1//===-- sanitizer_procmaps_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// Information about the process mappings (common parts). 11//===----------------------------------------------------------------------===// 12 13#include "sanitizer_platform.h" 14 15#if SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD || \ 16 SANITIZER_OPENBSD || SANITIZER_SOLARIS 17 18#include "sanitizer_common.h" 19#include "sanitizer_placement_new.h" 20#include "sanitizer_procmaps.h" 21 22namespace __sanitizer { 23 24static ProcSelfMapsBuff cached_proc_self_maps; 25static StaticSpinMutex cache_lock; 26 27static int TranslateDigit(char c) { 28 if (c >= '0' && c <= '9') 29 return c - '0'; 30 if (c >= 'a' && c <= 'f') 31 return c - 'a' + 10; 32 if (c >= 'A' && c <= 'F') 33 return c - 'A' + 10; 34 return -1; 35} 36 37// Parse a number and promote 'p' up to the first non-digit character. 38static uptr ParseNumber(const char **p, int base) { 39 uptr n = 0; 40 int d; 41 CHECK(base >= 2 && base <= 16); 42 while ((d = TranslateDigit(**p)) >= 0 && d < base) { 43 n = n * base + d; 44 (*p)++; 45 } 46 return n; 47} 48 49bool IsDecimal(char c) { 50 int d = TranslateDigit(c); 51 return d >= 0 && d < 10; 52} 53 54uptr ParseDecimal(const char **p) { 55 return ParseNumber(p, 10); 56} 57 58bool IsHex(char c) { 59 int d = TranslateDigit(c); 60 return d >= 0 && d < 16; 61} 62 63uptr ParseHex(const char **p) { 64 return ParseNumber(p, 16); 65} 66 67void MemoryMappedSegment::AddAddressRanges(LoadedModule *module) { 68 // data_ should be unused on this platform 69 CHECK(!data_); 70 module->addAddressRange(start, end, IsExecutable(), IsWritable()); 71} 72 73MemoryMappingLayout::MemoryMappingLayout(bool cache_enabled) { 74 // FIXME: in the future we may want to cache the mappings on demand only. 75 if (cache_enabled) 76 CacheMemoryMappings(); 77 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) 82 LoadFromCache(); 83 84 Reset(); 85} 86 87bool MemoryMappingLayout::Error() const { 88 return data_.current == nullptr; 89} 90 91MemoryMappingLayout::~MemoryMappingLayout() { 92 // Only unmap the buffer if it is different from the cached one. Otherwise 93 // it will be unmapped when the cache is refreshed. 94 if (data_.proc_self_maps.data != cached_proc_self_maps.data) 95 UnmapOrDie(data_.proc_self_maps.data, data_.proc_self_maps.mmaped_size); 96} 97 98void MemoryMappingLayout::Reset() { 99 data_.current = data_.proc_self_maps.data; 100} 101 102// static 103void MemoryMappingLayout::CacheMemoryMappings() { 104 ProcSelfMapsBuff new_proc_self_maps; 105 ReadProcMaps(&new_proc_self_maps); 106 // Don't invalidate the cache if the mappings are unavailable. 107 if (new_proc_self_maps.mmaped_size == 0) 108 return; 109 SpinMutexLock l(&cache_lock); 110 if (cached_proc_self_maps.mmaped_size) 111 UnmapOrDie(cached_proc_self_maps.data, cached_proc_self_maps.mmaped_size); 112 cached_proc_self_maps = new_proc_self_maps; 113} 114 115void MemoryMappingLayout::LoadFromCache() { 116 SpinMutexLock l(&cache_lock); 117 if (cached_proc_self_maps.data) 118 data_.proc_self_maps = cached_proc_self_maps; 119} 120 121void MemoryMappingLayout::DumpListOfModules( 122 InternalMmapVectorNoCtor<LoadedModule> *modules) { 123 Reset(); 124 InternalScopedString module_name(kMaxPathLength); 125 MemoryMappedSegment segment(module_name.data(), module_name.size()); 126 for (uptr i = 0; Next(&segment); i++) { 127 const char *cur_name = segment.filename; 128 if (cur_name[0] == '\0') 129 continue; 130 // Don't subtract 'cur_beg' from the first entry: 131 // * If a binary is compiled w/o -pie, then the first entry in 132 // process maps is likely the binary itself (all dynamic libs 133 // are mapped higher in address space). For such a binary, 134 // instruction offset in binary coincides with the actual 135 // instruction address in virtual memory (as code section 136 // is mapped to a fixed memory range). 137 // * If a binary is compiled with -pie, all the modules are 138 // mapped high at address space (in particular, higher than 139 // shadow memory of the tool), so the module can't be the 140 // first entry. 141 uptr base_address = (i ? segment.start : 0) - segment.offset; 142 LoadedModule cur_module; 143 cur_module.set(cur_name, base_address); 144 segment.AddAddressRanges(&cur_module); 145 modules->push_back(cur_module); 146 } 147} 148 149void GetMemoryProfile(fill_profile_f cb, uptr *stats, uptr stats_size) { 150 char *smaps = nullptr; 151 uptr smaps_cap = 0; 152 uptr smaps_len = 0; 153 if (!ReadFileToBuffer("/proc/self/smaps", &smaps, &smaps_cap, &smaps_len)) 154 return; 155 uptr start = 0; 156 bool file = false; 157 const char *pos = smaps; 158 while (pos < smaps + smaps_len) { 159 if (IsHex(pos[0])) { 160 start = ParseHex(&pos); 161 for (; *pos != '/' && *pos > '\n'; pos++) {} 162 file = *pos == '/'; 163 } else if (internal_strncmp(pos, "Rss:", 4) == 0) { 164 while (!IsDecimal(*pos)) pos++; 165 uptr rss = ParseDecimal(&pos) * 1024; 166 cb(start, rss, file, stats, stats_size); 167 } 168 while (*pos++ != '\n') {} 169 } 170 UnmapOrDie(smaps, smaps_cap); 171} 172 173} // namespace __sanitizer 174 175#endif 176