Created attachment 1603264 [details]
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:
3. Did it work previously in Fedora? If so, what kernel version did the issue
*first* appear? Old kernels are available for download at
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?:
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).
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. 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.
So this should be resolved in the 5.3.6 kernel that will be built tomorrow.