------- Comment From [email protected] 2020-05-26 04:04 EDT------- (In reply to comment #12) > Hi Niklas, please can you have a look at the SRU Justification that I've now > added to the bug description, with special focus on Test Case and Regression > Potential. > Please let me know if is inaccurate or missing or in case additional > information should be added (this is mandatory information needed for the > SRU). > Thx
Sounds good, maybe to add that this can be triggered with shipping user space tools (including in the Ubuntu repos) e.g.: 1. install the rdma tools: sudo apt-get install ibverbs-providers ibverbs-utils 2. verify you have some RDMA devices (requires ConnectX adapter) pcidev@T224LP06:~$ ibv_devices device node GUID ------ ---------------- mlx5_0 98039b0300c682b4 3. verify MIO instructions are enabled for the device pcidev@T224LP06:~$ cat /sys/bus/pci/devices/0000\:00\:00.0/mio_enabled 1 4. try to run an RDMA application from user space, e.g. ibv_rc_pingpong server process: ibv_rc_pingpong -d mlx5_0 -g 0 & client process: ibv_rc_pingpong -d mlx5_0 -g 0 localhost 5. verify that the kernel crashes [92406.190525] Unable to handle kernel pointer dereference in virtual kernel add ress space [92406.190529] Failing address: ed00000000090000 TEID: ed00000000090403 [92406.190529] Fault in home space mode while using kernel ASCE. [92406.190531] AS:0000000c1c98c007 R3:0000000ff3bd0007 S:0000000ff3bd6000 P:0000 00000009013d Also this patch made it into v5.7-rc7 and Linus himself commented: "And none of the fixes look like there's anything particularly scary going on. Most of it is very small, and the slightly larger patches aren't huge either and are well-contained (the two slightly larger patches are to s390 and rxrpc - and even those patches aren't really all _that_ big)" (this patch obviously being the bigger s390 change) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1874055 Title: [UBUNTU 20.04] s390x/pci: s390_pci_mmio_write/read fail when MIO instructions are available To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-z-systems/+bug/1874055/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
