Created attachment 1603264 [details] boot log 1. Please describe the problem: After upgrading from kernel kernel-5.1.20-300.fc30.armv7hl to kernel-5.2.7-200.fc30.armv7hl on a BeagleBone Black ( https://beagleboard.org/black/ ), I started getting kernel oops that starts with: [ 40.332718] Unable to handle kernel NULL pointer dereference at virtual address 0000001b [ 40.340986] pgd = 8a643b40 [ 40.343793] [0000001b] *pgd=00000000 [ 40.347443] Internal error: Oops: 5 [#1] SMP ARM The full log (retrieved using serial console) is attached. 2. What is the Version-Release number of the kernel: 5.2.7-200.fc30.armv7hl 3. Did it work previously in Fedora? If so, what kernel version did the issue *first* appear? Old kernels are available for download at https://koji.fedoraproject.org/koji/packageinfo?packageID=8 : Yes, it worked previously. The problem does not occur with 5.1.20-300.fc30.armv7hl. The problem first occurs with 5.2.1-200.fc30.armv7hl. 4. Can you reproduce this issue? If so, please provide the steps to reproduce the issue below: Yes, the issue happens on every boot. 5. Does this problem occur with the latest Rawhide kernel? To install the Rawhide kernel, run ``sudo dnf install fedora-repos-rawhide`` followed by ``sudo dnf update --enablerepo=rawhide kernel``: Yes. The problem also occurs with 5.3.0-0.rc3.git1.1.fc31.armv7hl. 6. Are you running any modules that not shipped with directly Fedora's kernel?: No. 7. Please attach the kernel logs. You can get the complete kernel log for a boot with ``journalctl --no-hostname -k > dmesg.txt``. If the issue occurred on a previous boot, use the journalctl ``-b`` flag. The system does not boot with the affected kernel, so the only log available is the boot log (attached).
More testing: 5.1.20-300.fc30.armv7hl: working 5.2.0-0.rc0.git6.1.fc31.armv7hl - 5.2.0-0.rc2.git1.1.fc31.armv7hl: freezes at boot, no output on serial console 5.2.0-0.rc2.git1.2.fc31.armv7hl: crashes with a different error 5.2.0-0.rc3.git0.1.fc31.armv7hl and beyond: crashes with this issue
Seems to be fixed in the latest Rawhide kernel (5.4.0-0.rc0.git4.1.fc32.armv7hl), but still broken in the latest F30 kernel (5.2.15-200.fc30.armv7hl). I've git-bisected this issue down to commit c4741b23059794bd99beef0f700103b0d983b3fd[1]. According to the commit message, kernel crashes are a known side-effect... > Note that on arm, a side effect of this change is that self-tests for > generic implementations may run before the unaligned access handler has > been installed. So, unaligned accesses will crash the kernel. This is > arguably a good thing as it makes it easier to detect that type of bug. [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?h=c4741b23059794bd99beef0f700103b0d983b3fd
So this should be resolved in the 5.3.6 kernel that will be built tomorrow.