Re: systemd 252.6-1 produces an Instruction fault, sysvinit works

[Michael Cree <mcree@orcon.net.nz>]

On Thu, May 18, 2023 at 01:01:25PM +0200, Frank Scheiner wrote:
> Welcome to Debian GNU/Linux 12 (bookworm)!
> 
> [   11.958978] CPU 1
> [   11.958978] systemd(1): Instruction fault 4
> [   12.032220] pc = [<fffffc0005163bfc>]  ra = [<fffffc0005163bf8>]  ps
> = 0000    Not tainted
> [   12.131829] pc is at 0xfffffc0005163bfc
> [   12.177728] ra is at 0xfffffc0005163bf8

Yeah, I think I have seen this one too when I tried out the new kernel.

Instruction fault 4 occurs on the execution of a reserved instruction
(i.e. an invalid opcode) or the execution of a privileged instruction
in user mode.  

Interestingly the program counter is in kernel space.  So raises the
question is it the kernel that tried to execute an invalid instruction?

Looking at the code:

> [   13.559563] Code:
> [   13.559563]  fffffc00
> [   13.582024]  00000000
> [   13.610344]  00000000
> [   13.638664]  05163bfc
> [   13.666985]  fffffc00
> [   13.695305]  02871148
> [   13.723625] <fffffc00>
> [   13.751946]  00000000
> [   13.779289]

These do not appear to be valid code.  They look more like addresses.
It has the appearance that the kernel has jumped into data and tried
to execute it as code!

Maybe report it to the Linux Kernel Mail List?

Cheers,
Michael