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zydis
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Various bugfixes 

- Fixed decoding of XOP/VEX instructions with 256-bit vector length
- Fixed decoding of instructions with hardcoded displacement values (e.g. MOFFS)
- Fixed decoding of instructions that make use of the "ANY" mandatory-prefix filter
This commit is contained in:
flobernd 2017-06-17 00:59:42 +02:00
parent 1d023c2997
commit 6794495f63
1 changed files with 43 additions and 28 deletions
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71
src/Decoder.c
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@ -263,12 +263,13 @@ static ZydisStatus ZydisDecodeXOP(ZydisDecoderContext* context, ZydisInstruction
info->details.xop.pp = (data[2] >> 0) & 0x03; info->details.xop.pp = (data[2] >> 0) & 0x03;
// Update internal fields // Update internal fields
context->cache.W = info->details.xop.W; context->cache.W = info->details.xop.W;
context->cache.R = 0x01 & ~info->details.xop.R; context->cache.R = 0x01 & ~info->details.xop.R;
context->cache.X = 0x01 & ~info->details.xop.X; context->cache.X = 0x01 & ~info->details.xop.X;
context->cache.B = 0x01 & ~info->details.xop.B; context->cache.B = 0x01 & ~info->details.xop.B;
context->cache.L = info->details.xop.L; context->cache.L = info->details.xop.L;
context->cache.v_vvvv = (0x0F & ~info->details.xop.vvvv); context->cache.LL = info->details.xop.L;
context->cache.v_vvvv = (0x0F & ~info->details.xop.vvvv);
return ZYDIS_STATUS_SUCCESS; return ZYDIS_STATUS_SUCCESS;
} }
@ -329,12 +330,13 @@ static ZydisStatus ZydisDecodeVEX(ZydisDecoderContext* context, ZydisInstruction
} }
// Update internal fields // Update internal fields
context->cache.W = info->details.vex.W; context->cache.W = info->details.vex.W;
context->cache.R = 0x01 & ~info->details.vex.R; context->cache.R = 0x01 & ~info->details.vex.R;
context->cache.X = 0x01 & ~info->details.vex.X; context->cache.X = 0x01 & ~info->details.vex.X;
context->cache.B = 0x01 & ~info->details.vex.B; context->cache.B = 0x01 & ~info->details.vex.B;
context->cache.L = info->details.vex.L; context->cache.L = info->details.vex.L;
context->cache.v_vvvv = (0x0F & ~info->details.vex.vvvv); context->cache.LL = info->details.vex.L;
context->cache.v_vvvv = (0x0F & ~info->details.vex.vvvv);
return ZYDIS_STATUS_SUCCESS; return ZYDIS_STATUS_SUCCESS;
} }
@ -395,14 +397,14 @@ static ZydisStatus ZydisDecodeEVEX(ZydisDecoderContext* context, ZydisInstructio
info->details.evex.aaa = (data[3] >> 0) & 0x07; info->details.evex.aaa = (data[3] >> 0) & 0x07;
// Update internal fields // Update internal fields
context->cache.W = info->details.evex.W; context->cache.W = info->details.evex.W;
context->cache.R = 0x01 & ~info->details.evex.R; context->cache.R = 0x01 & ~info->details.evex.R;
context->cache.X = 0x01 & ~info->details.evex.X; context->cache.X = 0x01 & ~info->details.evex.X;
context->cache.B = 0x01 & ~info->details.evex.B; context->cache.B = 0x01 & ~info->details.evex.B;
context->cache.LL = (data[3] >> 5) & 0x03; context->cache.LL = (data[3] >> 5) & 0x03;
context->cache.R2 = 0x01 & ~info->details.evex.R2; context->cache.R2 = 0x01 & ~info->details.evex.R2;
context->cache.V2 = 0x01 & ~info->details.evex.V2; context->cache.V2 = 0x01 & ~info->details.evex.V2;
context->cache.v_vvvv = context->cache.v_vvvv =
((0x01 & ~info->details.evex.V2) << 4) | (0x0F & ~info->details.evex.vvvv); ((0x01 & ~info->details.evex.V2) << 4) | (0x0F & ~info->details.evex.vvvv);
return ZYDIS_STATUS_SUCCESS; return ZYDIS_STATUS_SUCCESS;
@ -454,13 +456,13 @@ static ZydisStatus ZydisDecodeMVEX(ZydisDecoderContext* context, ZydisInstructio
info->details.mvex.kkk = (data[3] >> 0) & 0x07; info->details.mvex.kkk = (data[3] >> 0) & 0x07;
// Update internal fields // Update internal fields
context->cache.W = info->details.mvex.W; context->cache.W = info->details.mvex.W;
context->cache.R = 0x01 & ~info->details.mvex.R; context->cache.R = 0x01 & ~info->details.mvex.R;
context->cache.X = 0x01 & ~info->details.mvex.X; context->cache.X = 0x01 & ~info->details.mvex.X;
context->cache.B = 0x01 & ~info->details.mvex.B; context->cache.B = 0x01 & ~info->details.mvex.B;
context->cache.R2 = 0x01 & ~info->details.mvex.R2; context->cache.R2 = 0x01 & ~info->details.mvex.R2;
context->cache.V2 = 0x01 & ~info->details.mvex.V2; context->cache.V2 = 0x01 & ~info->details.mvex.V2;
context->cache.v_vvvv = context->cache.v_vvvv =
((0x01 & ~info->details.mvex.V2) << 4) | (0x0F & ~info->details.mvex.vvvv); ((0x01 & ~info->details.mvex.V2) << 4) | (0x0F & ~info->details.mvex.vvvv);
return ZYDIS_STATUS_SUCCESS; return ZYDIS_STATUS_SUCCESS;
@ -874,7 +876,7 @@ static ZydisStatus ZydisDecodeOptionalInstructionParts(ZydisDecoderContext* cont
if (optionalParts->flags & ZYDIS_INSTRPART_FLAG_HAS_DISP) if (optionalParts->flags & ZYDIS_INSTRPART_FLAG_HAS_DISP)
{ {
ZYDIS_CHECK(ZydisReadDisplacement( ZYDIS_CHECK(ZydisReadDisplacement(
context, info, optionalParts->disp.size[context->eoszIndex])); context, info, optionalParts->disp.size[context->easzIndex]));
} }
if (optionalParts->flags & ZYDIS_INSTRPART_FLAG_HAS_IMM0) if (optionalParts->flags & ZYDIS_INSTRPART_FLAG_HAS_IMM0)
@ -2940,6 +2942,7 @@ static ZydisStatus ZydisDecodeInstruction(ZydisDecoderContext* context, ZydisIns
// Iterate through the instruction table // Iterate through the instruction table
const ZydisInstructionTreeNode* node = ZydisInstructionTreeGetRootNode(); const ZydisInstructionTreeNode* node = ZydisInstructionTreeGetRootNode();
const ZydisInstructionTreeNode* temp = NULL;
ZydisInstructionTreeNodeType nodeType; ZydisInstructionTreeNodeType nodeType;
do do
{ {
@ -2949,6 +2952,17 @@ static ZydisStatus ZydisDecodeInstruction(ZydisDecoderContext* context, ZydisIns
switch (nodeType) switch (nodeType)
{ {
case ZYDIS_NODETYPE_INVALID: case ZYDIS_NODETYPE_INVALID:
if (temp)
{
node = temp;
temp = NULL;
nodeType = ZYDIS_NODETYPE_FILTER_MANDATORY_PREFIX;
if (context->mandatoryCandidate == 0x66)
{
info->attributes |= ZYDIS_ATTRIB_HAS_OPERANDSIZE;
}
continue;
}
return ZYDIS_STATUS_DECODING_ERROR; return ZYDIS_STATUS_DECODING_ERROR;
case ZYDIS_NODETYPE_FILTER_XOP: case ZYDIS_NODETYPE_FILTER_XOP:
status = ZydisNodeHandlerXOP(info, &index); status = ZydisNodeHandlerXOP(info, &index);
@ -2982,6 +2996,7 @@ static ZydisStatus ZydisDecodeInstruction(ZydisDecoderContext* context, ZydisIns
break; break;
case ZYDIS_NODETYPE_FILTER_MANDATORY_PREFIX: case ZYDIS_NODETYPE_FILTER_MANDATORY_PREFIX:
status = ZydisNodeHandlerMandatoryPrefix(context, info, &index); status = ZydisNodeHandlerMandatoryPrefix(context, info, &index);
temp = ZydisInstructionTreeGetChildNode(node, 0);
// TODO: Return to this point, if index == 0 contains a value and the previous path // TODO: Return to this point, if index == 0 contains a value and the previous path
// TODO: was not successfull // TODO: was not successfull
// TODO: Restore consumed prefix // TODO: Restore consumed prefix