diff options
Diffstat (limited to 'arch/x86/kernel/umip.c')
| -rw-r--r-- | arch/x86/kernel/umip.c | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/arch/x86/kernel/umip.c b/arch/x86/kernel/umip.c index 5a4b21389b1d..d432f3824f0c 100644 --- a/arch/x86/kernel/umip.c +++ b/arch/x86/kernel/umip.c @@ -156,15 +156,26 @@ static int identify_insn(struct insn *insn) if (!insn->modrm.nbytes) return -EINVAL; - /* All the instructions of interest start with 0x0f. */ - if (insn->opcode.bytes[0] != 0xf) + /* The instructions of interest have 2-byte opcodes: 0F 00 or 0F 01. */ + if (insn->opcode.nbytes < 2 || insn->opcode.bytes[0] != 0xf) return -EINVAL; if (insn->opcode.bytes[1] == 0x1) { switch (X86_MODRM_REG(insn->modrm.value)) { case 0: + /* The reg form of 0F 01 /0 encodes VMX instructions. */ + if (X86_MODRM_MOD(insn->modrm.value) == 3) + return -EINVAL; + return UMIP_INST_SGDT; case 1: + /* + * The reg form of 0F 01 /1 encodes MONITOR/MWAIT, + * STAC/CLAC, and ENCLS. + */ + if (X86_MODRM_MOD(insn->modrm.value) == 3) + return -EINVAL; + return UMIP_INST_SIDT; case 4: return UMIP_INST_SMSW; |