• David Howells's avatar
    MODSIGN: Move the magic string to the end of a module and eliminate the search · caabe240
    David Howells authored
    Emit the magic string that indicates a module has a signature after the
    signature data instead of before it.  This allows module_sig_check() to
    be made simpler and faster by the elimination of the search for the
    magic string.  Instead we just need to do a single memcmp().
    
    This works because at the end of the signature data there is the
    fixed-length signature information block.  This block then falls
    immediately prior to the magic number.
    
    From the contents of the information block, it is trivial to calculate
    the size of the signature data and thus the size of the actual module
    data.
    Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    caabe240