1//===-- tsan_platform_linux.cc --------------------------------------------===//
2//
3// This file is distributed under the University of Illinois Open Source
4// License. See LICENSE.TXT for details.
5//
6//===----------------------------------------------------------------------===//
7//
8// This file is a part of ThreadSanitizer (TSan), a race detector.
9//
10// Linux- and FreeBSD-specific code.
11//===----------------------------------------------------------------------===//
12
13
14#include "sanitizer_common/sanitizer_platform.h"
15#if SANITIZER_LINUX || SANITIZER_FREEBSD
16
17#include "sanitizer_common/sanitizer_common.h"
18#include "sanitizer_common/sanitizer_libc.h"
19#include "sanitizer_common/sanitizer_linux.h"
20#include "sanitizer_common/sanitizer_platform_limits_posix.h"
21#include "sanitizer_common/sanitizer_posix.h"
22#include "sanitizer_common/sanitizer_procmaps.h"
23#include "sanitizer_common/sanitizer_stoptheworld.h"
24#include "sanitizer_common/sanitizer_stackdepot.h"
25#include "tsan_platform.h"
26#include "tsan_rtl.h"
27#include "tsan_flags.h"
28
29#include <fcntl.h>
30#include <pthread.h>
31#include <signal.h>
32#include <stdio.h>
33#include <stdlib.h>
34#include <string.h>
35#include <stdarg.h>
36#include <sys/mman.h>
37#if SANITIZER_LINUX
38#include <sys/personality.h>
39#include <setjmp.h>
40#endif
41#include <sys/syscall.h>
42#include <sys/socket.h>
43#include <sys/time.h>
44#include <sys/types.h>
45#include <sys/resource.h>
46#include <sys/stat.h>
47#include <unistd.h>
48#include <sched.h>
49#include <dlfcn.h>
50#if SANITIZER_LINUX
51#define __need_res_state
52#include <resolv.h>
53#endif
54
55#ifdef sa_handler
56# undef sa_handler
57#endif
58
59#ifdef sa_sigaction
60# undef sa_sigaction
61#endif
62
63#if SANITIZER_FREEBSD
64extern "C" void *__libc_stack_end;
65void *__libc_stack_end = 0;
66#endif
67
68#if SANITIZER_LINUX && defined(__aarch64__)
69void InitializeGuardPtr() __attribute__((visibility("hidden")));
70#endif
71
72namespace __tsan {
73
74#ifdef TSAN_RUNTIME_VMA
75// Runtime detected VMA size.
76uptr vmaSize;
77#endif
78
79enum {
80 MemTotal = 0,
81 MemShadow = 1,
82 MemMeta = 2,
83 MemFile = 3,
84 MemMmap = 4,
85 MemTrace = 5,
86 MemHeap = 6,
87 MemOther = 7,
88 MemCount = 8,
89};
90
91void FillProfileCallback(uptr p, uptr rss, bool file,
92 uptr *mem, uptr stats_size) {
93 mem[MemTotal] += rss;
94 if (p >= ShadowBeg() && p < ShadowEnd())
95 mem[MemShadow] += rss;
96 else if (p >= MetaShadowBeg() && p < MetaShadowEnd())
97 mem[MemMeta] += rss;
98#if !SANITIZER_GO
99 else if (p >= HeapMemBeg() && p < HeapMemEnd())
100 mem[MemHeap] += rss;
101 else if (p >= LoAppMemBeg() && p < LoAppMemEnd())
102 mem[file ? MemFile : MemMmap] += rss;
103 else if (p >= HiAppMemBeg() && p < HiAppMemEnd())
104 mem[file ? MemFile : MemMmap] += rss;
105#else
106 else if (p >= AppMemBeg() && p < AppMemEnd())
107 mem[file ? MemFile : MemMmap] += rss;
108#endif
109 else if (p >= TraceMemBeg() && p < TraceMemEnd())
110 mem[MemTrace] += rss;
111 else
112 mem[MemOther] += rss;
113}
114
115void WriteMemoryProfile(char *buf, uptr buf_size, uptr nthread, uptr nlive) {
116 uptr mem[MemCount];
117 internal_memset(mem, 0, sizeof(mem[0]) * MemCount);
118 __sanitizer::GetMemoryProfile(FillProfileCallback, mem, 7);
119 StackDepotStats *stacks = StackDepotGetStats();
120 internal_snprintf(buf, buf_size,
121 "RSS %zd MB: shadow:%zd meta:%zd file:%zd mmap:%zd"
122 " trace:%zd heap:%zd other:%zd stacks=%zd[%zd] nthr=%zd/%zd\n",
123 mem[MemTotal] >> 20, mem[MemShadow] >> 20, mem[MemMeta] >> 20,
124 mem[MemFile] >> 20, mem[MemMmap] >> 20, mem[MemTrace] >> 20,
125 mem[MemHeap] >> 20, mem[MemOther] >> 20,
126 stacks->allocated >> 20, stacks->n_uniq_ids,
127 nlive, nthread);
128}
129
130#if SANITIZER_LINUX
131void FlushShadowMemoryCallback(
132 const SuspendedThreadsList &suspended_threads_list,
133 void *argument) {
134 ReleaseMemoryPagesToOS(ShadowBeg(), ShadowEnd());
135}
136#endif
137
138void FlushShadowMemory() {
139#if SANITIZER_LINUX
140 StopTheWorld(FlushShadowMemoryCallback, 0);
141#endif
142}
143
144#if !SANITIZER_GO
145// Mark shadow for .rodata sections with the special kShadowRodata marker.
146// Accesses to .rodata can't race, so this saves time, memory and trace space.
147static void MapRodata() {
148 // First create temp file.
149 const char *tmpdir = GetEnv("TMPDIR");
150 if (tmpdir == 0)
151 tmpdir = GetEnv("TEST_TMPDIR");
152#ifdef P_tmpdir
153 if (tmpdir == 0)
154 tmpdir = P_tmpdir;
155#endif
156 if (tmpdir == 0)
157 return;
158 char name[256];
159 internal_snprintf(name, sizeof(name), "%s/tsan.rodata.%d",
160 tmpdir, (int)internal_getpid());
161 uptr openrv = internal_open(name, O_RDWR | O_CREAT | O_EXCL, 0600);
162 if (internal_iserror(openrv))
163 return;
164 internal_unlink(name); // Unlink it now, so that we can reuse the buffer.
165 fd_t fd = openrv;
166 // Fill the file with kShadowRodata.
167 const uptr kMarkerSize = 512 * 1024 / sizeof(u64);
168 InternalScopedBuffer<u64> marker(kMarkerSize);
169 // volatile to prevent insertion of memset
170 for (volatile u64 *p = marker.data(); p < marker.data() + kMarkerSize; p++)
171 *p = kShadowRodata;
172 internal_write(fd, marker.data(), marker.size());
173 // Map the file into memory.
174 uptr page = internal_mmap(0, GetPageSizeCached(), PROT_READ | PROT_WRITE,
175 MAP_PRIVATE | MAP_ANONYMOUS, fd, 0);
176 if (internal_iserror(page)) {
177 internal_close(fd);
178 return;
179 }
180 // Map the file into shadow of .rodata sections.
181 MemoryMappingLayout proc_maps(/*cache_enabled*/true);
182 // Reusing the buffer 'name'.
183 MemoryMappedSegment segment(name, ARRAY_SIZE(name));
184 while (proc_maps.Next(&segment)) {
185 if (segment.filename[0] != 0 && segment.filename[0] != '[' &&
186 segment.IsReadable() && segment.IsExecutable() &&
187 !segment.IsWritable() && IsAppMem(segment.start)) {
188 // Assume it's .rodata
189 char *shadow_start = (char *)MemToShadow(segment.start);
190 char *shadow_end = (char *)MemToShadow(segment.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
200void InitializeShadowMemoryPlatform() {
201 MapRodata();
202}
203
204#endif // #if !SANITIZER_GO
205
206void InitializePlatformEarly() {
207#ifdef TSAN_RUNTIME_VMA
208 vmaSize =
209 (MostSignificantSetBitIndex(GET_CURRENT_FRAME()) + 1);
210#if defined(__aarch64__)
211 if (vmaSize != 39 && vmaSize != 42 && vmaSize != 48) {
212 Printf("FATAL: ThreadSanitizer: unsupported VMA range\n");
213 Printf("FATAL: Found %d - Supported 39, 42 and 48\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
226void 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 (!SANITIZER_GO) {
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 // Initialize the guard pointer used in {sig}{set,long}jump.
268 InitializeGuardPtr();
269#endif
270 if (reexec)
271 ReExec();
272 }
273
274#if !SANITIZER_GO
275 CheckAndProtect();
276 InitTlsSize();
277#endif
278}
279
280#if !SANITIZER_GO
281// Extract file descriptors passed to glibc internal __res_iclose function.
282// This is required to properly "close" the fds, because we do not see internal
283// closes within glibc. The code is a pure hack.
284int ExtractResolvFDs(void *state, int *fds, int nfd) {
285#if SANITIZER_LINUX && !SANITIZER_ANDROID
286 int cnt = 0;
287 struct __res_state *statp = (struct __res_state*)state;
288 for (int i = 0; i < MAXNS && cnt < nfd; i++) {
289 if (statp->_u._ext.nsaddrs[i] && statp->_u._ext.nssocks[i] != -1)
290 fds[cnt++] = statp->_u._ext.nssocks[i];
291 }
292 return cnt;
293#else
294 return 0;
295#endif
296}
297
298// Extract file descriptors passed via UNIX domain sockets.
299// This is requried to properly handle "open" of these fds.
300// see 'man recvmsg' and 'man 3 cmsg'.
301int ExtractRecvmsgFDs(void *msgp, int *fds, int nfd) {
302 int res = 0;
303 msghdr *msg = (msghdr*)msgp;
304 struct cmsghdr *cmsg = CMSG_FIRSTHDR(msg);
305 for (; cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
306 if (cmsg->cmsg_level != SOL_SOCKET || cmsg->cmsg_type != SCM_RIGHTS)
307 continue;
308 int n = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(fds[0]);
309 for (int i = 0; i < n; i++) {
310 fds[res++] = ((int*)CMSG_DATA(cmsg))[i];
311 if (res == nfd)
312 return res;
313 }
314 }
315 return res;
316}
317
318void ImitateTlsWrite(ThreadState *thr, uptr tls_addr, uptr tls_size) {
319 // Check that the thr object is in tls;
320 const uptr thr_beg = (uptr)thr;
321 const uptr thr_end = (uptr)thr + sizeof(*thr);
322 CHECK_GE(thr_beg, tls_addr);
323 CHECK_LE(thr_beg, tls_addr + tls_size);
324 CHECK_GE(thr_end, tls_addr);
325 CHECK_LE(thr_end, tls_addr + tls_size);
326 // Since the thr object is huge, skip it.
327 MemoryRangeImitateWrite(thr, /*pc=*/2, tls_addr, thr_beg - tls_addr);
328 MemoryRangeImitateWrite(thr, /*pc=*/2, thr_end,
329 tls_addr + tls_size - thr_end);
330}
331
332// Note: this function runs with async signals enabled,
333// so it must not touch any tsan state.
334int call_pthread_cancel_with_cleanup(int(*fn)(void *c, void *m,
335 void *abstime), void *c, void *m, void *abstime,
336 void(*cleanup)(void *arg), void *arg) {
337 // pthread_cleanup_push/pop are hardcore macros mess.
338 // We can't intercept nor call them w/o including pthread.h.
339 int res;
340 pthread_cleanup_push(cleanup, arg);
341 res = fn(c, m, abstime);
342 pthread_cleanup_pop(0);
343 return res;
344}
345#endif
346
347#if !SANITIZER_GO
348void ReplaceSystemMalloc() { }
349#endif
350
351#if !SANITIZER_GO
352#if SANITIZER_ANDROID
353// On Android, one thread can call intercepted functions after
354// DestroyThreadState(), so add a fake thread state for "dead" threads.
355static ThreadState *dead_thread_state = nullptr;
356
357ThreadState *cur_thread() {
358 ThreadState* thr = reinterpret_cast<ThreadState*>(*get_android_tls_ptr());
359 if (thr == nullptr) {
360 __sanitizer_sigset_t emptyset;
361 internal_sigfillset(&emptyset);
362 __sanitizer_sigset_t oldset;
363 CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, &emptyset, &oldset));
364 thr = reinterpret_cast<ThreadState*>(*get_android_tls_ptr());
365 if (thr == nullptr) {
366 thr = reinterpret_cast<ThreadState*>(MmapOrDie(sizeof(ThreadState),
367 "ThreadState"));
368 *get_android_tls_ptr() = reinterpret_cast<uptr>(thr);
369 if (dead_thread_state == nullptr) {
370 dead_thread_state = reinterpret_cast<ThreadState*>(
371 MmapOrDie(sizeof(ThreadState), "ThreadState"));
372 dead_thread_state->fast_state.SetIgnoreBit();
373 dead_thread_state->ignore_interceptors = 1;
374 dead_thread_state->is_dead = true;
375 *const_cast<int*>(&dead_thread_state->tid) = -1;
376 CHECK_EQ(0, internal_mprotect(dead_thread_state, sizeof(ThreadState),
377 PROT_READ));
378 }
379 }
380 CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, &oldset, nullptr));
381 }
382 return thr;
383}
384
385void cur_thread_finalize() {
386 __sanitizer_sigset_t emptyset;
387 internal_sigfillset(&emptyset);
388 __sanitizer_sigset_t oldset;
389 CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, &emptyset, &oldset));
390 ThreadState* thr = reinterpret_cast<ThreadState*>(*get_android_tls_ptr());
391 if (thr != dead_thread_state) {
392 *get_android_tls_ptr() = reinterpret_cast<uptr>(dead_thread_state);
393 UnmapOrDie(thr, sizeof(ThreadState));
394 }
395 CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, &oldset, nullptr));
396}
397#endif // SANITIZER_ANDROID
398#endif // if !SANITIZER_GO
399
400} // namespace __tsan
401
402#endif // SANITIZER_LINUX || SANITIZER_FREEBSD
403