//===-- sanitizer_linux.cpp -----------------------------------------------===// // // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. // See https://llvm.org/LICENSE.txt for license information. // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception // //===----------------------------------------------------------------------===// // // 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 || SANITIZER_NETBSD || \ SANITIZER_OPENBSD || SANITIZER_SOLARIS #include "sanitizer_common.h" #include "sanitizer_flags.h" #include "sanitizer_getauxval.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" #if SANITIZER_LINUX #include #endif // For mips64, syscall(__NR_stat) fills the buffer in the 'struct kernel_stat' // format. Struct kernel_stat is defined as 'struct stat' in asm/stat.h. To // access stat from asm/stat.h, without conflicting with definition in // sys/stat.h, we use this trick. #if defined(__mips64) #include #include #define stat kernel_stat #include #undef stat #endif #include #include #include #include #include #include #include #include #include #if !SANITIZER_SOLARIS #include #endif #include #include #include #include #include #if !SANITIZER_OPENBSD #include #endif #if SANITIZER_OPENBSD #include #include #endif #include #if SANITIZER_LINUX #include #endif #if SANITIZER_LINUX && !SANITIZER_ANDROID #include #endif #if SANITIZER_FREEBSD #include #include #include extern "C" { // must be included after and on // FreeBSD 9.2 and 10.0. #include } #include #endif // SANITIZER_FREEBSD #if SANITIZER_NETBSD #include // For NAME_MAX #include #include extern struct ps_strings *__ps_strings; #endif // SANITIZER_NETBSD #if SANITIZER_SOLARIS #include #include #define environ _environ #endif extern char **environ; #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; const int FUTEX_PRIVATE_FLAG = 128; const int FUTEX_WAIT_PRIVATE = FUTEX_WAIT | FUTEX_PRIVATE_FLAG; const int FUTEX_WAKE_PRIVATE = FUTEX_WAKE | FUTEX_PRIVATE_FLAG; #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__) || defined(__powerpc64__) || \ SANITIZER_WORDSIZE == 64) # define SANITIZER_LINUX_USES_64BIT_SYSCALLS 1 #else # define SANITIZER_LINUX_USES_64BIT_SYSCALLS 0 #endif // Note : FreeBSD had implemented both // Linux and OpenBSD apis, available from // future 12.x version most likely #if SANITIZER_LINUX && defined(__NR_getrandom) # if !defined(GRND_NONBLOCK) # define GRND_NONBLOCK 1 # endif # define SANITIZER_USE_GETRANDOM 1 #else # define SANITIZER_USE_GETRANDOM 0 #endif // SANITIZER_LINUX && defined(__NR_getrandom) #if SANITIZER_OPENBSD # define SANITIZER_USE_GETENTROPY 1 #else # if SANITIZER_FREEBSD && __FreeBSD_version >= 1200000 # define SANITIZER_USE_GETENTROPY 1 # else # define SANITIZER_USE_GETENTROPY 0 # endif #endif // SANITIZER_USE_GETENTROPY namespace __sanitizer { #if SANITIZER_LINUX && defined(__x86_64__) #include "sanitizer_syscall_linux_x86_64.inc" #elif SANITIZER_LINUX && defined(__aarch64__) #include "sanitizer_syscall_linux_aarch64.inc" #elif SANITIZER_LINUX && defined(__arm__) #include "sanitizer_syscall_linux_arm.inc" #else #include "sanitizer_syscall_generic.inc" #endif // --------------- sanitizer_libc.h #if !SANITIZER_SOLARIS && !SANITIZER_NETBSD #if !SANITIZER_S390 && !SANITIZER_OPENBSD 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 // mmap2 specifies file offset in 4096-byte units. CHECK(IsAligned(offset, 4096)); return internal_syscall(SYSCALL(mmap2), addr, length, prot, flags, fd, offset / 4096); #endif } #endif // !SANITIZER_S390 && !SANITIZER_OPENBSD #if !SANITIZER_OPENBSD uptr internal_munmap(void *addr, uptr length) { return internal_syscall(SYSCALL(munmap), (uptr)addr, length); } int internal_mprotect(void *addr, uptr length, int prot) { return internal_syscall(SYSCALL(mprotect), (uptr)addr, length, prot); } #endif 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 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, (OFF_T)size)); return res; } #if !SANITIZER_LINUX_USES_64BIT_SYSCALLS && SANITIZER_LINUX 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; } #endif #if defined(__mips64) // Undefine compatibility macros from // so that they would not clash with the kernel_stat // st_[a|m|c]time fields #undef st_atime #undef st_mtime #undef st_ctime #if defined(SANITIZER_ANDROID) // Bionic sys/stat.h defines additional macros // for compatibility with the old NDKs and // they clash with the kernel_stat structure // st_[a|m|c]time_nsec fields. #undef st_atime_nsec #undef st_mtime_nsec #undef st_ctime_nsec #endif static void kernel_stat_to_stat(struct kernel_stat *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; #if defined(__USE_MISC) || \ defined(__USE_XOPEN2K8) || \ defined(SANITIZER_ANDROID) out->st_atim.tv_sec = in->st_atime; out->st_atim.tv_nsec = in->st_atime_nsec; out->st_mtim.tv_sec = in->st_mtime; out->st_mtim.tv_nsec = in->st_mtime_nsec; out->st_ctim.tv_sec = in->st_ctime; out->st_ctim.tv_nsec = in->st_ctime_nsec; #else out->st_atime = in->st_atime; out->st_atimensec = in->st_atime_nsec; out->st_mtime = in->st_mtime; out->st_mtimensec = in->st_mtime_nsec; out->st_ctime = in->st_ctime; out->st_atimensec = in->st_ctime_nsec; #endif } #endif uptr internal_stat(const char *path, void *buf) { #if SANITIZER_FREEBSD || SANITIZER_OPENBSD return internal_syscall(SYSCALL(fstatat), AT_FDCWD, (uptr)path, (uptr)buf, 0); #elif SANITIZER_USES_CANONICAL_LINUX_SYSCALLS return internal_syscall(SYSCALL(newfstatat), AT_FDCWD, (uptr)path, (uptr)buf, 0); #elif SANITIZER_LINUX_USES_64BIT_SYSCALLS # if defined(__mips64) // For mips64, stat syscall fills buffer in the format of kernel_stat struct kernel_stat kbuf; int res = internal_syscall(SYSCALL(stat), path, &kbuf); kernel_stat_to_stat(&kbuf, (struct stat *)buf); return res; # else return internal_syscall(SYSCALL(stat), (uptr)path, (uptr)buf); # endif #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 || SANITIZER_OPENBSD return internal_syscall(SYSCALL(fstatat), AT_FDCWD, (uptr)path, (uptr)buf, AT_SYMLINK_NOFOLLOW); #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 # if SANITIZER_MIPS64 // For mips64, lstat syscall fills buffer in the format of kernel_stat struct kernel_stat kbuf; int res = internal_syscall(SYSCALL(lstat), path, &kbuf); kernel_stat_to_stat(&kbuf, (struct stat *)buf); return res; # else return internal_syscall(SYSCALL(lstat), (uptr)path, (uptr)buf); # endif #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_OPENBSD || \ SANITIZER_LINUX_USES_64BIT_SYSCALLS #if SANITIZER_MIPS64 && !SANITIZER_OPENBSD // For mips64, fstat syscall fills buffer in the format of kernel_stat struct kernel_stat kbuf; int res = internal_syscall(SYSCALL(fstat), fd, &kbuf); kernel_stat_to_stat(&kbuf, (struct stat *)buf); return res; # else return internal_syscall(SYSCALL(fstat), fd, (uptr)buf); # endif #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_dup(int oldfd) { return internal_syscall(SYSCALL(dup), oldfd); } 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); #elif SANITIZER_OPENBSD 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 || SANITIZER_OPENBSD 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 defined(__riscv) return internal_syscall(SYSCALL(renameat2), AT_FDCWD, (uptr)oldpath, AT_FDCWD, (uptr)newpath, 0); #elif SANITIZER_USES_CANONICAL_LINUX_SYSCALLS || SANITIZER_OPENBSD 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 || SANITIZER_OPENBSD internal_syscall(SYSCALL(exit), exitcode); #else internal_syscall(SYSCALL(exit_group), exitcode); #endif Die(); // Unreachable. } unsigned int internal_sleep(unsigned int seconds) { struct timespec ts; ts.tv_sec = seconds; ts.tv_nsec = 0; int res = internal_syscall(SYSCALL(nanosleep), &ts, &ts); if (res) return ts.tv_sec; return 0; } uptr internal_execve(const char *filename, char *const argv[], char *const envp[]) { return internal_syscall(SYSCALL(execve), (uptr)filename, (uptr)argv, (uptr)envp); } #endif // !SANITIZER_SOLARIS && !SANITIZER_NETBSD // ----------------- sanitizer_common.h bool FileExists(const char *filename) { if (ShouldMockFailureToOpen(filename)) return false; 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); } #if !SANITIZER_NETBSD tid_t GetTid() { #if SANITIZER_FREEBSD long Tid; thr_self(&Tid); return Tid; #elif SANITIZER_OPENBSD return internal_syscall(SYSCALL(getthrid)); #elif SANITIZER_SOLARIS return thr_self(); #else return internal_syscall(SYSCALL(gettid)); #endif } int TgKill(pid_t pid, tid_t tid, int sig) { #if SANITIZER_LINUX return internal_syscall(SYSCALL(tgkill), pid, tid, sig); #elif SANITIZER_FREEBSD return internal_syscall(SYSCALL(thr_kill2), pid, tid, sig); #elif SANITIZER_OPENBSD (void)pid; return internal_syscall(SYSCALL(thrkill), tid, sig, nullptr); #elif SANITIZER_SOLARIS (void)pid; return thr_kill(tid, sig); #endif } #endif #if !SANITIZER_SOLARIS && !SANITIZER_NETBSD u64 NanoTime() { #if SANITIZER_FREEBSD || SANITIZER_OPENBSD timeval tv; #else kernel_timeval tv; #endif internal_memset(&tv, 0, sizeof(tv)); internal_syscall(SYSCALL(gettimeofday), &tv, 0); return (u64)tv.tv_sec * 1000*1000*1000 + tv.tv_usec * 1000; } uptr internal_clock_gettime(__sanitizer_clockid_t clk_id, void *tp) { return internal_syscall(SYSCALL(clock_gettime), clk_id, tp); } #endif // !SANITIZER_SOLARIS && !SANITIZER_NETBSD // Like getenv, but reads env directly from /proc (on Linux) or parses the // 'environ' array (on some others) and does not use libc. This function // should be called first inside __asan_init. const char *GetEnv(const char *name) { #if SANITIZER_FREEBSD || SANITIZER_NETBSD || SANITIZER_OPENBSD || \ SANITIZER_SOLARIS 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; if (!ReadFileToBuffer("/proc/self/environ", &environ, &environ_size, &len)) environ = nullptr; } if (!environ || len == 0) return nullptr; 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) // this entry isn't NUL terminated return nullptr; else if (!internal_memcmp(p, name, namelen) && p[namelen] == '=') // Match. return p + namelen + 1; // point after = p = endp + 1; } return nullptr; // Not found. #else #error "Unsupported platform" #endif } #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD && !SANITIZER_OPENBSD extern "C" { SANITIZER_WEAK_ATTRIBUTE extern void *__libc_stack_end; } #endif #if !SANITIZER_GO && !SANITIZER_FREEBSD && !SANITIZER_NETBSD && \ !SANITIZER_OPENBSD static void ReadNullSepFileToArray(const char *path, char ***arr, int arr_size) { char *buff; uptr buff_size; uptr buff_len; *arr = (char **)MmapOrDie(arr_size * sizeof(char *), "NullSepFileArray"); if (!ReadFileToBuffer(path, &buff, &buff_size, &buff_len, 1024 * 1024)) { (*arr)[0] = nullptr; return; } (*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] = nullptr; } #endif #if !SANITIZER_OPENBSD static void GetArgsAndEnv(char ***argv, char ***envp) { #if SANITIZER_FREEBSD // On FreeBSD, retrieving the argument and environment arrays is done via the // kern.ps_strings sysctl, which returns a pointer to a structure containing // this information. See also . ps_strings *pss; uptr sz = sizeof(pss); if (internal_sysctlbyname("kern.ps_strings", &pss, &sz, NULL, 0) == -1) { Printf("sysctl kern.ps_strings failed\n"); Die(); } *argv = pss->ps_argvstr; *envp = pss->ps_envstr; #elif SANITIZER_NETBSD *argv = __ps_strings->ps_argvstr; *envp = __ps_strings->ps_envstr; #else // SANITIZER_FREEBSD #if !SANITIZER_GO if (&__libc_stack_end) { #endif // !SANITIZER_GO 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 // !SANITIZER_GO #endif // SANITIZER_FREEBSD } char **GetArgv() { char **argv, **envp; GetArgsAndEnv(&argv, &envp); return argv; } char **GetEnviron() { char **argv, **envp; GetArgsAndEnv(&argv, &envp); return envp; } #endif // !SANITIZER_OPENBSD #if !SANITIZER_SOLARIS enum MutexState { MtxUnlocked = 0, MtxLocked = 1, MtxSleeping = 2 }; BlockingMutex::BlockingMutex() { internal_memset(this, 0, sizeof(*this)); } void BlockingMutex::Lock() { CHECK_EQ(owner_, 0); 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); #elif SANITIZER_NETBSD sched_yield(); /* No userspace futex-like synchronization */ #else internal_syscall(SYSCALL(futex), (uptr)m, FUTEX_WAIT_PRIVATE, MtxSleeping, 0, 0, 0); #endif } } void BlockingMutex::Unlock() { atomic_uint32_t *m = reinterpret_cast(&opaque_storage_); u32 v = atomic_exchange(m, MtxUnlocked, memory_order_release); CHECK_NE(v, MtxUnlocked); if (v == MtxSleeping) { #if SANITIZER_FREEBSD _umtx_op(m, UMTX_OP_WAKE, 1, 0, 0); #elif SANITIZER_NETBSD /* No userspace futex-like synchronization */ #else internal_syscall(SYSCALL(futex), (uptr)m, FUTEX_WAKE_PRIVATE, 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)); } #endif // !SANITIZER_SOLARIS // ----------------- 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. #if SANITIZER_NETBSD // Not used #elif SANITIZER_OPENBSD // struct dirent is different for Linux and us. At this moment, we use only // d_fileno (Linux call this d_ino), d_reclen, and d_name. struct linux_dirent { u64 d_ino; // d_fileno u16 d_reclen; u16 d_namlen; // not used u8 d_type; // not used char d_name[NAME_MAX + 1]; }; #else struct linux_dirent { #if SANITIZER_X32 || defined(__aarch64__) u64 d_ino; u64 d_off; #else unsigned long d_ino; unsigned long d_off; #endif unsigned short d_reclen; #ifdef __aarch64__ unsigned char d_type; #endif char d_name[256]; }; #endif #if !SANITIZER_SOLARIS && !SANITIZER_NETBSD // 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_FREEBSD return internal_syscall(SYSCALL(getdirentries), fd, (uptr)dirp, count, NULL); #elif 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 void *ss, void *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_FREEBSD || SANITIZER_OPENBSD int internal_sysctl(const int *name, unsigned int namelen, void *oldp, uptr *oldlenp, const void *newp, uptr newlen) { #if SANITIZER_OPENBSD return sysctl(name, namelen, oldp, (size_t *)oldlenp, (void *)newp, (size_t)newlen); #else return internal_syscall(SYSCALL(__sysctl), name, namelen, oldp, (size_t *)oldlenp, newp, (size_t)newlen); #endif } #if SANITIZER_FREEBSD int internal_sysctlbyname(const char *sname, void *oldp, uptr *oldlenp, const void *newp, uptr newlen) { static decltype(sysctlbyname) *real = nullptr; if (!real) real = (decltype(sysctlbyname) *)dlsym(RTLD_NEXT, "sysctlbyname"); CHECK(real); return real(sname, oldp, (size_t *)oldlenp, newp, (size_t)newlen); } #endif #endif #if SANITIZER_LINUX #define SA_RESTORER 0x04000000 // Doesn't set sa_restorer if the caller did not set it, so 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)); // Without SA_RESTORER kernel ignores the calls (probably returns EINVAL). k_act.sa_flags = u_act->sa_flags | SA_RESTORER; // 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). #if !SANITIZER_ANDROID || !SANITIZER_MIPS32 k_act.sa_restorer = u_act->sa_restorer; #endif } uptr result = internal_syscall(SYSCALL(rt_sigaction), (uptr)signum, (uptr)(u_act ? &k_act : nullptr), (uptr)(u_oldact ? &k_oldact : nullptr), (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; #if !SANITIZER_ANDROID || !SANITIZER_MIPS32 u_oldact->sa_restorer = k_oldact.sa_restorer; #endif } return result; } #endif // SANITIZER_LINUX uptr internal_sigprocmask(int how, __sanitizer_sigset_t *set, __sanitizer_sigset_t *oldset) { #if SANITIZER_FREEBSD || SANITIZER_OPENBSD 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)); } void internal_sigemptyset(__sanitizer_sigset_t *set) { internal_memset(set, 0, 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); } bool internal_sigismember(__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); return k_set->sig[idx] & (1 << bit); } #elif SANITIZER_FREEBSD void internal_sigdelset(__sanitizer_sigset_t *set, int signum) { sigset_t *rset = reinterpret_cast(set); sigdelset(rset, signum); } bool internal_sigismember(__sanitizer_sigset_t *set, int signum) { sigset_t *rset = reinterpret_cast(set); return sigismember(rset, signum); } #endif #endif // !SANITIZER_SOLARIS #if !SANITIZER_NETBSD // ThreadLister implementation. ThreadLister::ThreadLister(pid_t pid) : pid_(pid), buffer_(4096) { char task_directory_path[80]; internal_snprintf(task_directory_path, sizeof(task_directory_path), "/proc/%d/task/", pid); descriptor_ = internal_open(task_directory_path, O_RDONLY | O_DIRECTORY); if (internal_iserror(descriptor_)) { Report("Can't open /proc/%d/task for reading.\n", pid); } } ThreadLister::Result ThreadLister::ListThreads( InternalMmapVector *threads) { if (internal_iserror(descriptor_)) return Error; internal_lseek(descriptor_, 0, SEEK_SET); threads->clear(); Result result = Ok; for (bool first_read = true;; first_read = false) { // Resize to max capacity if it was downsized by IsAlive. buffer_.resize(buffer_.capacity()); CHECK_GE(buffer_.size(), 4096); uptr read = internal_getdents( descriptor_, (struct linux_dirent *)buffer_.data(), buffer_.size()); if (!read) return result; if (internal_iserror(read)) { Report("Can't read directory entries from /proc/%d/task.\n", pid_); return Error; } for (uptr begin = (uptr)buffer_.data(), end = begin + read; begin < end;) { struct linux_dirent *entry = (struct linux_dirent *)begin; begin += entry->d_reclen; if (entry->d_ino == 1) { // Inode 1 is for bad blocks and also can be a reason for early return. // Should be emitted if kernel tried to output terminating thread. // See proc_task_readdir implementation in Linux. result = Incomplete; } if (entry->d_ino && *entry->d_name >= '0' && *entry->d_name <= '9') threads->push_back(internal_atoll(entry->d_name)); } // Now we are going to detect short-read or early EOF. In such cases Linux // can return inconsistent list with missing alive threads. // Code will just remember that the list can be incomplete but it will // continue reads to return as much as possible. if (!first_read) { // The first one was a short-read by definition. result = Incomplete; } else if (read > buffer_.size() - 1024) { // Read was close to the buffer size. So double the size and assume the // worst. buffer_.resize(buffer_.size() * 2); result = Incomplete; } else if (!threads->empty() && !IsAlive(threads->back())) { // Maybe Linux early returned from read on terminated thread (!pid_alive) // and failed to restore read position. // See next_tid and proc_task_instantiate in Linux. result = Incomplete; } } } bool ThreadLister::IsAlive(int tid) { // /proc/%d/task/%d/status uses same call to detect alive threads as // proc_task_readdir. See task_state implementation in Linux. char path[80]; internal_snprintf(path, sizeof(path), "/proc/%d/task/%d/status", pid_, tid); if (!ReadFileToVector(path, &buffer_) || buffer_.empty()) return false; buffer_.push_back(0); static const char kPrefix[] = "\nPPid:"; const char *field = internal_strstr(buffer_.data(), kPrefix); if (!field) return false; field += internal_strlen(kPrefix); return (int)internal_atoll(field) != 0; } ThreadLister::~ThreadLister() { if (!internal_iserror(descriptor_)) internal_close(descriptor_); } #endif #if SANITIZER_WORDSIZE == 32 // Take care of unusable kernel area in top gigabyte. static uptr GetKernelAreaSize() { #if SANITIZER_LINUX && !SANITIZER_X32 const uptr gbyte = 1UL << 30; // Firstly check if there are writable segments // mapped to top gigabyte (e.g. stack). MemoryMappingLayout proc_maps(/*cache_enabled*/true); if (proc_maps.Error()) return 0; MemoryMappedSegment segment; while (proc_maps.Next(&segment)) { if ((segment.end >= 3 * gbyte) && segment.IsWritable()) return 0; } #if !SANITIZER_ANDROID // Even if nothing is mapped, top Gb may still be accessible // if we are running on 64-bit kernel. // Uname may report misleading results if personality type // is modified (e.g. under schroot) so check this as well. struct utsname uname_info; int pers = personality(0xffffffffUL); if (!(pers & PER_MASK) && uname(&uname_info) == 0 && internal_strstr(uname_info.machine, "64")) return 0; #endif // SANITIZER_ANDROID // Top gigabyte is reserved for kernel. return gbyte; #else return 0; #endif // SANITIZER_LINUX && !SANITIZER_X32 } #endif // SANITIZER_WORDSIZE == 32 uptr GetMaxVirtualAddress() { #if (SANITIZER_NETBSD || SANITIZER_OPENBSD) && defined(__x86_64__) return 0x7f7ffffff000ULL; // (0x00007f8000000000 - PAGE_SIZE) #elif SANITIZER_WORDSIZE == 64 # if defined(__powerpc64__) || defined(__aarch64__) // On PowerPC64 we have two different address space layouts: 44- and 46-bit. // We somehow need to figure out which one we are using now and choose // one of 0x00000fffffffffffUL and 0x00003fffffffffffUL. // Note that with 'ulimit -s unlimited' the stack is moved away from the top // of the address space, so simply checking the stack address is not enough. // This should (does) work for both PowerPC64 Endian modes. // Similarly, aarch64 has multiple address space layouts: 39, 42 and 47-bit. return (1ULL << (MostSignificantSetBitIndex(GET_CURRENT_FRAME()) + 1)) - 1; # elif defined(__mips64) return (1ULL << 40) - 1; // 0x000000ffffffffffUL; # elif defined(__s390x__) return (1ULL << 53) - 1; // 0x001fffffffffffffUL; #elif defined(__sparc__) return ~(uptr)0; # else return (1ULL << 47) - 1; // 0x00007fffffffffffUL; # endif #else // SANITIZER_WORDSIZE == 32 # if defined(__s390__) return (1ULL << 31) - 1; // 0x7fffffff; # else return (1ULL << 32) - 1; // 0xffffffff; # endif #endif // SANITIZER_WORDSIZE } uptr GetMaxUserVirtualAddress() { uptr addr = GetMaxVirtualAddress(); #if SANITIZER_WORDSIZE == 32 && !defined(__s390__) if (!common_flags()->full_address_space) addr -= GetKernelAreaSize(); CHECK_LT(reinterpret_cast(&addr), addr); #endif return addr; } #if !SANITIZER_ANDROID uptr GetPageSize() { #if SANITIZER_LINUX && (defined(__x86_64__) || defined(__i386__)) return EXEC_PAGESIZE; #elif SANITIZER_FREEBSD || SANITIZER_NETBSD // Use sysctl as sysconf can trigger interceptors internally. int pz = 0; uptr pzl = sizeof(pz); int mib[2] = {CTL_HW, HW_PAGESIZE}; int rv = internal_sysctl(mib, 2, &pz, &pzl, nullptr, 0); CHECK_EQ(rv, 0); return (uptr)pz; #elif SANITIZER_USE_GETAUXVAL return getauxval(AT_PAGESZ); #else return sysconf(_SC_PAGESIZE); // EXEC_PAGESIZE may not be trustworthy. #endif } #endif // !SANITIZER_ANDROID #if !SANITIZER_OPENBSD uptr ReadBinaryName(/*out*/char *buf, uptr buf_len) { #if SANITIZER_SOLARIS const char *default_module_name = getexecname(); CHECK_NE(default_module_name, NULL); return internal_snprintf(buf, buf_len, "%s", default_module_name); #else #if SANITIZER_FREEBSD || SANITIZER_NETBSD #if SANITIZER_FREEBSD const int Mib[4] = {CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1}; #else const int Mib[4] = {CTL_KERN, KERN_PROC_ARGS, -1, KERN_PROC_PATHNAME}; #endif const char *default_module_name = "kern.proc.pathname"; uptr Size = buf_len; bool IsErr = (internal_sysctl(Mib, ARRAY_SIZE(Mib), buf, &Size, NULL, 0) != 0); int readlink_error = IsErr ? errno : 0; uptr module_name_len = Size; #else const char *default_module_name = "/proc/self/exe"; uptr module_name_len = internal_readlink( default_module_name, buf, buf_len); int readlink_error; bool IsErr = internal_iserror(module_name_len, &readlink_error); #endif // SANITIZER_SOLARIS if (IsErr) { // We can't read binary name for some reason, assume it's unknown. Report("WARNING: reading executable name failed with errno %d, " "some stack frames may not be symbolized\n", readlink_error); module_name_len = internal_snprintf(buf, buf_len, "%s", default_module_name); CHECK_LT(module_name_len, buf_len); } return module_name_len; #endif } #endif // !SANITIZER_OPENBSD uptr ReadLongProcessName(/*out*/ char *buf, uptr buf_len) { #if SANITIZER_LINUX char *tmpbuf; uptr tmpsize; uptr tmplen; if (ReadFileToBuffer("/proc/self/cmdline", &tmpbuf, &tmpsize, &tmplen, 1024 * 1024)) { internal_strncpy(buf, tmpbuf, buf_len); UnmapOrDie(tmpbuf, tmpsize); return internal_strlen(buf); } #endif return ReadBinaryName(buf, buf_len); } // 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)) { CHECK_NE(map, nullptr); #if !SANITIZER_FREEBSD && !SANITIZER_OPENBSD typedef ElfW(Phdr) Elf_Phdr; typedef ElfW(Ehdr) Elf_Ehdr; #endif // !SANITIZER_FREEBSD && !SANITIZER_OPENBSD 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) : "memory", "r11", "rcx"); return res; } #elif defined(__mips__) 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 *a3 __asm__("$7") = newtls; register int *a4 __asm__("$8") = child_tidptr; // We don't have proper CFI directives here because it requires alot of code // for very marginal benefits. __asm__ __volatile__( /* $v0 = syscall($v0 = __NR_clone, * $a0 = flags, * $a1 = child_stack, * $a2 = parent_tidptr, * $a3 = new_tls, * $a4 = child_tidptr) */ ".cprestore 16;\n" "move $4,%1;\n" "move $5,%2;\n" "move $6,%3;\n" "move $7,%4;\n" /* Store the fifth argument on stack * if we are using 32-bit abi. */ #if SANITIZER_WORDSIZE == 32 "lw %5,16($29);\n" #else "move $8,%5;\n" #endif "li $2,%6;\n" "syscall;\n" /* if ($v0 != 0) * return; */ "bnez $2,1f;\n" /* Call "fn(arg)". */ #if SANITIZER_WORDSIZE == 32 #ifdef __BIG_ENDIAN__ "lw $25,4($29);\n" "lw $4,12($29);\n" #else "lw $25,0($29);\n" "lw $4,8($29);\n" #endif #else "ld $25,0($29);\n" "ld $4,8($29);\n" #endif "jal $25;\n" /* Call _exit($v0). */ "move $4,$2;\n" "li $2,%7;\n" "syscall;\n" /* Return to parent. */ "1:\n" : "=r" (res) : "r"(flags), "r"(child_stack), "r"(parent_tidptr), "r"(a3), "r"(a4), "i"(__NR_clone), "i"(__NR_exit) : "memory", "$29" ); return res; } #elif defined(__aarch64__) 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 int (*__fn)(void *) __asm__("x0") = fn; register void *__stack __asm__("x1") = child_stack; register int __flags __asm__("x2") = flags; register void *__arg __asm__("x3") = arg; register int *__ptid __asm__("x4") = parent_tidptr; register void *__tls __asm__("x5") = newtls; register int *__ctid __asm__("x6") = child_tidptr; __asm__ __volatile__( "mov x0,x2\n" /* flags */ "mov x2,x4\n" /* ptid */ "mov x3,x5\n" /* tls */ "mov x4,x6\n" /* ctid */ "mov x8,%9\n" /* clone */ "svc 0x0\n" /* if (%r0 != 0) * return %r0; */ "cmp x0, #0\n" "bne 1f\n" /* In the child, now. Call "fn(arg)". */ "ldp x1, x0, [sp], #16\n" "blr x1\n" /* Call _exit(%r0). */ "mov x8, %10\n" "svc 0x0\n" "1:\n" : "=r" (res) : "i"(-EINVAL), "r"(__fn), "r"(__stack), "r"(__flags), "r"(__arg), "r"(__ptid), "r"(__tls), "r"(__ctid), "i"(__NR_clone), "i"(__NR_exit) : "x30", "memory"); return res; } #elif defined(__powerpc64__) uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg, int *parent_tidptr, void *newtls, int *child_tidptr) { long long res; // Stack frame structure. #if SANITIZER_PPC64V1 // Back chain == 0 (SP + 112) // Frame (112 bytes): // Parameter save area (SP + 48), 8 doublewords // TOC save area (SP + 40) // Link editor doubleword (SP + 32) // Compiler doubleword (SP + 24) // LR save area (SP + 16) // CR save area (SP + 8) // Back chain (SP + 0) # define FRAME_SIZE 112 # define FRAME_TOC_SAVE_OFFSET 40 #elif SANITIZER_PPC64V2 // Back chain == 0 (SP + 32) // Frame (32 bytes): // TOC save area (SP + 24) // LR save area (SP + 16) // CR save area (SP + 8) // Back chain (SP + 0) # define FRAME_SIZE 32 # define FRAME_TOC_SAVE_OFFSET 24 #else # error "Unsupported PPC64 ABI" #endif if (!fn || !child_stack) return -EINVAL; CHECK_EQ(0, (uptr)child_stack % 16); register int (*__fn)(void *) __asm__("r3") = fn; register void *__cstack __asm__("r4") = child_stack; register int __flags __asm__("r5") = flags; register void *__arg __asm__("r6") = arg; register int *__ptidptr __asm__("r7") = parent_tidptr; register void *__newtls __asm__("r8") = newtls; register int *__ctidptr __asm__("r9") = child_tidptr; __asm__ __volatile__( /* fn and arg are saved across the syscall */ "mr 28, %5\n\t" "mr 27, %8\n\t" /* syscall r0 == __NR_clone r3 == flags r4 == child_stack r5 == parent_tidptr r6 == newtls r7 == child_tidptr */ "mr 3, %7\n\t" "mr 5, %9\n\t" "mr 6, %10\n\t" "mr 7, %11\n\t" "li 0, %3\n\t" "sc\n\t" /* Test if syscall was successful */ "cmpdi cr1, 3, 0\n\t" "crandc cr1*4+eq, cr1*4+eq, cr0*4+so\n\t" "bne- cr1, 1f\n\t" /* Set up stack frame */ "li 29, 0\n\t" "stdu 29, -8(1)\n\t" "stdu 1, -%12(1)\n\t" /* Do the function call */ "std 2, %13(1)\n\t" #if SANITIZER_PPC64V1 "ld 0, 0(28)\n\t" "ld 2, 8(28)\n\t" "mtctr 0\n\t" #elif SANITIZER_PPC64V2 "mr 12, 28\n\t" "mtctr 12\n\t" #else # error "Unsupported PPC64 ABI" #endif "mr 3, 27\n\t" "bctrl\n\t" "ld 2, %13(1)\n\t" /* Call _exit(r3) */ "li 0, %4\n\t" "sc\n\t" /* Return to parent */ "1:\n\t" "mr %0, 3\n\t" : "=r" (res) : "0" (-1), "i" (EINVAL), "i" (__NR_clone), "i" (__NR_exit), "r" (__fn), "r" (__cstack), "r" (__flags), "r" (__arg), "r" (__ptidptr), "r" (__newtls), "r" (__ctidptr), "i" (FRAME_SIZE), "i" (FRAME_TOC_SAVE_OFFSET) : "cr0", "cr1", "memory", "ctr", "r0", "r27", "r28", "r29"); return res; } #elif defined(__i386__) && SANITIZER_LINUX uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg, int *parent_tidptr, void *newtls, int *child_tidptr) { int res; if (!fn || !child_stack) return -EINVAL; CHECK_EQ(0, (uptr)child_stack % 16); child_stack = (char *)child_stack - 7 * sizeof(unsigned int); ((unsigned int *)child_stack)[0] = (uptr)flags; ((unsigned int *)child_stack)[1] = (uptr)0; ((unsigned int *)child_stack)[2] = (uptr)fn; ((unsigned int *)child_stack)[3] = (uptr)arg; __asm__ __volatile__( /* %eax = syscall(%eax = SYSCALL(clone), * %ebx = flags, * %ecx = child_stack, * %edx = parent_tidptr, * %esi = new_tls, * %edi = child_tidptr) */ /* Obtain flags */ "movl (%%ecx), %%ebx\n" /* Do the system call */ "pushl %%ebx\n" "pushl %%esi\n" "pushl %%edi\n" /* Remember the flag value. */ "movl %%ebx, (%%ecx)\n" "int $0x80\n" "popl %%edi\n" "popl %%esi\n" "popl %%ebx\n" /* if (%eax != 0) * return; */ "test %%eax,%%eax\n" "jnz 1f\n" /* terminate the stack frame */ "xorl %%ebp,%%ebp\n" /* Call FN. */ "call *%%ebx\n" #ifdef PIC "call here\n" "here:\n" "popl %%ebx\n" "addl $_GLOBAL_OFFSET_TABLE_+[.-here], %%ebx\n" #endif /* Call exit */ "movl %%eax, %%ebx\n" "movl %2, %%eax\n" "int $0x80\n" "1:\n" : "=a" (res) : "a"(SYSCALL(clone)), "i"(SYSCALL(exit)), "c"(child_stack), "d"(parent_tidptr), "S"(newtls), "D"(child_tidptr) : "memory"); return res; } #elif defined(__arm__) && SANITIZER_LINUX uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg, int *parent_tidptr, void *newtls, int *child_tidptr) { unsigned int res; if (!fn || !child_stack) return -EINVAL; child_stack = (char *)child_stack - 2 * sizeof(unsigned int); ((unsigned int *)child_stack)[0] = (uptr)fn; ((unsigned int *)child_stack)[1] = (uptr)arg; register int r0 __asm__("r0") = flags; register void *r1 __asm__("r1") = child_stack; register int *r2 __asm__("r2") = parent_tidptr; register void *r3 __asm__("r3") = newtls; register int *r4 __asm__("r4") = child_tidptr; register int r7 __asm__("r7") = __NR_clone; #if __ARM_ARCH > 4 || defined (__ARM_ARCH_4T__) # define ARCH_HAS_BX #endif #if __ARM_ARCH > 4 # define ARCH_HAS_BLX #endif #ifdef ARCH_HAS_BX # ifdef ARCH_HAS_BLX # define BLX(R) "blx " #R "\n" # else # define BLX(R) "mov lr, pc; bx " #R "\n" # endif #else # define BLX(R) "mov lr, pc; mov pc," #R "\n" #endif __asm__ __volatile__( /* %r0 = syscall(%r7 = SYSCALL(clone), * %r0 = flags, * %r1 = child_stack, * %r2 = parent_tidptr, * %r3 = new_tls, * %r4 = child_tidptr) */ /* Do the system call */ "swi 0x0\n" /* if (%r0 != 0) * return %r0; */ "cmp r0, #0\n" "bne 1f\n" /* In the child, now. Call "fn(arg)". */ "ldr r0, [sp, #4]\n" "ldr ip, [sp], #8\n" BLX(ip) /* Call _exit(%r0). */ "mov r7, %7\n" "swi 0x0\n" "1:\n" "mov %0, r0\n" : "=r"(res) : "r"(r0), "r"(r1), "r"(r2), "r"(r3), "r"(r4), "r"(r7), "i"(__NR_exit) : "memory"); return res; } #endif // defined(__x86_64__) && SANITIZER_LINUX #if SANITIZER_ANDROID #if __ANDROID_API__ < 21 extern "C" __attribute__((weak)) int dl_iterate_phdr( int (*)(struct dl_phdr_info *, size_t, void *), void *); #endif static int dl_iterate_phdr_test_cb(struct dl_phdr_info *info, size_t size, void *data) { // Any name starting with "lib" indicates a bug in L where library base names // are returned instead of paths. if (info->dlpi_name && info->dlpi_name[0] == 'l' && info->dlpi_name[1] == 'i' && info->dlpi_name[2] == 'b') { *(bool *)data = true; return 1; } return 0; } static atomic_uint32_t android_api_level; static AndroidApiLevel AndroidDetectApiLevelStatic() { #if __ANDROID_API__ <= 19 return ANDROID_KITKAT; #elif __ANDROID_API__ <= 22 return ANDROID_LOLLIPOP_MR1; #else return ANDROID_POST_LOLLIPOP; #endif } static AndroidApiLevel AndroidDetectApiLevel() { if (!&dl_iterate_phdr) return ANDROID_KITKAT; // K or lower bool base_name_seen = false; dl_iterate_phdr(dl_iterate_phdr_test_cb, &base_name_seen); if (base_name_seen) return ANDROID_LOLLIPOP_MR1; // L MR1 return ANDROID_POST_LOLLIPOP; // post-L // Plain L (API level 21) is completely broken wrt ASan and not very // interesting to detect. } extern "C" __attribute__((weak)) void* _DYNAMIC; AndroidApiLevel AndroidGetApiLevel() { AndroidApiLevel level = (AndroidApiLevel)atomic_load(&android_api_level, memory_order_relaxed); if (level) return level; level = &_DYNAMIC == nullptr ? AndroidDetectApiLevelStatic() : AndroidDetectApiLevel(); atomic_store(&android_api_level, level, memory_order_relaxed); return level; } #endif static HandleSignalMode GetHandleSignalModeImpl(int signum) { switch (signum) { case SIGABRT: return common_flags()->handle_abort; case SIGILL: return common_flags()->handle_sigill; case SIGTRAP: return common_flags()->handle_sigtrap; case SIGFPE: return common_flags()->handle_sigfpe; case SIGSEGV: return common_flags()->handle_segv; case SIGBUS: return common_flags()->handle_sigbus; } return kHandleSignalNo; } HandleSignalMode GetHandleSignalMode(int signum) { HandleSignalMode result = GetHandleSignalModeImpl(signum); if (result == kHandleSignalYes && !common_flags()->allow_user_segv_handler) return kHandleSignalExclusive; return result; } #if !SANITIZER_GO void *internal_start_thread(void(*func)(void *arg), void *arg) { // Start the thread with signals blocked, otherwise it can steal user signals. __sanitizer_sigset_t set, old; internal_sigfillset(&set); #if SANITIZER_LINUX && !SANITIZER_ANDROID // Glibc uses SIGSETXID signal during setuid call. If this signal is blocked // on any thread, setuid call hangs (see test/tsan/setuid.c). internal_sigdelset(&set, 33); #endif internal_sigprocmask(SIG_SETMASK, &set, &old); void *th; real_pthread_create(&th, nullptr, (void*(*)(void *arg))func, arg); internal_sigprocmask(SIG_SETMASK, &old, nullptr); return th; } void internal_join_thread(void *th) { real_pthread_join(th, nullptr); } #else void *internal_start_thread(void (*func)(void *), void *arg) { return 0; } void internal_join_thread(void *th) {} #endif #if defined(__aarch64__) // Android headers in the older NDK releases miss this definition. struct __sanitizer_esr_context { struct _aarch64_ctx head; uint64_t esr; }; static bool Aarch64GetESR(ucontext_t *ucontext, u64 *esr) { static const u32 kEsrMagic = 0x45535201; u8 *aux = ucontext->uc_mcontext.__reserved; while (true) { _aarch64_ctx *ctx = (_aarch64_ctx *)aux; if (ctx->size == 0) break; if (ctx->magic == kEsrMagic) { *esr = ((__sanitizer_esr_context *)ctx)->esr; return true; } aux += ctx->size; } return false; } #endif #if SANITIZER_OPENBSD using Context = sigcontext; #else using Context = ucontext_t; #endif SignalContext::WriteFlag SignalContext::GetWriteFlag() const { Context *ucontext = (Context *)context; #if defined(__x86_64__) || defined(__i386__) static const uptr PF_WRITE = 1U << 1; #if SANITIZER_FREEBSD uptr err = ucontext->uc_mcontext.mc_err; #elif SANITIZER_NETBSD uptr err = ucontext->uc_mcontext.__gregs[_REG_ERR]; #elif SANITIZER_OPENBSD uptr err = ucontext->sc_err; #elif SANITIZER_SOLARIS && defined(__i386__) const int Err = 13; uptr err = ucontext->uc_mcontext.gregs[Err]; #else uptr err = ucontext->uc_mcontext.gregs[REG_ERR]; #endif // SANITIZER_FREEBSD return err & PF_WRITE ? WRITE : READ; #elif defined(__mips__) uint32_t *exception_source; uint32_t faulty_instruction; uint32_t op_code; exception_source = (uint32_t *)ucontext->uc_mcontext.pc; faulty_instruction = (uint32_t)(*exception_source); op_code = (faulty_instruction >> 26) & 0x3f; // FIXME: Add support for FPU, microMIPS, DSP, MSA memory instructions. switch (op_code) { case 0x28: // sb case 0x29: // sh case 0x2b: // sw case 0x3f: // sd #if __mips_isa_rev < 6 case 0x2c: // sdl case 0x2d: // sdr case 0x2a: // swl case 0x2e: // swr #endif return SignalContext::WRITE; case 0x20: // lb case 0x24: // lbu case 0x21: // lh case 0x25: // lhu case 0x23: // lw case 0x27: // lwu case 0x37: // ld #if __mips_isa_rev < 6 case 0x1a: // ldl case 0x1b: // ldr case 0x22: // lwl case 0x26: // lwr #endif return SignalContext::READ; #if __mips_isa_rev == 6 case 0x3b: // pcrel op_code = (faulty_instruction >> 19) & 0x3; switch (op_code) { case 0x1: // lwpc case 0x2: // lwupc return SignalContext::READ; } #endif } return SignalContext::UNKNOWN; #elif defined(__arm__) static const uptr FSR_WRITE = 1U << 11; uptr fsr = ucontext->uc_mcontext.error_code; return fsr & FSR_WRITE ? WRITE : READ; #elif defined(__aarch64__) static const u64 ESR_ELx_WNR = 1U << 6; u64 esr; if (!Aarch64GetESR(ucontext, &esr)) return UNKNOWN; return esr & ESR_ELx_WNR ? WRITE : READ; #elif defined(__sparc__) // Decode the instruction to determine the access type. // From OpenSolaris $SRC/uts/sun4/os/trap.c (get_accesstype). #if SANITIZER_SOLARIS uptr pc = ucontext->uc_mcontext.gregs[REG_PC]; #else // Historical BSDism here. struct sigcontext *scontext = (struct sigcontext *)context; #if defined(__arch64__) uptr pc = scontext->sigc_regs.tpc; #else uptr pc = scontext->si_regs.pc; #endif #endif u32 instr = *(u32 *)pc; return (instr >> 21) & 1 ? WRITE: READ; #else (void)ucontext; return UNKNOWN; // FIXME: Implement. #endif } bool SignalContext::IsTrueFaultingAddress() const { auto si = static_cast(siginfo); // SIGSEGV signals without a true fault address have si_code set to 128. return si->si_signo == SIGSEGV && si->si_code != 128; } void SignalContext::DumpAllRegisters(void *context) { // FIXME: Implement this. } static void GetPcSpBp(void *context, uptr *pc, uptr *sp, uptr *bp) { #if SANITIZER_NETBSD // This covers all NetBSD architectures ucontext_t *ucontext = (ucontext_t *)context; *pc = _UC_MACHINE_PC(ucontext); *bp = _UC_MACHINE_FP(ucontext); *sp = _UC_MACHINE_SP(ucontext); #elif defined(__arm__) ucontext_t *ucontext = (ucontext_t*)context; *pc = ucontext->uc_mcontext.arm_pc; *bp = ucontext->uc_mcontext.arm_fp; *sp = ucontext->uc_mcontext.arm_sp; #elif defined(__aarch64__) ucontext_t *ucontext = (ucontext_t*)context; *pc = ucontext->uc_mcontext.pc; *bp = ucontext->uc_mcontext.regs[29]; *sp = ucontext->uc_mcontext.sp; #elif defined(__hppa__) ucontext_t *ucontext = (ucontext_t*)context; *pc = ucontext->uc_mcontext.sc_iaoq[0]; /* GCC uses %r3 whenever a frame pointer is needed. */ *bp = ucontext->uc_mcontext.sc_gr[3]; *sp = ucontext->uc_mcontext.sc_gr[30]; #elif defined(__x86_64__) # if SANITIZER_FREEBSD ucontext_t *ucontext = (ucontext_t*)context; *pc = ucontext->uc_mcontext.mc_rip; *bp = ucontext->uc_mcontext.mc_rbp; *sp = ucontext->uc_mcontext.mc_rsp; #elif SANITIZER_OPENBSD sigcontext *ucontext = (sigcontext *)context; *pc = ucontext->sc_rip; *bp = ucontext->sc_rbp; *sp = ucontext->sc_rsp; # else ucontext_t *ucontext = (ucontext_t*)context; *pc = ucontext->uc_mcontext.gregs[REG_RIP]; *bp = ucontext->uc_mcontext.gregs[REG_RBP]; *sp = ucontext->uc_mcontext.gregs[REG_RSP]; # endif #elif defined(__i386__) # if SANITIZER_FREEBSD ucontext_t *ucontext = (ucontext_t*)context; *pc = ucontext->uc_mcontext.mc_eip; *bp = ucontext->uc_mcontext.mc_ebp; *sp = ucontext->uc_mcontext.mc_esp; #elif SANITIZER_OPENBSD sigcontext *ucontext = (sigcontext *)context; *pc = ucontext->sc_eip; *bp = ucontext->sc_ebp; *sp = ucontext->sc_esp; # else ucontext_t *ucontext = (ucontext_t*)context; # if SANITIZER_SOLARIS /* Use the numeric values: the symbolic ones are undefined by llvm include/llvm/Support/Solaris.h. */ # ifndef REG_EIP # define REG_EIP 14 // REG_PC # endif # ifndef REG_EBP # define REG_EBP 6 // REG_FP # endif # ifndef REG_ESP # define REG_ESP 17 // REG_SP # endif # endif *pc = ucontext->uc_mcontext.gregs[REG_EIP]; *bp = ucontext->uc_mcontext.gregs[REG_EBP]; *sp = ucontext->uc_mcontext.gregs[REG_ESP]; # endif #elif defined(__powerpc__) || defined(__powerpc64__) ucontext_t *ucontext = (ucontext_t*)context; *pc = ucontext->uc_mcontext.regs->nip; *sp = ucontext->uc_mcontext.regs->gpr[PT_R1]; // The powerpc{,64}-linux ABIs do not specify r31 as the frame // pointer, but GCC always uses r31 when we need a frame pointer. *bp = ucontext->uc_mcontext.regs->gpr[PT_R31]; #elif defined(__sparc__) #if defined(__arch64__) || defined(__sparcv9) #define STACK_BIAS 2047 #else #define STACK_BIAS 0 # endif # if SANITIZER_SOLARIS ucontext_t *ucontext = (ucontext_t *)context; *pc = ucontext->uc_mcontext.gregs[REG_PC]; *sp = ucontext->uc_mcontext.gregs[REG_O6] + STACK_BIAS; #else // Historical BSDism here. struct sigcontext *scontext = (struct sigcontext *)context; #if defined(__arch64__) *pc = scontext->sigc_regs.tpc; *sp = scontext->sigc_regs.u_regs[14] + STACK_BIAS; #else *pc = scontext->si_regs.pc; *sp = scontext->si_regs.u_regs[14]; #endif # endif *bp = (uptr)((uhwptr *)*sp)[14] + STACK_BIAS; #elif defined(__mips__) ucontext_t *ucontext = (ucontext_t*)context; *pc = ucontext->uc_mcontext.pc; *bp = ucontext->uc_mcontext.gregs[30]; *sp = ucontext->uc_mcontext.gregs[29]; #elif defined(__s390__) ucontext_t *ucontext = (ucontext_t*)context; # if defined(__s390x__) *pc = ucontext->uc_mcontext.psw.addr; # else *pc = ucontext->uc_mcontext.psw.addr & 0x7fffffff; # endif *bp = ucontext->uc_mcontext.gregs[11]; *sp = ucontext->uc_mcontext.gregs[15]; #elif defined(__riscv) ucontext_t *ucontext = (ucontext_t*)context; *pc = ucontext->uc_mcontext.__gregs[REG_PC]; *bp = ucontext->uc_mcontext.__gregs[REG_S0]; *sp = ucontext->uc_mcontext.__gregs[REG_SP]; #else # error "Unsupported arch" #endif } void SignalContext::InitPcSpBp() { GetPcSpBp(context, &pc, &sp, &bp); } void InitializePlatformEarly() { // Do nothing. } void MaybeReexec() { // No need to re-exec on Linux. } void CheckASLR() { #if SANITIZER_NETBSD int mib[3]; int paxflags; uptr len = sizeof(paxflags); mib[0] = CTL_PROC; mib[1] = internal_getpid(); mib[2] = PROC_PID_PAXFLAGS; if (UNLIKELY(internal_sysctl(mib, 3, &paxflags, &len, NULL, 0) == -1)) { Printf("sysctl failed\n"); Die(); } if (UNLIKELY(paxflags & CTL_PROC_PAXFLAGS_ASLR)) { Printf("This sanitizer is not compatible with enabled ASLR\n"); Die(); } #elif SANITIZER_PPC64V2 // Disable ASLR for Linux PPC64LE. int old_personality = personality(0xffffffff); if (old_personality != -1 && (old_personality & ADDR_NO_RANDOMIZE) == 0) { VReport(1, "WARNING: Program is being run with address space layout " "randomization (ASLR) enabled which prevents the thread and " "memory sanitizers from working on powerpc64le.\n" "ASLR will be disabled and the program re-executed.\n"); CHECK_NE(personality(old_personality | ADDR_NO_RANDOMIZE), -1); ReExec(); } #elif SANITIZER_FREEBSD int aslr_pie; uptr len = sizeof(aslr_pie); #if SANITIZER_WORDSIZE == 64 if (UNLIKELY(internal_sysctlbyname("kern.elf64.aslr.pie_enable", &aslr_pie, &len, NULL, 0) == -1)) { // We're making things less 'dramatic' here since // the OID is not necessarily guaranteed to be here // just yet regarding FreeBSD release return; } if (aslr_pie > 0) { Printf("This sanitizer is not compatible with enabled ASLR " "and binaries compiled with PIE\n"); Die(); } #endif // there might be 32 bits compat for 64 bits if (UNLIKELY(internal_sysctlbyname("kern.elf32.aslr.pie_enable", &aslr_pie, &len, NULL, 0) == -1)) { return; } if (aslr_pie > 0) { Printf("This sanitizer is not compatible with enabled ASLR " "and binaries compiled with PIE\n"); Die(); } #else // Do nothing #endif } void CheckMPROTECT() { #if SANITIZER_NETBSD int mib[3]; int paxflags; uptr len = sizeof(paxflags); mib[0] = CTL_PROC; mib[1] = internal_getpid(); mib[2] = PROC_PID_PAXFLAGS; if (UNLIKELY(internal_sysctl(mib, 3, &paxflags, &len, NULL, 0) == -1)) { Printf("sysctl failed\n"); Die(); } if (UNLIKELY(paxflags & CTL_PROC_PAXFLAGS_MPROTECT)) { Printf("This sanitizer is not compatible with enabled MPROTECT\n"); Die(); } #else // Do nothing #endif } void PrintModuleMap() { } void CheckNoDeepBind(const char *filename, int flag) { #ifdef RTLD_DEEPBIND if (flag & RTLD_DEEPBIND) { Report( "You are trying to dlopen a %s shared library with RTLD_DEEPBIND flag" " which is incompatibe with sanitizer runtime " "(see https://github.com/google/sanitizers/issues/611 for details" "). If you want to run %s library under sanitizers please remove " "RTLD_DEEPBIND from dlopen flags.\n", filename, filename); Die(); } #endif } uptr FindAvailableMemoryRange(uptr size, uptr alignment, uptr left_padding, uptr *largest_gap_found, uptr *max_occupied_addr) { UNREACHABLE("FindAvailableMemoryRange is not available"); return 0; } bool GetRandom(void *buffer, uptr length, bool blocking) { if (!buffer || !length || length > 256) return false; #if SANITIZER_USE_GETENTROPY uptr rnd = getentropy(buffer, length); int rverrno = 0; if (internal_iserror(rnd, &rverrno) && rverrno == EFAULT) return false; else if (rnd == 0) return true; #endif // SANITIZER_USE_GETENTROPY #if SANITIZER_USE_GETRANDOM static atomic_uint8_t skip_getrandom_syscall; if (!atomic_load_relaxed(&skip_getrandom_syscall)) { // Up to 256 bytes, getrandom will not be interrupted. uptr res = internal_syscall(SYSCALL(getrandom), buffer, length, blocking ? 0 : GRND_NONBLOCK); int rverrno = 0; if (internal_iserror(res, &rverrno) && rverrno == ENOSYS) atomic_store_relaxed(&skip_getrandom_syscall, 1); else if (res == length) return true; } #endif // SANITIZER_USE_GETRANDOM // Up to 256 bytes, a read off /dev/urandom will not be interrupted. // blocking is moot here, O_NONBLOCK has no effect when opening /dev/urandom. uptr fd = internal_open("/dev/urandom", O_RDONLY); if (internal_iserror(fd)) return false; uptr res = internal_read(fd, buffer, length); if (internal_iserror(res)) return false; internal_close(fd); return true; } } // namespace __sanitizer #endif