forked from OSchip/llvm-project
274 lines
9.3 KiB
C++
274 lines
9.3 KiB
C++
//===-- interception_linux.cc -----------------------------------*- C++ -*-===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This file is a part of AddressSanitizer, an address sanity checker.
|
|
//
|
|
// Windows-specific interception methods.
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifdef _WIN32
|
|
|
|
#include "interception.h"
|
|
#define WIN32_LEAN_AND_MEAN
|
|
#include <windows.h>
|
|
|
|
namespace __interception {
|
|
|
|
// FIXME: internal_str* and internal_mem* functions should be moved from the
|
|
// ASan sources into interception/.
|
|
|
|
static void _memset(void *p, int value, size_t sz) {
|
|
for (size_t i = 0; i < sz; ++i)
|
|
((char*)p)[i] = (char)value;
|
|
}
|
|
|
|
static void _memcpy(void *dst, void *src, size_t sz) {
|
|
char *dst_c = (char*)dst,
|
|
*src_c = (char*)src;
|
|
for (size_t i = 0; i < sz; ++i)
|
|
dst_c[i] = src_c[i];
|
|
}
|
|
|
|
static void WriteJumpInstruction(char *jmp_from, char *to) {
|
|
// jmp XXYYZZWW = E9 WW ZZ YY XX, where XXYYZZWW is an offset fromt jmp_from
|
|
// to the next instruction to the destination.
|
|
ptrdiff_t offset = to - jmp_from - 5;
|
|
*jmp_from = '\xE9';
|
|
*(ptrdiff_t*)(jmp_from + 1) = offset;
|
|
}
|
|
|
|
static char *GetMemoryForTrampoline(size_t size) {
|
|
// Trampolines are allocated from a common pool.
|
|
const int POOL_SIZE = 1024;
|
|
static char *pool = NULL;
|
|
static size_t pool_used = 0;
|
|
if (!pool) {
|
|
pool = (char *)VirtualAlloc(NULL, POOL_SIZE, MEM_RESERVE | MEM_COMMIT,
|
|
PAGE_EXECUTE_READWRITE);
|
|
// FIXME: Might want to apply PAGE_EXECUTE_READ access after all the
|
|
// interceptors are in place.
|
|
if (!pool)
|
|
return NULL;
|
|
_memset(pool, 0xCC /* int 3 */, POOL_SIZE);
|
|
}
|
|
|
|
if (pool_used + size > POOL_SIZE)
|
|
return NULL;
|
|
|
|
char *ret = pool + pool_used;
|
|
pool_used += size;
|
|
return ret;
|
|
}
|
|
|
|
// Returns 0 on error.
|
|
static size_t RoundUpToInstrBoundary(size_t size, char *code) {
|
|
size_t cursor = 0;
|
|
while (cursor < size) {
|
|
switch (code[cursor]) {
|
|
case '\x51': // push ecx
|
|
case '\x52': // push edx
|
|
case '\x53': // push ebx
|
|
case '\x54': // push esp
|
|
case '\x55': // push ebp
|
|
case '\x56': // push esi
|
|
case '\x57': // push edi
|
|
case '\x5D': // pop ebp
|
|
cursor++;
|
|
continue;
|
|
case '\x6A': // 6A XX = push XX
|
|
cursor += 2;
|
|
continue;
|
|
case '\xE9': // E9 XX YY ZZ WW = jmp WWZZYYXX
|
|
case '\xB8': // B8 XX YY ZZ WW = mov eax, WWZZYYXX
|
|
cursor += 5;
|
|
continue;
|
|
}
|
|
switch (*(unsigned short*)(code + cursor)) { // NOLINT
|
|
case 0xFF8B: // 8B FF = mov edi, edi
|
|
case 0xEC8B: // 8B EC = mov ebp, esp
|
|
case 0xC033: // 33 C0 = xor eax, eax
|
|
cursor += 2;
|
|
continue;
|
|
case 0x458B: // 8B 45 XX = mov eax, dword ptr [ebp+XXh]
|
|
case 0x5D8B: // 8B 5D XX = mov ebx, dword ptr [ebp+XXh]
|
|
case 0xEC83: // 83 EC XX = sub esp, XX
|
|
case 0x75FF: // FF 75 XX = push dword ptr [ebp+XXh]
|
|
cursor += 3;
|
|
continue;
|
|
case 0xC1F7: // F7 C1 XX YY ZZ WW = test ecx, WWZZYYXX
|
|
case 0x25FF: // FF 25 XX YY ZZ WW = jmp dword ptr ds:[WWZZYYXX]
|
|
cursor += 6;
|
|
continue;
|
|
case 0x3D83: // 83 3D XX YY ZZ WW TT = cmp TT, WWZZYYXX
|
|
cursor += 7;
|
|
continue;
|
|
}
|
|
switch (0x00FFFFFF & *(unsigned int*)(code + cursor)) {
|
|
case 0x24448A: // 8A 44 24 XX = mov eal, dword ptr [esp+XXh]
|
|
case 0x24448B: // 8B 44 24 XX = mov eax, dword ptr [esp+XXh]
|
|
case 0x244C8B: // 8B 4C 24 XX = mov ecx, dword ptr [esp+XXh]
|
|
case 0x24548B: // 8B 54 24 XX = mov edx, dword ptr [esp+XXh]
|
|
case 0x24748B: // 8B 74 24 XX = mov esi, dword ptr [esp+XXh]
|
|
case 0x247C8B: // 8B 7C 24 XX = mov edi, dword ptr [esp+XXh]
|
|
cursor += 4;
|
|
continue;
|
|
}
|
|
|
|
// Unknown instruction!
|
|
// FIXME: Unknown instruction failures might happen when we add a new
|
|
// interceptor or a new compiler version. In either case, they should result
|
|
// in visible and readable error messages. However, merely calling abort()
|
|
// leads to an infinite recursion in CheckFailed.
|
|
// Do we have a good way to abort with an error message here?
|
|
__debugbreak();
|
|
return 0;
|
|
}
|
|
|
|
return cursor;
|
|
}
|
|
|
|
bool OverrideFunction(uptr old_func, uptr new_func, uptr *orig_old_func) {
|
|
#ifdef _WIN64
|
|
#error OverrideFunction is not yet supported on x64
|
|
#endif
|
|
// Function overriding works basically like this:
|
|
// We write "jmp <new_func>" (5 bytes) at the beginning of the 'old_func'
|
|
// to override it.
|
|
// We might want to be able to execute the original 'old_func' from the
|
|
// wrapper, in this case we need to keep the leading 5+ bytes ('head')
|
|
// of the original code somewhere with a "jmp <old_func+head>".
|
|
// We call these 'head'+5 bytes of instructions a "trampoline".
|
|
char *old_bytes = (char *)old_func;
|
|
|
|
// We'll need at least 5 bytes for a 'jmp'.
|
|
size_t head = 5;
|
|
if (orig_old_func) {
|
|
// Find out the number of bytes of the instructions we need to copy
|
|
// to the trampoline and store it in 'head'.
|
|
head = RoundUpToInstrBoundary(head, old_bytes);
|
|
if (!head)
|
|
return false;
|
|
|
|
// Put the needed instructions into the trampoline bytes.
|
|
char *trampoline = GetMemoryForTrampoline(head + 5);
|
|
if (!trampoline)
|
|
return false;
|
|
_memcpy(trampoline, old_bytes, head);
|
|
WriteJumpInstruction(trampoline + head, old_bytes + head);
|
|
*orig_old_func = (uptr)trampoline;
|
|
}
|
|
|
|
// Now put the "jmp <new_func>" instruction at the original code location.
|
|
// We should preserve the EXECUTE flag as some of our own code might be
|
|
// located in the same page (sic!). FIXME: might consider putting the
|
|
// __interception code into a separate section or something?
|
|
DWORD old_prot, unused_prot;
|
|
if (!VirtualProtect((void *)old_bytes, head, PAGE_EXECUTE_READWRITE,
|
|
&old_prot))
|
|
return false;
|
|
|
|
WriteJumpInstruction(old_bytes, (char *)new_func);
|
|
_memset(old_bytes + 5, 0xCC /* int 3 */, head - 5);
|
|
|
|
// Restore the original permissions.
|
|
if (!VirtualProtect((void *)old_bytes, head, old_prot, &unused_prot))
|
|
return false; // not clear if this failure bothers us.
|
|
|
|
return true;
|
|
}
|
|
|
|
static void **InterestingDLLsAvailable() {
|
|
const char *InterestingDLLs[] = {
|
|
"kernel32.dll",
|
|
"msvcr110.dll", // VS2012
|
|
"msvcr120.dll", // VS2013
|
|
// NTDLL should go last as it exports some functions that we should override
|
|
// in the CRT [presumably only used internally].
|
|
"ntdll.dll", NULL
|
|
};
|
|
static void *result[ARRAY_SIZE(InterestingDLLs)] = { 0 };
|
|
if (!result[0]) {
|
|
for (size_t i = 0, j = 0; InterestingDLLs[i]; ++i) {
|
|
if (HMODULE h = GetModuleHandleA(InterestingDLLs[i]))
|
|
result[j++] = (void *)h;
|
|
}
|
|
}
|
|
return &result[0];
|
|
}
|
|
|
|
namespace {
|
|
// Utility for reading loaded PE images.
|
|
template <typename T> class RVAPtr {
|
|
public:
|
|
RVAPtr(void *module, uptr rva)
|
|
: ptr_(reinterpret_cast<T *>(reinterpret_cast<char *>(module) + rva)) {}
|
|
operator T *() { return ptr_; }
|
|
T *operator->() { return ptr_; }
|
|
T *operator++() { return ++ptr_; }
|
|
|
|
private:
|
|
T *ptr_;
|
|
};
|
|
} // namespace
|
|
|
|
// Internal implementation of GetProcAddress. At least since Windows 8,
|
|
// GetProcAddress appears to initialize DLLs before returning function pointers
|
|
// into them. This is problematic for the sanitizers, because they typically
|
|
// want to intercept malloc *before* MSVCRT initializes. Our internal
|
|
// implementation walks the export list manually without doing initialization.
|
|
uptr InternalGetProcAddress(void *module, const char *func_name) {
|
|
// Check that the module header is full and present.
|
|
RVAPtr<IMAGE_DOS_HEADER> dos_stub(module, 0);
|
|
RVAPtr<IMAGE_NT_HEADERS> headers(module, dos_stub->e_lfanew);
|
|
if (!module || dos_stub->e_magic != IMAGE_DOS_SIGNATURE || // "MZ"
|
|
headers->Signature != IMAGE_NT_SIGNATURE || // "PE\0\0"
|
|
headers->FileHeader.SizeOfOptionalHeader <
|
|
sizeof(IMAGE_OPTIONAL_HEADER)) {
|
|
return 0;
|
|
}
|
|
|
|
IMAGE_DATA_DIRECTORY *export_directory =
|
|
&headers->OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_EXPORT];
|
|
RVAPtr<IMAGE_EXPORT_DIRECTORY> exports(module,
|
|
export_directory->VirtualAddress);
|
|
RVAPtr<DWORD> functions(module, exports->AddressOfFunctions);
|
|
RVAPtr<DWORD> names(module, exports->AddressOfNames);
|
|
RVAPtr<WORD> ordinals(module, exports->AddressOfNameOrdinals);
|
|
|
|
for (DWORD i = 0; i < exports->NumberOfNames; i++) {
|
|
RVAPtr<char> name(module, names[i]);
|
|
if (!strcmp(func_name, name)) {
|
|
DWORD index = ordinals[i];
|
|
RVAPtr<char> func(module, functions[index]);
|
|
return (uptr)(char *)func;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static bool GetFunctionAddressInDLLs(const char *func_name, uptr *func_addr) {
|
|
*func_addr = 0;
|
|
void **DLLs = InterestingDLLsAvailable();
|
|
for (size_t i = 0; *func_addr == 0 && DLLs[i]; ++i)
|
|
*func_addr = InternalGetProcAddress(DLLs[i], func_name);
|
|
return (*func_addr != 0);
|
|
}
|
|
|
|
bool OverrideFunction(const char *name, uptr new_func, uptr *orig_old_func) {
|
|
uptr orig_func;
|
|
if (!GetFunctionAddressInDLLs(name, &orig_func))
|
|
return false;
|
|
return OverrideFunction(orig_func, new_func, orig_old_func);
|
|
}
|
|
|
|
} // namespace __interception
|
|
|
|
#endif // _WIN32
|