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));
88 // If s[i] is the \0 at the end of the string, and \0 is not the
89 // character we are searching for, then return null.
90 if (s[i] == 0 && c != 0) {
93 return const_cast<char *>(s + i);
98 DECLARE_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_memcmp, uptr caller_pc,
99 const void *s1, const void *s2, size_t n,
100 dfsan_label s1_label, dfsan_label s2_label,
103 SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_memcmp(const void *s1, const void *s2,
104 size_t n, dfsan_label s1_label,
105 dfsan_label s2_label,
107 dfsan_label *ret_label) {
108 CALL_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_memcmp, GET_CALLER_PC(), s1, s2, n,
109 s1_label, s2_label, n_label);
110 const char *cs1 = (const char *) s1, *cs2 = (const char *) s2;
111 for (size_t i = 0; i != n; ++i) {
112 if (cs1[i] != cs2[i]) {
113 if (flags().strict_data_dependencies) {
116 *ret_label = dfsan_union(dfsan_read_label(cs1, i + 1),
117 dfsan_read_label(cs2, i + 1));
119 return cs1[i] - cs2[i];
123 if (flags().strict_data_dependencies) {
126 *ret_label = dfsan_union(dfsan_read_label(cs1, n),
127 dfsan_read_label(cs2, n));
132 DECLARE_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_strcmp, uptr caller_pc,
133 const char *s1, const char *s2,
134 dfsan_label s1_label, dfsan_label s2_label)
136 SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_strcmp(const char *s1, const char *s2,
137 dfsan_label s1_label,
138 dfsan_label s2_label,
139 dfsan_label *ret_label) {
140 CALL_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_strcmp, GET_CALLER_PC(), s1, s2,
142 for (size_t i = 0;; ++i) {
143 if (s1[i] != s2[i] || s1[i] == 0 || s2[i] == 0) {
144 if (flags().strict_data_dependencies) {
147 *ret_label = dfsan_union(dfsan_read_label(s1, i + 1),
148 dfsan_read_label(s2, i + 1));
150 return s1[i] - s2[i];
156 SANITIZER_INTERFACE_ATTRIBUTE int
157 __dfsw_strcasecmp(const char *s1, const char *s2, dfsan_label s1_label,
158 dfsan_label s2_label, dfsan_label *ret_label) {
159 for (size_t i = 0;; ++i) {
160 char s1_lower = tolower(s1[i]);
161 char s2_lower = tolower(s2[i]);
163 if (s1_lower != s2_lower || s1[i] == 0 || s2[i] == 0) {
164 if (flags().strict_data_dependencies) {
167 *ret_label = dfsan_union(dfsan_read_label(s1, i + 1),
168 dfsan_read_label(s2, i + 1));
170 return s1_lower - s2_lower;
176 DECLARE_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_strncmp, uptr caller_pc,
177 const char *s1, const char *s2, size_t n,
178 dfsan_label s1_label, dfsan_label s2_label,
181 SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_strncmp(const char *s1, const char *s2,
182 size_t n, dfsan_label s1_label,
183 dfsan_label s2_label,
185 dfsan_label *ret_label) {
191 CALL_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_strncmp, GET_CALLER_PC(), s1, s2,
192 n, s1_label, s2_label, n_label);
194 for (size_t i = 0;; ++i) {
195 if (s1[i] != s2[i] || s1[i] == 0 || s2[i] == 0 || i == n - 1) {
196 if (flags().strict_data_dependencies) {
199 *ret_label = dfsan_union(dfsan_read_label(s1, i + 1),
200 dfsan_read_label(s2, i + 1));
202 return s1[i] - s2[i];
208 SANITIZER_INTERFACE_ATTRIBUTE int
209 __dfsw_strncasecmp(const char *s1, const char *s2, size_t n,
210 dfsan_label s1_label, dfsan_label s2_label,
211 dfsan_label n_label, dfsan_label *ret_label) {
217 for (size_t i = 0;; ++i) {
218 char s1_lower = tolower(s1[i]);
219 char s2_lower = tolower(s2[i]);
221 if (s1_lower != s2_lower || s1[i] == 0 || s2[i] == 0 || i == n - 1) {
222 if (flags().strict_data_dependencies) {
225 *ret_label = dfsan_union(dfsan_read_label(s1, i + 1),
226 dfsan_read_label(s2, i + 1));
228 return s1_lower - s2_lower;
234 SANITIZER_INTERFACE_ATTRIBUTE void *__dfsw_calloc(size_t nmemb, size_t size,
235 dfsan_label nmemb_label,
236 dfsan_label size_label,
237 dfsan_label *ret_label) {
238 void *p = calloc(nmemb, size);
239 dfsan_set_label(0, p, nmemb * size);
244 SANITIZER_INTERFACE_ATTRIBUTE size_t
245 __dfsw_strlen(const char *s, dfsan_label s_label, dfsan_label *ret_label) {
246 size_t ret = strlen(s);
247 if (flags().strict_data_dependencies) {
250 *ret_label = dfsan_read_label(s, ret + 1);
256 static void *dfsan_memcpy(void *dest, const void *src, size_t n) {
257 dfsan_label *sdest = shadow_for(dest);
258 const dfsan_label *ssrc = shadow_for(src);
259 internal_memcpy((void *)sdest, (const void *)ssrc, n * sizeof(dfsan_label));
260 return internal_memcpy(dest, src, n);
263 static void dfsan_memset(void *s, int c, dfsan_label c_label, size_t n) {
264 internal_memset(s, c, n);
265 dfsan_set_label(c_label, s, n);
268 SANITIZER_INTERFACE_ATTRIBUTE
269 void *__dfsw_memcpy(void *dest, const void *src, size_t n,
270 dfsan_label dest_label, dfsan_label src_label,
271 dfsan_label n_label, dfsan_label *ret_label) {
272 *ret_label = dest_label;
273 return dfsan_memcpy(dest, src, n);
276 SANITIZER_INTERFACE_ATTRIBUTE
277 void *__dfsw_memset(void *s, int c, size_t n,
278 dfsan_label s_label, dfsan_label c_label,
279 dfsan_label n_label, dfsan_label *ret_label) {
280 dfsan_memset(s, c, c_label, n);
281 *ret_label = s_label;
285 SANITIZER_INTERFACE_ATTRIBUTE char *
286 __dfsw_strdup(const char *s, dfsan_label s_label, dfsan_label *ret_label) {
287 size_t len = strlen(s);
288 void *p = malloc(len+1);
289 dfsan_memcpy(p, s, len+1);
291 return static_cast<char *>(p);
294 SANITIZER_INTERFACE_ATTRIBUTE char *
295 __dfsw_strncpy(char *s1, const char *s2, size_t n, dfsan_label s1_label,
296 dfsan_label s2_label, dfsan_label n_label,
297 dfsan_label *ret_label) {
298 size_t len = strlen(s2);
300 dfsan_memcpy(s1, s2, len+1);
301 dfsan_memset(s1+len+1, 0, 0, n-len-1);
303 dfsan_memcpy(s1, s2, n);
306 *ret_label = s1_label;
310 SANITIZER_INTERFACE_ATTRIBUTE ssize_t
311 __dfsw_pread(int fd, void *buf, size_t count, off_t offset,
312 dfsan_label fd_label, dfsan_label buf_label,
313 dfsan_label count_label, dfsan_label offset_label,
314 dfsan_label *ret_label) {
315 ssize_t ret = pread(fd, buf, count, offset);
317 dfsan_set_label(0, buf, ret);
322 SANITIZER_INTERFACE_ATTRIBUTE ssize_t
323 __dfsw_read(int fd, void *buf, size_t count,
324 dfsan_label fd_label, dfsan_label buf_label,
325 dfsan_label count_label,
326 dfsan_label *ret_label) {
327 ssize_t ret = read(fd, buf, count);
329 dfsan_set_label(0, buf, ret);
334 SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_clock_gettime(clockid_t clk_id,
336 dfsan_label clk_id_label,
337 dfsan_label tp_label,
338 dfsan_label *ret_label) {
339 int ret = clock_gettime(clk_id, tp);
341 dfsan_set_label(0, tp, sizeof(struct timespec));
346 static void unpoison(const void *ptr, uptr size) {
347 dfsan_set_label(0, const_cast<void *>(ptr), size);
350 // dlopen() ultimately calls mmap() down inside the loader, which generally
351 // doesn't participate in dynamic symbol resolution. Therefore we won't
352 // intercept its calls to mmap, and we have to hook it here.
353 SANITIZER_INTERFACE_ATTRIBUTE void *
354 __dfsw_dlopen(const char *filename, int flag, dfsan_label filename_label,
355 dfsan_label flag_label, dfsan_label *ret_label) {
356 void *handle = dlopen(filename, flag);
357 link_map *map = GET_LINK_MAP_BY_DLOPEN_HANDLE(handle);
359 ForEachMappedRegion(map, unpoison);
364 struct pthread_create_info {
365 void *(*start_routine_trampoline)(void *, void *, dfsan_label, dfsan_label *);
370 static void *pthread_create_cb(void *p) {
371 pthread_create_info pci(*(pthread_create_info *)p);
373 dfsan_label ret_label;
374 return pci.start_routine_trampoline(pci.start_routine, pci.arg, 0,
378 SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_pthread_create(
379 pthread_t *thread, const pthread_attr_t *attr,
380 void *(*start_routine_trampoline)(void *, void *, dfsan_label,
382 void *start_routine, void *arg, dfsan_label thread_label,
383 dfsan_label attr_label, dfsan_label start_routine_label,
384 dfsan_label arg_label, dfsan_label *ret_label) {
385 pthread_create_info *pci =
386 (pthread_create_info *)malloc(sizeof(pthread_create_info));
387 pci->start_routine_trampoline = start_routine_trampoline;
388 pci->start_routine = start_routine;
390 int rv = pthread_create(thread, attr, pthread_create_cb, (void *)pci);
397 struct dl_iterate_phdr_info {
398 int (*callback_trampoline)(void *callback, struct dl_phdr_info *info,
399 size_t size, void *data, dfsan_label info_label,
400 dfsan_label size_label, dfsan_label data_label,
401 dfsan_label *ret_label);
406 int dl_iterate_phdr_cb(struct dl_phdr_info *info, size_t size, void *data) {
407 dl_iterate_phdr_info *dipi = (dl_iterate_phdr_info *)data;
408 dfsan_set_label(0, *info);
409 dfsan_set_label(0, const_cast<char *>(info->dlpi_name),
410 strlen(info->dlpi_name) + 1);
412 0, const_cast<char *>(reinterpret_cast<const char *>(info->dlpi_phdr)),
413 sizeof(*info->dlpi_phdr) * info->dlpi_phnum);
414 dfsan_label ret_label;
415 return dipi->callback_trampoline(dipi->callback, info, size, dipi->data, 0, 0,
419 SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_dl_iterate_phdr(
420 int (*callback_trampoline)(void *callback, struct dl_phdr_info *info,
421 size_t size, void *data, dfsan_label info_label,
422 dfsan_label size_label, dfsan_label data_label,
423 dfsan_label *ret_label),
424 void *callback, void *data, dfsan_label callback_label,
425 dfsan_label data_label, dfsan_label *ret_label) {
426 dl_iterate_phdr_info dipi = { callback_trampoline, callback, data };
428 return dl_iterate_phdr(dl_iterate_phdr_cb, &dipi);
431 SANITIZER_INTERFACE_ATTRIBUTE
432 char *__dfsw_ctime_r(const time_t *timep, char *buf, dfsan_label timep_label,
433 dfsan_label buf_label, dfsan_label *ret_label) {
434 char *ret = ctime_r(timep, buf);
436 dfsan_set_label(dfsan_read_label(timep, sizeof(time_t)), buf,
438 *ret_label = buf_label;
445 SANITIZER_INTERFACE_ATTRIBUTE
446 char *__dfsw_fgets(char *s, int size, FILE *stream, dfsan_label s_label,
447 dfsan_label size_label, dfsan_label stream_label,
448 dfsan_label *ret_label) {
449 char *ret = fgets(s, size, stream);
451 dfsan_set_label(0, ret, strlen(ret) + 1);
452 *ret_label = s_label;
459 SANITIZER_INTERFACE_ATTRIBUTE
460 char *__dfsw_getcwd(char *buf, size_t size, dfsan_label buf_label,
461 dfsan_label size_label, dfsan_label *ret_label) {
462 char *ret = getcwd(buf, size);
464 dfsan_set_label(0, ret, strlen(ret) + 1);
465 *ret_label = buf_label;
472 SANITIZER_INTERFACE_ATTRIBUTE
473 char *__dfsw_get_current_dir_name(dfsan_label *ret_label) {
474 char *ret = get_current_dir_name();
476 dfsan_set_label(0, ret, strlen(ret) + 1);
482 SANITIZER_INTERFACE_ATTRIBUTE
483 int __dfsw_gethostname(char *name, size_t len, dfsan_label name_label,
484 dfsan_label len_label, dfsan_label *ret_label) {
485 int ret = gethostname(name, len);
487 dfsan_set_label(0, name, strlen(name) + 1);
493 SANITIZER_INTERFACE_ATTRIBUTE
494 int __dfsw_getrlimit(int resource, struct rlimit *rlim,
495 dfsan_label resource_label, dfsan_label rlim_label,
496 dfsan_label *ret_label) {
497 int ret = getrlimit(resource, rlim);
499 dfsan_set_label(0, rlim, sizeof(struct rlimit));
505 SANITIZER_INTERFACE_ATTRIBUTE
506 int __dfsw_getrusage(int who, struct rusage *usage, dfsan_label who_label,
507 dfsan_label usage_label, dfsan_label *ret_label) {
508 int ret = getrusage(who, usage);
510 dfsan_set_label(0, usage, sizeof(struct rusage));
516 SANITIZER_INTERFACE_ATTRIBUTE
517 char *__dfsw_strcpy(char *dest, const char *src, dfsan_label dst_label,
518 dfsan_label src_label, dfsan_label *ret_label) {
519 char *ret = strcpy(dest, src); // NOLINT
521 internal_memcpy(shadow_for(dest), shadow_for(src),
522 sizeof(dfsan_label) * (strlen(src) + 1));
524 *ret_label = dst_label;
528 SANITIZER_INTERFACE_ATTRIBUTE
529 long int __dfsw_strtol(const char *nptr, char **endptr, int base,
530 dfsan_label nptr_label, dfsan_label endptr_label,
531 dfsan_label base_label, dfsan_label *ret_label) {
533 long int ret = strtol(nptr, &tmp_endptr, base);
535 *endptr = tmp_endptr;
537 if (tmp_endptr > nptr) {
538 // If *tmp_endptr is '\0' include its label as well.
539 *ret_label = dfsan_union(
541 dfsan_read_label(nptr, tmp_endptr - nptr + (*tmp_endptr ? 0 : 1)));
548 SANITIZER_INTERFACE_ATTRIBUTE
549 double __dfsw_strtod(const char *nptr, char **endptr,
550 dfsan_label nptr_label, dfsan_label endptr_label,
551 dfsan_label *ret_label) {
553 double ret = strtod(nptr, &tmp_endptr);
555 *endptr = tmp_endptr;
557 if (tmp_endptr > nptr) {
558 // If *tmp_endptr is '\0' include its label as well.
559 *ret_label = dfsan_read_label(
561 tmp_endptr - nptr + (*tmp_endptr ? 0 : 1));
568 SANITIZER_INTERFACE_ATTRIBUTE
569 long long int __dfsw_strtoll(const char *nptr, char **endptr, int base,
570 dfsan_label nptr_label, dfsan_label endptr_label,
571 dfsan_label base_label, dfsan_label *ret_label) {
573 long long int ret = strtoll(nptr, &tmp_endptr, base);
575 *endptr = tmp_endptr;
577 if (tmp_endptr > nptr) {
578 // If *tmp_endptr is '\0' include its label as well.
579 *ret_label = dfsan_union(
581 dfsan_read_label(nptr, tmp_endptr - nptr + (*tmp_endptr ? 0 : 1)));
588 SANITIZER_INTERFACE_ATTRIBUTE
589 unsigned long int __dfsw_strtoul(const char *nptr, char **endptr, int base,
590 dfsan_label nptr_label, dfsan_label endptr_label,
591 dfsan_label base_label, dfsan_label *ret_label) {
593 unsigned long int ret = strtoul(nptr, &tmp_endptr, base);
595 *endptr = tmp_endptr;
597 if (tmp_endptr > nptr) {
598 // If *tmp_endptr is '\0' include its label as well.
599 *ret_label = dfsan_union(
601 dfsan_read_label(nptr, tmp_endptr - nptr + (*tmp_endptr ? 0 : 1)));
608 SANITIZER_INTERFACE_ATTRIBUTE
609 long long unsigned int __dfsw_strtoull(const char *nptr, char **endptr,
610 dfsan_label nptr_label,
611 int base, dfsan_label endptr_label,
612 dfsan_label base_label,
613 dfsan_label *ret_label) {
615 long long unsigned int ret = strtoull(nptr, &tmp_endptr, base);
617 *endptr = tmp_endptr;
619 if (tmp_endptr > nptr) {
620 // If *tmp_endptr is '\0' include its label as well.
621 *ret_label = dfsan_union(
623 dfsan_read_label(nptr, tmp_endptr - nptr + (*tmp_endptr ? 0 : 1)));
630 SANITIZER_INTERFACE_ATTRIBUTE
631 time_t __dfsw_time(time_t *t, dfsan_label t_label, dfsan_label *ret_label) {
632 time_t ret = time(t);
633 if (ret != (time_t) -1 && t) {
634 dfsan_set_label(0, t, sizeof(time_t));
640 SANITIZER_INTERFACE_ATTRIBUTE
641 int __dfsw_inet_pton(int af, const char *src, void *dst, dfsan_label af_label,
642 dfsan_label src_label, dfsan_label dst_label,
643 dfsan_label *ret_label) {
644 int ret = inet_pton(af, src, dst);
646 dfsan_set_label(dfsan_read_label(src, strlen(src) + 1), dst,
647 af == AF_INET ? sizeof(struct in_addr) : sizeof(in6_addr));
653 SANITIZER_INTERFACE_ATTRIBUTE
654 struct tm *__dfsw_localtime_r(const time_t *timep, struct tm *result,
655 dfsan_label timep_label, dfsan_label result_label,
656 dfsan_label *ret_label) {
657 struct tm *ret = localtime_r(timep, result);
659 dfsan_set_label(dfsan_read_label(timep, sizeof(time_t)), result,
661 *ret_label = result_label;
668 SANITIZER_INTERFACE_ATTRIBUTE
669 int __dfsw_getpwuid_r(id_t uid, struct passwd *pwd,
670 char *buf, size_t buflen, struct passwd **result,
671 dfsan_label uid_label, dfsan_label pwd_label,
672 dfsan_label buf_label, dfsan_label buflen_label,
673 dfsan_label result_label, dfsan_label *ret_label) {
674 // Store the data in pwd, the strings referenced from pwd in buf, and the
675 // address of pwd in *result. On failure, NULL is stored in *result.
676 int ret = getpwuid_r(uid, pwd, buf, buflen, result);
678 dfsan_set_label(0, pwd, sizeof(struct passwd));
679 dfsan_set_label(0, buf, strlen(buf) + 1);
682 dfsan_set_label(0, result, sizeof(struct passwd*));
686 SANITIZER_INTERFACE_ATTRIBUTE
687 int __dfsw_poll(struct pollfd *fds, nfds_t nfds, int timeout,
688 dfsan_label dfs_label, dfsan_label nfds_label,
689 dfsan_label timeout_label, dfsan_label *ret_label) {
690 int ret = poll(fds, nfds, timeout);
692 for (; nfds > 0; --nfds) {
693 dfsan_set_label(0, &fds[nfds - 1].revents, sizeof(fds[nfds - 1].revents));
700 SANITIZER_INTERFACE_ATTRIBUTE
701 int __dfsw_select(int nfds, fd_set *readfds, fd_set *writefds,
702 fd_set *exceptfds, struct timeval *timeout,
703 dfsan_label nfds_label, dfsan_label readfds_label,
704 dfsan_label writefds_label, dfsan_label exceptfds_label,
705 dfsan_label timeout_label, dfsan_label *ret_label) {
706 int ret = select(nfds, readfds, writefds, exceptfds, timeout);
707 // Clear everything (also on error) since their content is either set or
710 dfsan_set_label(0, readfds, sizeof(fd_set));
713 dfsan_set_label(0, writefds, sizeof(fd_set));
716 dfsan_set_label(0, exceptfds, sizeof(fd_set));
718 dfsan_set_label(0, timeout, sizeof(struct timeval));
723 SANITIZER_INTERFACE_ATTRIBUTE
724 int __dfsw_sched_getaffinity(pid_t pid, size_t cpusetsize, cpu_set_t *mask,
725 dfsan_label pid_label,
726 dfsan_label cpusetsize_label,
727 dfsan_label mask_label, dfsan_label *ret_label) {
728 int ret = sched_getaffinity(pid, cpusetsize, mask);
730 dfsan_set_label(0, mask, cpusetsize);
736 SANITIZER_INTERFACE_ATTRIBUTE
737 int __dfsw_sigemptyset(sigset_t *set, dfsan_label set_label,
738 dfsan_label *ret_label) {
739 int ret = sigemptyset(set);
740 dfsan_set_label(0, set, sizeof(sigset_t));
744 SANITIZER_INTERFACE_ATTRIBUTE
745 int __dfsw_sigaction(int signum, const struct sigaction *act,
746 struct sigaction *oldact, dfsan_label signum_label,
747 dfsan_label act_label, dfsan_label oldact_label,
748 dfsan_label *ret_label) {
749 int ret = sigaction(signum, act, oldact);
751 dfsan_set_label(0, oldact, sizeof(struct sigaction));
757 SANITIZER_INTERFACE_ATTRIBUTE
758 int __dfsw_gettimeofday(struct timeval *tv, struct timezone *tz,
759 dfsan_label tv_label, dfsan_label tz_label,
760 dfsan_label *ret_label) {
761 int ret = gettimeofday(tv, tz);
763 dfsan_set_label(0, tv, sizeof(struct timeval));
766 dfsan_set_label(0, tz, sizeof(struct timezone));
772 SANITIZER_INTERFACE_ATTRIBUTE void *__dfsw_memchr(void *s, int c, size_t n,
776 dfsan_label *ret_label) {
777 void *ret = memchr(s, c, n);
778 if (flags().strict_data_dependencies) {
779 *ret_label = ret ? s_label : 0;
782 ret ? reinterpret_cast<char *>(ret) - reinterpret_cast<char *>(s) + 1
785 dfsan_union(dfsan_read_label(s, len), dfsan_union(s_label, c_label));
790 SANITIZER_INTERFACE_ATTRIBUTE char *__dfsw_strrchr(char *s, int c,
793 dfsan_label *ret_label) {
794 char *ret = strrchr(s, c);
795 if (flags().strict_data_dependencies) {
796 *ret_label = ret ? s_label : 0;
799 dfsan_union(dfsan_read_label(s, strlen(s) + 1),
800 dfsan_union(s_label, c_label));
806 SANITIZER_INTERFACE_ATTRIBUTE char *__dfsw_strstr(char *haystack, char *needle,
807 dfsan_label haystack_label,
808 dfsan_label needle_label,
809 dfsan_label *ret_label) {
810 char *ret = strstr(haystack, needle);
811 if (flags().strict_data_dependencies) {
812 *ret_label = ret ? haystack_label : 0;
814 size_t len = ret ? ret + strlen(needle) - haystack : strlen(haystack) + 1;
816 dfsan_union(dfsan_read_label(haystack, len),
817 dfsan_union(dfsan_read_label(needle, strlen(needle) + 1),
818 dfsan_union(haystack_label, needle_label)));
824 SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_nanosleep(const struct timespec *req,
825 struct timespec *rem,
826 dfsan_label req_label,
827 dfsan_label rem_label,
828 dfsan_label *ret_label) {
829 int ret = nanosleep(req, rem);
832 // Interrupted by a signal, rem is filled with the remaining time.
833 dfsan_set_label(0, rem, sizeof(struct timespec));
838 SANITIZER_INTERFACE_ATTRIBUTE int
839 __dfsw_socketpair(int domain, int type, int protocol, int sv[2],
840 dfsan_label domain_label, dfsan_label type_label,
841 dfsan_label protocol_label, dfsan_label sv_label,
842 dfsan_label *ret_label) {
843 int ret = socketpair(domain, type, protocol, sv);
846 dfsan_set_label(0, sv, sizeof(*sv) * 2);
851 // Type of the trampoline function passed to the custom version of
852 // dfsan_set_write_callback.
853 typedef void (*write_trampoline_t)(
855 int fd, const void *buf, ssize_t count,
856 dfsan_label fd_label, dfsan_label buf_label, dfsan_label count_label);
858 // Calls to dfsan_set_write_callback() set the values in this struct.
859 // Calls to the custom version of write() read (and invoke) them.
861 write_trampoline_t write_callback_trampoline = nullptr;
862 void *write_callback = nullptr;
863 } write_callback_info;
865 SANITIZER_INTERFACE_ATTRIBUTE void
866 __dfsw_dfsan_set_write_callback(
867 write_trampoline_t write_callback_trampoline,
868 void *write_callback,
869 dfsan_label write_callback_label,
870 dfsan_label *ret_label) {
871 write_callback_info.write_callback_trampoline = write_callback_trampoline;
872 write_callback_info.write_callback = write_callback;
875 SANITIZER_INTERFACE_ATTRIBUTE int
876 __dfsw_write(int fd, const void *buf, size_t count,
877 dfsan_label fd_label, dfsan_label buf_label,
878 dfsan_label count_label, dfsan_label *ret_label) {
879 if (write_callback_info.write_callback) {
880 write_callback_info.write_callback_trampoline(
881 write_callback_info.write_callback,
883 fd_label, buf_label, count_label);
887 return write(fd, buf, count);
889 } // namespace __dfsan
891 // Type used to extract a dfsan_label with va_arg()
892 typedef int dfsan_label_va;
894 // Formats a chunk either a constant string or a single format directive (e.g.,
897 Formatter(char *str_, const char *fmt_, size_t size_)
898 : str(str_), str_off(0), size(size_), fmt_start(fmt_), fmt_cur(fmt_),
902 char *tmp_fmt = build_format_string();
904 snprintf(str + str_off, str_off < size ? size - str_off : 0, tmp_fmt,
905 0 /* used only to avoid warnings */);
910 template <typename T> int format(T arg) {
911 char *tmp_fmt = build_format_string();
914 retval = snprintf(str + str_off, str_off < size ? size - str_off : 0,
915 tmp_fmt, width, arg);
917 retval = snprintf(str + str_off, str_off < size ? size - str_off : 0,
924 char *build_format_string() {
925 size_t fmt_size = fmt_cur - fmt_start + 1;
926 char *new_fmt = (char *)malloc(fmt_size + 1);
928 internal_memcpy(new_fmt, fmt_start, fmt_size);
929 new_fmt[fmt_size] = '\0';
933 char *str_cur() { return str + str_off; }
935 size_t num_written_bytes(int retval) {
940 size_t num_avail = str_off < size ? size - str_off : 0;
941 if (num_avail == 0) {
945 size_t num_written = retval;
946 // A return value of {v,}snprintf of size or more means that the output was
948 if (num_written >= num_avail) {
949 num_written -= num_avail;
958 const char *fmt_start;
963 // Formats the input and propagates the input labels to the output. The output
964 // is stored in 'str'. 'size' bounds the number of output bytes. 'format' and
965 // 'ap' are the format string and the list of arguments for formatting. Returns
966 // the return value vsnprintf would return.
968 // The function tokenizes the format string in chunks representing either a
969 // constant string or a single format directive (e.g., '%.3f') and formats each
970 // chunk independently into the output string. This approach allows to figure
971 // out which bytes of the output string depends on which argument and thus to
972 // propagate labels more precisely.
974 // WARNING: This implementation does not support conversion specifiers with
975 // positional arguments.
976 static int format_buffer(char *str, size_t size, const char *fmt,
977 dfsan_label *va_labels, dfsan_label *ret_label,
979 Formatter formatter(str, fmt, size);
981 while (*formatter.fmt_cur) {
982 formatter.fmt_start = formatter.fmt_cur;
983 formatter.width = -1;
986 if (*formatter.fmt_cur != '%') {
987 // Ordinary character. Consume all the characters until a '%' or the end
989 for (; *(formatter.fmt_cur + 1) && *(formatter.fmt_cur + 1) != '%';
990 ++formatter.fmt_cur) {}
991 retval = formatter.format();
992 dfsan_set_label(0, formatter.str_cur(),
993 formatter.num_written_bytes(retval));
995 // Conversion directive. Consume all the characters until a conversion
996 // specifier or the end of the string.
997 bool end_fmt = false;
998 for (; *formatter.fmt_cur && !end_fmt; ) {
999 switch (*++formatter.fmt_cur) {
1006 switch (*(formatter.fmt_cur - 1)) {
1008 // Also covers the 'hh' case (since the size of the arg is still
1010 retval = formatter.format(va_arg(ap, int));
1013 if (formatter.fmt_cur - formatter.fmt_start >= 2 &&
1014 *(formatter.fmt_cur - 2) == 'l') {
1015 retval = formatter.format(va_arg(ap, long long int));
1017 retval = formatter.format(va_arg(ap, long int));
1021 retval = formatter.format(va_arg(ap, long long int));
1024 retval = formatter.format(va_arg(ap, intmax_t));
1028 retval = formatter.format(va_arg(ap, size_t));
1031 retval = formatter.format(va_arg(ap, int));
1033 dfsan_set_label(*va_labels++, formatter.str_cur(),
1034 formatter.num_written_bytes(retval));
1046 if (*(formatter.fmt_cur - 1) == 'L') {
1047 retval = formatter.format(va_arg(ap, long double));
1049 retval = formatter.format(va_arg(ap, double));
1051 dfsan_set_label(*va_labels++, formatter.str_cur(),
1052 formatter.num_written_bytes(retval));
1057 retval = formatter.format(va_arg(ap, int));
1058 dfsan_set_label(*va_labels++, formatter.str_cur(),
1059 formatter.num_written_bytes(retval));
1064 char *arg = va_arg(ap, char *);
1065 retval = formatter.format(arg);
1067 internal_memcpy(shadow_for(formatter.str_cur()), shadow_for(arg),
1068 sizeof(dfsan_label) *
1069 formatter.num_written_bytes(retval));
1075 retval = formatter.format(va_arg(ap, void *));
1076 dfsan_set_label(*va_labels++, formatter.str_cur(),
1077 formatter.num_written_bytes(retval));
1082 int *ptr = va_arg(ap, int *);
1083 *ptr = (int)formatter.str_off;
1085 dfsan_set_label(0, ptr, sizeof(ptr));
1091 retval = formatter.format();
1092 dfsan_set_label(0, formatter.str_cur(),
1093 formatter.num_written_bytes(retval));
1098 formatter.width = va_arg(ap, int);
1112 formatter.fmt_cur++;
1113 formatter.str_off += retval;
1118 // Number of bytes written in total.
1119 return formatter.str_off;
1123 SANITIZER_INTERFACE_ATTRIBUTE
1124 int __dfsw_sprintf(char *str, const char *format, dfsan_label str_label,
1125 dfsan_label format_label, dfsan_label *va_labels,
1126 dfsan_label *ret_label, ...) {
1128 va_start(ap, ret_label);
1129 int ret = format_buffer(str, ~0ul, format, va_labels, ret_label, ap);
1134 SANITIZER_INTERFACE_ATTRIBUTE
1135 int __dfsw_snprintf(char *str, size_t size, const char *format,
1136 dfsan_label str_label, dfsan_label size_label,
1137 dfsan_label format_label, dfsan_label *va_labels,
1138 dfsan_label *ret_label, ...) {
1140 va_start(ap, ret_label);
1141 int ret = format_buffer(str, size, format, va_labels, ret_label, ap);
1146 // Default empty implementations (weak). Users should redefine them.
1147 SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_pc_guard, u32 *) {}
1148 SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_pc_guard_init, u32 *,
1150 SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_pcs_init, void) {}
1151 SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_pc_indir, void) {}
1153 SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_cmp, void) {}
1154 SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_cmp1, void) {}
1155 SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_cmp2, void) {}
1156 SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_cmp4, void) {}
1157 SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_cmp8, void) {}
1158 SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_const_cmp1,
1160 SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_const_cmp2,
1162 SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_const_cmp4,
1164 SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_const_cmp8,
1166 SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_switch, void) {}