Hello Thomas,
On 5/4/22 10:15, Thomas Zimmermann wrote:
Hi
Am 03.05.22 um 22:19 schrieb Javier Martinez Canillas:
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.chang@intel.com Signed-off-by: Javier Martinez Canillas javierm@redhat.com
Reviewed-by: Thomas Zimmermann tzimmermann@suse.de
Thanks.
Please see my comment below.
[snip]
- if (!info)
return -ENODEV;This is consistent with other functions, but it's probably not the correct errno code. It means that a device is not available for opening.
But the situation here is rather as with close() on a disconnected-network file. The call to close() returns EIO in this case. Maybe we should consider changing this in a separate patch.
Indeed. Agree that -EIO makes more sense here.
Best regards Thomas