Re: [PATCH] mm/vmscan: avoid false-positive -Wuninitialized warning

[Andrew Morton]

On Fri, 13 Feb 2026 18:07:04 +0100 "Arnd Bergmann" <arnd@xxxxxxxx> wrote:

> On Fri, Feb 13, 2026, at 17:58, Andrew Morton wrote:
> > On Fri, 13 Feb 2026 13:38:56 +0100 Arnd Bergmann <arnd@xxxxxxxxxx> wrote:
> >
> >> From: Arnd Bergmann <arnd@xxxxxxxx>
> >> 
> >> When the -fsanitize=bounds sanitizer is enabled,
> >
> > Is this an option in current kernels?
> 
> Yes, this is CONFIG_UBSAN_ARRAY_BOUNDS. The actual warning
> only shows up in some configurations with that, so either there
> is some other dependency, or an element of chance based on gcc
> optimizations.

OK, I'll put a cc:stable on this, as people will want to compile older
kernels with gcc-16.

Aiming for upstreaming into 7.1-rc1 unless it's more urgent than I
think.

> > Seems a large change just to squish a compiler warning.  People might
> > prefer a simple 
> >
> > -	struct ctrl_pos sp, pv;
> > +	struct ctrl_pos sp, pv = {};
> 
> Right, that would clearly also shut up the warning.
> 
> To me this seems less intuitive without an extra comment,
> since read_ctrl_pos() is meant to initialize the entire
> struct, but please pick whichever you find most readable
> here.

Let's see what the MGLRU maintainers have to say.