michael@0: /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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 <windows.h>
michael@0: #include <tlhelp32.h>
michael@0: #include <dbghelp.h>
michael@0: #include <sstream>
michael@0: 
michael@0: #include "shared-libraries.h"
michael@0: #include "nsWindowsHelpers.h"
michael@0: 
michael@0: #define CV_SIGNATURE 0x53445352 // 'SDSR'
michael@0: 
michael@0: struct CodeViewRecord70
michael@0: {
michael@0:   uint32_t signature;
michael@0:   GUID pdbSignature;
michael@0:   uint32_t pdbAge;
michael@0:   char pdbFileName[1];
michael@0: };
michael@0: 
michael@0: static bool GetPdbInfo(uintptr_t aStart, nsID& aSignature, uint32_t& aAge, char** aPdbName)
michael@0: {
michael@0:   if (!aStart) {
michael@0:     return false;
michael@0:   }
michael@0: 
michael@0:   PIMAGE_DOS_HEADER dosHeader = reinterpret_cast<PIMAGE_DOS_HEADER>(aStart);
michael@0:   if (dosHeader->e_magic != IMAGE_DOS_SIGNATURE) {
michael@0:     return false;
michael@0:   }
michael@0: 
michael@0:   PIMAGE_NT_HEADERS ntHeaders = reinterpret_cast<PIMAGE_NT_HEADERS>(
michael@0:       aStart + dosHeader->e_lfanew);
michael@0:   if (ntHeaders->Signature != IMAGE_NT_SIGNATURE) {
michael@0:     return false;
michael@0:   }
michael@0: 
michael@0:   uint32_t relativeVirtualAddress =
michael@0:     ntHeaders->OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_DEBUG].VirtualAddress;
michael@0:   if (!relativeVirtualAddress) {
michael@0:     return false;
michael@0:   }
michael@0: 
michael@0:   PIMAGE_DEBUG_DIRECTORY debugDirectory =
michael@0:     reinterpret_cast<PIMAGE_DEBUG_DIRECTORY>(aStart + relativeVirtualAddress);
michael@0:   if (!debugDirectory || debugDirectory->Type != IMAGE_DEBUG_TYPE_CODEVIEW) {
michael@0:     return false;
michael@0:   }
michael@0: 
michael@0:   CodeViewRecord70 *debugInfo = reinterpret_cast<CodeViewRecord70 *>(
michael@0:       aStart + debugDirectory->AddressOfRawData);
michael@0:   if (!debugInfo || debugInfo->signature != CV_SIGNATURE) {
michael@0:     return false;
michael@0:   }
michael@0: 
michael@0:   aAge = debugInfo->pdbAge;
michael@0:   GUID& pdbSignature = debugInfo->pdbSignature;
michael@0:   aSignature.m0 = pdbSignature.Data1;
michael@0:   aSignature.m1 = pdbSignature.Data2;
michael@0:   aSignature.m2 = pdbSignature.Data3;
michael@0:   memcpy(aSignature.m3, pdbSignature.Data4, sizeof(pdbSignature.Data4));
michael@0: 
michael@0:   // The PDB file name could be different from module filename, so report both
michael@0:   // e.g. The PDB for C:\Windows\SysWOW64\ntdll.dll is wntdll.pdb
michael@0:   char * leafName = strrchr(debugInfo->pdbFileName, '\\');
michael@0:   if (leafName) {
michael@0:     // Only report the file portion of the path
michael@0:     *aPdbName = leafName + 1;
michael@0:   } else {
michael@0:     *aPdbName = debugInfo->pdbFileName;
michael@0:   }
michael@0: 
michael@0:   return true;
michael@0: }
michael@0: 
michael@0: static bool IsDashOrBraces(char c)
michael@0: {
michael@0:   return c == '-' || c == '{' || c == '}';
michael@0: }
michael@0: 
michael@0: SharedLibraryInfo SharedLibraryInfo::GetInfoForSelf()
michael@0: {
michael@0:   SharedLibraryInfo sharedLibraryInfo;
michael@0: 
michael@0:   nsAutoHandle snap(CreateToolhelp32Snapshot(TH32CS_SNAPMODULE, GetCurrentProcessId()));
michael@0: 
michael@0:   MODULEENTRY32 module = {0};
michael@0:   module.dwSize = sizeof(MODULEENTRY32);
michael@0:   if (Module32First(snap, &module)) {
michael@0:     do {
michael@0:       nsID pdbSig;
michael@0:       uint32_t pdbAge;
michael@0:       char *pdbName = NULL;
michael@0: 
michael@0:       // Load the module again to make sure that its handle will remain remain
michael@0:       // valid as we attempt to read the PDB information from it.  We load the
michael@0:       // DLL as a datafile so that if the module actually gets unloaded between
michael@0:       // the call to Module32Next and the following LoadLibraryEx, we don't end
michael@0:       // up running the now newly loaded module's DllMain function.  If the
michael@0:       // module is already loaded, LoadLibraryEx just increments its refcount.
michael@0:       //
michael@0:       // Note that because of the race condition above, merely loading the DLL
michael@0:       // again is not safe enough, therefore we also need to make sure that we
michael@0:       // can read the memory mapped at the base address before we can safely
michael@0:       // proceed to actually access those pages.
michael@0:       HMODULE handleLock = LoadLibraryEx(module.szExePath, NULL, LOAD_LIBRARY_AS_DATAFILE);
michael@0:       MEMORY_BASIC_INFORMATION vmemInfo = {0};
michael@0:       if (handleLock &&
michael@0:           sizeof(vmemInfo) == VirtualQuery(module.modBaseAddr, &vmemInfo, sizeof(vmemInfo)) &&
michael@0:           vmemInfo.State == MEM_COMMIT &&
michael@0:           GetPdbInfo((uintptr_t)module.modBaseAddr, pdbSig, pdbAge, &pdbName)) {
michael@0:         std::ostringstream stream;
michael@0:         stream << pdbSig.ToString() << std::hex << pdbAge;
michael@0:         std::string breakpadId = stream.str();
michael@0:         std::string::iterator end =
michael@0:           std::remove_if(breakpadId.begin(), breakpadId.end(), IsDashOrBraces);
michael@0:         breakpadId.erase(end, breakpadId.end());
michael@0:         std::transform(breakpadId.begin(), breakpadId.end(),
michael@0:                        breakpadId.begin(), toupper);
michael@0: 
michael@0:         SharedLibrary shlib((uintptr_t)module.modBaseAddr,
michael@0:                             (uintptr_t)module.modBaseAddr+module.modBaseSize,
michael@0:                             0, // DLLs are always mapped at offset 0 on Windows
michael@0:                             breakpadId,
michael@0:                             pdbName);
michael@0:         sharedLibraryInfo.AddSharedLibrary(shlib);
michael@0:       }
michael@0:       FreeLibrary(handleLock); // ok to free null handles
michael@0:     } while (Module32Next(snap, &module));
michael@0:   }
michael@0: 
michael@0:   return sharedLibraryInfo;
michael@0: }
michael@0: