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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-21 11:44:51 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-21 11:44:51 +0000
commit9e3c08db40b8916968b9f30096c7be3f00ce9647 (patch)
treea68f146d7fa01f0134297619fbe7e33db084e0aa /toolkit/xre/dllservices/mozglue/interceptor/PatcherNopSpace.h
parentInitial commit. (diff)
downloadthunderbird-upstream.tar.xz
thunderbird-upstream.zip
Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'toolkit/xre/dllservices/mozglue/interceptor/PatcherNopSpace.h')
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diff --git a/toolkit/xre/dllservices/mozglue/interceptor/PatcherNopSpace.h b/toolkit/xre/dllservices/mozglue/interceptor/PatcherNopSpace.h
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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_interceptor_PatcherNopSpace_h
+#define mozilla_interceptor_PatcherNopSpace_h
+
+#if defined(_M_IX86)
+
+# include "mozilla/interceptor/PatcherBase.h"
+
+namespace mozilla {
+namespace interceptor {
+
+template <typename VMPolicy>
+class WindowsDllNopSpacePatcher final : public WindowsDllPatcherBase<VMPolicy> {
+ typedef typename VMPolicy::MMPolicyT MMPolicyT;
+
+ // For remembering the addresses of functions we've patched.
+ mozilla::Vector<void*> mPatchedFns;
+
+ public:
+ template <typename... Args>
+ explicit WindowsDllNopSpacePatcher(Args&&... aArgs)
+ : WindowsDllPatcherBase<VMPolicy>(std::forward<Args>(aArgs)...) {}
+
+ ~WindowsDllNopSpacePatcher() { Clear(); }
+
+ WindowsDllNopSpacePatcher(const WindowsDllNopSpacePatcher&) = delete;
+ WindowsDllNopSpacePatcher(WindowsDllNopSpacePatcher&&) = delete;
+ WindowsDllNopSpacePatcher& operator=(const WindowsDllNopSpacePatcher&) =
+ delete;
+ WindowsDllNopSpacePatcher& operator=(WindowsDllNopSpacePatcher&&) = delete;
+
+ void Clear() {
+ // Restore the mov edi, edi to the beginning of each function we patched.
+
+ for (auto&& ptr : mPatchedFns) {
+ WritableTargetFunction<MMPolicyT> fn(
+ this->mVMPolicy, reinterpret_cast<uintptr_t>(ptr), sizeof(uint16_t));
+ if (!fn) {
+ continue;
+ }
+
+ // mov edi, edi
+ fn.CommitAndWriteShort(0xff8b);
+ }
+
+ mPatchedFns.clear();
+ }
+
+ /**
+ * NVIDIA Optimus drivers utilize Microsoft Detours 2.x to patch functions
+ * in our address space. There is a bug in Detours 2.x that causes it to
+ * patch at the wrong address when attempting to detour code that is already
+ * NOP space patched. This function is an effort to detect the presence of
+ * this NVIDIA code in our address space and disable NOP space patching if it
+ * is. We also check AppInit_DLLs since this is the mechanism that the Optimus
+ * drivers use to inject into our process.
+ */
+ static bool IsCompatible() {
+ // These DLLs are known to have bad interactions with this style of patching
+ const wchar_t* kIncompatibleDLLs[] = {L"detoured.dll", L"_etoured.dll",
+ L"nvd3d9wrap.dll", L"nvdxgiwrap.dll"};
+ // See if the infringing DLLs are already loaded
+ for (unsigned int i = 0; i < mozilla::ArrayLength(kIncompatibleDLLs); ++i) {
+ if (GetModuleHandleW(kIncompatibleDLLs[i])) {
+ return false;
+ }
+ }
+ if (GetModuleHandleW(L"user32.dll")) {
+ // user32 is loaded but the infringing DLLs are not, assume we're safe to
+ // proceed.
+ return true;
+ }
+ // If user32 has not loaded yet, check AppInit_DLLs to ensure that Optimus
+ // won't be loaded once user32 is initialized.
+ HKEY hkey = NULL;
+ if (!RegOpenKeyExW(
+ HKEY_LOCAL_MACHINE,
+ L"SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion\\Windows", 0,
+ KEY_QUERY_VALUE, &hkey)) {
+ nsAutoRegKey key(hkey);
+ DWORD numBytes = 0;
+ const wchar_t kAppInitDLLs[] = L"AppInit_DLLs";
+ // Query for required buffer size
+ LONG status = RegQueryValueExW(hkey, kAppInitDLLs, nullptr, nullptr,
+ nullptr, &numBytes);
+ mozilla::UniquePtr<wchar_t[]> data;
+ if (!status) {
+ // Allocate the buffer and query for the actual data
+ data = mozilla::MakeUnique<wchar_t[]>((numBytes + 1) / sizeof(wchar_t));
+ status = RegQueryValueExW(hkey, kAppInitDLLs, nullptr, nullptr,
+ (LPBYTE)data.get(), &numBytes);
+ }
+ if (!status) {
+ // For each token, split up the filename components and then check the
+ // name of the file.
+ const wchar_t kDelimiters[] = L", ";
+ wchar_t* tokenContext = nullptr;
+ wchar_t* token = wcstok_s(data.get(), kDelimiters, &tokenContext);
+ while (token) {
+ wchar_t fname[_MAX_FNAME] = {0};
+ if (!_wsplitpath_s(token, nullptr, 0, nullptr, 0, fname,
+ mozilla::ArrayLength(fname), nullptr, 0)) {
+ // nvinit.dll is responsible for bootstrapping the DLL injection, so
+ // that is the library that we check for here
+ const wchar_t kNvInitName[] = L"nvinit";
+ if (!_wcsnicmp(fname, kNvInitName,
+ mozilla::ArrayLength(kNvInitName))) {
+ return false;
+ }
+ }
+ token = wcstok_s(nullptr, kDelimiters, &tokenContext);
+ }
+ }
+ }
+ return true;
+ }
+
+ bool AddHook(FARPROC aTargetFn, intptr_t aHookDest, void** aOrigFunc) {
+ if (!IsCompatible()) {
+# if defined(MOZILLA_INTERNAL_API)
+ NS_WARNING("NOP space patching is unavailable for compatibility reasons");
+# endif
+ return false;
+ }
+
+ MOZ_ASSERT(aTargetFn);
+ if (!aTargetFn) {
+ return false;
+ }
+
+ ReadOnlyTargetFunction<MMPolicyT> readOnlyTargetFn(
+ this->ResolveRedirectedAddress(aTargetFn));
+
+ if (!WriteHook(readOnlyTargetFn, aHookDest, aOrigFunc)) {
+ return false;
+ }
+
+ return mPatchedFns.append(
+ reinterpret_cast<void*>(readOnlyTargetFn.GetBaseAddress()));
+ }
+
+ bool WriteHook(const ReadOnlyTargetFunction<MMPolicyT>& aFn,
+ intptr_t aHookDest, void** aOrigFunc) {
+ // Ensure we can read and write starting at fn - 5 (for the long jmp we're
+ // going to write) and ending at fn + 2 (for the short jmp up to the long
+ // jmp). These bytes may span two pages with different protection.
+ WritableTargetFunction<MMPolicyT> writableFn(aFn.Promote(7, -5));
+ if (!writableFn) {
+ return false;
+ }
+
+ // Check that the 5 bytes before the function are NOP's or INT 3's,
+ const uint8_t nopOrBp[] = {0x90, 0xCC};
+ if (!writableFn.template VerifyValuesAreOneOf<uint8_t, 5>(nopOrBp)) {
+ return false;
+ }
+
+ // ... and that the first 2 bytes of the function are mov(edi, edi).
+ // There are two ways to encode the same thing:
+ //
+ // 0x89 0xff == mov r/m, r
+ // 0x8b 0xff == mov r, r/m
+ //
+ // where "r" is register and "r/m" is register or memory.
+ // Windows seems to use 0x8B 0xFF. We include 0x89 0xFF out of paranoia.
+
+ // (These look backwards because little-endian)
+ const uint16_t possibleEncodings[] = {0xFF8B, 0xFF89};
+ if (!writableFn.template VerifyValuesAreOneOf<uint16_t, 1>(
+ possibleEncodings, 5)) {
+ return false;
+ }
+
+ // Write a long jump into the space above the function.
+ writableFn.WriteByte(0xe9); // jmp
+ if (!writableFn) {
+ return false;
+ }
+
+ writableFn.WriteDisp32(aHookDest); // target
+ if (!writableFn) {
+ return false;
+ }
+
+ // Set aOrigFunc here, because after this point, aHookDest might be called,
+ // and aHookDest might use the aOrigFunc pointer.
+ *aOrigFunc = reinterpret_cast<void*>(writableFn.GetCurrentAddress() +
+ sizeof(uint16_t));
+
+ // Short jump up into our long jump.
+ return writableFn.CommitAndWriteShort(0xF9EB); // jmp $-5
+ }
+};
+
+} // namespace interceptor
+} // namespace mozilla
+
+#endif // defined(_M_IX86)
+
+#endif // mozilla_interceptor_PatcherNopSpace_h