Date: Mon, 22 Nov 2021 13:16:14 -0500 From: Shawn Webb <shawn.webb@hardenedbsd.org> To: Kyle Evans <kevans@freebsd.org> Cc: Mark Johnston <markj@freebsd.org>, src-committers <src-committers@freebsd.org>, "<dev-commits-src-all@freebsd.org>" <dev-commits-src-all@freebsd.org>, dev-commits-src-branches@freebsd.org Subject: Re: git: 68396709e73a - releng/12.3 - libctf: Improve check for duplicate SOU definitions in ctf_add_type() Message-ID: <20211122181614.qiprd2oawy3h5ysa@mutt-hbsd> In-Reply-To: <CACNAnaF2OYsu1OEhB5FVnrxfwL423tFWgJ7kaVcMBnWyKPjs3Q@mail.gmail.com> References: <202111221634.1AMGYoK4064366@gitrepo.freebsd.org> <20211122172544.a3wi636tajsnsfme@mutt-hbsd> <CACNAnaF2OYsu1OEhB5FVnrxfwL423tFWgJ7kaVcMBnWyKPjs3Q@mail.gmail.com>
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--nvehbcspcrnalesi Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Nov 22, 2021 at 11:58:19AM -0600, Kyle Evans wrote: > On Mon, Nov 22, 2021 at 11:25 AM Shawn Webb <shawn.webb@hardenedbsd.org> = wrote: > > > > On Mon, Nov 22, 2021 at 04:34:50PM +0000, Mark Johnston wrote: > > > The branch releng/12.3 has been updated by markj: > > > > > > URL: https://cgit.FreeBSD.org/src/commit/?id=3D68396709e73a4cd392ffc0= 6fde6bfa44d79118a7 > > > > > > commit 68396709e73a4cd392ffc06fde6bfa44d79118a7 > > > Author: Mark Johnston <markj@FreeBSD.org> > > > AuthorDate: 2021-10-04 16:28:22 +0000 > > > Commit: Mark Johnston <markj@FreeBSD.org> > > > CommitDate: 2021-11-22 16:32:18 +0000 > > > > > > libctf: Improve check for duplicate SOU definitions in ctf_add_ty= pe() > > > > > > When copying a struct or union from one CTF container to another, > > > ctf_add_type() checks whether it matches an existing type in the > > > destination container. It does so by looking for a type with the= same > > > name and kind as the new type, and if one exists, it iterates ove= r all > > > members of the source type and checks whether a member with match= ing > > > name and offset exists in the matched destination type. This can > > > produce false positives, for example because member types are not > > > compared, but this is not expected to arise in practice. If the = match > > > fails, ctf_add_type() returns an error. > > > > > > The procedure used for member comparison breaks down in the face = of > > > anonymous struct and union members. ctf_member_iter() visits each > > > member in the source definition and looks up the corresponding me= mber in > > > the desination definition by name using ctf_member_info(), but th= is > > > function will descend into anonymous members and thus fail to mat= ch. > > > Fix the problem by introducing a custom comparison routine which = does > > > not assume member names are unique. This should also be faster f= or > > > types with many members; in the previous scheme, membcmp() would = perform > > > a linear scan of the desination type's members to perform a looku= p by > > > name. The new routine steps through the members of both types in= a > > > single loop. > > > > Hey Mark, > > > > Out of curiosity, would commits to releng branches necessitate an EN? > > > > Thanks, > > >=20 > This is just the in-progress release branch, so not here, at least. Ah. I should've paid closer attention. Thanks for the clarification. :-) --=20 Shawn Webb Cofounder / Security Engineer HardenedBSD https://git.hardenedbsd.org/hardenedbsd/pubkeys/-/raw/master/Shawn_Webb/03A= 4CBEBB82EA5A67D9F3853FF2E67A277F8E1FA.pub.asc --nvehbcspcrnalesi Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEEA6TL67gupaZ9nzhT/y5nonf44foFAmGb3mwACgkQ/y5nonf4 4fp8OQ//ZRMSX8uWU9qOGlTlvRxuoQrv09MexQAkHCpSa26Q0oR+zu+HoNggnsuX 7L+4i7JLoU46Qi4fgCtjRKdUOgFWT9nidc4/WnnWPasFKvthpE7a+3XEzvmXu53W cg1tviXkVSZpx7uR4SO0VQwgiJoiCpohKq5sD7hdDFmxivN+u/RPdr4/3iPKjs+C hPHYBfO+lsAhVDnyVvgLRxRnvo8J9gHCU4dgcTODNTQtD3vjs39xlzP54b03AH/u e5GyrPsuEGBn/Lc6osOWFvfIMENCE+/Sg3HEobu/fZfbVEkoMISKiytB/j6wNoFI QSSukNu7p6aj8+vBwovcCxiz3Y5fJ5vGKX6+jZ4ToWI/OgqE49UBIfPXGpCXnD/l c3vzSf5GYUA73HmKWUOqoEBKg99N+siA9EB4IhZZpZ+ol2tg4NtywH6BFKNymU66 X8FnIb0Oq0habX0SQrBt/nyOzVaGmvUZ3dxZDJJQXYWm6efmQ49SVHg8yZ7pRWm3 J+HjaKP4v9k25MOfMplttxOTfaL9Iwebxl0s4BpTYbXY11/B0Wf63LI3cXCjVUV0 DVl83hqGYc2v79nAW2IUHY7SGQAK+xde6UIrj4EGyhXLKA9jDrBQO00m+Mp9tXF3 z90CcyLnya7O3ckVdNMSqYzjnUtP+NrgH1sX/qum14744ZskQZM= =4mFH -----END PGP SIGNATURE----- --nvehbcspcrnalesi--
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