1 files changed, 123 insertions, 0 deletions
diff --git a/lib/lsan/lsan_common_linux.cc b/lib/lsan/lsan_common_linux.cc
new file mode 100644
index 000000000000..10a434b5f851
--- /dev/null
+++ b/lib/lsan/lsan_common_linux.cc
@@ -0,0 +1,123 @@
+//=-- lsan_common_linux.cc ------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a part of LeakSanitizer.
+// Implementation of common leak checking functionality. Linux-specific code.
+//
+//===----------------------------------------------------------------------===//
+
+#include "sanitizer_common/sanitizer_platform.h"
+#include "lsan_common.h"
+
+#if CAN_SANITIZE_LEAKS && SANITIZER_LINUX
+#include <link.h>
+
+#include "sanitizer_common/sanitizer_common.h"
+#include "sanitizer_common/sanitizer_linux.h"
+#include "sanitizer_common/sanitizer_stackdepot.h"
+
+namespace __lsan {
+
+static const char kLinkerName[] = "ld";
+// We request 2 modules matching "ld", so we can print a warning if there's more
+// than one match. But only the first one is actually used.
+static char linker_placeholder[2 * sizeof(LoadedModule)] ALIGNED(64);
+static LoadedModule *linker = 0;
+
+static bool IsLinker(const char* full_name) {
+  return LibraryNameIs(full_name, kLinkerName);
+}
+
+void InitializePlatformSpecificModules() {
+  internal_memset(linker_placeholder, 0, sizeof(linker_placeholder));
+  uptr num_matches = GetListOfModules(
+      reinterpret_cast<LoadedModule *>(linker_placeholder), 2, IsLinker);
+  if (num_matches == 1) {
+    linker = reinterpret_cast<LoadedModule *>(linker_placeholder);
+    return;
+  }
+  if (num_matches == 0)
+    Report("LeakSanitizer: Dynamic linker not found. "
+           "TLS will not be handled correctly.\n");
+  else if (num_matches > 1)
+    Report("LeakSanitizer: Multiple modules match \"%s\". "
+           "TLS will not be handled correctly.\n", kLinkerName);
+  linker = 0;
+}
+
+static int ProcessGlobalRegionsCallback(struct dl_phdr_info *info, size_t size,
+                                        void *data) {
+  InternalVector<uptr> *frontier =
+      reinterpret_cast<InternalVector<uptr> *>(data);
+  for (uptr j = 0; j < info->dlpi_phnum; j++) {
+    const ElfW(Phdr) *phdr = &(info->dlpi_phdr[j]);
+    // We're looking for .data and .bss sections, which reside in writeable,
+    // loadable segments.
+    if (!(phdr->p_flags & PF_W) || (phdr->p_type != PT_LOAD) ||
+        (phdr->p_memsz == 0))
+      continue;
+    uptr begin = info->dlpi_addr + phdr->p_vaddr;
+    uptr end = begin + phdr->p_memsz;
+    uptr allocator_begin = 0, allocator_end = 0;
+    GetAllocatorGlobalRange(&allocator_begin, &allocator_end);
+    if (begin <= allocator_begin && allocator_begin < end) {
+      CHECK_LE(allocator_begin, allocator_end);
+      CHECK_LT(allocator_end, end);
+      if (begin < allocator_begin)
+        ScanRangeForPointers(begin, allocator_begin, frontier, "GLOBAL",
+                             kReachable);
+      if (allocator_end < end)
+        ScanRangeForPointers(allocator_end, end, frontier, "GLOBAL",
+                             kReachable);
+    } else {
+      ScanRangeForPointers(begin, end, frontier, "GLOBAL", kReachable);
+    }
+  }
+  return 0;
+}
+
+// Scan global variables for heap pointers.
+void ProcessGlobalRegions(InternalVector<uptr> *frontier) {
+  // FIXME: dl_iterate_phdr acquires a linker lock, so we run a risk of
+  // deadlocking by running this under StopTheWorld. However, the lock is
+  // reentrant, so we should be able to fix this by acquiring the lock before
+  // suspending threads.
+  dl_iterate_phdr(ProcessGlobalRegionsCallback, frontier);
+}
+
+static uptr GetCallerPC(u32 stack_id) {
+  CHECK(stack_id);
+  uptr size = 0;
+  const uptr *trace = StackDepotGet(stack_id, &size);
+  // The top frame is our malloc/calloc/etc. The next frame is the caller.
+  CHECK_GE(size, 2);
+  return trace[1];
+}
+
+void ProcessPlatformSpecificAllocationsCb::operator()(void *p) const {
+  p = GetUserBegin(p);
+  LsanMetadata m(p);
+  if (m.allocated() && m.tag() != kReachable) {
+    if (linker->containsAddress(GetCallerPC(m.stack_trace_id()))) {
+      m.set_tag(kReachable);
+      frontier_->push_back(reinterpret_cast<uptr>(p));
+    }
+  }
+}
+
+// Handle dynamically allocated TLS blocks by treating all chunks allocated from
+// ld-linux.so as reachable.
+void ProcessPlatformSpecificAllocations(InternalVector<uptr> *frontier) {
+  if (!flags()->use_tls) return;
+  if (!linker) return;
+  ForEachChunk(ProcessPlatformSpecificAllocationsCb(frontier));
+}
+
+}  // namespace __lsan
+#endif  // CAN_SANITIZE_LEAKS && SANITIZER_LINUX