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

[Yu Zhao]

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.

> 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>