Re: IPMI related kernel panics since v4.19.286

[Corey Minyard <minyard@acm.org>]

On Mon, Jun 19, 2023 at 02:23:47PM +0200, Greg KH wrote:
> On Mon, Jun 19, 2023 at 11:11:16AM +0000, Janne Huttunen (Nokia) wrote:
> > 
> > We recently updated an internal test server from kernel v4.19.273
> > to v4.19.286 and since then it has already multiple times triggered
> > a kernel panic due to a hard lockup. The lockups look e.g. like
> > this:
> 
> Does this also happen on newer 5.4 and 6.4-rc7 releases?

If I am correct, no, it will not happen there.  I was surprised 

I believe the change that causes this issue was:

  b4a34aa6d "ipmi: Fix how the lower layers are told to watch for messages"

which was backported into 4.9.  But there was a locking change:

  e1891cffd4c4 "ipmi: Make the smi watcher be disabled immediately when not needed"

that came in 5.1.  That was required for b4a34aa6d to work correctly,
and I didn't realize that.  If Janne tests that patch (and the other fix
for it), then kernels 5.1 and later are good as they are.

Thanks,

-corey

> 
> thanks,
> 
> greg k-h