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1a4d82fc JJ |
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 | ||
17 | #if SANITIZER_POSIX | |
92a42be0 | 18 | |
1a4d82fc JJ |
19 | #include "sanitizer_common.h" |
20 | #include "sanitizer_flags.h" | |
21 | #include "sanitizer_platform_limits_posix.h" | |
92a42be0 SL |
22 | #include "sanitizer_posix.h" |
23 | #include "sanitizer_procmaps.h" | |
1a4d82fc | 24 | #include "sanitizer_stacktrace.h" |
92a42be0 | 25 | #include "sanitizer_symbolizer.h" |
1a4d82fc JJ |
26 | |
27 | #include <errno.h> | |
92a42be0 | 28 | #include <fcntl.h> |
1a4d82fc JJ |
29 | #include <pthread.h> |
30 | #include <signal.h> | |
31 | #include <stdlib.h> | |
32 | #include <sys/mman.h> | |
33 | #include <sys/resource.h> | |
92a42be0 | 34 | #include <sys/stat.h> |
1a4d82fc JJ |
35 | #include <sys/time.h> |
36 | #include <sys/types.h> | |
5bcae85e | 37 | #include <sys/wait.h> |
1a4d82fc JJ |
38 | #include <unistd.h> |
39 | ||
92a42be0 SL |
40 | #if SANITIZER_FREEBSD |
41 | // The MAP_NORESERVE define has been removed in FreeBSD 11.x, and even before | |
42 | // that, it was never implemented. So just define it to zero. | |
43 | #undef MAP_NORESERVE | |
44 | #define MAP_NORESERVE 0 | |
45 | #endif | |
46 | ||
1a4d82fc JJ |
47 | namespace __sanitizer { |
48 | ||
49 | u32 GetUid() { | |
50 | return getuid(); | |
51 | } | |
52 | ||
53 | uptr GetThreadSelf() { | |
54 | return (uptr)pthread_self(); | |
55 | } | |
56 | ||
57 | void FlushUnneededShadowMemory(uptr addr, uptr size) { | |
58 | madvise((void*)addr, size, MADV_DONTNEED); | |
59 | } | |
60 | ||
92a42be0 SL |
61 | void NoHugePagesInRegion(uptr addr, uptr size) { |
62 | #ifdef MADV_NOHUGEPAGE // May not be defined on old systems. | |
63 | madvise((void *)addr, size, MADV_NOHUGEPAGE); | |
64 | #endif // MADV_NOHUGEPAGE | |
1a4d82fc JJ |
65 | } |
66 | ||
92a42be0 SL |
67 | void DontDumpShadowMemory(uptr addr, uptr length) { |
68 | #ifdef MADV_DONTDUMP | |
69 | madvise((void *)addr, length, MADV_DONTDUMP); | |
70 | #endif | |
1a4d82fc JJ |
71 | } |
72 | ||
92a42be0 SL |
73 | static rlim_t getlim(int res) { |
74 | rlimit rlim; | |
75 | CHECK_EQ(0, getrlimit(res, &rlim)); | |
76 | return rlim.rlim_cur; | |
77 | } | |
78 | ||
79 | static void setlim(int res, rlim_t lim) { | |
80 | // The following magic is to prevent clang from replacing it with memset. | |
81 | volatile struct rlimit rlim; | |
82 | rlim.rlim_cur = lim; | |
83 | rlim.rlim_max = lim; | |
84 | if (setrlimit(res, const_cast<struct rlimit *>(&rlim))) { | |
1a4d82fc JJ |
85 | Report("ERROR: %s setrlimit() failed %d\n", SanitizerToolName, errno); |
86 | Die(); | |
87 | } | |
92a42be0 SL |
88 | } |
89 | ||
90 | void DisableCoreDumperIfNecessary() { | |
91 | if (common_flags()->disable_coredump) { | |
92 | setlim(RLIMIT_CORE, 0); | |
93 | } | |
94 | } | |
95 | ||
96 | bool StackSizeIsUnlimited() { | |
97 | rlim_t stack_size = getlim(RLIMIT_STACK); | |
98 | return (stack_size == RLIM_INFINITY); | |
99 | } | |
100 | ||
5bcae85e SL |
101 | uptr GetStackSizeLimitInBytes() { |
102 | return (uptr)getlim(RLIMIT_STACK); | |
103 | } | |
104 | ||
92a42be0 SL |
105 | void SetStackSizeLimitInBytes(uptr limit) { |
106 | setlim(RLIMIT_STACK, (rlim_t)limit); | |
1a4d82fc JJ |
107 | CHECK(!StackSizeIsUnlimited()); |
108 | } | |
109 | ||
92a42be0 SL |
110 | bool AddressSpaceIsUnlimited() { |
111 | rlim_t as_size = getlim(RLIMIT_AS); | |
112 | return (as_size == RLIM_INFINITY); | |
113 | } | |
114 | ||
115 | void SetAddressSpaceUnlimited() { | |
116 | setlim(RLIMIT_AS, RLIM_INFINITY); | |
117 | CHECK(AddressSpaceIsUnlimited()); | |
118 | } | |
119 | ||
1a4d82fc JJ |
120 | void SleepForSeconds(int seconds) { |
121 | sleep(seconds); | |
122 | } | |
123 | ||
124 | void SleepForMillis(int millis) { | |
125 | usleep(millis * 1000); | |
126 | } | |
127 | ||
128 | void Abort() { | |
129 | abort(); | |
130 | } | |
131 | ||
132 | int Atexit(void (*function)(void)) { | |
133 | #ifndef SANITIZER_GO | |
134 | return atexit(function); | |
135 | #else | |
136 | return 0; | |
137 | #endif | |
138 | } | |
139 | ||
92a42be0 SL |
140 | bool SupportsColoredOutput(fd_t fd) { |
141 | return isatty(fd) != 0; | |
1a4d82fc JJ |
142 | } |
143 | ||
144 | #ifndef SANITIZER_GO | |
145 | // TODO(glider): different tools may require different altstack size. | |
146 | static const uptr kAltStackSize = SIGSTKSZ * 4; // SIGSTKSZ is not enough. | |
147 | ||
148 | void SetAlternateSignalStack() { | |
149 | stack_t altstack, oldstack; | |
92a42be0 | 150 | CHECK_EQ(0, sigaltstack(nullptr, &oldstack)); |
1a4d82fc JJ |
151 | // If the alternate stack is already in place, do nothing. |
152 | // Android always sets an alternate stack, but it's too small for us. | |
153 | if (!SANITIZER_ANDROID && !(oldstack.ss_flags & SS_DISABLE)) return; | |
154 | // TODO(glider): the mapped stack should have the MAP_STACK flag in the | |
155 | // future. It is not required by man 2 sigaltstack now (they're using | |
156 | // malloc()). | |
157 | void* base = MmapOrDie(kAltStackSize, __func__); | |
158 | altstack.ss_sp = (char*) base; | |
159 | altstack.ss_flags = 0; | |
160 | altstack.ss_size = kAltStackSize; | |
92a42be0 | 161 | CHECK_EQ(0, sigaltstack(&altstack, nullptr)); |
1a4d82fc JJ |
162 | } |
163 | ||
164 | void UnsetAlternateSignalStack() { | |
165 | stack_t altstack, oldstack; | |
92a42be0 | 166 | altstack.ss_sp = nullptr; |
1a4d82fc JJ |
167 | altstack.ss_flags = SS_DISABLE; |
168 | altstack.ss_size = kAltStackSize; // Some sane value required on Darwin. | |
169 | CHECK_EQ(0, sigaltstack(&altstack, &oldstack)); | |
170 | UnmapOrDie(oldstack.ss_sp, oldstack.ss_size); | |
171 | } | |
172 | ||
173 | typedef void (*sa_sigaction_t)(int, siginfo_t *, void *); | |
174 | static void MaybeInstallSigaction(int signum, | |
175 | SignalHandlerType handler) { | |
5bcae85e | 176 | if (!IsHandledDeadlySignal(signum)) |
1a4d82fc JJ |
177 | return; |
178 | struct sigaction sigact; | |
179 | internal_memset(&sigact, 0, sizeof(sigact)); | |
180 | sigact.sa_sigaction = (sa_sigaction_t)handler; | |
92a42be0 SL |
181 | // Do not block the signal from being received in that signal's handler. |
182 | // Clients are responsible for handling this correctly. | |
183 | sigact.sa_flags = SA_SIGINFO | SA_NODEFER; | |
1a4d82fc | 184 | if (common_flags()->use_sigaltstack) sigact.sa_flags |= SA_ONSTACK; |
92a42be0 | 185 | CHECK_EQ(0, internal_sigaction(signum, &sigact, nullptr)); |
1a4d82fc JJ |
186 | VReport(1, "Installed the sigaction for signal %d\n", signum); |
187 | } | |
188 | ||
189 | void InstallDeadlySignalHandlers(SignalHandlerType handler) { | |
190 | // Set the alternate signal stack for the main thread. | |
191 | // This will cause SetAlternateSignalStack to be called twice, but the stack | |
192 | // will be actually set only once. | |
193 | if (common_flags()->use_sigaltstack) SetAlternateSignalStack(); | |
194 | MaybeInstallSigaction(SIGSEGV, handler); | |
195 | MaybeInstallSigaction(SIGBUS, handler); | |
92a42be0 SL |
196 | MaybeInstallSigaction(SIGABRT, handler); |
197 | MaybeInstallSigaction(SIGFPE, handler); | |
3157f602 | 198 | MaybeInstallSigaction(SIGILL, handler); |
1a4d82fc JJ |
199 | } |
200 | #endif // SANITIZER_GO | |
201 | ||
92a42be0 SL |
202 | bool IsAccessibleMemoryRange(uptr beg, uptr size) { |
203 | uptr page_size = GetPageSizeCached(); | |
204 | // Checking too large memory ranges is slow. | |
205 | CHECK_LT(size, page_size * 10); | |
206 | int sock_pair[2]; | |
207 | if (pipe(sock_pair)) | |
208 | return false; | |
209 | uptr bytes_written = | |
210 | internal_write(sock_pair[1], reinterpret_cast<void *>(beg), size); | |
211 | int write_errno; | |
212 | bool result; | |
213 | if (internal_iserror(bytes_written, &write_errno)) { | |
214 | CHECK_EQ(EFAULT, write_errno); | |
215 | result = false; | |
216 | } else { | |
217 | result = (bytes_written == size); | |
218 | } | |
219 | internal_close(sock_pair[0]); | |
220 | internal_close(sock_pair[1]); | |
221 | return result; | |
222 | } | |
223 | ||
224 | void PrepareForSandboxing(__sanitizer_sandbox_arguments *args) { | |
225 | // Some kinds of sandboxes may forbid filesystem access, so we won't be able | |
226 | // to read the file mappings from /proc/self/maps. Luckily, neither the | |
227 | // process will be able to load additional libraries, so it's fine to use the | |
228 | // cached mappings. | |
229 | MemoryMappingLayout::CacheMemoryMappings(); | |
230 | // Same for /proc/self/exe in the symbolizer. | |
231 | #if !SANITIZER_GO | |
232 | Symbolizer::GetOrInit()->PrepareForSandboxing(); | |
233 | CovPrepareForSandboxing(args); | |
234 | #endif | |
235 | } | |
236 | ||
3157f602 | 237 | #if SANITIZER_ANDROID || SANITIZER_GO |
92a42be0 SL |
238 | int GetNamedMappingFd(const char *name, uptr size) { |
239 | return -1; | |
240 | } | |
241 | #else | |
242 | int GetNamedMappingFd(const char *name, uptr size) { | |
243 | if (!common_flags()->decorate_proc_maps) | |
244 | return -1; | |
245 | char shmname[200]; | |
246 | CHECK(internal_strlen(name) < sizeof(shmname) - 10); | |
247 | internal_snprintf(shmname, sizeof(shmname), "%zu [%s]", internal_getpid(), | |
248 | name); | |
249 | int fd = shm_open(shmname, O_RDWR | O_CREAT | O_TRUNC, S_IRWXU); | |
250 | CHECK_GE(fd, 0); | |
251 | int res = internal_ftruncate(fd, size); | |
252 | CHECK_EQ(0, res); | |
253 | res = shm_unlink(shmname); | |
254 | CHECK_EQ(0, res); | |
255 | return fd; | |
256 | } | |
257 | #endif | |
258 | ||
259 | void *MmapFixedNoReserve(uptr fixed_addr, uptr size, const char *name) { | |
260 | int fd = name ? GetNamedMappingFd(name, size) : -1; | |
261 | unsigned flags = MAP_PRIVATE | MAP_FIXED | MAP_NORESERVE; | |
262 | if (fd == -1) flags |= MAP_ANON; | |
263 | ||
264 | uptr PageSize = GetPageSizeCached(); | |
265 | uptr p = internal_mmap((void *)(fixed_addr & ~(PageSize - 1)), | |
266 | RoundUpTo(size, PageSize), PROT_READ | PROT_WRITE, | |
267 | flags, fd, 0); | |
268 | int reserrno; | |
269 | if (internal_iserror(p, &reserrno)) | |
270 | Report("ERROR: %s failed to " | |
271 | "allocate 0x%zx (%zd) bytes at address %zx (errno: %d)\n", | |
272 | SanitizerToolName, size, size, fixed_addr, reserrno); | |
273 | IncreaseTotalMmap(size); | |
274 | return (void *)p; | |
275 | } | |
276 | ||
5bcae85e | 277 | void *MmapFixedNoAccess(uptr fixed_addr, uptr size, const char *name) { |
92a42be0 SL |
278 | int fd = name ? GetNamedMappingFd(name, size) : -1; |
279 | unsigned flags = MAP_PRIVATE | MAP_FIXED | MAP_NORESERVE; | |
280 | if (fd == -1) flags |= MAP_ANON; | |
281 | ||
282 | return (void *)internal_mmap((void *)fixed_addr, size, PROT_NONE, flags, fd, | |
283 | 0); | |
284 | } | |
285 | ||
5bcae85e SL |
286 | void *MmapNoAccess(uptr size) { |
287 | unsigned flags = MAP_PRIVATE | MAP_ANON | MAP_NORESERVE; | |
288 | return (void *)internal_mmap(nullptr, size, PROT_NONE, flags, -1, 0); | |
289 | } | |
290 | ||
92a42be0 SL |
291 | // This function is defined elsewhere if we intercepted pthread_attr_getstack. |
292 | extern "C" { | |
293 | SANITIZER_WEAK_ATTRIBUTE int | |
294 | real_pthread_attr_getstack(void *attr, void **addr, size_t *size); | |
295 | } // extern "C" | |
296 | ||
297 | int my_pthread_attr_getstack(void *attr, void **addr, uptr *size) { | |
298 | #if !SANITIZER_GO && !SANITIZER_MAC | |
299 | if (&real_pthread_attr_getstack) | |
300 | return real_pthread_attr_getstack((pthread_attr_t *)attr, addr, | |
301 | (size_t *)size); | |
302 | #endif | |
303 | return pthread_attr_getstack((pthread_attr_t *)attr, addr, (size_t *)size); | |
304 | } | |
305 | ||
306 | #if !SANITIZER_GO | |
307 | void AdjustStackSize(void *attr_) { | |
308 | pthread_attr_t *attr = (pthread_attr_t *)attr_; | |
309 | uptr stackaddr = 0; | |
310 | uptr stacksize = 0; | |
311 | my_pthread_attr_getstack(attr, (void**)&stackaddr, &stacksize); | |
312 | // GLibC will return (0 - stacksize) as the stack address in the case when | |
313 | // stacksize is set, but stackaddr is not. | |
314 | bool stack_set = (stackaddr != 0) && (stackaddr + stacksize != 0); | |
315 | // We place a lot of tool data into TLS, account for that. | |
316 | const uptr minstacksize = GetTlsSize() + 128*1024; | |
317 | if (stacksize < minstacksize) { | |
318 | if (!stack_set) { | |
319 | if (stacksize != 0) { | |
320 | VPrintf(1, "Sanitizer: increasing stacksize %zu->%zu\n", stacksize, | |
321 | minstacksize); | |
322 | pthread_attr_setstacksize(attr, minstacksize); | |
323 | } | |
324 | } else { | |
325 | Printf("Sanitizer: pre-allocated stack size is insufficient: " | |
326 | "%zu < %zu\n", stacksize, minstacksize); | |
327 | Printf("Sanitizer: pthread_create is likely to fail.\n"); | |
328 | } | |
329 | } | |
330 | } | |
331 | #endif // !SANITIZER_GO | |
332 | ||
5bcae85e SL |
333 | pid_t StartSubprocess(const char *program, const char *const argv[], |
334 | fd_t stdin_fd, fd_t stdout_fd, fd_t stderr_fd) { | |
335 | auto file_closer = at_scope_exit([&] { | |
336 | if (stdin_fd != kInvalidFd) { | |
337 | internal_close(stdin_fd); | |
338 | } | |
339 | if (stdout_fd != kInvalidFd) { | |
340 | internal_close(stdout_fd); | |
341 | } | |
342 | if (stderr_fd != kInvalidFd) { | |
343 | internal_close(stderr_fd); | |
344 | } | |
345 | }); | |
346 | ||
347 | int pid = internal_fork(); | |
348 | ||
349 | if (pid < 0) { | |
350 | int rverrno; | |
351 | if (internal_iserror(pid, &rverrno)) { | |
352 | Report("WARNING: failed to fork (errno %d)\n", rverrno); | |
353 | } | |
354 | return pid; | |
355 | } | |
356 | ||
357 | if (pid == 0) { | |
358 | // Child subprocess | |
359 | if (stdin_fd != kInvalidFd) { | |
360 | internal_close(STDIN_FILENO); | |
361 | internal_dup2(stdin_fd, STDIN_FILENO); | |
362 | internal_close(stdin_fd); | |
363 | } | |
364 | if (stdout_fd != kInvalidFd) { | |
365 | internal_close(STDOUT_FILENO); | |
366 | internal_dup2(stdout_fd, STDOUT_FILENO); | |
367 | internal_close(stdout_fd); | |
368 | } | |
369 | if (stderr_fd != kInvalidFd) { | |
370 | internal_close(STDERR_FILENO); | |
371 | internal_dup2(stderr_fd, STDERR_FILENO); | |
372 | internal_close(stderr_fd); | |
373 | } | |
374 | ||
375 | for (int fd = sysconf(_SC_OPEN_MAX); fd > 2; fd--) internal_close(fd); | |
376 | ||
377 | execv(program, const_cast<char **>(&argv[0])); | |
378 | internal__exit(1); | |
379 | } | |
380 | ||
381 | return pid; | |
382 | } | |
383 | ||
384 | bool IsProcessRunning(pid_t pid) { | |
385 | int process_status; | |
386 | uptr waitpid_status = internal_waitpid(pid, &process_status, WNOHANG); | |
387 | int local_errno; | |
388 | if (internal_iserror(waitpid_status, &local_errno)) { | |
389 | VReport(1, "Waiting on the process failed (errno %d).\n", local_errno); | |
390 | return false; | |
391 | } | |
392 | return waitpid_status == 0; | |
393 | } | |
394 | ||
395 | int WaitForProcess(pid_t pid) { | |
396 | int process_status; | |
397 | uptr waitpid_status = internal_waitpid(pid, &process_status, 0); | |
398 | int local_errno; | |
399 | if (internal_iserror(waitpid_status, &local_errno)) { | |
400 | VReport(1, "Waiting on the process failed (errno %d).\n", local_errno); | |
401 | return -1; | |
402 | } | |
403 | return process_status; | |
404 | } | |
405 | ||
92a42be0 | 406 | } // namespace __sanitizer |
1a4d82fc | 407 | |
92a42be0 | 408 | #endif // SANITIZER_POSIX |