6 files changed, 130 insertions, 0 deletions
diff --git a/components/nacl/loader/nacl_helper_linux.cc b/components/nacl/loader/nacl_helper_linux.cc
index 68d0ff6..1fbfdad 100644
--- a/components/nacl/loader/nacl_helper_linux.cc
+++ b/components/nacl/loader/nacl_helper_linux.cc
@@ -32,6 +32,7 @@
 #include "base/rand_util.h"
 #include "components/nacl/common/nacl_switches.h"
 #include "components/nacl/loader/nacl_listener.h"
+#include "components/nacl/loader/nonsfi/irt_exception_handling.h"
 #include "components/nacl/loader/sandbox_linux/nacl_sandbox_linux.h"
 #include "content/public/common/content_descriptors.h"
 #include "content/public/common/zygote_fork_delegate_linux.h"
@@ -82,6 +83,9 @@ void BecomeNaClLoader(const std::vector<int>& child_fds,
         base::GlobalDescriptors::kBaseDescriptor + kSandboxIPCChannel;
 
     ReplaceFDWithDummy(sandbox_ipc_channel);
+
+    // Install crash signal handlers before disallowing system calls.
+    nacl::nonsfi::InitializeSignalHandler();
   }
 
   // Finish layer-1 sandbox initialization and initialize the layer-2 sandbox.
diff --git a/components/nacl/loader/nonsfi/DEPS b/components/nacl/loader/nonsfi/DEPS
index 18f97f5..6052a40 100644
--- a/components/nacl/loader/nonsfi/DEPS
+++ b/components/nacl/loader/nonsfi/DEPS
@@ -1,4 +1,6 @@
 include_rules = [
   "+ppapi/nacl_irt",
   "+sandbox/linux/seccomp-bpf-helpers",
+  "+native_client/src/trusted/service_runtime/nacl_exception.h",
+  "+native_client/src/trusted/service_runtime/nacl_signal.h",
 ]
diff --git a/components/nacl/loader/nonsfi/irt_exception_handling.cc b/components/nacl/loader/nonsfi/irt_exception_handling.cc
new file mode 100644
index 0000000..c6bd26f
--- /dev/null
+++ b/components/nacl/loader/nonsfi/irt_exception_handling.cc
@@ -0,0 +1,106 @@
+// Copyright 2014 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 <errno.h>
+#include <pthread.h>
+#include <signal.h>
+
+#include "components/nacl/loader/nonsfi/irt_interfaces.h"
+#include "native_client/src/include/nacl_macros.h"
+#include "native_client/src/trusted/service_runtime/nacl_exception.h"
+#include "native_client/src/trusted/service_runtime/nacl_signal.h"
+
+namespace nacl {
+namespace nonsfi {
+namespace {
+
+// This is NonSFI version of exception handling codebase, NaCl side of
+// things resides in:
+// native_client/src/trusted/service_runtime/linux/nacl_signal.c
+// native_client/src/trusted/service_runtime/sys_exception.c
+
+// Crash signals to handle.  The differences from SFI NaCl are that
+// NonSFI NaCl does not use NACL_THREAD_SUSPEND_SIGNAL (==SIGUSR1),
+// and SIGSYS is reserved for seccomp-bpf.
+const int kSignals[] = {
+  SIGSTKFLT,
+  SIGINT, SIGQUIT, SIGILL, SIGTRAP, SIGBUS, SIGFPE, SIGSEGV,
+  // Handle SIGABRT in case someone sends it asynchronously using kill().
+  SIGABRT
+};
+
+pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
+NaClExceptionHandler signal_handler_function_pointer = NULL;
+
+// Signal handler, responsible for calling the registered handler.
+void SignalCatch(int sig, siginfo_t* info, void* uc) {
+  if (signal_handler_function_pointer) {
+    NaClSignalContext signal_context;
+    NaClSignalContextFromHandler(&signal_context, uc);
+    NaClExceptionFrame exception_frame;
+    NaClSignalSetUpExceptionFrame(&exception_frame,
+                                  &signal_context,
+                                  0 /* context_user_addr,
+                                       not useful for NonSFI NaCl. */);
+    signal_handler_function_pointer(&exception_frame.context);
+  }
+  _exit(-1);
+}
+
+int IrtExceptionHandler(NaClExceptionHandler handler,
+                               NaClExceptionHandler* old_handler) {
+  pthread_mutex_lock(&mutex);
+  if (old_handler)
+    *old_handler = signal_handler_function_pointer;
+  signal_handler_function_pointer = handler;
+  pthread_mutex_unlock(&mutex);
+  return 0;
+}
+
+int IrtExceptionStack(void* stack, size_t size) {
+  // TODO(uekawa): Implement this function so that the exception stack
+  // actually gets used for running an exception handler.  Currently
+  // we don't switch stack, which means we can't handle stack overflow
+  // exceptions.
+  return 0;
+}
+
+int IrtExceptionClearFlag(void) {
+  // TODO(uekawa): Implement clear_flag() to behave like SFI NaCl's
+  // implementation, so that a thread can handle a second exception
+  // after handling a first exception
+  return ENOSYS;
+}
+
+}  // namespace
+
+const struct nacl_irt_exception_handling kIrtExceptionHandling = {
+  IrtExceptionHandler,
+  IrtExceptionStack,
+  IrtExceptionClearFlag,
+};
+
+void InitializeSignalHandler() {
+  struct sigaction sa;
+  unsigned int a;
+
+  memset(&sa, 0, sizeof(sa));
+  sigemptyset(&sa.sa_mask);
+  sa.sa_sigaction = SignalCatch;
+  sa.sa_flags = SA_ONSTACK | SA_SIGINFO;
+
+  // Mask all signals we catch to prevent re-entry.
+  for (a = 0; a < NACL_ARRAY_SIZE(kSignals); a++) {
+    sigaddset(&sa.sa_mask, kSignals[a]);
+  }
+
+  // Install all handlers.
+  for (a = 0; a < NACL_ARRAY_SIZE(kSignals); a++) {
+    if (sigaction(kSignals[a], &sa, NULL) != 0)
+      NaClLog(LOG_FATAL, "sigaction to register signals failed.\n");
+  }
+}
+
+}  // namespace nonsfi
+}  // namespace nacl
diff --git a/components/nacl/loader/nonsfi/irt_exception_handling.h b/components/nacl/loader/nonsfi/irt_exception_handling.h
new file mode 100644
index 0000000..b6aafbd
--- /dev/null
+++ b/components/nacl/loader/nonsfi/irt_exception_handling.h
@@ -0,0 +1,16 @@
+// Copyright 2014 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.
+
+#ifndef COMPONENTS_NACL_LOADER_NONSFI_IRT_EXCEPTION_HANDLING_H_
+#define COMPONENTS_NACL_LOADER_NONSFI_IRT_EXCEPTION_HANDLING_H_
+
+namespace nacl {
+namespace nonsfi {
+
+void InitializeSignalHandler();
+
+}  // namespace nonsfi
+}  // namespace nacl
+
+#endif  // COMPONENTS_NACL_LOADER_NONSFI_IRT_EXCEPTION_HANDLING_H_
diff --git a/components/nacl/loader/nonsfi/irt_interfaces.cc b/components/nacl/loader/nonsfi/irt_interfaces.cc
index a8d3285..79bb8f5 100644
--- a/components/nacl/loader/nonsfi/irt_interfaces.cc
+++ b/components/nacl/loader/nonsfi/irt_interfaces.cc
@@ -31,6 +31,7 @@ const NaClInterfaceTable kIrtInterfaces[] = {
   NACL_INTERFACE_TABLE(NACL_IRT_CLOCK_v0_1, kIrtClock),
   NACL_INTERFACE_TABLE(NACL_IRT_PPAPIHOOK_v0_1, kIrtPpapiHook),
   NACL_INTERFACE_TABLE(NACL_IRT_RANDOM_v0_1, kIrtRandom),
+  NACL_INTERFACE_TABLE(NACL_IRT_EXCEPTION_HANDLING_v0_1, kIrtExceptionHandling),
 };
 #undef NACL_INTERFACE_TABLE
 
diff --git a/components/nacl/loader/nonsfi/irt_interfaces.h b/components/nacl/loader/nonsfi/irt_interfaces.h
index fae2d2d..6d723e6 100644
--- a/components/nacl/loader/nonsfi/irt_interfaces.h
+++ b/components/nacl/loader/nonsfi/irt_interfaces.h
@@ -24,6 +24,7 @@ extern const struct nacl_irt_tls kIrtTls;
 extern const struct nacl_irt_clock kIrtClock;
 extern const struct nacl_irt_ppapihook kIrtPpapiHook;
 extern const struct nacl_irt_random kIrtRandom;
+extern const struct nacl_irt_exception_handling kIrtExceptionHandling;
 
 }  // namespace nonsfi
 }  // namespace nacl