This comment needs to be simplified.

Remove the _DN suffix?

Remove the _DN suffix?

Remove the _DOWN suffix?

Could you please propose the complete name for the flag?

MAP_STACK seems natural but I suppose that would collide with mman.h.

MAP_STACK_REGION?

Hmm, prior to rGb21a0008bac990d201c41aabefccd3eddaeaaae3 we didn't have either of these flags at all. Can we just remove it entirely? We already require it unconditionally for vm_map_growstack?

No, not unconditionally. We detect the growable stack in vm_map_growstack() by presence of the gap-less pair of vm_map_entries, which should be guard on left, and MAP_STACK_GROWS_DOWN on right. Otherwise vm_map_growstack() bails out and does not extend.

This description makes me think that the name might be fine as is. I only was able to construct MAP_MAPPED_STACK_AREA name, if anybody likes it.

Might be MAP_ENTRY_STACK_MAPPED_AREA, for symmetry with MAP_ENTRY_STACK_GAP ?

It seems that no one ever sets the KVME_FLAG_GROWS_UP bit anymore, so that it can disappear and KVME_FLAG_GROWS_DOWN can drop the _DOWN.

We can drop the _DOWN from MAP_ENTRY_GROWS_DOWN

This comment is stale.

KVME_ flags form userspace API and ABI, we cannot change them, and must keep them even if no longer used.

But it still correctly describes the entry main feature. If you insist, I will come with some other name, but IMO this one is expressive.

Since the variable orient no longer exists, this comment should be deleted.