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
67extern "C" void *__libc_stack_end;
68void *__libc_stack_end = 0;
69#endif
70
71#if SANITIZER_LINUX && defined(__aarch64__)
72void InitializeGuardPtr() __attribute__((visibility("hidden")));
73#endif
74
75namespace __tsan {
76
77#ifdef TSAN_RUNTIME_VMA
78// Runtime detected VMA size.
79uptr vmaSize;
80#endif
81
82enum {
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
94void 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
118void 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
134void FlushShadowMemoryCallback(
135    const SuspendedThreadsList &suspended_threads_list,
136    void *argument) {
137  ReleaseMemoryPagesToOS(ShadowBeg(), ShadowEnd());
138}
139#endif
140
141void 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.
150static 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
204void InitializeShadowMemoryPlatform() {
205  MapRodata();
206}
207
208#endif  // #if !SANITIZER_GO
209
210void 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
246void 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.
304int 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'.
321int 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
338void 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.
354int 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
368void 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.
375static ThreadState *dead_thread_state = nullptr;
376
377ThreadState *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
405void 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