sanitizer_common.cc revision 321e1254d3bf8d67232aaff133961573fa0e3ec4 
1//===-- sanitizer_common.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.
12//===----------------------------------------------------------------------===//
13
14#include "sanitizer_common.h"
15#include "sanitizer_libc.h"
16
17namespace __sanitizer {
18
19uptr GetPageSizeCached() {
20  static uptr PageSize;
21  if (!PageSize)
22    PageSize = GetPageSize();
23  return PageSize;
24}
25
26// By default, dump to stderr. If report_fd is kInvalidFd, try to obtain file
27// descriptor by opening file in report_path.
28static fd_t report_fd = kStderrFd;
29static char report_path[4096];  // Set via __sanitizer_set_report_path.
30
31static void (*DieCallback)(void);
32void SetDieCallback(void (*callback)(void)) {
33  DieCallback = callback;
34}
35
36void NORETURN Die() {
37  if (DieCallback) {
38    DieCallback();
39  }
40  Exit(1);
41}
42
43static CheckFailedCallbackType CheckFailedCallback;
44void SetCheckFailedCallback(CheckFailedCallbackType callback) {
45  CheckFailedCallback = callback;
46}
47
48void NORETURN CheckFailed(const char *file, int line, const char *cond,
49                          u64 v1, u64 v2) {
50  if (CheckFailedCallback) {
51    CheckFailedCallback(file, line, cond, v1, v2);
52  }
53  Report("Sanitizer CHECK failed: %s:%d %s (%zd, %zd)\n", file, line, cond,
54                                                          v1, v2);
55  Die();
56}
57
58static void MaybeOpenReportFile() {
59  if (report_fd != kInvalidFd)
60    return;
61  fd_t fd = internal_open(report_path, true);
62  if (fd == kInvalidFd) {
63    report_fd = kStderrFd;
64    Report("ERROR: Can't open file: %s\n", report_path);
65    Die();
66  }
67  report_fd = fd;
68}
69
70bool PrintsToTty() {
71  MaybeOpenReportFile();
72  return internal_isatty(report_fd);
73}
74
75void RawWrite(const char *buffer) {
76  static const char *kRawWriteError = "RawWrite can't output requested buffer!";
77  uptr length = (uptr)internal_strlen(buffer);
78  MaybeOpenReportFile();
79  if (length != internal_write(report_fd, buffer, length)) {
80    internal_write(report_fd, kRawWriteError, internal_strlen(kRawWriteError));
81    Die();
82  }
83}
84
85uptr ReadFileToBuffer(const char *file_name, char **buff,
86                      uptr *buff_size, uptr max_len) {
87  uptr PageSize = GetPageSizeCached();
88  uptr kMinFileLen = PageSize;
89  uptr read_len = 0;
90  *buff = 0;
91  *buff_size = 0;
92  // The files we usually open are not seekable, so try different buffer sizes.
93  for (uptr size = kMinFileLen; size <= max_len; size *= 2) {
94    fd_t fd = internal_open(file_name, /*write*/ false);
95    if (fd == kInvalidFd) return 0;
96    UnmapOrDie(*buff, *buff_size);
97    *buff = (char*)MmapOrDie(size, __FUNCTION__);
98    *buff_size = size;
99    // Read up to one page at a time.
100    read_len = 0;
101    bool reached_eof = false;
102    while (read_len + PageSize <= size) {
103      uptr just_read = internal_read(fd, *buff + read_len, PageSize);
104      if (just_read == 0) {
105        reached_eof = true;
106        break;
107      }
108      read_len += just_read;
109    }
110    internal_close(fd);
111    if (reached_eof)  // We've read the whole file.
112      break;
113  }
114  return read_len;
115}
116
117// We don't want to use std::sort to avoid including <algorithm>, as
118// we may end up with two implementation of std::sort - one in instrumented
119// code, and the other in runtime.
120// qsort() from stdlib won't work as it calls malloc(), which results
121// in deadlock in ASan allocator.
122// We re-implement in-place sorting w/o recursion as straightforward heapsort.
123void SortArray(uptr *array, uptr size) {
124  if (size < 2)
125    return;
126  // Stage 1: insert elements to the heap.
127  for (uptr i = 1; i < size; i++) {
128    uptr j, p;
129    for (j = i; j > 0; j = p) {
130      p = (j - 1) / 2;
131      if (array[j] > array[p])
132        Swap(array[j], array[p]);
133      else
134        break;
135    }
136  }
137  // Stage 2: swap largest element with the last one,
138  // and sink the new top.
139  for (uptr i = size - 1; i > 0; i--) {
140    Swap(array[0], array[i]);
141    uptr j, max_ind;
142    for (j = 0; j < i; j = max_ind) {
143      uptr left = 2 * j + 1;
144      uptr right = 2 * j + 2;
145      max_ind = j;
146      if (left < i && array[left] > array[max_ind])
147        max_ind = left;
148      if (right < i && array[right] > array[max_ind])
149        max_ind = right;
150      if (max_ind != j)
151        Swap(array[j], array[max_ind]);
152      else
153        break;
154    }
155  }
156}
157
158// We want to map a chunk of address space aligned to 'alignment'.
159// We do it by maping a bit more and then unmaping redundant pieces.
160// We probably can do it with fewer syscalls in some OS-dependent way.
161void *MmapAlignedOrDie(uptr size, uptr alignment, const char *mem_type) {
162// uptr PageSize = GetPageSizeCached();
163  CHECK(IsPowerOfTwo(size));
164  CHECK(IsPowerOfTwo(alignment));
165  uptr map_size = size + alignment;
166  uptr map_res = (uptr)MmapOrDie(map_size, mem_type);
167  uptr map_end = map_res + map_size;
168  uptr res = map_res;
169  if (res & (alignment - 1))  // Not aligned.
170    res = (map_res + alignment) & ~(alignment - 1);
171  uptr end = res + size;
172  if (res != map_res)
173    UnmapOrDie((void*)map_res, res - map_res);
174  if (end != map_end)
175    UnmapOrDie((void*)end, map_end - end);
176  return (void*)res;
177}
178
179}  // namespace __sanitizer
180
181using namespace __sanitizer;  // NOLINT
182
183extern "C" {
184void __sanitizer_set_report_path(const char *path) {
185  if (!path) return;
186  uptr len = internal_strlen(path);
187  if (len > sizeof(report_path) - 100) {
188    Report("ERROR: Path is too long: %c%c%c%c%c%c%c%c...\n",
189           path[0], path[1], path[2], path[3],
190           path[4], path[5], path[6], path[7]);
191    Die();
192  }
193  internal_snprintf(report_path, sizeof(report_path), "%s.%d", path, GetPid());
194  report_fd = kInvalidFd;
195}
196
197void __sanitizer_set_report_fd(int fd) {
198  if (report_fd != kStdoutFd &&
199      report_fd != kStderrFd &&
200      report_fd != kInvalidFd)
201    internal_close(report_fd);
202  report_fd = fd;
203}
204
205void NOINLINE __sanitizer_sandbox_on_notify(void *reserved) {
206  (void)reserved;
207  PrepareForSandboxing();
208}
209}  // extern "C"
210