Date: Tue, 9 Nov 2010 09:37:39 -0500 From: John Baldwin <jhb@freebsd.org> To: Alexander Best <arundel@freebsd.org> Cc: freebsd-current@freebsd.org Subject: Re: kldunload(8) returns 0, although it fail Message-ID: <201011090937.40121.jhb@freebsd.org> In-Reply-To: <20101109141028.GA75878@freebsd.org> References: <20101109114612.GA58585@freebsd.org> <201011090844.28609.jhb@freebsd.org> <20101109141028.GA75878@freebsd.org>
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On Tuesday, November 09, 2010 9:10:28 am Alexander Best wrote: > On Tue Nov 9 10, John Baldwin wrote: > > On Tuesday, November 09, 2010 6:46:12 am Alexander Best wrote: > > > hi there, > > > > > > i posted this message on freebsd-questions@, but nobody could help me with it. > > > to me this looks like a bug, so i assume posting it again here on > > > freebsd-current@ might be better. > > > > > > please keep in mind that the issue here is not the fact that the second attempt > > > to unload sound.ko/netgraph.ko fails. it *should* fail, because both modules > > > have dependencies. however it should fail with the first attempt. right now > > > kldunloadf() returns zero, whereas it should actually return EBUSY (just like > > > the second attempt). > > > > > > i've attached two kdump outputs: one for the first 'kldunload' attempt and one > > > for the second. as you can see the problem is that for some reason kldunloadf() > > > returns zero, although it couldn't unload the module. > > > > Did you get an error message in dmesg? If you have manually loaded > > netgraph.ko (via netgraph_load="YES" in loader.conf or an explicit kldload) > > and then loaded other modules that depend on it (such as ng_foo.ko) then this > > is expected behavior. What your kldunload has done is to remove the manual > > reference from loader.conf or 'kldload netgraph.ko'. What this changes is what > > happens when you do 'kldunload ng_foo.ko'. If you unload ng_foo.ko now, then > > netgraph.ko will also be unloaded when its last reference drops (in this case > > it looks like you actually have two ng_*.ko objects loaded, so you would have > > to unload both of them, but I will assume a single ng_foo.ko to make the > > explanation simpler). If you had not done 'kldunload netgraph.ko' but had > > done 'kldunload ng_foo.ko', then the manual reference would have kept netgraph.ko > > loaded. > > > > All this logic exists so that if you do 'kldload foo.ko' and it auto-loads bar.ko > > as a dependency, then doing 'kldunload bar.ko' will unload both foo.ko and bar.ko. > > i have ng_ubt_load="YES" in my loader.conf and kldstat says: > > Id Refs Address Size Name > 1 37 0xffffffff80100000 a2ddb8 kernel > 2 1 0xffffffff80b2e000 295e8 snd_hda.ko > 3 1 0xffffffff80b58000 85110 sound.ko > 4 1 0xffffffff80bde000 cf79e0 nvidia.ko > 5 5 0xffffffff818d6000 418c0 linux.ko > 6 1 0xffffffff81918000 80e8 ng_ubt.ko > 7 2 0xffffffff81921000 fa78 ng_hci.ko > 8 2 0xffffffff81931000 2bd0 ng_bluetooth.ko > 9 3 0xffffffff81934000 15e68 netgraph.ko > 10 1 0xffffffff81a12000 3efb linprocfs.ko > 11 3 0xffffffff81a16000 4698 pseudofs.ko > 12 1 0xffffffff81a1b000 31b3 procfs.ko > 13 1 0xffffffff81a1f000 a37 linsysfs.ko > 14 1 0xffffffff81a20000 6f4 rtc.ko > > also the same happens with sound.ko. i have snd_hda_load="yes". and i think > snd_hda is the only dependecy for sound.ko. > > there was no error message in dmesg for the first kldunload attempt. > > i think i understand the logic, however the current behavior does not confirm > to the description in kldunload(2). Hmm, ok, fair enough. Do you get the same behavior if you kldload ng_ubt.ko after boot? -- John Baldwin
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