From: Dodji Seketeli <dodji@redhat.com>
To: Akhil Goyal <gakhil@marvell.com>
Cc: Ferruh Yigit <ferruh.yigit@amd.com>,
David Marchand <david.marchand@redhat.com>,
"dev@dpdk.org" <dev@dpdk.org>,
Dodji Seketeli <dodji@redhat.com>,
"thomas@monjalon.net" <thomas@monjalon.net>,
"hemant.agrawal@nxp.com" <hemant.agrawal@nxp.com>,
Anoob Joseph <anoobj@marvell.com>,
"pablo.de.lara.guarch@intel.com"
<pablo.de.lara.guarch@intel.com>,
"fiona.trahe@intel.com" <fiona.trahe@intel.com>,
"declan.doherty@intel.com" <declan.doherty@intel.com>,
"matan@nvidia.com" <matan@nvidia.com>,
"g.singh@nxp.com" <g.singh@nxp.com>,
"fanzhang.oss@gmail.com" <fanzhang.oss@gmail.com>,
"jianjay.zhou@huawei.com" <jianjay.zhou@huawei.com>,
"asomalap@amd.com" <asomalap@amd.com>,
"ruifeng.wang@arm.com" <ruifeng.wang@arm.com>,
"konstantin.v.ananyev@yandex.ru" <konstantin.v.ananyev@yandex.ru>,
"radu.nicolau@intel.com" <radu.nicolau@intel.com>,
"ajit.khaparde@broadcom.com" <ajit.khaparde@broadcom.com>,
Nagadheeraj Rottela <rnagadheeraj@marvell.com>,
"mdr@ashroe.eu" <mdr@ashroe.eu>
Subject: Re: [EXTERNAL] Re: [PATCH] [RFC] cryptodev: replace LIST_END enumerators with APIs
Date: Mon, 28 Oct 2024 12:15:43 +0100 [thread overview]
Message-ID: <87h68w32cg.fsf@redhat.com> (raw)
In-Reply-To: <CO6PR18MB4484C8F17CA2021E7AD5FCE8D8782@CO6PR18MB4484.namprd18.prod.outlook.com> (Akhil Goyal's message of "Thu, 10 Oct 2024 06:18:52 +0000")
Akhil Goyal <gakhil@marvell.com> writes:
>> >>> Now added inline APIs for getting the list end which need to be updated
>> >>> for each new entry to the enum. This shall help in avoiding ABI break
>> >>> for adding new algo.
>> >>>
>> >>
>> >> Hi Akhil,
>> >>
>> >> *I think* this hides the problem instead of fixing it, and this may be
>> >> partially because of the tooling (libabigail) limitation.
>> >>
>> >> This patch prevents the libabigail warning, true, but it doesn't improve
>> >> anything from the application's perspective.
>> >> Before or after this patch, application knows a fixed value as END value.
>> >>
>> >> Not all changes in the END (MAX) enum values cause ABI break, but tool
>> >> warns on all, that is why I think this may be tooling limitation [1].
>> >> (Just to stress, I am NOT talking about regular enum values change, I am
>> >> talking about only END (MAX) value changes caused by appending new enum
>> >> items.)
>> >>
>> >> As far as I can see (please Dodji, David correct me if I am wrong) ABI
>> >> break only happens if application and library exchange enum values in
>> >> the API (directly or within a struct).
>> >
>> > - There is also the following issue:
>> > A library publicly exports an array sized against a END (MAX) enum in the API.
>> > https://developers.redhat.com/blog/2019/05/06/how-c-array-sizes-become-part-of-the-binary-interface-of-a-library
>> >
>>
>> I see. And Dodji explained this requires source code to detect.
>>
>> I don't remember seeing a public array whose size is defined by an enum,
>> are you aware of any instance of this usage?
>
> https://patches.dpdk.org/project/dpdk/patch/20241009071151.1106-1-gmuthukrishn@marvell.com/
> This was merged yesterday.
I guess the problematic piece of the code is this:
diff --git a/lib/cryptodev/rte_cryptodev.h
b/lib/cryptodev/rte_cryptodev.h
index bec947f6d5..aa6ef3a94d 100644
--- a/lib/cryptodev/rte_cryptodev.h
+++ b/lib/cryptodev/rte_cryptodev.h
@@ -185,6 +185,9 @@ struct rte_cryptodev_asymmetric_xform_capability {
* Value 0 means unavailable, and application should pass the
required
* random value. Otherwise, PMD would internally compute
the random number.
*/
+
+ uint32_t op_capa[RTE_CRYPTO_ASYM_OP_LIST_END];
+ /**< Operation specific capabilities. */
};
Is it possible for the struct rte_cryptodev_asymmetric_xform_capability
to be made an opaque struct which definition would be present only in a
.c file of the library?
Its data members would then be retrieved by getter functions that take a
pointer to that struct in parameter.
That way, the uint32_t op_capa[RTE_CRYPTO_ASYM_OP_LIST_END] data member
would be "private" to the .c file and thus would not be part of the
ABI. Any change to the RTE_CRYPTO_ASYM_OP enum would then become
harmless to that struct.
I hope this helps.
--
Dodji
next prev parent reply other threads:[~2024-10-28 11:15 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-09-05 10:14 Akhil Goyal
2024-09-05 15:09 ` Morten Brørup
2024-09-05 15:26 ` Kusztal, ArkadiuszX
2024-09-06 6:32 ` fengchengwen
2024-09-06 7:45 ` [EXTERNAL] " Akhil Goyal
2024-10-04 3:56 ` Ferruh Yigit
2024-09-06 7:54 ` Morten Brørup
2024-09-23 20:41 ` Akhil Goyal
2024-10-03 7:00 ` Akhil Goyal
2024-10-06 11:10 ` Morten Brørup
2024-10-09 11:21 ` Akhil Goyal
2024-10-04 4:00 ` Ferruh Yigit
2024-10-04 17:26 ` [EXTERNAL] " Akhil Goyal
2024-10-04 3:54 ` Ferruh Yigit
2024-10-04 7:04 ` David Marchand
2024-10-04 17:27 ` [EXTERNAL] " Akhil Goyal
2024-10-10 0:49 ` Ferruh Yigit
2024-10-10 6:18 ` [EXTERNAL] " Akhil Goyal
2024-10-28 11:15 ` Dodji Seketeli [this message]
2024-10-04 9:38 ` Dodji Seketeli
2024-10-04 17:45 ` [EXTERNAL] " Akhil Goyal
2024-10-28 10:55 ` Dodji Seketeli
2024-10-10 0:35 ` Ferruh Yigit
2024-10-28 10:12 ` Dodji Seketeli
2024-10-09 11:24 ` [PATCH] cryptodev: remove unnecessary list end Akhil Goyal
2024-10-09 12:52 ` Morten Brørup
2024-10-09 20:38 ` Akhil Goyal
2024-10-09 14:06 ` Hemant Agrawal
2024-10-10 0:51 ` Ferruh Yigit
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