         };
545         struct sock_fprog prog = {
546                 .len = (unsigned short)ARRAY_SIZE(filter),
547                 .filter = filter,
548         };
549         long ret;
550         pid_t parent = getppid();
551         struct tms timebuf;
552         clock_t clock = times(&timebuf);
553 
554         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
555         ASSERT_EQ(0, ret);
556 
557         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
558         ASSERT_EQ(0, ret);
559 
560         EXPECT_EQ(parent, syscall(__NR_getppid));
561         EXPECT_LE(clock, syscall(__NR_times, &timebuf));
562         /* times() should never return. */
563         EXPECT_EQ(0, syscall(__NR_times, &fatal_address));
564 }
565 
566 TEST_SIGNAL(KILL_one_arg_six, SIGSYS)
567 {
568 #ifndef __NR_mmap2
569         int sysno = __NR_mmap;
570 #else
571         int sysno = __NR_mmap2;
572 #endif
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, sysno, 1, 0),
577                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
578                 /* Only both with lower 32-bit for now. */
579                 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(5)),
580                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 0x0C0FFEE, 0, 1),
581                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
582                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
583         };
584         struct sock_fprog prog = {
585                 .len = (unsigned short)ARRAY_SIZE(filter),
586                 .filter = filter,
587         };
588         long ret;
589         pid_t parent = getppid();
590         int fd;
591         void *map1, *map2;
592         int page_size = sysconf(_SC_PAGESIZE);
593 
594         ASSERT_LT(0, page_size);
595 
596         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
597         ASSERT_EQ(0, ret);
598 
599         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
600         ASSERT_EQ(0, ret);
601 
602         fd = open("/dev/zero", O_RDONLY);
603         ASSERT_NE(-1, fd);
604 
605         EXPECT_EQ(parent, syscall(__NR_getppid));
606         map1 = (void *)syscall(sysno,
607                 NULL, page_size, PROT_READ, MAP_PRIVATE, fd, page_size);
608         EXPECT_NE(MAP_FAILED, map1);
609         /* mmap2() should never return. */
610         map2 = (void *)syscall(sysno,
611                  NULL, page_size, PROT_READ, MAP_PRIVATE, fd, 0x0C0FFEE);
612         EXPECT_EQ(MAP_FAILED, map2);
613 
614         /* The test failed, so clean up the resources. */
615         munmap(map1, page_size);
616         munmap(map2, page_size);
617         close(fd);
618 }
619 
620 /* This is a thread task to die via seccomp filter violation. */
621 void *kill_thread(void *data)
622 {
623         bool die = (bool)data;
624 
625         if (die) {
626                 prctl(PR_GET_SECCOMP, 0, 0, 0, 0);
627                 return (void *)SIBLING_EXIT_FAILURE;
628         }
629 
630         return (void *)SIBLING_EXIT_UNKILLED;
631 }
632 
633 /* Prepare a thread that will kill itself or both of us. */
634 void kill_thread_or_group(struct __test_metadata *_metadata, bool kill_process)
635 {
636         pthread_t thread;
637         void *status;
638         /* Kill only when calling __NR_prctl. */
639         struct sock_filter filter_thread[] = {
640                 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
641                         offsetof(struct seccomp_data, nr)),
642                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1),
643                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL_THREAD),
644                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
645         };
646         struct sock_fprog prog_thread = {
647                 .len = (unsigned short)ARRAY_SIZE(filter_thread),
648                 .filter = filter_thread,
649         };
650         struct sock_filter filter_process[] = {
651                 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
652                         offsetof(struct seccomp_data, nr)),
653                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1),
654                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL_PROCESS),
655                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
656         };
657         struct sock_fprog prog_process = {
658                 .len = (unsigned short)ARRAY_SIZE(filter_process),
659                 .filter = filter_process,
660         };
661 
662         ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
663                 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
664         }
665 
666         ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0,
667                              kill_process ? &prog_process : &prog_thread));
668 
669         /*
670          * Add the KILL_THREAD rule again to make sure that the KILL_PROCESS
671          * flag cannot be downgraded by a new filter.
672          */
673         ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog_thread));
674 
675         /* Start a thread that will exit immediately. */
676         ASSERT_EQ(0, pthread_create(&thread, NULL, kill_thread, (void *)false));
677         ASSERT_EQ(0, pthread_join(thread, &status));
678         ASSERT_EQ(SIBLING_EXIT_UNKILLED, (unsigned long)status);
679 
680         /* Start a thread that will die immediately. */
681         ASSERT_EQ(0, pthread_create(&thread, NULL, kill_thread, (void *)true));
682         ASSERT_EQ(0, pthread_join(thread, &status));
683         ASSERT_NE(SIBLING_EXIT_FAILURE, (unsigned long)status);
684 
685         /*
686          * If we get here, only the spawned thread died. Let the parent know
687          * the whole process didn't die (i.e. this thread, the spawner,
688          * stayed running).
689          */
690         exit(42);
691 }
692 
693 TEST(KILL_thread)
694 {
695         int status;
696         pid_t child_pid;
697 
698         child_pid = fork();
699         ASSERT_LE(0, child_pid);
700         if (child_pid == 0) {
701                 kill_thread_or_group(_metadata, false);
702                 _exit(38);
703         }
704 
705         ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
706 
707         /* If only the thread was killed, we'll see exit 42. */
708         ASSERT_TRUE(WIFEXITED(status));
709         ASSERT_EQ(42, WEXITSTATUS(status));
710 }
711 
712 TEST(KILL_process)
713 {
714         int status;
715         pid_t child_pid;
716 
717         child_pid = fork();
718         ASSERT_LE(0, child_pid);
719         if (child_pid == 0) {
720                 kill_thread_or_group(_metadata, true);
721                 _exit(38);
722         }
723 
724         ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
725 
726         /* If the entire process was killed, we'll see SIGSYS. */
727         ASSERT_TRUE(WIFSIGNALED(status));
728         ASSERT_EQ(SIGSYS, WTERMSIG(status));
729 }
730 
731 /* TODO(wad) add 64-bit versus 32-bit arg tests. */
732 TEST(arg_out_of_range)
733 {
734         struct sock_filter filter[] = {
735                 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(6)),
736                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
737         };
738         struct sock_fprog prog = {
739                 .len = (unsigned short)ARRAY_SIZE(filter),
740                 .filter = filter,
741         };
742         long ret;
743 
744         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
745         ASSERT_EQ(0, ret);
746 
747         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
748         EXPECT_EQ(-1, ret);
749         EXPECT_EQ(EINVAL, errno);
750 }
751 
752 #define ERRNO_FILTER(name, errno)                                       \
753         struct sock_filter _read_filter_##name[] = {                    \
754                 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,                          \
755                         offsetof(struct seccomp_data, nr)),             \
756                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1),       \
757                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | errno),     \
758                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),             \
759         };                                                              \
760         struct sock_fprog prog_##name = {                               \
761                 .len = (unsigned short)ARRAY_SIZE(_read_filter_##name), \
762                 .filter = _read_filter_##name,                          \
763         }
764 
765 /* Make sure basic errno values are correctly passed through a filter. */
766 TEST(ERRNO_valid)
767 {
768         ERRNO_FILTER(valid, E2BIG);
769         long ret;
770         pid_t parent = getppid();
771 
772         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
773         ASSERT_EQ(0, ret);
774 
775         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_valid);
776         ASSERT_EQ(0, ret);
777 
778         EXPECT_EQ(parent, syscall(__NR_getppid));
779         EXPECT_EQ(-1, read(0, NULL, 0));
780         EXPECT_EQ(E2BIG, errno);
781 }
782 
783 /* Make sure an errno of zero is correctly handled by the arch code. */
784 TEST(ERRNO_zero)
785 {
786         ERRNO_FILTER(zero, 0);
787         long ret;
788         pid_t parent = getppid();
789 
790         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
791         ASSERT_EQ(0, ret);
792 
793         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_zero);
794         ASSERT_EQ(0, ret);
795 
796         EXPECT_EQ(parent, syscall(__NR_getppid));
797         /* "errno" of 0 is ok. */
798         EXPECT_EQ(0, read(0, NULL, 0));
799 }
800 
801 /*
802  * The SECCOMP_RET_DATA mask is 16 bits wide, but errno is smaller.
803  * This tests that the errno value gets capped correctly, fixed by
804  * 580c57f10768 ("seccomp: cap SECCOMP_RET_ERRNO data to MAX_ERRNO").
805  */
806 TEST(ERRNO_capped)
807 {
808         ERRNO_FILTER(capped, 4096);
809         long ret;
810         pid_t parent = getppid();
811 
812         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
813         ASSERT_EQ(0, ret);
814 
815         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_capped);
816         ASSERT_EQ(0, ret);
817 
818         EXPECT_EQ(parent, syscall(__NR_getppid));
819         EXPECT_EQ(-1, read(0, NULL, 0));
820         EXPECT_EQ(4095, errno);
821 }
822 
823 /*
824  * Filters are processed in reverse order: last applied is executed first.
825  * Since only the SECCOMP_RET_ACTION mask is tested for return values, the
826  * SECCOMP_RET_DATA mask results will follow the most recently applied
827  * matching filter return (and not the lowest or highest value).
828  */
829 TEST(ERRNO_order)
830 {
831         ERRNO_FILTER(first,  11);
832         ERRNO_FILTER(second, 13);
833         ERRNO_FILTER(third,  12);
834         long ret;
835         pid_t parent = getppid();
836 
837         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
838         ASSERT_EQ(0, ret);
839 
840         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_first);
841         ASSERT_EQ(0, ret);
842 
843         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_second);
844         ASSERT_EQ(0, ret);
845 
846         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_third);
847         ASSERT_EQ(0, ret);
848 
849         EXPECT_EQ(parent, syscall(__NR_getppid));
850         EXPECT_EQ(-1, read(0, NULL, 0));
851         EXPECT_EQ(12, errno);
852 }
853 
854 FIXTURE_DATA(TRAP) {
855         struct sock_fprog prog;
856 };
857 
858 FIXTURE_SETUP(TRAP)
859 {
860         struct sock_filter filter[] = {
861                 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
862                         offsetof(struct seccomp_data, nr)),
863                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
864                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRAP),
865                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
866         };
867 
868         memset(&self->prog, 0, sizeof(self->prog));
869         self->prog.filter = malloc(sizeof(filter));
870         ASSERT_NE(NULL, self->prog.filter);
871         memcpy(self->prog.filter, filter, sizeof(filter));
872         self->prog.len = (unsigned short)ARRAY_SIZE(filter);
873 }
874 
875 FIXTURE_TEARDOWN(TRAP)
876 {
877         if (self->prog.filter)
878                 free(self->prog.filter);
879 }
880 
881 TEST_F_SIGNAL(TRAP, dfl, SIGSYS)
882 {
883         long ret;
884 
885         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
886         ASSERT_EQ(0, ret);
887 
888         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog);
889         ASSERT_EQ(0, ret);
890         syscall(__NR_getpid);
891 }
892 
893 /* Ensure that SIGSYS overrides SIG_IGN */
894 TEST_F_SIGNAL(TRAP, ign, SIGSYS)
895 {
896         long ret;
897 
898         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
899         ASSERT_EQ(0, ret);
900 
901         signal(SIGSYS, SIG_IGN);
902 
903         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog);
904         ASSERT_EQ(0, ret);
905         syscall(__NR_getpid);
906 }
907 
908 static siginfo_t TRAP_info;
909 static volatile int TRAP_nr;
910 static void TRAP_action(int nr, siginfo_t *info, void *void_context)
911 {
912         memcpy(&TRAP_info, info, sizeof(TRAP_info));
913         TRAP_nr = nr;
914 }
915 
916 TEST_F(TRAP, handler)
917 {
918         int ret, test;
919         struct sigaction act;
920         sigset_t mask;
921 
922         memset(&act, 0, sizeof(act));
923         sigemptyset(&mask);
924         sigaddset(&mask, SIGSYS);
925 
926         act.sa_sigaction = &TRAP_action;
927         act.sa_flags = SA_SIGINFO;
928         ret = sigaction(SIGSYS, &act, NULL);
929         ASSERT_EQ(0, ret) {
930                 TH_LOG("sigaction failed");
931         }
932         ret = sigprocmask(SIG_UNBLOCK, &mask, NULL);
933         ASSERT_EQ(0, ret) {
934                 TH_LOG("sigprocmask failed");
935         }
936 
937         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
938         ASSERT_EQ(0, ret);
939         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog);
940         ASSERT_EQ(0, ret);
941         TRAP_nr = 0;
942         memset(&TRAP_info, 0, sizeof(TRAP_info));
943         /* Expect the registers to be rolled back. (nr = error) may vary
944          * based on arch. */
945         ret = syscall(__NR_getpid);
946         /* Silence gcc warning about volatile. */
947         test = TRAP_nr;
948         EXPECT_EQ(SIGSYS, test);
949         struct local_sigsys {
950                 void *_call_addr;       /* calling user insn */
951                 int _syscall;           /* triggering system call number */
952                 unsigned int _arch;     /* AUDIT_ARCH_* of syscall */
953         } *sigsys = (struct local_sigsys *)
954 #ifdef si_syscall
955                 &(TRAP_info.si_call_addr);
956 #else
957                 &TRAP_info.si_pid;
958 #endif
959         EXPECT_EQ(__NR_getpid, sigsys->_syscall);
960         /* Make sure arch is non-zero. */
961         EXPECT_NE(0, sigsys->_arch);
962         EXPECT_NE(0, (unsigned long)sigsys->_call_addr);
963 }
964 
965 FIXTURE_DATA(precedence) {
966         struct sock_fprog allow;
967         struct sock_fprog log;
968         struct sock_fprog trace;
969         struct sock_fprog error;
970         struct sock_fprog trap;
971         struct sock_fprog kill;
972 };
973 
974 FIXTURE_SETUP(precedence)
975 {
976         struct sock_filter allow_insns[] = {
977                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
978         };
979         struct sock_filter log_insns[] = {
980                 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
981                         offsetof(struct seccomp_data, nr)),
982                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
983                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
984                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_LOG),
985         };
986         struct sock_filter trace_insns[] = {
987                 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
988                         offsetof(struct seccomp_data, nr)),
989                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
990                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
991                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE),
992         };
993         struct sock_filter error_insns[] = {
994                 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
995                         offsetof(struct seccomp_data, nr)),
996                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
997                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
998                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO),
999         };
1000         struct sock_filter trap_insns[] = {
1001                 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1002                         offsetof(struct seccomp_data, nr)),
1003                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
1004                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1005                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRAP),
1006         };
1007         struct sock_filter kill_insns[] = {
1008                 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1009                         offsetof(struct seccomp_data, nr)),
1010                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
1011                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1012                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
1013         };
1014 
1015         memset(self, 0, sizeof(*self));
1016 #define FILTER_ALLOC(_x) \
1017         self->_x.filter = malloc(sizeof(_x##_insns)); \
1018         ASSERT_NE(NULL, self->_x.filter); \
1019         memcpy(self->_x.filter, &_x##_insns, sizeof(_x##_insns)); \
1020         self->_x.len = (unsigned short)ARRAY_SIZE(_x##_insns)
1021         FILTER_ALLOC(allow);
1022         FILTER_ALLOC(log);
1023         FILTER_ALLOC(trace);
1024         FILTER_ALLOC(error);
1025         FILTER_ALLOC(trap);
1026         FILTER_ALLOC(kill);
1027 }
1028 
1029 FIXTURE_TEARDOWN(precedence)
1030 {
1031 #define FILTER_FREE(_x) if (self->_x.filter) free(self->_x.filter)
1032         FILTER_FREE(allow);
1033         FILTER_FREE(log);
1034         FILTER_FREE(trace);
1035         FILTER_FREE(error);
1036         FILTER_FREE(trap);
1037         FILTER_FREE(kill);
1038 }
1039 
1040 TEST_F(precedence, allow_ok)
1041 {
1042         pid_t parent, res = 0;
1043         long ret;
1044 
1045         parent = getppid();
1046         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1047         ASSERT_EQ(0, ret);
1048 
1049         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1050         ASSERT_EQ(0, ret);
1051         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1052         ASSERT_EQ(0, ret);
1053         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1054         ASSERT_EQ(0, ret);
1055         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1056         ASSERT_EQ(0, ret);
1057         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
1058         ASSERT_EQ(0, ret);
1059         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill);
1060         ASSERT_EQ(0, ret);
1061         /* Should work just fine. */
1062         res = syscall(__NR_getppid);
1063         EXPECT_EQ(parent, res);
1064 }
1065 
1066 TEST_F_SIGNAL(precedence, kill_is_highest, SIGSYS)
1067 {
1068         pid_t parent, res = 0;
1069         long ret;
1070 
1071         parent = getppid();
1072         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1073         ASSERT_EQ(0, ret);
1074 
1075         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1076         ASSERT_EQ(0, ret);
1077         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1078         ASSERT_EQ(0, ret);
1079         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1080         ASSERT_EQ(0, ret);
1081         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1082         ASSERT_EQ(0, ret);
1083         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
1084         ASSERT_EQ(0, ret);
1085         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill);
1086         ASSERT_EQ(0, ret);
1087         /* Should work just fine. */
1088         res = syscall(__NR_getppid);
1089         EXPECT_EQ(parent, res);
1090         /* getpid() should never return. */
1091         res = syscall(__NR_getpid);
1092         EXPECT_EQ(0, res);
1093 }
1094 
1095 TEST_F_SIGNAL(precedence, kill_is_highest_in_any_order, SIGSYS)
1096 {
1097         pid_t parent;
1098         long ret;
1099 
1100         parent = getppid();
1101         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1102         ASSERT_EQ(0, ret);
1103 
1104         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1105         ASSERT_EQ(0, ret);
1106         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill);
1107         ASSERT_EQ(0, ret);
1108         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1109         ASSERT_EQ(0, ret);
1110         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1111         ASSERT_EQ(0, ret);
1112         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1113         ASSERT_EQ(0, ret);
1114         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
1115         ASSERT_EQ(0, ret);
1116         /* Should work just fine. */
1117         EXPECT_EQ(parent, syscall(__NR_getppid));
1118         /* getpid() should never return. */
1119         EXPECT_EQ(0, syscall(__NR_getpid));
1120 }
1121 
1122 TEST_F_SIGNAL(precedence, trap_is_second, SIGSYS)
1123 {
1124         pid_t parent;
1125         long ret;
1126 
1127         parent = getppid();
1128         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1129         ASSERT_EQ(0, ret);
1130 
1131         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1132         ASSERT_EQ(0, ret);
1133         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1134         ASSERT_EQ(0, ret);
1135         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1136         ASSERT_EQ(0, ret);
1137         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1138         ASSERT_EQ(0, ret);
1139         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
1140         ASSERT_EQ(0, ret);
1141         /* Should work just fine. */
1142         EXPECT_EQ(parent, syscall(__NR_getppid));
1143         /* getpid() should never return. */
1144         EXPECT_EQ(0, syscall(__NR_getpid));
1145 }
1146 
1147 TEST_F_SIGNAL(precedence, trap_is_second_in_any_order, SIGSYS)
1148 {
1149         pid_t parent;
1150         long ret;
1151 
1152         parent = getppid();
1153         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1154         ASSERT_EQ(0, ret);
1155 
1156         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1157         ASSERT_EQ(0, ret);
1158         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
1159         ASSERT_EQ(0, ret);
1160         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1161         ASSERT_EQ(0, ret);
1162         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1163         ASSERT_EQ(0, ret);
1164         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1165         ASSERT_EQ(0, ret);
1166         /* Should work just fine. */
1167         EXPECT_EQ(parent, syscall(__NR_getppid));
1168         /* getpid() should never return. */
1169         EXPECT_EQ(0, syscall(__NR_getpid));
1170 }
1171 
1172 TEST_F(precedence, errno_is_third)
1173 {
1174         pid_t parent;
1175         long ret;
1176 
1177         parent = getppid();
1178         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1179         ASSERT_EQ(0, ret);
1180 
1181         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1182         ASSERT_EQ(0, ret);
1183         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1184         ASSERT_EQ(0, ret);
1185         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1186         ASSERT_EQ(0, ret);
1187         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1188         ASSERT_EQ(0, ret);
1189         /* Should work just fine. */
1190         EXPECT_EQ(parent, syscall(__NR_getppid));
1191         EXPECT_EQ(0, syscall(__NR_getpid));
1192 }
1193 
1194 TEST_F(precedence, errno_is_third_in_any_order)
1195 {
1196         pid_t parent;
1197         long ret;
1198 
1199         parent = getppid();
1200         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1201         ASSERT_EQ(0, ret);
1202 
1203         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1204         ASSERT_EQ(0, ret);
1205         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1206         ASSERT_EQ(0, ret);
1207         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1208         ASSERT_EQ(0, ret);
1209         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1210         ASSERT_EQ(0, ret);
1211         /* Should work just fine. */
1212         EXPECT_EQ(parent, syscall(__NR_getppid));
1213         EXPECT_EQ(0, syscall(__NR_getpid));
1214 }
1215 
1216 TEST_F(precedence, trace_is_fourth)
1217 {
1218         pid_t parent;
1219         long ret;
1220 
1221         parent = getppid();
1222         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1223         ASSERT_EQ(0, ret);
1224 
1225         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1226         ASSERT_EQ(0, ret);
1227         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1228         ASSERT_EQ(0, ret);
1229         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1230         ASSERT_EQ(0, ret);
1231         /* Should work just fine. */
1232         EXPECT_EQ(parent, syscall(__NR_getppid));
1233         /* No ptracer */
1234         EXPECT_EQ(-1, syscall(__NR_getpid));
1235 }
1236 
1237 TEST_F(precedence, trace_is_fourth_in_any_order)
1238 {
1239         pid_t parent;
1240         long ret;
1241 
1242         parent = getppid();
1243         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1244         ASSERT_EQ(0, ret);
1245 
1246         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1247         ASSERT_EQ(0, ret);
1248         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1249         ASSERT_EQ(0, ret);
1250         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1251         ASSERT_EQ(0, ret);
1252         /* Should work just fine. */
1253         EXPECT_EQ(parent, syscall(__NR_getppid));
1254         /* No ptracer */
1255         EXPECT_EQ(-1, syscall(__NR_getpid));
1256 }
1257 
1258 TEST_F(precedence, log_is_fifth)
1259 {
1260         pid_t mypid, parent;
1261         long ret;
1262 
1263         mypid = getpid();
1264         parent = getppid();
1265         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1266         ASSERT_EQ(0, ret);
1267 
1268         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1269         ASSERT_EQ(0, ret);
1270         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1271         ASSERT_EQ(0, ret);
1272         /* Should work just fine. */
1273         EXPECT_EQ(parent, syscall(__NR_getppid));
1274         /* Should also work just fine */
1275         EXPECT_EQ(mypid, syscall(__NR_getpid));
1276 }
1277 
1278 TEST_F(precedence, log_is_fifth_in_any_order)
1279 {
1280         pid_t mypid, parent;
1281         long ret;
1282 
1283         mypid = getpid();
1284         parent = getppid();
1285         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1286         ASSERT_EQ(0, ret);
1287 
1288         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1289         ASSERT_EQ(0, ret);
1290         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1291         ASSERT_EQ(0, ret);
1292         /* Should work just fine. */
1293         EXPECT_EQ(parent, syscall(__NR_getppid));
1294         /* Should also work just fine */
1295         EXPECT_EQ(mypid, syscall(__NR_getpid));
1296 }
1297 
1298 #ifndef PTRACE_O_TRACESECCOMP
1299 #define PTRACE_O_TRACESECCOMP   0x00000080
1300 #endif
1301 
1302 /* Catch the Ubuntu 12.04 value error. */
1303 #if PTRACE_EVENT_SECCOMP != 7
1304 #undef PTRACE_EVENT_SECCOMP
1305 #endif
1306 
1307 #ifndef PTRACE_EVENT_SECCOMP
1308 #define PTRACE_EVENT_SECCOMP 7
1309 #endif
1310 
1311 #define IS_SECCOMP_EVENT(status) ((status >> 16) == PTRACE_EVENT_SECCOMP)
1312 bool tracer_running;
1313 void tracer_stop(int sig)
1314 {
1315         tracer_running = false;
1316 }
1317 
1318 typedef void tracer_func_t(struct __test_metadata *_metadata,
1319                            pid_t tracee, int status, void *args);
1320 
1321 void start_tracer(struct __test_metadata *_metadata, int fd, pid_t tracee,
1322             tracer_func_t tracer_func, void *args, bool ptrace_syscall)
1323 {
1324         int ret = -1;
1325         struct sigaction action = {
1326                 .sa_handler = tracer_stop,
1327         };
1328 
1329         /* Allow external shutdown. */
1330         tracer_running = true;
1331         ASSERT_EQ(0, sigaction(SIGUSR1, &action, NULL));
1332 
1333         errno = 0;
1334         while (ret == -1 && errno != EINVAL)
1335                 ret = ptrace(PTRACE_ATTACH, tracee, NULL, 0);
1336         ASSERT_EQ(0, ret) {
1337                 kill(tracee, SIGKILL);
1338         }
1339         /* Wait for attach stop */
1340         wait(NULL);
1341 
1342         ret = ptrace(PTRACE_SETOPTIONS, tracee, NULL, ptrace_syscall ?
1343                                                       PTRACE_O_TRACESYSGOOD :
1344                                                       PTRACE_O_TRACESECCOMP);
1345         ASSERT_EQ(0, ret) {
1346                 TH_LOG("Failed to set PTRACE_O_TRACESECCOMP");
1347                 kill(tracee, SIGKILL);
1348         }
1349         ret = ptrace(ptrace_syscall ? PTRACE_SYSCALL : PTRACE_CONT,
1350                      tracee, NULL, 0);
1351         ASSERT_EQ(0, ret);
1352 
1353         /* Unblock the tracee */
1354         ASSERT_EQ(1, write(fd, "A", 1));
1355         ASSERT_EQ(0, close(fd));
1356 
1357         /* Run until we're shut down. Must assert to stop execution. */
1358         while (tracer_running) {
1359                 int status;
1360 
1361                 if (wait(&status) != tracee)
1362                         continue;
1363                 if (WIFSIGNALED(status) || WIFEXITED(status))
1364                         /* Child is dead. Time to go. */
1365                         return;
1366 
1367                 /* Check if this is a seccomp event. */
1368                 ASSERT_EQ(!ptrace_syscall, IS_SECCOMP_EVENT(status));
1369 
1370                 tracer_func(_metadata, tracee, status, args);
1371 
1372                 ret = ptrace(ptrace_syscall ? PTRACE_SYSCALL : PTRACE_CONT,
1373                              tracee, NULL, 0);
1374                 ASSERT_EQ(0, ret);
1375         }
1376         /* Directly report the status of our test harness results. */
1377         syscall(__NR_exit, _metadata->passed ? EXIT_SUCCESS : EXIT_FAILURE);
1378 }
1379 
1380 /* Common tracer setup/teardown functions. */
1381 void cont_handler(int num)
1382 { }
1383 pid_t setup_trace_fixture(struct __test_metadata *_metadata,
1384                           tracer_func_t func, void *args, bool ptrace_syscall)
1385 {
1386         char sync;
1387         int pipefd[2];
1388         pid_t tracer_pid;
1389         pid_t tracee = getpid();
1390 
1391         /* Setup a pipe for clean synchronization. */
1392         ASSERT_EQ(0, pipe(pipefd));
1393 
1394         /* Fork a child which we'll promote to tracer */
1395         tracer_pid = fork();
1396         ASSERT_LE(0, tracer_pid);
1397         signal(SIGALRM, cont_handler);
1398         if (tracer_pid == 0) {
1399                 close(pipefd[0]);
1400                 start_tracer(_metadata, pipefd[1], tracee, func, args,
1401                              ptrace_syscall);
1402                 syscall(__NR_exit, 0);
1403         }
1404         close(pipefd[1]);
1405         prctl(PR_SET_PTRACER, tracer_pid, 0, 0, 0);
1406         read(pipefd[0], &sync, 1);
1407         close(pipefd[0]);
1408 
1409         return tracer_pid;
1410 }
1411 void teardown_trace_fixture(struct __test_metadata *_metadata,
1412                             pid_t tracer)
1413 {
1414         if (tracer) {
1415                 int status;
1416                 /*
1417                  * Extract the exit code from the other process and
1418                  * adopt it for ourselves in case its asserts failed.
1419                  */
1420                 ASSERT_EQ(0, kill(tracer, SIGUSR1));
1421                 ASSERT_EQ(tracer, waitpid(tracer, &status, 0));
1422                 if (WEXITSTATUS(status))
1423                         _metadata->passed = 0;
1424         }
1425 }
1426 
1427 /* "poke" tracer arguments and function. */
1428 struct tracer_args_poke_t {
1429         unsigned long poke_addr;
1430 };
1431 
1432 void tracer_poke(struct __test_metadata *_metadata, pid_t tracee, int status,
1433                  void *args)
1434 {
1435         int ret;
1436         unsigned long msg;
1437         struct tracer_args_poke_t *info = (struct tracer_args_poke_t *)args;
1438 
1439         ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg);
1440         EXPECT_EQ(0, ret);
1441         /* If this fails, don't try to recover. */
1442         ASSERT_EQ(0x1001, msg) {
1443                 kill(tracee, SIGKILL);
1444         }
1445         /*
1446          * Poke in the message.
1447          * Registers are not touched to try to keep this relatively arch
1448          * agnostic.
1449          */
1450         ret = ptrace(PTRACE_POKEDATA, tracee, info->poke_addr, 0x1001);
1451         EXPECT_EQ(0, ret);
1452 }
1453 
1454 FIXTURE_DATA(TRACE_poke) {
1455         struct sock_fprog prog;
1456         pid_t tracer;
1457         long poked;
1458         struct tracer_args_poke_t tracer_args;
1459 };
1460 
1461 FIXTURE_SETUP(TRACE_poke)
1462 {
1463         struct sock_filter filter[] = {
1464                 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1465                         offsetof(struct seccomp_data, nr)),
1466                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1),
1467                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1001),
1468                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1469         };
1470 
1471         self->poked = 0;
1472         memset(&self->prog, 0, sizeof(self->prog));
1473         self->prog.filter = malloc(sizeof(filter));
1474         ASSERT_NE(NULL, self->prog.filter);
1475         memcpy(self->prog.filter, filter, sizeof(filter));
1476         self->prog.len = (unsigned short)ARRAY_SIZE(filter);
1477 
1478         /* Set up tracer args. */
1479         self->tracer_args.poke_addr = (unsigned long)&self->poked;
1480 
1481         /* Launch tracer. */
1482         self->tracer = setup_trace_fixture(_metadata, tracer_poke,
1483                                            &self->tracer_args, false);
1484 }
1485 
1486 FIXTURE_TEARDOWN(TRACE_poke)
1487 {
1488         teardown_trace_fixture(_metadata, self->tracer);
1489         if (self->prog.filter)
1490                 free(self->prog.filter);
1491 }
1492 
1493 TEST_F(TRACE_poke, read_has_side_effects)
1494 {
1495         ssize_t ret;
1496 
1497         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1498         ASSERT_EQ(0, ret);
1499 
1500         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1501         ASSERT_EQ(0, ret);
1502 
1503         EXPECT_EQ(0, self->poked);
1504         ret = read(-1, NULL, 0);
1505         EXPECT_EQ(-1, ret);
1506         EXPECT_EQ(0x1001, self->poked);
1507 }
1508 
1509 TEST_F(TRACE_poke, getpid_runs_normally)
1510 {
1511         long ret;
1512 
1513         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1514         ASSERT_EQ(0, ret);
1515 
1516         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1517         ASSERT_EQ(0, ret);
1518 
1519         EXPECT_EQ(0, self->poked);
1520         EXPECT_NE(0, syscall(__NR_getpid));
1521         EXPECT_EQ(0, self->poked);
1522 }
1523 
1524 #if defined(__x86_64__)
1525 # define ARCH_REGS      struct user_regs_struct
1526 # define SYSCALL_NUM    orig_rax
1527 # define SYSCALL_RET    rax
1528 #elif defined(__i386__)
1529 # define ARCH_REGS      struct user_regs_struct
1530 # define SYSCALL_NUM    orig_eax
1531 # define SYSCALL_RET    eax
1532 #elif defined(__arm__)
1533 # define ARCH_REGS      struct pt_regs
1534 # define SYSCALL_NUM    ARM_r7
1535 # define SYSCALL_RET    ARM_r0
1536 #elif defined(__aarch64__)
1537 # define ARCH_REGS      struct user_pt_regs
1538 # define SYSCALL_NUM    regs[8]
1539 # define SYSCALL_RET    regs[0]
1540 #elif defined(__hppa__)
1541 # define ARCH_REGS      struct user_regs_struct
1542 # define SYSCALL_NUM    gr[20]
1543 # define SYSCALL_RET    gr[28]
1544 #elif defined(__powerpc__)
1545 # define ARCH_REGS      struct pt_regs
1546 # define SYSCALL_NUM    gpr[0]
1547 # define SYSCALL_RET    gpr[3]
1548 #elif defined(__s390__)
1549 # define ARCH_REGS     s390_regs
1550 # define SYSCALL_NUM   gprs[2]
1551 # define SYSCALL_RET   gprs[2]
1552 #elif defined(__mips__)
1553 # define ARCH_REGS      struct pt_regs
1554 # define SYSCALL_NUM    regs[2]
1555 # define SYSCALL_SYSCALL_NUM regs[4]
1556 # define SYSCALL_RET    regs[2]
1557 # define SYSCALL_NUM_RET_SHARE_REG
1558 #else
1559 # error "Do not know how to find your architecture's registers and syscalls"
1560 #endif
1561 
1562 /* When the syscall return can't be changed, stub out the tests for it. */
1563 #ifdef SYSCALL_NUM_RET_SHARE_REG
1564 # define EXPECT_SYSCALL_RETURN(val, action)     EXPECT_EQ(-1, action)
1565 #else
1566 # define EXPECT_SYSCALL_RETURN(val, action)     EXPECT_EQ(val, action)
1567 #endif
1568 
1569 /* Use PTRACE_GETREGS and PTRACE_SETREGS when available. This is useful for
1570  * architectures without HAVE_ARCH_TRACEHOOK (e.g. User-mode Linux).
1571  */
1572 #if defined(__x86_64__) || defined(__i386__) || defined(__mips__)
1573 #define HAVE_GETREGS
1574 #endif
1575 
1576 /* Architecture-specific syscall fetching routine. */
1577 int get_syscall(struct __test_metadata *_metadata, pid_t tracee)
1578 {
1579         ARCH_REGS regs;
1580 #ifdef HAVE_GETREGS
1581         EXPECT_EQ(0, ptrace(PTRACE_GETREGS, tracee, 0, &regs)) {
1582                 TH_LOG("PTRACE_GETREGS failed");
1583                 return -1;
1584         }
1585 #else
1586         struct iovec iov;
1587 
1588         iov.iov_base = &regs;
1589         iov.iov_len = sizeof(regs);
1590         EXPECT_EQ(0, ptrace(PTRACE_GETREGSET, tracee, NT_PRSTATUS, &iov)) {
1591                 TH_LOG("PTRACE_GETREGSET failed");
1592                 return -1;
1593         }
1594 #endif
1595 
1596 #if defined(__mips__)
1597         if (regs.SYSCALL_NUM == __NR_O32_Linux)
1598                 return regs.SYSCALL_SYSCALL_NUM;
1599 #endif
1600         return regs.SYSCALL_NUM;
1601 }
1602 
1603 /* Architecture-specific syscall changing routine. */
1604 void change_syscall(struct __test_metadata *_metadata,
1605                     pid_t tracee, int syscall)
1606 {
1607         int ret;
1608         ARCH_REGS regs;
1609 #ifdef HAVE_GETREGS
1610         ret = ptrace(PTRACE_GETREGS, tracee, 0, &regs);
1611 #else
1612         struct iovec iov;
1613         iov.iov_base = &regs;
1614         iov.iov_len = sizeof(regs);
1615         ret = ptrace(PTRACE_GETREGSET, tracee, NT_PRSTATUS, &iov);
1616 #endif
1617         EXPECT_EQ(0, ret) {}
1618 
1619 #if defined(__x86_64__) || defined(__i386__) || defined(__powerpc__) || \
1620     defined(__s390__) || defined(__hppa__)
1621         {
1622                 regs.SYSCALL_NUM = syscall;
1623         }
1624 #elif defined(__mips__)
1625         {
1626                 if (regs.SYSCALL_NUM == __NR_O32_Linux)
1627                         regs.SYSCALL_SYSCALL_NUM = syscall;
1628                 else
1629                         regs.SYSCALL_NUM = syscall;
1630         }
1631 
1632 #elif defined(__arm__)
1633 # ifndef PTRACE_SET_SYSCALL
1634 #  define PTRACE_SET_SYSCALL   23
1635 # endif
1636         {
1637                 ret = ptrace(PTRACE_SET_SYSCALL, tracee, NULL, syscall);
1638                 EXPECT_EQ(0, ret);
1639         }
1640 
1641 #elif defined(__aarch64__)
1642 # ifndef NT_ARM_SYSTEM_CALL
1643 #  define NT_ARM_SYSTEM_CALL 0x404
1644 # endif
1645         {
1646                 iov.iov_base = &syscall;
1647                 iov.iov_len = sizeof(syscall);
1648                 ret = ptrace(PTRACE_SETREGSET, tracee, NT_ARM_SYSTEM_CALL,
1649                              &iov);
1650                 EXPECT_EQ(0, ret);
1651         }
1652 
1653 #else
1654         ASSERT_EQ(1, 0) {
1655                 TH_LOG("How is the syscall changed on this architecture?");
1656         }
1657 #endif
1658 
1659         /* If syscall is skipped, change return value. */
1660         if (syscall == -1)
1661 #ifdef SYSCALL_NUM_RET_SHARE_REG
1662                 TH_LOG("Can't modify syscall return on this architecture");
1663 #else
1664                 regs.SYSCALL_RET = EPERM;
1665 #endif
1666 
1667 #ifdef HAVE_GETREGS
1668         ret = ptrace(PTRACE_SETREGS, tracee, 0, &regs);
1669 #else
1670         iov.iov_base = &regs;
1671         iov.iov_len = sizeof(regs);
1672         ret = ptrace(PTRACE_SETREGSET, tracee, NT_PRSTATUS, &iov);
1673 #endif
1674         EXPECT_EQ(0, ret);
1675 }
1676 
1677 void tracer_syscall(struct __test_metadata *_metadata, pid_t tracee,
1678                     int status, void *args)
1679 {
1680         int ret;
1681         unsigned long msg;
1682 
1683         /* Make sure we got the right message. */
1684         ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg);
1685         EXPECT_EQ(0, ret);
1686 
1687         /* Validate and take action on expected syscalls. */
1688         switch (msg) {
1689         case 0x1002:
1690                 /* change getpid to getppid. */
1691                 EXPECT_EQ(__NR_getpid, get_syscall(_metadata, tracee));
1692                 change_syscall(_metadata, tracee, __NR_getppid);
1693                 break;
1694         case 0x1003:
1695                 /* skip gettid. */
1696                 EXPECT_EQ(__NR_gettid, get_syscall(_metadata, tracee));
1697                 change_syscall(_metadata, tracee, -1);
1698                 break;
1699         case 0x1004:
1700                 /* do nothing (allow getppid) */
1701                 EXPECT_EQ(__NR_getppid, get_syscall(_metadata, tracee));
1702                 break;
1703         default:
1704                 EXPECT_EQ(0, msg) {
1705                         TH_LOG("Unknown PTRACE_GETEVENTMSG: 0x%lx", msg);
1706                         kill(tracee, SIGKILL);
1707                 }
1708         }
1709 
1710 }
1711 
1712 void tracer_ptrace(struct __test_metadata *_metadata, pid_t tracee,
1713                    int status, void *args)
1714 {
1715         int ret, nr;
1716         unsigned long msg;
1717         static bool entry;
1718 
1719         /* Make sure we got an empty message. */
1720         ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg);
1721         EXPECT_EQ(0, ret);
1722         EXPECT_EQ(0, msg);
1723 
1724         /* The only way to tell PTRACE_SYSCALL entry/exit is by counting. */
1725         entry = !entry;
1726         if (!entry)
1727                 return;
1728 
1729         nr = get_syscall(_metadata, tracee);
1730 
1731         if (nr == __NR_getpid)
1732                 change_syscall(_metadata, tracee, __NR_getppid);
1733         if (nr == __NR_openat)
1734                 change_syscall(_metadata, tracee, -1);
1735 }
1736 
1737 FIXTURE_DATA(TRACE_syscall) {
1738         struct sock_fprog prog;
1739         pid_t tracer, mytid, mypid, parent;
1740 };
1741 
1742 FIXTURE_SETUP(TRACE_syscall)
1743 {
1744         struct sock_filter filter[] = {
1745                 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1746                         offsetof(struct seccomp_data, nr)),
1747                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
1748                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1002),
1749                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_gettid, 0, 1),
1750                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1003),
1751                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
1752                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1004),
1753                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1754         };
1755 
1756         memset(&self->prog, 0, sizeof(self->prog));
1757         self->prog.filter = malloc(sizeof(filter));
1758         ASSERT_NE(NULL, self->prog.filter);
1759         memcpy(self->prog.filter, filter, sizeof(filter));
1760         self->prog.len = (unsigned short)ARRAY_SIZE(filter);
1761 
1762         /* Prepare some testable syscall results. */
1763         self->mytid = syscall(__NR_gettid);
1764         ASSERT_GT(self->mytid, 0);
1765         ASSERT_NE(self->mytid, 1) {
1766                 TH_LOG("Running this test as init is not supported. :)");
1767         }
1768 
1769         self->mypid = getpid();
1770         ASSERT_GT(self->mypid, 0);
1771         ASSERT_EQ(self->mytid, self->mypid);
1772 
1773         self->parent = getppid();
1774         ASSERT_GT(self->parent, 0);
1775         ASSERT_NE(self->parent, self->mypid);
1776 
1777         /* Launch tracer. */
1778         self->tracer = setup_trace_fixture(_metadata, tracer_syscall, NULL,
1779                                            false);
1780 }
1781 
1782 FIXTURE_TEARDOWN(TRACE_syscall)
1783 {
1784         teardown_trace_fixture(_metadata, self->tracer);
1785         if (self->prog.filter)
1786                 free(self->prog.filter);
1787 }
1788 
1789 TEST_F(TRACE_syscall, ptrace_syscall_redirected)
1790 {
1791         /* Swap SECCOMP_RET_TRACE tracer for PTRACE_SYSCALL tracer. */
1792         teardown_trace_fixture(_metadata, self->tracer);
1793         self->tracer = setup_trace_fixture(_metadata, tracer_ptrace, NULL,
1794                                            true);
1795 
1796         /* Tracer will redirect getpid to getppid. */
1797         EXPECT_NE(self->mypid, syscall(__NR_getpid));
1798 }
1799 
1800 TEST_F(TRACE_syscall, ptrace_syscall_dropped)
1801 {
1802         /* Swap SECCOMP_RET_TRACE tracer for PTRACE_SYSCALL tracer. */
1803         teardown_trace_fixture(_metadata, self->tracer);
1804         self->tracer = setup_trace_fixture(_metadata, tracer_ptrace, NULL,
1805                                            true);
1806 
1807         /* Tracer should skip the open syscall, resulting in EPERM. */
1808         EXPECT_SYSCALL_RETURN(EPERM, syscall(__NR_openat));
1809 }
1810 
1811 TEST_F(TRACE_syscall, syscall_allowed)
1812 {
1813         long ret;
1814 
1815         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1816         ASSERT_EQ(0, ret);
1817 
1818         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1819         ASSERT_EQ(0, ret);
1820 
1821         /* getppid works as expected (no changes). */
1822         EXPECT_EQ(self->parent, syscall(__NR_getppid));
1823         EXPECT_NE(self->mypid, syscall(__NR_getppid));
1824 }
1825 
1826 TEST_F(TRACE_syscall, syscall_redirected)
1827 {
1828         long ret;
1829 
1830         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1831         ASSERT_EQ(0, ret);
1832 
1833         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1834         ASSERT_EQ(0, ret);
1835 
1836         /* getpid has been redirected to getppid as expected. */
1837         EXPECT_EQ(self->parent, syscall(__NR_getpid));
1838         EXPECT_NE(self->mypid, syscall(__NR_getpid));
1839 }
1840 
1841 TEST_F(TRACE_syscall, syscall_dropped)
1842 {
1843         long ret;
1844 
1845         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1846         ASSERT_EQ(0, ret);
1847 
1848         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1849         ASSERT_EQ(0, ret);
1850 
1851         /* gettid has been skipped and an altered return value stored. */
1852         EXPECT_SYSCALL_RETURN(EPERM, syscall(__NR_gettid));
1853         EXPECT_NE(self->mytid, syscall(__NR_gettid));
1854 }
1855 
1856 TEST_F(TRACE_syscall, skip_after_RET_TRACE)
1857 {
1858         struct sock_filter filter[] = {
1859                 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1860                         offsetof(struct seccomp_data, nr)),
1861                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
1862                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EPERM),
1863                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1864         };
1865         struct sock_fprog prog = {
1866                 .len = (unsigned short)ARRAY_SIZE(filter),
1867                 .filter = filter,
1868         };
1869         long ret;
1870 
1871         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1872         ASSERT_EQ(0, ret);
1873 
1874         /* Install fixture filter. */
1875         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1876         ASSERT_EQ(0, ret);
1877 
1878         /* Install "errno on getppid" filter. */
1879         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
1880         ASSERT_EQ(0, ret);
1881 
1882         /* Tracer will redirect getpid to getppid, and we should see EPERM. */
1883         errno = 0;
1884         EXPECT_EQ(-1, syscall(__NR_getpid));
1885         EXPECT_EQ(EPERM, errno);
1886 }
1887 
1888 TEST_F_SIGNAL(TRACE_syscall, kill_after_RET_TRACE, SIGSYS)
1889 {
1890         struct sock_filter filter[] = {
1891                 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1892                         offsetof(struct seccomp_data, nr)),
1893                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
1894                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
1895                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1896         };
1897         struct sock_fprog prog = {
1898                 .len = (unsigned short)ARRAY_SIZE(filter),
1899                 .filter = filter,
1900         };
1901         long ret;
1902 
1903         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1904         ASSERT_EQ(0, ret);
1905 
1906         /* Install fixture filter. */
1907         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1908         ASSERT_EQ(0, ret);
1909 
1910         /* Install "death on getppid" filter. */
1911         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
1912         ASSERT_EQ(0, ret);
1913 
1914         /* Tracer will redirect getpid to getppid, and we should die. */
1915         EXPECT_NE(self->mypid, syscall(__NR_getpid));
1916 }
1917 
1918 TEST_F(TRACE_syscall, skip_after_ptrace)
1919 {
1920         struct sock_filter filter[] = {
1921                 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1922                         offsetof(struct seccomp_data, nr)),
1923                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
1924                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EPERM),
1925                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1926         };
1927         struct sock_fprog prog = {
1928                 .len = (unsigned short)ARRAY_SIZE(filter),
1929                 .filter = filter,
1930         };
1931         long ret;
1932 
1933         /* Swap SECCOMP_RET_TRACE tracer for PTRACE_SYSCALL tracer. */
1934         teardown_trace_fixture(_metadata, self->tracer);
1935         self->tracer = setup_trace_fixture(_metadata, tracer_ptrace, NULL,
1936                                            true);
1937 
1938         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1939         ASSERT_EQ(0, ret);
1940 
1941         /* Install "errno on getppid" filter. */
1942         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
1943         ASSERT_EQ(0, ret);
1944 
1945         /* Tracer will redirect getpid to getppid, and we should see EPERM. */
1946         EXPECT_EQ(-1, syscall(__NR_getpid));
1947         EXPECT_EQ(EPERM, errno);
1948 }
1949 
1950 TEST_F_SIGNAL(TRACE_syscall, kill_after_ptrace, SIGSYS)
1951 {
1952         struct sock_filter filter[] = {
1953                 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1954                         offsetof(struct seccomp_data, nr)),
1955                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
1956                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
1957                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1958         };
1959         struct sock_fprog prog = {
1960                 .len = (unsigned short)ARRAY_SIZE(filter),
1961                 .filter = filter,
1962         };
1963         long ret;
1964 
1965         /* Swap SECCOMP_RET_TRACE tracer for PTRACE_SYSCALL tracer. */
1966         teardown_trace_fixture(_metadata, self->tracer);
1967         self->tracer = setup_trace_fixture(_metadata, tracer_ptrace, NULL,
1968                                            true);
1969 
1970         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1971         ASSERT_EQ(0, ret);
1972 
1973         /* Install "death on getppid" filter. */
1974         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
1975         ASSERT_EQ(0, ret);
1976 
1977         /* Tracer will redirect getpid to getppid, and we should die. */
1978         EXPECT_NE(self->mypid, syscall(__NR_getpid));
1979 }
1980 
1981 TEST(seccomp_syscall)
1982 {
1983         struct sock_filter filter[] = {
1984                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1985         };
1986         struct sock_fprog prog = {
1987                 .len = (unsigned short)ARRAY_SIZE(filter),
1988                 .filter = filter,
1989         };
1990         long ret;
1991 
1992         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1993         ASSERT_EQ(0, ret) {
1994                 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
1995         }
1996 
1997         /* Reject insane operation. */
1998         ret = seccomp(-1, 0, &prog);
1999         ASSERT_NE(ENOSYS, errno) {
2000                 TH_LOG("Kernel does not support seccomp syscall!");
2001         }
2002         EXPECT_EQ(EINVAL, errno) {
2003                 TH_LOG("Did not reject crazy op value!");
2004         }
2005 
2006         /* Reject strict with flags or pointer. */
2007         ret = seccomp(SECCOMP_SET_MODE_STRICT, -1, NULL);
2008         EXPECT_EQ(EINVAL, errno) {
2009                 TH_LOG("Did not reject mode strict with flags!");
2010         }
2011         ret = seccomp(SECCOMP_SET_MODE_STRICT, 0, &prog);
2012         EXPECT_EQ(EINVAL, errno) {
2013                 TH_LOG("Did not reject mode strict with uargs!");
2014         }
2015 
2016         /* Reject insane args for filter. */
2017         ret = seccomp(SECCOMP_SET_MODE_FILTER, -1, &prog);
2018         EXPECT_EQ(EINVAL, errno) {
2019                 TH_LOG("Did not reject crazy filter flags!");
2020         }
2021         ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, NULL);
2022         EXPECT_EQ(EFAULT, errno) {
2023                 TH_LOG("Did not reject NULL filter!");
2024         }
2025 
2026         ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
2027         EXPECT_EQ(0, errno) {
2028                 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER: %s",
2029                         strerror(errno));
2030         }
2031 }
2032 
2033 TEST(seccomp_syscall_mode_lock)
2034 {
2035         struct sock_filter filter[] = {
2036                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2037         };
2038         struct sock_fprog prog = {
2039                 .len = (unsigned short)ARRAY_SIZE(filter),
2040                 .filter = filter,
2041         };
2042         long ret;
2043 
2044         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
2045         ASSERT_EQ(0, ret) {
2046                 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2047         }
2048 
2049         ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
2050         ASSERT_NE(ENOSYS, errno) {
2051                 TH_LOG("Kernel does not support seccomp syscall!");
2052         }
2053         EXPECT_EQ(0, ret) {
2054                 TH_LOG("Could not install filter!");
2055         }
2056 
2057         /* Make sure neither entry point will switch to strict. */
2058         ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, 0, 0, 0);
2059         EXPECT_EQ(EINVAL, errno) {
2060                 TH_LOG("Switched to mode strict!");
2061         }
2062 
2063         ret = seccomp(SECCOMP_SET_MODE_STRICT, 0, NULL);
2064         EXPECT_EQ(EINVAL, errno) {
2065                 TH_LOG("Switched to mode strict!");
2066         }
2067 }
2068 
2069 /*
2070  * Test detection of known and unknown filter flags. Userspace needs to be able
2071  * to check if a filter flag is supported by the current kernel and a good way
2072  * of doing that is by attempting to enter filter mode, with the flag bit in
2073  * question set, and a NULL pointer for the _args_ parameter. EFAULT indicates
2074  * that the flag is valid and EINVAL indicates that the flag is invalid.
2075  */
2076 TEST(detect_seccomp_filter_flags)
2077 {
2078         unsigned int flags[] = { SECCOMP_FILTER_FLAG_TSYNC,
2079                                  SECCOMP_FILTER_FLAG_LOG,
2080                                  SECCOMP_FILTER_FLAG_SPEC_ALLOW };
2081         unsigned int flag, all_flags;
2082         int i;
2083         long ret;
2084 
2085         /* Test detection of known-good filter flags */
2086         for (i = 0, all_flags = 0; i < ARRAY_SIZE(flags); i++) {
2087                 int bits = 0;
2088 
2089                 flag = flags[i];
2090                 /* Make sure the flag is a single bit! */
2091                 while (flag) {
2092                         if (flag & 0x1)
2093                                 bits ++;
2094                         flag >>= 1;
2095                 }
2096                 ASSERT_EQ(1, bits);
2097                 flag = flags[i];
2098 
2099                 ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL);
2100                 ASSERT_NE(ENOSYS, errno) {
2101                         TH_LOG("Kernel does not support seccomp syscall!");
2102                 }
2103                 EXPECT_EQ(-1, ret);
2104                 EXPECT_EQ(EFAULT, errno) {
2105                         TH_LOG("Failed to detect that a known-good filter flag (0x%X) is supported!",
2106                                flag);
2107                 }
2108 
2109                 all_flags |= flag;
2110         }
2111 
2112         /* Test detection of all known-good filter flags */
2113         ret = seccomp(SECCOMP_SET_MODE_FILTER, all_flags, NULL);
2114         EXPECT_EQ(-1, ret);
2115         EXPECT_EQ(EFAULT, errno) {
2116                 TH_LOG("Failed to detect that all known-good filter flags (0x%X) are supported!",
2117                        all_flags);
2118         }
2119 
2120         /* Test detection of an unknown filter flag */
2121         flag = -1;
2122         ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL);
2123         EXPECT_EQ(-1, ret);
2124         EXPECT_EQ(EINVAL, errno) {
2125                 TH_LOG("Failed to detect that an unknown filter flag (0x%X) is unsupported!",
2126                        flag);
2127         }
2128 
2129         /*
2130          * Test detection of an unknown filter flag that may simply need to be
2131          * added to this test
2132          */
2133         flag = flags[ARRAY_SIZE(flags) - 1] << 1;
2134         ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL);
2135         EXPECT_EQ(-1, ret);
2136         EXPECT_EQ(EINVAL, errno) {
2137                 TH_LOG("Failed to detect that an unknown filter flag (0x%X) is unsupported! Does a new flag need to be added to this test?",
2138                        flag);
2139         }
2140 }
2141 
2142 TEST(TSYNC_first)
2143 {
2144         struct sock_filter filter[] = {
2145                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2146         };
2147         struct sock_fprog prog = {
2148                 .len = (unsigned short)ARRAY_SIZE(filter),
2149                 .filter = filter,
2150         };
2151         long ret;
2152 
2153         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
2154         ASSERT_EQ(0, ret) {
2155                 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2156         }
2157 
2158         ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2159                       &prog);
2160         ASSERT_NE(ENOSYS, errno) {
2161                 TH_LOG("Kernel does not support seccomp syscall!");
2162         }
2163         EXPECT_EQ(0, ret) {
2164                 TH_LOG("Could not install initial filter with TSYNC!");
2165         }
2166 }
2167 
2168 #define TSYNC_SIBLINGS 2
2169 struct tsync_sibling {
2170         pthread_t tid;
2171         pid_t system_tid;
2172         sem_t *started;
2173         pthread_cond_t *cond;
2174         pthread_mutex_t *mutex;
2175         int diverge;
2176         int num_waits;
2177         struct sock_fprog *prog;
2178         struct __test_metadata *metadata;
2179 };
2180 
2181 /*
2182  * To avoid joining joined threads (which is not allowed by Bionic),
2183  * make sure we both successfully join and clear the tid to skip a
2184  * later join attempt during fixture teardown. Any remaining threads
2185  * will be directly killed during teardown.
2186  */
2187 #define PTHREAD_JOIN(tid, status)                                       \
2188         do {                                                            \
2189                 int _rc = pthread_join(tid, status);                    \
2190                 if (_rc) {                                              \
2191                         TH_LOG("pthread_join of tid %u failed: %d\n",   \
2192                                 (unsigned int)tid, _rc);                \
2193                 } else {                                                \
2194                         tid = 0;                                        \
2195                 }                                                       \
2196         } while (0)
2197 
2198 FIXTURE_DATA(TSYNC) {
2199         struct sock_fprog root_prog, apply_prog;
2200         struct tsync_sibling sibling[TSYNC_SIBLINGS];
2201         sem_t started;
2202         pthread_cond_t cond;
2203         pthread_mutex_t mutex;
2204         int sibling_count;
2205 };
2206 
2207 FIXTURE_SETUP(TSYNC)
2208 {
2209         struct sock_filter root_filter[] = {
2210                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2211         };
2212         struct sock_filter apply_filter[] = {
2213                 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2214                         offsetof(struct seccomp_data, nr)),
2215                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1),
2216                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
2217                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2218         };
2219 
2220         memset(&self->root_prog, 0, sizeof(self->root_prog));
2221         memset(&self->apply_prog, 0, sizeof(self->apply_prog));
2222         memset(&self->sibling, 0, sizeof(self->sibling));
2223         self->root_prog.filter = malloc(sizeof(root_filter));
2224         ASSERT_NE(NULL, self->root_prog.filter);
2225         memcpy(self->root_prog.filter, &root_filter, sizeof(root_filter));
2226         self->root_prog.len = (unsigned short)ARRAY_SIZE(root_filter);
2227 
2228         self->apply_prog.filter = malloc(sizeof(apply_filter));
2229         ASSERT_NE(NULL, self->apply_prog.filter);
2230         memcpy(self->apply_prog.filter, &apply_filter, sizeof(apply_filter));
2231         self->apply_prog.len = (unsigned short)ARRAY_SIZE(apply_filter);
2232 
2233         self->sibling_count = 0;
2234         pthread_mutex_init(&self->mutex, NULL);
2235         pthread_cond_init(&self->cond, NULL);
2236         sem_init(&self->started, 0, 0);
2237         self->sibling[0].tid = 0;
2238         self->sibling[0].cond = &self->cond;
2239         self->sibling[0].started = &self->started;
2240         self->sibling[0].mutex = &self->mutex;
2241         self->sibling[0].diverge = 0;
2242         self->sibling[0].num_waits = 1;
2243         self->sibling[0].prog = &self->root_prog;
2244         self->sibling[0].metadata = _metadata;
2245         self->sibling[1].tid = 0;
2246         self->sibling[1].cond = &self->cond;
2247         self->sibling[1].started = &self->started;
2248         self->sibling[1].mutex = &self->mutex;
2249         self->sibling[1].diverge = 0;
2250         self->sibling[1].prog = &self->root_prog;
2251         self->sibling[1].num_waits = 1;
2252         self->sibling[1].metadata = _metadata;
2253 }
2254 
2255 FIXTURE_TEARDOWN(TSYNC)
2256 {
2257         int sib = 0;
2258 
2259         if (self->root_prog.filter)
2260                 free(self->root_prog.filter);
2261         if (self->apply_prog.filter)
2262                 free(self->apply_prog.filter);
2263 
2264         for ( ; sib < self->sibling_count; ++sib) {
2265                 struct tsync_sibling *s = &self->sibling[sib];
2266 
2267                 if (!s->tid)
2268                         continue;
2269                 /*
2270                  * If a thread is still running, it may be stuck, so hit
2271                  * it over the head really hard.
2272                  */
2273                 pthread_kill(s->tid, 9);
2274         }
2275         pthread_mutex_destroy(&self->mutex);
2276         pthread_cond_destroy(&self->cond);
2277         sem_destroy(&self->started);
2278 }
2279 
2280 void *tsync_sibling(void *data)
2281 {
2282         long ret = 0;
2283         struct tsync_sibling *me = data;
2284 
2285         me->system_tid = syscall(__NR_gettid);
2286 
2287         pthread_mutex_lock(me->mutex);
2288         if (me->diverge) {
2289                 /* Just re-apply the root prog to fork the tree */
2290                 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER,
2291                                 me->prog, 0, 0);
2292         }
2293         sem_post(me->started);
2294         /* Return outside of started so parent notices failures. */
2295         if (ret) {
2296                 pthread_mutex_unlock(me->mutex);
2297                 return (void *)SIBLING_EXIT_FAILURE;
2298         }
2299         do {
2300                 pthread_cond_wait(me->cond, me->mutex);
2301                 me->num_waits = me->num_waits - 1;
2302         } while (me->num_waits);
2303         pthread_mutex_unlock(me->mutex);
2304 
2305         ret = prctl(PR_GET_NO_NEW_PRIVS, 0, 0, 0, 0);
2306         if (!ret)
2307                 return (void *)SIBLING_EXIT_NEWPRIVS;
2308         read(0, NULL, 0);
2309         return (void *)SIBLING_EXIT_UNKILLED;
2310 }
2311 
2312 void tsync_start_sibling(struct tsync_sibling *sibling)
2313 {
2314         pthread_create(&sibling->tid, NULL, tsync_sibling, (void *)sibling);
2315 }
2316 
2317 TEST_F(TSYNC, siblings_fail_prctl)
2318 {
2319         long ret;
2320         void *status;
2321         struct sock_filter filter[] = {
2322                 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2323                         offsetof(struct seccomp_data, nr)),
2324                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1),
2325                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EINVAL),
2326                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2327         };
2328         struct sock_fprog prog = {
2329                 .len = (unsigned short)ARRAY_SIZE(filter),
2330                 .filter = filter,
2331         };
2332 
2333         ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2334                 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2335         }
2336 
2337         /* Check prctl failure detection by requesting sib 0 diverge. */
2338         ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
2339         ASSERT_NE(ENOSYS, errno) {
2340                 TH_LOG("Kernel does not support seccomp syscall!");
2341         }
2342         ASSERT_EQ(0, ret) {
2343                 TH_LOG("setting filter failed");
2344         }
2345 
2346         self->sibling[0].diverge = 1;
2347         tsync_start_sibling(&self->sibling[0]);
2348         tsync_start_sibling(&self->sibling[1]);
2349 
2350         while (self->sibling_count < TSYNC_SIBLINGS) {
2351                 sem_wait(&self->started);
2352                 self->sibling_count++;
2353         }
2354 
2355         /* Signal the threads to clean up*/
2356         pthread_mutex_lock(&self->mutex);
2357         ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2358                 TH_LOG("cond broadcast non-zero");
2359         }
2360         pthread_mutex_unlock(&self->mutex);
2361 
2362         /* Ensure diverging sibling failed to call prctl. */
2363         PTHREAD_JOIN(self->sibling[0].tid, &status);
2364         EXPECT_EQ(SIBLING_EXIT_FAILURE, (long)status);
2365         PTHREAD_JOIN(self->sibling[1].tid, &status);
2366         EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2367 }
2368 
2369 TEST_F(TSYNC, two_siblings_with_ancestor)
2370 {
2371         long ret;
2372         void *status;
2373 
2374         ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2375                 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2376         }
2377 
2378         ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
2379         ASSERT_NE(ENOSYS, errno) {
2380                 TH_LOG("Kernel does not support seccomp syscall!");
2381         }
2382         ASSERT_EQ(0, ret) {
2383                 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
2384         }
2385         tsync_start_sibling(&self->sibling[0]);
2386         tsync_start_sibling(&self->sibling[1]);
2387 
2388         while (self->sibling_count < TSYNC_SIBLINGS) {
2389                 sem_wait(&self->started);
2390                 self->sibling_count++;
2391         }
2392 
2393         ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2394                       &self->apply_prog);
2395         ASSERT_EQ(0, ret) {
2396                 TH_LOG("Could install filter on all threads!");
2397         }
2398         /* Tell the siblings to test the policy */
2399         pthread_mutex_lock(&self->mutex);
2400         ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2401                 TH_LOG("cond broadcast non-zero");
2402         }
2403         pthread_mutex_unlock(&self->mutex);
2404         /* Ensure they are both killed and don't exit cleanly. */
2405         PTHREAD_JOIN(self->sibling[0].tid, &status);
2406         EXPECT_EQ(0x0, (long)status);
2407         PTHREAD_JOIN(self->sibling[1].tid, &status);
2408         EXPECT_EQ(0x0, (long)status);
2409 }
2410 
2411 TEST_F(TSYNC, two_sibling_want_nnp)
2412 {
2413         void *status;
2414 
2415         /* start siblings before any prctl() operations */
2416         tsync_start_sibling(&self->sibling[0]);
2417         tsync_start_sibling(&self->sibling[1]);
2418         while (self->sibling_count < TSYNC_SIBLINGS) {
2419                 sem_wait(&self->started);
2420                 self->sibling_count++;
2421         }
2422 
2423         /* Tell the siblings to test no policy */
2424         pthread_mutex_lock(&self->mutex);
2425         ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2426                 TH_LOG("cond broadcast non-zero");
2427         }
2428         pthread_mutex_unlock(&self->mutex);
2429 
2430         /* Ensure they are both upset about lacking nnp. */
2431         PTHREAD_JOIN(self->sibling[0].tid, &status);
2432         EXPECT_EQ(SIBLING_EXIT_NEWPRIVS, (long)status);
2433         PTHREAD_JOIN(self->sibling[1].tid, &status);
2434         EXPECT_EQ(SIBLING_EXIT_NEWPRIVS, (long)status);
2435 }
2436 
2437 TEST_F(TSYNC, two_siblings_with_no_filter)
2438 {
2439         long ret;
2440         void *status;
2441 
2442         /* start siblings before any prctl() operations */
2443         tsync_start_sibling(&self->sibling[0]);
2444         tsync_start_sibling(&self->sibling[1]);
2445         while (self->sibling_count < TSYNC_SIBLINGS) {
2446                 sem_wait(&self->started);
2447                 self->sibling_count++;
2448         }
2449 
2450         ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2451                 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2452         }
2453 
2454         ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2455                       &self->apply_prog);
2456         ASSERT_NE(ENOSYS, errno) {
2457                 TH_LOG("Kernel does not support seccomp syscall!");
2458         }
2459         ASSERT_EQ(0, ret) {
2460                 TH_LOG("Could install filter on all threads!");
2461         }
2462 
2463         /* Tell the siblings to test the policy */
2464         pthread_mutex_lock(&self->mutex);
2465         ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2466                 TH_LOG("cond broadcast non-zero");
2467         }
2468         pthread_mutex_unlock(&self->mutex);
2469 
2470         /* Ensure they are both killed and don't exit cleanly. */
2471         PTHREAD_JOIN(self->sibling[0].tid, &status);
2472         EXPECT_EQ(0x0, (long)status);
2473         PTHREAD_JOIN(self->sibling[1].tid, &status);
2474         EXPECT_EQ(0x0, (long)status);
2475 }
2476 
2477 TEST_F(TSYNC, two_siblings_with_one_divergence)
2478 {
2479         long ret;
2480         void *status;
2481 
2482         ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2483                 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2484         }
2485 
2486         ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
2487         ASSERT_NE(ENOSYS, errno) {
2488                 TH_LOG("Kernel does not support seccomp syscall!");
2489         }
2490         ASSERT_EQ(0, ret) {
2491                 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
2492         }
2493         self->sibling[0].diverge = 1;
2494         tsync_start_sibling(&self->sibling[0]);
2495         tsync_start_sibling(&self->sibling[1]);
2496 
2497         while (self->sibling_count < TSYNC_SIBLINGS) {
2498                 sem_wait(&self->started);
2499                 self->sibling_count++;
2500         }
2501 
2502         ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2503                       &self->apply_prog);
2504         ASSERT_EQ(self->sibling[0].system_tid, ret) {
2505                 TH_LOG("Did not fail on diverged sibling.");
2506         }
2507 
2508         /* Wake the threads */
2509         pthread_mutex_lock(&self->mutex);
2510         ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2511                 TH_LOG("cond broadcast non-zero");
2512         }
2513         pthread_mutex_unlock(&self->mutex);
2514 
2515         /* Ensure they are both unkilled. */
2516         PTHREAD_JOIN(self->sibling[0].tid, &status);
2517         EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2518         PTHREAD_JOIN(self->sibling[1].tid, &status);
2519         EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2520 }
2521 
2522 TEST_F(TSYNC, two_siblings_not_under_filter)
2523 {
2524         long ret, sib;
2525         void *status;
2526 
2527         ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2528                 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2529         }
2530 
2531         /*
2532          * Sibling 0 will have its own seccomp policy
2533          * and Sibling 1 will not be under seccomp at
2534          * all. Sibling 1 will enter seccomp and 0
2535          * will cause failure.
2536          */
2537         self->sibling[0].diverge = 1;
2538         tsync_start_sibling(&self->sibling[0]);
2539         tsync_start_sibling(&self->sibling[1]);
2540 
2541         while (self->sibling_count < TSYNC_SIBLINGS) {
2542                 sem_wait(&self->started);
2543                 self->sibling_count++;
2544         }
2545 
2546         ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
2547         ASSERT_NE(ENOSYS, errno) {
2548                 TH_LOG("Kernel does not support seccomp syscall!");
2549         }
2550         ASSERT_EQ(0, ret) {
2551                 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
2552         }
2553 
2554         ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2555                       &self->apply_prog);
2556         ASSERT_EQ(ret, self->sibling[0].system_tid) {
2557                 TH_LOG("Did not fail on diverged sibling.");
2558         }
2559         sib = 1;
2560         if (ret == self->sibling[0].system_tid)
2561                 sib = 0;
2562 
2563         pthread_mutex_lock(&self->mutex);
2564 
2565         /* Increment the other siblings num_waits so we can clean up
2566          * the one we just saw.
2567          */
2568         self->sibling[!sib].num_waits += 1;
2569 
2570         /* Signal the thread to clean up*/
2571         ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2572                 TH_LOG("cond broadcast non-zero");
2573         }
2574         pthread_mutex_unlock(&self->mutex);
2575         PTHREAD_JOIN(self->sibling[sib].tid, &status);
2576         EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2577         /* Poll for actual task death. pthread_join doesn't guarantee it. */
2578         while (!kill(self->sibling[sib].system_tid, 0))
2579                 sleep(0.1);
2580         /* Switch to the remaining sibling */
2581         sib = !sib;
2582 
2583         ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2584                       &self->apply_prog);
2585         ASSERT_EQ(0, ret) {
2586                 TH_LOG("Expected the remaining sibling to sync");
2587         };
2588 
2589         pthread_mutex_lock(&self->mutex);
2590 
2591         /* If remaining sibling didn't have a chance to wake up during
2592          * the first broadcast, manually reduce the num_waits now.
2593          */
2594         if (self->sibling[sib].num_waits > 1)
2595                 self->sibling[sib].num_waits = 1;
2596         ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2597                 TH_LOG("cond broadcast non-zero");
2598         }
2599         pthread_mutex_unlock(&self->mutex);
2600         PTHREAD_JOIN(self->sibling[sib].tid, &status);
2601         EXPECT_EQ(0, (long)status);
2602         /* Poll for actual task death. pthread_join doesn't guarantee it. */
2603         while (!kill(self->sibling[sib].system_tid, 0))
2604                 sleep(0.1);
2605 
2606         ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2607                       &self->apply_prog);
2608         ASSERT_EQ(0, ret);  /* just us chickens */
2609 }
2610 
2611 /* Make sure restarted syscalls are seen directly as "restart_syscall". */
2612 TEST(syscall_restart)
2613 {
2614         long ret;
2615         unsigned long msg;
2616         pid_t child_pid;
2617         int pipefd[2];
2618         int status;
2619         siginfo_t info = { };
2620         struct sock_filter filter[] = {
2621                 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2622                          offsetof(struct seccomp_data, nr)),
2623 
2624 #ifdef __NR_sigreturn
2625                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_sigreturn, 6, 0),
2626 #endif
2627                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 5, 0),
2628                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_exit, 4, 0),
2629                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_rt_sigreturn, 3, 0),
2630                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_nanosleep, 4, 0),
2631                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_restart_syscall, 4, 0),
2632 
2633                 /* Allow __NR_write for easy logging. */
2634                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_write, 0, 1),
2635                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2636                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
2637                 /* The nanosleep jump target. */
2638                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x100),
2639                 /* The restart_syscall jump target. */
2640                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x200),
2641         };
2642         struct sock_fprog prog = {
2643                 .len = (unsigned short)ARRAY_SIZE(filter),
2644                 .filter = filter,
2645         };
2646 #if defined(__arm__)
2647         struct utsname utsbuf;
2648 #endif
2649 
2650         ASSERT_EQ(0, pipe(pipefd));
2651 
2652         child_pid = fork();
2653         ASSERT_LE(0, child_pid);
2654         if (child_pid == 0) {
2655                 /* Child uses EXPECT not ASSERT to deliver status correctly. */
2656                 char buf = ' ';
2657                 struct timespec timeout = { };
2658 
2659                 /* Attach parent as tracer and stop. */
2660                 EXPECT_EQ(0, ptrace(PTRACE_TRACEME));
2661                 EXPECT_EQ(0, raise(SIGSTOP));
2662 
2663                 EXPECT_EQ(0, close(pipefd[1]));
2664 
2665                 EXPECT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2666                         TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2667                 }
2668 
2669                 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
2670                 EXPECT_EQ(0, ret) {
2671                         TH_LOG("Failed to install filter!");
2672                 }
2673 
2674                 EXPECT_EQ(1, read(pipefd[0], &buf, 1)) {
2675                         TH_LOG("Failed to read() sync from parent");
2676                 }
2677                 EXPECT_EQ('.', buf) {
2678                         TH_LOG("Failed to get sync data from read()");
2679                 }
2680 
2681                 /* Start nanosleep to be interrupted. */
2682                 timeout.tv_sec = 1;
2683                 errno = 0;
2684                 EXPECT_EQ(0, nanosleep(&timeout, NULL)) {
2685                         TH_LOG("Call to nanosleep() failed (errno %d)", errno);
2686                 }
2687 
2688                 /* Read final sync from parent. */
2689                 EXPECT_EQ(1, read(pipefd[0], &buf, 1)) {
2690                         TH_LOG("Failed final read() from parent");
2691                 }
2692                 EXPECT_EQ('!', buf) {
2693                         TH_LOG("Failed to get final data from read()");
2694                 }
2695 
2696                 /* Directly report the status of our test harness results. */
2697                 syscall(__NR_exit, _metadata->passed ? EXIT_SUCCESS
2698                                                      : EXIT_FAILURE);
2699         }
2700         EXPECT_EQ(0, close(pipefd[0]));
2701 
2702         /* Attach to child, setup options, and release. */
2703         ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2704         ASSERT_EQ(true, WIFSTOPPED(status));
2705         ASSERT_EQ(0, ptrace(PTRACE_SETOPTIONS, child_pid, NULL,
2706                             PTRACE_O_TRACESECCOMP));
2707         ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2708         ASSERT_EQ(1, write(pipefd[1], ".", 1));
2709 
2710         /* Wait for nanosleep() to start. */
2711         ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2712         ASSERT_EQ(true, WIFSTOPPED(status));
2713         ASSERT_EQ(SIGTRAP, WSTOPSIG(status));
2714         ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16));
2715         ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg));
2716         ASSERT_EQ(0x100, msg);
2717         EXPECT_EQ(__NR_nanosleep, get_syscall(_metadata, child_pid));
2718 
2719         /* Might as well check siginfo for sanity while we're here. */
2720         ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info));
2721         ASSERT_EQ(SIGTRAP, info.si_signo);
2722         ASSERT_EQ(SIGTRAP | (PTRACE_EVENT_SECCOMP << 8), info.si_code);
2723         EXPECT_EQ(0, info.si_errno);
2724         EXPECT_EQ(getuid(), info.si_uid);
2725         /* Verify signal delivery came from child (seccomp-triggered). */
2726         EXPECT_EQ(child_pid, info.si_pid);
2727 
2728         /* Interrupt nanosleep with SIGSTOP (which we'll need to handle). */
2729         ASSERT_EQ(0, kill(child_pid, SIGSTOP));
2730         ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2731         ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2732         ASSERT_EQ(true, WIFSTOPPED(status));
2733         ASSERT_EQ(SIGSTOP, WSTOPSIG(status));
2734         /* Verify signal delivery came from parent now. */
2735         ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info));
2736         EXPECT_EQ(getpid(), info.si_pid);
2737 
2738         /* Restart nanosleep with SIGCONT, which triggers restart_syscall. */
2739         ASSERT_EQ(0, kill(child_pid, SIGCONT));
2740         ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2741         ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2742         ASSERT_EQ(true, WIFSTOPPED(status));
2743         ASSERT_EQ(SIGCONT, WSTOPSIG(status));
2744         ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2745 
2746         /* Wait for restart_syscall() to start. */
2747         ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2748         ASSERT_EQ(true, WIFSTOPPED(status));
2749         ASSERT_EQ(SIGTRAP, WSTOPSIG(status));
2750         ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16));
2751         ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg));
2752 
2753         ASSERT_EQ(0x200, msg);
2754         ret = get_syscall(_metadata, child_pid);
2755 #if defined(__arm__)
2756         /*
2757          * FIXME:
2758          * - native ARM registers do NOT expose true syscall.
2759          * - compat ARM registers on ARM64 DO expose true syscall.
2760          */
2761         ASSERT_EQ(0, uname(&utsbuf));
2762         if (strncmp(utsbuf.machine, "arm", 3) == 0) {
2763                 EXPECT_EQ(__NR_nanosleep, ret);
2764         } else
2765 #endif
2766         {
2767                 EXPECT_EQ(__NR_restart_syscall, ret);
2768         }
2769 
2770         /* Write again to end test. */
2771         ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
2772         ASSERT_EQ(1, write(pipefd[1], "!", 1));
2773         EXPECT_EQ(0, close(pipefd[1]));
2774 
2775         ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
2776         if (WIFSIGNALED(status) || WEXITSTATUS(status))
2777                 _metadata->passed = 0;
2778 }
2779 
2780 TEST_SIGNAL(filter_flag_log, SIGSYS)
2781 {
2782         struct sock_filter allow_filter[] = {
2783                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2784         };
2785         struct sock_filter kill_filter[] = {
2786                 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2787                         offsetof(struct seccomp_data, nr)),
2788                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
2789                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
2790                 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2791         };
2792         struct sock_fprog allow_prog = {
2793                 .len = (unsigned short)ARRAY_SIZE(allow_filter),
2794                 .filter = allow_filter,
2795         };
2796         struct sock_fprog kill_prog = {
2797                 .len = (unsigned short)ARRAY_SIZE(kill_filter),
2798                 .filter = kill_filter,
2799         };
2800         long ret;
2801         pid_t parent = getppid();
2802 
2803         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
2804         ASSERT_EQ(0, ret);
2805 
2806         /* Verify that the FILTER_FLAG_LOG flag isn't accepted in strict mode */
2807         ret = seccomp(SECCOMP_SET_MODE_STRICT, SECCOMP_FILTER_FLAG_LOG,
2808                       &allow_prog);
2809         ASSERT_NE(ENOSYS, errno) {
2810                 TH_LOG("Kernel does not support seccomp syscall!");
2811         }
2812         EXPECT_NE(0, ret) {
2813                 TH_LOG("Kernel accepted FILTER_FLAG_LOG flag in strict mode!");
2814         }
2815         EXPECT_EQ(EINVAL, errno) {
2816                 TH_LOG("Kernel returned unexpected errno for FILTER_FLAG_LOG flag in strict mode!");
2817         }
2818 
2819         /* Verify that a simple, permissive filter can be added with no flags */
2820         ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &allow_prog);
2821         EXPECT_EQ(0, ret);
2822 
2823         /* See if the same filter can be added with the FILTER_FLAG_LOG flag */
2824         ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_LOG,
2825                       &allow_prog);
2826         ASSERT_NE(EINVAL, errno) {
2827                 TH_LOG("Kernel does not support the FILTER_FLAG_LOG flag!");
2828         }
2829         EXPECT_EQ(0, ret);
2830 
2831         /* Ensure that the kill filter works with the FILTER_FLAG_LOG flag */
2832         ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_LOG,
2833                       &kill_prog);
2834         EXPECT_EQ(0, ret);
2835 
2836         EXPECT_EQ(parent, syscall(__NR_getppid));
2837         /* getpid() should never return. */
2838         EXPECT_EQ(0, syscall(__NR_getpid));
2839 }
2840 
2841 TEST(get_action_avail)
2842 {
2843         __u32 actions[] = { SECCOMP_RET_KILL_THREAD, SECCOMP_RET_TRAP,
2844                             SECCOMP_RET_ERRNO, SECCOMP_RET_TRACE,
2845                             SECCOMP_RET_LOG,   SECCOMP_RET_ALLOW };
2846         __u32 unknown_action = 0x10000000U;
2847         int i;
2848         long ret;
2849 
2850         ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &actions[0]);
2851         ASSERT_NE(ENOSYS, errno) {
2852                 TH_LOG("Kernel does not support seccomp syscall!");
2853         }
2854         ASSERT_NE(EINVAL, errno) {
2855                 TH_LOG("Kernel does not support SECCOMP_GET_ACTION_AVAIL operation!");
2856         }
2857         EXPECT_EQ(ret, 0);
2858 
2859         for (i = 0; i < ARRAY_SIZE(actions); i++) {
2860                 ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &actions[i]);
2861                 EXPECT_EQ(ret, 0) {
2862                         TH_LOG("Expected action (0x%X) not available!",
2863                                actions[i]);
2864                 }
2865         }
2866 
2867         /* Check that an unknown action is handled properly (EOPNOTSUPP) */
2868         ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &unknown_action);
2869         EXPECT_EQ(ret, -1);
2870         EXPECT_EQ(errno, EOPNOTSUPP);
2871 }
2872 
2873 TEST(get_metadata)
2874 {
2875         pid_t pid;
2876         int pipefd[2];
2877         char buf;
2878         struct seccomp_metadata md;
2879         long ret;
2880 
2881         ASSERT_EQ(0, pipe(pipefd));
2882 
2883         pid = fork();
2884         ASSERT_GE(pid, 0);
2885         if (pid == 0) {
2886                 struct sock_filter filter[] = {
2887                         BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2888                 };
2889                 struct sock_fprog prog = {
2890                         .len = (unsigned short)ARRAY_SIZE(filter),
2891                         .filter = filter,
2892                 };
2893 
2894                 /* one with log, one without */
2895                 ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER,
2896                                      SECCOMP_FILTER_FLAG_LOG, &prog));
2897                 ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog));
2898 
2899                 ASSERT_EQ(0, close(pipefd[0]));
2900                 ASSERT_EQ(1, write(pipefd[1], "1", 1));
2901                 ASSERT_EQ(0, close(pipefd[1]));
2902 
2903                 while (1)
2904                         sleep(100);
2905         }
2906 
2907         ASSERT_EQ(0, close(pipefd[1]));
2908         ASSERT_EQ(1, read(pipefd[0], &buf, 1));
2909 
2910         ASSERT_EQ(0, ptrace(PTRACE_ATTACH, pid));
2911         ASSERT_EQ(pid, waitpid(pid, NULL, 0));
2912 
2913         /* Past here must not use ASSERT or child process is never killed. */
2914 
2915         md.filter_off = 0;
2916         errno = 0;
2917         ret = ptrace(PTRACE_SECCOMP_GET_METADATA, pid, sizeof(md), &md);
2918         EXPECT_EQ(sizeof(md), ret) {
2919                 if (errno == EINVAL)
2920                         XFAIL(goto skip, "Kernel does not support PTRACE_SECCOMP_GET_METADATA (missing CONFIG_CHECKPOINT_RESTORE?)");
2921         }
2922 
2923         EXPECT_EQ(md.flags, SECCOMP_FILTER_FLAG_LOG);
2924         EXPECT_EQ(md.filter_off, 0);
2925 
2926         md.filter_off = 1;
2927         ret = ptrace(PTRACE_SECCOMP_GET_METADATA, pid, sizeof(md), &md);
2928         EXPECT_EQ(sizeof(md), ret);
2929         EXPECT_EQ(md.flags, 0);
2930         EXPECT_EQ(md.filter_off, 1);
2931 
2932 skip:
2933         ASSERT_EQ(0, kill(pid, SIGKILL));
2934 }
2935 
2936 /*
2937  * TODO:
2938  * - add microbenchmarks
2939  * - expand NNP testing
2940  * - better arch-specific TRACE and TRAP handlers.
2941  * - endianness checking when appropriate
2942  * - 64-bit arg prodding
2943  * - arch value testing (x86 modes especially)
2944  * - verify that FILTER_FLAG_LOG filters generate log messages
2945  * - verify that RET_LOG generates log messages
2946  * - ...
2947  */
2948 
2949 TEST_HARNESS_MAIN
2950 

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