Peter Collingbourne | 04a2281 | 2013-05-21 10:27:07 +0000 | [diff] [blame] | 1 | //===-- sanitizer_posix_libcdep.cc ----------------------------------------===// |
| 2 | // |
| 3 | // The LLVM Compiler Infrastructure |
| 4 | // |
| 5 | // This file is distributed under the University of Illinois Open Source |
| 6 | // License. See LICENSE.TXT for details. |
| 7 | // |
| 8 | //===----------------------------------------------------------------------===// |
| 9 | // |
| 10 | // This file is shared between AddressSanitizer and ThreadSanitizer |
| 11 | // run-time libraries and implements libc-dependent POSIX-specific functions |
| 12 | // from sanitizer_libc.h. |
| 13 | //===----------------------------------------------------------------------===// |
| 14 | |
| 15 | #include "sanitizer_platform.h" |
| 16 | |
Stephen Hines | 2d1fdb2 | 2014-05-28 23:58:16 -0700 | [diff] [blame] | 17 | #if SANITIZER_POSIX |
Pirama Arumuga Nainar | 799172d | 2016-03-03 15:50:30 -0800 | [diff] [blame^] | 18 | |
Peter Collingbourne | 04a2281 | 2013-05-21 10:27:07 +0000 | [diff] [blame] | 19 | #include "sanitizer_common.h" |
Stephen Hines | 2d1fdb2 | 2014-05-28 23:58:16 -0700 | [diff] [blame] | 20 | #include "sanitizer_flags.h" |
| 21 | #include "sanitizer_platform_limits_posix.h" |
Pirama Arumuga Nainar | 259f706 | 2015-05-06 11:49:53 -0700 | [diff] [blame] | 22 | #include "sanitizer_posix.h" |
| 23 | #include "sanitizer_procmaps.h" |
Peter Collingbourne | 04a2281 | 2013-05-21 10:27:07 +0000 | [diff] [blame] | 24 | #include "sanitizer_stacktrace.h" |
Pirama Arumuga Nainar | 259f706 | 2015-05-06 11:49:53 -0700 | [diff] [blame] | 25 | #include "sanitizer_symbolizer.h" |
Peter Collingbourne | 04a2281 | 2013-05-21 10:27:07 +0000 | [diff] [blame] | 26 | |
| 27 | #include <errno.h> |
Pirama Arumuga Nainar | cdce50b | 2015-07-01 12:26:56 -0700 | [diff] [blame] | 28 | #include <fcntl.h> |
Peter Collingbourne | 04a2281 | 2013-05-21 10:27:07 +0000 | [diff] [blame] | 29 | #include <pthread.h> |
Stephen Hines | 2d1fdb2 | 2014-05-28 23:58:16 -0700 | [diff] [blame] | 30 | #include <signal.h> |
Peter Collingbourne | 04a2281 | 2013-05-21 10:27:07 +0000 | [diff] [blame] | 31 | #include <stdlib.h> |
| 32 | #include <sys/mman.h> |
| 33 | #include <sys/resource.h> |
Pirama Arumuga Nainar | 799172d | 2016-03-03 15:50:30 -0800 | [diff] [blame^] | 34 | #include <sys/stat.h> |
Peter Collingbourne | 04a2281 | 2013-05-21 10:27:07 +0000 | [diff] [blame] | 35 | #include <sys/time.h> |
| 36 | #include <sys/types.h> |
| 37 | #include <unistd.h> |
| 38 | |
Pirama Arumuga Nainar | cdce50b | 2015-07-01 12:26:56 -0700 | [diff] [blame] | 39 | #if SANITIZER_FREEBSD |
| 40 | // The MAP_NORESERVE define has been removed in FreeBSD 11.x, and even before |
| 41 | // that, it was never implemented. So just define it to zero. |
| 42 | #undef MAP_NORESERVE |
| 43 | #define MAP_NORESERVE 0 |
| 44 | #endif |
| 45 | |
Peter Collingbourne | 04a2281 | 2013-05-21 10:27:07 +0000 | [diff] [blame] | 46 | namespace __sanitizer { |
| 47 | |
| 48 | u32 GetUid() { |
| 49 | return getuid(); |
| 50 | } |
| 51 | |
| 52 | uptr GetThreadSelf() { |
| 53 | return (uptr)pthread_self(); |
| 54 | } |
| 55 | |
| 56 | void FlushUnneededShadowMemory(uptr addr, uptr size) { |
| 57 | madvise((void*)addr, size, MADV_DONTNEED); |
| 58 | } |
| 59 | |
Stephen Hines | 86277eb | 2015-03-23 12:06:32 -0700 | [diff] [blame] | 60 | void NoHugePagesInRegion(uptr addr, uptr size) { |
| 61 | #ifdef MADV_NOHUGEPAGE // May not be defined on old systems. |
| 62 | madvise((void *)addr, size, MADV_NOHUGEPAGE); |
| 63 | #endif // MADV_NOHUGEPAGE |
| 64 | } |
| 65 | |
| 66 | void DontDumpShadowMemory(uptr addr, uptr length) { |
| 67 | #ifdef MADV_DONTDUMP |
| 68 | madvise((void *)addr, length, MADV_DONTDUMP); |
| 69 | #endif |
| 70 | } |
| 71 | |
Stephen Hines | 6d18623 | 2014-11-26 17:56:19 -0800 | [diff] [blame] | 72 | static rlim_t getlim(int res) { |
| 73 | rlimit rlim; |
| 74 | CHECK_EQ(0, getrlimit(res, &rlim)); |
| 75 | return rlim.rlim_cur; |
Peter Collingbourne | 04a2281 | 2013-05-21 10:27:07 +0000 | [diff] [blame] | 76 | } |
| 77 | |
Stephen Hines | 6d18623 | 2014-11-26 17:56:19 -0800 | [diff] [blame] | 78 | static void setlim(int res, rlim_t lim) { |
| 79 | // The following magic is to prevent clang from replacing it with memset. |
| 80 | volatile struct rlimit rlim; |
| 81 | rlim.rlim_cur = lim; |
| 82 | rlim.rlim_max = lim; |
| 83 | if (setrlimit(res, const_cast<struct rlimit *>(&rlim))) { |
Peter Collingbourne | 04a2281 | 2013-05-21 10:27:07 +0000 | [diff] [blame] | 84 | Report("ERROR: %s setrlimit() failed %d\n", SanitizerToolName, errno); |
| 85 | Die(); |
| 86 | } |
Stephen Hines | 6d18623 | 2014-11-26 17:56:19 -0800 | [diff] [blame] | 87 | } |
| 88 | |
| 89 | void DisableCoreDumperIfNecessary() { |
| 90 | if (common_flags()->disable_coredump) { |
| 91 | setlim(RLIMIT_CORE, 0); |
| 92 | } |
| 93 | } |
| 94 | |
| 95 | bool StackSizeIsUnlimited() { |
| 96 | rlim_t stack_size = getlim(RLIMIT_STACK); |
| 97 | return (stack_size == RLIM_INFINITY); |
| 98 | } |
| 99 | |
| 100 | void SetStackSizeLimitInBytes(uptr limit) { |
| 101 | setlim(RLIMIT_STACK, (rlim_t)limit); |
Peter Collingbourne | 04a2281 | 2013-05-21 10:27:07 +0000 | [diff] [blame] | 102 | CHECK(!StackSizeIsUnlimited()); |
| 103 | } |
| 104 | |
Stephen Hines | 6d18623 | 2014-11-26 17:56:19 -0800 | [diff] [blame] | 105 | bool AddressSpaceIsUnlimited() { |
| 106 | rlim_t as_size = getlim(RLIMIT_AS); |
| 107 | return (as_size == RLIM_INFINITY); |
| 108 | } |
| 109 | |
| 110 | void SetAddressSpaceUnlimited() { |
| 111 | setlim(RLIMIT_AS, RLIM_INFINITY); |
| 112 | CHECK(AddressSpaceIsUnlimited()); |
| 113 | } |
| 114 | |
Peter Collingbourne | 04a2281 | 2013-05-21 10:27:07 +0000 | [diff] [blame] | 115 | void SleepForSeconds(int seconds) { |
| 116 | sleep(seconds); |
| 117 | } |
| 118 | |
| 119 | void SleepForMillis(int millis) { |
| 120 | usleep(millis * 1000); |
| 121 | } |
| 122 | |
| 123 | void Abort() { |
| 124 | abort(); |
| 125 | } |
| 126 | |
| 127 | int Atexit(void (*function)(void)) { |
| 128 | #ifndef SANITIZER_GO |
| 129 | return atexit(function); |
| 130 | #else |
| 131 | return 0; |
| 132 | #endif |
| 133 | } |
| 134 | |
Pirama Arumuga Nainar | 259f706 | 2015-05-06 11:49:53 -0700 | [diff] [blame] | 135 | bool SupportsColoredOutput(fd_t fd) { |
| 136 | return isatty(fd) != 0; |
Peter Collingbourne | 04a2281 | 2013-05-21 10:27:07 +0000 | [diff] [blame] | 137 | } |
| 138 | |
Stephen Hines | 2d1fdb2 | 2014-05-28 23:58:16 -0700 | [diff] [blame] | 139 | #ifndef SANITIZER_GO |
| 140 | // TODO(glider): different tools may require different altstack size. |
| 141 | static const uptr kAltStackSize = SIGSTKSZ * 4; // SIGSTKSZ is not enough. |
| 142 | |
| 143 | void SetAlternateSignalStack() { |
| 144 | stack_t altstack, oldstack; |
Pirama Arumuga Nainar | 799172d | 2016-03-03 15:50:30 -0800 | [diff] [blame^] | 145 | CHECK_EQ(0, sigaltstack(nullptr, &oldstack)); |
Stephen Hines | 2d1fdb2 | 2014-05-28 23:58:16 -0700 | [diff] [blame] | 146 | // If the alternate stack is already in place, do nothing. |
| 147 | // Android always sets an alternate stack, but it's too small for us. |
| 148 | if (!SANITIZER_ANDROID && !(oldstack.ss_flags & SS_DISABLE)) return; |
| 149 | // TODO(glider): the mapped stack should have the MAP_STACK flag in the |
| 150 | // future. It is not required by man 2 sigaltstack now (they're using |
| 151 | // malloc()). |
| 152 | void* base = MmapOrDie(kAltStackSize, __func__); |
| 153 | altstack.ss_sp = (char*) base; |
| 154 | altstack.ss_flags = 0; |
| 155 | altstack.ss_size = kAltStackSize; |
Pirama Arumuga Nainar | 799172d | 2016-03-03 15:50:30 -0800 | [diff] [blame^] | 156 | CHECK_EQ(0, sigaltstack(&altstack, nullptr)); |
Stephen Hines | 2d1fdb2 | 2014-05-28 23:58:16 -0700 | [diff] [blame] | 157 | } |
| 158 | |
| 159 | void UnsetAlternateSignalStack() { |
| 160 | stack_t altstack, oldstack; |
Pirama Arumuga Nainar | 799172d | 2016-03-03 15:50:30 -0800 | [diff] [blame^] | 161 | altstack.ss_sp = nullptr; |
Stephen Hines | 2d1fdb2 | 2014-05-28 23:58:16 -0700 | [diff] [blame] | 162 | altstack.ss_flags = SS_DISABLE; |
| 163 | altstack.ss_size = kAltStackSize; // Some sane value required on Darwin. |
| 164 | CHECK_EQ(0, sigaltstack(&altstack, &oldstack)); |
| 165 | UnmapOrDie(oldstack.ss_sp, oldstack.ss_size); |
| 166 | } |
| 167 | |
| 168 | typedef void (*sa_sigaction_t)(int, siginfo_t *, void *); |
| 169 | static void MaybeInstallSigaction(int signum, |
| 170 | SignalHandlerType handler) { |
| 171 | if (!IsDeadlySignal(signum)) |
| 172 | return; |
| 173 | struct sigaction sigact; |
| 174 | internal_memset(&sigact, 0, sizeof(sigact)); |
| 175 | sigact.sa_sigaction = (sa_sigaction_t)handler; |
Stephen Hines | 6d18623 | 2014-11-26 17:56:19 -0800 | [diff] [blame] | 176 | // Do not block the signal from being received in that signal's handler. |
| 177 | // Clients are responsible for handling this correctly. |
| 178 | sigact.sa_flags = SA_SIGINFO | SA_NODEFER; |
Stephen Hines | 2d1fdb2 | 2014-05-28 23:58:16 -0700 | [diff] [blame] | 179 | if (common_flags()->use_sigaltstack) sigact.sa_flags |= SA_ONSTACK; |
Pirama Arumuga Nainar | 799172d | 2016-03-03 15:50:30 -0800 | [diff] [blame^] | 180 | CHECK_EQ(0, internal_sigaction(signum, &sigact, nullptr)); |
Stephen Hines | 2d1fdb2 | 2014-05-28 23:58:16 -0700 | [diff] [blame] | 181 | VReport(1, "Installed the sigaction for signal %d\n", signum); |
| 182 | } |
| 183 | |
| 184 | void InstallDeadlySignalHandlers(SignalHandlerType handler) { |
| 185 | // Set the alternate signal stack for the main thread. |
| 186 | // This will cause SetAlternateSignalStack to be called twice, but the stack |
| 187 | // will be actually set only once. |
| 188 | if (common_flags()->use_sigaltstack) SetAlternateSignalStack(); |
| 189 | MaybeInstallSigaction(SIGSEGV, handler); |
| 190 | MaybeInstallSigaction(SIGBUS, handler); |
Pirama Arumuga Nainar | cdce50b | 2015-07-01 12:26:56 -0700 | [diff] [blame] | 191 | MaybeInstallSigaction(SIGABRT, handler); |
Pirama Arumuga Nainar | 799172d | 2016-03-03 15:50:30 -0800 | [diff] [blame^] | 192 | MaybeInstallSigaction(SIGFPE, handler); |
| 193 | MaybeInstallSigaction(SIGILL, handler); |
Stephen Hines | 2d1fdb2 | 2014-05-28 23:58:16 -0700 | [diff] [blame] | 194 | } |
| 195 | #endif // SANITIZER_GO |
| 196 | |
Stephen Hines | 6d18623 | 2014-11-26 17:56:19 -0800 | [diff] [blame] | 197 | bool IsAccessibleMemoryRange(uptr beg, uptr size) { |
| 198 | uptr page_size = GetPageSizeCached(); |
| 199 | // Checking too large memory ranges is slow. |
| 200 | CHECK_LT(size, page_size * 10); |
| 201 | int sock_pair[2]; |
| 202 | if (pipe(sock_pair)) |
| 203 | return false; |
| 204 | uptr bytes_written = |
| 205 | internal_write(sock_pair[1], reinterpret_cast<void *>(beg), size); |
| 206 | int write_errno; |
| 207 | bool result; |
| 208 | if (internal_iserror(bytes_written, &write_errno)) { |
| 209 | CHECK_EQ(EFAULT, write_errno); |
| 210 | result = false; |
| 211 | } else { |
| 212 | result = (bytes_written == size); |
| 213 | } |
| 214 | internal_close(sock_pair[0]); |
| 215 | internal_close(sock_pair[1]); |
| 216 | return result; |
| 217 | } |
| 218 | |
Pirama Arumuga Nainar | 259f706 | 2015-05-06 11:49:53 -0700 | [diff] [blame] | 219 | void PrepareForSandboxing(__sanitizer_sandbox_arguments *args) { |
| 220 | // Some kinds of sandboxes may forbid filesystem access, so we won't be able |
| 221 | // to read the file mappings from /proc/self/maps. Luckily, neither the |
| 222 | // process will be able to load additional libraries, so it's fine to use the |
| 223 | // cached mappings. |
| 224 | MemoryMappingLayout::CacheMemoryMappings(); |
| 225 | // Same for /proc/self/exe in the symbolizer. |
| 226 | #if !SANITIZER_GO |
| 227 | Symbolizer::GetOrInit()->PrepareForSandboxing(); |
| 228 | CovPrepareForSandboxing(args); |
| 229 | #endif |
| 230 | } |
| 231 | |
Pirama Arumuga Nainar | 799172d | 2016-03-03 15:50:30 -0800 | [diff] [blame^] | 232 | #if SANITIZER_ANDROID || SANITIZER_GO |
Pirama Arumuga Nainar | cdce50b | 2015-07-01 12:26:56 -0700 | [diff] [blame] | 233 | int GetNamedMappingFd(const char *name, uptr size) { |
| 234 | return -1; |
| 235 | } |
| 236 | #else |
| 237 | int GetNamedMappingFd(const char *name, uptr size) { |
| 238 | if (!common_flags()->decorate_proc_maps) |
| 239 | return -1; |
| 240 | char shmname[200]; |
| 241 | CHECK(internal_strlen(name) < sizeof(shmname) - 10); |
| 242 | internal_snprintf(shmname, sizeof(shmname), "%zu [%s]", internal_getpid(), |
| 243 | name); |
| 244 | int fd = shm_open(shmname, O_RDWR | O_CREAT | O_TRUNC, S_IRWXU); |
| 245 | CHECK_GE(fd, 0); |
| 246 | int res = internal_ftruncate(fd, size); |
| 247 | CHECK_EQ(0, res); |
| 248 | res = shm_unlink(shmname); |
| 249 | CHECK_EQ(0, res); |
| 250 | return fd; |
| 251 | } |
| 252 | #endif |
| 253 | |
| 254 | void *MmapFixedNoReserve(uptr fixed_addr, uptr size, const char *name) { |
| 255 | int fd = name ? GetNamedMappingFd(name, size) : -1; |
| 256 | unsigned flags = MAP_PRIVATE | MAP_FIXED | MAP_NORESERVE; |
| 257 | if (fd == -1) flags |= MAP_ANON; |
| 258 | |
| 259 | uptr PageSize = GetPageSizeCached(); |
| 260 | uptr p = internal_mmap((void *)(fixed_addr & ~(PageSize - 1)), |
| 261 | RoundUpTo(size, PageSize), PROT_READ | PROT_WRITE, |
| 262 | flags, fd, 0); |
| 263 | int reserrno; |
| 264 | if (internal_iserror(p, &reserrno)) |
| 265 | Report("ERROR: %s failed to " |
| 266 | "allocate 0x%zx (%zd) bytes at address %zx (errno: %d)\n", |
| 267 | SanitizerToolName, size, size, fixed_addr, reserrno); |
| 268 | IncreaseTotalMmap(size); |
| 269 | return (void *)p; |
| 270 | } |
| 271 | |
| 272 | void *MmapNoAccess(uptr fixed_addr, uptr size, const char *name) { |
| 273 | int fd = name ? GetNamedMappingFd(name, size) : -1; |
| 274 | unsigned flags = MAP_PRIVATE | MAP_FIXED | MAP_NORESERVE; |
| 275 | if (fd == -1) flags |= MAP_ANON; |
| 276 | |
| 277 | return (void *)internal_mmap((void *)fixed_addr, size, PROT_NONE, flags, fd, |
| 278 | 0); |
| 279 | } |
| 280 | |
Pirama Arumuga Nainar | 799172d | 2016-03-03 15:50:30 -0800 | [diff] [blame^] | 281 | // This function is defined elsewhere if we intercepted pthread_attr_getstack. |
| 282 | extern "C" { |
| 283 | SANITIZER_WEAK_ATTRIBUTE int |
| 284 | real_pthread_attr_getstack(void *attr, void **addr, size_t *size); |
| 285 | } // extern "C" |
Peter Collingbourne | 04a2281 | 2013-05-21 10:27:07 +0000 | [diff] [blame] | 286 | |
Pirama Arumuga Nainar | 799172d | 2016-03-03 15:50:30 -0800 | [diff] [blame^] | 287 | int my_pthread_attr_getstack(void *attr, void **addr, uptr *size) { |
| 288 | #if !SANITIZER_GO && !SANITIZER_MAC |
| 289 | if (&real_pthread_attr_getstack) |
| 290 | return real_pthread_attr_getstack((pthread_attr_t *)attr, addr, |
| 291 | (size_t *)size); |
| 292 | #endif |
| 293 | return pthread_attr_getstack((pthread_attr_t *)attr, addr, (size_t *)size); |
| 294 | } |
| 295 | |
| 296 | #if !SANITIZER_GO |
| 297 | void AdjustStackSize(void *attr_) { |
| 298 | pthread_attr_t *attr = (pthread_attr_t *)attr_; |
| 299 | uptr stackaddr = 0; |
| 300 | uptr stacksize = 0; |
| 301 | my_pthread_attr_getstack(attr, (void**)&stackaddr, &stacksize); |
| 302 | // GLibC will return (0 - stacksize) as the stack address in the case when |
| 303 | // stacksize is set, but stackaddr is not. |
| 304 | bool stack_set = (stackaddr != 0) && (stackaddr + stacksize != 0); |
| 305 | // We place a lot of tool data into TLS, account for that. |
| 306 | const uptr minstacksize = GetTlsSize() + 128*1024; |
| 307 | if (stacksize < minstacksize) { |
| 308 | if (!stack_set) { |
| 309 | if (stacksize != 0) { |
| 310 | VPrintf(1, "Sanitizer: increasing stacksize %zu->%zu\n", stacksize, |
| 311 | minstacksize); |
| 312 | pthread_attr_setstacksize(attr, minstacksize); |
| 313 | } |
| 314 | } else { |
| 315 | Printf("Sanitizer: pre-allocated stack size is insufficient: " |
| 316 | "%zu < %zu\n", stacksize, minstacksize); |
| 317 | Printf("Sanitizer: pthread_create is likely to fail.\n"); |
| 318 | } |
| 319 | } |
| 320 | } |
| 321 | #endif // !SANITIZER_GO |
| 322 | |
| 323 | } // namespace __sanitizer |
| 324 | |
| 325 | #endif // SANITIZER_POSIX |