On Tue, Dec 28, 2010 at 2:12 PM, Felipe Contreras <felipe.contreras@xxxxxxxxx> wrote: > I haven't investigated why that happens, but kernel-space should not > panic regardless of what user-space does. Agree of course. But that's not what we were discussing... >> Anyhow, a thread that is calling proc_*_dma() will both increase the >> reference count and decrease it back before going back to user space. >> Otherwise your patch would be problematic as well - who will unlock >> the mutex you take in proc_*_dma() ? > > I'm saying that user-space might crash *before* proc_*_dma() finishes, > before the reference count has been decreased. > > In my patch there would be no issue because proc_un_map() would wait > until proc_*_dma() has released the lock. But what will happen if, as you say, user-space would crash before proc_*_dma() has released the lock ? how could proc_un_map() run ? > Because: > 1) Your patch changes 114 lines, mine 18 > 2) It hasn't been reviewed, nor tested by other people > 3) At least I see a potential issue > 4) 2.6.37 is imminent > > IMO one patch has chances going into 2.6.37, the other one doesn't. I > don't see the problem of pushing my patch to 2.6.37, and once your > patch has been properly reviewed, and tested, put it for the 2.6.38 > merge window. Anyway, it's looking more and more that this patch would > not be ack'ed in time, so I guess we would have to wait to see what > other people (Omar?) say, which would probably be 2.6.38 timeline. This is all good, and I have no problem with it. As I said, I don't resist your patch as a temporary fix. But it doesn't mean I like it... -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
