# PATCHED run — drm.ko rebuilt from /usr/src/sys with fix.diff applied
# (same zposnull.ko PoC, same call, only drm_blend.c differs)
$ kldload /usr/src/sys/dev/drm/drm/drm.ko && kldstat | grep -E "drm|zposnull"
 4    1 0xffffffff82600000    72000 drm.ko
$ echo "--- loading zposnull against PATCHED drm.ko ---"
$ kldload /root/zposnull/zposnull.ko && echo "KLDLOAD_RETURNED_0 (no panic)"
--- loading zposnull against PATCHED drm.ko ---
KLDLOAD_RETURNED_0 (no panic)
HAMMER2: INITIATE SPANs
swap low/high-water marks set to 41940/62910
zposnull: calling stock drm_atomic_normalize_zpos (expect NULL-deref panic)
zposnull: SURVIVED drm_atomic_normalize_zpos