diff --git a/llvm/include/llvm/MC/MCObjectFileInfo.h b/llvm/include/llvm/MC/MCObjectFileInfo.h
--- a/llvm/include/llvm/MC/MCObjectFileInfo.h
+++ b/llvm/include/llvm/MC/MCObjectFileInfo.h
@@ -412,9 +412,7 @@
   // XCOFF specific sections
   MCSection *getTOCBaseSection() const { return TOCBaseSection; }
 
-  MCSection *getEHFrameSection() {
-    return EHFrameSection;
-  }
+  MCSection *getEHFrameSection() const { return EHFrameSection; }
 
   enum Environment { IsMachO, IsELF, IsCOFF, IsWasm, IsXCOFF };
   Environment getObjectFileType() const { return Env; }
diff --git a/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp b/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
--- a/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
+++ b/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
@@ -507,6 +507,199 @@
   return Flags;
 }
 
+/// Return true if one of the default sections
+static bool isDefaultELFSection(const MCContext &C, const MCSectionELF &S) {
+  const MCObjectFileInfo &OFI = *C.getObjectFileInfo();
+  if (&S == OFI.getTextSection())
+    return true;
+  if (&S == OFI.getDataSection())
+    return true;
+  if (&S == OFI.getBSSSection())
+    return true;
+  if (&S == OFI.getReadOnlySection())
+    return true;
+  if (&S == OFI.getCompactUnwindSection())
+    return true;
+  if (&S == OFI.getDwarfAbbrevSection())
+    return true;
+  if (&S == OFI.getDwarfInfoSection())
+    return true;
+  if (&S == OFI.getDwarfLineSection())
+    return true;
+  if (&S == OFI.getDwarfLineStrSection())
+    return true;
+  if (&S == OFI.getDwarfFrameSection())
+    return true;
+  if (&S == OFI.getDwarfPubNamesSection())
+    return true;
+  if (&S == OFI.getDwarfPubTypesSection())
+    return true;
+  if (&S == OFI.getDwarfGnuPubNamesSection())
+    return true;
+  if (&S == OFI.getDwarfGnuPubTypesSection())
+    return true;
+  if (&S == OFI.getDwarfDebugInlineSection())
+    return true;
+  if (&S == OFI.getDwarfStrSection())
+    return true;
+  if (&S == OFI.getDwarfLocSection())
+    return true;
+  if (&S == OFI.getDwarfARangesSection())
+    return true;
+  if (&S == OFI.getDwarfRangesSection())
+    return true;
+  if (&S == OFI.getDwarfRnglistsSection())
+    return true;
+  if (&S == OFI.getDwarfLoclistsSection())
+    return true;
+  if (&S == OFI.getDwarfMacinfoSection())
+    return true;
+  if (&S == OFI.getDwarfMacroSection())
+    return true;
+  if (&S == OFI.getDwarfDebugNamesSection())
+    return true;
+  if (&S == OFI.getDwarfAccelNamesSection())
+    return true;
+  if (&S == OFI.getDwarfAccelObjCSection())
+    return true;
+  if (&S == OFI.getDwarfAccelNamespaceSection())
+    return true;
+  if (&S == OFI.getDwarfAccelTypesSection())
+    return true;
+  if (&S == OFI.getDwarfInfoDWOSection())
+    return true;
+  // if(S == OFI.getDwarfTypesSection(hash) return true;
+  if (&S == OFI.getDwarfTypesDWOSection())
+    return true;
+  if (&S == OFI.getDwarfAbbrevDWOSection())
+    return true;
+  if (&S == OFI.getDwarfStrDWOSection())
+    return true;
+  if (&S == OFI.getDwarfLineDWOSection())
+    return true;
+  if (&S == OFI.getDwarfLocDWOSection())
+    return true;
+  if (&S == OFI.getDwarfStrOffDWOSection())
+    return true;
+  if (&S == OFI.getDwarfStrOffSection())
+    return true;
+  if (&S == OFI.getDwarfAddrSection())
+    return true;
+  if (&S == OFI.getDwarfRnglistsDWOSection())
+    return true;
+  if (&S == OFI.getDwarfLoclistsDWOSection())
+    return true;
+  if (&S == OFI.getDwarfMacroDWOSection())
+    return true;
+  if (&S == OFI.getDwarfMacinfoDWOSection())
+    return true;
+  if (&S == OFI.getDwarfCUIndexSection())
+    return true;
+  if (&S == OFI.getDwarfTUIndexSection())
+    return true;
+  if (&S == OFI.getDwarfSwiftASTSection())
+    return true;
+  if (&S == OFI.getCOFFDebugSymbolsSection())
+    return true;
+  if (&S == OFI.getCOFFDebugTypesSection())
+    return true;
+  if (&S == OFI.getCOFFGlobalTypeHashesSection())
+    return true;
+  if (&S == OFI.getTLSExtraDataSection())
+    return true;
+  if (&S == OFI.getTLSDataSection())
+    return true;
+  if (&S == OFI.getTLSBSSSection())
+    return true;
+  if (&S == OFI.getStackMapSection())
+    return true;
+  if (&S == OFI.getFaultMapSection())
+    return true;
+  if (&S == OFI.getRemarksSection())
+    return true;
+  if (&S == OFI.getStackSizesSection(*OFI.getTextSection()))
+    return true;
+  if (&S == OFI.getBBAddrMapSection(*OFI.getTextSection()))
+    return true;
+  if (&S == OFI.getPseudoProbeSection(OFI.getTextSection()))
+    return true;
+  // if(S == OFI.getPseudoProbeDescSection(function) return true;
+  if (&S == OFI.getDataRelROSection())
+    return true;
+  if (&S == OFI.getMergeableConst4Section())
+    return true;
+  if (&S == OFI.getMergeableConst8Section())
+    return true;
+  if (&S == OFI.getMergeableConst16Section())
+    return true;
+  if (&S == OFI.getMergeableConst32Section())
+    return true;
+  if (&S == OFI.getTLSTLVSection())
+    return true;
+  if (&S == OFI.getTLSThreadInitSection())
+    return true;
+  if (&S == OFI.getCStringSection())
+    return true;
+  if (&S == OFI.getUStringSection())
+    return true;
+  if (&S == OFI.getTextCoalSection())
+    return true;
+  if (&S == OFI.getConstTextCoalSection())
+    return true;
+  if (&S == OFI.getConstDataSection())
+    return true;
+  if (&S == OFI.getDataCoalSection())
+    return true;
+  if (&S == OFI.getConstDataCoalSection())
+    return true;
+  if (&S == OFI.getDataCommonSection())
+    return true;
+  if (&S == OFI.getDataBSSSection())
+    return true;
+  if (&S == OFI.getFourByteConstantSection())
+    return true;
+  if (&S == OFI.getEightByteConstantSection())
+    return true;
+  if (&S == OFI.getSixteenByteConstantSection())
+    return true;
+  if (&S == OFI.getLazySymbolPointerSection())
+    return true;
+  if (&S == OFI.getNonLazySymbolPointerSection())
+    return true;
+  if (&S == OFI.getThreadLocalPointerSection())
+    return true;
+  if (&S == OFI.getDrectveSection())
+    return true;
+  if (&S == OFI.getPDataSection())
+    return true;
+  if (&S == OFI.getXDataSection())
+    return true;
+  if (&S == OFI.getSXDataSection())
+    return true;
+  if (&S == OFI.getGFIDsSection())
+    return true;
+  if (&S == OFI.getGIATsSection())
+    return true;
+  if (&S == OFI.getGLJMPSection())
+    return true;
+  if (&S == OFI.getTOCBaseSection())
+    return true;
+  if (&S == OFI.getEHFrameSection())
+    return true;
+  return false;
+}
+
+/// Return true if the section is compatible with the given flags.
+static bool flagsCompatible(const unsigned OldFlags, const unsigned NewFlags) {
+  // WRITE and EXECINSTR are not compatible
+  if (OldFlags & ELF::SHF_EXECINSTR && NewFlags & ELF::SHF_WRITE)
+    return false;
+  if (OldFlags & ELF::SHF_WRITE && NewFlags & ELF::SHF_EXECINSTR)
+    return false;
+
+  return true;
+}
+
 static const Comdat *getELFComdat(const GlobalValue *GV) {
   const Comdat *C = GV->getComdat();
   if (!C)
@@ -726,6 +919,29 @@
   assert(Section->getLinkedToSymbol() == LinkedToSym &&
          "Associated symbol mismatch between sections");
 
+  // Update the seen flags of user defined sections, raise an error if invalid
+  // combinations are seen. Don't update flags of standard sections (.text etc).
+  if (Section->getFlags() != Flags &&
+      !isDefaultELFSection(getContext(), *Section)) {
+    if (flagsCompatible(Section->getFlags(), Flags)) {
+      // If all flags are compatible then add any new ones to the section.
+      const auto MergedFlags = Section->getFlags() | Flags;
+      if (MergedFlags != Section->getFlags()) {
+        Section->setFlags(MergedFlags);
+        GO->getContext().diagnose(LoweringDiagnosticInfo(
+            "Symbol " + GO->getName() + ": updating section flags: " +
+                SectionName + " 0x" + utohexstr(MergedFlags),
+            DS_Remark));
+      }
+    } else {
+      GO->getContext().diagnose(LoweringDiagnosticInfo(
+          "Symbol '" + GO->getName() +
+          "' implies incompatible flags for section '" + SectionName +
+          "'. Old: 0x" + utohexstr(Section->getFlags()) + ", New: 0x" +
+          utohexstr(Flags)));
+    }
+  }
+
   if (!getContext().getAsmInfo()->useIntegratedAssembler()) {
     // If we are not using the integrated assembler then this symbol might have
     // been placed in an incompatible mergeable section. Emit an error if this
diff --git a/llvm/test/CodeGen/AArch64/aarch64-section-flags-incompatible.ll b/llvm/test/CodeGen/AArch64/aarch64-section-flags-incompatible.ll
new file mode 100644
--- /dev/null
+++ b/llvm/test/CodeGen/AArch64/aarch64-section-flags-incompatible.ll
@@ -0,0 +1,43 @@
+; RUN: not llc -mtriple=aarch64-arm-none-eabi %s -o - 2>&1 | FileCheck %s
+; RUN: not llc -mtriple=aarch64-arm-none-eabi %s -o - 2> /dev/null | FileCheck %s --check-prefix=ASSEMBLY
+
+; User creates globals with SHF_WRITE and SHF_EXECINSTR
+@rw_s1 = global i32 10, section "s1_ax", align 4
+define i32 @fn_s1() section "s1_ax" {
+    entry:
+    ret i32 0
+}
+; CHECK: error: Symbol 'rw_s1' implies incompatible flags for section 's1_ax'. Old: 0x6, New: 0x3
+
+; This is fine; constant can live in SHF_EXECINSTR section
+@ro_s2 = constant i32 10, section "s2_ax", align 4
+define i32 @fn_s2() section "s2_ax" {
+    entry:
+    ret i32 0
+}
+; CHECK-NOT: error: Symbol 'ro_s2' implies incompatible flags for section 's2_ax'.
+; CHECK-NOT: remark: Symbol ro_s2: updating section flags
+; ASSEMBLY: .section s2_ax,"ax",@progbits
+; ASSEMBLY: .section s2_ax,"ax",@progbits
+
+; This is also fine; constant can live in SHF_WRITE
+@ro_s3 = constant i32 10, section "s3_aw", align 4
+@rw_s3 = global i32 10, section "s3_aw", align 4
+; CHECK-NOT: error: Symbol 'rw_s3' implies incompatible flags for section 's3_aw'.
+; CHECK: remark: Symbol rw_s3: updating section flags: s3_aw 0x3
+; ASSEMBLY:  .section s3_aw,"a",@progbits
+
+; This is fine; .text is read only, but the flags shouldn't change
+@ro_text = constant i32 10, section ".text", align 4
+; CHECK-NOT: error: Symbol 'ro_text' implies incompatible flags for section '.text'.
+; CHECK-NOT: remark: Symbol ro_text: updating section flags: .text
+
+; This is fine; .text is read only, but mutable globals are not necessarily written to
+@rw_text = global i32 10, section ".text", align 4
+; CHECK-NOT: error: Symbol 'rw_text' implies incompatible flags for section '.text'. Old: 0x6, New: 0x3
+; CHECK-NOT: remark: Symbol rw_text: updating section flags: .text
+
+; This is fine; .data is writeable, but the flags shouldn't change and constants are allowed
+@ro_data = constant i32 10, section ".data", align 4
+; CHECK-NOT: error: Symbol 'ro_data' implies incompatible flags for section '.data'.
+; CHECK-NOT: remark: Symbol ro_data: updating section flags: .data