svn commit: r339669 - projects/clang700-import/contrib/llvm/tools/lld/ELF
Dimitry Andric
dim at FreeBSD.org
Tue Oct 23 20:57:00 UTC 2018
Author: dim
Date: Tue Oct 23 20:56:59 2018
New Revision: 339669
URL: https://svnweb.freebsd.org/changeset/base/339669
Log:
Pull in r345002 from upstream lld trunk:
Don't mess up RelIplt symbols during relocatable processing
Summary:
During upgrading of the FreeBSD source tree with lld 7.0.0, I noticed
that it started complaining about crt1.o having an "index past the
end of the symbol table".
Such a symbol table looks approximately like this, viewed with
readelf -s (note the Ndx field being messed up):
Symbol table '.symtab' contains 4 entries:
Num: Value Size Type Bind Vis Ndx Name
0: 00000000 0 NOTYPE LOCAL DEFAULT UND
1: 00000000 0 SECTION LOCAL DEFAULT 1
2: 00000000 0 NOTYPE WEAK HIDDEN RSV[0xffff] __rel_iplt_end
3: 00000000 0 NOTYPE WEAK HIDDEN RSV[0xffff] __rel_iplt_start
At first, it seemed that recent ifunc relocation work had caused this:
<https://reviews.freebsd.org/rS339351>, but it turned out that it was
due to incorrect processing of the object files by lld, when using -r
(a.k.a. --relocatable).
Bisecting showed that rL324421 ("Convert a use of Config->Static") was
the commit where this new behavior began. Simply reverting it solved
the issue, and the __rel_iplt symbols had an index of UND again.
Looking at Rafael's commit message, I think he simply missed the
possibility of --relocatable being in effect, so I have added an
additional check for it.
I also added a simple regression test case.
Reviewers: grimar, ruiu, emaste, espindola
Reviewed By: ruiu
Subscribers: arichardson, krytarowski, llvm-commits
Differential Revision: https://reviews.llvm.org/D53515
This fixes a problem in lld where it places incorrect indexes for ifunc
related symbols in crt1.o and friends, making it impossible to link most
normal programs with it.
Modified:
projects/clang700-import/contrib/llvm/tools/lld/ELF/Writer.cpp
Modified: projects/clang700-import/contrib/llvm/tools/lld/ELF/Writer.cpp
==============================================================================
--- projects/clang700-import/contrib/llvm/tools/lld/ELF/Writer.cpp Tue Oct 23 20:45:46 2018 (r339668)
+++ projects/clang700-import/contrib/llvm/tools/lld/ELF/Writer.cpp Tue Oct 23 20:56:59 2018 (r339669)
@@ -874,7 +874,7 @@ void PhdrEntry::add(OutputSection *Sec) {
// need these symbols, since IRELATIVE relocs are resolved through GOT
// and PLT. For details, see http://www.airs.com/blog/archives/403.
template <class ELFT> void Writer<ELFT>::addRelIpltSymbols() {
- if (needsInterpSection())
+ if (Config->Relocatable || needsInterpSection())
return;
StringRef S = Config->IsRela ? "__rela_iplt_start" : "__rel_iplt_start";
addOptionalRegular(S, InX::RelaIplt, 0, STV_HIDDEN, STB_WEAK);
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