diff mbox

[2/2] Add an x86 IFUNC testcase for [BZ #20019]

Message ID CAMe9rOpEYGGw3MxO9v+J0u3WWN1A-Nm8p9=J1m7_7g9SA4e3pg@mail.gmail.com
State Superseded
Headers show

Commit Message

H.J. Lu Jan. 13, 2017, 7:03 p.m. UTC 
On Wed, Oct 12, 2016 at 3:19 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
> On Tue, Oct 11, 2016 at 10:45 PM, Carlos O'Donell <carlos@redhat.com> wrote:

>> On 10/05/2016 02:16 PM, H.J. Lu wrote:

>>> On Tue, Oct 4, 2016 at 5:09 PM, Joseph Myers <joseph@codesourcery.com> wrote:

>>>> On Wed, 5 Oct 2016, H.J. Lu wrote:

>>>>

>>>>> I can try __builtin_memcpy, instread of __builtin_memmove.   There are 2

>>>

>>> I changed it to use __builtin_memset.

>>>

>>>>> acceptable results.  One is ld.so issues an error and the other is program runs.

>>>>> On x86, ld.so issues an error.  I don't know what should happen on others.

>>>>

>>>> You could make the test pass on either of those results (while failing if

>>>> ld.so crashes).

>>>>

>>>

>>> I moved the test to elf.  It passes if the test runs or ld.so issues an

>>> error.  Please try it on arm, powerpc and s390.

>>

>> This is the wrong way to test this.

>>

>> The point of this test is this:

>>

>> - Verify that an unversioned symbol reference in DSO A which has no DT_NEEDED

>>   on DSO B, when resolved to a symbol definition in DSO B, when the symbol in

>>   DSO B is an IFUNC with a resolver, that DSO B is relocated _before_ the IFUNC

>>   resolver is called, because DSO B's resolver might need global data to make

>>   the IFUNC decision e.g. GOT setup.

>>

>> The invariant we want to hold true for IFUNC is that to call the resolver

>> function you must have relocated the DSO which contains the resolver. This _should_

>> have been done by a symbol reocation dependency analysis, but that isn't working

>> correctly IMO or needs deeper analysis in the dynamic loader.

>>

>> The solution we want in place today is to issue some kind of diagnostic until we

>> fix the real problem.

>>

>> The test should look like this:

>>

>> - DSO A with an unversioned symbol reference to 'foo'.

>> - DSO B with a symbol definition of 'foo' as an ifunc with 'foo_resolver' as the

>>   resolver function which references global data from DSO C to decide which of

>>   two functions to return.

>> - DSO C with global data set to a value.

>>

>> The point is that DSO B depends on DSO C and has DT_NEEDED on it, so C will get

>> relocated first, then B, such that B's GOT is setup to access C's global data.

>>

>> When handling the reference to 'foo' in DSO A we should on x86_64 and i686

>> get the error about needing to relink DSO A so it depends on DSO B, to form

>> the initialization order of C->B->A.

>>

>> I expect this test case will now crash the other arches, rather than just

>> avoiding the crash by relying on internal libc.so details about which ifuncs

>> you're using.

>>

>> This is one step towards a better definition of IFUNC semantics, which need to

>> be more clearly defined (something I wish I had time to define and fix so

>> more projects could use them).

>

> IFUNC resolver can fail for various reasons.  My goal is to make sure

> that IFUNC inside of glibc works correctly or an error message is given

> when glibc isn't used properly.  In case of x86,  CPU feature info is

> retrieved and stored in ld.so very early at startup, which is used by IFUNC

> and only accessible in libc.so and libm.so after they have been relocated.

> My change in x86 ld.so checks it and my test verifies the check.  My fix

> won't cover other possible IFUNC failures.

>


When the IFUNC relocation is performed before the providing shared
library is unrelocated, the returned function address will be 0 and
program will segfault when the function is called.

Please apply this patch and run the test if your platform has IFUNC.  I only
enabled the unsafe resolver check for i386 and x86-64.  It is straightforward
to add check for other platforms.


H.J.

Comments

Khem Raj Jan. 13, 2017, 7:30 p.m. UTC | #1 
On 1/13/17 11:03 AM, H.J. Lu wrote:
> On Wed, Oct 12, 2016 at 3:19 PM, H.J. Lu <hjl.tools@gmail.com> wrote:

>> On Tue, Oct 11, 2016 at 10:45 PM, Carlos O'Donell <carlos@redhat.com> wrote:

>>> On 10/05/2016 02:16 PM, H.J. Lu wrote:

>>>> On Tue, Oct 4, 2016 at 5:09 PM, Joseph Myers <joseph@codesourcery.com> wrote:

>>>>> On Wed, 5 Oct 2016, H.J. Lu wrote:

>>>>>

>>>>>> I can try __builtin_memcpy, instread of __builtin_memmove.   There are 2

>>>>

>>>> I changed it to use __builtin_memset.

>>>>

>>>>>> acceptable results.  One is ld.so issues an error and the other is program runs.

>>>>>> On x86, ld.so issues an error.  I don't know what should happen on others.

>>>>>

>>>>> You could make the test pass on either of those results (while failing if

>>>>> ld.so crashes).

>>>>>

>>>>

>>>> I moved the test to elf.  It passes if the test runs or ld.so issues an

>>>> error.  Please try it on arm, powerpc and s390.

>>>

>>> This is the wrong way to test this.

>>>

>>> The point of this test is this:

>>>

>>> - Verify that an unversioned symbol reference in DSO A which has no DT_NEEDED

>>>   on DSO B, when resolved to a symbol definition in DSO B, when the symbol in

>>>   DSO B is an IFUNC with a resolver, that DSO B is relocated _before_ the IFUNC

>>>   resolver is called, because DSO B's resolver might need global data to make

>>>   the IFUNC decision e.g. GOT setup.

>>>

>>> The invariant we want to hold true for IFUNC is that to call the resolver

>>> function you must have relocated the DSO which contains the resolver. This _should_

>>> have been done by a symbol reocation dependency analysis, but that isn't working

>>> correctly IMO or needs deeper analysis in the dynamic loader.

>>>

>>> The solution we want in place today is to issue some kind of diagnostic until we

>>> fix the real problem.

>>>

>>> The test should look like this:

>>>

>>> - DSO A with an unversioned symbol reference to 'foo'.

>>> - DSO B with a symbol definition of 'foo' as an ifunc with 'foo_resolver' as the

>>>   resolver function which references global data from DSO C to decide which of

>>>   two functions to return.

>>> - DSO C with global data set to a value.

>>>

>>> The point is that DSO B depends on DSO C and has DT_NEEDED on it, so C will get

>>> relocated first, then B, such that B's GOT is setup to access C's global data.

>>>

>>> When handling the reference to 'foo' in DSO A we should on x86_64 and i686

>>> get the error about needing to relink DSO A so it depends on DSO B, to form

>>> the initialization order of C->B->A.

>>>

>>> I expect this test case will now crash the other arches, rather than just

>>> avoiding the crash by relying on internal libc.so details about which ifuncs

>>> you're using.

>>>

>>> This is one step towards a better definition of IFUNC semantics, which need to

>>> be more clearly defined (something I wish I had time to define and fix so

>>> more projects could use them).

>>

>> IFUNC resolver can fail for various reasons.  My goal is to make sure

>> that IFUNC inside of glibc works correctly or an error message is given

>> when glibc isn't used properly.  In case of x86,  CPU feature info is

>> retrieved and stored in ld.so very early at startup, which is used by IFUNC

>> and only accessible in libc.so and libm.so after they have been relocated.

>> My change in x86 ld.so checks it and my test verifies the check.  My fix

>> won't cover other possible IFUNC failures.

>>

> 

> When the IFUNC relocation is performed before the providing shared

> library is unrelocated, the returned function address will be 0 and

> program will segfault when the function is called.

> 

> Please apply this patch and run the test if your platform has IFUNC.  I only

> enabled the unsafe resolver check for i386 and x86-64.  It is straightforward

> to add check for other platforms.


I will test it out shortly. One thing I see, the runner script for test
is calling out for /bin/bash and the script does not use any bash
extentions perhaps using /bin/sh is enough.



> 

> 

> H.J.

>
diff mbox

Patch

From 5db1cdaef209ba5b742308d5dcb299aaacdf3f92 Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Thu, 12 Jan 2017 15:27:05 -0800
Subject: [PATCH] Add an IFUNC testcase for [BZ #20019]

When the IFUNC relocation is performed before the providing shared
library is unrelocated, the returned function address will be 0 and
program will segfault when the function is called.  Add a testcase
to verify that ld.so issues a diagnostic.

	[BZ #20019]
	* elf/Makefile (modules-names): Add tst-ifuncmod1a,
	tst-ifuncmod1b, tst-ifuncmod1c and tst-ifuncmod1d.
	(tests): Add tst-ifunc1.
	(tests-special): Add $(objpfx)tst-ifunc1.out.
	($(objpfx)tst-ifunc1.out): New rule.
	($(objpfx)tst-ifunc1): New dependency.
	($(objpfx)tst-ifuncmod1a.so): LIkewise.
	($(objpfx)tst-ifuncmod1b.so): LIkewise.
	($(objpfx)tst-ifuncmod1c.so): LIkewise.
	(LDFLAGS-tst-ifuncmod1b.so): New.
	* elf/tst-ifunc1.c: New file.
	* elf/tst-ifunc1.sh: LIkewise.
	* elf/tst-ifuncmod1a.c: LIkewise.
	* elf/tst-ifuncmod1b.c: LIkewise.
	* elf/tst-ifuncmod1c.c: LIkewise.
	* elf/tst-ifuncmod1d.c: LIkewise.
	* sysdeps/generic/ldsodefs.h (dl_check_ifunc_resolver): New
	function.
	* sysdeps/i386/dl-machine.h (elf_machine_rel): Use it.
	* sysdeps/x86_64/dl-machine.h (elf_machine_rela): LIkewise.
---
 elf/Makefile                | 19 +++++++++++++++++--
 elf/tst-ifunc1.c            | 26 ++++++++++++++++++++++++++
 elf/tst-ifunc1.sh           | 43 +++++++++++++++++++++++++++++++++++++++++++
 elf/tst-ifuncmod1a.c        | 25 +++++++++++++++++++++++++
 elf/tst-ifuncmod1b.c        | 25 +++++++++++++++++++++++++
 elf/tst-ifuncmod1c.c        | 27 +++++++++++++++++++++++++++
 elf/tst-ifuncmod1d.c        | 24 ++++++++++++++++++++++++
 sysdeps/generic/ldsodefs.h  | 26 ++++++++++++++++++++++++++
 sysdeps/i386/dl-machine.h   | 13 +------------
 sysdeps/x86_64/dl-machine.h | 13 +------------
 10 files changed, 215 insertions(+), 26 deletions(-)
 create mode 100644 elf/tst-ifunc1.c
 create mode 100755 elf/tst-ifunc1.sh
 create mode 100644 elf/tst-ifuncmod1a.c
 create mode 100644 elf/tst-ifuncmod1b.c
 create mode 100644 elf/tst-ifuncmod1c.c
 create mode 100644 elf/tst-ifuncmod1d.c

diff --git a/elf/Makefile b/elf/Makefile
index c7a2969..259362d 100644
--- a/elf/Makefile
+++ b/elf/Makefile
@@ -307,9 +307,11 @@  tests += ifuncmain1 ifuncmain1pic ifuncmain1vis ifuncmain1vispic \
 	 ifuncmain1staticpic \
 	 ifuncmain2 ifuncmain2pic ifuncmain3 ifuncmain4 \
 	 ifuncmain5 ifuncmain5pic ifuncmain5staticpic \
-	 ifuncmain7 ifuncmain7pic
+	 ifuncmain7 ifuncmain7pic tst-ifunc1
+tests-special += $(objpfx)tst-ifunc1.out
 ifunc-test-modules = ifuncdep1 ifuncdep1pic ifuncdep2 ifuncdep2pic \
-		     ifuncdep5 ifuncdep5pic
+		     ifuncdep5 ifuncdep5pic tst-ifuncmod1a \
+		     tst-ifuncmod1b tst-ifuncmod1c tst-ifuncmod1d
 extra-test-objs += $(ifunc-test-modules:=.o)
 test-extras += $(ifunc-test-modules)
 ifeq (yes,$(have-fpie))
@@ -1026,6 +1028,19 @@  CFLAGS-tst-pie2.c += $(pie-ccflag)
 $(objpfx)tst-piemod1.so: $(libsupport)
 $(objpfx)tst-pie1: $(objpfx)tst-piemod1.so
 
+$(objpfx)tst-ifunc1.out: tst-ifunc1.sh $(objpfx)tst-ifunc1
+	$(BASH) $< $(objpfx) '$(test-via-rtld-prefix)' \
+	  '$(test-wrapper-env)' '$(run-program-env)'; \
+	$(evaluate-test)
+
+$(objpfx)tst-ifunc1: $(objpfx)tst-ifuncmod1a.so \
+		     $(objpfx)tst-ifuncmod1c.so \
+		     $(objpfx)tst-ifuncmod1d.so
+$(objpfx)tst-ifuncmod1a.so: $(objpfx)tst-ifuncmod1b.so
+$(objpfx)tst-ifuncmod1b.so: $(objpfx)tst-ifuncmod1d.so
+$(objpfx)tst-ifuncmod1c.so: $(objpfx)tst-ifuncmod1d.so
+LDFLAGS-tst-ifuncmod1b.so = -Wl,-z,now
+
 ifeq (yes,$(build-shared))
 all-built-dso := $(common-objpfx)elf/ld.so $(common-objpfx)libc.so \
 		 $(filter-out $(common-objpfx)linkobj/libc.so, \
diff --git a/elf/tst-ifunc1.c b/elf/tst-ifunc1.c
new file mode 100644
index 0000000..e44dbc3
--- /dev/null
+++ b/elf/tst-ifunc1.c
@@ -0,0 +1,26 @@ 
+/* Test case for unsafe IFUNC resolver.
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+extern void foo (void);
+
+int
+main (void)
+{
+  foo ();
+  return 0;
+}
diff --git a/elf/tst-ifunc1.sh b/elf/tst-ifunc1.sh
new file mode 100755
index 0000000..e523b44
--- /dev/null
+++ b/elf/tst-ifunc1.sh
@@ -0,0 +1,43 @@ 
+#!/bin/bash
+# A Test case for unsafe IFUNC resolver.
+# Copyright (C) 2017 Free Software Foundation, Inc.
+# This file is part of the GNU C Library.
+
+# The GNU C Library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+
+# The GNU C Library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+
+# You should have received a copy of the GNU Lesser General Public
+# License along with the GNU C Library; if not, see
+# <http://www.gnu.org/licenses/>.
+
+set -e
+
+objpfx=$1; shift
+test_via_rtld_prefix=$1; shift
+test_wrapper_env=$1; shift
+run_program_env=$1; shift
+logfile=${objpfx}tst-ifunc1.out
+
+> $logfile
+fail=0
+
+${test_wrapper_env} \
+${run_program_env} \
+${objpfx}tst-ifunc1 2>&1 || fail=1
+
+if test $fail = 1; then
+  # If it fails to run, check for the expected error from ld.so.
+  fail=0
+  ${test_wrapper_env} \
+  ${run_program_env} \
+  ${objpfx}tst-ifunc1 2>&1 | grep Relink >> $logfile || fail=1
+fi
+
+exit $fail
diff --git a/elf/tst-ifuncmod1a.c b/elf/tst-ifuncmod1a.c
new file mode 100644
index 0000000..5e2183c
--- /dev/null
+++ b/elf/tst-ifuncmod1a.c
@@ -0,0 +1,25 @@ 
+/* Test case for unsafe IFUNC resolver.
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+extern void bar (void);
+
+void
+foo (void)
+{
+  bar ();
+}
diff --git a/elf/tst-ifuncmod1b.c b/elf/tst-ifuncmod1b.c
new file mode 100644
index 0000000..0c6fe10
--- /dev/null
+++ b/elf/tst-ifuncmod1b.c
@@ -0,0 +1,25 @@ 
+/* Test case for unsafe IFUNC resolver.
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+extern void xxx (void);
+
+void
+bar (void)
+{
+  xxx ();
+}
diff --git a/elf/tst-ifuncmod1c.c b/elf/tst-ifuncmod1c.c
new file mode 100644
index 0000000..81cd31c
--- /dev/null
+++ b/elf/tst-ifuncmod1c.c
@@ -0,0 +1,27 @@ 
+/* Test case for unsafe IFUNC resolver.
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+extern void real_xxx (void);
+
+static void *
+xxx_resolver (void)
+{
+  return &real_xxx;
+}
+
+extern void xxx (void) __attribute__ ((ifunc ("xxx_resolver")));
diff --git a/elf/tst-ifuncmod1d.c b/elf/tst-ifuncmod1d.c
new file mode 100644
index 0000000..5715ded
--- /dev/null
+++ b/elf/tst-ifuncmod1d.c
@@ -0,0 +1,24 @@ 
+/* Test case for unsafe IFUNC resolver.
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+void
+xxx (void)
+{
+}
+
+__typeof (xxx) real_xxx __attribute__ ((alias("xxx")));
diff --git a/sysdeps/generic/ldsodefs.h b/sysdeps/generic/ldsodefs.h
index f26a8b2..0c53c70 100644
--- a/sysdeps/generic/ldsodefs.h
+++ b/sysdeps/generic/ldsodefs.h
@@ -1085,6 +1085,32 @@  extern void _dl_non_dynamic_init (void) internal_function;
 extern void _dl_aux_init (ElfW(auxv_t) *av) internal_function;
 
 
+# ifdef STDERR_FILENO
+/* Define here after RTLD_PROGNAME is defined and if STDERR_FILENO is
+   defined.  Since it is unsafe for IFUNC resolver to reference external
+   symbols, issue a fatal error when it happens.  */
+static __always_inline void
+dl_check_ifunc_resolver (struct link_map *sym_map, struct link_map *map,
+			 const ElfW(Sym) *const refsym)
+{
+  if (sym_map != map
+      && sym_map->l_type != lt_executable
+      && !sym_map->l_relocated)
+    {
+      const char *strtab
+	= (const char *) D_PTR (map, l_info[DT_STRTAB]);
+      _dl_fatal_printf ("\
+%s: Relink `%s' with `%s' or place `%s' before `%s' for IFUNC symbol `%s'\n",
+			RTLD_PROGNAME,
+			map->l_libname->name,
+			sym_map->l_libname->name,
+			sym_map->l_libname->name,
+			map->l_libname->name,
+			strtab + refsym->st_name);
+    }
+}
+# endif
+
 __END_DECLS
 
 #endif /* ldsodefs.h */
diff --git a/sysdeps/i386/dl-machine.h b/sysdeps/i386/dl-machine.h
index 6eca69d..b13d97c 100644
--- a/sysdeps/i386/dl-machine.h
+++ b/sysdeps/i386/dl-machine.h
@@ -323,18 +323,7 @@  elf_machine_rel (struct link_map *map, const Elf32_Rel *reloc,
 	  && __builtin_expect (!skip_ifunc, 1))
 	{
 # ifndef RTLD_BOOTSTRAP
-	  if (sym_map != map
-	      && sym_map->l_type != lt_executable
-	      && !sym_map->l_relocated)
-	    {
-	      const char *strtab
-		= (const char *) D_PTR (map, l_info[DT_STRTAB]);
-	      _dl_fatal_printf ("\
-%s: Relink `%s' with `%s' for IFUNC symbol `%s'\n",
-				RTLD_PROGNAME, map->l_name,
-				sym_map->l_name,
-				strtab + refsym->st_name);
-	    }
+	  dl_check_ifunc_resolver (sym_map, map, refsym);
 # endif
 	  value = ((Elf32_Addr (*) (void)) value) ();
 	}
diff --git a/sysdeps/x86_64/dl-machine.h b/sysdeps/x86_64/dl-machine.h
index 3e7ae22..5737955 100644
--- a/sysdeps/x86_64/dl-machine.h
+++ b/sysdeps/x86_64/dl-machine.h
@@ -333,18 +333,7 @@  elf_machine_rela (struct link_map *map, const ElfW(Rela) *reloc,
 	  && __builtin_expect (!skip_ifunc, 1))
 	{
 # ifndef RTLD_BOOTSTRAP
-	  if (sym_map != map
-	      && sym_map->l_type != lt_executable
-	      && !sym_map->l_relocated)
-	    {
-	      const char *strtab
-		= (const char *) D_PTR (map, l_info[DT_STRTAB]);
-	      _dl_fatal_printf ("\
-%s: Relink `%s' with `%s' for IFUNC symbol `%s'\n",
-				RTLD_PROGNAME, map->l_name,
-				sym_map->l_name,
-				strtab + refsym->st_name);
-	    }
+	  dl_check_ifunc_resolver (sym_map, map, refsym);
 # endif
 	  value = ((ElfW(Addr) (*) (void)) value) ();
 	}
-- 
2.9.3