On Tue, May 03, 2022 at 10:19:34PM +0200, Javier Martinez Canillas wrote:
> A reference to the framebuffer device struct fb_info is stored in the file
> private data, but this reference could no longer be valid and must not be
> accessed directly. Instead, the file_fb_info() accessor function must be
> used since it does sanity checking to make sure that the fb_info is valid.
>
> This can happen for example if the registered framebuffer device is for a
> driver that just uses a framebuffer provided by the system firmware. In
> that case, the fbdev core would unregister the framebuffer device when a
> real video driver is probed and ask to remove conflicting framebuffers.
>
> Most fbdev file operations already use the helper to get the fb_info but
> get_fb_unmapped_area() and fb_deferred_io_fsync() don't. Fix those two.
>
> Since fb_deferred_io_fsync() is not in fbmem.o, the helper has to be
> exported. Rename it and add a fb_ prefix to denote that is public now.
>
> Reported-by: Junxiao Chang <junxiao.ch...@intel.com>
> Signed-off-by: Javier Martinez Canillas <javi...@redhat.com>
Acked-by: Sam Ravnborg <s...@ravnborg.org>
