WRSSD/WRSSQ—Write to Shadow StackInstruction Operand EncodingDescriptionWrites bytes in register source to the shadow stack.OperationIF CPL = 3IF (CR4.CET & IA32_U_CET.SH_STK_EN) = 0THEN #UD; FI;IF (IA32_U_CET.WR_SHSTK_EN) = 0THEN #UD; FI;ELSEIF (CR4.CET & IA32_S_CET.SH_STK_EN) = 0THEN #UD; FI;IF (IA32_S_CET.WR_SHSTK_EN) = 0THEN #UD; FI;FI;DEST_LA = Linear_Address(mem operand)IF (operand size is 64 bit)THEN(* Destination not 8B aligned *)IF DEST_LA[2:0]THEN GP(0); FI;Shadow_stack_store 8 bytes of SRC to DEST_LA;ELSE(* Destination not 4B aligned *)IF DEST_LA[1:0]THEN GP(0); FI;Shadow_stack_store 4 bytes of SRC[31:0] to DEST_LA;FI;Flags AffectedNone.C/C++ Compiler Intrinsic EquivalentWRSSDvoid _wrssd(__int32, void *);WRSSQvoid _wrssq(__int64, void *);Opcode/InstructionOp/ En64/32 bit Mode SupportCPUID Feature FlagDescription0F 38 F6 !(11):rrr:bbbWRSSD m32, r32MRV/VCET_SSWrite 4 bytes to shadow stack.REX.W 0F 38 F6 !(11):rrr:bbbWRSSQ m64, r64MRV/N.E.CET_SSWrite 8 bytes to shadow stack.Op/EnOperand 1Operand 2Operand 3Operand 4MRModRM:r/m (w)ModRM:reg (r)NANA
This UNOFFICIAL reference was generated from the official Intel® 64 and IA-32 Architectures Software Developer’s Manual by a dumb script. There is no guarantee that some parts aren't mangled or broken and is distributed WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.