From: Jerin Jacob Kollanukkaran <jerinj@marvell.com> To: Neil Horman <nhorman@tuxdriver.com>, Bruce Richardson <bruce.richardson@intel.com> Cc: "dev@dpdk.org" <dev@dpdk.org>, Thomas Monjalon <thomas@monjalon.net> Subject: Re: [dpdk-dev] [EXT] [RFC PATCH 0/2] introduce __rte_internal tag Date: Thu, 6 Jun 2019 09:44:52 +0000 Message-ID: <BYAPR18MB24240EF19CFA1ADFE6B52AD1C8170@BYAPR18MB2424.namprd18.prod.outlook.com> (raw) In-Reply-To: <20190605181108.GC554@hmswarspite.think-freely.org> > -----Original Message----- > From: Neil Horman <nhorman@tuxdriver.com> > Sent: Wednesday, June 5, 2019 11:41 PM > To: Bruce Richardson <bruce.richardson@intel.com> > Cc: Jerin Jacob Kollanukkaran <jerinj@marvell.com>; dev@dpdk.org; Thomas > Monjalon <thomas@monjalon.net> > Subject: Re: [EXT] [RFC PATCH 0/2] introduce __rte_internal tag > > On Wed, Jun 05, 2019 at 05:45:41PM +0100, Bruce Richardson wrote: > > On Wed, Jun 05, 2019 at 04:24:09PM +0000, Jerin Jacob Kollanukkaran > wrote: > > > > -----Original Message----- > > > > From: Neil Horman <nhorman@tuxdriver.com> > > > > Sent: Sunday, May 26, 2019 12:14 AM > > > > To: dev@dpdk.org > > > > Cc: Neil Horman <nhorman@tuxdriver.com>; Jerin Jacob Kollanukkaran > > > > <jerinj@marvell.com>; Bruce Richardson > > > > <bruce.richardson@intel.com>; Thomas Monjalon > > > > <thomas@monjalon.net> > > > > Subject: [EXT] [RFC PATCH 0/2] introduce __rte_internal tag > > > > > > > > Hey- > > > > Based on our recent conversations regarding the use of symbols > > > > only meant for internal dpdk consumption (between dpdk libraries), > > > > this is an idea that I've come up with that I'd like to get some > > > > feedback on > > > > > > > > Summary: > > > > 1) We have symbols in the DPDK that are meant to be used between > > > > DPDK libraries, but not by applications linking to them > > > > 2) We would like to document those symbols in the code, so as to > > > > note them clearly as for being meant for internal use only > > > > 3) Linker symbol visibility is a very coarse grained tool, and so > > > > there is no good way in a single library to mark items as being > > > > meant for use only by other DPDK libraries, at least not without > > > > some extensive runtime checking > > > > > > > > > > > > Proposal: > > > > I'm proposing that we introduce the __rte_internal tag. From a > > > > coding standpoint it works a great deal like the > > > > __rte_experimental tag in that it expempts the tagged symbol from > > > > ABI constraints (as the only users should be represented in the > > > > DPDK build environment). Additionally, the __rte_internal macro > > > > resolves differently based on the definition of the > > > > BUILDING_RTE_SDK flag (working under the assumption that said flag > > > > should only ever be set if we are actually building DPDK libraries > > > > which will make use of internal calls). If the BUILDING_RTE_SDK > > > > flag is set __rte_internal resolves to __attribute__((section > > > > "text.internal)), placing it in a special text section which is > > > > then used to validate that the the symbol appears in the INTERNAL > > > > section of the corresponding library version map). If > > > > BUILDING_RTE_SDK is not set, then __rte_internal resolves to > __attribute__((error("..."))), which causes any caller of the tagged function > to throw an error at compile time, indicating that the symbol is not available > for external use. > > > > > > > > This isn't a perfect solution, as applications can still hack > > > > around it of course, > > > > > > I think, one way to, avoid, hack around could be to, > > > > > > 1) at config stage, create a random number for the build > > > 2) introduce RTE_CALL_INTERNAL macro for calling internal function, > > > compare the generated random number for allowing the calls to make > > > within the library. i.e leverage the fact that external library > > > would never know the random number generated for the DPDK build > and internal driver code does. > > > > > Do we really need to care about this. If have some determined enough > > to hack around our limitations, then they surely know that they have > > an unsupported configuration. We just need to protect against > > inadvertent use of internals, IMHO. > > > I agree, I too had thought about doing some sort of internal runtime checking > to match internal only symbols, such that they were only accessable by > internally approved users, but it started to feel like a great deal of overhead. > Its a good idea for a general mechanism I think, but I believe the value here is > more to internally document which apis we want to mark as being for > internal use only, and create a lightweight roadblock at build time to catch > users inadvertently using them. Determined users will get around anything, > and theres not much we can do to stop them. I agree too. IMHO, Simply having following items would be enough 1) Avoid exposing the internal function prototype through public header files 2) Add @internal to API documentation 3) Just decide the name space for internal API for tooling(i.e not start with rte_ or so) Using objdump scheme to detect internal functions requires the the library to build prior to run the checkpatch. > > If we really wanted to go down that road, we could use a mechainsm > simmilar to the EXPORT_SYMBOL / EXPORT_SYMBOL_GPL infrastructure that > the kernel uses, but that would required building our own custom linker > script, which seems like overkill here. > > Best > Neil > > > /Bruce > >
next prev parent reply index Thread overview: 104+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-05-25 18:43 [dpdk-dev] " Neil Horman 2019-05-25 18:43 ` [dpdk-dev] [RFC PATCH 1/2] Add __rte_internal tag for functions and version target Neil Horman 2019-06-05 16:14 ` [dpdk-dev] [EXT] " Jerin Jacob Kollanukkaran 2019-05-25 18:43 ` [dpdk-dev] [RFC PATCH 2/2] Convert dpaa driver to tag internal-only symbols appropriately Neil Horman 2019-06-05 16:24 ` [dpdk-dev] [EXT] [RFC PATCH 0/2] introduce __rte_internal tag Jerin Jacob Kollanukkaran 2019-06-05 16:45 ` Bruce Richardson 2019-06-05 18:11 ` Neil Horman 2019-06-06 9:44 ` Jerin Jacob Kollanukkaran [this message] 2019-06-06 11:34 ` Neil Horman 2019-06-06 12:04 ` Jerin Jacob Kollanukkaran 2019-06-06 13:18 ` Wiles, Keith 2019-06-06 13:43 ` Neil Horman 2019-06-06 13:53 ` Wiles, Keith 2019-06-06 14:46 ` Neil Horman 2019-06-06 13:35 ` Neil Horman 2019-06-06 14:02 ` Jerin Jacob Kollanukkaran 2019-06-06 15:03 ` Neil Horman 2019-06-06 15:14 ` Jerin Jacob Kollanukkaran 2019-06-06 15:26 ` Neil Horman 2019-06-06 16:23 ` Jerin Jacob Kollanukkaran 2019-06-06 16:55 ` Neil Horman 2019-06-07 9:41 ` Jerin Jacob Kollanukkaran 2019-06-07 10:35 ` Neil Horman 2019-06-07 15:42 ` Ray Kinsella 2019-06-07 18:21 ` Wiles, Keith 2020-01-09 15:49 ` Neil Horman 2019-06-12 20:38 ` [dpdk-dev] [PATCH v1 0/9] dpdk: " Neil Horman 2019-06-12 20:38 ` [dpdk-dev] [PATCH v1 1/9] Add __rte_internal tag for functions and version target Neil Horman 2019-06-12 20:38 ` [dpdk-dev] [PATCH v1 2/9] Exempt INTERNAL symbols from checking Neil Horman 2019-06-12 20:38 ` [dpdk-dev] [PATCH v1 3/9] mark dpaa driver internal-only symbols with __rte_internal Neil Horman 2019-06-12 20:38 ` [dpdk-dev] [PATCH v1 4/9] fslmc: identify internal only functions and tag them as __rte_internal Neil Horman 2019-06-12 20:38 ` [dpdk-dev] [PATCH v1 5/9] dpaa2: Adjust dpaa2 driver to mark internal symbols with __rte_internal Neil Horman 2019-06-12 20:39 ` [dpdk-dev] [PATCH v1 6/9] dpaax: mark internal functions " Neil Horman 2019-06-12 20:39 ` [dpdk-dev] [PATCH v1 7/9] cpt: " Neil Horman 2019-06-17 5:27 ` [dpdk-dev] [EXT] " Anoob Joseph 2019-06-12 20:39 ` [dpdk-dev] [PATCH v1 8/9] octeonx: " Neil Horman 2019-06-12 20:39 ` [dpdk-dev] [PATCH v1 9/9] dpaa2: " Neil Horman 2019-06-12 21:14 ` Aaron Conole 2019-06-13 10:24 ` Neil Horman 2019-06-13 7:53 ` [dpdk-dev] [PATCH v1 0/9] dpdk: introduce __rte_internal tag David Marchand 2019-06-13 10:30 ` Neil Horman 2019-06-13 14:23 ` [dpdk-dev] [PATCH v2 0/10] " Neil Horman 2019-06-13 14:23 ` [dpdk-dev] [PATCH v2 01/10] Add __rte_internal tag for functions and version target Neil Horman 2020-04-17 2:04 ` Wang, Haiyue 2020-04-17 2:38 ` Neil Horman 2020-04-17 4:40 ` Wang, Haiyue 2019-06-13 14:23 ` [dpdk-dev] [PATCH v2 02/10] meson: add BUILDING_RTE_SDK Neil Horman 2019-06-13 14:44 ` Bruce Richardson 2019-06-19 10:39 ` Neil Horman 2019-06-19 10:46 ` Bruce Richardson 2019-06-19 18:34 ` Neil Horman 2019-06-20 10:20 ` Bruce Richardson 2019-06-20 10:21 ` Bruce Richardson 2019-06-13 14:23 ` [dpdk-dev] [PATCH v2 03/10] Exempt INTERNAL symbols from checking Neil Horman 2019-06-13 14:23 ` [dpdk-dev] [PATCH v2 04/10] mark dpaa driver internal-only symbols with __rte_internal Neil Horman 2019-06-13 14:23 ` [dpdk-dev] [PATCH v2 05/10] fslmc: identify internal only functions and tag them as __rte_internal Neil Horman 2019-06-17 7:30 ` Hemant Agrawal 2019-06-19 10:45 ` Neil Horman 2020-04-02 9:49 ` Hemant Agrawal 2020-04-02 11:30 ` Neil Horman 2020-04-02 15:44 ` Hemant Agrawal 2019-06-13 14:23 ` [dpdk-dev] [PATCH v2 06/10] dpaa2: Adjust dpaa2 driver to mark internal symbols with __rte_internal Neil Horman 2019-06-13 14:23 ` [dpdk-dev] [PATCH v2 07/10] dpaax: mark internal functions " Neil Horman 2019-06-13 14:23 ` [dpdk-dev] [PATCH v2 08/10] cpt: " Neil Horman 2019-06-13 14:23 ` [dpdk-dev] [PATCH v2 09/10] octeonx: " Neil Horman 2019-06-13 14:23 ` [dpdk-dev] [PATCH v2 10/10] dpaa2: " Neil Horman 2019-08-06 10:03 ` [dpdk-dev] [PATCH v2 0/10] dpdk: introduce __rte_internal tag Thomas Monjalon 2019-08-06 12:21 ` Neil Horman 2020-01-09 9:55 ` David Marchand 2020-01-09 11:46 ` Neil Horman 2020-01-09 11:53 ` David Marchand 2020-04-22 13:52 ` [dpdk-dev] [PATCH v3 0/1] " Haiyue Wang 2020-04-22 13:52 ` [dpdk-dev] [PATCH v3 1/1] eal: add internal ABI mark support Haiyue Wang 2020-04-22 14:13 ` David Marchand 2020-04-22 16:44 ` Wang, Haiyue 2020-04-22 16:37 ` [dpdk-dev] [PATCH v4 0/1] dpdk: introduce __rte_internal tag Haiyue Wang 2020-04-22 16:37 ` [dpdk-dev] [PATCH v4 1/1] eal: add internal ABI mark support Haiyue Wang 2020-04-23 3:19 ` [dpdk-dev] [PATCH v5 0/1] dpdk: introduce __rte_internal tag Haiyue Wang 2020-04-23 3:19 ` [dpdk-dev] [PATCH v5 1/1] eal: add internal ABI marking support Haiyue Wang 2020-04-24 14:52 ` David Marchand 2020-04-25 6:10 ` Wang, Haiyue 2020-04-25 14:21 ` David Marchand 2020-04-25 14:24 ` Thomas Monjalon 2020-04-25 6:04 ` [dpdk-dev] [PATCH v6 0/6] dpdk: introduce __rte_internal tag Haiyue Wang 2020-04-25 6:04 ` [dpdk-dev] [PATCH v6 1/6] eal: add internal ABI tag definition Haiyue Wang 2020-04-25 6:04 ` [dpdk-dev] [PATCH v6 2/6] build: enable internal API tag Haiyue Wang 2020-04-25 6:04 ` [dpdk-dev] [PATCH v6 3/6] mk: add internal tag check Haiyue Wang 2020-04-25 6:04 ` [dpdk-dev] [PATCH v6 4/6] devtools: ignore internal ABI check Haiyue Wang 2020-04-25 6:04 ` [dpdk-dev] [PATCH v6 5/6] devtools: exempt internal ABI checking Haiyue Wang 2020-04-25 6:04 ` [dpdk-dev] [PATCH v6 6/6] devtools: enforce internal tag at the beginning Haiyue Wang 2020-04-25 10:56 ` [dpdk-dev] [PATCH v7 0/6] dpdk: introduce __rte_internal tag Haiyue Wang 2020-04-25 10:56 ` [dpdk-dev] [PATCH v7 1/6] eal: add internal ABI tag definition Haiyue Wang 2020-04-25 10:56 ` [dpdk-dev] [PATCH v7 2/6] build: enable internal API tag Haiyue Wang 2020-04-25 10:56 ` [dpdk-dev] [PATCH v7 3/6] mk: add internal tag check Haiyue Wang 2020-04-25 14:34 ` David Marchand 2020-04-25 10:56 ` [dpdk-dev] [PATCH v7 4/6] devtools: ignore internal ABI check Haiyue Wang 2020-04-25 10:56 ` [dpdk-dev] [PATCH v7 5/6] devtools: exempt internal ABI checking Haiyue Wang 2020-04-25 14:34 ` David Marchand 2020-04-25 10:56 ` [dpdk-dev] [PATCH v7 6/6] devtools: enforce internal tag at the beginning Haiyue Wang 2020-04-25 14:39 ` [dpdk-dev] [PATCH v7 0/6] dpdk: introduce __rte_internal tag David Marchand 2020-04-25 16:34 ` Wang, Haiyue 2020-04-25 18:09 ` Wang, Haiyue 2020-04-29 8:22 ` David Marchand 2020-04-29 8:24 ` Wang, Haiyue
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