Re: [PATCH net-next] net: mvpp2: Initialize link in mvpp2_isr_handle_{xlg,gmac_internal}

From: Nathan Chancellor
Date: Fri Sep 11 2020 - 12:02:26 EST


On Fri, Sep 11, 2020 at 08:22:36AM -0700, Jakub Kicinski wrote:
> On Fri, 11 Sep 2020 12:11:58 +0100 Russell King - ARM Linux admin wrote:
> > On Thu, Sep 10, 2020 at 05:31:42PM -0700, Nathan Chancellor wrote:
> > > Ah great, that is indeed cleaner, thank you for letting me know!
> >
> > Hmm, I'm not sure why gcc didn't find that. Strangely, the 0-day bot
> > seems to have only picked up on it with clang, not gcc.
>
> May be similar to: https://lkml.org/lkml/2019/2/25/1092
>
> Recent GCC is so bad at catching uninitialized vars I was considering
> build testing with GCC8 :/

It is even simpler than that, the warning was straight up disabled in
commit 78a5255ffb6a ("Stop the ad-hoc games with -Wno-maybe-initialized").

clang's -Wuninitialized and -Wsometimes-uninitialized are generally more
accurate but can have some false positives because the semantic analysis
phase happens before inlining and dead code elimination.

Cheers,
Nathan