On Wed, Sep 30, 2020 at 01:52:11PM +0200, Greg Kroah-Hartman wrote:

On Wed, Sep 30, 2020 at 01:25:14PM +0200, Daniel Vetter wrote:

quoted

On Wed, Sep 30, 2020 at 12:56 PM Peilin Ye [off-list ref] wrote:

quoted

Yes, and built-in fonts don't use refcount. Or maybe we can let
find_font() and get_default_font() kmalloc() a copy of built-in font
data, then keep track of refcount for both user and built-in fonts, but
that will waste a few K of memory for each built-in font we use...

A possible trick for this would be to make sure built-in fonts start
out with a refcount of 1. So never get freed. Plus maybe a check that
if the name is set, then it's a built-in font and if we ever underflow
the refcount we just WARN, but don't free anything.

Another trick would be kern_font_get/put wrappers (we'd want those
anyway if the userspace fonts are refcounted) and if kern_font->name
!= NULL (i.e. built-in font with name) then we simply don't call
kref_get/put.

Ick, don't do that, the first trick of having them start out with an
increased reference count is the best way here.  Makes the code simpler
and no special cases for the tear-down path.

I see, I'll just let them start out with 1, and only check `->name !=
NULL` in kern_font_put(). Thank you!

Peilin Ye

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