From 54ca11a48eba11788445247b16bc77637e3aa84a Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Thu, 22 Jul 2021 13:07:27 +0200 Subject: x86: correct EVEX.V' handling outside of 64-bit mode Unlike the high bit of VEX.vvvv / EVEX.vvvv, EVEX.V' is not ignored outside of 64-bit mode. Oddly enough there already are tests for these cases, but their expectations were wrong. (This may have been based on an old SDM version, where the restriction wasn't properly spelled out.) --- opcodes/i386-dis.c | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-) (limited to 'opcodes') diff --git a/opcodes/i386-dis.c b/opcodes/i386-dis.c index ddb659f..267d58d 100644 --- a/opcodes/i386-dis.c +++ b/opcodes/i386-dis.c @@ -9316,7 +9316,6 @@ get_valid_dis386 (const struct dis386 *dp, disassemble_info *info) /* In 16/32-bit mode silently ignore following bits. */ rex &= ~REX_B; vex.r = 1; - vex.v = 1; } need_vex = 1; @@ -11718,8 +11717,13 @@ OP_E_memory (int bytemode, int sizeflag) *obufp = '\0'; } if (haveindex) - oappend (address_mode == mode_64bit && !addr32flag - ? indexes64[vindex] : indexes32[vindex]); + { + if (address_mode == mode_64bit || vindex < 16) + oappend (address_mode == mode_64bit && !addr32flag + ? indexes64[vindex] : indexes32[vindex]); + else + oappend ("(bad)"); + } else oappend (address_mode == mode_64bit && !addr32flag ? index64 : index32); @@ -13256,7 +13260,15 @@ OP_VEX (int bytemode, int sizeflag ATTRIBUTE_UNUSED) reg = vex.register_specifier; vex.register_specifier = 0; if (address_mode != mode_64bit) - reg &= 7; + { + if (vex.evex && !vex.v) + { + oappend ("(bad)"); + return; + } + + reg &= 7; + } else if (vex.evex && !vex.v) reg += 16; -- cgit v1.1