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
18
19 #include "sanitizer_common.h"
20 #include "sanitizer_flags.h"
21 #include "sanitizer_internal_defs.h"
22 #include "sanitizer_libc.h"
23 #include "sanitizer_linux.h"
24 #include "sanitizer_mutex.h"
25 #include "sanitizer_placement_new.h"
26 #include "sanitizer_procmaps.h"
27 #include "sanitizer_stacktrace.h"
28 #include "sanitizer_symbolizer.h"
29
30 #if !SANITIZER_FREEBSD
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 <sys/mman.h>
53 #include <sys/ptrace.h>
54 #include <sys/resource.h>
55 #include <sys/stat.h>
56 #include <sys/syscall.h>
57 #include <sys/time.h>
58 #include <sys/types.h>
59 #include <ucontext.h>
60 #include <unistd.h>
61
62 #if SANITIZER_FREEBSD
63 #include <sys/exec.h>
64 #include <sys/sysctl.h>
65 #include <vm/vm_param.h>
66 #include <vm/pmap.h>
67 #include <machine/atomic.h>
68 extern "C" {
69 // <sys/umtx.h> must be included after <errno.h> and <sys/types.h> on
70 // FreeBSD 9.2 and 10.0.
71 #include <sys/umtx.h>
72 }
73 extern char **environ; // provided by crt1
74 #endif // SANITIZER_FREEBSD
75
76 #if !SANITIZER_ANDROID
77 #include <sys/signal.h>
78 #endif
79
80 #if SANITIZER_LINUX
81 // <linux/time.h>
82 struct kernel_timeval {
83 long tv_sec;
84 long tv_usec;
85 };
86
87 // <linux/futex.h> is broken on some linux distributions.
88 const int FUTEX_WAIT = 0;
89 const int FUTEX_WAKE = 1;
90 #endif // SANITIZER_LINUX
91
92 // Are we using 32-bit or 64-bit Linux syscalls?
93 // x32 (which defines __x86_64__) has SANITIZER_WORDSIZE == 32
94 // but it still needs to use 64-bit syscalls.
95 #if SANITIZER_LINUX && (defined(__x86_64__) || defined(__powerpc64__) || \
96 SANITIZER_WORDSIZE == 64)
97 # define SANITIZER_LINUX_USES_64BIT_SYSCALLS 1
98 #else
99 # define SANITIZER_LINUX_USES_64BIT_SYSCALLS 0
100 #endif
101
102 #if defined(__x86_64__)
103 extern "C" {
104 extern void internal_sigreturn();
105 }
106 #endif
107
108 namespace __sanitizer {
109
110 #if SANITIZER_LINUX && defined(__x86_64__)
111 #include "sanitizer_syscall_linux_x86_64.inc"
112 #elif SANITIZER_LINUX && defined(__aarch64__)
113 #include "sanitizer_syscall_linux_aarch64.inc"
114 #else
115 #include "sanitizer_syscall_generic.inc"
116 #endif
117
118 // --------------- sanitizer_libc.h
119 #if !SANITIZER_S390
internal_mmap(void * addr,uptr length,int prot,int flags,int fd,OFF_T offset)120 uptr internal_mmap(void *addr, uptr length, int prot, int flags, int fd,
121 OFF_T offset) {
122 #if SANITIZER_FREEBSD || SANITIZER_LINUX_USES_64BIT_SYSCALLS
123 return internal_syscall(SYSCALL(mmap), (uptr)addr, length, prot, flags, fd,
124 offset);
125 #else
126 // mmap2 specifies file offset in 4096-byte units.
127 CHECK(IsAligned(offset, 4096));
128 return internal_syscall(SYSCALL(mmap2), addr, length, prot, flags, fd,
129 offset / 4096);
130 #endif
131 }
132 #endif // !SANITIZER_S390
133
internal_munmap(void * addr,uptr length)134 uptr internal_munmap(void *addr, uptr length) {
135 return internal_syscall(SYSCALL(munmap), (uptr)addr, length);
136 }
137
internal_mprotect(void * addr,uptr length,int prot)138 int internal_mprotect(void *addr, uptr length, int prot) {
139 return internal_syscall(SYSCALL(mprotect), (uptr)addr, length, prot);
140 }
141
internal_close(fd_t fd)142 uptr internal_close(fd_t fd) {
143 return internal_syscall(SYSCALL(close), fd);
144 }
145
internal_open(const char * filename,int flags)146 uptr internal_open(const char *filename, int flags) {
147 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
148 return internal_syscall(SYSCALL(openat), AT_FDCWD, (uptr)filename, flags);
149 #else
150 return internal_syscall(SYSCALL(open), (uptr)filename, flags);
151 #endif
152 }
153
internal_open(const char * filename,int flags,u32 mode)154 uptr internal_open(const char *filename, int flags, u32 mode) {
155 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
156 return internal_syscall(SYSCALL(openat), AT_FDCWD, (uptr)filename, flags,
157 mode);
158 #else
159 return internal_syscall(SYSCALL(open), (uptr)filename, flags, mode);
160 #endif
161 }
162
internal_read(fd_t fd,void * buf,uptr count)163 uptr internal_read(fd_t fd, void *buf, uptr count) {
164 sptr res;
165 HANDLE_EINTR(res, (sptr)internal_syscall(SYSCALL(read), fd, (uptr)buf,
166 count));
167 return res;
168 }
169
internal_write(fd_t fd,const void * buf,uptr count)170 uptr internal_write(fd_t fd, const void *buf, uptr count) {
171 sptr res;
172 HANDLE_EINTR(res, (sptr)internal_syscall(SYSCALL(write), fd, (uptr)buf,
173 count));
174 return res;
175 }
176
internal_ftruncate(fd_t fd,uptr size)177 uptr internal_ftruncate(fd_t fd, uptr size) {
178 sptr res;
179 HANDLE_EINTR(res, (sptr)internal_syscall(SYSCALL(ftruncate), fd,
180 (OFF_T)size));
181 return res;
182 }
183
184 #if !SANITIZER_LINUX_USES_64BIT_SYSCALLS && !SANITIZER_FREEBSD
stat64_to_stat(struct stat64 * in,struct stat * out)185 static void stat64_to_stat(struct stat64 *in, struct stat *out) {
186 internal_memset(out, 0, sizeof(*out));
187 out->st_dev = in->st_dev;
188 out->st_ino = in->st_ino;
189 out->st_mode = in->st_mode;
190 out->st_nlink = in->st_nlink;
191 out->st_uid = in->st_uid;
192 out->st_gid = in->st_gid;
193 out->st_rdev = in->st_rdev;
194 out->st_size = in->st_size;
195 out->st_blksize = in->st_blksize;
196 out->st_blocks = in->st_blocks;
197 out->st_atime = in->st_atime;
198 out->st_mtime = in->st_mtime;
199 out->st_ctime = in->st_ctime;
200 out->st_ino = in->st_ino;
201 }
202 #endif
203
204 #if defined(__mips64)
kernel_stat_to_stat(struct kernel_stat * in,struct stat * out)205 static void kernel_stat_to_stat(struct kernel_stat *in, struct stat *out) {
206 internal_memset(out, 0, sizeof(*out));
207 out->st_dev = in->st_dev;
208 out->st_ino = in->st_ino;
209 out->st_mode = in->st_mode;
210 out->st_nlink = in->st_nlink;
211 out->st_uid = in->st_uid;
212 out->st_gid = in->st_gid;
213 out->st_rdev = in->st_rdev;
214 out->st_size = in->st_size;
215 out->st_blksize = in->st_blksize;
216 out->st_blocks = in->st_blocks;
217 out->st_atime = in->st_atime_nsec;
218 out->st_mtime = in->st_mtime_nsec;
219 out->st_ctime = in->st_ctime_nsec;
220 out->st_ino = in->st_ino;
221 }
222 #endif
223
internal_stat(const char * path,void * buf)224 uptr internal_stat(const char *path, void *buf) {
225 #if SANITIZER_FREEBSD
226 return internal_syscall(SYSCALL(stat), path, buf);
227 #elif SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
228 return internal_syscall(SYSCALL(newfstatat), AT_FDCWD, (uptr)path,
229 (uptr)buf, 0);
230 #elif SANITIZER_LINUX_USES_64BIT_SYSCALLS
231 # if defined(__mips64)
232 // For mips64, stat syscall fills buffer in the format of kernel_stat
233 struct kernel_stat kbuf;
234 int res = internal_syscall(SYSCALL(stat), path, &kbuf);
235 kernel_stat_to_stat(&kbuf, (struct stat *)buf);
236 return res;
237 # else
238 return internal_syscall(SYSCALL(stat), (uptr)path, (uptr)buf);
239 # endif
240 #else
241 struct stat64 buf64;
242 int res = internal_syscall(SYSCALL(stat64), path, &buf64);
243 stat64_to_stat(&buf64, (struct stat *)buf);
244 return res;
245 #endif
246 }
247
internal_lstat(const char * path,void * buf)248 uptr internal_lstat(const char *path, void *buf) {
249 #if SANITIZER_FREEBSD
250 return internal_syscall(SYSCALL(lstat), path, buf);
251 #elif SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
252 return internal_syscall(SYSCALL(newfstatat), AT_FDCWD, (uptr)path,
253 (uptr)buf, AT_SYMLINK_NOFOLLOW);
254 #elif SANITIZER_LINUX_USES_64BIT_SYSCALLS
255 # if SANITIZER_MIPS64
256 // For mips64, lstat syscall fills buffer in the format of kernel_stat
257 struct kernel_stat kbuf;
258 int res = internal_syscall(SYSCALL(lstat), path, &kbuf);
259 kernel_stat_to_stat(&kbuf, (struct stat *)buf);
260 return res;
261 # else
262 return internal_syscall(SYSCALL(lstat), (uptr)path, (uptr)buf);
263 # endif
264 #else
265 struct stat64 buf64;
266 int res = internal_syscall(SYSCALL(lstat64), path, &buf64);
267 stat64_to_stat(&buf64, (struct stat *)buf);
268 return res;
269 #endif
270 }
271
internal_fstat(fd_t fd,void * buf)272 uptr internal_fstat(fd_t fd, void *buf) {
273 #if SANITIZER_FREEBSD || SANITIZER_LINUX_USES_64BIT_SYSCALLS
274 # if SANITIZER_MIPS64
275 // For mips64, fstat syscall fills buffer in the format of kernel_stat
276 struct kernel_stat kbuf;
277 int res = internal_syscall(SYSCALL(fstat), fd, &kbuf);
278 kernel_stat_to_stat(&kbuf, (struct stat *)buf);
279 return res;
280 # else
281 return internal_syscall(SYSCALL(fstat), fd, (uptr)buf);
282 # endif
283 #else
284 struct stat64 buf64;
285 int res = internal_syscall(SYSCALL(fstat64), fd, &buf64);
286 stat64_to_stat(&buf64, (struct stat *)buf);
287 return res;
288 #endif
289 }
290
internal_filesize(fd_t fd)291 uptr internal_filesize(fd_t fd) {
292 struct stat st;
293 if (internal_fstat(fd, &st))
294 return -1;
295 return (uptr)st.st_size;
296 }
297
internal_dup2(int oldfd,int newfd)298 uptr internal_dup2(int oldfd, int newfd) {
299 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
300 return internal_syscall(SYSCALL(dup3), oldfd, newfd, 0);
301 #else
302 return internal_syscall(SYSCALL(dup2), oldfd, newfd);
303 #endif
304 }
305
internal_readlink(const char * path,char * buf,uptr bufsize)306 uptr internal_readlink(const char *path, char *buf, uptr bufsize) {
307 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
308 return internal_syscall(SYSCALL(readlinkat), AT_FDCWD,
309 (uptr)path, (uptr)buf, bufsize);
310 #else
311 return internal_syscall(SYSCALL(readlink), (uptr)path, (uptr)buf, bufsize);
312 #endif
313 }
314
internal_unlink(const char * path)315 uptr internal_unlink(const char *path) {
316 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
317 return internal_syscall(SYSCALL(unlinkat), AT_FDCWD, (uptr)path, 0);
318 #else
319 return internal_syscall(SYSCALL(unlink), (uptr)path);
320 #endif
321 }
322
internal_rename(const char * oldpath,const char * newpath)323 uptr internal_rename(const char *oldpath, const char *newpath) {
324 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
325 return internal_syscall(SYSCALL(renameat), AT_FDCWD, (uptr)oldpath, AT_FDCWD,
326 (uptr)newpath);
327 #else
328 return internal_syscall(SYSCALL(rename), (uptr)oldpath, (uptr)newpath);
329 #endif
330 }
331
internal_sched_yield()332 uptr internal_sched_yield() {
333 return internal_syscall(SYSCALL(sched_yield));
334 }
335
internal__exit(int exitcode)336 void internal__exit(int exitcode) {
337 #if SANITIZER_FREEBSD
338 internal_syscall(SYSCALL(exit), exitcode);
339 #else
340 internal_syscall(SYSCALL(exit_group), exitcode);
341 #endif
342 Die(); // Unreachable.
343 }
344
internal_sleep(unsigned int seconds)345 unsigned int internal_sleep(unsigned int seconds) {
346 struct timespec ts;
347 ts.tv_sec = 1;
348 ts.tv_nsec = 0;
349 int res = internal_syscall(SYSCALL(nanosleep), &ts, &ts);
350 if (res) return ts.tv_sec;
351 return 0;
352 }
353
internal_execve(const char * filename,char * const argv[],char * const envp[])354 uptr internal_execve(const char *filename, char *const argv[],
355 char *const envp[]) {
356 return internal_syscall(SYSCALL(execve), (uptr)filename, (uptr)argv,
357 (uptr)envp);
358 }
359
360 // ----------------- sanitizer_common.h
FileExists(const char * filename)361 bool FileExists(const char *filename) {
362 struct stat st;
363 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
364 if (internal_syscall(SYSCALL(newfstatat), AT_FDCWD, filename, &st, 0))
365 #else
366 if (internal_stat(filename, &st))
367 #endif
368 return false;
369 // Sanity check: filename is a regular file.
370 return S_ISREG(st.st_mode);
371 }
372
GetTid()373 uptr GetTid() {
374 #if SANITIZER_FREEBSD
375 return (uptr)pthread_self();
376 #else
377 return internal_syscall(SYSCALL(gettid));
378 #endif
379 }
380
NanoTime()381 u64 NanoTime() {
382 #if SANITIZER_FREEBSD
383 timeval tv;
384 #else
385 kernel_timeval tv;
386 #endif
387 internal_memset(&tv, 0, sizeof(tv));
388 internal_syscall(SYSCALL(gettimeofday), (uptr)&tv, 0);
389 return (u64)tv.tv_sec * 1000*1000*1000 + tv.tv_usec * 1000;
390 }
391
392 // Like getenv, but reads env directly from /proc (on Linux) or parses the
393 // 'environ' array (on FreeBSD) and does not use libc. This function should be
394 // called first inside __asan_init.
GetEnv(const char * name)395 const char *GetEnv(const char *name) {
396 #if SANITIZER_FREEBSD
397 if (::environ != 0) {
398 uptr NameLen = internal_strlen(name);
399 for (char **Env = ::environ; *Env != 0; Env++) {
400 if (internal_strncmp(*Env, name, NameLen) == 0 && (*Env)[NameLen] == '=')
401 return (*Env) + NameLen + 1;
402 }
403 }
404 return 0; // Not found.
405 #elif SANITIZER_LINUX
406 static char *environ;
407 static uptr len;
408 static bool inited;
409 if (!inited) {
410 inited = true;
411 uptr environ_size;
412 if (!ReadFileToBuffer("/proc/self/environ", &environ, &environ_size, &len))
413 environ = nullptr;
414 }
415 if (!environ || len == 0) return nullptr;
416 uptr namelen = internal_strlen(name);
417 const char *p = environ;
418 while (*p != '\0') { // will happen at the \0\0 that terminates the buffer
419 // proc file has the format NAME=value\0NAME=value\0NAME=value\0...
420 const char* endp =
421 (char*)internal_memchr(p, '\0', len - (p - environ));
422 if (!endp) // this entry isn't NUL terminated
423 return nullptr;
424 else if (!internal_memcmp(p, name, namelen) && p[namelen] == '=') // Match.
425 return p + namelen + 1; // point after =
426 p = endp + 1;
427 }
428 return nullptr; // Not found.
429 #else
430 #error "Unsupported platform"
431 #endif
432 }
433
434 #if !SANITIZER_FREEBSD
435 extern "C" {
436 SANITIZER_WEAK_ATTRIBUTE extern void *__libc_stack_end;
437 }
438 #endif
439
440 #if !SANITIZER_GO && !SANITIZER_FREEBSD
ReadNullSepFileToArray(const char * path,char *** arr,int arr_size)441 static void ReadNullSepFileToArray(const char *path, char ***arr,
442 int arr_size) {
443 char *buff;
444 uptr buff_size;
445 uptr buff_len;
446 *arr = (char **)MmapOrDie(arr_size * sizeof(char *), "NullSepFileArray");
447 if (!ReadFileToBuffer(path, &buff, &buff_size, &buff_len, 1024 * 1024)) {
448 (*arr)[0] = nullptr;
449 return;
450 }
451 (*arr)[0] = buff;
452 int count, i;
453 for (count = 1, i = 1; ; i++) {
454 if (buff[i] == 0) {
455 if (buff[i+1] == 0) break;
456 (*arr)[count] = &buff[i+1];
457 CHECK_LE(count, arr_size - 1); // FIXME: make this more flexible.
458 count++;
459 }
460 }
461 (*arr)[count] = nullptr;
462 }
463 #endif
464
GetArgsAndEnv(char *** argv,char *** envp)465 static void GetArgsAndEnv(char ***argv, char ***envp) {
466 #if !SANITIZER_FREEBSD
467 #if !SANITIZER_GO
468 if (&__libc_stack_end) {
469 #endif
470 uptr* stack_end = (uptr*)__libc_stack_end;
471 int argc = *stack_end;
472 *argv = (char**)(stack_end + 1);
473 *envp = (char**)(stack_end + argc + 2);
474 #if !SANITIZER_GO
475 } else {
476 static const int kMaxArgv = 2000, kMaxEnvp = 2000;
477 ReadNullSepFileToArray("/proc/self/cmdline", argv, kMaxArgv);
478 ReadNullSepFileToArray("/proc/self/environ", envp, kMaxEnvp);
479 }
480 #endif
481 #else
482 // On FreeBSD, retrieving the argument and environment arrays is done via the
483 // kern.ps_strings sysctl, which returns a pointer to a structure containing
484 // this information. See also <sys/exec.h>.
485 ps_strings *pss;
486 size_t sz = sizeof(pss);
487 if (sysctlbyname("kern.ps_strings", &pss, &sz, NULL, 0) == -1) {
488 Printf("sysctl kern.ps_strings failed\n");
489 Die();
490 }
491 *argv = pss->ps_argvstr;
492 *envp = pss->ps_envstr;
493 #endif
494 }
495
GetArgv()496 char **GetArgv() {
497 char **argv, **envp;
498 GetArgsAndEnv(&argv, &envp);
499 return argv;
500 }
501
ReExec()502 void ReExec() {
503 char **argv, **envp;
504 GetArgsAndEnv(&argv, &envp);
505 uptr rv = internal_execve("/proc/self/exe", argv, envp);
506 int rverrno;
507 CHECK_EQ(internal_iserror(rv, &rverrno), true);
508 Printf("execve failed, errno %d\n", rverrno);
509 Die();
510 }
511
512 enum MutexState {
513 MtxUnlocked = 0,
514 MtxLocked = 1,
515 MtxSleeping = 2
516 };
517
BlockingMutex()518 BlockingMutex::BlockingMutex() {
519 internal_memset(this, 0, sizeof(*this));
520 }
521
Lock()522 void BlockingMutex::Lock() {
523 CHECK_EQ(owner_, 0);
524 atomic_uint32_t *m = reinterpret_cast<atomic_uint32_t *>(&opaque_storage_);
525 if (atomic_exchange(m, MtxLocked, memory_order_acquire) == MtxUnlocked)
526 return;
527 while (atomic_exchange(m, MtxSleeping, memory_order_acquire) != MtxUnlocked) {
528 #if SANITIZER_FREEBSD
529 _umtx_op(m, UMTX_OP_WAIT_UINT, MtxSleeping, 0, 0);
530 #else
531 internal_syscall(SYSCALL(futex), (uptr)m, FUTEX_WAIT, MtxSleeping, 0, 0, 0);
532 #endif
533 }
534 }
535
Unlock()536 void BlockingMutex::Unlock() {
537 atomic_uint32_t *m = reinterpret_cast<atomic_uint32_t *>(&opaque_storage_);
538 u32 v = atomic_exchange(m, MtxUnlocked, memory_order_relaxed);
539 CHECK_NE(v, MtxUnlocked);
540 if (v == MtxSleeping) {
541 #if SANITIZER_FREEBSD
542 _umtx_op(m, UMTX_OP_WAKE, 1, 0, 0);
543 #else
544 internal_syscall(SYSCALL(futex), (uptr)m, FUTEX_WAKE, 1, 0, 0, 0);
545 #endif
546 }
547 }
548
CheckLocked()549 void BlockingMutex::CheckLocked() {
550 atomic_uint32_t *m = reinterpret_cast<atomic_uint32_t *>(&opaque_storage_);
551 CHECK_NE(MtxUnlocked, atomic_load(m, memory_order_relaxed));
552 }
553
554 // ----------------- sanitizer_linux.h
555 // The actual size of this structure is specified by d_reclen.
556 // Note that getdents64 uses a different structure format. We only provide the
557 // 32-bit syscall here.
558 struct linux_dirent {
559 #if SANITIZER_X32 || defined(__aarch64__)
560 u64 d_ino;
561 u64 d_off;
562 #else
563 unsigned long d_ino;
564 unsigned long d_off;
565 #endif
566 unsigned short d_reclen;
567 #ifdef __aarch64__
568 unsigned char d_type;
569 #endif
570 char d_name[256];
571 };
572
573 // Syscall wrappers.
internal_ptrace(int request,int pid,void * addr,void * data)574 uptr internal_ptrace(int request, int pid, void *addr, void *data) {
575 return internal_syscall(SYSCALL(ptrace), request, pid, (uptr)addr,
576 (uptr)data);
577 }
578
internal_waitpid(int pid,int * status,int options)579 uptr internal_waitpid(int pid, int *status, int options) {
580 return internal_syscall(SYSCALL(wait4), pid, (uptr)status, options,
581 0 /* rusage */);
582 }
583
internal_getpid()584 uptr internal_getpid() {
585 return internal_syscall(SYSCALL(getpid));
586 }
587
internal_getppid()588 uptr internal_getppid() {
589 return internal_syscall(SYSCALL(getppid));
590 }
591
internal_getdents(fd_t fd,struct linux_dirent * dirp,unsigned int count)592 uptr internal_getdents(fd_t fd, struct linux_dirent *dirp, unsigned int count) {
593 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
594 return internal_syscall(SYSCALL(getdents64), fd, (uptr)dirp, count);
595 #else
596 return internal_syscall(SYSCALL(getdents), fd, (uptr)dirp, count);
597 #endif
598 }
599
internal_lseek(fd_t fd,OFF_T offset,int whence)600 uptr internal_lseek(fd_t fd, OFF_T offset, int whence) {
601 return internal_syscall(SYSCALL(lseek), fd, offset, whence);
602 }
603
604 #if SANITIZER_LINUX
internal_prctl(int option,uptr arg2,uptr arg3,uptr arg4,uptr arg5)605 uptr internal_prctl(int option, uptr arg2, uptr arg3, uptr arg4, uptr arg5) {
606 return internal_syscall(SYSCALL(prctl), option, arg2, arg3, arg4, arg5);
607 }
608 #endif
609
internal_sigaltstack(const struct sigaltstack * ss,struct sigaltstack * oss)610 uptr internal_sigaltstack(const struct sigaltstack *ss,
611 struct sigaltstack *oss) {
612 return internal_syscall(SYSCALL(sigaltstack), (uptr)ss, (uptr)oss);
613 }
614
internal_fork()615 int internal_fork() {
616 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
617 return internal_syscall(SYSCALL(clone), SIGCHLD, 0);
618 #else
619 return internal_syscall(SYSCALL(fork));
620 #endif
621 }
622
623 #if SANITIZER_LINUX
624 #define SA_RESTORER 0x04000000
625 // Doesn't set sa_restorer if the caller did not set it, so use with caution
626 //(see below).
internal_sigaction_norestorer(int signum,const void * act,void * oldact)627 int internal_sigaction_norestorer(int signum, const void *act, void *oldact) {
628 __sanitizer_kernel_sigaction_t k_act, k_oldact;
629 internal_memset(&k_act, 0, sizeof(__sanitizer_kernel_sigaction_t));
630 internal_memset(&k_oldact, 0, sizeof(__sanitizer_kernel_sigaction_t));
631 const __sanitizer_sigaction *u_act = (const __sanitizer_sigaction *)act;
632 __sanitizer_sigaction *u_oldact = (__sanitizer_sigaction *)oldact;
633 if (u_act) {
634 k_act.handler = u_act->handler;
635 k_act.sigaction = u_act->sigaction;
636 internal_memcpy(&k_act.sa_mask, &u_act->sa_mask,
637 sizeof(__sanitizer_kernel_sigset_t));
638 // Without SA_RESTORER kernel ignores the calls (probably returns EINVAL).
639 k_act.sa_flags = u_act->sa_flags | SA_RESTORER;
640 // FIXME: most often sa_restorer is unset, however the kernel requires it
641 // to point to a valid signal restorer that calls the rt_sigreturn syscall.
642 // If sa_restorer passed to the kernel is NULL, the program may crash upon
643 // signal delivery or fail to unwind the stack in the signal handler.
644 // libc implementation of sigaction() passes its own restorer to
645 // rt_sigaction, so we need to do the same (we'll need to reimplement the
646 // restorers; for x86_64 the restorer address can be obtained from
647 // oldact->sa_restorer upon a call to sigaction(xxx, NULL, oldact).
648 #if !SANITIZER_ANDROID || !SANITIZER_MIPS32
649 k_act.sa_restorer = u_act->sa_restorer;
650 #endif
651 }
652
653 uptr result = internal_syscall(SYSCALL(rt_sigaction), (uptr)signum,
654 (uptr)(u_act ? &k_act : nullptr),
655 (uptr)(u_oldact ? &k_oldact : nullptr),
656 (uptr)sizeof(__sanitizer_kernel_sigset_t));
657
658 if ((result == 0) && u_oldact) {
659 u_oldact->handler = k_oldact.handler;
660 u_oldact->sigaction = k_oldact.sigaction;
661 internal_memcpy(&u_oldact->sa_mask, &k_oldact.sa_mask,
662 sizeof(__sanitizer_kernel_sigset_t));
663 u_oldact->sa_flags = k_oldact.sa_flags;
664 #if !SANITIZER_ANDROID || !SANITIZER_MIPS32
665 u_oldact->sa_restorer = k_oldact.sa_restorer;
666 #endif
667 }
668 return result;
669 }
670
671 // Invokes sigaction via a raw syscall with a restorer, but does not support
672 // all platforms yet.
673 // We disable for Go simply because we have not yet added to buildgo.sh.
674 #if defined(__x86_64__) && !SANITIZER_GO
internal_sigaction_syscall(int signum,const void * act,void * oldact)675 int internal_sigaction_syscall(int signum, const void *act, void *oldact) {
676 if (act == nullptr)
677 return internal_sigaction_norestorer(signum, act, oldact);
678 __sanitizer_sigaction u_adjust;
679 internal_memcpy(&u_adjust, act, sizeof(u_adjust));
680 #if !SANITIZER_ANDROID || !SANITIZER_MIPS32
681 if (u_adjust.sa_restorer == nullptr) {
682 u_adjust.sa_restorer = internal_sigreturn;
683 }
684 #endif
685 return internal_sigaction_norestorer(signum, (const void *)&u_adjust,
686 oldact);
687 }
688 #endif // defined(__x86_64__) && !SANITIZER_GO
689 #endif // SANITIZER_LINUX
690
internal_sigprocmask(int how,__sanitizer_sigset_t * set,__sanitizer_sigset_t * oldset)691 uptr internal_sigprocmask(int how, __sanitizer_sigset_t *set,
692 __sanitizer_sigset_t *oldset) {
693 #if SANITIZER_FREEBSD
694 return internal_syscall(SYSCALL(sigprocmask), how, set, oldset);
695 #else
696 __sanitizer_kernel_sigset_t *k_set = (__sanitizer_kernel_sigset_t *)set;
697 __sanitizer_kernel_sigset_t *k_oldset = (__sanitizer_kernel_sigset_t *)oldset;
698 return internal_syscall(SYSCALL(rt_sigprocmask), (uptr)how,
699 (uptr)&k_set->sig[0], (uptr)&k_oldset->sig[0],
700 sizeof(__sanitizer_kernel_sigset_t));
701 #endif
702 }
703
internal_sigfillset(__sanitizer_sigset_t * set)704 void internal_sigfillset(__sanitizer_sigset_t *set) {
705 internal_memset(set, 0xff, sizeof(*set));
706 }
707
internal_sigemptyset(__sanitizer_sigset_t * set)708 void internal_sigemptyset(__sanitizer_sigset_t *set) {
709 internal_memset(set, 0, sizeof(*set));
710 }
711
712 #if SANITIZER_LINUX
internal_sigdelset(__sanitizer_sigset_t * set,int signum)713 void internal_sigdelset(__sanitizer_sigset_t *set, int signum) {
714 signum -= 1;
715 CHECK_GE(signum, 0);
716 CHECK_LT(signum, sizeof(*set) * 8);
717 __sanitizer_kernel_sigset_t *k_set = (__sanitizer_kernel_sigset_t *)set;
718 const uptr idx = signum / (sizeof(k_set->sig[0]) * 8);
719 const uptr bit = signum % (sizeof(k_set->sig[0]) * 8);
720 k_set->sig[idx] &= ~(1 << bit);
721 }
722
internal_sigismember(__sanitizer_sigset_t * set,int signum)723 bool internal_sigismember(__sanitizer_sigset_t *set, int signum) {
724 signum -= 1;
725 CHECK_GE(signum, 0);
726 CHECK_LT(signum, sizeof(*set) * 8);
727 __sanitizer_kernel_sigset_t *k_set = (__sanitizer_kernel_sigset_t *)set;
728 const uptr idx = signum / (sizeof(k_set->sig[0]) * 8);
729 const uptr bit = signum % (sizeof(k_set->sig[0]) * 8);
730 return k_set->sig[idx] & (1 << bit);
731 }
732 #endif // SANITIZER_LINUX
733
734 // ThreadLister implementation.
ThreadLister(int pid)735 ThreadLister::ThreadLister(int pid)
736 : pid_(pid),
737 descriptor_(-1),
738 buffer_(4096),
739 error_(true),
740 entry_((struct linux_dirent *)buffer_.data()),
741 bytes_read_(0) {
742 char task_directory_path[80];
743 internal_snprintf(task_directory_path, sizeof(task_directory_path),
744 "/proc/%d/task/", pid);
745 uptr openrv = internal_open(task_directory_path, O_RDONLY | O_DIRECTORY);
746 if (internal_iserror(openrv)) {
747 error_ = true;
748 Report("Can't open /proc/%d/task for reading.\n", pid);
749 } else {
750 error_ = false;
751 descriptor_ = openrv;
752 }
753 }
754
GetNextTID()755 int ThreadLister::GetNextTID() {
756 int tid = -1;
757 do {
758 if (error_)
759 return -1;
760 if ((char *)entry_ >= &buffer_[bytes_read_] && !GetDirectoryEntries())
761 return -1;
762 if (entry_->d_ino != 0 && entry_->d_name[0] >= '0' &&
763 entry_->d_name[0] <= '9') {
764 // Found a valid tid.
765 tid = (int)internal_atoll(entry_->d_name);
766 }
767 entry_ = (struct linux_dirent *)(((char *)entry_) + entry_->d_reclen);
768 } while (tid < 0);
769 return tid;
770 }
771
Reset()772 void ThreadLister::Reset() {
773 if (error_ || descriptor_ < 0)
774 return;
775 internal_lseek(descriptor_, 0, SEEK_SET);
776 }
777
~ThreadLister()778 ThreadLister::~ThreadLister() {
779 if (descriptor_ >= 0)
780 internal_close(descriptor_);
781 }
782
error()783 bool ThreadLister::error() { return error_; }
784
GetDirectoryEntries()785 bool ThreadLister::GetDirectoryEntries() {
786 CHECK_GE(descriptor_, 0);
787 CHECK_NE(error_, true);
788 bytes_read_ = internal_getdents(descriptor_,
789 (struct linux_dirent *)buffer_.data(),
790 buffer_.size());
791 if (internal_iserror(bytes_read_)) {
792 Report("Can't read directory entries from /proc/%d/task.\n", pid_);
793 error_ = true;
794 return false;
795 } else if (bytes_read_ == 0) {
796 return false;
797 }
798 entry_ = (struct linux_dirent *)buffer_.data();
799 return true;
800 }
801
GetPageSize()802 uptr GetPageSize() {
803 // Android post-M sysconf(_SC_PAGESIZE) crashes if called from .preinit_array.
804 #if SANITIZER_ANDROID
805 return 4096;
806 #elif SANITIZER_LINUX && (defined(__x86_64__) || defined(__i386__))
807 return EXEC_PAGESIZE;
808 #else
809 return sysconf(_SC_PAGESIZE); // EXEC_PAGESIZE may not be trustworthy.
810 #endif
811 }
812
ReadBinaryName(char * buf,uptr buf_len)813 uptr ReadBinaryName(/*out*/char *buf, uptr buf_len) {
814 #if SANITIZER_FREEBSD
815 const int Mib[] = { CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1 };
816 const char *default_module_name = "kern.proc.pathname";
817 size_t Size = buf_len;
818 bool IsErr = (sysctl(Mib, ARRAY_SIZE(Mib), buf, &Size, NULL, 0) != 0);
819 int readlink_error = IsErr ? errno : 0;
820 uptr module_name_len = Size;
821 #else
822 const char *default_module_name = "/proc/self/exe";
823 uptr module_name_len = internal_readlink(
824 default_module_name, buf, buf_len);
825 int readlink_error;
826 bool IsErr = internal_iserror(module_name_len, &readlink_error);
827 #endif
828 if (IsErr) {
829 // We can't read binary name for some reason, assume it's unknown.
830 Report("WARNING: reading executable name failed with errno %d, "
831 "some stack frames may not be symbolized\n", readlink_error);
832 module_name_len = internal_snprintf(buf, buf_len, "%s",
833 default_module_name);
834 CHECK_LT(module_name_len, buf_len);
835 }
836 return module_name_len;
837 }
838
ReadLongProcessName(char * buf,uptr buf_len)839 uptr ReadLongProcessName(/*out*/ char *buf, uptr buf_len) {
840 #if SANITIZER_LINUX
841 char *tmpbuf;
842 uptr tmpsize;
843 uptr tmplen;
844 if (ReadFileToBuffer("/proc/self/cmdline", &tmpbuf, &tmpsize, &tmplen,
845 1024 * 1024)) {
846 internal_strncpy(buf, tmpbuf, buf_len);
847 UnmapOrDie(tmpbuf, tmpsize);
848 return internal_strlen(buf);
849 }
850 #endif
851 return ReadBinaryName(buf, buf_len);
852 }
853
854 // Match full names of the form /path/to/base_name{-,.}*
LibraryNameIs(const char * full_name,const char * base_name)855 bool LibraryNameIs(const char *full_name, const char *base_name) {
856 const char *name = full_name;
857 // Strip path.
858 while (*name != '\0') name++;
859 while (name > full_name && *name != '/') name--;
860 if (*name == '/') name++;
861 uptr base_name_length = internal_strlen(base_name);
862 if (internal_strncmp(name, base_name, base_name_length)) return false;
863 return (name[base_name_length] == '-' || name[base_name_length] == '.');
864 }
865
866 #if !SANITIZER_ANDROID
867 // Call cb for each region mapped by map.
ForEachMappedRegion(link_map * map,void (* cb)(const void *,uptr))868 void ForEachMappedRegion(link_map *map, void (*cb)(const void *, uptr)) {
869 CHECK_NE(map, nullptr);
870 #if !SANITIZER_FREEBSD
871 typedef ElfW(Phdr) Elf_Phdr;
872 typedef ElfW(Ehdr) Elf_Ehdr;
873 #endif // !SANITIZER_FREEBSD
874 char *base = (char *)map->l_addr;
875 Elf_Ehdr *ehdr = (Elf_Ehdr *)base;
876 char *phdrs = base + ehdr->e_phoff;
877 char *phdrs_end = phdrs + ehdr->e_phnum * ehdr->e_phentsize;
878
879 // Find the segment with the minimum base so we can "relocate" the p_vaddr
880 // fields. Typically ET_DYN objects (DSOs) have base of zero and ET_EXEC
881 // objects have a non-zero base.
882 uptr preferred_base = (uptr)-1;
883 for (char *iter = phdrs; iter != phdrs_end; iter += ehdr->e_phentsize) {
884 Elf_Phdr *phdr = (Elf_Phdr *)iter;
885 if (phdr->p_type == PT_LOAD && preferred_base > (uptr)phdr->p_vaddr)
886 preferred_base = (uptr)phdr->p_vaddr;
887 }
888
889 // Compute the delta from the real base to get a relocation delta.
890 sptr delta = (uptr)base - preferred_base;
891 // Now we can figure out what the loader really mapped.
892 for (char *iter = phdrs; iter != phdrs_end; iter += ehdr->e_phentsize) {
893 Elf_Phdr *phdr = (Elf_Phdr *)iter;
894 if (phdr->p_type == PT_LOAD) {
895 uptr seg_start = phdr->p_vaddr + delta;
896 uptr seg_end = seg_start + phdr->p_memsz;
897 // None of these values are aligned. We consider the ragged edges of the
898 // load command as defined, since they are mapped from the file.
899 seg_start = RoundDownTo(seg_start, GetPageSizeCached());
900 seg_end = RoundUpTo(seg_end, GetPageSizeCached());
901 cb((void *)seg_start, seg_end - seg_start);
902 }
903 }
904 }
905 #endif
906
907 #if defined(__x86_64__) && SANITIZER_LINUX
908 // We cannot use glibc's clone wrapper, because it messes with the child
909 // task's TLS. It writes the PID and TID of the child task to its thread
910 // descriptor, but in our case the child task shares the thread descriptor with
911 // the parent (because we don't know how to allocate a new thread
912 // descriptor to keep glibc happy). So the stock version of clone(), when
913 // 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)914 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
915 int *parent_tidptr, void *newtls, int *child_tidptr) {
916 long long res;
917 if (!fn || !child_stack)
918 return -EINVAL;
919 CHECK_EQ(0, (uptr)child_stack % 16);
920 child_stack = (char *)child_stack - 2 * sizeof(unsigned long long);
921 ((unsigned long long *)child_stack)[0] = (uptr)fn;
922 ((unsigned long long *)child_stack)[1] = (uptr)arg;
923 register void *r8 __asm__("r8") = newtls;
924 register int *r10 __asm__("r10") = child_tidptr;
925 __asm__ __volatile__(
926 /* %rax = syscall(%rax = SYSCALL(clone),
927 * %rdi = flags,
928 * %rsi = child_stack,
929 * %rdx = parent_tidptr,
930 * %r8 = new_tls,
931 * %r10 = child_tidptr)
932 */
933 "syscall\n"
934
935 /* if (%rax != 0)
936 * return;
937 */
938 "testq %%rax,%%rax\n"
939 "jnz 1f\n"
940
941 /* In the child. Terminate unwind chain. */
942 // XXX: We should also terminate the CFI unwind chain
943 // here. Unfortunately clang 3.2 doesn't support the
944 // necessary CFI directives, so we skip that part.
945 "xorq %%rbp,%%rbp\n"
946
947 /* Call "fn(arg)". */
948 "popq %%rax\n"
949 "popq %%rdi\n"
950 "call *%%rax\n"
951
952 /* Call _exit(%rax). */
953 "movq %%rax,%%rdi\n"
954 "movq %2,%%rax\n"
955 "syscall\n"
956
957 /* Return to parent. */
958 "1:\n"
959 : "=a" (res)
960 : "a"(SYSCALL(clone)), "i"(SYSCALL(exit)),
961 "S"(child_stack),
962 "D"(flags),
963 "d"(parent_tidptr),
964 "r"(r8),
965 "r"(r10)
966 : "rsp", "memory", "r11", "rcx");
967 return res;
968 }
969 #elif defined(__mips__)
internal_clone(int (* fn)(void *),void * child_stack,int flags,void * arg,int * parent_tidptr,void * newtls,int * child_tidptr)970 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
971 int *parent_tidptr, void *newtls, int *child_tidptr) {
972 long long res;
973 if (!fn || !child_stack)
974 return -EINVAL;
975 CHECK_EQ(0, (uptr)child_stack % 16);
976 child_stack = (char *)child_stack - 2 * sizeof(unsigned long long);
977 ((unsigned long long *)child_stack)[0] = (uptr)fn;
978 ((unsigned long long *)child_stack)[1] = (uptr)arg;
979 register void *a3 __asm__("$7") = newtls;
980 register int *a4 __asm__("$8") = child_tidptr;
981 // We don't have proper CFI directives here because it requires alot of code
982 // for very marginal benefits.
983 __asm__ __volatile__(
984 /* $v0 = syscall($v0 = __NR_clone,
985 * $a0 = flags,
986 * $a1 = child_stack,
987 * $a2 = parent_tidptr,
988 * $a3 = new_tls,
989 * $a4 = child_tidptr)
990 */
991 ".cprestore 16;\n"
992 "move $4,%1;\n"
993 "move $5,%2;\n"
994 "move $6,%3;\n"
995 "move $7,%4;\n"
996 /* Store the fifth argument on stack
997 * if we are using 32-bit abi.
998 */
999 #if SANITIZER_WORDSIZE == 32
1000 "lw %5,16($29);\n"
1001 #else
1002 "move $8,%5;\n"
1003 #endif
1004 "li $2,%6;\n"
1005 "syscall;\n"
1006
1007 /* if ($v0 != 0)
1008 * return;
1009 */
1010 "bnez $2,1f;\n"
1011
1012 /* Call "fn(arg)". */
1013 #if SANITIZER_WORDSIZE == 32
1014 #ifdef __BIG_ENDIAN__
1015 "lw $25,4($29);\n"
1016 "lw $4,12($29);\n"
1017 #else
1018 "lw $25,0($29);\n"
1019 "lw $4,8($29);\n"
1020 #endif
1021 #else
1022 "ld $25,0($29);\n"
1023 "ld $4,8($29);\n"
1024 #endif
1025 "jal $25;\n"
1026
1027 /* Call _exit($v0). */
1028 "move $4,$2;\n"
1029 "li $2,%7;\n"
1030 "syscall;\n"
1031
1032 /* Return to parent. */
1033 "1:\n"
1034 : "=r" (res)
1035 : "r"(flags),
1036 "r"(child_stack),
1037 "r"(parent_tidptr),
1038 "r"(a3),
1039 "r"(a4),
1040 "i"(__NR_clone),
1041 "i"(__NR_exit)
1042 : "memory", "$29" );
1043 return res;
1044 }
1045 #elif defined(__aarch64__)
internal_clone(int (* fn)(void *),void * child_stack,int flags,void * arg,int * parent_tidptr,void * newtls,int * child_tidptr)1046 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
1047 int *parent_tidptr, void *newtls, int *child_tidptr) {
1048 long long res;
1049 if (!fn || !child_stack)
1050 return -EINVAL;
1051 CHECK_EQ(0, (uptr)child_stack % 16);
1052 child_stack = (char *)child_stack - 2 * sizeof(unsigned long long);
1053 ((unsigned long long *)child_stack)[0] = (uptr)fn;
1054 ((unsigned long long *)child_stack)[1] = (uptr)arg;
1055
1056 register int (*__fn)(void *) __asm__("x0") = fn;
1057 register void *__stack __asm__("x1") = child_stack;
1058 register int __flags __asm__("x2") = flags;
1059 register void *__arg __asm__("x3") = arg;
1060 register int *__ptid __asm__("x4") = parent_tidptr;
1061 register void *__tls __asm__("x5") = newtls;
1062 register int *__ctid __asm__("x6") = child_tidptr;
1063
1064 __asm__ __volatile__(
1065 "mov x0,x2\n" /* flags */
1066 "mov x2,x4\n" /* ptid */
1067 "mov x3,x5\n" /* tls */
1068 "mov x4,x6\n" /* ctid */
1069 "mov x8,%9\n" /* clone */
1070
1071 "svc 0x0\n"
1072
1073 /* if (%r0 != 0)
1074 * return %r0;
1075 */
1076 "cmp x0, #0\n"
1077 "bne 1f\n"
1078
1079 /* In the child, now. Call "fn(arg)". */
1080 "ldp x1, x0, [sp], #16\n"
1081 "blr x1\n"
1082
1083 /* Call _exit(%r0). */
1084 "mov x8, %10\n"
1085 "svc 0x0\n"
1086 "1:\n"
1087
1088 : "=r" (res)
1089 : "i"(-EINVAL),
1090 "r"(__fn), "r"(__stack), "r"(__flags), "r"(__arg),
1091 "r"(__ptid), "r"(__tls), "r"(__ctid),
1092 "i"(__NR_clone), "i"(__NR_exit)
1093 : "x30", "memory");
1094 return res;
1095 }
1096 #elif defined(__powerpc64__)
internal_clone(int (* fn)(void *),void * child_stack,int flags,void * arg,int * parent_tidptr,void * newtls,int * child_tidptr)1097 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
1098 int *parent_tidptr, void *newtls, int *child_tidptr) {
1099 long long res;
1100 /* Stack frame offsets. */
1101 #if _CALL_ELF != 2
1102 #define FRAME_MIN_SIZE 112
1103 #define FRAME_TOC_SAVE 40
1104 #else
1105 #define FRAME_MIN_SIZE 32
1106 #define FRAME_TOC_SAVE 24
1107 #endif
1108 if (!fn || !child_stack)
1109 return -EINVAL;
1110 CHECK_EQ(0, (uptr)child_stack % 16);
1111 child_stack = (char *)child_stack - 2 * sizeof(unsigned long long);
1112 ((unsigned long long *)child_stack)[0] = (uptr)fn;
1113 ((unsigned long long *)child_stack)[1] = (uptr)arg;
1114
1115 register int (*__fn)(void *) __asm__("r3") = fn;
1116 register void *__cstack __asm__("r4") = child_stack;
1117 register int __flags __asm__("r5") = flags;
1118 register void * __arg __asm__("r6") = arg;
1119 register int * __ptidptr __asm__("r7") = parent_tidptr;
1120 register void * __newtls __asm__("r8") = newtls;
1121 register int * __ctidptr __asm__("r9") = child_tidptr;
1122
1123 __asm__ __volatile__(
1124 /* fn, arg, child_stack are saved acrVoss the syscall */
1125 "mr 28, %5\n\t"
1126 "mr 29, %6\n\t"
1127 "mr 27, %8\n\t"
1128
1129 /* syscall
1130 r3 == flags
1131 r4 == child_stack
1132 r5 == parent_tidptr
1133 r6 == newtls
1134 r7 == child_tidptr */
1135 "mr 3, %7\n\t"
1136 "mr 5, %9\n\t"
1137 "mr 6, %10\n\t"
1138 "mr 7, %11\n\t"
1139 "li 0, %3\n\t"
1140 "sc\n\t"
1141
1142 /* Test if syscall was successful */
1143 "cmpdi cr1, 3, 0\n\t"
1144 "crandc cr1*4+eq, cr1*4+eq, cr0*4+so\n\t"
1145 "bne- cr1, 1f\n\t"
1146
1147 /* Do the function call */
1148 "std 2, %13(1)\n\t"
1149 #if _CALL_ELF != 2
1150 "ld 0, 0(28)\n\t"
1151 "ld 2, 8(28)\n\t"
1152 "mtctr 0\n\t"
1153 #else
1154 "mr 12, 28\n\t"
1155 "mtctr 12\n\t"
1156 #endif
1157 "mr 3, 27\n\t"
1158 "bctrl\n\t"
1159 "ld 2, %13(1)\n\t"
1160
1161 /* Call _exit(r3) */
1162 "li 0, %4\n\t"
1163 "sc\n\t"
1164
1165 /* Return to parent */
1166 "1:\n\t"
1167 "mr %0, 3\n\t"
1168 : "=r" (res)
1169 : "0" (-1), "i" (EINVAL),
1170 "i" (__NR_clone), "i" (__NR_exit),
1171 "r" (__fn), "r" (__cstack), "r" (__flags),
1172 "r" (__arg), "r" (__ptidptr), "r" (__newtls),
1173 "r" (__ctidptr), "i" (FRAME_MIN_SIZE), "i" (FRAME_TOC_SAVE)
1174 : "cr0", "cr1", "memory", "ctr",
1175 "r0", "r29", "r27", "r28");
1176 return res;
1177 }
1178 #endif // defined(__x86_64__) && SANITIZER_LINUX
1179
1180 #if SANITIZER_ANDROID
1181 #if __ANDROID_API__ < 21
1182 extern "C" __attribute__((weak)) int dl_iterate_phdr(
1183 int (*)(struct dl_phdr_info *, size_t, void *), void *);
1184 #endif
1185
dl_iterate_phdr_test_cb(struct dl_phdr_info * info,size_t size,void * data)1186 static int dl_iterate_phdr_test_cb(struct dl_phdr_info *info, size_t size,
1187 void *data) {
1188 // Any name starting with "lib" indicates a bug in L where library base names
1189 // are returned instead of paths.
1190 if (info->dlpi_name && info->dlpi_name[0] == 'l' &&
1191 info->dlpi_name[1] == 'i' && info->dlpi_name[2] == 'b') {
1192 *(bool *)data = true;
1193 return 1;
1194 }
1195 return 0;
1196 }
1197
1198 static atomic_uint32_t android_api_level;
1199
AndroidDetectApiLevel()1200 static AndroidApiLevel AndroidDetectApiLevel() {
1201 if (!&dl_iterate_phdr)
1202 return ANDROID_KITKAT; // K or lower
1203 bool base_name_seen = false;
1204 dl_iterate_phdr(dl_iterate_phdr_test_cb, &base_name_seen);
1205 if (base_name_seen)
1206 return ANDROID_LOLLIPOP_MR1; // L MR1
1207 return ANDROID_POST_LOLLIPOP; // post-L
1208 // Plain L (API level 21) is completely broken wrt ASan and not very
1209 // interesting to detect.
1210 }
1211
AndroidGetApiLevel()1212 AndroidApiLevel AndroidGetApiLevel() {
1213 AndroidApiLevel level =
1214 (AndroidApiLevel)atomic_load(&android_api_level, memory_order_relaxed);
1215 if (level) return level;
1216 level = AndroidDetectApiLevel();
1217 atomic_store(&android_api_level, level, memory_order_relaxed);
1218 return level;
1219 }
1220
1221 #endif
1222
IsHandledDeadlySignal(int signum)1223 bool IsHandledDeadlySignal(int signum) {
1224 if (common_flags()->handle_abort && signum == SIGABRT)
1225 return true;
1226 if (common_flags()->handle_sigill && signum == SIGILL)
1227 return true;
1228 if (common_flags()->handle_sigfpe && signum == SIGFPE)
1229 return true;
1230 return (signum == SIGSEGV || signum == SIGBUS) && common_flags()->handle_segv;
1231 }
1232
1233 #ifndef SANITIZER_GO
internal_start_thread(void (* func)(void * arg),void * arg)1234 void *internal_start_thread(void(*func)(void *arg), void *arg) {
1235 // Start the thread with signals blocked, otherwise it can steal user signals.
1236 __sanitizer_sigset_t set, old;
1237 internal_sigfillset(&set);
1238 #if SANITIZER_LINUX && !SANITIZER_ANDROID
1239 // Glibc uses SIGSETXID signal during setuid call. If this signal is blocked
1240 // on any thread, setuid call hangs (see test/tsan/setuid.c).
1241 internal_sigdelset(&set, 33);
1242 #endif
1243 internal_sigprocmask(SIG_SETMASK, &set, &old);
1244 void *th;
1245 real_pthread_create(&th, nullptr, (void*(*)(void *arg))func, arg);
1246 internal_sigprocmask(SIG_SETMASK, &old, nullptr);
1247 return th;
1248 }
1249
internal_join_thread(void * th)1250 void internal_join_thread(void *th) {
1251 real_pthread_join(th, nullptr);
1252 }
1253 #else
internal_start_thread(void (* func)(void *),void * arg)1254 void *internal_start_thread(void (*func)(void *), void *arg) { return 0; }
1255
internal_join_thread(void * th)1256 void internal_join_thread(void *th) {}
1257 #endif
1258
1259 #if defined(__aarch64__)
1260 // Android headers in the older NDK releases miss this definition.
1261 struct __sanitizer_esr_context {
1262 struct _aarch64_ctx head;
1263 uint64_t esr;
1264 };
1265
Aarch64GetESR(ucontext_t * ucontext,u64 * esr)1266 static bool Aarch64GetESR(ucontext_t *ucontext, u64 *esr) {
1267 static const u32 kEsrMagic = 0x45535201;
1268 u8 *aux = ucontext->uc_mcontext.__reserved;
1269 while (true) {
1270 _aarch64_ctx *ctx = (_aarch64_ctx *)aux;
1271 if (ctx->size == 0) break;
1272 if (ctx->magic == kEsrMagic) {
1273 *esr = ((__sanitizer_esr_context *)ctx)->esr;
1274 return true;
1275 }
1276 aux += ctx->size;
1277 }
1278 return false;
1279 }
1280 #endif
1281
GetWriteFlag(void * context)1282 SignalContext::WriteFlag SignalContext::GetWriteFlag(void *context) {
1283 ucontext_t *ucontext = (ucontext_t *)context;
1284 #if defined(__x86_64__) || defined(__i386__)
1285 static const uptr PF_WRITE = 1U << 1;
1286 #if SANITIZER_FREEBSD
1287 uptr err = ucontext->uc_mcontext.mc_err;
1288 #else
1289 uptr err = ucontext->uc_mcontext.gregs[REG_ERR];
1290 #endif
1291 return err & PF_WRITE ? WRITE : READ;
1292 #elif defined(__arm__)
1293 static const uptr FSR_WRITE = 1U << 11;
1294 uptr fsr = ucontext->uc_mcontext.error_code;
1295 // FSR bits 5:0 describe the abort type, and are never 0 (or so it seems).
1296 // Zero FSR indicates an older kernel that does not pass this information to
1297 // the userspace.
1298 if (fsr == 0) return UNKNOWN;
1299 return fsr & FSR_WRITE ? WRITE : READ;
1300 #elif defined(__aarch64__)
1301 static const u64 ESR_ELx_WNR = 1U << 6;
1302 u64 esr;
1303 if (!Aarch64GetESR(ucontext, &esr)) return UNKNOWN;
1304 return esr & ESR_ELx_WNR ? WRITE : READ;
1305 #else
1306 (void)ucontext;
1307 return UNKNOWN; // FIXME: Implement.
1308 #endif
1309 }
1310
GetPcSpBp(void * context,uptr * pc,uptr * sp,uptr * bp)1311 void GetPcSpBp(void *context, uptr *pc, uptr *sp, uptr *bp) {
1312 #if defined(__arm__)
1313 ucontext_t *ucontext = (ucontext_t*)context;
1314 *pc = ucontext->uc_mcontext.arm_pc;
1315 *bp = ucontext->uc_mcontext.arm_fp;
1316 *sp = ucontext->uc_mcontext.arm_sp;
1317 #elif defined(__aarch64__)
1318 ucontext_t *ucontext = (ucontext_t*)context;
1319 *pc = ucontext->uc_mcontext.pc;
1320 *bp = ucontext->uc_mcontext.regs[29];
1321 *sp = ucontext->uc_mcontext.sp;
1322 #elif defined(__hppa__)
1323 ucontext_t *ucontext = (ucontext_t*)context;
1324 *pc = ucontext->uc_mcontext.sc_iaoq[0];
1325 /* GCC uses %r3 whenever a frame pointer is needed. */
1326 *bp = ucontext->uc_mcontext.sc_gr[3];
1327 *sp = ucontext->uc_mcontext.sc_gr[30];
1328 #elif defined(__x86_64__)
1329 # if SANITIZER_FREEBSD
1330 ucontext_t *ucontext = (ucontext_t*)context;
1331 *pc = ucontext->uc_mcontext.mc_rip;
1332 *bp = ucontext->uc_mcontext.mc_rbp;
1333 *sp = ucontext->uc_mcontext.mc_rsp;
1334 # else
1335 ucontext_t *ucontext = (ucontext_t*)context;
1336 *pc = ucontext->uc_mcontext.gregs[REG_RIP];
1337 *bp = ucontext->uc_mcontext.gregs[REG_RBP];
1338 *sp = ucontext->uc_mcontext.gregs[REG_RSP];
1339 # endif
1340 #elif defined(__i386__)
1341 # if SANITIZER_FREEBSD
1342 ucontext_t *ucontext = (ucontext_t*)context;
1343 *pc = ucontext->uc_mcontext.mc_eip;
1344 *bp = ucontext->uc_mcontext.mc_ebp;
1345 *sp = ucontext->uc_mcontext.mc_esp;
1346 # else
1347 ucontext_t *ucontext = (ucontext_t*)context;
1348 *pc = ucontext->uc_mcontext.gregs[REG_EIP];
1349 *bp = ucontext->uc_mcontext.gregs[REG_EBP];
1350 *sp = ucontext->uc_mcontext.gregs[REG_ESP];
1351 # endif
1352 #elif defined(__powerpc__) || defined(__powerpc64__)
1353 ucontext_t *ucontext = (ucontext_t*)context;
1354 *pc = ucontext->uc_mcontext.regs->nip;
1355 *sp = ucontext->uc_mcontext.regs->gpr[PT_R1];
1356 // The powerpc{,64}-linux ABIs do not specify r31 as the frame
1357 // pointer, but GCC always uses r31 when we need a frame pointer.
1358 *bp = ucontext->uc_mcontext.regs->gpr[PT_R31];
1359 #elif defined(__sparc__)
1360 ucontext_t *ucontext = (ucontext_t*)context;
1361 uptr *stk_ptr;
1362 # if defined (__arch64__)
1363 *pc = ucontext->uc_mcontext.mc_gregs[MC_PC];
1364 *sp = ucontext->uc_mcontext.mc_gregs[MC_O6];
1365 stk_ptr = (uptr *) (*sp + 2047);
1366 *bp = stk_ptr[15];
1367 # else
1368 *pc = ucontext->uc_mcontext.gregs[REG_PC];
1369 *sp = ucontext->uc_mcontext.gregs[REG_O6];
1370 stk_ptr = (uptr *) *sp;
1371 *bp = stk_ptr[15];
1372 # endif
1373 #elif defined(__mips__)
1374 ucontext_t *ucontext = (ucontext_t*)context;
1375 *pc = ucontext->uc_mcontext.pc;
1376 *bp = ucontext->uc_mcontext.gregs[30];
1377 *sp = ucontext->uc_mcontext.gregs[29];
1378 #elif defined(__s390__)
1379 ucontext_t *ucontext = (ucontext_t*)context;
1380 # if defined(__s390x__)
1381 *pc = ucontext->uc_mcontext.psw.addr;
1382 # else
1383 *pc = ucontext->uc_mcontext.psw.addr & 0x7fffffff;
1384 # endif
1385 *bp = ucontext->uc_mcontext.gregs[11];
1386 *sp = ucontext->uc_mcontext.gregs[15];
1387 #else
1388 # error "Unsupported arch"
1389 #endif
1390 }
1391
MaybeReexec()1392 void MaybeReexec() {
1393 // No need to re-exec on Linux.
1394 }
1395
1396 } // namespace __sanitizer
1397
1398 #endif // SANITIZER_FREEBSD || SANITIZER_LINUX
1399