Re: [PATCH] Enable '-Werror' by default for all kernel builds

[Guenter Roeck]

On 9/6/21 6:12 PM, Linus Torvalds wrote:
> On Mon, Sep 6, 2021 at 4:49 PM Guenter Roeck <linux@xxxxxxxxxxxx> wrote:
> > > but I'm not seeing why that one happens on sparc64, but not on arm64
> > > or x86-64. There doesn't seem to be anything architecture-specific
> > > anywhere in that area.
> > >
> > > Funky.
> >
> > Not really. That is because de->di_fname is always 16 bytes but size
> > can be 48 if the node is really a link. The use of de is overloaded
> > in that case; de is struct qnx4_inode_entry (where di_fname is 16 bytes)
> > but the actual data is struct qnx4_link_info where the name is 48 bytes
> > long. A possible fix (compile tested only) is below.
> >
> > I think the warning/error is only reported with gcc 11.x. Do you possibly
> > use an older compiler for x86/arm64 ?
>
> No. Literally the same exact version. All of them are
>
>      gcc version 11.2.1 20210728
>
> from F34.
>
> I suspect it's something about the config - a sparc64 allmodconfig
> presumably doesn't end up having some of the things x86-64 has enabled
> (because of different core config parameters), and then optimizes
> differently as a result and shows the issue that way.
>
> Or something. <wild handwaving>

Looks like Arnd stumbled into the qnx4 problem before:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99578

He might have an idea how to fix it for good.

Guenter