commit 89a83a0c69c81a25ce91002b90ca27ed86132a0a upstream. Add a test modelled on the RFI flush test which counts the number of L1D misses doing a simple syscall with the entry flush on and off. For simplicity of backporting, this test duplicates a lot of code from the upstream rfi_flush. This is cleaned up upstream, but we don't clean it up here because it would involve bringing in even more commits. Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>