diff options
Diffstat (limited to 'arch/x86/lib/insn.c')
| -rw-r--r-- | arch/x86/lib/insn.c | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/arch/x86/lib/insn.c b/arch/x86/lib/insn.c index 9f483179a8a6..9f33b984d0ef 100644 --- a/arch/x86/lib/insn.c +++ b/arch/x86/lib/insn.c @@ -28,6 +28,9 @@ #define peek_next(t, insn) \ ({t r; r = *(t*)insn->next_byte; r; }) +#define peek_nbyte_next(t, insn, n) \ + ({t r; r = *(t*)((insn)->next_byte + n); r; }) + /** * insn_init() - initialize struct insn * @insn: &struct insn to be initialized @@ -107,6 +110,7 @@ found: insn->prefixes.bytes[3] = lb; } + /* Decode REX prefix */ if (insn->x86_64) { b = peek_next(insn_byte_t, insn); attr = inat_get_opcode_attribute(b); @@ -120,6 +124,39 @@ found: } } insn->rex_prefix.got = 1; + + /* Decode VEX prefix */ + b = peek_next(insn_byte_t, insn); + attr = inat_get_opcode_attribute(b); + if (inat_is_vex_prefix(attr)) { + insn_byte_t b2 = peek_nbyte_next(insn_byte_t, insn, 1); + if (!insn->x86_64) { + /* + * In 32-bits mode, if the [7:6] bits (mod bits of + * ModRM) on the second byte are not 11b, it is + * LDS or LES. + */ + if (X86_MODRM_MOD(b2) != 3) + goto vex_end; + } + insn->vex_prefix.bytes[0] = b; + insn->vex_prefix.bytes[1] = b2; + if (inat_is_vex3_prefix(attr)) { + b2 = peek_nbyte_next(insn_byte_t, insn, 2); + insn->vex_prefix.bytes[2] = b2; + insn->vex_prefix.nbytes = 3; + insn->next_byte += 3; + if (insn->x86_64 && X86_VEX_W(b2)) + /* VEX.W overrides opnd_size */ + insn->opnd_bytes = 8; + } else { + insn->vex_prefix.nbytes = 2; + insn->next_byte += 2; + } + } +vex_end: + insn->vex_prefix.got = 1; + prefixes->got = 1; return; } @@ -147,6 +184,18 @@ void insn_get_opcode(struct insn *insn) op = get_next(insn_byte_t, insn); opcode->bytes[0] = op; opcode->nbytes = 1; + + /* Check if there is VEX prefix or not */ + if (insn_is_avx(insn)) { + insn_byte_t m, p; + m = insn_vex_m_bits(insn); + p = insn_vex_p_bits(insn); + insn->attr = inat_get_avx_attribute(op, m, p); + if (!inat_accept_vex(insn->attr)) + insn->attr = 0; /* This instruction is bad */ + goto end; /* VEX has only 1 byte for opcode */ + } + insn->attr = inat_get_opcode_attribute(op); while (inat_is_escape(insn->attr)) { /* Get escaped opcode */ @@ -155,6 +204,9 @@ void insn_get_opcode(struct insn *insn) pfx = insn_last_prefix(insn); insn->attr = inat_get_escape_attribute(op, pfx, insn->attr); } + if (inat_must_vex(insn->attr)) + insn->attr = 0; /* This instruction is bad */ +end: opcode->got = 1; } |