Re: [PATCH] crypto: vmx -- disable preemption to enable vsx in aes_ctr.c

[Paulo Flabiano Smorigo <pfsmorigo@linux.vnet.ibm.com>]

On Fri, 20 Jan 2017 16:35:33 +0800
Li Zhong <zhong@linux.vnet.ibm.com> wrote:

> Some preemptible check warnings were reported from
> enable_kernel_vsx(). This patch disables preemption in aes_ctr.c
> before enabling vsx, and they are now consistent with other files in
> the same directory.
> 
> Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
> ---
>  drivers/crypto/vmx/aes_ctr.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/drivers/crypto/vmx/aes_ctr.c
> b/drivers/crypto/vmx/aes_ctr.c index 38ed10d..7cf6d31 100644
> --- a/drivers/crypto/vmx/aes_ctr.c
> +++ b/drivers/crypto/vmx/aes_ctr.c
> @@ -80,11 +80,13 @@ static int p8_aes_ctr_setkey(struct crypto_tfm
> *tfm, const u8 *key, int ret;
>  	struct p8_aes_ctr_ctx *ctx = crypto_tfm_ctx(tfm);
> 
> +	preempt_disable();
>  	pagefault_disable();
>  	enable_kernel_vsx();
>  	ret = aes_p8_set_encrypt_key(key, keylen * 8, &ctx->enc_key);
>  	disable_kernel_vsx();
>  	pagefault_enable();
> +	preempt_enable();
> 
>  	ret += crypto_blkcipher_setkey(ctx->fallback, key, keylen);
>  	return ret;
> @@ -99,11 +101,13 @@ static void p8_aes_ctr_final(struct
> p8_aes_ctr_ctx *ctx, u8 *dst = walk->dst.virt.addr;
>  	unsigned int nbytes = walk->nbytes;
> 
> +	preempt_disable();
>  	pagefault_disable();
>  	enable_kernel_vsx();
>  	aes_p8_encrypt(ctrblk, keystream, &ctx->enc_key);
>  	disable_kernel_vsx();
>  	pagefault_enable();
> +	preempt_enable();
> 
>  	crypto_xor(keystream, src, nbytes);
>  	memcpy(dst, keystream, nbytes);
> @@ -132,6 +136,7 @@ static int p8_aes_ctr_crypt(struct blkcipher_desc
> *desc, blkcipher_walk_init(&walk, dst, src, nbytes);
>  		ret = blkcipher_walk_virt_block(desc, &walk,
> AES_BLOCK_SIZE); while ((nbytes = walk.nbytes) >= AES_BLOCK_SIZE) {
> +			preempt_disable();
>  			pagefault_disable();
>  			enable_kernel_vsx();
>  			aes_p8_ctr32_encrypt_blocks(walk.src.virt.addr,
> @@ -143,6 +148,7 @@ static int p8_aes_ctr_crypt(struct blkcipher_desc
> *desc, walk.iv);
>  			disable_kernel_vsx();
>  			pagefault_enable();
> +			preempt_enable();
> 
>  			/* We need to update IV mostly for last
> bytes/round */ inc = (nbytes & AES_BLOCK_MASK) / AES_BLOCK_SIZE;
> 
> 

Well observed, Thanks.