1 //===-- sanitizer_procmaps_common.cc --------------------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // Information about the process mappings (common parts).
11 //===----------------------------------------------------------------------===//
13 #include "sanitizer_platform.h"
15 #if SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD || \
16 SANITIZER_OPENBSD || SANITIZER_SOLARIS
18 #include "sanitizer_common.h"
19 #include "sanitizer_placement_new.h"
20 #include "sanitizer_procmaps.h"
22 namespace __sanitizer {
24 static ProcSelfMapsBuff cached_proc_self_maps;
25 static StaticSpinMutex cache_lock;
27 static int TranslateDigit(char c) {
28 if (c >= '0' && c <= '9')
30 if (c >= 'a' && c <= 'f')
32 if (c >= 'A' && c <= 'F')
37 // Parse a number and promote 'p' up to the first non-digit character.
38 static uptr ParseNumber(const char **p, int base) {
41 CHECK(base >= 2 && base <= 16);
42 while ((d = TranslateDigit(**p)) >= 0 && d < base) {
49 bool IsDecimal(char c) {
50 int d = TranslateDigit(c);
51 return d >= 0 && d < 10;
54 uptr ParseDecimal(const char **p) {
55 return ParseNumber(p, 10);
59 int d = TranslateDigit(c);
60 return d >= 0 && d < 16;
63 uptr ParseHex(const char **p) {
64 return ParseNumber(p, 16);
67 void MemoryMappedSegment::AddAddressRanges(LoadedModule *module) {
68 // data_ should be unused on this platform
70 module->addAddressRange(start, end, IsExecutable(), IsWritable());
73 MemoryMappingLayout::MemoryMappingLayout(bool cache_enabled) {
74 // FIXME: in the future we may want to cache the mappings on demand only.
76 CacheMemoryMappings();
78 // Read maps after the cache update to capture the maps/unmaps happening in
79 // the process of updating.
80 ReadProcMaps(&data_.proc_self_maps);
81 if (cache_enabled && data_.proc_self_maps.mmaped_size == 0)
83 CHECK_GT(data_.proc_self_maps.mmaped_size, 0);
84 CHECK_GT(data_.proc_self_maps.len, 0);
89 MemoryMappingLayout::~MemoryMappingLayout() {
90 // Only unmap the buffer if it is different from the cached one. Otherwise
91 // it will be unmapped when the cache is refreshed.
92 if (data_.proc_self_maps.data != cached_proc_self_maps.data)
93 UnmapOrDie(data_.proc_self_maps.data, data_.proc_self_maps.mmaped_size);
96 void MemoryMappingLayout::Reset() {
97 data_.current = data_.proc_self_maps.data;
101 void MemoryMappingLayout::CacheMemoryMappings() {
102 ProcSelfMapsBuff new_proc_self_maps;
103 ReadProcMaps(&new_proc_self_maps);
104 // Don't invalidate the cache if the mappings are unavailable.
105 if (new_proc_self_maps.mmaped_size == 0)
107 SpinMutexLock l(&cache_lock);
108 if (cached_proc_self_maps.mmaped_size)
109 UnmapOrDie(cached_proc_self_maps.data, cached_proc_self_maps.mmaped_size);
110 cached_proc_self_maps = new_proc_self_maps;
113 void MemoryMappingLayout::LoadFromCache() {
114 SpinMutexLock l(&cache_lock);
115 if (cached_proc_self_maps.data)
116 data_.proc_self_maps = cached_proc_self_maps;
119 void MemoryMappingLayout::DumpListOfModules(
120 InternalMmapVectorNoCtor<LoadedModule> *modules) {
122 InternalScopedString module_name(kMaxPathLength);
123 MemoryMappedSegment segment(module_name.data(), module_name.size());
124 for (uptr i = 0; Next(&segment); i++) {
125 const char *cur_name = segment.filename;
126 if (cur_name[0] == '\0')
128 // Don't subtract 'cur_beg' from the first entry:
129 // * If a binary is compiled w/o -pie, then the first entry in
130 // process maps is likely the binary itself (all dynamic libs
131 // are mapped higher in address space). For such a binary,
132 // instruction offset in binary coincides with the actual
133 // instruction address in virtual memory (as code section
134 // is mapped to a fixed memory range).
135 // * If a binary is compiled with -pie, all the modules are
136 // mapped high at address space (in particular, higher than
137 // shadow memory of the tool), so the module can't be the
139 uptr base_address = (i ? segment.start : 0) - segment.offset;
140 LoadedModule cur_module;
141 cur_module.set(cur_name, base_address);
142 segment.AddAddressRanges(&cur_module);
143 modules->push_back(cur_module);
147 void GetMemoryProfile(fill_profile_f cb, uptr *stats, uptr stats_size) {
148 char *smaps = nullptr;
151 if (!ReadFileToBuffer("/proc/self/smaps", &smaps, &smaps_cap, &smaps_len))
155 const char *pos = smaps;
156 while (pos < smaps + smaps_len) {
158 start = ParseHex(&pos);
159 for (; *pos != '/' && *pos > '\n'; pos++) {}
161 } else if (internal_strncmp(pos, "Rss:", 4) == 0) {
162 while (!IsDecimal(*pos)) pos++;
163 uptr rss = ParseDecimal(&pos) * 1024;
164 cb(start, rss, file, stats, stats_size);
166 while (*pos++ != '\n') {}
168 UnmapOrDie(smaps, smaps_cap);
171 } // namespace __sanitizer