TARGET_ARCH=powerpc64 jump from head -r326192 to -r327075: g_event crashes with "instruction storage interrupt" [sidestepped by avoiding use of drive labels]

[Mark Millard]

[Avoiding referencing partitions via labels
avoided the crash.]

On 2017-Dec-22, at 9:26 PM, Mark Millard <markmi at dsl-only.net> wrote:

> [Note: I experiment with using clang as the build and
> system compiler for TARGET_ARCH=powerpc64 .]
> 
> I attempted to update a old so-called PowerMac "Quad Core"
> from head -r326192 to -r328075, noting special instructions
> that have been published. (This was a non-debug kernel
> build.)
> 
> Unfortunately around the:
> 
> . . .
> cd0: 66.700MB/s transfers (UDMA4, ATPI 12bytes, PIO 65534bytes)
> cd0: Attempt
> Trying to mount from ufs:/dev/ufs/FBSDG5Lrootfs [rw,noatime]. . .
> 
> There ends up being a repeatable kernel trap:
> (transcribed from pictures, but with notes added)
> 
> fatal kernel trap:
> (NOTE: The above can be the line before the "Trying to mount" line,
> after the "cd0: Attempt" line.)
> 
> exception       = 0x400 (instruction storage interrupt)
> virtual address = 0x3c4c009438427518
> srr0            = 0x3c4c009438427518
> srr1            = 0x9000000040009032
> lr              = 0x14234e8
> curthread       = 0x3d52a80
>  pid = 13, comm = g_event
> 
> [ thread pid 13 tid 100019 ]
> Stopped at 0x3c4c009438427518
> 
> It reports:
> 
> Tracing command geom pid 13 tid 100019 td 0x3d52a80 (CPU 0)
> 0xC0000000032966b0: at g_new_provider_event+0x144
> 0xC0000000032966f0: at g_run_events+0x530
> 0xC000000003296830: at g_event_procbody+0x94
> 0xC000000003296860: at fork_exit+0xd8
> 0xC0000000032968f0: at fork_trampoline+0x18
> 0xC000000003296920: at blocked_loop+0x38
> 
> These details do not vary between attempts.
> 
> From what I gather the code jumped to 0x3c4c009438427518
> but that is not from an executable page for the context
> at the time.
> 
> On the -r326192 powerpc system /dev/ufs/FBSDG5Lrootfs
> mounts just fine.
> 

I adjusted:

/boot/loader.conf
/etc/rc.conf

/etc/fstab

to avoid use of:

geom_label_load="YES"
dumpdev="/dev/label/FBSDG5Lswap"

/dev/ufs/FBSDG5Lrootfs /               ufs     rw,noatime      1       1
/dev/label/FBSDG5Lswap none            swap    sw              0       0

Using instead:

dumpdev="/dev/ada0s4"

/dev/ada0s3     /               ufs     rw,noatime      1       1
/dev/ada0s4     none            swap    sw              0       0

This allowed the boot to work normally.

===
Mark Millard
markmi at dsl-only.net