From 36d22d82aa202bb199967e9512281e9a53db42c9 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 21:33:14 +0200 Subject: Adding upstream version 115.7.0esr. Signed-off-by: Daniel Baumann --- mozglue/misc/WindowsStackCookie.h | 63 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 63 insertions(+) create mode 100644 mozglue/misc/WindowsStackCookie.h (limited to 'mozglue/misc/WindowsStackCookie.h') diff --git a/mozglue/misc/WindowsStackCookie.h b/mozglue/misc/WindowsStackCookie.h new file mode 100644 index 0000000000..c4196b3853 --- /dev/null +++ b/mozglue/misc/WindowsStackCookie.h @@ -0,0 +1,63 @@ +/* -*- 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_WindowsStackCookie_h +#define mozilla_WindowsStackCookie_h + +#if defined(DEBUG) && defined(_M_X64) && !defined(__MINGW64__) + +# include +# include + +# include + +# include "mozilla/Types.h" + +namespace mozilla { + +// This function does pattern matching on the instructions generated for a +// given function, to detect whether it uses stack buffers. More specifically, +// it looks for instructions that characterize the presence of stack cookie +// checks. When this function returns true, it can be a false positive, but we +// use a rather long pattern to make false positives very unlikely. +// Note: Do not use this function inside the function that lives at +// aFunctionAddress, as that could introduce stack buffers. +// Note: The pattern we use does not work for MinGW builds. +inline bool HasStackCookieCheck(uintptr_t aFunctionAddress) { + DWORD64 imageBase{}; + auto entry = ::RtlLookupFunctionEntry( + reinterpret_cast(aFunctionAddress), &imageBase, nullptr); + if (entry && entry->EndAddress > entry->BeginAddress + 14) { + auto begin = reinterpret_cast(imageBase + entry->BeginAddress); + auto end = reinterpret_cast(imageBase + entry->EndAddress - 14); + for (auto pc = begin; pc != end; ++pc) { + // 48 8b 05 XX XX XX XX: mov rax, qword ptr [rip + XXXXXXXX] + if ((pc[0] == 0x48 && pc[1] == 0x8b && pc[2] == 0x05) && + // 48 31 e0: xor rax, rsp + (pc[7] == 0x48 && pc[8] == 0x31 && pc[9] == 0xe0) && + // 48 89 (8|4)4 24 ...: mov qword ptr [rsp + ...], rax + (pc[10] == 0x48 && pc[11] == 0x89 && + (pc[12] == 0x44 || pc[12] == 0x84) && pc[13] == 0x24)) { + return true; + } + } + } + // In x64, if there is no entry, then there is no stack allocation, hence + // there is no stack cookie check: "Table-based exception handling requires a + // table entry for all functions that allocate stack space or call another + // function (for example, nonleaf functions)." + // https://learn.microsoft.com/en-us/cpp/build/exception-handling-x64 + // Similarly, if the gap between begin and end is less than 14 bytes, then + // the function cannot contain the pattern we are looking for, therefore it + // has no cookie check either. + return false; +} + +} // namespace mozilla + +#endif // defined(DEBUG) && defined(_M_X64) && !defined(__MINGW64__) + +#endif // mozilla_WindowsStackCookie_h -- cgit v1.2.3