Re: git: 68396709e73a - releng/12.3 - libctf: Improve check for duplicate SOU definitions in ctf_add_type()
- Reply: Kyle Evans : "Re: git: 68396709e73a - releng/12.3 - libctf: Improve check for duplicate SOU definitions in ctf_add_type()"
- In reply to: Mark Johnston : "git: 68396709e73a - releng/12.3 - libctf: Improve check for duplicate SOU definitions in ctf_add_type()"
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Date: Mon, 22 Nov 2021 17:25:44 UTC
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=68396709e73a4cd392ffc06fde6bfa44d79118a7 > > 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_type() > > 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 over all > members of the source type and checks whether a member with matching > 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 member in > the desination definition by name using ctf_member_info(), but this > function will descend into anonymous members and thus fail to match. > Fix the problem by introducing a custom comparison routine which does > not assume member names are unique. This should also be faster for > types with many members; in the previous scheme, membcmp() would perform > a linear scan of the desination type's members to perform a lookup 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, -- Shawn Webb Cofounder / Security Engineer HardenedBSD https://git.hardenedbsd.org/hardenedbsd/pubkeys/-/raw/master/Shawn_Webb/03A4CBEBB82EA5A67D9F3853FF2E67A277F8E1FA.pub.asc