Index: lib/CodeGen/AsmPrinter/AsmPrinter.cpp
===================================================================
--- lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -636,8 +636,18 @@
   if (MAI->hasFunctionAlignment())
     EmitAlignment(MF->getAlignment(), F);
 
-  if (MAI->hasDotTypeDotSizeDirective())
-    OutStreamer->EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
+  if (MAI->hasDotTypeDotSizeDirective()) {
+    // We can't treat symbols with prefix data as functions since these
+    // will be relocated via trampoline, which will break references to
+    // prefix data. This can be observed on ELF, and rectified by treating
+    // the symbol as object rather than function.
+    //
+    // For Mach-O, the use of MCSA_AltEntry is used to prevent the
+    // breaking linker from stripping the prefix data.
+    MCSymbolAttr attr = F->hasPrefixData() ? MCSA_ELF_TypeObject
+                                           : MCSA_ELF_TypeFunction;
+    OutStreamer->EmitSymbolAttribute(CurrentFnSym, attr);
+  }
 
   if (isVerbose()) {
     F->printAsOperand(OutStreamer->GetCommentOS(),
Index: test/CodeGen/AArch64/prefixdata-symbol-type.ll
===================================================================
--- /dev/null
+++ test/CodeGen/AArch64/prefixdata-symbol-type.ll
@@ -0,0 +1,14 @@
+; RUN: llc < %s -mtriple=aarch64-pc-linux | FileCheck %s
+
+; functions with prefix data, should be of type
+; object to prevent them being relocated through
+; the PLT and making the prefix data inaccessable.
+; CHECK: .type f,@object
+define i32 @f() prefix i32 42 {
+  ret i32 0;
+}
+
+; CHECK .type g,@function
+define i32 @g() {
+  ret i32 0;
+}
\ No newline at end of file
Index: test/CodeGen/ARM/prefixdata-symbol-type.ll
===================================================================
--- /dev/null
+++ test/CodeGen/ARM/prefixdata-symbol-type.ll
@@ -0,0 +1,14 @@
+; RUN: llc < %s -mtriple=armv7-pc-linux | FileCheck %s
+
+; functions with prefix data, should be of type
+; object to prevent them being relocated through
+; the PLT and making the prefix data inaccessable.
+; CHECK: .type f,%object
+define i32 @f() prefix i32 42 {
+  ret i32 0;
+}
+
+; CHECK .type g,%function
+define i32 @g() {
+  ret i32 0;
+}
\ No newline at end of file
Index: test/CodeGen/X86/prefixdata-symbol-type.ll
===================================================================
--- /dev/null
+++ test/CodeGen/X86/prefixdata-symbol-type.ll
@@ -0,0 +1,14 @@
+; RUN: llc < %s -mtriple=x86_64-pc-linux | FileCheck %s
+
+; functions with prefix data, should be of type
+; object to prevent them being relocated through
+; the PLT and making the prefix data inaccessable.
+; CHECK: .type f,@object
+define i32 @f() prefix i32 42 {
+  ret i32 0;
+}
+
+; CHECK .type g,@function
+define i32 @g() {
+  ret i32 0;
+}
\ No newline at end of file