Re: [PATCH] x86/kbuild: enable modversions for symbols exported from asm

From: Linus Torvalds
Date: Tue Nov 29 2016 - 11:18:01 EST


On Tue, Nov 29, 2016 at 8:03 AM, Michal Marek <mmarek@xxxxxxxx> wrote:
>
> The original and easily observable bug is that were are not generating
> symbol checksums for the asm-exported symbols, so they default to 0.
> This can be seen e.g. in the Module.symvers file. This seemed like a
> minor issue, because with the functions written in asm, the type
> checking is rather weak (this has been the case even before Al's
> patches). However, there is another bug that with _some_ toolchains /
> architectures, the checksums do not default to 0, but they are simply
> missing in the ___kcrctab* sections and the module loader complains. We
> can of course research into the details of the second bug, but we
> already know that we are not generating the checksums while we should be.

So let's just say that "toolchain is buggy" and make a missing kcrctab
entry mean zero (or mean "matches anything"). And just shut up the
warning.

I do *not* want to add random bandaids for something like a broken
toolchain issue when I'd really rather just delete the feature.

Linus