The Tor Browser: tools/profiler/local_debug_info_symbolizer.cc@97036ab72558 (annotated)

tools/profiler/local_debug_info_symbolizer.cc@97036ab72558 (annotated)

tools/profiler/local_debug_info_symbolizer.cc

Tue, 06 Jan 2015 21:39:09 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Tue, 06 Jan 2015 21:39:09 +0100
branch: TOR_BUG_9701
changeset 8: 97036ab72558
permissions: -rw-r--r--

Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 #include "PlatformMacros.h"
 #include "nsAutoPtr.h"
 #if !defined(SPS_OS_windows)
 # include "common/module.h"
 # include "processor/cfi_frame_info.h"
 #endif
 #include "google_breakpad/processor/code_module.h"
 #include "google_breakpad/processor/code_modules.h"
 #include "google_breakpad/processor/stack_frame.h"
 #include "common/logging.h"
 #if defined(SPS_PLAT_amd64_linux) || defined(SPS_PLAT_arm_android) \
     || defined(SPS_PLAT_x86_linux) || defined(SPS_PLAT_x86_android)
 # include "common/linux/dump_symbols.h"
 #elif defined(SPS_PLAT_amd64_darwin) || defined(SPS_PLAT_x86_darwin)
 # include "shim_mac_dump_syms.h"
 #elif defined(SPS_OS_windows)
   /* This is all stubbed out anyway, so don't do anything. */
 #else
 # error "Unknown platform"
 #endif
 #if defined(SPS_OS_android) && !defined(MOZ_WIDGET_GONK)
 # include "mozilla/Types.h"
 # include "ElfLoader.h"
 # include <dlfcn.h>
 # include <sys/mman.h>
 # include "nsString.h"
 # include "nsDirectoryServiceUtils.h"
 # include "nsDirectoryServiceDefs.h"
 # include <sys/stat.h>
 # include <fcntl.h>
 #endif
 #include "local_debug_info_symbolizer.h"
 namespace google_breakpad {
 LocalDebugInfoSymbolizer::~LocalDebugInfoSymbolizer() {
 # if !defined(SPS_OS_windows)
   for (SymbolMap::iterator it = symbols_.begin();
        it != symbols_.end();
        ++it) {
     delete it->second;
   }
 # endif
 }
 #if defined(SPS_OS_android) && !defined(MOZ_WIDGET_GONK)
 // Find out where the installation's lib directory is, since we'll
 // have to look in there to get hold of libmozglue.so.  Returned
 // C string is heap allocated and the caller must deallocate it.
 static char* get_installation_lib_dir ( void )
 {
   nsCOMPtr<nsIProperties>
     directoryService(do_GetService(NS_DIRECTORY_SERVICE_CONTRACTID));
   if (!directoryService) return NULL;
   nsCOMPtr<nsIFile> greDir;
   nsresult rv = directoryService->Get(NS_GRE_DIR, NS_GET_IID(nsIFile),
                                       getter_AddRefs(greDir));
   if (NS_FAILED(rv)) return NULL;
   nsCString path;
   rv = greDir->GetNativePath(path);
   if (NS_FAILED(rv)) return NULL;
   return strdup(path.get());
 }
 // Read symbol data from a file on Android.  OBJ_FILENAME has
 // three possible cases:
 //
 // (1) /foo/bar/xyzzy/blah.apk!/libwurble.so
 //     We hand it as-is to faulty.lib and let it fish the relevant
 //     bits out of the APK.
 //
 // (2) libmozglue.so
 //     This is part of the Fennec installation, but is not in the
 //     APK.  Instead we have to figure out the installation path
 //     and look for it there. Because of faulty.lib limitations,
 //     we have to use regular open/mmap instead of faulty.lib.
 //
 // (3) libanythingelse.so
 //     faulty.lib assumes this is a system library, and prepends
 //     "/system/lib/" to the path.  So as in (1), we can give it
 //     as-is to faulty.lib.
 //
 // Hence only (2) requires special-casing here.
 //
 static bool ReadSymbolData_ANDROID(const string& obj_filename,
                                    const std::vector<string>& debug_dirs,
                                    SymbolData symbol_data,
                                    Module** module)
 {
   string obj_file_to_use = obj_filename;
   // Do (2) in the comment above.
   if (obj_file_to_use == "libmozglue.so") {
     char* libdir = get_installation_lib_dir();
     if (libdir) {
       obj_file_to_use = string(libdir) + "/lib/" + obj_file_to_use;
       free(libdir);
     }
     // Use regular open/mmap here because of faulty.lib limitations
     int fd = open(obj_file_to_use.c_str(), O_RDONLY);
     if (fd == -1) {
       BPLOG(INFO) << "ReadSymbolData_APK: Failed to open \'"
                   << obj_file_to_use << "\'";
       return false;
     }
     struct stat st;
     if (fstat(fd, &st) != 0) {
       close(fd);
       BPLOG(INFO) << "ReadSymbolData_APK: Failed to fstat \'"
                   << obj_file_to_use << "\'";
       return false;
     }
     void* image = mmap(nullptr, st.st_size, PROT_READ, MAP_SHARED, fd, 0);
     if (image == MAP_FAILED) {
       close(fd);
       BPLOG(INFO) << "ReadSymbolData_APK: Failed to mmap \'"
                   << obj_file_to_use << "\'";
       return false;
     }
     bool ok = ReadSymbolDataInternal((const uint8_t*)image,
                                      obj_file_to_use, debug_dirs,
                                      symbol_data, module);
     munmap(image, st.st_size);
     close(fd);
     return ok;
   }
   // Regardless of whether the file is inside an APK or not, we ask
   // faulty.lib to map it, then call ReadSymbolDataInternal, then
   // unmap and dlclose it.
   void* hdl = dlopen(obj_file_to_use.c_str(), RTLD_GLOBAL | RTLD_LAZY);
   if (!hdl) {
     BPLOG(INFO) << "ReadSymbolData_APK: Failed to get handle for ELF file \'"
                 << obj_file_to_use << "\'";
     return false;
   }
   size_t sz = __dl_get_mappable_length(hdl);
   if (sz == 0) {
     dlclose(hdl);
     BPLOG(INFO) << "ReadSymbolData_APK: Unable to get size for ELF file \'"
                 << obj_file_to_use << "\'";
     return false;
   }
   void* image = __dl_mmap(hdl, NULL, sz, 0);
   if (image == MAP_FAILED) {
     dlclose(hdl);
     BPLOG(INFO) << "ReadSymbolData_APK: Failed to mmap ELF file \'"
                 << obj_file_to_use << "\'";
     return false;
   }
   bool ok = ReadSymbolDataInternal((const uint8_t*)image,
                                    obj_file_to_use, debug_dirs,
                                    symbol_data, module);
   __dl_munmap(hdl, image, sz);
   dlclose(hdl);
   return ok;
 }
 #endif /* defined(SPS_OS_android) && !defined(MOZ_WIDGET_GONK) */
 StackFrameSymbolizer::SymbolizerResult
 LocalDebugInfoSymbolizer::FillSourceLineInfo(const CodeModules* modules,
                                              const SystemInfo* system_info,
                                              StackFrame* frame) {
   if (!modules) {
     return kError;
   }
   const CodeModule* module = modules->GetModuleForAddress(frame->instruction);
   if (!module) {
     return kError;
   }
   frame->module = module;
 # if !defined(SPS_OS_windows)
   Module* debug_info_module = NULL;
   SymbolMap::const_iterator it = symbols_.find(module->code_file());
   if (it == symbols_.end()) {
     if (no_symbol_modules_.find(module->code_file()) !=
         no_symbol_modules_.end()) {
       return kNoError;
     }
     bool ok = false;
 #   if defined(SPS_OS_android) && !defined(MOZ_WIDGET_GONK)
     ok = ReadSymbolData_ANDROID(module->code_file(), debug_dirs_,
                                 ONLY_CFI, &debug_info_module);
 #   elif defined(SPS_PLAT_amd64_darwin) || defined(SPS_PLAT_x86_darwin)
     ok = ReadSymbolData_DARWIN(module->code_file(), debug_dirs_,
                         ONLY_CFI, &debug_info_module);
 #   else
     ok = ReadSymbolData(module->code_file(), debug_dirs_,
                         ONLY_CFI, &debug_info_module);
 #   endif
     if (!ok) {
       if (debug_info_module)
         delete debug_info_module;
       no_symbol_modules_.insert(module->code_file());
       return kNoError;
     }
     symbols_[module->code_file()] = debug_info_module;
   } else {
     debug_info_module = it->second;
   }
   u_int64_t address = frame->instruction - frame->module->base_address();
   Module::Function* function =
       debug_info_module->FindFunctionByAddress(address);
   if (function) {
     frame->function_name = function->name;
     //TODO: line info: function->lines
   } else {
     Module::Extern* ex = debug_info_module->FindExternByAddress(address);
     if (ex) {
       frame->function_name = ex->name;
     }
   }
 # endif /* !defined(SPS_OS_windows) */
   return kNoError;
 }
 WindowsFrameInfo* LocalDebugInfoSymbolizer::FindWindowsFrameInfo(
     const StackFrame* frame) {
   // Not currently implemented, would require PDBSourceLineWriter to
   // implement an API to return symbol data.
   return NULL;
 }
 #if !defined(SPS_OS_windows)
 // Taken wholesale from source_line_resolver_base.cc
 bool ParseCFIRuleSet(const string& rule_set, CFIFrameInfo* frame_info) {
   CFIFrameInfoParseHandler handler(frame_info);
   CFIRuleParser parser(&handler);
   return parser.Parse(rule_set);
 }
 static void ConvertCFI(const UniqueString* name, const Module::Expr& rule,
                        CFIFrameInfo* frame_info) {
   if (name == ustr__ZDcfa()) frame_info->SetCFARule(rule);
   else if (name == ustr__ZDra()) frame_info->SetRARule(rule);
   else frame_info->SetRegisterRule(name, rule);
 }
 static void ConvertCFI(const Module::RuleMap& rule_map,
                        CFIFrameInfo* frame_info) {
   for (Module::RuleMap::const_iterator it = rule_map.begin();
        it != rule_map.end(); ++it) {
     ConvertCFI(it->first, it->second, frame_info);
   }
 }
 #endif
 CFIFrameInfo* LocalDebugInfoSymbolizer::FindCFIFrameInfo(
     const StackFrame* frame) {
 #if defined(SPS_OS_windows)
   return NULL;
 #else
   if (!frame || !frame->module) return NULL;
   SymbolMap::const_iterator it = symbols_.find(frame->module->code_file());
   if (it == symbols_.end()) return NULL;
   Module* module = it->second;
   u_int64_t address = frame->instruction - frame->module->base_address();
   Module::StackFrameEntry* entry =
       module->FindStackFrameEntryByAddress(address);
   if (!entry)
     return NULL;
   //TODO: can we cache this data per-address? does that make sense?
   // TODO: Maybe this should use google_breakpad::scoped_ptr, since we're in
   // "namespace google_breakpad". Not using scoped_ptr currently, because its
   // header triggers build warnings -- see bug 855010.
   nsAutoPtr<CFIFrameInfo> rules(new CFIFrameInfo());
   ConvertCFI(entry->initial_rules, rules);
   for (Module::RuleChangeMap::const_iterator delta_it =
            entry->rule_changes.begin();
        delta_it != entry->rule_changes.end() && delta_it->first < address;
        ++delta_it) {
     ConvertCFI(delta_it->second, rules);
   }
   return rules.forget();
 #endif /* defined(SPS_OS_windows) */
 }
 }  // namespace google_breakpad

The Tor Browser / annotate

tools/profiler/local_debug_info_symbolizer.cc@97036ab72558 (annotated)

tools/profiler/local_debug_info_symbolizer.cc