1 //===-- sanitizer_linux.cc ------------------------------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file is shared between AddressSanitizer and ThreadSanitizer
11 // run-time libraries and implements linux-specific functions from
13 //===----------------------------------------------------------------------===//
15 #include "sanitizer_platform.h"
16 #if SANITIZER_FREEBSD || SANITIZER_LINUX
18 #include "sanitizer_allocator_internal.h"
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"
30 #if !SANITIZER_FREEBSD
31 #include <asm/param.h>
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.
39 #include <sys/types.h>
40 #define stat kernel_stat
48 #if !SANITIZER_ANDROID
54 #include <sys/ptrace.h>
55 #include <sys/resource.h>
57 #include <sys/syscall.h>
59 #include <sys/types.h>
63 #include <sys/sysctl.h>
64 #include <machine/atomic.h>
66 // <sys/umtx.h> must be included after <errno.h> and <sys/types.h> on
67 // FreeBSD 9.2 and 10.0.
70 extern char **environ; // provided by crt1
71 #endif // SANITIZER_FREEBSD
73 #if !SANITIZER_ANDROID
74 #include <sys/signal.h>
78 #include <android/log.h>
79 #include <sys/system_properties.h>
84 struct kernel_timeval {
89 // <linux/futex.h> is broken on some linux distributions.
90 const int FUTEX_WAIT = 0;
91 const int FUTEX_WAKE = 1;
92 #endif // SANITIZER_LINUX
94 // Are we using 32-bit or 64-bit Linux syscalls?
95 // x32 (which defines __x86_64__) has SANITIZER_WORDSIZE == 32
96 // but it still needs to use 64-bit syscalls.
97 #if SANITIZER_LINUX && (defined(__x86_64__) || SANITIZER_WORDSIZE == 64)
98 # define SANITIZER_LINUX_USES_64BIT_SYSCALLS 1
100 # define SANITIZER_LINUX_USES_64BIT_SYSCALLS 0
103 namespace __sanitizer {
105 #if SANITIZER_LINUX && defined(__x86_64__)
106 #include "sanitizer_syscall_linux_x86_64.inc"
108 #include "sanitizer_syscall_generic.inc"
111 // --------------- sanitizer_libc.h
112 uptr internal_mmap(void *addr, uptr length, int prot, int flags, int fd,
114 #if SANITIZER_FREEBSD || SANITIZER_LINUX_USES_64BIT_SYSCALLS
115 return internal_syscall(SYSCALL(mmap), (uptr)addr, length, prot, flags, fd,
118 // mmap2 specifies file offset in 4096-byte units.
119 CHECK(IsAligned(offset, 4096));
120 return internal_syscall(SYSCALL(mmap2), addr, length, prot, flags, fd,
125 uptr internal_munmap(void *addr, uptr length) {
126 return internal_syscall(SYSCALL(munmap), (uptr)addr, length);
129 uptr internal_close(fd_t fd) {
130 return internal_syscall(SYSCALL(close), fd);
133 uptr internal_open(const char *filename, int flags) {
134 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
135 return internal_syscall(SYSCALL(openat), AT_FDCWD, (uptr)filename, flags);
137 return internal_syscall(SYSCALL(open), (uptr)filename, flags);
141 uptr internal_open(const char *filename, int flags, u32 mode) {
142 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
143 return internal_syscall(SYSCALL(openat), AT_FDCWD, (uptr)filename, flags,
146 return internal_syscall(SYSCALL(open), (uptr)filename, flags, mode);
150 uptr OpenFile(const char *filename, bool write) {
151 return internal_open(filename,
152 write ? O_RDWR | O_CREAT /*| O_CLOEXEC*/ : O_RDONLY, 0660);
155 uptr internal_read(fd_t fd, void *buf, uptr count) {
157 HANDLE_EINTR(res, (sptr)internal_syscall(SYSCALL(read), fd, (uptr)buf,
162 uptr internal_write(fd_t fd, const void *buf, uptr count) {
164 HANDLE_EINTR(res, (sptr)internal_syscall(SYSCALL(write), fd, (uptr)buf,
169 uptr internal_ftruncate(fd_t fd, uptr size) {
171 HANDLE_EINTR(res, (sptr)internal_syscall(SYSCALL(ftruncate), fd, size));
175 #if !SANITIZER_LINUX_USES_64BIT_SYSCALLS && !SANITIZER_FREEBSD
176 static void stat64_to_stat(struct stat64 *in, struct stat *out) {
177 internal_memset(out, 0, sizeof(*out));
178 out->st_dev = in->st_dev;
179 out->st_ino = in->st_ino;
180 out->st_mode = in->st_mode;
181 out->st_nlink = in->st_nlink;
182 out->st_uid = in->st_uid;
183 out->st_gid = in->st_gid;
184 out->st_rdev = in->st_rdev;
185 out->st_size = in->st_size;
186 out->st_blksize = in->st_blksize;
187 out->st_blocks = in->st_blocks;
188 out->st_atime = in->st_atime;
189 out->st_mtime = in->st_mtime;
190 out->st_ctime = in->st_ctime;
191 out->st_ino = in->st_ino;
195 #if defined(__mips64)
196 static void kernel_stat_to_stat(struct kernel_stat *in, struct stat *out) {
197 internal_memset(out, 0, sizeof(*out));
198 out->st_dev = in->st_dev;
199 out->st_ino = in->st_ino;
200 out->st_mode = in->st_mode;
201 out->st_nlink = in->st_nlink;
202 out->st_uid = in->st_uid;
203 out->st_gid = in->st_gid;
204 out->st_rdev = in->st_rdev;
205 out->st_size = in->st_size;
206 out->st_blksize = in->st_blksize;
207 out->st_blocks = in->st_blocks;
208 out->st_atime = in->st_atime_nsec;
209 out->st_mtime = in->st_mtime_nsec;
210 out->st_ctime = in->st_ctime_nsec;
211 out->st_ino = in->st_ino;
215 uptr internal_stat(const char *path, void *buf) {
216 #if SANITIZER_FREEBSD
217 return internal_syscall(SYSCALL(stat), path, buf);
218 #elif SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
219 return internal_syscall(SYSCALL(newfstatat), AT_FDCWD, (uptr)path,
221 #elif SANITIZER_LINUX_USES_64BIT_SYSCALLS
222 # if defined(__mips64)
223 // For mips64, stat syscall fills buffer in the format of kernel_stat
224 struct kernel_stat kbuf;
225 int res = internal_syscall(SYSCALL(stat), path, &kbuf);
226 kernel_stat_to_stat(&kbuf, (struct stat *)buf);
229 return internal_syscall(SYSCALL(stat), (uptr)path, (uptr)buf);
233 int res = internal_syscall(SYSCALL(stat64), path, &buf64);
234 stat64_to_stat(&buf64, (struct stat *)buf);
239 uptr internal_lstat(const char *path, void *buf) {
240 #if SANITIZER_FREEBSD
241 return internal_syscall(SYSCALL(lstat), path, buf);
242 #elif SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
243 return internal_syscall(SYSCALL(newfstatat), AT_FDCWD, (uptr)path,
244 (uptr)buf, AT_SYMLINK_NOFOLLOW);
245 #elif SANITIZER_LINUX_USES_64BIT_SYSCALLS
246 return internal_syscall(SYSCALL(lstat), (uptr)path, (uptr)buf);
249 int res = internal_syscall(SYSCALL(lstat64), path, &buf64);
250 stat64_to_stat(&buf64, (struct stat *)buf);
255 uptr internal_fstat(fd_t fd, void *buf) {
256 #if SANITIZER_FREEBSD || SANITIZER_LINUX_USES_64BIT_SYSCALLS
257 return internal_syscall(SYSCALL(fstat), fd, (uptr)buf);
260 int res = internal_syscall(SYSCALL(fstat64), fd, &buf64);
261 stat64_to_stat(&buf64, (struct stat *)buf);
266 uptr internal_filesize(fd_t fd) {
268 if (internal_fstat(fd, &st))
270 return (uptr)st.st_size;
273 uptr internal_dup2(int oldfd, int newfd) {
274 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
275 return internal_syscall(SYSCALL(dup3), oldfd, newfd, 0);
277 return internal_syscall(SYSCALL(dup2), oldfd, newfd);
281 uptr internal_readlink(const char *path, char *buf, uptr bufsize) {
282 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
283 return internal_syscall(SYSCALL(readlinkat), AT_FDCWD,
284 (uptr)path, (uptr)buf, bufsize);
286 return internal_syscall(SYSCALL(readlink), (uptr)path, (uptr)buf, bufsize);
290 uptr internal_unlink(const char *path) {
291 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
292 return internal_syscall(SYSCALL(unlinkat), AT_FDCWD, (uptr)path, 0);
294 return internal_syscall(SYSCALL(unlink), (uptr)path);
298 uptr internal_rename(const char *oldpath, const char *newpath) {
299 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
300 return internal_syscall(SYSCALL(renameat), AT_FDCWD, (uptr)oldpath, AT_FDCWD,
303 return internal_syscall(SYSCALL(rename), (uptr)oldpath, (uptr)newpath);
307 uptr internal_sched_yield() {
308 return internal_syscall(SYSCALL(sched_yield));
311 void internal__exit(int exitcode) {
312 #if SANITIZER_FREEBSD
313 internal_syscall(SYSCALL(exit), exitcode);
315 internal_syscall(SYSCALL(exit_group), exitcode);
317 Die(); // Unreachable.
320 uptr internal_execve(const char *filename, char *const argv[],
321 char *const envp[]) {
322 return internal_syscall(SYSCALL(execve), (uptr)filename, (uptr)argv,
326 // ----------------- sanitizer_common.h
327 bool FileExists(const char *filename) {
329 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
330 if (internal_syscall(SYSCALL(newfstatat), AT_FDCWD, filename, &st, 0))
332 if (internal_stat(filename, &st))
335 // Sanity check: filename is a regular file.
336 return S_ISREG(st.st_mode);
340 #if SANITIZER_FREEBSD
341 return (uptr)pthread_self();
343 return internal_syscall(SYSCALL(gettid));
348 #if SANITIZER_FREEBSD
353 internal_memset(&tv, 0, sizeof(tv));
354 internal_syscall(SYSCALL(gettimeofday), (uptr)&tv, 0);
355 return (u64)tv.tv_sec * 1000*1000*1000 + tv.tv_usec * 1000;
358 // Like getenv, but reads env directly from /proc (on Linux) or parses the
359 // 'environ' array (on FreeBSD) and does not use libc. This function should be
360 // called first inside __asan_init.
361 const char *GetEnv(const char *name) {
362 #if SANITIZER_FREEBSD
363 if (::environ != 0) {
364 uptr NameLen = internal_strlen(name);
365 for (char **Env = ::environ; *Env != 0; Env++) {
366 if (internal_strncmp(*Env, name, NameLen) == 0 && (*Env)[NameLen] == '=')
367 return (*Env) + NameLen + 1;
370 return 0; // Not found.
371 #elif SANITIZER_LINUX
372 static char *environ;
378 len = ReadFileToBuffer("/proc/self/environ",
379 &environ, &environ_size, 1 << 26);
381 if (!environ || len == 0) return 0;
382 uptr namelen = internal_strlen(name);
383 const char *p = environ;
384 while (*p != '\0') { // will happen at the \0\0 that terminates the buffer
385 // proc file has the format NAME=value\0NAME=value\0NAME=value\0...
387 (char*)internal_memchr(p, '\0', len - (p - environ));
388 if (endp == 0) // this entry isn't NUL terminated
390 else if (!internal_memcmp(p, name, namelen) && p[namelen] == '=') // Match.
391 return p + namelen + 1; // point after =
394 return 0; // Not found.
396 #error "Unsupported platform"
401 SANITIZER_WEAK_ATTRIBUTE extern void *__libc_stack_end;
405 static void ReadNullSepFileToArray(const char *path, char ***arr,
409 *arr = (char **)MmapOrDie(arr_size * sizeof(char *), "NullSepFileArray");
410 ReadFileToBuffer(path, &buff, &buff_size, 1024 * 1024);
413 for (count = 1, i = 1; ; i++) {
415 if (buff[i+1] == 0) break;
416 (*arr)[count] = &buff[i+1];
417 CHECK_LE(count, arr_size - 1); // FIXME: make this more flexible.
425 static void GetArgsAndEnv(char*** argv, char*** envp) {
427 if (&__libc_stack_end) {
429 uptr* stack_end = (uptr*)__libc_stack_end;
430 int argc = *stack_end;
431 *argv = (char**)(stack_end + 1);
432 *envp = (char**)(stack_end + argc + 2);
435 static const int kMaxArgv = 2000, kMaxEnvp = 2000;
436 ReadNullSepFileToArray("/proc/self/cmdline", argv, kMaxArgv);
437 ReadNullSepFileToArray("/proc/self/environ", envp, kMaxEnvp);
444 GetArgsAndEnv(&argv, &envp);
445 uptr rv = internal_execve("/proc/self/exe", argv, envp);
447 CHECK_EQ(internal_iserror(rv, &rverrno), true);
448 Printf("execve failed, errno %d\n", rverrno);
458 BlockingMutex::BlockingMutex() {
459 internal_memset(this, 0, sizeof(*this));
462 void BlockingMutex::Lock() {
464 atomic_uint32_t *m = reinterpret_cast<atomic_uint32_t *>(&opaque_storage_);
465 if (atomic_exchange(m, MtxLocked, memory_order_acquire) == MtxUnlocked)
467 while (atomic_exchange(m, MtxSleeping, memory_order_acquire) != MtxUnlocked) {
468 #if SANITIZER_FREEBSD
469 _umtx_op(m, UMTX_OP_WAIT_UINT, MtxSleeping, 0, 0);
471 internal_syscall(SYSCALL(futex), (uptr)m, FUTEX_WAIT, MtxSleeping, 0, 0, 0);
476 void BlockingMutex::Unlock() {
477 atomic_uint32_t *m = reinterpret_cast<atomic_uint32_t *>(&opaque_storage_);
478 u32 v = atomic_exchange(m, MtxUnlocked, memory_order_relaxed);
479 CHECK_NE(v, MtxUnlocked);
480 if (v == MtxSleeping) {
481 #if SANITIZER_FREEBSD
482 _umtx_op(m, UMTX_OP_WAKE, 1, 0, 0);
484 internal_syscall(SYSCALL(futex), (uptr)m, FUTEX_WAKE, 1, 0, 0, 0);
489 void BlockingMutex::CheckLocked() {
490 atomic_uint32_t *m = reinterpret_cast<atomic_uint32_t *>(&opaque_storage_);
491 CHECK_NE(MtxUnlocked, atomic_load(m, memory_order_relaxed));
494 // ----------------- sanitizer_linux.h
495 // The actual size of this structure is specified by d_reclen.
496 // Note that getdents64 uses a different structure format. We only provide the
497 // 32-bit syscall here.
498 struct linux_dirent {
506 unsigned short d_reclen;
511 uptr internal_ptrace(int request, int pid, void *addr, void *data) {
512 return internal_syscall(SYSCALL(ptrace), request, pid, (uptr)addr,
516 uptr internal_waitpid(int pid, int *status, int options) {
517 return internal_syscall(SYSCALL(wait4), pid, (uptr)status, options,
521 uptr internal_getpid() {
522 return internal_syscall(SYSCALL(getpid));
525 uptr internal_getppid() {
526 return internal_syscall(SYSCALL(getppid));
529 uptr internal_getdents(fd_t fd, struct linux_dirent *dirp, unsigned int count) {
530 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
531 return internal_syscall(SYSCALL(getdents64), fd, (uptr)dirp, count);
533 return internal_syscall(SYSCALL(getdents), fd, (uptr)dirp, count);
537 uptr internal_lseek(fd_t fd, OFF_T offset, int whence) {
538 return internal_syscall(SYSCALL(lseek), fd, offset, whence);
542 uptr internal_prctl(int option, uptr arg2, uptr arg3, uptr arg4, uptr arg5) {
543 return internal_syscall(SYSCALL(prctl), option, arg2, arg3, arg4, arg5);
547 uptr internal_sigaltstack(const struct sigaltstack *ss,
548 struct sigaltstack *oss) {
549 return internal_syscall(SYSCALL(sigaltstack), (uptr)ss, (uptr)oss);
552 int internal_fork() {
553 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
554 return internal_syscall(SYSCALL(clone), SIGCHLD, 0);
556 return internal_syscall(SYSCALL(fork));
561 // Doesn't set sa_restorer, use with caution (see below).
562 int internal_sigaction_norestorer(int signum, const void *act, void *oldact) {
563 __sanitizer_kernel_sigaction_t k_act, k_oldact;
564 internal_memset(&k_act, 0, sizeof(__sanitizer_kernel_sigaction_t));
565 internal_memset(&k_oldact, 0, sizeof(__sanitizer_kernel_sigaction_t));
566 const __sanitizer_sigaction *u_act = (const __sanitizer_sigaction *)act;
567 __sanitizer_sigaction *u_oldact = (__sanitizer_sigaction *)oldact;
569 k_act.handler = u_act->handler;
570 k_act.sigaction = u_act->sigaction;
571 internal_memcpy(&k_act.sa_mask, &u_act->sa_mask,
572 sizeof(__sanitizer_kernel_sigset_t));
573 k_act.sa_flags = u_act->sa_flags;
574 // FIXME: most often sa_restorer is unset, however the kernel requires it
575 // to point to a valid signal restorer that calls the rt_sigreturn syscall.
576 // If sa_restorer passed to the kernel is NULL, the program may crash upon
577 // signal delivery or fail to unwind the stack in the signal handler.
578 // libc implementation of sigaction() passes its own restorer to
579 // rt_sigaction, so we need to do the same (we'll need to reimplement the
580 // restorers; for x86_64 the restorer address can be obtained from
581 // oldact->sa_restorer upon a call to sigaction(xxx, NULL, oldact).
582 k_act.sa_restorer = u_act->sa_restorer;
585 uptr result = internal_syscall(SYSCALL(rt_sigaction), (uptr)signum,
586 (uptr)(u_act ? &k_act : NULL),
587 (uptr)(u_oldact ? &k_oldact : NULL),
588 (uptr)sizeof(__sanitizer_kernel_sigset_t));
590 if ((result == 0) && u_oldact) {
591 u_oldact->handler = k_oldact.handler;
592 u_oldact->sigaction = k_oldact.sigaction;
593 internal_memcpy(&u_oldact->sa_mask, &k_oldact.sa_mask,
594 sizeof(__sanitizer_kernel_sigset_t));
595 u_oldact->sa_flags = k_oldact.sa_flags;
596 u_oldact->sa_restorer = k_oldact.sa_restorer;
600 #endif // SANITIZER_LINUX
602 uptr internal_sigprocmask(int how, __sanitizer_sigset_t *set,
603 __sanitizer_sigset_t *oldset) {
604 #if SANITIZER_FREEBSD
605 return internal_syscall(SYSCALL(sigprocmask), how, set, oldset);
607 __sanitizer_kernel_sigset_t *k_set = (__sanitizer_kernel_sigset_t *)set;
608 __sanitizer_kernel_sigset_t *k_oldset = (__sanitizer_kernel_sigset_t *)oldset;
609 return internal_syscall(SYSCALL(rt_sigprocmask), (uptr)how,
610 (uptr)&k_set->sig[0], (uptr)&k_oldset->sig[0],
611 sizeof(__sanitizer_kernel_sigset_t));
615 void internal_sigfillset(__sanitizer_sigset_t *set) {
616 internal_memset(set, 0xff, sizeof(*set));
620 void internal_sigdelset(__sanitizer_sigset_t *set, int signum) {
623 CHECK_LT(signum, sizeof(*set) * 8);
624 __sanitizer_kernel_sigset_t *k_set = (__sanitizer_kernel_sigset_t *)set;
625 const uptr idx = signum / (sizeof(k_set->sig[0]) * 8);
626 const uptr bit = signum % (sizeof(k_set->sig[0]) * 8);
627 k_set->sig[idx] &= ~(1 << bit);
629 #endif // SANITIZER_LINUX
631 // ThreadLister implementation.
632 ThreadLister::ThreadLister(int pid)
637 entry_((struct linux_dirent *)buffer_.data()),
639 char task_directory_path[80];
640 internal_snprintf(task_directory_path, sizeof(task_directory_path),
641 "/proc/%d/task/", pid);
642 uptr openrv = internal_open(task_directory_path, O_RDONLY | O_DIRECTORY);
643 if (internal_iserror(openrv)) {
645 Report("Can't open /proc/%d/task for reading.\n", pid);
648 descriptor_ = openrv;
652 int ThreadLister::GetNextTID() {
657 if ((char *)entry_ >= &buffer_[bytes_read_] && !GetDirectoryEntries())
659 if (entry_->d_ino != 0 && entry_->d_name[0] >= '0' &&
660 entry_->d_name[0] <= '9') {
661 // Found a valid tid.
662 tid = (int)internal_atoll(entry_->d_name);
664 entry_ = (struct linux_dirent *)(((char *)entry_) + entry_->d_reclen);
669 void ThreadLister::Reset() {
670 if (error_ || descriptor_ < 0)
672 internal_lseek(descriptor_, 0, SEEK_SET);
675 ThreadLister::~ThreadLister() {
676 if (descriptor_ >= 0)
677 internal_close(descriptor_);
680 bool ThreadLister::error() { return error_; }
682 bool ThreadLister::GetDirectoryEntries() {
683 CHECK_GE(descriptor_, 0);
684 CHECK_NE(error_, true);
685 bytes_read_ = internal_getdents(descriptor_,
686 (struct linux_dirent *)buffer_.data(),
688 if (internal_iserror(bytes_read_)) {
689 Report("Can't read directory entries from /proc/%d/task.\n", pid_);
692 } else if (bytes_read_ == 0) {
695 entry_ = (struct linux_dirent *)buffer_.data();
700 #if SANITIZER_LINUX && (defined(__x86_64__) || defined(__i386__))
701 return EXEC_PAGESIZE;
703 return sysconf(_SC_PAGESIZE); // EXEC_PAGESIZE may not be trustworthy.
707 static char proc_self_exe_cache_str[kMaxPathLength];
708 static uptr proc_self_exe_cache_len = 0;
710 uptr ReadBinaryName(/*out*/char *buf, uptr buf_len) {
711 if (proc_self_exe_cache_len > 0) {
712 // If available, use the cached module name.
713 uptr module_name_len =
714 internal_snprintf(buf, buf_len, "%s", proc_self_exe_cache_str);
715 CHECK_LT(module_name_len, buf_len);
716 return module_name_len;
718 #if SANITIZER_FREEBSD
719 const int Mib[4] = { CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1 };
720 size_t Size = buf_len;
721 bool IsErr = (sysctl(Mib, 4, buf, &Size, NULL, 0) != 0);
722 int readlink_error = IsErr ? errno : 0;
723 uptr module_name_len = Size;
725 uptr module_name_len = internal_readlink(
726 "/proc/self/exe", buf, buf_len);
728 bool IsErr = internal_iserror(module_name_len, &readlink_error);
731 // We can't read /proc/self/exe for some reason, assume the name of the
732 // binary is unknown.
733 Report("WARNING: readlink(\"/proc/self/exe\") failed with errno %d, "
734 "some stack frames may not be symbolized\n", readlink_error);
735 module_name_len = internal_snprintf(buf, buf_len, "/proc/self/exe");
736 CHECK_LT(module_name_len, buf_len);
738 return module_name_len;
741 void CacheBinaryName() {
742 if (!proc_self_exe_cache_len) {
743 proc_self_exe_cache_len =
744 ReadBinaryName(proc_self_exe_cache_str, kMaxPathLength);
748 // Match full names of the form /path/to/base_name{-,.}*
749 bool LibraryNameIs(const char *full_name, const char *base_name) {
750 const char *name = full_name;
752 while (*name != '\0') name++;
753 while (name > full_name && *name != '/') name--;
754 if (*name == '/') name++;
755 uptr base_name_length = internal_strlen(base_name);
756 if (internal_strncmp(name, base_name, base_name_length)) return false;
757 return (name[base_name_length] == '-' || name[base_name_length] == '.');
760 #if !SANITIZER_ANDROID
761 // Call cb for each region mapped by map.
762 void ForEachMappedRegion(link_map *map, void (*cb)(const void *, uptr)) {
763 CHECK_NE(map, nullptr);
764 #if !SANITIZER_FREEBSD
765 typedef ElfW(Phdr) Elf_Phdr;
766 typedef ElfW(Ehdr) Elf_Ehdr;
767 #endif // !SANITIZER_FREEBSD
768 char *base = (char *)map->l_addr;
769 Elf_Ehdr *ehdr = (Elf_Ehdr *)base;
770 char *phdrs = base + ehdr->e_phoff;
771 char *phdrs_end = phdrs + ehdr->e_phnum * ehdr->e_phentsize;
773 // Find the segment with the minimum base so we can "relocate" the p_vaddr
774 // fields. Typically ET_DYN objects (DSOs) have base of zero and ET_EXEC
775 // objects have a non-zero base.
776 uptr preferred_base = (uptr)-1;
777 for (char *iter = phdrs; iter != phdrs_end; iter += ehdr->e_phentsize) {
778 Elf_Phdr *phdr = (Elf_Phdr *)iter;
779 if (phdr->p_type == PT_LOAD && preferred_base > (uptr)phdr->p_vaddr)
780 preferred_base = (uptr)phdr->p_vaddr;
783 // Compute the delta from the real base to get a relocation delta.
784 sptr delta = (uptr)base - preferred_base;
785 // Now we can figure out what the loader really mapped.
786 for (char *iter = phdrs; iter != phdrs_end; iter += ehdr->e_phentsize) {
787 Elf_Phdr *phdr = (Elf_Phdr *)iter;
788 if (phdr->p_type == PT_LOAD) {
789 uptr seg_start = phdr->p_vaddr + delta;
790 uptr seg_end = seg_start + phdr->p_memsz;
791 // None of these values are aligned. We consider the ragged edges of the
792 // load command as defined, since they are mapped from the file.
793 seg_start = RoundDownTo(seg_start, GetPageSizeCached());
794 seg_end = RoundUpTo(seg_end, GetPageSizeCached());
795 cb((void *)seg_start, seg_end - seg_start);
801 #if defined(__x86_64__) && SANITIZER_LINUX
802 // We cannot use glibc's clone wrapper, because it messes with the child
803 // task's TLS. It writes the PID and TID of the child task to its thread
804 // descriptor, but in our case the child task shares the thread descriptor with
805 // the parent (because we don't know how to allocate a new thread
806 // descriptor to keep glibc happy). So the stock version of clone(), when
807 // used with CLONE_VM, would end up corrupting the parent's thread descriptor.
808 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
809 int *parent_tidptr, void *newtls, int *child_tidptr) {
811 if (!fn || !child_stack)
813 CHECK_EQ(0, (uptr)child_stack % 16);
814 child_stack = (char *)child_stack - 2 * sizeof(unsigned long long);
815 ((unsigned long long *)child_stack)[0] = (uptr)fn;
816 ((unsigned long long *)child_stack)[1] = (uptr)arg;
817 register void *r8 __asm__("r8") = newtls;
818 register int *r10 __asm__("r10") = child_tidptr;
819 __asm__ __volatile__(
820 /* %rax = syscall(%rax = SYSCALL(clone),
822 * %rsi = child_stack,
823 * %rdx = parent_tidptr,
825 * %r10 = child_tidptr)
832 "testq %%rax,%%rax\n"
835 /* In the child. Terminate unwind chain. */
836 // XXX: We should also terminate the CFI unwind chain
837 // here. Unfortunately clang 3.2 doesn't support the
838 // necessary CFI directives, so we skip that part.
841 /* Call "fn(arg)". */
846 /* Call _exit(%rax). */
851 /* Return to parent. */
854 : "a"(SYSCALL(clone)), "i"(SYSCALL(exit)),
860 : "rsp", "memory", "r11", "rcx");
863 #elif defined(__mips__)
864 // TODO(sagarthakur): clone function is to be rewritten in assembly.
865 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
866 int *parent_tidptr, void *newtls, int *child_tidptr) {
867 return clone(fn, child_stack, flags, arg, parent_tidptr,
868 newtls, child_tidptr);
870 #endif // defined(__x86_64__) && SANITIZER_LINUX
872 #if SANITIZER_ANDROID
873 static atomic_uint8_t android_log_initialized;
875 void AndroidLogInit() {
876 atomic_store(&android_log_initialized, 1, memory_order_release);
878 // This thing is not, strictly speaking, async signal safe, but it does not seem
879 // to cause any issues. Alternative is writing to log devices directly, but
880 // their location and message format might change in the future, so we'd really
881 // like to avoid that.
882 void AndroidLogWrite(const char *buffer) {
883 if (!atomic_load(&android_log_initialized, memory_order_acquire))
886 char *copy = internal_strdup(buffer);
889 // __android_log_write has an implicit message length limit.
890 // Print one line at a time.
892 q = internal_strchr(p, '\n');
894 __android_log_write(ANDROID_LOG_INFO, NULL, p);
900 void GetExtraActivationFlags(char *buf, uptr size) {
901 CHECK(size > PROP_VALUE_MAX);
902 __system_property_get("asan.options", buf);
906 bool IsDeadlySignal(int signum) {
907 return (signum == SIGSEGV || signum == SIGBUS) && common_flags()->handle_segv;
911 void *internal_start_thread(void(*func)(void *arg), void *arg) {
912 // Start the thread with signals blocked, otherwise it can steal user signals.
913 __sanitizer_sigset_t set, old;
914 internal_sigfillset(&set);
915 internal_sigprocmask(SIG_SETMASK, &set, &old);
917 real_pthread_create(&th, 0, (void*(*)(void *arg))func, arg);
918 internal_sigprocmask(SIG_SETMASK, &old, 0);
922 void internal_join_thread(void *th) {
923 real_pthread_join(th, 0);
926 void *internal_start_thread(void (*func)(void *), void *arg) { return 0; }
928 void internal_join_thread(void *th) {}
931 } // namespace __sanitizer
933 #endif // SANITIZER_FREEBSD || SANITIZER_LINUX