Messages in this thread | | | Date | Wed, 8 Apr 2020 16:25:36 +0900 | From | Masami Hiramatsu <> | Subject | Re: [PATCH 3/4] x86,module: Detect VMX vs SLD conflicts |
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On Wed, 8 Apr 2020 01:51:24 +0900 Masami Hiramatsu <mhiramat@kernel.org> wrote:
> Hi Peter, > > On Tue, 07 Apr 2020 13:02:39 +0200 > Peter Zijlstra <peterz@infradead.org> wrote: > > > +static bool insn_is_vmx(struct insn *insn) > > +{ > > + u8 modrm = insn->modrm.bytes[0]; > > + u8 modrm_mod = X86_MODRM_MOD(modrm); > > + u8 modrm_reg = X86_MODRM_REG(modrm); > > + > > + u8 prefix = insn->prefixes.bytes[0]; > > + > > + if (insn->opcode.bytes[0] != 0x0f) > > + return false; > > + > > + switch (insn->opcode.bytes[1]) { > > + case 0x01: > > + switch (insn->opcode.bytes[2]) { > > + case 0xc1: /* VMCALL */ > > + case 0xc2: /* VMLAUNCH */ > > + case 0xc3: /* VMRESUME */ > > + case 0xc4: /* VMXOFF */ > > + return true; > > + > > + default: > > + break; > > + } > > + break; > > + > > + case 0x78: /* VMREAD */ > > + case 0x79: /* VMWRITE */ > > + return true; > > + > > + case 0xc7: > > + /* VMPTRLD, VMPTRST, VMCLEAR, VMXON */ > > + if (modrm_mod == 0x03) > > + break; > > + > > + if ((modrm_reg == 6 && (!prefix || prefix == 0x66 || prefix == 0xf3)) || > > + (modrm_reg == 7 && (!prefix || prefix == 0xf3))) > > + return true; > > + > > + break; > > + > > + default: > > + break; > > + } > > + > > + return false; > > +} > > OK, so here is what you need ;) > > From 36f4f6aec623b0190fde95c8630a6a1d8c23ffc9 Mon Sep 17 00:00:00 2001 > From: Masami Hiramatsu <mhiramat@kernel.org> > Date: Wed, 8 Apr 2020 01:04:41 +0900 > Subject: [PATCH] x86: insn: Add insn_is_vmx() > > Add insn_is_vmx() to identify the given instruction is > for VMX or not. This is simply identifying those instructions > by mnemonic pattern. >
Hmm, I found that this is still not enough... since the inat_tables mixes the instruction attributes on same entry in group tables. It distinguishes opcodes by last-prefix variants, but not by MOD & R/M bits, since it is designed only for decoding instructions.
Thank you,
-- Masami Hiramatsu <mhiramat@kernel.org>
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