From: Prachotan Bathi <prachotan.bathi@arm.com>
To: Jarkko Sakkinen <jarkko@kernel.org>
Cc: Peter Huewe <peterhuewe@gmx.de>, Jason Gunthorpe <jgg@ziepe.ca>,
Stuart Yoder <stuart.yoder@arm.com>,
linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v8 2/3] tpm_crb_ffa:Introduce memzero macro to replace memset
Date: Wed, 2 Jul 2025 22:58:56 -0500 [thread overview]
Message-ID: <151a612b-198a-4f7e-94e7-10426831ab94@arm.com> (raw)
In-Reply-To: <aGWvtzhs5ksKgaYo@kernel.org>
On 7/2/25 5:16 PM, Jarkko Sakkinen wrote:
> On Thu, Jun 26, 2025 at 01:45:20PM -0500, Prachotan Bathi wrote:
>> Add a memzero macro to simplify and standardize zeroing
>> FF-A data args, replacing direct uses of memset for
>> improved readability and maintainability.
>>
>> Signed-off-by: Prachotan Bathi <prachotan.bathi@arm.com>
>> ---
>> drivers/char/tpm/tpm_crb_ffa.c | 6 ++++--
>> 1 file changed, 4 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/char/tpm/tpm_crb_ffa.c b/drivers/char/tpm/tpm_crb_ffa.c
>> index 089d1e54bb46..397cc3b0a478 100644
>> --- a/drivers/char/tpm/tpm_crb_ffa.c
>> +++ b/drivers/char/tpm/tpm_crb_ffa.c
>> @@ -12,6 +12,8 @@
>> #include <linux/arm_ffa.h>
>> #include "tpm_crb_ffa.h"
>>
>> +#define memzero(s, n) memset((s), 0, (n))
>> +
>> /* TPM service function status codes */
>> #define CRB_FFA_OK 0x05000001
>> #define CRB_FFA_OK_RESULTS_RETURNED 0x05000002
>> @@ -192,7 +194,7 @@ static int __tpm_crb_ffa_send_receive(unsigned long func_id,
>> msg_ops = tpm_crb_ffa->ffa_dev->ops->msg_ops;
>>
>> if (ffa_partition_supports_direct_req2_recv(tpm_crb_ffa->ffa_dev)) {
>> - memset(&tpm_crb_ffa->direct_msg_data2, 0x00,
>> + memzero(&tpm_crb_ffa->direct_msg_data2,
>> sizeof(struct ffa_send_direct_data2));
>>
>> tpm_crb_ffa->direct_msg_data2.data[0] = func_id;
>> @@ -205,7 +207,7 @@ static int __tpm_crb_ffa_send_receive(unsigned long func_id,
>> if (!ret)
>> ret = tpm_crb_ffa_to_linux_errno(tpm_crb_ffa->direct_msg_data2.data[0]);
>> } else {
>> - memset(&tpm_crb_ffa->direct_msg_data, 0x00,
>> + memzero(&tpm_crb_ffa->direct_msg_data,
>> sizeof(struct ffa_send_direct_data));
>>
>> tpm_crb_ffa->direct_msg_data.data1 = func_id;
>> --
>> 2.43.0
>>
> It adds a ross-reference to the source code, meaning that you have to
> jump back and forth in the source code just to see that there is a
> function that wraps up a single memset() call.
>
> How does that map to "readability"?
>
> BR, Jarkko
Hi Jarkko
I've implemented this change post your feedback on v4 of the initial patch
series, maybe this should've been a question at that point, but what was the
reasoning for recommending that I use memzero instead? I'll use the same
reasoning to rephrase the commit message.
Best
Prachotan.
Sorry for the spam, Thunderbird keeps defaulting to html emails.
On 7/2/25 5:16 PM, Jarkko Sakkinen wrote:
> On Thu, Jun 26, 2025 at 01:45:20PM -0500, Prachotan Bathi wrote:
>> Add a memzero macro to simplify and standardize zeroing
>> FF-A data args, replacing direct uses of memset for
>> improved readability and maintainability.
>>
>> Signed-off-by: Prachotan Bathi <prachotan.bathi@arm.com>
>> ---
>> drivers/char/tpm/tpm_crb_ffa.c | 6 ++++--
>> 1 file changed, 4 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/char/tpm/tpm_crb_ffa.c b/drivers/char/tpm/tpm_crb_ffa.c
>> index 089d1e54bb46..397cc3b0a478 100644
>> --- a/drivers/char/tpm/tpm_crb_ffa.c
>> +++ b/drivers/char/tpm/tpm_crb_ffa.c
>> @@ -12,6 +12,8 @@
>> #include <linux/arm_ffa.h>
>> #include "tpm_crb_ffa.h"
>>
>> +#define memzero(s, n) memset((s), 0, (n))
>> +
>> /* TPM service function status codes */
>> #define CRB_FFA_OK 0x05000001
>> #define CRB_FFA_OK_RESULTS_RETURNED 0x05000002
>> @@ -192,7 +194,7 @@ static int __tpm_crb_ffa_send_receive(unsigned long func_id,
>> msg_ops = tpm_crb_ffa->ffa_dev->ops->msg_ops;
>>
>> if (ffa_partition_supports_direct_req2_recv(tpm_crb_ffa->ffa_dev)) {
>> - memset(&tpm_crb_ffa->direct_msg_data2, 0x00,
>> + memzero(&tpm_crb_ffa->direct_msg_data2,
>> sizeof(struct ffa_send_direct_data2));
>>
>> tpm_crb_ffa->direct_msg_data2.data[0] = func_id;
>> @@ -205,7 +207,7 @@ static int __tpm_crb_ffa_send_receive(unsigned long func_id,
>> if (!ret)
>> ret = tpm_crb_ffa_to_linux_errno(tpm_crb_ffa->direct_msg_data2.data[0]);
>> } else {
>> - memset(&tpm_crb_ffa->direct_msg_data, 0x00,
>> + memzero(&tpm_crb_ffa->direct_msg_data,
>> sizeof(struct ffa_send_direct_data));
>>
>> tpm_crb_ffa->direct_msg_data.data1 = func_id;
>> --
>> 2.43.0
>>
> It adds a ross-reference to the source code, meaning that you have to
> jump back and forth in the source code just to see that there is a
> function that wraps up a single memset() call.
>
> How does that map to "readability"?
>
> BR, Jarkko
next prev parent reply other threads:[~2025-07-03 3:58 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-06-26 18:45 [PATCH v8 0/3] tpm_crb_ffa: handle tpm busy return code Prachotan Bathi
2025-06-26 18:45 ` [PATCH v8 1/3] tpm_crb_ffa: Fix typos in function name Prachotan Bathi
2025-07-02 21:38 ` Jarkko Sakkinen
2025-06-26 18:45 ` [PATCH v8 2/3] tpm_crb_ffa:Introduce memzero macro to replace memset Prachotan Bathi
2025-07-02 22:16 ` Jarkko Sakkinen
2025-07-03 3:58 ` Prachotan Bathi [this message]
2025-07-04 2:45 ` Jarkko Sakkinen
2025-07-04 2:56 ` Jarkko Sakkinen
2025-07-04 10:40 ` David Laight
2025-07-04 14:04 ` Jarkko Sakkinen
2025-07-05 7:10 ` David Laight
2025-07-05 17:11 ` Jarkko Sakkinen
2025-06-26 18:45 ` [PATCH v8 3/3] tpm_crb_ffa: handle tpm busy return code Prachotan Bathi
2025-07-02 22:22 ` Jarkko Sakkinen
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