Message-ID: <44049b2c-42af-f9be-2af3-46716dd83344@suse.cz>
Date:   Tue, 21 Mar 2023 08:59:29 +0100
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Subject: Re: [PATCH 05/10] genwqe: Fix MAX_ORDER usage
Content-Language: en-US
To:     "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Mel Gorman <mgorman@suse.de>,
        David Hildenbrand <david@redhat.com>
Cc:     linux-mm@kvack.org, linux-arch@vger.kernel.org,
        linux-kernel@vger.kernel.org, Frank Haverkamp <haver@linux.ibm.com>
References: <20230315113133.11326-1-kirill.shutemov@linux.intel.com>
 <20230315113133.11326-6-kirill.shutemov@linux.intel.com>
From:   Vlastimil Babka <vbabka@suse.cz>
In-Reply-To: <20230315113133.11326-6-kirill.shutemov@linux.intel.com>
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Precedence: bulk

On 3/15/23 12:31, Kirill A. Shutemov wrote:
> MAX_ORDER is not inclusive: the maximum allocation order buddy allocator
> can deliver is MAX_ORDER-1.
> 
> Fix MAX_ORDER usage in genwqe driver.
> 
> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>

Acked-by: Vlastimil Babka <vbabka@suse.cz>

> Cc: Frank Haverkamp <haver@linux.ibm.com>
> ---
>  drivers/misc/genwqe/card_dev.c   | 2 +-
>  drivers/misc/genwqe/card_utils.c | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/misc/genwqe/card_dev.c b/drivers/misc/genwqe/card_dev.c
> index 55fc5b80e649..d0e27438a73c 100644
> --- a/drivers/misc/genwqe/card_dev.c
> +++ b/drivers/misc/genwqe/card_dev.c
> @@ -443,7 +443,7 @@ static int genwqe_mmap(struct file *filp, struct vm_area_struct *vma)
>  	if (vsize == 0)
>  		return -EINVAL;
>  
> -	if (get_order(vsize) > MAX_ORDER)
> +	if (get_order(vsize) >= MAX_ORDER)
>  		return -ENOMEM;
>  
>  	dma_map = kzalloc(sizeof(struct dma_mapping), GFP_KERNEL);
> diff --git a/drivers/misc/genwqe/card_utils.c b/drivers/misc/genwqe/card_utils.c
> index f778e11237a6..ac29698d085a 100644
> --- a/drivers/misc/genwqe/card_utils.c
> +++ b/drivers/misc/genwqe/card_utils.c
> @@ -308,7 +308,7 @@ int genwqe_alloc_sync_sgl(struct genwqe_dev *cd, struct genwqe_sgl *sgl,
>  	sgl->write = write;
>  	sgl->sgl_size = genwqe_sgl_size(sgl->nr_pages);
>  
> -	if (get_order(sgl->sgl_size) > MAX_ORDER) {
> +	if (get_order(sgl->sgl_size) >= MAX_ORDER) {
>  		dev_err(&pci_dev->dev,
>  			"[%s] err: too much memory requested!\n", __func__);
>  		return ret;