C library system-call wrappers, or the lack thereof

Posted Nov 15, 2018 18:14 UTC (Thu) by mathstuf (subscriber, #69389)
In reply to: C library system-call wrappers, or the lack thereof by rweikusat2
Parent article: C library system-call wrappers, or the lack thereof

On their own, true, but there is a section of binaries which contains the hierarchy of symbol versions in the library. That is what gives the ordering, not the text of the symbol version itself.

C library system-call wrappers, or the lack thereof

Posted Nov 15, 2018 18:49 UTC (Thu) by rweikusat2 (subscriber, #117920) [Link] (2 responses)

Version nodes don't need to have any kind of hierarchy.

C library system-call wrappers, or the lack thereof

Posted Nov 15, 2018 18:57 UTC (Thu) by mathstuf (subscriber, #69389) [Link] (1 responses)

Need? No. But glibc does provide it and I don't see why it couldn't be used.

C library system-call wrappers, or the lack thereof

Posted Nov 15, 2018 22:22 UTC (Thu) by nix (subscriber, #2304) [Link]

Quite. If they don't provide a hierarchy in their version script, I think it's reasonable to assume that there is no ordering over the versions (which is a legitimate use of symbol versioning, though glibc doesn't use it where it should: GLIBC_PRIVATE is declared to depend upon the highest version currently in use rather than standing alone as it probably should.)