sanitizer_posix.cc revision 821acfaccc7d11b987e2882b022e8d167b0c8a54 
1//===-- sanitizer_posix.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 shared between AddressSanitizer and ThreadSanitizer
11// run-time libraries and implements POSIX-specific functions from
12// sanitizer_libc.h.
13//===----------------------------------------------------------------------===//
14
15#include "sanitizer_platform.h"
16#if SANITIZER_LINUX || SANITIZER_MAC
17
18#include "sanitizer_common.h"
19#include "sanitizer_libc.h"
20#include "sanitizer_procmaps.h"
21#include "sanitizer_stacktrace.h"
22
23#include <sys/mman.h>
24
25namespace __sanitizer {
26
27// ------------- sanitizer_common.h
28uptr GetMmapGranularity() {
29  return GetPageSize();
30}
31
32uptr GetMaxVirtualAddress() {
33#if SANITIZER_WORDSIZE == 64
34# if defined(__powerpc64__)
35  // On PowerPC64 we have two different address space layouts: 44- and 46-bit.
36  // We somehow need to figure our which one we are using now and choose
37  // one of 0x00000fffffffffffUL and 0x00003fffffffffffUL.
38  // Note that with 'ulimit -s unlimited' the stack is moved away from the top
39  // of the address space, so simply checking the stack address is not enough.
40  return (1ULL << 44) - 1;  // 0x00000fffffffffffUL
41# else
42  return (1ULL << 47) - 1;  // 0x00007fffffffffffUL;
43# endif
44#else  // SANITIZER_WORDSIZE == 32
45  // FIXME: We can probably lower this on Android?
46  return (1ULL << 32) - 1;  // 0xffffffff;
47#endif  // SANITIZER_WORDSIZE
48}
49
50void *MmapOrDie(uptr size, const char *mem_type) {
51  size = RoundUpTo(size, GetPageSizeCached());
52  uptr res = internal_mmap(0, size,
53                            PROT_READ | PROT_WRITE,
54                            MAP_PRIVATE | MAP_ANON, -1, 0);
55  int reserrno;
56  if (internal_iserror(res, &reserrno)) {
57    static int recursion_count;
58    if (recursion_count) {
59      // The Report() and CHECK calls below may call mmap recursively and fail.
60      // If we went into recursion, just die.
61      RawWrite("ERROR: Failed to mmap\n");
62      Die();
63    }
64    recursion_count++;
65    Report("ERROR: %s failed to allocate 0x%zx (%zd) bytes of %s: %d\n",
66           SanitizerToolName, size, size, mem_type, reserrno);
67    DumpProcessMap();
68    CHECK("unable to mmap" && 0);
69  }
70  return (void *)res;
71}
72
73void UnmapOrDie(void *addr, uptr size) {
74  if (!addr || !size) return;
75  uptr res = internal_munmap(addr, size);
76  if (internal_iserror(res)) {
77    Report("ERROR: %s failed to deallocate 0x%zx (%zd) bytes at address %p\n",
78           SanitizerToolName, size, size, addr);
79    CHECK("unable to unmap" && 0);
80  }
81}
82
83void *MmapFixedNoReserve(uptr fixed_addr, uptr size) {
84  uptr PageSize = GetPageSizeCached();
85  uptr p = internal_mmap((void*)(fixed_addr & ~(PageSize - 1)),
86      RoundUpTo(size, PageSize),
87      PROT_READ | PROT_WRITE,
88      MAP_PRIVATE | MAP_ANON | MAP_FIXED | MAP_NORESERVE,
89      -1, 0);
90  int reserrno;
91  if (internal_iserror(p, &reserrno))
92    Report("ERROR: "
93           "%s failed to allocate 0x%zx (%zd) bytes at address %p (%d)\n",
94           SanitizerToolName, size, size, fixed_addr, reserrno);
95  return (void *)p;
96}
97
98void *MmapFixedOrDie(uptr fixed_addr, uptr size) {
99  uptr PageSize = GetPageSizeCached();
100  uptr p = internal_mmap((void*)(fixed_addr & ~(PageSize - 1)),
101      RoundUpTo(size, PageSize),
102      PROT_READ | PROT_WRITE,
103      MAP_PRIVATE | MAP_ANON | MAP_FIXED,
104      -1, 0);
105  int reserrno;
106  if (internal_iserror(p, &reserrno)) {
107    Report("ERROR:"
108           " %s failed to allocate 0x%zx (%zd) bytes at address %p (%d)\n",
109           SanitizerToolName, size, size, fixed_addr, reserrno);
110    CHECK("unable to mmap" && 0);
111  }
112  return (void *)p;
113}
114
115void *Mprotect(uptr fixed_addr, uptr size) {
116  return (void *)internal_mmap((void*)fixed_addr, size,
117                               PROT_NONE,
118                               MAP_PRIVATE | MAP_ANON | MAP_FIXED |
119                               MAP_NORESERVE, -1, 0);
120}
121
122void *MapFileToMemory(const char *file_name, uptr *buff_size) {
123  uptr openrv = OpenFile(file_name, false);
124  CHECK(!internal_iserror(openrv));
125  fd_t fd = openrv;
126  uptr fsize = internal_filesize(fd);
127  CHECK_NE(fsize, (uptr)-1);
128  CHECK_GT(fsize, 0);
129  *buff_size = RoundUpTo(fsize, GetPageSizeCached());
130  uptr map = internal_mmap(0, *buff_size, PROT_READ, MAP_PRIVATE, fd, 0);
131  return internal_iserror(map) ? 0 : (void *)map;
132}
133
134
135static inline bool IntervalsAreSeparate(uptr start1, uptr end1,
136                                        uptr start2, uptr end2) {
137  CHECK(start1 <= end1);
138  CHECK(start2 <= end2);
139  return (end1 < start2) || (end2 < start1);
140}
141
142// FIXME: this is thread-unsafe, but should not cause problems most of the time.
143// When the shadow is mapped only a single thread usually exists (plus maybe
144// several worker threads on Mac, which aren't expected to map big chunks of
145// memory).
146bool MemoryRangeIsAvailable(uptr range_start, uptr range_end) {
147  MemoryMappingLayout proc_maps(/*cache_enabled*/true);
148  uptr start, end;
149  while (proc_maps.Next(&start, &end,
150                        /*offset*/0, /*filename*/0, /*filename_size*/0,
151                        /*protection*/0)) {
152    if (!IntervalsAreSeparate(start, end, range_start, range_end))
153      return false;
154  }
155  return true;
156}
157
158void DumpProcessMap() {
159  MemoryMappingLayout proc_maps(/*cache_enabled*/true);
160  uptr start, end;
161  const sptr kBufSize = 4095;
162  char *filename = (char*)MmapOrDie(kBufSize, __FUNCTION__);
163  Report("Process memory map follows:\n");
164  while (proc_maps.Next(&start, &end, /* file_offset */0,
165                        filename, kBufSize, /* protection */0)) {
166    Printf("\t%p-%p\t%s\n", (void*)start, (void*)end, filename);
167  }
168  Report("End of process memory map.\n");
169  UnmapOrDie(filename, kBufSize);
170}
171
172const char *GetPwd() {
173  return GetEnv("PWD");
174}
175
176char *FindPathToBinary(const char *name) {
177  const char *path = GetEnv("PATH");
178  if (!path)
179    return 0;
180  uptr name_len = internal_strlen(name);
181  InternalScopedBuffer<char> buffer(kMaxPathLength);
182  const char *beg = path;
183  while (true) {
184    const char *end = internal_strchrnul(beg, ':');
185    uptr prefix_len = end - beg;
186    if (prefix_len + name_len + 2 <= kMaxPathLength) {
187      internal_memcpy(buffer.data(), beg, prefix_len);
188      buffer[prefix_len] = '/';
189      internal_memcpy(&buffer[prefix_len + 1], name, name_len);
190      buffer[prefix_len + 1 + name_len] = '\0';
191      if (FileExists(buffer.data()))
192        return internal_strdup(buffer.data());
193    }
194    if (*end == '\0') break;
195    beg = end + 1;
196  }
197  return 0;
198}
199
200void MaybeOpenReportFile() {
201  if (!log_to_file || (report_fd_pid == internal_getpid())) return;
202  InternalScopedBuffer<char> report_path_full(4096);
203  internal_snprintf(report_path_full.data(), report_path_full.size(),
204                    "%s.%d", report_path_prefix, internal_getpid());
205  uptr openrv = OpenFile(report_path_full.data(), true);
206  if (internal_iserror(openrv)) {
207    report_fd = kStderrFd;
208    log_to_file = false;
209    Report("ERROR: Can't open file: %s\n", report_path_full.data());
210    Die();
211  }
212  if (report_fd != kInvalidFd) {
213    // We're in the child. Close the parent's log.
214    internal_close(report_fd);
215  }
216  report_fd = openrv;
217  report_fd_pid = internal_getpid();
218}
219
220void RawWrite(const char *buffer) {
221  static const char *kRawWriteError =
222      "RawWrite can't output requested buffer!\n";
223  uptr length = (uptr)internal_strlen(buffer);
224  MaybeOpenReportFile();
225  if (length != internal_write(report_fd, buffer, length)) {
226    internal_write(report_fd, kRawWriteError, internal_strlen(kRawWriteError));
227    Die();
228  }
229}
230
231bool GetCodeRangeForFile(const char *module, uptr *start, uptr *end) {
232  uptr s, e, off, prot;
233  InternalMmapVector<char> fn(4096);
234  fn.push_back(0);
235  MemoryMappingLayout proc_maps(/*cache_enabled*/false);
236  while (proc_maps.Next(&s, &e, &off, &fn[0], fn.capacity(), &prot)) {
237    if ((prot & MemoryMappingLayout::kProtectionExecute) != 0
238        && internal_strcmp(module, &fn[0]) == 0) {
239      *start = s;
240      *end = e;
241      return true;
242    }
243  }
244  return false;
245}
246
247}  // namespace __sanitizer
248
249#endif  // SANITIZER_LINUX || SANITIZER_MAC
250