Hello,
On Sat, May 15, 2021 at 11:08:17AM -0700, trix@xxxxxxxxxx wrote:
> From: Tom Rix <trix@xxxxxxxxxx>
>
> Static analysis reports this problem
> percpu.c:2945:6: warning: Assigned value is garbage or undefined
> upa = best_upa;
> ^ ~~~~~~~~
> best_upa may not be set, so initialize it.
>
> Signed-off-by: Tom Rix <trix@xxxxxxxxxx>
> ---
> mm/percpu.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/mm/percpu.c b/mm/percpu.c
> index a257c3efdf18b..6578b706fae81 100644
> --- a/mm/percpu.c
> +++ b/mm/percpu.c
> @@ -2916,6 +2916,7 @@ static struct pcpu_alloc_info * __init __flatten pcpu_build_alloc_info(
> * Related to atom_size, which could be much larger than the unit_size.
> */
> last_allocs = INT_MAX;
> + best_upa = max_upa;
> for (upa = max_upa; upa; upa--) {
> int allocs = 0, wasted = 0;
>
> --
> 2.26.3
>
I think the proper fix would be:
best_upa = 0;
for (...) { }
BUG_ON(!best_upa);
upa = best_upa;
If you're fine with this I'll make the changes and apply it to
for-5.13-fixes.
Can you also tell me what static analysis tool produced this? I'm just a
little curious because this code hasn't changed in several years so I'd
have expected some static analyzer to have caught this by now.
Thanks,
Dennis
