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@xxxxxxxxx> >> Signed-off-by: Javier Martinez Canillas <javierm@xxxxxxxxxx> > > Reviewed-by: Thomas Zimmermann <tzimmermann@xxxxxxx> > 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 > -- Best regards, Javier Martinez Canillas Linux Engineering Red Hat
