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author | Tom Stellard <tstellar@redhat.com> | 2018-10-31 17:14:17 +0000 |
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committer | Tom Stellard <tstellar@redhat.com> | 2018-10-31 17:14:17 +0000 |
commit | b9f34e3a65782a9f33fe9eaf2240ec4f1f6e3f6e (patch) | |
tree | 86a9f12e073bf610283641d1ecbbc8dc1aaa03c8 | |
parent | 22d86791526b83733a51b107c70e68a54fbd3370 (diff) |
Merging r345002:release_70
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r345002 | dim | 2018-10-22 22:53:15 -0700 (Mon, 22 Oct 2018) | 41 lines
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
------------------------------------------------------------------------
git-svn-id: https://llvm.org/svn/llvm-project/lld/branches/release_70@345739 91177308-0d34-0410-b5e6-96231b3b80d8
-rw-r--r-- | ELF/Writer.cpp | 2 | ||||
-rw-r--r-- | test/ELF/relocatable-rel-iplt.s | 56 |
2 files changed, 57 insertions, 1 deletions
diff --git a/ELF/Writer.cpp b/ELF/Writer.cpp index 88a2d5c71..09a17049f 100644 --- a/ELF/Writer.cpp +++ b/ELF/Writer.cpp @@ -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); diff --git a/test/ELF/relocatable-rel-iplt.s b/test/ELF/relocatable-rel-iplt.s new file mode 100644 index 000000000..773a09f52 --- /dev/null +++ b/test/ELF/relocatable-rel-iplt.s @@ -0,0 +1,56 @@ +# REQUIRES: x86 +# RUN: llvm-mc -filetype=obj -triple=i686-- %s -o %t1.o +# RUN: ld.lld -r %t1.o -o %t2.o +# RUN: llvm-readobj -t %t2.o | FileCheck %s + +// CHECK: Symbols [ +// CHECK-NEXT: Symbol { +// CHECK-NEXT: Name: (0) +// CHECK-NEXT: Value: 0x0 +// CHECK-NEXT: Size: 0 +// CHECK-NEXT: Binding: Local (0x0) +// CHECK-NEXT: Type: None (0x0) +// CHECK-NEXT: Other: 0 +// CHECK-NEXT: Section: Undefined (0x0) +// CHECK-NEXT: } +// CHECK-NEXT: Symbol { +// CHECK-NEXT: Name: (0) +// CHECK-NEXT: Value: 0x0 +// CHECK-NEXT: Size: 0 +// CHECK-NEXT: Binding: Local (0x0) +// CHECK-NEXT: Type: Section (0x3) +// CHECK-NEXT: Other: 0 +// CHECK-NEXT: Section: .text (0x1) +// CHECK-NEXT: } +// CHECK-NEXT: Symbol { +// CHECK-NEXT: Name: __rel_iplt_end (1) +// CHECK-NEXT: Value: 0x0 +// CHECK-NEXT: Size: 0 +// CHECK-NEXT: Binding: Weak (0x2) +// CHECK-NEXT: Type: None (0x0) +// CHECK-NEXT: Other [ (0x2) +// CHECK-NEXT: STV_HIDDEN (0x2) +// CHECK-NEXT: ] +// CHECK-NEXT: Section: Undefined (0x0) +// CHECK-NEXT: } +// CHECK-NEXT: Symbol { +// CHECK-NEXT: Name: __rel_iplt_start (16) +// CHECK-NEXT: Value: 0x0 +// CHECK-NEXT: Size: 0 +// CHECK-NEXT: Binding: Weak (0x2) +// CHECK-NEXT: Type: None (0x0) +// CHECK-NEXT: Other [ (0x2) +// CHECK-NEXT: STV_HIDDEN (0x2) +// CHECK-NEXT: ] +// CHECK-NEXT: Section: Undefined (0x0) +// CHECK-NEXT: } +// CHECK-NEXT: ] + + movl __rel_iplt_start, %eax + movl __rel_iplt_end, %eax + ret + + .hidden __rel_iplt_start + .hidden __rel_iplt_end + .weak __rel_iplt_start + .weak __rel_iplt_end |