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Diffstat (limited to 'ipc/chromium/src/chrome/common/process_watcher_win.cc')
| -rw-r--r-- | ipc/chromium/src/chrome/common/process_watcher_win.cc | 252 |
1 files changed, 252 insertions, 0 deletions
diff --git a/ipc/chromium/src/chrome/common/process_watcher_win.cc b/ipc/chromium/src/chrome/common/process_watcher_win.cc new file mode 100644 index 0000000000..2e0efbf6a7 --- /dev/null +++ b/ipc/chromium/src/chrome/common/process_watcher_win.cc @@ -0,0 +1,252 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +// Copyright (c) 2006-2008 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 "chrome/common/process_watcher.h" + +#include <algorithm> +#include <processthreadsapi.h> +#include <synchapi.h> +#include "base/message_loop.h" +#include "base/object_watcher.h" +#include "prenv.h" + +// Maximum amount of time (in milliseconds) to wait for the process to exit. +static constexpr int kWaitInterval = 2000; + +// This is somewhat arbitrary, but based on Try run results. When +// changing this, be aware of toolkit.asyncshutdown.crash_timeout +// (currently 60s), after which the parent process will be killed. +#ifdef MOZ_CODE_COVERAGE +// Child processes seem to take longer to shut down on ccov builds, at +// least in the wdspec tests; ~20s has been observed, and we'll spam +// false positives unless this is increased. +static constexpr DWORD kShutdownWaitMs = 80000; +#elif defined(MOZ_ASAN) || defined(MOZ_TSAN) +// Sanitizers also slow things down in some cases; see bug 1806224. +static constexpr DWORD kShutdownWaitMs = 40000; +#else +static constexpr DWORD kShutdownWaitMs = 8000; +#endif + +namespace { + +static bool IsProcessDead(base::ProcessHandle process) { + return WaitForSingleObject(process, 0) == WAIT_OBJECT_0; +} + +class ChildReaper : public mozilla::Runnable, + public base::ObjectWatcher::Delegate, + public MessageLoop::DestructionObserver { + public: + explicit ChildReaper(base::ProcessHandle process, bool force) + : mozilla::Runnable("ChildReaper"), process_(process), force_(force) { + watcher_.StartWatching(process_, this); + } + + virtual ~ChildReaper() { + if (process_) { + KillProcess(); + DCHECK(!process_) << "Make sure to close the handle."; + } + } + + // MessageLoop::DestructionObserver ----------------------------------------- + + virtual void WillDestroyCurrentMessageLoop() { + MOZ_ASSERT(!force_); + if (process_) { + // Exception for the fake hang tests in ipc/glue/test/browser + if (!PR_GetEnv("MOZ_TEST_CHILD_EXIT_HANG")) { + CrashProcessIfHanging(); + } + WaitForSingleObject(process_, INFINITE); + base::CloseProcessHandle(process_); + process_ = 0; + + MessageLoop::current()->RemoveDestructionObserver(this); + delete this; + } + } + + // Task --------------------------------------------------------------------- + + NS_IMETHOD Run() override { + MOZ_ASSERT(force_); + if (process_) { + KillProcess(); + } + return NS_OK; + } + + // MessageLoop::Watcher ----------------------------------------------------- + + virtual void OnObjectSignaled(HANDLE object) { + // When we're called from KillProcess, the ObjectWatcher may still be + // watching. the process handle, so make sure it has stopped. + watcher_.StopWatching(); + + base::CloseProcessHandle(process_); + process_ = 0; + + if (!force_) { + MessageLoop::current()->RemoveDestructionObserver(this); + delete this; + } + } + + private: + void KillProcess() { + MOZ_ASSERT(force_); + + // OK, time to get frisky. We don't actually care when the process + // terminates. We just care that it eventually terminates, and that's what + // TerminateProcess should do for us. Don't check for the result code since + // it fails quite often. This should be investigated eventually. + TerminateProcess(process_, base::PROCESS_END_PROCESS_WAS_HUNG); + + // Now, just cleanup as if the process exited normally. + OnObjectSignaled(process_); + } + + void CrashProcessIfHanging() { + if (IsProcessDead(process_)) { + return; + } + DWORD pid = GetProcessId(process_); + DCHECK(pid != 0); + + // If child processes seems to be hanging on shutdown, wait for a + // reasonable time. The wait is global instead of per-process + // because the child processes should be shutting down in + // parallel, and also we're potentially racing global timeouts + // like nsTerminator. (The counter doesn't need to be atomic; + // this is always called on the I/O thread.) + static DWORD sWaitMs = kShutdownWaitMs; + if (sWaitMs > 0) { + CHROMIUM_LOG(WARNING) + << "Process " << pid + << " may be hanging at shutdown; will wait for up to " << sWaitMs + << "ms"; + } + const auto beforeWait = mozilla::TimeStamp::NowLoRes(); + const DWORD waitStatus = WaitForSingleObject(process_, sWaitMs); + + const double elapsed = + (mozilla::TimeStamp::NowLoRes() - beforeWait).ToMilliseconds(); + sWaitMs -= static_cast<DWORD>( + std::clamp(elapsed, 0.0, static_cast<double>(sWaitMs))); + + switch (waitStatus) { + case WAIT_TIMEOUT: + // The process is still running. + break; + case WAIT_OBJECT_0: + // The process exited. + return; + case WAIT_FAILED: + CHROMIUM_LOG(ERROR) << "Waiting for process " << pid + << " failed; error " << GetLastError(); + DCHECK(false) << "WaitForSingleObject failed"; + // Process status unclear; assume it's gone. + return; + default: + DCHECK(false) << "WaitForSingleObject returned " << waitStatus; + // Again, not clear what's happening so avoid touching the process + return; + } + + // We want TreeHerder to flag this log line as an error, so that + // this is more obviously a deliberate crash; "fatal error" is one + // of the strings it looks for. + CHROMIUM_LOG(ERROR) + << "Process " << pid + << " hanging at shutdown; attempting crash report (fatal error)"; + + // We're going to use CreateRemoteThread to call DbgBreakPoint in + // the target process; it's in a "known DLL" so it should be at + // the same address in all processes. (Normal libraries, like + // xul.dll, are usually at the same address but can be relocated + // in case of conflict.) + // + // DbgBreakPoint doesn't take an argument, so we can give it an + // arbitrary value to make it easier to identify these crash + // reports. (reinterpret_cast isn't constexpr, so this is + // declared as an integer and cast to the required type later.) + // The primary use case for all of this is in CI, where we'll also + // have log messages, but if these crashes end up in Socorro in + // significant numbers then we'll be able to look for this value. + static constexpr uint64_t kIpcMagic = 0x43504900435049; + + const HMODULE ntdll = GetModuleHandleW(L"ntdll.dll"); + if (!ntdll) { + CHROMIUM_LOG(ERROR) << "couldn't find ntdll.dll: error " + << GetLastError(); + return; + } + const auto dbgBreak = reinterpret_cast<LPTHREAD_START_ROUTINE>( + GetProcAddress(ntdll, "DbgBreakPoint")); + if (!dbgBreak) { + CHROMIUM_LOG(ERROR) << "couldn't find DbgBreakPoint: error " + << GetLastError(); + return; + } + + const DWORD rights = PROCESS_CREATE_THREAD | PROCESS_QUERY_INFORMATION | + PROCESS_VM_OPERATION | PROCESS_VM_WRITE | + PROCESS_VM_READ; + HANDLE process_priv = nullptr; + if (!DuplicateHandle(GetCurrentProcess(), process_, GetCurrentProcess(), + &process_priv, rights, /* inherit */ FALSE, + /* options */ 0)) { + const auto error = GetLastError(); + CHROMIUM_LOG(ERROR) << "OpenProcess: error " << error; + } else { + DCHECK(process_priv); + HANDLE thread = + CreateRemoteThread(process_priv, /* sec attr */ nullptr, + /* stack */ 0, dbgBreak, (LPVOID)kIpcMagic, + /* flags */ 0, nullptr); + if (!thread) { + const auto error = GetLastError(); + CHROMIUM_LOG(ERROR) << "CreateRemoteThread: error " << error; + } else { + CloseHandle(thread); + } + CloseHandle(process_priv); + } + } + + // The process that we are watching. + base::ProcessHandle process_; + + base::ObjectWatcher watcher_; + + bool force_; + + DISALLOW_EVIL_CONSTRUCTORS(ChildReaper); +}; + +} // namespace + +// static +void ProcessWatcher::EnsureProcessTerminated(base::ProcessHandle process, + bool force) { + DCHECK(process != GetCurrentProcess()); + + // If already signaled, then we are done! + if (IsProcessDead(process)) { + base::CloseProcessHandle(process); + return; + } + + MessageLoopForIO* loop = MessageLoopForIO::current(); + if (force) { + RefPtr<mozilla::Runnable> task = new ChildReaper(process, force); + loop->PostDelayedTask(task.forget(), kWaitInterval); + } else { + loop->AddDestructionObserver(new ChildReaper(process, force)); + } +} |