Re: [PATCH 2/5] powerpc/msi: Treat bitmap size as allocation failure

[Madhavan Srinivasan <maddy@linux.ibm.com>]

On 7/9/26 7:33 AM, Yury Norov wrote:
> bitmap_find_next_zero_area() uses an out-of-range return value to
> indicate failure. Check for values greater than or equal to the bitmap
> size so the caller does not depend on the exact failure sentinel.
Changes seems to fine.
Acked-by: Madhavan Srinivasan <maddy@linux.ibm.com>

When reviewing this, I did find the return value of 
bitmap_find_next_zero_area
to be unsigned long, but we are casting it to int. Not as concern at 
this point
this will be an issue when irq_count exceeds. May be a follow patch is 
needed
to fix this I guess.
Maddy

> Signed-off-by: Yury Norov <ynorov@nvidia.com>
> ---
>   arch/powerpc/sysdev/msi_bitmap.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/powerpc/sysdev/msi_bitmap.c b/arch/powerpc/sysdev/msi_bitmap.c
> index 456a4f64ae0a..2f38d4b41ad3 100644
> --- a/arch/powerpc/sysdev/msi_bitmap.c
> +++ b/arch/powerpc/sysdev/msi_bitmap.c
> @@ -21,7 +21,7 @@ int msi_bitmap_alloc_hwirqs(struct msi_bitmap *bmp, int num)
>   
>   	offset = bitmap_find_next_zero_area(bmp->bitmap, bmp->irq_count, 0,
>   					    num, (1 << order) - 1);
> -	if (offset > bmp->irq_count)
> +	if (offset >= bmp->irq_count)
>   		goto err;
>   
>   	bitmap_set(bmp->bitmap, offset, num);