• Steven Rostedt's avatar
    x86/jump-label: Use best default nops for inital jump label calls · c3c7f14a
    Steven Rostedt authored
    As specified by H. Peter Anvin, the best nops for x86 without knowing
    the running computer is:
    
    32bit:
      0x3e, 0x8d, 0x74, 0x26, 0x00 also known as GENERIC_NOP5_ATOMIC
    
    64bit:
      0x0f, 0x1f, 0x44, 0x00, 0x00  also known as P6_NOP5_ATOMIC
    
    Currently the default nop that is used by jump label is:
    
     0xe9 0x00 0x00 0x00 0x00
    
    Which is really a 5byte jump to the next position.
    
    It's better to use a real nop than a jmp.
    
    Cc: H. Peter Anvin <hpa@linux.intel.com>
    Cc: Jason Baron <jbaron@redhat.com>
    Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
    c3c7f14a
jump_label.h 870 Bytes