[PPC64] Add ifunc support in libcsu
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Authored by luporl on Jul 25 2019, 7:53 PM.

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Reviewers

bdragon
jhibbits

Commits

rS352255: [PPC64] Add ifunc support in libcsu

Summary

When ifuncs are used in statically linked binaries, the C runtime
must perform the needed dynamic relocations, to make calls to ifuncs
work correctly.

The plan is to land this together with ifunc support in rtld, right after
the switch to ELFv2 ABI.

Diff Detail

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Unit

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Build Status

Buildable 25510
Build 24128: arc lint + arc unit

Event Timeline

luporl created this revision.Jul 25 2019, 7:53 PM

Harbormaster completed remote builds in B25510: Diff 60147.Jul 25 2019, 7:53 PM

luporl added a child revision: D15369: strncpy optimization for PowerPC64.Jul 31 2019, 7:01 PM

bdragon added inline comments.Aug 7 2019, 8:27 PM

sys/sys/elf_common.h
1223	As an aside -- This line is needed for pretty much everything ifunc related kernel and user, I think it should be a priority to get this oneliner in just so it doesn't have to get duplicated between diffs doing different parts of the ifunc work.

bdragon added inline comments.Aug 7 2019, 8:52 PM

sys/sys/elf_common.h
1223	jhibbits pointed out in IRC that there should also be #define R_PPC_IRELATIVE 248 in the previous block.

bdragon added inline comments.Aug 7 2019, 8:56 PM

sys/sys/elf_common.h
1223	Correction, it should be named R_PPC_IRELATIVE in the first place instead of being duplicated. as per the convention in this file of using the R_PPC prefix for relocations that aren't unique to PPC64.

luporl added a child revision: D15118: memcpy optimization for powerpc64.Aug 8 2019, 1:54 PM

luporl added inline comments.Aug 8 2019, 1:58 PM

sys/sys/elf_common.h
1223	Ok, so you suggest moving this change to a separate revision, right? And also change R_PPC64_IRELATIVE to R_PPC_IRELATIVE, correct?

jhibbits added inline comments.Sep 5 2019, 9:55 PM

sys/sys/elf_common.h
1223	Yep, precisely.

Separate elf_common.h change
Change R_PPC64_IRELATIVE to R_PPC_IRELATIVE in code

Harbormaster completed remote builds in B26384: Diff 61890.Sep 10 2019, 4:01 PM

luporl marked 4 inline comments as done.Sep 10 2019, 4:03 PM

luporl added a parent revision: D21587: Add R_PPC_IRELATIVE relocation.Sep 10 2019, 4:09 PM

This should be able to go in before flag day, there's nothing preventing it from working (we don't need linker support just for this, it's all in code).

This revision is now accepted and ready to land.Sep 12 2019, 3:03 PM

Closed by commit rS352255: [PPC64] Add ifunc support in libcsu (authored by luporl). · Explain WhySep 12 2019, 4:45 PM

This revision was automatically updated to reflect the committed changes.

luporl added a commit: rS352255: [PPC64] Add ifunc support in libcsu.

Herald added a subscriber: imp. · View Herald TranscriptSep 12 2019, 4:45 PM