Bug 192253 - [INCOMPLETE] [PATCH] Add GNU hash support to kernel link_elf, kldxref
Summary: [INCOMPLETE] [PATCH] Add GNU hash support to kernel link_elf, kldxref
Status: New
Alias: None
Product: Base System
Classification: Unclassified
Component: kern (show other bugs)
Version: CURRENT
Hardware: Any Any
: --- Affects Only Me
Assignee: freebsd-bugs mailing list
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2014-07-29 20:09 UTC by Conrad Meyer
Modified: 2018-04-10 01:02 UTC (History)
2 users (show)

See Also:


Attachments
(patch -p1 in src/ ; applies against recent-ish CURRENT) (16.17 KB, patch)
2014-07-29 20:09 UTC, Conrad Meyer
no flags Details | Diff

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Description Conrad Meyer 2014-07-29 20:09:35 UTC
Created attachment 145127 [details]
(patch -p1 in src/ ; applies against recent-ish CURRENT)

This incomplete patch ports r234841 (GNU hash for rtld-elf) to the kernel linker and kldxref ELF implementations. To finish the work, someone will have to port support to the bootloader as well (OR, switch '--hash-style=gnu' to '--hash-style=both' and eat the additional hash table bloat).

We abandoned this route because it doesn't help very much on AMD64 (relocatable ELF object kmodules do not get any hash table) and we got 99.9% of the gains we wanted with the patch in bug 192249. Also, it is obnoxious how many different ELF implementations exist and most of them lack GNU hash support (bug 192252).

Still, maybe this is useful to someone or other (embedded?) architectures where kernel modules are proper shared objects.

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