Index: ELF/Symbols.h
===================================================================
--- ELF/Symbols.h
+++ ELF/Symbols.h
@@ -340,6 +340,9 @@
   // The content for __ehdr_start symbol.
   static DefinedSynthetic *EhdrStart;
 
+  // The content for __bss_start symbol.
+  static DefinedSynthetic *BssStart;
+
   // The content for _etext and etext symbols.
   static DefinedSynthetic *Etext;
   static DefinedSynthetic *Etext2;
@@ -358,6 +361,7 @@
   static DefinedRegular<ELFT> *MipsGp;
 };
 
+template <class ELFT> DefinedSynthetic *ElfSym<ELFT>::BssStart;
 template <class ELFT> DefinedSynthetic *ElfSym<ELFT>::EhdrStart;
 template <class ELFT> DefinedSynthetic *ElfSym<ELFT>::Etext;
 template <class ELFT> DefinedSynthetic *ElfSym<ELFT>::Etext2;
Index: ELF/Writer.cpp
===================================================================
--- ELF/Writer.cpp
+++ ELF/Writer.cpp
@@ -840,6 +840,10 @@
   ElfSym<ELFT>::EhdrStart =
       addOptionalSynthetic<ELFT>("__ehdr_start", Out::ElfHeader, 0);
 
+  // __bss_start is the location of .bss.* sections.
+  ElfSym<ELFT>::BssStart =
+      addOptionalSynthetic<ELFT>("__bss_start", nullptr, 0, STV_DEFAULT);
+
   auto Define = [](StringRef S, DefinedSynthetic *&Sym1,
                    DefinedSynthetic *&Sym2) {
     Sym1 = addOptionalSynthetic<ELFT>(S, nullptr, 0, STV_DEFAULT);
@@ -1661,6 +1665,16 @@
     Set(ElfSym<ELFT>::Edata, ElfSym<ELFT>::Edata2, LastRW->First,
         LastRW->p_filesz);
 
+  // __bss_start should point to the first .bss.* output section.
+  for (OutputSection *OS : OutputSections) {
+    bool IsBSS = (In<ELFT>::Common && In<ELFT>::Common->OutSec == OS) ||
+                 OS == Out::Bss || OS == Out::BssRelRo;
+    if (!IsBSS)
+      continue;
+    Set(ElfSym<ELFT>::BssStart, nullptr, OS, 0);
+    break;
+  }
+
   // Setup MIPS _gp_disp/__gnu_local_gp symbols which should
   // be equal to the _gp symbol's value.
   if (Config->EMachine == EM_MIPS) {
Index: test/ELF/Inputs/bss-start.s
===================================================================
--- test/ELF/Inputs/bss-start.s
+++ test/ELF/Inputs/bss-start.s
@@ -0,0 +1,13 @@
+.rodata
+.globl a
+.size a, 4
+.type a, @object
+a:
+.word 1
+
+.section .data,"aw",%progbits
+.globl b
+.size b, 4
+.type b, @object
+b:
+.word 2
Index: test/ELF/bss-start.s
===================================================================
--- test/ELF/bss-start.s
+++ test/ELF/bss-start.s
@@ -0,0 +1,22 @@
+# REQUIRES: x86
+# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t
+# RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %p/Inputs/bss-start.s -o %t2.o
+# RUN: ld.lld -shared %t2.o -o %t.so
+# RUN: ld.lld %t %t.so -o %t2
+# RUN: llvm-objdump -t -section-headers %t2 | FileCheck %s
+
+# CHECK: Sections:
+# CHECK: Idx Name          Size      Address          Type
+# CHECK:   7 .bss.rel.ro   00000004 00000000002020b0 BSS
+# CHECK:   8 .bss          00000004 0000000000203000 BSS
+# CHECK:   9 .bss          00000004 0000000000203004 BSS
+# CHECK: SYMBOL TABLE:
+# CHECK: 00000000002020b0  .bss.rel.ro 00000000 __bss_start
+
+.global __bss_start
+.text
+_start:
+.comm sym1,4,4
+
+ movl $1, a
+ movl $1, b
Index: test/ELF/bss-start2.s
===================================================================
--- test/ELF/bss-start2.s
+++ test/ELF/bss-start2.s
@@ -0,0 +1,17 @@
+# REQUIRES: x86
+# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t
+# RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %p/Inputs/bss-start.s -o %t2.o
+# RUN: ld.lld -shared %t2.o -o %t.so
+# RUN: ld.lld %t %t.so -o %t2
+# RUN: llvm-objdump -t -section-headers %t2 | FileCheck %s
+
+# CHECK: Sections:
+# CHECK: Idx Name          Size      Address          Type
+# CHECK:   7 .bss          00000004 0000000000203000 BSS
+# CHECK: SYMBOL TABLE:
+# CHECK: 0000000000203000  .bss 00000000 __bss_start
+
+.global __bss_start
+.text
+_start:
+ movl $1, b
Index: test/ELF/bss-start3.s
===================================================================
--- test/ELF/bss-start3.s
+++ test/ELF/bss-start3.s
@@ -0,0 +1,15 @@
+# REQUIRES: x86
+# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t
+# RUN: ld.lld %t -o %t2
+# RUN: llvm-objdump -t -section-headers %t2 | FileCheck %s
+
+# CHECK: Sections:
+# CHECK: Idx Name          Size      Address          Type
+# CHECK:   2 .bss          00000004 0000000000201000 BSS
+# CHECK: SYMBOL TABLE:
+# CHECK: 0000000000201000  .bss 00000000 __bss_start
+
+.global __bss_start
+.text
+_start:
+.comm sym1,4,4