On Wed, 11 May 2011 16:09:29 Tim Gardner wrote: > On 05/10/2011 11:44 PM, Bruno PrÃmont wrote: > > On Tue, 10 May 2011 Tim Gardner<tim.gardner@xxxxxxxxxxxxx> wrote: > > This only partially protects the list and count as two concurrent > > framebuffer registrations do still race against each other. > > For the issue addressed by this patch I don't think it makes sense to > > have this spinlock at all as it's only used in get_framebuffer_info() > > and in put_framebuffer_info() and put_framebuffer_info() doesn't even > > look at registered_fb or num_registered_fb. > > Such a spinlock makes sense in a separate patch that really protects > > all access to registered_fb or num_registered_fb, be it during framebuffer > > (un)registration or during access from fbcon. > > > > Our goal was merely to stop the user space open/close races. I agree > that the framebuffer registration list needs more orthogonal protection, > but that is going to be a much larger patch. I know that such a protection needs a much larger patch. (that would be for 2.6.40 or 2.6.41, I have preparing patches for that cooking) My main issue for tis patch is that the comment reads as if spinlock was protecting registered_fb[] and num_registered_fb. So changing the comment would be a good thing (say it protects fb_info->ref_count). Later patch can then protect registered_fb against concurrent framebuffer registrations. Bruno -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
