Magic-Mirror/gecko-dev
1
0
Fork 0
mirror of https://github.com/mozilla/gecko-dev.git synced 2024-11-29 07:42:04 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

Bug 681238 part 0 - Support a few more opcodes and fix x86 mov r, [r] test. r=vlad

Browse Source
This commit is contained in:
Mike Hommey 2011-08-29 13:23:21 +02:00
parent 88a9c09421
commit c1d8e2fb2f
1 changed files with 41 additions and 28 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

69
toolkit/xre/nsWindowsDllInterceptor.h
View File

@ -188,6 +188,8 @@ protected:
byteptr_t origBytes = (byteptr_t) origFunction;
int nBytes = 0;
int pJmp32 = -1;
#if defined(_M_IX86)
while (nBytes < 5) {
// Understand some simple instructions that might be found in a
@ -196,17 +198,31 @@ protected:
// Note! If we ever need to understand jump instructions, we'll
// need to rewrite the displacement argument.
if (origBytes[nBytes] >= 0x88 && origBytes[nBytes] <= 0x8B) {
// various MOVs; but only handle the case where it truly is a 2-byte instruction
// various MOVs
unsigned char b = origBytes[nBytes+1];
if (((b & 0xc0) == 0xc0) ||
(((b & 0xc0) == 0x00) &&
((b & 0x38) != 0x20) && ((b & 0x38) != 0x28)))
((b & 0x07) != 0x04) && ((b & 0x07) != 0x05)))
{
// REG=r, R/M=r or REG=r, R/M=[r]
nBytes += 2;
} else if (((b & 0xc0) == 0x40) && ((b & 0x38) != 0x20)) {
// REG=r, R/M=[r + disp8]
nBytes += 3;
} else {
// complex MOV, bail
return 0;
}
} else if (origBytes[nBytes] == 0x83) {
// ADD|ODR|ADC|SBB|AND|SUB|XOR|CMP r/m, imm8
unsigned char b = origBytes[nBytes+1];
if ((b & 0xc0) == 0xc0) {
// ADD|ODR|ADC|SBB|AND|SUB|XOR|CMP r, imm8
nBytes += 3;
} else {
// bail
return 0;
}
} else if (origBytes[nBytes] == 0x68) {
// PUSH with 4-byte operand
nBytes += 5;
@ -216,14 +232,16 @@ protected:
} else if (origBytes[nBytes] == 0x6A) {
// PUSH imm8
nBytes += 2;
} else if (origBytes[nBytes] == 0xe9) {
pJmp32 = nBytes;
// jmp 32bit offset
nBytes += 5;
} else {
//printf ("Unknown x86 instruction byte 0x%02x, aborting trampoline\n", origBytes[nBytes]);
return 0;
}
}
#elif defined(_M_X64)
int pJmp32 = -1;
while (nBytes < 13) {
// if found JMP 32bit offset, next bytes must be NOP
@ -257,8 +275,8 @@ protected:
} else {
return 0;
}
} else if (origBytes[nBytes] == 0x48) {
// REX.W
} else if ((origBytes[nBytes] & 0xfb) == 0x48) {
// REX.W | REX.WR
nBytes++;
if (origBytes[nBytes] == 0x81 && (origBytes[nBytes+1] & 0xf8) == 0xe8) {
@ -272,32 +290,20 @@ protected:
(origBytes[nBytes+1] & 0xf8) == 0x60) {
// and [r+d], imm8
nBytes += 5;
} else if (origBytes[nBytes] == 0x89) {
// MOV r/m64, r64
} else if ((origBytes[nBytes] & 0xfd) == 0x89) {
// MOV r/m64, r64 | MOV r64, r/m64
if ((origBytes[nBytes+1] & 0xc0) == 0x40) {
if ((origBytes[nBytes+1] & 0x7) == 0x04) {
// mov [SIB+disp8], r64
// R/M=[SIB+disp8], REG=r64
nBytes += 4;
} else {
// mov [r64+disp8], r64
// R/M=[r64+disp8], REG=r64
nBytes += 3;
}
} else {
// complex mov
return 0;
}
} else if (origBytes[nBytes] == 0x8b) {
// mov r64, r/m64
if ((origBytes[nBytes+1] & 0xc0) == 0x40) {
if ((origBytes[nBytes+1] & 0x7) == 0x04) {
// mov r64, [SIB+disp8]
nBytes += 4;
} else {
// mov r64, [r64+disp8]
nBytes += 3;
}
} else if ((origBytes[nBytes+1] & 0xc0) == 0xc0) {
// MOV r64, r64
} else if (((origBytes[nBytes+1] & 0xc0) == 0xc0) ||
(((origBytes[nBytes+1] & 0xc0) == 0x00) &&
((origBytes[nBytes+1] & 0x07) != 0x04) && ((origBytes[nBytes+1] & 0x07) != 0x05))) {
// REG=r64, R/M=r64 or REG=r64, R/M=[r64]
nBytes += 2;
} else {
// complex MOV
@ -349,8 +355,15 @@ protected:
byteptr_t trampDest = origBytes + nBytes;
#if defined(_M_IX86)
tramp[nBytes] = 0xE9; // jmp
*((intptr_t*)(tramp+nBytes+1)) = (intptr_t)trampDest - (intptr_t)(tramp+nBytes+5); // target displacement
if (pJmp32 >= 0) {
// Jump directly to the original target of the jump instead of jumping to the
// original function.
// Adjust jump target displacement to jump location in the trampoline.
*((intptr_t*)(tramp+pJmp32+1)) += origBytes + pJmp32 - tramp;
} else {
tramp[nBytes] = 0xE9; // jmp
*((intptr_t*)(tramp+nBytes+1)) = (intptr_t)trampDest - (intptr_t)(tramp+nBytes+5); // target displacement
}
#elif defined(_M_X64)
// If JMP32 opcode found, we don't insert to trampoline jump
if (pJmp32 >= 0) {