On Thu, 2007-11-15 at 16:14 +0800, Dave Young wrote: > On Thu, Nov 15, 2007 at 03:38:13AM +0100, Kay Sievers wrote: > > On Thu, 2007-11-15 at 09:01 +0800, Dave Young wrote: > > > On Nov 15, 2007 5:27 AM, Kay Sievers <[EMAIL PROTECTED]> wrote: > > > > On Wed, 2007-11-14 at 20:19 +0100, Jiri Kosina wrote: > > > > > On Wed, 14 Nov 2007, Kay Sievers wrote: > > > > > > > > > > > Could it be an init-order problem, where something tries to use the > > > > > > block subsystem? Before it is initialized with: > > > > > > block/genhd.c :: subsys_initcall(genhd_device_init); > > > > > > If that's the case, we have an old bug that nobody noticed with > > > > > > static > > > > > > structures, which are zeroed that time, but definitely not properly > > > > > > initialized. I'll try to build loop non-modular now, and see if that > > > > > > makes the bug appear here. > > > > > > > > > my .config with which I reproduc this on 2.6.24-rc2-mm1 reliably can > > > > > be > > > > > obtained from http://www.jikos.cz/jikos/junk/.config > > > > > > > > Hmm, that config doesn't do anything here, and if I make it boot, it > > > > does not show the bug. > > > > > > > > Could you possibly enable kobject debugging and see if that exposes > > > > something, maybe something goes wrong with the kset refcount and it gets > > > > released while in use. > > > > > > > Hi, > > > I would do that. > > > > That would be great. > > > > > BTW, The bug report as EIP at __list_add with CONFIG_DEBUG_LIST=y > > > > Yeah, that hints that the kset, which contains the list, is not > > allocated at the time it is used, or it is already released (kfree) > > again by some buggy logic.
> Yes, I debugged it, there's some new findings. > It is freed by put_disk. > The floppy driver alloc_disk and then call put_disk without register_disk. > in kobject_cleanup line 551: > if(s) > kset_put(s); > Now the kset is set in alloc_disk after kobject_init, so it is not refereced > yet. Yeah, that looks like it. It still does not fail here, but I can simulate the behavior of floppy.c, and that gets fixed by your patch. Great! Thanks a lot, Kay - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
