LSM: Better reporting of actual LSMs at boot

LSM: Better reporting of actual LSMs at boot

Enhance the details reported by "lsm.debug" in several ways:

- report contents of "security="
- report contents of "CONFIG_LSM"
- report contents of "lsm="
- report any early LSM details
- whitespace-align the output of similar phases for easier visual parsing
- change "disabled" to more accurate "skipped"
- explain what "skipped" and "ignored" mean in a parenthetical

Upgrade the "security= is ignored" warning from pr_info to pr_warn,
and include full arguments list to make the cause even more clear.

Replace static "Security Framework initializing" pr_info with specific
list of the resulting order of enabled LSMs.

For example, if the kernel is built with:

CONFIG_SECURITY_SELINUX=y
CONFIG_SECURITY_APPARMOR=y
CONFIG_SECURITY_LOADPIN=y
CONFIG_SECURITY_YAMA=y
CONFIG_SECURITY_SAFESETID=y
CONFIG_SECURITY_LOCKDOWN_LSM=y
CONFIG_SECURITY_LANDLOCK=y
CONFIG_INTEGRITY=y
CONFIG_BPF_LSM=y
CONFIG_DEFAULT_SECURITY_APPARMOR=y
CONFIG_LSM="landlock,lockdown,yama,loadpin,safesetid,integrity,selinux,
            smack,tomoyo,apparmor,bpf"

Booting without options will show:

LSM: initializing lsm=lockdown,capability,landlock,yama,loadpin,
     safesetid,integrity,selinux,bpf
landlock: Up and running.
Yama: becoming mindful.
LoadPin: ready to pin (currently not enforcing)
SELinux:  Initializing.
LSM support for eBPF active

Boot with "lsm.debug" will show:

LSM: legacy security= *unspecified*
LSM: CONFIG_LSM=landlock,lockdown,yama,loadpin,safesetid,integrity,
                selinux,smack,tomoyo,apparmor,bpf
LSM: boot arg lsm= *unspecified*
LSM:   early started: lockdown (enabled)
LSM:   first ordered: capability (enabled)
LSM: builtin ordered: landlock (enabled)
LSM: builtin ignored: lockdown (not built into kernel)
LSM: builtin ordered: yama (enabled)
LSM: builtin ordered: loadpin (enabled)
LSM: builtin ordered: safesetid (enabled)
LSM: builtin ordered: integrity (enabled)
LSM: builtin ordered: selinux (enabled)
LSM: builtin ignored: smack (not built into kernel)
LSM: builtin ignored: tomoyo (not built into kernel)
LSM: builtin ordered: apparmor (enabled)
LSM: builtin ordered: bpf (enabled)
LSM: exclusive chosen:   selinux
LSM: exclusive disabled: apparmor
LSM: initializing lsm=lockdown,capability,landlock,yama,loadpin,
                      safesetid,integrity,selinux,bpf
LSM: cred blob size       = 32
LSM: file blob size       = 16
LSM: inode blob size      = 72
LSM: ipc blob size        = 8
LSM: msg_msg blob size    = 4
LSM: superblock blob size = 80
LSM: task blob size       = 8
LSM: initializing capability
LSM: initializing landlock
landlock: Up and running.
LSM: initializing yama
Yama: becoming mindful.
LSM: initializing loadpin
LoadPin: ready to pin (currently not enforcing)
LSM: initializing safesetid
LSM: initializing integrity
LSM: initializing selinux
SELinux:  Initializing.
LSM: initializing bpf
LSM support for eBPF active

And some examples of how the lsm.debug ordering report changes...

With "lsm.debug security=selinux":

LSM: legacy security=selinux
LSM: CONFIG_LSM=landlock,lockdown,yama,loadpin,safesetid,integrity,
                selinux,smack,tomoyo,apparmor,bpf
LSM: boot arg lsm= *unspecified*
LSM:   early started: lockdown (enabled)
LSM:   first ordered: capability (enabled)
LSM: security=selinux disabled: apparmor (only one legacy major LSM)
LSM: builtin ordered: landlock (enabled)
LSM: builtin ignored: lockdown (not built into kernel)
LSM: builtin ordered: yama (enabled)
LSM: builtin ordered: loadpin (enabled)
LSM: builtin ordered: safesetid (enabled)
LSM: builtin ordered: integrity (enabled)
LSM: builtin ordered: selinux (enabled)
LSM: builtin ignored: smack (not built into kernel)
LSM: builtin ignored: tomoyo (not built into kernel)
LSM: builtin ordered: apparmor (disabled)
LSM: builtin ordered: bpf (enabled)
LSM: exclusive chosen:   selinux
LSM: initializing lsm=lockdown,capability,landlock,yama,loadpin,
		      safesetid,integrity,selinux,bpf

With "lsm.debug lsm=integrity,selinux,loadpin,crabability,bpf,
                    loadpin,loadpin":

LSM: legacy security= *unspecified*
LSM: CONFIG_LSM=landlock,lockdown,yama,loadpin,safesetid,integrity,
                selinux,smack,tomoyo,apparmor,bpf
LSM: boot arg lsm=integrity,selinux,loadpin,capability,bpf,loadpin,
		  loadpin
LSM:   early started: lockdown (enabled)
LSM:   first ordered: capability (enabled)
LSM: cmdline ordered: integrity (enabled)
LSM: cmdline ordered: selinux (enabled)
LSM: cmdline ordered: loadpin (enabled)
LSM: cmdline ignored: crabability (not built into kernel)
LSM: cmdline ordered: bpf (enabled)
LSM: cmdline skipped: apparmor (not in requested order)
LSM: cmdline skipped: yama (not in requested order)
LSM: cmdline skipped: safesetid (not in requested order)
LSM: cmdline skipped: landlock (not in requested order)
LSM: exclusive chosen:   selinux
LSM: initializing lsm=lockdown,capability,integrity,selinux,loadpin,bpf

Cc: Paul Moore <paul@paul-moore.com>
Cc: James Morris <jmorris@namei.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: linux-security-module@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: Mickaël Salaün <mic@digikod.net>
[PM: line wrapped commit description]
Signed-off-by: Paul Moore <paul@paul-moore.com>