1 //===-- sanitizer_linux.cc ------------------------------------------------===//
2 //
3 // This file is distributed under the University of Illinois Open Source
4 // License. See LICENSE.TXT for details.
5 //
6 //===----------------------------------------------------------------------===//
7 //
8 // This file is shared between AddressSanitizer and ThreadSanitizer
9 // run-time libraries and implements linux-specific functions from
10 // sanitizer_libc.h.
11 //===----------------------------------------------------------------------===//
12
13 #include "sanitizer_platform.h"
14
15 #if SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD || \
16 SANITIZER_OPENBSD || SANITIZER_SOLARIS
17
18 #include "sanitizer_common.h"
19 #include "sanitizer_flags.h"
20 #include "sanitizer_getauxval.h"
21 #include "sanitizer_internal_defs.h"
22 #include "sanitizer_libc.h"
23 #include "sanitizer_linux.h"
24 #include "sanitizer_mutex.h"
25 #include "sanitizer_placement_new.h"
26 #include "sanitizer_procmaps.h"
27
28 #if SANITIZER_LINUX
29 #include <asm/param.h>
30 #endif
31
32 // For mips64, syscall(__NR_stat) fills the buffer in the 'struct kernel_stat'
33 // format. Struct kernel_stat is defined as 'struct stat' in asm/stat.h. To
34 // access stat from asm/stat.h, without conflicting with definition in
35 // sys/stat.h, we use this trick.
36 #if SANITIZER_LINUX
37 #if defined(__mips64)
38 #include <asm/unistd.h>
39 #include <sys/types.h>
40 #define stat kernel_stat
41 #include <asm/stat.h>
42 #undef stat
43 #endif
44 #endif
45
46 #if SANITIZER_NETBSD
47 #include <lwp.h>
48 #endif
49
50 #include <dlfcn.h>
51 #include <errno.h>
52 #include <fcntl.h>
53 #include <link.h>
54 #include <pthread.h>
55 #include <sched.h>
56 #include <signal.h>
57 #include <sys/mman.h>
58 #include <sys/param.h>
59 #if !SANITIZER_SOLARIS
60 #include <sys/ptrace.h>
61 #endif
62 #include <sys/resource.h>
63 #include <sys/stat.h>
64 #include <sys/syscall.h>
65 #include <sys/time.h>
66 #include <sys/types.h>
67 #if !SANITIZER_OPENBSD
68 #include <ucontext.h>
69 #endif
70 #if SANITIZER_OPENBSD
71 #include <sys/futex.h>
72 #include <sys/sysctl.h>
73 #endif
74 #include <unistd.h>
75
76 #if SANITIZER_LINUX
77 #include <sys/utsname.h>
78 #endif
79
80 #if SANITIZER_LINUX && !SANITIZER_ANDROID
81 #include <sys/personality.h>
82 #endif
83
84 #if SANITIZER_FREEBSD
85 #include <sys/exec.h>
86 #include <sys/sysctl.h>
87 #include <machine/atomic.h>
88 extern "C" {
89 // <sys/umtx.h> must be included after <errno.h> and <sys/types.h> on
90 // FreeBSD 9.2 and 10.0.
91 #include <sys/umtx.h>
92 }
93 #include <sys/thr.h>
94 #endif // SANITIZER_FREEBSD
95 #if SANITIZER_NETBSD
96 #include <limits.h> // For NAME_MAX
97 #include <sys/sysctl.h>
98 #include <sys/exec.h>
99 extern struct ps_strings *__ps_strings;
100 extern char **environ; // provided by crt1
101 #endif // SANITIZER_NETBSD
102
103 #if SANITIZER_NETBSD
104 #include <limits.h> // For NAME_MAX
105 #include <sys/sysctl.h>
106 #include <sys/exec.h>
107 extern struct ps_strings *__ps_strings;
108 #endif // SANITIZER_NETBSD
109
110 #if SANITIZER_SOLARIS
111 #include <stdlib.h>
112 #include <thread.h>
113 #define environ _environ
114 #endif
115
116 extern char **environ;
117
118 #if SANITIZER_LINUX
119 // <linux/time.h>
120 struct kernel_timeval {
121 long tv_sec;
122 long tv_usec;
123 };
124
125 // <linux/futex.h> is broken on some linux distributions.
126 const int FUTEX_WAIT = 0;
127 const int FUTEX_WAKE = 1;
128 const int FUTEX_PRIVATE_FLAG = 128;
129 const int FUTEX_WAIT_PRIVATE = FUTEX_WAIT | FUTEX_PRIVATE_FLAG;
130 const int FUTEX_WAKE_PRIVATE = FUTEX_WAKE | FUTEX_PRIVATE_FLAG;
131 #endif // SANITIZER_LINUX
132
133 // Are we using 32-bit or 64-bit Linux syscalls?
134 // x32 (which defines __x86_64__) has SANITIZER_WORDSIZE == 32
135 // but it still needs to use 64-bit syscalls.
136 #if SANITIZER_LINUX && (defined(__x86_64__) || defined(__powerpc64__) || \
137 SANITIZER_WORDSIZE == 64)
138 # define SANITIZER_LINUX_USES_64BIT_SYSCALLS 1
139 #else
140 # define SANITIZER_LINUX_USES_64BIT_SYSCALLS 0
141 #endif
142
143 #if defined(__x86_64__) || SANITIZER_MIPS64
144 extern "C" {
145 extern void internal_sigreturn();
146 }
147 #endif
148
149 // Note : FreeBSD had implemented both
150 // Linux and OpenBSD apis, available from
151 // future 12.x version most likely
152 #if SANITIZER_LINUX && defined(__NR_getrandom)
153 # if !defined(GRND_NONBLOCK)
154 # define GRND_NONBLOCK 1
155 # endif
156 # define SANITIZER_USE_GETRANDOM 1
157 #else
158 # define SANITIZER_USE_GETRANDOM 0
159 #endif // SANITIZER_LINUX && defined(__NR_getrandom)
160
161 #if SANITIZER_OPENBSD
162 # define SANITIZER_USE_GETENTROPY 1
163 #else
164 # if SANITIZER_FREEBSD && __FreeBSD_version >= 1200000
165 # define SANITIZER_USE_GETENTROPY 1
166 # else
167 # define SANITIZER_USE_GETENTROPY 0
168 # endif
169 #endif // SANITIZER_USE_GETENTROPY
170
171 namespace __sanitizer {
172
173 #if SANITIZER_LINUX && defined(__x86_64__)
174 #include "sanitizer_syscall_linux_x86_64.inc"
175 #elif SANITIZER_LINUX && defined(__aarch64__)
176 #include "sanitizer_syscall_linux_aarch64.inc"
177 #elif SANITIZER_LINUX && defined(__arm__)
178 #include "sanitizer_syscall_linux_arm.inc"
179 #else
180 #include "sanitizer_syscall_generic.inc"
181 #endif
182
183 // --------------- sanitizer_libc.h
184 #if !SANITIZER_SOLARIS && !SANITIZER_NETBSD
185 #if !SANITIZER_S390 && !SANITIZER_OPENBSD
internal_mmap(void * addr,uptr length,int prot,int flags,int fd,OFF_T offset)186 uptr internal_mmap(void *addr, uptr length, int prot, int flags, int fd,
187 OFF_T offset) {
188 #if SANITIZER_NETBSD
189
190 #if !defined(_LP64) && BYTE_ORDER == _BIG_ENDIAN
191 #define __SYSCALL_TO_UINTPTR_T(V) ((uintptr_t)((V)>>32))
192 #else
193 #define __SYSCALL_TO_UINTPTR_T(V) ((uintptr_t)(V))
194 #endif
195
196 return __SYSCALL_TO_UINTPTR_T(
197 internal_syscall64(SYSCALL(mmap), addr, length, prot, flags, fd,
198 (long)0, offset));
199 //return internal_syscall_ptr(SYSCALL(mmap), addr, length, prot, flags, fd,
200 // (long)0, offset);
201 #elif SANITIZER_FREEBSD || SANITIZER_LINUX_USES_64BIT_SYSCALLS
202 return internal_syscall(SYSCALL(mmap), (uptr)addr, length, prot, flags, fd,
203 offset, 0);
204 #else
205 // mmap2 specifies file offset in 4096-byte units.
206 CHECK(IsAligned(offset, 4096));
207 return internal_syscall(SYSCALL(mmap2), addr, length, prot, flags, fd,
208 offset / 4096);
209 #endif
210 }
211 #endif // !SANITIZER_S390 && !SANITIZER_OPENBSD
212
213 #if !SANITIZER_OPENBSD
internal_munmap(void * addr,uptr length)214 uptr internal_munmap(void *addr, uptr length) {
215 return internal_syscall_ptr(SYSCALL(munmap), (uptr)addr, length);
216 }
217
internal_mprotect(void * addr,uptr length,int prot)218 int internal_mprotect(void *addr, uptr length, int prot) {
219 return internal_syscall_ptr(SYSCALL(mprotect), (uptr)addr, length, prot);
220 }
221 #endif
222
internal_close(fd_t fd)223 uptr internal_close(fd_t fd) {
224 return internal_syscall(SYSCALL(close), fd);
225 }
226
internal_open(const char * filename,int flags)227 uptr internal_open(const char *filename, int flags) {
228 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
229 return internal_syscall(SYSCALL(openat), AT_FDCWD, (uptr)filename, flags);
230 #else
231 return internal_syscall_ptr(SYSCALL(open), (uptr)filename, flags);
232 #endif
233 }
234
internal_open(const char * filename,int flags,u32 mode)235 uptr internal_open(const char *filename, int flags, u32 mode) {
236 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
237 return internal_syscall(SYSCALL(openat), AT_FDCWD, (uptr)filename, flags,
238 mode);
239 #else
240 return internal_syscall_ptr(SYSCALL(open), (uptr)filename, flags, mode);
241 #endif
242 }
243
internal_read(fd_t fd,void * buf,uptr count)244 uptr internal_read(fd_t fd, void *buf, uptr count) {
245 sptr res;
246 HANDLE_EINTR(res,
247 (sptr)internal_syscall(SYSCALL(read), fd, (uptr)buf, count));
248 return res;
249 }
250
internal_write(fd_t fd,const void * buf,uptr count)251 uptr internal_write(fd_t fd, const void *buf, uptr count) {
252 sptr res;
253 HANDLE_EINTR(res,
254 (sptr)internal_syscall(SYSCALL(write), fd, (uptr)buf, count));
255 return res;
256 }
257
internal_ftruncate(fd_t fd,uptr size)258 uptr internal_ftruncate(fd_t fd, uptr size) {
259 sptr res;
260 #if SANITIZER_NETBSD
261 //HANDLE_EINTR(res, internal_syscall64(SYSCALL(ftruncate), fd, 0, (s64)size));
262 HANDLE_EINTR(res, internal_syscall(SYSCALL(ftruncate), fd, 0, (s64)size));
263 #else
264 HANDLE_EINTR(res, (sptr)internal_syscall(SYSCALL(ftruncate), fd,
265 (OFF_T)size));
266 #endif
267 return res;
268 }
269
270 #if !SANITIZER_LINUX_USES_64BIT_SYSCALLS && SANITIZER_LINUX
stat64_to_stat(struct stat64 * in,struct stat * out)271 static void stat64_to_stat(struct stat64 *in, struct stat *out) {
272 internal_memset(out, 0, sizeof(*out));
273 out->st_dev = in->st_dev;
274 out->st_ino = in->st_ino;
275 out->st_mode = in->st_mode;
276 out->st_nlink = in->st_nlink;
277 out->st_uid = in->st_uid;
278 out->st_gid = in->st_gid;
279 out->st_rdev = in->st_rdev;
280 out->st_size = in->st_size;
281 out->st_blksize = in->st_blksize;
282 out->st_blocks = in->st_blocks;
283 out->st_atime = in->st_atime;
284 out->st_mtime = in->st_mtime;
285 out->st_ctime = in->st_ctime;
286 }
287 #endif
288
289 #if defined(__mips64) && SANITIZER_LINUX
290 // Undefine compatibility macros from <sys/stat.h>
291 // so that they would not clash with the kernel_stat
292 // st_[a|m|c]time fields
293 #undef st_atime
294 #undef st_mtime
295 #undef st_ctime
296 #if defined(SANITIZER_ANDROID)
297 // Bionic sys/stat.h defines additional macros
298 // for compatibility with the old NDKs and
299 // they clash with the kernel_stat structure
300 // st_[a|m|c]time_nsec fields.
301 #undef st_atime_nsec
302 #undef st_mtime_nsec
303 #undef st_ctime_nsec
304 #endif
305
kernel_stat_to_stat(struct kernel_stat * in,struct stat * out)306 static void kernel_stat_to_stat(struct kernel_stat *in, struct stat *out) {
307 internal_memset(out, 0, sizeof(*out));
308 out->st_dev = in->st_dev;
309 out->st_ino = in->st_ino;
310 out->st_mode = in->st_mode;
311 out->st_nlink = in->st_nlink;
312 out->st_uid = in->st_uid;
313 out->st_gid = in->st_gid;
314 out->st_rdev = in->st_rdev;
315 out->st_size = in->st_size;
316 out->st_blksize = in->st_blksize;
317 out->st_blocks = in->st_blocks;
318 #if defined(__USE_MISC) || \
319 defined(__USE_XOPEN2K8) || \
320 defined(SANITIZER_ANDROID)
321 out->st_atim.tv_sec = in->st_atime;
322 out->st_atim.tv_nsec = in->st_atime_nsec;
323 out->st_mtim.tv_sec = in->st_mtime;
324 out->st_mtim.tv_nsec = in->st_mtime_nsec;
325 out->st_ctim.tv_sec = in->st_ctime;
326 out->st_ctim.tv_nsec = in->st_ctime_nsec;
327 #else
328 out->st_atime = in->st_atime;
329 out->st_atimensec = in->st_atime_nsec;
330 out->st_mtime = in->st_mtime;
331 out->st_mtimensec = in->st_mtime_nsec;
332 out->st_ctime = in->st_ctime;
333 out->st_atimensec = in->st_ctime_nsec;
334 #endif
335 }
336 #endif
337
internal_stat(const char * path,void * buf)338 uptr internal_stat(const char *path, void *buf) {
339 #if SANITIZER_FREEBSD || SANITIZER_NETBSD || SANITIZER_OPENBSD
340 return internal_syscall(SYSCALL(fstatat), AT_FDCWD, (uptr)path, (uptr)buf, 0);
341 #elif SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
342 return internal_syscall(SYSCALL(newfstatat), AT_FDCWD, (uptr)path, (uptr)buf,
343 0);
344 #elif SANITIZER_LINUX_USES_64BIT_SYSCALLS
345 # if defined(__mips64)
346 // For mips64, stat syscall fills buffer in the format of kernel_stat
347 struct kernel_stat kbuf;
348 int res = internal_syscall(SYSCALL(stat), path, &kbuf);
349 kernel_stat_to_stat(&kbuf, (struct stat *)buf);
350 return res;
351 # else
352 return internal_syscall(SYSCALL(stat), (uptr)path, (uptr)buf);
353 # endif
354 #else
355 struct stat64 buf64;
356 int res = internal_syscall(SYSCALL(stat64), path, &buf64);
357 stat64_to_stat(&buf64, (struct stat *)buf);
358 return res;
359 #endif
360 }
361
internal_lstat(const char * path,void * buf)362 uptr internal_lstat(const char *path, void *buf) {
363 #if SANITIZER_NETBSD
364 return internal_syscall(SYSCALL(lstat), path, buf);
365 #elif SANITIZER_FREEBSD || SANITIZER_OPENBSD
366 return internal_syscall(SYSCALL(fstatat), AT_FDCWD, (uptr)path, (uptr)buf,
367 AT_SYMLINK_NOFOLLOW);
368 #elif SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
369 return internal_syscall(SYSCALL(newfstatat), AT_FDCWD, (uptr)path, (uptr)buf,
370 AT_SYMLINK_NOFOLLOW);
371 #elif SANITIZER_LINUX_USES_64BIT_SYSCALLS
372 # if SANITIZER_MIPS64
373 // For mips64, lstat syscall fills buffer in the format of kernel_stat
374 struct kernel_stat kbuf;
375 int res = internal_syscall(SYSCALL(lstat), path, &kbuf);
376 kernel_stat_to_stat(&kbuf, (struct stat *)buf);
377 return res;
378 # else
379 return internal_syscall(SYSCALL(lstat), (uptr)path, (uptr)buf);
380 # endif
381 #else
382 struct stat64 buf64;
383 int res = internal_syscall(SYSCALL(lstat64), path, &buf64);
384 stat64_to_stat(&buf64, (struct stat *)buf);
385 return res;
386 #endif
387 }
388
internal_fstat(fd_t fd,void * buf)389 uptr internal_fstat(fd_t fd, void *buf) {
390 #if SANITIZER_NETBSD
391 return internal_syscall_ptr(SYSCALL(fstat), fd, (uptr)buf);
392 #elif SANITIZER_FREEBSD || SANITIZER_OPENBSD || \
393 SANITIZER_LINUX_USES_64BIT_SYSCALLS
394 #if SANITIZER_MIPS64 && !SANITIZER_OPENBSD
395 // For mips64, fstat syscall fills buffer in the format of kernel_stat
396 struct kernel_stat kbuf;
397 int res = internal_syscall(SYSCALL(fstat), fd, &kbuf);
398 kernel_stat_to_stat(&kbuf, (struct stat *)buf);
399 return res;
400 # else
401 return internal_syscall(SYSCALL(fstat), fd, (uptr)buf);
402 # endif
403 #else
404 struct stat64 buf64;
405 int res = internal_syscall(SYSCALL(fstat64), fd, &buf64);
406 stat64_to_stat(&buf64, (struct stat *)buf);
407 return res;
408 #endif
409 }
410
internal_filesize(fd_t fd)411 uptr internal_filesize(fd_t fd) {
412 struct stat st;
413 if (internal_fstat(fd, &st))
414 return -1;
415 return (uptr)st.st_size;
416 }
417
internal_dup2(int oldfd,int newfd)418 uptr internal_dup2(int oldfd, int newfd) {
419 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
420 return internal_syscall(SYSCALL(dup3), oldfd, newfd, 0);
421 #else
422 return internal_syscall(SYSCALL(dup2), oldfd, newfd);
423 #endif
424 }
425
internal_readlink(const char * path,char * buf,uptr bufsize)426 uptr internal_readlink(const char *path, char *buf, uptr bufsize) {
427 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
428 return internal_syscall(SYSCALL(readlinkat), AT_FDCWD, (uptr)path, (uptr)buf,
429 bufsize);
430 #elif SANITIZER_OPENBSD
431 return internal_syscall(SYSCALL(readlinkat), AT_FDCWD, (uptr)path, (uptr)buf,
432 bufsize);
433 #else
434 return internal_syscall(SYSCALL(readlink), (uptr)path, (uptr)buf, bufsize);
435 #endif
436 }
437
internal_unlink(const char * path)438 uptr internal_unlink(const char *path) {
439 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS || SANITIZER_OPENBSD
440 return internal_syscall(SYSCALL(unlinkat), AT_FDCWD, (uptr)path, 0);
441 #else
442 return internal_syscall_ptr(SYSCALL(unlink), (uptr)path);
443 #endif
444 }
445
internal_rename(const char * oldpath,const char * newpath)446 uptr internal_rename(const char *oldpath, const char *newpath) {
447 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS || SANITIZER_OPENBSD
448 return internal_syscall(SYSCALL(renameat), AT_FDCWD, (uptr)oldpath, AT_FDCWD,
449 (uptr)newpath);
450 #else
451 return internal_syscall_ptr(SYSCALL(rename), (uptr)oldpath, (uptr)newpath);
452 #endif
453 }
454
internal_sched_yield()455 uptr internal_sched_yield() {
456 return internal_syscall(SYSCALL(sched_yield));
457 }
458
internal__exit(int exitcode)459 void internal__exit(int exitcode) {
460 #if SANITIZER_FREEBSD || SANITIZER_OPENBSD
461 internal_syscall(SYSCALL(exit), exitcode);
462 #else
463 internal_syscall(SYSCALL(exit_group), exitcode);
464 #endif
465 Die(); // Unreachable.
466 }
467
internal_sleep(unsigned int seconds)468 unsigned int internal_sleep(unsigned int seconds) {
469 struct timespec ts;
470 ts.tv_sec = 1;
471 ts.tv_nsec = 0;
472 int res = internal_syscall_ptr(SYSCALL(nanosleep), &ts, &ts);
473 if (res) return ts.tv_sec;
474 return 0;
475 }
476
internal_execve(const char * filename,char * const argv[],char * const envp[])477 uptr internal_execve(const char *filename, char *const argv[],
478 char *const envp[]) {
479 return internal_syscall_ptr(SYSCALL(execve), (uptr)filename, (uptr)argv,
480 (uptr)envp);
481 }
482 #endif // !SANITIZER_SOLARIS && !SANITIZER_NETBSD
483
484 // ----------------- sanitizer_common.h
FileExists(const char * filename)485 bool FileExists(const char *filename) {
486 struct stat st;
487 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
488 if (internal_syscall(SYSCALL(newfstatat), AT_FDCWD, filename, &st, 0))
489 #else
490 if (internal_stat(filename, &st))
491 #endif
492 return false;
493 // Sanity check: filename is a regular file.
494 return S_ISREG(st.st_mode);
495 }
496
497 #if !SANITIZER_NETBSD
GetTid()498 tid_t GetTid() {
499 #if SANITIZER_FREEBSD
500 long Tid;
501 thr_self(&Tid);
502 return Tid;
503 #elif SANITIZER_OPENBSD
504 return internal_syscall(SYSCALL(getthrid));
505 #elif SANITIZER_SOLARIS
506 return thr_self();
507 #else
508 return internal_syscall(SYSCALL(gettid));
509 #endif
510 }
511
TgKill(pid_t pid,tid_t tid,int sig)512 int TgKill(pid_t pid, tid_t tid, int sig) {
513 #if SANITIZER_LINUX
514 return internal_syscall(SYSCALL(tgkill), pid, tid, sig);
515 #elif SANITIZER_FREEBSD
516 return internal_syscall(SYSCALL(thr_kill2), pid, tid, sig);
517 #elif SANITIZER_OPENBSD
518 (void)pid;
519 return internal_syscall(SYSCALL(thrkill), tid, sig, nullptr);
520 #elif SANITIZER_SOLARIS
521 (void)pid;
522 return thr_kill(tid, sig);
523 #endif
524 }
525 #endif
526
527 #if !SANITIZER_SOLARIS && !SANITIZER_NETBSD
NanoTime()528 u64 NanoTime() {
529 #if SANITIZER_FREEBSD || SANITIZER_OPENBSD
530 timeval tv;
531 #else
532 kernel_timeval tv;
533 #endif
534 internal_memset(&tv, 0, sizeof(tv));
535 internal_syscall(SYSCALL(gettimeofday), &tv, 0);
536 return (u64)tv.tv_sec * 1000*1000*1000 + tv.tv_usec * 1000;
537 }
538
internal_clock_gettime(__sanitizer_clockid_t clk_id,void * tp)539 uptr internal_clock_gettime(__sanitizer_clockid_t clk_id, void *tp) {
540 return internal_syscall(SYSCALL(clock_gettime), clk_id, tp);
541 }
542 #endif // !SANITIZER_SOLARIS && !SANITIZER_NETBSD
543
544 // Like getenv, but reads env directly from /proc (on Linux) or parses the
545 // 'environ' array (on some others) and does not use libc. This function
546 // should be called first inside __asan_init.
GetEnv(const char * name)547 const char *GetEnv(const char *name) {
548 #if SANITIZER_FREEBSD || SANITIZER_NETBSD || SANITIZER_OPENBSD || \
549 SANITIZER_SOLARIS
550 if (::environ != 0) {
551 uptr NameLen = internal_strlen(name);
552 for (char **Env = ::environ; *Env != 0; Env++) {
553 if (internal_strncmp(*Env, name, NameLen) == 0 && (*Env)[NameLen] == '=')
554 return (*Env) + NameLen + 1;
555 }
556 }
557 return 0; // Not found.
558 #elif SANITIZER_LINUX
559 static char *environ;
560 static uptr len;
561 static bool inited;
562 if (!inited) {
563 inited = true;
564 uptr environ_size;
565 if (!ReadFileToBuffer("/proc/self/environ", &environ, &environ_size, &len))
566 environ = nullptr;
567 }
568 if (!environ || len == 0) return nullptr;
569 uptr namelen = internal_strlen(name);
570 const char *p = environ;
571 while (*p != '\0') { // will happen at the \0\0 that terminates the buffer
572 // proc file has the format NAME=value\0NAME=value\0NAME=value\0...
573 const char* endp =
574 (char*)internal_memchr(p, '\0', len - (p - environ));
575 if (!endp) // this entry isn't NUL terminated
576 return nullptr;
577 else if (!internal_memcmp(p, name, namelen) && p[namelen] == '=') // Match.
578 return p + namelen + 1; // point after =
579 p = endp + 1;
580 }
581 return nullptr; // Not found.
582 #else
583 #error "Unsupported platform"
584 #endif
585 }
586
587 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD && !SANITIZER_OPENBSD
588 extern "C" {
589 SANITIZER_WEAK_ATTRIBUTE extern void *__libc_stack_end;
590 }
591 #endif
592
593 #if !SANITIZER_GO && !SANITIZER_FREEBSD && !SANITIZER_NETBSD && \
594 !SANITIZER_OPENBSD
ReadNullSepFileToArray(const char * path,char *** arr,int arr_size)595 static void ReadNullSepFileToArray(const char *path, char ***arr,
596 int arr_size) {
597 char *buff;
598 uptr buff_size;
599 uptr buff_len;
600 *arr = (char **)MmapOrDie(arr_size * sizeof(char *), "NullSepFileArray");
601 if (!ReadFileToBuffer(path, &buff, &buff_size, &buff_len, 1024 * 1024)) {
602 (*arr)[0] = nullptr;
603 return;
604 }
605 (*arr)[0] = buff;
606 int count, i;
607 for (count = 1, i = 1; ; i++) {
608 if (buff[i] == 0) {
609 if (buff[i+1] == 0) break;
610 (*arr)[count] = &buff[i+1];
611 CHECK_LE(count, arr_size - 1); // FIXME: make this more flexible.
612 count++;
613 }
614 }
615 (*arr)[count] = nullptr;
616 }
617 #endif
618
619 #if !SANITIZER_OPENBSD
GetArgsAndEnv(char *** argv,char *** envp)620 static void GetArgsAndEnv(char ***argv, char ***envp) {
621 #if SANITIZER_FREEBSD
622 // On FreeBSD, retrieving the argument and environment arrays is done via the
623 // kern.ps_strings sysctl, which returns a pointer to a structure containing
624 // this information. See also <sys/exec.h>.
625 ps_strings *pss;
626 uptr sz = sizeof(pss);
627 if (internal_sysctlbyname("kern.ps_strings", &pss, &sz, NULL, 0) == -1) {
628 Printf("sysctl kern.ps_strings failed\n");
629 Die();
630 }
631 *argv = pss->ps_argvstr;
632 *envp = pss->ps_envstr;
633 #elif SANITIZER_NETBSD
634 *argv = __ps_strings->ps_argvstr;
635 *envp = __ps_strings->ps_envstr;
636 #else // SANITIZER_FREEBSD
637 #if !SANITIZER_GO
638 if (&__libc_stack_end) {
639 #endif // !SANITIZER_GO
640 uptr* stack_end = (uptr*)__libc_stack_end;
641 int argc = *stack_end;
642 *argv = (char**)(stack_end + 1);
643 *envp = (char**)(stack_end + argc + 2);
644 #if !SANITIZER_GO
645 } else {
646 static const int kMaxArgv = 2000, kMaxEnvp = 2000;
647 ReadNullSepFileToArray("/proc/self/cmdline", argv, kMaxArgv);
648 ReadNullSepFileToArray("/proc/self/environ", envp, kMaxEnvp);
649 }
650 #endif // !SANITIZER_GO
651 #endif // SANITIZER_FREEBSD
652 }
653
GetArgv()654 char **GetArgv() {
655 char **argv, **envp;
656 GetArgsAndEnv(&argv, &envp);
657 return argv;
658 }
659
ReExec()660 void ReExec() {
661 char **argv, **envp;
662 const char *pathname = "/proc/self/exe";
663
664 #if SANITIZER_NETBSD
665 static const int name[] = {
666 CTL_KERN, KERN_PROC_ARGS, -1, KERN_PROC_PATHNAME,
667 };
668 char path[400];
669 uptr len;
670
671 len = sizeof(path);
672 if (internal_sysctl(name, ARRAY_SIZE(name), path, &len, NULL, 0) != -1)
673 pathname = path;
674 #elif SANITIZER_SOLARIS
675 pathname = getexecname();
676 CHECK_NE(pathname, NULL);
677 #endif
678
679 GetArgsAndEnv(&argv, &envp);
680 uptr rv = internal_execve(pathname, argv, envp);
681 int rverrno;
682 CHECK_EQ(internal_iserror(rv, &rverrno), true);
683 Printf("execve failed, errno %d\n", rverrno);
684 Die();
685 }
686 #endif
687
688 #if !SANITIZER_SOLARIS
689 enum MutexState {
690 MtxUnlocked = 0,
691 MtxLocked = 1,
692 MtxSleeping = 2
693 };
694
BlockingMutex()695 BlockingMutex::BlockingMutex() {
696 internal_memset(this, 0, sizeof(*this));
697 }
698
Lock()699 void BlockingMutex::Lock() {
700 CHECK_EQ(owner_, 0);
701 atomic_uint32_t *m = reinterpret_cast<atomic_uint32_t *>(&opaque_storage_);
702 if (atomic_exchange(m, MtxLocked, memory_order_acquire) == MtxUnlocked)
703 return;
704 while (atomic_exchange(m, MtxSleeping, memory_order_acquire) != MtxUnlocked) {
705 #if SANITIZER_FREEBSD
706 _umtx_op(m, UMTX_OP_WAIT_UINT, MtxSleeping, 0, 0);
707 #elif SANITIZER_NETBSD
708 sched_yield(); /* No userspace futex-like synchronization */
709 #else
710 internal_syscall(SYSCALL(futex), (uptr)m, FUTEX_WAIT_PRIVATE, MtxSleeping,
711 0, 0, 0);
712 #endif
713 }
714 }
715
Unlock()716 void BlockingMutex::Unlock() {
717 atomic_uint32_t *m = reinterpret_cast<atomic_uint32_t *>(&opaque_storage_);
718 u32 v = atomic_exchange(m, MtxUnlocked, memory_order_release);
719 CHECK_NE(v, MtxUnlocked);
720 if (v == MtxSleeping) {
721 #if SANITIZER_FREEBSD
722 _umtx_op(m, UMTX_OP_WAKE, 1, 0, 0);
723 #elif SANITIZER_NETBSD
724 /* No userspace futex-like synchronization */
725 #else
726 internal_syscall(SYSCALL(futex), (uptr)m, FUTEX_WAKE_PRIVATE, 1, 0, 0, 0);
727 #endif
728 }
729 }
730
CheckLocked()731 void BlockingMutex::CheckLocked() {
732 atomic_uint32_t *m = reinterpret_cast<atomic_uint32_t *>(&opaque_storage_);
733 CHECK_NE(MtxUnlocked, atomic_load(m, memory_order_relaxed));
734 }
735 #endif // !SANITIZER_SOLARIS
736
737 // ----------------- sanitizer_linux.h
738 // The actual size of this structure is specified by d_reclen.
739 // Note that getdents64 uses a different structure format. We only provide the
740 // 32-bit syscall here.
741 #if SANITIZER_NETBSD
742 // Not used
743 #elif SANITIZER_OPENBSD
744 // struct dirent is different for Linux and us. At this moment, we use only
745 // d_fileno (Linux call this d_ino), d_reclen, and d_name.
746 struct linux_dirent {
747 u64 d_ino; // d_fileno
748 u16 d_reclen;
749 u16 d_namlen; // not used
750 u8 d_type; // not used
751 char d_name[NAME_MAX + 1];
752 };
753 #else
754 struct linux_dirent {
755 #if SANITIZER_X32 || defined(__aarch64__)
756 u64 d_ino;
757 u64 d_off;
758 #else
759 unsigned long d_ino;
760 unsigned long d_off;
761 #endif
762 unsigned short d_reclen;
763 #ifdef __aarch64__
764 unsigned char d_type;
765 #endif
766 char d_name[256];
767 };
768 #endif
769
770 #if !SANITIZER_SOLARIS && !SANITIZER_NETBSD
771 // Syscall wrappers.
internal_ptrace(int request,int pid,void * addr,void * data)772 uptr internal_ptrace(int request, int pid, void *addr, void *data) {
773 return internal_syscall(SYSCALL(ptrace), request, pid, (uptr)addr,
774 (uptr)data);
775 }
776
internal_waitpid(int pid,int * status,int options)777 uptr internal_waitpid(int pid, int *status, int options) {
778 return internal_syscall(SYSCALL(wait4), pid, (uptr)status, options,
779 0 /* rusage */);
780 }
781
internal_getpid()782 uptr internal_getpid() {
783 return internal_syscall(SYSCALL(getpid));
784 }
785
internal_getppid()786 uptr internal_getppid() {
787 return internal_syscall(SYSCALL(getppid));
788 }
789
internal_dlinfo(void * handle,int request,void * p)790 int internal_dlinfo(void *handle, int request, void *p) {
791 #if SANITIZER_FREEBSD || (SANITIZER_LINUX && !SANITIZER_ANDROID) || \
792 SANITIZER_SOLARIS
793 return dlinfo(handle, request, p);
794 #else
795 UNIMPLEMENTED();
796 #endif
797 }
798
internal_getdents(fd_t fd,struct linux_dirent * dirp,unsigned int count)799 uptr internal_getdents(fd_t fd, struct linux_dirent *dirp, unsigned int count) {
800 #if SANITIZER_FREEBSD
801 return internal_syscall(SYSCALL(getdirentries), fd, (uptr)dirp, count, NULL);
802 #elif SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
803 return internal_syscall(SYSCALL(getdents64), fd, (uptr)dirp, count);
804 #else
805 return internal_syscall(SYSCALL(getdents), fd, (uptr)dirp, count);
806 #endif
807 }
808
internal_lseek(fd_t fd,OFF_T offset,int whence)809 uptr internal_lseek(fd_t fd, OFF_T offset, int whence) {
810 return internal_syscall(SYSCALL(lseek), fd, offset, whence);
811 }
812
813 #if SANITIZER_LINUX
internal_prctl(int option,uptr arg2,uptr arg3,uptr arg4,uptr arg5)814 uptr internal_prctl(int option, uptr arg2, uptr arg3, uptr arg4, uptr arg5) {
815 return internal_syscall(SYSCALL(prctl), option, arg2, arg3, arg4, arg5);
816 }
817 #endif
818
internal_sigaltstack(const void * ss,void * oss)819 uptr internal_sigaltstack(const void *ss, void *oss) {
820 return internal_syscall_ptr(SYSCALL(sigaltstack), (uptr)ss, (uptr)oss);
821 }
822
internal_fork()823 int internal_fork() {
824 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
825 return internal_syscall(SYSCALL(clone), SIGCHLD, 0);
826 #else
827 return internal_syscall(SYSCALL(fork));
828 #endif
829 }
830
831 #if SANITIZER_NETBSD
832 #include <signal.h>
833 extern "C" int __sigaction_siginfo(int, const struct sigaction *, struct sigaction *);
internal_sigaction_norestorer(int signum,const void * act,void * oldact)834 int internal_sigaction_norestorer(int signum, const void *act, void *oldact) {
835
836 return __sigaction_siginfo(signum,
837 reinterpret_cast<const struct sigaction *>(act),
838 reinterpret_cast<struct sigaction *>(oldact));
839 }
840 #endif
841
842 #if SANITIZER_FREEBSD || SANITIZER_OPENBSD
internal_sysctl(const int * name,unsigned int namelen,void * oldp,uptr * oldlenp,const void * newp,uptr newlen)843 int internal_sysctl(const int *name, unsigned int namelen, void *oldp,
844 uptr *oldlenp, const void *newp, uptr newlen) {
845 #if SANITIZER_OPENBSD
846 return sysctl(name, namelen, oldp, (size_t *)oldlenp, (void *)newp,
847 (size_t)newlen);
848 #else
849 return sysctl(name, namelen, oldp, (size_t *)oldlenp, newp, (size_t)newlen);
850 #endif
851 }
852
853 #if SANITIZER_FREEBSD
internal_sysctlbyname(const char * sname,void * oldp,uptr * oldlenp,const void * newp,uptr newlen)854 int internal_sysctlbyname(const char *sname, void *oldp, uptr *oldlenp,
855 const void *newp, uptr newlen) {
856 return sysctlbyname(sname, oldp, (size_t *)oldlenp, newp, (size_t)newlen);
857 }
858 #endif
859 #endif
860
861 #if SANITIZER_LINUX
862 #define SA_RESTORER 0x04000000
863 // Doesn't set sa_restorer if the caller did not set it, so use with caution
864 //(see below).
internal_sigaction_norestorer(int signum,const void * act,void * oldact)865 int internal_sigaction_norestorer(int signum, const void *act, void *oldact) {
866 __sanitizer_kernel_sigaction_t k_act, k_oldact;
867 internal_memset(&k_act, 0, sizeof(__sanitizer_kernel_sigaction_t));
868 internal_memset(&k_oldact, 0, sizeof(__sanitizer_kernel_sigaction_t));
869 const __sanitizer_sigaction *u_act = (const __sanitizer_sigaction *)act;
870 __sanitizer_sigaction *u_oldact = (__sanitizer_sigaction *)oldact;
871 if (u_act) {
872 k_act.handler = u_act->handler;
873 k_act.sigaction = u_act->sigaction;
874 internal_memcpy(&k_act.sa_mask, &u_act->sa_mask,
875 sizeof(__sanitizer_kernel_sigset_t));
876 // Without SA_RESTORER kernel ignores the calls (probably returns EINVAL).
877 k_act.sa_flags = u_act->sa_flags | SA_RESTORER;
878 // FIXME: most often sa_restorer is unset, however the kernel requires it
879 // to point to a valid signal restorer that calls the rt_sigreturn syscall.
880 // If sa_restorer passed to the kernel is NULL, the program may crash upon
881 // signal delivery or fail to unwind the stack in the signal handler.
882 // libc implementation of sigaction() passes its own restorer to
883 // rt_sigaction, so we need to do the same (we'll need to reimplement the
884 // restorers; for x86_64 the restorer address can be obtained from
885 // oldact->sa_restorer upon a call to sigaction(xxx, NULL, oldact).
886 #if !SANITIZER_ANDROID || !SANITIZER_MIPS32
887 k_act.sa_restorer = u_act->sa_restorer;
888 #endif
889 }
890
891 uptr result = internal_syscall(SYSCALL(rt_sigaction), (uptr)signum,
892 (uptr)(u_act ? &k_act : nullptr),
893 (uptr)(u_oldact ? &k_oldact : nullptr),
894 (uptr)sizeof(__sanitizer_kernel_sigset_t));
895
896 if ((result == 0) && u_oldact) {
897 u_oldact->handler = k_oldact.handler;
898 u_oldact->sigaction = k_oldact.sigaction;
899 internal_memcpy(&u_oldact->sa_mask, &k_oldact.sa_mask,
900 sizeof(__sanitizer_kernel_sigset_t));
901 u_oldact->sa_flags = k_oldact.sa_flags;
902 #if !SANITIZER_ANDROID || !SANITIZER_MIPS32
903 u_oldact->sa_restorer = k_oldact.sa_restorer;
904 #endif
905 }
906 return result;
907 }
908
909 // Invokes sigaction via a raw syscall with a restorer, but does not support
910 // all platforms yet.
911 // We disable for Go simply because we have not yet added to buildgo.sh.
912 #if (defined(__x86_64__) || SANITIZER_MIPS64) && !SANITIZER_GO
internal_sigaction_syscall(int signum,const void * act,void * oldact)913 int internal_sigaction_syscall(int signum, const void *act, void *oldact) {
914 if (act == nullptr)
915 return internal_sigaction_norestorer(signum, act, oldact);
916 __sanitizer_sigaction u_adjust;
917 internal_memcpy(&u_adjust, act, sizeof(u_adjust));
918 #if !SANITIZER_ANDROID || !SANITIZER_MIPS32
919 if (u_adjust.sa_restorer == nullptr) {
920 u_adjust.sa_restorer = internal_sigreturn;
921 }
922 #endif
923 return internal_sigaction_norestorer(signum, (const void *)&u_adjust, oldact);
924 }
925 #endif // defined(__x86_64__) && !SANITIZER_GO
926 #endif // SANITIZER_LINUX
927
internal_sigprocmask(int how,__sanitizer_sigset_t * set,__sanitizer_sigset_t * oldset)928 uptr internal_sigprocmask(int how, __sanitizer_sigset_t *set,
929 __sanitizer_sigset_t *oldset) {
930 #if SANITIZER_FREEBSD || SANITIZER_OPENBSD
931 return internal_syscall(SYSCALL(sigprocmask), how, set, oldset);
932 #else
933 __sanitizer_kernel_sigset_t *k_set = (__sanitizer_kernel_sigset_t *)set;
934 __sanitizer_kernel_sigset_t *k_oldset = (__sanitizer_kernel_sigset_t *)oldset;
935 return internal_syscall(SYSCALL(rt_sigprocmask), (uptr)how,
936 (uptr)&k_set->sig[0], (uptr)&k_oldset->sig[0],
937 sizeof(__sanitizer_kernel_sigset_t));
938 #endif
939 }
940
internal_sigfillset(__sanitizer_sigset_t * set)941 void internal_sigfillset(__sanitizer_sigset_t *set) {
942 internal_memset(set, 0xff, sizeof(*set));
943 }
944
internal_sigemptyset(__sanitizer_sigset_t * set)945 void internal_sigemptyset(__sanitizer_sigset_t *set) {
946 internal_memset(set, 0, sizeof(*set));
947 }
948
949 #if SANITIZER_LINUX
internal_sigdelset(__sanitizer_sigset_t * set,int signum)950 void internal_sigdelset(__sanitizer_sigset_t *set, int signum) {
951 signum -= 1;
952 CHECK_GE(signum, 0);
953 CHECK_LT(signum, sizeof(*set) * 8);
954 __sanitizer_kernel_sigset_t *k_set = (__sanitizer_kernel_sigset_t *)set;
955 const uptr idx = signum / (sizeof(k_set->sig[0]) * 8);
956 const uptr bit = signum % (sizeof(k_set->sig[0]) * 8);
957 k_set->sig[idx] &= ~(1 << bit);
958 }
959
internal_sigismember(__sanitizer_sigset_t * set,int signum)960 bool internal_sigismember(__sanitizer_sigset_t *set, int signum) {
961 signum -= 1;
962 CHECK_GE(signum, 0);
963 CHECK_LT(signum, sizeof(*set) * 8);
964 __sanitizer_kernel_sigset_t *k_set = (__sanitizer_kernel_sigset_t *)set;
965 const uptr idx = signum / (sizeof(k_set->sig[0]) * 8);
966 const uptr bit = signum % (sizeof(k_set->sig[0]) * 8);
967 return k_set->sig[idx] & (1 << bit);
968 }
969 #elif SANITIZER_FREEBSD
internal_sigdelset(__sanitizer_sigset_t * set,int signum)970 void internal_sigdelset(__sanitizer_sigset_t *set, int signum) {
971 sigset_t *rset = reinterpret_cast<sigset_t *>(set);
972 sigdelset(rset, signum);
973 }
974
internal_sigismember(__sanitizer_sigset_t * set,int signum)975 bool internal_sigismember(__sanitizer_sigset_t *set, int signum) {
976 sigset_t *rset = reinterpret_cast<sigset_t *>(set);
977 return sigismember(rset, signum);
978 }
979 #endif
980 #endif // !SANITIZER_SOLARIS
981
982 #if !SANITIZER_NETBSD
983 // ThreadLister implementation.
ThreadLister(pid_t pid)984 ThreadLister::ThreadLister(pid_t pid) : pid_(pid), buffer_(4096) {
985 char task_directory_path[80];
986 internal_snprintf(task_directory_path, sizeof(task_directory_path),
987 "/proc/%d/task/", pid);
988 descriptor_ = internal_open(task_directory_path, O_RDONLY | O_DIRECTORY);
989 if (internal_iserror(descriptor_)) {
990 Report("Can't open /proc/%d/task for reading.\n", pid);
991 }
992 }
993
ListThreads(InternalMmapVector<tid_t> * threads)994 ThreadLister::Result ThreadLister::ListThreads(
995 InternalMmapVector<tid_t> *threads) {
996 if (internal_iserror(descriptor_))
997 return Error;
998 internal_lseek(descriptor_, 0, SEEK_SET);
999 threads->clear();
1000
1001 Result result = Ok;
1002 for (bool first_read = true;; first_read = false) {
1003 // Resize to max capacity if it was downsized by IsAlive.
1004 buffer_.resize(buffer_.capacity());
1005 CHECK_GE(buffer_.size(), 4096);
1006 uptr read = internal_getdents(
1007 descriptor_, (struct linux_dirent *)buffer_.data(), buffer_.size());
1008 if (!read)
1009 return result;
1010 if (internal_iserror(read)) {
1011 Report("Can't read directory entries from /proc/%d/task.\n", pid_);
1012 return Error;
1013 }
1014
1015 for (uptr begin = (uptr)buffer_.data(), end = begin + read; begin < end;) {
1016 struct linux_dirent *entry = (struct linux_dirent *)begin;
1017 begin += entry->d_reclen;
1018 if (entry->d_ino == 1) {
1019 // Inode 1 is for bad blocks and also can be a reason for early return.
1020 // Should be emitted if kernel tried to output terminating thread.
1021 // See proc_task_readdir implementation in Linux.
1022 result = Incomplete;
1023 }
1024 if (entry->d_ino && *entry->d_name >= '0' && *entry->d_name <= '9')
1025 threads->push_back(internal_atoll(entry->d_name));
1026 }
1027
1028 // Now we are going to detect short-read or early EOF. In such cases Linux
1029 // can return inconsistent list with missing alive threads.
1030 // Code will just remember that the list can be incomplete but it will
1031 // continue reads to return as much as possible.
1032 if (!first_read) {
1033 // The first one was a short-read by definition.
1034 result = Incomplete;
1035 } else if (read > buffer_.size() - 1024) {
1036 // Read was close to the buffer size. So double the size and assume the
1037 // worst.
1038 buffer_.resize(buffer_.size() * 2);
1039 result = Incomplete;
1040 } else if (!threads->empty() && !IsAlive(threads->back())) {
1041 // Maybe Linux early returned from read on terminated thread (!pid_alive)
1042 // and failed to restore read position.
1043 // See next_tid and proc_task_instantiate in Linux.
1044 result = Incomplete;
1045 }
1046 }
1047 }
1048
IsAlive(int tid)1049 bool ThreadLister::IsAlive(int tid) {
1050 // /proc/%d/task/%d/status uses same call to detect alive threads as
1051 // proc_task_readdir. See task_state implementation in Linux.
1052 char path[80];
1053 internal_snprintf(path, sizeof(path), "/proc/%d/task/%d/status", pid_, tid);
1054 if (!ReadFileToVector(path, &buffer_) || buffer_.empty())
1055 return false;
1056 buffer_.push_back(0);
1057 static const char kPrefix[] = "\nPPid:";
1058 const char *field = internal_strstr(buffer_.data(), kPrefix);
1059 if (!field)
1060 return false;
1061 field += internal_strlen(kPrefix);
1062 return (int)internal_atoll(field) != 0;
1063 }
1064
~ThreadLister()1065 ThreadLister::~ThreadLister() {
1066 if (!internal_iserror(descriptor_))
1067 internal_close(descriptor_);
1068 }
1069 #endif
1070
1071 #if SANITIZER_WORDSIZE == 32
1072 // Take care of unusable kernel area in top gigabyte.
GetKernelAreaSize()1073 static uptr GetKernelAreaSize() {
1074 #if SANITIZER_LINUX && !SANITIZER_X32
1075 const uptr gbyte = 1UL << 30;
1076
1077 // Firstly check if there are writable segments
1078 // mapped to top gigabyte (e.g. stack).
1079 MemoryMappingLayout proc_maps(/*cache_enabled*/true);
1080 MemoryMappedSegment segment;
1081 while (proc_maps.Next(&segment)) {
1082 if ((segment.end >= 3 * gbyte) && segment.IsWritable()) return 0;
1083 }
1084
1085 #if !SANITIZER_ANDROID
1086 // Even if nothing is mapped, top Gb may still be accessible
1087 // if we are running on 64-bit kernel.
1088 // Uname may report misleading results if personality type
1089 // is modified (e.g. under schroot) so check this as well.
1090 struct utsname uname_info;
1091 int pers = personality(0xffffffffUL);
1092 if (!(pers & PER_MASK)
1093 && uname(&uname_info) == 0
1094 && internal_strstr(uname_info.machine, "64"))
1095 return 0;
1096 #endif // SANITIZER_ANDROID
1097
1098 // Top gigabyte is reserved for kernel.
1099 return gbyte;
1100 #else
1101 return 0;
1102 #endif // SANITIZER_LINUX && !SANITIZER_X32
1103 }
1104 #endif // SANITIZER_WORDSIZE == 32
1105
GetMaxVirtualAddress()1106 uptr GetMaxVirtualAddress() {
1107 #if (SANITIZER_NETBSD || SANITIZER_OPENBSD) && defined(__x86_64__)
1108 return 0x7f7ffffff000ULL; // (0x00007f8000000000 - PAGE_SIZE)
1109 #elif SANITIZER_WORDSIZE == 64
1110 # if defined(__powerpc64__) || defined(__aarch64__)
1111 // On PowerPC64 we have two different address space layouts: 44- and 46-bit.
1112 // We somehow need to figure out which one we are using now and choose
1113 // one of 0x00000fffffffffffUL and 0x00003fffffffffffUL.
1114 // Note that with 'ulimit -s unlimited' the stack is moved away from the top
1115 // of the address space, so simply checking the stack address is not enough.
1116 // This should (does) work for both PowerPC64 Endian modes.
1117 // Similarly, aarch64 has multiple address space layouts: 39, 42 and 47-bit.
1118 return (1ULL << (MostSignificantSetBitIndex(GET_CURRENT_FRAME()) + 1)) - 1;
1119 # elif defined(__mips64)
1120 return (1ULL << 40) - 1; // 0x000000ffffffffffUL;
1121 # elif defined(__s390x__)
1122 return (1ULL << 53) - 1; // 0x001fffffffffffffUL;
1123 # elif defined(__sparc__)
1124 return ~(uptr)0;
1125 # else
1126 return (1ULL << 47) - 1; // 0x00007fffffffffffUL;
1127 # endif
1128 #else // SANITIZER_WORDSIZE == 32
1129 # if defined(__s390__)
1130 return (1ULL << 31) - 1; // 0x7fffffff;
1131 # else
1132 return (1ULL << 32) - 1; // 0xffffffff;
1133 # endif
1134 #endif // SANITIZER_WORDSIZE
1135 }
1136
GetMaxUserVirtualAddress()1137 uptr GetMaxUserVirtualAddress() {
1138 uptr addr = GetMaxVirtualAddress();
1139 #if SANITIZER_WORDSIZE == 32 && !defined(__s390__)
1140 if (!common_flags()->full_address_space)
1141 addr -= GetKernelAreaSize();
1142 CHECK_LT(reinterpret_cast<uptr>(&addr), addr);
1143 #endif
1144 return addr;
1145 }
1146
GetPageSize()1147 uptr GetPageSize() {
1148 // Android post-M sysconf(_SC_PAGESIZE) crashes if called from .preinit_array.
1149 #if SANITIZER_ANDROID
1150 return 4096;
1151 #elif SANITIZER_FREEBSD || SANITIZER_NETBSD
1152 // Use sysctl as sysconf can trigger interceptors internally.
1153 int pz = 0;
1154 uptr pzl = sizeof(pz);
1155 int mib[2] = {CTL_HW, HW_PAGESIZE};
1156 int rv = internal_sysctl(mib, 2, &pz, &pzl, nullptr, 0);
1157 CHECK_EQ(rv, 0);
1158 return (uptr)pz;
1159 #elif SANITIZER_LINUX && (defined(__x86_64__) || defined(__i386__))
1160 return EXEC_PAGESIZE;
1161 #elif SANITIZER_USE_GETAUXVAL
1162 return getauxval(AT_PAGESZ);
1163 #else
1164 return sysconf(_SC_PAGESIZE); // EXEC_PAGESIZE may not be trustworthy.
1165 #endif
1166 }
1167
1168 #if !SANITIZER_OPENBSD
ReadBinaryName(char * buf,uptr buf_len)1169 uptr ReadBinaryName(/*out*/char *buf, uptr buf_len) {
1170 #if SANITIZER_SOLARIS
1171 const char *default_module_name = getexecname();
1172 CHECK_NE(default_module_name, NULL);
1173 return internal_snprintf(buf, buf_len, "%s", default_module_name);
1174 #else
1175 #if SANITIZER_FREEBSD || SANITIZER_NETBSD
1176 #if SANITIZER_FREEBSD
1177 const int Mib[4] = {CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1};
1178 #else
1179 const int Mib[4] = {CTL_KERN, KERN_PROC_ARGS, -1, KERN_PROC_PATHNAME};
1180 #endif
1181 const char *default_module_name = "kern.proc.pathname";
1182 uptr Size = buf_len;
1183 bool IsErr =
1184 (internal_sysctl(Mib, ARRAY_SIZE(Mib), buf, &Size, NULL, 0) != 0);
1185 int readlink_error = IsErr ? errno : 0;
1186 uptr module_name_len = Size;
1187 #else
1188 const char *default_module_name = "/proc/self/exe";
1189 uptr module_name_len = internal_readlink(
1190 default_module_name, buf, buf_len);
1191 int readlink_error;
1192 bool IsErr = internal_iserror(module_name_len, &readlink_error);
1193 #endif // SANITIZER_SOLARIS
1194 if (IsErr) {
1195 // We can't read binary name for some reason, assume it's unknown.
1196 Report("WARNING: reading executable name failed with errno %d, "
1197 "some stack frames may not be symbolized\n", readlink_error);
1198 module_name_len = internal_snprintf(buf, buf_len, "%s",
1199 default_module_name);
1200 CHECK_LT(module_name_len, buf_len);
1201 }
1202 return module_name_len;
1203 #endif
1204 }
1205 #endif // !SANITIZER_OPENBSD
1206
ReadLongProcessName(char * buf,uptr buf_len)1207 uptr ReadLongProcessName(/*out*/ char *buf, uptr buf_len) {
1208 #if SANITIZER_LINUX
1209 char *tmpbuf;
1210 uptr tmpsize;
1211 uptr tmplen;
1212 if (ReadFileToBuffer("/proc/self/cmdline", &tmpbuf, &tmpsize, &tmplen,
1213 1024 * 1024)) {
1214 internal_strncpy(buf, tmpbuf, buf_len);
1215 UnmapOrDie(tmpbuf, tmpsize);
1216 return internal_strlen(buf);
1217 }
1218 #endif
1219 return ReadBinaryName(buf, buf_len);
1220 }
1221
1222 // Match full names of the form /path/to/base_name{-,.}*
LibraryNameIs(const char * full_name,const char * base_name)1223 bool LibraryNameIs(const char *full_name, const char *base_name) {
1224 const char *name = full_name;
1225 // Strip path.
1226 while (*name != '\0') name++;
1227 while (name > full_name && *name != '/') name--;
1228 if (*name == '/') name++;
1229 uptr base_name_length = internal_strlen(base_name);
1230 if (internal_strncmp(name, base_name, base_name_length)) return false;
1231 return (name[base_name_length] == '-' || name[base_name_length] == '.');
1232 }
1233
1234 #if !SANITIZER_ANDROID
1235 // Call cb for each region mapped by map.
ForEachMappedRegion(link_map * map,void (* cb)(const void *,uptr))1236 void ForEachMappedRegion(link_map *map, void (*cb)(const void *, uptr)) {
1237 CHECK_NE(map, nullptr);
1238 #if !SANITIZER_FREEBSD && !SANITIZER_OPENBSD
1239 typedef ElfW(Phdr) Elf_Phdr;
1240 typedef ElfW(Ehdr) Elf_Ehdr;
1241 #endif // !SANITIZER_FREEBSD && !SANITIZER_OPENBSD
1242 char *base = (char *)map->l_addr;
1243 Elf_Ehdr *ehdr = (Elf_Ehdr *)base;
1244 char *phdrs = base + ehdr->e_phoff;
1245 char *phdrs_end = phdrs + ehdr->e_phnum * ehdr->e_phentsize;
1246
1247 // Find the segment with the minimum base so we can "relocate" the p_vaddr
1248 // fields. Typically ET_DYN objects (DSOs) have base of zero and ET_EXEC
1249 // objects have a non-zero base.
1250 uptr preferred_base = (uptr)-1;
1251 for (char *iter = phdrs; iter != phdrs_end; iter += ehdr->e_phentsize) {
1252 Elf_Phdr *phdr = (Elf_Phdr *)iter;
1253 if (phdr->p_type == PT_LOAD && preferred_base > (uptr)phdr->p_vaddr)
1254 preferred_base = (uptr)phdr->p_vaddr;
1255 }
1256
1257 // Compute the delta from the real base to get a relocation delta.
1258 sptr delta = (uptr)base - preferred_base;
1259 // Now we can figure out what the loader really mapped.
1260 for (char *iter = phdrs; iter != phdrs_end; iter += ehdr->e_phentsize) {
1261 Elf_Phdr *phdr = (Elf_Phdr *)iter;
1262 if (phdr->p_type == PT_LOAD) {
1263 uptr seg_start = phdr->p_vaddr + delta;
1264 uptr seg_end = seg_start + phdr->p_memsz;
1265 // None of these values are aligned. We consider the ragged edges of the
1266 // load command as defined, since they are mapped from the file.
1267 seg_start = RoundDownTo(seg_start, GetPageSizeCached());
1268 seg_end = RoundUpTo(seg_end, GetPageSizeCached());
1269 cb((void *)seg_start, seg_end - seg_start);
1270 }
1271 }
1272 }
1273 #endif
1274
1275 #if defined(__x86_64__) && SANITIZER_LINUX
1276 // We cannot use glibc's clone wrapper, because it messes with the child
1277 // task's TLS. It writes the PID and TID of the child task to its thread
1278 // descriptor, but in our case the child task shares the thread descriptor with
1279 // the parent (because we don't know how to allocate a new thread
1280 // descriptor to keep glibc happy). So the stock version of clone(), when
1281 // used with CLONE_VM, would end up corrupting the parent's thread descriptor.
internal_clone(int (* fn)(void *),void * child_stack,int flags,void * arg,int * parent_tidptr,void * newtls,int * child_tidptr)1282 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
1283 int *parent_tidptr, void *newtls, int *child_tidptr) {
1284 long long res;
1285 if (!fn || !child_stack)
1286 return -EINVAL;
1287 CHECK_EQ(0, (uptr)child_stack % 16);
1288 child_stack = (char *)child_stack - 2 * sizeof(unsigned long long);
1289 ((unsigned long long *)child_stack)[0] = (uptr)fn;
1290 ((unsigned long long *)child_stack)[1] = (uptr)arg;
1291 register void *r8 __asm__("r8") = newtls;
1292 register int *r10 __asm__("r10") = child_tidptr;
1293 __asm__ __volatile__(
1294 /* %rax = syscall(%rax = SYSCALL(clone),
1295 * %rdi = flags,
1296 * %rsi = child_stack,
1297 * %rdx = parent_tidptr,
1298 * %r8 = new_tls,
1299 * %r10 = child_tidptr)
1300 */
1301 "syscall\n"
1302
1303 /* if (%rax != 0)
1304 * return;
1305 */
1306 "testq %%rax,%%rax\n"
1307 "jnz 1f\n"
1308
1309 /* In the child. Terminate unwind chain. */
1310 // XXX: We should also terminate the CFI unwind chain
1311 // here. Unfortunately clang 3.2 doesn't support the
1312 // necessary CFI directives, so we skip that part.
1313 "xorq %%rbp,%%rbp\n"
1314
1315 /* Call "fn(arg)". */
1316 "popq %%rax\n"
1317 "popq %%rdi\n"
1318 "call *%%rax\n"
1319
1320 /* Call _exit(%rax). */
1321 "movq %%rax,%%rdi\n"
1322 "movq %2,%%rax\n"
1323 "syscall\n"
1324
1325 /* Return to parent. */
1326 "1:\n"
1327 : "=a" (res)
1328 : "a"(SYSCALL(clone)), "i"(SYSCALL(exit)),
1329 "S"(child_stack),
1330 "D"(flags),
1331 "d"(parent_tidptr),
1332 "r"(r8),
1333 "r"(r10)
1334 : "memory", "r11", "rcx");
1335 return res;
1336 }
1337 #elif defined(__mips__) && SANITIZER_LINUX
internal_clone(int (* fn)(void *),void * child_stack,int flags,void * arg,int * parent_tidptr,void * newtls,int * child_tidptr)1338 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
1339 int *parent_tidptr, void *newtls, int *child_tidptr) {
1340 long long res;
1341 if (!fn || !child_stack)
1342 return -EINVAL;
1343 CHECK_EQ(0, (uptr)child_stack % 16);
1344 child_stack = (char *)child_stack - 2 * sizeof(unsigned long long);
1345 ((unsigned long long *)child_stack)[0] = (uptr)fn;
1346 ((unsigned long long *)child_stack)[1] = (uptr)arg;
1347 register void *a3 __asm__("$7") = newtls;
1348 register int *a4 __asm__("$8") = child_tidptr;
1349 // We don't have proper CFI directives here because it requires alot of code
1350 // for very marginal benefits.
1351 __asm__ __volatile__(
1352 /* $v0 = syscall($v0 = __NR_clone,
1353 * $a0 = flags,
1354 * $a1 = child_stack,
1355 * $a2 = parent_tidptr,
1356 * $a3 = new_tls,
1357 * $a4 = child_tidptr)
1358 */
1359 ".cprestore 16;\n"
1360 "move $4,%1;\n"
1361 "move $5,%2;\n"
1362 "move $6,%3;\n"
1363 "move $7,%4;\n"
1364 /* Store the fifth argument on stack
1365 * if we are using 32-bit abi.
1366 */
1367 #if SANITIZER_WORDSIZE == 32
1368 "lw %5,16($29);\n"
1369 #else
1370 "move $8,%5;\n"
1371 #endif
1372 "li $2,%6;\n"
1373 "syscall;\n"
1374
1375 /* if ($v0 != 0)
1376 * return;
1377 */
1378 "bnez $2,1f;\n"
1379
1380 /* Call "fn(arg)". */
1381 #if SANITIZER_WORDSIZE == 32
1382 #ifdef __BIG_ENDIAN__
1383 "lw $25,4($29);\n"
1384 "lw $4,12($29);\n"
1385 #else
1386 "lw $25,0($29);\n"
1387 "lw $4,8($29);\n"
1388 #endif
1389 #else
1390 "ld $25,0($29);\n"
1391 "ld $4,8($29);\n"
1392 #endif
1393 "jal $25;\n"
1394
1395 /* Call _exit($v0). */
1396 "move $4,$2;\n"
1397 "li $2,%7;\n"
1398 "syscall;\n"
1399
1400 /* Return to parent. */
1401 "1:\n"
1402 : "=r" (res)
1403 : "r"(flags),
1404 "r"(child_stack),
1405 "r"(parent_tidptr),
1406 "r"(a3),
1407 "r"(a4),
1408 "i"(__NR_clone),
1409 "i"(__NR_exit)
1410 : "memory", "$29" );
1411 return res;
1412 }
1413 #elif defined(__aarch64__) && SANITIZER_LINUX
internal_clone(int (* fn)(void *),void * child_stack,int flags,void * arg,int * parent_tidptr,void * newtls,int * child_tidptr)1414 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
1415 int *parent_tidptr, void *newtls, int *child_tidptr) {
1416 long long res;
1417 if (!fn || !child_stack)
1418 return -EINVAL;
1419 CHECK_EQ(0, (uptr)child_stack % 16);
1420 child_stack = (char *)child_stack - 2 * sizeof(unsigned long long);
1421 ((unsigned long long *)child_stack)[0] = (uptr)fn;
1422 ((unsigned long long *)child_stack)[1] = (uptr)arg;
1423
1424 register int (*__fn)(void *) __asm__("x0") = fn;
1425 register void *__stack __asm__("x1") = child_stack;
1426 register int __flags __asm__("x2") = flags;
1427 register void *__arg __asm__("x3") = arg;
1428 register int *__ptid __asm__("x4") = parent_tidptr;
1429 register void *__tls __asm__("x5") = newtls;
1430 register int *__ctid __asm__("x6") = child_tidptr;
1431
1432 __asm__ __volatile__(
1433 "mov x0,x2\n" /* flags */
1434 "mov x2,x4\n" /* ptid */
1435 "mov x3,x5\n" /* tls */
1436 "mov x4,x6\n" /* ctid */
1437 "mov x8,%9\n" /* clone */
1438
1439 "svc 0x0\n"
1440
1441 /* if (%r0 != 0)
1442 * return %r0;
1443 */
1444 "cmp x0, #0\n"
1445 "bne 1f\n"
1446
1447 /* In the child, now. Call "fn(arg)". */
1448 "ldp x1, x0, [sp], #16\n"
1449 "blr x1\n"
1450
1451 /* Call _exit(%r0). */
1452 "mov x8, %10\n"
1453 "svc 0x0\n"
1454 "1:\n"
1455
1456 : "=r" (res)
1457 : "i"(-EINVAL),
1458 "r"(__fn), "r"(__stack), "r"(__flags), "r"(__arg),
1459 "r"(__ptid), "r"(__tls), "r"(__ctid),
1460 "i"(__NR_clone), "i"(__NR_exit)
1461 : "x30", "memory");
1462 return res;
1463 }
1464 #elif defined(__powerpc64__) && SANITIZER_LINUX
internal_clone(int (* fn)(void *),void * child_stack,int flags,void * arg,int * parent_tidptr,void * newtls,int * child_tidptr)1465 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
1466 int *parent_tidptr, void *newtls, int *child_tidptr) {
1467 long long res;
1468 // Stack frame structure.
1469 #if SANITIZER_PPC64V1
1470 // Back chain == 0 (SP + 112)
1471 // Frame (112 bytes):
1472 // Parameter save area (SP + 48), 8 doublewords
1473 // TOC save area (SP + 40)
1474 // Link editor doubleword (SP + 32)
1475 // Compiler doubleword (SP + 24)
1476 // LR save area (SP + 16)
1477 // CR save area (SP + 8)
1478 // Back chain (SP + 0)
1479 # define FRAME_SIZE 112
1480 # define FRAME_TOC_SAVE_OFFSET 40
1481 #elif SANITIZER_PPC64V2
1482 // Back chain == 0 (SP + 32)
1483 // Frame (32 bytes):
1484 // TOC save area (SP + 24)
1485 // LR save area (SP + 16)
1486 // CR save area (SP + 8)
1487 // Back chain (SP + 0)
1488 # define FRAME_SIZE 32
1489 # define FRAME_TOC_SAVE_OFFSET 24
1490 #else
1491 # error "Unsupported PPC64 ABI"
1492 #endif
1493 if (!fn || !child_stack)
1494 return -EINVAL;
1495 CHECK_EQ(0, (uptr)child_stack % 16);
1496
1497 register int (*__fn)(void *) __asm__("r3") = fn;
1498 register void *__cstack __asm__("r4") = child_stack;
1499 register int __flags __asm__("r5") = flags;
1500 register void *__arg __asm__("r6") = arg;
1501 register int *__ptidptr __asm__("r7") = parent_tidptr;
1502 register void *__newtls __asm__("r8") = newtls;
1503 register int *__ctidptr __asm__("r9") = child_tidptr;
1504
1505 __asm__ __volatile__(
1506 /* fn and arg are saved across the syscall */
1507 "mr 28, %5\n\t"
1508 "mr 27, %8\n\t"
1509
1510 /* syscall
1511 r0 == __NR_clone
1512 r3 == flags
1513 r4 == child_stack
1514 r5 == parent_tidptr
1515 r6 == newtls
1516 r7 == child_tidptr */
1517 "mr 3, %7\n\t"
1518 "mr 5, %9\n\t"
1519 "mr 6, %10\n\t"
1520 "mr 7, %11\n\t"
1521 "li 0, %3\n\t"
1522 "sc\n\t"
1523
1524 /* Test if syscall was successful */
1525 "cmpdi cr1, 3, 0\n\t"
1526 "crandc cr1*4+eq, cr1*4+eq, cr0*4+so\n\t"
1527 "bne- cr1, 1f\n\t"
1528
1529 /* Set up stack frame */
1530 "li 29, 0\n\t"
1531 "stdu 29, -8(1)\n\t"
1532 "stdu 1, -%12(1)\n\t"
1533 /* Do the function call */
1534 "std 2, %13(1)\n\t"
1535 #if SANITIZER_PPC64V1
1536 "ld 0, 0(28)\n\t"
1537 "ld 2, 8(28)\n\t"
1538 "mtctr 0\n\t"
1539 #elif SANITIZER_PPC64V2
1540 "mr 12, 28\n\t"
1541 "mtctr 12\n\t"
1542 #else
1543 # error "Unsupported PPC64 ABI"
1544 #endif
1545 "mr 3, 27\n\t"
1546 "bctrl\n\t"
1547 "ld 2, %13(1)\n\t"
1548
1549 /* Call _exit(r3) */
1550 "li 0, %4\n\t"
1551 "sc\n\t"
1552
1553 /* Return to parent */
1554 "1:\n\t"
1555 "mr %0, 3\n\t"
1556 : "=r" (res)
1557 : "0" (-1),
1558 "i" (EINVAL),
1559 "i" (__NR_clone),
1560 "i" (__NR_exit),
1561 "r" (__fn),
1562 "r" (__cstack),
1563 "r" (__flags),
1564 "r" (__arg),
1565 "r" (__ptidptr),
1566 "r" (__newtls),
1567 "r" (__ctidptr),
1568 "i" (FRAME_SIZE),
1569 "i" (FRAME_TOC_SAVE_OFFSET)
1570 : "cr0", "cr1", "memory", "ctr", "r0", "r27", "r28", "r29");
1571 return res;
1572 }
1573 #elif defined(__i386__) && SANITIZER_LINUX
internal_clone(int (* fn)(void *),void * child_stack,int flags,void * arg,int * parent_tidptr,void * newtls,int * child_tidptr)1574 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
1575 int *parent_tidptr, void *newtls, int *child_tidptr) {
1576 int res;
1577 if (!fn || !child_stack)
1578 return -EINVAL;
1579 CHECK_EQ(0, (uptr)child_stack % 16);
1580 child_stack = (char *)child_stack - 7 * sizeof(unsigned int);
1581 ((unsigned int *)child_stack)[0] = (uptr)flags;
1582 ((unsigned int *)child_stack)[1] = (uptr)0;
1583 ((unsigned int *)child_stack)[2] = (uptr)fn;
1584 ((unsigned int *)child_stack)[3] = (uptr)arg;
1585 __asm__ __volatile__(
1586 /* %eax = syscall(%eax = SYSCALL(clone),
1587 * %ebx = flags,
1588 * %ecx = child_stack,
1589 * %edx = parent_tidptr,
1590 * %esi = new_tls,
1591 * %edi = child_tidptr)
1592 */
1593
1594 /* Obtain flags */
1595 "movl (%%ecx), %%ebx\n"
1596 /* Do the system call */
1597 "pushl %%ebx\n"
1598 "pushl %%esi\n"
1599 "pushl %%edi\n"
1600 /* Remember the flag value. */
1601 "movl %%ebx, (%%ecx)\n"
1602 "int $0x80\n"
1603 "popl %%edi\n"
1604 "popl %%esi\n"
1605 "popl %%ebx\n"
1606
1607 /* if (%eax != 0)
1608 * return;
1609 */
1610
1611 "test %%eax,%%eax\n"
1612 "jnz 1f\n"
1613
1614 /* terminate the stack frame */
1615 "xorl %%ebp,%%ebp\n"
1616 /* Call FN. */
1617 "call *%%ebx\n"
1618 #ifdef PIC
1619 "call here\n"
1620 "here:\n"
1621 "popl %%ebx\n"
1622 "addl $_GLOBAL_OFFSET_TABLE_+[.-here], %%ebx\n"
1623 #endif
1624 /* Call exit */
1625 "movl %%eax, %%ebx\n"
1626 "movl %2, %%eax\n"
1627 "int $0x80\n"
1628 "1:\n"
1629 : "=a" (res)
1630 : "a"(SYSCALL(clone)), "i"(SYSCALL(exit)),
1631 "c"(child_stack),
1632 "d"(parent_tidptr),
1633 "S"(newtls),
1634 "D"(child_tidptr)
1635 : "memory");
1636 return res;
1637 }
1638 #elif defined(__arm__) && SANITIZER_LINUX
internal_clone(int (* fn)(void *),void * child_stack,int flags,void * arg,int * parent_tidptr,void * newtls,int * child_tidptr)1639 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
1640 int *parent_tidptr, void *newtls, int *child_tidptr) {
1641 unsigned int res;
1642 if (!fn || !child_stack)
1643 return -EINVAL;
1644 child_stack = (char *)child_stack - 2 * sizeof(unsigned int);
1645 ((unsigned int *)child_stack)[0] = (uptr)fn;
1646 ((unsigned int *)child_stack)[1] = (uptr)arg;
1647 register int r0 __asm__("r0") = flags;
1648 register void *r1 __asm__("r1") = child_stack;
1649 register int *r2 __asm__("r2") = parent_tidptr;
1650 register void *r3 __asm__("r3") = newtls;
1651 register int *r4 __asm__("r4") = child_tidptr;
1652 register int r7 __asm__("r7") = __NR_clone;
1653
1654 #if __ARM_ARCH > 4 || defined (__ARM_ARCH_4T__)
1655 # define ARCH_HAS_BX
1656 #endif
1657 #if __ARM_ARCH > 4
1658 # define ARCH_HAS_BLX
1659 #endif
1660
1661 #ifdef ARCH_HAS_BX
1662 # ifdef ARCH_HAS_BLX
1663 # define BLX(R) "blx " #R "\n"
1664 # else
1665 # define BLX(R) "mov lr, pc; bx " #R "\n"
1666 # endif
1667 #else
1668 # define BLX(R) "mov lr, pc; mov pc," #R "\n"
1669 #endif
1670
1671 __asm__ __volatile__(
1672 /* %r0 = syscall(%r7 = SYSCALL(clone),
1673 * %r0 = flags,
1674 * %r1 = child_stack,
1675 * %r2 = parent_tidptr,
1676 * %r3 = new_tls,
1677 * %r4 = child_tidptr)
1678 */
1679
1680 /* Do the system call */
1681 "swi 0x0\n"
1682
1683 /* if (%r0 != 0)
1684 * return %r0;
1685 */
1686 "cmp r0, #0\n"
1687 "bne 1f\n"
1688
1689 /* In the child, now. Call "fn(arg)". */
1690 "ldr r0, [sp, #4]\n"
1691 "ldr ip, [sp], #8\n"
1692 BLX(ip)
1693 /* Call _exit(%r0). */
1694 "mov r7, %7\n"
1695 "swi 0x0\n"
1696 "1:\n"
1697 "mov %0, r0\n"
1698 : "=r"(res)
1699 : "r"(r0), "r"(r1), "r"(r2), "r"(r3), "r"(r4), "r"(r7),
1700 "i"(__NR_exit)
1701 : "memory");
1702 return res;
1703 }
1704 #endif // defined(__x86_64__) && SANITIZER_LINUX
1705
1706 #if SANITIZER_ANDROID
1707 #if __ANDROID_API__ < 21
1708 extern "C" __attribute__((weak)) int dl_iterate_phdr(
1709 int (*)(struct dl_phdr_info *, size_t, void *), void *);
1710 #endif
1711
dl_iterate_phdr_test_cb(struct dl_phdr_info * info,size_t size,void * data)1712 static int dl_iterate_phdr_test_cb(struct dl_phdr_info *info, size_t size,
1713 void *data) {
1714 // Any name starting with "lib" indicates a bug in L where library base names
1715 // are returned instead of paths.
1716 if (info->dlpi_name && info->dlpi_name[0] == 'l' &&
1717 info->dlpi_name[1] == 'i' && info->dlpi_name[2] == 'b') {
1718 *(bool *)data = true;
1719 return 1;
1720 }
1721 return 0;
1722 }
1723
1724 static atomic_uint32_t android_api_level;
1725
AndroidDetectApiLevelStatic()1726 static AndroidApiLevel AndroidDetectApiLevelStatic() {
1727 #if __ANDROID_API__ <= 19
1728 return ANDROID_KITKAT;
1729 #elif __ANDROID_API__ <= 22
1730 return ANDROID_LOLLIPOP_MR1;
1731 #else
1732 return ANDROID_POST_LOLLIPOP;
1733 #endif
1734 }
1735
AndroidDetectApiLevel()1736 static AndroidApiLevel AndroidDetectApiLevel() {
1737 if (!&dl_iterate_phdr)
1738 return ANDROID_KITKAT; // K or lower
1739 bool base_name_seen = false;
1740 dl_iterate_phdr(dl_iterate_phdr_test_cb, &base_name_seen);
1741 if (base_name_seen)
1742 return ANDROID_LOLLIPOP_MR1; // L MR1
1743 return ANDROID_POST_LOLLIPOP; // post-L
1744 // Plain L (API level 21) is completely broken wrt ASan and not very
1745 // interesting to detect.
1746 }
1747
1748 extern "C" __attribute__((weak)) void* _DYNAMIC;
1749
AndroidGetApiLevel()1750 AndroidApiLevel AndroidGetApiLevel() {
1751 AndroidApiLevel level =
1752 (AndroidApiLevel)atomic_load(&android_api_level, memory_order_relaxed);
1753 if (level) return level;
1754 level = &_DYNAMIC == nullptr ? AndroidDetectApiLevelStatic()
1755 : AndroidDetectApiLevel();
1756 atomic_store(&android_api_level, level, memory_order_relaxed);
1757 return level;
1758 }
1759
1760 #endif
1761
GetHandleSignalModeImpl(int signum)1762 static HandleSignalMode GetHandleSignalModeImpl(int signum) {
1763 switch (signum) {
1764 case SIGABRT:
1765 return common_flags()->handle_abort;
1766 case SIGILL:
1767 return common_flags()->handle_sigill;
1768 case SIGTRAP:
1769 return common_flags()->handle_sigtrap;
1770 case SIGFPE:
1771 return common_flags()->handle_sigfpe;
1772 case SIGSEGV:
1773 return common_flags()->handle_segv;
1774 case SIGBUS:
1775 return common_flags()->handle_sigbus;
1776 }
1777 return kHandleSignalNo;
1778 }
1779
GetHandleSignalMode(int signum)1780 HandleSignalMode GetHandleSignalMode(int signum) {
1781 HandleSignalMode result = GetHandleSignalModeImpl(signum);
1782 if (result == kHandleSignalYes && !common_flags()->allow_user_segv_handler)
1783 return kHandleSignalExclusive;
1784 return result;
1785 }
1786
1787 #if !SANITIZER_GO
internal_start_thread(void (* func)(void * arg),void * arg)1788 void *internal_start_thread(void(*func)(void *arg), void *arg) {
1789 // Start the thread with signals blocked, otherwise it can steal user signals.
1790 __sanitizer_sigset_t set, old;
1791 internal_sigfillset(&set);
1792 #if SANITIZER_LINUX && !SANITIZER_ANDROID
1793 // Glibc uses SIGSETXID signal during setuid call. If this signal is blocked
1794 // on any thread, setuid call hangs (see test/tsan/setuid.c).
1795 internal_sigdelset(&set, 33);
1796 #endif
1797 internal_sigprocmask(SIG_SETMASK, &set, &old);
1798 void *th;
1799 real_pthread_create(&th, nullptr, (void*(*)(void *arg))func, arg);
1800 internal_sigprocmask(SIG_SETMASK, &old, nullptr);
1801 return th;
1802 }
1803
internal_join_thread(void * th)1804 void internal_join_thread(void *th) {
1805 real_pthread_join(th, nullptr);
1806 }
1807 #else
internal_start_thread(void (* func)(void *),void * arg)1808 void *internal_start_thread(void (*func)(void *), void *arg) { return 0; }
1809
internal_join_thread(void * th)1810 void internal_join_thread(void *th) {}
1811 #endif
1812
1813 #if defined(__aarch64__)
1814 #if SANITIZER_LINUX
1815 // Android headers in the older NDK releases miss this definition.
1816 struct __sanitizer_esr_context {
1817 struct _aarch64_ctx head;
1818 uint64_t esr;
1819 };
1820
Aarch64GetESR(ucontext_t * ucontext,u64 * esr)1821 static bool Aarch64GetESR(ucontext_t *ucontext, u64 *esr) {
1822 static const u32 kEsrMagic = 0x45535201;
1823 u8 *aux = ucontext->uc_mcontext.__reserved;
1824 while (true) {
1825 _aarch64_ctx *ctx = (_aarch64_ctx *)aux;
1826 if (ctx->size == 0) break;
1827 if (ctx->magic == kEsrMagic) {
1828 *esr = ((__sanitizer_esr_context *)ctx)->esr;
1829 return true;
1830 }
1831 aux += ctx->size;
1832 }
1833 return false;
1834 }
1835 #else
Aarch64GetESR(ucontext_t * ucontext,u64 * esr)1836 static bool Aarch64GetESR(ucontext_t *ucontext, u64 *esr) {
1837 return false;
1838 }
1839 #endif
1840 #endif
1841
1842 #if SANITIZER_OPENBSD
1843 using Context = sigcontext;
1844 #else
1845 using Context = ucontext_t;
1846 #endif
1847
GetWriteFlag() const1848 SignalContext::WriteFlag SignalContext::GetWriteFlag() const {
1849 Context *ucontext = (Context *)context;
1850 #if defined(__x86_64__) || defined(__i386__)
1851 static const uptr PF_WRITE = 1U << 1;
1852 #if SANITIZER_FREEBSD
1853 uptr err = ucontext->uc_mcontext.mc_err;
1854 #elif SANITIZER_NETBSD
1855 uptr err = ucontext->uc_mcontext.__gregs[_REG_ERR];
1856 #elif SANITIZER_OPENBSD
1857 uptr err = ucontext->sc_err;
1858 #elif SANITIZER_SOLARIS && defined(__i386__)
1859 const int Err = 13;
1860 uptr err = ucontext->uc_mcontext.gregs[Err];
1861 #else
1862 uptr err = ucontext->uc_mcontext.gregs[REG_ERR];
1863 #endif // SANITIZER_FREEBSD
1864 return err & PF_WRITE ? WRITE : READ;
1865 #elif defined(__mips__)
1866 uint32_t *exception_source;
1867 uint32_t faulty_instruction;
1868 uint32_t op_code;
1869
1870 #if SANITIZER_NETBSD
1871 ucontext_t *nucontext = (ucontext_t *)ucontext;
1872 exception_source = (uint32_t *)_UC_MACHINE_PC(nucontext);
1873 #else
1874 exception_source = (uint32_t *)ucontext->uc_mcontext.pc;
1875 #endif
1876 faulty_instruction = (uint32_t)(*exception_source);
1877
1878 op_code = (faulty_instruction >> 26) & 0x3f;
1879
1880 // FIXME: Add support for FPU, microMIPS, DSP, MSA memory instructions.
1881 switch (op_code) {
1882 case 0x28: // sb
1883 case 0x29: // sh
1884 case 0x2b: // sw
1885 case 0x3f: // sd
1886 #if __mips_isa_rev < 6
1887 case 0x2c: // sdl
1888 case 0x2d: // sdr
1889 case 0x2a: // swl
1890 case 0x2e: // swr
1891 #endif
1892 return SignalContext::WRITE;
1893
1894 case 0x20: // lb
1895 case 0x24: // lbu
1896 case 0x21: // lh
1897 case 0x25: // lhu
1898 case 0x23: // lw
1899 case 0x27: // lwu
1900 case 0x37: // ld
1901 #if __mips_isa_rev < 6
1902 case 0x1a: // ldl
1903 case 0x1b: // ldr
1904 case 0x22: // lwl
1905 case 0x26: // lwr
1906 #endif
1907 return SignalContext::READ;
1908 #if __mips_isa_rev == 6
1909 case 0x3b: // pcrel
1910 op_code = (faulty_instruction >> 19) & 0x3;
1911 switch (op_code) {
1912 case 0x1: // lwpc
1913 case 0x2: // lwupc
1914 return SignalContext::READ;
1915 }
1916 #endif
1917 }
1918 return SignalContext::UNKNOWN;
1919 #elif defined(__arm__) && !SANITIZER_NETBSD
1920 static const uptr FSR_WRITE = 1U << 11;
1921 uptr fsr = ucontext->uc_mcontext.error_code;
1922 return fsr & FSR_WRITE ? WRITE : READ;
1923 #elif defined(__aarch64__)
1924 static const u64 ESR_ELx_WNR = 1U << 6;
1925 u64 esr;
1926 if (!Aarch64GetESR(ucontext, &esr)) return UNKNOWN;
1927 return esr & ESR_ELx_WNR ? WRITE : READ;
1928 #elif defined(__sparc__)
1929 // Decode the instruction to determine the access type.
1930 // From OpenSolaris $SRC/uts/sun4/os/trap.c (get_accesstype).
1931 # if SANITIZER_SOLARIS
1932 uptr pc = ucontext->uc_mcontext.gregs[REG_PC];
1933 # elif SANITIZER_NETBSD
1934 uptr pc = ucontext->uc_mcontext.__gregs[_REG_PC];
1935 # else
1936 // Historical BSDism here.
1937 struct sigcontext *scontext = (struct sigcontext *)ucontext;
1938 # if defined(__arch64__)
1939 uptr pc = scontext->sigc_regs.tpc;
1940 # else
1941 uptr pc = scontext->si_regs.pc;
1942 # endif
1943 # endif
1944 u32 instr = *(u32 *)pc;
1945 return (instr >> 21) & 1 ? WRITE: READ;
1946 #else
1947 (void)ucontext;
1948 return UNKNOWN; // FIXME: Implement.
1949 #endif
1950 }
1951
DumpAllRegisters(void * context)1952 void SignalContext::DumpAllRegisters(void *context) {
1953 // FIXME: Implement this.
1954 }
1955
GetPcSpBp(void * context,uptr * pc,uptr * sp,uptr * bp)1956 static void GetPcSpBp(void *context, uptr *pc, uptr *sp, uptr *bp) {
1957 #if SANITIZER_NETBSD
1958 // This covers all NetBSD architectures
1959 ucontext_t *ucontext = (ucontext_t *)context;
1960 *pc = _UC_MACHINE_PC(ucontext);
1961 *bp = _UC_MACHINE_FP(ucontext);
1962 *sp = _UC_MACHINE_SP(ucontext);
1963 #elif defined(__arm__)
1964 ucontext_t *ucontext = (ucontext_t*)context;
1965 *pc = ucontext->uc_mcontext.arm_pc;
1966 *bp = ucontext->uc_mcontext.arm_fp;
1967 *sp = ucontext->uc_mcontext.arm_sp;
1968 #elif defined(__aarch64__)
1969 ucontext_t *ucontext = (ucontext_t*)context;
1970 *pc = ucontext->uc_mcontext.pc;
1971 *bp = ucontext->uc_mcontext.regs[29];
1972 *sp = ucontext->uc_mcontext.sp;
1973 #elif defined(__hppa__)
1974 ucontext_t *ucontext = (ucontext_t*)context;
1975 *pc = ucontext->uc_mcontext.sc_iaoq[0];
1976 /* GCC uses %r3 whenever a frame pointer is needed. */
1977 *bp = ucontext->uc_mcontext.sc_gr[3];
1978 *sp = ucontext->uc_mcontext.sc_gr[30];
1979 #elif defined(__x86_64__)
1980 # if SANITIZER_FREEBSD
1981 ucontext_t *ucontext = (ucontext_t*)context;
1982 *pc = ucontext->uc_mcontext.mc_rip;
1983 *bp = ucontext->uc_mcontext.mc_rbp;
1984 *sp = ucontext->uc_mcontext.mc_rsp;
1985 #elif SANITIZER_OPENBSD
1986 sigcontext *ucontext = (sigcontext *)context;
1987 *pc = ucontext->sc_rip;
1988 *bp = ucontext->sc_rbp;
1989 *sp = ucontext->sc_rsp;
1990 # else
1991 ucontext_t *ucontext = (ucontext_t*)context;
1992 *pc = ucontext->uc_mcontext.gregs[REG_RIP];
1993 *bp = ucontext->uc_mcontext.gregs[REG_RBP];
1994 *sp = ucontext->uc_mcontext.gregs[REG_RSP];
1995 # endif
1996 #elif defined(__i386__)
1997 # if SANITIZER_FREEBSD
1998 ucontext_t *ucontext = (ucontext_t*)context;
1999 *pc = ucontext->uc_mcontext.mc_eip;
2000 *bp = ucontext->uc_mcontext.mc_ebp;
2001 *sp = ucontext->uc_mcontext.mc_esp;
2002 #elif SANITIZER_OPENBSD
2003 sigcontext *ucontext = (sigcontext *)context;
2004 *pc = ucontext->sc_eip;
2005 *bp = ucontext->sc_ebp;
2006 *sp = ucontext->sc_esp;
2007 # else
2008 ucontext_t *ucontext = (ucontext_t*)context;
2009 # if SANITIZER_SOLARIS
2010 /* Use the numeric values: the symbolic ones are undefined by llvm
2011 include/llvm/Support/Solaris.h. */
2012 # ifndef REG_EIP
2013 # define REG_EIP 14 // REG_PC
2014 # endif
2015 # ifndef REG_EBP
2016 # define REG_EBP 6 // REG_FP
2017 # endif
2018 # ifndef REG_ESP
2019 # define REG_ESP 17 // REG_SP
2020 # endif
2021 # endif
2022 *pc = ucontext->uc_mcontext.gregs[REG_EIP];
2023 *bp = ucontext->uc_mcontext.gregs[REG_EBP];
2024 *sp = ucontext->uc_mcontext.gregs[REG_ESP];
2025 # endif
2026 #elif defined(__powerpc__) || defined(__powerpc64__)
2027 ucontext_t *ucontext = (ucontext_t*)context;
2028 *pc = ucontext->uc_mcontext.regs->nip;
2029 *sp = ucontext->uc_mcontext.regs->gpr[PT_R1];
2030 // The powerpc{,64}-linux ABIs do not specify r31 as the frame
2031 // pointer, but GCC always uses r31 when we need a frame pointer.
2032 *bp = ucontext->uc_mcontext.regs->gpr[PT_R31];
2033 #elif defined(__sparc__)
2034 # if defined(__arch64__) || defined(__sparcv9)
2035 # define STACK_BIAS 2047
2036 # else
2037 # define STACK_BIAS 0
2038 # endif
2039 # if SANITIZER_SOLARIS
2040 ucontext_t *ucontext = (ucontext_t*)context;
2041 *pc = ucontext->uc_mcontext.gregs[REG_PC];
2042 *sp = ucontext->uc_mcontext.gregs[REG_O6] + STACK_BIAS;
2043 # elif SANITIZER_NETBSD
2044 *pc = ucontext->uc_mcontext.__gregs[_REG_PC];
2045 *sp = ucontext->uc_mcontext.__gregs[_REG_O6] + STACK_BIAS;
2046 # else
2047 // Historical BSDism here.
2048 struct sigcontext *scontext = (struct sigcontext *)context;
2049 # if defined(__arch64__)
2050 *pc = scontext->sigc_regs.tpc;
2051 *sp = scontext->sigc_regs.u_regs[14] + STACK_BIAS;
2052 # else
2053 *pc = scontext->si_regs.pc;
2054 *sp = scontext->si_regs.u_regs[14];
2055 # endif
2056 # endif
2057 *bp = (uptr) ((uhwptr *) *sp)[14] + STACK_BIAS;
2058 #elif defined(__mips__)
2059 ucontext_t *ucontext = (ucontext_t*)context;
2060 *pc = ucontext->uc_mcontext.pc;
2061 *bp = ucontext->uc_mcontext.gregs[30];
2062 *sp = ucontext->uc_mcontext.gregs[29];
2063 #elif defined(__s390__)
2064 ucontext_t *ucontext = (ucontext_t*)context;
2065 # if defined(__s390x__)
2066 *pc = ucontext->uc_mcontext.psw.addr;
2067 # else
2068 *pc = ucontext->uc_mcontext.psw.addr & 0x7fffffff;
2069 # endif
2070 *bp = ucontext->uc_mcontext.gregs[11];
2071 *sp = ucontext->uc_mcontext.gregs[15];
2072 #else
2073 # error "Unsupported arch"
2074 #endif
2075 }
2076
InitPcSpBp()2077 void SignalContext::InitPcSpBp() { GetPcSpBp(context, &pc, &sp, &bp); }
2078
MaybeReexec()2079 void MaybeReexec() {
2080 // No need to re-exec on Linux.
2081 }
2082
CheckASLR()2083 void CheckASLR() {
2084 #if SANITIZER_NETBSD
2085 int mib[3];
2086 int paxflags;
2087 uptr len = sizeof(paxflags);
2088
2089 mib[0] = CTL_PROC;
2090 mib[1] = internal_getpid();
2091 mib[2] = PROC_PID_PAXFLAGS;
2092
2093 if (UNLIKELY(internal_sysctl(mib, 3, &paxflags, &len, NULL, 0) == -1)) {
2094 Printf("sysctl failed\n");
2095 Die();
2096 }
2097
2098 if (UNLIKELY(paxflags & CTL_PROC_PAXFLAGS_ASLR)) {
2099 Printf("This sanitizer is not compatible with enabled ASLR\n");
2100 Die();
2101 }
2102 #elif SANITIZER_PPC64V2
2103 // Disable ASLR for Linux PPC64LE.
2104 int old_personality = personality(0xffffffff);
2105 if (old_personality != -1 && (old_personality & ADDR_NO_RANDOMIZE) == 0) {
2106 VReport(1, "WARNING: Program is being run with address space layout "
2107 "randomization (ASLR) enabled which prevents the thread and "
2108 "memory sanitizers from working on powerpc64le.\n"
2109 "ASLR will be disabled and the program re-executed.\n");
2110 CHECK_NE(personality(old_personality | ADDR_NO_RANDOMIZE), -1);
2111 ReExec();
2112 }
2113 #else
2114 // Do nothing
2115 #endif
2116 }
2117
PrintModuleMap()2118 void PrintModuleMap() { }
2119
CheckNoDeepBind(const char * filename,int flag)2120 void CheckNoDeepBind(const char *filename, int flag) {
2121 #ifdef RTLD_DEEPBIND
2122 if (flag & RTLD_DEEPBIND) {
2123 Report(
2124 "You are trying to dlopen a %s shared library with RTLD_DEEPBIND flag"
2125 " which is incompatibe with sanitizer runtime "
2126 "(see https://github.com/google/sanitizers/issues/611 for details"
2127 "). If you want to run %s library under sanitizers please remove "
2128 "RTLD_DEEPBIND from dlopen flags.\n",
2129 filename, filename);
2130 Die();
2131 }
2132 #endif
2133 }
2134
FindAvailableMemoryRange(uptr size,uptr alignment,uptr left_padding,uptr * largest_gap_found,uptr * max_occupied_addr)2135 uptr FindAvailableMemoryRange(uptr size, uptr alignment, uptr left_padding,
2136 uptr *largest_gap_found,
2137 uptr *max_occupied_addr) {
2138 UNREACHABLE("FindAvailableMemoryRange is not available");
2139 return 0;
2140 }
2141
GetRandom(void * buffer,uptr length,bool blocking)2142 bool GetRandom(void *buffer, uptr length, bool blocking) {
2143 if (!buffer || !length || length > 256)
2144 return false;
2145 #if SANITIZER_USE_GETENTROPY
2146 uptr rnd = getentropy(buffer, length);
2147 int rverrno = 0;
2148 if (internal_iserror(rnd, &rverrno) && rverrno == EFAULT)
2149 return false;
2150 else if (rnd == 0)
2151 return true;
2152 #endif // SANITIZER_USE_GETENTROPY
2153
2154 #if SANITIZER_USE_GETRANDOM
2155 static atomic_uint8_t skip_getrandom_syscall;
2156 if (!atomic_load_relaxed(&skip_getrandom_syscall)) {
2157 // Up to 256 bytes, getrandom will not be interrupted.
2158 uptr res = internal_syscall(SYSCALL(getrandom), buffer, length,
2159 blocking ? 0 : GRND_NONBLOCK);
2160 int rverrno = 0;
2161 if (internal_iserror(res, &rverrno) && rverrno == ENOSYS)
2162 atomic_store_relaxed(&skip_getrandom_syscall, 1);
2163 else if (res == length)
2164 return true;
2165 }
2166 #endif // SANITIZER_USE_GETRANDOM
2167 // Up to 256 bytes, a read off /dev/urandom will not be interrupted.
2168 // blocking is moot here, O_NONBLOCK has no effect when opening /dev/urandom.
2169 uptr fd = internal_open("/dev/urandom", O_RDONLY);
2170 if (internal_iserror(fd))
2171 return false;
2172 uptr res = internal_read(fd, buffer, length);
2173 if (internal_iserror(res))
2174 return false;
2175 internal_close(fd);
2176 return true;
2177 }
2178
2179 } // namespace __sanitizer
2180
2181 #endif
2182