Re: PCI: Race condition in pci_create_sysfs_dev_files (can't boot)

From: Bjorn Helgaas
Date: Thu Jan 20 2022 - 18:00:55 EST


On Fri, Jul 30, 2021 at 10:18:44AM +0200, Krzysztof Hałasa wrote:
> Pali, et al,
>
> I'm encountering a problem booting an i.MX6-based device (Gateworks
> Ventana SBC). This is apparently a known issue:
> https://lkml.org/lkml/2020/7/16/388
>
> Do you guys know of a fix for this? Booting this machine reliably is
> lately impossible.

Hi Krzysztof, is this still an issue?

e1d3f3268b0e ("PCI/sysfs: Convert "config" to static attribute") and
similar patches appeared in v5.13, and they should resolve things like
this:

sysfs: cannot create duplicate filename '/devices/platform/soc/d0070000.pcie/pci0000:00/0000:00:00.0/config'

But your report is different because it looks like we have a problem
when creating a *directory*:

> sysfs: cannot create duplicate filename '/devices/platform/soc/1ffc000.pcie/pci0000:00/0000:00:00.0/0000:e0'

and then it seems that we corrupted a pointer:

> Unable to handle kernel paging request at virtual address 6f736572 (ASCII = "reso")

which is even more worrisome.

Bjorn