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Commit f246eadc by Jack Howarth Committed by Kostya Serebryany
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[libsanitizer] add mach_override and enable libsanitizer on darwin 

From-SVN: r193781
parent 9f1b2dcb
Showing with 1217 additions and 7 deletions
gcc/ChangeLog
2012-11-24 Jack Howarth <howarth@bromo.med.uc.edu>
* config/darwin.h (LINK_COMMAND_SPEC_A): Deal with -fsanitize=address.
2012-11-24 Matthias Klose <doko@ubuntu.com>
* configure.ac (multiarch): Use $enableval instead of $withval.
gcc/config/darwin.h
......@@ -180,6 +180,9 @@ extern GTY(()) int darwin_ms_struct;
%{L*} %(link_libgcc) %o %{fprofile-arcs|fprofile-generate*|coverage:-lgcov} \
%{fopenmp|ftree-parallelize-loops=*: \
%{static|static-libgcc|static-libstdc++|static-libgfortran: libgomp.a%s; : -lgomp } } \
%{fsanitize=address: \
%{static|static-libasan|static-libgcc|static-libgfortran: -framework CoreFoundation -lstdc++ libasan.a%s; \
static-libstdc++: -framework CoreFoundation libstdc++.a%s libasan.a%s; : -framework CoreFoundation -lasan } } \
%{fgnu-tm: \
%{static|static-libgcc|static-libstdc++|static-libgfortran: libitm.a%s; : -litm } } \
%{!nostdlib:%{!nodefaultlibs:\
......
libsanitizer/ChangeLog
2012-11-24 Kostya Serebryany kcc@google.com
Jack Howarth <howarth@bromo.med.uc.edu>
* interception/mach_override/mach_override.c: Migrate from llvm.
* interception/mach_override/mach_override.h: Likewise.
* interception/mach_override/LICENSE.txt: Likewise.
* configure.tgt: Add darwin to supported targets.
* configure.ac: Define USING_MACH_OVERRIDE when on darwin.
* interception/Makefile.am: Compile mach_override.c when
USING_MACH_OVERRIDE defined.
* configure: Regenerated.
* interception/Makefile.in: Likewise.
2012-11-23 H.J. Lu <hongjiu.lu@intel.com>
PR sanitizer/55450
......
libsanitizer/configure
......@@ -604,6 +604,8 @@ ac_subst_vars='am__EXEEXT_FALSE
am__EXEEXT_TRUE
LTLIBOBJS
LIBOBJS
USING_MACH_OVERRIDE_FALSE
USING_MACH_OVERRIDE_TRUE
TSAN_SUPPORTED_FALSE
TSAN_SUPPORTED_TRUE
enable_static
......@@ -11078,7 +11080,7 @@ else
lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
lt_status=$lt_dlunknown
cat > conftest.$ac_ext <<_LT_EOF
#line 11081 "configure"
#line 11083 "configure"
#include "confdefs.h"
#if HAVE_DLFCN_H
......@@ -11184,7 +11186,7 @@ else
lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
lt_status=$lt_dlunknown
cat > conftest.$ac_ext <<_LT_EOF
#line 11187 "configure"
#line 11189 "configure"
#include "confdefs.h"
#if HAVE_DLFCN_H
......@@ -14494,6 +14496,19 @@ else
fi
case "$host" in
*-*-darwin*) MACH_OVERRIDE=true ;;
*) MACH_OVERRIDE=false ;;
esac
if $MACH_OVERRIDE; then
USING_MACH_OVERRIDE_TRUE=
USING_MACH_OVERRIDE_FALSE='#'
else
USING_MACH_OVERRIDE_TRUE='#'
USING_MACH_OVERRIDE_FALSE=
fi
ac_config_files="$ac_config_files Makefile"
......@@ -14670,6 +14685,10 @@ if test -z "${TSAN_SUPPORTED_TRUE}" && test -z "${TSAN_SUPPORTED_FALSE}"; then
as_fn_error "conditional \"TSAN_SUPPORTED\" was never defined.
Usually this means the macro was only invoked conditionally." "$LINENO" 5
fi
if test -z "${USING_MACH_OVERRIDE_TRUE}" && test -z "${USING_MACH_OVERRIDE_FALSE}"; then
as_fn_error "conditional \"USING_MACH_OVERRIDE\" was never defined.
Usually this means the macro was only invoked conditionally." "$LINENO" 5
fi
: ${CONFIG_STATUS=./config.status}
ac_write_fail=0
......
libsanitizer/configure.ac
......@@ -80,6 +80,12 @@ unset TSAN_SUPPORTED
. ${srcdir}/configure.tgt
AM_CONDITIONAL(TSAN_SUPPORTED, [test "x$TSAN_SUPPORTED" = "xyes"])
case "$host" in
*-*-darwin*) MACH_OVERRIDE=true ;;
*) MACH_OVERRIDE=false ;;
esac
AM_CONDITIONAL(USING_MACH_OVERRIDE, $MACH_OVERRIDE)
AC_CONFIG_FILES([Makefile])
AC_CONFIG_FILES(AC_FOREACH([DIR], [interception sanitizer_common asan], [DIR/Makefile ]),
......
libsanitizer/configure.tgt
......@@ -27,6 +27,9 @@ case "${target}" in
;;
sparc*-*-linux*)
;;
x86_64-*-darwin* | i?86-*-darwin*)
TSAN_SUPPORTED=no
;;
*)
UNSUPPORTED=1
;;
......
libsanitizer/interception/Makefile.am
......@@ -14,7 +14,11 @@ interception_files = \
interception_mac.cc \
interception_win.cc
libinterception_la_SOURCES = $(interception_files)
if USING_MACH_OVERRIDE
libinterception_la_SOURCES = $(interception_files) mach_override/mach_override.c
else
libinterception_la_SOURCES = $(interception_files)
endif
# Work around what appears to be a GNU make bug handling MAKEFLAGS
# values defined in terms of make variables, as is the case for CC and
......
libsanitizer/interception/Makefile.in
......@@ -53,14 +53,29 @@ CONFIG_CLEAN_FILES =
CONFIG_CLEAN_VPATH_FILES =
LTLIBRARIES = $(noinst_LTLIBRARIES)
libinterception_la_LIBADD =
am__libinterception_la_SOURCES_DIST = interception_linux.cc \
interception_mac.cc interception_win.cc \
mach_override/mach_override.c
am__objects_1 = interception_linux.lo interception_mac.lo \
interception_win.lo
am_libinterception_la_OBJECTS = $(am__objects_1)
@USING_MACH_OVERRIDE_FALSE@am_libinterception_la_OBJECTS = \
@USING_MACH_OVERRIDE_FALSE@ $(am__objects_1)
@USING_MACH_OVERRIDE_TRUE@am_libinterception_la_OBJECTS = \
@USING_MACH_OVERRIDE_TRUE@ $(am__objects_1) mach_override.lo
libinterception_la_OBJECTS = $(am_libinterception_la_OBJECTS)
DEFAULT_INCLUDES = -I.@am__isrc@
depcomp = $(SHELL) $(top_srcdir)/../depcomp
am__depfiles_maybe = depfiles
am__mv = mv -f
COMPILE = $(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) \
$(CPPFLAGS) $(AM_CFLAGS) $(CFLAGS)
LTCOMPILE = $(LIBTOOL) --tag=CC $(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) \
--mode=compile $(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) \
$(AM_CPPFLAGS) $(CPPFLAGS) $(AM_CFLAGS) $(CFLAGS)
CCLD = $(CC)
LINK = $(LIBTOOL) --tag=CC $(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) \
--mode=link $(CCLD) $(AM_CFLAGS) $(CFLAGS) $(AM_LDFLAGS) \
$(LDFLAGS) -o $@
CXXCOMPILE = $(CXX) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) \
$(AM_CPPFLAGS) $(CPPFLAGS) $(AM_CXXFLAGS) $(CXXFLAGS)
LTCXXCOMPILE = $(LIBTOOL) --tag=CXX $(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) \
......@@ -71,7 +86,7 @@ CXXLINK = $(LIBTOOL) --tag=CXX $(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) \
--mode=link $(CXXLD) $(AM_CXXFLAGS) $(CXXFLAGS) $(AM_LDFLAGS) \
$(LDFLAGS) -o $@
SOURCES = $(libinterception_la_SOURCES)
DIST_SOURCES = $(libinterception_la_SOURCES)
DIST_SOURCES = $(am__libinterception_la_SOURCES_DIST)
ETAGS = etags
CTAGS = ctags
DISTFILES = $(DIST_COMMON) $(DIST_SOURCES) $(TEXINFOS) $(EXTRA_DIST)
......@@ -215,7 +230,8 @@ interception_files = \
interception_mac.cc \
interception_win.cc
libinterception_la_SOURCES = $(interception_files)
@USING_MACH_OVERRIDE_FALSE@libinterception_la_SOURCES = $(interception_files)
@USING_MACH_OVERRIDE_TRUE@libinterception_la_SOURCES = $(interception_files) mach_override/mach_override.c
# Work around what appears to be a GNU make bug handling MAKEFLAGS
# values defined in terms of make variables, as is the case for CC and
......@@ -261,7 +277,7 @@ MAKEOVERRIDES =
all: all-am
.SUFFIXES:
.SUFFIXES: .cc .lo .o .obj
.SUFFIXES: .c .cc .lo .o .obj
$(srcdir)/Makefile.in: @MAINTAINER_MODE_TRUE@ $(srcdir)/Makefile.am $(am__configure_deps)
@for dep in $?; do \
case '$(am__configure_deps)' in \
......@@ -313,6 +329,35 @@ distclean-compile:
@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/interception_linux.Plo@am__quote@
@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/interception_mac.Plo@am__quote@
@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/interception_win.Plo@am__quote@
@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/mach_override.Plo@am__quote@
.c.o:
@am__fastdepCC_TRUE@ $(COMPILE) -MT $@ -MD -MP -MF $(DEPDIR)/$*.Tpo -c -o $@ $<
@am__fastdepCC_TRUE@ $(am__mv) $(DEPDIR)/$*.Tpo $(DEPDIR)/$*.Po
@AMDEP_TRUE@@am__fastdepCC_FALSE@ source='$<' object='$@' libtool=no @AMDEPBACKSLASH@
@AMDEP_TRUE@@am__fastdepCC_FALSE@ DEPDIR=$(DEPDIR) $(CCDEPMODE) $(depcomp) @AMDEPBACKSLASH@
@am__fastdepCC_FALSE@ $(COMPILE) -c $<
.c.obj:
@am__fastdepCC_TRUE@ $(COMPILE) -MT $@ -MD -MP -MF $(DEPDIR)/$*.Tpo -c -o $@ `$(CYGPATH_W) '$<'`
@am__fastdepCC_TRUE@ $(am__mv) $(DEPDIR)/$*.Tpo $(DEPDIR)/$*.Po
@AMDEP_TRUE@@am__fastdepCC_FALSE@ source='$<' object='$@' libtool=no @AMDEPBACKSLASH@
@AMDEP_TRUE@@am__fastdepCC_FALSE@ DEPDIR=$(DEPDIR) $(CCDEPMODE) $(depcomp) @AMDEPBACKSLASH@
@am__fastdepCC_FALSE@ $(COMPILE) -c `$(CYGPATH_W) '$<'`
.c.lo:
@am__fastdepCC_TRUE@ $(LTCOMPILE) -MT $@ -MD -MP -MF $(DEPDIR)/$*.Tpo -c -o $@ $<
@am__fastdepCC_TRUE@ $(am__mv) $(DEPDIR)/$*.Tpo $(DEPDIR)/$*.Plo
@AMDEP_TRUE@@am__fastdepCC_FALSE@ source='$<' object='$@' libtool=yes @AMDEPBACKSLASH@
@AMDEP_TRUE@@am__fastdepCC_FALSE@ DEPDIR=$(DEPDIR) $(CCDEPMODE) $(depcomp) @AMDEPBACKSLASH@
@am__fastdepCC_FALSE@ $(LTCOMPILE) -c -o $@ $<
mach_override.lo: mach_override/mach_override.c
@am__fastdepCC_TRUE@ $(LIBTOOL) --tag=CC $(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) --mode=compile $(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(AM_CFLAGS) $(CFLAGS) -MT mach_override.lo -MD -MP -MF $(DEPDIR)/mach_override.Tpo -c -o mach_override.lo `test -f 'mach_override/mach_override.c' || echo '$(srcdir)/'`mach_override/mach_override.c
@am__fastdepCC_TRUE@ $(am__mv) $(DEPDIR)/mach_override.Tpo $(DEPDIR)/mach_override.Plo
@AMDEP_TRUE@@am__fastdepCC_FALSE@ source='mach_override/mach_override.c' object='mach_override.lo' libtool=yes @AMDEPBACKSLASH@
@AMDEP_TRUE@@am__fastdepCC_FALSE@ DEPDIR=$(DEPDIR) $(CCDEPMODE) $(depcomp) @AMDEPBACKSLASH@
@am__fastdepCC_FALSE@ $(LIBTOOL) --tag=CC $(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) --mode=compile $(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(AM_CFLAGS) $(CFLAGS) -c -o mach_override.lo `test -f 'mach_override/mach_override.c' || echo '$(srcdir)/'`mach_override/mach_override.c
.cc.o:
@am__fastdepCXX_TRUE@ $(CXXCOMPILE) -MT $@ -MD -MP -MF $(DEPDIR)/$*.Tpo -c -o $@ $<
......
libsanitizer/interception/mach_override/LICENSE.txt 0 → 100644
Copyright (c) 2003-2009 Jonathan 'Wolf' Rentzsch: <http://rentzsch.com>
Some rights reserved: <http://opensource.org/licenses/mit-license.php>
libsanitizer/interception/mach_override/mach_override.c 0 → 100644
/*******************************************************************************
mach_override.c
Copyright (c) 2003-2009 Jonathan 'Wolf' Rentzsch: <http://rentzsch.com>
Some rights reserved: <http://opensource.org/licenses/mit-license.php>
***************************************************************************/
#ifdef __APPLE__
#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>
//#define DEBUG_DISASM 1
#undef DEBUG_DISASM
/**************************
*
* Constants
*
**************************/
#pragma mark -
#pragma mark (Constants)
#if defined(__ppc__) || defined(__POWERPC__)
static
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
static
unsigned 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
static
unsigned 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)
static mach_error_t
allocateBranchIsland(
BranchIsland **island,
int allocateHigh,
void *originalFunctionAddress);
static mach_error_t
freeBranchIsland(
BranchIsland *island );
static mach_error_t
defaultIslandMalloc(
void **ptr, size_t unused_size, void *hint);
static mach_error_t
defaultIslandFree(
void *ptr);
#if defined(__ppc__) || defined(__POWERPC__)
static mach_error_t
setBranchIslandTarget(
BranchIsland *island,
const void *branchTo,
long instruction );
#endif
#if defined(__i386__) || defined(__x86_64__)
static mach_error_t
setBranchIslandTarget_i386(
BranchIsland *island,
const void *branchTo,
char* instructions );
// Can't be made static because there's no C implementation for atomic_mov64
// on i386.
void
atomic_mov64(
uint64_t *targetAddress,
uint64_t value ) __attribute__((visibility("hidden")));
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 );
#ifdef DEBUG_DISASM
static void
dump16Bytes(
void *ptr);
#endif // DEBUG_DISASM
#endif
/*******************************************************************************
*
* Interface
*
*******************************************************************************/
#pragma mark -
#pragma mark (Interface)
#if defined(__i386__) || defined(__x86_64__)
static 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
static mach_error_t
defaultIslandMalloc(
void **ptr, size_t unused_size, void *hint) {
return allocateBranchIsland( (BranchIsland**)ptr, kAllocateHigh, hint );
}
static mach_error_t
defaultIslandFree(
void *ptr) {
return freeBranchIsland(ptr);
}
mach_error_t
__asan_mach_override_ptr(
void *originalFunctionAddress,
const void *overrideFunctionAddress,
void **originalFunctionReentryIsland )
{
return __asan_mach_override_ptr_custom(originalFunctionAddress,
overrideFunctionAddress,
originalFunctionReentryIsland,
defaultIslandMalloc,
defaultIslandFree);
}
mach_error_t
__asan_mach_override_ptr_custom(
void *originalFunctionAddress,
const void *overrideFunctionAddress,
void **originalFunctionReentryIsland,
island_malloc *alloc,
island_free *dealloc)
{
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
#ifdef DEBUG_DISASM
{
fprintf(stderr, "Replacing function at %p\n", originalFunctionAddress);
fprintf(stderr, "First 16 bytes of the function: ");
unsigned char *orig = (unsigned char *)originalFunctionAddress;
int i;
for (i = 0; i < 16; i++) {
fprintf(stderr, "%x ", (unsigned int) orig[i]);
}
fprintf(stderr, "\n");
fprintf(stderr,
"To disassemble, save the following function as disas.c"
" and run:\n gcc -c disas.c && gobjdump -d disas.o\n"
"The first 16 bytes of the original function will start"
" after four nop instructions.\n");
fprintf(stderr, "\nvoid foo() {\n asm volatile(\"nop;nop;nop;nop;\");\n");
int j = 0;
for (j = 0; j < 2; j++) {
fprintf(stderr, " asm volatile(\".byte ");
for (i = 8 * j; i < 8 * (j+1) - 1; i++) {
fprintf(stderr, "0x%x, ", (unsigned int) orig[i]);
}
fprintf(stderr, "0x%x;\");\n", (unsigned int) orig[8 * (j+1) - 1]);
}
fprintf(stderr, "}\n\n");
}
#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 );
#ifdef DEBUG_DISASM
if (!overridePossible) fprintf(stderr, "overridePossible = false @%d\n", __LINE__);
#endif
if (eatenCount > kOriginalInstructionsSize) {
#ifdef DEBUG_DISASM
fprintf(stderr, "Too many instructions eaten\n");
#endif
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 = alloc( (void**)&escapeIsland, sizeof(BranchIsland), 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 = alloc( (void**)&reentryIsland, sizeof(BranchIsland), 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 )
dealloc( reentryIsland );
if( escapeIsland )
dealloc( escapeIsland );
}
#ifdef DEBUG_DISASM
{
fprintf(stderr, "First 16 bytes of the function after slicing: ");
unsigned char *orig = (unsigned char *)originalFunctionAddress;
int i;
for (i = 0; i < 16; i++) {
fprintf(stderr, "%x ", (unsigned int) orig[i]);
}
fprintf(stderr, "\n");
}
#endif
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
***************************************************************************/
static 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
***************************************************************************/
static 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__)
static 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__)
static 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__)
static 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 %esp; mov %esp,%ebp; leave; ret
{ 0x1, {0xFF}, {0x90} }, // nop
{ 0x1, {0xF8}, {0x50} }, // push %reg
{ 0x2, {0xFF, 0xFF}, {0x89, 0xE5} }, // mov %esp,%ebp
{ 0x3, {0xFF, 0xFF, 0xFF}, {0x89, 0x1C, 0x24} }, // mov %ebx,(%esp)
{ 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
{ 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
{ 0x3, {0xFF, 0xCF, 0x00}, {0x8B, 0x4D, 0x00} }, // mov $imm(%rpb), %reg
{ 0x3, {0xFF, 0x4F, 0x00}, {0x8A, 0x4D, 0x00} }, // mov $imm(%ebp), %cl
{ 0x4, {0xFF, 0xFF, 0xFF, 0x00}, {0x8B, 0x4C, 0x24, 0x00} }, // mov $imm(%esp), %ecx
{ 0x4, {0xFF, 0x00, 0x00, 0x00}, {0x8B, 0x00, 0x00, 0x00} }, // mov r16,r/m16 or r32,r/m32
{ 0x5, {0xFF, 0x00, 0x00, 0x00, 0x00}, {0xB9, 0x00, 0x00, 0x00, 0x00} }, // mov $imm, %ecx
{ 0x5, {0xFF, 0x00, 0x00, 0x00, 0x00}, {0xB8, 0x00, 0x00, 0x00, 0x00} }, // mov $imm, %eax
{ 0x4, {0xFF, 0xFF, 0xFF, 0x00}, {0x66, 0x0F, 0xEF, 0x00} }, // pxor xmm2/128, xmm1
{ 0x2, {0xFF, 0xFF}, {0xDB, 0xE3} }, // fninit
{ 0x5, {0xFF, 0x00, 0x00, 0x00, 0x00}, {0xE8, 0x00, 0x00, 0x00, 0x00} }, // call $imm
{ 0x4, {0xFF, 0xFF, 0xFF, 0x00}, {0x0F, 0xBE, 0x55, 0x00} }, // movsbl $imm(%ebp), %edx
{ 0x0, {0x00}, {0x00} }
};
#elif defined(__x86_64__)
// TODO(glider): disassembling the "0x48, 0x89" sequences is trickier than it's done below.
// If it stops working, refer to http://ref.x86asm.net/geek.html#modrm_byte_32_64 to do it
// more accurately.
// Note: 0x48 is in fact the REX.W prefix, but it might be wrong to treat it as a separate
// instruction.
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
{ 0x1, {0xFF}, {0x65} }, // GS prefix
{ 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, 0x07, 0x00}, {0x48, 0x89, 0x05, 0x00} }, // move onto rbp
{ 0x3, {0xFB, 0xFF, 0x00}, {0x48, 0x89, 0x00} }, // mov %reg, %reg
{ 0x3, {0xFB, 0xFF, 0x00}, {0x49, 0x89, 0x00} }, // mov %reg, %reg (REX.WB)
{ 0x2, {0xFF, 0x00}, {0x41, 0x00} }, // push %rXX
{ 0x2, {0xFF, 0x00}, {0x84, 0x00} }, // test %rX8,%rX8
{ 0x2, {0xFF, 0x00}, {0x85, 0x00} }, // test %rX,%rX
{ 0x2, {0xFF, 0x00}, {0x77, 0x00} }, // ja $i8
{ 0x2, {0xFF, 0x00}, {0x74, 0x00} }, // je $i8
{ 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
{ 0x5, {0xFF, 0x00, 0x00, 0x00, 0x00}, {0x25, 0x00, 0x00, 0x00, 0x00} }, // and $imm, %eax
{ 0x3, {0xFF, 0xFF, 0xFF}, {0x80, 0x3F, 0x00} }, // cmpb $imm, (%rdi)
{ 0x8, {0xFF, 0xFF, 0xCF, 0xFF, 0x00, 0x00, 0x00, 0x00},
{0x48, 0x8B, 0x04, 0x25, 0x00, 0x00, 0x00, 0x00}, }, // mov $imm, %{rax,rdx,rsp,rsi}
{ 0x4, {0xFF, 0xFF, 0xFF, 0x00}, {0x48, 0x83, 0xFA, 0x00}, }, // cmp $i8, %rdx
{ 0x4, {0xFF, 0xFF, 0x00, 0x00}, {0x83, 0x7f, 0x00, 0x00}, }, // cmpl $imm, $imm(%rdi)
{ 0xa, {0xFF, 0xFF, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
{0x48, 0xB8, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00} }, // mov $imm, %rax
{ 0x6, {0xFF, 0xFF, 0x00, 0x00, 0x00, 0x00},
{0x81, 0xE6, 0x00, 0x00, 0x00, 0x00} }, // and $imm, %esi
{ 0x6, {0xFF, 0xFF, 0x00, 0x00, 0x00, 0x00},
{0xFF, 0x25, 0x00, 0x00, 0x00, 0x00} }, // jmpq *(%rip)
{ 0x4, {0xFF, 0xFF, 0xFF, 0x00}, {0x66, 0x0F, 0xEF, 0x00} }, // pxor xmm2/128, xmm1
{ 0x2, {0xFF, 0x00}, {0x89, 0x00} }, // mov r/m32,r32 or r/m16,r16
{ 0x3, {0xFF, 0xFF, 0xFF}, {0x49, 0x89, 0xF8} }, // mov %rdi,%r8
{ 0x4, {0xFF, 0xFF, 0xFF, 0xFF}, {0x40, 0x0F, 0xBE, 0xCE} }, // movsbl %sil,%ecx
{ 0x7, {0xFF, 0xFF, 0xFF, 0x00, 0x00, 0x00, 0x00},
{0x48, 0x8D, 0x05, 0x00, 0x00, 0x00, 0x00} }, // lea $imm(%rip),%rax
{ 0x3, {0xFF, 0xFF, 0xFF}, {0x0F, 0xBE, 0xCE} }, // movsbl, %dh, %ecx
{ 0x3, {0xFF, 0xFF, 0x00}, {0xFF, 0x77, 0x00} }, // pushq $imm(%rdi)
{ 0x2, {0xFF, 0xFF}, {0xDB, 0xE3} }, // fninit
{ 0x3, {0xFF, 0xFF, 0xFF}, {0x48, 0x85, 0xD2} }, // test %rdx,%rdx
{ 0x0, {0x00}, {0x00} }
};
#endif
static Boolean codeMatchesInstruction(unsigned char *code, AsmInstructionMatch* instruction)
{
Boolean match = true;
size_t i;
assert(instruction);
#ifdef DEBUG_DISASM
fprintf(stderr, "Matching: ");
#endif
for (i=0; i<instruction->length; i++) {
unsigned char mask = instruction->mask[i];
unsigned char constraint = instruction->constraint[i];
unsigned char codeValue = code[i];
#ifdef DEBUG_DISASM
fprintf(stderr, "%x ", (unsigned)codeValue);
#endif
match = ((codeValue & mask) == constraint);
if (!match) break;
}
#ifdef DEBUG_DISASM
if (match) {
fprintf(stderr, " OK\n");
} else {
fprintf(stderr, " FAIL\n");
}
#endif
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 {
#ifdef DEBUG_DISASM
fprintf(stderr, "Not enough space in island to store original instructions. Adapt the island definition and kOriginalInstructionsSize\n");
#endif
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 )
{
void *initialOriginalFunction = originalFunction;
int index, fixed_size, code_size = 0;
for (index = 0;index < instructionCount;index += 1)
code_size += instructionSizes[index];
#ifdef DEBUG_DISASM
void *initialInstructionsToFix = instructionsToFix;
fprintf(stderr, "BEFORE FIXING:\n");
dump16Bytes(initialOriginalFunction);
dump16Bytes(initialInstructionsToFix);
#endif // DEBUG_DISASM
for (index = 0;index < instructionCount;index += 1)
{
fixed_size = instructionSizes[index];
if ((*(uint8_t*)instructionsToFix == 0xE9) || // 32-bit jump relative
(*(uint8_t*)instructionsToFix == 0xE8)) // 32-bit call relative
{
uint32_t offset = (uintptr_t)originalFunction - (uintptr_t)escapeIsland;
uint32_t *jumpOffsetPtr = (uint32_t*)((uintptr_t)instructionsToFix + 1);
*jumpOffsetPtr += offset;
}
if ((*(uint8_t*)instructionsToFix == 0x74) || // Near jump if equal (je), 2 bytes.
(*(uint8_t*)instructionsToFix == 0x77)) // Near jump if above (ja), 2 bytes.
{
// We replace a near je/ja instruction, "7P JJ", with a 32-bit je/ja, "0F 8P WW XX YY ZZ".
// This is critical, otherwise a near jump will likely fall outside the original function.
uint32_t offset = (uintptr_t)initialOriginalFunction - (uintptr_t)escapeIsland;
uint32_t jumpOffset = *(uint8_t*)((uintptr_t)instructionsToFix + 1);
*((uint8_t*)instructionsToFix + 1) = *(uint8_t*)instructionsToFix + 0x10;
*(uint8_t*)instructionsToFix = 0x0F;
uint32_t *jumpOffsetPtr = (uint32_t*)((uintptr_t)instructionsToFix + 2 );
*jumpOffsetPtr = offset + jumpOffset;
fixed_size = 6;
}
originalFunction = (void*)((uintptr_t)originalFunction + instructionSizes[index]);
escapeIsland = (void*)((uintptr_t)escapeIsland + instructionSizes[index]);
instructionsToFix = (void*)((uintptr_t)instructionsToFix + fixed_size);
// Expanding short instructions into longer ones may overwrite the next instructions,
// so we must restore them.
code_size -= fixed_size;
if ((code_size > 0) && (fixed_size != instructionSizes[index])) {
bcopy(originalFunction, instructionsToFix, code_size);
}
}
#ifdef DEBUG_DISASM
fprintf(stderr, "AFTER_FIXING:\n");
dump16Bytes(initialOriginalFunction);
dump16Bytes(initialInstructionsToFix);
#endif // DEBUG_DISASM
}
#ifdef DEBUG_DISASM
#define HEX_DIGIT(x) ((((x) % 16) < 10) ? ('0' + ((x) % 16)) : ('A' + ((x) % 16 - 10)))
static void
dump16Bytes(
void *ptr) {
int i;
char buf[3];
uint8_t *bytes = (uint8_t*)ptr;
for (i = 0; i < 16; i++) {
buf[0] = HEX_DIGIT(bytes[i] / 16);
buf[1] = HEX_DIGIT(bytes[i] % 16);
buf[2] = ' ';
write(2, buf, 3);
}
write(2, "\n", 1);
}
#endif // DEBUG_DISASM
#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
#endif // __APPLE__
libsanitizer/interception/mach_override/mach_override.h 0 → 100644
/*******************************************************************************
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.
***************************************************************************/
#ifdef __APPLE__
#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.
************************************************************************************/
// We're prefixing mach_override_ptr() with "__asan_" to avoid name conflicts with other
// mach_override_ptr() implementations that may appear in the client program.
mach_error_t
__asan_mach_override_ptr(
void *originalFunctionAddress,
const void *overrideFunctionAddress,
void **originalFunctionReentryIsland );
// Allow to use custom allocation and deallocation routines with mach_override_ptr().
// This should help to speed up the things on x86_64.
typedef mach_error_t island_malloc( void **ptr, size_t size, void *hint );
typedef mach_error_t island_free( void *ptr );
mach_error_t
__asan_mach_override_ptr_custom(
void *originalFunctionAddress,
const void *overrideFunctionAddress,
void **originalFunctionReentryIsland,
island_malloc *alloc,
island_free *dealloc );
/************************************************************************************//**
************************************************************************************/
#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_
#endif // __APPLE__
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