Index: ELF/Writer.cpp
===================================================================
--- ELF/Writer.cpp
+++ ELF/Writer.cpp
@@ -519,6 +519,29 @@
   }
 }
 
+// The InX::BssRelRo inserts a .bss.rel.ro sections into the parent
+// Section. As .bss.rel.ro can easily match in a linker script with
+// the pattern *(.bss.*) we have two cases to handle:
+// 1.) There are no .bss.rel.ro sections, we are non relro.
+// 2.) There is at least one .bss.rel.ro and at least one non
+//     .bss.rel.ro, give an error message.
+static bool isBssRelRoContents(const OutputSection *Sec) {
+  bool HaveRelRo = false;
+  bool HaveNonRelRo = false;
+  for (BaseCommand *Base : Sec->SectionCommands)
+    if (auto *ISD = dyn_cast<InputSectionDescription>(Base)) {
+      for (InputSection *&IS : ISD->Sections)
+        if (isa<BssSection>(IS) && IS->Name == ".bss.rel.ro")
+          HaveRelRo = true;
+        else
+          HaveNonRelRo = true;
+    }
+  if (HaveRelRo && HaveNonRelRo)
+    error("section: " + Sec->Name + " has mix of relro and non relro" +
+          " sections");
+  return HaveRelRo;
+}
+
 // Today's loaders have a feature to make segments read-only after
 // processing dynamic relocations to enhance security. PT_GNU_RELRO
 // is defined for that.
@@ -576,20 +599,26 @@
   if (Sec == InX::Dynamic->getParent())
     return true;
 
-  // .bss.rel.ro is used for copy relocations for read-only symbols.
-  // Since the dynamic linker needs to process copy relocations, the
-  // section cannot be read-only, but once initialized, they shouldn't
-  // change.
-  if (Sec == InX::BssRelRo->getParent())
-    return true;
-
   // Sections with some special names are put into RELRO. This is a
   // bit unfortunate because section names shouldn't be significant in
   // ELF in spirit. But in reality many linker features depend on
   // magic section names.
   StringRef S = Sec->Name;
-  return S == ".data.rel.ro" || S == ".ctors" || S == ".dtors" || S == ".jcr" ||
-         S == ".eh_frame" || S == ".openbsd.randomdata";
+  if (S == ".data.rel.ro" || S == ".ctors" || S == ".dtors" || S == ".jcr" ||
+      S == ".eh_frame" || S == ".openbsd.randomdata")
+    return true;
+
+  // .bss.rel.ro is used for copy relocations for read-only symbols.
+  // Since the dynamic linker needs to process copy relocations, the
+  // section cannot be read-only, but once initialized, they shouldn't
+  // change.
+  if (Sec == InX::BssRelRo->getParent()) {
+    if (!Script->HasSectionsCommand || Sec->Name == ".bss.rel.ro")
+      return true;
+    return isBssRelRoContents(Sec);
+  }
+
+  return false;
 }
 
 // We compute a rank for each section. The rank indicates where the
Index: test/ELF/relro-copyrel-bss-script-error.s
===================================================================
--- /dev/null
+++ test/ELF/relro-copyrel-bss-script-error.s
@@ -0,0 +1,31 @@
+// REQUIRES: x86
+// RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %p/Inputs/shared.s -o %t.o
+// RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %p/Inputs/copy-in-shared.s -o %t2.o
+// RUN: ld.lld -shared %t.o %t2.o -o %t.so
+
+// A linker script that will map .bss.rel.ro into .bss. Error if we mix relro
+// and non relro .bss
+// RUN: echo "SECTIONS { \
+// RUN: .bss : { *(.bss) *(.bss.*) } \
+// RUN: } " > %t.script
+
+// RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t3.o
+// RUN: not ld.lld %t3.o %t.so -z relro -o %t --script=%t.script 2>&1 | FileCheck %s
+
+// CHECK: error: section: .bss has mix of relro and non relro sections
+        .section .text, "ax", @progbits
+        .global bar
+        .global foo
+        .global _start
+_start:
+        callq bar
+        .quad foo
+
+        .data
+        .space 4
+
+        // Non relro bss
+        .bss
+        // make large enough to affect PT_GNU_RELRO MemSize if this was marked
+        // as relro.
+        .space 0x2000
Index: test/ELF/relro-copyrel-bss-script.s
===================================================================
--- /dev/null
+++ test/ELF/relro-copyrel-bss-script.s
@@ -0,0 +1,37 @@
+// REQUIRES: x86
+// RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %p/Inputs/shared.s -o %t.o
+// RUN: ld.lld -shared %t.o -o %t.so
+// A linker script that will map .bss.rel.ro into .bss. If we don't have any
+// .bss.rel.ro then we don't want to mark .bss as being relro.
+// RUN: echo "SECTIONS { \
+// RUN: .bss : { *(.bss) *(.bss.*) } \
+// RUN: } " > %t.script
+
+// RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t2.o
+// RUN: ld.lld %t2.o %t.so -z relro -o %t --script=%t.script
+// RUN: llvm-readobj --program-headers %t | FileCheck %s
+        .section .text, "ax", @progbits
+        .global _start
+_start:
+        callq bar
+
+        .data
+        .space 4
+
+        // Non relro bss
+        .bss
+        // make large enough to affect PT_GNU_RELRO MemSize if this was marked
+        // as relro.
+        .space 0x2000
+
+// CHECK:     Type: PT_GNU_RELRO (0x6474E552)
+// CHECK-NEXT:     Offset:
+// CHECK-NEXT:     VirtualAddress:
+// CHECK-NEXT:     PhysicalAddress:
+// CHECK-NEXT:     FileSize:
+// CHECK-NEXT:     MemSize: 4096
+// CHECK-NEXT:     Flags [ (0x4)
+// CHECK-NEXT:       PF_R (0x4)
+// CHECK-NEXT:     ]
+// CHECK-NEXT:     Alignment: 1
+// CHECK-NEXT:   }