From: Nadav Amit <[email protected]> 3.12-stable review patch. If anyone has any objections, please let me know.
=============== commit 58b7075d059f7d37ca86c76fb1446fa3447b9f4f upstream. In 64-bit, stack operations default to 64-bits, but can be overriden (to 16-bit) using opsize override prefix. In contrast, near-branches are always 64-bit. This patch distinguish between the different behaviors. Signed-off-by: Nadav Amit <[email protected]> Signed-off-by: Bruce Rogers <[email protected]> Signed-off-by: Jiri Slaby <[email protected]> --- arch/x86/kvm/emulate.c | 23 ++++++++++++++--------- 1 file changed, 14 insertions(+), 9 deletions(-) diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 4cb80f2c6fdb..987fdb379df6 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -161,6 +161,7 @@ #define Fastop ((u64)1 << 44) /* Use opcode::u.fastop */ #define NoWrite ((u64)1 << 45) /* No writeback */ #define SrcWrite ((u64)1 << 46) /* Write back src operand */ +#define NearBranch ((u64)1 << 52) /* Near branches */ #define DstXacc (DstAccLo | SrcAccHi | SrcWrite) @@ -3646,9 +3647,9 @@ static const struct opcode group4[] = { static const struct opcode group5[] = { F(DstMem | SrcNone | Lock, em_inc), F(DstMem | SrcNone | Lock, em_dec), - I(SrcMem | Stack, em_call_near_abs), + I(SrcMem | NearBranch, em_call_near_abs), I(SrcMemFAddr | ImplicitOps | Stack, em_call_far), - I(SrcMem | Stack, em_jmp_abs), + I(SrcMem | NearBranch, em_jmp_abs), I(SrcMemFAddr | ImplicitOps, em_jmp_far), I(SrcMem | Stack, em_push), D(Undefined), }; @@ -3812,7 +3813,7 @@ static const struct opcode opcode_table[256] = { I2bvIP(DstDI | SrcDX | Mov | String | Unaligned, em_in, ins, check_perm_in), /* insb, insw/insd */ I2bvIP(SrcSI | DstDX | String, em_out, outs, check_perm_out), /* outsb, outsw/outsd */ /* 0x70 - 0x7F */ - X16(D(SrcImmByte)), + X16(D(SrcImmByte | NearBranch)), /* 0x80 - 0x87 */ G(ByteOp | DstMem | SrcImm, group1), G(DstMem | SrcImm, group1), @@ -3850,8 +3851,8 @@ static const struct opcode opcode_table[256] = { X8(I(DstReg | SrcImm64 | Mov, em_mov)), /* 0xC0 - 0xC7 */ G(ByteOp | Src2ImmByte, group2), G(Src2ImmByte, group2), - I(ImplicitOps | Stack | SrcImmU16, em_ret_near_imm), - I(ImplicitOps | Stack, em_ret), + I(ImplicitOps | NearBranch | SrcImmU16, em_ret_near_imm), + I(ImplicitOps | NearBranch, em_ret), I(DstReg | SrcMemFAddr | ModRM | No64 | Src2ES, em_lseg), I(DstReg | SrcMemFAddr | ModRM | No64 | Src2DS, em_lseg), G(ByteOp, group11), G(0, group11), @@ -3872,11 +3873,11 @@ static const struct opcode opcode_table[256] = { N, E(0, &escape_d9), N, E(0, &escape_db), N, E(0, &escape_dd), N, N, /* 0xE0 - 0xE7 */ X3(I(SrcImmByte, em_loop)), - I(SrcImmByte, em_jcxz), + I(SrcImmByte | NearBranch, em_jcxz), I2bvIP(SrcImmUByte | DstAcc, em_in, in, check_perm_in), I2bvIP(SrcAcc | DstImmUByte, em_out, out, check_perm_out), /* 0xE8 - 0xEF */ - I(SrcImm | Stack, em_call), D(SrcImm | ImplicitOps), + I(SrcImm | NearBranch, em_call), D(SrcImm | ImplicitOps), I(SrcImmFAddr | No64, em_jmp_far), D(SrcImmByte | ImplicitOps), I2bvIP(SrcDX | DstAcc, em_in, in, check_perm_in), I2bvIP(SrcAcc | DstDX, em_out, out, check_perm_out), @@ -4356,8 +4357,12 @@ done_prefixes: if (!(ctxt->d & VendorSpecific) && ctxt->only_vendor_specific_insn) return EMULATION_FAILED; - if (mode == X86EMUL_MODE_PROT64 && (ctxt->d & Stack)) - ctxt->op_bytes = 8; + if (mode == X86EMUL_MODE_PROT64) { + if (ctxt->op_bytes == 4 && (ctxt->d & Stack)) + ctxt->op_bytes = 8; + else if (ctxt->d & NearBranch) + ctxt->op_bytes = 8; + } if (ctxt->d & Op3264) { if (mode == X86EMUL_MODE_PROT64) -- 2.2.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
