Index: ELF/OutputSections.cpp
===================================================================
--- ELF/OutputSections.cpp
+++ ELF/OutputSections.cpp
@@ -839,7 +839,7 @@
 // This function is called after we sort input sections
 // and scan relocations to setup sections' offsets.
 template <class ELFT> void OutputSection<ELFT>::assignOffsets() {
-  uintX_t Off = 0;
+  uintX_t Off = this->Header.sh_size;
   for (InputSection<ELFT> *S : Sections) {
     Off = alignTo(Off, S->Align);
     S->OutSecOff = Off;
Index: ELF/Writer.cpp
===================================================================
--- ELF/Writer.cpp
+++ ELF/Writer.cpp
@@ -96,7 +96,7 @@
 
   void ensureBss();
   void addCommonSymbols(std::vector<DefinedCommon *> &Syms);
-  void addCopyRelSymbols(std::vector<SharedSymbol<ELFT> *> &Syms);
+  void addCopyRelSymbol(SharedSymbol<ELFT> *Sym);
 
   std::unique_ptr<llvm::FileOutputBuffer> Buffer;
 
@@ -385,9 +385,7 @@
       if (B->needsCopy())
         continue;
       if (Target->needsCopyRel<ELFT>(Type, *B)) {
-        B->NeedsCopyOrPltAddr = true;
-        Out<ELFT>::RelaDyn->addReloc(
-            {Target->CopyRel, DynamicReloc<ELFT>::Off_Bss, B});
+        addCopyRelSymbol(B);
         continue;
       }
     }
@@ -743,21 +741,34 @@
   return 1 << TrailingZeros;
 }
 
-// Reserve space in .bss for copy relocations.
+// Reserve space in .bss for copy relocation.
 template <class ELFT>
-void Writer<ELFT>::addCopyRelSymbols(std::vector<SharedSymbol<ELFT> *> &Syms) {
-  if (Syms.empty())
-    return;
+void Writer<ELFT>::addCopyRelSymbol(SharedSymbol<ELFT> *SS) {
   ensureBss();
   uintX_t Off = Out<ELFT>::Bss->getSize();
+  uintX_t Align = getAlignment(SS);
+  Off = alignTo(Off, Align);
   uintX_t MaxAlign = Out<ELFT>::Bss->getAlign();
-  for (SharedSymbol<ELFT> *SS : Syms) {
-    uintX_t Align = getAlignment(SS);
-    Off = alignTo(Off, Align);
-    SS->OffsetInBss = Off;
-    Off += SS->Sym.st_size;
-    MaxAlign = std::max(MaxAlign, Align);
+  MaxAlign = std::max(MaxAlign, Align);
+  uintX_t Shndx = SS->Sym.st_shndx;
+  uintX_t Value = SS->Sym.st_value;
+  SharedSymbol<ELFT> *CopyRelSS = SS;
+  // Look through the DSO's dynamic symbol for aliases and create a dynamic
+  // symbol for each one. This causes the copy relocation to correctly interpose
+  // any aliases.
+  for (SharedSymbol<ELFT> &SSInFile : SS->File->getSharedSymbols()) {
+    if (SSInFile.Sym.st_shndx == Shndx && SSInFile.Sym.st_value == Value) {
+      SSInFile.OffsetInBss = Off;
+      SSInFile.NeedsCopyOrPltAddr = true;
+      SSInFile.setUsedInRegularObj();
+      SSInFile.MustBeInDynSym = true;
+      if (SSInFile.Sym.getBinding() == ELF::STB_GLOBAL)
+        CopyRelSS = &SSInFile;
+    }
   }
+  Out<ELFT>::RelaDyn->addReloc(
+      {Target->CopyRel, DynamicReloc<ELFT>::Off_Bss, CopyRelSS});
+  Off += SS->Sym.st_size;
   Out<ELFT>::Bss->setSize(Off);
   Out<ELFT>::Bss->updateAlign(MaxAlign);
 }
@@ -1061,7 +1072,6 @@
   // Now that we have defined all possible symbols including linker-
   // synthesized ones. Visit all symbols to give the finishing touches.
   std::vector<DefinedCommon *> CommonSymbols;
-  std::vector<SharedSymbol<ELFT> *> CopyRelSymbols;
   for (auto &P : Symtab.getSymbols()) {
     SymbolBody *Body = P.second->Body;
     if (auto *U = dyn_cast<Undefined>(Body))
@@ -1070,9 +1080,6 @@
 
     if (auto *C = dyn_cast<DefinedCommon>(Body))
       CommonSymbols.push_back(C);
-    if (auto *SC = dyn_cast<SharedSymbol<ELFT>>(Body))
-      if (SC->needsCopy())
-        CopyRelSymbols.push_back(SC);
 
     if (!includeInSymtab<ELFT>(*Body))
       continue;
@@ -1088,7 +1095,6 @@
     return;
 
   addCommonSymbols(CommonSymbols);
-  addCopyRelSymbols(CopyRelSymbols);
 
   // So far we have added sections from input object files.
   // This function adds linker-created Out<ELFT>::* sections.
Index: test/ELF/Inputs/relocation-copy-alias.s
===================================================================
--- /dev/null
+++ test/ELF/Inputs/relocation-copy-alias.s
@@ -0,0 +1,25 @@
+.data
+
+.globl a1
+.type a1, @object
+.size a1, 1
+a1:
+.weak a2
+.type a2, @object
+.size a2, 1
+a2:
+.byte 1
+
+.weak b1
+.type b1, @object
+.size b1, 1
+b1:
+.weak b2
+.type b2, @object
+.size b2, 1
+b2:
+.globl b3
+.type b3, @object
+.size b3, 1
+b3:
+.byte 1
Index: test/ELF/relocation-copy-alias.s
===================================================================
--- /dev/null
+++ test/ELF/relocation-copy-alias.s
@@ -0,0 +1,72 @@
+// REQUIRES: x86
+// RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t.o
+// RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %p/Inputs/relocation-copy-alias.s -o %t2.o
+// RUN: ld.lld -shared %t2.o -o %t.so
+// RUN: ld.lld %t.o %t.so -o %t3
+// RUN: llvm-readobj --dyn-symbols -r --expand-relocs %t3 | FileCheck %s
+
+.global _start
+_start:
+movl $5, a1
+movl $5, b1
+movl $5, b2
+
+// CHECK-NOT: Relocation {
+
+// CHECK:      Relocation {
+// CHECK-NEXT:   Offset:
+// CHECK-NEXT:   Type: R_X86_64_COPY
+// CHECK-NEXT:   Symbol: a1
+// CHECK-NEXT:   Addend: 0x0
+// CHECK-NEXT: }
+
+// CHECK-NOT: Relocation {
+
+// CHECK:      Relocation {
+// CHECK-NEXT:   Offset:
+// CHECK-NEXT:   Type: R_X86_64_COPY
+// CHECK-NEXT:   Symbol: b3
+// CHECK-NEXT:   Addend: 0x0
+// CHECK-NEXT: }
+
+// CHECK-NOT: Relocation {
+
+// CHECK:      Name: a1
+// CHECK-NEXT: Value: [[A:.*]]
+// CHECK-NEXT: Size: 1
+// CHECK-NEXT: Binding: Global (0x1)
+// CHECK-NEXT: Type: Object (0x1)
+// CHECK-NEXT: Other: 0
+// CHECK-NEXT: Section: .bss (0x7)
+
+// CHECK:      Name: b1
+// CHECK-NEXT: Value: [[B:.*]]
+// CHECK-NEXT: Size: 1
+// CHECK-NEXT: Binding: Weak (0x2)
+// CHECK-NEXT: Type: Object (0x1)
+// CHECK-NEXT: Other: 0
+// CHECK-NEXT: Section: .bss
+
+// CHECK:      Name: b2
+// CHECK-NEXT: Value: [[B]]
+// CHECK-NEXT: Size: 1
+// CHECK-NEXT: Binding: Weak (0x2)
+// CHECK-NEXT: Type: Object (0x1)
+// CHECK-NEXT: Other: 0
+// CHECK-NEXT: Section: .bss
+
+// CHECK:      Name: a2
+// CHECK-NEXT: Value: [[A]]
+// CHECK-NEXT: Size: 1
+// CHECK-NEXT: Binding: Weak (0x2)
+// CHECK-NEXT: Type: Object (0x1)
+// CHECK-NEXT: Other: 0
+// CHECK-NEXT: Section: .bss
+
+// CHECK:      Name: b3
+// CHECK-NEXT: Value: [[B]]
+// CHECK-NEXT: Size: 1
+// CHECK-NEXT: Binding: Global (0x1)
+// CHECK-NEXT: Type: Object (0x1)
+// CHECK-NEXT: Other: 0
+// CHECK-NEXT: Section: .bss