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Add mach_override as a 3rdparty dep and hook it into the OS X overlay.

Browse Source 
Prior versions of mach_override were small (a single file),
and we just had its source live in the OS X overlay directory.

Newer versions of mach_override use libudis86, so the file count
goes up a fair bit. So much so that it doesn't make sense to
have it live inside the OS X overlay anymore.

Because of that, this commit moves it into 3rdparty.
This commit is contained in:
Mikkel Krautz 2015-02-05 22:55:43 +01:00
parent 32f327378f
commit 403aedb35d
7 changed files with 48 additions and 867 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
.gitmodules vendored
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@ -19,3 +19,6 @@
[submodule "3rdparty/minhook-src"]
path = 3rdparty/minhook-src
url = https://github.com/mumble-voip/minhook.git
[submodule "3rdparty/mach-override-src"]
path = 3rdparty/mach-override-src
url = git@github.com:rentzsch/mach_override.git

36
3rdparty/mach-override-build/mach-override-build.pro vendored Normal file
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@ -0,0 +1,36 @@
include(../../compiler.pri)
BUILDDIR=$$basename(PWD)
SOURCEDIR=$$replace(BUILDDIR,-build,-src)
!exists(../$$SOURCEDIR/README.markdown) {
message("The $$SOURCEDIR/ directory was not found. Please update your submodules (git submodule update --init).")
error("Aborting configuration")
}
CONFIG(debug, debug|release) {
CONFIG += console
DESTDIR = ../../debug
}
CONFIG(release, debug|release) {
DESTDIR = ../../release
}
TEMPLATE = lib
CONFIG -= qt
CONFIG += debug_and_release
CONFIG += staticlib
VPATH = ../mach-override-src
TARGET = mach-override
INCLUDEPATH = ../mach-override-src/ ../mach-override-src/libudis86
SOURCES *= \
mach_override.c \
libudis86/decode.c \
libudis86/input.c \
libudis86/itab.c \
libudis86/syn-att.c \
libudis86/syn-intel.c \
libudis86/syn.c \
libudis86/udis86.c

1
3rdparty/mach-override-src vendored Submodule

@ -0,0 +1 @@
Subproject commit 919148f94db54fc04d287eb6a42c0c36b166bbfa

744
macx/overlay/mach_override.c
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@ -1,744 +0,0 @@
/*******************************************************************************
mach_override.c
Copyright (c) 2003-2009 Jonathan 'Wolf' Rentzsch: <http://rentzsch.com>
Some rights reserved: <http://opensource.org/licenses/mit-license.php>
***************************************************************************/
#include "mach_override.h"
#include <mach-o/dyld.h>
#include <mach/mach_host.h>
#include <mach/mach_init.h>
#include <mach/vm_map.h>
#include <sys/mman.h>
#include <CoreServices/CoreServices.h>
/**************************
*
* Constants
*
**************************/
#pragma mark -
#pragma mark (Constants)
#define kPageSize 4096
#if defined(__ppc__) || defined(__POWERPC__)
long kIslandTemplate[] = {
0x9001FFFC, // stw r0,-4(SP)
0x3C00DEAD, // lis r0,0xDEAD
0x6000BEEF, // ori r0,r0,0xBEEF
0x7C0903A6, // mtctr r0
0x8001FFFC, // lwz r0,-4(SP)
0x60000000, // nop ; optionally replaced
0x4E800420 // bctr
};
#define kAddressHi 3
#define kAddressLo 5
#define kInstructionHi 10
#define kInstructionLo 11
#elif defined(__i386__)
#define kOriginalInstructionsSize 16
char kIslandTemplate[] = {
// kOriginalInstructionsSize nop instructions so that we
// should have enough space to host original instructions
0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
// Now the real jump instruction
0xE9, 0xEF, 0xBE, 0xAD, 0xDE
};
#define kInstructions 0
#define kJumpAddress kInstructions + kOriginalInstructionsSize + 1
#elif defined(__x86_64__)
#define kOriginalInstructionsSize 32
#define kJumpAddress kOriginalInstructionsSize + 6
char kIslandTemplate[] = {
// kOriginalInstructionsSize nop instructions so that we
// should have enough space to host original instructions
0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
// Now the real jump instruction
0xFF, 0x25, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00
};
#endif
/**************************
*
* Data Types
*
**************************/
#pragma mark -
#pragma mark (Data Types)
typedef struct {
char instructions[sizeof(kIslandTemplate)];
} BranchIsland;
/**************************
*
* Funky Protos
*
**************************/
#pragma mark -
#pragma mark (Funky Protos)
mach_error_t
allocateBranchIsland(
BranchIsland **island,
void *originalFunctionAddress);
mach_error_t
freeBranchIsland(
BranchIsland *island );
#if defined(__ppc__) || defined(__POWERPC__)
mach_error_t
setBranchIslandTarget(
BranchIsland *island,
const void *branchTo,
long instruction );
#endif
#if defined(__i386__) || defined(__x86_64__)
mach_error_t
setBranchIslandTarget_i386(
BranchIsland *island,
const void *branchTo,
char* instructions );
void
atomic_mov64(
uint64_t *targetAddress,
uint64_t value );
static Boolean
eatKnownInstructions(
unsigned char *code,
uint64_t *newInstruction,
int *howManyEaten,
char *originalInstructions,
int *originalInstructionCount,
uint8_t *originalInstructionSizes );
static void
fixupInstructions(
void *originalFunction,
void *escapeIsland,
void *instructionsToFix,
int instructionCount,
uint8_t *instructionSizes );
#endif
/*******************************************************************************
*
* Interface
*
*******************************************************************************/
#pragma mark -
#pragma mark (Interface)
#if defined(__i386__) || defined(__x86_64__)
mach_error_t makeIslandExecutable(void *address) {
mach_error_t err = err_none;
uintptr_t page = (uintptr_t)address & ~(uintptr_t)(kPageSize-1);
int e = err_none;
e |= mprotect((void *)page, kPageSize, PROT_EXEC | PROT_READ | PROT_WRITE);
e |= msync((void *)page, kPageSize, MS_INVALIDATE );
if (e) {
err = err_cannot_override;
}
return err;
}
#endif
mach_error_t
mach_override_ptr(
void *originalFunctionAddress,
const void *overrideFunctionAddress,
void **originalFunctionReentryIsland )
{
assert( originalFunctionAddress );
assert( overrideFunctionAddress );
// this addresses overriding such functions as AudioOutputUnitStart()
// test with modified DefaultOutputUnit project
#if defined(__x86_64__)
for(;;){
if(*(uint16_t*)originalFunctionAddress==0x25FF) // jmp qword near [rip+0x????????]
originalFunctionAddress=*(void**)((char*)originalFunctionAddress+6+*(int32_t *)((uint16_t*)originalFunctionAddress+1));
else break;
}
#elif defined(__i386__)
for(;;){
if(*(uint16_t*)originalFunctionAddress==0x25FF) // jmp *0x????????
originalFunctionAddress=**(void***)((uint16_t*)originalFunctionAddress+1);
else break;
}
#endif
long *originalFunctionPtr = (long*) originalFunctionAddress;
mach_error_t err = err_none;
#if defined(__ppc__) || defined(__POWERPC__)
// Ensure first instruction isn't 'mfctr'.
#define kMFCTRMask 0xfc1fffff
#define kMFCTRInstruction 0x7c0903a6
long originalInstruction = *originalFunctionPtr;
if( !err && ((originalInstruction & kMFCTRMask) == kMFCTRInstruction) )
err = err_cannot_override;
#elif defined(__i386__) || defined(__x86_64__)
int eatenCount = 0;
int originalInstructionCount = 0;
char originalInstructions[kOriginalInstructionsSize];
uint8_t originalInstructionSizes[kOriginalInstructionsSize];
uint64_t jumpRelativeInstruction = 0; // JMP
Boolean overridePossible = eatKnownInstructions ((unsigned char *)originalFunctionPtr,
&jumpRelativeInstruction, &eatenCount,
originalInstructions, &originalInstructionCount,
originalInstructionSizes );
if (eatenCount > kOriginalInstructionsSize) {
//printf ("Too many instructions eaten\n");
overridePossible = false;
}
if (!overridePossible) err = err_cannot_override;
if (err) fprintf(stderr, "err = %x %s:%d\n", err, __FILE__, __LINE__);
#endif
// Make the original function implementation writable.
if( !err ) {
err = vm_protect( mach_task_self(),
(vm_address_t) originalFunctionPtr, 8, false,
(VM_PROT_ALL | VM_PROT_COPY) );
if( err )
err = vm_protect( mach_task_self(),
(vm_address_t) originalFunctionPtr, 8, false,
(VM_PROT_DEFAULT | VM_PROT_COPY) );
}
if (err) fprintf(stderr, "err = %x %s:%d\n", err, __FILE__, __LINE__);
// Allocate and target the escape island to the overriding function.
BranchIsland *escapeIsland = NULL;
if( !err )
err = allocateBranchIsland( &escapeIsland, originalFunctionAddress );
if (err) fprintf(stderr, "err = %x %s:%d\n", err, __FILE__, __LINE__);
#if defined(__ppc__) || defined(__POWERPC__)
if( !err )
err = setBranchIslandTarget( escapeIsland, overrideFunctionAddress, 0 );
// Build the branch absolute instruction to the escape island.
long branchAbsoluteInstruction = 0; // Set to 0 just to silence warning.
if( !err ) {
long escapeIslandAddress = ((long) escapeIsland) & 0x3FFFFFF;
branchAbsoluteInstruction = 0x48000002 | escapeIslandAddress;
}
#elif defined(__i386__) || defined(__x86_64__)
if (err) fprintf(stderr, "err = %x %s:%d\n", err, __FILE__, __LINE__);
if( !err )
err = setBranchIslandTarget_i386( escapeIsland, overrideFunctionAddress, 0 );
if (err) fprintf(stderr, "err = %x %s:%d\n", err, __FILE__, __LINE__);
// Build the jump relative instruction to the escape island
#endif
#if defined(__i386__) || defined(__x86_64__)
if (!err) {
uint32_t addressOffset = ((char*)escapeIsland - (char*)originalFunctionPtr - 5);
addressOffset = OSSwapInt32(addressOffset);
jumpRelativeInstruction |= 0xE900000000000000LL;
jumpRelativeInstruction |= ((uint64_t)addressOffset & 0xffffffff) << 24;
jumpRelativeInstruction = OSSwapInt64(jumpRelativeInstruction);
}
#endif
// Optionally allocate & return the reentry island. This may contain relocated
// jmp instructions and so has all the same addressing reachability requirements
// the escape island has to the original function, except the escape island is
// technically our original function.
BranchIsland *reentryIsland = NULL;
if( !err && originalFunctionReentryIsland ) {
err = allocateBranchIsland( &reentryIsland, escapeIsland);
if( !err )
*originalFunctionReentryIsland = reentryIsland;
}
#if defined(__ppc__) || defined(__POWERPC__)
// Atomically:
// o If the reentry island was allocated:
// o Insert the original instruction into the reentry island.
// o Target the reentry island at the 2nd instruction of the
// original function.
// o Replace the original instruction with the branch absolute.
if( !err ) {
int escapeIslandEngaged = false;
do {
if( reentryIsland )
err = setBranchIslandTarget( reentryIsland,
(void*) (originalFunctionPtr+1), originalInstruction );
if( !err ) {
escapeIslandEngaged = CompareAndSwap( originalInstruction,
branchAbsoluteInstruction,
(UInt32*)originalFunctionPtr );
if( !escapeIslandEngaged ) {
// Someone replaced the instruction out from under us,
// re-read the instruction, make sure it's still not
// 'mfctr' and try again.
originalInstruction = *originalFunctionPtr;
if( (originalInstruction & kMFCTRMask) == kMFCTRInstruction)
err = err_cannot_override;
}
}
} while( !err && !escapeIslandEngaged );
}
#elif defined(__i386__) || defined(__x86_64__)
// Atomically:
// o If the reentry island was allocated:
// o Insert the original instructions into the reentry island.
// o Target the reentry island at the first non-replaced
// instruction of the original function.
// o Replace the original first instructions with the jump relative.
//
// Note that on i386, we do not support someone else changing the code under our feet
if ( !err ) {
fixupInstructions(originalFunctionPtr, reentryIsland, originalInstructions,
originalInstructionCount, originalInstructionSizes );
if( reentryIsland )
err = setBranchIslandTarget_i386( reentryIsland,
(void*) ((char *)originalFunctionPtr+eatenCount), originalInstructions );
// try making islands executable before planting the jmp
#if defined(__x86_64__) || defined(__i386__)
if( !err )
err = makeIslandExecutable(escapeIsland);
if( !err && reentryIsland )
err = makeIslandExecutable(reentryIsland);
#endif
if ( !err )
atomic_mov64((uint64_t *)originalFunctionPtr, jumpRelativeInstruction);
}
#endif
// Clean up on error.
if( err ) {
if( reentryIsland )
freeBranchIsland( reentryIsland );
if( escapeIsland )
freeBranchIsland( escapeIsland );
}
return err;
}
/*******************************************************************************
*
* Implementation
*
*******************************************************************************/
#pragma mark -
#pragma mark (Implementation)
/***************************************************************************//**
Implementation: Allocates memory for a branch island.
@param island <- The allocated island.
@result <- mach_error_t
***************************************************************************/
mach_error_t
allocateBranchIsland(
BranchIsland **island,
void *originalFunctionAddress)
{
assert( island );
assert( sizeof( BranchIsland ) <= kPageSize );
vm_map_t task_self = mach_task_self();
vm_address_t original_address = (vm_address_t) originalFunctionAddress;
static vm_address_t last_allocated = 0;
vm_address_t address =
last_allocated ? last_allocated : original_address;
for (;;) {
vm_size_t vmsize = 0;
memory_object_name_t object = 0;
kern_return_t kr = 0;
vm_region_flavor_t flavor = VM_REGION_BASIC_INFO;
// Find the page the address is in.
#if __WORDSIZE == 32
vm_region_basic_info_data_t info;
mach_msg_type_number_t info_count = VM_REGION_BASIC_INFO_COUNT;
kr = vm_region(task_self, &address, &vmsize, flavor,
(vm_region_info_t)&info, &info_count, &object);
#else
vm_region_basic_info_data_64_t info;
mach_msg_type_number_t info_count = VM_REGION_BASIC_INFO_COUNT_64;
kr = vm_region_64(task_self, &address, &vmsize, flavor,
(vm_region_info_t)&info, &info_count, &object);
#endif
if (kr != KERN_SUCCESS)
return kr;
// Don't underflow. This could be made to work, but this is a
// convenient place to give up.
assert((address & (kPageSize - 1)) == 0);
if (address == 0)
break;
// Go back one page.
vm_address_t new_address = address - kPageSize;
#if __WORDSIZE == 64
if(original_address - new_address - 5 > INT32_MAX)
break;
#endif
address = new_address;
// Try to allocate this page.
kr = vm_allocate(task_self, &address, kPageSize, 0);
if (kr == KERN_SUCCESS) {
*island = (BranchIsland*) address;
last_allocated = address;
return err_none;
}
if (kr != KERN_NO_SPACE)
return kr;
}
return KERN_NO_SPACE;
}
/***************************************************************************//**
Implementation: Deallocates memory for a branch island.
@param island -> The island to deallocate.
@result <- mach_error_t
***************************************************************************/
mach_error_t
freeBranchIsland(
BranchIsland *island )
{
assert( island );
assert( (*(long*)&island->instructions[0]) == kIslandTemplate[0] );
assert( sizeof( BranchIsland ) <= kPageSize );
return vm_deallocate( mach_task_self(), (vm_address_t) island,
kPageSize );
}
/***************************************************************************//**
Implementation: Sets the branch island's target, with an optional
instruction.
@param island -> The branch island to insert target into.
@param branchTo -> The address of the target.
@param instruction -> Optional instruction to execute prior to branch. Set
to zero for nop.
@result <- mach_error_t
***************************************************************************/
#if defined(__ppc__) || defined(__POWERPC__)
mach_error_t
setBranchIslandTarget(
BranchIsland *island,
const void *branchTo,
long instruction )
{
// Copy over the template code.
bcopy( kIslandTemplate, island->instructions, sizeof( kIslandTemplate ) );
// Fill in the address.
((short*)island->instructions)[kAddressLo] = ((long) branchTo) & 0x0000FFFF;
((short*)island->instructions)[kAddressHi]
= (((long) branchTo) >> 16) & 0x0000FFFF;
// Fill in the (optional) instuction.
if( instruction != 0 ) {
((short*)island->instructions)[kInstructionLo]
= instruction & 0x0000FFFF;
((short*)island->instructions)[kInstructionHi]
= (instruction >> 16) & 0x0000FFFF;
}
//MakeDataExecutable( island->instructions, sizeof( kIslandTemplate ) );
msync( island->instructions, sizeof( kIslandTemplate ), MS_INVALIDATE );
return err_none;
}
#endif
#if defined(__i386__)
mach_error_t
setBranchIslandTarget_i386(
BranchIsland *island,
const void *branchTo,
char* instructions )
{
// Copy over the template code.
bcopy( kIslandTemplate, island->instructions, sizeof( kIslandTemplate ) );
// copy original instructions
if (instructions) {
bcopy (instructions, island->instructions + kInstructions, kOriginalInstructionsSize);
}
// Fill in the address.
int32_t addressOffset = (char *)branchTo - (island->instructions + kJumpAddress + 4);
*((int32_t *)(island->instructions + kJumpAddress)) = addressOffset;
msync( island->instructions, sizeof( kIslandTemplate ), MS_INVALIDATE );
return err_none;
}
#elif defined(__x86_64__)
mach_error_t
setBranchIslandTarget_i386(
BranchIsland *island,
const void *branchTo,
char* instructions )
{
// Copy over the template code.
bcopy( kIslandTemplate, island->instructions, sizeof( kIslandTemplate ) );
// Copy original instructions.
if (instructions) {
bcopy (instructions, island->instructions, kOriginalInstructionsSize);
}
// Fill in the address.
*((uint64_t *)(island->instructions + kJumpAddress)) = (uint64_t)branchTo;
msync( island->instructions, sizeof( kIslandTemplate ), MS_INVALIDATE );
return err_none;
}
#endif
#if defined(__i386__) || defined(__x86_64__)
// simplistic instruction matching
typedef struct {
unsigned int length; // max 15
unsigned char mask[15]; // sequence of bytes in memory order
unsigned char constraint[15]; // sequence of bytes in memory order
} AsmInstructionMatch;
#if defined(__i386__)
static AsmInstructionMatch possibleInstructions[] = {
{ 0x5, {0xFF, 0x00, 0x00, 0x00, 0x00}, {0xE9, 0x00, 0x00, 0x00, 0x00} }, // jmp 0x????????
{ 0x5, {0xFF, 0xFF, 0xFF, 0xFF, 0xFF}, {0x55, 0x89, 0xe5, 0xc9, 0xc3} }, // push %ebp; mov %esp,%ebp; leave; ret
{ 0x1, {0xFF}, {0x90} }, // nop
{ 0x1, {0xFF}, {0x55} }, // push %esp
{ 0x2, {0xFF, 0xFF}, {0x89, 0xE5} }, // mov %esp,%ebp
{ 0x1, {0xFF}, {0x53} }, // push %ebx
{ 0x3, {0xFF, 0xFF, 0x00}, {0x83, 0xEC, 0x00} }, // sub 0x??, %esp
{ 0x6, {0xFF, 0xFF, 0x00, 0x00, 0x00, 0x00}, {0x81, 0xEC, 0x00, 0x00, 0x00, 0x00} }, // sub 0x??, %esp with 32bit immediate
{ 0x1, {0xFF}, {0x57} }, // push %edi
{ 0x1, {0xFF}, {0x56} }, // push %esi
{ 0x2, {0xFF, 0xFF}, {0x31, 0xC0} }, // xor %eax, %eax
{ 0x3, {0xFF, 0x4F, 0x00}, {0x8B, 0x45, 0x00} }, // mov $imm(%ebp), %reg
{ 0x3, {0xFF, 0x4C, 0x00}, {0x8B, 0x40, 0x00} }, // mov $imm(%eax-%edx), %reg
{ 0x4, {0xFF, 0xFF, 0xFF, 0x00}, {0x8B, 0x4C, 0x24, 0x00} }, // mov $imm(%esp), %ecx
{ 0x5, {0xFF, 0x00, 0x00, 0x00, 0x00}, {0xB8, 0x00, 0x00, 0x00, 0x00} }, // mov $imm, %eax
{ 0x0 }
};
#elif defined(__x86_64__)
static AsmInstructionMatch possibleInstructions[] = {
{ 0x5, {0xFF, 0x00, 0x00, 0x00, 0x00}, {0xE9, 0x00, 0x00, 0x00, 0x00} }, // jmp 0x????????
{ 0x1, {0xFF}, {0x90} }, // nop
{ 0x1, {0xF8}, {0x50} }, // push %rX
{ 0x3, {0xFF, 0xFF, 0xFF}, {0x48, 0x89, 0xE5} }, // mov %rsp,%rbp
{ 0x4, {0xFF, 0xFF, 0xFF, 0x00}, {0x48, 0x83, 0xEC, 0x00} }, // sub 0x??, %rsp
{ 0x4, {0xFB, 0xFF, 0x00, 0x00}, {0x48, 0x89, 0x00, 0x00} }, // move onto rbp
{ 0x4, {0xFF, 0xFF, 0xFF, 0xFF}, {0x40, 0x0f, 0xbe, 0xce} }, // movsbl %sil, %ecx
{ 0x2, {0xFF, 0x00}, {0x41, 0x00} }, // push %rXX
{ 0x2, {0xFF, 0x00}, {0x85, 0x00} }, // test %rX,%rX
{ 0x5, {0xF8, 0x00, 0x00, 0x00, 0x00}, {0xB8, 0x00, 0x00, 0x00, 0x00} }, // mov $imm, %reg
{ 0x3, {0xFF, 0xFF, 0x00}, {0xFF, 0x77, 0x00} }, // pushq $imm(%rdi)
{ 0x2, {0xFF, 0xFF}, {0x31, 0xC0} }, // xor %eax, %eax
{ 0x2, {0xFF, 0xFF}, {0x89, 0xF8} }, // mov %edi, %eax
{ 0x0 }
};
#endif
static Boolean codeMatchesInstruction(unsigned char *code, AsmInstructionMatch* instruction)
{
Boolean match = true;
size_t i;
for (i=0; i<instruction->length; i++) {
unsigned char mask = instruction->mask[i];
unsigned char constraint = instruction->constraint[i];
unsigned char codeValue = code[i];
match = ((codeValue & mask) == constraint);
if (!match) break;
}
return match;
}
#if defined(__i386__) || defined(__x86_64__)
static Boolean
eatKnownInstructions(
unsigned char *code,
uint64_t *newInstruction,
int *howManyEaten,
char *originalInstructions,
int *originalInstructionCount,
uint8_t *originalInstructionSizes )
{
Boolean allInstructionsKnown = true;
int totalEaten = 0;
unsigned char* ptr = code;
int remainsToEat = 5; // a JMP instruction takes 5 bytes
int instructionIndex = 0;
if (howManyEaten) *howManyEaten = 0;
if (originalInstructionCount) *originalInstructionCount = 0;
while (remainsToEat > 0) {
Boolean curInstructionKnown = false;
// See if instruction matches one we know
AsmInstructionMatch* curInstr = possibleInstructions;
do {
if ((curInstructionKnown = codeMatchesInstruction(ptr, curInstr))) break;
curInstr++;
} while (curInstr->length > 0);
// if all instruction matches failed, we don't know current instruction then, stop here
if (!curInstructionKnown) {
allInstructionsKnown = false;
fprintf(stderr, "mach_override: some instructions unknown! Need to update mach_override.c\n");
break;
}
// At this point, we've matched curInstr
int eaten = curInstr->length;
ptr += eaten;
remainsToEat -= eaten;
totalEaten += eaten;
if (originalInstructionSizes) originalInstructionSizes[instructionIndex] = eaten;
instructionIndex += 1;
if (originalInstructionCount) *originalInstructionCount = instructionIndex;
}
if (howManyEaten) *howManyEaten = totalEaten;
if (originalInstructions) {
Boolean enoughSpaceForOriginalInstructions = (totalEaten < kOriginalInstructionsSize);
if (enoughSpaceForOriginalInstructions) {
memset(originalInstructions, 0x90 /* NOP */, kOriginalInstructionsSize); // fill instructions with NOP
bcopy(code, originalInstructions, totalEaten);
} else {
// printf ("Not enough space in island to store original instructions. Adapt the island definition and kOriginalInstructionsSize\n");
return false;
}
}
if (allInstructionsKnown) {
// save last 3 bytes of first 64bits of codre we'll replace
uint64_t currentFirst64BitsOfCode = *((uint64_t *)code);
currentFirst64BitsOfCode = OSSwapInt64(currentFirst64BitsOfCode); // back to memory representation
currentFirst64BitsOfCode &= 0x0000000000FFFFFFLL;
// keep only last 3 instructions bytes, first 5 will be replaced by JMP instr
*newInstruction &= 0xFFFFFFFFFF000000LL; // clear last 3 bytes
*newInstruction |= (currentFirst64BitsOfCode & 0x0000000000FFFFFFLL); // set last 3 bytes
}
return allInstructionsKnown;
}
static void
fixupInstructions(
void *originalFunction,
void *escapeIsland,
void *instructionsToFix,
int instructionCount,
uint8_t *instructionSizes )
{
int index;
for (index = 0;index < instructionCount;index += 1)
{
if (*(uint8_t*)instructionsToFix == 0xE9) // 32-bit jump relative
{
uint32_t offset = (uintptr_t)originalFunction - (uintptr_t)escapeIsland;
uint32_t *jumpOffsetPtr = (uint32_t*)((uintptr_t)instructionsToFix + 1);
*jumpOffsetPtr += offset;
}
originalFunction = (void*)((uintptr_t)originalFunction + instructionSizes[index]);
escapeIsland = (void*)((uintptr_t)escapeIsland + instructionSizes[index]);
instructionsToFix = (void*)((uintptr_t)instructionsToFix + instructionSizes[index]);
}
}
#endif
#if defined(__i386__)
__asm(
".text;"
".align 2, 0x90;"
"_atomic_mov64:;"
" pushl %ebp;"
" movl %esp, %ebp;"
" pushl %esi;"
" pushl %ebx;"
" pushl %ecx;"
" pushl %eax;"
" pushl %edx;"
// atomic push of value to an address
// we use cmpxchg8b, which compares content of an address with
// edx:eax. If they are equal, it atomically puts 64bit value
// ecx:ebx in address.
// We thus put contents of address in edx:eax to force ecx:ebx
// in address
" mov 8(%ebp), %esi;" // esi contains target address
" mov 12(%ebp), %ebx;"
" mov 16(%ebp), %ecx;" // ecx:ebx now contains value to put in target address
" mov (%esi), %eax;"
" mov 4(%esi), %edx;" // edx:eax now contains value currently contained in target address
" lock; cmpxchg8b (%esi);" // atomic move.
// restore registers
" popl %edx;"
" popl %eax;"
" popl %ecx;"
" popl %ebx;"
" popl %esi;"
" popl %ebp;"
" ret"
);
#elif defined(__x86_64__)
void atomic_mov64(
uint64_t *targetAddress,
uint64_t value )
{
*targetAddress = value;
}
#endif
#endif

121
macx/overlay/mach_override.h
View File

@ -1,121 +0,0 @@
/*******************************************************************************
mach_override.h
Copyright (c) 2003-2009 Jonathan 'Wolf' Rentzsch: <http://rentzsch.com>
Some rights reserved: <http://opensource.org/licenses/mit-license.php>
***************************************************************************/
/***************************************************************************//**
@mainpage mach_override
@author Jonathan 'Wolf' Rentzsch: <http://rentzsch.com>
This package, coded in C to the Mach API, allows you to override ("patch")
program- and system-supplied functions at runtime. You can fully replace
functions with your implementations, or merely head- or tail-patch the
original implementations.
Use it by #include'ing mach_override.h from your .c, .m or .mm file(s).
@todo Discontinue use of Carbon's MakeDataExecutable() and
CompareAndSwap() calls and start using the Mach equivalents, if they
exist. If they don't, write them and roll them in. That way, this
code will be pure Mach, which will make it easier to use everywhere.
Update: MakeDataExecutable() has been replaced by
msync(MS_INVALIDATE). There is an OSCompareAndSwap in libkern, but
I'm currently unsure if I can link against it. May have to roll in
my own version...
@todo Stop using an entire 4K high-allocated VM page per 28-byte escape
branch island. Done right, this will dramatically speed up escape
island allocations when they number over 250. Then again, if you're
overriding more than 250 functions, maybe speed isn't your main
concern...
@todo Add detection of: b, bl, bla, bc, bcl, bcla, bcctrl, bclrl
first-instructions. Initially, we should refuse to override
functions beginning with these instructions. Eventually, we should
dynamically rewrite them to make them position-independent.
@todo Write mach_unoverride(), which would remove an override placed on a
function. Must be multiple-override aware, which means an almost
complete rewrite under the covers, because the target address can't
be spread across two load instructions like it is now since it will
need to be atomically updatable.
@todo Add non-rentry variants of overrides to test_mach_override.
***************************************************************************/
#ifndef MUMBLE_MACH_OVERRIDE_H_
#define MUMBLE_MACH_OVERRIDE_H_
#include <sys/types.h>
#include <mach/error.h>
#ifdef __cplusplus
extern "C" {
#endif
/**
Returned if the function to be overrided begins with a 'mfctr' instruction.
*/
#define err_cannot_override (err_local|1)
/************************************************************************************//**
Dynamically overrides the function implementation referenced by
originalFunctionAddress with the implentation pointed to by overrideFunctionAddress.
Optionally returns a pointer to a "reentry island" which, if jumped to, will resume
the original implementation.
@param originalFunctionAddress -> Required address of the function to
override (with overrideFunctionAddress).
@param overrideFunctionAddress -> Required address to the overriding
function.
@param originalFunctionReentryIsland <- Optional pointer to pointer to the
reentry island. Can be NULL.
@result <- err_cannot_override if the original
function's implementation begins with
the 'mfctr' instruction.
************************************************************************************/
mach_error_t
mach_override_ptr(
void *originalFunctionAddress,
const void *overrideFunctionAddress,
void **originalFunctionReentryIsland );
/************************************************************************************//**
************************************************************************************/
#ifdef __cplusplus
#define MACH_OVERRIDE( ORIGINAL_FUNCTION_RETURN_TYPE, ORIGINAL_FUNCTION_NAME, ORIGINAL_FUNCTION_ARGS, ERR ) \
{ \
static ORIGINAL_FUNCTION_RETURN_TYPE (*ORIGINAL_FUNCTION_NAME##_reenter)ORIGINAL_FUNCTION_ARGS; \
static bool ORIGINAL_FUNCTION_NAME##_overriden = false; \
class mach_override_class__##ORIGINAL_FUNCTION_NAME { \
public: \
static kern_return_t override(void *originalFunctionPtr) { \
kern_return_t result = err_none; \
if (!ORIGINAL_FUNCTION_NAME##_overriden) { \
ORIGINAL_FUNCTION_NAME##_overriden = true; \
result = mach_override_ptr( (void*)originalFunctionPtr, \
(void*)mach_override_class__##ORIGINAL_FUNCTION_NAME::replacement, \
(void**)&ORIGINAL_FUNCTION_NAME##_reenter ); \
} \
return result; \
} \
static ORIGINAL_FUNCTION_RETURN_TYPE replacement ORIGINAL_FUNCTION_ARGS {
#define END_MACH_OVERRIDE( ORIGINAL_FUNCTION_NAME ) \
} \
}; \
\
err = mach_override_class__##ORIGINAL_FUNCTION_NAME::override((void*)ORIGINAL_FUNCTION_NAME); \
}
#endif
#ifdef __cplusplus
}
#endif
#endif

9
macx/overlay/overlay.pro
View File

@ -19,16 +19,21 @@ TARGET = mumbleoverlay
QMAKE_LFLAGS_PLUGIN += -undefined dynamic_lookup -dynamic
QMAKE_LFLAGS = -framework CoreFoundation
SOURCES = mach_override.c
INCLUDEPATH *= ../../3rdparty/mach-override-src
LIBS *= -lmach-override
OBJECTIVE_SOURCES = overlay.m
HEADERS = mach_override.h avail.h
HEADERS = avail.h
DIST = overlay.plist avail.pl
CONFIG(debug, debug|release) {
QMAKE_LIBDIR *= ../../debug
DESTDIR = ../../debug
}
CONFIG(release, debug|release) {
QMAKE_LIBDIR *= ../../release
DESTDIR = ../../release
}

1
main.pro
View File

@ -62,6 +62,7 @@ CONFIG *= ordered debug_and_release
isEmpty(MUMBLE_PREFIX) {
error("Missing $MUMBLE_PREFIX environment variable");
}
SUBDIRS *= 3rdparty/mach-override-build
SUBDIRS *= macx
!exists($$(MUMBLE_PREFIX)/../LCDSDK) {
CONFIG *= no-g15