1 files changed, 174 insertions, 0 deletions
diff --git a/lib/sanitizer_common/sanitizer_procmaps_common.cpp b/lib/sanitizer_common/sanitizer_procmaps_common.cpp
new file mode 100644
index 000000000000..e0cb47f8ca9a
--- /dev/null
+++ b/lib/sanitizer_common/sanitizer_procmaps_common.cpp
@@ -0,0 +1,174 @@
+//===-- sanitizer_procmaps_common.cpp -------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// Information about the process mappings (common parts).
+//===----------------------------------------------------------------------===//
+
+#include "sanitizer_platform.h"
+
+#if SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD ||                \
+    SANITIZER_OPENBSD || SANITIZER_SOLARIS
+
+#include "sanitizer_common.h"
+#include "sanitizer_placement_new.h"
+#include "sanitizer_procmaps.h"
+
+namespace __sanitizer {
+
+static ProcSelfMapsBuff cached_proc_self_maps;
+static StaticSpinMutex cache_lock;
+
+static int TranslateDigit(char c) {
+  if (c >= '0' && c <= '9')
+    return c - '0';
+  if (c >= 'a' && c <= 'f')
+    return c - 'a' + 10;
+  if (c >= 'A' && c <= 'F')
+    return c - 'A' + 10;
+  return -1;
+}
+
+// Parse a number and promote 'p' up to the first non-digit character.
+static uptr ParseNumber(const char **p, int base) {
+  uptr n = 0;
+  int d;
+  CHECK(base >= 2 && base <= 16);
+  while ((d = TranslateDigit(**p)) >= 0 && d < base) {
+    n = n * base + d;
+    (*p)++;
+  }
+  return n;
+}
+
+bool IsDecimal(char c) {
+  int d = TranslateDigit(c);
+  return d >= 0 && d < 10;
+}
+
+uptr ParseDecimal(const char **p) {
+  return ParseNumber(p, 10);
+}
+
+bool IsHex(char c) {
+  int d = TranslateDigit(c);
+  return d >= 0 && d < 16;
+}
+
+uptr ParseHex(const char **p) {
+  return ParseNumber(p, 16);
+}
+
+void MemoryMappedSegment::AddAddressRanges(LoadedModule *module) {
+  // data_ should be unused on this platform
+  CHECK(!data_);
+  module->addAddressRange(start, end, IsExecutable(), IsWritable());
+}
+
+MemoryMappingLayout::MemoryMappingLayout(bool cache_enabled) {
+  // FIXME: in the future we may want to cache the mappings on demand only.
+  if (cache_enabled)
+    CacheMemoryMappings();
+
+  // Read maps after the cache update to capture the maps/unmaps happening in
+  // the process of updating.
+  ReadProcMaps(&data_.proc_self_maps);
+  if (cache_enabled && data_.proc_self_maps.mmaped_size == 0)
+    LoadFromCache();
+
+  Reset();
+}
+
+bool MemoryMappingLayout::Error() const {
+  return data_.current == nullptr;
+}
+
+MemoryMappingLayout::~MemoryMappingLayout() {
+  // Only unmap the buffer if it is different from the cached one. Otherwise
+  // it will be unmapped when the cache is refreshed.
+  if (data_.proc_self_maps.data != cached_proc_self_maps.data)
+    UnmapOrDie(data_.proc_self_maps.data, data_.proc_self_maps.mmaped_size);
+}
+
+void MemoryMappingLayout::Reset() {
+  data_.current = data_.proc_self_maps.data;
+}
+
+// static
+void MemoryMappingLayout::CacheMemoryMappings() {
+  ProcSelfMapsBuff new_proc_self_maps;
+  ReadProcMaps(&new_proc_self_maps);
+  // Don't invalidate the cache if the mappings are unavailable.
+  if (new_proc_self_maps.mmaped_size == 0)
+    return;
+  SpinMutexLock l(&cache_lock);
+  if (cached_proc_self_maps.mmaped_size)
+    UnmapOrDie(cached_proc_self_maps.data, cached_proc_self_maps.mmaped_size);
+  cached_proc_self_maps = new_proc_self_maps;
+}
+
+void MemoryMappingLayout::LoadFromCache() {
+  SpinMutexLock l(&cache_lock);
+  if (cached_proc_self_maps.data)
+    data_.proc_self_maps = cached_proc_self_maps;
+}
+
+void MemoryMappingLayout::DumpListOfModules(
+    InternalMmapVectorNoCtor<LoadedModule> *modules) {
+  Reset();
+  InternalScopedString module_name(kMaxPathLength);
+  MemoryMappedSegment segment(module_name.data(), module_name.size());
+  for (uptr i = 0; Next(&segment); i++) {
+    const char *cur_name = segment.filename;
+    if (cur_name[0] == '\0')
+      continue;
+    // Don't subtract 'cur_beg' from the first entry:
+    // * If a binary is compiled w/o -pie, then the first entry in
+    //   process maps is likely the binary itself (all dynamic libs
+    //   are mapped higher in address space). For such a binary,
+    //   instruction offset in binary coincides with the actual
+    //   instruction address in virtual memory (as code section
+    //   is mapped to a fixed memory range).
+    // * If a binary is compiled with -pie, all the modules are
+    //   mapped high at address space (in particular, higher than
+    //   shadow memory of the tool), so the module can't be the
+    //   first entry.
+    uptr base_address = (i ? segment.start : 0) - segment.offset;
+    LoadedModule cur_module;
+    cur_module.set(cur_name, base_address);
+    segment.AddAddressRanges(&cur_module);
+    modules->push_back(cur_module);
+  }
+}
+
+void GetMemoryProfile(fill_profile_f cb, uptr *stats, uptr stats_size) {
+  char *smaps = nullptr;
+  uptr smaps_cap = 0;
+  uptr smaps_len = 0;
+  if (!ReadFileToBuffer("/proc/self/smaps", &smaps, &smaps_cap, &smaps_len))
+    return;
+  uptr start = 0;
+  bool file = false;
+  const char *pos = smaps;
+  while (pos < smaps + smaps_len) {
+    if (IsHex(pos[0])) {
+      start = ParseHex(&pos);
+      for (; *pos != '/' && *pos > '\n'; pos++) {}
+      file = *pos == '/';
+    } else if (internal_strncmp(pos, "Rss:", 4) == 0) {
+      while (!IsDecimal(*pos)) pos++;
+      uptr rss = ParseDecimal(&pos) * 1024;
+      cb(start, rss, file, stats, stats_size);
+    }
+    while (*pos++ != '\n') {}
+  }
+  UnmapOrDie(smaps, smaps_cap);
+}
+
+} // namespace __sanitizer
+
+#endif