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_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 #include <sys/syscall.h>
38 #include <sys/socket.h>
39 #include <sys/time.h>
40 #include <sys/types.h>
41 #include <sys/resource.h>
42 #include <sys/stat.h>
43 #include <unistd.h>
44 #include <errno.h>
45 #include <sched.h>
46 #include <dlfcn.h>
47 #if SANITIZER_LINUX
48 #define __need_res_state
49 #include <resolv.h>
50 #endif
51
52 #ifdef sa_handler
53 # undef sa_handler
54 #endif
55
56 #ifdef sa_sigaction
57 # undef sa_sigaction
58 #endif
59
60 #if SANITIZER_FREEBSD
61 extern "C" void *__libc_stack_end;
62 void *__libc_stack_end = 0;
63 #endif
64
65 namespace __tsan {
66
67 static uptr g_data_start;
68 static uptr g_data_end;
69
70 #ifdef TSAN_RUNTIME_VMA
71 // Runtime detected VMA size.
72 uptr vmaSize;
73 #endif
74
75 enum {
76 MemTotal = 0,
77 MemShadow = 1,
78 MemMeta = 2,
79 MemFile = 3,
80 MemMmap = 4,
81 MemTrace = 5,
82 MemHeap = 6,
83 MemOther = 7,
84 MemCount = 8,
85 };
86
FillProfileCallback(uptr p,uptr rss,bool file,uptr * mem,uptr stats_size)87 void FillProfileCallback(uptr p, uptr rss, bool file,
88 uptr *mem, uptr stats_size) {
89 mem[MemTotal] += rss;
90 if (p >= ShadowBeg() && p < ShadowEnd())
91 mem[MemShadow] += rss;
92 else if (p >= MetaShadowBeg() && p < MetaShadowEnd())
93 mem[MemMeta] += rss;
94 #ifndef SANITIZER_GO
95 else if (p >= HeapMemBeg() && p < HeapMemEnd())
96 mem[MemHeap] += rss;
97 else if (p >= LoAppMemBeg() && p < LoAppMemEnd())
98 mem[file ? MemFile : MemMmap] += rss;
99 else if (p >= HiAppMemBeg() && p < HiAppMemEnd())
100 mem[file ? MemFile : MemMmap] += rss;
101 #else
102 else if (p >= AppMemBeg() && p < AppMemEnd())
103 mem[file ? MemFile : MemMmap] += rss;
104 #endif
105 else if (p >= TraceMemBeg() && p < TraceMemEnd())
106 mem[MemTrace] += rss;
107 else
108 mem[MemOther] += rss;
109 }
110
WriteMemoryProfile(char * buf,uptr buf_size,uptr nthread,uptr nlive)111 void WriteMemoryProfile(char *buf, uptr buf_size, uptr nthread, uptr nlive) {
112 uptr mem[MemCount];
113 internal_memset(mem, 0, sizeof(mem[0]) * MemCount);
114 __sanitizer::GetMemoryProfile(FillProfileCallback, mem, 7);
115 StackDepotStats *stacks = StackDepotGetStats();
116 internal_snprintf(buf, buf_size,
117 "RSS %zd MB: shadow:%zd meta:%zd file:%zd mmap:%zd"
118 " trace:%zd heap:%zd other:%zd stacks=%zd[%zd] nthr=%zd/%zd\n",
119 mem[MemTotal] >> 20, mem[MemShadow] >> 20, mem[MemMeta] >> 20,
120 mem[MemFile] >> 20, mem[MemMmap] >> 20, mem[MemTrace] >> 20,
121 mem[MemHeap] >> 20, mem[MemOther] >> 20,
122 stacks->allocated >> 20, stacks->n_uniq_ids,
123 nlive, nthread);
124 }
125
126 #if SANITIZER_LINUX
FlushShadowMemoryCallback(const SuspendedThreadsList & suspended_threads_list,void * argument)127 void FlushShadowMemoryCallback(
128 const SuspendedThreadsList &suspended_threads_list,
129 void *argument) {
130 FlushUnneededShadowMemory(ShadowBeg(), ShadowEnd() - ShadowBeg());
131 }
132 #endif
133
FlushShadowMemory()134 void FlushShadowMemory() {
135 #if SANITIZER_LINUX
136 StopTheWorld(FlushShadowMemoryCallback, 0);
137 #endif
138 }
139
140 #ifndef SANITIZER_GO
141 // Mark shadow for .rodata sections with the special kShadowRodata marker.
142 // Accesses to .rodata can't race, so this saves time, memory and trace space.
MapRodata()143 static void MapRodata() {
144 // First create temp file.
145 const char *tmpdir = GetEnv("TMPDIR");
146 if (tmpdir == 0)
147 tmpdir = GetEnv("TEST_TMPDIR");
148 #ifdef P_tmpdir
149 if (tmpdir == 0)
150 tmpdir = P_tmpdir;
151 #endif
152 if (tmpdir == 0)
153 return;
154 char name[256];
155 internal_snprintf(name, sizeof(name), "%s/tsan.rodata.%d",
156 tmpdir, (int)internal_getpid());
157 uptr openrv = internal_open(name, O_RDWR | O_CREAT | O_EXCL, 0600);
158 if (internal_iserror(openrv))
159 return;
160 internal_unlink(name); // Unlink it now, so that we can reuse the buffer.
161 fd_t fd = openrv;
162 // Fill the file with kShadowRodata.
163 const uptr kMarkerSize = 512 * 1024 / sizeof(u64);
164 InternalScopedBuffer<u64> marker(kMarkerSize);
165 // volatile to prevent insertion of memset
166 for (volatile u64 *p = marker.data(); p < marker.data() + kMarkerSize; p++)
167 *p = kShadowRodata;
168 internal_write(fd, marker.data(), marker.size());
169 // Map the file into memory.
170 uptr page = internal_mmap(0, GetPageSizeCached(), PROT_READ | PROT_WRITE,
171 MAP_PRIVATE | MAP_ANONYMOUS, fd, 0);
172 if (internal_iserror(page)) {
173 internal_close(fd);
174 return;
175 }
176 // Map the file into shadow of .rodata sections.
177 MemoryMappingLayout proc_maps(/*cache_enabled*/true);
178 uptr start, end, offset, prot;
179 // Reusing the buffer 'name'.
180 while (proc_maps.Next(&start, &end, &offset, name, ARRAY_SIZE(name), &prot)) {
181 if (name[0] != 0 && name[0] != '['
182 && (prot & MemoryMappingLayout::kProtectionRead)
183 && (prot & MemoryMappingLayout::kProtectionExecute)
184 && !(prot & MemoryMappingLayout::kProtectionWrite)
185 && IsAppMem(start)) {
186 // Assume it's .rodata
187 char *shadow_start = (char*)MemToShadow(start);
188 char *shadow_end = (char*)MemToShadow(end);
189 for (char *p = shadow_start; p < shadow_end; p += marker.size()) {
190 internal_mmap(p, Min<uptr>(marker.size(), shadow_end - p),
191 PROT_READ, MAP_PRIVATE | MAP_FIXED, fd, 0);
192 }
193 }
194 }
195 internal_close(fd);
196 }
197
InitializeShadowMemoryPlatform()198 void InitializeShadowMemoryPlatform() {
199 MapRodata();
200 }
201
InitDataSeg()202 static void InitDataSeg() {
203 MemoryMappingLayout proc_maps(true);
204 uptr start, end, offset;
205 char name[128];
206 #if SANITIZER_FREEBSD
207 // On FreeBSD BSS is usually the last block allocated within the
208 // low range and heap is the last block allocated within the range
209 // 0x800000000-0x8ffffffff.
210 while (proc_maps.Next(&start, &end, &offset, name, ARRAY_SIZE(name),
211 /*protection*/ 0)) {
212 DPrintf("%p-%p %p %s\n", start, end, offset, name);
213 if ((start & 0xffff00000000ULL) == 0 && (end & 0xffff00000000ULL) == 0 &&
214 name[0] == '\0') {
215 g_data_start = start;
216 g_data_end = end;
217 }
218 }
219 #else
220 bool prev_is_data = false;
221 while (proc_maps.Next(&start, &end, &offset, name, ARRAY_SIZE(name),
222 /*protection*/ 0)) {
223 DPrintf("%p-%p %p %s\n", start, end, offset, name);
224 bool is_data = offset != 0 && name[0] != 0;
225 // BSS may get merged with [heap] in /proc/self/maps. This is not very
226 // reliable.
227 bool is_bss = offset == 0 &&
228 (name[0] == 0 || internal_strcmp(name, "[heap]") == 0) && prev_is_data;
229 if (g_data_start == 0 && is_data)
230 g_data_start = start;
231 if (is_bss)
232 g_data_end = end;
233 prev_is_data = is_data;
234 }
235 #endif
236 DPrintf("guessed data_start=%p data_end=%p\n", g_data_start, g_data_end);
237 CHECK_LT(g_data_start, g_data_end);
238 CHECK_GE((uptr)&g_data_start, g_data_start);
239 CHECK_LT((uptr)&g_data_start, g_data_end);
240 }
241
242 #endif // #ifndef SANITIZER_GO
243
InitializePlatformEarly()244 void InitializePlatformEarly() {
245 #ifdef TSAN_RUNTIME_VMA
246 vmaSize =
247 (MostSignificantSetBitIndex(GET_CURRENT_FRAME()) + 1);
248 #if defined(__aarch64__)
249 if (vmaSize != 39 && vmaSize != 42) {
250 Printf("FATAL: ThreadSanitizer: unsupported VMA range\n");
251 Printf("FATAL: Found %d - Supported 39 and 42\n", vmaSize);
252 Die();
253 }
254 #elif defined(__powerpc64__)
255 if (vmaSize != 44 && vmaSize != 46) {
256 Printf("FATAL: ThreadSanitizer: unsupported VMA range\n");
257 Printf("FATAL: Found %d - Supported 44 and 46\n", vmaSize);
258 Die();
259 }
260 #endif
261 #endif
262 }
263
InitializePlatform()264 void InitializePlatform() {
265 DisableCoreDumperIfNecessary();
266
267 // Go maps shadow memory lazily and works fine with limited address space.
268 // Unlimited stack is not a problem as well, because the executable
269 // is not compiled with -pie.
270 if (kCppMode) {
271 bool reexec = false;
272 // TSan doesn't play well with unlimited stack size (as stack
273 // overlaps with shadow memory). If we detect unlimited stack size,
274 // we re-exec the program with limited stack size as a best effort.
275 if (StackSizeIsUnlimited()) {
276 const uptr kMaxStackSize = 32 * 1024 * 1024;
277 VReport(1, "Program is run with unlimited stack size, which wouldn't "
278 "work with ThreadSanitizer.\n"
279 "Re-execing with stack size limited to %zd bytes.\n",
280 kMaxStackSize);
281 SetStackSizeLimitInBytes(kMaxStackSize);
282 reexec = true;
283 }
284
285 if (!AddressSpaceIsUnlimited()) {
286 Report("WARNING: Program is run with limited virtual address space,"
287 " which wouldn't work with ThreadSanitizer.\n");
288 Report("Re-execing with unlimited virtual address space.\n");
289 SetAddressSpaceUnlimited();
290 reexec = true;
291 }
292 if (reexec)
293 ReExec();
294 }
295
296 #ifndef SANITIZER_GO
297 CheckAndProtect();
298 InitTlsSize();
299 InitDataSeg();
300 #endif
301 }
302
IsGlobalVar(uptr addr)303 bool IsGlobalVar(uptr addr) {
304 return g_data_start && addr >= g_data_start && addr < g_data_end;
305 }
306
307 #ifndef SANITIZER_GO
308 // Extract file descriptors passed to glibc internal __res_iclose function.
309 // This is required to properly "close" the fds, because we do not see internal
310 // closes within glibc. The code is a pure hack.
ExtractResolvFDs(void * state,int * fds,int nfd)311 int ExtractResolvFDs(void *state, int *fds, int nfd) {
312 #if SANITIZER_LINUX && !SANITIZER_ANDROID
313 int cnt = 0;
314 __res_state *statp = (__res_state*)state;
315 for (int i = 0; i < MAXNS && cnt < nfd; i++) {
316 if (statp->_u._ext.nsaddrs[i] && statp->_u._ext.nssocks[i] != -1)
317 fds[cnt++] = statp->_u._ext.nssocks[i];
318 }
319 return cnt;
320 #else
321 return 0;
322 #endif
323 }
324
325 // Extract file descriptors passed via UNIX domain sockets.
326 // This is requried to properly handle "open" of these fds.
327 // see 'man recvmsg' and 'man 3 cmsg'.
ExtractRecvmsgFDs(void * msgp,int * fds,int nfd)328 int ExtractRecvmsgFDs(void *msgp, int *fds, int nfd) {
329 int res = 0;
330 msghdr *msg = (msghdr*)msgp;
331 struct cmsghdr *cmsg = CMSG_FIRSTHDR(msg);
332 for (; cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
333 if (cmsg->cmsg_level != SOL_SOCKET || cmsg->cmsg_type != SCM_RIGHTS)
334 continue;
335 int n = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(fds[0]);
336 for (int i = 0; i < n; i++) {
337 fds[res++] = ((int*)CMSG_DATA(cmsg))[i];
338 if (res == nfd)
339 return res;
340 }
341 }
342 return res;
343 }
344
345 // Note: this function runs with async signals enabled,
346 // 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)347 int call_pthread_cancel_with_cleanup(int(*fn)(void *c, void *m,
348 void *abstime), void *c, void *m, void *abstime,
349 void(*cleanup)(void *arg), void *arg) {
350 // pthread_cleanup_push/pop are hardcore macros mess.
351 // We can't intercept nor call them w/o including pthread.h.
352 int res;
353 pthread_cleanup_push(cleanup, arg);
354 res = fn(c, m, abstime);
355 pthread_cleanup_pop(0);
356 return res;
357 }
358 #endif
359
360 #ifndef SANITIZER_GO
ReplaceSystemMalloc()361 void ReplaceSystemMalloc() { }
362 #endif
363
364 } // namespace __tsan
365
366 #endif // SANITIZER_LINUX || SANITIZER_FREEBSD
367