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1 //===-- dfsan.cc ----------------------------------------------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file is a part of DataFlowSanitizer.
11 //
12 // This file defines the custom functions listed in done_abilist.txt.
13 //===----------------------------------------------------------------------===//
14 
15 #include "sanitizer_common/sanitizer_common.h"
16 #include "sanitizer_common/sanitizer_internal_defs.h"
17 #include "sanitizer_common/sanitizer_linux.h"
18 
19 #include "dfsan/dfsan.h"
20 
21 #include <arpa/inet.h>
22 #include <assert.h>
23 #include <ctype.h>
24 #include <dlfcn.h>
25 #include <link.h>
26 #include <poll.h>
27 #include <pthread.h>
28 #include <pwd.h>
29 #include <sched.h>
30 #include <signal.h>
31 #include <stdarg.h>
32 #include <stdint.h>
33 #include <stdio.h>
34 #include <stdlib.h>
35 #include <string.h>
36 #include <sys/resource.h>
37 #include <sys/select.h>
38 #include <sys/stat.h>
39 #include <sys/time.h>
40 #include <sys/types.h>
41 #include <time.h>
42 #include <unistd.h>
43 
44 using namespace __dfsan;
45 
46 extern "C" {
47 SANITIZER_INTERFACE_ATTRIBUTE int
__dfsw_stat(const char * path,struct stat * buf,dfsan_label path_label,dfsan_label buf_label,dfsan_label * ret_label)48 __dfsw_stat(const char *path, struct stat *buf, dfsan_label path_label,
49             dfsan_label buf_label, dfsan_label *ret_label) {
50   int ret = stat(path, buf);
51   if (ret == 0)
52     dfsan_set_label(0, buf, sizeof(struct stat));
53   *ret_label = 0;
54   return ret;
55 }
56 
__dfsw_fstat(int fd,struct stat * buf,dfsan_label fd_label,dfsan_label buf_label,dfsan_label * ret_label)57 SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_fstat(int fd, struct stat *buf,
58                                                dfsan_label fd_label,
59                                                dfsan_label buf_label,
60                                                dfsan_label *ret_label) {
61   int ret = fstat(fd, buf);
62   if (ret == 0)
63     dfsan_set_label(0, buf, sizeof(struct stat));
64   *ret_label = 0;
65   return ret;
66 }
67 
__dfsw_strchr(const char * s,int c,dfsan_label s_label,dfsan_label c_label,dfsan_label * ret_label)68 SANITIZER_INTERFACE_ATTRIBUTE char *__dfsw_strchr(const char *s, int c,
69                                                   dfsan_label s_label,
70                                                   dfsan_label c_label,
71                                                   dfsan_label *ret_label) {
72   for (size_t i = 0;; ++i) {
73     if (s[i] == c || s[i] == 0) {
74       if (flags().strict_data_dependencies) {
75         *ret_label = s_label;
76       } else {
77         *ret_label = dfsan_union(dfsan_read_label(s, i + 1),
78                                  dfsan_union(s_label, c_label));
79       }
80       return s[i] == 0 ? 0 : const_cast<char *>(s+i);
81     }
82   }
83 }
84 
__dfsw_memcmp(const void * s1,const void * s2,size_t n,dfsan_label s1_label,dfsan_label s2_label,dfsan_label n_label,dfsan_label * ret_label)85 SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_memcmp(const void *s1, const void *s2,
86                                                 size_t n, dfsan_label s1_label,
87                                                 dfsan_label s2_label,
88                                                 dfsan_label n_label,
89                                                 dfsan_label *ret_label) {
90   const char *cs1 = (const char *) s1, *cs2 = (const char *) s2;
91   for (size_t i = 0; i != n; ++i) {
92     if (cs1[i] != cs2[i]) {
93       if (flags().strict_data_dependencies) {
94         *ret_label = 0;
95       } else {
96         *ret_label = dfsan_union(dfsan_read_label(cs1, i + 1),
97                                  dfsan_read_label(cs2, i + 1));
98       }
99       return cs1[i] - cs2[i];
100     }
101   }
102 
103   if (flags().strict_data_dependencies) {
104     *ret_label = 0;
105   } else {
106     *ret_label = dfsan_union(dfsan_read_label(cs1, n),
107                              dfsan_read_label(cs2, n));
108   }
109   return 0;
110 }
111 
__dfsw_strcmp(const char * s1,const char * s2,dfsan_label s1_label,dfsan_label s2_label,dfsan_label * ret_label)112 SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_strcmp(const char *s1, const char *s2,
113                                                 dfsan_label s1_label,
114                                                 dfsan_label s2_label,
115                                                 dfsan_label *ret_label) {
116   for (size_t i = 0;; ++i) {
117     if (s1[i] != s2[i] || s1[i] == 0 || s2[i] == 0) {
118       if (flags().strict_data_dependencies) {
119         *ret_label = 0;
120       } else {
121         *ret_label = dfsan_union(dfsan_read_label(s1, i + 1),
122                                  dfsan_read_label(s2, i + 1));
123       }
124       return s1[i] - s2[i];
125     }
126   }
127   return 0;
128 }
129 
130 SANITIZER_INTERFACE_ATTRIBUTE int
__dfsw_strcasecmp(const char * s1,const char * s2,dfsan_label s1_label,dfsan_label s2_label,dfsan_label * ret_label)131 __dfsw_strcasecmp(const char *s1, const char *s2, dfsan_label s1_label,
132                   dfsan_label s2_label, dfsan_label *ret_label) {
133   for (size_t i = 0;; ++i) {
134     if (tolower(s1[i]) != tolower(s2[i]) || s1[i] == 0 || s2[i] == 0) {
135       if (flags().strict_data_dependencies) {
136         *ret_label = 0;
137       } else {
138         *ret_label = dfsan_union(dfsan_read_label(s1, i + 1),
139                                  dfsan_read_label(s2, i + 1));
140       }
141       return s1[i] - s2[i];
142     }
143   }
144   return 0;
145 }
146 
__dfsw_strncmp(const char * s1,const char * s2,size_t n,dfsan_label s1_label,dfsan_label s2_label,dfsan_label n_label,dfsan_label * ret_label)147 SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_strncmp(const char *s1, const char *s2,
148                                                  size_t n, dfsan_label s1_label,
149                                                  dfsan_label s2_label,
150                                                  dfsan_label n_label,
151                                                  dfsan_label *ret_label) {
152   if (n == 0) {
153     *ret_label = 0;
154     return 0;
155   }
156 
157   for (size_t i = 0;; ++i) {
158     if (s1[i] != s2[i] || s1[i] == 0 || s2[i] == 0 || i == n - 1) {
159       if (flags().strict_data_dependencies) {
160         *ret_label = 0;
161       } else {
162         *ret_label = dfsan_union(dfsan_read_label(s1, i + 1),
163                                  dfsan_read_label(s2, i + 1));
164       }
165       return s1[i] - s2[i];
166     }
167   }
168   return 0;
169 }
170 
171 SANITIZER_INTERFACE_ATTRIBUTE int
__dfsw_strncasecmp(const char * s1,const char * s2,size_t n,dfsan_label s1_label,dfsan_label s2_label,dfsan_label n_label,dfsan_label * ret_label)172 __dfsw_strncasecmp(const char *s1, const char *s2, size_t n,
173                    dfsan_label s1_label, dfsan_label s2_label,
174                    dfsan_label n_label, dfsan_label *ret_label) {
175   if (n == 0) {
176     *ret_label = 0;
177     return 0;
178   }
179 
180   for (size_t i = 0;; ++i) {
181     if (tolower(s1[i]) != tolower(s2[i]) || s1[i] == 0 || s2[i] == 0 ||
182         i == n - 1) {
183       if (flags().strict_data_dependencies) {
184         *ret_label = 0;
185       } else {
186         *ret_label = dfsan_union(dfsan_read_label(s1, i + 1),
187                                  dfsan_read_label(s2, i + 1));
188       }
189       return s1[i] - s2[i];
190     }
191   }
192   return 0;
193 }
194 
__dfsw_calloc(size_t nmemb,size_t size,dfsan_label nmemb_label,dfsan_label size_label,dfsan_label * ret_label)195 SANITIZER_INTERFACE_ATTRIBUTE void *__dfsw_calloc(size_t nmemb, size_t size,
196                                                   dfsan_label nmemb_label,
197                                                   dfsan_label size_label,
198                                                   dfsan_label *ret_label) {
199   void *p = calloc(nmemb, size);
200   dfsan_set_label(0, p, nmemb * size);
201   *ret_label = 0;
202   return p;
203 }
204 
205 SANITIZER_INTERFACE_ATTRIBUTE size_t
__dfsw_strlen(const char * s,dfsan_label s_label,dfsan_label * ret_label)206 __dfsw_strlen(const char *s, dfsan_label s_label, dfsan_label *ret_label) {
207   size_t ret = strlen(s);
208   if (flags().strict_data_dependencies) {
209     *ret_label = 0;
210   } else {
211     *ret_label = dfsan_read_label(s, ret + 1);
212   }
213   return ret;
214 }
215 
216 
dfsan_memcpy(void * dest,const void * src,size_t n)217 static void *dfsan_memcpy(void *dest, const void *src, size_t n) {
218   dfsan_label *sdest = shadow_for(dest);
219   const dfsan_label *ssrc = shadow_for(src);
220   internal_memcpy((void *)sdest, (const void *)ssrc, n * sizeof(dfsan_label));
221   return internal_memcpy(dest, src, n);
222 }
223 
dfsan_memset(void * s,int c,dfsan_label c_label,size_t n)224 static void dfsan_memset(void *s, int c, dfsan_label c_label, size_t n) {
225   internal_memset(s, c, n);
226   dfsan_set_label(c_label, s, n);
227 }
228 
229 SANITIZER_INTERFACE_ATTRIBUTE
__dfsw_memcpy(void * dest,const void * src,size_t n,dfsan_label dest_label,dfsan_label src_label,dfsan_label n_label,dfsan_label * ret_label)230 void *__dfsw_memcpy(void *dest, const void *src, size_t n,
231                     dfsan_label dest_label, dfsan_label src_label,
232                     dfsan_label n_label, dfsan_label *ret_label) {
233   *ret_label = dest_label;
234   return dfsan_memcpy(dest, src, n);
235 }
236 
237 SANITIZER_INTERFACE_ATTRIBUTE
__dfsw_memset(void * s,int c,size_t n,dfsan_label s_label,dfsan_label c_label,dfsan_label n_label,dfsan_label * ret_label)238 void *__dfsw_memset(void *s, int c, size_t n,
239                     dfsan_label s_label, dfsan_label c_label,
240                     dfsan_label n_label, dfsan_label *ret_label) {
241   dfsan_memset(s, c, c_label, n);
242   *ret_label = s_label;
243   return s;
244 }
245 
246 SANITIZER_INTERFACE_ATTRIBUTE char *
__dfsw_strdup(const char * s,dfsan_label s_label,dfsan_label * ret_label)247 __dfsw_strdup(const char *s, dfsan_label s_label, dfsan_label *ret_label) {
248   size_t len = strlen(s);
249   void *p = malloc(len+1);
250   dfsan_memcpy(p, s, len+1);
251   *ret_label = 0;
252   return static_cast<char *>(p);
253 }
254 
255 SANITIZER_INTERFACE_ATTRIBUTE char *
__dfsw_strncpy(char * s1,const char * s2,size_t n,dfsan_label s1_label,dfsan_label s2_label,dfsan_label n_label,dfsan_label * ret_label)256 __dfsw_strncpy(char *s1, const char *s2, size_t n, dfsan_label s1_label,
257                dfsan_label s2_label, dfsan_label n_label,
258                dfsan_label *ret_label) {
259   size_t len = strlen(s2);
260   if (len < n) {
261     dfsan_memcpy(s1, s2, len+1);
262     dfsan_memset(s1+len+1, 0, 0, n-len-1);
263   } else {
264     dfsan_memcpy(s1, s2, n);
265   }
266 
267   *ret_label = s1_label;
268   return s1;
269 }
270 
271 SANITIZER_INTERFACE_ATTRIBUTE ssize_t
__dfsw_pread(int fd,void * buf,size_t count,off_t offset,dfsan_label fd_label,dfsan_label buf_label,dfsan_label count_label,dfsan_label offset_label,dfsan_label * ret_label)272 __dfsw_pread(int fd, void *buf, size_t count, off_t offset,
273              dfsan_label fd_label, dfsan_label buf_label,
274              dfsan_label count_label, dfsan_label offset_label,
275              dfsan_label *ret_label) {
276   ssize_t ret = pread(fd, buf, count, offset);
277   if (ret > 0)
278     dfsan_set_label(0, buf, ret);
279   *ret_label = 0;
280   return ret;
281 }
282 
283 SANITIZER_INTERFACE_ATTRIBUTE ssize_t
__dfsw_read(int fd,void * buf,size_t count,dfsan_label fd_label,dfsan_label buf_label,dfsan_label count_label,dfsan_label * ret_label)284 __dfsw_read(int fd, void *buf, size_t count,
285              dfsan_label fd_label, dfsan_label buf_label,
286              dfsan_label count_label,
287              dfsan_label *ret_label) {
288   ssize_t ret = read(fd, buf, count);
289   if (ret > 0)
290     dfsan_set_label(0, buf, ret);
291   *ret_label = 0;
292   return ret;
293 }
294 
__dfsw_clock_gettime(clockid_t clk_id,struct timespec * tp,dfsan_label clk_id_label,dfsan_label tp_label,dfsan_label * ret_label)295 SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_clock_gettime(clockid_t clk_id,
296                                                        struct timespec *tp,
297                                                        dfsan_label clk_id_label,
298                                                        dfsan_label tp_label,
299                                                        dfsan_label *ret_label) {
300   int ret = clock_gettime(clk_id, tp);
301   if (ret == 0)
302     dfsan_set_label(0, tp, sizeof(struct timespec));
303   *ret_label = 0;
304   return ret;
305 }
306 
unpoison(const void * ptr,uptr size)307 static void unpoison(const void *ptr, uptr size) {
308   dfsan_set_label(0, const_cast<void *>(ptr), size);
309 }
310 
311 // dlopen() ultimately calls mmap() down inside the loader, which generally
312 // doesn't participate in dynamic symbol resolution.  Therefore we won't
313 // intercept its calls to mmap, and we have to hook it here.
314 SANITIZER_INTERFACE_ATTRIBUTE void *
__dfsw_dlopen(const char * filename,int flag,dfsan_label filename_label,dfsan_label flag_label,dfsan_label * ret_label)315 __dfsw_dlopen(const char *filename, int flag, dfsan_label filename_label,
316               dfsan_label flag_label, dfsan_label *ret_label) {
317   void *handle = dlopen(filename, flag);
318   link_map *map = GET_LINK_MAP_BY_DLOPEN_HANDLE(handle);
319   if (map)
320     ForEachMappedRegion(map, unpoison);
321   *ret_label = 0;
322   return handle;
323 }
324 
325 struct pthread_create_info {
326   void *(*start_routine_trampoline)(void *, void *, dfsan_label, dfsan_label *);
327   void *start_routine;
328   void *arg;
329 };
330 
pthread_create_cb(void * p)331 static void *pthread_create_cb(void *p) {
332   pthread_create_info pci(*(pthread_create_info *)p);
333   free(p);
334   dfsan_label ret_label;
335   return pci.start_routine_trampoline(pci.start_routine, pci.arg, 0,
336                                       &ret_label);
337 }
338 
__dfsw_pthread_create(pthread_t * thread,const pthread_attr_t * attr,void * (* start_routine_trampoline)(void *,void *,dfsan_label,dfsan_label *),void * start_routine,void * arg,dfsan_label thread_label,dfsan_label attr_label,dfsan_label start_routine_label,dfsan_label arg_label,dfsan_label * ret_label)339 SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_pthread_create(
340     pthread_t *thread, const pthread_attr_t *attr,
341     void *(*start_routine_trampoline)(void *, void *, dfsan_label,
342                                       dfsan_label *),
343     void *start_routine, void *arg, dfsan_label thread_label,
344     dfsan_label attr_label, dfsan_label start_routine_label,
345     dfsan_label arg_label, dfsan_label *ret_label) {
346   pthread_create_info *pci =
347       (pthread_create_info *)malloc(sizeof(pthread_create_info));
348   pci->start_routine_trampoline = start_routine_trampoline;
349   pci->start_routine = start_routine;
350   pci->arg = arg;
351   int rv = pthread_create(thread, attr, pthread_create_cb, (void *)pci);
352   if (rv != 0)
353     free(pci);
354   *ret_label = 0;
355   return rv;
356 }
357 
358 struct dl_iterate_phdr_info {
359   int (*callback_trampoline)(void *callback, struct dl_phdr_info *info,
360                              size_t size, void *data, dfsan_label info_label,
361                              dfsan_label size_label, dfsan_label data_label,
362                              dfsan_label *ret_label);
363   void *callback;
364   void *data;
365 };
366 
dl_iterate_phdr_cb(struct dl_phdr_info * info,size_t size,void * data)367 int dl_iterate_phdr_cb(struct dl_phdr_info *info, size_t size, void *data) {
368   dl_iterate_phdr_info *dipi = (dl_iterate_phdr_info *)data;
369   dfsan_set_label(0, *info);
370   dfsan_set_label(0, const_cast<char *>(info->dlpi_name),
371                   strlen(info->dlpi_name) + 1);
372   dfsan_set_label(
373       0, const_cast<char *>(reinterpret_cast<const char *>(info->dlpi_phdr)),
374       sizeof(*info->dlpi_phdr) * info->dlpi_phnum);
375   dfsan_label ret_label;
376   return dipi->callback_trampoline(dipi->callback, info, size, dipi->data, 0, 0,
377                                    0, &ret_label);
378 }
379 
__dfsw_dl_iterate_phdr(int (* callback_trampoline)(void * callback,struct dl_phdr_info * info,size_t size,void * data,dfsan_label info_label,dfsan_label size_label,dfsan_label data_label,dfsan_label * ret_label),void * callback,void * data,dfsan_label callback_label,dfsan_label data_label,dfsan_label * ret_label)380 SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_dl_iterate_phdr(
381     int (*callback_trampoline)(void *callback, struct dl_phdr_info *info,
382                                size_t size, void *data, dfsan_label info_label,
383                                dfsan_label size_label, dfsan_label data_label,
384                                dfsan_label *ret_label),
385     void *callback, void *data, dfsan_label callback_label,
386     dfsan_label data_label, dfsan_label *ret_label) {
387   dl_iterate_phdr_info dipi = { callback_trampoline, callback, data };
388   *ret_label = 0;
389   return dl_iterate_phdr(dl_iterate_phdr_cb, &dipi);
390 }
391 
392 SANITIZER_INTERFACE_ATTRIBUTE
__dfsw_ctime_r(const time_t * timep,char * buf,dfsan_label timep_label,dfsan_label buf_label,dfsan_label * ret_label)393 char *__dfsw_ctime_r(const time_t *timep, char *buf, dfsan_label timep_label,
394                      dfsan_label buf_label, dfsan_label *ret_label) {
395   char *ret = ctime_r(timep, buf);
396   if (ret) {
397     dfsan_set_label(dfsan_read_label(timep, sizeof(time_t)), buf,
398                     strlen(buf) + 1);
399     *ret_label = buf_label;
400   } else {
401     *ret_label = 0;
402   }
403   return ret;
404 }
405 
406 SANITIZER_INTERFACE_ATTRIBUTE
__dfsw_fgets(char * s,int size,FILE * stream,dfsan_label s_label,dfsan_label size_label,dfsan_label stream_label,dfsan_label * ret_label)407 char *__dfsw_fgets(char *s, int size, FILE *stream, dfsan_label s_label,
408                    dfsan_label size_label, dfsan_label stream_label,
409                    dfsan_label *ret_label) {
410   char *ret = fgets(s, size, stream);
411   if (ret) {
412     dfsan_set_label(0, ret, strlen(ret) + 1);
413     *ret_label = s_label;
414   } else {
415     *ret_label = 0;
416   }
417   return ret;
418 }
419 
420 SANITIZER_INTERFACE_ATTRIBUTE
__dfsw_getcwd(char * buf,size_t size,dfsan_label buf_label,dfsan_label size_label,dfsan_label * ret_label)421 char *__dfsw_getcwd(char *buf, size_t size, dfsan_label buf_label,
422                     dfsan_label size_label, dfsan_label *ret_label) {
423   char *ret = getcwd(buf, size);
424   if (ret) {
425     dfsan_set_label(0, ret, strlen(ret) + 1);
426     *ret_label = buf_label;
427   } else {
428     *ret_label = 0;
429   }
430   return ret;
431 }
432 
433 SANITIZER_INTERFACE_ATTRIBUTE
__dfsw_get_current_dir_name(dfsan_label * ret_label)434 char *__dfsw_get_current_dir_name(dfsan_label *ret_label) {
435   char *ret = get_current_dir_name();
436   if (ret) {
437     dfsan_set_label(0, ret, strlen(ret) + 1);
438   }
439   *ret_label = 0;
440   return ret;
441 }
442 
443 SANITIZER_INTERFACE_ATTRIBUTE
__dfsw_gethostname(char * name,size_t len,dfsan_label name_label,dfsan_label len_label,dfsan_label * ret_label)444 int __dfsw_gethostname(char *name, size_t len, dfsan_label name_label,
445                        dfsan_label len_label, dfsan_label *ret_label) {
446   int ret = gethostname(name, len);
447   if (ret == 0) {
448     dfsan_set_label(0, name, strlen(name) + 1);
449   }
450   *ret_label = 0;
451   return ret;
452 }
453 
454 SANITIZER_INTERFACE_ATTRIBUTE
__dfsw_getrlimit(int resource,struct rlimit * rlim,dfsan_label resource_label,dfsan_label rlim_label,dfsan_label * ret_label)455 int __dfsw_getrlimit(int resource, struct rlimit *rlim,
456                      dfsan_label resource_label, dfsan_label rlim_label,
457                      dfsan_label *ret_label) {
458   int ret = getrlimit(resource, rlim);
459   if (ret == 0) {
460     dfsan_set_label(0, rlim, sizeof(struct rlimit));
461   }
462   *ret_label = 0;
463   return ret;
464 }
465 
466 SANITIZER_INTERFACE_ATTRIBUTE
__dfsw_getrusage(int who,struct rusage * usage,dfsan_label who_label,dfsan_label usage_label,dfsan_label * ret_label)467 int __dfsw_getrusage(int who, struct rusage *usage, dfsan_label who_label,
468                      dfsan_label usage_label, dfsan_label *ret_label) {
469   int ret = getrusage(who, usage);
470   if (ret == 0) {
471     dfsan_set_label(0, usage, sizeof(struct rusage));
472   }
473   *ret_label = 0;
474   return ret;
475 }
476 
477 SANITIZER_INTERFACE_ATTRIBUTE
__dfsw_strcpy(char * dest,const char * src,dfsan_label dst_label,dfsan_label src_label,dfsan_label * ret_label)478 char *__dfsw_strcpy(char *dest, const char *src, dfsan_label dst_label,
479                     dfsan_label src_label, dfsan_label *ret_label) {
480   char *ret = strcpy(dest, src);
481   if (ret) {
482     internal_memcpy(shadow_for(dest), shadow_for(src),
483                     sizeof(dfsan_label) * (strlen(src) + 1));
484   }
485   *ret_label = dst_label;
486   return ret;
487 }
488 
489 SANITIZER_INTERFACE_ATTRIBUTE
__dfsw_strtol(const char * nptr,char ** endptr,int base,dfsan_label nptr_label,dfsan_label endptr_label,dfsan_label base_label,dfsan_label * ret_label)490 long int __dfsw_strtol(const char *nptr, char **endptr, int base,
491                        dfsan_label nptr_label, dfsan_label endptr_label,
492                        dfsan_label base_label, dfsan_label *ret_label) {
493   char *tmp_endptr;
494   long int ret = strtol(nptr, &tmp_endptr, base);
495   if (endptr) {
496     *endptr = tmp_endptr;
497   }
498   if (tmp_endptr > nptr) {
499     // If *tmp_endptr is '\0' include its label as well.
500     *ret_label = dfsan_union(
501         base_label,
502         dfsan_read_label(nptr, tmp_endptr - nptr + (*tmp_endptr ? 0 : 1)));
503   } else {
504     *ret_label = 0;
505   }
506   return ret;
507 }
508 
509 SANITIZER_INTERFACE_ATTRIBUTE
__dfsw_strtod(const char * nptr,char ** endptr,dfsan_label nptr_label,dfsan_label endptr_label,dfsan_label * ret_label)510 double __dfsw_strtod(const char *nptr, char **endptr,
511                        dfsan_label nptr_label, dfsan_label endptr_label,
512                        dfsan_label *ret_label) {
513   char *tmp_endptr;
514   double ret = strtod(nptr, &tmp_endptr);
515   if (endptr) {
516     *endptr = tmp_endptr;
517   }
518   if (tmp_endptr > nptr) {
519     // If *tmp_endptr is '\0' include its label as well.
520     *ret_label = dfsan_read_label(
521         nptr,
522         tmp_endptr - nptr + (*tmp_endptr ? 0 : 1));
523   } else {
524     *ret_label = 0;
525   }
526   return ret;
527 }
528 
529 SANITIZER_INTERFACE_ATTRIBUTE
__dfsw_strtoll(const char * nptr,char ** endptr,int base,dfsan_label nptr_label,dfsan_label endptr_label,dfsan_label base_label,dfsan_label * ret_label)530 long long int __dfsw_strtoll(const char *nptr, char **endptr, int base,
531                        dfsan_label nptr_label, dfsan_label endptr_label,
532                        dfsan_label base_label, dfsan_label *ret_label) {
533   char *tmp_endptr;
534   long long int ret = strtoll(nptr, &tmp_endptr, base);
535   if (endptr) {
536     *endptr = tmp_endptr;
537   }
538   if (tmp_endptr > nptr) {
539     // If *tmp_endptr is '\0' include its label as well.
540     *ret_label = dfsan_union(
541         base_label,
542         dfsan_read_label(nptr, tmp_endptr - nptr + (*tmp_endptr ? 0 : 1)));
543   } else {
544     *ret_label = 0;
545   }
546   return ret;
547 }
548 
549 SANITIZER_INTERFACE_ATTRIBUTE
__dfsw_strtoul(const char * nptr,char ** endptr,int base,dfsan_label nptr_label,dfsan_label endptr_label,dfsan_label base_label,dfsan_label * ret_label)550 unsigned long int __dfsw_strtoul(const char *nptr, char **endptr, int base,
551                        dfsan_label nptr_label, dfsan_label endptr_label,
552                        dfsan_label base_label, dfsan_label *ret_label) {
553   char *tmp_endptr;
554   unsigned long int ret = strtoul(nptr, &tmp_endptr, base);
555   if (endptr) {
556     *endptr = tmp_endptr;
557   }
558   if (tmp_endptr > nptr) {
559     // If *tmp_endptr is '\0' include its label as well.
560     *ret_label = dfsan_union(
561         base_label,
562         dfsan_read_label(nptr, tmp_endptr - nptr + (*tmp_endptr ? 0 : 1)));
563   } else {
564     *ret_label = 0;
565   }
566   return ret;
567 }
568 
569 SANITIZER_INTERFACE_ATTRIBUTE
__dfsw_strtoull(const char * nptr,char ** endptr,dfsan_label nptr_label,int base,dfsan_label endptr_label,dfsan_label base_label,dfsan_label * ret_label)570 long long unsigned int __dfsw_strtoull(const char *nptr, char **endptr,
571                                        dfsan_label nptr_label,
572                                        int base, dfsan_label endptr_label,
573                                        dfsan_label base_label,
574                                        dfsan_label *ret_label) {
575   char *tmp_endptr;
576   long long unsigned int ret = strtoull(nptr, &tmp_endptr, base);
577   if (endptr) {
578     *endptr = tmp_endptr;
579   }
580   if (tmp_endptr > nptr) {
581     // If *tmp_endptr is '\0' include its label as well.
582     *ret_label = dfsan_union(
583         base_label,
584         dfsan_read_label(nptr, tmp_endptr - nptr + (*tmp_endptr ? 0 : 1)));
585   } else {
586     *ret_label = 0;
587   }
588   return ret;
589 }
590 
591 SANITIZER_INTERFACE_ATTRIBUTE
__dfsw_time(time_t * t,dfsan_label t_label,dfsan_label * ret_label)592 time_t __dfsw_time(time_t *t, dfsan_label t_label, dfsan_label *ret_label) {
593   time_t ret = time(t);
594   if (ret != (time_t) -1 && t) {
595     dfsan_set_label(0, t, sizeof(time_t));
596   }
597   *ret_label = 0;
598   return ret;
599 }
600 
601 SANITIZER_INTERFACE_ATTRIBUTE
__dfsw_inet_pton(int af,const char * src,void * dst,dfsan_label af_label,dfsan_label src_label,dfsan_label dst_label,dfsan_label * ret_label)602 int __dfsw_inet_pton(int af, const char *src, void *dst, dfsan_label af_label,
603                      dfsan_label src_label, dfsan_label dst_label,
604                      dfsan_label *ret_label) {
605   int ret = inet_pton(af, src, dst);
606   if (ret == 1) {
607     dfsan_set_label(dfsan_read_label(src, strlen(src) + 1), dst,
608                     af == AF_INET ? sizeof(struct in_addr) : sizeof(in6_addr));
609   }
610   *ret_label = 0;
611   return ret;
612 }
613 
614 SANITIZER_INTERFACE_ATTRIBUTE
__dfsw_localtime_r(const time_t * timep,struct tm * result,dfsan_label timep_label,dfsan_label result_label,dfsan_label * ret_label)615 struct tm *__dfsw_localtime_r(const time_t *timep, struct tm *result,
616                               dfsan_label timep_label, dfsan_label result_label,
617                               dfsan_label *ret_label) {
618   struct tm *ret = localtime_r(timep, result);
619   if (ret) {
620     dfsan_set_label(dfsan_read_label(timep, sizeof(time_t)), result,
621                     sizeof(struct tm));
622     *ret_label = result_label;
623   } else {
624     *ret_label = 0;
625   }
626   return ret;
627 }
628 
629 SANITIZER_INTERFACE_ATTRIBUTE
__dfsw_getpwuid_r(id_t uid,struct passwd * pwd,char * buf,size_t buflen,struct passwd ** result,dfsan_label uid_label,dfsan_label pwd_label,dfsan_label buf_label,dfsan_label buflen_label,dfsan_label result_label,dfsan_label * ret_label)630 int __dfsw_getpwuid_r(id_t uid, struct passwd *pwd,
631                       char *buf, size_t buflen, struct passwd **result,
632                       dfsan_label uid_label, dfsan_label pwd_label,
633                       dfsan_label buf_label, dfsan_label buflen_label,
634                       dfsan_label result_label, dfsan_label *ret_label) {
635   // Store the data in pwd, the strings referenced from pwd in buf, and the
636   // address of pwd in *result.  On failure, NULL is stored in *result.
637   int ret = getpwuid_r(uid, pwd, buf, buflen, result);
638   if (ret == 0) {
639     dfsan_set_label(0, pwd, sizeof(struct passwd));
640     dfsan_set_label(0, buf, strlen(buf) + 1);
641   }
642   *ret_label = 0;
643   dfsan_set_label(0, result, sizeof(struct passwd*));
644   return ret;
645 }
646 
647 SANITIZER_INTERFACE_ATTRIBUTE
__dfsw_poll(struct pollfd * fds,nfds_t nfds,int timeout,dfsan_label dfs_label,dfsan_label nfds_label,dfsan_label timeout_label,dfsan_label * ret_label)648 int __dfsw_poll(struct pollfd *fds, nfds_t nfds, int timeout,
649                 dfsan_label dfs_label, dfsan_label nfds_label,
650                 dfsan_label timeout_label, dfsan_label *ret_label) {
651   int ret = poll(fds, nfds, timeout);
652   if (ret >= 0) {
653     for (; nfds > 0; --nfds) {
654       dfsan_set_label(0, &fds[nfds - 1].revents, sizeof(fds[nfds - 1].revents));
655     }
656   }
657   *ret_label = 0;
658   return ret;
659 }
660 
661 SANITIZER_INTERFACE_ATTRIBUTE
__dfsw_select(int nfds,fd_set * readfds,fd_set * writefds,fd_set * exceptfds,struct timeval * timeout,dfsan_label nfds_label,dfsan_label readfds_label,dfsan_label writefds_label,dfsan_label exceptfds_label,dfsan_label timeout_label,dfsan_label * ret_label)662 int __dfsw_select(int nfds, fd_set *readfds, fd_set *writefds,
663                   fd_set *exceptfds, struct timeval *timeout,
664                   dfsan_label nfds_label, dfsan_label readfds_label,
665                   dfsan_label writefds_label, dfsan_label exceptfds_label,
666                   dfsan_label timeout_label, dfsan_label *ret_label) {
667   int ret = select(nfds, readfds, writefds, exceptfds, timeout);
668   // Clear everything (also on error) since their content is either set or
669   // undefined.
670   if (readfds) {
671     dfsan_set_label(0, readfds, sizeof(fd_set));
672   }
673   if (writefds) {
674     dfsan_set_label(0, writefds, sizeof(fd_set));
675   }
676   if (exceptfds) {
677     dfsan_set_label(0, exceptfds, sizeof(fd_set));
678   }
679   dfsan_set_label(0, timeout, sizeof(struct timeval));
680   *ret_label = 0;
681   return ret;
682 }
683 
684 SANITIZER_INTERFACE_ATTRIBUTE
__dfsw_sched_getaffinity(pid_t pid,size_t cpusetsize,cpu_set_t * mask,dfsan_label pid_label,dfsan_label cpusetsize_label,dfsan_label mask_label,dfsan_label * ret_label)685 int __dfsw_sched_getaffinity(pid_t pid, size_t cpusetsize, cpu_set_t *mask,
686                              dfsan_label pid_label,
687                              dfsan_label cpusetsize_label,
688                              dfsan_label mask_label, dfsan_label *ret_label) {
689   int ret = sched_getaffinity(pid, cpusetsize, mask);
690   if (ret == 0) {
691     dfsan_set_label(0, mask, cpusetsize);
692   }
693   *ret_label = 0;
694   return ret;
695 }
696 
697 SANITIZER_INTERFACE_ATTRIBUTE
__dfsw_sigemptyset(sigset_t * set,dfsan_label set_label,dfsan_label * ret_label)698 int __dfsw_sigemptyset(sigset_t *set, dfsan_label set_label,
699                        dfsan_label *ret_label) {
700   int ret = sigemptyset(set);
701   dfsan_set_label(0, set, sizeof(sigset_t));
702   return ret;
703 }
704 
705 SANITIZER_INTERFACE_ATTRIBUTE
__dfsw_sigaction(int signum,const struct sigaction * act,struct sigaction * oldact,dfsan_label signum_label,dfsan_label act_label,dfsan_label oldact_label,dfsan_label * ret_label)706 int __dfsw_sigaction(int signum, const struct sigaction *act,
707                      struct sigaction *oldact, dfsan_label signum_label,
708                      dfsan_label act_label, dfsan_label oldact_label,
709                      dfsan_label *ret_label) {
710   int ret = sigaction(signum, act, oldact);
711   if (oldact) {
712     dfsan_set_label(0, oldact, sizeof(struct sigaction));
713   }
714   *ret_label = 0;
715   return ret;
716 }
717 
718 SANITIZER_INTERFACE_ATTRIBUTE
__dfsw_gettimeofday(struct timeval * tv,struct timezone * tz,dfsan_label tv_label,dfsan_label tz_label,dfsan_label * ret_label)719 int __dfsw_gettimeofday(struct timeval *tv, struct timezone *tz,
720                         dfsan_label tv_label, dfsan_label tz_label,
721                         dfsan_label *ret_label) {
722   int ret = gettimeofday(tv, tz);
723   if (tv) {
724     dfsan_set_label(0, tv, sizeof(struct timeval));
725   }
726   if (tz) {
727     dfsan_set_label(0, tz, sizeof(struct timezone));
728   }
729   *ret_label = 0;
730   return ret;
731 }
732 
__dfsw_memchr(void * s,int c,size_t n,dfsan_label s_label,dfsan_label c_label,dfsan_label n_label,dfsan_label * ret_label)733 SANITIZER_INTERFACE_ATTRIBUTE void *__dfsw_memchr(void *s, int c, size_t n,
734                                                   dfsan_label s_label,
735                                                   dfsan_label c_label,
736                                                   dfsan_label n_label,
737                                                   dfsan_label *ret_label) {
738   void *ret = memchr(s, c, n);
739   if (flags().strict_data_dependencies) {
740     *ret_label = ret ? s_label : 0;
741   } else {
742     size_t len =
743         ret ? reinterpret_cast<char *>(ret) - reinterpret_cast<char *>(s) + 1
744             : n;
745     *ret_label =
746         dfsan_union(dfsan_read_label(s, len), dfsan_union(s_label, c_label));
747   }
748   return ret;
749 }
750 
__dfsw_strrchr(char * s,int c,dfsan_label s_label,dfsan_label c_label,dfsan_label * ret_label)751 SANITIZER_INTERFACE_ATTRIBUTE char *__dfsw_strrchr(char *s, int c,
752                                                    dfsan_label s_label,
753                                                    dfsan_label c_label,
754                                                    dfsan_label *ret_label) {
755   char *ret = strrchr(s, c);
756   if (flags().strict_data_dependencies) {
757     *ret_label = ret ? s_label : 0;
758   } else {
759     *ret_label =
760         dfsan_union(dfsan_read_label(s, strlen(s) + 1),
761                     dfsan_union(s_label, c_label));
762   }
763 
764   return ret;
765 }
766 
__dfsw_strstr(char * haystack,char * needle,dfsan_label haystack_label,dfsan_label needle_label,dfsan_label * ret_label)767 SANITIZER_INTERFACE_ATTRIBUTE char *__dfsw_strstr(char *haystack, char *needle,
768                                                   dfsan_label haystack_label,
769                                                   dfsan_label needle_label,
770                                                   dfsan_label *ret_label) {
771   char *ret = strstr(haystack, needle);
772   if (flags().strict_data_dependencies) {
773     *ret_label = ret ? haystack_label : 0;
774   } else {
775     size_t len = ret ? ret + strlen(needle) - haystack : strlen(haystack) + 1;
776     *ret_label =
777         dfsan_union(dfsan_read_label(haystack, len),
778                     dfsan_union(dfsan_read_label(needle, strlen(needle) + 1),
779                                 dfsan_union(haystack_label, needle_label)));
780   }
781 
782   return ret;
783 }
784 
__dfsw_nanosleep(const struct timespec * req,struct timespec * rem,dfsan_label req_label,dfsan_label rem_label,dfsan_label * ret_label)785 SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_nanosleep(const struct timespec *req,
786                                                    struct timespec *rem,
787                                                    dfsan_label req_label,
788                                                    dfsan_label rem_label,
789                                                    dfsan_label *ret_label) {
790   int ret = nanosleep(req, rem);
791   *ret_label = 0;
792   if (ret == -1) {
793     // Interrupted by a signal, rem is filled with the remaining time.
794     dfsan_set_label(0, rem, sizeof(struct timespec));
795   }
796   return ret;
797 }
798 
799 SANITIZER_INTERFACE_ATTRIBUTE int
__dfsw_socketpair(int domain,int type,int protocol,int sv[2],dfsan_label domain_label,dfsan_label type_label,dfsan_label protocol_label,dfsan_label sv_label,dfsan_label * ret_label)800 __dfsw_socketpair(int domain, int type, int protocol, int sv[2],
801                   dfsan_label domain_label, dfsan_label type_label,
802                   dfsan_label protocol_label, dfsan_label sv_label,
803                   dfsan_label *ret_label) {
804   int ret = socketpair(domain, type, protocol, sv);
805   *ret_label = 0;
806   if (ret == 0) {
807     dfsan_set_label(0, sv, sizeof(*sv) * 2);
808   }
809   return ret;
810 }
811 
812 // Type of the trampoline function passed to the custom version of
813 // dfsan_set_write_callback.
814 typedef void (*write_trampoline_t)(
815     void *callback,
816     int fd, const void *buf, ssize_t count,
817     dfsan_label fd_label, dfsan_label buf_label, dfsan_label count_label);
818 
819 // Calls to dfsan_set_write_callback() set the values in this struct.
820 // Calls to the custom version of write() read (and invoke) them.
821 static struct {
822   write_trampoline_t write_callback_trampoline = NULL;
823   void *write_callback = NULL;
824 } write_callback_info;
825 
826 SANITIZER_INTERFACE_ATTRIBUTE void
__dfsw_dfsan_set_write_callback(write_trampoline_t write_callback_trampoline,void * write_callback,dfsan_label write_callback_label,dfsan_label * ret_label)827 __dfsw_dfsan_set_write_callback(
828     write_trampoline_t write_callback_trampoline,
829     void *write_callback,
830     dfsan_label write_callback_label,
831     dfsan_label *ret_label) {
832   write_callback_info.write_callback_trampoline = write_callback_trampoline;
833   write_callback_info.write_callback = write_callback;
834 }
835 
836 SANITIZER_INTERFACE_ATTRIBUTE int
__dfsw_write(int fd,const void * buf,size_t count,dfsan_label fd_label,dfsan_label buf_label,dfsan_label count_label,dfsan_label * ret_label)837 __dfsw_write(int fd, const void *buf, size_t count,
838              dfsan_label fd_label, dfsan_label buf_label,
839              dfsan_label count_label, dfsan_label *ret_label) {
840   if (write_callback_info.write_callback != NULL) {
841     write_callback_info.write_callback_trampoline(
842         write_callback_info.write_callback,
843         fd, buf, count,
844         fd_label, buf_label, count_label);
845   }
846 
847   *ret_label = 0;
848   return write(fd, buf, count);
849 }
850 }
851 
852 // Type used to extract a dfsan_label with va_arg()
853 typedef int dfsan_label_va;
854 
855 // Formats a chunk either a constant string or a single format directive (e.g.,
856 // '%.3f').
857 struct Formatter {
FormatterFormatter858   Formatter(char *str_, const char *fmt_, size_t size_)
859       : str(str_), str_off(0), size(size_), fmt_start(fmt_), fmt_cur(fmt_),
860         width(-1) {}
861 
formatFormatter862   int format() {
863     char *tmp_fmt = build_format_string();
864     int retval =
865         snprintf(str + str_off, str_off < size ? size - str_off : 0, tmp_fmt,
866                  0 /* used only to avoid warnings */);
867     free(tmp_fmt);
868     return retval;
869   }
870 
formatFormatter871   template <typename T> int format(T arg) {
872     char *tmp_fmt = build_format_string();
873     int retval;
874     if (width >= 0) {
875       retval = snprintf(str + str_off, str_off < size ? size - str_off : 0,
876                         tmp_fmt, width, arg);
877     } else {
878       retval = snprintf(str + str_off, str_off < size ? size - str_off : 0,
879                         tmp_fmt, arg);
880     }
881     free(tmp_fmt);
882     return retval;
883   }
884 
build_format_stringFormatter885   char *build_format_string() {
886     size_t fmt_size = fmt_cur - fmt_start + 1;
887     char *new_fmt = (char *)malloc(fmt_size + 1);
888     assert(new_fmt);
889     internal_memcpy(new_fmt, fmt_start, fmt_size);
890     new_fmt[fmt_size] = '\0';
891     return new_fmt;
892   }
893 
str_curFormatter894   char *str_cur() { return str + str_off; }
895 
num_written_bytesFormatter896   size_t num_written_bytes(int retval) {
897     if (retval < 0) {
898       return 0;
899     }
900 
901     size_t num_avail = str_off < size ? size - str_off : 0;
902     if (num_avail == 0) {
903       return 0;
904     }
905 
906     size_t num_written = retval;
907     // A return value of {v,}snprintf of size or more means that the output was
908     // truncated.
909     if (num_written >= num_avail) {
910       num_written -= num_avail;
911     }
912 
913     return num_written;
914   }
915 
916   char *str;
917   size_t str_off;
918   size_t size;
919   const char *fmt_start;
920   const char *fmt_cur;
921   int width;
922 };
923 
924 // Formats the input and propagates the input labels to the output. The output
925 // is stored in 'str'. 'size' bounds the number of output bytes. 'format' and
926 // 'ap' are the format string and the list of arguments for formatting. Returns
927 // the return value vsnprintf would return.
928 //
929 // The function tokenizes the format string in chunks representing either a
930 // constant string or a single format directive (e.g., '%.3f') and formats each
931 // chunk independently into the output string. This approach allows to figure
932 // out which bytes of the output string depends on which argument and thus to
933 // propagate labels more precisely.
934 //
935 // WARNING: This implementation does not support conversion specifiers with
936 // positional arguments.
format_buffer(char * str,size_t size,const char * fmt,dfsan_label * va_labels,dfsan_label * ret_label,va_list ap)937 static int format_buffer(char *str, size_t size, const char *fmt,
938                          dfsan_label *va_labels, dfsan_label *ret_label,
939                          va_list ap) {
940   Formatter formatter(str, fmt, size);
941 
942   while (*formatter.fmt_cur) {
943     formatter.fmt_start = formatter.fmt_cur;
944     formatter.width = -1;
945     int retval = 0;
946 
947     if (*formatter.fmt_cur != '%') {
948       // Ordinary character. Consume all the characters until a '%' or the end
949       // of the string.
950       for (; *(formatter.fmt_cur + 1) && *(formatter.fmt_cur + 1) != '%';
951            ++formatter.fmt_cur) {}
952       retval = formatter.format();
953       dfsan_set_label(0, formatter.str_cur(),
954                       formatter.num_written_bytes(retval));
955     } else {
956       // Conversion directive. Consume all the characters until a conversion
957       // specifier or the end of the string.
958       bool end_fmt = false;
959       for (; *formatter.fmt_cur && !end_fmt; ) {
960         switch (*++formatter.fmt_cur) {
961         case 'd':
962         case 'i':
963         case 'o':
964         case 'u':
965         case 'x':
966         case 'X':
967           switch (*(formatter.fmt_cur - 1)) {
968           case 'h':
969             // Also covers the 'hh' case (since the size of the arg is still
970             // an int).
971             retval = formatter.format(va_arg(ap, int));
972             break;
973           case 'l':
974             if (formatter.fmt_cur - formatter.fmt_start >= 2 &&
975                 *(formatter.fmt_cur - 2) == 'l') {
976               retval = formatter.format(va_arg(ap, long long int));
977             } else {
978               retval = formatter.format(va_arg(ap, long int));
979             }
980             break;
981           case 'q':
982             retval = formatter.format(va_arg(ap, long long int));
983             break;
984           case 'j':
985             retval = formatter.format(va_arg(ap, intmax_t));
986             break;
987           case 'z':
988           case 't':
989             retval = formatter.format(va_arg(ap, size_t));
990             break;
991           default:
992             retval = formatter.format(va_arg(ap, int));
993           }
994           dfsan_set_label(*va_labels++, formatter.str_cur(),
995                           formatter.num_written_bytes(retval));
996           end_fmt = true;
997           break;
998 
999         case 'a':
1000         case 'A':
1001         case 'e':
1002         case 'E':
1003         case 'f':
1004         case 'F':
1005         case 'g':
1006         case 'G':
1007           if (*(formatter.fmt_cur - 1) == 'L') {
1008             retval = formatter.format(va_arg(ap, long double));
1009           } else {
1010             retval = formatter.format(va_arg(ap, double));
1011           }
1012           dfsan_set_label(*va_labels++, formatter.str_cur(),
1013                           formatter.num_written_bytes(retval));
1014           end_fmt = true;
1015           break;
1016 
1017         case 'c':
1018           retval = formatter.format(va_arg(ap, int));
1019           dfsan_set_label(*va_labels++, formatter.str_cur(),
1020                           formatter.num_written_bytes(retval));
1021           end_fmt = true;
1022           break;
1023 
1024         case 's': {
1025           char *arg = va_arg(ap, char *);
1026           retval = formatter.format(arg);
1027           va_labels++;
1028           internal_memcpy(shadow_for(formatter.str_cur()), shadow_for(arg),
1029                           sizeof(dfsan_label) *
1030                               formatter.num_written_bytes(retval));
1031           end_fmt = true;
1032           break;
1033         }
1034 
1035         case 'p':
1036           retval = formatter.format(va_arg(ap, void *));
1037           dfsan_set_label(*va_labels++, formatter.str_cur(),
1038                           formatter.num_written_bytes(retval));
1039           end_fmt = true;
1040           break;
1041 
1042         case 'n': {
1043           int *ptr = va_arg(ap, int *);
1044           *ptr = (int)formatter.str_off;
1045           va_labels++;
1046           dfsan_set_label(0, ptr, sizeof(ptr));
1047           end_fmt = true;
1048           break;
1049         }
1050 
1051         case '%':
1052           retval = formatter.format();
1053           dfsan_set_label(0, formatter.str_cur(),
1054                           formatter.num_written_bytes(retval));
1055           end_fmt = true;
1056           break;
1057 
1058         case '*':
1059           formatter.width = va_arg(ap, int);
1060           va_labels++;
1061           break;
1062 
1063         default:
1064           break;
1065         }
1066       }
1067     }
1068 
1069     if (retval < 0) {
1070       return retval;
1071     }
1072 
1073     formatter.fmt_cur++;
1074     formatter.str_off += retval;
1075   }
1076 
1077   *ret_label = 0;
1078 
1079   // Number of bytes written in total.
1080   return formatter.str_off;
1081 }
1082 
1083 extern "C" {
1084 SANITIZER_INTERFACE_ATTRIBUTE
__dfsw_sprintf(char * str,const char * format,dfsan_label str_label,dfsan_label format_label,dfsan_label * va_labels,dfsan_label * ret_label,...)1085 int __dfsw_sprintf(char *str, const char *format, dfsan_label str_label,
1086                    dfsan_label format_label, dfsan_label *va_labels,
1087                    dfsan_label *ret_label, ...) {
1088   va_list ap;
1089   va_start(ap, ret_label);
1090   int ret = format_buffer(str, ~0ul, format, va_labels, ret_label, ap);
1091   va_end(ap);
1092   return ret;
1093 }
1094 
1095 SANITIZER_INTERFACE_ATTRIBUTE
__dfsw_snprintf(char * str,size_t size,const char * format,dfsan_label str_label,dfsan_label size_label,dfsan_label format_label,dfsan_label * va_labels,dfsan_label * ret_label,...)1096 int __dfsw_snprintf(char *str, size_t size, const char *format,
1097                     dfsan_label str_label, dfsan_label size_label,
1098                     dfsan_label format_label, dfsan_label *va_labels,
1099                     dfsan_label *ret_label, ...) {
1100   va_list ap;
1101   va_start(ap, ret_label);
1102   int ret = format_buffer(str, size, format, va_labels, ret_label, ap);
1103   va_end(ap);
1104   return ret;
1105 }
1106 }
1107