[PATCH V4 16/16] perf, x86: Discard zero length call entries in LBR call stack

"Zero length call" uses the attribute of the call instruction to push the immediate instruction pointer on to the stack and then pops off that address into a register. This is accomplished without any matching return instruction. It confuses the hardware and make the recorded call stack incorrect.

[PATCH v4 16/16] perf, x86: Discard zero length call entries in LBR call stack

"Zero length call" uses the attribute of the call instruction to push the immediate instruction pointer on to the stack and then pops off that address into a register. This is accomplished without any matching return instruction. It confuses the hardware and make the recorded call stack incorrect.