Re: [PATCH v4 0/4] Properly handle module_kobject creation

[Petr Pavlu <petr.pavlu@suse.com>]

On 2/27/25 19:49, Shyam Saini wrote:
> Hi Everyone,
> 
> This patch series fixes handling of module_kobject creation.
> A driver expect module_kset list populated with its corresponding
> module_kobject to create its /sys/module/<built-in-module>/drivers
> directory.
> 
> Since,
> [1] commit 96a1a2412acb ("kernel/params.c: defer most of param_sysfs_init() to late_initcall time")
> Call to populate module_kset list is deferred to save init time so that
> external watchdog doesn't fireup on some boards and Linux can take
> responsibility of feeding watchdog before it spuriously resets the
> system. However, [1] this fix caused another issue i.e, consumers
> of module_kset can't get related module_kobject during driver
> initialisation and hence can't create their
> /sys/module/<built-in-module>/drivers directory.
> 
> Consequently, [1] breaks user-space applications for eg: DPDK, which
> expects /sys/module/vfio_pci/drivers/pci:vfio-pci/new_id to be present.
> 
> The second issue was reported and the [2] revert of [1] was
> proposed. However, [2] the Revert doesn't address the original issue
> reported in [1].
> 
> This patch series addresses both issues reported in [1] and [2].
> 
> [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=96a1a2412acb
> [2] https://lore.kernel.org/lkml/20250130225803.321004-1-shyamsaini@linux.microsoft.com/

I've queued now the series on modules-fixes, with some minor cleanups to
the commit messages.

I changed the "Cc: stable@kernel.org" tag on the last patch to "Cc:
stable@vger.kernel.org". Documentation/process/stable-kernel-rules.rst
recommends using the latter address by default, unless the patch is
fixing unpublished vulnerabilities.

I've removed "Fixes: 96a1a2412acb" and "Cc: stable@kernel.org" from the
first three patches because only the final patch contains the actual
fix. I suspect the stable tooling should automatically determine the
dependencies in this case, but to be explicit, I added a note to
stable@vger.kernel.org on the last patch indicating that it requires all
other patches from the series.

-- 
Thanks,
Petr