1 //===-- sanitizer_linux.cpp -----------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file is shared between AddressSanitizer and ThreadSanitizer
10 // run-time libraries and implements linux-specific functions from
11 // sanitizer_libc.h.
12 //===----------------------------------------------------------------------===//
13
14 #include "sanitizer_platform.h"
15
16 #if SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD || \
17 SANITIZER_SOLARIS
18
19 #include "sanitizer_common.h"
20 #include "sanitizer_flags.h"
21 #include "sanitizer_getauxval.h"
22 #include "sanitizer_internal_defs.h"
23 #include "sanitizer_libc.h"
24 #include "sanitizer_linux.h"
25 #include "sanitizer_mutex.h"
26 #include "sanitizer_placement_new.h"
27 #include "sanitizer_procmaps.h"
28
29 #if SANITIZER_LINUX && !SANITIZER_GO
30 #include <asm/param.h>
31 #endif
32
33 // For mips64, syscall(__NR_stat) fills the buffer in the 'struct kernel_stat'
34 // format. Struct kernel_stat is defined as 'struct stat' in asm/stat.h. To
35 // access stat from asm/stat.h, without conflicting with definition in
36 // sys/stat.h, we use this trick.
37 #if defined(__mips64)
38 #include <asm/unistd.h>
39 #include <sys/types.h>
40 #define stat kernel_stat
41 #if SANITIZER_GO
42 #undef st_atime
43 #undef st_mtime
44 #undef st_ctime
45 #define st_atime st_atim
46 #define st_mtime st_mtim
47 #define st_ctime st_ctim
48 #endif
49 #include <asm/stat.h>
50 #undef stat
51 #endif
52
53 #include <dlfcn.h>
54 #include <errno.h>
55 #include <fcntl.h>
56 #include <link.h>
57 #include <pthread.h>
58 #include <sched.h>
59 #include <signal.h>
60 #include <sys/mman.h>
61 #include <sys/param.h>
62 #if !SANITIZER_SOLARIS
63 #include <sys/ptrace.h>
64 #endif
65 #include <sys/resource.h>
66 #include <sys/stat.h>
67 #include <sys/syscall.h>
68 #include <sys/time.h>
69 #include <sys/types.h>
70 #include <ucontext.h>
71 #include <unistd.h>
72
73 #if SANITIZER_LINUX
74 #include <sys/utsname.h>
75 #endif
76
77 #if SANITIZER_LINUX && !SANITIZER_ANDROID
78 #include <sys/personality.h>
79 #endif
80
81 #if SANITIZER_FREEBSD
82 #include <sys/exec.h>
83 #include <sys/sysctl.h>
84 #include <machine/atomic.h>
85 extern "C" {
86 // <sys/umtx.h> must be included after <errno.h> and <sys/types.h> on
87 // FreeBSD 9.2 and 10.0.
88 #include <sys/umtx.h>
89 }
90 #include <sys/thr.h>
91 #endif // SANITIZER_FREEBSD
92
93 #if SANITIZER_NETBSD
94 #include <limits.h> // For NAME_MAX
95 #include <sys/sysctl.h>
96 #include <sys/exec.h>
97 extern struct ps_strings *__ps_strings;
98 #endif // SANITIZER_NETBSD
99
100 #if SANITIZER_SOLARIS
101 #include <stdlib.h>
102 #include <thread.h>
103 #define environ _environ
104 #endif
105
106 extern char **environ;
107
108 #if SANITIZER_LINUX
109 // <linux/time.h>
110 struct kernel_timeval {
111 long tv_sec;
112 long tv_usec;
113 };
114
115 // <linux/futex.h> is broken on some linux distributions.
116 const int FUTEX_WAIT = 0;
117 const int FUTEX_WAKE = 1;
118 const int FUTEX_PRIVATE_FLAG = 128;
119 const int FUTEX_WAIT_PRIVATE = FUTEX_WAIT | FUTEX_PRIVATE_FLAG;
120 const int FUTEX_WAKE_PRIVATE = FUTEX_WAKE | FUTEX_PRIVATE_FLAG;
121 #endif // SANITIZER_LINUX
122
123 // Are we using 32-bit or 64-bit Linux syscalls?
124 // x32 (which defines __x86_64__) has SANITIZER_WORDSIZE == 32
125 // but it still needs to use 64-bit syscalls.
126 #if SANITIZER_LINUX && (defined(__x86_64__) || defined(__powerpc64__) || \
127 SANITIZER_WORDSIZE == 64)
128 # define SANITIZER_LINUX_USES_64BIT_SYSCALLS 1
129 #else
130 # define SANITIZER_LINUX_USES_64BIT_SYSCALLS 0
131 #endif
132
133 // Note : FreeBSD had implemented both
134 // Linux apis, available from
135 // future 12.x version most likely
136 #if SANITIZER_LINUX && defined(__NR_getrandom)
137 # if !defined(GRND_NONBLOCK)
138 # define GRND_NONBLOCK 1
139 # endif
140 # define SANITIZER_USE_GETRANDOM 1
141 #else
142 # define SANITIZER_USE_GETRANDOM 0
143 #endif // SANITIZER_LINUX && defined(__NR_getrandom)
144
145 #if SANITIZER_FREEBSD && __FreeBSD_version >= 1200000
146 # define SANITIZER_USE_GETENTROPY 1
147 #else
148 # define SANITIZER_USE_GETENTROPY 0
149 #endif
150
151 namespace __sanitizer {
152
SetSigProcMask(__sanitizer_sigset_t * set,__sanitizer_sigset_t * old)153 void SetSigProcMask(__sanitizer_sigset_t *set, __sanitizer_sigset_t *old) {
154 CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, set, old));
155 }
156
ScopedBlockSignals(__sanitizer_sigset_t * copy)157 ScopedBlockSignals::ScopedBlockSignals(__sanitizer_sigset_t *copy) {
158 __sanitizer_sigset_t set;
159 internal_sigfillset(&set);
160 # if SANITIZER_LINUX && !SANITIZER_ANDROID
161 // Glibc uses SIGSETXID signal during setuid call. If this signal is blocked
162 // on any thread, setuid call hangs.
163 // See test/sanitizer_common/TestCases/Linux/setuid.c.
164 internal_sigdelset(&set, 33);
165 # endif
166 SetSigProcMask(&set, &saved_);
167 if (copy)
168 internal_memcpy(copy, &saved_, sizeof(saved_));
169 }
170
~ScopedBlockSignals()171 ScopedBlockSignals::~ScopedBlockSignals() { SetSigProcMask(&saved_, nullptr); }
172
173 # if SANITIZER_LINUX && defined(__x86_64__)
174 # include "sanitizer_syscall_linux_x86_64.inc"
175 # elif SANITIZER_LINUX && SANITIZER_RISCV64
176 # include "sanitizer_syscall_linux_riscv64.inc"
177 # elif SANITIZER_LINUX && defined(__aarch64__)
178 # include "sanitizer_syscall_linux_aarch64.inc"
179 # elif SANITIZER_LINUX && defined(__arm__)
180 # include "sanitizer_syscall_linux_arm.inc"
181 # elif SANITIZER_LINUX && defined(__hexagon__)
182 # include "sanitizer_syscall_linux_hexagon.inc"
183 # else
184 # include "sanitizer_syscall_generic.inc"
185 # endif
186
187 // --------------- sanitizer_libc.h
188 #if !SANITIZER_SOLARIS && !SANITIZER_NETBSD
189 #if !SANITIZER_S390
internal_mmap(void * addr,uptr length,int prot,int flags,int fd,u64 offset)190 uptr internal_mmap(void *addr, uptr length, int prot, int flags, int fd,
191 u64 offset) {
192 #if SANITIZER_FREEBSD || SANITIZER_LINUX_USES_64BIT_SYSCALLS
193 return internal_syscall(SYSCALL(mmap), (uptr)addr, length, prot, flags, fd,
194 offset);
195 #else
196 // mmap2 specifies file offset in 4096-byte units.
197 CHECK(IsAligned(offset, 4096));
198 return internal_syscall(SYSCALL(mmap2), addr, length, prot, flags, fd,
199 offset / 4096);
200 #endif
201 }
202 #endif // !SANITIZER_S390
203
internal_munmap(void * addr,uptr length)204 uptr internal_munmap(void *addr, uptr length) {
205 return internal_syscall(SYSCALL(munmap), (uptr)addr, length);
206 }
207
208 #if SANITIZER_LINUX
internal_mremap(void * old_address,uptr old_size,uptr new_size,int flags,void * new_address)209 uptr internal_mremap(void *old_address, uptr old_size, uptr new_size, int flags,
210 void *new_address) {
211 return internal_syscall(SYSCALL(mremap), (uptr)old_address, old_size,
212 new_size, flags, (uptr)new_address);
213 }
214 #endif
215
internal_mprotect(void * addr,uptr length,int prot)216 int internal_mprotect(void *addr, uptr length, int prot) {
217 return internal_syscall(SYSCALL(mprotect), (uptr)addr, length, prot);
218 }
219
internal_madvise(uptr addr,uptr length,int advice)220 int internal_madvise(uptr addr, uptr length, int advice) {
221 return internal_syscall(SYSCALL(madvise), addr, length, advice);
222 }
223
internal_close(fd_t fd)224 uptr internal_close(fd_t fd) {
225 return internal_syscall(SYSCALL(close), fd);
226 }
227
internal_open(const char * filename,int flags)228 uptr internal_open(const char *filename, int flags) {
229 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
230 return internal_syscall(SYSCALL(openat), AT_FDCWD, (uptr)filename, flags);
231 #else
232 return internal_syscall(SYSCALL(open), (uptr)filename, flags);
233 #endif
234 }
235
internal_open(const char * filename,int flags,u32 mode)236 uptr internal_open(const char *filename, int flags, u32 mode) {
237 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
238 return internal_syscall(SYSCALL(openat), AT_FDCWD, (uptr)filename, flags,
239 mode);
240 #else
241 return internal_syscall(SYSCALL(open), (uptr)filename, flags, mode);
242 #endif
243 }
244
internal_read(fd_t fd,void * buf,uptr count)245 uptr internal_read(fd_t fd, void *buf, uptr count) {
246 sptr res;
247 HANDLE_EINTR(res,
248 (sptr)internal_syscall(SYSCALL(read), fd, (uptr)buf, count));
249 return res;
250 }
251
internal_write(fd_t fd,const void * buf,uptr count)252 uptr internal_write(fd_t fd, const void *buf, uptr count) {
253 sptr res;
254 HANDLE_EINTR(res,
255 (sptr)internal_syscall(SYSCALL(write), fd, (uptr)buf, count));
256 return res;
257 }
258
internal_ftruncate(fd_t fd,uptr size)259 uptr internal_ftruncate(fd_t fd, uptr size) {
260 sptr res;
261 HANDLE_EINTR(res, (sptr)internal_syscall(SYSCALL(ftruncate), fd,
262 (OFF_T)size));
263 return res;
264 }
265
266 #if !SANITIZER_LINUX_USES_64BIT_SYSCALLS && SANITIZER_LINUX
stat64_to_stat(struct stat64 * in,struct stat * out)267 static void stat64_to_stat(struct stat64 *in, struct stat *out) {
268 internal_memset(out, 0, sizeof(*out));
269 out->st_dev = in->st_dev;
270 out->st_ino = in->st_ino;
271 out->st_mode = in->st_mode;
272 out->st_nlink = in->st_nlink;
273 out->st_uid = in->st_uid;
274 out->st_gid = in->st_gid;
275 out->st_rdev = in->st_rdev;
276 out->st_size = in->st_size;
277 out->st_blksize = in->st_blksize;
278 out->st_blocks = in->st_blocks;
279 out->st_atime = in->st_atime;
280 out->st_mtime = in->st_mtime;
281 out->st_ctime = in->st_ctime;
282 }
283 #endif
284
285 #if defined(__mips64)
286 // Undefine compatibility macros from <sys/stat.h>
287 // so that they would not clash with the kernel_stat
288 // st_[a|m|c]time fields
289 #if !SANITIZER_GO
290 #undef st_atime
291 #undef st_mtime
292 #undef st_ctime
293 #endif
294 #if defined(SANITIZER_ANDROID)
295 // Bionic sys/stat.h defines additional macros
296 // for compatibility with the old NDKs and
297 // they clash with the kernel_stat structure
298 // st_[a|m|c]time_nsec fields.
299 #undef st_atime_nsec
300 #undef st_mtime_nsec
301 #undef st_ctime_nsec
302 #endif
kernel_stat_to_stat(struct kernel_stat * in,struct stat * out)303 static void kernel_stat_to_stat(struct kernel_stat *in, struct stat *out) {
304 internal_memset(out, 0, sizeof(*out));
305 out->st_dev = in->st_dev;
306 out->st_ino = in->st_ino;
307 out->st_mode = in->st_mode;
308 out->st_nlink = in->st_nlink;
309 out->st_uid = in->st_uid;
310 out->st_gid = in->st_gid;
311 out->st_rdev = in->st_rdev;
312 out->st_size = in->st_size;
313 out->st_blksize = in->st_blksize;
314 out->st_blocks = in->st_blocks;
315 #if defined(__USE_MISC) || \
316 defined(__USE_XOPEN2K8) || \
317 defined(SANITIZER_ANDROID)
318 out->st_atim.tv_sec = in->st_atime;
319 out->st_atim.tv_nsec = in->st_atime_nsec;
320 out->st_mtim.tv_sec = in->st_mtime;
321 out->st_mtim.tv_nsec = in->st_mtime_nsec;
322 out->st_ctim.tv_sec = in->st_ctime;
323 out->st_ctim.tv_nsec = in->st_ctime_nsec;
324 #else
325 out->st_atime = in->st_atime;
326 out->st_atimensec = in->st_atime_nsec;
327 out->st_mtime = in->st_mtime;
328 out->st_mtimensec = in->st_mtime_nsec;
329 out->st_ctime = in->st_ctime;
330 out->st_atimensec = in->st_ctime_nsec;
331 #endif
332 }
333 #endif
334
internal_stat(const char * path,void * buf)335 uptr internal_stat(const char *path, void *buf) {
336 #if SANITIZER_FREEBSD
337 return internal_syscall(SYSCALL(fstatat), AT_FDCWD, (uptr)path, (uptr)buf, 0);
338 #elif SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
339 return internal_syscall(SYSCALL(newfstatat), AT_FDCWD, (uptr)path, (uptr)buf,
340 0);
341 #elif SANITIZER_LINUX_USES_64BIT_SYSCALLS
342 # if defined(__mips64)
343 // For mips64, stat syscall fills buffer in the format of kernel_stat
344 struct kernel_stat kbuf;
345 int res = internal_syscall(SYSCALL(stat), path, &kbuf);
346 kernel_stat_to_stat(&kbuf, (struct stat *)buf);
347 return res;
348 # else
349 return internal_syscall(SYSCALL(stat), (uptr)path, (uptr)buf);
350 # endif
351 #else
352 struct stat64 buf64;
353 int res = internal_syscall(SYSCALL(stat64), path, &buf64);
354 stat64_to_stat(&buf64, (struct stat *)buf);
355 return res;
356 #endif
357 }
358
internal_lstat(const char * path,void * buf)359 uptr internal_lstat(const char *path, void *buf) {
360 #if SANITIZER_FREEBSD
361 return internal_syscall(SYSCALL(fstatat), AT_FDCWD, (uptr)path, (uptr)buf,
362 AT_SYMLINK_NOFOLLOW);
363 #elif SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
364 return internal_syscall(SYSCALL(newfstatat), AT_FDCWD, (uptr)path, (uptr)buf,
365 AT_SYMLINK_NOFOLLOW);
366 #elif SANITIZER_LINUX_USES_64BIT_SYSCALLS
367 # if SANITIZER_MIPS64
368 // For mips64, lstat syscall fills buffer in the format of kernel_stat
369 struct kernel_stat kbuf;
370 int res = internal_syscall(SYSCALL(lstat), path, &kbuf);
371 kernel_stat_to_stat(&kbuf, (struct stat *)buf);
372 return res;
373 # else
374 return internal_syscall(SYSCALL(lstat), (uptr)path, (uptr)buf);
375 # endif
376 #else
377 struct stat64 buf64;
378 int res = internal_syscall(SYSCALL(lstat64), path, &buf64);
379 stat64_to_stat(&buf64, (struct stat *)buf);
380 return res;
381 #endif
382 }
383
internal_fstat(fd_t fd,void * buf)384 uptr internal_fstat(fd_t fd, void *buf) {
385 #if SANITIZER_FREEBSD || SANITIZER_LINUX_USES_64BIT_SYSCALLS
386 #if SANITIZER_MIPS64
387 // For mips64, fstat syscall fills buffer in the format of kernel_stat
388 struct kernel_stat kbuf;
389 int res = internal_syscall(SYSCALL(fstat), fd, &kbuf);
390 kernel_stat_to_stat(&kbuf, (struct stat *)buf);
391 return res;
392 # else
393 return internal_syscall(SYSCALL(fstat), fd, (uptr)buf);
394 # endif
395 #else
396 struct stat64 buf64;
397 int res = internal_syscall(SYSCALL(fstat64), fd, &buf64);
398 stat64_to_stat(&buf64, (struct stat *)buf);
399 return res;
400 #endif
401 }
402
internal_filesize(fd_t fd)403 uptr internal_filesize(fd_t fd) {
404 struct stat st;
405 if (internal_fstat(fd, &st))
406 return -1;
407 return (uptr)st.st_size;
408 }
409
internal_dup(int oldfd)410 uptr internal_dup(int oldfd) {
411 return internal_syscall(SYSCALL(dup), oldfd);
412 }
413
internal_dup2(int oldfd,int newfd)414 uptr internal_dup2(int oldfd, int newfd) {
415 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
416 return internal_syscall(SYSCALL(dup3), oldfd, newfd, 0);
417 #else
418 return internal_syscall(SYSCALL(dup2), oldfd, newfd);
419 #endif
420 }
421
internal_readlink(const char * path,char * buf,uptr bufsize)422 uptr internal_readlink(const char *path, char *buf, uptr bufsize) {
423 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
424 return internal_syscall(SYSCALL(readlinkat), AT_FDCWD, (uptr)path, (uptr)buf,
425 bufsize);
426 #else
427 return internal_syscall(SYSCALL(readlink), (uptr)path, (uptr)buf, bufsize);
428 #endif
429 }
430
internal_unlink(const char * path)431 uptr internal_unlink(const char *path) {
432 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
433 return internal_syscall(SYSCALL(unlinkat), AT_FDCWD, (uptr)path, 0);
434 #else
435 return internal_syscall(SYSCALL(unlink), (uptr)path);
436 #endif
437 }
438
internal_rename(const char * oldpath,const char * newpath)439 uptr internal_rename(const char *oldpath, const char *newpath) {
440 #if defined(__riscv) && defined(__linux__)
441 return internal_syscall(SYSCALL(renameat2), AT_FDCWD, (uptr)oldpath, AT_FDCWD,
442 (uptr)newpath, 0);
443 #elif SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
444 return internal_syscall(SYSCALL(renameat), AT_FDCWD, (uptr)oldpath, AT_FDCWD,
445 (uptr)newpath);
446 #else
447 return internal_syscall(SYSCALL(rename), (uptr)oldpath, (uptr)newpath);
448 #endif
449 }
450
internal_sched_yield()451 uptr internal_sched_yield() {
452 return internal_syscall(SYSCALL(sched_yield));
453 }
454
internal_usleep(u64 useconds)455 void internal_usleep(u64 useconds) {
456 struct timespec ts;
457 ts.tv_sec = useconds / 1000000;
458 ts.tv_nsec = (useconds % 1000000) * 1000;
459 internal_syscall(SYSCALL(nanosleep), &ts, &ts);
460 }
461
internal_execve(const char * filename,char * const argv[],char * const envp[])462 uptr internal_execve(const char *filename, char *const argv[],
463 char *const envp[]) {
464 return internal_syscall(SYSCALL(execve), (uptr)filename, (uptr)argv,
465 (uptr)envp);
466 }
467 #endif // !SANITIZER_SOLARIS && !SANITIZER_NETBSD
468
469 #if !SANITIZER_NETBSD
internal__exit(int exitcode)470 void internal__exit(int exitcode) {
471 #if SANITIZER_FREEBSD || SANITIZER_SOLARIS
472 internal_syscall(SYSCALL(exit), exitcode);
473 #else
474 internal_syscall(SYSCALL(exit_group), exitcode);
475 #endif
476 Die(); // Unreachable.
477 }
478 #endif // !SANITIZER_NETBSD
479
480 // ----------------- sanitizer_common.h
FileExists(const char * filename)481 bool FileExists(const char *filename) {
482 if (ShouldMockFailureToOpen(filename))
483 return false;
484 struct stat st;
485 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
486 if (internal_syscall(SYSCALL(newfstatat), AT_FDCWD, filename, &st, 0))
487 #else
488 if (internal_stat(filename, &st))
489 #endif
490 return false;
491 // Sanity check: filename is a regular file.
492 return S_ISREG(st.st_mode);
493 }
494
495 #if !SANITIZER_NETBSD
GetTid()496 tid_t GetTid() {
497 #if SANITIZER_FREEBSD
498 long Tid;
499 thr_self(&Tid);
500 return Tid;
501 #elif SANITIZER_SOLARIS
502 return thr_self();
503 #else
504 return internal_syscall(SYSCALL(gettid));
505 #endif
506 }
507
TgKill(pid_t pid,tid_t tid,int sig)508 int TgKill(pid_t pid, tid_t tid, int sig) {
509 #if SANITIZER_LINUX
510 return internal_syscall(SYSCALL(tgkill), pid, tid, sig);
511 #elif SANITIZER_FREEBSD
512 return internal_syscall(SYSCALL(thr_kill2), pid, tid, sig);
513 #elif SANITIZER_SOLARIS
514 (void)pid;
515 return thr_kill(tid, sig);
516 #endif
517 }
518 #endif
519
520 #if SANITIZER_GLIBC
NanoTime()521 u64 NanoTime() {
522 kernel_timeval tv;
523 internal_memset(&tv, 0, sizeof(tv));
524 internal_syscall(SYSCALL(gettimeofday), &tv, 0);
525 return (u64)tv.tv_sec * 1000 * 1000 * 1000 + tv.tv_usec * 1000;
526 }
527 // Used by real_clock_gettime.
internal_clock_gettime(__sanitizer_clockid_t clk_id,void * tp)528 uptr internal_clock_gettime(__sanitizer_clockid_t clk_id, void *tp) {
529 return internal_syscall(SYSCALL(clock_gettime), clk_id, tp);
530 }
531 #elif !SANITIZER_SOLARIS && !SANITIZER_NETBSD
NanoTime()532 u64 NanoTime() {
533 struct timespec ts;
534 clock_gettime(CLOCK_REALTIME, &ts);
535 return (u64)ts.tv_sec * 1000 * 1000 * 1000 + ts.tv_nsec;
536 }
537 #endif
538
539 // Like getenv, but reads env directly from /proc (on Linux) or parses the
540 // 'environ' array (on some others) and does not use libc. This function
541 // should be called first inside __asan_init.
GetEnv(const char * name)542 const char *GetEnv(const char *name) {
543 #if SANITIZER_FREEBSD || SANITIZER_NETBSD || SANITIZER_SOLARIS
544 if (::environ != 0) {
545 uptr NameLen = internal_strlen(name);
546 for (char **Env = ::environ; *Env != 0; Env++) {
547 if (internal_strncmp(*Env, name, NameLen) == 0 && (*Env)[NameLen] == '=')
548 return (*Env) + NameLen + 1;
549 }
550 }
551 return 0; // Not found.
552 #elif SANITIZER_LINUX
553 static char *environ;
554 static uptr len;
555 static bool inited;
556 if (!inited) {
557 inited = true;
558 uptr environ_size;
559 if (!ReadFileToBuffer("/proc/self/environ", &environ, &environ_size, &len))
560 environ = nullptr;
561 }
562 if (!environ || len == 0) return nullptr;
563 uptr namelen = internal_strlen(name);
564 const char *p = environ;
565 while (*p != '\0') { // will happen at the \0\0 that terminates the buffer
566 // proc file has the format NAME=value\0NAME=value\0NAME=value\0...
567 const char* endp =
568 (char*)internal_memchr(p, '\0', len - (p - environ));
569 if (!endp) // this entry isn't NUL terminated
570 return nullptr;
571 else if (!internal_memcmp(p, name, namelen) && p[namelen] == '=') // Match.
572 return p + namelen + 1; // point after =
573 p = endp + 1;
574 }
575 return nullptr; // Not found.
576 #else
577 #error "Unsupported platform"
578 #endif
579 }
580
581 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD && !SANITIZER_GO
582 extern "C" {
583 SANITIZER_WEAK_ATTRIBUTE extern void *__libc_stack_end;
584 }
585 #endif
586
587 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
ReadNullSepFileToArray(const char * path,char *** arr,int arr_size)588 static void ReadNullSepFileToArray(const char *path, char ***arr,
589 int arr_size) {
590 char *buff;
591 uptr buff_size;
592 uptr buff_len;
593 *arr = (char **)MmapOrDie(arr_size * sizeof(char *), "NullSepFileArray");
594 if (!ReadFileToBuffer(path, &buff, &buff_size, &buff_len, 1024 * 1024)) {
595 (*arr)[0] = nullptr;
596 return;
597 }
598 (*arr)[0] = buff;
599 int count, i;
600 for (count = 1, i = 1; ; i++) {
601 if (buff[i] == 0) {
602 if (buff[i+1] == 0) break;
603 (*arr)[count] = &buff[i+1];
604 CHECK_LE(count, arr_size - 1); // FIXME: make this more flexible.
605 count++;
606 }
607 }
608 (*arr)[count] = nullptr;
609 }
610 #endif
611
GetArgsAndEnv(char *** argv,char *** envp)612 static void GetArgsAndEnv(char ***argv, char ***envp) {
613 #if SANITIZER_FREEBSD
614 // On FreeBSD, retrieving the argument and environment arrays is done via the
615 // kern.ps_strings sysctl, which returns a pointer to a structure containing
616 // this information. See also <sys/exec.h>.
617 ps_strings *pss;
618 uptr sz = sizeof(pss);
619 if (internal_sysctlbyname("kern.ps_strings", &pss, &sz, NULL, 0) == -1) {
620 Printf("sysctl kern.ps_strings failed\n");
621 Die();
622 }
623 *argv = pss->ps_argvstr;
624 *envp = pss->ps_envstr;
625 #elif SANITIZER_NETBSD
626 *argv = __ps_strings->ps_argvstr;
627 *envp = __ps_strings->ps_envstr;
628 #else // SANITIZER_FREEBSD
629 #if !SANITIZER_GO
630 if (&__libc_stack_end) {
631 uptr* stack_end = (uptr*)__libc_stack_end;
632 // Normally argc can be obtained from *stack_end, however, on ARM glibc's
633 // _start clobbers it:
634 // https://sourceware.org/git/?p=glibc.git;a=blob;f=sysdeps/arm/start.S;hb=refs/heads/release/2.31/master#l75
635 // Do not special-case ARM and infer argc from argv everywhere.
636 int argc = 0;
637 while (stack_end[argc + 1]) argc++;
638 *argv = (char**)(stack_end + 1);
639 *envp = (char**)(stack_end + argc + 2);
640 } else {
641 #endif // !SANITIZER_GO
642 static const int kMaxArgv = 2000, kMaxEnvp = 2000;
643 ReadNullSepFileToArray("/proc/self/cmdline", argv, kMaxArgv);
644 ReadNullSepFileToArray("/proc/self/environ", envp, kMaxEnvp);
645 #if !SANITIZER_GO
646 }
647 #endif // !SANITIZER_GO
648 #endif // SANITIZER_FREEBSD
649 }
650
GetArgv()651 char **GetArgv() {
652 char **argv, **envp;
653 GetArgsAndEnv(&argv, &envp);
654 return argv;
655 }
656
GetEnviron()657 char **GetEnviron() {
658 char **argv, **envp;
659 GetArgsAndEnv(&argv, &envp);
660 return envp;
661 }
662
663 #if !SANITIZER_SOLARIS
FutexWait(atomic_uint32_t * p,u32 cmp)664 void FutexWait(atomic_uint32_t *p, u32 cmp) {
665 # if SANITIZER_FREEBSD
666 _umtx_op(p, UMTX_OP_WAIT_UINT, cmp, 0, 0);
667 # elif SANITIZER_NETBSD
668 sched_yield(); /* No userspace futex-like synchronization */
669 # else
670 internal_syscall(SYSCALL(futex), (uptr)p, FUTEX_WAIT_PRIVATE, cmp, 0, 0, 0);
671 # endif
672 }
673
FutexWake(atomic_uint32_t * p,u32 count)674 void FutexWake(atomic_uint32_t *p, u32 count) {
675 # if SANITIZER_FREEBSD
676 _umtx_op(p, UMTX_OP_WAKE, count, 0, 0);
677 # elif SANITIZER_NETBSD
678 /* No userspace futex-like synchronization */
679 # else
680 internal_syscall(SYSCALL(futex), (uptr)p, FUTEX_WAKE_PRIVATE, count, 0, 0, 0);
681 # endif
682 }
683
684 # endif // !SANITIZER_SOLARIS
685
686 // ----------------- sanitizer_linux.h
687 // The actual size of this structure is specified by d_reclen.
688 // Note that getdents64 uses a different structure format. We only provide the
689 // 32-bit syscall here.
690 #if SANITIZER_NETBSD
691 // Not used
692 #else
693 struct linux_dirent {
694 #if SANITIZER_X32 || defined(__aarch64__) || SANITIZER_RISCV64
695 u64 d_ino;
696 u64 d_off;
697 #else
698 unsigned long d_ino;
699 unsigned long d_off;
700 #endif
701 unsigned short d_reclen;
702 #if defined(__aarch64__) || SANITIZER_RISCV64
703 unsigned char d_type;
704 #endif
705 char d_name[256];
706 };
707 #endif
708
709 #if !SANITIZER_SOLARIS && !SANITIZER_NETBSD
710 // Syscall wrappers.
internal_ptrace(int request,int pid,void * addr,void * data)711 uptr internal_ptrace(int request, int pid, void *addr, void *data) {
712 return internal_syscall(SYSCALL(ptrace), request, pid, (uptr)addr,
713 (uptr)data);
714 }
715
internal_waitpid(int pid,int * status,int options)716 uptr internal_waitpid(int pid, int *status, int options) {
717 return internal_syscall(SYSCALL(wait4), pid, (uptr)status, options,
718 0 /* rusage */);
719 }
720
internal_getpid()721 uptr internal_getpid() {
722 return internal_syscall(SYSCALL(getpid));
723 }
724
internal_getppid()725 uptr internal_getppid() {
726 return internal_syscall(SYSCALL(getppid));
727 }
728
internal_dlinfo(void * handle,int request,void * p)729 int internal_dlinfo(void *handle, int request, void *p) {
730 #if SANITIZER_FREEBSD
731 return dlinfo(handle, request, p);
732 #else
733 UNIMPLEMENTED();
734 #endif
735 }
736
internal_getdents(fd_t fd,struct linux_dirent * dirp,unsigned int count)737 uptr internal_getdents(fd_t fd, struct linux_dirent *dirp, unsigned int count) {
738 #if SANITIZER_FREEBSD
739 return internal_syscall(SYSCALL(getdirentries), fd, (uptr)dirp, count, NULL);
740 #elif SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
741 return internal_syscall(SYSCALL(getdents64), fd, (uptr)dirp, count);
742 #else
743 return internal_syscall(SYSCALL(getdents), fd, (uptr)dirp, count);
744 #endif
745 }
746
internal_lseek(fd_t fd,OFF_T offset,int whence)747 uptr internal_lseek(fd_t fd, OFF_T offset, int whence) {
748 return internal_syscall(SYSCALL(lseek), fd, offset, whence);
749 }
750
751 #if SANITIZER_LINUX
internal_prctl(int option,uptr arg2,uptr arg3,uptr arg4,uptr arg5)752 uptr internal_prctl(int option, uptr arg2, uptr arg3, uptr arg4, uptr arg5) {
753 return internal_syscall(SYSCALL(prctl), option, arg2, arg3, arg4, arg5);
754 }
755 #endif
756
internal_sigaltstack(const void * ss,void * oss)757 uptr internal_sigaltstack(const void *ss, void *oss) {
758 return internal_syscall(SYSCALL(sigaltstack), (uptr)ss, (uptr)oss);
759 }
760
internal_fork()761 int internal_fork() {
762 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
763 return internal_syscall(SYSCALL(clone), SIGCHLD, 0);
764 #else
765 return internal_syscall(SYSCALL(fork));
766 #endif
767 }
768
769 #if SANITIZER_FREEBSD
internal_sysctl(const int * name,unsigned int namelen,void * oldp,uptr * oldlenp,const void * newp,uptr newlen)770 int internal_sysctl(const int *name, unsigned int namelen, void *oldp,
771 uptr *oldlenp, const void *newp, uptr newlen) {
772 return internal_syscall(SYSCALL(__sysctl), name, namelen, oldp,
773 (size_t *)oldlenp, newp, (size_t)newlen);
774 }
775
internal_sysctlbyname(const char * sname,void * oldp,uptr * oldlenp,const void * newp,uptr newlen)776 int internal_sysctlbyname(const char *sname, void *oldp, uptr *oldlenp,
777 const void *newp, uptr newlen) {
778 // Note: this function can be called during startup, so we need to avoid
779 // calling any interceptable functions. On FreeBSD >= 1300045 sysctlbyname()
780 // is a real syscall, but for older versions it calls sysctlnametomib()
781 // followed by sysctl(). To avoid calling the intercepted version and
782 // asserting if this happens during startup, call the real sysctlnametomib()
783 // followed by internal_sysctl() if the syscall is not available.
784 #ifdef SYS___sysctlbyname
785 return internal_syscall(SYSCALL(__sysctlbyname), sname,
786 internal_strlen(sname), oldp, (size_t *)oldlenp, newp,
787 (size_t)newlen);
788 #else
789 static decltype(sysctlnametomib) *real_sysctlnametomib = nullptr;
790 if (!real_sysctlnametomib)
791 real_sysctlnametomib =
792 (decltype(sysctlnametomib) *)dlsym(RTLD_NEXT, "sysctlnametomib");
793 CHECK(real_sysctlnametomib);
794
795 int oid[CTL_MAXNAME];
796 size_t len = CTL_MAXNAME;
797 if (real_sysctlnametomib(sname, oid, &len) == -1)
798 return (-1);
799 return internal_sysctl(oid, len, oldp, oldlenp, newp, newlen);
800 #endif
801 }
802 #endif
803
804 #if SANITIZER_LINUX
805 #define SA_RESTORER 0x04000000
806 // Doesn't set sa_restorer if the caller did not set it, so use with caution
807 //(see below).
internal_sigaction_norestorer(int signum,const void * act,void * oldact)808 int internal_sigaction_norestorer(int signum, const void *act, void *oldact) {
809 __sanitizer_kernel_sigaction_t k_act, k_oldact;
810 internal_memset(&k_act, 0, sizeof(__sanitizer_kernel_sigaction_t));
811 internal_memset(&k_oldact, 0, sizeof(__sanitizer_kernel_sigaction_t));
812 const __sanitizer_sigaction *u_act = (const __sanitizer_sigaction *)act;
813 __sanitizer_sigaction *u_oldact = (__sanitizer_sigaction *)oldact;
814 if (u_act) {
815 k_act.handler = u_act->handler;
816 k_act.sigaction = u_act->sigaction;
817 internal_memcpy(&k_act.sa_mask, &u_act->sa_mask,
818 sizeof(__sanitizer_kernel_sigset_t));
819 // Without SA_RESTORER kernel ignores the calls (probably returns EINVAL).
820 k_act.sa_flags = u_act->sa_flags | SA_RESTORER;
821 // FIXME: most often sa_restorer is unset, however the kernel requires it
822 // to point to a valid signal restorer that calls the rt_sigreturn syscall.
823 // If sa_restorer passed to the kernel is NULL, the program may crash upon
824 // signal delivery or fail to unwind the stack in the signal handler.
825 // libc implementation of sigaction() passes its own restorer to
826 // rt_sigaction, so we need to do the same (we'll need to reimplement the
827 // restorers; for x86_64 the restorer address can be obtained from
828 // oldact->sa_restorer upon a call to sigaction(xxx, NULL, oldact).
829 #if !SANITIZER_ANDROID || !SANITIZER_MIPS32
830 k_act.sa_restorer = u_act->sa_restorer;
831 #endif
832 }
833
834 uptr result = internal_syscall(SYSCALL(rt_sigaction), (uptr)signum,
835 (uptr)(u_act ? &k_act : nullptr),
836 (uptr)(u_oldact ? &k_oldact : nullptr),
837 (uptr)sizeof(__sanitizer_kernel_sigset_t));
838
839 if ((result == 0) && u_oldact) {
840 u_oldact->handler = k_oldact.handler;
841 u_oldact->sigaction = k_oldact.sigaction;
842 internal_memcpy(&u_oldact->sa_mask, &k_oldact.sa_mask,
843 sizeof(__sanitizer_kernel_sigset_t));
844 u_oldact->sa_flags = k_oldact.sa_flags;
845 #if !SANITIZER_ANDROID || !SANITIZER_MIPS32
846 u_oldact->sa_restorer = k_oldact.sa_restorer;
847 #endif
848 }
849 return result;
850 }
851 #endif // SANITIZER_LINUX
852
internal_sigprocmask(int how,__sanitizer_sigset_t * set,__sanitizer_sigset_t * oldset)853 uptr internal_sigprocmask(int how, __sanitizer_sigset_t *set,
854 __sanitizer_sigset_t *oldset) {
855 #if SANITIZER_FREEBSD
856 return internal_syscall(SYSCALL(sigprocmask), how, set, oldset);
857 #else
858 __sanitizer_kernel_sigset_t *k_set = (__sanitizer_kernel_sigset_t *)set;
859 __sanitizer_kernel_sigset_t *k_oldset = (__sanitizer_kernel_sigset_t *)oldset;
860 return internal_syscall(SYSCALL(rt_sigprocmask), (uptr)how, (uptr)k_set,
861 (uptr)k_oldset, sizeof(__sanitizer_kernel_sigset_t));
862 #endif
863 }
864
internal_sigfillset(__sanitizer_sigset_t * set)865 void internal_sigfillset(__sanitizer_sigset_t *set) {
866 internal_memset(set, 0xff, sizeof(*set));
867 }
868
internal_sigemptyset(__sanitizer_sigset_t * set)869 void internal_sigemptyset(__sanitizer_sigset_t *set) {
870 internal_memset(set, 0, sizeof(*set));
871 }
872
873 #if SANITIZER_LINUX
internal_sigdelset(__sanitizer_sigset_t * set,int signum)874 void internal_sigdelset(__sanitizer_sigset_t *set, int signum) {
875 signum -= 1;
876 CHECK_GE(signum, 0);
877 CHECK_LT(signum, sizeof(*set) * 8);
878 __sanitizer_kernel_sigset_t *k_set = (__sanitizer_kernel_sigset_t *)set;
879 const uptr idx = signum / (sizeof(k_set->sig[0]) * 8);
880 const uptr bit = signum % (sizeof(k_set->sig[0]) * 8);
881 k_set->sig[idx] &= ~((uptr)1 << bit);
882 }
883
internal_sigismember(__sanitizer_sigset_t * set,int signum)884 bool internal_sigismember(__sanitizer_sigset_t *set, int signum) {
885 signum -= 1;
886 CHECK_GE(signum, 0);
887 CHECK_LT(signum, sizeof(*set) * 8);
888 __sanitizer_kernel_sigset_t *k_set = (__sanitizer_kernel_sigset_t *)set;
889 const uptr idx = signum / (sizeof(k_set->sig[0]) * 8);
890 const uptr bit = signum % (sizeof(k_set->sig[0]) * 8);
891 return k_set->sig[idx] & ((uptr)1 << bit);
892 }
893 #elif SANITIZER_FREEBSD
internal_sigdelset(__sanitizer_sigset_t * set,int signum)894 void internal_sigdelset(__sanitizer_sigset_t *set, int signum) {
895 sigset_t *rset = reinterpret_cast<sigset_t *>(set);
896 sigdelset(rset, signum);
897 }
898
internal_sigismember(__sanitizer_sigset_t * set,int signum)899 bool internal_sigismember(__sanitizer_sigset_t *set, int signum) {
900 sigset_t *rset = reinterpret_cast<sigset_t *>(set);
901 return sigismember(rset, signum);
902 }
903 #endif
904 #endif // !SANITIZER_SOLARIS
905
906 #if !SANITIZER_NETBSD
907 // ThreadLister implementation.
ThreadLister(pid_t pid)908 ThreadLister::ThreadLister(pid_t pid) : pid_(pid), buffer_(4096) {
909 char task_directory_path[80];
910 internal_snprintf(task_directory_path, sizeof(task_directory_path),
911 "/proc/%d/task/", pid);
912 descriptor_ = internal_open(task_directory_path, O_RDONLY | O_DIRECTORY);
913 if (internal_iserror(descriptor_)) {
914 Report("Can't open /proc/%d/task for reading.\n", pid);
915 }
916 }
917
ListThreads(InternalMmapVector<tid_t> * threads)918 ThreadLister::Result ThreadLister::ListThreads(
919 InternalMmapVector<tid_t> *threads) {
920 if (internal_iserror(descriptor_))
921 return Error;
922 internal_lseek(descriptor_, 0, SEEK_SET);
923 threads->clear();
924
925 Result result = Ok;
926 for (bool first_read = true;; first_read = false) {
927 // Resize to max capacity if it was downsized by IsAlive.
928 buffer_.resize(buffer_.capacity());
929 CHECK_GE(buffer_.size(), 4096);
930 uptr read = internal_getdents(
931 descriptor_, (struct linux_dirent *)buffer_.data(), buffer_.size());
932 if (!read)
933 return result;
934 if (internal_iserror(read)) {
935 Report("Can't read directory entries from /proc/%d/task.\n", pid_);
936 return Error;
937 }
938
939 for (uptr begin = (uptr)buffer_.data(), end = begin + read; begin < end;) {
940 struct linux_dirent *entry = (struct linux_dirent *)begin;
941 begin += entry->d_reclen;
942 if (entry->d_ino == 1) {
943 // Inode 1 is for bad blocks and also can be a reason for early return.
944 // Should be emitted if kernel tried to output terminating thread.
945 // See proc_task_readdir implementation in Linux.
946 result = Incomplete;
947 }
948 if (entry->d_ino && *entry->d_name >= '0' && *entry->d_name <= '9')
949 threads->push_back(internal_atoll(entry->d_name));
950 }
951
952 // Now we are going to detect short-read or early EOF. In such cases Linux
953 // can return inconsistent list with missing alive threads.
954 // Code will just remember that the list can be incomplete but it will
955 // continue reads to return as much as possible.
956 if (!first_read) {
957 // The first one was a short-read by definition.
958 result = Incomplete;
959 } else if (read > buffer_.size() - 1024) {
960 // Read was close to the buffer size. So double the size and assume the
961 // worst.
962 buffer_.resize(buffer_.size() * 2);
963 result = Incomplete;
964 } else if (!threads->empty() && !IsAlive(threads->back())) {
965 // Maybe Linux early returned from read on terminated thread (!pid_alive)
966 // and failed to restore read position.
967 // See next_tid and proc_task_instantiate in Linux.
968 result = Incomplete;
969 }
970 }
971 }
972
IsAlive(int tid)973 bool ThreadLister::IsAlive(int tid) {
974 // /proc/%d/task/%d/status uses same call to detect alive threads as
975 // proc_task_readdir. See task_state implementation in Linux.
976 char path[80];
977 internal_snprintf(path, sizeof(path), "/proc/%d/task/%d/status", pid_, tid);
978 if (!ReadFileToVector(path, &buffer_) || buffer_.empty())
979 return false;
980 buffer_.push_back(0);
981 static const char kPrefix[] = "\nPPid:";
982 const char *field = internal_strstr(buffer_.data(), kPrefix);
983 if (!field)
984 return false;
985 field += internal_strlen(kPrefix);
986 return (int)internal_atoll(field) != 0;
987 }
988
~ThreadLister()989 ThreadLister::~ThreadLister() {
990 if (!internal_iserror(descriptor_))
991 internal_close(descriptor_);
992 }
993 #endif
994
995 #if SANITIZER_WORDSIZE == 32
996 // Take care of unusable kernel area in top gigabyte.
GetKernelAreaSize()997 static uptr GetKernelAreaSize() {
998 #if SANITIZER_LINUX && !SANITIZER_X32
999 const uptr gbyte = 1UL << 30;
1000
1001 // Firstly check if there are writable segments
1002 // mapped to top gigabyte (e.g. stack).
1003 MemoryMappingLayout proc_maps(/*cache_enabled*/true);
1004 if (proc_maps.Error())
1005 return 0;
1006 MemoryMappedSegment segment;
1007 while (proc_maps.Next(&segment)) {
1008 if ((segment.end >= 3 * gbyte) && segment.IsWritable()) return 0;
1009 }
1010
1011 #if !SANITIZER_ANDROID
1012 // Even if nothing is mapped, top Gb may still be accessible
1013 // if we are running on 64-bit kernel.
1014 // Uname may report misleading results if personality type
1015 // is modified (e.g. under schroot) so check this as well.
1016 struct utsname uname_info;
1017 int pers = personality(0xffffffffUL);
1018 if (!(pers & PER_MASK) && internal_uname(&uname_info) == 0 &&
1019 internal_strstr(uname_info.machine, "64"))
1020 return 0;
1021 #endif // SANITIZER_ANDROID
1022
1023 // Top gigabyte is reserved for kernel.
1024 return gbyte;
1025 #else
1026 return 0;
1027 #endif // SANITIZER_LINUX && !SANITIZER_X32
1028 }
1029 #endif // SANITIZER_WORDSIZE == 32
1030
GetMaxVirtualAddress()1031 uptr GetMaxVirtualAddress() {
1032 #if SANITIZER_NETBSD && defined(__x86_64__)
1033 return 0x7f7ffffff000ULL; // (0x00007f8000000000 - PAGE_SIZE)
1034 #elif SANITIZER_WORDSIZE == 64
1035 # if defined(__powerpc64__) || defined(__aarch64__)
1036 // On PowerPC64 we have two different address space layouts: 44- and 46-bit.
1037 // We somehow need to figure out which one we are using now and choose
1038 // one of 0x00000fffffffffffUL and 0x00003fffffffffffUL.
1039 // Note that with 'ulimit -s unlimited' the stack is moved away from the top
1040 // of the address space, so simply checking the stack address is not enough.
1041 // This should (does) work for both PowerPC64 Endian modes.
1042 // Similarly, aarch64 has multiple address space layouts: 39, 42 and 47-bit.
1043 return (1ULL << (MostSignificantSetBitIndex(GET_CURRENT_FRAME()) + 1)) - 1;
1044 #elif SANITIZER_RISCV64
1045 return (1ULL << 38) - 1;
1046 # elif defined(__mips64)
1047 return (1ULL << 40) - 1; // 0x000000ffffffffffUL;
1048 # elif defined(__s390x__)
1049 return (1ULL << 53) - 1; // 0x001fffffffffffffUL;
1050 #elif defined(__sparc__)
1051 return ~(uptr)0;
1052 # else
1053 return (1ULL << 47) - 1; // 0x00007fffffffffffUL;
1054 # endif
1055 #else // SANITIZER_WORDSIZE == 32
1056 # if defined(__s390__)
1057 return (1ULL << 31) - 1; // 0x7fffffff;
1058 # else
1059 return (1ULL << 32) - 1; // 0xffffffff;
1060 # endif
1061 #endif // SANITIZER_WORDSIZE
1062 }
1063
GetMaxUserVirtualAddress()1064 uptr GetMaxUserVirtualAddress() {
1065 uptr addr = GetMaxVirtualAddress();
1066 #if SANITIZER_WORDSIZE == 32 && !defined(__s390__)
1067 if (!common_flags()->full_address_space)
1068 addr -= GetKernelAreaSize();
1069 CHECK_LT(reinterpret_cast<uptr>(&addr), addr);
1070 #endif
1071 return addr;
1072 }
1073
1074 #if !SANITIZER_ANDROID
GetPageSize()1075 uptr GetPageSize() {
1076 #if SANITIZER_LINUX && (defined(__x86_64__) || defined(__i386__)) && \
1077 defined(EXEC_PAGESIZE)
1078 return EXEC_PAGESIZE;
1079 #elif SANITIZER_FREEBSD || SANITIZER_NETBSD
1080 // Use sysctl as sysconf can trigger interceptors internally.
1081 int pz = 0;
1082 uptr pzl = sizeof(pz);
1083 int mib[2] = {CTL_HW, HW_PAGESIZE};
1084 int rv = internal_sysctl(mib, 2, &pz, &pzl, nullptr, 0);
1085 CHECK_EQ(rv, 0);
1086 return (uptr)pz;
1087 #elif SANITIZER_USE_GETAUXVAL
1088 return getauxval(AT_PAGESZ);
1089 #else
1090 return sysconf(_SC_PAGESIZE); // EXEC_PAGESIZE may not be trustworthy.
1091 #endif
1092 }
1093 #endif // !SANITIZER_ANDROID
1094
ReadBinaryName(char * buf,uptr buf_len)1095 uptr ReadBinaryName(/*out*/char *buf, uptr buf_len) {
1096 #if SANITIZER_SOLARIS
1097 const char *default_module_name = getexecname();
1098 CHECK_NE(default_module_name, NULL);
1099 return internal_snprintf(buf, buf_len, "%s", default_module_name);
1100 #else
1101 #if SANITIZER_FREEBSD || SANITIZER_NETBSD
1102 #if SANITIZER_FREEBSD
1103 const int Mib[4] = {CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1};
1104 #else
1105 const int Mib[4] = {CTL_KERN, KERN_PROC_ARGS, -1, KERN_PROC_PATHNAME};
1106 #endif
1107 const char *default_module_name = "kern.proc.pathname";
1108 uptr Size = buf_len;
1109 bool IsErr =
1110 (internal_sysctl(Mib, ARRAY_SIZE(Mib), buf, &Size, NULL, 0) != 0);
1111 int readlink_error = IsErr ? errno : 0;
1112 uptr module_name_len = Size;
1113 #else
1114 const char *default_module_name = "/proc/self/exe";
1115 uptr module_name_len = internal_readlink(
1116 default_module_name, buf, buf_len);
1117 int readlink_error;
1118 bool IsErr = internal_iserror(module_name_len, &readlink_error);
1119 #endif // SANITIZER_SOLARIS
1120 if (IsErr) {
1121 // We can't read binary name for some reason, assume it's unknown.
1122 Report("WARNING: reading executable name failed with errno %d, "
1123 "some stack frames may not be symbolized\n", readlink_error);
1124 module_name_len = internal_snprintf(buf, buf_len, "%s",
1125 default_module_name);
1126 CHECK_LT(module_name_len, buf_len);
1127 }
1128 return module_name_len;
1129 #endif
1130 }
1131
ReadLongProcessName(char * buf,uptr buf_len)1132 uptr ReadLongProcessName(/*out*/ char *buf, uptr buf_len) {
1133 #if SANITIZER_LINUX
1134 char *tmpbuf;
1135 uptr tmpsize;
1136 uptr tmplen;
1137 if (ReadFileToBuffer("/proc/self/cmdline", &tmpbuf, &tmpsize, &tmplen,
1138 1024 * 1024)) {
1139 internal_strncpy(buf, tmpbuf, buf_len);
1140 UnmapOrDie(tmpbuf, tmpsize);
1141 return internal_strlen(buf);
1142 }
1143 #endif
1144 return ReadBinaryName(buf, buf_len);
1145 }
1146
1147 // Match full names of the form /path/to/base_name{-,.}*
LibraryNameIs(const char * full_name,const char * base_name)1148 bool LibraryNameIs(const char *full_name, const char *base_name) {
1149 const char *name = full_name;
1150 // Strip path.
1151 while (*name != '\0') name++;
1152 while (name > full_name && *name != '/') name--;
1153 if (*name == '/') name++;
1154 uptr base_name_length = internal_strlen(base_name);
1155 if (internal_strncmp(name, base_name, base_name_length)) return false;
1156 return (name[base_name_length] == '-' || name[base_name_length] == '.');
1157 }
1158
1159 #if !SANITIZER_ANDROID
1160 // Call cb for each region mapped by map.
ForEachMappedRegion(link_map * map,void (* cb)(const void *,uptr))1161 void ForEachMappedRegion(link_map *map, void (*cb)(const void *, uptr)) {
1162 CHECK_NE(map, nullptr);
1163 #if !SANITIZER_FREEBSD
1164 typedef ElfW(Phdr) Elf_Phdr;
1165 typedef ElfW(Ehdr) Elf_Ehdr;
1166 #endif // !SANITIZER_FREEBSD
1167 char *base = (char *)map->l_addr;
1168 Elf_Ehdr *ehdr = (Elf_Ehdr *)base;
1169 char *phdrs = base + ehdr->e_phoff;
1170 char *phdrs_end = phdrs + ehdr->e_phnum * ehdr->e_phentsize;
1171
1172 // Find the segment with the minimum base so we can "relocate" the p_vaddr
1173 // fields. Typically ET_DYN objects (DSOs) have base of zero and ET_EXEC
1174 // objects have a non-zero base.
1175 uptr preferred_base = (uptr)-1;
1176 for (char *iter = phdrs; iter != phdrs_end; iter += ehdr->e_phentsize) {
1177 Elf_Phdr *phdr = (Elf_Phdr *)iter;
1178 if (phdr->p_type == PT_LOAD && preferred_base > (uptr)phdr->p_vaddr)
1179 preferred_base = (uptr)phdr->p_vaddr;
1180 }
1181
1182 // Compute the delta from the real base to get a relocation delta.
1183 sptr delta = (uptr)base - preferred_base;
1184 // Now we can figure out what the loader really mapped.
1185 for (char *iter = phdrs; iter != phdrs_end; iter += ehdr->e_phentsize) {
1186 Elf_Phdr *phdr = (Elf_Phdr *)iter;
1187 if (phdr->p_type == PT_LOAD) {
1188 uptr seg_start = phdr->p_vaddr + delta;
1189 uptr seg_end = seg_start + phdr->p_memsz;
1190 // None of these values are aligned. We consider the ragged edges of the
1191 // load command as defined, since they are mapped from the file.
1192 seg_start = RoundDownTo(seg_start, GetPageSizeCached());
1193 seg_end = RoundUpTo(seg_end, GetPageSizeCached());
1194 cb((void *)seg_start, seg_end - seg_start);
1195 }
1196 }
1197 }
1198 #endif
1199
1200 #if SANITIZER_LINUX
1201 #if defined(__x86_64__)
1202 // We cannot use glibc's clone wrapper, because it messes with the child
1203 // task's TLS. It writes the PID and TID of the child task to its thread
1204 // descriptor, but in our case the child task shares the thread descriptor with
1205 // the parent (because we don't know how to allocate a new thread
1206 // descriptor to keep glibc happy). So the stock version of clone(), when
1207 // 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)1208 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
1209 int *parent_tidptr, void *newtls, int *child_tidptr) {
1210 long long res;
1211 if (!fn || !child_stack)
1212 return -EINVAL;
1213 CHECK_EQ(0, (uptr)child_stack % 16);
1214 child_stack = (char *)child_stack - 2 * sizeof(unsigned long long);
1215 ((unsigned long long *)child_stack)[0] = (uptr)fn;
1216 ((unsigned long long *)child_stack)[1] = (uptr)arg;
1217 register void *r8 __asm__("r8") = newtls;
1218 register int *r10 __asm__("r10") = child_tidptr;
1219 __asm__ __volatile__(
1220 /* %rax = syscall(%rax = SYSCALL(clone),
1221 * %rdi = flags,
1222 * %rsi = child_stack,
1223 * %rdx = parent_tidptr,
1224 * %r8 = new_tls,
1225 * %r10 = child_tidptr)
1226 */
1227 "syscall\n"
1228
1229 /* if (%rax != 0)
1230 * return;
1231 */
1232 "testq %%rax,%%rax\n"
1233 "jnz 1f\n"
1234
1235 /* In the child. Terminate unwind chain. */
1236 // XXX: We should also terminate the CFI unwind chain
1237 // here. Unfortunately clang 3.2 doesn't support the
1238 // necessary CFI directives, so we skip that part.
1239 "xorq %%rbp,%%rbp\n"
1240
1241 /* Call "fn(arg)". */
1242 "popq %%rax\n"
1243 "popq %%rdi\n"
1244 "call *%%rax\n"
1245
1246 /* Call _exit(%rax). */
1247 "movq %%rax,%%rdi\n"
1248 "movq %2,%%rax\n"
1249 "syscall\n"
1250
1251 /* Return to parent. */
1252 "1:\n"
1253 : "=a" (res)
1254 : "a"(SYSCALL(clone)), "i"(SYSCALL(exit)),
1255 "S"(child_stack),
1256 "D"(flags),
1257 "d"(parent_tidptr),
1258 "r"(r8),
1259 "r"(r10)
1260 : "memory", "r11", "rcx");
1261 return res;
1262 }
1263 #elif defined(__mips__)
internal_clone(int (* fn)(void *),void * child_stack,int flags,void * arg,int * parent_tidptr,void * newtls,int * child_tidptr)1264 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
1265 int *parent_tidptr, void *newtls, int *child_tidptr) {
1266 long long res;
1267 if (!fn || !child_stack)
1268 return -EINVAL;
1269 CHECK_EQ(0, (uptr)child_stack % 16);
1270 child_stack = (char *)child_stack - 2 * sizeof(unsigned long long);
1271 ((unsigned long long *)child_stack)[0] = (uptr)fn;
1272 ((unsigned long long *)child_stack)[1] = (uptr)arg;
1273 register void *a3 __asm__("$7") = newtls;
1274 register int *a4 __asm__("$8") = child_tidptr;
1275 // We don't have proper CFI directives here because it requires alot of code
1276 // for very marginal benefits.
1277 __asm__ __volatile__(
1278 /* $v0 = syscall($v0 = __NR_clone,
1279 * $a0 = flags,
1280 * $a1 = child_stack,
1281 * $a2 = parent_tidptr,
1282 * $a3 = new_tls,
1283 * $a4 = child_tidptr)
1284 */
1285 ".cprestore 16;\n"
1286 "move $4,%1;\n"
1287 "move $5,%2;\n"
1288 "move $6,%3;\n"
1289 "move $7,%4;\n"
1290 /* Store the fifth argument on stack
1291 * if we are using 32-bit abi.
1292 */
1293 #if SANITIZER_WORDSIZE == 32
1294 "lw %5,16($29);\n"
1295 #else
1296 "move $8,%5;\n"
1297 #endif
1298 "li $2,%6;\n"
1299 "syscall;\n"
1300
1301 /* if ($v0 != 0)
1302 * return;
1303 */
1304 "bnez $2,1f;\n"
1305
1306 /* Call "fn(arg)". */
1307 #if SANITIZER_WORDSIZE == 32
1308 #ifdef __BIG_ENDIAN__
1309 "lw $25,4($29);\n"
1310 "lw $4,12($29);\n"
1311 #else
1312 "lw $25,0($29);\n"
1313 "lw $4,8($29);\n"
1314 #endif
1315 #else
1316 "ld $25,0($29);\n"
1317 "ld $4,8($29);\n"
1318 #endif
1319 "jal $25;\n"
1320
1321 /* Call _exit($v0). */
1322 "move $4,$2;\n"
1323 "li $2,%7;\n"
1324 "syscall;\n"
1325
1326 /* Return to parent. */
1327 "1:\n"
1328 : "=r" (res)
1329 : "r"(flags),
1330 "r"(child_stack),
1331 "r"(parent_tidptr),
1332 "r"(a3),
1333 "r"(a4),
1334 "i"(__NR_clone),
1335 "i"(__NR_exit)
1336 : "memory", "$29" );
1337 return res;
1338 }
1339 #elif SANITIZER_RISCV64
internal_clone(int (* fn)(void *),void * child_stack,int flags,void * arg,int * parent_tidptr,void * newtls,int * child_tidptr)1340 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
1341 int *parent_tidptr, void *newtls, int *child_tidptr) {
1342 if (!fn || !child_stack)
1343 return -EINVAL;
1344
1345 CHECK_EQ(0, (uptr)child_stack % 16);
1346
1347 register int res __asm__("a0");
1348 register int __flags __asm__("a0") = flags;
1349 register void *__stack __asm__("a1") = child_stack;
1350 register int *__ptid __asm__("a2") = parent_tidptr;
1351 register void *__tls __asm__("a3") = newtls;
1352 register int *__ctid __asm__("a4") = child_tidptr;
1353 register int (*__fn)(void *) __asm__("a5") = fn;
1354 register void *__arg __asm__("a6") = arg;
1355 register int nr_clone __asm__("a7") = __NR_clone;
1356
1357 __asm__ __volatile__(
1358 "ecall\n"
1359
1360 /* if (a0 != 0)
1361 * return a0;
1362 */
1363 "bnez a0, 1f\n"
1364
1365 // In the child, now. Call "fn(arg)".
1366 "mv a0, a6\n"
1367 "jalr a5\n"
1368
1369 // Call _exit(a0).
1370 "addi a7, zero, %9\n"
1371 "ecall\n"
1372 "1:\n"
1373
1374 : "=r"(res)
1375 : "0"(__flags), "r"(__stack), "r"(__ptid), "r"(__tls), "r"(__ctid),
1376 "r"(__fn), "r"(__arg), "r"(nr_clone), "i"(__NR_exit)
1377 : "memory");
1378 return res;
1379 }
1380 #elif defined(__aarch64__)
internal_clone(int (* fn)(void *),void * child_stack,int flags,void * arg,int * parent_tidptr,void * newtls,int * child_tidptr)1381 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
1382 int *parent_tidptr, void *newtls, int *child_tidptr) {
1383 long long res;
1384 if (!fn || !child_stack)
1385 return -EINVAL;
1386 CHECK_EQ(0, (uptr)child_stack % 16);
1387 child_stack = (char *)child_stack - 2 * sizeof(unsigned long long);
1388 ((unsigned long long *)child_stack)[0] = (uptr)fn;
1389 ((unsigned long long *)child_stack)[1] = (uptr)arg;
1390
1391 register int (*__fn)(void *) __asm__("x0") = fn;
1392 register void *__stack __asm__("x1") = child_stack;
1393 register int __flags __asm__("x2") = flags;
1394 register void *__arg __asm__("x3") = arg;
1395 register int *__ptid __asm__("x4") = parent_tidptr;
1396 register void *__tls __asm__("x5") = newtls;
1397 register int *__ctid __asm__("x6") = child_tidptr;
1398
1399 __asm__ __volatile__(
1400 "mov x0,x2\n" /* flags */
1401 "mov x2,x4\n" /* ptid */
1402 "mov x3,x5\n" /* tls */
1403 "mov x4,x6\n" /* ctid */
1404 "mov x8,%9\n" /* clone */
1405
1406 "svc 0x0\n"
1407
1408 /* if (%r0 != 0)
1409 * return %r0;
1410 */
1411 "cmp x0, #0\n"
1412 "bne 1f\n"
1413
1414 /* In the child, now. Call "fn(arg)". */
1415 "ldp x1, x0, [sp], #16\n"
1416 "blr x1\n"
1417
1418 /* Call _exit(%r0). */
1419 "mov x8, %10\n"
1420 "svc 0x0\n"
1421 "1:\n"
1422
1423 : "=r" (res)
1424 : "i"(-EINVAL),
1425 "r"(__fn), "r"(__stack), "r"(__flags), "r"(__arg),
1426 "r"(__ptid), "r"(__tls), "r"(__ctid),
1427 "i"(__NR_clone), "i"(__NR_exit)
1428 : "x30", "memory");
1429 return res;
1430 }
1431 #elif defined(__powerpc64__)
internal_clone(int (* fn)(void *),void * child_stack,int flags,void * arg,int * parent_tidptr,void * newtls,int * child_tidptr)1432 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
1433 int *parent_tidptr, void *newtls, int *child_tidptr) {
1434 long long res;
1435 // Stack frame structure.
1436 #if SANITIZER_PPC64V1
1437 // Back chain == 0 (SP + 112)
1438 // Frame (112 bytes):
1439 // Parameter save area (SP + 48), 8 doublewords
1440 // TOC save area (SP + 40)
1441 // Link editor doubleword (SP + 32)
1442 // Compiler doubleword (SP + 24)
1443 // LR save area (SP + 16)
1444 // CR save area (SP + 8)
1445 // Back chain (SP + 0)
1446 # define FRAME_SIZE 112
1447 # define FRAME_TOC_SAVE_OFFSET 40
1448 #elif SANITIZER_PPC64V2
1449 // Back chain == 0 (SP + 32)
1450 // Frame (32 bytes):
1451 // TOC save area (SP + 24)
1452 // LR save area (SP + 16)
1453 // CR save area (SP + 8)
1454 // Back chain (SP + 0)
1455 # define FRAME_SIZE 32
1456 # define FRAME_TOC_SAVE_OFFSET 24
1457 #else
1458 # error "Unsupported PPC64 ABI"
1459 #endif
1460 if (!fn || !child_stack)
1461 return -EINVAL;
1462 CHECK_EQ(0, (uptr)child_stack % 16);
1463
1464 register int (*__fn)(void *) __asm__("r3") = fn;
1465 register void *__cstack __asm__("r4") = child_stack;
1466 register int __flags __asm__("r5") = flags;
1467 register void *__arg __asm__("r6") = arg;
1468 register int *__ptidptr __asm__("r7") = parent_tidptr;
1469 register void *__newtls __asm__("r8") = newtls;
1470 register int *__ctidptr __asm__("r9") = child_tidptr;
1471
1472 __asm__ __volatile__(
1473 /* fn and arg are saved across the syscall */
1474 "mr 28, %5\n\t"
1475 "mr 27, %8\n\t"
1476
1477 /* syscall
1478 r0 == __NR_clone
1479 r3 == flags
1480 r4 == child_stack
1481 r5 == parent_tidptr
1482 r6 == newtls
1483 r7 == child_tidptr */
1484 "mr 3, %7\n\t"
1485 "mr 5, %9\n\t"
1486 "mr 6, %10\n\t"
1487 "mr 7, %11\n\t"
1488 "li 0, %3\n\t"
1489 "sc\n\t"
1490
1491 /* Test if syscall was successful */
1492 "cmpdi cr1, 3, 0\n\t"
1493 "crandc cr1*4+eq, cr1*4+eq, cr0*4+so\n\t"
1494 "bne- cr1, 1f\n\t"
1495
1496 /* Set up stack frame */
1497 "li 29, 0\n\t"
1498 "stdu 29, -8(1)\n\t"
1499 "stdu 1, -%12(1)\n\t"
1500 /* Do the function call */
1501 "std 2, %13(1)\n\t"
1502 #if SANITIZER_PPC64V1
1503 "ld 0, 0(28)\n\t"
1504 "ld 2, 8(28)\n\t"
1505 "mtctr 0\n\t"
1506 #elif SANITIZER_PPC64V2
1507 "mr 12, 28\n\t"
1508 "mtctr 12\n\t"
1509 #else
1510 # error "Unsupported PPC64 ABI"
1511 #endif
1512 "mr 3, 27\n\t"
1513 "bctrl\n\t"
1514 "ld 2, %13(1)\n\t"
1515
1516 /* Call _exit(r3) */
1517 "li 0, %4\n\t"
1518 "sc\n\t"
1519
1520 /* Return to parent */
1521 "1:\n\t"
1522 "mr %0, 3\n\t"
1523 : "=r" (res)
1524 : "0" (-1),
1525 "i" (EINVAL),
1526 "i" (__NR_clone),
1527 "i" (__NR_exit),
1528 "r" (__fn),
1529 "r" (__cstack),
1530 "r" (__flags),
1531 "r" (__arg),
1532 "r" (__ptidptr),
1533 "r" (__newtls),
1534 "r" (__ctidptr),
1535 "i" (FRAME_SIZE),
1536 "i" (FRAME_TOC_SAVE_OFFSET)
1537 : "cr0", "cr1", "memory", "ctr", "r0", "r27", "r28", "r29");
1538 return res;
1539 }
1540 #elif defined(__i386__)
internal_clone(int (* fn)(void *),void * child_stack,int flags,void * arg,int * parent_tidptr,void * newtls,int * child_tidptr)1541 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
1542 int *parent_tidptr, void *newtls, int *child_tidptr) {
1543 int res;
1544 if (!fn || !child_stack)
1545 return -EINVAL;
1546 CHECK_EQ(0, (uptr)child_stack % 16);
1547 child_stack = (char *)child_stack - 7 * sizeof(unsigned int);
1548 ((unsigned int *)child_stack)[0] = (uptr)flags;
1549 ((unsigned int *)child_stack)[1] = (uptr)0;
1550 ((unsigned int *)child_stack)[2] = (uptr)fn;
1551 ((unsigned int *)child_stack)[3] = (uptr)arg;
1552 __asm__ __volatile__(
1553 /* %eax = syscall(%eax = SYSCALL(clone),
1554 * %ebx = flags,
1555 * %ecx = child_stack,
1556 * %edx = parent_tidptr,
1557 * %esi = new_tls,
1558 * %edi = child_tidptr)
1559 */
1560
1561 /* Obtain flags */
1562 "movl (%%ecx), %%ebx\n"
1563 /* Do the system call */
1564 "pushl %%ebx\n"
1565 "pushl %%esi\n"
1566 "pushl %%edi\n"
1567 /* Remember the flag value. */
1568 "movl %%ebx, (%%ecx)\n"
1569 "int $0x80\n"
1570 "popl %%edi\n"
1571 "popl %%esi\n"
1572 "popl %%ebx\n"
1573
1574 /* if (%eax != 0)
1575 * return;
1576 */
1577
1578 "test %%eax,%%eax\n"
1579 "jnz 1f\n"
1580
1581 /* terminate the stack frame */
1582 "xorl %%ebp,%%ebp\n"
1583 /* Call FN. */
1584 "call *%%ebx\n"
1585 #ifdef PIC
1586 "call here\n"
1587 "here:\n"
1588 "popl %%ebx\n"
1589 "addl $_GLOBAL_OFFSET_TABLE_+[.-here], %%ebx\n"
1590 #endif
1591 /* Call exit */
1592 "movl %%eax, %%ebx\n"
1593 "movl %2, %%eax\n"
1594 "int $0x80\n"
1595 "1:\n"
1596 : "=a" (res)
1597 : "a"(SYSCALL(clone)), "i"(SYSCALL(exit)),
1598 "c"(child_stack),
1599 "d"(parent_tidptr),
1600 "S"(newtls),
1601 "D"(child_tidptr)
1602 : "memory");
1603 return res;
1604 }
1605 #elif defined(__arm__)
internal_clone(int (* fn)(void *),void * child_stack,int flags,void * arg,int * parent_tidptr,void * newtls,int * child_tidptr)1606 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
1607 int *parent_tidptr, void *newtls, int *child_tidptr) {
1608 unsigned int res;
1609 if (!fn || !child_stack)
1610 return -EINVAL;
1611 child_stack = (char *)child_stack - 2 * sizeof(unsigned int);
1612 ((unsigned int *)child_stack)[0] = (uptr)fn;
1613 ((unsigned int *)child_stack)[1] = (uptr)arg;
1614 register int r0 __asm__("r0") = flags;
1615 register void *r1 __asm__("r1") = child_stack;
1616 register int *r2 __asm__("r2") = parent_tidptr;
1617 register void *r3 __asm__("r3") = newtls;
1618 register int *r4 __asm__("r4") = child_tidptr;
1619 register int r7 __asm__("r7") = __NR_clone;
1620
1621 #if __ARM_ARCH > 4 || defined (__ARM_ARCH_4T__)
1622 # define ARCH_HAS_BX
1623 #endif
1624 #if __ARM_ARCH > 4
1625 # define ARCH_HAS_BLX
1626 #endif
1627
1628 #ifdef ARCH_HAS_BX
1629 # ifdef ARCH_HAS_BLX
1630 # define BLX(R) "blx " #R "\n"
1631 # else
1632 # define BLX(R) "mov lr, pc; bx " #R "\n"
1633 # endif
1634 #else
1635 # define BLX(R) "mov lr, pc; mov pc," #R "\n"
1636 #endif
1637
1638 __asm__ __volatile__(
1639 /* %r0 = syscall(%r7 = SYSCALL(clone),
1640 * %r0 = flags,
1641 * %r1 = child_stack,
1642 * %r2 = parent_tidptr,
1643 * %r3 = new_tls,
1644 * %r4 = child_tidptr)
1645 */
1646
1647 /* Do the system call */
1648 "swi 0x0\n"
1649
1650 /* if (%r0 != 0)
1651 * return %r0;
1652 */
1653 "cmp r0, #0\n"
1654 "bne 1f\n"
1655
1656 /* In the child, now. Call "fn(arg)". */
1657 "ldr r0, [sp, #4]\n"
1658 "ldr ip, [sp], #8\n"
1659 BLX(ip)
1660 /* Call _exit(%r0). */
1661 "mov r7, %7\n"
1662 "swi 0x0\n"
1663 "1:\n"
1664 "mov %0, r0\n"
1665 : "=r"(res)
1666 : "r"(r0), "r"(r1), "r"(r2), "r"(r3), "r"(r4), "r"(r7),
1667 "i"(__NR_exit)
1668 : "memory");
1669 return res;
1670 }
1671 #endif
1672 #endif // SANITIZER_LINUX
1673
1674 #if SANITIZER_LINUX
internal_uname(struct utsname * buf)1675 int internal_uname(struct utsname *buf) {
1676 return internal_syscall(SYSCALL(uname), buf);
1677 }
1678 #endif
1679
1680 #if SANITIZER_ANDROID
1681 #if __ANDROID_API__ < 21
1682 extern "C" __attribute__((weak)) int dl_iterate_phdr(
1683 int (*)(struct dl_phdr_info *, size_t, void *), void *);
1684 #endif
1685
dl_iterate_phdr_test_cb(struct dl_phdr_info * info,size_t size,void * data)1686 static int dl_iterate_phdr_test_cb(struct dl_phdr_info *info, size_t size,
1687 void *data) {
1688 // Any name starting with "lib" indicates a bug in L where library base names
1689 // are returned instead of paths.
1690 if (info->dlpi_name && info->dlpi_name[0] == 'l' &&
1691 info->dlpi_name[1] == 'i' && info->dlpi_name[2] == 'b') {
1692 *(bool *)data = true;
1693 return 1;
1694 }
1695 return 0;
1696 }
1697
1698 static atomic_uint32_t android_api_level;
1699
AndroidDetectApiLevelStatic()1700 static AndroidApiLevel AndroidDetectApiLevelStatic() {
1701 #if __ANDROID_API__ <= 19
1702 return ANDROID_KITKAT;
1703 #elif __ANDROID_API__ <= 22
1704 return ANDROID_LOLLIPOP_MR1;
1705 #else
1706 return ANDROID_POST_LOLLIPOP;
1707 #endif
1708 }
1709
AndroidDetectApiLevel()1710 static AndroidApiLevel AndroidDetectApiLevel() {
1711 if (!&dl_iterate_phdr)
1712 return ANDROID_KITKAT; // K or lower
1713 bool base_name_seen = false;
1714 dl_iterate_phdr(dl_iterate_phdr_test_cb, &base_name_seen);
1715 if (base_name_seen)
1716 return ANDROID_LOLLIPOP_MR1; // L MR1
1717 return ANDROID_POST_LOLLIPOP; // post-L
1718 // Plain L (API level 21) is completely broken wrt ASan and not very
1719 // interesting to detect.
1720 }
1721
1722 extern "C" __attribute__((weak)) void* _DYNAMIC;
1723
AndroidGetApiLevel()1724 AndroidApiLevel AndroidGetApiLevel() {
1725 AndroidApiLevel level =
1726 (AndroidApiLevel)atomic_load(&android_api_level, memory_order_relaxed);
1727 if (level) return level;
1728 level = &_DYNAMIC == nullptr ? AndroidDetectApiLevelStatic()
1729 : AndroidDetectApiLevel();
1730 atomic_store(&android_api_level, level, memory_order_relaxed);
1731 return level;
1732 }
1733
1734 #endif
1735
GetHandleSignalModeImpl(int signum)1736 static HandleSignalMode GetHandleSignalModeImpl(int signum) {
1737 switch (signum) {
1738 case SIGABRT:
1739 return common_flags()->handle_abort;
1740 case SIGILL:
1741 return common_flags()->handle_sigill;
1742 case SIGTRAP:
1743 return common_flags()->handle_sigtrap;
1744 case SIGFPE:
1745 return common_flags()->handle_sigfpe;
1746 case SIGSEGV:
1747 return common_flags()->handle_segv;
1748 case SIGBUS:
1749 return common_flags()->handle_sigbus;
1750 }
1751 return kHandleSignalNo;
1752 }
1753
GetHandleSignalMode(int signum)1754 HandleSignalMode GetHandleSignalMode(int signum) {
1755 HandleSignalMode result = GetHandleSignalModeImpl(signum);
1756 if (result == kHandleSignalYes && !common_flags()->allow_user_segv_handler)
1757 return kHandleSignalExclusive;
1758 return result;
1759 }
1760
1761 #if !SANITIZER_GO
internal_start_thread(void * (* func)(void * arg),void * arg)1762 void *internal_start_thread(void *(*func)(void *arg), void *arg) {
1763 // Start the thread with signals blocked, otherwise it can steal user signals.
1764 ScopedBlockSignals block(nullptr);
1765 void *th;
1766 real_pthread_create(&th, nullptr, func, arg);
1767 return th;
1768 }
1769
internal_join_thread(void * th)1770 void internal_join_thread(void *th) {
1771 real_pthread_join(th, nullptr);
1772 }
1773 #else
internal_start_thread(void * (* func)(void *),void * arg)1774 void *internal_start_thread(void *(*func)(void *), void *arg) { return 0; }
1775
internal_join_thread(void * th)1776 void internal_join_thread(void *th) {}
1777 #endif
1778
1779 #if defined(__aarch64__)
1780 // Android headers in the older NDK releases miss this definition.
1781 struct __sanitizer_esr_context {
1782 struct _aarch64_ctx head;
1783 uint64_t esr;
1784 };
1785
Aarch64GetESR(ucontext_t * ucontext,u64 * esr)1786 static bool Aarch64GetESR(ucontext_t *ucontext, u64 *esr) {
1787 static const u32 kEsrMagic = 0x45535201;
1788 u8 *aux = reinterpret_cast<u8 *>(ucontext->uc_mcontext.__reserved);
1789 while (true) {
1790 _aarch64_ctx *ctx = (_aarch64_ctx *)aux;
1791 if (ctx->size == 0) break;
1792 if (ctx->magic == kEsrMagic) {
1793 *esr = ((__sanitizer_esr_context *)ctx)->esr;
1794 return true;
1795 }
1796 aux += ctx->size;
1797 }
1798 return false;
1799 }
1800 #endif
1801
1802 using Context = ucontext_t;
1803
GetWriteFlag() const1804 SignalContext::WriteFlag SignalContext::GetWriteFlag() const {
1805 Context *ucontext = (Context *)context;
1806 #if defined(__x86_64__) || defined(__i386__)
1807 static const uptr PF_WRITE = 1U << 1;
1808 #if SANITIZER_FREEBSD
1809 uptr err = ucontext->uc_mcontext.mc_err;
1810 #elif SANITIZER_NETBSD
1811 uptr err = ucontext->uc_mcontext.__gregs[_REG_ERR];
1812 #elif SANITIZER_SOLARIS && defined(__i386__)
1813 const int Err = 13;
1814 uptr err = ucontext->uc_mcontext.gregs[Err];
1815 #else
1816 uptr err = ucontext->uc_mcontext.gregs[REG_ERR];
1817 #endif // SANITIZER_FREEBSD
1818 return err & PF_WRITE ? WRITE : READ;
1819 #elif defined(__mips__)
1820 uint32_t *exception_source;
1821 uint32_t faulty_instruction;
1822 uint32_t op_code;
1823
1824 exception_source = (uint32_t *)ucontext->uc_mcontext.pc;
1825 faulty_instruction = (uint32_t)(*exception_source);
1826
1827 op_code = (faulty_instruction >> 26) & 0x3f;
1828
1829 // FIXME: Add support for FPU, microMIPS, DSP, MSA memory instructions.
1830 switch (op_code) {
1831 case 0x28: // sb
1832 case 0x29: // sh
1833 case 0x2b: // sw
1834 case 0x3f: // sd
1835 #if __mips_isa_rev < 6
1836 case 0x2c: // sdl
1837 case 0x2d: // sdr
1838 case 0x2a: // swl
1839 case 0x2e: // swr
1840 #endif
1841 return SignalContext::WRITE;
1842
1843 case 0x20: // lb
1844 case 0x24: // lbu
1845 case 0x21: // lh
1846 case 0x25: // lhu
1847 case 0x23: // lw
1848 case 0x27: // lwu
1849 case 0x37: // ld
1850 #if __mips_isa_rev < 6
1851 case 0x1a: // ldl
1852 case 0x1b: // ldr
1853 case 0x22: // lwl
1854 case 0x26: // lwr
1855 #endif
1856 return SignalContext::READ;
1857 #if __mips_isa_rev == 6
1858 case 0x3b: // pcrel
1859 op_code = (faulty_instruction >> 19) & 0x3;
1860 switch (op_code) {
1861 case 0x1: // lwpc
1862 case 0x2: // lwupc
1863 return SignalContext::READ;
1864 }
1865 #endif
1866 }
1867 return SignalContext::UNKNOWN;
1868 #elif defined(__arm__)
1869 static const uptr FSR_WRITE = 1U << 11;
1870 uptr fsr = ucontext->uc_mcontext.error_code;
1871 return fsr & FSR_WRITE ? WRITE : READ;
1872 #elif defined(__aarch64__)
1873 static const u64 ESR_ELx_WNR = 1U << 6;
1874 u64 esr;
1875 if (!Aarch64GetESR(ucontext, &esr)) return UNKNOWN;
1876 return esr & ESR_ELx_WNR ? WRITE : READ;
1877 #elif defined(__sparc__)
1878 // Decode the instruction to determine the access type.
1879 // From OpenSolaris $SRC/uts/sun4/os/trap.c (get_accesstype).
1880 #if SANITIZER_SOLARIS
1881 uptr pc = ucontext->uc_mcontext.gregs[REG_PC];
1882 #else
1883 // Historical BSDism here.
1884 struct sigcontext *scontext = (struct sigcontext *)context;
1885 #if defined(__arch64__)
1886 uptr pc = scontext->sigc_regs.tpc;
1887 #else
1888 uptr pc = scontext->si_regs.pc;
1889 #endif
1890 #endif
1891 u32 instr = *(u32 *)pc;
1892 return (instr >> 21) & 1 ? WRITE: READ;
1893 #elif defined(__riscv)
1894 #if SANITIZER_FREEBSD
1895 unsigned long pc = ucontext->uc_mcontext.mc_gpregs.gp_sepc;
1896 #else
1897 unsigned long pc = ucontext->uc_mcontext.__gregs[REG_PC];
1898 #endif
1899 unsigned faulty_instruction = *(uint16_t *)pc;
1900
1901 #if defined(__riscv_compressed)
1902 if ((faulty_instruction & 0x3) != 0x3) { // it's a compressed instruction
1903 // set op_bits to the instruction bits [1, 0, 15, 14, 13]
1904 unsigned op_bits =
1905 ((faulty_instruction & 0x3) << 3) | (faulty_instruction >> 13);
1906 unsigned rd = faulty_instruction & 0xF80; // bits 7-11, inclusive
1907 switch (op_bits) {
1908 case 0b10'010: // c.lwsp (rd != x0)
1909 #if __riscv_xlen == 64
1910 case 0b10'011: // c.ldsp (rd != x0)
1911 #endif
1912 return rd ? SignalContext::READ : SignalContext::UNKNOWN;
1913 case 0b00'010: // c.lw
1914 #if __riscv_flen >= 32 && __riscv_xlen == 32
1915 case 0b10'011: // c.flwsp
1916 #endif
1917 #if __riscv_flen >= 32 || __riscv_xlen == 64
1918 case 0b00'011: // c.flw / c.ld
1919 #endif
1920 #if __riscv_flen == 64
1921 case 0b00'001: // c.fld
1922 case 0b10'001: // c.fldsp
1923 #endif
1924 return SignalContext::READ;
1925 case 0b00'110: // c.sw
1926 case 0b10'110: // c.swsp
1927 #if __riscv_flen >= 32 || __riscv_xlen == 64
1928 case 0b00'111: // c.fsw / c.sd
1929 case 0b10'111: // c.fswsp / c.sdsp
1930 #endif
1931 #if __riscv_flen == 64
1932 case 0b00'101: // c.fsd
1933 case 0b10'101: // c.fsdsp
1934 #endif
1935 return SignalContext::WRITE;
1936 default:
1937 return SignalContext::UNKNOWN;
1938 }
1939 }
1940 #endif
1941
1942 unsigned opcode = faulty_instruction & 0x7f; // lower 7 bits
1943 unsigned funct3 = (faulty_instruction >> 12) & 0x7; // bits 12-14, inclusive
1944 switch (opcode) {
1945 case 0b0000011: // loads
1946 switch (funct3) {
1947 case 0b000: // lb
1948 case 0b001: // lh
1949 case 0b010: // lw
1950 #if __riscv_xlen == 64
1951 case 0b011: // ld
1952 #endif
1953 case 0b100: // lbu
1954 case 0b101: // lhu
1955 return SignalContext::READ;
1956 default:
1957 return SignalContext::UNKNOWN;
1958 }
1959 case 0b0100011: // stores
1960 switch (funct3) {
1961 case 0b000: // sb
1962 case 0b001: // sh
1963 case 0b010: // sw
1964 #if __riscv_xlen == 64
1965 case 0b011: // sd
1966 #endif
1967 return SignalContext::WRITE;
1968 default:
1969 return SignalContext::UNKNOWN;
1970 }
1971 #if __riscv_flen >= 32
1972 case 0b0000111: // floating-point loads
1973 switch (funct3) {
1974 case 0b010: // flw
1975 #if __riscv_flen == 64
1976 case 0b011: // fld
1977 #endif
1978 return SignalContext::READ;
1979 default:
1980 return SignalContext::UNKNOWN;
1981 }
1982 case 0b0100111: // floating-point stores
1983 switch (funct3) {
1984 case 0b010: // fsw
1985 #if __riscv_flen == 64
1986 case 0b011: // fsd
1987 #endif
1988 return SignalContext::WRITE;
1989 default:
1990 return SignalContext::UNKNOWN;
1991 }
1992 #endif
1993 default:
1994 return SignalContext::UNKNOWN;
1995 }
1996 #else
1997 (void)ucontext;
1998 return UNKNOWN; // FIXME: Implement.
1999 #endif
2000 }
2001
IsTrueFaultingAddress() const2002 bool SignalContext::IsTrueFaultingAddress() const {
2003 auto si = static_cast<const siginfo_t *>(siginfo);
2004 // SIGSEGV signals without a true fault address have si_code set to 128.
2005 return si->si_signo == SIGSEGV && si->si_code != 128;
2006 }
2007
DumpAllRegisters(void * context)2008 void SignalContext::DumpAllRegisters(void *context) {
2009 // FIXME: Implement this.
2010 }
2011
GetPcSpBp(void * context,uptr * pc,uptr * sp,uptr * bp)2012 static void GetPcSpBp(void *context, uptr *pc, uptr *sp, uptr *bp) {
2013 #if SANITIZER_NETBSD
2014 // This covers all NetBSD architectures
2015 ucontext_t *ucontext = (ucontext_t *)context;
2016 *pc = _UC_MACHINE_PC(ucontext);
2017 *bp = _UC_MACHINE_FP(ucontext);
2018 *sp = _UC_MACHINE_SP(ucontext);
2019 #elif defined(__arm__)
2020 ucontext_t *ucontext = (ucontext_t*)context;
2021 *pc = ucontext->uc_mcontext.arm_pc;
2022 *bp = ucontext->uc_mcontext.arm_fp;
2023 *sp = ucontext->uc_mcontext.arm_sp;
2024 #elif defined(__aarch64__)
2025 ucontext_t *ucontext = (ucontext_t*)context;
2026 *pc = ucontext->uc_mcontext.pc;
2027 *bp = ucontext->uc_mcontext.regs[29];
2028 *sp = ucontext->uc_mcontext.sp;
2029 #elif defined(__hppa__)
2030 ucontext_t *ucontext = (ucontext_t*)context;
2031 *pc = ucontext->uc_mcontext.sc_iaoq[0];
2032 /* GCC uses %r3 whenever a frame pointer is needed. */
2033 *bp = ucontext->uc_mcontext.sc_gr[3];
2034 *sp = ucontext->uc_mcontext.sc_gr[30];
2035 #elif defined(__x86_64__)
2036 # if SANITIZER_FREEBSD
2037 ucontext_t *ucontext = (ucontext_t*)context;
2038 *pc = ucontext->uc_mcontext.mc_rip;
2039 *bp = ucontext->uc_mcontext.mc_rbp;
2040 *sp = ucontext->uc_mcontext.mc_rsp;
2041 # else
2042 ucontext_t *ucontext = (ucontext_t*)context;
2043 *pc = ucontext->uc_mcontext.gregs[REG_RIP];
2044 *bp = ucontext->uc_mcontext.gregs[REG_RBP];
2045 *sp = ucontext->uc_mcontext.gregs[REG_RSP];
2046 # endif
2047 #elif defined(__i386__)
2048 # if SANITIZER_FREEBSD
2049 ucontext_t *ucontext = (ucontext_t*)context;
2050 *pc = ucontext->uc_mcontext.mc_eip;
2051 *bp = ucontext->uc_mcontext.mc_ebp;
2052 *sp = ucontext->uc_mcontext.mc_esp;
2053 # else
2054 ucontext_t *ucontext = (ucontext_t*)context;
2055 # if SANITIZER_SOLARIS
2056 /* Use the numeric values: the symbolic ones are undefined by llvm
2057 include/llvm/Support/Solaris.h. */
2058 # ifndef REG_EIP
2059 # define REG_EIP 14 // REG_PC
2060 # endif
2061 # ifndef REG_EBP
2062 # define REG_EBP 6 // REG_FP
2063 # endif
2064 # ifndef REG_UESP
2065 # define REG_UESP 17 // REG_SP
2066 # endif
2067 # endif
2068 *pc = ucontext->uc_mcontext.gregs[REG_EIP];
2069 *bp = ucontext->uc_mcontext.gregs[REG_EBP];
2070 *sp = ucontext->uc_mcontext.gregs[REG_UESP];
2071 # endif
2072 #elif defined(__powerpc__) || defined(__powerpc64__)
2073 ucontext_t *ucontext = (ucontext_t*)context;
2074 *pc = ucontext->uc_mcontext.regs->nip;
2075 *sp = ucontext->uc_mcontext.regs->gpr[PT_R1];
2076 // The powerpc{,64}-linux ABIs do not specify r31 as the frame
2077 // pointer, but GCC always uses r31 when we need a frame pointer.
2078 *bp = ucontext->uc_mcontext.regs->gpr[PT_R31];
2079 #elif defined(__sparc__)
2080 #if defined(__arch64__) || defined(__sparcv9)
2081 #define STACK_BIAS 2047
2082 #else
2083 #define STACK_BIAS 0
2084 # endif
2085 # if SANITIZER_SOLARIS
2086 ucontext_t *ucontext = (ucontext_t *)context;
2087 *pc = ucontext->uc_mcontext.gregs[REG_PC];
2088 *sp = ucontext->uc_mcontext.gregs[REG_O6] + STACK_BIAS;
2089 #else
2090 // Historical BSDism here.
2091 struct sigcontext *scontext = (struct sigcontext *)context;
2092 #if defined(__arch64__)
2093 *pc = scontext->sigc_regs.tpc;
2094 *sp = scontext->sigc_regs.u_regs[14] + STACK_BIAS;
2095 #else
2096 *pc = scontext->si_regs.pc;
2097 *sp = scontext->si_regs.u_regs[14];
2098 #endif
2099 # endif
2100 *bp = (uptr)((uhwptr *)*sp)[14] + STACK_BIAS;
2101 #elif defined(__mips__)
2102 ucontext_t *ucontext = (ucontext_t*)context;
2103 *pc = ucontext->uc_mcontext.pc;
2104 *bp = ucontext->uc_mcontext.gregs[30];
2105 *sp = ucontext->uc_mcontext.gregs[29];
2106 #elif defined(__s390__)
2107 ucontext_t *ucontext = (ucontext_t*)context;
2108 # if defined(__s390x__)
2109 *pc = ucontext->uc_mcontext.psw.addr;
2110 # else
2111 *pc = ucontext->uc_mcontext.psw.addr & 0x7fffffff;
2112 # endif
2113 *bp = ucontext->uc_mcontext.gregs[11];
2114 *sp = ucontext->uc_mcontext.gregs[15];
2115 #elif defined(__riscv)
2116 ucontext_t *ucontext = (ucontext_t*)context;
2117 # if SANITIZER_FREEBSD
2118 *pc = ucontext->uc_mcontext.mc_gpregs.gp_sepc;
2119 *bp = ucontext->uc_mcontext.mc_gpregs.gp_s[0];
2120 *sp = ucontext->uc_mcontext.mc_gpregs.gp_sp;
2121 # else
2122 *pc = ucontext->uc_mcontext.__gregs[REG_PC];
2123 *bp = ucontext->uc_mcontext.__gregs[REG_S0];
2124 *sp = ucontext->uc_mcontext.__gregs[REG_SP];
2125 # endif
2126 # elif defined(__hexagon__)
2127 ucontext_t *ucontext = (ucontext_t *)context;
2128 *pc = ucontext->uc_mcontext.pc;
2129 *bp = ucontext->uc_mcontext.r30;
2130 *sp = ucontext->uc_mcontext.r29;
2131 # else
2132 # error "Unsupported arch"
2133 # endif
2134 }
2135
InitPcSpBp()2136 void SignalContext::InitPcSpBp() { GetPcSpBp(context, &pc, &sp, &bp); }
2137
InitializePlatformEarly()2138 void InitializePlatformEarly() {
2139 // Do nothing.
2140 }
2141
MaybeReexec()2142 void MaybeReexec() {
2143 // No need to re-exec on Linux.
2144 }
2145
CheckASLR()2146 void CheckASLR() {
2147 #if SANITIZER_NETBSD
2148 int mib[3];
2149 int paxflags;
2150 uptr len = sizeof(paxflags);
2151
2152 mib[0] = CTL_PROC;
2153 mib[1] = internal_getpid();
2154 mib[2] = PROC_PID_PAXFLAGS;
2155
2156 if (UNLIKELY(internal_sysctl(mib, 3, &paxflags, &len, NULL, 0) == -1)) {
2157 Printf("sysctl failed\n");
2158 Die();
2159 }
2160
2161 if (UNLIKELY(paxflags & CTL_PROC_PAXFLAGS_ASLR)) {
2162 Printf("This sanitizer is not compatible with enabled ASLR.\n"
2163 "To disable ASLR, please run \"paxctl +a %s\" and try again.\n",
2164 GetArgv()[0]);
2165 Die();
2166 }
2167 #elif SANITIZER_PPC64V2
2168 // Disable ASLR for Linux PPC64LE.
2169 int old_personality = personality(0xffffffff);
2170 if (old_personality != -1 && (old_personality & ADDR_NO_RANDOMIZE) == 0) {
2171 VReport(1, "WARNING: Program is being run with address space layout "
2172 "randomization (ASLR) enabled which prevents the thread and "
2173 "memory sanitizers from working on powerpc64le.\n"
2174 "ASLR will be disabled and the program re-executed.\n");
2175 CHECK_NE(personality(old_personality | ADDR_NO_RANDOMIZE), -1);
2176 ReExec();
2177 }
2178 #elif SANITIZER_FREEBSD
2179 int aslr_pie;
2180 uptr len = sizeof(aslr_pie);
2181 #if SANITIZER_WORDSIZE == 64
2182 if (UNLIKELY(internal_sysctlbyname("kern.elf64.aslr.pie_enable",
2183 &aslr_pie, &len, NULL, 0) == -1)) {
2184 // We're making things less 'dramatic' here since
2185 // the OID is not necessarily guaranteed to be here
2186 // just yet regarding FreeBSD release
2187 return;
2188 }
2189
2190 if (aslr_pie > 0) {
2191 Printf("This sanitizer is not compatible with enabled ASLR "
2192 "and binaries compiled with PIE\n");
2193 Die();
2194 }
2195 #endif
2196 // there might be 32 bits compat for 64 bits
2197 if (UNLIKELY(internal_sysctlbyname("kern.elf32.aslr.pie_enable",
2198 &aslr_pie, &len, NULL, 0) == -1)) {
2199 return;
2200 }
2201
2202 if (aslr_pie > 0) {
2203 Printf("This sanitizer is not compatible with enabled ASLR "
2204 "and binaries compiled with PIE\n");
2205 Die();
2206 }
2207 #else
2208 // Do nothing
2209 #endif
2210 }
2211
CheckMPROTECT()2212 void CheckMPROTECT() {
2213 #if SANITIZER_NETBSD
2214 int mib[3];
2215 int paxflags;
2216 uptr len = sizeof(paxflags);
2217
2218 mib[0] = CTL_PROC;
2219 mib[1] = internal_getpid();
2220 mib[2] = PROC_PID_PAXFLAGS;
2221
2222 if (UNLIKELY(internal_sysctl(mib, 3, &paxflags, &len, NULL, 0) == -1)) {
2223 Printf("sysctl failed\n");
2224 Die();
2225 }
2226
2227 if (UNLIKELY(paxflags & CTL_PROC_PAXFLAGS_MPROTECT)) {
2228 Printf("This sanitizer is not compatible with enabled MPROTECT\n");
2229 Die();
2230 }
2231 #else
2232 // Do nothing
2233 #endif
2234 }
2235
CheckNoDeepBind(const char * filename,int flag)2236 void CheckNoDeepBind(const char *filename, int flag) {
2237 #ifdef RTLD_DEEPBIND
2238 if (flag & RTLD_DEEPBIND) {
2239 Report(
2240 "You are trying to dlopen a %s shared library with RTLD_DEEPBIND flag"
2241 " which is incompatible with sanitizer runtime "
2242 "(see https://github.com/google/sanitizers/issues/611 for details"
2243 "). If you want to run %s library under sanitizers please remove "
2244 "RTLD_DEEPBIND from dlopen flags.\n",
2245 filename, filename);
2246 Die();
2247 }
2248 #endif
2249 }
2250
FindAvailableMemoryRange(uptr size,uptr alignment,uptr left_padding,uptr * largest_gap_found,uptr * max_occupied_addr)2251 uptr FindAvailableMemoryRange(uptr size, uptr alignment, uptr left_padding,
2252 uptr *largest_gap_found,
2253 uptr *max_occupied_addr) {
2254 UNREACHABLE("FindAvailableMemoryRange is not available");
2255 return 0;
2256 }
2257
GetRandom(void * buffer,uptr length,bool blocking)2258 bool GetRandom(void *buffer, uptr length, bool blocking) {
2259 if (!buffer || !length || length > 256)
2260 return false;
2261 #if SANITIZER_USE_GETENTROPY
2262 uptr rnd = getentropy(buffer, length);
2263 int rverrno = 0;
2264 if (internal_iserror(rnd, &rverrno) && rverrno == EFAULT)
2265 return false;
2266 else if (rnd == 0)
2267 return true;
2268 #endif // SANITIZER_USE_GETENTROPY
2269
2270 #if SANITIZER_USE_GETRANDOM
2271 static atomic_uint8_t skip_getrandom_syscall;
2272 if (!atomic_load_relaxed(&skip_getrandom_syscall)) {
2273 // Up to 256 bytes, getrandom will not be interrupted.
2274 uptr res = internal_syscall(SYSCALL(getrandom), buffer, length,
2275 blocking ? 0 : GRND_NONBLOCK);
2276 int rverrno = 0;
2277 if (internal_iserror(res, &rverrno) && rverrno == ENOSYS)
2278 atomic_store_relaxed(&skip_getrandom_syscall, 1);
2279 else if (res == length)
2280 return true;
2281 }
2282 #endif // SANITIZER_USE_GETRANDOM
2283 // Up to 256 bytes, a read off /dev/urandom will not be interrupted.
2284 // blocking is moot here, O_NONBLOCK has no effect when opening /dev/urandom.
2285 uptr fd = internal_open("/dev/urandom", O_RDONLY);
2286 if (internal_iserror(fd))
2287 return false;
2288 uptr res = internal_read(fd, buffer, length);
2289 if (internal_iserror(res))
2290 return false;
2291 internal_close(fd);
2292 return true;
2293 }
2294
2295 } // namespace __sanitizer
2296
2297 #endif
2298