Check SELinux enforce state instead of selinuxfs existence

[karthikvetrivel]

Resolves NVIDIA/gpu-operator#1489.

Problem

The previous check [ -e /sys/fs/selinux ] returns true even when SELinux is in permissive mode or disabled, causing unnecessary chcon calls on systems where SELinux isn't enforcing.

Solution

Read the enforce state directly: cat /sys/fs/selinux/enforce returns 1 only when SELinux is actively enforcing. This aligns RHEL9 detection with the correct behavior.

NOTE: Implemented only for RHEL 9 right now. I'll update other distros (RHEL 7/8, Fedora, Azure Linux) after an initial approval.

Testing

Environment

• RHEL 9.2 kernel (5.14.0-284.43.1.el9_2.x86_64)
• 2x NVIDIA A40
• Image: ghcr.io/karthikvetrivel/driver:570.195.03-rhel9.6

Test Results

SELinux State	enforce value	Detection Output	Status
Enforcing	1	"SELinux is enabled" (runs chcon)	PASS
Permissive	0	"SELinux is disabled, skipping..."	PASS

Verification

• Driver loads successfully (nvidia-smi works)
• No chcon errors in logs
• Container exits cleanly