[PATCH RFC] x86: SYSENTER/SYSEXIT are unavailable in 64-bit mode on AMD

Jan Beulich jbeulich@suse.com
Mon Nov 11 12:01:00 GMT 2019


opcodes/
2019-11-XX  Jan Beulich  <jbeulich@suse.com>

	* i386-opc.tbl (sysenter, sysexit): Split into AMD64 and Intel64
	forms.
	* i386-tbl.h: Re-generate.
---
RFC because this is liable to cause problems for existing code, but I
think we should still correct this. We may want to have a directive
(besides the command line option) such that the accepted ISA can be
overridden in a more fine granular manner.

--- a/opcodes/i386-opc.tbl
+++ b/opcodes/i386-opc.tbl
@@ -891,8 +891,10 @@ rdmsr, 0, 0xf32, None, 2, Cpu586, No_bSu
 cmpxchg8b, 1, 0xfc7, 0x1, 2, Cpu586, Modrm|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_ldSuf|IsLockable|NoRex64|HLEPrefixOk, { Qword|Unspecified|BaseIndex }
 
 // Pentium II/Pentium Pro extensions.
-sysenter, 0, 0xf34, None, 2, Cpu686, No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { 0 }
-sysexit, 0, 0xf35, None, 2, Cpu686, No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { 0 }
+sysenter, 0, 0xf34, None, 2, Cpu686, Intel64|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { 0 }
+sysenter, 0, 0xf34, None, 2, Cpu686|CpuNo64, AMD64|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { 0 }
+sysexit, 0, 0xf35, None, 2, Cpu686, Intel64|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { 0 }
+sysexit, 0, 0xf35, None, 2, Cpu686|CpuNo64, AMD64|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { 0 }
 fxsave, 1, 0xfae, 0x0, 2, CpuFXSR, Modrm|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_ldSuf, { Unspecified|BaseIndex }
 fxsave64, 1, 0xfae, 0x0, 2, CpuFXSR|Cpu64, Modrm|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|Rex64, { Unspecified|BaseIndex }
 fxrstor, 1, 0xfae, 0x1, 2, CpuFXSR, Modrm|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_ldSuf, { Unspecified|BaseIndex }



More information about the Binutils mailing list