The past content in the crypto section lacks informative descriptions,
and there should be a proper procedure to demonstrate how Linux
cryptography works. Due to poor maintenance, let's drop the section.
In Debian, the name syscall conflicts with this patch:
in debian kernel source tree:
debian/patches/features/x86/x86-make-x32-syscall-support-conditional.patch
mailing list url:
https://lore.kernel.org/lkml/1415245982.3398.53.camel@decadent.org.uk/T/#u
which introduces a parameter named syscall.x32. So change our name.
This patch introduces static key technique and adds a kernel module
to demostrate how to use static key to optimize an almost unlikely
branch, the module can interact with userspace thru a character device.
Signed-off-by: Peter Lin <peterlin@qilai.dev>