On Sun, 8 Nov 2020 at 04:05, Jakub Kicinski [off-list ref] wrote:
Hi Jakub,
Thank you for the review!
On Sat, 7 Nov 2020 17:21:31 +0000 Taehee Yoo wrote:
quoted
When debugfs file is opened, its module should not be removed until
it's closed.
Because debugfs internally uses the module's data.
So, it could access freed memory.
In order to avoid panic, it just sets .owner to THIS_MODULE.
So that all modules will be held when its debugfs file is opened.
Hm, looks like some of the patches need to be revised because
.owner is already set in the ops, and a warning gets generated.
Thanks, I found my mistake via patchwork.
I will fix this problem.
Also it'd be good to mention why Johannes's approach was abandoned.
I'm sorry about skipping the explanation of the situation,
Johannes sent RFC[1], which fixes this problem in the debugfs core logic.
I tested it and it actually avoids this problem well.
And I think there would be more discussion.
So, I thought this series' approach is reasonable right now.
I think setting .owner to THIS_MODULE is a common behavior and it
doesn't hurt our logic even if Johannes's approach is merged.
I'm expecting that both approaches of this series and Johannes are
doing separately.
[1] https://www.spinics.net/lists/linux-wireless/msg204171.html
When you repost please separate out all the patches for
drivers/net/wireless/ and send that to Kalle's wireless drivers tree.
Patch 1 needs to be split in two. Patches 2 and 3 would go via Johannes.
The wimax patch needs to go to staging (wimax code has been moved).
The remaining patches can be posted individually, not as a series.
Okay, I will do this.
Thanks a lot!
Taehee Yoo