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Date:      Tue, 23 Oct 2018 20:56:59 +0000 (UTC)
From:      Dimitry Andric <dim@FreeBSD.org>
To:        src-committers@freebsd.org, svn-src-projects@freebsd.org
Subject:   svn commit: r339669 - projects/clang700-import/contrib/llvm/tools/lld/ELF
Message-ID:  <201810232056.w9NKux50061630@repo.freebsd.org>
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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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