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:
On Wed, Sep 30, 2020 at 12:56 PM Peilin Ye yepeilin.cs@gmail.com wrote:
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