Re: KUBSan & alignment

[Martin Husemann <martin%duskware.de@localhost>]

On Fri, May 17, 2019 at 12:15:16PM -0500, David Young wrote:
> On Fri, May 17, 2019 at 05:19:40PM +0100, Patrick Welche wrote:
> > What should one do about
> > 
> > UBSan: Undefined Behavior in ../../../../external/bsd/acpica/dist/events/evregion.c:611:14, load of misaligned address 0xffffffff8302d4f3 for type 'const ACPI_NAME' which requires 4 byte alignment
> > UBSan: Undefined Behavior in ../../../../external/bsd/acpica/dist/resources/rsaddr.c:331:22, member access within misaligned address 0xffffe967d71420e2 for type 'union AML_RESOURCE' which requires 4 byte alignment

Have not looked at those...

> > UBSan: Undefined Behavior in ../../../../arch/x86/pci/pci_machdep.c:1134:15, member access within misaligned address 0xffffffff85a87c7c for type 'struct btinfo_framebuffer' which requires 8 byte alignment
> 
> Supposing the authors really intended for the objects to be accessed in
> this way, label each declaration with __aligned(n) for some n?

Since this code is in pci *machdep* and the behaviour is well defined for
those CPUs, just ignore it (or fix UBSan).

Martin