Re: [dpdk-dev] [dpdk-stable] [PATCH v3] crypto/qat: fix uninitilized compiler warning

[Ferruh Yigit <ferruh.yigit@intel.com>]

On 5/17/2021 10:07 AM, Feifei Wang wrote:
> In Arm platform, when "RTE_ARCH_ARM64_MEMCPY" is set as true, compiler
> will report variable uninitilized warning:
> 
> ../drivers/crypto/qat/qat_sym_session.c:
> In function ‘partial_hash_compute’:
> ../lib/eal/include/generic/rte_byteorder.h:241:24: warning:
> ‘<U35a0>’ may be used uninitialized in this function
> 	[-Wmaybe-uninitialized]
> 	241 | #define rte_bswap32(x) __builtin_bswap32(x)
> 	...
> 
> This is because "digest" will be initialized by "rte_memcpy" function
> rather than "memcpy" if "RTE_ARCH_ARM64_MEMCPY" is set as true. However,

How 'digest' is initialized by 'rte_memcpy'?

> compiler cannot know it is initialized by the function.
> 
> To fix this, use "calloc" to initialize "digest".
> 
> Fixes: cd7fc8a84b48 ("eal/arm64: optimize memcpy")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Feifei Wang <feifei.wang2@arm.com>
> Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
> ---
> v2: add check and free for memory dynamic allocation (David Marchand)
> v3: fix compiler error
> 
>  drivers/crypto/qat/qat_sym_session.c | 27 ++++++++++++++++++---------
>  1 file changed, 18 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/crypto/qat/qat_sym_session.c b/drivers/crypto/qat/qat_sym_session.c
> index 231b1640da..105a10957a 100644
> --- a/drivers/crypto/qat/qat_sym_session.c
> +++ b/drivers/crypto/qat/qat_sym_session.c
> @@ -1190,8 +1190,7 @@ static int partial_hash_compute(enum icp_qat_hw_auth_algo hash_alg,
>  			uint8_t *data_out)
>  {
>  	int digest_size;
> -	uint8_t digest[qat_hash_get_digest_size(
> -			ICP_QAT_HW_AUTH_ALGO_DELIMITER)];
> +	uint8_t *digest;

Will a memset 'digest' work too? Although not sure which one is better.