On Tue, Dec 16, 2008 at 12:52:50PM -0800, Jesse Barnes wrote: > On Tuesday, December 16, 2008 11:56 am Neil Horman wrote: > > On Tue, Dec 16, 2008 at 10:42:08AM -0800, Jesse Barnes wrote: > > > On Wednesday, December 10, 2008 11:43 am Neil Horman wrote: > > > > Hey- > > > > I happened to notice that the ibmphp hotplug driver does something > > > > rather silly in its init routine. It purposely calls module_put so as > > > > to underflow its module ref count to avoid being removed from the > > > > kernel. This is bad practice, and wrong, since it provides a window for > > > > subsequent module_gets to reset the refcount to zero, allowing an > > > > unload to race in and cause all sorts of mysterious panics. If the > > > > module is unsafe to load, it should inform the kernel as such with a > > > > call to __unsafe. The patch below does that. > > > > > > Thanks Neil, applied this to my for-linus branch since it sounds > > > potentially serious (but also low risk since who uses ibmphp anymore? :) > > > > Dang it! Sorry, Jesse. Yes, youre absolutely right, it is low risk. It > > really just a bit of sillyness all around. > > > > Unfortunately, I took part in the sillyness. The problem was reported to > > me on RHEL, and I tested there, without checking upstream too closely. As > > aresult, the patch I gave you is a bit out of date, and won't compile. > > I've tested the new patch here much more closely. apologies. I informed > > akpm who was looking at it, but neglected to copy you. > > > > This patch corrects the same problem in that it prevents module unloads in > > a sane fashion, by not registering an exit routine > > > > Signed-off-by: Neil Horman <nhorman@xxxxxxxxxxxxx> > > Ah was just doing my testing & building now so I would have caught it in a > minute. :) I'll replace the patch I have with this one, thanks. > > Jesse > Thank you, that matches what Andrew has in his tree. Apologies for the noise Neil -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
