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
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_posix.h"
23 #include "sanitizer_common/sanitizer_posix.h"
24 #include "sanitizer_common/sanitizer_procmaps.h"
25 #include "sanitizer_common/sanitizer_stoptheworld.h"
26 #include "sanitizer_common/sanitizer_stackdepot.h"
27 #include "tsan_platform.h"
28 #include "tsan_rtl.h"
29 #include "tsan_flags.h"
30
31 #include <fcntl.h>
32 #include <pthread.h>
33 #include <signal.h>
34 #include <stdio.h>
35 #include <stdlib.h>
36 #include <string.h>
37 #include <stdarg.h>
38 #include <sys/mman.h>
39 #if SANITIZER_LINUX
40 #include <sys/personality.h>
41 #endif
42 #include <sys/syscall.h>
43 #include <sys/socket.h>
44 #include <sys/time.h>
45 #include <sys/types.h>
46 #include <sys/resource.h>
47 #include <sys/stat.h>
48 #include <unistd.h>
49 #include <errno.h>
50 #include <sched.h>
51 #include <dlfcn.h>
52 #if SANITIZER_LINUX
53 #define __need_res_state
54 #include <resolv.h>
55 #endif
56
57 #ifdef sa_handler
58 # undef sa_handler
59 #endif
60
61 #ifdef sa_sigaction
62 # undef sa_sigaction
63 #endif
64
65 #if SANITIZER_FREEBSD
66 extern "C" void *__libc_stack_end;
67 void *__libc_stack_end = 0;
68 #endif
69
70 namespace __tsan {
71
72 #ifdef TSAN_RUNTIME_VMA
73 // Runtime detected VMA size.
74 uptr vmaSize;
75 #endif
76
77 enum {
78 MemTotal = 0,
79 MemShadow = 1,
80 MemMeta = 2,
81 MemFile = 3,
82 MemMmap = 4,
83 MemTrace = 5,
84 MemHeap = 6,
85 MemOther = 7,
86 MemCount = 8,
87 };
88
FillProfileCallback(uptr p,uptr rss,bool file,uptr * mem,uptr stats_size)89 void FillProfileCallback(uptr p, uptr rss, bool file,
90 uptr *mem, uptr stats_size) {
91 mem[MemTotal] += rss;
92 if (p >= ShadowBeg() && p < ShadowEnd())
93 mem[MemShadow] += rss;
94 else if (p >= MetaShadowBeg() && p < MetaShadowEnd())
95 mem[MemMeta] += rss;
96 #ifndef SANITIZER_GO
97 else if (p >= HeapMemBeg() && p < HeapMemEnd())
98 mem[MemHeap] += rss;
99 else if (p >= LoAppMemBeg() && p < LoAppMemEnd())
100 mem[file ? MemFile : MemMmap] += rss;
101 else if (p >= HiAppMemBeg() && p < HiAppMemEnd())
102 mem[file ? MemFile : MemMmap] += rss;
103 #else
104 else if (p >= AppMemBeg() && p < AppMemEnd())
105 mem[file ? MemFile : MemMmap] += rss;
106 #endif
107 else if (p >= TraceMemBeg() && p < TraceMemEnd())
108 mem[MemTrace] += rss;
109 else
110 mem[MemOther] += rss;
111 }
112
WriteMemoryProfile(char * buf,uptr buf_size,uptr nthread,uptr nlive)113 void WriteMemoryProfile(char *buf, uptr buf_size, uptr nthread, uptr nlive) {
114 uptr mem[MemCount];
115 internal_memset(mem, 0, sizeof(mem[0]) * MemCount);
116 __sanitizer::GetMemoryProfile(FillProfileCallback, mem, 7);
117 StackDepotStats *stacks = StackDepotGetStats();
118 internal_snprintf(buf, buf_size,
119 "RSS %zd MB: shadow:%zd meta:%zd file:%zd mmap:%zd"
120 " trace:%zd heap:%zd other:%zd stacks=%zd[%zd] nthr=%zd/%zd\n",
121 mem[MemTotal] >> 20, mem[MemShadow] >> 20, mem[MemMeta] >> 20,
122 mem[MemFile] >> 20, mem[MemMmap] >> 20, mem[MemTrace] >> 20,
123 mem[MemHeap] >> 20, mem[MemOther] >> 20,
124 stacks->allocated >> 20, stacks->n_uniq_ids,
125 nlive, nthread);
126 }
127
128 #if SANITIZER_LINUX
FlushShadowMemoryCallback(const SuspendedThreadsList & suspended_threads_list,void * argument)129 void FlushShadowMemoryCallback(
130 const SuspendedThreadsList &suspended_threads_list,
131 void *argument) {
132 FlushUnneededShadowMemory(ShadowBeg(), ShadowEnd() - ShadowBeg());
133 }
134 #endif
135
FlushShadowMemory()136 void FlushShadowMemory() {
137 #if SANITIZER_LINUX
138 StopTheWorld(FlushShadowMemoryCallback, 0);
139 #endif
140 }
141
142 #ifndef SANITIZER_GO
143 // Mark shadow for .rodata sections with the special kShadowRodata marker.
144 // Accesses to .rodata can't race, so this saves time, memory and trace space.
MapRodata()145 static void MapRodata() {
146 // First create temp file.
147 const char *tmpdir = GetEnv("TMPDIR");
148 if (tmpdir == 0)
149 tmpdir = GetEnv("TEST_TMPDIR");
150 #ifdef P_tmpdir
151 if (tmpdir == 0)
152 tmpdir = P_tmpdir;
153 #endif
154 if (tmpdir == 0)
155 return;
156 char name[256];
157 internal_snprintf(name, sizeof(name), "%s/tsan.rodata.%d",
158 tmpdir, (int)internal_getpid());
159 uptr openrv = internal_open(name, O_RDWR | O_CREAT | O_EXCL, 0600);
160 if (internal_iserror(openrv))
161 return;
162 internal_unlink(name); // Unlink it now, so that we can reuse the buffer.
163 fd_t fd = openrv;
164 // Fill the file with kShadowRodata.
165 const uptr kMarkerSize = 512 * 1024 / sizeof(u64);
166 InternalScopedBuffer<u64> marker(kMarkerSize);
167 // volatile to prevent insertion of memset
168 for (volatile u64 *p = marker.data(); p < marker.data() + kMarkerSize; p++)
169 *p = kShadowRodata;
170 internal_write(fd, marker.data(), marker.size());
171 // Map the file into memory.
172 uptr page = internal_mmap(0, GetPageSizeCached(), PROT_READ | PROT_WRITE,
173 MAP_PRIVATE | MAP_ANONYMOUS, fd, 0);
174 if (internal_iserror(page)) {
175 internal_close(fd);
176 return;
177 }
178 // Map the file into shadow of .rodata sections.
179 MemoryMappingLayout proc_maps(/*cache_enabled*/true);
180 uptr start, end, offset, prot;
181 // Reusing the buffer 'name'.
182 while (proc_maps.Next(&start, &end, &offset, name, ARRAY_SIZE(name), &prot)) {
183 if (name[0] != 0 && name[0] != '['
184 && (prot & MemoryMappingLayout::kProtectionRead)
185 && (prot & MemoryMappingLayout::kProtectionExecute)
186 && !(prot & MemoryMappingLayout::kProtectionWrite)
187 && IsAppMem(start)) {
188 // Assume it's .rodata
189 char *shadow_start = (char*)MemToShadow(start);
190 char *shadow_end = (char*)MemToShadow(end);
191 for (char *p = shadow_start; p < shadow_end; p += marker.size()) {
192 internal_mmap(p, Min<uptr>(marker.size(), shadow_end - p),
193 PROT_READ, MAP_PRIVATE | MAP_FIXED, fd, 0);
194 }
195 }
196 }
197 internal_close(fd);
198 }
199
InitializeShadowMemoryPlatform()200 void InitializeShadowMemoryPlatform() {
201 MapRodata();
202 }
203
204 #endif // #ifndef SANITIZER_GO
205
InitializePlatformEarly()206 void InitializePlatformEarly() {
207 #ifdef TSAN_RUNTIME_VMA
208 vmaSize =
209 (MostSignificantSetBitIndex(GET_CURRENT_FRAME()) + 1);
210 #if defined(__aarch64__)
211 if (vmaSize != 39 && vmaSize != 42) {
212 Printf("FATAL: ThreadSanitizer: unsupported VMA range\n");
213 Printf("FATAL: Found %d - Supported 39 and 42\n", vmaSize);
214 Die();
215 }
216 #elif defined(__powerpc64__)
217 if (vmaSize != 44 && vmaSize != 46) {
218 Printf("FATAL: ThreadSanitizer: unsupported VMA range\n");
219 Printf("FATAL: Found %d - Supported 44 and 46\n", vmaSize);
220 Die();
221 }
222 #endif
223 #endif
224 }
225
InitializePlatform()226 void InitializePlatform() {
227 DisableCoreDumperIfNecessary();
228
229 // Go maps shadow memory lazily and works fine with limited address space.
230 // Unlimited stack is not a problem as well, because the executable
231 // is not compiled with -pie.
232 if (kCppMode) {
233 bool reexec = false;
234 // TSan doesn't play well with unlimited stack size (as stack
235 // overlaps with shadow memory). If we detect unlimited stack size,
236 // we re-exec the program with limited stack size as a best effort.
237 if (StackSizeIsUnlimited()) {
238 const uptr kMaxStackSize = 32 * 1024 * 1024;
239 VReport(1, "Program is run with unlimited stack size, which wouldn't "
240 "work with ThreadSanitizer.\n"
241 "Re-execing with stack size limited to %zd bytes.\n",
242 kMaxStackSize);
243 SetStackSizeLimitInBytes(kMaxStackSize);
244 reexec = true;
245 }
246
247 if (!AddressSpaceIsUnlimited()) {
248 Report("WARNING: Program is run with limited virtual address space,"
249 " which wouldn't work with ThreadSanitizer.\n");
250 Report("Re-execing with unlimited virtual address space.\n");
251 SetAddressSpaceUnlimited();
252 reexec = true;
253 }
254 #if SANITIZER_LINUX && defined(__aarch64__)
255 // After patch "arm64: mm: support ARCH_MMAP_RND_BITS." is introduced in
256 // linux kernel, the random gap between stack and mapped area is increased
257 // from 128M to 36G on 39-bit aarch64. As it is almost impossible to cover
258 // this big range, we should disable randomized virtual space on aarch64.
259 int old_personality = personality(0xffffffff);
260 if (old_personality != -1 && (old_personality & ADDR_NO_RANDOMIZE) == 0) {
261 VReport(1, "WARNING: Program is run with randomized virtual address "
262 "space, which wouldn't work with ThreadSanitizer.\n"
263 "Re-execing with fixed virtual address space.\n");
264 CHECK_NE(personality(old_personality | ADDR_NO_RANDOMIZE), -1);
265 reexec = true;
266 }
267 #endif
268 if (reexec)
269 ReExec();
270 }
271
272 #ifndef SANITIZER_GO
273 CheckAndProtect();
274 InitTlsSize();
275 #endif
276 }
277
278 #ifndef SANITIZER_GO
279 // Extract file descriptors passed to glibc internal __res_iclose function.
280 // This is required to properly "close" the fds, because we do not see internal
281 // closes within glibc. The code is a pure hack.
ExtractResolvFDs(void * state,int * fds,int nfd)282 int ExtractResolvFDs(void *state, int *fds, int nfd) {
283 #if SANITIZER_LINUX && !SANITIZER_ANDROID
284 int cnt = 0;
285 __res_state *statp = (__res_state*)state;
286 for (int i = 0; i < MAXNS && cnt < nfd; i++) {
287 if (statp->_u._ext.nsaddrs[i] && statp->_u._ext.nssocks[i] != -1)
288 fds[cnt++] = statp->_u._ext.nssocks[i];
289 }
290 return cnt;
291 #else
292 return 0;
293 #endif
294 }
295
296 // Extract file descriptors passed via UNIX domain sockets.
297 // This is requried to properly handle "open" of these fds.
298 // see 'man recvmsg' and 'man 3 cmsg'.
ExtractRecvmsgFDs(void * msgp,int * fds,int nfd)299 int ExtractRecvmsgFDs(void *msgp, int *fds, int nfd) {
300 int res = 0;
301 msghdr *msg = (msghdr*)msgp;
302 struct cmsghdr *cmsg = CMSG_FIRSTHDR(msg);
303 for (; cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
304 if (cmsg->cmsg_level != SOL_SOCKET || cmsg->cmsg_type != SCM_RIGHTS)
305 continue;
306 int n = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(fds[0]);
307 for (int i = 0; i < n; i++) {
308 fds[res++] = ((int*)CMSG_DATA(cmsg))[i];
309 if (res == nfd)
310 return res;
311 }
312 }
313 return res;
314 }
315
316 // Note: this function runs with async signals enabled,
317 // 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)318 int call_pthread_cancel_with_cleanup(int(*fn)(void *c, void *m,
319 void *abstime), void *c, void *m, void *abstime,
320 void(*cleanup)(void *arg), void *arg) {
321 // pthread_cleanup_push/pop are hardcore macros mess.
322 // We can't intercept nor call them w/o including pthread.h.
323 int res;
324 pthread_cleanup_push(cleanup, arg);
325 res = fn(c, m, abstime);
326 pthread_cleanup_pop(0);
327 return res;
328 }
329 #endif
330
331 #ifndef SANITIZER_GO
ReplaceSystemMalloc()332 void ReplaceSystemMalloc() { }
333 #endif
334
335 #ifndef SANITIZER_GO
336 #if SANITIZER_ANDROID
337
338 #if defined(__aarch64__)
339 # define __get_tls() \
340 ({ void** __val; __asm__("mrs %0, tpidr_el0" : "=r"(__val)); __val; })
341 #elif defined(__x86_64__)
342 # define __get_tls() \
343 ({ void** __val; __asm__("mov %%fs:0, %0" : "=r"(__val)); __val; })
344 #else
345 #error unsupported architecture
346 #endif
347
348 // On Android, __thread is not supported. So we store the pointer to ThreadState
349 // in TLS_SLOT_TSAN, which is the tls slot allocated by Android bionic for tsan.
350 static const int TLS_SLOT_TSAN = 8;
351 // On Android, one thread can call intercepted functions after
352 // DestroyThreadState(), so add a fake thread state for "dead" threads.
353 static ThreadState *dead_thread_state = nullptr;
354
cur_thread()355 ThreadState *cur_thread() {
356 ThreadState* thr = (ThreadState*)__get_tls()[TLS_SLOT_TSAN];
357 if (thr == nullptr) {
358 __sanitizer_sigset_t emptyset;
359 internal_sigfillset(&emptyset);
360 __sanitizer_sigset_t oldset;
361 CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, &emptyset, &oldset));
362 thr = reinterpret_cast<ThreadState*>(__get_tls()[TLS_SLOT_TSAN]);
363 if (thr == nullptr) {
364 thr = reinterpret_cast<ThreadState*>(MmapOrDie(sizeof(ThreadState),
365 "ThreadState"));
366 __get_tls()[TLS_SLOT_TSAN] = thr;
367 if (dead_thread_state == nullptr) {
368 dead_thread_state = reinterpret_cast<ThreadState*>(
369 MmapOrDie(sizeof(ThreadState), "ThreadState"));
370 dead_thread_state->fast_state.SetIgnoreBit();
371 dead_thread_state->ignore_interceptors = 1;
372 dead_thread_state->is_dead = true;
373 *const_cast<int*>(&dead_thread_state->tid) = -1;
374 CHECK_EQ(0, internal_mprotect(dead_thread_state, sizeof(ThreadState),
375 PROT_READ));
376 }
377 }
378 CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, &oldset, nullptr));
379 }
380 return thr;
381 }
382
cur_thread_finalize()383 void cur_thread_finalize() {
384 __sanitizer_sigset_t emptyset;
385 internal_sigfillset(&emptyset);
386 __sanitizer_sigset_t oldset;
387 CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, &emptyset, &oldset));
388 ThreadState* thr = (ThreadState*)__get_tls()[TLS_SLOT_TSAN];
389 if (thr != dead_thread_state) {
390 __get_tls()[TLS_SLOT_TSAN] = dead_thread_state;
391 UnmapOrDie(thr, sizeof(ThreadState));
392 }
393 CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, &oldset, nullptr));
394 }
395 #endif // SANITIZER_ANDROID
396 #endif // ifndef SANITIZER_GO
397
398 } // namespace __tsan
399
400 #endif // SANITIZER_LINUX || SANITIZER_FREEBSD
401