Regression on linux-next (next-20241120) and drm-tip

[Thomas Weißschuh]

On 2024-12-03 15:33:21+0100, Rafael J. Wysocki wrote:
> On Tue, Dec 3, 2024 at 1:04 PM Thomas Weißschuh <linux at weissschuh.net> wrote:
> >
> > On 2024-12-03 12:54:54+0100, Rafael J. Wysocki wrote:
> > > On Tue, Dec 3, 2024 at 7:51 AM Thomas Weißschuh <linux at weissschuh.net> wrote:
> > > >
> > > > (+Cc Sebastian)
> > > >
> > > > Hi Chaitanya,
> > > >
> > > > On 2024-12-03 05:07:47+0000, Borah, Chaitanya Kumar wrote:
> > > > > Hope you are doing well. I am Chaitanya from the linux graphics team in Intel.
> > > > >
> > > > > This mail is regarding a regression we are seeing in our CI runs[1] on linux-next repository.
> > > >
> > > > Thanks for the report.
> > > >
> > > > > Since the version next-20241120 [2], we are seeing the following regression
> > > > >
> > > > > `````````````````````````````````````````````````````````````````````````````````
> > > > > <4>[   19.990743] Oops: general protection fault, probably for non-canonical address 0xb11675ef8d1ccbce: 0000 [#1] PREEMPT SMP NOPTI
> > > > > <4>[   19.990760] CPU: 21 UID: 110 PID: 867 Comm: prometheus-node Not tainted 6.12.0-next-20241120-next-20241120-gac24e26aa08f+ #1
> > > > > <4>[   19.990771] Hardware name: Intel Corporation Arrow Lake Client Platform/MTL-S UDIMM 2DPC EVCRB, BIOS MTLSFWI1.R00.4400.D85.2410100007 10/10/2024
> > > > > <4>[   19.990782] RIP: 0010:power_supply_get_property+0x3e/0xe0
> > > > > `````````````````````````````````````````````````````````````````````````````````
> > > > > Details log can be found in [3].
> > > > >
> > > > > After bisecting the tree, the following patch [4] seems to be the first "bad"
> > > > > commit
> > > > >
> > > > > `````````````````````````````````````````````````````````````````````````````````````````````````````````
> > > > > Commit 49000fee9e639f62ba1f965ed2ae4c5ad18d19e2
> > > > > Author:     Thomas Weißschuh <mailto:linux at weissschuh.net>
> > > > > AuthorDate: Sat Oct 5 12:05:03 2024 +0200
> > > > > Commit:     Sebastian Reichel <mailto:sebastian.reichel at collabora.com>
> > > > > CommitDate: Tue Oct 15 22:22:20 2024 +0200
> > > > >     power: supply: core: add wakeup source inhibit by power_supply_config
> > > > > `````````````````````````````````````````````````````````````````````````````````````````````````````````
> > > > >
> > > > > This is now seen in our drm-tip runs as well. [5]
> > > > >
> > > > > Could you please check why the patch causes this regression and provide a fix if necessary?
> > > >
> > > > I don't see how this patch can lead to this error.
> > >
> > > It looks like the cfg->no_wakeup_source access reaches beyond the
> > > struct boundary for some reason.
> >
> > But the access to this field is only done in __power_supply_register().
> > The error reports however don't show this function at all,
> > they come from power_supply_uevent() and power_supply_get_property() by
> > which time the call to __power_supply_register() is long over.
> >
> > FWIW there is an uninitialized 'struct power_supply_config' in
> > drivers/hid/hid-corsair-void.c. But I highly doubt the test machines are
> > using that. (I'll send a patch later for it)
> 
> So the only way I can think about in which the commit in question may
> lead to the reported issues is that changing the size of struct
> power_supply_config or its alignment makes an unexpected functional
> difference somewhere.

Indeed. I'd really like to see this issue reproduced with KASAN.

> AFAICS, this commit cannot be reverted by itself, so which commits on
> top of it need to be reverted in order to revert it cleanly?

All the other patches from this series:
https://lore.kernel.org/lkml/20241005-power-supply-no-wakeup-source-v1-0-1d62bf9bcb1d@weissschuh.net/

Could you point me to the full boot log in the drm-tip CI?