Disclosed last year by Arm was their processors affected by a straight-line speculation vulnerability. In this case the processor could speculatively execute instructions linearly in memory past an unconditional change in control flow. There has been talk about possible straight-line speculation on x86/x86_64 but without any action while now GCC and LLVM/Clang compiler developers along with Linux kernel developers are preparing such mitigation support…

Source: Phoronix – Linux + GCC/Clang Patches Coming For Straight-Line Speculation Mitigation On x86/x86_64