Re: [PATCH v3] UML: pata_cs5536: fix build for X86_32 UML with TRACEPOINTS

From: Johannes Berg
Date: Fri Apr 14 2023 - 09:55:21 EST


On Sun, 2023-04-09 at 18:13 -0700, Randy Dunlap wrote:
> Current build of pata_cs5536 for i386 UML fails with:
>
> ERROR: modpost: "__tracepoint_write_msr" [drivers/ata/pata_cs5536.ko] undefined!
> ERROR: modpost: "do_trace_write_msr" [drivers/ata/pata_cs5536.ko] undefined!
> ERROR: modpost: "__tracepoint_read_msr" [drivers/ata/pata_cs5536.ko] undefined!
> ERROR: modpost: "do_trace_read_msr" [drivers/ata/pata_cs5536.ko] undefined!
>
> Add the arch/x86/lib/msr.o binary to resolve these undefined symbols.
>

Hm. Does this make sense? I can't see it'd work on UML to configure an
IDE device through MSRs? Surely that can't work? IOW, that entire driver
can't really work anyway can it?

OTOH, maybe theoretically it could work in PCI, just not with MSRs, and
then this patch makes some sense?

johannes