Re: [PATCH v3 0/3] debugfs: make debugfs_create_str() read-only

[Danilo Krummrich]

On Thu Oct 1, 2026 at 2:51 PM CEST, Greg KH wrote:
> On Fri, Aug 07, 2026 at 06:00:50PM +0800, Yichong Chen wrote:
>> debugfs_create_str() has a generic write implementation that replaces the
>> backing string.  Concurrent writers can race and free the same old string
>> twice.
>> 
>> Instead of adding more locking to the generic helper, convert the existing
>> writable in-tree users to local file operations and make
>> debugfs_create_str() read-only.
>> 
>> Changes since v2:
>> - Use scoped mutex guards in the interconnect and SoundWire conversions.
>> - Clarify why GFP_KERNEL is safe in the interconnect conversion after the
>>   RCU read-side critical section is removed.
>> - Drop the unnecessary firmware_file = NULL assignment in the SoundWire
>>   exit path.
>> - Use WARN() instead of WARN_ONCE() so each writable debugfs_create_str()
>>   caller can be reported.
>
> Sorry for the delay, now applied.

This series fell through the cracks on my end. I also reported this issue in [1]
and I agree making debugfs_create_str() read-only is the best fix for now.

However, it duplicates code and I think having a proper helper as suggested in
[1] would be nice follow-up.

[1] https://lore.kernel.org/driver-core/DLPDB44JJRGJ.3K6JNS746M7QC@xxxxxxxxxx/