=======LoadPin======= LoadPin is a Linux Security Module that ensures all kernel-loaded files(modules, firmware, etc) all originate from the same filesystem, withthe expectation that such a filesystem is backed by a read-only devicesuch as dm-verity or CDROM. This allows systems that have a verifiedand/or unchangeable filesystem to enforce module and firmware loadingrestrictions without needing to sign the files individually. The LSM is selectable at build-time with ``CONFIG_SECURITY_LOADPIN``, andcan be controlled at boot-time with the kernel command line option"``loadpin.enabled``". By default, it is enabled, but can be disabled atboot ("``loadpin.enabled=0``"). LoadPin starts pinning when it sees the first file loaded. If theblock device backing the filesystem is not read-only, a sysctl iscreated to toggle pinning: ``/proc/sys/kernel/loadpin/enabled``. (Havinga mutable filesystem means pinning is mutable too, but having thesysctl allows for easy testing on systems with a mutable filesystem.) It's also possible to exclude specific file types from LoadPin using kernelcommand line option "``loadpin.exclude``". By default, all files areincluded, but they can be excluded using kernel command line option suchas "``loadpin.exclude=kernel-module,kexec-image``". This allows to usedifferent mechanisms such as ``CONFIG_MODULE_SIG`` and``CONFIG_KEXEC_VERIFY_SIG`` to verify kernel module and kernel image whilestill use LoadPin to protect the integrity of other files kernel loads. Thefull list of valid file types can be found in ``kernel_read_file_str``defined in ``include/linux/fs.h``.