On Mon, Oct 28, 2013 at 11:23:41AM -0600, Bjorn Helgaas wrote: > [+cc Veaceslav] > > On Sun, Oct 27, 2013 at 3:24 PM, Greg Kroah-Hartman > <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > > On Sun, Oct 27, 2013 at 09:13:29PM +0000, Linus Torvalds wrote: > >> .. and one more case of freeing a delayed work object (likely a kobject again): > >> > >> This time it looks like it's in the PCI layer, freeing the msi irq information. > >> > >> It looks like that code simply does > >> > >> kobject_del(&entry->kobj); > >> kobject_put(&entry->kobj); > >> list_del(&entry->list); > >> kfree(entry); > >> > >> and the problem is that the "entry->kobj" may have *other* references > >> to it, thanks to people accessing it through /sys, so despite doing a > >> kojbect_del/kobject_put(), it's not at all ok to then do a "kfree()" > >> on it. The embedded kobj might still be in use. > >> > >> Afaik, that code should do the kfree() on the kobject in the _release_ > >> method, not synchronously like that. > >> > >> We already have a msi_kobj_release(), I'm wondering why that doesn't > >> do the kfree(). > >> > >> Bjorn? Yinghai? Greg, comments about that msi kobj usage? > > > > Ick, it really should be doing a kfree() in the release only. Bjorn has > > had a bunch of changes in this area recently, perhaps they are in > > linux-next waiting for 3.13, and I've talked to him about getting rid of > > all of the kobjects for msi files, as I don't think it's needed at all. > > IIRC, you said you might take a look at converting this to attributes > on the train back home, so I haven't looked into it myself :) Yes, I was supposed to, but James and I ended up splitting a bottle of wine on the train, and it's not a good idea to do driver model work with wine. Hard liquor is usually needed :) It's on my todo list... thanks, greg k-h -- 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
