1 //===-- dfsan.cc ----------------------------------------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file is a part of DataFlowSanitizer.
12 // This file defines the custom functions listed in done_abilist.txt.
13 //===----------------------------------------------------------------------===//
15 #include "sanitizer_common/sanitizer_common.h"
16 #include "sanitizer_common/sanitizer_internal_defs.h"
17 #include "sanitizer_common/sanitizer_linux.h"
19 #include "dfsan/dfsan.h"
21 #include <arpa/inet.h>
36 #include <sys/resource.h>
37 #include <sys/select.h>
40 #include <sys/types.h>
44 using namespace __dfsan;
46 #define CALL_WEAK_INTERCEPTOR_HOOK(f, ...) \
51 #define DECLARE_WEAK_INTERCEPTOR_HOOK(f, ...) \
52 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE void f(__VA_ARGS__);
55 SANITIZER_INTERFACE_ATTRIBUTE int
56 __dfsw_stat(const char *path, struct stat *buf, dfsan_label path_label,
57 dfsan_label buf_label, dfsan_label *ret_label) {
58 int ret = stat(path, buf);
60 dfsan_set_label(0, buf, sizeof(struct stat));
65 SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_fstat(int fd, struct stat *buf,
67 dfsan_label buf_label,
68 dfsan_label *ret_label) {
69 int ret = fstat(fd, buf);
71 dfsan_set_label(0, buf, sizeof(struct stat));
76 SANITIZER_INTERFACE_ATTRIBUTE char *__dfsw_strchr(const char *s, int c,
79 dfsan_label *ret_label) {
80 for (size_t i = 0;; ++i) {
81 if (s[i] == c || s[i] == 0) {
82 if (flags().strict_data_dependencies) {
85 *ret_label = dfsan_union(dfsan_read_label(s, i + 1),
86 dfsan_union(s_label, c_label));
88 return s[i] == 0 ? nullptr : const_cast<char *>(s+i);
93 DECLARE_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_memcmp, uptr caller_pc,
94 const void *s1, const void *s2, size_t n,
95 dfsan_label s1_label, dfsan_label s2_label,
98 SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_memcmp(const void *s1, const void *s2,
99 size_t n, dfsan_label s1_label,
100 dfsan_label s2_label,
102 dfsan_label *ret_label) {
103 CALL_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_memcmp, GET_CALLER_PC(), s1, s2, n,
104 s1_label, s2_label, n_label);
105 const char *cs1 = (const char *) s1, *cs2 = (const char *) s2;
106 for (size_t i = 0; i != n; ++i) {
107 if (cs1[i] != cs2[i]) {
108 if (flags().strict_data_dependencies) {
111 *ret_label = dfsan_union(dfsan_read_label(cs1, i + 1),
112 dfsan_read_label(cs2, i + 1));
114 return cs1[i] - cs2[i];
118 if (flags().strict_data_dependencies) {
121 *ret_label = dfsan_union(dfsan_read_label(cs1, n),
122 dfsan_read_label(cs2, n));
127 DECLARE_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_strcmp, uptr caller_pc,
128 const char *s1, const char *s2,
129 dfsan_label s1_label, dfsan_label s2_label)
131 SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_strcmp(const char *s1, const char *s2,
132 dfsan_label s1_label,
133 dfsan_label s2_label,
134 dfsan_label *ret_label) {
135 CALL_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_strcmp, GET_CALLER_PC(), s1, s2,
137 for (size_t i = 0;; ++i) {
138 if (s1[i] != s2[i] || s1[i] == 0 || s2[i] == 0) {
139 if (flags().strict_data_dependencies) {
142 *ret_label = dfsan_union(dfsan_read_label(s1, i + 1),
143 dfsan_read_label(s2, i + 1));
145 return s1[i] - s2[i];
151 SANITIZER_INTERFACE_ATTRIBUTE int
152 __dfsw_strcasecmp(const char *s1, const char *s2, dfsan_label s1_label,
153 dfsan_label s2_label, dfsan_label *ret_label) {
154 for (size_t i = 0;; ++i) {
155 if (tolower(s1[i]) != tolower(s2[i]) || s1[i] == 0 || s2[i] == 0) {
156 if (flags().strict_data_dependencies) {
159 *ret_label = dfsan_union(dfsan_read_label(s1, i + 1),
160 dfsan_read_label(s2, i + 1));
162 return s1[i] - s2[i];
168 DECLARE_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_strncmp, uptr caller_pc,
169 const char *s1, const char *s2, size_t n,
170 dfsan_label s1_label, dfsan_label s2_label,
173 SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_strncmp(const char *s1, const char *s2,
174 size_t n, dfsan_label s1_label,
175 dfsan_label s2_label,
177 dfsan_label *ret_label) {
183 CALL_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_strncmp, GET_CALLER_PC(), s1, s2,
184 n, s1_label, s2_label, n_label);
186 for (size_t i = 0;; ++i) {
187 if (s1[i] != s2[i] || s1[i] == 0 || s2[i] == 0 || i == n - 1) {
188 if (flags().strict_data_dependencies) {
191 *ret_label = dfsan_union(dfsan_read_label(s1, i + 1),
192 dfsan_read_label(s2, i + 1));
194 return s1[i] - s2[i];
200 SANITIZER_INTERFACE_ATTRIBUTE int
201 __dfsw_strncasecmp(const char *s1, const char *s2, size_t n,
202 dfsan_label s1_label, dfsan_label s2_label,
203 dfsan_label n_label, dfsan_label *ret_label) {
209 for (size_t i = 0;; ++i) {
210 if (tolower(s1[i]) != tolower(s2[i]) || s1[i] == 0 || s2[i] == 0 ||
212 if (flags().strict_data_dependencies) {
215 *ret_label = dfsan_union(dfsan_read_label(s1, i + 1),
216 dfsan_read_label(s2, i + 1));
218 return s1[i] - s2[i];
224 SANITIZER_INTERFACE_ATTRIBUTE void *__dfsw_calloc(size_t nmemb, size_t size,
225 dfsan_label nmemb_label,
226 dfsan_label size_label,
227 dfsan_label *ret_label) {
228 void *p = calloc(nmemb, size);
229 dfsan_set_label(0, p, nmemb * size);
234 SANITIZER_INTERFACE_ATTRIBUTE size_t
235 __dfsw_strlen(const char *s, dfsan_label s_label, dfsan_label *ret_label) {
236 size_t ret = strlen(s);
237 if (flags().strict_data_dependencies) {
240 *ret_label = dfsan_read_label(s, ret + 1);
246 static void *dfsan_memcpy(void *dest, const void *src, size_t n) {
247 dfsan_label *sdest = shadow_for(dest);
248 const dfsan_label *ssrc = shadow_for(src);
249 internal_memcpy((void *)sdest, (const void *)ssrc, n * sizeof(dfsan_label));
250 return internal_memcpy(dest, src, n);
253 static void dfsan_memset(void *s, int c, dfsan_label c_label, size_t n) {
254 internal_memset(s, c, n);
255 dfsan_set_label(c_label, s, n);
258 SANITIZER_INTERFACE_ATTRIBUTE
259 void *__dfsw_memcpy(void *dest, const void *src, size_t n,
260 dfsan_label dest_label, dfsan_label src_label,
261 dfsan_label n_label, dfsan_label *ret_label) {
262 *ret_label = dest_label;
263 return dfsan_memcpy(dest, src, n);
266 SANITIZER_INTERFACE_ATTRIBUTE
267 void *__dfsw_memset(void *s, int c, size_t n,
268 dfsan_label s_label, dfsan_label c_label,
269 dfsan_label n_label, dfsan_label *ret_label) {
270 dfsan_memset(s, c, c_label, n);
271 *ret_label = s_label;
275 SANITIZER_INTERFACE_ATTRIBUTE char *
276 __dfsw_strdup(const char *s, dfsan_label s_label, dfsan_label *ret_label) {
277 size_t len = strlen(s);
278 void *p = malloc(len+1);
279 dfsan_memcpy(p, s, len+1);
281 return static_cast<char *>(p);
284 SANITIZER_INTERFACE_ATTRIBUTE char *
285 __dfsw_strncpy(char *s1, const char *s2, size_t n, dfsan_label s1_label,
286 dfsan_label s2_label, dfsan_label n_label,
287 dfsan_label *ret_label) {
288 size_t len = strlen(s2);
290 dfsan_memcpy(s1, s2, len+1);
291 dfsan_memset(s1+len+1, 0, 0, n-len-1);
293 dfsan_memcpy(s1, s2, n);
296 *ret_label = s1_label;
300 SANITIZER_INTERFACE_ATTRIBUTE ssize_t
301 __dfsw_pread(int fd, void *buf, size_t count, off_t offset,
302 dfsan_label fd_label, dfsan_label buf_label,
303 dfsan_label count_label, dfsan_label offset_label,
304 dfsan_label *ret_label) {
305 ssize_t ret = pread(fd, buf, count, offset);
307 dfsan_set_label(0, buf, ret);
312 SANITIZER_INTERFACE_ATTRIBUTE ssize_t
313 __dfsw_read(int fd, void *buf, size_t count,
314 dfsan_label fd_label, dfsan_label buf_label,
315 dfsan_label count_label,
316 dfsan_label *ret_label) {
317 ssize_t ret = read(fd, buf, count);
319 dfsan_set_label(0, buf, ret);
324 SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_clock_gettime(clockid_t clk_id,
326 dfsan_label clk_id_label,
327 dfsan_label tp_label,
328 dfsan_label *ret_label) {
329 int ret = clock_gettime(clk_id, tp);
331 dfsan_set_label(0, tp, sizeof(struct timespec));
336 static void unpoison(const void *ptr, uptr size) {
337 dfsan_set_label(0, const_cast<void *>(ptr), size);
340 // dlopen() ultimately calls mmap() down inside the loader, which generally
341 // doesn't participate in dynamic symbol resolution. Therefore we won't
342 // intercept its calls to mmap, and we have to hook it here.
343 SANITIZER_INTERFACE_ATTRIBUTE void *
344 __dfsw_dlopen(const char *filename, int flag, dfsan_label filename_label,
345 dfsan_label flag_label, dfsan_label *ret_label) {
346 void *handle = dlopen(filename, flag);
347 link_map *map = GET_LINK_MAP_BY_DLOPEN_HANDLE(handle);
349 ForEachMappedRegion(map, unpoison);
354 struct pthread_create_info {
355 void *(*start_routine_trampoline)(void *, void *, dfsan_label, dfsan_label *);
360 static void *pthread_create_cb(void *p) {
361 pthread_create_info pci(*(pthread_create_info *)p);
363 dfsan_label ret_label;
364 return pci.start_routine_trampoline(pci.start_routine, pci.arg, 0,
368 SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_pthread_create(
369 pthread_t *thread, const pthread_attr_t *attr,
370 void *(*start_routine_trampoline)(void *, void *, dfsan_label,
372 void *start_routine, void *arg, dfsan_label thread_label,
373 dfsan_label attr_label, dfsan_label start_routine_label,
374 dfsan_label arg_label, dfsan_label *ret_label) {
375 pthread_create_info *pci =
376 (pthread_create_info *)malloc(sizeof(pthread_create_info));
377 pci->start_routine_trampoline = start_routine_trampoline;
378 pci->start_routine = start_routine;
380 int rv = pthread_create(thread, attr, pthread_create_cb, (void *)pci);
387 struct dl_iterate_phdr_info {
388 int (*callback_trampoline)(void *callback, struct dl_phdr_info *info,
389 size_t size, void *data, dfsan_label info_label,
390 dfsan_label size_label, dfsan_label data_label,
391 dfsan_label *ret_label);
396 int dl_iterate_phdr_cb(struct dl_phdr_info *info, size_t size, void *data) {
397 dl_iterate_phdr_info *dipi = (dl_iterate_phdr_info *)data;
398 dfsan_set_label(0, *info);
399 dfsan_set_label(0, const_cast<char *>(info->dlpi_name),
400 strlen(info->dlpi_name) + 1);
402 0, const_cast<char *>(reinterpret_cast<const char *>(info->dlpi_phdr)),
403 sizeof(*info->dlpi_phdr) * info->dlpi_phnum);
404 dfsan_label ret_label;
405 return dipi->callback_trampoline(dipi->callback, info, size, dipi->data, 0, 0,
409 SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_dl_iterate_phdr(
410 int (*callback_trampoline)(void *callback, struct dl_phdr_info *info,
411 size_t size, void *data, dfsan_label info_label,
412 dfsan_label size_label, dfsan_label data_label,
413 dfsan_label *ret_label),
414 void *callback, void *data, dfsan_label callback_label,
415 dfsan_label data_label, dfsan_label *ret_label) {
416 dl_iterate_phdr_info dipi = { callback_trampoline, callback, data };
418 return dl_iterate_phdr(dl_iterate_phdr_cb, &dipi);
421 SANITIZER_INTERFACE_ATTRIBUTE
422 char *__dfsw_ctime_r(const time_t *timep, char *buf, dfsan_label timep_label,
423 dfsan_label buf_label, dfsan_label *ret_label) {
424 char *ret = ctime_r(timep, buf);
426 dfsan_set_label(dfsan_read_label(timep, sizeof(time_t)), buf,
428 *ret_label = buf_label;
435 SANITIZER_INTERFACE_ATTRIBUTE
436 char *__dfsw_fgets(char *s, int size, FILE *stream, dfsan_label s_label,
437 dfsan_label size_label, dfsan_label stream_label,
438 dfsan_label *ret_label) {
439 char *ret = fgets(s, size, stream);
441 dfsan_set_label(0, ret, strlen(ret) + 1);
442 *ret_label = s_label;
449 SANITIZER_INTERFACE_ATTRIBUTE
450 char *__dfsw_getcwd(char *buf, size_t size, dfsan_label buf_label,
451 dfsan_label size_label, dfsan_label *ret_label) {
452 char *ret = getcwd(buf, size);
454 dfsan_set_label(0, ret, strlen(ret) + 1);
455 *ret_label = buf_label;
462 SANITIZER_INTERFACE_ATTRIBUTE
463 char *__dfsw_get_current_dir_name(dfsan_label *ret_label) {
464 char *ret = get_current_dir_name();
466 dfsan_set_label(0, ret, strlen(ret) + 1);
472 SANITIZER_INTERFACE_ATTRIBUTE
473 int __dfsw_gethostname(char *name, size_t len, dfsan_label name_label,
474 dfsan_label len_label, dfsan_label *ret_label) {
475 int ret = gethostname(name, len);
477 dfsan_set_label(0, name, strlen(name) + 1);
483 SANITIZER_INTERFACE_ATTRIBUTE
484 int __dfsw_getrlimit(int resource, struct rlimit *rlim,
485 dfsan_label resource_label, dfsan_label rlim_label,
486 dfsan_label *ret_label) {
487 int ret = getrlimit(resource, rlim);
489 dfsan_set_label(0, rlim, sizeof(struct rlimit));
495 SANITIZER_INTERFACE_ATTRIBUTE
496 int __dfsw_getrusage(int who, struct rusage *usage, dfsan_label who_label,
497 dfsan_label usage_label, dfsan_label *ret_label) {
498 int ret = getrusage(who, usage);
500 dfsan_set_label(0, usage, sizeof(struct rusage));
506 SANITIZER_INTERFACE_ATTRIBUTE
507 char *__dfsw_strcpy(char *dest, const char *src, dfsan_label dst_label,
508 dfsan_label src_label, dfsan_label *ret_label) {
509 char *ret = strcpy(dest, src);
511 internal_memcpy(shadow_for(dest), shadow_for(src),
512 sizeof(dfsan_label) * (strlen(src) + 1));
514 *ret_label = dst_label;
518 SANITIZER_INTERFACE_ATTRIBUTE
519 long int __dfsw_strtol(const char *nptr, char **endptr, int base,
520 dfsan_label nptr_label, dfsan_label endptr_label,
521 dfsan_label base_label, dfsan_label *ret_label) {
523 long int ret = strtol(nptr, &tmp_endptr, base);
525 *endptr = tmp_endptr;
527 if (tmp_endptr > nptr) {
528 // If *tmp_endptr is '\0' include its label as well.
529 *ret_label = dfsan_union(
531 dfsan_read_label(nptr, tmp_endptr - nptr + (*tmp_endptr ? 0 : 1)));
538 SANITIZER_INTERFACE_ATTRIBUTE
539 double __dfsw_strtod(const char *nptr, char **endptr,
540 dfsan_label nptr_label, dfsan_label endptr_label,
541 dfsan_label *ret_label) {
543 double ret = strtod(nptr, &tmp_endptr);
545 *endptr = tmp_endptr;
547 if (tmp_endptr > nptr) {
548 // If *tmp_endptr is '\0' include its label as well.
549 *ret_label = dfsan_read_label(
551 tmp_endptr - nptr + (*tmp_endptr ? 0 : 1));
558 SANITIZER_INTERFACE_ATTRIBUTE
559 long long int __dfsw_strtoll(const char *nptr, char **endptr, int base,
560 dfsan_label nptr_label, dfsan_label endptr_label,
561 dfsan_label base_label, dfsan_label *ret_label) {
563 long long int ret = strtoll(nptr, &tmp_endptr, base);
565 *endptr = tmp_endptr;
567 if (tmp_endptr > nptr) {
568 // If *tmp_endptr is '\0' include its label as well.
569 *ret_label = dfsan_union(
571 dfsan_read_label(nptr, tmp_endptr - nptr + (*tmp_endptr ? 0 : 1)));
578 SANITIZER_INTERFACE_ATTRIBUTE
579 unsigned long int __dfsw_strtoul(const char *nptr, char **endptr, int base,
580 dfsan_label nptr_label, dfsan_label endptr_label,
581 dfsan_label base_label, dfsan_label *ret_label) {
583 unsigned long int ret = strtoul(nptr, &tmp_endptr, base);
585 *endptr = tmp_endptr;
587 if (tmp_endptr > nptr) {
588 // If *tmp_endptr is '\0' include its label as well.
589 *ret_label = dfsan_union(
591 dfsan_read_label(nptr, tmp_endptr - nptr + (*tmp_endptr ? 0 : 1)));
598 SANITIZER_INTERFACE_ATTRIBUTE
599 long long unsigned int __dfsw_strtoull(const char *nptr, char **endptr,
600 dfsan_label nptr_label,
601 int base, dfsan_label endptr_label,
602 dfsan_label base_label,
603 dfsan_label *ret_label) {
605 long long unsigned int ret = strtoull(nptr, &tmp_endptr, base);
607 *endptr = tmp_endptr;
609 if (tmp_endptr > nptr) {
610 // If *tmp_endptr is '\0' include its label as well.
611 *ret_label = dfsan_union(
613 dfsan_read_label(nptr, tmp_endptr - nptr + (*tmp_endptr ? 0 : 1)));
620 SANITIZER_INTERFACE_ATTRIBUTE
621 time_t __dfsw_time(time_t *t, dfsan_label t_label, dfsan_label *ret_label) {
622 time_t ret = time(t);
623 if (ret != (time_t) -1 && t) {
624 dfsan_set_label(0, t, sizeof(time_t));
630 SANITIZER_INTERFACE_ATTRIBUTE
631 int __dfsw_inet_pton(int af, const char *src, void *dst, dfsan_label af_label,
632 dfsan_label src_label, dfsan_label dst_label,
633 dfsan_label *ret_label) {
634 int ret = inet_pton(af, src, dst);
636 dfsan_set_label(dfsan_read_label(src, strlen(src) + 1), dst,
637 af == AF_INET ? sizeof(struct in_addr) : sizeof(in6_addr));
643 SANITIZER_INTERFACE_ATTRIBUTE
644 struct tm *__dfsw_localtime_r(const time_t *timep, struct tm *result,
645 dfsan_label timep_label, dfsan_label result_label,
646 dfsan_label *ret_label) {
647 struct tm *ret = localtime_r(timep, result);
649 dfsan_set_label(dfsan_read_label(timep, sizeof(time_t)), result,
651 *ret_label = result_label;
658 SANITIZER_INTERFACE_ATTRIBUTE
659 int __dfsw_getpwuid_r(id_t uid, struct passwd *pwd,
660 char *buf, size_t buflen, struct passwd **result,
661 dfsan_label uid_label, dfsan_label pwd_label,
662 dfsan_label buf_label, dfsan_label buflen_label,
663 dfsan_label result_label, dfsan_label *ret_label) {
664 // Store the data in pwd, the strings referenced from pwd in buf, and the
665 // address of pwd in *result. On failure, NULL is stored in *result.
666 int ret = getpwuid_r(uid, pwd, buf, buflen, result);
668 dfsan_set_label(0, pwd, sizeof(struct passwd));
669 dfsan_set_label(0, buf, strlen(buf) + 1);
672 dfsan_set_label(0, result, sizeof(struct passwd*));
676 SANITIZER_INTERFACE_ATTRIBUTE
677 int __dfsw_poll(struct pollfd *fds, nfds_t nfds, int timeout,
678 dfsan_label dfs_label, dfsan_label nfds_label,
679 dfsan_label timeout_label, dfsan_label *ret_label) {
680 int ret = poll(fds, nfds, timeout);
682 for (; nfds > 0; --nfds) {
683 dfsan_set_label(0, &fds[nfds - 1].revents, sizeof(fds[nfds - 1].revents));
690 SANITIZER_INTERFACE_ATTRIBUTE
691 int __dfsw_select(int nfds, fd_set *readfds, fd_set *writefds,
692 fd_set *exceptfds, struct timeval *timeout,
693 dfsan_label nfds_label, dfsan_label readfds_label,
694 dfsan_label writefds_label, dfsan_label exceptfds_label,
695 dfsan_label timeout_label, dfsan_label *ret_label) {
696 int ret = select(nfds, readfds, writefds, exceptfds, timeout);
697 // Clear everything (also on error) since their content is either set or
700 dfsan_set_label(0, readfds, sizeof(fd_set));
703 dfsan_set_label(0, writefds, sizeof(fd_set));
706 dfsan_set_label(0, exceptfds, sizeof(fd_set));
708 dfsan_set_label(0, timeout, sizeof(struct timeval));
713 SANITIZER_INTERFACE_ATTRIBUTE
714 int __dfsw_sched_getaffinity(pid_t pid, size_t cpusetsize, cpu_set_t *mask,
715 dfsan_label pid_label,
716 dfsan_label cpusetsize_label,
717 dfsan_label mask_label, dfsan_label *ret_label) {
718 int ret = sched_getaffinity(pid, cpusetsize, mask);
720 dfsan_set_label(0, mask, cpusetsize);
726 SANITIZER_INTERFACE_ATTRIBUTE
727 int __dfsw_sigemptyset(sigset_t *set, dfsan_label set_label,
728 dfsan_label *ret_label) {
729 int ret = sigemptyset(set);
730 dfsan_set_label(0, set, sizeof(sigset_t));
734 SANITIZER_INTERFACE_ATTRIBUTE
735 int __dfsw_sigaction(int signum, const struct sigaction *act,
736 struct sigaction *oldact, dfsan_label signum_label,
737 dfsan_label act_label, dfsan_label oldact_label,
738 dfsan_label *ret_label) {
739 int ret = sigaction(signum, act, oldact);
741 dfsan_set_label(0, oldact, sizeof(struct sigaction));
747 SANITIZER_INTERFACE_ATTRIBUTE
748 int __dfsw_gettimeofday(struct timeval *tv, struct timezone *tz,
749 dfsan_label tv_label, dfsan_label tz_label,
750 dfsan_label *ret_label) {
751 int ret = gettimeofday(tv, tz);
753 dfsan_set_label(0, tv, sizeof(struct timeval));
756 dfsan_set_label(0, tz, sizeof(struct timezone));
762 SANITIZER_INTERFACE_ATTRIBUTE void *__dfsw_memchr(void *s, int c, size_t n,
766 dfsan_label *ret_label) {
767 void *ret = memchr(s, c, n);
768 if (flags().strict_data_dependencies) {
769 *ret_label = ret ? s_label : 0;
772 ret ? reinterpret_cast<char *>(ret) - reinterpret_cast<char *>(s) + 1
775 dfsan_union(dfsan_read_label(s, len), dfsan_union(s_label, c_label));
780 SANITIZER_INTERFACE_ATTRIBUTE char *__dfsw_strrchr(char *s, int c,
783 dfsan_label *ret_label) {
784 char *ret = strrchr(s, c);
785 if (flags().strict_data_dependencies) {
786 *ret_label = ret ? s_label : 0;
789 dfsan_union(dfsan_read_label(s, strlen(s) + 1),
790 dfsan_union(s_label, c_label));
796 SANITIZER_INTERFACE_ATTRIBUTE char *__dfsw_strstr(char *haystack, char *needle,
797 dfsan_label haystack_label,
798 dfsan_label needle_label,
799 dfsan_label *ret_label) {
800 char *ret = strstr(haystack, needle);
801 if (flags().strict_data_dependencies) {
802 *ret_label = ret ? haystack_label : 0;
804 size_t len = ret ? ret + strlen(needle) - haystack : strlen(haystack) + 1;
806 dfsan_union(dfsan_read_label(haystack, len),
807 dfsan_union(dfsan_read_label(needle, strlen(needle) + 1),
808 dfsan_union(haystack_label, needle_label)));
814 SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_nanosleep(const struct timespec *req,
815 struct timespec *rem,
816 dfsan_label req_label,
817 dfsan_label rem_label,
818 dfsan_label *ret_label) {
819 int ret = nanosleep(req, rem);
822 // Interrupted by a signal, rem is filled with the remaining time.
823 dfsan_set_label(0, rem, sizeof(struct timespec));
828 SANITIZER_INTERFACE_ATTRIBUTE int
829 __dfsw_socketpair(int domain, int type, int protocol, int sv[2],
830 dfsan_label domain_label, dfsan_label type_label,
831 dfsan_label protocol_label, dfsan_label sv_label,
832 dfsan_label *ret_label) {
833 int ret = socketpair(domain, type, protocol, sv);
836 dfsan_set_label(0, sv, sizeof(*sv) * 2);
841 // Type of the trampoline function passed to the custom version of
842 // dfsan_set_write_callback.
843 typedef void (*write_trampoline_t)(
845 int fd, const void *buf, ssize_t count,
846 dfsan_label fd_label, dfsan_label buf_label, dfsan_label count_label);
848 // Calls to dfsan_set_write_callback() set the values in this struct.
849 // Calls to the custom version of write() read (and invoke) them.
851 write_trampoline_t write_callback_trampoline = nullptr;
852 void *write_callback = nullptr;
853 } write_callback_info;
855 SANITIZER_INTERFACE_ATTRIBUTE void
856 __dfsw_dfsan_set_write_callback(
857 write_trampoline_t write_callback_trampoline,
858 void *write_callback,
859 dfsan_label write_callback_label,
860 dfsan_label *ret_label) {
861 write_callback_info.write_callback_trampoline = write_callback_trampoline;
862 write_callback_info.write_callback = write_callback;
865 SANITIZER_INTERFACE_ATTRIBUTE int
866 __dfsw_write(int fd, const void *buf, size_t count,
867 dfsan_label fd_label, dfsan_label buf_label,
868 dfsan_label count_label, dfsan_label *ret_label) {
869 if (write_callback_info.write_callback) {
870 write_callback_info.write_callback_trampoline(
871 write_callback_info.write_callback,
873 fd_label, buf_label, count_label);
877 return write(fd, buf, count);
879 } // namespace __dfsan
881 // Type used to extract a dfsan_label with va_arg()
882 typedef int dfsan_label_va;
884 // Formats a chunk either a constant string or a single format directive (e.g.,
887 Formatter(char *str_, const char *fmt_, size_t size_)
888 : str(str_), str_off(0), size(size_), fmt_start(fmt_), fmt_cur(fmt_),
892 char *tmp_fmt = build_format_string();
894 snprintf(str + str_off, str_off < size ? size - str_off : 0, tmp_fmt,
895 0 /* used only to avoid warnings */);
900 template <typename T> int format(T arg) {
901 char *tmp_fmt = build_format_string();
904 retval = snprintf(str + str_off, str_off < size ? size - str_off : 0,
905 tmp_fmt, width, arg);
907 retval = snprintf(str + str_off, str_off < size ? size - str_off : 0,
914 char *build_format_string() {
915 size_t fmt_size = fmt_cur - fmt_start + 1;
916 char *new_fmt = (char *)malloc(fmt_size + 1);
918 internal_memcpy(new_fmt, fmt_start, fmt_size);
919 new_fmt[fmt_size] = '\0';
923 char *str_cur() { return str + str_off; }
925 size_t num_written_bytes(int retval) {
930 size_t num_avail = str_off < size ? size - str_off : 0;
931 if (num_avail == 0) {
935 size_t num_written = retval;
936 // A return value of {v,}snprintf of size or more means that the output was
938 if (num_written >= num_avail) {
939 num_written -= num_avail;
948 const char *fmt_start;
953 // Formats the input and propagates the input labels to the output. The output
954 // is stored in 'str'. 'size' bounds the number of output bytes. 'format' and
955 // 'ap' are the format string and the list of arguments for formatting. Returns
956 // the return value vsnprintf would return.
958 // The function tokenizes the format string in chunks representing either a
959 // constant string or a single format directive (e.g., '%.3f') and formats each
960 // chunk independently into the output string. This approach allows to figure
961 // out which bytes of the output string depends on which argument and thus to
962 // propagate labels more precisely.
964 // WARNING: This implementation does not support conversion specifiers with
965 // positional arguments.
966 static int format_buffer(char *str, size_t size, const char *fmt,
967 dfsan_label *va_labels, dfsan_label *ret_label,
969 Formatter formatter(str, fmt, size);
971 while (*formatter.fmt_cur) {
972 formatter.fmt_start = formatter.fmt_cur;
973 formatter.width = -1;
976 if (*formatter.fmt_cur != '%') {
977 // Ordinary character. Consume all the characters until a '%' or the end
979 for (; *(formatter.fmt_cur + 1) && *(formatter.fmt_cur + 1) != '%';
980 ++formatter.fmt_cur) {}
981 retval = formatter.format();
982 dfsan_set_label(0, formatter.str_cur(),
983 formatter.num_written_bytes(retval));
985 // Conversion directive. Consume all the characters until a conversion
986 // specifier or the end of the string.
987 bool end_fmt = false;
988 for (; *formatter.fmt_cur && !end_fmt; ) {
989 switch (*++formatter.fmt_cur) {
996 switch (*(formatter.fmt_cur - 1)) {
998 // Also covers the 'hh' case (since the size of the arg is still
1000 retval = formatter.format(va_arg(ap, int));
1003 if (formatter.fmt_cur - formatter.fmt_start >= 2 &&
1004 *(formatter.fmt_cur - 2) == 'l') {
1005 retval = formatter.format(va_arg(ap, long long int));
1007 retval = formatter.format(va_arg(ap, long int));
1011 retval = formatter.format(va_arg(ap, long long int));
1014 retval = formatter.format(va_arg(ap, intmax_t));
1018 retval = formatter.format(va_arg(ap, size_t));
1021 retval = formatter.format(va_arg(ap, int));
1023 dfsan_set_label(*va_labels++, formatter.str_cur(),
1024 formatter.num_written_bytes(retval));
1036 if (*(formatter.fmt_cur - 1) == 'L') {
1037 retval = formatter.format(va_arg(ap, long double));
1039 retval = formatter.format(va_arg(ap, double));
1041 dfsan_set_label(*va_labels++, formatter.str_cur(),
1042 formatter.num_written_bytes(retval));
1047 retval = formatter.format(va_arg(ap, int));
1048 dfsan_set_label(*va_labels++, formatter.str_cur(),
1049 formatter.num_written_bytes(retval));
1054 char *arg = va_arg(ap, char *);
1055 retval = formatter.format(arg);
1057 internal_memcpy(shadow_for(formatter.str_cur()), shadow_for(arg),
1058 sizeof(dfsan_label) *
1059 formatter.num_written_bytes(retval));
1065 retval = formatter.format(va_arg(ap, void *));
1066 dfsan_set_label(*va_labels++, formatter.str_cur(),
1067 formatter.num_written_bytes(retval));
1072 int *ptr = va_arg(ap, int *);
1073 *ptr = (int)formatter.str_off;
1075 dfsan_set_label(0, ptr, sizeof(ptr));
1081 retval = formatter.format();
1082 dfsan_set_label(0, formatter.str_cur(),
1083 formatter.num_written_bytes(retval));
1088 formatter.width = va_arg(ap, int);
1102 formatter.fmt_cur++;
1103 formatter.str_off += retval;
1108 // Number of bytes written in total.
1109 return formatter.str_off;
1113 SANITIZER_INTERFACE_ATTRIBUTE
1114 int __dfsw_sprintf(char *str, const char *format, dfsan_label str_label,
1115 dfsan_label format_label, dfsan_label *va_labels,
1116 dfsan_label *ret_label, ...) {
1118 va_start(ap, ret_label);
1119 int ret = format_buffer(str, ~0ul, format, va_labels, ret_label, ap);
1124 SANITIZER_INTERFACE_ATTRIBUTE
1125 int __dfsw_snprintf(char *str, size_t size, const char *format,
1126 dfsan_label str_label, dfsan_label size_label,
1127 dfsan_label format_label, dfsan_label *va_labels,
1128 dfsan_label *ret_label, ...) {
1130 va_start(ap, ret_label);
1131 int ret = format_buffer(str, size, format, va_labels, ret_label, ap);
1136 // Default empty implementations (weak). Users should redefine them.
1137 SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_pc_guard, u32 *) {}
1138 SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_pc_guard_init, u32 *,
1140 SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_pcs_init, void) {}
1141 SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_pc_indir, void) {}
1143 SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_cmp, void) {}
1144 SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_cmp1, void) {}
1145 SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_cmp2, void) {}
1146 SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_cmp4, void) {}
1147 SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_cmp8, void) {}
1148 SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_const_cmp1,
1150 SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_const_cmp2,
1152 SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_const_cmp4,
1154 SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_const_cmp8,
1156 SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_switch, void) {}