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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 #include "msan_thread.h"
20 
21 #include <elf.h>
22 #include <link.h>
23 #include <pthread.h>
24 #include <stdio.h>
25 #include <stdlib.h>
26 #include <signal.h>
27 #include <unistd.h>
28 #include <unwind.h>
29 #include <execinfo.h>
30 #include <sys/time.h>
31 #include <sys/resource.h>
32 
33 #include "sanitizer_common/sanitizer_common.h"
34 #include "sanitizer_common/sanitizer_procmaps.h"
35 
36 namespace __msan {
37 
38 static const uptr kMemBeg     = 0x600000000000;
39 static const uptr kMemEnd     = 0x7fffffffffff;
40 static const uptr kShadowBeg  = MEM_TO_SHADOW(kMemBeg);
41 static const uptr kShadowEnd  = MEM_TO_SHADOW(kMemEnd);
42 static const uptr kBad1Beg    = 0;
43 static const uptr kBad1End    = kShadowBeg - 1;
44 static const uptr kBad2Beg    = kShadowEnd + 1;
45 static const uptr kBad2End    = kMemBeg - 1;
46 static const uptr kOriginsBeg = kBad2Beg;
47 static const uptr kOriginsEnd = kBad2End;
48 
InitShadow(bool prot1,bool prot2,bool map_shadow,bool init_origins)49 bool InitShadow(bool prot1, bool prot2, bool map_shadow, bool init_origins) {
50   if ((uptr) & InitShadow < kMemBeg) {
51     Printf("FATAL: Code below application range: %p < %p. Non-PIE build?\n",
52            &InitShadow, (void *)kMemBeg);
53     return false;
54   }
55 
56   VPrintf(1, "__msan_init %p\n", &__msan_init);
57   VPrintf(1, "Memory   : %p %p\n", kMemBeg, kMemEnd);
58   VPrintf(1, "Bad2     : %p %p\n", kBad2Beg, kBad2End);
59   VPrintf(1, "Origins  : %p %p\n", kOriginsBeg, kOriginsEnd);
60   VPrintf(1, "Shadow   : %p %p\n", kShadowBeg, kShadowEnd);
61   VPrintf(1, "Bad1     : %p %p\n", kBad1Beg, kBad1End);
62 
63   if (!MemoryRangeIsAvailable(kShadowBeg,
64                               init_origins ? kOriginsEnd : kShadowEnd) ||
65       (prot1 && !MemoryRangeIsAvailable(kBad1Beg, kBad1End)) ||
66       (prot2 && !MemoryRangeIsAvailable(kBad2Beg, kBad2End))) {
67     Printf("FATAL: Shadow memory range is not available.\n");
68     return false;
69   }
70 
71   if (prot1 && !Mprotect(kBad1Beg, kBad1End - kBad1Beg))
72     return false;
73   if (prot2 && !Mprotect(kBad2Beg, kBad2End - kBad2Beg))
74     return false;
75   if (map_shadow) {
76     void *shadow = MmapFixedNoReserve(kShadowBeg, kShadowEnd - kShadowBeg);
77     if (shadow != (void*)kShadowBeg) return false;
78   }
79   if (init_origins) {
80     void *origins = MmapFixedNoReserve(kOriginsBeg, kOriginsEnd - kOriginsBeg);
81     if (origins != (void*)kOriginsBeg) return false;
82   }
83   return true;
84 }
85 
MsanDie()86 void MsanDie() {
87   if (death_callback)
88     death_callback();
89   _exit(flags()->exit_code);
90 }
91 
MsanAtExit(void)92 static void MsanAtExit(void) {
93   if (flags()->print_stats && (flags()->atexit || msan_report_count > 0))
94     ReportStats();
95   if (msan_report_count > 0) {
96     ReportAtExitStatistics();
97     if (flags()->exit_code) _exit(flags()->exit_code);
98   }
99 }
100 
InstallAtExitHandler()101 void InstallAtExitHandler() {
102   atexit(MsanAtExit);
103 }
104 
105 // ---------------------- TSD ---------------- {{{1
106 
107 static pthread_key_t tsd_key;
108 static bool tsd_key_inited = false;
MsanTSDInit(void (* destructor)(void * tsd))109 void MsanTSDInit(void (*destructor)(void *tsd)) {
110   CHECK(!tsd_key_inited);
111   tsd_key_inited = true;
112   CHECK_EQ(0, pthread_key_create(&tsd_key, destructor));
113 }
114 
MsanTSDGet()115 void *MsanTSDGet() {
116   CHECK(tsd_key_inited);
117   return pthread_getspecific(tsd_key);
118 }
119 
MsanTSDSet(void * tsd)120 void MsanTSDSet(void *tsd) {
121   CHECK(tsd_key_inited);
122   pthread_setspecific(tsd_key, tsd);
123 }
124 
MsanTSDDtor(void * tsd)125 void MsanTSDDtor(void *tsd) {
126   MsanThread *t = (MsanThread*)tsd;
127   if (t->destructor_iterations_ > 1) {
128     t->destructor_iterations_--;
129     CHECK_EQ(0, pthread_setspecific(tsd_key, tsd));
130     return;
131   }
132   MsanThread::TSDDtor(tsd);
133 }
134 
135 }  // namespace __msan
136 
137 #endif  // __linux__
138