Add sandbox support for AsanCoverage.

content/common/sandbox_linux/sandbox_linux.cc

 // Copyright (c) 2012 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 <dirent.h>
 #include <fcntl.h>
 #include <sys/resource.h>
 #include <sys/stat.h>
 #include <sys/time.h>
 #include <sys/types.h>
@@ skipping 16 matching lines @@
 #include "build/build_config.h"
 #include "content/common/sandbox_linux/sandbox_linux.h"
 #include "content/common/sandbox_linux/sandbox_seccomp_bpf_linux.h"
 #include "content/public/common/content_switches.h"
 #include "content/public/common/sandbox_linux.h"
 #include "sandbox/linux/services/credentials.h"
 #include "sandbox/linux/services/thread_helpers.h"
 #include "sandbox/linux/services/yama.h"
 #include "sandbox/linux/suid/client/setuid_sandbox_client.h"
 
+#if defined(ADDRESS_SANITIZER) || defined(MEMORY_SANITIZER) || \
+     defined(LEAK_SANITIZER)
+#include <sanitizer/common_interface_defs.h>
+#endif
+
 using sandbox::Yama;
 
 namespace {
 
 struct FDCloser {
   inline void operator()(int* fd) const {
     DCHECK(fd);
     PCHECK(0 == IGNORE_EINTR(close(*fd)));
     *fd = -1;
   }
@@ skipping 55 matching lines @@
 
 namespace content {
 
 LinuxSandbox::LinuxSandbox()
     : proc_fd_(-1),
       seccomp_bpf_started_(false),
       sandbox_status_flags_(kSandboxLinuxInvalid),
       pre_initialized_(false),
       seccomp_bpf_supported_(false),
       yama_is_enforcing_(false),
-      setuid_sandbox_client_(sandbox::SetuidSandboxClient::Create()) {
+      setuid_sandbox_client_(sandbox::SetuidSandboxClient::Create())
+#if defined(ADDRESS_SANITIZER) || defined(MEMORY_SANITIZER) || \
+    defined(LEAK_SANITIZER)
+      , sanitizer_args_(new __sanitizer_sandbox_arguments)
+#endif

[jln (very slow on Chromium), 2014/05/14 17:49:41]

Maybe just put it below in the body of the constructor rather than in the
initializer list then?

[earthdok, 2014/05/20 16:53:57]

Done.

+{
   if (setuid_sandbox_client_ == NULL) {
     LOG(FATAL) << "Failed to instantiate the setuid sandbox client.";
   }
+#if defined(ADDRESS_SANITIZER) || defined(MEMORY_SANITIZER) || \
+    defined(LEAK_SANITIZER)
+  *sanitizer_args_ = {0};
+#endif
 }
 
 LinuxSandbox::~LinuxSandbox() {
 }
 
 LinuxSandbox* LinuxSandbox::GetInstance() {
   LinuxSandbox* instance = Singleton<LinuxSandbox>::get();
   CHECK(instance);
   return instance;
 }
 
-#if (defined(ADDRESS_SANITIZER) || defined(MEMORY_SANITIZER) || \
-     defined(LEAK_SANITIZER))  && defined(OS_LINUX)
-// Sanitizer API call to notify the tool the sandbox is going to be turned on.
-extern "C" void __sanitizer_sandbox_on_notify(void *reserved);
-#endif
-
 void LinuxSandbox::PreinitializeSandbox() {
   CHECK(!pre_initialized_);
   seccomp_bpf_supported_ = false;
-#if (defined(ADDRESS_SANITIZER) || defined(MEMORY_SANITIZER) || \
-     defined(LEAK_SANITIZER))  && defined(OS_LINUX)
+#if defined(ADDRESS_SANITIZER) || defined(MEMORY_SANITIZER) || \
+     defined(LEAK_SANITIZER)
   // Sanitizers need to open some resources before the sandbox is enabled.
   // This should not fork, not launch threads, not open a directory.
-  __sanitizer_sandbox_on_notify(/*reserved*/ NULL);
+  __sanitizer_sandbox_on_notify(sanitizer_args());

[jln (very slow on Chromium), 2014/05/14 17:49:41]

Before the process exits, when the LinuxSandbox singleton gets destroyed, what
happens if we delete the sanitizer_args?

I would think that this needs to survive for the lifetime of the process, no? In
that case I would .release() here to pass ownership (and *SAN itself can "leak"
it, i.e. pass ownership to the kernel to bind it to the process' life time).

[earthdok, 2014/05/14 19:21:47]

In the current implementation, the structure is only read once, in
__sanitizer_sandbox_on_notify(). We don't care about it after we leave that
function.

[jln (very slow on Chromium), 2014/05/14 23:26:30]

Ok. Let's have a GetSanitizerArgs() that .Pass() the scoped ptr then. And let's
.reset() it after it's passed to __sanitizer_sandbox_on_notify().

This will serve as documentation of how ownership of the pointer works and also
guard against any future use of that pointer by mistake.

[jln (very slow on Chromium), 2014/05/14 23:27:41]

err, no need to .reset() manually, it will happen automatically once this
function returns.

[earthdok, 2014/05/20 16:53:57]

Making this accessor .Pass() the pointer is incorrect if we want to keep using
it to set structure members in ZygoteMain() and gpu::StartSandboxLinux().

I've added a reset() call.

 #endif
 
 #if !defined(NDEBUG)
   // The in-process stack dumping needs to open /proc/self/maps and cache
   // its contents before the sandbox is enabled.  It also pre-opens the
   // object files that are already loaded in the process address space.
   base::debug::EnableInProcessStackDumpingForSandbox();
 
   // Open proc_fd_ only in Debug mode so that forgetting to close it doesn't
   // produce a sandbox escape in Release mode.
@@ skipping 253 matching lines @@
 
 void LinuxSandbox::StopThreadAndEnsureNotCounted(base::Thread* thread) const {
   DCHECK(thread);
   base::ScopedFD proc_self_task(OpenProcTaskFd(proc_fd_));
   PCHECK(proc_self_task.is_valid());
   CHECK(sandbox::ThreadHelpers::StopThreadAndWatchProcFS(proc_self_task.get(),
                                                          thread));
 }
 
 }  // namespace content