msan_linux.cc revision 6866dba92ac842fc513ba339ba849a953ffb7507 
1//===-- msan_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 MemorySanitizer.
11//
12// Linux-specific code.
13//===----------------------------------------------------------------------===//
14
15#include "sanitizer_common/sanitizer_platform.h"
16#if SANITIZER_LINUX
17
18#include "msan.h"
19
20#include <elf.h>
21#include <link.h>
22#include <stdio.h>
23#include <stdlib.h>
24#include <signal.h>
25#include <unistd.h>
26#include <unwind.h>
27#include <execinfo.h>
28#include <sys/time.h>
29#include <sys/resource.h>
30
31#include "sanitizer_common/sanitizer_common.h"
32#include "sanitizer_common/sanitizer_procmaps.h"
33
34namespace __msan {
35
36static const uptr kMemBeg     = 0x600000000000;
37static const uptr kMemEnd     = 0x7fffffffffff;
38static const uptr kShadowBeg  = MEM_TO_SHADOW(kMemBeg);
39static const uptr kShadowEnd  = MEM_TO_SHADOW(kMemEnd);
40static const uptr kBad1Beg    = 0x100000000;  // 4G
41static const uptr kBad1End    = kShadowBeg - 1;
42static const uptr kBad2Beg    = kShadowEnd + 1;
43static const uptr kBad2End    = kMemBeg - 1;
44static const uptr kOriginsBeg = kBad2Beg;
45static const uptr kOriginsEnd = kBad2End;
46
47bool InitShadow(bool prot1, bool prot2, bool map_shadow, bool init_origins) {
48  if (common_flags()->verbosity) {
49    Printf("__msan_init %p\n", &__msan_init);
50    Printf("Memory   : %p %p\n", kMemBeg, kMemEnd);
51    Printf("Bad2     : %p %p\n", kBad2Beg, kBad2End);
52    Printf("Origins  : %p %p\n", kOriginsBeg, kOriginsEnd);
53    Printf("Shadow   : %p %p\n", kShadowBeg, kShadowEnd);
54    Printf("Bad1     : %p %p\n", kBad1Beg, kBad1End);
55  }
56
57  if (!MemoryRangeIsAvailable(kShadowBeg,
58                              init_origins ? kOriginsEnd : kShadowEnd)) {
59    Printf("FATAL: Shadow memory range is not available.\n");
60    return false;
61  }
62
63  if (prot1 && !Mprotect(kBad1Beg, kBad1End - kBad1Beg))
64    return false;
65  if (prot2 && !Mprotect(kBad2Beg, kBad2End - kBad2Beg))
66    return false;
67  if (map_shadow) {
68    void *shadow = MmapFixedNoReserve(kShadowBeg, kShadowEnd - kShadowBeg);
69    if (shadow != (void*)kShadowBeg) return false;
70  }
71  if (init_origins) {
72    void *origins = MmapFixedNoReserve(kOriginsBeg, kOriginsEnd - kOriginsBeg);
73    if (origins != (void*)kOriginsBeg) return false;
74  }
75  return true;
76}
77
78void MsanDie() {
79  _exit(flags()->exit_code);
80}
81
82static void MsanAtExit(void) {
83  if (msan_report_count > 0) {
84    ReportAtExitStatistics();
85    if (flags()->exit_code)
86      _exit(flags()->exit_code);
87  }
88}
89
90void InstallAtExitHandler() {
91  atexit(MsanAtExit);
92}
93
94}  // namespace __msan
95
96#endif  // __linux__
97