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

[David Marchand <david.marchand@redhat.com>]

On Fri, May 14, 2021 at 9:41 AM Feifei Wang <feifei.wang2@arm.com> 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,
> 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>
> ---
>  drivers/crypto/qat/qat_sym_session.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/crypto/qat/qat_sym_session.c b/drivers/crypto/qat/qat_sym_session.c
> index 231b1640da..dab23a3290 100644
> --- a/drivers/crypto/qat/qat_sym_session.c
> +++ b/drivers/crypto/qat/qat_sym_session.c
> @@ -1190,8 +1190,8 @@ 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 = (uint8_t *)calloc(qat_hash_get_digest_size(
> +                               ICP_QAT_HW_AUTH_ALGO_DELIMITER), sizeof(uint8_t));

calloc can fail.
cast is unneded.

A simple uint8_t digest[...] = { 0 } would do the job.


>         uint32_t *hash_state_out_be32;
>         uint64_t *hash_state_out_be64;
>         int i;
> --
> 2.25.1
>



-- 
David Marchand