The Tor Browser: toolkit/crashreporter/google-breakpad/src/client/linux/handler/exception

toolkit/crashreporter/google-breakpad/src/client/linux/handler/exception_handler.h@129ffea94266 (annotated)

toolkit/crashreporter/google-breakpad/src/client/linux/handler/exception_handler.h

Sat, 03 Jan 2015 20:18:00 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Sat, 03 Jan 2015 20:18:00 +0100
branch: TOR_BUG_3246
changeset 7: 129ffea94266
permissions: -rw-r--r--

Conditionally enable double key logic according to:
private browsing mode or privacy.thirdparty.isolate preference and
implement in GetCookieStringCommon and FindCookie where it counts...
With some reservations of how to convince FindCookie users to test
condition and pass a nullptr when disabling double key logic.

 // Copyright (c) 2010 Google Inc.
 // All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 // notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 // copyright notice, this list of conditions and the following disclaimer
 // in the documentation and/or other materials provided with the
 // distribution.
 //     * Neither the name of Google Inc. nor the names of its
 // contributors may be used to endorse or promote products derived from
 // this software without specific prior written permission.
 //
 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #ifndef CLIENT_LINUX_HANDLER_EXCEPTION_HANDLER_H_
 #define CLIENT_LINUX_HANDLER_EXCEPTION_HANDLER_H_
 #include <string>
 #include <vector>
 #include <pthread.h>
 #include <signal.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <sys/ucontext.h>
 #include "client/linux/crash_generation/crash_generation_client.h"
 #include "client/linux/handler/minidump_descriptor.h"
 #include "client/linux/minidump_writer/minidump_writer.h"
 #include "common/scoped_ptr.h"
 #include "common/using_std_string.h"
 #include "google_breakpad/common/minidump_format.h"
 namespace google_breakpad {
 // ExceptionHandler
 //
 // ExceptionHandler can write a minidump file when an exception occurs,
 // or when WriteMinidump() is called explicitly by your program.
 //
 // To have the exception handler write minidumps when an uncaught exception
 // (crash) occurs, you should create an instance early in the execution
 // of your program, and keep it around for the entire time you want to
 // have crash handling active (typically, until shutdown).
 // (NOTE): There should be only be one this kind of exception handler
 // object per process.
 //
 // If you want to write minidumps without installing the exception handler,
 // you can create an ExceptionHandler with install_handler set to false,
 // then call WriteMinidump.  You can also use this technique if you want to
 // use different minidump callbacks for different call sites.
 //
 // In either case, a callback function is called when a minidump is written,
 // which receives the full path or file descriptor of the minidump.  The
 // caller can collect and write additional application state to that minidump,
 // and launch an external crash-reporting application.
 //
 // Caller should try to make the callbacks as crash-friendly as possible,
 // it should avoid use heap memory allocation as much as possible.
 class ExceptionHandler {
  public:
   // A callback function to run before Breakpad performs any substantial
   // processing of an exception.  A FilterCallback is called before writing
   // a minidump.  |context| is the parameter supplied by the user as
   // callback_context when the handler was created.
   //
   // If a FilterCallback returns true, Breakpad will continue processing,
   // attempting to write a minidump.  If a FilterCallback returns false,
   // Breakpad  will immediately report the exception as unhandled without
   // writing a minidump, allowing another handler the opportunity to handle it.
   typedef bool (*FilterCallback)(void *context);
   // A callback function to run after the minidump has been written.
   // |descriptor| contains the file descriptor or file path containing the
   // minidump. |context| is the parameter supplied by the user as
   // callback_context when the handler was created.  |succeeded| indicates
   // whether a minidump file was successfully written.
   //
   // If an exception occurred and the callback returns true, Breakpad will
   // treat the exception as fully-handled, suppressing any other handlers from
   // being notified of the exception.  If the callback returns false, Breakpad
   // will treat the exception as unhandled, and allow another handler to handle
   // it. If there are no other handlers, Breakpad will report the exception to
   // the system as unhandled, allowing a debugger or native crash dialog the
   // opportunity to handle the exception.  Most callback implementations
   // should normally return the value of |succeeded|, or when they wish to
   // not report an exception of handled, false.  Callbacks will rarely want to
   // return true directly (unless |succeeded| is true).
   typedef bool (*MinidumpCallback)(const MinidumpDescriptor& descriptor,
                                    void* context,
                                    bool succeeded);
   // In certain cases, a user may wish to handle the generation of the minidump
   // themselves. In this case, they can install a handler callback which is
   // called when a crash has occurred. If this function returns true, no other
   // processing of occurs and the process will shortly be crashed. If this
   // returns false, the normal processing continues.
   typedef bool (*HandlerCallback)(const void* crash_context,
                                   size_t crash_context_size,
                                   void* context);
   // Creates a new ExceptionHandler instance to handle writing minidumps.
   // Before writing a minidump, the optional |filter| callback will be called.
   // Its return value determines whether or not Breakpad should write a
   // minidump.  The minidump content will be written to the file path or file
   // descriptor from |descriptor|, and the optional |callback| is called after
   // writing the dump file, as described above.
   // If install_handler is true, then a minidump will be written whenever
   // an unhandled exception occurs.  If it is false, minidumps will only
   // be written when WriteMinidump is called.
   // If |server_fd| is valid, the minidump is generated out-of-process.  If it
   // is -1, in-process generation will always be used.
   ExceptionHandler(const MinidumpDescriptor& descriptor,
                    FilterCallback filter,
                    MinidumpCallback callback,
                    void *callback_context,
                    bool install_handler,
                    const int server_fd);
   ~ExceptionHandler();
   const MinidumpDescriptor& minidump_descriptor() const {
     return minidump_descriptor_;
   }
   void set_minidump_descriptor(const MinidumpDescriptor& descriptor) {
     minidump_descriptor_ = descriptor;
   }
   void set_crash_handler(HandlerCallback callback) {
     crash_handler_ = callback;
   }
   // Writes a minidump immediately.  This can be used to capture the execution
   // state independently of a crash.
   // Returns true on success.
   // If the ExceptionHandler has been created with a path, a new file is
   // generated for each minidump.  The file path can be retrieved in the
   // MinidumpDescriptor passed to the MinidumpCallback or by accessing the
   // MinidumpDescriptor directly from the ExceptionHandler (with
   // minidump_descriptor()).
   // If the ExceptionHandler has been created with a file descriptor, the file
   // descriptor is repositioned to its beginning and the previous generated
   // minidump is overwritten.
   // Note that this method is not supposed to be called from a compromised
   // context as it uses the heap.
   bool WriteMinidump();
   // Convenience form of WriteMinidump which does not require an
   // ExceptionHandler instance.
   static bool WriteMinidump(const string& dump_path,
                             MinidumpCallback callback,
                             void* callback_context);
   // Write a minidump of |child| immediately.  This can be used to
   // capture the execution state of |child| independently of a crash.
   // Pass a meaningful |child_blamed_thread| to make that thread in
   // the child process the one from which a crash signature is
   // extracted.
   //
   // WARNING: the return of this function *must* happen before
   // the code that will eventually reap |child| executes.
   // Otherwise there's a pernicious race condition in which |child|
   // exits, is reaped, another process created with its pid, then that
   // new process dumped.
   static bool WriteMinidumpForChild(pid_t child,
                                     pid_t child_blamed_thread,
                                     const string& dump_path,
                                     MinidumpCallback callback,
                                     void* callback_context);
   // This structure is passed to minidump_writer.h:WriteMinidump via an opaque
   // blob. It shouldn't be needed in any user code.
   struct CrashContext {
     siginfo_t siginfo;
     pid_t tid;  // the crashing thread.
     struct ucontext context;
 #if !defined(__ARM_EABI__)
     // #ifdef this out because FP state is not part of user ABI for Linux ARM.
     struct _libc_fpstate float_state;
 #endif
   };
   // Returns whether out-of-process dump generation is used or not.
   bool IsOutOfProcess() const {
       return crash_generation_client_.get() != NULL;
   }
   // Add information about a memory mapping. This can be used if
   // a custom library loader is used that maps things in a way
   // that the linux dumper can't handle by reading the maps file.
   void AddMappingInfo(const string& name,
                       const uint8_t identifier[sizeof(MDGUID)],
                       uintptr_t start_address,
                       size_t mapping_size,
                       size_t file_offset);
   // Register a block of memory of length bytes starting at address ptr
   // to be copied to the minidump when a crash happens.
   void RegisterAppMemory(void* ptr, size_t length);
   // Unregister a block of memory that was registered with RegisterAppMemory.
   void UnregisterAppMemory(void* ptr);
   // Force signal handling for the specified signal.
   bool SimulateSignalDelivery(int sig);
   // Report a crash signal from an SA_SIGINFO signal handler.
   bool HandleSignal(int sig, siginfo_t* info, void* uc);
  private:
   // Save the old signal handlers and install new ones.
   static bool InstallHandlersLocked();
   // Restore the old signal handlers.
   static void RestoreHandlersLocked();
   void PreresolveSymbols();
   bool GenerateDump(CrashContext *context);
   void SendContinueSignalToChild();
   void WaitForContinueSignal();
   static void SignalHandler(int sig, siginfo_t* info, void* uc);
   static int ThreadEntry(void* arg);
   bool DoDump(pid_t crashing_process, const void* context,
               size_t context_size);
   const FilterCallback filter_;
   const MinidumpCallback callback_;
   void* const callback_context_;
   scoped_ptr<CrashGenerationClient> crash_generation_client_;
   MinidumpDescriptor minidump_descriptor_;
   HandlerCallback crash_handler_;
   // The global exception handler stack. This is need becuase there may exist
   // multiple ExceptionHandler instances in a process. Each will have itself
   // registered in this stack.
   static std::vector<ExceptionHandler*> *handler_stack_;
   static pthread_mutex_t handler_stack_mutex_;
   // We need to explicitly enable ptrace of parent processes on some
   // kernels, but we need to know the PID of the cloned process before we
   // can do this. We create a pipe which we can use to block the
   // cloned process after creating it, until we have explicitly enabled
   // ptrace. This is used to store the file descriptors for the pipe
   int fdes[2];
   // Callers can add extra info about mappings for cases where the
   // dumper code cannot extract enough information from /proc/<pid>/maps.
   MappingList mapping_list_;
   // Callers can request additional memory regions to be included in
   // the dump.
   AppMemoryList app_memory_list_;
 };
 }  // namespace google_breakpad
 #endif  // CLIENT_LINUX_HANDLER_EXCEPTION_HANDLER_H_

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toolkit/crashreporter/google-breakpad/src/client/linux/handler/exception_handler.h@129ffea94266 (annotated)

toolkit/crashreporter/google-breakpad/src/client/linux/handler/exception_handler.h