/* Cydia Substrate - Powerful Code Insertion Platform
* Copyright (C) 2008-2010 Jay Freeman (saurik)
*/
/* GNU Lesser General Public License, Version 3 {{{ */
/*
* Substrate is free software: you can redistribute it and/or modify it under
* the terms of the GNU Lesser General Public License as published by the
* Free Software Foundation, either version 3 of the License, or (at your
* option) any later version.
*
* Substrate is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
* License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with Substrate. If not, see .
**/
/* }}} */
#include
#include "CydiaSubstrate.h"
#define _trace() do { \
fprintf(stderr, "_trace(%u)\n", __LINE__); \
} while (false)
#if defined(__i386__) || defined(__x86_64__)
#include "hde64.h"
#endif
#include "Debug.hpp"
template
_disused static void MSWrite(uint8_t *&buffer, Type_ value) {
*reinterpret_cast(buffer) = value;
buffer += sizeof(Type_);
}
_disused static void MSWrite(uint8_t *&buffer, uint8_t *data, size_t size) {
memcpy(buffer, data, size);
buffer += size;
}
#ifdef __arm__
/* WebCore (ARM) PC-Relative:
X 1 ldr r*,[pc,r*] !=
2 fldd d*,[pc,#*]
X 5 str r*,[pc,r*] !=
8 flds s*,[pc,#*]
400 ldr r*,[pc,r*] ==
515 add r*, pc,r* ==
X 4790 ldr r*,[pc,#*] */
// x=0; while IFS= read -r line; do if [[ ${#line} -ne 0 && $line == +([^\;]): ]]; then x=2; elif [[ $line == ' +'* && $x -ne 0 ]]; then ((--x)); echo "$x${line}"; fi; done WebCore.pc
// grep pc WebCore.pc | cut -c 40- | sed -Ee 's/^ldr *(ip|r[0-9]*),\[pc,\#0x[0-9a-f]*\].*/ ldr r*,[pc,#*]/;s/^add *r[0-9]*,pc,r[0-9]*.*/ add r*, pc,r*/;s/^(st|ld)r *r([0-9]*),\[pc,r([0-9]*)\].*/ \1r r\2,[pc,r\3]/;s/^fld(s|d) *(s|d)[0-9]*,\[pc,#0x[0-9a-f]*].*/fld\1 \2*,[pc,#*]/' | sort | uniq -c | sort -n
#include "ARM.hpp"
#define T$pop_$r0$ 0xbc01 // pop {r0}
#define T$b(im) /* b im */ \
(0xde00 | (im & 0xff))
#define T$blx(rm) /* blx rm */ \
(0x4780 | (rm << 3))
#define T$bx(rm) /* bx rm */ \
(0x4700 | (rm << 3))
#define T$nop /* nop */ \
(0x46c0)
#define T$add_rd_rm(rd, rm) /* add rd, rm */ \
(0x4400 | (((rd) & 0x8) >> 3 << 7) | (((rm) & 0x8) >> 3 << 6) | (((rm) & 0x7) << 3) | ((rd) & 0x7))
#define T$push_r(r) /* push r... */ \
(0xb400 | (((r) & (1 << A$lr)) >> A$lr << 8) | ((r) & 0xff))
#define T$pop_r(r) /* pop r... */ \
(0xbc00 | (((r) & (1 << A$pc)) >> A$pc << 8) | ((r) & 0xff))
#define T$mov_rd_rm(rd, rm) /* mov rd, rm */ \
(0x4600 | (((rd) & 0x8) >> 3 << 7) | (((rm) & 0x8) >> 3 << 6) | (((rm) & 0x7) << 3) | ((rd) & 0x7))
#define T$ldr_rd_$rn_im_4$(rd, rn, im) /* ldr rd, [rn, #im * 4] */ \
(0x6800 | (((im) & 0x1f) << 6) | ((rn) << 3) | (rd))
#define T$ldr_rd_$pc_im_4$(rd, im) /* ldr rd, [PC, #im * 4] */ \
(0x4800 | ((rd) << 8) | ((im) & 0xff))
#define T$cmp_rn_$im(rn, im) /* cmp rn, #im */ \
(0x2000 | ((rn) << 8) | ((im) & 0xff))
#define T$it$_cd(cd, ms) /* it, cd */ \
(0xbf00 | ((cd) << 4) | (ms))
#define T$cbz$_rn_$im(op,rn,im) /* cbz rn, #im */ \
(0xb100 | ((op) << 11) | (((im) & 0x40) >> 6 << 9) | (((im) & 0x3e) >> 1 << 3) | (rn))
#define T$b$_$im(cond,im) /* b #im */ \
(cond == A$al ? 0xe000 | (((im) >> 1) & 0x7ff) : 0xd000 | ((cond) << 8) | (((im) >> 1) & 0xff))
#define T1$ldr_rt_$pc_im$(rt, im) /* ldr rt, [PC, #im] */ \
(0xf85f | (im < 0 ? 0 : 1))
#define T2$ldr_rt_$pc_im$(rt, im) /* ldr rt, [PC, #im] */ \
(((rt) << 12) | abs(im))
#define T1$mrs_rd_apsr(rd) /* mrs rd, apsr */ \
(0xf3ef)
#define T2$mrs_rd_apsr(rd) /* mrs rd, apsr */ \
(0x8000 | ((rd) << 8))
#define T1$msr_apsr_nzcvqg_rn(rn) /* msr apsr, rn */ \
(0xf380 | (rn))
#define T2$msr_apsr_nzcvqg_rn(rn) /* msr apsr, rn */ \
(0x8c00)
#define T$msr_apsr_nzcvqg_rn(rn) /* msr apsr, rn */ \
(T2$msr_apsr_nzcvqg_rn(rn) << 16 | T1$msr_apsr_nzcvqg_rn(rn))
static inline bool A$pcrel$r(uint32_t ic) {
return (ic & 0x0c000000) == 0x04000000 && (ic & 0xf0000000) != 0xf0000000 && (ic & 0x000f0000) == 0x000f0000;
}
static inline bool T$32bit$i(uint16_t ic) {
return ((ic & 0xe000) == 0xe000 && (ic & 0x1800) != 0x0000);
}
static inline bool T$pcrel$cbz(uint16_t ic) {
return (ic & 0xf500) == 0xb100;
}
static inline bool T$pcrel$b(uint16_t ic) {
return (ic & 0xf000) == 0xd000 && (ic & 0x0e00) != 0x0e00;
}
static inline bool T2$pcrel$b(uint16_t *ic) {
return (ic[0] & 0xf800) == 0xf000 && ((ic[1] & 0xd000) == 0x9000 || (ic[1] & 0xd000) == 0x8000 && (ic[0] & 0x0380) != 0x0380);
}
static inline bool T$pcrel$bl(uint16_t *ic) {
return (ic[0] & 0xf800) == 0xf000 && ((ic[1] & 0xd000) == 0xd000 || (ic[1] & 0xd001) == 0xc000);
}
static inline bool T$pcrel$ldr(uint16_t ic) {
return (ic & 0xf800) == 0x4800;
}
static inline bool T$pcrel$add(uint16_t ic) {
return (ic & 0xff78) == 0x4478;
}
static inline bool T$pcrel$ldrw(uint16_t ic) {
return (ic & 0xff7f) == 0xf85f;
}
static size_t MSGetInstructionWidthThumb(void *start) {
uint16_t *thumb(reinterpret_cast(start));
return T$32bit$i(thumb[0]) ? 4 : 2;
}
static size_t MSGetInstructionWidthARM(void *start) {
return 4;
}
extern "C" size_t MSGetInstructionWidth(void *start) {
if ((reinterpret_cast(start) & 0x1) == 0)
return MSGetInstructionWidthARM(start);
else
return MSGetInstructionWidthThumb(reinterpret_cast(reinterpret_cast(start) & ~0x1));
}
static void MSHookFunctionThumb(void *symbol, void *replace, void **result) {
if (symbol == NULL)
return;
uint16_t *area(reinterpret_cast(symbol));
unsigned align((reinterpret_cast(area) & 0x2) == 0 ? 0 : 1);
uint16_t *thumb(area + align);
uint32_t *arm(reinterpret_cast(thumb + 2));
uint16_t *trail(reinterpret_cast(arm + 2));
size_t required((trail - area) * sizeof(uint16_t));
size_t used(0);
while (used < required)
used += MSGetInstructionWidthThumb(reinterpret_cast(area) + used);
used = (used + sizeof(uint16_t) - 1) / sizeof(uint16_t) * sizeof(uint16_t);
size_t blank((used - required) / sizeof(uint16_t));
uint16_t backup[used / sizeof(uint16_t)];
MSHookMemory code(area, used);
if (
(align == 0 || area[0] == T$nop) &&
thumb[0] == T$bx(A$pc) &&
thumb[1] == T$nop &&
arm[0] == A$ldr_rd_$rn_im$(A$pc, A$pc, 4 - 8)
) {
if (result != NULL) {
*result = reinterpret_cast(arm[1]);
result = NULL;
}
arm[1] = reinterpret_cast(replace);
MSClearCache(arm + 1, sizeof(uint32_t) * 1);
} else {
if (MSDebug) {
char name[16];
sprintf(name, "%p", area);
MSLogHex(area, used + sizeof(uint16_t), name);
}
memcpy(backup, area, used);
if (align != 0)
area[0] = T$nop;
thumb[0] = T$bx(A$pc);
thumb[1] = T$nop;
arm[0] = A$ldr_rd_$rn_im$(A$pc, A$pc, 4 - 8);
arm[1] = reinterpret_cast(replace);
for (unsigned offset(0); offset != blank; ++offset)
trail[offset] = T$nop;
MSClearCache(area, used);
}
code.Close();
if (MSDebug) {
char name[16];
sprintf(name, "%p", area);
MSLogHex(area, used + sizeof(uint16_t), name);
}
// XXX: impedence mismatch
used /= sizeof(uint16_t);
if (result != NULL) {
size_t size(used);
for (unsigned offset(0); offset != used; ++offset)
if (T$pcrel$ldr(backup[offset]))
size += 3;
else if (T$pcrel$b(backup[offset]))
size += 6;
else if (T2$pcrel$b(backup + offset)) {
size += 5;
++offset;
} else if (T$pcrel$bl(backup + offset)) {
size += 5;
++offset;
} else if (T$pcrel$cbz(backup[offset])) {
size += 16;
} else if (T$pcrel$ldrw(backup[offset])) {
size += 2;
++offset;
} else if (T$pcrel$add(backup[offset]))
size += 6;
else if (T$32bit$i(backup[offset]))
++offset;
unsigned pad((size & 0x1) == 0 ? 0 : 1);
size += pad + 2 + 2 * sizeof(uint32_t) / sizeof(uint16_t);
size_t length(sizeof(uint16_t) * size);
uint16_t *buffer(reinterpret_cast(mmap(
NULL, length, PROT_READ | PROT_WRITE, MAP_ANON | MAP_PRIVATE, -1, 0
)));
if (buffer == MAP_FAILED) {
fprintf(stderr, "MS:Error:mmap() = %d\n", errno);
*result = NULL;
return;
}
if (false) fail: {
munmap(buffer, length);
*result = NULL;
return;
}
size_t start(pad), end(size);
uint32_t *trailer(reinterpret_cast(buffer + end));
for (unsigned offset(0); offset != used; ++offset) {
if (T$pcrel$ldr(backup[offset])) {
union {
uint16_t value;
struct {
uint16_t immediate : 8;
uint16_t rd : 3;
uint16_t : 5;
};
} bits = {backup[offset+0]};
buffer[start+0] = T$ldr_rd_$pc_im_4$(bits.rd, ((end-2 - (start+0)) * 2 - 4 + 2) / 4);
buffer[start+1] = T$ldr_rd_$rn_im_4$(bits.rd, bits.rd, 0);
*--trailer = ((reinterpret_cast(area + offset) + 4) & ~0x2) + bits.immediate * 4;
start += 2;
end -= 2;
} else if (T$pcrel$b(backup[offset])) {
union {
uint16_t value;
struct {
uint16_t imm8 : 8;
uint16_t cond : 4;
uint16_t /*1101*/ : 4;
};
} bits = {backup[offset+0]};
intptr_t jump(bits.imm8 << 1);
jump |= 1;
jump <<= 23;
jump >>= 23;
buffer[start+0] = T$b$_$im(bits.cond, (end-6 - (start+0)) * 2 - 4);
*--trailer = reinterpret_cast(area + offset) + 4 + jump;
*--trailer = A$ldr_rd_$rn_im$(A$pc, A$pc, 4 - 8);
*--trailer = T$nop << 16 | T$bx(A$pc);
start += 1;
end -= 6;
} else if (T2$pcrel$b(backup + offset)) {
union {
uint16_t value;
struct {
uint16_t imm6 : 6;
uint16_t cond : 4;
uint16_t s : 1;
uint16_t : 5;
};
} bits = {backup[offset+0]};
union {
uint16_t value;
struct {
uint16_t imm11 : 11;
uint16_t j2 : 1;
uint16_t a : 1;
uint16_t j1 : 1;
uint16_t : 2;
};
} exts = {backup[offset+1]};
intptr_t jump(1);
jump |= exts.imm11 << 1;
jump |= bits.imm6 << 12;
if (exts.a) {
jump |= bits.s << 24;
jump |= (~(bits.s ^ exts.j1) & 0x1) << 23;
jump |= (~(bits.s ^ exts.j2) & 0x1) << 22;
jump |= bits.cond << 18;
jump <<= 7;
jump >>= 7;
} else {
jump |= bits.s << 20;
jump |= exts.j2 << 19;
jump |= exts.j1 << 18;
jump <<= 11;
jump >>= 11;
}
buffer[start+0] = T$b$_$im(exts.a ? A$al : bits.cond, (end-6 - (start+0)) * 2 - 4);
*--trailer = reinterpret_cast(area + offset) + 4 + jump;
*--trailer = A$ldr_rd_$rn_im$(A$pc, A$pc, 4 - 8);
*--trailer = T$nop << 16 | T$bx(A$pc);
++offset;
start += 1;
end -= 6;
} else if (T$pcrel$bl(backup + offset)) {
union {
uint16_t value;
struct {
uint16_t immediate : 10;
uint16_t s : 1;
uint16_t : 5;
};
} bits = {backup[offset+0]};
union {
uint16_t value;
struct {
uint16_t immediate : 11;
uint16_t j2 : 1;
uint16_t x : 1;
uint16_t j1 : 1;
uint16_t : 2;
};
} exts = {backup[offset+1]};
intptr_t jump(0);
jump |= bits.s << 24;
jump |= (~(bits.s ^ exts.j1) & 0x1) << 23;
jump |= (~(bits.s ^ exts.j2) & 0x1) << 22;
jump |= bits.immediate << 12;
jump |= exts.immediate << 1;
jump |= exts.x;
jump <<= 7;
jump >>= 7;
buffer[start+0] = T$push_r(1 << A$r7);
buffer[start+1] = T$ldr_rd_$pc_im_4$(A$r7, ((end-2 - (start+1)) * 2 - 4 + 2) / 4);
buffer[start+2] = T$mov_rd_rm(A$lr, A$r7);
buffer[start+3] = T$pop_r(1 << A$r7);
buffer[start+4] = T$blx(A$lr);
*--trailer = reinterpret_cast(area + offset) + 4 + jump;
++offset;
start += 5;
end -= 2;
} else if (T$pcrel$cbz(backup[offset])) {
union {
uint16_t value;
struct {
uint16_t rn : 3;
uint16_t immediate : 5;
uint16_t : 1;
uint16_t i : 1;
uint16_t : 1;
uint16_t op : 1;
uint16_t : 4;
};
} bits = {backup[offset+0]};
intptr_t jump(1);
jump |= bits.i << 6;
jump |= bits.immediate << 1;
//jump <<= 24;
//jump >>= 24;
unsigned rn(bits.rn);
unsigned rt(rn == A$r7 ? A$r6 : A$r7);
buffer[start+0] = T$push_r(1 << rt);
buffer[start+1] = T1$mrs_rd_apsr(rt);
buffer[start+2] = T2$mrs_rd_apsr(rt);
buffer[start+3] = T$cbz$_rn_$im(bits.op, rn, (end-10 - (start+3)) * 2 - 4);
buffer[start+4] = T1$msr_apsr_nzcvqg_rn(rt);
buffer[start+5] = T2$msr_apsr_nzcvqg_rn(rt);
buffer[start+6] = T$pop_r(1 << rt);
*--trailer = reinterpret_cast(area + offset) + 4 + jump;
*--trailer = A$ldr_rd_$rn_im$(A$pc, A$pc, 4 - 8);
*--trailer = T$nop << 16 | T$bx(A$pc);
*--trailer = T$nop << 16 | T$pop_r(1 << rt);
*--trailer = T$msr_apsr_nzcvqg_rn(rt);
#if 0
if ((start & 0x1) == 0)
buffer[start++] = T$nop;
buffer[start++] = T$bx(A$pc);
buffer[start++] = T$nop;
uint32_t *arm(reinterpret_cast(buffer + start));
arm[0] = A$add(A$lr, A$pc, 1);
arm[1] = A$ldr_rd_$rn_im$(A$pc, A$pc, (trailer - arm) * sizeof(uint32_t) - 8);
#endif
start += 7;
end -= 10;
} else if (T$pcrel$ldrw(backup[offset])) {
union {
uint16_t value;
struct {
uint16_t : 7;
uint16_t u : 1;
uint16_t : 8;
};
} bits = {backup[offset+0]};
union {
uint16_t value;
struct {
uint16_t immediate : 12;
uint16_t rd : 4;
};
} exts = {backup[offset+1]};
buffer[start+0] = T$ldr_rd_$pc_im_4$(exts.rd, ((end-2 - (start+0)) * 2 - 4 + 2) / 4);
buffer[start+1] = T$ldr_rd_$rn_im_4$(exts.rd, exts.rd, 0);
*--trailer = ((reinterpret_cast(area + offset) + 4) & ~0x2) + (bits.u == 0 ? -exts.immediate : exts.immediate);
++offset;
start += 2;
end -= 2;
} else if (T$pcrel$add(backup[offset])) {
union {
uint16_t value;
struct {
uint16_t rd : 3;
uint16_t rm : 3;
uint16_t h2 : 1;
uint16_t h1 : 1;
uint16_t : 8;
};
} bits = {backup[offset+0]};
if (bits.h1) {
fprintf(stderr, "MS:Error:pcrel(%u):add (rd > r7)\n", offset);
goto fail;
}
unsigned rt(bits.rd == A$r7 ? A$r6 : A$r7);
buffer[start+0] = T$push_r(1 << rt);
buffer[start+1] = T$mov_rd_rm(rt, (bits.h1 << 3) | bits.rd);
buffer[start+2] = T$ldr_rd_$pc_im_4$(bits.rd, ((end-2 - (start+2)) * 2 - 4 + 2) / 4);
buffer[start+3] = T$add_rd_rm((bits.h1 << 3) | bits.rd, rt);
buffer[start+4] = T$pop_r(1 << rt);
*--trailer = reinterpret_cast(area + offset) + 4;
start += 5;
end -= 2;
} else if (T$32bit$i(backup[offset])) {
buffer[start++] = backup[offset];
buffer[start++] = backup[++offset];
} else {
buffer[start++] = backup[offset];
}
}
buffer[start++] = T$bx(A$pc);
buffer[start++] = T$nop;
uint32_t *transfer = reinterpret_cast(buffer + start);
transfer[0] = A$ldr_rd_$rn_im$(A$pc, A$pc, 4 - 8);
transfer[1] = reinterpret_cast(area + used) + 1;
if (mprotect(buffer, length, PROT_READ | PROT_EXEC) == -1) {
fprintf(stderr, "MS:Error:mprotect():%d\n", errno);
return;
}
*result = reinterpret_cast(buffer + pad) + 1;
if (MSDebug) {
char name[16];
sprintf(name, "%p", *result);
MSLogHex(buffer, length, name);
}
}
}
static void MSHookFunctionARM(void *symbol, void *replace, void **result) {
if (symbol == NULL)
return;
uint32_t *area(reinterpret_cast(symbol));
uint32_t *arm(area);
const size_t used(2);
uint32_t backup[used] = {arm[0], arm[1]};
MSHookMemory code(symbol, 8);
arm[0] = A$ldr_rd_$rn_im$(A$pc, A$pc, 4 - 8);
arm[1] = reinterpret_cast(replace);
MSClearCache(area, sizeof(uint32_t) * used);
code.Close();
if (result == NULL)
return;
if (backup[0] == A$ldr_rd_$rn_im$(A$pc, A$pc, 4 - 8)) {
*result = reinterpret_cast(backup[1]);
return;
}
size_t size(used);
for (unsigned offset(0); offset != used; ++offset)
if (A$pcrel$r(backup[offset]))
size += 2;
size += 2;
size_t length(sizeof(uint32_t) * size);
uint32_t *buffer(reinterpret_cast(mmap(
NULL, length, PROT_READ | PROT_WRITE, MAP_ANON | MAP_PRIVATE, -1, 0
)));
if (buffer == MAP_FAILED) {
fprintf(stderr, "MS:Error:mmap() = %d\n", errno);
*result = NULL;
return;
}
if (false) fail: {
munmap(buffer, length);
*result = NULL;
return;
}
size_t start(0), end(size);
uint32_t *trailer(reinterpret_cast(buffer + end));
for (unsigned offset(0); offset != used; ++offset)
if (A$pcrel$r(backup[offset])) {
union {
uint32_t value;
struct {
uint32_t rm : 4;
uint32_t : 1;
uint32_t shift : 2;
uint32_t shiftamount : 5;
uint32_t rd : 4;
uint32_t rn : 4;
uint32_t l : 1;
uint32_t w : 1;
uint32_t b : 1;
uint32_t u : 1;
uint32_t p : 1;
uint32_t mode : 1;
uint32_t type : 2;
uint32_t cond : 4;
};
} bits = {backup[offset+0]};
if (bits.mode != 0 && bits.rd == bits.rm) {
fprintf(stderr, "MS:Error:pcrel(%u):%s (rd == rm)\n", offset, bits.l == 0 ? "str" : "ldr");
goto fail;
} else {
buffer[start+0] = A$ldr_rd_$rn_im$(bits.rd, A$pc, (end-1 - (start+0)) * 4 - 8);
*--trailer = reinterpret_cast(area + offset) + 8;
start += 1;
end -= 1;
}
bits.rn = bits.rd;
buffer[start++] = bits.value;
} else
buffer[start++] = backup[offset];
buffer[start+0] = A$ldr_rd_$rn_im$(A$pc, A$pc, 4 - 8);
buffer[start+1] = reinterpret_cast(area + used);
if (mprotect(buffer, length, PROT_READ | PROT_EXEC) == -1) {
fprintf(stderr, "MS:Error:mprotect():%d\n", errno);
goto fail;
}
*result = buffer;
}
_extern void MSHookFunction(void *symbol, void *replace, void **result) {
if (MSDebug)
fprintf(stderr, "MSHookFunction(%p, %p, %p)\n", symbol, replace, result);
if ((reinterpret_cast(symbol) & 0x1) == 0)
return MSHookFunctionARM(symbol, replace, result);
else
return MSHookFunctionThumb(reinterpret_cast(reinterpret_cast(symbol) & ~0x1), replace, result);
}
#endif
#if defined(__i386__) || defined(__x86_64__)
static size_t MSGetInstructionWidthIntel(void *start) {
hde64s decode;
return hde64_disasm(start, &decode);
}
#ifdef __LP64__
static const bool ia32 = false;
#else
static const bool ia32 = true;
#endif
_disused static bool MSIs32BitOffset(uintptr_t target, uintptr_t source) {
intptr_t offset(target - source);
return int32_t(offset) == offset;
}
_disused static size_t MSSizeOfSkip() {
return 5;
}
_disused static size_t MSSizeOfPushPointer(uintptr_t target) {
return uint64_t(target) >> 32 == 0 ? 5 : 13;
}
_disused static size_t MSSizeOfPushPointer(void *target) {
return MSSizeOfPushPointer(reinterpret_cast(target));
}
_disused static size_t MSSizeOfJump(bool blind, uintptr_t target, uintptr_t source = 0) {
if (ia32 || !blind && MSIs32BitOffset(target, source + 5))
return MSSizeOfSkip();
else
return MSSizeOfPushPointer(target) + 1;
}
_disused static size_t MSSizeOfJump(uintptr_t target, uintptr_t source) {
return MSSizeOfJump(false, target, source);
}
_disused static size_t MSSizeOfJump(uintptr_t target) {
return MSSizeOfJump(true, target);
}
_disused static size_t MSSizeOfJump(void *target, void *source) {
return MSSizeOfJump(reinterpret_cast(target), reinterpret_cast(source));
}
_disused static size_t MSSizeOfJump(void *target) {
return MSSizeOfJump(reinterpret_cast(target));
}
_disused static void MSWriteSkip(uint8_t *¤t, ssize_t size) {
MSWrite(current, 0xe9);
MSWrite(current, size);
}
_disused static void MSPushPointer(uint8_t *¤t, uintptr_t target) {
MSWrite(current, 0x68);
MSWrite(current, target);
if (uint32_t high = uint64_t(target) >> 32) {
MSWrite(current, 0xc7);
MSWrite(current, 0x44);
MSWrite(current, 0x24);
MSWrite(current, 0x04);
MSWrite(current, high);
}
}
_disused static void MSPushPointer(uint8_t *¤t, void *target) {
return MSPushPointer(current, reinterpret_cast(target));
}
_disused static void MSWriteJump(uint8_t *¤t, uintptr_t target) {
uintptr_t source(reinterpret_cast(current));
if (ia32 || MSIs32BitOffset(target, source + 5))
MSWriteSkip(current, target - (source + 5));
else {
MSPushPointer(current, target);
MSWrite(current, 0xc3);
}
}
_disused static void MSWriteJump(uint8_t *¤t, void *target) {
return MSWriteJump(current, reinterpret_cast(target));
}
_disused static void MSWritePop(uint8_t *¤t, uint8_t target) {
if (target >> 3 != 0)
MSWrite(current, 0x40 | (target & 0x08) >> 3);
MSWrite(current, 0x58 | target & 0x07);
}
_disused static size_t MSSizeOfPop(uint8_t target) {
return target >> 3 != 0 ? 2 : 1;
}
_disused static void MSWriteMove64(uint8_t *¤t, uint8_t source, uint8_t target) {
MSWrite(current, 0x48 | (target & 0x08) >> 3 << 2 | (source & 0x08) >> 3);
MSWrite(current, 0x8b);
MSWrite(current, (target & 0x07) << 3 | source & 0x07);
}
_disused static size_t MSSizeOfMove64() {
return 3;
}
enum I$r {
I$rax, I$rcx, I$rdx, I$rbx,
I$rsp, I$rbp, I$rsi, I$rdi,
I$r8, I$r9, I$r10, I$r11,
I$r12, I$r13, I$r14, I$r15,
};
_extern void MSHookFunction(void *symbol, void *replace, void **result) {
if (MSDebug)
fprintf(stderr, "MSHookFunction(%p, %p, %p)\n", symbol, replace, result);
if (symbol == NULL)
return;
uintptr_t source(reinterpret_cast(symbol));
uintptr_t target(reinterpret_cast(replace));
uint8_t *area(reinterpret_cast(symbol));
size_t required(MSSizeOfJump(target, source));
if (MSDebug) {
char name[16];
sprintf(name, "%p", area);
MSLogHex(area, 32, name);
}
size_t used(0);
while (used < required) {
size_t width(MSGetInstructionWidthIntel(area + used));
if (width == 0) {
fprintf(stderr, "MS:Error:MSGetInstructionWidthIntel(%p) == 0", area + used);
return;
}
used += width;
}
size_t blank(used - required);
if (MSDebug) {
char name[16];
sprintf(name, "%p", area);
MSLogHex(area, used + sizeof(uint16_t), name);
}
uint8_t backup[used];
memcpy(backup, area, used);
MSHookMemory code(area, used); {
uint8_t *current(area);
MSWriteJump(current, target);
for (unsigned offset(0); offset != blank; ++offset)
MSWrite(current, 0x90);
MSClearCache(area, used);
} code.Close();
if (MSDebug) {
char name[16];
sprintf(name, "%p", area);
MSLogHex(area, used + sizeof(uint16_t), name);
}
if (result == NULL)
return;
if (backup[0] == 0xe9) {
*result = reinterpret_cast(source + 5 + *reinterpret_cast(backup + 1));
return;
}
if (!ia32 && backup[0] == 0xff && backup[1] == 0x25) {
*result = *reinterpret_cast(source + 6 + *reinterpret_cast(backup + 2));
return;
}
size_t length(used + MSSizeOfJump(source + used));
for (size_t offset(0), width; offset != used; offset += width) {
hde64s decode;
hde64_disasm(backup + offset, &decode);
width = decode.len;
//_assert(width != 0 && offset + width <= used);
#ifdef __LP64__
if ((decode.modrm & 0xc7) == 0x05) {
if (decode.opcode == 0x8b) {
void *destiny(area + offset + width + int32_t(decode.disp.disp32));
uint8_t reg(decode.rex_r << 3 | decode.modrm_reg);
length -= decode.len;
length += MSSizeOfPushPointer(destiny);
length += MSSizeOfPop(reg);
length += MSSizeOfMove64();
} else {
fprintf(stderr, "MS:Error: Unknown RIP-Relative (%.2x %.2x)\n", decode.opcode, decode.opcode2);
continue;
}
} else
#endif
if (backup[offset] == 0xe8) {
int32_t relative(*reinterpret_cast(backup + offset + 1));
void *destiny(area + offset + decode.len + relative);
if (relative == 0) {
length -= decode.len;
length += MSSizeOfPushPointer(destiny);
} else {
length += MSSizeOfSkip();
length += MSSizeOfJump(destiny);
}
} else if (backup[offset] == 0xeb) {
length -= decode.len;
length += MSSizeOfJump(area + offset + decode.len + *reinterpret_cast(backup + offset + 1));
} else if (backup[offset] == 0xe9) {
length -= decode.len;
length += MSSizeOfJump(area + offset + decode.len + *reinterpret_cast(backup + offset + 1));
} else if (
backup[offset] == 0xe3 ||
(backup[offset] & 0xf0) == 0x70
// XXX: opcode2 & 0xf0 is 0x80?
) {
length += decode.len;
length += MSSizeOfJump(area + offset + decode.len + *reinterpret_cast(backup + offset + 1));
}
}
uint8_t *buffer(reinterpret_cast(mmap(
NULL, length, PROT_READ | PROT_WRITE, MAP_ANON | MAP_PRIVATE, -1, 0
)));
if (buffer == MAP_FAILED) {
fprintf(stderr, "MS:Error:mmap() = %d\n", errno);
*result = NULL;
return;
}
if (false) fail: {
munmap(buffer, length);
*result = NULL;
return;
}
{
uint8_t *current(buffer);
for (size_t offset(0), width; offset != used; offset += width) {
hde64s decode;
hde64_disasm(backup + offset, &decode);
width = decode.len;
//_assert(width != 0 && offset + width <= used);
#ifdef __LP64__
if ((decode.modrm & 0xc7) == 0x05) {
if (decode.opcode == 0x8b) {
void *destiny(area + offset + width + int32_t(decode.disp.disp32));
uint8_t reg(decode.rex_r << 3 | decode.modrm_reg);
MSPushPointer(current, destiny);
MSWritePop(current, reg);
MSWriteMove64(current, reg, reg);
} else {
fprintf(stderr, "MS:Error: Unknown RIP-Relative (%.2x %.2x)\n", decode.opcode, decode.opcode2);
goto copy;
}
} else
#endif
if (backup[offset] == 0xe8) {
int32_t relative(*reinterpret_cast(backup + offset + 1));
if (relative == 0)
MSPushPointer(current, area + offset + decode.len);
else {
MSWrite(current, 0xe8);
MSWrite(current, MSSizeOfSkip());
void *destiny(area + offset + decode.len + relative);
MSWriteSkip(current, MSSizeOfJump(destiny, current + MSSizeOfSkip()));
MSWriteJump(current, destiny);
}
} else if (backup[offset] == 0xeb)
MSWriteJump(current, area + offset + decode.len + *reinterpret_cast(backup + offset + 1));
else if (backup[offset] == 0xe9)
MSWriteJump(current, area + offset + decode.len + *reinterpret_cast(backup + offset + 1));
else if (
backup[offset] == 0xe3 ||
(backup[offset] & 0xf0) == 0x70
) {
MSWrite(current, backup[offset]);
MSWrite(current, 2);
MSWrite(current, 0xeb);
void *destiny(area + offset + decode.len + *reinterpret_cast(backup + offset + 1));
MSWrite(current, MSSizeOfJump(destiny, current + 1));
MSWriteJump(current, destiny);
} else
#ifdef __LP64__
copy:
#endif
{
MSWrite(current, backup + offset, width);
}
}
MSWriteJump(current, area + used);
}
if (mprotect(buffer, length, PROT_READ | PROT_EXEC) == -1) {
fprintf(stderr, "MS:Error:mprotect():%d\n", errno);
goto fail;
}
*result = buffer;
if (MSDebug) {
char name[16];
sprintf(name, "%p", *result);
MSLogHex(buffer, length, name);
}
}
#endif
#if defined(__APPLE__) && defined(__arm__)
_extern void _Z14MSHookFunctionPvS_PS_(void *symbol, void *replace, void **result) {
return MSHookFunction(symbol, replace, result);
}
#endif