1 //===-- tsan_platform_linux.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 a part of ThreadSanitizer (TSan), a race detector.
11 //
12 // Linux- and FreeBSD-specific code.
13 //===----------------------------------------------------------------------===//
14
15
16 #include "sanitizer_common/sanitizer_platform.h"
17 #if SANITIZER_LINUX || SANITIZER_FREEBSD || SANITIZER_NETBSD
18
19 #include "sanitizer_common/sanitizer_common.h"
20 #include "sanitizer_common/sanitizer_libc.h"
21 #include "sanitizer_common/sanitizer_linux.h"
22 #include "sanitizer_common/sanitizer_platform_limits_netbsd.h"
23 #include "sanitizer_common/sanitizer_platform_limits_posix.h"
24 #include "sanitizer_common/sanitizer_posix.h"
25 #include "sanitizer_common/sanitizer_procmaps.h"
26 #include "sanitizer_common/sanitizer_stoptheworld.h"
27 #include "sanitizer_common/sanitizer_stackdepot.h"
28 #include "tsan_platform.h"
29 #include "tsan_rtl.h"
30 #include "tsan_flags.h"
31
32 #include <fcntl.h>
33 #include <pthread.h>
34 #include <signal.h>
35 #include <stdio.h>
36 #include <stdlib.h>
37 #include <string.h>
38 #include <stdarg.h>
39 #include <sys/mman.h>
40 #if SANITIZER_LINUX
41 #include <sys/personality.h>
42 #include <setjmp.h>
43 #endif
44 #include <sys/syscall.h>
45 #include <sys/socket.h>
46 #include <sys/time.h>
47 #include <sys/types.h>
48 #include <sys/resource.h>
49 #include <sys/stat.h>
50 #include <unistd.h>
51 #include <sched.h>
52 #include <dlfcn.h>
53 #if SANITIZER_LINUX
54 #define __need_res_state
55 #include <resolv.h>
56 #endif
57
58 #ifdef sa_handler
59 # undef sa_handler
60 #endif
61
62 #ifdef sa_sigaction
63 # undef sa_sigaction
64 #endif
65
66 #if SANITIZER_FREEBSD
67 extern "C" void *__libc_stack_end;
68 void *__libc_stack_end = 0;
69 #endif
70
71 #if SANITIZER_LINUX && defined(__aarch64__)
72 void InitializeGuardPtr() __attribute__((visibility("hidden")));
73 #endif
74
75 namespace __tsan {
76
77 #ifdef TSAN_RUNTIME_VMA
78 // Runtime detected VMA size.
79 uptr vmaSize;
80 #endif
81
82 enum {
83 MemTotal = 0,
84 MemShadow = 1,
85 MemMeta = 2,
86 MemFile = 3,
87 MemMmap = 4,
88 MemTrace = 5,
89 MemHeap = 6,
90 MemOther = 7,
91 MemCount = 8,
92 };
93
FillProfileCallback(uptr p,uptr rss,bool file,uptr * mem,uptr stats_size)94 void FillProfileCallback(uptr p, uptr rss, bool file,
95 uptr *mem, uptr stats_size) {
96 mem[MemTotal] += rss;
97 if (p >= ShadowBeg() && p < ShadowEnd())
98 mem[MemShadow] += rss;
99 else if (p >= MetaShadowBeg() && p < MetaShadowEnd())
100 mem[MemMeta] += rss;
101 #if !SANITIZER_GO
102 else if (p >= HeapMemBeg() && p < HeapMemEnd())
103 mem[MemHeap] += rss;
104 else if (p >= LoAppMemBeg() && p < LoAppMemEnd())
105 mem[file ? MemFile : MemMmap] += rss;
106 else if (p >= HiAppMemBeg() && p < HiAppMemEnd())
107 mem[file ? MemFile : MemMmap] += rss;
108 #else
109 else if (p >= AppMemBeg() && p < AppMemEnd())
110 mem[file ? MemFile : MemMmap] += rss;
111 #endif
112 else if (p >= TraceMemBeg() && p < TraceMemEnd())
113 mem[MemTrace] += rss;
114 else
115 mem[MemOther] += rss;
116 }
117
WriteMemoryProfile(char * buf,uptr buf_size,uptr nthread,uptr nlive)118 void WriteMemoryProfile(char *buf, uptr buf_size, uptr nthread, uptr nlive) {
119 uptr mem[MemCount];
120 internal_memset(mem, 0, sizeof(mem[0]) * MemCount);
121 __sanitizer::GetMemoryProfile(FillProfileCallback, mem, 7);
122 StackDepotStats *stacks = StackDepotGetStats();
123 internal_snprintf(buf, buf_size,
124 "RSS %zd MB: shadow:%zd meta:%zd file:%zd mmap:%zd"
125 " trace:%zd heap:%zd other:%zd stacks=%zd[%zd] nthr=%zd/%zd\n",
126 mem[MemTotal] >> 20, mem[MemShadow] >> 20, mem[MemMeta] >> 20,
127 mem[MemFile] >> 20, mem[MemMmap] >> 20, mem[MemTrace] >> 20,
128 mem[MemHeap] >> 20, mem[MemOther] >> 20,
129 stacks->allocated >> 20, stacks->n_uniq_ids,
130 nlive, nthread);
131 }
132
133 #if SANITIZER_LINUX
FlushShadowMemoryCallback(const SuspendedThreadsList & suspended_threads_list,void * argument)134 void FlushShadowMemoryCallback(
135 const SuspendedThreadsList &suspended_threads_list,
136 void *argument) {
137 ReleaseMemoryPagesToOS(ShadowBeg(), ShadowEnd());
138 }
139 #endif
140
FlushShadowMemory()141 void FlushShadowMemory() {
142 #if SANITIZER_LINUX
143 StopTheWorld(FlushShadowMemoryCallback, 0);
144 #endif
145 }
146
147 #if !SANITIZER_GO
148 // Mark shadow for .rodata sections with the special kShadowRodata marker.
149 // Accesses to .rodata can't race, so this saves time, memory and trace space.
MapRodata()150 static void MapRodata() {
151 // First create temp file.
152 const char *tmpdir = GetEnv("TMPDIR");
153 if (tmpdir == 0)
154 tmpdir = GetEnv("TEST_TMPDIR");
155 #ifdef P_tmpdir
156 if (tmpdir == 0)
157 tmpdir = P_tmpdir;
158 #endif
159 if (tmpdir == 0)
160 return;
161 char name[256];
162 internal_snprintf(name, sizeof(name), "%s/tsan.rodata.%d",
163 tmpdir, (int)internal_getpid());
164 uptr openrv = internal_open(name, O_RDWR | O_CREAT | O_EXCL, 0600);
165 if (internal_iserror(openrv))
166 return;
167 internal_unlink(name); // Unlink it now, so that we can reuse the buffer.
168 fd_t fd = openrv;
169 // Fill the file with kShadowRodata.
170 const uptr kMarkerSize = 512 * 1024 / sizeof(u64);
171 InternalMmapVector<u64> marker(kMarkerSize);
172 // volatile to prevent insertion of memset
173 for (volatile u64 *p = marker.data(); p < marker.data() + kMarkerSize; p++)
174 *p = kShadowRodata;
175 internal_write(fd, marker.data(), marker.size() * sizeof(u64));
176 // Map the file into memory.
177 uptr page = internal_mmap(0, GetPageSizeCached(), PROT_READ | PROT_WRITE,
178 MAP_PRIVATE | MAP_ANONYMOUS, fd, 0);
179 if (internal_iserror(page)) {
180 internal_close(fd);
181 return;
182 }
183 // Map the file into shadow of .rodata sections.
184 MemoryMappingLayout proc_maps(/*cache_enabled*/true);
185 // Reusing the buffer 'name'.
186 MemoryMappedSegment segment(name, ARRAY_SIZE(name));
187 while (proc_maps.Next(&segment)) {
188 if (segment.filename[0] != 0 && segment.filename[0] != '[' &&
189 segment.IsReadable() && segment.IsExecutable() &&
190 !segment.IsWritable() && IsAppMem(segment.start)) {
191 // Assume it's .rodata
192 char *shadow_start = (char *)MemToShadow(segment.start);
193 char *shadow_end = (char *)MemToShadow(segment.end);
194 for (char *p = shadow_start; p < shadow_end;
195 p += marker.size() * sizeof(u64)) {
196 internal_mmap(p, Min<uptr>(marker.size() * sizeof(u64), shadow_end - p),
197 PROT_READ, MAP_PRIVATE | MAP_FIXED, fd, 0);
198 }
199 }
200 }
201 internal_close(fd);
202 }
203
InitializeShadowMemoryPlatform()204 void InitializeShadowMemoryPlatform() {
205 MapRodata();
206 }
207
208 #endif // #if !SANITIZER_GO
209
InitializePlatformEarly()210 void InitializePlatformEarly() {
211 #ifdef TSAN_RUNTIME_VMA
212 vmaSize =
213 (MostSignificantSetBitIndex(GET_CURRENT_FRAME()) + 1);
214 #if defined(__aarch64__)
215 # if !SANITIZER_GO
216 if (vmaSize != 39 && vmaSize != 42 && vmaSize != 48) {
217 Printf("FATAL: ThreadSanitizer: unsupported VMA range\n");
218 Printf("FATAL: Found %zd - Supported 39, 42 and 48\n", vmaSize);
219 Die();
220 }
221 #else
222 if (vmaSize != 48) {
223 Printf("FATAL: ThreadSanitizer: unsupported VMA range\n");
224 Printf("FATAL: Found %zd - Supported 48\n", vmaSize);
225 Die();
226 }
227 #endif
228 #elif defined(__powerpc64__)
229 # if !SANITIZER_GO
230 if (vmaSize != 44 && vmaSize != 46 && vmaSize != 47) {
231 Printf("FATAL: ThreadSanitizer: unsupported VMA range\n");
232 Printf("FATAL: Found %zd - Supported 44, 46, and 47\n", vmaSize);
233 Die();
234 }
235 # else
236 if (vmaSize != 46 && vmaSize != 47) {
237 Printf("FATAL: ThreadSanitizer: unsupported VMA range\n");
238 Printf("FATAL: Found %zd - Supported 46, and 47\n", vmaSize);
239 Die();
240 }
241 # endif
242 #endif
243 #endif
244 }
245
InitializePlatform()246 void InitializePlatform() {
247 DisableCoreDumperIfNecessary();
248
249 // Go maps shadow memory lazily and works fine with limited address space.
250 // Unlimited stack is not a problem as well, because the executable
251 // is not compiled with -pie.
252 if (!SANITIZER_GO) {
253 bool reexec = false;
254 // TSan doesn't play well with unlimited stack size (as stack
255 // overlaps with shadow memory). If we detect unlimited stack size,
256 // we re-exec the program with limited stack size as a best effort.
257 if (StackSizeIsUnlimited()) {
258 const uptr kMaxStackSize = 32 * 1024 * 1024;
259 VReport(1, "Program is run with unlimited stack size, which wouldn't "
260 "work with ThreadSanitizer.\n"
261 "Re-execing with stack size limited to %zd bytes.\n",
262 kMaxStackSize);
263 SetStackSizeLimitInBytes(kMaxStackSize);
264 reexec = true;
265 }
266
267 if (!AddressSpaceIsUnlimited()) {
268 Report("WARNING: Program is run with limited virtual address space,"
269 " which wouldn't work with ThreadSanitizer.\n");
270 Report("Re-execing with unlimited virtual address space.\n");
271 SetAddressSpaceUnlimited();
272 reexec = true;
273 }
274 #if SANITIZER_LINUX && defined(__aarch64__)
275 // After patch "arm64: mm: support ARCH_MMAP_RND_BITS." is introduced in
276 // linux kernel, the random gap between stack and mapped area is increased
277 // from 128M to 36G on 39-bit aarch64. As it is almost impossible to cover
278 // this big range, we should disable randomized virtual space on aarch64.
279 int old_personality = personality(0xffffffff);
280 if (old_personality != -1 && (old_personality & ADDR_NO_RANDOMIZE) == 0) {
281 VReport(1, "WARNING: Program is run with randomized virtual address "
282 "space, which wouldn't work with ThreadSanitizer.\n"
283 "Re-execing with fixed virtual address space.\n");
284 CHECK_NE(personality(old_personality | ADDR_NO_RANDOMIZE), -1);
285 reexec = true;
286 }
287 // Initialize the guard pointer used in {sig}{set,long}jump.
288 InitializeGuardPtr();
289 #endif
290 if (reexec)
291 ReExec();
292 }
293
294 #if !SANITIZER_GO
295 CheckAndProtect();
296 InitTlsSize();
297 #endif
298 }
299
300 #if !SANITIZER_GO
301 // Extract file descriptors passed to glibc internal __res_iclose function.
302 // This is required to properly "close" the fds, because we do not see internal
303 // closes within glibc. The code is a pure hack.
ExtractResolvFDs(void * state,int * fds,int nfd)304 int ExtractResolvFDs(void *state, int *fds, int nfd) {
305 #if SANITIZER_LINUX && !SANITIZER_ANDROID
306 int cnt = 0;
307 struct __res_state *statp = (struct __res_state*)state;
308 for (int i = 0; i < MAXNS && cnt < nfd; i++) {
309 if (statp->_u._ext.nsaddrs[i] && statp->_u._ext.nssocks[i] != -1)
310 fds[cnt++] = statp->_u._ext.nssocks[i];
311 }
312 return cnt;
313 #else
314 return 0;
315 #endif
316 }
317
318 // Extract file descriptors passed via UNIX domain sockets.
319 // This is requried to properly handle "open" of these fds.
320 // see 'man recvmsg' and 'man 3 cmsg'.
ExtractRecvmsgFDs(void * msgp,int * fds,int nfd)321 int ExtractRecvmsgFDs(void *msgp, int *fds, int nfd) {
322 int res = 0;
323 msghdr *msg = (msghdr*)msgp;
324 struct cmsghdr *cmsg = CMSG_FIRSTHDR(msg);
325 for (; cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
326 if (cmsg->cmsg_level != SOL_SOCKET || cmsg->cmsg_type != SCM_RIGHTS)
327 continue;
328 int n = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(fds[0]);
329 for (int i = 0; i < n; i++) {
330 fds[res++] = ((int*)CMSG_DATA(cmsg))[i];
331 if (res == nfd)
332 return res;
333 }
334 }
335 return res;
336 }
337
ImitateTlsWrite(ThreadState * thr,uptr tls_addr,uptr tls_size)338 void ImitateTlsWrite(ThreadState *thr, uptr tls_addr, uptr tls_size) {
339 // Check that the thr object is in tls;
340 const uptr thr_beg = (uptr)thr;
341 const uptr thr_end = (uptr)thr + sizeof(*thr);
342 CHECK_GE(thr_beg, tls_addr);
343 CHECK_LE(thr_beg, tls_addr + tls_size);
344 CHECK_GE(thr_end, tls_addr);
345 CHECK_LE(thr_end, tls_addr + tls_size);
346 // Since the thr object is huge, skip it.
347 MemoryRangeImitateWrite(thr, /*pc=*/2, tls_addr, thr_beg - tls_addr);
348 MemoryRangeImitateWrite(thr, /*pc=*/2, thr_end,
349 tls_addr + tls_size - thr_end);
350 }
351
352 // Note: this function runs with async signals enabled,
353 // so it must not touch any tsan state.
call_pthread_cancel_with_cleanup(int (* fn)(void * c,void * m,void * abstime),void * c,void * m,void * abstime,void (* cleanup)(void * arg),void * arg)354 int call_pthread_cancel_with_cleanup(int(*fn)(void *c, void *m,
355 void *abstime), void *c, void *m, void *abstime,
356 void(*cleanup)(void *arg), void *arg) {
357 // pthread_cleanup_push/pop are hardcore macros mess.
358 // We can't intercept nor call them w/o including pthread.h.
359 int res;
360 pthread_cleanup_push(cleanup, arg);
361 res = fn(c, m, abstime);
362 pthread_cleanup_pop(0);
363 return res;
364 }
365 #endif
366
367 #if !SANITIZER_GO
ReplaceSystemMalloc()368 void ReplaceSystemMalloc() { }
369 #endif
370
371 #if !SANITIZER_GO
372 #if SANITIZER_ANDROID
373 // On Android, one thread can call intercepted functions after
374 // DestroyThreadState(), so add a fake thread state for "dead" threads.
375 static ThreadState *dead_thread_state = nullptr;
376
cur_thread()377 ThreadState *cur_thread() {
378 ThreadState* thr = reinterpret_cast<ThreadState*>(*get_android_tls_ptr());
379 if (thr == nullptr) {
380 __sanitizer_sigset_t emptyset;
381 internal_sigfillset(&emptyset);
382 __sanitizer_sigset_t oldset;
383 CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, &emptyset, &oldset));
384 thr = reinterpret_cast<ThreadState*>(*get_android_tls_ptr());
385 if (thr == nullptr) {
386 thr = reinterpret_cast<ThreadState*>(MmapOrDie(sizeof(ThreadState),
387 "ThreadState"));
388 *get_android_tls_ptr() = reinterpret_cast<uptr>(thr);
389 if (dead_thread_state == nullptr) {
390 dead_thread_state = reinterpret_cast<ThreadState*>(
391 MmapOrDie(sizeof(ThreadState), "ThreadState"));
392 dead_thread_state->fast_state.SetIgnoreBit();
393 dead_thread_state->ignore_interceptors = 1;
394 dead_thread_state->is_dead = true;
395 *const_cast<int*>(&dead_thread_state->tid) = -1;
396 CHECK_EQ(0, internal_mprotect(dead_thread_state, sizeof(ThreadState),
397 PROT_READ));
398 }
399 }
400 CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, &oldset, nullptr));
401 }
402 return thr;
403 }
404
cur_thread_finalize()405 void cur_thread_finalize() {
406 __sanitizer_sigset_t emptyset;
407 internal_sigfillset(&emptyset);
408 __sanitizer_sigset_t oldset;
409 CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, &emptyset, &oldset));
410 ThreadState* thr = reinterpret_cast<ThreadState*>(*get_android_tls_ptr());
411 if (thr != dead_thread_state) {
412 *get_android_tls_ptr() = reinterpret_cast<uptr>(dead_thread_state);
413 UnmapOrDie(thr, sizeof(ThreadState));
414 }
415 CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, &oldset, nullptr));
416 }
417 #endif // SANITIZER_ANDROID
418 #endif // if !SANITIZER_GO
419
420 } // namespace __tsan
421
422 #endif // SANITIZER_LINUX || SANITIZER_FREEBSD || SANITIZER_NETBSD
423