1 //===-- sanitizer_linux.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 shared between AddressSanitizer and ThreadSanitizer
11 // run-time libraries and implements linux-specific functions from
12 // sanitizer_libc.h.
13 //===----------------------------------------------------------------------===//
14
15 #include "sanitizer_platform.h"
16
17 #if SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD || \
18 SANITIZER_OPENBSD || SANITIZER_SOLARIS
19
20 #include "sanitizer_common.h"
21 #include "sanitizer_flags.h"
22 #include "sanitizer_getauxval.h"
23 #include "sanitizer_internal_defs.h"
24 #include "sanitizer_libc.h"
25 #include "sanitizer_linux.h"
26 #include "sanitizer_mutex.h"
27 #include "sanitizer_placement_new.h"
28 #include "sanitizer_procmaps.h"
29
30 #if SANITIZER_LINUX
31 #include <asm/param.h>
32 #endif
33
34 // For mips64, syscall(__NR_stat) fills the buffer in the 'struct kernel_stat'
35 // format. Struct kernel_stat is defined as 'struct stat' in asm/stat.h. To
36 // access stat from asm/stat.h, without conflicting with definition in
37 // sys/stat.h, we use this trick.
38 #if defined(__mips64)
39 #include <asm/unistd.h>
40 #include <sys/types.h>
41 #define stat kernel_stat
42 #include <asm/stat.h>
43 #undef stat
44 #endif
45
46 #include <dlfcn.h>
47 #include <errno.h>
48 #include <fcntl.h>
49 #include <link.h>
50 #include <pthread.h>
51 #include <sched.h>
52 #include <signal.h>
53 #include <sys/mman.h>
54 #include <sys/param.h>
55 #if !SANITIZER_SOLARIS
56 #include <sys/ptrace.h>
57 #endif
58 #include <sys/resource.h>
59 #include <sys/stat.h>
60 #include <sys/syscall.h>
61 #include <sys/time.h>
62 #include <sys/types.h>
63 #if !SANITIZER_OPENBSD
64 #include <ucontext.h>
65 #endif
66 #if SANITIZER_OPENBSD
67 #include <sys/futex.h>
68 #include <sys/sysctl.h>
69 #endif
70 #include <unistd.h>
71
72 #if SANITIZER_LINUX
73 #include <sys/utsname.h>
74 #endif
75
76 #if SANITIZER_LINUX && !SANITIZER_ANDROID
77 #include <sys/personality.h>
78 #endif
79
80 #if SANITIZER_FREEBSD
81 #include <sys/exec.h>
82 #include <sys/sysctl.h>
83 #include <machine/atomic.h>
84 extern "C" {
85 // <sys/umtx.h> must be included after <errno.h> and <sys/types.h> on
86 // FreeBSD 9.2 and 10.0.
87 #include <sys/umtx.h>
88 }
89 #include <sys/thr.h>
90 #endif // SANITIZER_FREEBSD
91
92 #if SANITIZER_NETBSD
93 #include <limits.h> // For NAME_MAX
94 #include <sys/sysctl.h>
95 #include <sys/exec.h>
96 extern struct ps_strings *__ps_strings;
97 #endif // SANITIZER_NETBSD
98
99 #if SANITIZER_SOLARIS
100 #include <stdlib.h>
101 #include <thread.h>
102 #define environ _environ
103 #endif
104
105 extern char **environ;
106
107 #if SANITIZER_LINUX
108 // <linux/time.h>
109 struct kernel_timeval {
110 long tv_sec;
111 long tv_usec;
112 };
113
114 // <linux/futex.h> is broken on some linux distributions.
115 const int FUTEX_WAIT = 0;
116 const int FUTEX_WAKE = 1;
117 const int FUTEX_PRIVATE_FLAG = 128;
118 const int FUTEX_WAIT_PRIVATE = FUTEX_WAIT | FUTEX_PRIVATE_FLAG;
119 const int FUTEX_WAKE_PRIVATE = FUTEX_WAKE | FUTEX_PRIVATE_FLAG;
120 #endif // SANITIZER_LINUX
121
122 // Are we using 32-bit or 64-bit Linux syscalls?
123 // x32 (which defines __x86_64__) has SANITIZER_WORDSIZE == 32
124 // but it still needs to use 64-bit syscalls.
125 #if SANITIZER_LINUX && (defined(__x86_64__) || defined(__powerpc64__) || \
126 SANITIZER_WORDSIZE == 64)
127 # define SANITIZER_LINUX_USES_64BIT_SYSCALLS 1
128 #else
129 # define SANITIZER_LINUX_USES_64BIT_SYSCALLS 0
130 #endif
131
132 #if defined(__x86_64__) || SANITIZER_MIPS64
133 extern "C" {
134 extern void internal_sigreturn();
135 }
136 #endif
137
138 // Note : FreeBSD had implemented both
139 // Linux and OpenBSD apis, available from
140 // future 12.x version most likely
141 #if SANITIZER_LINUX && defined(__NR_getrandom)
142 # if !defined(GRND_NONBLOCK)
143 # define GRND_NONBLOCK 1
144 # endif
145 # define SANITIZER_USE_GETRANDOM 1
146 #else
147 # define SANITIZER_USE_GETRANDOM 0
148 #endif // SANITIZER_LINUX && defined(__NR_getrandom)
149
150 #if SANITIZER_OPENBSD
151 # define SANITIZER_USE_GETENTROPY 1
152 #else
153 # if SANITIZER_FREEBSD && __FreeBSD_version >= 1200000
154 # define SANITIZER_USE_GETENTROPY 1
155 # else
156 # define SANITIZER_USE_GETENTROPY 0
157 # endif
158 #endif // SANITIZER_USE_GETENTROPY
159
160 namespace __sanitizer {
161
162 #if SANITIZER_LINUX && defined(__x86_64__)
163 #include "sanitizer_syscall_linux_x86_64.inc"
164 #elif SANITIZER_LINUX && defined(__aarch64__)
165 #include "sanitizer_syscall_linux_aarch64.inc"
166 #elif SANITIZER_LINUX && defined(__arm__)
167 #include "sanitizer_syscall_linux_arm.inc"
168 #else
169 #include "sanitizer_syscall_generic.inc"
170 #endif
171
172 // --------------- sanitizer_libc.h
173 #if !SANITIZER_SOLARIS && !SANITIZER_NETBSD
174 #if !SANITIZER_S390 && !SANITIZER_OPENBSD
internal_mmap(void * addr,uptr length,int prot,int flags,int fd,OFF_T offset)175 uptr internal_mmap(void *addr, uptr length, int prot, int flags, int fd,
176 OFF_T offset) {
177 #if SANITIZER_FREEBSD || SANITIZER_LINUX_USES_64BIT_SYSCALLS
178 return internal_syscall(SYSCALL(mmap), (uptr)addr, length, prot, flags, fd,
179 offset);
180 #else
181 // mmap2 specifies file offset in 4096-byte units.
182 CHECK(IsAligned(offset, 4096));
183 return internal_syscall(SYSCALL(mmap2), addr, length, prot, flags, fd,
184 offset / 4096);
185 #endif
186 }
187 #endif // !SANITIZER_S390 && !SANITIZER_OPENBSD
188
189 #if !SANITIZER_OPENBSD
internal_munmap(void * addr,uptr length)190 uptr internal_munmap(void *addr, uptr length) {
191 return internal_syscall(SYSCALL(munmap), (uptr)addr, length);
192 }
193
internal_mprotect(void * addr,uptr length,int prot)194 int internal_mprotect(void *addr, uptr length, int prot) {
195 return internal_syscall(SYSCALL(mprotect), (uptr)addr, length, prot);
196 }
197 #endif
198
internal_close(fd_t fd)199 uptr internal_close(fd_t fd) {
200 return internal_syscall(SYSCALL(close), fd);
201 }
202
internal_open(const char * filename,int flags)203 uptr internal_open(const char *filename, int flags) {
204 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
205 return internal_syscall(SYSCALL(openat), AT_FDCWD, (uptr)filename, flags);
206 #else
207 return internal_syscall(SYSCALL(open), (uptr)filename, flags);
208 #endif
209 }
210
internal_open(const char * filename,int flags,u32 mode)211 uptr internal_open(const char *filename, int flags, u32 mode) {
212 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
213 return internal_syscall(SYSCALL(openat), AT_FDCWD, (uptr)filename, flags,
214 mode);
215 #else
216 return internal_syscall(SYSCALL(open), (uptr)filename, flags, mode);
217 #endif
218 }
219
internal_read(fd_t fd,void * buf,uptr count)220 uptr internal_read(fd_t fd, void *buf, uptr count) {
221 sptr res;
222 HANDLE_EINTR(res,
223 (sptr)internal_syscall(SYSCALL(read), fd, (uptr)buf, count));
224 return res;
225 }
226
internal_write(fd_t fd,const void * buf,uptr count)227 uptr internal_write(fd_t fd, const void *buf, uptr count) {
228 sptr res;
229 HANDLE_EINTR(res,
230 (sptr)internal_syscall(SYSCALL(write), fd, (uptr)buf, count));
231 return res;
232 }
233
internal_ftruncate(fd_t fd,uptr size)234 uptr internal_ftruncate(fd_t fd, uptr size) {
235 sptr res;
236 HANDLE_EINTR(res, (sptr)internal_syscall(SYSCALL(ftruncate), fd,
237 (OFF_T)size));
238 return res;
239 }
240
241 #if !SANITIZER_LINUX_USES_64BIT_SYSCALLS && SANITIZER_LINUX
stat64_to_stat(struct stat64 * in,struct stat * out)242 static void stat64_to_stat(struct stat64 *in, struct stat *out) {
243 internal_memset(out, 0, sizeof(*out));
244 out->st_dev = in->st_dev;
245 out->st_ino = in->st_ino;
246 out->st_mode = in->st_mode;
247 out->st_nlink = in->st_nlink;
248 out->st_uid = in->st_uid;
249 out->st_gid = in->st_gid;
250 out->st_rdev = in->st_rdev;
251 out->st_size = in->st_size;
252 out->st_blksize = in->st_blksize;
253 out->st_blocks = in->st_blocks;
254 out->st_atime = in->st_atime;
255 out->st_mtime = in->st_mtime;
256 out->st_ctime = in->st_ctime;
257 }
258 #endif
259
260 #if defined(__mips64)
261 // Undefine compatibility macros from <sys/stat.h>
262 // so that they would not clash with the kernel_stat
263 // st_[a|m|c]time fields
264 #undef st_atime
265 #undef st_mtime
266 #undef st_ctime
267 #if defined(SANITIZER_ANDROID)
268 // Bionic sys/stat.h defines additional macros
269 // for compatibility with the old NDKs and
270 // they clash with the kernel_stat structure
271 // st_[a|m|c]time_nsec fields.
272 #undef st_atime_nsec
273 #undef st_mtime_nsec
274 #undef st_ctime_nsec
275 #endif
kernel_stat_to_stat(struct kernel_stat * in,struct stat * out)276 static void kernel_stat_to_stat(struct kernel_stat *in, struct stat *out) {
277 internal_memset(out, 0, sizeof(*out));
278 out->st_dev = in->st_dev;
279 out->st_ino = in->st_ino;
280 out->st_mode = in->st_mode;
281 out->st_nlink = in->st_nlink;
282 out->st_uid = in->st_uid;
283 out->st_gid = in->st_gid;
284 out->st_rdev = in->st_rdev;
285 out->st_size = in->st_size;
286 out->st_blksize = in->st_blksize;
287 out->st_blocks = in->st_blocks;
288 #if defined(__USE_MISC) || \
289 defined(__USE_XOPEN2K8) || \
290 defined(SANITIZER_ANDROID)
291 out->st_atim.tv_sec = in->st_atime;
292 out->st_atim.tv_nsec = in->st_atime_nsec;
293 out->st_mtim.tv_sec = in->st_mtime;
294 out->st_mtim.tv_nsec = in->st_mtime_nsec;
295 out->st_ctim.tv_sec = in->st_ctime;
296 out->st_ctim.tv_nsec = in->st_ctime_nsec;
297 #else
298 out->st_atime = in->st_atime;
299 out->st_atimensec = in->st_atime_nsec;
300 out->st_mtime = in->st_mtime;
301 out->st_mtimensec = in->st_mtime_nsec;
302 out->st_ctime = in->st_ctime;
303 out->st_atimensec = in->st_ctime_nsec;
304 #endif
305 }
306 #endif
307
internal_stat(const char * path,void * buf)308 uptr internal_stat(const char *path, void *buf) {
309 #if SANITIZER_FREEBSD || SANITIZER_OPENBSD
310 return internal_syscall(SYSCALL(fstatat), AT_FDCWD, (uptr)path, (uptr)buf, 0);
311 #elif SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
312 return internal_syscall(SYSCALL(newfstatat), AT_FDCWD, (uptr)path, (uptr)buf,
313 0);
314 #elif SANITIZER_LINUX_USES_64BIT_SYSCALLS
315 # if defined(__mips64)
316 // For mips64, stat syscall fills buffer in the format of kernel_stat
317 struct kernel_stat kbuf;
318 int res = internal_syscall(SYSCALL(stat), path, &kbuf);
319 kernel_stat_to_stat(&kbuf, (struct stat *)buf);
320 return res;
321 # else
322 return internal_syscall(SYSCALL(stat), (uptr)path, (uptr)buf);
323 # endif
324 #else
325 struct stat64 buf64;
326 int res = internal_syscall(SYSCALL(stat64), path, &buf64);
327 stat64_to_stat(&buf64, (struct stat *)buf);
328 return res;
329 #endif
330 }
331
internal_lstat(const char * path,void * buf)332 uptr internal_lstat(const char *path, void *buf) {
333 #if SANITIZER_FREEBSD || SANITIZER_OPENBSD
334 return internal_syscall(SYSCALL(fstatat), AT_FDCWD, (uptr)path, (uptr)buf,
335 AT_SYMLINK_NOFOLLOW);
336 #elif SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
337 return internal_syscall(SYSCALL(newfstatat), AT_FDCWD, (uptr)path, (uptr)buf,
338 AT_SYMLINK_NOFOLLOW);
339 #elif SANITIZER_LINUX_USES_64BIT_SYSCALLS
340 # if SANITIZER_MIPS64
341 // For mips64, lstat syscall fills buffer in the format of kernel_stat
342 struct kernel_stat kbuf;
343 int res = internal_syscall(SYSCALL(lstat), path, &kbuf);
344 kernel_stat_to_stat(&kbuf, (struct stat *)buf);
345 return res;
346 # else
347 return internal_syscall(SYSCALL(lstat), (uptr)path, (uptr)buf);
348 # endif
349 #else
350 struct stat64 buf64;
351 int res = internal_syscall(SYSCALL(lstat64), path, &buf64);
352 stat64_to_stat(&buf64, (struct stat *)buf);
353 return res;
354 #endif
355 }
356
internal_fstat(fd_t fd,void * buf)357 uptr internal_fstat(fd_t fd, void *buf) {
358 #if SANITIZER_FREEBSD || SANITIZER_OPENBSD || \
359 SANITIZER_LINUX_USES_64BIT_SYSCALLS
360 #if SANITIZER_MIPS64 && !SANITIZER_OPENBSD
361 // For mips64, fstat syscall fills buffer in the format of kernel_stat
362 struct kernel_stat kbuf;
363 int res = internal_syscall(SYSCALL(fstat), fd, &kbuf);
364 kernel_stat_to_stat(&kbuf, (struct stat *)buf);
365 return res;
366 # else
367 return internal_syscall(SYSCALL(fstat), fd, (uptr)buf);
368 # endif
369 #else
370 struct stat64 buf64;
371 int res = internal_syscall(SYSCALL(fstat64), fd, &buf64);
372 stat64_to_stat(&buf64, (struct stat *)buf);
373 return res;
374 #endif
375 }
376
internal_filesize(fd_t fd)377 uptr internal_filesize(fd_t fd) {
378 struct stat st;
379 if (internal_fstat(fd, &st))
380 return -1;
381 return (uptr)st.st_size;
382 }
383
internal_dup(int oldfd)384 uptr internal_dup(int oldfd) {
385 return internal_syscall(SYSCALL(dup), oldfd);
386 }
387
internal_dup2(int oldfd,int newfd)388 uptr internal_dup2(int oldfd, int newfd) {
389 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
390 return internal_syscall(SYSCALL(dup3), oldfd, newfd, 0);
391 #else
392 return internal_syscall(SYSCALL(dup2), oldfd, newfd);
393 #endif
394 }
395
internal_readlink(const char * path,char * buf,uptr bufsize)396 uptr internal_readlink(const char *path, char *buf, uptr bufsize) {
397 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
398 return internal_syscall(SYSCALL(readlinkat), AT_FDCWD, (uptr)path, (uptr)buf,
399 bufsize);
400 #elif SANITIZER_OPENBSD
401 return internal_syscall(SYSCALL(readlinkat), AT_FDCWD, (uptr)path, (uptr)buf,
402 bufsize);
403 #else
404 return internal_syscall(SYSCALL(readlink), path, buf, bufsize);
405 #endif
406 }
407
internal_unlink(const char * path)408 uptr internal_unlink(const char *path) {
409 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS || SANITIZER_OPENBSD
410 return internal_syscall(SYSCALL(unlinkat), AT_FDCWD, (uptr)path, 0);
411 #else
412 return internal_syscall(SYSCALL(unlink), (uptr)path);
413 #endif
414 }
415
internal_rename(const char * oldpath,const char * newpath)416 uptr internal_rename(const char *oldpath, const char *newpath) {
417 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS || SANITIZER_OPENBSD
418 return internal_syscall(SYSCALL(renameat), AT_FDCWD, (uptr)oldpath, AT_FDCWD,
419 (uptr)newpath);
420 #else
421 return internal_syscall(SYSCALL(rename), (uptr)oldpath, (uptr)newpath);
422 #endif
423 }
424
internal_sched_yield()425 uptr internal_sched_yield() {
426 return internal_syscall(SYSCALL(sched_yield));
427 }
428
internal__exit(int exitcode)429 void internal__exit(int exitcode) {
430 #if SANITIZER_FREEBSD || SANITIZER_OPENBSD
431 internal_syscall(SYSCALL(exit), exitcode);
432 #else
433 internal_syscall(SYSCALL(exit_group), exitcode);
434 #endif
435 Die(); // Unreachable.
436 }
437
internal_sleep(unsigned int seconds)438 unsigned int internal_sleep(unsigned int seconds) {
439 struct timespec ts;
440 ts.tv_sec = seconds;
441 ts.tv_nsec = 0;
442 int res = internal_syscall(SYSCALL(nanosleep), &ts, &ts);
443 if (res) return ts.tv_sec;
444 return 0;
445 }
446
internal_execve(const char * filename,char * const argv[],char * const envp[])447 uptr internal_execve(const char *filename, char *const argv[],
448 char *const envp[]) {
449 return internal_syscall(SYSCALL(execve), (uptr)filename, (uptr)argv,
450 (uptr)envp);
451 }
452 #endif // !SANITIZER_SOLARIS && !SANITIZER_NETBSD
453
454 // ----------------- sanitizer_common.h
FileExists(const char * filename)455 bool FileExists(const char *filename) {
456 if (ShouldMockFailureToOpen(filename))
457 return false;
458 struct stat st;
459 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
460 if (internal_syscall(SYSCALL(newfstatat), AT_FDCWD, filename, &st, 0))
461 #else
462 if (internal_stat(filename, &st))
463 #endif
464 return false;
465 // Sanity check: filename is a regular file.
466 return S_ISREG(st.st_mode);
467 }
468
469 #if !SANITIZER_NETBSD
GetTid()470 tid_t GetTid() {
471 #if SANITIZER_FREEBSD
472 long Tid;
473 thr_self(&Tid);
474 return Tid;
475 #elif SANITIZER_OPENBSD
476 return internal_syscall(SYSCALL(getthrid));
477 #elif SANITIZER_SOLARIS
478 return thr_self();
479 #else
480 return internal_syscall(SYSCALL(gettid));
481 #endif
482 }
483
TgKill(pid_t pid,tid_t tid,int sig)484 int TgKill(pid_t pid, tid_t tid, int sig) {
485 #if SANITIZER_LINUX
486 return internal_syscall(SYSCALL(tgkill), pid, tid, sig);
487 #elif SANITIZER_FREEBSD
488 return internal_syscall(SYSCALL(thr_kill2), pid, tid, sig);
489 #elif SANITIZER_OPENBSD
490 (void)pid;
491 return internal_syscall(SYSCALL(thrkill), tid, sig, nullptr);
492 #elif SANITIZER_SOLARIS
493 (void)pid;
494 return thr_kill(tid, sig);
495 #endif
496 }
497 #endif
498
499 #if !SANITIZER_SOLARIS && !SANITIZER_NETBSD
NanoTime()500 u64 NanoTime() {
501 #if SANITIZER_FREEBSD || SANITIZER_OPENBSD
502 timeval tv;
503 #else
504 kernel_timeval tv;
505 #endif
506 internal_memset(&tv, 0, sizeof(tv));
507 internal_syscall(SYSCALL(gettimeofday), &tv, 0);
508 return (u64)tv.tv_sec * 1000*1000*1000 + tv.tv_usec * 1000;
509 }
510
internal_clock_gettime(__sanitizer_clockid_t clk_id,void * tp)511 uptr internal_clock_gettime(__sanitizer_clockid_t clk_id, void *tp) {
512 return internal_syscall(SYSCALL(clock_gettime), clk_id, tp);
513 }
514 #endif // !SANITIZER_SOLARIS && !SANITIZER_NETBSD
515
516 // Like getenv, but reads env directly from /proc (on Linux) or parses the
517 // 'environ' array (on some others) and does not use libc. This function
518 // should be called first inside __asan_init.
GetEnv(const char * name)519 const char *GetEnv(const char *name) {
520 #if SANITIZER_FREEBSD || SANITIZER_NETBSD || SANITIZER_OPENBSD || \
521 SANITIZER_SOLARIS
522 if (::environ != 0) {
523 uptr NameLen = internal_strlen(name);
524 for (char **Env = ::environ; *Env != 0; Env++) {
525 if (internal_strncmp(*Env, name, NameLen) == 0 && (*Env)[NameLen] == '=')
526 return (*Env) + NameLen + 1;
527 }
528 }
529 return 0; // Not found.
530 #elif SANITIZER_LINUX
531 static char *environ;
532 static uptr len;
533 static bool inited;
534 if (!inited) {
535 inited = true;
536 uptr environ_size;
537 if (!ReadFileToBuffer("/proc/self/environ", &environ, &environ_size, &len))
538 environ = nullptr;
539 }
540 if (!environ || len == 0) return nullptr;
541 uptr namelen = internal_strlen(name);
542 const char *p = environ;
543 while (*p != '\0') { // will happen at the \0\0 that terminates the buffer
544 // proc file has the format NAME=value\0NAME=value\0NAME=value\0...
545 const char* endp =
546 (char*)internal_memchr(p, '\0', len - (p - environ));
547 if (!endp) // this entry isn't NUL terminated
548 return nullptr;
549 else if (!internal_memcmp(p, name, namelen) && p[namelen] == '=') // Match.
550 return p + namelen + 1; // point after =
551 p = endp + 1;
552 }
553 return nullptr; // Not found.
554 #else
555 #error "Unsupported platform"
556 #endif
557 }
558
559 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD && !SANITIZER_OPENBSD
560 extern "C" {
561 SANITIZER_WEAK_ATTRIBUTE extern void *__libc_stack_end;
562 }
563 #endif
564
565 #if !SANITIZER_GO && !SANITIZER_FREEBSD && !SANITIZER_NETBSD && \
566 !SANITIZER_OPENBSD
ReadNullSepFileToArray(const char * path,char *** arr,int arr_size)567 static void ReadNullSepFileToArray(const char *path, char ***arr,
568 int arr_size) {
569 char *buff;
570 uptr buff_size;
571 uptr buff_len;
572 *arr = (char **)MmapOrDie(arr_size * sizeof(char *), "NullSepFileArray");
573 if (!ReadFileToBuffer(path, &buff, &buff_size, &buff_len, 1024 * 1024)) {
574 (*arr)[0] = nullptr;
575 return;
576 }
577 (*arr)[0] = buff;
578 int count, i;
579 for (count = 1, i = 1; ; i++) {
580 if (buff[i] == 0) {
581 if (buff[i+1] == 0) break;
582 (*arr)[count] = &buff[i+1];
583 CHECK_LE(count, arr_size - 1); // FIXME: make this more flexible.
584 count++;
585 }
586 }
587 (*arr)[count] = nullptr;
588 }
589 #endif
590
591 #if !SANITIZER_OPENBSD
GetArgsAndEnv(char *** argv,char *** envp)592 static void GetArgsAndEnv(char ***argv, char ***envp) {
593 #if SANITIZER_FREEBSD
594 // On FreeBSD, retrieving the argument and environment arrays is done via the
595 // kern.ps_strings sysctl, which returns a pointer to a structure containing
596 // this information. See also <sys/exec.h>.
597 ps_strings *pss;
598 uptr sz = sizeof(pss);
599 if (internal_sysctlbyname("kern.ps_strings", &pss, &sz, NULL, 0) == -1) {
600 Printf("sysctl kern.ps_strings failed\n");
601 Die();
602 }
603 *argv = pss->ps_argvstr;
604 *envp = pss->ps_envstr;
605 #elif SANITIZER_NETBSD
606 *argv = __ps_strings->ps_argvstr;
607 *envp = __ps_strings->ps_envstr;
608 #else // SANITIZER_FREEBSD
609 #if !SANITIZER_GO
610 if (&__libc_stack_end) {
611 #endif // !SANITIZER_GO
612 uptr* stack_end = (uptr*)__libc_stack_end;
613 int argc = *stack_end;
614 *argv = (char**)(stack_end + 1);
615 *envp = (char**)(stack_end + argc + 2);
616 #if !SANITIZER_GO
617 } else {
618 static const int kMaxArgv = 2000, kMaxEnvp = 2000;
619 ReadNullSepFileToArray("/proc/self/cmdline", argv, kMaxArgv);
620 ReadNullSepFileToArray("/proc/self/environ", envp, kMaxEnvp);
621 }
622 #endif // !SANITIZER_GO
623 #endif // SANITIZER_FREEBSD
624 }
625
GetArgv()626 char **GetArgv() {
627 char **argv, **envp;
628 GetArgsAndEnv(&argv, &envp);
629 return argv;
630 }
631
GetEnviron()632 char **GetEnviron() {
633 char **argv, **envp;
634 GetArgsAndEnv(&argv, &envp);
635 return envp;
636 }
637
638 #endif // !SANITIZER_OPENBSD
639
640 #if !SANITIZER_SOLARIS
641 enum MutexState {
642 MtxUnlocked = 0,
643 MtxLocked = 1,
644 MtxSleeping = 2
645 };
646
BlockingMutex()647 BlockingMutex::BlockingMutex() {
648 internal_memset(this, 0, sizeof(*this));
649 }
650
Lock()651 void BlockingMutex::Lock() {
652 CHECK_EQ(owner_, 0);
653 atomic_uint32_t *m = reinterpret_cast<atomic_uint32_t *>(&opaque_storage_);
654 if (atomic_exchange(m, MtxLocked, memory_order_acquire) == MtxUnlocked)
655 return;
656 while (atomic_exchange(m, MtxSleeping, memory_order_acquire) != MtxUnlocked) {
657 #if SANITIZER_FREEBSD
658 _umtx_op(m, UMTX_OP_WAIT_UINT, MtxSleeping, 0, 0);
659 #elif SANITIZER_NETBSD
660 sched_yield(); /* No userspace futex-like synchronization */
661 #else
662 internal_syscall(SYSCALL(futex), (uptr)m, FUTEX_WAIT_PRIVATE, MtxSleeping,
663 0, 0, 0);
664 #endif
665 }
666 }
667
Unlock()668 void BlockingMutex::Unlock() {
669 atomic_uint32_t *m = reinterpret_cast<atomic_uint32_t *>(&opaque_storage_);
670 u32 v = atomic_exchange(m, MtxUnlocked, memory_order_release);
671 CHECK_NE(v, MtxUnlocked);
672 if (v == MtxSleeping) {
673 #if SANITIZER_FREEBSD
674 _umtx_op(m, UMTX_OP_WAKE, 1, 0, 0);
675 #elif SANITIZER_NETBSD
676 /* No userspace futex-like synchronization */
677 #else
678 internal_syscall(SYSCALL(futex), (uptr)m, FUTEX_WAKE_PRIVATE, 1, 0, 0, 0);
679 #endif
680 }
681 }
682
CheckLocked()683 void BlockingMutex::CheckLocked() {
684 atomic_uint32_t *m = reinterpret_cast<atomic_uint32_t *>(&opaque_storage_);
685 CHECK_NE(MtxUnlocked, atomic_load(m, memory_order_relaxed));
686 }
687 #endif // !SANITIZER_SOLARIS
688
689 // ----------------- sanitizer_linux.h
690 // The actual size of this structure is specified by d_reclen.
691 // Note that getdents64 uses a different structure format. We only provide the
692 // 32-bit syscall here.
693 #if SANITIZER_NETBSD
694 // Not used
695 #elif SANITIZER_OPENBSD
696 // struct dirent is different for Linux and us. At this moment, we use only
697 // d_fileno (Linux call this d_ino), d_reclen, and d_name.
698 struct linux_dirent {
699 u64 d_ino; // d_fileno
700 u16 d_reclen;
701 u16 d_namlen; // not used
702 u8 d_type; // not used
703 char d_name[NAME_MAX + 1];
704 };
705 #else
706 struct linux_dirent {
707 #if SANITIZER_X32 || defined(__aarch64__)
708 u64 d_ino;
709 u64 d_off;
710 #else
711 unsigned long d_ino;
712 unsigned long d_off;
713 #endif
714 unsigned short d_reclen;
715 #ifdef __aarch64__
716 unsigned char d_type;
717 #endif
718 char d_name[256];
719 };
720 #endif
721
722 #if !SANITIZER_SOLARIS && !SANITIZER_NETBSD
723 // Syscall wrappers.
internal_ptrace(int request,int pid,void * addr,void * data)724 uptr internal_ptrace(int request, int pid, void *addr, void *data) {
725 return internal_syscall(SYSCALL(ptrace), request, pid, (uptr)addr,
726 (uptr)data);
727 }
728
internal_waitpid(int pid,int * status,int options)729 uptr internal_waitpid(int pid, int *status, int options) {
730 return internal_syscall(SYSCALL(wait4), pid, (uptr)status, options,
731 0 /* rusage */);
732 }
733
internal_getpid()734 uptr internal_getpid() {
735 return internal_syscall(SYSCALL(getpid));
736 }
737
internal_getppid()738 uptr internal_getppid() {
739 return internal_syscall(SYSCALL(getppid));
740 }
741
internal_getdents(fd_t fd,struct linux_dirent * dirp,unsigned int count)742 uptr internal_getdents(fd_t fd, struct linux_dirent *dirp, unsigned int count) {
743 #if SANITIZER_FREEBSD
744 return internal_syscall(SYSCALL(getdirentries), fd, (uptr)dirp, count, NULL);
745 #elif SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
746 return internal_syscall(SYSCALL(getdents64), fd, (uptr)dirp, count);
747 #else
748 return internal_syscall(SYSCALL(getdents), fd, (uptr)dirp, count);
749 #endif
750 }
751
internal_lseek(fd_t fd,OFF_T offset,int whence)752 uptr internal_lseek(fd_t fd, OFF_T offset, int whence) {
753 return internal_syscall(SYSCALL(lseek), fd, offset, whence);
754 }
755
756 #if SANITIZER_LINUX
internal_prctl(int option,uptr arg2,uptr arg3,uptr arg4,uptr arg5)757 uptr internal_prctl(int option, uptr arg2, uptr arg3, uptr arg4, uptr arg5) {
758 return internal_syscall(SYSCALL(prctl), option, arg2, arg3, arg4, arg5);
759 }
760 #endif
761
internal_sigaltstack(const void * ss,void * oss)762 uptr internal_sigaltstack(const void *ss, void *oss) {
763 return internal_syscall(SYSCALL(sigaltstack), (uptr)ss, (uptr)oss);
764 }
765
internal_fork()766 int internal_fork() {
767 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
768 return internal_syscall(SYSCALL(clone), SIGCHLD, 0);
769 #else
770 return internal_syscall(SYSCALL(fork));
771 #endif
772 }
773
774 #if SANITIZER_FREEBSD || SANITIZER_OPENBSD
internal_sysctl(const int * name,unsigned int namelen,void * oldp,uptr * oldlenp,const void * newp,uptr newlen)775 int internal_sysctl(const int *name, unsigned int namelen, void *oldp,
776 uptr *oldlenp, const void *newp, uptr newlen) {
777 #if SANITIZER_OPENBSD
778 return sysctl(name, namelen, oldp, (size_t *)oldlenp, (void *)newp,
779 (size_t)newlen);
780 #else
781 return internal_syscall(SYSCALL(__sysctl), name, namelen, oldp,
782 (size_t *)oldlenp, newp, (size_t)newlen);
783 #endif
784 }
785
786 #if SANITIZER_FREEBSD
internal_sysctlbyname(const char * sname,void * oldp,uptr * oldlenp,const void * newp,uptr newlen)787 int internal_sysctlbyname(const char *sname, void *oldp, uptr *oldlenp,
788 const void *newp, uptr newlen) {
789 return sysctlbyname(sname, oldp, (size_t *)oldlenp, newp, (size_t)newlen);
790 }
791 #endif
792 #endif
793
794 #if SANITIZER_LINUX
795 #define SA_RESTORER 0x04000000
796 // Doesn't set sa_restorer if the caller did not set it, so use with caution
797 //(see below).
internal_sigaction_norestorer(int signum,const void * act,void * oldact)798 int internal_sigaction_norestorer(int signum, const void *act, void *oldact) {
799 __sanitizer_kernel_sigaction_t k_act, k_oldact;
800 internal_memset(&k_act, 0, sizeof(__sanitizer_kernel_sigaction_t));
801 internal_memset(&k_oldact, 0, sizeof(__sanitizer_kernel_sigaction_t));
802 const __sanitizer_sigaction *u_act = (const __sanitizer_sigaction *)act;
803 __sanitizer_sigaction *u_oldact = (__sanitizer_sigaction *)oldact;
804 if (u_act) {
805 k_act.handler = u_act->handler;
806 k_act.sigaction = u_act->sigaction;
807 internal_memcpy(&k_act.sa_mask, &u_act->sa_mask,
808 sizeof(__sanitizer_kernel_sigset_t));
809 // Without SA_RESTORER kernel ignores the calls (probably returns EINVAL).
810 k_act.sa_flags = u_act->sa_flags | SA_RESTORER;
811 // FIXME: most often sa_restorer is unset, however the kernel requires it
812 // to point to a valid signal restorer that calls the rt_sigreturn syscall.
813 // If sa_restorer passed to the kernel is NULL, the program may crash upon
814 // signal delivery or fail to unwind the stack in the signal handler.
815 // libc implementation of sigaction() passes its own restorer to
816 // rt_sigaction, so we need to do the same (we'll need to reimplement the
817 // restorers; for x86_64 the restorer address can be obtained from
818 // oldact->sa_restorer upon a call to sigaction(xxx, NULL, oldact).
819 #if !SANITIZER_ANDROID || !SANITIZER_MIPS32
820 k_act.sa_restorer = u_act->sa_restorer;
821 #endif
822 }
823
824 uptr result = internal_syscall(SYSCALL(rt_sigaction), (uptr)signum,
825 (uptr)(u_act ? &k_act : nullptr),
826 (uptr)(u_oldact ? &k_oldact : nullptr),
827 (uptr)sizeof(__sanitizer_kernel_sigset_t));
828
829 if ((result == 0) && u_oldact) {
830 u_oldact->handler = k_oldact.handler;
831 u_oldact->sigaction = k_oldact.sigaction;
832 internal_memcpy(&u_oldact->sa_mask, &k_oldact.sa_mask,
833 sizeof(__sanitizer_kernel_sigset_t));
834 u_oldact->sa_flags = k_oldact.sa_flags;
835 #if !SANITIZER_ANDROID || !SANITIZER_MIPS32
836 u_oldact->sa_restorer = k_oldact.sa_restorer;
837 #endif
838 }
839 return result;
840 }
841
842 // Invokes sigaction via a raw syscall with a restorer, but does not support
843 // all platforms yet.
844 // We disable for Go simply because we have not yet added to buildgo.sh.
845 #if (defined(__x86_64__) || SANITIZER_MIPS64) && !SANITIZER_GO
internal_sigaction_syscall(int signum,const void * act,void * oldact)846 int internal_sigaction_syscall(int signum, const void *act, void *oldact) {
847 if (act == nullptr)
848 return internal_sigaction_norestorer(signum, act, oldact);
849 __sanitizer_sigaction u_adjust;
850 internal_memcpy(&u_adjust, act, sizeof(u_adjust));
851 #if !SANITIZER_ANDROID || !SANITIZER_MIPS32
852 if (u_adjust.sa_restorer == nullptr) {
853 u_adjust.sa_restorer = internal_sigreturn;
854 }
855 #endif
856 return internal_sigaction_norestorer(signum, (const void *)&u_adjust, oldact);
857 }
858 #endif // defined(__x86_64__) && !SANITIZER_GO
859 #endif // SANITIZER_LINUX
860
internal_sigprocmask(int how,__sanitizer_sigset_t * set,__sanitizer_sigset_t * oldset)861 uptr internal_sigprocmask(int how, __sanitizer_sigset_t *set,
862 __sanitizer_sigset_t *oldset) {
863 #if SANITIZER_FREEBSD || SANITIZER_OPENBSD
864 return internal_syscall(SYSCALL(sigprocmask), how, set, oldset);
865 #else
866 __sanitizer_kernel_sigset_t *k_set = (__sanitizer_kernel_sigset_t *)set;
867 __sanitizer_kernel_sigset_t *k_oldset = (__sanitizer_kernel_sigset_t *)oldset;
868 return internal_syscall(SYSCALL(rt_sigprocmask), (uptr)how,
869 (uptr)&k_set->sig[0], (uptr)&k_oldset->sig[0],
870 sizeof(__sanitizer_kernel_sigset_t));
871 #endif
872 }
873
internal_sigfillset(__sanitizer_sigset_t * set)874 void internal_sigfillset(__sanitizer_sigset_t *set) {
875 internal_memset(set, 0xff, sizeof(*set));
876 }
877
internal_sigemptyset(__sanitizer_sigset_t * set)878 void internal_sigemptyset(__sanitizer_sigset_t *set) {
879 internal_memset(set, 0, sizeof(*set));
880 }
881
882 #if SANITIZER_LINUX
internal_sigdelset(__sanitizer_sigset_t * set,int signum)883 void internal_sigdelset(__sanitizer_sigset_t *set, int signum) {
884 signum -= 1;
885 CHECK_GE(signum, 0);
886 CHECK_LT(signum, sizeof(*set) * 8);
887 __sanitizer_kernel_sigset_t *k_set = (__sanitizer_kernel_sigset_t *)set;
888 const uptr idx = signum / (sizeof(k_set->sig[0]) * 8);
889 const uptr bit = signum % (sizeof(k_set->sig[0]) * 8);
890 k_set->sig[idx] &= ~(1 << bit);
891 }
892
internal_sigismember(__sanitizer_sigset_t * set,int signum)893 bool internal_sigismember(__sanitizer_sigset_t *set, int signum) {
894 signum -= 1;
895 CHECK_GE(signum, 0);
896 CHECK_LT(signum, sizeof(*set) * 8);
897 __sanitizer_kernel_sigset_t *k_set = (__sanitizer_kernel_sigset_t *)set;
898 const uptr idx = signum / (sizeof(k_set->sig[0]) * 8);
899 const uptr bit = signum % (sizeof(k_set->sig[0]) * 8);
900 return k_set->sig[idx] & (1 << bit);
901 }
902 #elif SANITIZER_FREEBSD
internal_sigdelset(__sanitizer_sigset_t * set,int signum)903 void internal_sigdelset(__sanitizer_sigset_t *set, int signum) {
904 sigset_t *rset = reinterpret_cast<sigset_t *>(set);
905 sigdelset(rset, signum);
906 }
907
internal_sigismember(__sanitizer_sigset_t * set,int signum)908 bool internal_sigismember(__sanitizer_sigset_t *set, int signum) {
909 sigset_t *rset = reinterpret_cast<sigset_t *>(set);
910 return sigismember(rset, signum);
911 }
912 #endif
913 #endif // !SANITIZER_SOLARIS
914
915 #if !SANITIZER_NETBSD
916 // ThreadLister implementation.
ThreadLister(pid_t pid)917 ThreadLister::ThreadLister(pid_t pid) : pid_(pid), buffer_(4096) {
918 char task_directory_path[80];
919 internal_snprintf(task_directory_path, sizeof(task_directory_path),
920 "/proc/%d/task/", pid);
921 descriptor_ = internal_open(task_directory_path, O_RDONLY | O_DIRECTORY);
922 if (internal_iserror(descriptor_)) {
923 Report("Can't open /proc/%d/task for reading.\n", pid);
924 }
925 }
926
ListThreads(InternalMmapVector<tid_t> * threads)927 ThreadLister::Result ThreadLister::ListThreads(
928 InternalMmapVector<tid_t> *threads) {
929 if (internal_iserror(descriptor_))
930 return Error;
931 internal_lseek(descriptor_, 0, SEEK_SET);
932 threads->clear();
933
934 Result result = Ok;
935 for (bool first_read = true;; first_read = false) {
936 // Resize to max capacity if it was downsized by IsAlive.
937 buffer_.resize(buffer_.capacity());
938 CHECK_GE(buffer_.size(), 4096);
939 uptr read = internal_getdents(
940 descriptor_, (struct linux_dirent *)buffer_.data(), buffer_.size());
941 if (!read)
942 return result;
943 if (internal_iserror(read)) {
944 Report("Can't read directory entries from /proc/%d/task.\n", pid_);
945 return Error;
946 }
947
948 for (uptr begin = (uptr)buffer_.data(), end = begin + read; begin < end;) {
949 struct linux_dirent *entry = (struct linux_dirent *)begin;
950 begin += entry->d_reclen;
951 if (entry->d_ino == 1) {
952 // Inode 1 is for bad blocks and also can be a reason for early return.
953 // Should be emitted if kernel tried to output terminating thread.
954 // See proc_task_readdir implementation in Linux.
955 result = Incomplete;
956 }
957 if (entry->d_ino && *entry->d_name >= '0' && *entry->d_name <= '9')
958 threads->push_back(internal_atoll(entry->d_name));
959 }
960
961 // Now we are going to detect short-read or early EOF. In such cases Linux
962 // can return inconsistent list with missing alive threads.
963 // Code will just remember that the list can be incomplete but it will
964 // continue reads to return as much as possible.
965 if (!first_read) {
966 // The first one was a short-read by definition.
967 result = Incomplete;
968 } else if (read > buffer_.size() - 1024) {
969 // Read was close to the buffer size. So double the size and assume the
970 // worst.
971 buffer_.resize(buffer_.size() * 2);
972 result = Incomplete;
973 } else if (!threads->empty() && !IsAlive(threads->back())) {
974 // Maybe Linux early returned from read on terminated thread (!pid_alive)
975 // and failed to restore read position.
976 // See next_tid and proc_task_instantiate in Linux.
977 result = Incomplete;
978 }
979 }
980 }
981
IsAlive(int tid)982 bool ThreadLister::IsAlive(int tid) {
983 // /proc/%d/task/%d/status uses same call to detect alive threads as
984 // proc_task_readdir. See task_state implementation in Linux.
985 char path[80];
986 internal_snprintf(path, sizeof(path), "/proc/%d/task/%d/status", pid_, tid);
987 if (!ReadFileToVector(path, &buffer_) || buffer_.empty())
988 return false;
989 buffer_.push_back(0);
990 static const char kPrefix[] = "\nPPid:";
991 const char *field = internal_strstr(buffer_.data(), kPrefix);
992 if (!field)
993 return false;
994 field += internal_strlen(kPrefix);
995 return (int)internal_atoll(field) != 0;
996 }
997
~ThreadLister()998 ThreadLister::~ThreadLister() {
999 if (!internal_iserror(descriptor_))
1000 internal_close(descriptor_);
1001 }
1002 #endif
1003
1004 #if SANITIZER_WORDSIZE == 32
1005 // Take care of unusable kernel area in top gigabyte.
GetKernelAreaSize()1006 static uptr GetKernelAreaSize() {
1007 #if SANITIZER_LINUX && !SANITIZER_X32
1008 const uptr gbyte = 1UL << 30;
1009
1010 // Firstly check if there are writable segments
1011 // mapped to top gigabyte (e.g. stack).
1012 MemoryMappingLayout proc_maps(/*cache_enabled*/true);
1013 if (proc_maps.Error())
1014 return 0;
1015 MemoryMappedSegment segment;
1016 while (proc_maps.Next(&segment)) {
1017 if ((segment.end >= 3 * gbyte) && segment.IsWritable()) return 0;
1018 }
1019
1020 #if !SANITIZER_ANDROID
1021 // Even if nothing is mapped, top Gb may still be accessible
1022 // if we are running on 64-bit kernel.
1023 // Uname may report misleading results if personality type
1024 // is modified (e.g. under schroot) so check this as well.
1025 struct utsname uname_info;
1026 int pers = personality(0xffffffffUL);
1027 if (!(pers & PER_MASK)
1028 && uname(&uname_info) == 0
1029 && internal_strstr(uname_info.machine, "64"))
1030 return 0;
1031 #endif // SANITIZER_ANDROID
1032
1033 // Top gigabyte is reserved for kernel.
1034 return gbyte;
1035 #else
1036 return 0;
1037 #endif // SANITIZER_LINUX && !SANITIZER_X32
1038 }
1039 #endif // SANITIZER_WORDSIZE == 32
1040
GetMaxVirtualAddress()1041 uptr GetMaxVirtualAddress() {
1042 #if (SANITIZER_NETBSD || SANITIZER_OPENBSD) && defined(__x86_64__)
1043 return 0x7f7ffffff000ULL; // (0x00007f8000000000 - PAGE_SIZE)
1044 #elif SANITIZER_WORDSIZE == 64
1045 # if defined(__powerpc64__) || defined(__aarch64__)
1046 // On PowerPC64 we have two different address space layouts: 44- and 46-bit.
1047 // We somehow need to figure out which one we are using now and choose
1048 // one of 0x00000fffffffffffUL and 0x00003fffffffffffUL.
1049 // Note that with 'ulimit -s unlimited' the stack is moved away from the top
1050 // of the address space, so simply checking the stack address is not enough.
1051 // This should (does) work for both PowerPC64 Endian modes.
1052 // Similarly, aarch64 has multiple address space layouts: 39, 42 and 47-bit.
1053 return (1ULL << (MostSignificantSetBitIndex(GET_CURRENT_FRAME()) + 1)) - 1;
1054 # elif defined(__mips64)
1055 return (1ULL << 40) - 1; // 0x000000ffffffffffUL;
1056 # elif defined(__s390x__)
1057 return (1ULL << 53) - 1; // 0x001fffffffffffffUL;
1058 # else
1059 return (1ULL << 47) - 1; // 0x00007fffffffffffUL;
1060 # endif
1061 #else // SANITIZER_WORDSIZE == 32
1062 # if defined(__s390__)
1063 return (1ULL << 31) - 1; // 0x7fffffff;
1064 # else
1065 return (1ULL << 32) - 1; // 0xffffffff;
1066 # endif
1067 #endif // SANITIZER_WORDSIZE
1068 }
1069
GetMaxUserVirtualAddress()1070 uptr GetMaxUserVirtualAddress() {
1071 uptr addr = GetMaxVirtualAddress();
1072 #if SANITIZER_WORDSIZE == 32 && !defined(__s390__)
1073 if (!common_flags()->full_address_space)
1074 addr -= GetKernelAreaSize();
1075 CHECK_LT(reinterpret_cast<uptr>(&addr), addr);
1076 #endif
1077 return addr;
1078 }
1079
GetPageSize()1080 uptr GetPageSize() {
1081 // Android post-M sysconf(_SC_PAGESIZE) crashes if called from .preinit_array.
1082 #if SANITIZER_ANDROID
1083 return 4096;
1084 #elif SANITIZER_LINUX && (defined(__x86_64__) || defined(__i386__))
1085 return EXEC_PAGESIZE;
1086 #elif SANITIZER_USE_GETAUXVAL
1087 return getauxval(AT_PAGESZ);
1088 #elif SANITIZER_FREEBSD || SANITIZER_NETBSD
1089 // Use sysctl as sysconf can trigger interceptors internally.
1090 int pz = 0;
1091 uptr pzl = sizeof(pz);
1092 int mib[2] = {CTL_HW, HW_PAGESIZE};
1093 int rv = internal_sysctl(mib, 2, &pz, &pzl, nullptr, 0);
1094 CHECK_EQ(rv, 0);
1095 return (uptr)pz;
1096 #else
1097 return sysconf(_SC_PAGESIZE); // EXEC_PAGESIZE may not be trustworthy.
1098 #endif
1099 }
1100
1101 #if !SANITIZER_OPENBSD
ReadBinaryName(char * buf,uptr buf_len)1102 uptr ReadBinaryName(/*out*/char *buf, uptr buf_len) {
1103 #if SANITIZER_SOLARIS
1104 const char *default_module_name = getexecname();
1105 CHECK_NE(default_module_name, NULL);
1106 return internal_snprintf(buf, buf_len, "%s", default_module_name);
1107 #else
1108 #if SANITIZER_FREEBSD || SANITIZER_NETBSD
1109 #if SANITIZER_FREEBSD
1110 const int Mib[4] = {CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1};
1111 #else
1112 const int Mib[4] = {CTL_KERN, KERN_PROC_ARGS, -1, KERN_PROC_PATHNAME};
1113 #endif
1114 const char *default_module_name = "kern.proc.pathname";
1115 uptr Size = buf_len;
1116 bool IsErr =
1117 (internal_sysctl(Mib, ARRAY_SIZE(Mib), buf, &Size, NULL, 0) != 0);
1118 int readlink_error = IsErr ? errno : 0;
1119 uptr module_name_len = Size;
1120 #else
1121 const char *default_module_name = "/proc/self/exe";
1122 uptr module_name_len = internal_readlink(
1123 default_module_name, buf, buf_len);
1124 int readlink_error;
1125 bool IsErr = internal_iserror(module_name_len, &readlink_error);
1126 #endif // SANITIZER_SOLARIS
1127 if (IsErr) {
1128 // We can't read binary name for some reason, assume it's unknown.
1129 Report("WARNING: reading executable name failed with errno %d, "
1130 "some stack frames may not be symbolized\n", readlink_error);
1131 module_name_len = internal_snprintf(buf, buf_len, "%s",
1132 default_module_name);
1133 CHECK_LT(module_name_len, buf_len);
1134 }
1135 return module_name_len;
1136 #endif
1137 }
1138 #endif // !SANITIZER_OPENBSD
1139
ReadLongProcessName(char * buf,uptr buf_len)1140 uptr ReadLongProcessName(/*out*/ char *buf, uptr buf_len) {
1141 #if SANITIZER_LINUX
1142 char *tmpbuf;
1143 uptr tmpsize;
1144 uptr tmplen;
1145 if (ReadFileToBuffer("/proc/self/cmdline", &tmpbuf, &tmpsize, &tmplen,
1146 1024 * 1024)) {
1147 internal_strncpy(buf, tmpbuf, buf_len);
1148 UnmapOrDie(tmpbuf, tmpsize);
1149 return internal_strlen(buf);
1150 }
1151 #endif
1152 return ReadBinaryName(buf, buf_len);
1153 }
1154
1155 // Match full names of the form /path/to/base_name{-,.}*
LibraryNameIs(const char * full_name,const char * base_name)1156 bool LibraryNameIs(const char *full_name, const char *base_name) {
1157 const char *name = full_name;
1158 // Strip path.
1159 while (*name != '\0') name++;
1160 while (name > full_name && *name != '/') name--;
1161 if (*name == '/') name++;
1162 uptr base_name_length = internal_strlen(base_name);
1163 if (internal_strncmp(name, base_name, base_name_length)) return false;
1164 return (name[base_name_length] == '-' || name[base_name_length] == '.');
1165 }
1166
1167 #if !SANITIZER_ANDROID
1168 // Call cb for each region mapped by map.
ForEachMappedRegion(link_map * map,void (* cb)(const void *,uptr))1169 void ForEachMappedRegion(link_map *map, void (*cb)(const void *, uptr)) {
1170 CHECK_NE(map, nullptr);
1171 #if !SANITIZER_FREEBSD && !SANITIZER_OPENBSD
1172 typedef ElfW(Phdr) Elf_Phdr;
1173 typedef ElfW(Ehdr) Elf_Ehdr;
1174 #endif // !SANITIZER_FREEBSD && !SANITIZER_OPENBSD
1175 char *base = (char *)map->l_addr;
1176 Elf_Ehdr *ehdr = (Elf_Ehdr *)base;
1177 char *phdrs = base + ehdr->e_phoff;
1178 char *phdrs_end = phdrs + ehdr->e_phnum * ehdr->e_phentsize;
1179
1180 // Find the segment with the minimum base so we can "relocate" the p_vaddr
1181 // fields. Typically ET_DYN objects (DSOs) have base of zero and ET_EXEC
1182 // objects have a non-zero base.
1183 uptr preferred_base = (uptr)-1;
1184 for (char *iter = phdrs; iter != phdrs_end; iter += ehdr->e_phentsize) {
1185 Elf_Phdr *phdr = (Elf_Phdr *)iter;
1186 if (phdr->p_type == PT_LOAD && preferred_base > (uptr)phdr->p_vaddr)
1187 preferred_base = (uptr)phdr->p_vaddr;
1188 }
1189
1190 // Compute the delta from the real base to get a relocation delta.
1191 sptr delta = (uptr)base - preferred_base;
1192 // Now we can figure out what the loader really mapped.
1193 for (char *iter = phdrs; iter != phdrs_end; iter += ehdr->e_phentsize) {
1194 Elf_Phdr *phdr = (Elf_Phdr *)iter;
1195 if (phdr->p_type == PT_LOAD) {
1196 uptr seg_start = phdr->p_vaddr + delta;
1197 uptr seg_end = seg_start + phdr->p_memsz;
1198 // None of these values are aligned. We consider the ragged edges of the
1199 // load command as defined, since they are mapped from the file.
1200 seg_start = RoundDownTo(seg_start, GetPageSizeCached());
1201 seg_end = RoundUpTo(seg_end, GetPageSizeCached());
1202 cb((void *)seg_start, seg_end - seg_start);
1203 }
1204 }
1205 }
1206 #endif
1207
1208 #if defined(__x86_64__) && SANITIZER_LINUX
1209 // We cannot use glibc's clone wrapper, because it messes with the child
1210 // task's TLS. It writes the PID and TID of the child task to its thread
1211 // descriptor, but in our case the child task shares the thread descriptor with
1212 // the parent (because we don't know how to allocate a new thread
1213 // descriptor to keep glibc happy). So the stock version of clone(), when
1214 // 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)1215 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
1216 int *parent_tidptr, void *newtls, int *child_tidptr) {
1217 long long res;
1218 if (!fn || !child_stack)
1219 return -EINVAL;
1220 CHECK_EQ(0, (uptr)child_stack % 16);
1221 child_stack = (char *)child_stack - 2 * sizeof(unsigned long long);
1222 ((unsigned long long *)child_stack)[0] = (uptr)fn;
1223 ((unsigned long long *)child_stack)[1] = (uptr)arg;
1224 register void *r8 __asm__("r8") = newtls;
1225 register int *r10 __asm__("r10") = child_tidptr;
1226 __asm__ __volatile__(
1227 /* %rax = syscall(%rax = SYSCALL(clone),
1228 * %rdi = flags,
1229 * %rsi = child_stack,
1230 * %rdx = parent_tidptr,
1231 * %r8 = new_tls,
1232 * %r10 = child_tidptr)
1233 */
1234 "syscall\n"
1235
1236 /* if (%rax != 0)
1237 * return;
1238 */
1239 "testq %%rax,%%rax\n"
1240 "jnz 1f\n"
1241
1242 /* In the child. Terminate unwind chain. */
1243 // XXX: We should also terminate the CFI unwind chain
1244 // here. Unfortunately clang 3.2 doesn't support the
1245 // necessary CFI directives, so we skip that part.
1246 "xorq %%rbp,%%rbp\n"
1247
1248 /* Call "fn(arg)". */
1249 "popq %%rax\n"
1250 "popq %%rdi\n"
1251 "call *%%rax\n"
1252
1253 /* Call _exit(%rax). */
1254 "movq %%rax,%%rdi\n"
1255 "movq %2,%%rax\n"
1256 "syscall\n"
1257
1258 /* Return to parent. */
1259 "1:\n"
1260 : "=a" (res)
1261 : "a"(SYSCALL(clone)), "i"(SYSCALL(exit)),
1262 "S"(child_stack),
1263 "D"(flags),
1264 "d"(parent_tidptr),
1265 "r"(r8),
1266 "r"(r10)
1267 : "memory", "r11", "rcx");
1268 return res;
1269 }
1270 #elif defined(__mips__)
internal_clone(int (* fn)(void *),void * child_stack,int flags,void * arg,int * parent_tidptr,void * newtls,int * child_tidptr)1271 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
1272 int *parent_tidptr, void *newtls, int *child_tidptr) {
1273 long long res;
1274 if (!fn || !child_stack)
1275 return -EINVAL;
1276 CHECK_EQ(0, (uptr)child_stack % 16);
1277 child_stack = (char *)child_stack - 2 * sizeof(unsigned long long);
1278 ((unsigned long long *)child_stack)[0] = (uptr)fn;
1279 ((unsigned long long *)child_stack)[1] = (uptr)arg;
1280 register void *a3 __asm__("$7") = newtls;
1281 register int *a4 __asm__("$8") = child_tidptr;
1282 // We don't have proper CFI directives here because it requires alot of code
1283 // for very marginal benefits.
1284 __asm__ __volatile__(
1285 /* $v0 = syscall($v0 = __NR_clone,
1286 * $a0 = flags,
1287 * $a1 = child_stack,
1288 * $a2 = parent_tidptr,
1289 * $a3 = new_tls,
1290 * $a4 = child_tidptr)
1291 */
1292 ".cprestore 16;\n"
1293 "move $4,%1;\n"
1294 "move $5,%2;\n"
1295 "move $6,%3;\n"
1296 "move $7,%4;\n"
1297 /* Store the fifth argument on stack
1298 * if we are using 32-bit abi.
1299 */
1300 #if SANITIZER_WORDSIZE == 32
1301 "lw %5,16($29);\n"
1302 #else
1303 "move $8,%5;\n"
1304 #endif
1305 "li $2,%6;\n"
1306 "syscall;\n"
1307
1308 /* if ($v0 != 0)
1309 * return;
1310 */
1311 "bnez $2,1f;\n"
1312
1313 /* Call "fn(arg)". */
1314 #if SANITIZER_WORDSIZE == 32
1315 #ifdef __BIG_ENDIAN__
1316 "lw $25,4($29);\n"
1317 "lw $4,12($29);\n"
1318 #else
1319 "lw $25,0($29);\n"
1320 "lw $4,8($29);\n"
1321 #endif
1322 #else
1323 "ld $25,0($29);\n"
1324 "ld $4,8($29);\n"
1325 #endif
1326 "jal $25;\n"
1327
1328 /* Call _exit($v0). */
1329 "move $4,$2;\n"
1330 "li $2,%7;\n"
1331 "syscall;\n"
1332
1333 /* Return to parent. */
1334 "1:\n"
1335 : "=r" (res)
1336 : "r"(flags),
1337 "r"(child_stack),
1338 "r"(parent_tidptr),
1339 "r"(a3),
1340 "r"(a4),
1341 "i"(__NR_clone),
1342 "i"(__NR_exit)
1343 : "memory", "$29" );
1344 return res;
1345 }
1346 #elif defined(__aarch64__)
internal_clone(int (* fn)(void *),void * child_stack,int flags,void * arg,int * parent_tidptr,void * newtls,int * child_tidptr)1347 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
1348 int *parent_tidptr, void *newtls, int *child_tidptr) {
1349 long long res;
1350 if (!fn || !child_stack)
1351 return -EINVAL;
1352 CHECK_EQ(0, (uptr)child_stack % 16);
1353 child_stack = (char *)child_stack - 2 * sizeof(unsigned long long);
1354 ((unsigned long long *)child_stack)[0] = (uptr)fn;
1355 ((unsigned long long *)child_stack)[1] = (uptr)arg;
1356
1357 register int (*__fn)(void *) __asm__("x0") = fn;
1358 register void *__stack __asm__("x1") = child_stack;
1359 register int __flags __asm__("x2") = flags;
1360 register void *__arg __asm__("x3") = arg;
1361 register int *__ptid __asm__("x4") = parent_tidptr;
1362 register void *__tls __asm__("x5") = newtls;
1363 register int *__ctid __asm__("x6") = child_tidptr;
1364
1365 __asm__ __volatile__(
1366 "mov x0,x2\n" /* flags */
1367 "mov x2,x4\n" /* ptid */
1368 "mov x3,x5\n" /* tls */
1369 "mov x4,x6\n" /* ctid */
1370 "mov x8,%9\n" /* clone */
1371
1372 "svc 0x0\n"
1373
1374 /* if (%r0 != 0)
1375 * return %r0;
1376 */
1377 "cmp x0, #0\n"
1378 "bne 1f\n"
1379
1380 /* In the child, now. Call "fn(arg)". */
1381 "ldp x1, x0, [sp], #16\n"
1382 "blr x1\n"
1383
1384 /* Call _exit(%r0). */
1385 "mov x8, %10\n"
1386 "svc 0x0\n"
1387 "1:\n"
1388
1389 : "=r" (res)
1390 : "i"(-EINVAL),
1391 "r"(__fn), "r"(__stack), "r"(__flags), "r"(__arg),
1392 "r"(__ptid), "r"(__tls), "r"(__ctid),
1393 "i"(__NR_clone), "i"(__NR_exit)
1394 : "x30", "memory");
1395 return res;
1396 }
1397 #elif defined(__powerpc64__)
internal_clone(int (* fn)(void *),void * child_stack,int flags,void * arg,int * parent_tidptr,void * newtls,int * child_tidptr)1398 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
1399 int *parent_tidptr, void *newtls, int *child_tidptr) {
1400 long long res;
1401 // Stack frame structure.
1402 #if SANITIZER_PPC64V1
1403 // Back chain == 0 (SP + 112)
1404 // Frame (112 bytes):
1405 // Parameter save area (SP + 48), 8 doublewords
1406 // TOC save area (SP + 40)
1407 // Link editor doubleword (SP + 32)
1408 // Compiler doubleword (SP + 24)
1409 // LR save area (SP + 16)
1410 // CR save area (SP + 8)
1411 // Back chain (SP + 0)
1412 # define FRAME_SIZE 112
1413 # define FRAME_TOC_SAVE_OFFSET 40
1414 #elif SANITIZER_PPC64V2
1415 // Back chain == 0 (SP + 32)
1416 // Frame (32 bytes):
1417 // TOC save area (SP + 24)
1418 // LR save area (SP + 16)
1419 // CR save area (SP + 8)
1420 // Back chain (SP + 0)
1421 # define FRAME_SIZE 32
1422 # define FRAME_TOC_SAVE_OFFSET 24
1423 #else
1424 # error "Unsupported PPC64 ABI"
1425 #endif
1426 if (!fn || !child_stack)
1427 return -EINVAL;
1428 CHECK_EQ(0, (uptr)child_stack % 16);
1429
1430 register int (*__fn)(void *) __asm__("r3") = fn;
1431 register void *__cstack __asm__("r4") = child_stack;
1432 register int __flags __asm__("r5") = flags;
1433 register void *__arg __asm__("r6") = arg;
1434 register int *__ptidptr __asm__("r7") = parent_tidptr;
1435 register void *__newtls __asm__("r8") = newtls;
1436 register int *__ctidptr __asm__("r9") = child_tidptr;
1437
1438 __asm__ __volatile__(
1439 /* fn and arg are saved across the syscall */
1440 "mr 28, %5\n\t"
1441 "mr 27, %8\n\t"
1442
1443 /* syscall
1444 r0 == __NR_clone
1445 r3 == flags
1446 r4 == child_stack
1447 r5 == parent_tidptr
1448 r6 == newtls
1449 r7 == child_tidptr */
1450 "mr 3, %7\n\t"
1451 "mr 5, %9\n\t"
1452 "mr 6, %10\n\t"
1453 "mr 7, %11\n\t"
1454 "li 0, %3\n\t"
1455 "sc\n\t"
1456
1457 /* Test if syscall was successful */
1458 "cmpdi cr1, 3, 0\n\t"
1459 "crandc cr1*4+eq, cr1*4+eq, cr0*4+so\n\t"
1460 "bne- cr1, 1f\n\t"
1461
1462 /* Set up stack frame */
1463 "li 29, 0\n\t"
1464 "stdu 29, -8(1)\n\t"
1465 "stdu 1, -%12(1)\n\t"
1466 /* Do the function call */
1467 "std 2, %13(1)\n\t"
1468 #if SANITIZER_PPC64V1
1469 "ld 0, 0(28)\n\t"
1470 "ld 2, 8(28)\n\t"
1471 "mtctr 0\n\t"
1472 #elif SANITIZER_PPC64V2
1473 "mr 12, 28\n\t"
1474 "mtctr 12\n\t"
1475 #else
1476 # error "Unsupported PPC64 ABI"
1477 #endif
1478 "mr 3, 27\n\t"
1479 "bctrl\n\t"
1480 "ld 2, %13(1)\n\t"
1481
1482 /* Call _exit(r3) */
1483 "li 0, %4\n\t"
1484 "sc\n\t"
1485
1486 /* Return to parent */
1487 "1:\n\t"
1488 "mr %0, 3\n\t"
1489 : "=r" (res)
1490 : "0" (-1),
1491 "i" (EINVAL),
1492 "i" (__NR_clone),
1493 "i" (__NR_exit),
1494 "r" (__fn),
1495 "r" (__cstack),
1496 "r" (__flags),
1497 "r" (__arg),
1498 "r" (__ptidptr),
1499 "r" (__newtls),
1500 "r" (__ctidptr),
1501 "i" (FRAME_SIZE),
1502 "i" (FRAME_TOC_SAVE_OFFSET)
1503 : "cr0", "cr1", "memory", "ctr", "r0", "r27", "r28", "r29");
1504 return res;
1505 }
1506 #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)1507 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
1508 int *parent_tidptr, void *newtls, int *child_tidptr) {
1509 int res;
1510 if (!fn || !child_stack)
1511 return -EINVAL;
1512 CHECK_EQ(0, (uptr)child_stack % 16);
1513 child_stack = (char *)child_stack - 7 * sizeof(unsigned int);
1514 ((unsigned int *)child_stack)[0] = (uptr)flags;
1515 ((unsigned int *)child_stack)[1] = (uptr)0;
1516 ((unsigned int *)child_stack)[2] = (uptr)fn;
1517 ((unsigned int *)child_stack)[3] = (uptr)arg;
1518 __asm__ __volatile__(
1519 /* %eax = syscall(%eax = SYSCALL(clone),
1520 * %ebx = flags,
1521 * %ecx = child_stack,
1522 * %edx = parent_tidptr,
1523 * %esi = new_tls,
1524 * %edi = child_tidptr)
1525 */
1526
1527 /* Obtain flags */
1528 "movl (%%ecx), %%ebx\n"
1529 /* Do the system call */
1530 "pushl %%ebx\n"
1531 "pushl %%esi\n"
1532 "pushl %%edi\n"
1533 /* Remember the flag value. */
1534 "movl %%ebx, (%%ecx)\n"
1535 "int $0x80\n"
1536 "popl %%edi\n"
1537 "popl %%esi\n"
1538 "popl %%ebx\n"
1539
1540 /* if (%eax != 0)
1541 * return;
1542 */
1543
1544 "test %%eax,%%eax\n"
1545 "jnz 1f\n"
1546
1547 /* terminate the stack frame */
1548 "xorl %%ebp,%%ebp\n"
1549 /* Call FN. */
1550 "call *%%ebx\n"
1551 #ifdef PIC
1552 "call here\n"
1553 "here:\n"
1554 "popl %%ebx\n"
1555 "addl $_GLOBAL_OFFSET_TABLE_+[.-here], %%ebx\n"
1556 #endif
1557 /* Call exit */
1558 "movl %%eax, %%ebx\n"
1559 "movl %2, %%eax\n"
1560 "int $0x80\n"
1561 "1:\n"
1562 : "=a" (res)
1563 : "a"(SYSCALL(clone)), "i"(SYSCALL(exit)),
1564 "c"(child_stack),
1565 "d"(parent_tidptr),
1566 "S"(newtls),
1567 "D"(child_tidptr)
1568 : "memory");
1569 return res;
1570 }
1571 #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)1572 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
1573 int *parent_tidptr, void *newtls, int *child_tidptr) {
1574 unsigned int res;
1575 if (!fn || !child_stack)
1576 return -EINVAL;
1577 child_stack = (char *)child_stack - 2 * sizeof(unsigned int);
1578 ((unsigned int *)child_stack)[0] = (uptr)fn;
1579 ((unsigned int *)child_stack)[1] = (uptr)arg;
1580 register int r0 __asm__("r0") = flags;
1581 register void *r1 __asm__("r1") = child_stack;
1582 register int *r2 __asm__("r2") = parent_tidptr;
1583 register void *r3 __asm__("r3") = newtls;
1584 register int *r4 __asm__("r4") = child_tidptr;
1585 register int r7 __asm__("r7") = __NR_clone;
1586
1587 #if __ARM_ARCH > 4 || defined (__ARM_ARCH_4T__)
1588 # define ARCH_HAS_BX
1589 #endif
1590 #if __ARM_ARCH > 4
1591 # define ARCH_HAS_BLX
1592 #endif
1593
1594 #ifdef ARCH_HAS_BX
1595 # ifdef ARCH_HAS_BLX
1596 # define BLX(R) "blx " #R "\n"
1597 # else
1598 # define BLX(R) "mov lr, pc; bx " #R "\n"
1599 # endif
1600 #else
1601 # define BLX(R) "mov lr, pc; mov pc," #R "\n"
1602 #endif
1603
1604 __asm__ __volatile__(
1605 /* %r0 = syscall(%r7 = SYSCALL(clone),
1606 * %r0 = flags,
1607 * %r1 = child_stack,
1608 * %r2 = parent_tidptr,
1609 * %r3 = new_tls,
1610 * %r4 = child_tidptr)
1611 */
1612
1613 /* Do the system call */
1614 "swi 0x0\n"
1615
1616 /* if (%r0 != 0)
1617 * return %r0;
1618 */
1619 "cmp r0, #0\n"
1620 "bne 1f\n"
1621
1622 /* In the child, now. Call "fn(arg)". */
1623 "ldr r0, [sp, #4]\n"
1624 "ldr ip, [sp], #8\n"
1625 BLX(ip)
1626 /* Call _exit(%r0). */
1627 "mov r7, %7\n"
1628 "swi 0x0\n"
1629 "1:\n"
1630 "mov %0, r0\n"
1631 : "=r"(res)
1632 : "r"(r0), "r"(r1), "r"(r2), "r"(r3), "r"(r4), "r"(r7),
1633 "i"(__NR_exit)
1634 : "memory");
1635 return res;
1636 }
1637 #endif // defined(__x86_64__) && SANITIZER_LINUX
1638
1639 #if SANITIZER_ANDROID
1640 #if __ANDROID_API__ < 21
1641 extern "C" __attribute__((weak)) int dl_iterate_phdr(
1642 int (*)(struct dl_phdr_info *, size_t, void *), void *);
1643 #endif
1644
dl_iterate_phdr_test_cb(struct dl_phdr_info * info,size_t size,void * data)1645 static int dl_iterate_phdr_test_cb(struct dl_phdr_info *info, size_t size,
1646 void *data) {
1647 // Any name starting with "lib" indicates a bug in L where library base names
1648 // are returned instead of paths.
1649 if (info->dlpi_name && info->dlpi_name[0] == 'l' &&
1650 info->dlpi_name[1] == 'i' && info->dlpi_name[2] == 'b') {
1651 *(bool *)data = true;
1652 return 1;
1653 }
1654 return 0;
1655 }
1656
1657 static atomic_uint32_t android_api_level;
1658
AndroidDetectApiLevelStatic()1659 static AndroidApiLevel AndroidDetectApiLevelStatic() {
1660 #if __ANDROID_API__ <= 19
1661 return ANDROID_KITKAT;
1662 #elif __ANDROID_API__ <= 22
1663 return ANDROID_LOLLIPOP_MR1;
1664 #else
1665 return ANDROID_POST_LOLLIPOP;
1666 #endif
1667 }
1668
AndroidDetectApiLevel()1669 static AndroidApiLevel AndroidDetectApiLevel() {
1670 if (!&dl_iterate_phdr)
1671 return ANDROID_KITKAT; // K or lower
1672 bool base_name_seen = false;
1673 dl_iterate_phdr(dl_iterate_phdr_test_cb, &base_name_seen);
1674 if (base_name_seen)
1675 return ANDROID_LOLLIPOP_MR1; // L MR1
1676 return ANDROID_POST_LOLLIPOP; // post-L
1677 // Plain L (API level 21) is completely broken wrt ASan and not very
1678 // interesting to detect.
1679 }
1680
1681 extern "C" __attribute__((weak)) void* _DYNAMIC;
1682
AndroidGetApiLevel()1683 AndroidApiLevel AndroidGetApiLevel() {
1684 AndroidApiLevel level =
1685 (AndroidApiLevel)atomic_load(&android_api_level, memory_order_relaxed);
1686 if (level) return level;
1687 level = &_DYNAMIC == nullptr ? AndroidDetectApiLevelStatic()
1688 : AndroidDetectApiLevel();
1689 atomic_store(&android_api_level, level, memory_order_relaxed);
1690 return level;
1691 }
1692
1693 #endif
1694
GetHandleSignalModeImpl(int signum)1695 static HandleSignalMode GetHandleSignalModeImpl(int signum) {
1696 switch (signum) {
1697 case SIGABRT:
1698 return common_flags()->handle_abort;
1699 case SIGILL:
1700 return common_flags()->handle_sigill;
1701 case SIGTRAP:
1702 return common_flags()->handle_sigtrap;
1703 case SIGFPE:
1704 return common_flags()->handle_sigfpe;
1705 case SIGSEGV:
1706 return common_flags()->handle_segv;
1707 case SIGBUS:
1708 return common_flags()->handle_sigbus;
1709 }
1710 return kHandleSignalNo;
1711 }
1712
GetHandleSignalMode(int signum)1713 HandleSignalMode GetHandleSignalMode(int signum) {
1714 HandleSignalMode result = GetHandleSignalModeImpl(signum);
1715 if (result == kHandleSignalYes && !common_flags()->allow_user_segv_handler)
1716 return kHandleSignalExclusive;
1717 return result;
1718 }
1719
1720 #if !SANITIZER_GO
internal_start_thread(void (* func)(void * arg),void * arg)1721 void *internal_start_thread(void(*func)(void *arg), void *arg) {
1722 // Start the thread with signals blocked, otherwise it can steal user signals.
1723 __sanitizer_sigset_t set, old;
1724 internal_sigfillset(&set);
1725 #if SANITIZER_LINUX && !SANITIZER_ANDROID
1726 // Glibc uses SIGSETXID signal during setuid call. If this signal is blocked
1727 // on any thread, setuid call hangs (see test/tsan/setuid.c).
1728 internal_sigdelset(&set, 33);
1729 #endif
1730 internal_sigprocmask(SIG_SETMASK, &set, &old);
1731 void *th;
1732 real_pthread_create(&th, nullptr, (void*(*)(void *arg))func, arg);
1733 internal_sigprocmask(SIG_SETMASK, &old, nullptr);
1734 return th;
1735 }
1736
internal_join_thread(void * th)1737 void internal_join_thread(void *th) {
1738 real_pthread_join(th, nullptr);
1739 }
1740 #else
internal_start_thread(void (* func)(void *),void * arg)1741 void *internal_start_thread(void (*func)(void *), void *arg) { return 0; }
1742
internal_join_thread(void * th)1743 void internal_join_thread(void *th) {}
1744 #endif
1745
1746 #if defined(__aarch64__)
1747 // Android headers in the older NDK releases miss this definition.
1748 struct __sanitizer_esr_context {
1749 struct _aarch64_ctx head;
1750 uint64_t esr;
1751 };
1752
Aarch64GetESR(ucontext_t * ucontext,u64 * esr)1753 static bool Aarch64GetESR(ucontext_t *ucontext, u64 *esr) {
1754 static const u32 kEsrMagic = 0x45535201;
1755 u8 *aux = ucontext->uc_mcontext.__reserved;
1756 while (true) {
1757 _aarch64_ctx *ctx = (_aarch64_ctx *)aux;
1758 if (ctx->size == 0) break;
1759 if (ctx->magic == kEsrMagic) {
1760 *esr = ((__sanitizer_esr_context *)ctx)->esr;
1761 return true;
1762 }
1763 aux += ctx->size;
1764 }
1765 return false;
1766 }
1767 #endif
1768
1769 #if SANITIZER_OPENBSD
1770 using Context = sigcontext;
1771 #else
1772 using Context = ucontext_t;
1773 #endif
1774
GetWriteFlag() const1775 SignalContext::WriteFlag SignalContext::GetWriteFlag() const {
1776 Context *ucontext = (Context *)context;
1777 #if defined(__x86_64__) || defined(__i386__)
1778 static const uptr PF_WRITE = 1U << 1;
1779 #if SANITIZER_FREEBSD
1780 uptr err = ucontext->uc_mcontext.mc_err;
1781 #elif SANITIZER_NETBSD
1782 uptr err = ucontext->uc_mcontext.__gregs[_REG_ERR];
1783 #elif SANITIZER_OPENBSD
1784 uptr err = ucontext->sc_err;
1785 #elif SANITIZER_SOLARIS && defined(__i386__)
1786 const int Err = 13;
1787 uptr err = ucontext->uc_mcontext.gregs[Err];
1788 #else
1789 uptr err = ucontext->uc_mcontext.gregs[REG_ERR];
1790 #endif // SANITIZER_FREEBSD
1791 return err & PF_WRITE ? WRITE : READ;
1792 #elif defined(__mips__)
1793 uint32_t *exception_source;
1794 uint32_t faulty_instruction;
1795 uint32_t op_code;
1796
1797 exception_source = (uint32_t *)ucontext->uc_mcontext.pc;
1798 faulty_instruction = (uint32_t)(*exception_source);
1799
1800 op_code = (faulty_instruction >> 26) & 0x3f;
1801
1802 // FIXME: Add support for FPU, microMIPS, DSP, MSA memory instructions.
1803 switch (op_code) {
1804 case 0x28: // sb
1805 case 0x29: // sh
1806 case 0x2b: // sw
1807 case 0x3f: // sd
1808 #if __mips_isa_rev < 6
1809 case 0x2c: // sdl
1810 case 0x2d: // sdr
1811 case 0x2a: // swl
1812 case 0x2e: // swr
1813 #endif
1814 return SignalContext::WRITE;
1815
1816 case 0x20: // lb
1817 case 0x24: // lbu
1818 case 0x21: // lh
1819 case 0x25: // lhu
1820 case 0x23: // lw
1821 case 0x27: // lwu
1822 case 0x37: // ld
1823 #if __mips_isa_rev < 6
1824 case 0x1a: // ldl
1825 case 0x1b: // ldr
1826 case 0x22: // lwl
1827 case 0x26: // lwr
1828 #endif
1829 return SignalContext::READ;
1830 #if __mips_isa_rev == 6
1831 case 0x3b: // pcrel
1832 op_code = (faulty_instruction >> 19) & 0x3;
1833 switch (op_code) {
1834 case 0x1: // lwpc
1835 case 0x2: // lwupc
1836 return SignalContext::READ;
1837 }
1838 #endif
1839 }
1840 return SignalContext::UNKNOWN;
1841 #elif defined(__arm__)
1842 static const uptr FSR_WRITE = 1U << 11;
1843 uptr fsr = ucontext->uc_mcontext.error_code;
1844 return fsr & FSR_WRITE ? WRITE : READ;
1845 #elif defined(__aarch64__)
1846 static const u64 ESR_ELx_WNR = 1U << 6;
1847 u64 esr;
1848 if (!Aarch64GetESR(ucontext, &esr)) return UNKNOWN;
1849 return esr & ESR_ELx_WNR ? WRITE : READ;
1850 #elif SANITIZER_SOLARIS && defined(__sparc__)
1851 // Decode the instruction to determine the access type.
1852 // From OpenSolaris $SRC/uts/sun4/os/trap.c (get_accesstype).
1853 uptr pc = ucontext->uc_mcontext.gregs[REG_PC];
1854 u32 instr = *(u32 *)pc;
1855 return (instr >> 21) & 1 ? WRITE: READ;
1856 #else
1857 (void)ucontext;
1858 return UNKNOWN; // FIXME: Implement.
1859 #endif
1860 }
1861
DumpAllRegisters(void * context)1862 void SignalContext::DumpAllRegisters(void *context) {
1863 // FIXME: Implement this.
1864 }
1865
GetPcSpBp(void * context,uptr * pc,uptr * sp,uptr * bp)1866 static void GetPcSpBp(void *context, uptr *pc, uptr *sp, uptr *bp) {
1867 #if SANITIZER_NETBSD
1868 // This covers all NetBSD architectures
1869 ucontext_t *ucontext = (ucontext_t *)context;
1870 *pc = _UC_MACHINE_PC(ucontext);
1871 *bp = _UC_MACHINE_FP(ucontext);
1872 *sp = _UC_MACHINE_SP(ucontext);
1873 #elif defined(__arm__)
1874 ucontext_t *ucontext = (ucontext_t*)context;
1875 *pc = ucontext->uc_mcontext.arm_pc;
1876 *bp = ucontext->uc_mcontext.arm_fp;
1877 *sp = ucontext->uc_mcontext.arm_sp;
1878 #elif defined(__aarch64__)
1879 ucontext_t *ucontext = (ucontext_t*)context;
1880 *pc = ucontext->uc_mcontext.pc;
1881 *bp = ucontext->uc_mcontext.regs[29];
1882 *sp = ucontext->uc_mcontext.sp;
1883 #elif defined(__hppa__)
1884 ucontext_t *ucontext = (ucontext_t*)context;
1885 *pc = ucontext->uc_mcontext.sc_iaoq[0];
1886 /* GCC uses %r3 whenever a frame pointer is needed. */
1887 *bp = ucontext->uc_mcontext.sc_gr[3];
1888 *sp = ucontext->uc_mcontext.sc_gr[30];
1889 #elif defined(__x86_64__)
1890 # if SANITIZER_FREEBSD
1891 ucontext_t *ucontext = (ucontext_t*)context;
1892 *pc = ucontext->uc_mcontext.mc_rip;
1893 *bp = ucontext->uc_mcontext.mc_rbp;
1894 *sp = ucontext->uc_mcontext.mc_rsp;
1895 #elif SANITIZER_OPENBSD
1896 sigcontext *ucontext = (sigcontext *)context;
1897 *pc = ucontext->sc_rip;
1898 *bp = ucontext->sc_rbp;
1899 *sp = ucontext->sc_rsp;
1900 # else
1901 ucontext_t *ucontext = (ucontext_t*)context;
1902 *pc = ucontext->uc_mcontext.gregs[REG_RIP];
1903 *bp = ucontext->uc_mcontext.gregs[REG_RBP];
1904 *sp = ucontext->uc_mcontext.gregs[REG_RSP];
1905 # endif
1906 #elif defined(__i386__)
1907 # if SANITIZER_FREEBSD
1908 ucontext_t *ucontext = (ucontext_t*)context;
1909 *pc = ucontext->uc_mcontext.mc_eip;
1910 *bp = ucontext->uc_mcontext.mc_ebp;
1911 *sp = ucontext->uc_mcontext.mc_esp;
1912 #elif SANITIZER_OPENBSD
1913 sigcontext *ucontext = (sigcontext *)context;
1914 *pc = ucontext->sc_eip;
1915 *bp = ucontext->sc_ebp;
1916 *sp = ucontext->sc_esp;
1917 # else
1918 ucontext_t *ucontext = (ucontext_t*)context;
1919 # if SANITIZER_SOLARIS
1920 /* Use the numeric values: the symbolic ones are undefined by llvm
1921 include/llvm/Support/Solaris.h. */
1922 # ifndef REG_EIP
1923 # define REG_EIP 14 // REG_PC
1924 # endif
1925 # ifndef REG_EBP
1926 # define REG_EBP 6 // REG_FP
1927 # endif
1928 # ifndef REG_ESP
1929 # define REG_ESP 17 // REG_SP
1930 # endif
1931 # endif
1932 *pc = ucontext->uc_mcontext.gregs[REG_EIP];
1933 *bp = ucontext->uc_mcontext.gregs[REG_EBP];
1934 *sp = ucontext->uc_mcontext.gregs[REG_ESP];
1935 # endif
1936 #elif defined(__powerpc__) || defined(__powerpc64__)
1937 ucontext_t *ucontext = (ucontext_t*)context;
1938 *pc = ucontext->uc_mcontext.regs->nip;
1939 *sp = ucontext->uc_mcontext.regs->gpr[PT_R1];
1940 // The powerpc{,64}-linux ABIs do not specify r31 as the frame
1941 // pointer, but GCC always uses r31 when we need a frame pointer.
1942 *bp = ucontext->uc_mcontext.regs->gpr[PT_R31];
1943 #elif defined(__sparc__)
1944 ucontext_t *ucontext = (ucontext_t*)context;
1945 uptr *stk_ptr;
1946 # if defined(__sparcv9) || defined (__arch64__)
1947 # ifndef MC_PC
1948 # define MC_PC REG_PC
1949 # endif
1950 # ifndef MC_O6
1951 # define MC_O6 REG_O6
1952 # endif
1953 # if SANITIZER_SOLARIS
1954 # define mc_gregs gregs
1955 # endif
1956 *pc = ucontext->uc_mcontext.mc_gregs[MC_PC];
1957 *sp = ucontext->uc_mcontext.mc_gregs[MC_O6];
1958 stk_ptr = (uptr *) (*sp + 2047);
1959 *bp = stk_ptr[15];
1960 # else
1961 *pc = ucontext->uc_mcontext.gregs[REG_PC];
1962 *sp = ucontext->uc_mcontext.gregs[REG_O6];
1963 stk_ptr = (uptr *) *sp;
1964 *bp = stk_ptr[15];
1965 # endif
1966 #elif defined(__mips__)
1967 ucontext_t *ucontext = (ucontext_t*)context;
1968 *pc = ucontext->uc_mcontext.pc;
1969 *bp = ucontext->uc_mcontext.gregs[30];
1970 *sp = ucontext->uc_mcontext.gregs[29];
1971 #elif defined(__s390__)
1972 ucontext_t *ucontext = (ucontext_t*)context;
1973 # if defined(__s390x__)
1974 *pc = ucontext->uc_mcontext.psw.addr;
1975 # else
1976 *pc = ucontext->uc_mcontext.psw.addr & 0x7fffffff;
1977 # endif
1978 *bp = ucontext->uc_mcontext.gregs[11];
1979 *sp = ucontext->uc_mcontext.gregs[15];
1980 #else
1981 # error "Unsupported arch"
1982 #endif
1983 }
1984
InitPcSpBp()1985 void SignalContext::InitPcSpBp() { GetPcSpBp(context, &pc, &sp, &bp); }
1986
InitializePlatformEarly()1987 void InitializePlatformEarly() {
1988 // Do nothing.
1989 }
1990
MaybeReexec()1991 void MaybeReexec() {
1992 // No need to re-exec on Linux.
1993 }
1994
CheckASLR()1995 void CheckASLR() {
1996 #if SANITIZER_NETBSD
1997 int mib[3];
1998 int paxflags;
1999 uptr len = sizeof(paxflags);
2000
2001 mib[0] = CTL_PROC;
2002 mib[1] = internal_getpid();
2003 mib[2] = PROC_PID_PAXFLAGS;
2004
2005 if (UNLIKELY(internal_sysctl(mib, 3, &paxflags, &len, NULL, 0) == -1)) {
2006 Printf("sysctl failed\n");
2007 Die();
2008 }
2009
2010 if (UNLIKELY(paxflags & CTL_PROC_PAXFLAGS_ASLR)) {
2011 Printf("This sanitizer is not compatible with enabled ASLR\n");
2012 Die();
2013 }
2014 #elif SANITIZER_PPC64V2
2015 // Disable ASLR for Linux PPC64LE.
2016 int old_personality = personality(0xffffffff);
2017 if (old_personality != -1 && (old_personality & ADDR_NO_RANDOMIZE) == 0) {
2018 VReport(1, "WARNING: Program is being run with address space layout "
2019 "randomization (ASLR) enabled which prevents the thread and "
2020 "memory sanitizers from working on powerpc64le.\n"
2021 "ASLR will be disabled and the program re-executed.\n");
2022 CHECK_NE(personality(old_personality | ADDR_NO_RANDOMIZE), -1);
2023 ReExec();
2024 }
2025 #else
2026 // Do nothing
2027 #endif
2028 }
2029
CheckMPROTECT()2030 void CheckMPROTECT() {
2031 #if SANITIZER_NETBSD
2032 int mib[3];
2033 int paxflags;
2034 uptr len = sizeof(paxflags);
2035
2036 mib[0] = CTL_PROC;
2037 mib[1] = internal_getpid();
2038 mib[2] = PROC_PID_PAXFLAGS;
2039
2040 if (UNLIKELY(internal_sysctl(mib, 3, &paxflags, &len, NULL, 0) == -1)) {
2041 Printf("sysctl failed\n");
2042 Die();
2043 }
2044
2045 if (UNLIKELY(paxflags & CTL_PROC_PAXFLAGS_MPROTECT)) {
2046 Printf("This sanitizer is not compatible with enabled MPROTECT\n");
2047 Die();
2048 }
2049 #else
2050 // Do nothing
2051 #endif
2052 }
2053
PrintModuleMap()2054 void PrintModuleMap() { }
2055
CheckNoDeepBind(const char * filename,int flag)2056 void CheckNoDeepBind(const char *filename, int flag) {
2057 #ifdef RTLD_DEEPBIND
2058 if (flag & RTLD_DEEPBIND) {
2059 Report(
2060 "You are trying to dlopen a %s shared library with RTLD_DEEPBIND flag"
2061 " which is incompatibe with sanitizer runtime "
2062 "(see https://github.com/google/sanitizers/issues/611 for details"
2063 "). If you want to run %s library under sanitizers please remove "
2064 "RTLD_DEEPBIND from dlopen flags.\n",
2065 filename, filename);
2066 Die();
2067 }
2068 #endif
2069 }
2070
FindAvailableMemoryRange(uptr size,uptr alignment,uptr left_padding,uptr * largest_gap_found,uptr * max_occupied_addr)2071 uptr FindAvailableMemoryRange(uptr size, uptr alignment, uptr left_padding,
2072 uptr *largest_gap_found,
2073 uptr *max_occupied_addr) {
2074 UNREACHABLE("FindAvailableMemoryRange is not available");
2075 return 0;
2076 }
2077
GetRandom(void * buffer,uptr length,bool blocking)2078 bool GetRandom(void *buffer, uptr length, bool blocking) {
2079 if (!buffer || !length || length > 256)
2080 return false;
2081 #if SANITIZER_USE_GETENTROPY
2082 uptr rnd = getentropy(buffer, length);
2083 int rverrno = 0;
2084 if (internal_iserror(rnd, &rverrno) && rverrno == EFAULT)
2085 return false;
2086 else if (rnd == 0)
2087 return true;
2088 #endif // SANITIZER_USE_GETENTROPY
2089
2090 #if SANITIZER_USE_GETRANDOM
2091 static atomic_uint8_t skip_getrandom_syscall;
2092 if (!atomic_load_relaxed(&skip_getrandom_syscall)) {
2093 // Up to 256 bytes, getrandom will not be interrupted.
2094 uptr res = internal_syscall(SYSCALL(getrandom), buffer, length,
2095 blocking ? 0 : GRND_NONBLOCK);
2096 int rverrno = 0;
2097 if (internal_iserror(res, &rverrno) && rverrno == ENOSYS)
2098 atomic_store_relaxed(&skip_getrandom_syscall, 1);
2099 else if (res == length)
2100 return true;
2101 }
2102 #endif // SANITIZER_USE_GETRANDOM
2103 // Up to 256 bytes, a read off /dev/urandom will not be interrupted.
2104 // blocking is moot here, O_NONBLOCK has no effect when opening /dev/urandom.
2105 uptr fd = internal_open("/dev/urandom", O_RDONLY);
2106 if (internal_iserror(fd))
2107 return false;
2108 uptr res = internal_read(fd, buffer, length);
2109 if (internal_iserror(res))
2110 return false;
2111 internal_close(fd);
2112 return true;
2113 }
2114
2115 } // namespace __sanitizer
2116
2117 #endif
2118