Index: lld/trunk/ELF/Config.h
===================================================================
--- lld/trunk/ELF/Config.h
+++ lld/trunk/ELF/Config.h
@@ -176,6 +176,7 @@
   bool UseAndroidRelrTags = false;
   bool WarnBackrefs;
   bool WarnCommon;
+  bool WarnIfuncTextrel;
   bool WarnMissingEntry;
   bool WarnSymbolOrdering;
   bool WriteAddends;
Index: lld/trunk/ELF/Driver.cpp
===================================================================
--- lld/trunk/ELF/Driver.cpp
+++ lld/trunk/ELF/Driver.cpp
@@ -857,6 +857,8 @@
   Config->WarnBackrefs =
       Args.hasFlag(OPT_warn_backrefs, OPT_no_warn_backrefs, false);
   Config->WarnCommon = Args.hasFlag(OPT_warn_common, OPT_no_warn_common, false);
+  Config->WarnIfuncTextrel =
+      Args.hasFlag(OPT_warn_ifunc_textrel, OPT_no_warn_ifunc_textrel, false);
   Config->WarnSymbolOrdering =
       Args.hasFlag(OPT_warn_symbol_ordering, OPT_no_warn_symbol_ordering, true);
   Config->ZCombreloc = getZFlag(Args, "combreloc", "nocombreloc", true);
Index: lld/trunk/ELF/Options.td
===================================================================
--- lld/trunk/ELF/Options.td
+++ lld/trunk/ELF/Options.td
@@ -352,6 +352,10 @@
     "Warn about duplicate common symbols",
     "Do not warn about duplicate common symbols (default)">;
 
+defm warn_ifunc_textrel: B<"warn-ifunc-textrel",
+    "Warn about using ifunc symbols with text relocations",
+    "Do not warn about using ifunc symbols with text relocations (default)">;
+
 defm warn_symbol_ordering: B<"warn-symbol-ordering",
     "Warn about problems with the symbol ordering file (default)",
     "Do not warn about problems with the symbol ordering file">;
Index: lld/trunk/ELF/Relocations.cpp
===================================================================
--- lld/trunk/ELF/Relocations.cpp
+++ lld/trunk/ELF/Relocations.cpp
@@ -50,6 +50,7 @@
 #include "SyntheticSections.h"
 #include "Target.h"
 #include "Thunks.h"
+#include "lld/Common/ErrorHandler.h"
 #include "lld/Common/Memory.h"
 #include "lld/Common/Strings.h"
 #include "llvm/ADT/SmallSet.h"
@@ -979,12 +980,22 @@
   // all dynamic symbols that can be resolved within the executable will
   // actually be resolved that way at runtime, because the main exectuable
   // is always at the beginning of a search list. We can leverage that fact.
-  if (Sym.isGnuIFunc())
+  if (Sym.isGnuIFunc()) {
+    if (!Config->ZText && Config->WarnIfuncTextrel) {
+      warn("using ifunc symbols when text relocations are allowed may produce "
+           "a binary that will segfault, if the object file is linked with "
+           "old version of glibc (glibc 2.28 and earlier). If this applies to "
+           "you, consider recompiling the object files without -fPIC and "
+           "without -Wl,-z,notext option. Use -no-warn-ifunc-textrel to "
+           "turn off this warning." +
+           getLocation(Sec, Sym, Offset));
+    }
     Expr = toPlt(Expr);
-  else if (!Sym.IsPreemptible && Expr == R_GOT_PC && !isAbsoluteValue(Sym))
+  } else if (!Sym.IsPreemptible && Expr == R_GOT_PC && !isAbsoluteValue(Sym)) {
     Expr = Target->adjustRelaxExpr(Type, RelocatedAddr, Expr);
-  else if (!Sym.IsPreemptible)
+  } else if (!Sym.IsPreemptible) {
     Expr = fromPlt(Expr);
+  }
 
   // This relocation does not require got entry, but it is relative to got and
   // needs it to be created. Here we request for that.
Index: lld/trunk/docs/ld.lld.1
===================================================================
--- lld/trunk/docs/ld.lld.1
+++ lld/trunk/docs/ld.lld.1
@@ -446,6 +446,17 @@
 traditional Unix-like linkers.
 .It Fl -warn-common
 Warn about duplicate common symbols.
+.It Fl -warn-ifunc-textrel
+Warn about using ifunc symbols in conjunction with text relocations.
+Older versions of glibc library (2.28 and earlier) has a bug that causes
+the segment that includes ifunc symbols to be marked as not executable when
+they are relocated. As a result, although the program compiles and links
+successfully, it gives segmentation fault when the instruction pointer reaches
+an ifunc symbol. Use -warn-ifunc-textrel to let lld give a warning, if the
+code may include ifunc symbols, may do text relocations and be linked with
+an older glibc version. Otherwise, there is no need to use it, as the default
+value does not give a warning. This flag has been introduced in late 2018,
+has no counter part in ld and gold linkers, and may be removed in the future.
 .It Fl -warn-unresolved-symbols
 Report unresolved symbols as warnings.
 .It Fl -whole-archive
Index: lld/trunk/test/ELF/textrel.s
===================================================================
--- lld/trunk/test/ELF/textrel.s
+++ lld/trunk/test/ELF/textrel.s
@@ -0,0 +1,40 @@
+# REQUIRES: x86
+# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux-gnu %s -o %t.o
+
+# Without --warn-text-ifunc, lld should run fine:
+# RUN: ld.lld -z notext %t.o -o %t2
+
+# With --warn-text-ifunc, lld should run with warnings:
+# RUN: ld.lld --warn-ifunc-textrel -z notext %t.o -o /dev/null 2>&1 | FileCheck %s
+# CHECK: using ifunc symbols when text relocations are allowed may produce
+# CHECK-SAME: a binary that will segfault, if the object file is linked with
+# CHECK-SAME: old version of glibc (glibc 2.28 and earlier). If this applies to
+# CHECK-SAME: you, consider recompiling the object files without -fPIC and
+# CHECK-SAME: without -Wl,-z,notext option. Use -no-warn-ifunc-textrel to
+# CHECK-SAME: turn off this warning.
+# CHECK: >>> defined in {{.*}}
+# CHECK: >>> referenced by {{.*}}:(.text+0x8)
+
+# Without text relocations, lld should run fine:
+# RUN: ld.lld --fatal-warnings %t.o -o /dev/null
+
+.text
+.globl a_func_impl
+a_func_impl:
+  nop
+
+.globl selector
+.type selector,@function
+selector:
+  movl $a_func_impl, %eax
+  retq
+
+.globl a_func
+.type a_func,@gnu_indirect_function
+.set a_func, selector
+
+.globl _start
+.type _start,@function
+main:
+  callq a_func
+  retq