Re: [PATCH] mm/vmscan: Initialize dirty to prevent uninitialized use

[Purva Yeshi]

On 26/03/25 02:05, Yu Zhao wrote:
> On Tue, Mar 25, 2025 at 1:49 PM Purva Yeshi <purvayeshi550@xxxxxxxxx> wrote:
> > Fix Smatch-detected error:
> > mm/vmscan.c:3509 walk_pte_range() error: uninitialized symbol 'dirty'.
> > mm/vmscan.c:3522 walk_pte_range() error: uninitialized symbol 'dirty'.
> > mm/vmscan.c:3600 walk_pmd_range_locked() error: uninitialized symbol 'dirty'.
> > mm/vmscan.c:3614 walk_pmd_range_locked() error: uninitialized symbol 'dirty'.
> > mm/vmscan.c:4220 lru_gen_look_around() error: uninitialized symbol 'dirty'.
> > mm/vmscan.c:4232 lru_gen_look_around() error: uninitialized symbol 'dirty'.
> >
> > Smatch reports 'dirty' as uninitialized, leading to potential
> > undefined behavior.
>
> Thanks -- this seems like false positives from Smatch, where the
> problem should be fixed.

Should we make modifications to address this Smatch error, or is it safe 
to ignore?

> > Explicitly initialize dirty to 0 in walk_pte_range(),
> > walk_pmd_range_locked(), and lru_gen_look_around() in mm/vmscan.c
> > to fix Smatch error.
> >
> > Signed-off-by: Purva Yeshi <purvayeshi550@xxxxxxxxx>