I'm having trouble getting Debian Buster up and running on qemu-system- sparc64 and so haven't been able to reproduce. Is this currently working for people?
I just reinstalled the machine from https://cdimage.debian.org/cdimage/ports/2019-05-09/debian-10.0-sparc64-NETINST-1.iso and there's a even newer build upe one directory level.
This patch involves re-setting memory permissions when freeing executable memory. It looks like Sparc64 Linux doesn't have support for the set_memory_() functions so that part shouldn't be changing anything. The main other thing that is changed here is always doing a TLB flush in vfree when the BPF JITs are freed. It will already sometimes happen so that shouldn't be too different either.
That part I do not know.
So it doesn't seem extra especially likely to cause a sparc specific problem that I can see. Is there any chance this is an intermittent issue?
So far it seemed 100% reproducible, at least in the bisect that led here. The only variation I saw was if it just sat there for newer git snapshot or spew out RCU and workqueue lockup warnings soon like I posed. I can do some tests and boot the same kernel some more times. -- Meelis Roos
