diff --git a/llvm/lib/Target/BPF/BTFDebug.cpp b/llvm/lib/Target/BPF/BTFDebug.cpp
--- a/llvm/lib/Target/BPF/BTFDebug.cpp
+++ b/llvm/lib/Target/BPF/BTFDebug.cpp
@@ -1372,7 +1372,16 @@
     // This instruction will be skipped, no LineInfo has
     // been generated, construct one based on function signature.
     if (LineInfoGenerated == false) {
-      auto *S = MI->getMF()->getFunction().getSubprogram();
+      const Function &F = MI->getMF()->getFunction();
+      auto *S = F.getSubprogram();
+      if (!S) {
+        std::string Str;
+        {
+          raw_string_ostream OS(Str);
+          OS << "call to subprogram '" << F.getName() << "' without line info";
+        }
+        report_fatal_error(Str.c_str());
+      }
       MCSymbol *FuncLabel = Asm->getFunctionBegin();
       constructLineInfo(S->getFile(), FuncLabel, S->getLine(), 0);
       LineInfoGenerated = true;