Re: [PATCH] selinux: add selinux_is_enforced() function

[Stephen Smalley <sds@tycho.nsa.gov>]

On Wed, 2017-04-12 at 15:30 +0200, Sebastien Buisson wrote:
> 2017-04-12 13:55 GMT+02:00 Paul Moore <pmoore@redhat.com>:
> > As currently written this code isn't something we would want to
> > merge
> > upstream for two important reasons:
> > 
> > * No clear user of this functionality.  There needs to be a well
> > defined user of this functionality in the kernel.
> 
> The use case for this new functionality (and the other one) is
> getting
> SELinux information from the Lustre client code in kernel space.
> Latest patch can be accessed at:
> https://review.whamcloud.com/24421
> Actual user is sptlrpc_get_sepol() function in
> lustre/lustre/ptlrpc/sec.c file.
> This code will be pushed to the upstream kernel as soon as it is
> landed into Lustre master branch.

How are you using this SELinux information in the kernel and/or in
userspace?  What's the purpose of it?  What are you comparing it
against?  Why do you care if it changes?

Note btw that the notion of a policy name/type and the policy file path
is purely a userspace construct and shouldn't be embedded in your
kernel code.  Android for example doesn't follow that convention at
all; their SELinux policy file is simply /sepolicy.  On modern kernels,
you can always read the currently loaded policy from the kernel itself
via /sys/fs/selinux/policy (formerly just /selinux/policy).