Index: test/tools/yaml2obj/dynamic-relocations.yaml
===================================================================
--- test/tools/yaml2obj/dynamic-relocations.yaml
+++ test/tools/yaml2obj/dynamic-relocations.yaml
@@ -0,0 +1,64 @@
+# Show that yaml2obj uses the correct set of symbols for relocation sections
+# referencing the dynamic symbol table.
+
+# RUN: yaml2obj %s -o %t
+# RUN: llvm-readelf -r %t | FileCheck %s
+
+# CHECK:      Relocation section '.rela.dyn' at offset {{.*}} contains 2 entries:
+# CHECK-NEXT:     Offset             Info             Type               Symbol's Value  Symbol's Name
+# CHECK-NEXT: 0000000000000000  0000000100000000 R_X86_64_NONE          0000000012345678 dynamic
+# CHECK-NEXT: 0000000000000008  0000000200000000 R_X86_64_NONE          0000000087654321 both
+# CHECK-EMPTY:
+# CHECK-NEXT: Relocation section '.rela.data' at offset {{.*}} contains 2 entries:
+# CHECK-NEXT:     Offset             Info             Type               Symbol's Value  Symbol's Name
+# CHECK-NEXT: 0000000000000010  0000000100000000 R_X86_64_NONE          0000000011223344 static
+# CHECK-NEXT: 0000000000000018  0000000200000000 R_X86_64_NONE          0000000088776655 both
+
+!ELF
+FileHeader:
+  Class:           ELFCLASS64
+  Data:            ELFDATA2LSB
+  Type:            ET_DYN
+  Machine:         EM_X86_64
+Sections:
+  - Name: .data
+    Type: SHT_PROGBITS
+    Size: 32
+  - Name: .rela.dyn
+    Type: SHT_REL
+    Link: .dynsym
+    Info: .data
+    Relocations:
+      - Offset: 0
+        Type: R_X86_64_NONE
+        Symbol: dynamic
+      - Offset: 8
+        Type: R_X86_64_NONE
+        Symbol: both
+  - Name: .rela.data
+    Type: SHT_REL
+    Link: .symtab
+    Info: .data
+    Relocations:
+      - Offset: 16
+        Type: R_X86_64_NONE
+        Symbol: static
+      - Offset: 24
+        Type: R_X86_64_NONE
+        Symbol: both
+DynamicSymbols:
+  Global:
+    - Name: dynamic
+      Section: .data
+      Value: 0x12345678
+    - Name: both
+      Section: .data
+      Value: 0x87654321
+Symbols:
+  Global:
+    - Name: static
+      Section: .data
+      Value: 0x11223344
+    - Name: both
+      Section: .data
+      Value: 0x88776655
Index: tools/yaml2obj/yaml2elf.cpp
===================================================================
--- tools/yaml2obj/yaml2elf.cpp
+++ tools/yaml2obj/yaml2elf.cpp
@@ -130,10 +130,12 @@
 
   NameToIdxMap SN2I;
   NameToIdxMap SymN2I;
+  NameToIdxMap DynSymN2I;
   const ELFYAML::Object &Doc;
 
   bool buildSectionIndex();
   bool buildSymbolIndex(std::size_t &StartIndex,
+                        NameToIdxMap &IndexMap,
                         const std::vector<ELFYAML::Symbol> &Symbols);
   void initELFHeader(Elf_Ehdr &Header);
   void initProgramHeaders(std::vector<Elf_Phdr> &PHeaders);
@@ -529,6 +531,8 @@
   SHeader.sh_size = SHeader.sh_entsize * Section.Relocations.size();
 
   auto &OS = CBA.getOSAndAlignedOffset(SHeader.sh_offset, SHeader.sh_addralign);
+  const NameToIdxMap &SymIndexMap =
+      Section.Link == ".dynsym" ? DynSymN2I : SymN2I;
 
   for (const auto &Rel : Section.Relocations) {
     unsigned SymIdx = 0;
@@ -536,7 +540,7 @@
     // an external reference.  So it ignores the return value of lookup()
     // here.
     if (Rel.Symbol)
-      SymN2I.lookup(*Rel.Symbol, SymIdx);
+      SymIndexMap.lookup(*Rel.Symbol, SymIdx);
 
     if (IsRela) {
       Elf_Rela REntry;
@@ -782,12 +786,13 @@
 template <class ELFT>
 bool
 ELFState<ELFT>::buildSymbolIndex(std::size_t &StartIndex,
+                                 NameToIdxMap &IndexMap,
                                  const std::vector<ELFYAML::Symbol> &Symbols) {
   for (const auto &Sym : Symbols) {
     ++StartIndex;
     if (Sym.Name.empty())
       continue;
-    if (SymN2I.addName(Sym.Name, StartIndex)) {
+    if (IndexMap.addName(Sym.Name, StartIndex)) {
       WithColor::error() << "Repeated symbol name: '" << Sym.Name << "'.\n";
       return false;
     }
@@ -848,9 +853,18 @@
     return 1;
 
   std::size_t StartSymIndex = 0;
-  if (!State.buildSymbolIndex(StartSymIndex, Doc.Symbols.Local) ||
-      !State.buildSymbolIndex(StartSymIndex, Doc.Symbols.Global) ||
-      !State.buildSymbolIndex(StartSymIndex, Doc.Symbols.Weak))
+  if (!State.buildSymbolIndex(StartSymIndex, State.SymN2I, Doc.Symbols.Local) ||
+      !State.buildSymbolIndex(StartSymIndex, State.SymN2I,
+                              Doc.Symbols.Global) ||
+      !State.buildSymbolIndex(StartSymIndex, State.SymN2I, Doc.Symbols.Weak))
+    return 1;
+  StartSymIndex = 0;
+  if (!State.buildSymbolIndex(StartSymIndex, State.DynSymN2I,
+                              Doc.DynamicSymbols.Local) ||
+      !State.buildSymbolIndex(StartSymIndex, State.DynSymN2I,
+                              Doc.DynamicSymbols.Global) ||
+      !State.buildSymbolIndex(StartSymIndex, State.DynSymN2I,
+                              Doc.DynamicSymbols.Weak))
     return 1;
 
   Elf_Ehdr Header;