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Subject: Re: [PATCH -next] misc: ibmvmc: Use GFP_ATOMIC under spin lock
To:     Wei Yongjun <weiyongjun1@huawei.com>,
        "Bryant G. Ly" <bryantly@linux.vnet.ibm.com>,
        Steven Royer <seroyer@linux.vnet.ibm.com>,
        Arnd Bergmann <arnd@arndb.de>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc:     linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org
References: <1527327959-83701-1-git-send-email-weiyongjun1@huawei.com>
From:   "Bryant G. Ly" <bryantly@linux.ibm.com>
Date:   Tue, 29 May 2018 09:15:39 -0500
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On 5/26/18 4:45 AM, Wei Yongjun wrote:

> The function alloc_dma_buffer() is called from ibmvmc_add_buffer(),
> in which a spin lock be held here, so we should use GFP_ATOMIC when
> a lock is held.
>
> Fixes: 0eca353e7ae7 ("misc: IBM Virtual Management Channel Driver (VMC)")
> Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
> ---
>  drivers/misc/ibmvmc.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/misc/ibmvmc.c b/drivers/misc/ibmvmc.c
> index fb83d13..8f82bb9 100644
> --- a/drivers/misc/ibmvmc.c
> +++ b/drivers/misc/ibmvmc.c
> @@ -273,7 +273,7 @@ static void *alloc_dma_buffer(struct vio_dev *vdev, size_t size,
>  			      dma_addr_t *dma_handle)
>  {
>  	/* allocate memory */
> -	void *buffer = kzalloc(size, GFP_KERNEL);
> +	void *buffer = kzalloc(size, GFP_ATOMIC);
>
>  	if (!buffer) {
>  		*dma_handle = 0;
>
Reviewed-by: Bryant G. Ly <bryantly@linux.vnet.ibm.com>