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

[Feifei Wang <Feifei.Wang2@arm.com>]

Hi， 

> -----邮件原件-----
> 发件人: Dybkowski, AdamX <adamx.dybkowski@intel.com>
> 发送时间: 2021年5月19日 21:17
> 收件人: Feifei Wang <Feifei.Wang2@arm.com>; Griffin, John
> <john.griffin@intel.com>; Trahe, Fiona <fiona.trahe@intel.com>; Jain,
> Deepak K <deepak.k.jain@intel.com>; Jerin Jacob
> <jerin.jacob@caviumnetworks.com>; Herbert Guan
> <Herbert.Guan@arm.com>
> 抄送: dev@dpdk.org; david.marchand@redhat.com; nd <nd@arm.com>;
> stable@dpdk.org; Ruifeng Wang <Ruifeng.Wang@arm.com>
> 主题: RE: [dpdk-dev] [PATCH v3] crypto/qat: fix uninitilized compiler warning
> 
> Hi.
> 
> I checked how it works on QAT hardware, and it does no harm. All unit tests
> still pass.
> Verified on two QAT-enabled machines.
Thanks very much for your testing.
> 
> The question is: should this patch be simplified to just add a call to memset
> (to zero the digest variable while still keeping it on the stack) at the function
> begin? And that will be a faster solution in run-time (using the variable on the
> stack instead of calloc that uses the heap).
> 
A good comment for this. I try to apply it and it also can solve the warning.
And actually maybe memset is more faster.
I will update this in the next version.

Best Regards
Feifei

> Adam
> 
> > -----Original Message-----
> > From: dev <dev-bounces@dpdk.org> On Behalf Of Feifei Wang
> > Sent: Monday, 17 May, 2021 11:07
> > To: Griffin, John <john.griffin@intel.com>; Trahe, Fiona
> > <fiona.trahe@intel.com>; Jain, Deepak K <deepak.k.jain@intel.com>;
> > Jerin Jacob <jerin.jacob@caviumnetworks.com>; Herbert Guan
> > <herbert.guan@arm.com>
> > Cc: dev@dpdk.org; david.marchand@redhat.com; nd@arm.com; Feifei
> Wang
> > <feifei.wang2@arm.com>; stable@dpdk.org; Ruifeng Wang
> > <ruifeng.wang@arm.com>
> > Subject: [dpdk-dev] [PATCH v3] crypto/qat: fix uninitilized compiler
> > warning
> >
> > 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>
> > ---
> > 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;
> >  	uint32_t *hash_state_out_be32;
> >  	uint64_t *hash_state_out_be64;
> >  	int i;
> > @@ -1200,55 +1199,65 @@ static int partial_hash_compute(enum
> > icp_qat_hw_auth_algo hash_alg,
> >  	if (digest_size <= 0)
> >  		return -EFAULT;
> >
> > +	digest = calloc(qat_hash_get_digest_size(
> > +				ICP_QAT_HW_AUTH_ALGO_DELIMITER),
> > sizeof(uint8_t));
> > +	if (!digest)
> > +		return -ENOMEM;
> > +
> >  	hash_state_out_be32 = (uint32_t *)data_out;
> >  	hash_state_out_be64 = (uint64_t *)data_out;
> >
> >  	switch (hash_alg) {
> >  	case ICP_QAT_HW_AUTH_ALGO_SHA1:
> >  		if (partial_hash_sha1(data_in, digest))
> > -			return -EFAULT;
> > +			goto fail;
> >  		for (i = 0; i < digest_size >> 2; i++, hash_state_out_be32++)
> >  			*hash_state_out_be32 =
> >  				rte_bswap32(*(((uint32_t *)digest)+i));
> >  		break;
> >  	case ICP_QAT_HW_AUTH_ALGO_SHA224:
> >  		if (partial_hash_sha224(data_in, digest))
> > -			return -EFAULT;
> > +			goto fail;
> >  		for (i = 0; i < digest_size >> 2; i++, hash_state_out_be32++)
> >  			*hash_state_out_be32 =
> >  				rte_bswap32(*(((uint32_t *)digest)+i));
> >  		break;
> >  	case ICP_QAT_HW_AUTH_ALGO_SHA256:
> >  		if (partial_hash_sha256(data_in, digest))
> > -			return -EFAULT;
> > +			goto fail;
> >  		for (i = 0; i < digest_size >> 2; i++, hash_state_out_be32++)
> >  			*hash_state_out_be32 =
> >  				rte_bswap32(*(((uint32_t *)digest)+i));
> >  		break;
> >  	case ICP_QAT_HW_AUTH_ALGO_SHA384:
> >  		if (partial_hash_sha384(data_in, digest))
> > -			return -EFAULT;
> > +			goto fail;
> >  		for (i = 0; i < digest_size >> 3; i++, hash_state_out_be64++)
> >  			*hash_state_out_be64 =
> >  				rte_bswap64(*(((uint64_t *)digest)+i));
> >  		break;
> >  	case ICP_QAT_HW_AUTH_ALGO_SHA512:
> >  		if (partial_hash_sha512(data_in, digest))
> > -			return -EFAULT;
> > +			goto fail;
> >  		for (i = 0; i < digest_size >> 3; i++, hash_state_out_be64++)
> >  			*hash_state_out_be64 =
> >  				rte_bswap64(*(((uint64_t *)digest)+i));
> >  		break;
> >  	case ICP_QAT_HW_AUTH_ALGO_MD5:
> >  		if (partial_hash_md5(data_in, data_out))
> > -			return -EFAULT;
> > +			goto fail;
> >  		break;
> >  	default:
> >  		QAT_LOG(ERR, "invalid hash alg %u", hash_alg);
> > -		return -EFAULT;
> > +		goto fail;
> >  	}
> >
> > +	free(digest);
> >  	return 0;
> > +
> > +fail:
> > +	free(digest);
> > +	return -EFAULT;
> >  }
> >  #define HMAC_IPAD_VALUE	0x36
> >  #define HMAC_OPAD_VALUE	0x5c
> > --
> > 2.25.1