Android: Add chrome-specific dynamic linker.

third_party/crazy_linker/crazy_linker/src/crazy_linker_library_list.cpp

Index: third_party/crazy_linker/crazy_linker/src/crazy_linker_library_list.cpp
diff --git a/third_party/crazy_linker/crazy_linker/src/crazy_linker_library_list.cpp b/third_party/crazy_linker/crazy_linker/src/crazy_linker_library_list.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..6894b782c13183fb95702427e323ee9158de238f
--- /dev/null
+++ b/third_party/crazy_linker/crazy_linker/src/crazy_linker_library_list.cpp
@@ -0,0 +1,398 @@
+// Copyright (c) 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "crazy_linker_library_list.h"
+
+#include <dlfcn.h>
+
+#include "crazy_linker_debug.h"
+#include "crazy_linker_library_view.h"
+#include "crazy_linker_globals.h"
+#include "crazy_linker_rdebug.h"
+#include "crazy_linker_shared_library.h"
+#include "crazy_linker_system.h"
+
+namespace crazy {
+
+namespace {
+
+// A helper struct used when looking up symbols in libraries.
+struct SymbolLookupState {
+  void* found_addr;
+  void* weak_addr;
+  int weak_count;
+
+  SymbolLookupState()
+    : found_addr(NULL),
+      weak_addr(NULL),
+      weak_count(0) {}
+
+  // Check a symbol entry.
+  bool CheckSymbol(const char* symbol, SharedLibrary* lib) {
+    ELF::Sym* entry = lib->LookupSymbolEntry(symbol);
+    if (!entry)
+      return false;
+
+    void* address = reinterpret_cast<void*>(lib->base + entry->st_value);
+
+    // If this is a strong symbol, record it and return true.
+    if (ELF_ST_BIND(entry->st_info) == STB_GLOBAL) {
+      found_addr = address;
+      return true;
+    }
+    // If this is a weak symbol, record the first one and
+    // increment the weak_count.
+    if (++weak_count == 1)
+      weak_addr = address;
+
+    return false;
+  }
+};
+
+}  // namespace
+
+LibraryList::LibraryList()
+ : head_(0), count_(0), has_error_(false) {
+  // Nothing for now
+}
+
+LibraryList::~LibraryList() {\
+  // Invalidate crazy library list.
+  head_ = NULL;
+
+  // Destroy all known libraries.
+  while (!known_libraries_.IsEmpty()) {
+    LibraryView* wrap = known_libraries_.PopLast();
+    delete wrap;
+  }
+}
+
+LibraryView* LibraryList::FindLibraryByName(const char* base_name) {
+  // Sanity check.
+  if (!base_name || strchr(base_name, '/'))
+    return NULL;
+
+  for (size_t n = 0; n < known_libraries_.GetCount(); ++n) {
+    LibraryView* wrap = known_libraries_[n];
+    if (!strcmp(base_name, wrap->GetName()))
+      return wrap;
+  }
+  return NULL;
+}
+
+void* LibraryList::FindSymbolFrom(const char* symbol_name,
+                                  LibraryView* from) {
+  SymbolLookupState lookup_state;
+
+  if (!from)
+    return NULL;
+
+  // Use a work-queue and a set to ensure to perform a breadth-first
+  // search.
+  Vector<LibraryView*> work_queue;
+  Set<LibraryView*> visited_set;
+
+  work_queue.PushBack(from);
+
+  while (!work_queue.IsEmpty()) {
+    LibraryView* lib = work_queue.PopFirst();
+    if (lib->IsCrazy()) {
+      if (lookup_state.CheckSymbol(symbol_name, lib->GetCrazy()))
+        return lookup_state.found_addr;
+    } else if (lib->IsSystem()) {
+      // TODO(digit): Support weak symbols in system libraries.
+      // With the current code, all symbols in system libraries
+      // are assumed to be non-weak.
+      void* addr = lib->LookupSymbol(symbol_name);
+      if (addr)
+        return addr;
+    }
+
+    // If this is a crazy library, add non-visited dependencies
+    // to the work queue.
+    if (lib->IsCrazy()) {
+      SharedLibrary::DependencyIterator iter(lib->GetCrazy());
+      while (iter.GetNext()) {
+        LibraryView* dependency = FindKnownLibrary(iter.GetName());
+        if (dependency && !visited_set.Has(dependency)) {
+          work_queue.PushBack(dependency);
+          visited_set.Add(dependency);
+        }
+      }
+    }
+  }
+
+  if (lookup_state.weak_count >= 1) {
+    // There was at least a single weak symbol definition, so use
+    // the first one found in breadth-first search order.
+    return lookup_state.weak_addr;
+  }
+
+  // There was no symbol definition.
+  return NULL;
+}
+
+LibraryView* LibraryList::FindLibraryForAddress(void* address) {
+  // Linearly scan all libraries, looking for one that contains
+  // a given address. NOTE: This doesn't check that this falls
+  // inside one of the mapped library segments.
+  uintptr_t addr = reinterpret_cast<uintptr_t>(address);
+
+  for (size_t n = 0; n < known_libraries_.GetCount(); ++n) {
+    LibraryView* wrap = known_libraries_[n];
+    // TODO(digit): Search addresses inside system libraries.
+    if (wrap->IsCrazy()) {
+      SharedLibrary* lib = wrap->GetCrazy();
+      if (lib->base <= addr && addr < lib->base + lib->size)
+        return wrap;
+    }
+  }
+  return NULL;
+}
+
+#ifdef __arm__
+_Unwind_Ptr LibraryList::FindArmExIdx(void* pc, int* count) {
+  uintptr_t addr = reinterpret_cast<uintptr_t>(pc);
+
+  for (SharedLibrary* lib = head_; lib; lib = lib->list_next) {
+    if (addr >= lib->base && addr < lib->base + lib->size) {
+      *count = static_cast<int>(lib->ARM_exidx_count);
+      return reinterpret_cast<_Unwind_Ptr>(lib->ARM_exidx);
+    }
+  }
+  *count = 0;
+  return NULL;
+}
+#else  // !__arm__
+int LibraryList::IteratePhdr(PhdrIterationCallback callback,
+                               void* data) {
+  int result = 0;
+  for (SharedLibrary* lib = head_; lib; lib = lib->list_next) {
+    dl_phdr_info info;
+    info.dlpi_addr = lib->link_map.l_addr;
+    info.dlpi_name = lib->link_map.l_name;
+    info.dlpi_phdr = lib->phdr;
+    info.dlpi_phnum = lib->phnum;
+    result = callback(&info, sizeof(info), data);
+    if (result)
+      break;
+  }
+  return result;
+}
+#endif  // !__arm__
+
+void LibraryList::UnloadLibrary(LibraryView* wrap) {
+  // Sanity check.
+  LOG("%s: for %s (ref_count=%d)\n",
+      __FUNCTION__, wrap->GetName(), wrap->ref_count());
+
+  if (!wrap->IsSystem() && !wrap->IsCrazy())
+    return;
+
+  if (!wrap->SafeDeref())
+    return;
+
+  // If this is a crazy library, perform manual cleanup first.
+  if (wrap->IsCrazy()) {
+    SharedLibrary* lib = wrap->GetCrazy();
+
+    // Remove from internal list of crazy libraries.
+    if (lib->list_next)
+      lib->list_next->list_prev = lib->list_prev;
+    if (lib->list_prev)
+      lib->list_prev->list_next = lib->list_next;
+    if (lib == head_)
+      head_ = lib->list_next;
+
+    // Call the destructors.
+    lib->CallDestructors();
+
+    // Unload the dependencies recursively.
+    SharedLibrary::DependencyIterator iter(lib);
+    while (iter.GetNext()) {
+      LibraryView* dependency = FindKnownLibrary(iter.GetName());
+      if (dependency)
+        UnloadLibrary(dependency);
+    }
+
+    // Tell GDB of this removal.
+    Globals::GetRDebug()->DelEntry(&lib->link_map);
+  }
+
+  known_libraries_.Remove(wrap);
+
+  // Delete the wrapper, which will delete the crazy library, or
+  // dlclose() the system one.
+  delete wrap;
+}
+
+LibraryView* LibraryList::LoadLibrary(const char* lib_name,
+                                      int dlopen_mode,
+                                      uintptr_t load_address,
+                                      off_t file_offset,
+                                      SearchPathList* search_path_list,
+                                      Error* error) {
+
+  const char* base_name = GetBaseNamePtr(lib_name);
+
+  LOG("%s: lib_name='%s'\n", __FUNCTION__, lib_name);
+
+  // First check whether a library with the same base name was
+  // already loaded.
+  LibraryView* wrap = FindKnownLibrary(lib_name);
+  if (wrap) {
+    if (load_address) {
+      // Check that this is a crazy library and that is was loaded at
+      // the correct address.
+      if (!wrap->IsCrazy()) {
+        error->Format("System library can't be loaded at fixed address %08x",
+                      load_address);
+        return NULL;
+      }
+      uintptr_t actual_address = wrap->GetCrazy()->base;
+      if (actual_address != load_address) {
+        error->Format(
+            "Library already loaded at @%08x, can't load it at @%08x",
+            actual_address, load_address);
+        return NULL;
+      }
+    }
+    wrap->AddRef();
+    return wrap;
+  }
+
+  if (IsSystemLibrary(lib_name)) {
+    // This is a system library, probably because we're loading the
+    // library as a dependency.
+    LOG("%s: Loading system library '%s'\n", __FUNCTION__, lib_name);
+    ::dlerror();
+    void* system_lib = dlopen(lib_name, dlopen_mode);
+    if (!system_lib) {
+      error->Format("Can't load system library %s: %s",
+                    lib_name, ::dlerror());
+      return NULL;
+    }
+
+    LibraryView* wrap = new LibraryView();
+    wrap->SetSystem(system_lib, lib_name);
+    known_libraries_.PushBack(wrap);
+
+    LOG("%s: System library %s loaded at %p\n", __FUNCTION__, lib_name, wrap);
+    LOG("  name=%s\n", wrap->GetName());
+    return wrap;
+  }
+
+  ScopedPtr<SharedLibrary> lib(new SharedLibrary());
+
+  // Find the full library path.
+  String full_path;
+
+  if (!strchr(lib_name, '/')) {
+    LOG("%s: Looking through the search path list\n", __FUNCTION__);
+    const char* path = search_path_list->FindFile(lib_name);
+    if (!path) {
+      error->Format("Can't find library file %s", lib_name);
+      return NULL;
+    }
+    full_path = path;
+  } else {
+    if (lib_name[0] != '/') {
+      // Need to transform this into a full path.
+      full_path = GetCurrentDirectory();
+      if (full_path.size() && full_path[full_path.size() - 1] != '/')
+        full_path += '/';
+      full_path += lib_name;
+    } else {
+      // Absolute path. Easy.
+      full_path = lib_name;
+    }
+    LOG("%s: Full library path: %s\n", __FUNCTION__, full_path.c_str());
+    if (!PathIsFile(full_path.c_str())) {
+      error->Format("Library file doesn't exist: %s", full_path.c_str());
+      return NULL;
+    }
+  }
+
+  // Load the library
+  if (!lib->Load(full_path.c_str(), load_address, file_offset, error))
+    return NULL;
+
+  // Load all dependendent libraries.
+  LOG("%s: Loading dependencies of %s\n", __FUNCTION__, base_name);
+  SharedLibrary::DependencyIterator iter(lib.Get());
+  Vector<LibraryView*> dependencies;
+  while (iter.GetNext()) {
+    Error dep_error;
+    LibraryView* dependency =
+        LoadLibrary(iter.GetName(),
+                    dlopen_mode,
+                    0U /* load address */,
+                    0U /* file offset */,
+                    search_path_list,
+                    &dep_error);
+    if (!dependency) {
+      error->Format("When loading %s: %s",
+                     base_name, dep_error.c_str());
+      return NULL;
+    }
+    dependencies.PushBack(dependency);
+  }
+  if (CRAZY_DEBUG) {
+    LOG("%s: Dependencies loaded for %s\n", __FUNCTION__, base_name);
+    for (size_t n = 0; n < dependencies.GetCount(); ++n)
+      LOG("  ... %p %s\n", dependencies[n], dependencies[n]->GetName());
+    LOG("    dependencies @%p\n", &dependencies);
+  }
+
+  // Relocate the library.
+  LOG("%s: Relocating %s", __FUNCTION__, base_name);
+  if (!lib->Relocate(this, &dependencies, error))
+    return NULL;
+
+  // Notify GDB of load.
+  lib->link_map.l_addr = lib->base;
+  lib->link_map.l_name = const_cast<char*>(lib->base_name);
+  lib->link_map.l_ld   = reinterpret_cast<uintptr_t>(lib->dynamic);
+  Globals::GetRDebug()->AddEntry(&lib->link_map);
+
+  // The library was properly loaded, add it to the list of crazy
+  // libraries. IMPORTANT: Do this _before_ calling the constructors
+  // because these could call dlopen().
+  lib->list_next = head_;
+  lib->list_prev = NULL;
+  if (head_)
+    head_->list_prev = lib.Get();
+  head_ = lib.Get();
+
+  // Then create a new LibraryView for it.
+  wrap = new LibraryView();
+  wrap->SetCrazy(lib.Get(), lib_name);
+  known_libraries_.PushBack(wrap);
+
+  LOG("%s: Running constructors for %s\n", __FUNCTION__, base_name);
+
+  // Now run the constructors.
+  lib->CallConstructors();
+
+  LOG("%s: Done loading %s\n", __FUNCTION__, base_name);
+  lib.Release();
+
+  return wrap;
+}
+
+void LibraryList::AddLibrary(LibraryView* wrap) {
+  known_libraries_.PushBack(wrap);
+}
+
+LibraryView* LibraryList::FindKnownLibrary(const char* name) {
+  const char* base_name = GetBaseNamePtr(name);
+  for (size_t n = 0; n < known_libraries_.GetCount(); ++n) {
+    LibraryView* wrap = known_libraries_[n];
+    if (!strcmp(base_name, wrap->GetName()))
+      return wrap;
+  }
+  return NULL;
+}
+
+}  // namespace crazy