1 //===-- dfsan.cpp ---------------------------------------------------------===//
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //===----------------------------------------------------------------------===//
9 // This file is a part of DataFlowSanitizer.
11 // This file defines the custom functions listed in done_abilist.txt.
12 //===----------------------------------------------------------------------===//
14 #include "sanitizer_common/sanitizer_common.h"
15 #include "sanitizer_common/sanitizer_internal_defs.h"
16 #include "sanitizer_common/sanitizer_linux.h"
18 #include "dfsan/dfsan.h"
20 #include <arpa/inet.h>
35 #include <sys/resource.h>
36 #include <sys/select.h>
39 #include <sys/types.h>
43 using namespace __dfsan;
45 #define CALL_WEAK_INTERCEPTOR_HOOK(f, ...) \
50 #define DECLARE_WEAK_INTERCEPTOR_HOOK(f, ...) \
51 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE void f(__VA_ARGS__);
54 SANITIZER_INTERFACE_ATTRIBUTE int
55 __dfsw_stat(const char *path, struct stat *buf, dfsan_label path_label,
56 dfsan_label buf_label, dfsan_label *ret_label) {
57 int ret = stat(path, buf);
59 dfsan_set_label(0, buf, sizeof(struct stat));
64 SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_fstat(int fd, struct stat *buf,
66 dfsan_label buf_label,
67 dfsan_label *ret_label) {
68 int ret = fstat(fd, buf);
70 dfsan_set_label(0, buf, sizeof(struct stat));
75 SANITIZER_INTERFACE_ATTRIBUTE char *__dfsw_strchr(const char *s, int c,
78 dfsan_label *ret_label) {
79 for (size_t i = 0;; ++i) {
80 if (s[i] == c || s[i] == 0) {
81 if (flags().strict_data_dependencies) {
84 *ret_label = dfsan_union(dfsan_read_label(s, i + 1),
85 dfsan_union(s_label, c_label));
87 return s[i] == 0 ? nullptr : const_cast<char *>(s+i);
92 DECLARE_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_memcmp, uptr caller_pc,
93 const void *s1, const void *s2, size_t n,
94 dfsan_label s1_label, dfsan_label s2_label,
97 SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_memcmp(const void *s1, const void *s2,
98 size_t n, dfsan_label s1_label,
101 dfsan_label *ret_label) {
102 CALL_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_memcmp, GET_CALLER_PC(), s1, s2, n,
103 s1_label, s2_label, n_label);
104 const char *cs1 = (const char *) s1, *cs2 = (const char *) s2;
105 for (size_t i = 0; i != n; ++i) {
106 if (cs1[i] != cs2[i]) {
107 if (flags().strict_data_dependencies) {
110 *ret_label = dfsan_union(dfsan_read_label(cs1, i + 1),
111 dfsan_read_label(cs2, i + 1));
113 return cs1[i] - cs2[i];
117 if (flags().strict_data_dependencies) {
120 *ret_label = dfsan_union(dfsan_read_label(cs1, n),
121 dfsan_read_label(cs2, n));
126 DECLARE_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_strcmp, uptr caller_pc,
127 const char *s1, const char *s2,
128 dfsan_label s1_label, dfsan_label s2_label)
130 SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_strcmp(const char *s1, const char *s2,
131 dfsan_label s1_label,
132 dfsan_label s2_label,
133 dfsan_label *ret_label) {
134 CALL_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_strcmp, GET_CALLER_PC(), s1, s2,
136 for (size_t i = 0;; ++i) {
137 if (s1[i] != s2[i] || s1[i] == 0 || s2[i] == 0) {
138 if (flags().strict_data_dependencies) {
141 *ret_label = dfsan_union(dfsan_read_label(s1, i + 1),
142 dfsan_read_label(s2, i + 1));
144 return s1[i] - s2[i];
150 SANITIZER_INTERFACE_ATTRIBUTE int
151 __dfsw_strcasecmp(const char *s1, const char *s2, dfsan_label s1_label,
152 dfsan_label s2_label, dfsan_label *ret_label) {
153 for (size_t i = 0;; ++i) {
154 if (tolower(s1[i]) != tolower(s2[i]) || s1[i] == 0 || s2[i] == 0) {
155 if (flags().strict_data_dependencies) {
158 *ret_label = dfsan_union(dfsan_read_label(s1, i + 1),
159 dfsan_read_label(s2, i + 1));
161 return s1[i] - s2[i];
167 DECLARE_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_strncmp, uptr caller_pc,
168 const char *s1, const char *s2, size_t n,
169 dfsan_label s1_label, dfsan_label s2_label,
172 SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_strncmp(const char *s1, const char *s2,
173 size_t n, dfsan_label s1_label,
174 dfsan_label s2_label,
176 dfsan_label *ret_label) {
182 CALL_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_strncmp, GET_CALLER_PC(), s1, s2,
183 n, s1_label, s2_label, n_label);
185 for (size_t i = 0;; ++i) {
186 if (s1[i] != s2[i] || s1[i] == 0 || s2[i] == 0 || i == n - 1) {
187 if (flags().strict_data_dependencies) {
190 *ret_label = dfsan_union(dfsan_read_label(s1, i + 1),
191 dfsan_read_label(s2, i + 1));
193 return s1[i] - s2[i];
199 SANITIZER_INTERFACE_ATTRIBUTE int
200 __dfsw_strncasecmp(const char *s1, const char *s2, size_t n,
201 dfsan_label s1_label, dfsan_label s2_label,
202 dfsan_label n_label, dfsan_label *ret_label) {
208 for (size_t i = 0;; ++i) {
209 if (tolower(s1[i]) != tolower(s2[i]) || s1[i] == 0 || s2[i] == 0 ||
211 if (flags().strict_data_dependencies) {
214 *ret_label = dfsan_union(dfsan_read_label(s1, i + 1),
215 dfsan_read_label(s2, i + 1));
217 return s1[i] - s2[i];
223 SANITIZER_INTERFACE_ATTRIBUTE void *__dfsw_calloc(size_t nmemb, size_t size,
224 dfsan_label nmemb_label,
225 dfsan_label size_label,
226 dfsan_label *ret_label) {
227 void *p = calloc(nmemb, size);
228 dfsan_set_label(0, p, nmemb * size);
233 SANITIZER_INTERFACE_ATTRIBUTE size_t
234 __dfsw_strlen(const char *s, dfsan_label s_label, dfsan_label *ret_label) {
235 size_t ret = strlen(s);
236 if (flags().strict_data_dependencies) {
239 *ret_label = dfsan_read_label(s, ret + 1);
245 static void *dfsan_memcpy(void *dest, const void *src, size_t n) {
246 dfsan_label *sdest = shadow_for(dest);
247 const dfsan_label *ssrc = shadow_for(src);
248 internal_memcpy((void *)sdest, (const void *)ssrc, n * sizeof(dfsan_label));
249 return internal_memcpy(dest, src, n);
252 static void dfsan_memset(void *s, int c, dfsan_label c_label, size_t n) {
253 internal_memset(s, c, n);
254 dfsan_set_label(c_label, s, n);
257 SANITIZER_INTERFACE_ATTRIBUTE
258 void *__dfsw_memcpy(void *dest, const void *src, size_t n,
259 dfsan_label dest_label, dfsan_label src_label,
260 dfsan_label n_label, dfsan_label *ret_label) {
261 *ret_label = dest_label;
262 return dfsan_memcpy(dest, src, n);
265 SANITIZER_INTERFACE_ATTRIBUTE
266 void *__dfsw_memset(void *s, int c, size_t n,
267 dfsan_label s_label, dfsan_label c_label,
268 dfsan_label n_label, dfsan_label *ret_label) {
269 dfsan_memset(s, c, c_label, n);
270 *ret_label = s_label;
274 SANITIZER_INTERFACE_ATTRIBUTE char *
275 __dfsw_strdup(const char *s, dfsan_label s_label, dfsan_label *ret_label) {
276 size_t len = strlen(s);
277 void *p = malloc(len+1);
278 dfsan_memcpy(p, s, len+1);
280 return static_cast<char *>(p);
283 SANITIZER_INTERFACE_ATTRIBUTE char *
284 __dfsw_strncpy(char *s1, const char *s2, size_t n, dfsan_label s1_label,
285 dfsan_label s2_label, dfsan_label n_label,
286 dfsan_label *ret_label) {
287 size_t len = strlen(s2);
289 dfsan_memcpy(s1, s2, len+1);
290 dfsan_memset(s1+len+1, 0, 0, n-len-1);
292 dfsan_memcpy(s1, s2, n);
295 *ret_label = s1_label;
299 SANITIZER_INTERFACE_ATTRIBUTE ssize_t
300 __dfsw_pread(int fd, void *buf, size_t count, off_t offset,
301 dfsan_label fd_label, dfsan_label buf_label,
302 dfsan_label count_label, dfsan_label offset_label,
303 dfsan_label *ret_label) {
304 ssize_t ret = pread(fd, buf, count, offset);
306 dfsan_set_label(0, buf, ret);
311 SANITIZER_INTERFACE_ATTRIBUTE ssize_t
312 __dfsw_read(int fd, void *buf, size_t count,
313 dfsan_label fd_label, dfsan_label buf_label,
314 dfsan_label count_label,
315 dfsan_label *ret_label) {
316 ssize_t ret = read(fd, buf, count);
318 dfsan_set_label(0, buf, ret);
323 SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_clock_gettime(clockid_t clk_id,
325 dfsan_label clk_id_label,
326 dfsan_label tp_label,
327 dfsan_label *ret_label) {
328 int ret = clock_gettime(clk_id, tp);
330 dfsan_set_label(0, tp, sizeof(struct timespec));
335 static void unpoison(const void *ptr, uptr size) {
336 dfsan_set_label(0, const_cast<void *>(ptr), size);
339 // dlopen() ultimately calls mmap() down inside the loader, which generally
340 // doesn't participate in dynamic symbol resolution. Therefore we won't
341 // intercept its calls to mmap, and we have to hook it here.
342 SANITIZER_INTERFACE_ATTRIBUTE void *
343 __dfsw_dlopen(const char *filename, int flag, dfsan_label filename_label,
344 dfsan_label flag_label, dfsan_label *ret_label) {
345 void *handle = dlopen(filename, flag);
346 link_map *map = GET_LINK_MAP_BY_DLOPEN_HANDLE(handle);
348 ForEachMappedRegion(map, unpoison);
353 struct pthread_create_info {
354 void *(*start_routine_trampoline)(void *, void *, dfsan_label, dfsan_label *);
359 static void *pthread_create_cb(void *p) {
360 pthread_create_info pci(*(pthread_create_info *)p);
362 dfsan_label ret_label;
363 return pci.start_routine_trampoline(pci.start_routine, pci.arg, 0,
367 SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_pthread_create(
368 pthread_t *thread, const pthread_attr_t *attr,
369 void *(*start_routine_trampoline)(void *, void *, dfsan_label,
371 void *start_routine, void *arg, dfsan_label thread_label,
372 dfsan_label attr_label, dfsan_label start_routine_label,
373 dfsan_label arg_label, dfsan_label *ret_label) {
374 pthread_create_info *pci =
375 (pthread_create_info *)malloc(sizeof(pthread_create_info));
376 pci->start_routine_trampoline = start_routine_trampoline;
377 pci->start_routine = start_routine;
379 int rv = pthread_create(thread, attr, pthread_create_cb, (void *)pci);
386 struct dl_iterate_phdr_info {
387 int (*callback_trampoline)(void *callback, struct dl_phdr_info *info,
388 size_t size, void *data, dfsan_label info_label,
389 dfsan_label size_label, dfsan_label data_label,
390 dfsan_label *ret_label);
395 int dl_iterate_phdr_cb(struct dl_phdr_info *info, size_t size, void *data) {
396 dl_iterate_phdr_info *dipi = (dl_iterate_phdr_info *)data;
397 dfsan_set_label(0, *info);
398 dfsan_set_label(0, const_cast<char *>(info->dlpi_name),
399 strlen(info->dlpi_name) + 1);
401 0, const_cast<char *>(reinterpret_cast<const char *>(info->dlpi_phdr)),
402 sizeof(*info->dlpi_phdr) * info->dlpi_phnum);
403 dfsan_label ret_label;
404 return dipi->callback_trampoline(dipi->callback, info, size, dipi->data, 0, 0,
408 SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_dl_iterate_phdr(
409 int (*callback_trampoline)(void *callback, struct dl_phdr_info *info,
410 size_t size, void *data, dfsan_label info_label,
411 dfsan_label size_label, dfsan_label data_label,
412 dfsan_label *ret_label),
413 void *callback, void *data, dfsan_label callback_label,
414 dfsan_label data_label, dfsan_label *ret_label) {
415 dl_iterate_phdr_info dipi = { callback_trampoline, callback, data };
417 return dl_iterate_phdr(dl_iterate_phdr_cb, &dipi);
420 SANITIZER_INTERFACE_ATTRIBUTE
421 char *__dfsw_ctime_r(const time_t *timep, char *buf, dfsan_label timep_label,
422 dfsan_label buf_label, dfsan_label *ret_label) {
423 char *ret = ctime_r(timep, buf);
425 dfsan_set_label(dfsan_read_label(timep, sizeof(time_t)), buf,
427 *ret_label = buf_label;
434 SANITIZER_INTERFACE_ATTRIBUTE
435 char *__dfsw_fgets(char *s, int size, FILE *stream, dfsan_label s_label,
436 dfsan_label size_label, dfsan_label stream_label,
437 dfsan_label *ret_label) {
438 char *ret = fgets(s, size, stream);
440 dfsan_set_label(0, ret, strlen(ret) + 1);
441 *ret_label = s_label;
448 SANITIZER_INTERFACE_ATTRIBUTE
449 char *__dfsw_getcwd(char *buf, size_t size, dfsan_label buf_label,
450 dfsan_label size_label, dfsan_label *ret_label) {
451 char *ret = getcwd(buf, size);
453 dfsan_set_label(0, ret, strlen(ret) + 1);
454 *ret_label = buf_label;
461 SANITIZER_INTERFACE_ATTRIBUTE
462 char *__dfsw_get_current_dir_name(dfsan_label *ret_label) {
463 char *ret = get_current_dir_name();
465 dfsan_set_label(0, ret, strlen(ret) + 1);
471 SANITIZER_INTERFACE_ATTRIBUTE
472 int __dfsw_gethostname(char *name, size_t len, dfsan_label name_label,
473 dfsan_label len_label, dfsan_label *ret_label) {
474 int ret = gethostname(name, len);
476 dfsan_set_label(0, name, strlen(name) + 1);
482 SANITIZER_INTERFACE_ATTRIBUTE
483 int __dfsw_getrlimit(int resource, struct rlimit *rlim,
484 dfsan_label resource_label, dfsan_label rlim_label,
485 dfsan_label *ret_label) {
486 int ret = getrlimit(resource, rlim);
488 dfsan_set_label(0, rlim, sizeof(struct rlimit));
494 SANITIZER_INTERFACE_ATTRIBUTE
495 int __dfsw_getrusage(int who, struct rusage *usage, dfsan_label who_label,
496 dfsan_label usage_label, dfsan_label *ret_label) {
497 int ret = getrusage(who, usage);
499 dfsan_set_label(0, usage, sizeof(struct rusage));
505 SANITIZER_INTERFACE_ATTRIBUTE
506 char *__dfsw_strcpy(char *dest, const char *src, dfsan_label dst_label,
507 dfsan_label src_label, dfsan_label *ret_label) {
508 char *ret = strcpy(dest, src); // NOLINT
510 internal_memcpy(shadow_for(dest), shadow_for(src),
511 sizeof(dfsan_label) * (strlen(src) + 1));
513 *ret_label = dst_label;
517 SANITIZER_INTERFACE_ATTRIBUTE
518 long int __dfsw_strtol(const char *nptr, char **endptr, int base,
519 dfsan_label nptr_label, dfsan_label endptr_label,
520 dfsan_label base_label, dfsan_label *ret_label) {
522 long int ret = strtol(nptr, &tmp_endptr, base);
524 *endptr = tmp_endptr;
526 if (tmp_endptr > nptr) {
527 // If *tmp_endptr is '\0' include its label as well.
528 *ret_label = dfsan_union(
530 dfsan_read_label(nptr, tmp_endptr - nptr + (*tmp_endptr ? 0 : 1)));
537 SANITIZER_INTERFACE_ATTRIBUTE
538 double __dfsw_strtod(const char *nptr, char **endptr,
539 dfsan_label nptr_label, dfsan_label endptr_label,
540 dfsan_label *ret_label) {
542 double ret = strtod(nptr, &tmp_endptr);
544 *endptr = tmp_endptr;
546 if (tmp_endptr > nptr) {
547 // If *tmp_endptr is '\0' include its label as well.
548 *ret_label = dfsan_read_label(
550 tmp_endptr - nptr + (*tmp_endptr ? 0 : 1));
557 SANITIZER_INTERFACE_ATTRIBUTE
558 long long int __dfsw_strtoll(const char *nptr, char **endptr, int base,
559 dfsan_label nptr_label, dfsan_label endptr_label,
560 dfsan_label base_label, dfsan_label *ret_label) {
562 long long int ret = strtoll(nptr, &tmp_endptr, base);
564 *endptr = tmp_endptr;
566 if (tmp_endptr > nptr) {
567 // If *tmp_endptr is '\0' include its label as well.
568 *ret_label = dfsan_union(
570 dfsan_read_label(nptr, tmp_endptr - nptr + (*tmp_endptr ? 0 : 1)));
577 SANITIZER_INTERFACE_ATTRIBUTE
578 unsigned long int __dfsw_strtoul(const char *nptr, char **endptr, int base,
579 dfsan_label nptr_label, dfsan_label endptr_label,
580 dfsan_label base_label, dfsan_label *ret_label) {
582 unsigned long int ret = strtoul(nptr, &tmp_endptr, base);
584 *endptr = tmp_endptr;
586 if (tmp_endptr > nptr) {
587 // If *tmp_endptr is '\0' include its label as well.
588 *ret_label = dfsan_union(
590 dfsan_read_label(nptr, tmp_endptr - nptr + (*tmp_endptr ? 0 : 1)));
597 SANITIZER_INTERFACE_ATTRIBUTE
598 long long unsigned int __dfsw_strtoull(const char *nptr, char **endptr,
599 dfsan_label nptr_label,
600 int base, dfsan_label endptr_label,
601 dfsan_label base_label,
602 dfsan_label *ret_label) {
604 long long unsigned int ret = strtoull(nptr, &tmp_endptr, base);
606 *endptr = tmp_endptr;
608 if (tmp_endptr > nptr) {
609 // If *tmp_endptr is '\0' include its label as well.
610 *ret_label = dfsan_union(
612 dfsan_read_label(nptr, tmp_endptr - nptr + (*tmp_endptr ? 0 : 1)));
619 SANITIZER_INTERFACE_ATTRIBUTE
620 time_t __dfsw_time(time_t *t, dfsan_label t_label, dfsan_label *ret_label) {
621 time_t ret = time(t);
622 if (ret != (time_t) -1 && t) {
623 dfsan_set_label(0, t, sizeof(time_t));
629 SANITIZER_INTERFACE_ATTRIBUTE
630 int __dfsw_inet_pton(int af, const char *src, void *dst, dfsan_label af_label,
631 dfsan_label src_label, dfsan_label dst_label,
632 dfsan_label *ret_label) {
633 int ret = inet_pton(af, src, dst);
635 dfsan_set_label(dfsan_read_label(src, strlen(src) + 1), dst,
636 af == AF_INET ? sizeof(struct in_addr) : sizeof(in6_addr));
642 SANITIZER_INTERFACE_ATTRIBUTE
643 struct tm *__dfsw_localtime_r(const time_t *timep, struct tm *result,
644 dfsan_label timep_label, dfsan_label result_label,
645 dfsan_label *ret_label) {
646 struct tm *ret = localtime_r(timep, result);
648 dfsan_set_label(dfsan_read_label(timep, sizeof(time_t)), result,
650 *ret_label = result_label;
657 SANITIZER_INTERFACE_ATTRIBUTE
658 int __dfsw_getpwuid_r(id_t uid, struct passwd *pwd,
659 char *buf, size_t buflen, struct passwd **result,
660 dfsan_label uid_label, dfsan_label pwd_label,
661 dfsan_label buf_label, dfsan_label buflen_label,
662 dfsan_label result_label, dfsan_label *ret_label) {
663 // Store the data in pwd, the strings referenced from pwd in buf, and the
664 // address of pwd in *result. On failure, NULL is stored in *result.
665 int ret = getpwuid_r(uid, pwd, buf, buflen, result);
667 dfsan_set_label(0, pwd, sizeof(struct passwd));
668 dfsan_set_label(0, buf, strlen(buf) + 1);
671 dfsan_set_label(0, result, sizeof(struct passwd*));
675 SANITIZER_INTERFACE_ATTRIBUTE
676 int __dfsw_poll(struct pollfd *fds, nfds_t nfds, int timeout,
677 dfsan_label dfs_label, dfsan_label nfds_label,
678 dfsan_label timeout_label, dfsan_label *ret_label) {
679 int ret = poll(fds, nfds, timeout);
681 for (; nfds > 0; --nfds) {
682 dfsan_set_label(0, &fds[nfds - 1].revents, sizeof(fds[nfds - 1].revents));
689 SANITIZER_INTERFACE_ATTRIBUTE
690 int __dfsw_select(int nfds, fd_set *readfds, fd_set *writefds,
691 fd_set *exceptfds, struct timeval *timeout,
692 dfsan_label nfds_label, dfsan_label readfds_label,
693 dfsan_label writefds_label, dfsan_label exceptfds_label,
694 dfsan_label timeout_label, dfsan_label *ret_label) {
695 int ret = select(nfds, readfds, writefds, exceptfds, timeout);
696 // Clear everything (also on error) since their content is either set or
699 dfsan_set_label(0, readfds, sizeof(fd_set));
702 dfsan_set_label(0, writefds, sizeof(fd_set));
705 dfsan_set_label(0, exceptfds, sizeof(fd_set));
707 dfsan_set_label(0, timeout, sizeof(struct timeval));
712 SANITIZER_INTERFACE_ATTRIBUTE
713 int __dfsw_sched_getaffinity(pid_t pid, size_t cpusetsize, cpu_set_t *mask,
714 dfsan_label pid_label,
715 dfsan_label cpusetsize_label,
716 dfsan_label mask_label, dfsan_label *ret_label) {
717 int ret = sched_getaffinity(pid, cpusetsize, mask);
719 dfsan_set_label(0, mask, cpusetsize);
725 SANITIZER_INTERFACE_ATTRIBUTE
726 int __dfsw_sigemptyset(sigset_t *set, dfsan_label set_label,
727 dfsan_label *ret_label) {
728 int ret = sigemptyset(set);
729 dfsan_set_label(0, set, sizeof(sigset_t));
733 SANITIZER_INTERFACE_ATTRIBUTE
734 int __dfsw_sigaction(int signum, const struct sigaction *act,
735 struct sigaction *oldact, dfsan_label signum_label,
736 dfsan_label act_label, dfsan_label oldact_label,
737 dfsan_label *ret_label) {
738 int ret = sigaction(signum, act, oldact);
740 dfsan_set_label(0, oldact, sizeof(struct sigaction));
746 SANITIZER_INTERFACE_ATTRIBUTE
747 int __dfsw_gettimeofday(struct timeval *tv, struct timezone *tz,
748 dfsan_label tv_label, dfsan_label tz_label,
749 dfsan_label *ret_label) {
750 int ret = gettimeofday(tv, tz);
752 dfsan_set_label(0, tv, sizeof(struct timeval));
755 dfsan_set_label(0, tz, sizeof(struct timezone));
761 SANITIZER_INTERFACE_ATTRIBUTE void *__dfsw_memchr(void *s, int c, size_t n,
765 dfsan_label *ret_label) {
766 void *ret = memchr(s, c, n);
767 if (flags().strict_data_dependencies) {
768 *ret_label = ret ? s_label : 0;
771 ret ? reinterpret_cast<char *>(ret) - reinterpret_cast<char *>(s) + 1
774 dfsan_union(dfsan_read_label(s, len), dfsan_union(s_label, c_label));
779 SANITIZER_INTERFACE_ATTRIBUTE char *__dfsw_strrchr(char *s, int c,
782 dfsan_label *ret_label) {
783 char *ret = strrchr(s, c);
784 if (flags().strict_data_dependencies) {
785 *ret_label = ret ? s_label : 0;
788 dfsan_union(dfsan_read_label(s, strlen(s) + 1),
789 dfsan_union(s_label, c_label));
795 SANITIZER_INTERFACE_ATTRIBUTE char *__dfsw_strstr(char *haystack, char *needle,
796 dfsan_label haystack_label,
797 dfsan_label needle_label,
798 dfsan_label *ret_label) {
799 char *ret = strstr(haystack, needle);
800 if (flags().strict_data_dependencies) {
801 *ret_label = ret ? haystack_label : 0;
803 size_t len = ret ? ret + strlen(needle) - haystack : strlen(haystack) + 1;
805 dfsan_union(dfsan_read_label(haystack, len),
806 dfsan_union(dfsan_read_label(needle, strlen(needle) + 1),
807 dfsan_union(haystack_label, needle_label)));
813 SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_nanosleep(const struct timespec *req,
814 struct timespec *rem,
815 dfsan_label req_label,
816 dfsan_label rem_label,
817 dfsan_label *ret_label) {
818 int ret = nanosleep(req, rem);
821 // Interrupted by a signal, rem is filled with the remaining time.
822 dfsan_set_label(0, rem, sizeof(struct timespec));
827 SANITIZER_INTERFACE_ATTRIBUTE int
828 __dfsw_socketpair(int domain, int type, int protocol, int sv[2],
829 dfsan_label domain_label, dfsan_label type_label,
830 dfsan_label protocol_label, dfsan_label sv_label,
831 dfsan_label *ret_label) {
832 int ret = socketpair(domain, type, protocol, sv);
835 dfsan_set_label(0, sv, sizeof(*sv) * 2);
840 // Type of the trampoline function passed to the custom version of
841 // dfsan_set_write_callback.
842 typedef void (*write_trampoline_t)(
844 int fd, const void *buf, ssize_t count,
845 dfsan_label fd_label, dfsan_label buf_label, dfsan_label count_label);
847 // Calls to dfsan_set_write_callback() set the values in this struct.
848 // Calls to the custom version of write() read (and invoke) them.
850 write_trampoline_t write_callback_trampoline = nullptr;
851 void *write_callback = nullptr;
852 } write_callback_info;
854 SANITIZER_INTERFACE_ATTRIBUTE void
855 __dfsw_dfsan_set_write_callback(
856 write_trampoline_t write_callback_trampoline,
857 void *write_callback,
858 dfsan_label write_callback_label,
859 dfsan_label *ret_label) {
860 write_callback_info.write_callback_trampoline = write_callback_trampoline;
861 write_callback_info.write_callback = write_callback;
864 SANITIZER_INTERFACE_ATTRIBUTE int
865 __dfsw_write(int fd, const void *buf, size_t count,
866 dfsan_label fd_label, dfsan_label buf_label,
867 dfsan_label count_label, dfsan_label *ret_label) {
868 if (write_callback_info.write_callback) {
869 write_callback_info.write_callback_trampoline(
870 write_callback_info.write_callback,
872 fd_label, buf_label, count_label);
876 return write(fd, buf, count);
878 } // namespace __dfsan
880 // Type used to extract a dfsan_label with va_arg()
881 typedef int dfsan_label_va;
883 // Formats a chunk either a constant string or a single format directive (e.g.,
886 Formatter(char *str_, const char *fmt_, size_t size_)
887 : str(str_), str_off(0), size(size_), fmt_start(fmt_), fmt_cur(fmt_),
891 char *tmp_fmt = build_format_string();
893 snprintf(str + str_off, str_off < size ? size - str_off : 0, tmp_fmt,
894 0 /* used only to avoid warnings */);
899 template <typename T> int format(T arg) {
900 char *tmp_fmt = build_format_string();
903 retval = snprintf(str + str_off, str_off < size ? size - str_off : 0,
904 tmp_fmt, width, arg);
906 retval = snprintf(str + str_off, str_off < size ? size - str_off : 0,
913 char *build_format_string() {
914 size_t fmt_size = fmt_cur - fmt_start + 1;
915 char *new_fmt = (char *)malloc(fmt_size + 1);
917 internal_memcpy(new_fmt, fmt_start, fmt_size);
918 new_fmt[fmt_size] = '\0';
922 char *str_cur() { return str + str_off; }
924 size_t num_written_bytes(int retval) {
929 size_t num_avail = str_off < size ? size - str_off : 0;
930 if (num_avail == 0) {
934 size_t num_written = retval;
935 // A return value of {v,}snprintf of size or more means that the output was
937 if (num_written >= num_avail) {
938 num_written -= num_avail;
947 const char *fmt_start;
952 // Formats the input and propagates the input labels to the output. The output
953 // is stored in 'str'. 'size' bounds the number of output bytes. 'format' and
954 // 'ap' are the format string and the list of arguments for formatting. Returns
955 // the return value vsnprintf would return.
957 // The function tokenizes the format string in chunks representing either a
958 // constant string or a single format directive (e.g., '%.3f') and formats each
959 // chunk independently into the output string. This approach allows to figure
960 // out which bytes of the output string depends on which argument and thus to
961 // propagate labels more precisely.
963 // WARNING: This implementation does not support conversion specifiers with
964 // positional arguments.
965 static int format_buffer(char *str, size_t size, const char *fmt,
966 dfsan_label *va_labels, dfsan_label *ret_label,
968 Formatter formatter(str, fmt, size);
970 while (*formatter.fmt_cur) {
971 formatter.fmt_start = formatter.fmt_cur;
972 formatter.width = -1;
975 if (*formatter.fmt_cur != '%') {
976 // Ordinary character. Consume all the characters until a '%' or the end
978 for (; *(formatter.fmt_cur + 1) && *(formatter.fmt_cur + 1) != '%';
979 ++formatter.fmt_cur) {}
980 retval = formatter.format();
981 dfsan_set_label(0, formatter.str_cur(),
982 formatter.num_written_bytes(retval));
984 // Conversion directive. Consume all the characters until a conversion
985 // specifier or the end of the string.
986 bool end_fmt = false;
987 for (; *formatter.fmt_cur && !end_fmt; ) {
988 switch (*++formatter.fmt_cur) {
995 switch (*(formatter.fmt_cur - 1)) {
997 // Also covers the 'hh' case (since the size of the arg is still
999 retval = formatter.format(va_arg(ap, int));
1002 if (formatter.fmt_cur - formatter.fmt_start >= 2 &&
1003 *(formatter.fmt_cur - 2) == 'l') {
1004 retval = formatter.format(va_arg(ap, long long int));
1006 retval = formatter.format(va_arg(ap, long int));
1010 retval = formatter.format(va_arg(ap, long long int));
1013 retval = formatter.format(va_arg(ap, intmax_t));
1017 retval = formatter.format(va_arg(ap, size_t));
1020 retval = formatter.format(va_arg(ap, int));
1022 dfsan_set_label(*va_labels++, formatter.str_cur(),
1023 formatter.num_written_bytes(retval));
1035 if (*(formatter.fmt_cur - 1) == 'L') {
1036 retval = formatter.format(va_arg(ap, long double));
1038 retval = formatter.format(va_arg(ap, double));
1040 dfsan_set_label(*va_labels++, formatter.str_cur(),
1041 formatter.num_written_bytes(retval));
1046 retval = formatter.format(va_arg(ap, int));
1047 dfsan_set_label(*va_labels++, formatter.str_cur(),
1048 formatter.num_written_bytes(retval));
1053 char *arg = va_arg(ap, char *);
1054 retval = formatter.format(arg);
1056 internal_memcpy(shadow_for(formatter.str_cur()), shadow_for(arg),
1057 sizeof(dfsan_label) *
1058 formatter.num_written_bytes(retval));
1064 retval = formatter.format(va_arg(ap, void *));
1065 dfsan_set_label(*va_labels++, formatter.str_cur(),
1066 formatter.num_written_bytes(retval));
1071 int *ptr = va_arg(ap, int *);
1072 *ptr = (int)formatter.str_off;
1074 dfsan_set_label(0, ptr, sizeof(ptr));
1080 retval = formatter.format();
1081 dfsan_set_label(0, formatter.str_cur(),
1082 formatter.num_written_bytes(retval));
1087 formatter.width = va_arg(ap, int);
1101 formatter.fmt_cur++;
1102 formatter.str_off += retval;
1107 // Number of bytes written in total.
1108 return formatter.str_off;
1112 SANITIZER_INTERFACE_ATTRIBUTE
1113 int __dfsw_sprintf(char *str, const char *format, dfsan_label str_label,
1114 dfsan_label format_label, dfsan_label *va_labels,
1115 dfsan_label *ret_label, ...) {
1117 va_start(ap, ret_label);
1118 int ret = format_buffer(str, ~0ul, format, va_labels, ret_label, ap);
1123 SANITIZER_INTERFACE_ATTRIBUTE
1124 int __dfsw_snprintf(char *str, size_t size, const char *format,
1125 dfsan_label str_label, dfsan_label size_label,
1126 dfsan_label format_label, dfsan_label *va_labels,
1127 dfsan_label *ret_label, ...) {
1129 va_start(ap, ret_label);
1130 int ret = format_buffer(str, size, format, va_labels, ret_label, ap);
1135 // Default empty implementations (weak). Users should redefine them.
1136 SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_pc_guard, u32 *) {}
1137 SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_pc_guard_init, u32 *,
1139 SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_pcs_init, void) {}
1140 SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_pc_indir, void) {}
1142 SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_cmp, void) {}
1143 SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_cmp1, void) {}
1144 SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_cmp2, void) {}
1145 SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_cmp4, void) {}
1146 SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_cmp8, void) {}
1147 SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_const_cmp1,
1149 SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_const_cmp2,
1151 SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_const_cmp4,
1153 SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_const_cmp8,
1155 SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_switch, void) {}