On Sat, 2020-11-07 at 11:05 -0800, Jakub Kicinski wrote:
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.
Also it'd be good to mention why Johannes's approach was abandoned.
Well, I had two.
One was awful, and worked in all cases.
The other was less awful, and didn't work in all cases.
I think both gave Al Viro hives ;-)
Patch 1 needs to be split in two. Patches 2 and 3 would go via Johannes.
FWIW, I'm happy for you to take patches 2 and 3 as well, but I guess if
patch 1 needs to be split there's a resend coming anyway, so then I'll
be happy to take the patches 2/3 from a separate set.
johannes