ENDBR64—Terminate an Indirect Branch in 64-bit Mode

Opcode/Instruction Op /En 64/32 bit Mode Support CPUID Feature Flag Description
F3 0F 1E FA ENDBR64 ZO V/V CET_IBT Terminate indirect branch in 64 bit mode.

Instruction Operand Encoding

Op/En Tuple Type Operand 1 Operand 2 Operand 3 Operand 4
ZO NA NA NA NA NA

Description

Terminate an indirect branch in 64 bit mode.

Operation

IF EndbranchEnabled(CPL) & IA32_EFER.LMA = 1 & CS.L = 1
    IF CPL = 3
         THEN
              IA32_U_CET.TRACKER = IDLE
              IA32_U_CET.SUPPRESS = 0
         ELSE
              IA32_S_CET.TRACKER = IDLE
              IA32_S_CET.SUPPRESS = 0
    FI;
FI;

Flags Affected

None.

Exceptions

None.