Re: Recurring INEQUIVALENT ALIASES issues and userland corruption/crashes

[Helge Deller <deller@gmx.de>]

On 3/22/22 20:37, Sam James wrote:
>> On 22 Mar 2022, at 18:19, John David Anglin <dave.anglin@bell.net> wrote:
>>
>> On 2022-03-22 1:52 p.m., Sam James wrote:
>>> Hi all,
>>>
>>> In Gentoo, we've just got our hands on an RP3440 (PA8800) which seems to quite easily hit inequivalent aliasing issues.
>>>
>>> We've found that under some workloads, the machine copes fine, none of that appears in dmesg, and all is well - even for
>>> over a week. But as soon as we start other workloads (the problematic one is building "stages" -- release media for Gentoo),
>>> within 30m or so, the machine is in a broken state, with these messages flooding dmesg:
>>> ```
>>> Mar 22 04:19:55 muta.hppa.dev.gentoo.org kernel: INEQUIVALENT ALIASES 0x42994000 and 0x426e1000 in file bash
>>> Mar 22 04:19:55 muta.hppa.dev.gentoo.org kernel: INEQUIVALENT ALIASES 0x426e1000 and 0x41b56000 in file bash
>>> Mar 22 04:19:55 muta.hppa.dev.gentoo.org kernel: INEQUIVALENT ALIASES 0x41b56000 and 0x41aae000 in file bash
>>> Mar 22 04:19:55 muta.hppa.dev.gentoo.org kernel: INEQUIVALENT ALIASES 0x41aae000 and 0x42774000 in file bash
>>> Mar 22 04:19:55 muta.hppa.dev.gentoo.org kernel: INEQUIVALENT ALIASES 0x42774000 and 0x41202000 in file bash
>>> Mar 22 04:19:55 muta.hppa.dev.gentoo.org kernel: INEQUIVALENT ALIASES 0x41202000 and 0x428dd000 in file bash
>>> Mar 22 04:19:55 muta.hppa.dev.gentoo.org kernel: INEQUIVALENT ALIASES 0x41e2c000 and 0x418f6000 in file bash
>>> Mar 22 04:19:55 muta.hppa.dev.gentoo.org kernel: INEQUIVALENT ALIASES 0x418f6000 and 0x42980000 in file bash
>>> Mar 22 04:19:55 muta.hppa.dev.gentoo.org kernel: INEQUIVALENT ALIASES 0x42980000 and 0x426cd000 in file bash
>>> Mar 22 04:19:55 muta.hppa.dev.gentoo.org kernel: INEQUIVALENT ALIASES 0x426cd000 and 0x41b42000 in file bash
>>> Mar 22 04:19:55 muta.hppa.dev.gentoo.org kernel: INEQUIVALENT ALIASES 0x41b42000 and 0x41a9a000 in file bash
>>> Mar 22 04:19:55 muta.hppa.dev.gentoo.org kernel: INEQUIVALENT ALIASES 0x41a9a000 and 0x42760000 in file bash
>>> Mar 22 04:19:55 muta.hppa.dev.gentoo.org kernel: INEQUIVALENT ALIASES 0x42760000 and 0x411ee000 in file bash
>>> Mar 22 04:19:55 muta.hppa.dev.gentoo.org kernel: INEQUIVALENT ALIASES 0x411ee000 and 0x428c9000 in file bash
>> I don't think this is new.  There are no changes to the code that detects INEQUIVALENT ALIASES in the latest pull.
>>
>
> Sorry, to be clear: I wasn't trying to suggest the issue is new -- just saying that we've been trying 5.10, 5.15+ to
> see if latest changes helped at all, but they haven't.
>
> In our experience so far, there has been no good kernel version for us on this hardware.

One of the debian buildd servers I mentioned earlier is a 4-way rp3440, and 5.10 runs stable on it for me.
Did you tried plain 5.10.0, or including all patches from the stable branches?
This is the kernel config I used:
http://backup.parisc-linux.org/kernel/STABLE/debian-config

>> I've seen this before but it's not occurring in my current builds for rp3440 and c8000.  I've been running for-next
>> changes on c8000 for several weeks.
>>
>
> Yeah, I haven't seen this at all on my C8000 (or Gentoo's other HW, a C3600).
>
>> I suspect a problem with shmat but I'm not sure.

I suspected that as well, because I had the impression we still carry a patch in
debian's glibc. But I checked debian glibc sources again, and I think all such
relevant patches are now upstreamed.

Helge