//===-- sanitizer_linux.cc ------------------------------------------------===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // This file is shared between AddressSanitizer and ThreadSanitizer // run-time libraries and implements linux-specific functions from // sanitizer_libc.h. //===----------------------------------------------------------------------===// #include "sanitizer_platform.h" #if SANITIZER_FREEBSD || SANITIZER_LINUX #include "sanitizer_allocator_internal.h" #include "sanitizer_common.h" #include "sanitizer_flags.h" #include "sanitizer_internal_defs.h" #include "sanitizer_libc.h" #include "sanitizer_linux.h" #include "sanitizer_mutex.h" #include "sanitizer_placement_new.h" #include "sanitizer_procmaps.h" #include "sanitizer_stacktrace.h" #include "sanitizer_symbolizer.h" #if !SANITIZER_FREEBSD #include #endif #include #include #include #if !SANITIZER_ANDROID #include #endif #include #include #include #include #include #include #include #include #include #include #if SANITIZER_FREEBSD #include #include extern "C" { // must be included after and on // FreeBSD 9.2 and 10.0. #include } extern char **environ; // provided by crt1 #endif // SANITIZER_FREEBSD #if !SANITIZER_ANDROID #include #endif #if SANITIZER_ANDROID #include #include #endif #if SANITIZER_LINUX // struct kernel_timeval { long tv_sec; long tv_usec; }; // is broken on some linux distributions. const int FUTEX_WAIT = 0; const int FUTEX_WAKE = 1; #endif // SANITIZER_LINUX // Are we using 32-bit or 64-bit Linux syscalls? // x32 (which defines __x86_64__) has SANITIZER_WORDSIZE == 32 // but it still needs to use 64-bit syscalls. #if SANITIZER_LINUX && (defined(__x86_64__) || SANITIZER_WORDSIZE == 64) # define SANITIZER_LINUX_USES_64BIT_SYSCALLS 1 #else # define SANITIZER_LINUX_USES_64BIT_SYSCALLS 0 #endif namespace __sanitizer { #if SANITIZER_LINUX && defined(__x86_64__) #include "sanitizer_syscall_linux_x86_64.inc" #else #include "sanitizer_syscall_generic.inc" #endif // --------------- sanitizer_libc.h uptr internal_mmap(void *addr, uptr length, int prot, int flags, int fd, u64 offset) { #if SANITIZER_FREEBSD || SANITIZER_LINUX_USES_64BIT_SYSCALLS return internal_syscall(SYSCALL(mmap), (uptr)addr, length, prot, flags, fd, offset); #else return internal_syscall(SYSCALL(mmap2), addr, length, prot, flags, fd, offset); #endif } uptr internal_munmap(void *addr, uptr length) { return internal_syscall(SYSCALL(munmap), (uptr)addr, length); } uptr internal_close(fd_t fd) { return internal_syscall(SYSCALL(close), fd); } uptr internal_open(const char *filename, int flags) { #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS return internal_syscall(SYSCALL(openat), AT_FDCWD, (uptr)filename, flags); #else return internal_syscall(SYSCALL(open), (uptr)filename, flags); #endif } uptr internal_open(const char *filename, int flags, u32 mode) { #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS return internal_syscall(SYSCALL(openat), AT_FDCWD, (uptr)filename, flags, mode); #else return internal_syscall(SYSCALL(open), (uptr)filename, flags, mode); #endif } uptr OpenFile(const char *filename, bool write) { return internal_open(filename, write ? O_RDWR | O_CREAT /*| O_CLOEXEC*/ : O_RDONLY, 0660); } uptr internal_read(fd_t fd, void *buf, uptr count) { sptr res; HANDLE_EINTR(res, (sptr)internal_syscall(SYSCALL(read), fd, (uptr)buf, count)); return res; } uptr internal_write(fd_t fd, const void *buf, uptr count) { sptr res; HANDLE_EINTR(res, (sptr)internal_syscall(SYSCALL(write), fd, (uptr)buf, count)); return res; } uptr internal_ftruncate(fd_t fd, uptr size) { sptr res; HANDLE_EINTR(res, (sptr)internal_syscall(SYSCALL(ftruncate), fd, size)); return res; } #if !SANITIZER_LINUX_USES_64BIT_SYSCALLS && !SANITIZER_FREEBSD static void stat64_to_stat(struct stat64 *in, struct stat *out) { internal_memset(out, 0, sizeof(*out)); out->st_dev = in->st_dev; out->st_ino = in->st_ino; out->st_mode = in->st_mode; out->st_nlink = in->st_nlink; out->st_uid = in->st_uid; out->st_gid = in->st_gid; out->st_rdev = in->st_rdev; out->st_size = in->st_size; out->st_blksize = in->st_blksize; out->st_blocks = in->st_blocks; out->st_atime = in->st_atime; out->st_mtime = in->st_mtime; out->st_ctime = in->st_ctime; out->st_ino = in->st_ino; } #endif uptr internal_stat(const char *path, void *buf) { #if SANITIZER_FREEBSD return internal_syscall(SYSCALL(stat), path, buf); #elif SANITIZER_USES_CANONICAL_LINUX_SYSCALLS return internal_syscall(SYSCALL(newfstatat), AT_FDCWD, (uptr)path, (uptr)buf, 0); #elif SANITIZER_LINUX_USES_64BIT_SYSCALLS return internal_syscall(SYSCALL(stat), (uptr)path, (uptr)buf); #else struct stat64 buf64; int res = internal_syscall(SYSCALL(stat64), path, &buf64); stat64_to_stat(&buf64, (struct stat *)buf); return res; #endif } uptr internal_lstat(const char *path, void *buf) { #if SANITIZER_FREEBSD return internal_syscall(SYSCALL(lstat), path, buf); #elif SANITIZER_USES_CANONICAL_LINUX_SYSCALLS return internal_syscall(SYSCALL(newfstatat), AT_FDCWD, (uptr)path, (uptr)buf, AT_SYMLINK_NOFOLLOW); #elif SANITIZER_LINUX_USES_64BIT_SYSCALLS return internal_syscall(SYSCALL(lstat), (uptr)path, (uptr)buf); #else struct stat64 buf64; int res = internal_syscall(SYSCALL(lstat64), path, &buf64); stat64_to_stat(&buf64, (struct stat *)buf); return res; #endif } uptr internal_fstat(fd_t fd, void *buf) { #if SANITIZER_FREEBSD || SANITIZER_LINUX_USES_64BIT_SYSCALLS return internal_syscall(SYSCALL(fstat), fd, (uptr)buf); #else struct stat64 buf64; int res = internal_syscall(SYSCALL(fstat64), fd, &buf64); stat64_to_stat(&buf64, (struct stat *)buf); return res; #endif } uptr internal_filesize(fd_t fd) { struct stat st; if (internal_fstat(fd, &st)) return -1; return (uptr)st.st_size; } uptr internal_dup2(int oldfd, int newfd) { #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS return internal_syscall(SYSCALL(dup3), oldfd, newfd, 0); #else return internal_syscall(SYSCALL(dup2), oldfd, newfd); #endif } uptr internal_readlink(const char *path, char *buf, uptr bufsize) { #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS return internal_syscall(SYSCALL(readlinkat), AT_FDCWD, (uptr)path, (uptr)buf, bufsize); #else return internal_syscall(SYSCALL(readlink), (uptr)path, (uptr)buf, bufsize); #endif } uptr internal_unlink(const char *path) { #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS return internal_syscall(SYSCALL(unlinkat), AT_FDCWD, (uptr)path, 0); #else return internal_syscall(SYSCALL(unlink), (uptr)path); #endif } uptr internal_rename(const char *oldpath, const char *newpath) { #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS return internal_syscall(SYSCALL(renameat), AT_FDCWD, (uptr)oldpath, AT_FDCWD, (uptr)newpath); #else return internal_syscall(SYSCALL(rename), (uptr)oldpath, (uptr)newpath); #endif } uptr internal_sched_yield() { return internal_syscall(SYSCALL(sched_yield)); } void internal__exit(int exitcode) { #if SANITIZER_FREEBSD internal_syscall(SYSCALL(exit), exitcode); #else internal_syscall(SYSCALL(exit_group), exitcode); #endif Die(); // Unreachable. } uptr internal_execve(const char *filename, char *const argv[], char *const envp[]) { return internal_syscall(SYSCALL(execve), (uptr)filename, (uptr)argv, (uptr)envp); } // ----------------- sanitizer_common.h bool FileExists(const char *filename) { struct stat st; #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS if (internal_syscall(SYSCALL(newfstatat), AT_FDCWD, filename, &st, 0)) #else if (internal_stat(filename, &st)) #endif return false; // Sanity check: filename is a regular file. return S_ISREG(st.st_mode); } uptr GetTid() { #if SANITIZER_FREEBSD return (uptr)pthread_self(); #else return internal_syscall(SYSCALL(gettid)); #endif } u64 NanoTime() { #if SANITIZER_FREEBSD timeval tv; #else kernel_timeval tv; #endif internal_memset(&tv, 0, sizeof(tv)); internal_syscall(SYSCALL(gettimeofday), (uptr)&tv, 0); return (u64)tv.tv_sec * 1000*1000*1000 + tv.tv_usec * 1000; } // Like getenv, but reads env directly from /proc (on Linux) or parses the // 'environ' array (on FreeBSD) and does not use libc. This function should be // called first inside __asan_init. const char *GetEnv(const char *name) { #if SANITIZER_FREEBSD if (::environ != 0) { uptr NameLen = internal_strlen(name); for (char **Env = ::environ; *Env != 0; Env++) { if (internal_strncmp(*Env, name, NameLen) == 0 && (*Env)[NameLen] == '=') return (*Env) + NameLen + 1; } } return 0; // Not found. #elif SANITIZER_LINUX static char *environ; static uptr len; static bool inited; if (!inited) { inited = true; uptr environ_size; len = ReadFileToBuffer("/proc/self/environ", &environ, &environ_size, 1 << 26); } if (!environ || len == 0) return 0; uptr namelen = internal_strlen(name); const char *p = environ; while (*p != '\0') { // will happen at the \0\0 that terminates the buffer // proc file has the format NAME=value\0NAME=value\0NAME=value\0... const char* endp = (char*)internal_memchr(p, '\0', len - (p - environ)); if (endp == 0) // this entry isn't NUL terminated return 0; else if (!internal_memcmp(p, name, namelen) && p[namelen] == '=') // Match. return p + namelen + 1; // point after = p = endp + 1; } return 0; // Not found. #else #error "Unsupported platform" #endif } extern "C" { SANITIZER_WEAK_ATTRIBUTE extern void *__libc_stack_end; } #if !SANITIZER_GO static void ReadNullSepFileToArray(const char *path, char ***arr, int arr_size) { char *buff; uptr buff_size = 0; *arr = (char **)MmapOrDie(arr_size * sizeof(char *), "NullSepFileArray"); ReadFileToBuffer(path, &buff, &buff_size, 1024 * 1024); (*arr)[0] = buff; int count, i; for (count = 1, i = 1; ; i++) { if (buff[i] == 0) { if (buff[i+1] == 0) break; (*arr)[count] = &buff[i+1]; CHECK_LE(count, arr_size - 1); // FIXME: make this more flexible. count++; } } (*arr)[count] = 0; } #endif uptr GetRSS() { uptr fd = OpenFile("/proc/self/statm", false); if ((sptr)fd < 0) return 0; char buf[64]; uptr len = internal_read(fd, buf, sizeof(buf) - 1); internal_close(fd); if ((sptr)len <= 0) return 0; buf[len] = 0; // The format of the file is: // 1084 89 69 11 0 79 0 // We need the second number which is RSS in 4K units. char *pos = buf; // Skip the first number. while (*pos >= '0' && *pos <= '9') pos++; // Skip whitespaces. while (!(*pos >= '0' && *pos <= '9') && *pos != 0) pos++; // Read the number. uptr rss = 0; while (*pos >= '0' && *pos <= '9') rss = rss * 10 + *pos++ - '0'; return rss * 4096; } static void GetArgsAndEnv(char*** argv, char*** envp) { #if !SANITIZER_GO if (&__libc_stack_end) { #endif uptr* stack_end = (uptr*)__libc_stack_end; int argc = *stack_end; *argv = (char**)(stack_end + 1); *envp = (char**)(stack_end + argc + 2); #if !SANITIZER_GO } else { static const int kMaxArgv = 2000, kMaxEnvp = 2000; ReadNullSepFileToArray("/proc/self/cmdline", argv, kMaxArgv); ReadNullSepFileToArray("/proc/self/environ", envp, kMaxEnvp); } #endif } void ReExec() { char **argv, **envp; GetArgsAndEnv(&argv, &envp); uptr rv = internal_execve("/proc/self/exe", argv, envp); int rverrno; CHECK_EQ(internal_iserror(rv, &rverrno), true); Printf("execve failed, errno %d\n", rverrno); Die(); } // Stub implementation of GetThreadStackAndTls for Go. #if SANITIZER_GO void GetThreadStackAndTls(bool main, uptr *stk_addr, uptr *stk_size, uptr *tls_addr, uptr *tls_size) { *stk_addr = 0; *stk_size = 0; *tls_addr = 0; *tls_size = 0; } #endif // SANITIZER_GO enum MutexState { MtxUnlocked = 0, MtxLocked = 1, MtxSleeping = 2 }; BlockingMutex::BlockingMutex(LinkerInitialized) { CHECK_EQ(owner_, 0); } BlockingMutex::BlockingMutex() { internal_memset(this, 0, sizeof(*this)); } void BlockingMutex::Lock() { atomic_uint32_t *m = reinterpret_cast(&opaque_storage_); if (atomic_exchange(m, MtxLocked, memory_order_acquire) == MtxUnlocked) return; while (atomic_exchange(m, MtxSleeping, memory_order_acquire) != MtxUnlocked) { #if SANITIZER_FREEBSD _umtx_op(m, UMTX_OP_WAIT_UINT, MtxSleeping, 0, 0); #else internal_syscall(SYSCALL(futex), (uptr)m, FUTEX_WAIT, MtxSleeping, 0, 0, 0); #endif } } void BlockingMutex::Unlock() { atomic_uint32_t *m = reinterpret_cast(&opaque_storage_); u32 v = atomic_exchange(m, MtxUnlocked, memory_order_relaxed); CHECK_NE(v, MtxUnlocked); if (v == MtxSleeping) { #if SANITIZER_FREEBSD _umtx_op(m, UMTX_OP_WAKE, 1, 0, 0); #else internal_syscall(SYSCALL(futex), (uptr)m, FUTEX_WAKE, 1, 0, 0, 0); #endif } } void BlockingMutex::CheckLocked() { atomic_uint32_t *m = reinterpret_cast(&opaque_storage_); CHECK_NE(MtxUnlocked, atomic_load(m, memory_order_relaxed)); } // ----------------- sanitizer_linux.h // The actual size of this structure is specified by d_reclen. // Note that getdents64 uses a different structure format. We only provide the // 32-bit syscall here. struct linux_dirent { #if SANITIZER_X32 u64 d_ino; u64 d_off; #else unsigned long d_ino; unsigned long d_off; #endif unsigned short d_reclen; char d_name[256]; }; // Syscall wrappers. uptr internal_ptrace(int request, int pid, void *addr, void *data) { return internal_syscall(SYSCALL(ptrace), request, pid, (uptr)addr, (uptr)data); } uptr internal_waitpid(int pid, int *status, int options) { return internal_syscall(SYSCALL(wait4), pid, (uptr)status, options, 0 /* rusage */); } uptr internal_getpid() { return internal_syscall(SYSCALL(getpid)); } uptr internal_getppid() { return internal_syscall(SYSCALL(getppid)); } uptr internal_getdents(fd_t fd, struct linux_dirent *dirp, unsigned int count) { #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS return internal_syscall(SYSCALL(getdents64), fd, (uptr)dirp, count); #else return internal_syscall(SYSCALL(getdents), fd, (uptr)dirp, count); #endif } uptr internal_lseek(fd_t fd, OFF_T offset, int whence) { return internal_syscall(SYSCALL(lseek), fd, offset, whence); } #if SANITIZER_LINUX uptr internal_prctl(int option, uptr arg2, uptr arg3, uptr arg4, uptr arg5) { return internal_syscall(SYSCALL(prctl), option, arg2, arg3, arg4, arg5); } #endif uptr internal_sigaltstack(const struct sigaltstack *ss, struct sigaltstack *oss) { return internal_syscall(SYSCALL(sigaltstack), (uptr)ss, (uptr)oss); } int internal_fork() { #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS return internal_syscall(SYSCALL(clone), SIGCHLD, 0); #else return internal_syscall(SYSCALL(fork)); #endif } #if SANITIZER_LINUX // Doesn't set sa_restorer, use with caution (see below). int internal_sigaction_norestorer(int signum, const void *act, void *oldact) { __sanitizer_kernel_sigaction_t k_act, k_oldact; internal_memset(&k_act, 0, sizeof(__sanitizer_kernel_sigaction_t)); internal_memset(&k_oldact, 0, sizeof(__sanitizer_kernel_sigaction_t)); const __sanitizer_sigaction *u_act = (const __sanitizer_sigaction *)act; __sanitizer_sigaction *u_oldact = (__sanitizer_sigaction *)oldact; if (u_act) { k_act.handler = u_act->handler; k_act.sigaction = u_act->sigaction; internal_memcpy(&k_act.sa_mask, &u_act->sa_mask, sizeof(__sanitizer_kernel_sigset_t)); k_act.sa_flags = u_act->sa_flags; // FIXME: most often sa_restorer is unset, however the kernel requires it // to point to a valid signal restorer that calls the rt_sigreturn syscall. // If sa_restorer passed to the kernel is NULL, the program may crash upon // signal delivery or fail to unwind the stack in the signal handler. // libc implementation of sigaction() passes its own restorer to // rt_sigaction, so we need to do the same (we'll need to reimplement the // restorers; for x86_64 the restorer address can be obtained from // oldact->sa_restorer upon a call to sigaction(xxx, NULL, oldact). k_act.sa_restorer = u_act->sa_restorer; } uptr result = internal_syscall(SYSCALL(rt_sigaction), (uptr)signum, (uptr)(u_act ? &k_act : NULL), (uptr)(u_oldact ? &k_oldact : NULL), (uptr)sizeof(__sanitizer_kernel_sigset_t)); if ((result == 0) && u_oldact) { u_oldact->handler = k_oldact.handler; u_oldact->sigaction = k_oldact.sigaction; internal_memcpy(&u_oldact->sa_mask, &k_oldact.sa_mask, sizeof(__sanitizer_kernel_sigset_t)); u_oldact->sa_flags = k_oldact.sa_flags; u_oldact->sa_restorer = k_oldact.sa_restorer; } return result; } #endif // SANITIZER_LINUX uptr internal_sigprocmask(int how, __sanitizer_sigset_t *set, __sanitizer_sigset_t *oldset) { #if SANITIZER_FREEBSD return internal_syscall(SYSCALL(sigprocmask), how, set, oldset); #else __sanitizer_kernel_sigset_t *k_set = (__sanitizer_kernel_sigset_t *)set; __sanitizer_kernel_sigset_t *k_oldset = (__sanitizer_kernel_sigset_t *)oldset; return internal_syscall(SYSCALL(rt_sigprocmask), (uptr)how, (uptr)&k_set->sig[0], (uptr)&k_oldset->sig[0], sizeof(__sanitizer_kernel_sigset_t)); #endif } void internal_sigfillset(__sanitizer_sigset_t *set) { internal_memset(set, 0xff, sizeof(*set)); } #if SANITIZER_LINUX void internal_sigdelset(__sanitizer_sigset_t *set, int signum) { signum -= 1; CHECK_GE(signum, 0); CHECK_LT(signum, sizeof(*set) * 8); __sanitizer_kernel_sigset_t *k_set = (__sanitizer_kernel_sigset_t *)set; const uptr idx = signum / (sizeof(k_set->sig[0]) * 8); const uptr bit = signum % (sizeof(k_set->sig[0]) * 8); k_set->sig[idx] &= ~(1 << bit); } #endif // SANITIZER_LINUX // ThreadLister implementation. ThreadLister::ThreadLister(int pid) : pid_(pid), descriptor_(-1), buffer_(4096), error_(true), entry_((struct linux_dirent *)buffer_.data()), bytes_read_(0) { char task_directory_path[80]; internal_snprintf(task_directory_path, sizeof(task_directory_path), "/proc/%d/task/", pid); uptr openrv = internal_open(task_directory_path, O_RDONLY | O_DIRECTORY); if (internal_iserror(openrv)) { error_ = true; Report("Can't open /proc/%d/task for reading.\n", pid); } else { error_ = false; descriptor_ = openrv; } } int ThreadLister::GetNextTID() { int tid = -1; do { if (error_) return -1; if ((char *)entry_ >= &buffer_[bytes_read_] && !GetDirectoryEntries()) return -1; if (entry_->d_ino != 0 && entry_->d_name[0] >= '0' && entry_->d_name[0] <= '9') { // Found a valid tid. tid = (int)internal_atoll(entry_->d_name); } entry_ = (struct linux_dirent *)(((char *)entry_) + entry_->d_reclen); } while (tid < 0); return tid; } void ThreadLister::Reset() { if (error_ || descriptor_ < 0) return; internal_lseek(descriptor_, 0, SEEK_SET); } ThreadLister::~ThreadLister() { if (descriptor_ >= 0) internal_close(descriptor_); } bool ThreadLister::error() { return error_; } bool ThreadLister::GetDirectoryEntries() { CHECK_GE(descriptor_, 0); CHECK_NE(error_, true); bytes_read_ = internal_getdents(descriptor_, (struct linux_dirent *)buffer_.data(), buffer_.size()); if (internal_iserror(bytes_read_)) { Report("Can't read directory entries from /proc/%d/task.\n", pid_); error_ = true; return false; } else if (bytes_read_ == 0) { return false; } entry_ = (struct linux_dirent *)buffer_.data(); return true; } uptr GetPageSize() { #if SANITIZER_LINUX && (defined(__x86_64__) || defined(__i386__)) return EXEC_PAGESIZE; #else return sysconf(_SC_PAGESIZE); // EXEC_PAGESIZE may not be trustworthy. #endif } static char proc_self_exe_cache_str[kMaxPathLength]; static uptr proc_self_exe_cache_len = 0; uptr ReadBinaryName(/*out*/char *buf, uptr buf_len) { if (proc_self_exe_cache_len > 0) { // If available, use the cached module name. uptr module_name_len = internal_snprintf(buf, buf_len, "%s", proc_self_exe_cache_str); CHECK_LT(module_name_len, buf_len); return module_name_len; } #if SANITIZER_FREEBSD const int Mib[4] = { CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1 }; size_t Size = buf_len; bool IsErr = (sysctl(Mib, 4, buf, &Size, NULL, 0) != 0); int readlink_error = IsErr ? errno : 0; uptr module_name_len = Size; #else uptr module_name_len = internal_readlink( "/proc/self/exe", buf, buf_len); int readlink_error; bool IsErr = internal_iserror(module_name_len, &readlink_error); #endif if (IsErr) { // We can't read /proc/self/exe for some reason, assume the name of the // binary is unknown. Report("WARNING: readlink(\"/proc/self/exe\") failed with errno %d, " "some stack frames may not be symbolized\n", readlink_error); module_name_len = internal_snprintf(buf, buf_len, "/proc/self/exe"); CHECK_LT(module_name_len, buf_len); } return module_name_len; } void CacheBinaryName() { if (!proc_self_exe_cache_len) { proc_self_exe_cache_len = ReadBinaryName(proc_self_exe_cache_str, kMaxPathLength); } } // Match full names of the form /path/to/base_name{-,.}* bool LibraryNameIs(const char *full_name, const char *base_name) { const char *name = full_name; // Strip path. while (*name != '\0') name++; while (name > full_name && *name != '/') name--; if (*name == '/') name++; uptr base_name_length = internal_strlen(base_name); if (internal_strncmp(name, base_name, base_name_length)) return false; return (name[base_name_length] == '-' || name[base_name_length] == '.'); } #if !SANITIZER_ANDROID // Call cb for each region mapped by map. void ForEachMappedRegion(link_map *map, void (*cb)(const void *, uptr)) { #if !SANITIZER_FREEBSD typedef ElfW(Phdr) Elf_Phdr; typedef ElfW(Ehdr) Elf_Ehdr; #endif // !SANITIZER_FREEBSD char *base = (char *)map->l_addr; Elf_Ehdr *ehdr = (Elf_Ehdr *)base; char *phdrs = base + ehdr->e_phoff; char *phdrs_end = phdrs + ehdr->e_phnum * ehdr->e_phentsize; // Find the segment with the minimum base so we can "relocate" the p_vaddr // fields. Typically ET_DYN objects (DSOs) have base of zero and ET_EXEC // objects have a non-zero base. uptr preferred_base = (uptr)-1; for (char *iter = phdrs; iter != phdrs_end; iter += ehdr->e_phentsize) { Elf_Phdr *phdr = (Elf_Phdr *)iter; if (phdr->p_type == PT_LOAD && preferred_base > (uptr)phdr->p_vaddr) preferred_base = (uptr)phdr->p_vaddr; } // Compute the delta from the real base to get a relocation delta. sptr delta = (uptr)base - preferred_base; // Now we can figure out what the loader really mapped. for (char *iter = phdrs; iter != phdrs_end; iter += ehdr->e_phentsize) { Elf_Phdr *phdr = (Elf_Phdr *)iter; if (phdr->p_type == PT_LOAD) { uptr seg_start = phdr->p_vaddr + delta; uptr seg_end = seg_start + phdr->p_memsz; // None of these values are aligned. We consider the ragged edges of the // load command as defined, since they are mapped from the file. seg_start = RoundDownTo(seg_start, GetPageSizeCached()); seg_end = RoundUpTo(seg_end, GetPageSizeCached()); cb((void *)seg_start, seg_end - seg_start); } } } #endif #if defined(__x86_64__) && SANITIZER_LINUX // We cannot use glibc's clone wrapper, because it messes with the child // task's TLS. It writes the PID and TID of the child task to its thread // descriptor, but in our case the child task shares the thread descriptor with // the parent (because we don't know how to allocate a new thread // descriptor to keep glibc happy). So the stock version of clone(), when // used with CLONE_VM, would end up corrupting the parent's thread descriptor. uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg, int *parent_tidptr, void *newtls, int *child_tidptr) { long long res; if (!fn || !child_stack) return -EINVAL; CHECK_EQ(0, (uptr)child_stack % 16); child_stack = (char *)child_stack - 2 * sizeof(unsigned long long); ((unsigned long long *)child_stack)[0] = (uptr)fn; ((unsigned long long *)child_stack)[1] = (uptr)arg; register void *r8 __asm__("r8") = newtls; register int *r10 __asm__("r10") = child_tidptr; __asm__ __volatile__( /* %rax = syscall(%rax = SYSCALL(clone), * %rdi = flags, * %rsi = child_stack, * %rdx = parent_tidptr, * %r8 = new_tls, * %r10 = child_tidptr) */ "syscall\n" /* if (%rax != 0) * return; */ "testq %%rax,%%rax\n" "jnz 1f\n" /* In the child. Terminate unwind chain. */ // XXX: We should also terminate the CFI unwind chain // here. Unfortunately clang 3.2 doesn't support the // necessary CFI directives, so we skip that part. "xorq %%rbp,%%rbp\n" /* Call "fn(arg)". */ "popq %%rax\n" "popq %%rdi\n" "call *%%rax\n" /* Call _exit(%rax). */ "movq %%rax,%%rdi\n" "movq %2,%%rax\n" "syscall\n" /* Return to parent. */ "1:\n" : "=a" (res) : "a"(SYSCALL(clone)), "i"(SYSCALL(exit)), "S"(child_stack), "D"(flags), "d"(parent_tidptr), "r"(r8), "r"(r10) : "rsp", "memory", "r11", "rcx"); return res; } #endif // defined(__x86_64__) && SANITIZER_LINUX #if SANITIZER_ANDROID static atomic_uint8_t android_log_initialized; void AndroidLogInit() { atomic_store(&android_log_initialized, 1, memory_order_release); } // This thing is not, strictly speaking, async signal safe, but it does not seem // to cause any issues. Alternative is writing to log devices directly, but // their location and message format might change in the future, so we'd really // like to avoid that. void AndroidLogWrite(const char *buffer) { if (!atomic_load(&android_log_initialized, memory_order_acquire)) return; char *copy = internal_strdup(buffer); char *p = copy; char *q; // __android_log_write has an implicit message length limit. // Print one line at a time. do { q = internal_strchr(p, '\n'); if (q) *q = '\0'; __android_log_write(ANDROID_LOG_INFO, NULL, p); if (q) p = q + 1; } while (q); InternalFree(copy); } void GetExtraActivationFlags(char *buf, uptr size) { CHECK(size > PROP_VALUE_MAX); __system_property_get("asan.options", buf); } #endif bool IsDeadlySignal(int signum) { return (signum == SIGSEGV) && common_flags()->handle_segv; } } // namespace __sanitizer #endif // SANITIZER_FREEBSD || SANITIZER_LINUX