From 73239888b37b95101d55d1d58b0acb663496b8d7 Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Tue, 9 Jun 2020 08:59:04 +0200 Subject: [PATCH] x86: consistently print prefixes explicitly which are invalid with VEX etc All of data size, rep, lock, and rex prefixes are invalid with VEX- and alike encoded insns. Make sure they get printed explicitly in all cases, to signal the anomaly. With this, do away with "rex_ignored" - if there is a rex prefix, we want to print it anyway for VEX etc (and there's nothing "ignored" about it in the first place - such an instruction will raise #UD). --- gas/ChangeLog | 6 ++++++ gas/testsuite/gas/i386/prefix.d | 5 ++++- gas/testsuite/gas/i386/prefix.s | 5 +++++ opcodes/ChangeLog | 8 ++++++++ opcodes/i386-dis.c | 16 +++------------- 5 files changed, 26 insertions(+), 14 deletions(-) diff --git a/gas/ChangeLog b/gas/ChangeLog index 78ffd807ce..8b78964f81 100644 --- a/gas/ChangeLog +++ b/gas/ChangeLog @@ -1,3 +1,9 @@ +2020-06-09 Jan Beulich + + * testsuite/gas/i386/prefix.s: Add bogus prefix-with-VEX/EVEX + encoding tests. + * testsuite/gas/i386/prefix.d: Adjust expectations. + 2020-06-09 Jan Beulich * testsuite/gas/i386/prefix.s: Add bogus REP / EVEX.W prefix diff --git a/gas/testsuite/gas/i386/prefix.d b/gas/testsuite/gas/i386/prefix.d index 9e293bce2a..02e1813ea7 100644 --- a/gas/testsuite/gas/i386/prefix.d +++ b/gas/testsuite/gas/i386/prefix.d @@ -86,8 +86,11 @@ Disassembly of section .text: [ ]*[a-f0-9]+: ff cc dec %esp [ ]*[a-f0-9]+: 62 f1 ff 08 28 \(bad\) * [ ]*[a-f0-9]+: ff cc dec %esp +[ ]*[a-f0-9]+: 66 c5 f8 28 c0 data16 vmovaps %xmm0,%xmm0 +[ ]*[a-f0-9]+: f3 c4 e1 78 28 c0 repz vmovaps %xmm0,%xmm0 +[ ]*[a-f0-9]+: f2 c5 f8 28 c0 repnz vmovaps %xmm0,%xmm0 +[ ]*[a-f0-9]+: f0 62 f1 7c 08 28 c0 lock vmovaps %xmm0,%xmm0 [ ]*[a-f0-9]+: c5 fb e6 40 20 vcvtpd2dqx 0x20\(%eax\),%xmm0 [ ]*[a-f0-9]+: 62 f1 ff 18 e6 40 04 vcvtpd2dq 0x20\(%eax\)\{1to2\},%xmm0 [ ]*[a-f0-9]+: c5 fb e6 40 20 vcvtpd2dqx 0x20\(%eax\),%xmm0 - ... #pass diff --git a/gas/testsuite/gas/i386/prefix.s b/gas/testsuite/gas/i386/prefix.s index 78fd478c3f..8d563e1626 100644 --- a/gas/testsuite/gas/i386/prefix.s +++ b/gas/testsuite/gas/i386/prefix.s @@ -451,6 +451,11 @@ int $3 + .byte 0x66; vmovaps %xmm0, %xmm0 + repz; {vex3} vmovaps %xmm0, %xmm0 + repnz; vmovaps %xmm0, %xmm0 + lock; {evex} vmovaps %xmm0, %xmm0 + vcvtpd2dqx 0x20(%eax),%xmm0 vcvtpd2dq 0x20(%eax){1to2},%xmm0 vcvtpd2dqx 0x20(%eax),%xmm0 diff --git a/opcodes/ChangeLog b/opcodes/ChangeLog index c6f1d2691e..6b3869f0f0 100644 --- a/opcodes/ChangeLog +++ b/opcodes/ChangeLog @@ -1,3 +1,11 @@ +2020-06-09 Jan Beulich + + * i386-dis.c (rex_ignored): Delete. + (ckprefix): Drop rex_ignored initialization. + (get_valid_dis386): Drop setting of rex_ignored. + (print_insn): Drop checking of rex_ignored. Don't record data + size prefix as used with VEX-and-alike encodings. + 2020-06-09 Jan Beulich * i386-dis.c (MOD_0F12_PREFIX_2, MOD_0F16_PREFIX_2, diff --git a/opcodes/i386-dis.c b/opcodes/i386-dis.c index 3861371ed4..be6958a236 100644 --- a/opcodes/i386-dis.c +++ b/opcodes/i386-dis.c @@ -153,8 +153,6 @@ static int prefixes; static int rex; /* Bits of REX we've already used. */ static int rex_used; -/* REX bits in original REX prefix ignored. */ -static int rex_ignored; /* Mark parts used in the REX prefix. When we are testing for empty prefix (for 8bit register REX extension), just mask it out. Otherwise test for REX bit is excuse for existence of REX @@ -11057,7 +11055,6 @@ ckprefix (void) { int newrex, i, length; rex = 0; - rex_ignored = 0; prefixes = 0; used_prefixes = 0; rex_used = 0; @@ -11517,8 +11514,6 @@ get_valid_dis386 (const struct dis386 *dp, disassemble_info *info) case USE_XOP_8F_TABLE: FETCH_DATA (info, codep + 3); - /* All bits in the REX prefix are ignored. */ - rex_ignored = rex; rex = ~(*codep >> 5) & 0x7; /* VEX_TABLE_INDEX is the mmmmm part of the XOP byte 1 "RCB.mmmmm". */ @@ -11580,8 +11575,6 @@ get_valid_dis386 (const struct dis386 *dp, disassemble_info *info) case USE_VEX_C4_TABLE: /* VEX prefix. */ FETCH_DATA (info, codep + 3); - /* All bits in the REX prefix are ignored. */ - rex_ignored = rex; rex = ~(*codep >> 5) & 0x7; switch ((*codep & 0x1f)) { @@ -11647,8 +11640,6 @@ get_valid_dis386 (const struct dis386 *dp, disassemble_info *info) case USE_VEX_C5_TABLE: /* VEX prefix. */ FETCH_DATA (info, codep + 2); - /* All bits in the REX prefix are ignored. */ - rex_ignored = rex; rex = (*codep & 0x80) ? 0 : REX_R; /* For the 2-byte VEX prefix in 32-bit mode, the highest bit in @@ -11697,8 +11688,6 @@ get_valid_dis386 (const struct dis386 *dp, disassemble_info *info) /* EVEX prefix. */ vex.evex = 1; FETCH_DATA (info, codep + 4); - /* All bits in the REX prefix are ignored. */ - rex_ignored = rex; /* The first byte after 0x62. */ rex = ~(*codep >> 5) & 0x7; vex.r = *codep & 0x10; @@ -12179,7 +12168,7 @@ print_insn (bfd_vma pc, disassemble_info *info) } /* Check if the REX prefix is used. */ - if (rex_ignored == 0 && (rex ^ rex_used) == 0 && last_rex_prefix >= 0) + if ((rex ^ rex_used) == 0 && !need_vex && last_rex_prefix >= 0) all_prefixes[last_rex_prefix] = 0; /* Check if the SEG prefix is used. */ @@ -12195,7 +12184,8 @@ print_insn (bfd_vma pc, disassemble_info *info) /* Check if the DATA prefix is used. */ if ((prefixes & PREFIX_DATA) != 0 - && (used_prefixes & PREFIX_DATA) != 0) + && (used_prefixes & PREFIX_DATA) != 0 + && !need_vex) all_prefixes[last_data_prefix] = 0; /* Print the extra prefixes. */ -- 2.34.1