[llvm] 0136f22 - [MC] Don't resolve relocations referencing STB_LOCAL STT_GNU_IFUNC

[Fangrui Song via llvm-commits]

Author: Fangrui Song
Date: 2020-01-13T23:36:06-08:00
New Revision: 0136f226c4e46258ea73fcb994f6559cec4a9aa2

URL: https://github.com/llvm/llvm-project/commit/0136f226c4e46258ea73fcb994f6559cec4a9aa2
DIFF: https://github.com/llvm/llvm-project/commit/0136f226c4e46258ea73fcb994f6559cec4a9aa2.diff

LOG: [MC] Don't resolve relocations referencing STB_LOCAL STT_GNU_IFUNC

Added: 
    

Modified: 
    llvm/lib/MC/ELFObjectWriter.cpp
    llvm/test/MC/ELF/target-in-same-section.s

Removed: 
    


################################################################################
diff  --git a/llvm/lib/MC/ELFObjectWriter.cpp b/llvm/lib/MC/ELFObjectWriter.cpp
index b421d0b2bf68..6b4b45eb8eff 100644
--- a/llvm/lib/MC/ELFObjectWriter.cpp
+++ b/llvm/lib/MC/ELFObjectWriter.cpp
@@ -1514,7 +1514,8 @@ bool ELFObjectWriter::isSymbolRefDifferenceFullyResolvedImpl(
   const auto &SymA = cast<MCSymbolELF>(SA);
   if (IsPCRel) {
     assert(!InSet);
-    if (SymA.getBinding() != ELF::STB_LOCAL)
+    if (SymA.getBinding() != ELF::STB_LOCAL ||
+        SymA.getType() == ELF::STT_GNU_IFUNC)
       return false;
   }
   return MCObjectWriter::isSymbolRefDifferenceFullyResolvedImpl(Asm, SymA, FB,

diff  --git a/llvm/test/MC/ELF/target-in-same-section.s b/llvm/test/MC/ELF/target-in-same-section.s
index dbdacaffdb7f..8e8e1e7c6078 100644
--- a/llvm/test/MC/ELF/target-in-same-section.s
+++ b/llvm/test/MC/ELF/target-in-same-section.s
@@ -9,6 +9,7 @@
 # RELOC-NEXT:   0xA R_X86_64_PLT32 weak 0xFFFFFFFFFFFFFFFC
 # RELOC-NEXT:   0x19 R_X86_64_PLT32 global 0xFFFFFFFFFFFFFFFC
 # RELOC-NEXT:   0x1E R_X86_64_PLT32 weak 0xFFFFFFFFFFFFFFFC
+# RELOC-NEXT:   0x23 R_X86_64_PLT32 ifunc 0xFFFFFFFFFFFFFFFC
 # RELOC-NEXT: }
 
 # CHECK:      0: jmp
@@ -19,14 +20,17 @@
 # CHECK-NEXT: 13: callq
 # CHECK-NEXT: 18: callq
 # CHECK-NEXT: 1d: callq
-# CHECK-NEXT: 22: retq
+# CHECK-NEXT: 22: callq
+# CHECK-NEXT: 27: retq
 
 .globl global
 .weak weak
+.type ifunc, at gnu_indirect_function
 global:
 weak:
 local:
 .set var,global
+ifunc:
   jmp var
   jmp local
   jmp global
@@ -36,4 +40,6 @@ local:
   call local
   call global
   call weak
+
+  call ifunc
   ret