x86: Add NOTRACK prefix support

For register indirect branches, NOTRACK prefix (0x3e), which is also
the DS segment register prefix, can be used to ignore the CET indirect
branch track.

gas/

	* config/tc-i386.c (REX_PREFIX): Changed to 7.
	(NOTRACK_PREFIX): New.
	(MAX_PREFIXES): Changed to 8.
	(_i386_insn): Add notrack_prefix.
	(PREFIX_GROUP): Add PREFIX_DS.
	(add_prefix): Return PREFIX_DS for DS_PREFIX_OPCODE.
	(md_assemble): Check if NOTRACK prefix is supported.
	(parse_insn): Set notrack_prefix and issue an error for
	other prefixes after NOTRACK prefix.
	* testsuite/gas/i386/i386.exp: Run tests for NOTRACK prefix.
	* testsuite/gas/i386/notrack-intel.d: New file.
	* testsuite/gas/i386/notrack.d: Likewise.
	* testsuite/gas/i386/notrack.s: Likewise.
	* testsuite/gas/i386/notrackbad.l: Likewise.
	* testsuite/gas/i386/notrackbad.s: Likewise.
	* testsuite/gas/i386/x86-64-notrack-intel.d: Likewise.
	* testsuite/gas/i386/x86-64-notrack.d: Likewise.
	* testsuite/gas/i386/x86-64-notrack.s: Likewise.
	* testsuite/gas/i386/x86-64-notrackbad.l: Likewise.
	* testsuite/gas/i386/x86-64-notrackbad.s: Likewise.

include/

	* include/opcode/i386.h (NOTRACK_PREFIX_OPCODE): New.

opcodes/

	* i386-dis.c (NOTRACK_Fixup): New.
	(NOTRACK): Likewise.
	(NOTRACK_PREFIX): Likewise.
	(last_active_prefix): Likewise.
	(reg_table): Use NOTRACK on indirect call and jmp.
	(ckprefix): Set last_active_prefix.
	(prefix_name): Return "notrack" for NOTRACK_PREFIX.
	* i386-gen.c (opcode_modifiers): Add NoTrackPrefixOk.
	* i386-opc.h (NoTrackPrefixOk): New.
	(i386_opcode_modifier): Add notrackprefixok.
	* i386-opc.tbl: Add NoTrackPrefixOk to indirect call and jmp.
	Add notrack.
	* i386-tbl.h: Regenerated.

1 files changed, 9 insertions, 6 deletions

diff --git a/opcodes/i386-opc.tbl b/opcodes/i386-opc.tbl
index 242bbf5..5b1a4fd 100644
--- a/opcodes/i386-opc.tbl
+++ b/opcodes/i386-opc.tbl
@@ -312,9 +312,9 @@ shrd, 2, 0xfad, None, 2, Cpu386, Modrm|CheckRegSize|No_bSuf|No_sSuf|No_ldSuf, {
 call, 1, 0xe8, None, 1, CpuNo64, JumpDword|DefaultSize|No_bSuf|No_sSuf|No_qSuf|No_ldSuf|BNDPrefixOk, { Disp16|Disp32 }
 call, 1, 0xe8, None, 1, Cpu64, AMD64|JumpDword|DefaultSize|No_bSuf|No_lSuf|No_sSuf|No_ldSuf|NoRex64|BNDPrefixOk, { Disp16|Disp32S }
 call, 1, 0xe8, None, 1, Cpu64, Intel64|JumpDword|DefaultSize|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_ldSuf|NoRex64|BNDPrefixOk, { Disp32S }
-call, 1, 0xff, 0x2, 1, CpuNo64, Modrm|DefaultSize|No_bSuf|No_sSuf|No_qSuf|No_ldSuf|BNDPrefixOk, { Reg16|Reg32|Word|Dword|Unspecified|BaseIndex|Disp8|Disp16|Disp32|JumpAbsolute }
-call, 1, 0xff, 0x2, 1, Cpu64, AMD64|Modrm|DefaultSize|No_bSuf|No_lSuf|No_sSuf|No_ldSuf|NoRex64|BNDPrefixOk, { Reg16|Reg64|Word|Qword|Unspecified|BaseIndex|Disp8|Disp32|Disp32S|JumpAbsolute }
-call, 1, 0xff, 0x2, 1, Cpu64, Intel64|Modrm|DefaultSize|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_ldSuf|NoRex64|BNDPrefixOk, { Reg64|Qword|Unspecified|BaseIndex|Disp8|Disp32|Disp32S|JumpAbsolute }
+call, 1, 0xff, 0x2, 1, CpuNo64, Modrm|DefaultSize|No_bSuf|No_sSuf|No_qSuf|No_ldSuf|BNDPrefixOk|NoTrackPrefixOk, { Reg16|Reg32|Word|Dword|Unspecified|BaseIndex|Disp8|Disp16|Disp32|JumpAbsolute }
+call, 1, 0xff, 0x2, 1, Cpu64, AMD64|Modrm|DefaultSize|No_bSuf|No_lSuf|No_sSuf|No_ldSuf|NoRex64|BNDPrefixOk|NoTrackPrefixOk, { Reg16|Reg64|Word|Qword|Unspecified|BaseIndex|Disp8|Disp32|Disp32S|JumpAbsolute }
+call, 1, 0xff, 0x2, 1, Cpu64, Intel64|Modrm|DefaultSize|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_ldSuf|NoRex64|BNDPrefixOk|NoTrackPrefixOk, { Reg64|Qword|Unspecified|BaseIndex|Disp8|Disp32|Disp32S|JumpAbsolute }
 // Intel Syntax
 call, 2, 0x9a, None, 1, CpuNo64, JumpInterSegment|DefaultSize|No_bSuf|No_sSuf|No_qSuf|No_ldSuf, { Imm16, Imm16|Imm32 }
 // Intel Syntax
@@ -325,9 +325,9 @@ lcall, 1, 0xff, 0x3, 1, 0, Modrm|DefaultSize|No_bSuf|No_sSuf|No_qSuf|No_ldSuf, {
 jmp, 1, 0xeb, None, 1, CpuNo64, Jump|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|BNDPrefixOk, { Disp8|Disp16|Disp32 }
 jmp, 1, 0xeb, None, 1, Cpu64, AMD64|Jump|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|BNDPrefixOk, { Disp8|Disp16|Disp32S }
 jmp, 1, 0xeb, None, 1, Cpu64, Intel64|Jump|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|BNDPrefixOk, { Disp8|Disp32S }
-jmp, 1, 0xff, 0x4, 1, CpuNo64, Modrm|No_bSuf|No_sSuf|No_qSuf|No_ldSuf|BNDPrefixOk, { Reg16|Reg32|Word|Dword|Unspecified|BaseIndex|Disp8|Disp16|Disp32|JumpAbsolute }
-jmp, 1, 0xff, 0x4, 1, Cpu64, AMD64|Modrm|No_bSuf|No_lSuf|No_sSuf|No_ldSuf|NoRex64|BNDPrefixOk, { Reg16|Reg64|Word|Qword|Unspecified|BaseIndex|Disp8|Disp32|Disp32S|JumpAbsolute }
-jmp, 1, 0xff, 0x4, 1, Cpu64, Intel64|Modrm|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_ldSuf|NoRex64|BNDPrefixOk, { Reg64|Qword|Unspecified|BaseIndex|Disp8|Disp32|Disp32S|JumpAbsolute }
+jmp, 1, 0xff, 0x4, 1, CpuNo64, Modrm|No_bSuf|No_sSuf|No_qSuf|No_ldSuf|BNDPrefixOk|NoTrackPrefixOk, { Reg16|Reg32|Word|Dword|Unspecified|BaseIndex|Disp8|Disp16|Disp32|JumpAbsolute }
+jmp, 1, 0xff, 0x4, 1, Cpu64, AMD64|Modrm|No_bSuf|No_lSuf|No_sSuf|No_ldSuf|NoRex64|BNDPrefixOk|NoTrackPrefixOk, { Reg16|Reg64|Word|Qword|Unspecified|BaseIndex|Disp8|Disp32|Disp32S|JumpAbsolute }
+jmp, 1, 0xff, 0x4, 1, Cpu64, Intel64|Modrm|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_ldSuf|NoRex64|BNDPrefixOk|NoTrackPrefixOk, { Reg64|Qword|Unspecified|BaseIndex|Disp8|Disp32|Disp32S|JumpAbsolute }
 // Intel Syntax.
 jmp, 2, 0xea, None, 1, CpuNo64, JumpInterSegment|No_bSuf|No_sSuf|No_qSuf|No_ldSuf, { Imm16, Imm16|Imm32 }
 // Intel Syntax.
@@ -6024,4 +6024,7 @@ clrssbsy, 1, 0xf30fae, 0x6, 2, CpuCET, Modrm|IgnoreSize|No_bSuf|No_wSuf|No_lSuf|
 endbr64, 0, 0xf30f1efa, None, 3, CpuCET, IgnoreSize|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { 0 }
 endbr32, 0, 0xf30f1efb, None, 3, CpuCET, IgnoreSize|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { 0 }
 
+// notrack prefix
+notrack, 0, 0x3e, None, 1, CpuCET, No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|IsPrefix, { 0 }
+
 // CET instructions end.