Bug 732173 - poison write during shutdown in a debug build. r=ted.

With this patch we now patch the write functions during shutdown in a debug
build and abort if a non white listed write is found.
This commit is contained in:
Rafael Ávila de Espíndola 2012-07-03 09:15:34 -04:00
parent e6050ef2f4
commit c60b1db79c
12 changed files with 1258 additions and 24 deletions

View File

@ -37,6 +37,8 @@ namespace google_breakpad {
CrashGenerationServer::CrashGenerationServer(
const char *mach_port_name,
FilterCallback filter,
void *filter_context,
OnClientDumpRequestCallback dump_callback,
void *dump_context,
OnClientExitingCallback exit_callback,
@ -44,6 +46,8 @@ CrashGenerationServer::CrashGenerationServer(
bool generate_dumps,
const std::string &dump_path)
: dump_callback_(dump_callback),
filter_(filter),
filter_context_(filter_context),
dump_context_(dump_context),
exit_callback_(exit_callback),
exit_context_(exit_context),
@ -110,7 +114,7 @@ bool CrashGenerationServer::WaitForOneMessage() {
bool result;
std::string dump_path;
if (generate_dumps_) {
if (generate_dumps_ && (!filter_ || filter_(filter_context_))) {
ScopedTaskSuspend suspend(remote_task);
MinidumpGenerator generator(remote_task, handler_thread);

View File

@ -65,10 +65,14 @@ class CrashGenerationServer {
typedef void (*OnClientExitingCallback)(void *context,
const ClientInfo &client_info);
typedef bool (*FilterCallback)(void *context);
// Create an instance with the given parameters.
//
// mach_port_name: Named server port to listen on.
// filter: Callback for a client to know that we are about to write a dump
// and mabybe prevent it.
// filter_context: Context for the filte callback.
// dump_callback: Callback for a client crash dump request.
// dump_context: Context for client crash dump request callback.
// exit_callback: Callback for client process exit.
@ -80,6 +84,8 @@ class CrashGenerationServer {
// dump_path: Path for generating dumps; required only if true is
// passed for generateDumps parameter; NULL can be passed otherwise.
CrashGenerationServer(const char *mach_port_name,
FilterCallback filter,
void *filter_context,
OnClientDumpRequestCallback dump_callback,
void *dump_context,
OnClientExitingCallback exit_callback,
@ -109,6 +115,9 @@ class CrashGenerationServer {
// if a quit message was received or if an error occurred.
bool WaitForOneMessage();
FilterCallback filter_;
void *filter_context_;
OnClientDumpRequestCallback dump_callback_;
void *dump_context_;

View File

@ -79,6 +79,7 @@
#include <vector>
#include "mozilla/mozalloc_oom.h"
#include "mozilla/mozPoisonWrite.h"
#if defined(XP_MACOSX)
CFStringRef reporterClientAppID = CFSTR("org.mozilla.crashreporter");
@ -634,6 +635,14 @@ static bool ShouldReport()
return !(envvar && *envvar);
}
namespace {
bool Filter(void* context) {
mozilla::DisableWritePoisoning();
return true;
}
}
nsresult SetExceptionHandler(nsIFile* aXREDirectory,
bool force/*=false*/)
{
@ -792,7 +801,7 @@ nsresult SetExceptionHandler(nsIFile* aXREDirectory,
#ifdef XP_WIN
FPEFilter,
#else
nsnull,
Filter,
#endif
MinidumpCallback,
nsnull,
@ -1913,6 +1922,11 @@ OOPInitialized()
return pidToMinidump != NULL;
}
static bool ChildFilter(void *context) {
mozilla::DisableWritePoisoning();
return true;
}
static void
OOPInit()
{
@ -1963,6 +1977,8 @@ OOPInit()
crashServer = new CrashGenerationServer(
childCrashNotifyPipe,
ChildFilter,
NULL,
OnChildProcessDumpRequested, NULL,
NULL, NULL,
true, // automatically generate dumps
@ -2105,7 +2121,7 @@ SetRemoteExceptionHandler(const nsACString& crashPipe)
gExceptionHandler = new google_breakpad::
ExceptionHandler("",
NULL, // no filter callback
Filter,
NULL, // no minidump callback
NULL, // no callback context
true, // install signal handlers

View File

@ -35,6 +35,7 @@
#include "nsStackWalk.h"
#include "nsTraceMallocCallbacks.h"
#include "nsTypeInfo.h"
#include "mozilla/mozPoisonWrite.h"
#if defined(XP_MACOSX)
@ -1329,6 +1330,9 @@ NS_TraceMallocStartup(int logfd)
PR_ASSERT(logfp == &default_logfile);
tracing_enabled = (logfd >= 0);
if (logfd >= 3)
MozillaRegisterDebugFD(logfd);
/* stacks are disabled if this env var is set to a non-empty value */
stack_disable_env = PR_GetEnv("NS_TRACE_MALLOC_DISABLE_STACKS");
stacks_enabled = !stack_disable_env || !*stack_disable_env;
@ -1527,6 +1531,7 @@ NS_TraceMallocShutdown(void)
log_tmstats(fp);
flush_logfile(fp);
if (fp->fd >= 0) {
MozillaUnRegisterDebugFD(fp->fd);
close(fp->fd);
fp->fd = -1;
}
@ -1663,6 +1668,7 @@ NS_TraceMallocCloseLogFD(int fd)
}
TM_EXIT_LOCK_AND_UNSUPPRESS_TRACING(t);
MozillaUnRegisterDebugFD(fd);
close(fd);
}
@ -1757,6 +1763,7 @@ NS_TraceMallocDumpAllocations(const char *pathname)
{
FILE *ofp;
int rv;
int fd;
tm_thread *t = tm_get_thread();
@ -1764,12 +1771,15 @@ NS_TraceMallocDumpAllocations(const char *pathname)
ofp = fopen(pathname, WRITE_FLAGS);
if (ofp) {
MozillaRegisterDebugFD(fileno(ofp));
if (allocations) {
PL_HashTableEnumerateEntries(allocations, allocation_enumerator,
ofp);
}
rv = ferror(ofp) ? -1 : 0;
fclose(ofp);
fd = fileno(ofp);
fclose(ofp); /* May call write. */
MozillaUnRegisterDebugFD(fd);
} else {
rv = -1;
}

View File

@ -34,6 +34,7 @@
#endif
#include "mozilla/BlockingResourceBase.h"
#include "mozilla/mozPoisonWrite.h"
#ifdef HAVE_DLOPEN
#include <dlfcn.h>
@ -646,6 +647,7 @@ static bool InitLog(const char* envVar, const char* msg, FILE* *result)
}
stream = ::fopen(fname.get(), "w" FOPEN_NO_INHERIT);
if (stream != NULL) {
MozillaRegisterDebugFD(fileno(stream));
*result = stream;
fprintf(stdout, "### %s defined -- logging %s to %s\n",
envVar, msg, fname.get());
@ -1235,6 +1237,17 @@ nsTraceRefcntImpl::Startup()
{
}
static void maybeUnregisterAndCloseFile(FILE *&f) {
if (!f)
return;
int fd = fileno(f);
fclose(f);
if (fd != 1 && fd != 2)
MozillaUnRegisterDebugFD(fd);
f = nsnull;
}
void
nsTraceRefcntImpl::Shutdown()
{
@ -1256,26 +1269,11 @@ nsTraceRefcntImpl::Shutdown()
PL_HashTableDestroy(gSerialNumbers);
gSerialNumbers = nsnull;
}
if (gBloatLog) {
fclose(gBloatLog);
gBloatLog = nsnull;
}
if (gRefcntsLog) {
fclose(gRefcntsLog);
gRefcntsLog = nsnull;
}
if (gAllocLog) {
fclose(gAllocLog);
gAllocLog = nsnull;
}
if (gLeakyLog) {
fclose(gLeakyLog);
gLeakyLog = nsnull;
}
if (gCOMPtrLog) {
fclose(gCOMPtrLog);
gCOMPtrLog = nsnull;
}
maybeUnregisterAndCloseFile(gBloatLog);
maybeUnregisterAndCloseFile(gRefcntsLog);
maybeUnregisterAndCloseFile(gAllocLog);
maybeUnregisterAndCloseFile(gLeakyLog);
maybeUnregisterAndCloseFile(gCOMPtrLog);
#endif
}

View File

@ -27,6 +27,10 @@ ifeq ($(OS_ARCH),Linux)
DEFINES += -DXP_LINUX
endif
ifeq (Darwin, $(OS_ARCH))
CSRCS = mach_override.c
endif
CPPSRCS = \
$(XPCOM_GLUE_SRC_LCPPSRCS) \
$(XPCOM_GLUENS_SRC_LCPPSRCS) \
@ -37,6 +41,12 @@ CPPSRCS = \
FileLocation.cpp \
$(NULL)
ifeq (Darwin, $(OS_ARCH))
CPPSRCS += mozPoisonWriteMac.cpp
else
CPPSRCS += mozPoisonWriteStub.cpp
endif
ifeq ($(OS_ARCH),WINNT)
CPPSRCS += perfprobe.cpp
endif
@ -95,6 +105,7 @@ EXPORTS_mozilla = \
ServiceList.h \
Omnijar.h \
FileLocation.h \
mozPoisonWrite.h \
$(NULL)
ifeq ($(OS_ARCH),WINNT)

768
xpcom/build/mach_override.c Normal file
View File

@ -0,0 +1,768 @@
/* copied from https://github.com/rentzsch/mach_star */
/*******************************************************************************
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)
#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
#define kAllocateHigh 1
#define kAllocateNormal 0
/**************************
*
* Data Types
*
**************************/
#pragma mark -
#pragma mark (Data Types)
typedef struct {
char instructions[sizeof(kIslandTemplate)];
int allocatedHigh;
} BranchIsland;
/**************************
*
* Funky Protos
*
**************************/
#pragma mark -
#pragma mark (Funky Protos)
mach_error_t
allocateBranchIsland(
BranchIsland **island,
int allocateHigh,
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;
vm_size_t pageSize;
host_page_size( mach_host_self(), &pageSize );
uintptr_t page = (uintptr_t)address & ~(uintptr_t)(pageSize-1);
int e = err_none;
e |= mprotect((void *)page, pageSize, PROT_EXEC | PROT_READ | PROT_WRITE);
e |= msync((void *)page, pageSize, 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, kAllocateHigh, 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, kAllocateHigh, 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.
@param allocateHigh -> Whether to allocate the island at the end of the
address space (for use with the branch absolute
instruction).
@result <- mach_error_t
***************************************************************************/
mach_error_t
allocateBranchIsland(
BranchIsland **island,
int allocateHigh,
void *originalFunctionAddress)
{
assert( island );
mach_error_t err = err_none;
if( allocateHigh ) {
vm_size_t pageSize;
err = host_page_size( mach_host_self(), &pageSize );
if( !err ) {
assert( sizeof( BranchIsland ) <= pageSize );
#if defined(__ppc__) || defined(__POWERPC__)
vm_address_t first = 0xfeffffff;
vm_address_t last = 0xfe000000 + pageSize;
#elif defined(__x86_64__)
vm_address_t first = (uint64_t)originalFunctionAddress & ~(uint64_t)(((uint64_t)1 << 31) - 1) | ((uint64_t)1 << 31); // start in the middle of the page?
vm_address_t last = 0x0;
#else
vm_address_t first = 0xffc00000;
vm_address_t last = 0xfffe0000;
#endif
vm_address_t page = first;
int allocated = 0;
vm_map_t task_self = mach_task_self();
while( !err && !allocated && page != last ) {
err = vm_allocate( task_self, &page, pageSize, 0 );
if( err == err_none )
allocated = 1;
else if( err == KERN_NO_SPACE ) {
#if defined(__x86_64__)
page -= pageSize;
#else
page += pageSize;
#endif
err = err_none;
}
}
if( allocated )
*island = (BranchIsland*) page;
else if( !allocated && !err )
err = KERN_NO_SPACE;
}
} else {
void *block = malloc( sizeof( BranchIsland ) );
if( block )
*island = block;
else
err = KERN_NO_SPACE;
}
if( !err )
(**island).allocatedHigh = allocateHigh;
return err;
}
/***************************************************************************//**
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( island->allocatedHigh );
mach_error_t err = err_none;
if( island->allocatedHigh ) {
vm_size_t pageSize;
err = host_page_size( mach_host_self(), &pageSize );
if( !err ) {
assert( sizeof( BranchIsland ) <= pageSize );
err = vm_deallocate(
mach_task_self(),
(vm_address_t) island, pageSize );
}
} else {
free( island );
}
return err;
}
/***************************************************************************//**
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
{ 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
{ 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
xpcom/build/mach_override.h Normal file
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@ -0,0 +1,121 @@
/*******************************************************************************
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 _mach_override_
#define _mach_override_
#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 // _mach_override_

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@ -0,0 +1,19 @@
/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* vim:set ts=4 sw=4 sts=4 ci et: */
/* 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 http://mozilla.org/MPL/2.0/. */
#include "mozilla/Types.h"
MOZ_BEGIN_EXTERN_C
void MozillaRegisterDebugFD(int fd);
void MozillaUnRegisterDebugFD(int fd);
MOZ_END_EXTERN_C
#ifdef __cplusplus
namespace mozilla {
void PoisonWrite();
void DisableWritePoisoning();
}
#endif

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@ -0,0 +1,257 @@
/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* vim:set ts=4 sw=4 sts=4 ci et: */
/* 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 http://mozilla.org/MPL/2.0/. */
#include "mozilla/mozPoisonWrite.h"
#include "mozilla/Util.h"
#include "nsTraceRefcntImpl.h"
#include "mozilla/Assertions.h"
#include "mozilla/Scoped.h"
#include "mozilla/Mutex.h"
#include "nsStackWalk.h"
#include "mach_override.h"
#include <sys/stat.h>
#include <vector>
#include <algorithm>
#include <string.h>
#include <sys/uio.h>
#include <aio.h>
#include <dlfcn.h>
namespace {
using namespace mozilla;
struct FuncData {
const char *Name; // Name of the function for the ones we use dlsym
const void *Wrapper; // The function that we will replace 'Function' with
void *Function; // The function that will be replaced with 'Wrapper'
void *Buffer; // Will point to the jump buffer that lets us call
// 'Function' after it has been replaced.
};
typedef ssize_t (*write_t)(int fd, const void *buf, size_t count);
void AbortOnBadWrite(int fd, const void *wbuf, size_t count);
template<FuncData &foo>
ssize_t wrap_write_temp(int fd, const void *buf, size_t count) {
AbortOnBadWrite(fd, buf, count);
write_t old_write = (write_t) foo.Buffer;
return old_write(fd, buf, count);
}
// FIXME: clang accepts usinging wrap_data_temp<X ## _data> in the struct
// initialization. Is this a gcc 4.2 bug?
// Define a FuncData for a function that can be found without dlsym.
#define DEFINE_F_DATA(X) \
ssize_t wrap_ ## X (int fd, const void *buf, size_t count); \
FuncData X ## _data = { 0, (void*) wrap_ ## X, (void*) X }; \
ssize_t wrap_ ## X (int fd, const void *buf, size_t count) { \
return wrap_write_temp<X ## _data>(fd, buf, count); \
}
// Define a FuncData for a function that can only be found with dlsym.
#define DEFINE_F_DATA_DYN(X, NAME) \
ssize_t wrap_ ## X (int fd, const void *buf, size_t count); \
FuncData X ## _data = { NAME, (void*) wrap_ ## X }; \
ssize_t wrap_ ## X (int fd, const void *buf, size_t count) { \
return wrap_write_temp<X ## _data>(fd, buf, count); \
}
// Define a simple FuncData that just aborts.
#define DEFINE_F_DATA_ABORT(X) \
void wrap_ ## X() { abort(); } \
FuncData X ## _data = { 0, (void*) wrap_ ## X, (void*) X }
// Define a simple FuncData that just aborts for a function that needs dlsym.
#define DEFINE_F_DATA_ABORT_DYN(X, NAME) \
void wrap_ ## X() { abort(); } \
FuncData X ## _data = { NAME, (void*) wrap_ ## X }
DEFINE_F_DATA_ABORT(aio_write);
DEFINE_F_DATA_ABORT(pwrite);
// These exist on 32 bit OS X
DEFINE_F_DATA_ABORT_DYN(writev_NOCANCEL_UNIX2003, "writev$NOCANCEL$UNIX2003");
DEFINE_F_DATA_ABORT_DYN(writev_UNIX2003, "writev$UNIX2003");
DEFINE_F_DATA_ABORT_DYN(pwrite_NOCANCEL_UNIX2003, "pwrite$NOCANCEL$UNIX2003");
DEFINE_F_DATA_ABORT_DYN(pwrite_UNIX2003, "pwrite$UNIX2003");
// These exist on 64 bit OS X
DEFINE_F_DATA_ABORT_DYN(writev_NOCANCEL, "writev$NOCANCEL");
DEFINE_F_DATA_ABORT_DYN(pwrite_NOCANCEL, "pwrite$NOCANCEL");
DEFINE_F_DATA(write);
typedef ssize_t (*writev_t)(int fd, const struct iovec *iov, int iovcnt);
ssize_t wrap_writev(int fd, const struct iovec *iov, int iovcnt);
FuncData writev_data = { 0, (void*) wrap_writev, (void*) writev };
ssize_t wrap_writev(int fd, const struct iovec *iov, int iovcnt) {
AbortOnBadWrite(fd, 0, iovcnt);
writev_t old_write = (writev_t) writev_data.Buffer;
return old_write(fd, iov, iovcnt);
}
// These exist on 32 bit OS X
DEFINE_F_DATA_DYN(write_NOCANCEL_UNIX2003, "write$NOCANCEL$UNIX2003");
DEFINE_F_DATA_DYN(write_UNIX2003, "write$UNIX2003");
// These exist on 64 bit OS X
DEFINE_F_DATA_DYN(write_NOCANCEL, "write$NOCANCEL");
FuncData *Functions[] = { &aio_write_data,
&pwrite_data,
&pwrite_NOCANCEL_UNIX2003_data,
&pwrite_UNIX2003_data,
&pwrite_NOCANCEL_data,
&write_data,
&write_NOCANCEL_UNIX2003_data,
&write_UNIX2003_data,
&write_NOCANCEL_data,
&writev_data,
&writev_NOCANCEL_UNIX2003_data,
&writev_UNIX2003_data,
&writev_NOCANCEL_data};
const int NumFunctions = ArrayLength(Functions);
std::vector<int>& getDebugFDs() {
// We have to use new as some write happen during static destructors
// so an static std::vector might be destroyed while we still need it.
static std::vector<int> *DebugFDs = new std::vector<int>();
return *DebugFDs;
}
struct AutoLockTraits {
typedef PRLock *type;
const static type empty() {
return NULL;
}
const static void release(type aL) {
PR_Unlock(aL);
}
};
class MyAutoLock : public Scoped<AutoLockTraits> {
public:
static PRLock *getDebugFDsLock() {
// We have to use something lower level than a mutex. If we don't, we
// can get recursive in here when called from logging a call to free.
static PRLock *Lock = PR_NewLock();
return Lock;
}
MyAutoLock() : Scoped<AutoLockTraits>(getDebugFDsLock()) {
PR_Lock(get());
}
};
bool PoisoningDisabled = false;
void AbortOnBadWrite(int fd, const void *wbuf, size_t count) {
if (PoisoningDisabled)
return;
// Ignore writes of zero bytes, firefox does some during shutdown.
if (count == 0)
return;
// Stdout and Stderr are OK.
if(fd == 1 || fd == 2)
return;
struct stat buf;
int rv = fstat(fd, &buf);
MOZ_ASSERT(rv == 0);
// FIFOs are used for thread communication during shutdown.
if ((buf.st_mode & S_IFMT) == S_IFIFO)
return;
MyAutoLock lockedScope;
// Debugging FDs are OK
std::vector<int> &Vec = getDebugFDs();
if (std::find(Vec.begin(), Vec.end(), fd) != Vec.end())
return;
// For writev we pass NULL in wbuf. We should only get here from
// dbm, and it uses write, so assert that we have wbuf.
MOZ_ASSERT(wbuf);
// As a really bad hack, accept writes that don't change the on disk
// content. This is needed because dbm doesn't keep track of dirty bits
// and can end up writing the same data to disk twice. Once when the
// user (nss) asks it to sync and once when closing the database.
void *wbuf2 = malloc(count);
MOZ_ASSERT(wbuf2);
off_t pos = lseek(fd, 0, SEEK_CUR);
MOZ_ASSERT(pos != -1);
ssize_t r = read(fd, wbuf2, count);
MOZ_ASSERT(r == count);
int cmp = memcmp(wbuf, wbuf2, count);
MOZ_ASSERT(cmp == 0);
free(wbuf2);
off_t pos2 = lseek(fd, pos, SEEK_SET);
MOZ_ASSERT(pos2 == pos);
}
// We cannot use destructors to free the lock and the list of debug fds since
// we don't control the order the destructors are called. Instead, we use
// libc funcion __cleanup callback which runs after the destructors.
void (*OldCleanup)();
extern "C" void (*__cleanup)();
void FinalCleanup() {
if (OldCleanup)
OldCleanup();
delete &getDebugFDs();
PR_DestroyLock(MyAutoLock::getDebugFDsLock());
}
} // anonymous namespace
extern "C" {
void MozillaRegisterDebugFD(int fd) {
MyAutoLock lockedScope;
std::vector<int> &Vec = getDebugFDs();
MOZ_ASSERT(std::find(Vec.begin(), Vec.end(), fd) == Vec.end());
Vec.push_back(fd);
}
void MozillaUnRegisterDebugFD(int fd) {
MyAutoLock lockedScope;
std::vector<int> &Vec = getDebugFDs();
std::vector<int>::iterator i = std::find(Vec.begin(), Vec.end(), fd);
MOZ_ASSERT(i != Vec.end());
Vec.erase(i);
}
}
namespace mozilla {
void PoisonWrite() {
// For now only poison writes in debug builds.
#ifndef DEBUG
return;
#endif
PoisoningDisabled = false;
OldCleanup = __cleanup;
__cleanup = FinalCleanup;
for (int i = 0; i < NumFunctions; ++i) {
FuncData *d = Functions[i];
if (!d->Function)
d->Function = dlsym(RTLD_DEFAULT, d->Name);
if (!d->Function)
continue;
mach_error_t t = mach_override_ptr(d->Function, d->Wrapper,
&d->Buffer);
MOZ_ASSERT(t == err_none);
}
}
void DisableWritePoisoning() {
PoisoningDisabled = true;
}
}

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@ -0,0 +1,18 @@
/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* vim:set ts=4 sw=4 sts=4 ci et: */
/* 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 http://mozilla.org/MPL/2.0/. */
namespace mozilla {
void PoisonWrite() {
}
void DisableWritePoisoning() {
}
}
extern "C" {
void MozillaRegisterDebugFD(int fd) {
}
void MozillaUnRegisterDebugFD(int fd) {
}
}

View File

@ -106,6 +106,7 @@ extern nsresult nsStringInputStreamConstructor(nsISupports *, REFNSIID, void **)
#include "nsChromeRegistry.h"
#include "nsChromeProtocolHandler.h"
#include "mozilla/mozPoisonWrite.h"
#include "mozilla/scache/StartupCache.h"
@ -647,6 +648,8 @@ ShutdownXPCOM(nsIServiceManager* servMgr)
nsCycleCollector_shutdown();
mozilla::PoisonWrite();
if (moduleLoaders) {
bool more;
nsCOMPtr<nsISupports> el;