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Re: tty: kmalloc size WARNING in vc_do_resize

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> 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

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Thread

tty: kmalloc size WARNING in vc_do_resize Dmitry Vyukov <dvyukov@google.com> - 2016-01-24 12:30 +0100
  Re: tty: kmalloc size WARNING in vc_do_resize One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk> - 2016-01-25 17:20 +0100
    Re: tty: kmalloc size WARNING in vc_do_resize Dmitry Vyukov <dvyukov@google.com> - 2016-01-25 18:10 +0100

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