Re: tty: kmalloc size WARNING in vc_do_resize

[One Thousand Gnomes]

> I think that either the kmalloc should use __GFP_NOWARN or
> vc_do_resize should do stricter size check.

vc_do_resize doesn't know enough to do a stricter size check. There are
not many methods it calls but those are:

vgacon_resize doesn't error when stupid things happen because of a silly
hack for legacy svgatextmode tools.

sisusbcon_resize does the right checks but we can get in a situation
where we unplug during a resize so attempting to resize and size back
might fail.

fbcon_resize does the right thing, but again can error if we go
size/resize/size back.

That means we really have to guess or would have to add 'max size' info
the structures. Right now it's clamped to 1Gbyte which is a 32767 x 32767
character display and probably ludicrous. Clamping to 4048 x 1024 chars
would cover displays up to 16K x 6K even with the 4x6 font (which is
insane on a 4K display, let alone 4 of them).

Alan