Re: [PATCH 7/8] membarrier: Remove arm (32) support for SYNC_CORE

On Fri, Jun 18, 2021 at 02:54:05PM +0200, Linus Walleij wrote:

On Wed, Jun 16, 2021 at 6:27 PM Russell King (Oracle)
[off-list ref] wrote:

quoted

Arnd tells me that the current remaining ARM11MPCore users are:
- CNS3xxx (where there is some martinal interest in the Gateworks
  Laguna platform)
- Similar for OXNAS
- There used to be the Realview MPCore tile - I haven't turned that on
  in ages, and it may be that the 3V cell that backs up the encryption
  keys is dead so it may not even boot.

I have this machine with 4 x ARM11 MPCore, it works like a charm.
I use it to test exactly this kind of stuff, I know if a kernel works
on ARM11MPCore it works on anything because of how fragile
it is.

quoted

So it seems to come down to a question about CNS3xxx and OXNAS. If
these aren't being used, maybe we can drop ARM11MPCore support and
the associated platforms?

Linus, Krzysztof, Neil, any input?

I don't especially need to keep the ARM11MPCore machine alive,
it is just a testchip after all. The Oxnas is another story, that has wide
deployment and was contributed recently (2016) and has excellent
support in OpenWrt so I wouldn't really want
to axe that.

So I suppose the next question is... are these issues (with userland
self-modifying code and kernel module loading) entirely theoretical
or can they be produced on real hardware?

If they can't be produced on real hardware, and we attempt to fix them
how do we know that the fix has worked...

-- 
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