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 // 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.

 // The ExceptionHandler object installs signal handlers for a number of

 // signals. We rely on the signal handler running on the thread which crashed

 // in order to identify it. This is true of the synchronous signals (SEGV etc),

 // but not true of ABRT. Thus, if you send ABRT to yourself in a program which

 // uses ExceptionHandler, you need to use tgkill to direct it to the current

 // thread.

 //

 // The signal flow looks like this:

 //

 //   SignalHandler (uses a global stack of ExceptionHandler objects to find

 //        |         one to handle the signal. If the first rejects it, try

 //        |         the second etc...)

 //        V

 //   HandleSignal ----------------------------| (clones a new process which

 //        |                                   |  shares an address space with

 //   (wait for cloned                         |  the crashed process. This

 //     process)                               |  allows us to ptrace the crashed

 //        |                                   |  process)

 //        V                                   V

 //   (set signal handler to             ThreadEntry (static function to bounce

 //    SIG_DFL and rethrow,                    |      back into the object)

 //    killing the crashed                     |

 //    process)                                V

 //                                          DoDump  (writes minidump)

 //                                            |

 //                                            V

 //                                         sys_exit

 //

 // This code is a little fragmented. Different functions of the ExceptionHandler

 // class run in a number of different contexts. Some of them run in a normal

 // context and are easy to code, others run in a compromised context and the

 // restrictions at the top of minidump_writer.cc apply: no libc and use the

 // alternative malloc. Each function should have comment above it detailing the

 // context which it runs in.

 #include "client/linux/handler/exception_handler.h"

 #include <errno.h>

 #include <fcntl.h>

 #include <linux/limits.h>

 #include <sched.h>

 #include <signal.h>

 #include <stdio.h>

 #include <sys/mman.h>

 #include <sys/prctl.h>

 #include <sys/syscall.h>

 #include <sys/wait.h>

 #include <unistd.h>

 #include <sys/signal.h>

 #include <sys/ucontext.h>

 #include <sys/user.h>

 #include <ucontext.h>

 #include <algorithm>

 #include <utility>

 #include <vector>

 #include "common/linux/linux_libc_support.h"

 #include "common/memory.h"

 #include "client/linux/log/log.h"

 #include "client/linux/minidump_writer/linux_dumper.h"

 #include "client/linux/minidump_writer/minidump_writer.h"

 #include "common/linux/eintr_wrapper.h"

 #include "third_party/lss/linux_syscall_support.h"

 #include "linux/sched.h"

 #ifndef PR_SET_PTRACER

 #define PR_SET_PTRACER 0x59616d61

 #endif

 // A wrapper for the tgkill syscall: send a signal to a specific thread.

 static int tgkill(pid_t tgid, pid_t tid, int sig) {

   return syscall(__NR_tgkill, tgid, tid, sig);

   return 0;

 }

 namespace google_breakpad {

 namespace {

 // The list of signals which we consider to be crashes. The default action for

 // all these signals must be Core (see man 7 signal) because we rethrow the

 // signal after handling it and expect that it'll be fatal.

 const int kExceptionSignals[] = {

   SIGSEGV, SIGABRT, SIGFPE, SIGILL, SIGBUS

 };

 const int kNumHandledSignals =

     sizeof(kExceptionSignals) / sizeof(kExceptionSignals[0]);

 struct sigaction old_handlers[kNumHandledSignals];

 bool handlers_installed = false;

 // InstallAlternateStackLocked will store the newly installed stack in new_stack

 // and (if it exists) the previously installed stack in old_stack.

 stack_t old_stack;

 stack_t new_stack;

 bool stack_installed = false;

 // Create an alternative stack to run the signal handlers on. This is done since

 // the signal might have been caused by a stack overflow.

 // Runs before crashing: normal context.

 void InstallAlternateStackLocked() {

   if (stack_installed)

     return;

   memset(&old_stack, 0, sizeof(old_stack));

   memset(&new_stack, 0, sizeof(new_stack));

   // SIGSTKSZ may be too small to prevent the signal handlers from overrunning

   // the alternative stack. Ensure that the size of the alternative stack is

   // large enough.

   static const unsigned kSigStackSize = std::max(8192, SIGSTKSZ);

   // Only set an alternative stack if there isn't already one, or if the current

   // one is too small.

   if (sys_sigaltstack(NULL, &old_stack) == -1 || !old_stack.ss_sp ||

       old_stack.ss_size < kSigStackSize) {

     new_stack.ss_sp = malloc(kSigStackSize);

     new_stack.ss_size = kSigStackSize;

     if (sys_sigaltstack(&new_stack, NULL) == -1) {

       free(new_stack.ss_sp);

       return;

     }

     stack_installed = true;

   }

 }

 // Runs before crashing: normal context.

 void RestoreAlternateStackLocked() {

   if (!stack_installed)

     return;

   stack_t current_stack;

   if (sys_sigaltstack(NULL, &current_stack) == -1)

     return;

   // Only restore the old_stack if the current alternative stack is the one

   // installed by the call to InstallAlternateStackLocked.

   if (current_stack.ss_sp == new_stack.ss_sp) {

     if (old_stack.ss_sp) {

       if (sys_sigaltstack(&old_stack, NULL) == -1)

         return;

     } else {

       stack_t disable_stack;

       disable_stack.ss_flags = SS_DISABLE;

       if (sys_sigaltstack(&disable_stack, NULL) == -1)

         return;

     }

   }

   free(new_stack.ss_sp);

   stack_installed = false;

 }

 }  // namespace

 // We can stack multiple exception handlers. In that case, this is the global

 // which holds the stack.

 std::vector<ExceptionHandler*>* ExceptionHandler::handler_stack_ = NULL;

 pthread_mutex_t ExceptionHandler::handler_stack_mutex_ =

     PTHREAD_MUTEX_INITIALIZER;

 // Runs before crashing: normal context.

 ExceptionHandler::ExceptionHandler(const MinidumpDescriptor& descriptor,

                                    FilterCallback filter,

                                    MinidumpCallback callback,

                                    void* callback_context,

                                    bool install_handler,

                                    const int server_fd)

     : filter_(filter),

       callback_(callback),

       callback_context_(callback_context),

       minidump_descriptor_(descriptor),

       crash_handler_(NULL) {

   if (server_fd >= 0)

     crash_generation_client_.reset(CrashGenerationClient::TryCreate(server_fd));

   if (!IsOutOfProcess() && !minidump_descriptor_.IsFD())

     minidump_descriptor_.UpdatePath();

   pthread_mutex_lock(&handler_stack_mutex_);

   if (!handler_stack_)

     handler_stack_ = new std::vector<ExceptionHandler*>;

   if (install_handler) {

     InstallAlternateStackLocked();

     InstallHandlersLocked();

   }

   handler_stack_->push_back(this);

   pthread_mutex_unlock(&handler_stack_mutex_);

 }

 // Runs before crashing: normal context.

 ExceptionHandler::~ExceptionHandler() {

   pthread_mutex_lock(&handler_stack_mutex_);

   std::vector<ExceptionHandler*>::iterator handler =

       std::find(handler_stack_->begin(), handler_stack_->end(), this);

   handler_stack_->erase(handler);

   if (handler_stack_->empty()) {

     RestoreAlternateStackLocked();

     RestoreHandlersLocked();

   }

   pthread_mutex_unlock(&handler_stack_mutex_);

 }

 // Runs before crashing: normal context.

 // static

 bool ExceptionHandler::InstallHandlersLocked() {

   if (handlers_installed)

     return false;

   // Fail if unable to store all the old handlers.

   for (int i = 0; i < kNumHandledSignals; ++i) {

     if (sigaction(kExceptionSignals[i], NULL, &old_handlers[i]) == -1)

       return false;

   }

   struct sigaction sa;

   memset(&sa, 0, sizeof(sa));

   sigemptyset(&sa.sa_mask);

   // Mask all exception signals when we're handling one of them.

   for (int i = 0; i < kNumHandledSignals; ++i)

     sigaddset(&sa.sa_mask, kExceptionSignals[i]);

   sa.sa_sigaction = SignalHandler;

   sa.sa_flags = SA_ONSTACK | SA_SIGINFO;

   for (int i = 0; i < kNumHandledSignals; ++i) {

     if (sigaction(kExceptionSignals[i], &sa, NULL) == -1) {

       // At this point it is impractical to back out changes, and so failure to

       // install a signal is intentionally ignored.

     }

   }

   handlers_installed = true;

   return true;

 }

 // This function runs in a compromised context: see the top of the file.

 // Runs on the crashing thread.

 // static

 void ExceptionHandler::RestoreHandlersLocked() {

   if (!handlers_installed)

     return;

   for (int i = 0; i < kNumHandledSignals; ++i) {

     if (sigaction(kExceptionSignals[i], &old_handlers[i], NULL) == -1) {

       signal(kExceptionSignals[i], SIG_DFL);

     }

   }

   handlers_installed = false;

 }

 // void ExceptionHandler::set_crash_handler(HandlerCallback callback) {

 //   crash_handler_ = callback;

 // }

 // This function runs in a compromised context: see the top of the file.

 // Runs on the crashing thread.

 // static

 void ExceptionHandler::SignalHandler(int sig, siginfo_t* info, void* uc) {

   // All the exception signals are blocked at this point.

   pthread_mutex_lock(&handler_stack_mutex_);

   // Sometimes, Breakpad runs inside a process where some other buggy code

   // saves and restores signal handlers temporarily with 'signal'

   // instead of 'sigaction'. This loses the SA_SIGINFO flag associated

   // with this function. As a consequence, the values of 'info' and 'uc'

   // become totally bogus, generally inducing a crash.

   //

   // The following code tries to detect this case. When it does, it

   // resets the signal handlers with sigaction + SA_SIGINFO and returns.

   // This forces the signal to be thrown again, but this time the kernel

   // will call the function with the right arguments.

   struct sigaction cur_handler;

   if (sigaction(sig, NULL, &cur_handler) == 0 &&

       (cur_handler.sa_flags & SA_SIGINFO) == 0) {

     // Reset signal handler with the right flags.

     sigemptyset(&cur_handler.sa_mask);

     sigaddset(&cur_handler.sa_mask, sig);

     cur_handler.sa_sigaction = SignalHandler;

     cur_handler.sa_flags = SA_ONSTACK | SA_SIGINFO;

     if (sigaction(sig, &cur_handler, NULL) == -1) {

       // When resetting the handler fails, try to reset the

       // default one to avoid an infinite loop here.

       signal(sig, SIG_DFL);

     }

     pthread_mutex_unlock(&handler_stack_mutex_);

     return;

   }

   bool handled = false;

   for (int i = handler_stack_->size() - 1; !handled && i >= 0; --i) {

     handled = (*handler_stack_)[i]->HandleSignal(sig, info, uc);

   }

   // Upon returning from this signal handler, sig will become unmasked and then

   // it will be retriggered. If one of the ExceptionHandlers handled it

   // successfully, restore the default handler. Otherwise, restore the

   // previously installed handler. Then, when the signal is retriggered, it will

   // be delivered to the appropriate handler.

   if (handled) {

     signal(sig, SIG_DFL);

   } else {

     RestoreHandlersLocked();

   }

   pthread_mutex_unlock(&handler_stack_mutex_);

   if (info->si_code <= 0) {

     // This signal was sent by another process.  (Positive values of

     // si_code are reserved for kernel-originated signals.)  In order

     // to retrigger it, we have to queue a new signal.

     if (tgkill(getpid(), syscall(__NR_gettid), sig) < 0) {

       // If we failed to kill ourselves (e.g. because a sandbox disallows us

       // to do so), we instead resort to terminating our process. This will

       // result in an incorrect exit code.

       _exit(1);

     }

   } else {

     // This was a synchronous signal triggered by a hard fault (e.g. SIGSEGV).

     // No need to reissue the signal. It will automatically trigger again,

     // when we return from the signal handler.

   }

 }

 struct ThreadArgument {

   pid_t pid;  // the crashing process

   const MinidumpDescriptor* minidump_descriptor;

   ExceptionHandler* handler;

   const void* context;  // a CrashContext structure

   size_t context_size;

 };

 // This is the entry function for the cloned process. We are in a compromised

 // context here: see the top of the file.

 // static

 int ExceptionHandler::ThreadEntry(void *arg) {

   const ThreadArgument *thread_arg = reinterpret_cast<ThreadArgument*>(arg);

   // Block here until the crashing process unblocks us when

   // we're allowed to use ptrace

   thread_arg->handler->WaitForContinueSignal();

   return thread_arg->handler->DoDump(thread_arg->pid, thread_arg->context,

                                      thread_arg->context_size) == false;

 }

 // This function runs in a compromised context: see the top of the file.

 // Runs on the crashing thread.

 bool ExceptionHandler::HandleSignal(int sig, siginfo_t* info, void* uc) {

   if (filter_ && !filter_(callback_context_))

     return false;

   // Allow ourselves to be dumped if the signal is trusted.

   bool signal_trusted = info->si_code > 0;

   bool signal_pid_trusted = info->si_code == SI_USER ||

       info->si_code == SI_TKILL;

   if (signal_trusted || (signal_pid_trusted && info->si_pid == getpid())) {

     sys_prctl(PR_SET_DUMPABLE, 1);

   }

   CrashContext context;

   memcpy(&context.siginfo, info, sizeof(siginfo_t));

   memcpy(&context.context, uc, sizeof(struct ucontext));

 #if !defined(__ARM_EABI__)

   // FP state is not part of user ABI on ARM Linux.

   struct ucontext *uc_ptr = (struct ucontext*)uc;

   if (uc_ptr->uc_mcontext.fpregs) {

     memcpy(&context.float_state,

            uc_ptr->uc_mcontext.fpregs,

            sizeof(context.float_state));

   }

 #endif

   context.tid = syscall(__NR_gettid);

   if (crash_handler_ != NULL) {

     if (crash_handler_(&context, sizeof(context), callback_context_)) {

       return true;

     }

   }

   return GenerateDump(&context);

 }

 // This is a public interface to HandleSignal that allows the client to

 // generate a crash dump. This function may run in a compromised context.

 bool ExceptionHandler::SimulateSignalDelivery(int sig) {

   siginfo_t siginfo = {};

   // Mimic a trusted signal to allow tracing the process (see

   // ExceptionHandler::HandleSignal().

   siginfo.si_code = SI_USER;

   siginfo.si_pid = getpid();

   struct ucontext context;

   getcontext(&context);

   return HandleSignal(sig, &siginfo, &context);

 }

 // This function may run in a compromised context: see the top of the file.

 bool ExceptionHandler::GenerateDump(CrashContext *context) {

   if (IsOutOfProcess())

     return crash_generation_client_->RequestDump(context, sizeof(*context));

   static const unsigned kChildStackSize = 8000;

   PageAllocator allocator;

   uint8_t* stack = (uint8_t*) allocator.Alloc(kChildStackSize);

   if (!stack)

     return false;

   // clone() needs the top-most address. (scrub just to be safe)

   stack += kChildStackSize;

   my_memset(stack - 16, 0, 16);

   ThreadArgument thread_arg;

   thread_arg.handler = this;

   thread_arg.minidump_descriptor = &minidump_descriptor_;

   thread_arg.pid = getpid();

   thread_arg.context = context;

   thread_arg.context_size = sizeof(*context);

   // 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. Create a pipe here which we can use to block the

   // cloned process after creating it, until we have explicitly enabled ptrace

   if(sys_pipe(fdes) == -1) {

     // Creating the pipe failed. We'll log an error but carry on anyway,

     // as we'll probably still get a useful crash report. All that will happen

     // is the write() and read() calls will fail with EBADF

     static const char no_pipe_msg[] = "ExceptionHandler::GenerateDump \

                                        sys_pipe failed:";

     logger::write(no_pipe_msg, sizeof(no_pipe_msg) - 1);

     logger::write(strerror(errno), strlen(strerror(errno)));

     logger::write("\n", 1);

   }

   const pid_t child = sys_clone(

       ThreadEntry, stack, CLONE_FILES | CLONE_FS | CLONE_UNTRACED,

       &thread_arg, NULL, NULL, NULL);

   int r, status;

   // Allow the child to ptrace us

   sys_prctl(PR_SET_PTRACER, child);

   SendContinueSignalToChild();

   do {

     r = sys_waitpid(child, &status, __WALL);

   } while (r == -1 && errno == EINTR);

   sys_close(fdes[0]);

   sys_close(fdes[1]);

   if (r == -1) {

     static const char msg[] = "ExceptionHandler::GenerateDump waitpid failed:";

     logger::write(msg, sizeof(msg) - 1);

     logger::write(strerror(errno), strlen(strerror(errno)));

     logger::write("\n", 1);

   }

   bool success = r != -1 && WIFEXITED(status) && WEXITSTATUS(status) == 0;

   if (callback_)

     success = callback_(minidump_descriptor_, callback_context_, success);

   return success;

 }

 // This function runs in a compromised context: see the top of the file.

 void ExceptionHandler::SendContinueSignalToChild() {

   static const char okToContinueMessage = 'a';

   int r;

   r = HANDLE_EINTR(sys_write(fdes[1], &okToContinueMessage, sizeof(char)));

   if(r == -1) {

     static const char msg[] = "ExceptionHandler::SendContinueSignalToChild \

                                sys_write failed:";

     logger::write(msg, sizeof(msg) - 1);

     logger::write(strerror(errno), strlen(strerror(errno)));

     logger::write("\n", 1);

   }

 }

 // This function runs in a compromised context: see the top of the file.

 // Runs on the cloned process.

 void ExceptionHandler::WaitForContinueSignal() {

   int r;

   char receivedMessage;

   r = HANDLE_EINTR(sys_read(fdes[0], &receivedMessage, sizeof(char)));

   if(r == -1) {

     static const char msg[] = "ExceptionHandler::WaitForContinueSignal \

                                sys_read failed:";

     logger::write(msg, sizeof(msg) - 1);

     logger::write(strerror(errno), strlen(strerror(errno)));

     logger::write("\n", 1);

   }

 }

 // This function runs in a compromised context: see the top of the file.

 // Runs on the cloned process.

 bool ExceptionHandler::DoDump(pid_t crashing_process, const void* context,

                               size_t context_size) {

   if (minidump_descriptor_.IsFD()) {

     return google_breakpad::WriteMinidump(minidump_descriptor_.fd(),

                                           minidump_descriptor_.size_limit(),

                                           crashing_process,

                                           context,

                                           context_size,

                                           mapping_list_,

                                           app_memory_list_);

   }

   return google_breakpad::WriteMinidump(minidump_descriptor_.path(),

                                         minidump_descriptor_.size_limit(),

                                         crashing_process,

                                         context,

                                         context_size,

                                         mapping_list_,

                                         app_memory_list_);

 }

 // static

 bool ExceptionHandler::WriteMinidump(const string& dump_path,

                                      MinidumpCallback callback,

                                      void* callback_context) {

   MinidumpDescriptor descriptor(dump_path);

   ExceptionHandler eh(descriptor, NULL, callback, callback_context, false, -1);

   return eh.WriteMinidump();

 }

 bool ExceptionHandler::WriteMinidump() {

   if (!IsOutOfProcess() && !minidump_descriptor_.IsFD()) {

     // Update the path of the minidump so that this can be called multiple times

     // and new files are created for each minidump.  This is done before the

     // generation happens, as clients may want to access the MinidumpDescriptor

     // after this call to find the exact path to the minidump file.

     minidump_descriptor_.UpdatePath();

   } else if (minidump_descriptor_.IsFD()) {

     // Reposition the FD to its beginning and resize it to get rid of the

     // previous minidump info.

     lseek(minidump_descriptor_.fd(), 0, SEEK_SET);

     static_cast<void>(ftruncate(minidump_descriptor_.fd(), 0));

   }

   // Allow this process to be dumped.

   sys_prctl(PR_SET_DUMPABLE, 1);

   CrashContext context;

   int getcontext_result = getcontext(&context.context);

   if (getcontext_result)

     return false;

 #if !defined(__ARM_EABI__)

   // FPU state is not part of ARM EABI ucontext_t.

   memcpy(&context.float_state, context.context.uc_mcontext.fpregs,

          sizeof(context.float_state));

 #endif

   context.tid = sys_gettid();

   // Add an exception stream to the minidump for better reporting.

   memset(&context.siginfo, 0, sizeof(context.siginfo));

   context.siginfo.si_signo = MD_EXCEPTION_CODE_LIN_DUMP_REQUESTED;

 #if defined(__i386__)

   context.siginfo.si_addr =

       reinterpret_cast<void*>(context.context.uc_mcontext.gregs[REG_EIP]);

 #elif defined(__x86_64__)

   context.siginfo.si_addr =

       reinterpret_cast<void*>(context.context.uc_mcontext.gregs[REG_RIP]);

 #elif defined(__arm__)

   context.siginfo.si_addr =

       reinterpret_cast<void*>(context.context.uc_mcontext.arm_pc);

 #else

 #error "This code has not been ported to your platform yet."

 #endif

   return GenerateDump(&context);

 }

 void ExceptionHandler::AddMappingInfo(const string& name,

                                       const uint8_t identifier[sizeof(MDGUID)],

                                       uintptr_t start_address,

                                       size_t mapping_size,

                                       size_t file_offset) {

   MappingInfo info;

   info.start_addr = start_address;

   info.size = mapping_size;

   info.offset = file_offset;

   strncpy(info.name, name.c_str(), sizeof(info.name) - 1);

   info.name[sizeof(info.name) - 1] = '\0';

   MappingEntry mapping;

   mapping.first = info;

   memcpy(mapping.second, identifier, sizeof(MDGUID));

   mapping_list_.push_back(mapping);

 }

 void ExceptionHandler::RegisterAppMemory(void* ptr, size_t length) {

   AppMemoryList::iterator iter =

     std::find(app_memory_list_.begin(), app_memory_list_.end(), ptr);

   if (iter != app_memory_list_.end()) {

     // Don't allow registering the same pointer twice.

     return;

   }

   AppMemory app_memory;

   app_memory.ptr = ptr;

   app_memory.length = length;

   app_memory_list_.push_back(app_memory);

 }

 void ExceptionHandler::UnregisterAppMemory(void* ptr) {

   AppMemoryList::iterator iter =

     std::find(app_memory_list_.begin(), app_memory_list_.end(), ptr);

   if (iter != app_memory_list_.end()) {

     app_memory_list_.erase(iter);

   }

 }

 // static

 bool ExceptionHandler::WriteMinidumpForChild(pid_t child,

                                              pid_t child_blamed_thread,

                                              const string& dump_path,

                                              MinidumpCallback callback,

                                              void* callback_context) {

   // This function is not run in a compromised context.

   MinidumpDescriptor descriptor(dump_path);

   descriptor.UpdatePath();

   if (!google_breakpad::WriteMinidump(descriptor.path(),

                                       child,

                                       child_blamed_thread))

       return false;

   return callback ? callback(descriptor, callback_context, true) : true;

 }

 }  // namespace google_breakpad