I was looking at latest changes since 5.11 to powerpc64 BPF JIT and found the following commit:
commit 20ccb004bad659c186f9091015a956da220d615d Author: Naveen N. Rao <[email protected]> Date: Wed Jun 9 14:30:24 2021 +0530 powerpc/bpf: Use bctrl for making function calls blrl corrupts the link stack. Instead use bctrl when making function calls from BPF programs. Reported-by: Anton Blanchard <[email protected]> Signed-off-by: Naveen N. Rao <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/[email protected] Though the link stack is unarchitected, that is, it should be transparent to the user aside from branch prediction performance, perhaps there is a bug in the implementation. Considering we have only observed this on POWER8 and with different stack traces, I wouldn't discard the possibility. As this is not present on 5.13 either, I am building a test kernel with a backport so it can be tested. Cascardo. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1927076 Title: IPv6 TCP in reuseport_bpf_cpu from ubuntu_kernel_selftests/net crash P8 node entei on 5.8 kernel (Oops: Exception in kernel mode, sig: 4 [#1]) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-kernel-tests/+bug/1927076/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
