[lsan] Common leak checking module.
Leak checking functionality which will be shared between
LSan/ASan/MSan.
git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@182249 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/lsan/lsan_common_linux.cc b/lib/lsan/lsan_common_linux.cc
new file mode 100644
index 0000000..a354aee
--- /dev/null
+++ b/lib/lsan/lsan_common_linux.cc
@@ -0,0 +1,122 @@
+//=-- 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"
+#if SANITIZER_LINUX
+#include "lsan_common.h"
+
+#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("%s: Dynamic linker not found. TLS will not be handled correctly.\n",
+ SanitizerToolName);
+ else if (num_matches > 1)
+ Report("%s: Multiple modules match \"%s\". TLS will not be handled "
+ "correctly.\n", SanitizerToolName, 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 {
+ 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 // SANITIZER_LINUX