michael@0: /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
michael@0: /* vim:set ts=4 sw=4 sts=4 ci et: */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #include <algorithm>
michael@0: 
michael@0: #include "mozilla/IOInterposer.h"
michael@0: #include "mozilla/PoisonIOInterposer.h"
michael@0: #include "mozilla/ProcessedStack.h"
michael@0: #include "mozilla/SHA1.h"
michael@0: #include "mozilla/Scoped.h"
michael@0: #include "mozilla/StaticPtr.h"
michael@0: #include "mozilla/Telemetry.h"
michael@0: #include "nsAppDirectoryServiceDefs.h"
michael@0: #include "nsDirectoryServiceUtils.h"
michael@0: #include "nsPrintfCString.h"
michael@0: #include "nsStackWalk.h"
michael@0: #include "plstr.h"
michael@0: 
michael@0: #ifdef XP_WIN
michael@0: #define NS_T(str) L ## str
michael@0: #define NS_SLASH "\\"
michael@0: #include <fcntl.h>
michael@0: #include <io.h>
michael@0: #include <stdio.h>
michael@0: #include <stdlib.h>
michael@0: #include <sys/stat.h>
michael@0: #include <windows.h>
michael@0: #else
michael@0: #define NS_SLASH "/"
michael@0: #endif
michael@0: 
michael@0: #include "LateWriteChecks.h"
michael@0: 
michael@0: #if !defined(XP_WIN) || (!defined(MOZ_OPTIMIZE) || defined(MOZ_PROFILING) || defined(DEBUG))
michael@0: #define OBSERVE_LATE_WRITES
michael@0: #endif
michael@0: 
michael@0: using namespace mozilla;
michael@0: 
michael@0: /*************************** Auxiliary Declarations ***************************/
michael@0: 
michael@0: // This a wrapper over a file descriptor that provides a Printf method and
michael@0: // computes the sha1 of the data that passes through it.
michael@0: class SHA1Stream
michael@0: {
michael@0: public:
michael@0:     explicit SHA1Stream(FILE *stream)
michael@0:       : mFile(stream)
michael@0:     {
michael@0:       MozillaRegisterDebugFILE(mFile);
michael@0:     }
michael@0: 
michael@0:     void Printf(const char *aFormat, ...)
michael@0:     {
michael@0:         MOZ_ASSERT(mFile);
michael@0:         va_list list;
michael@0:         va_start(list, aFormat);
michael@0:         nsAutoCString str;
michael@0:         str.AppendPrintf(aFormat, list);
michael@0:         va_end(list);
michael@0:         mSHA1.update(str.get(), str.Length());
michael@0:         fwrite(str.get(), 1, str.Length(), mFile);
michael@0:     }
michael@0:     void Finish(SHA1Sum::Hash &aHash)
michael@0:     {
michael@0:         int fd = fileno(mFile);
michael@0:         fflush(mFile);
michael@0:         MozillaUnRegisterDebugFD(fd);
michael@0:         fclose(mFile);
michael@0:         mSHA1.finish(aHash);
michael@0:         mFile = nullptr;
michael@0:     }
michael@0: private:
michael@0:     FILE *mFile;
michael@0:     SHA1Sum mSHA1;
michael@0: };
michael@0: 
michael@0: static void RecordStackWalker(void *aPC, void *aSP, void *aClosure)
michael@0: {
michael@0:     std::vector<uintptr_t> *stack =
michael@0:         static_cast<std::vector<uintptr_t>*>(aClosure);
michael@0:     stack->push_back(reinterpret_cast<uintptr_t>(aPC));
michael@0: }
michael@0: 
michael@0: /**************************** Late-Write Observer  ****************************/
michael@0: 
michael@0: /**
michael@0:  * An implementation of IOInterposeObserver to be registered with IOInterposer.
michael@0:  * This observer logs all writes as late writes.
michael@0:  */
michael@0: class LateWriteObserver MOZ_FINAL : public IOInterposeObserver
michael@0: {
michael@0: public:
michael@0:   LateWriteObserver(const char* aProfileDirectory)
michael@0:     : mProfileDirectory(PL_strdup(aProfileDirectory))
michael@0:   {
michael@0:   }
michael@0:   ~LateWriteObserver() {
michael@0:     PL_strfree(mProfileDirectory);
michael@0:     mProfileDirectory = nullptr;
michael@0:   }
michael@0: 
michael@0:   void Observe(IOInterposeObserver::Observation& aObservation);
michael@0: private:
michael@0:   char* mProfileDirectory;
michael@0: };
michael@0: 
michael@0: void LateWriteObserver::Observe(IOInterposeObserver::Observation& aOb)
michael@0: {
michael@0: #ifdef OBSERVE_LATE_WRITES
michael@0:   // Crash if that is the shutdown check mode
michael@0:   if (gShutdownChecks == SCM_CRASH) {
michael@0:     MOZ_CRASH();
michael@0:   }
michael@0: 
michael@0:   // If we have shutdown mode SCM_NOTHING or we can't record then abort
michael@0:   if (gShutdownChecks == SCM_NOTHING || !Telemetry::CanRecord()) {
michael@0:     return;
michael@0:   }
michael@0: 
michael@0:   // Write the stack and loaded libraries to a file. We can get here
michael@0:   // concurrently from many writes, so we use multiple temporary files.
michael@0:   std::vector<uintptr_t> rawStack;
michael@0: 
michael@0:   NS_StackWalk(RecordStackWalker, /* skipFrames */ 0, /* maxFrames */ 0,
michael@0:                reinterpret_cast<void*>(&rawStack), 0, nullptr);
michael@0:   Telemetry::ProcessedStack stack = Telemetry::GetStackAndModules(rawStack);
michael@0: 
michael@0:   nsPrintfCString nameAux("%s%s%s", mProfileDirectory,
michael@0:                           NS_SLASH, "Telemetry.LateWriteTmpXXXXXX");
michael@0:   char *name;
michael@0:   nameAux.GetMutableData(&name);
michael@0: 
michael@0:   // We want the sha1 of the entire file, so please don't write to fd
michael@0:   // directly; use sha1Stream.
michael@0:   FILE *stream;
michael@0: #ifdef XP_WIN
michael@0:   HANDLE hFile;
michael@0:   do {
michael@0:     // mkstemp isn't supported so keep trying until we get a file
michael@0:     int result = _mktemp_s(name, strlen(name) + 1);
michael@0:     hFile = CreateFileA(name, GENERIC_WRITE, 0, nullptr, CREATE_NEW,
michael@0:                         FILE_ATTRIBUTE_NORMAL, nullptr);
michael@0:   } while (GetLastError() == ERROR_FILE_EXISTS);
michael@0: 
michael@0:   if (hFile == INVALID_HANDLE_VALUE) {
michael@0:     NS_RUNTIMEABORT("Um, how did we get here?");
michael@0:   }
michael@0: 
michael@0:   // http://support.microsoft.com/kb/139640
michael@0:   int fd = _open_osfhandle((intptr_t)hFile, _O_APPEND);
michael@0:   if (fd == -1) {
michael@0:     NS_RUNTIMEABORT("Um, how did we get here?");
michael@0:   }
michael@0: 
michael@0:   stream = _fdopen(fd, "w");
michael@0: #else
michael@0:   int fd = mkstemp(name);
michael@0:   stream = fdopen(fd, "w");
michael@0: #endif
michael@0: 
michael@0:   SHA1Stream sha1Stream(stream);
michael@0: 
michael@0:   size_t numModules = stack.GetNumModules();
michael@0:   sha1Stream.Printf("%u\n", (unsigned)numModules);
michael@0:   for (size_t i = 0; i < numModules; ++i) {
michael@0:     Telemetry::ProcessedStack::Module module = stack.GetModule(i);
michael@0:     sha1Stream.Printf("%s %s\n", module.mBreakpadId.c_str(),
michael@0:                       module.mName.c_str());
michael@0:   }
michael@0: 
michael@0:   size_t numFrames = stack.GetStackSize();
michael@0:   sha1Stream.Printf("%u\n", (unsigned)numFrames);
michael@0:   for (size_t i = 0; i < numFrames; ++i) {
michael@0:     const Telemetry::ProcessedStack::Frame &frame =
michael@0:         stack.GetFrame(i);
michael@0:     // NOTE: We write the offsets, while the atos tool expects a value with
michael@0:     // the virtual address added. For example, running otool -l on the the firefox
michael@0:     // binary shows
michael@0:     //      cmd LC_SEGMENT_64
michael@0:     //      cmdsize 632
michael@0:     //      segname __TEXT
michael@0:     //      vmaddr 0x0000000100000000
michael@0:     // so to print the line matching the offset 123 one has to run
michael@0:     // atos -o firefox 0x100000123.
michael@0:     sha1Stream.Printf("%d %x\n", frame.mModIndex, (unsigned)frame.mOffset);
michael@0:   }
michael@0: 
michael@0:   SHA1Sum::Hash sha1;
michael@0:   sha1Stream.Finish(sha1);
michael@0: 
michael@0:   // Note: These files should be deleted by telemetry once it reads them. If
michael@0:   // there were no telemetry runs by the time we shut down, we just add files
michael@0:   // to the existing ones instead of replacing them. Given that each of these
michael@0:   // files is a bug to be fixed, that is probably the right thing to do.
michael@0: 
michael@0:   // We append the sha1 of the contents to the file name. This provides a simple
michael@0:   // client side deduplication.
michael@0:   nsPrintfCString finalName("%s%s", mProfileDirectory,
michael@0:                             "/Telemetry.LateWriteFinal-");
michael@0:   for (int i = 0; i < 20; ++i) {
michael@0:     finalName.AppendPrintf("%02x", sha1[i]);
michael@0:   }
michael@0:   PR_Delete(finalName.get());
michael@0:   PR_Rename(name, finalName.get());
michael@0: #endif
michael@0: }
michael@0: 
michael@0: /******************************* Setup/Teardown *******************************/
michael@0: 
michael@0: static StaticAutoPtr<LateWriteObserver> sLateWriteObserver;
michael@0: 
michael@0: namespace mozilla{
michael@0: 
michael@0: void InitLateWriteChecks()
michael@0: {
michael@0:   nsCOMPtr<nsIFile> mozFile;
michael@0:   NS_GetSpecialDirectory(NS_APP_USER_PROFILE_50_DIR, getter_AddRefs(mozFile));
michael@0:   if (mozFile) {
michael@0:     nsAutoCString nativePath;
michael@0:     nsresult rv = mozFile->GetNativePath(nativePath);
michael@0:     if (NS_SUCCEEDED(rv) && nativePath.get()) {
michael@0:       sLateWriteObserver = new LateWriteObserver(nativePath.get());
michael@0:     }
michael@0:   }
michael@0: }
michael@0: 
michael@0: void BeginLateWriteChecks()
michael@0: {
michael@0:   if (sLateWriteObserver) {
michael@0:     IOInterposer::Register(
michael@0:       IOInterposeObserver::OpWriteFSync,
michael@0:       sLateWriteObserver
michael@0:     );
michael@0:   }
michael@0: }
michael@0: 
michael@0: void StopLateWriteChecks()
michael@0: {
michael@0:   if (sLateWriteObserver) {
michael@0:     IOInterposer::Unregister(
michael@0:       IOInterposeObserver::OpAll,
michael@0:       sLateWriteObserver
michael@0:     );
michael@0:     // Deallocation would not be thread-safe, and StopLateWriteChecks() is
michael@0:     // called at shutdown and only in special cases.
michael@0:     // sLateWriteObserver = nullptr;
michael@0:   }
michael@0: }
michael@0: 
michael@0: } // namespace mozilla