diff mbox series

[2/2] ld.so: Hide _r_debug to support DT_DEBUG [BZ #28130]

Message ID 20210802042940.932692-2-hjl.tools@gmail.com
State Superseded
Headers show
Series [1/2] Map ABI/VERSION of rtld to ABI/VERSION of ld [BZ #28132] | expand

Checks

Context Check Description
dj/TryBot-apply_patch success Patch applied to master at the time it was sent
dj/TryBot-32bit success Build for i686

Commit Message

H.J. Lu Aug. 2, 2021, 4:29 a.m. UTC
<link.h> has

extern struct r_debug _r_debug;

which is exported from ld.so.  rtld.c has

  /* Initialize _r_debug.  */
  struct r_debug *r = _dl_debug_initialize (GL(dl_rtld_map).l_addr,
                                            LM_ID_BASE);
...
  if (main_map->l_info[DT_DEBUG] != NULL)
    /* There is a DT_DEBUG entry in the dynamic section.  Fill it in
       with the run-time address of the r_debug structure  */
    main_map->l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r;

With COPY relocation, the address of _r_debug at run-time may be in the
executable if it references _r_debug.  Since debugger uses DT_DEBUG, it
will reference the staled original definition of _r_debug in ld.so.

1. Add a function, __r_debug_location, which returns the address of
_r_debug:

/* Return the address of that structure used by the dynamic linker.  */
extern struct r_debug * __r_debug_location (void) __attribute_const__;

It has a special glibc version, GLIBC_DEBUG.

2. Hide _r_debug in ld.so by defining _r_debug with __r_debug_location:

 #define _r_debug (*__r_debug_location ())

The existing dynamic executables with _r_debug reference will get a copy
of _r_debug which won't be updated by ld.so.  But DT_DEBUG will work with
debuggers.
3. The static executables linked against glibc 2.35 will get the _r_debug
symbol from __r_debug_location definition in libc.a.

This fixes BZ #28130.
---
 elf/Makefile                                  | 14 +++-
 elf/Versions                                  |  4 ++
 elf/dl-debug.c                                | 23 ++++--
 elf/link.h                                    |  5 +-
 elf/tst-dlopen-static.c                       | 71 +++++++++++++++++++
 sysdeps/mach/hurd/i386/ld.abilist             |  1 +
 sysdeps/unix/sysv/linux/aarch64/ld.abilist    |  1 +
 sysdeps/unix/sysv/linux/alpha/ld.abilist      |  1 +
 sysdeps/unix/sysv/linux/arc/ld.abilist        |  1 +
 sysdeps/unix/sysv/linux/arm/be/ld.abilist     |  1 +
 sysdeps/unix/sysv/linux/arm/le/ld.abilist     |  1 +
 sysdeps/unix/sysv/linux/csky/ld.abilist       |  1 +
 sysdeps/unix/sysv/linux/hppa/ld.abilist       |  1 +
 sysdeps/unix/sysv/linux/i386/ld.abilist       |  1 +
 sysdeps/unix/sysv/linux/ia64/ld.abilist       |  1 +
 .../unix/sysv/linux/m68k/coldfire/ld.abilist  |  1 +
 .../unix/sysv/linux/m68k/m680x0/ld.abilist    |  1 +
 sysdeps/unix/sysv/linux/microblaze/ld.abilist |  1 +
 .../unix/sysv/linux/mips/mips32/ld.abilist    |  1 +
 .../sysv/linux/mips/mips64/n32/ld.abilist     |  1 +
 .../sysv/linux/mips/mips64/n64/ld.abilist     |  1 +
 sysdeps/unix/sysv/linux/nios2/ld.abilist      |  1 +
 .../sysv/linux/powerpc/powerpc32/ld.abilist   |  1 +
 .../linux/powerpc/powerpc64/be/ld.abilist     |  1 +
 .../linux/powerpc/powerpc64/le/ld.abilist     |  1 +
 sysdeps/unix/sysv/linux/riscv/rv32/ld.abilist |  1 +
 sysdeps/unix/sysv/linux/riscv/rv64/ld.abilist |  1 +
 .../unix/sysv/linux/s390/s390-32/ld.abilist   |  1 +
 .../unix/sysv/linux/s390/s390-64/ld.abilist   |  1 +
 sysdeps/unix/sysv/linux/sh/be/ld.abilist      |  1 +
 sysdeps/unix/sysv/linux/sh/le/ld.abilist      |  1 +
 .../unix/sysv/linux/sparc/sparc32/ld.abilist  |  1 +
 .../unix/sysv/linux/sparc/sparc64/ld.abilist  |  1 +
 sysdeps/unix/sysv/linux/x86_64/64/ld.abilist  |  1 +
 sysdeps/unix/sysv/linux/x86_64/x32/ld.abilist |  1 +
 35 files changed, 139 insertions(+), 8 deletions(-)
 create mode 100644 elf/tst-dlopen-static.c

Comments

Andreas Schwab Aug. 2, 2021, 1:29 p.m. UTC | #1
On Aug 01 2021, H.J. Lu via Libc-alpha wrote:

> 1. Add a function, __r_debug_location, which returns the address of
> _r_debug:
>
> /* Return the address of that structure used by the dynamic linker.  */
> extern struct r_debug * __r_debug_location (void) __attribute_const__;
>
> It has a special glibc version, GLIBC_DEBUG.
>
> 2. Hide _r_debug in ld.so by defining _r_debug with __r_debug_location:
>
>  #define _r_debug (*__r_debug_location ())

There is no need for that.  Nobody should be using _r_debug.

Andreas.
H.J. Lu Aug. 2, 2021, 8:43 p.m. UTC | #2
On Mon, Aug 2, 2021 at 6:29 AM Andreas Schwab <schwab@linux-m68k.org> wrote:
>
> On Aug 01 2021, H.J. Lu via Libc-alpha wrote:
>
> > 1. Add a function, __r_debug_location, which returns the address of
> > _r_debug:
> >
> > /* Return the address of that structure used by the dynamic linker.  */
> > extern struct r_debug * __r_debug_location (void) __attribute_const__;
> >
> > It has a special glibc version, GLIBC_DEBUG.
> >
> > 2. Hide _r_debug in ld.so by defining _r_debug with __r_debug_location:
> >
> >  #define _r_debug (*__r_debug_location ())
>
> There is no need for that.  Nobody should be using _r_debug.
>

Removed from the v2 patch.
Florian Weimer Aug. 2, 2021, 9:19 p.m. UTC | #3
* Andreas Schwab:

> On Aug 01 2021, H.J. Lu via Libc-alpha wrote:
>
>> 1. Add a function, __r_debug_location, which returns the address of
>> _r_debug:
>>
>> /* Return the address of that structure used by the dynamic linker.  */
>> extern struct r_debug * __r_debug_location (void) __attribute_const__;
>>
>> It has a special glibc version, GLIBC_DEBUG.
>>
>> 2. Hide _r_debug in ld.so by defining _r_debug with __r_debug_location:
>>
>>  #define _r_debug (*__r_debug_location ())
>
> There is no need for that.  Nobody should be using _r_debug.

It's declared in a public header.  GNAT and Spindle use it.  Maybe this
needs to be deprecated first before it can be removed.

Thanks,
Florian
H.J. Lu Aug. 2, 2021, 9:46 p.m. UTC | #4
On Mon, Aug 2, 2021 at 2:20 PM Florian Weimer via Libc-alpha
<libc-alpha@sourceware.org> wrote:
>
> * Andreas Schwab:
>
> > On Aug 01 2021, H.J. Lu via Libc-alpha wrote:
> >
> >> 1. Add a function, __r_debug_location, which returns the address of
> >> _r_debug:
> >>
> >> /* Return the address of that structure used by the dynamic linker.  */
> >> extern struct r_debug * __r_debug_location (void) __attribute_const__;
> >>
> >> It has a special glibc version, GLIBC_DEBUG.
> >>
> >> 2. Hide _r_debug in ld.so by defining _r_debug with __r_debug_location:
> >>
> >>  #define _r_debug (*__r_debug_location ())
> >
> > There is no need for that.  Nobody should be using _r_debug.
>
> It's declared in a public header.  GNAT and Spindle use it.  Maybe this

It is wrong to use it to begin with.

> needs to be deprecated first before it can be removed.

My v2 patch includes an alternative in libsupport.
H.J. Lu Aug. 2, 2021, 11:06 p.m. UTC | #5
On Mon, Aug 2, 2021 at 2:46 PM H.J. Lu <hjl.tools@gmail.com> wrote:
>
> On Mon, Aug 2, 2021 at 2:20 PM Florian Weimer via Libc-alpha
> <libc-alpha@sourceware.org> wrote:
> >
> > * Andreas Schwab:
> >
> > > On Aug 01 2021, H.J. Lu via Libc-alpha wrote:
> > >
> > >> 1. Add a function, __r_debug_location, which returns the address of
> > >> _r_debug:
> > >>
> > >> /* Return the address of that structure used by the dynamic linker.  */
> > >> extern struct r_debug * __r_debug_location (void) __attribute_const__;
> > >>
> > >> It has a special glibc version, GLIBC_DEBUG.
> > >>
> > >> 2. Hide _r_debug in ld.so by defining _r_debug with __r_debug_location:
> > >>
> > >>  #define _r_debug (*__r_debug_location ())
> > >
> > > There is no need for that.  Nobody should be using _r_debug.
> >
> > It's declared in a public header.  GNAT and Spindle use it.  Maybe this
>
> It is wrong to use it to begin with.

We need to support usages of _r_debug for some applications.

extern struct r_debug * __r_debug_location (void) __attribute_const__;
#define _r_debug (*__r_debug_location ())

works here.

> > needs to be deprecated first before it can be removed.
>
> My v2 patch includes an alternative in libsupport.
>
> --
> H.J.
diff mbox series

Patch

diff --git a/elf/Makefile b/elf/Makefile
index d05f410592..8fad633d2c 100644
--- a/elf/Makefile
+++ b/elf/Makefile
@@ -187,11 +187,14 @@  tests-internal := tst-tls1 tst-tls2 $(tests-static-internal)
 tests-static := $(tests-static-normal) $(tests-static-internal)
 
 ifeq (yes,$(build-shared))
-tests-static += tst-tls9-static tst-single_threaded-static-dlopen
+tests-static += tst-tls9-static tst-single_threaded-static-dlopen \
+	tst-dlopen-static
+tests-special += $(objpfx)tst-dlopen-static-_r_debug.out
 static-dlopen-environment = \
   LD_LIBRARY_PATH=$(ld-library-path):$(common-objpfx)dlfcn
 tst-tls9-static-ENV = $(static-dlopen-environment)
 tst-single_threaded-static-dlopen-ENV = $(static-dlopen-environment)
+tst-dlopen-static-ENV = $(static-dlopen-environment)
 
 tests += restest1 preloadtest loadfail multiload origtest resolvfail \
 	 constload1 order noload filter \
@@ -609,6 +612,8 @@  $(objpfx)ld.so: $(objpfx)librtld.os $(ld-map)
 	$(call after-link,$@.new)
 	$(READELF) -s $@.new \
 	  | $(AWK) '($$7 ~ /^UND(|EF)$$/ && $$1 != "0:" && $$4 != "REGISTER") { print; p=1 } END { exit p != 0 }'
+	$(READELF) -rW $@.new \
+	  | $(AWK) '($$5 ~/_r_debug/) { print; p=1 } END { exit p != 0 }'
 	mv -f $@.new $@
 
 ifeq (yes,$(build-shared))
@@ -1710,6 +1715,13 @@  $(objpfx)tst-single_threaded-pthread.out: \
   $(objpfx)tst-single_threaded-mod4.so
 $(objpfx)tst-single_threaded-pthread-static: $(static-thread-library)
 
+$(objpfx)tst-dlopen-static: $(objpfx)tst-single_threaded-mod1.o
+$(objpfx)tst-dlopen-static.out: $(objpfx)tst-single_threaded-mod2.so
+$(objpfx)tst-dlopen-static-_r_debug.out: $(objpfx)tst-dlopen-static
+	$(READELF) -sW $< \
+	  | $(AWK) '($$8 ~ /_r_debug$$/) { print; p=1 } END { exit p == 0 }' > $@
+	$(evaluate-test)
+
 $(objpfx)tst-tls-ie: $(shared-thread-library)
 $(objpfx)tst-tls-ie.out: \
   $(objpfx)tst-tls-ie-mod0.so \
diff --git a/elf/Versions b/elf/Versions
index 775aab62af..75170f2ebc 100644
--- a/elf/Versions
+++ b/elf/Versions
@@ -48,6 +48,10 @@  ld {
     # stack canary
     __stack_chk_guard;
   }
+  GLIBC_DEBUG {
+    # Adddess of _r_debug
+    __r_debug_location;
+  }
   GLIBC_PRIVATE {
     # Those are in the dynamic linker, but used by libc.so.
     __libc_enable_secure;
diff --git a/elf/dl-debug.c b/elf/dl-debug.c
index 2cd5f09753..6ae9d7839f 100644
--- a/elf/dl-debug.c
+++ b/elf/dl-debug.c
@@ -17,7 +17,7 @@ 
    <https://www.gnu.org/licenses/>.  */
 
 #include <ldsodefs.h>
-
+#include <shlib-compat.h>
 
 /* These are the members in the public `struct link_map' type.
    Sanity check that the internal type and the public type match.  */
@@ -34,11 +34,19 @@  extern const int verify_link_map_members[(VERIFY_MEMBER (l_addr)
    normally finds it via the DT_DEBUG entry in the dynamic section, but in
    a statically-linked program there is no dynamic section for the debugger
    to examine and it looks for this particular symbol name.  */
+#undef _r_debug
 struct r_debug _r_debug;
 
+extern struct r_debug _r_debug_internal attribute_hidden;
+strong_alias (_r_debug, _r_debug_internal)
+
+#if SHLIB_COMPAT (rtld, GLIBC_2_0, GLIBC_2_34)
+strong_alias (_r_debug, _r_debug_compat)
+compat_symbol (rtld, _r_debug_compat, _r_debug, GLIBC_2_0);
+#endif
 
-/* Initialize _r_debug if it has not already been done.  The argument is
-   the run-time load address of the dynamic linker, to be put in
+/* Initialize _r_debug if it has not already been done.  The argument
+   is the run-time load address of the dynamic linker, to be put in
    _r_debug.r_ldbase.  Returns the address of _r_debug.  */
 
 struct r_debug *
@@ -47,7 +55,7 @@  _dl_debug_initialize (ElfW(Addr) ldbase, Lmid_t ns)
   struct r_debug *r;
 
   if (ns == LM_ID_BASE)
-    r = &_r_debug;
+    r = &_r_debug_internal;
   else
     r = &GL(dl_ns)[ns]._ns_debug;
 
@@ -55,7 +63,7 @@  _dl_debug_initialize (ElfW(Addr) ldbase, Lmid_t ns)
     {
       /* Tell the debugger where to find the map of loaded objects.  */
       r->r_version = 1	/* R_DEBUG_VERSION XXX */;
-      r->r_ldbase = ldbase ?: _r_debug.r_ldbase;
+      r->r_ldbase = ldbase ?: _r_debug_internal.r_ldbase;
       r->r_map = (void *) GL(dl_ns)[ns]._ns_loaded;
       r->r_brk = (ElfW(Addr)) &_dl_debug_state;
     }
@@ -63,6 +71,11 @@  _dl_debug_initialize (ElfW(Addr) ldbase, Lmid_t ns)
   return r;
 }
 
+struct r_debug *
+__r_debug_location (void)
+{
+  return &_r_debug_internal;
+}
 
 /* This function exists solely to have a breakpoint set on it by the
    debugger.  The debugger is supposed to find this function's address by
diff --git a/elf/link.h b/elf/link.h
index ff3a85c847..17477a2409 100644
--- a/elf/link.h
+++ b/elf/link.h
@@ -63,8 +63,9 @@  struct r_debug
     ElfW(Addr) r_ldbase;	/* Base address the linker is loaded at.  */
   };
 
-/* This is the instance of that structure used by the dynamic linker.  */
-extern struct r_debug _r_debug;
+/* Return the address of that structure used by the dynamic linker.  */
+extern struct r_debug * __r_debug_location (void) __attribute_const__;
+#define _r_debug (*__r_debug_location ())
 
 /* This symbol refers to the "dynamic structure" in the `.dynamic' section
    of whatever module refers to `_DYNAMIC'.  So, to find its own
diff --git a/elf/tst-dlopen-static.c b/elf/tst-dlopen-static.c
new file mode 100644
index 0000000000..e9e06c0873
--- /dev/null
+++ b/elf/tst-dlopen-static.c
@@ -0,0 +1,71 @@ 
+/* Test static dlopen with _r_debug.
+   Copyright (C) 2021 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
+   <https://www.gnu.org/licenses/>.  */
+
+#include <stddef.h>
+#include <stdio.h>
+#include <string.h>
+#include <link.h>
+#include <support/check.h>
+#include <support/xdlfcn.h>
+#include <sys/single_threaded.h>
+
+static int
+do_test (void)
+{
+  TEST_VERIFY (__libc_single_threaded);
+
+  /* Defined in tst-single-threaded-mod1.o.  */
+  extern _Bool single_threaded_1 (void);
+  TEST_VERIFY (single_threaded_1 ());
+
+  /* A failed dlopen does not change the multi-threaded status.  */
+  TEST_VERIFY (dlopen ("tst-single_threaded-does-not-exist.so", RTLD_LAZY)
+               == NULL);
+  TEST_VERIFY (__libc_single_threaded);
+  TEST_VERIFY (single_threaded_1 ());
+
+  /* And neither does a successful dlopen for outer (static) libc.  */
+  const char *mod2 = "tst-single_threaded-mod2.so";
+  void *handle_mod2 = xdlopen (mod2, RTLD_LAZY);
+  _Bool (*single_threaded_2) (void)
+    = xdlsym (handle_mod2, "single_threaded_2");
+  TEST_VERIFY (__libc_single_threaded);
+  TEST_VERIFY (single_threaded_1 ());
+  /* The inner libc always assumes multi-threaded use.  */
+  TEST_VERIFY (!single_threaded_2 ());
+
+  /* Check the working _r_debug.  */
+  struct link_map *map;
+  int missing_mod2 = 1;
+  for (map = _r_debug.r_map; map != NULL; map = map->l_next)
+    {
+      const char *name = basename (map->l_name);
+      printf ("module name = '%s'\n", name);
+      if (strcmp (mod2, name) == 0)
+	missing_mod2 = 0;
+    }
+
+  if (missing_mod2)
+    FAIL_EXIT1 ("'%s' is missing in _r_debug\n", mod2);
+
+  xdlclose (handle_mod2);
+
+  return 0;
+}
+
+#include <support/test-driver.c>
diff --git a/sysdeps/mach/hurd/i386/ld.abilist b/sysdeps/mach/hurd/i386/ld.abilist
index 7e20c5e7ce..787f3823d2 100644
--- a/sysdeps/mach/hurd/i386/ld.abilist
+++ b/sysdeps/mach/hurd/i386/ld.abilist
@@ -16,3 +16,4 @@  GLIBC_2.2.6 _r_debug D 0x14
 GLIBC_2.2.6 abort F
 GLIBC_2.3 ___tls_get_addr F
 GLIBC_2.3 __tls_get_addr F
+GLIBC_DEBUG __r_debug_location F
diff --git a/sysdeps/unix/sysv/linux/aarch64/ld.abilist b/sysdeps/unix/sysv/linux/aarch64/ld.abilist
index 80b2fe6725..7f9f98d82b 100644
--- a/sysdeps/unix/sysv/linux/aarch64/ld.abilist
+++ b/sysdeps/unix/sysv/linux/aarch64/ld.abilist
@@ -3,3 +3,4 @@  GLIBC_2.17 __stack_chk_guard D 0x8
 GLIBC_2.17 __tls_get_addr F
 GLIBC_2.17 _dl_mcount F
 GLIBC_2.17 _r_debug D 0x28
+GLIBC_DEBUG __r_debug_location F
diff --git a/sysdeps/unix/sysv/linux/alpha/ld.abilist b/sysdeps/unix/sysv/linux/alpha/ld.abilist
index 98a03f611f..df2c12874b 100644
--- a/sysdeps/unix/sysv/linux/alpha/ld.abilist
+++ b/sysdeps/unix/sysv/linux/alpha/ld.abilist
@@ -3,3 +3,4 @@  GLIBC_2.1 __libc_stack_end D 0x8
 GLIBC_2.1 _dl_mcount F
 GLIBC_2.3 __tls_get_addr F
 GLIBC_2.4 __stack_chk_guard D 0x8
+GLIBC_DEBUG __r_debug_location F
diff --git a/sysdeps/unix/sysv/linux/arc/ld.abilist b/sysdeps/unix/sysv/linux/arc/ld.abilist
index 048f17c848..2ef94c4b0c 100644
--- a/sysdeps/unix/sysv/linux/arc/ld.abilist
+++ b/sysdeps/unix/sysv/linux/arc/ld.abilist
@@ -3,3 +3,4 @@  GLIBC_2.32 __stack_chk_guard D 0x4
 GLIBC_2.32 __tls_get_addr F
 GLIBC_2.32 _dl_mcount F
 GLIBC_2.32 _r_debug D 0x14
+GLIBC_DEBUG __r_debug_location F
diff --git a/sysdeps/unix/sysv/linux/arm/be/ld.abilist b/sysdeps/unix/sysv/linux/arm/be/ld.abilist
index cc8825c3bc..20fe887a08 100644
--- a/sysdeps/unix/sysv/linux/arm/be/ld.abilist
+++ b/sysdeps/unix/sysv/linux/arm/be/ld.abilist
@@ -3,3 +3,4 @@  GLIBC_2.4 __stack_chk_guard D 0x4
 GLIBC_2.4 __tls_get_addr F
 GLIBC_2.4 _dl_mcount F
 GLIBC_2.4 _r_debug D 0x14
+GLIBC_DEBUG __r_debug_location F
diff --git a/sysdeps/unix/sysv/linux/arm/le/ld.abilist b/sysdeps/unix/sysv/linux/arm/le/ld.abilist
index cc8825c3bc..20fe887a08 100644
--- a/sysdeps/unix/sysv/linux/arm/le/ld.abilist
+++ b/sysdeps/unix/sysv/linux/arm/le/ld.abilist
@@ -3,3 +3,4 @@  GLIBC_2.4 __stack_chk_guard D 0x4
 GLIBC_2.4 __tls_get_addr F
 GLIBC_2.4 _dl_mcount F
 GLIBC_2.4 _r_debug D 0x14
+GLIBC_DEBUG __r_debug_location F
diff --git a/sysdeps/unix/sysv/linux/csky/ld.abilist b/sysdeps/unix/sysv/linux/csky/ld.abilist
index 564ac09737..f81f677ac2 100644
--- a/sysdeps/unix/sysv/linux/csky/ld.abilist
+++ b/sysdeps/unix/sysv/linux/csky/ld.abilist
@@ -3,3 +3,4 @@  GLIBC_2.29 __stack_chk_guard D 0x4
 GLIBC_2.29 __tls_get_addr F
 GLIBC_2.29 _dl_mcount F
 GLIBC_2.29 _r_debug D 0x14
+GLIBC_DEBUG __r_debug_location F
diff --git a/sysdeps/unix/sysv/linux/hppa/ld.abilist b/sysdeps/unix/sysv/linux/hppa/ld.abilist
index d155a59843..04eddb99b4 100644
--- a/sysdeps/unix/sysv/linux/hppa/ld.abilist
+++ b/sysdeps/unix/sysv/linux/hppa/ld.abilist
@@ -3,3 +3,4 @@  GLIBC_2.2 _dl_mcount F
 GLIBC_2.2 _r_debug D 0x14
 GLIBC_2.3 __tls_get_addr F
 GLIBC_2.4 __stack_chk_guard D 0x4
+GLIBC_DEBUG __r_debug_location F
diff --git a/sysdeps/unix/sysv/linux/i386/ld.abilist b/sysdeps/unix/sysv/linux/i386/ld.abilist
index 0478e22071..7e5e14aaa9 100644
--- a/sysdeps/unix/sysv/linux/i386/ld.abilist
+++ b/sysdeps/unix/sysv/linux/i386/ld.abilist
@@ -3,3 +3,4 @@  GLIBC_2.1 __libc_stack_end D 0x4
 GLIBC_2.1 _dl_mcount F
 GLIBC_2.3 ___tls_get_addr F
 GLIBC_2.3 __tls_get_addr F
+GLIBC_DEBUG __r_debug_location F
diff --git a/sysdeps/unix/sysv/linux/ia64/ld.abilist b/sysdeps/unix/sysv/linux/ia64/ld.abilist
index 33f91199bf..60753bba7b 100644
--- a/sysdeps/unix/sysv/linux/ia64/ld.abilist
+++ b/sysdeps/unix/sysv/linux/ia64/ld.abilist
@@ -2,3 +2,4 @@  GLIBC_2.2 __libc_stack_end D 0x8
 GLIBC_2.2 _dl_mcount F
 GLIBC_2.2 _r_debug D 0x28
 GLIBC_2.3 __tls_get_addr F
+GLIBC_DEBUG __r_debug_location F
diff --git a/sysdeps/unix/sysv/linux/m68k/coldfire/ld.abilist b/sysdeps/unix/sysv/linux/m68k/coldfire/ld.abilist
index cc8825c3bc..20fe887a08 100644
--- a/sysdeps/unix/sysv/linux/m68k/coldfire/ld.abilist
+++ b/sysdeps/unix/sysv/linux/m68k/coldfire/ld.abilist
@@ -3,3 +3,4 @@  GLIBC_2.4 __stack_chk_guard D 0x4
 GLIBC_2.4 __tls_get_addr F
 GLIBC_2.4 _dl_mcount F
 GLIBC_2.4 _r_debug D 0x14
+GLIBC_DEBUG __r_debug_location F
diff --git a/sysdeps/unix/sysv/linux/m68k/m680x0/ld.abilist b/sysdeps/unix/sysv/linux/m68k/m680x0/ld.abilist
index 3ba474c27f..0120721413 100644
--- a/sysdeps/unix/sysv/linux/m68k/m680x0/ld.abilist
+++ b/sysdeps/unix/sysv/linux/m68k/m680x0/ld.abilist
@@ -3,3 +3,4 @@  GLIBC_2.1 __libc_stack_end D 0x4
 GLIBC_2.1 _dl_mcount F
 GLIBC_2.3 __tls_get_addr F
 GLIBC_2.4 __stack_chk_guard D 0x4
+GLIBC_DEBUG __r_debug_location F
diff --git a/sysdeps/unix/sysv/linux/microblaze/ld.abilist b/sysdeps/unix/sysv/linux/microblaze/ld.abilist
index a4933c3541..7ca079e207 100644
--- a/sysdeps/unix/sysv/linux/microblaze/ld.abilist
+++ b/sysdeps/unix/sysv/linux/microblaze/ld.abilist
@@ -3,3 +3,4 @@  GLIBC_2.18 __stack_chk_guard D 0x4
 GLIBC_2.18 __tls_get_addr F
 GLIBC_2.18 _dl_mcount F
 GLIBC_2.18 _r_debug D 0x14
+GLIBC_DEBUG __r_debug_location F
diff --git a/sysdeps/unix/sysv/linux/mips/mips32/ld.abilist b/sysdeps/unix/sysv/linux/mips/mips32/ld.abilist
index be09641a48..a25c73d95d 100644
--- a/sysdeps/unix/sysv/linux/mips/mips32/ld.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips32/ld.abilist
@@ -3,3 +3,4 @@  GLIBC_2.2 __libc_stack_end D 0x4
 GLIBC_2.2 _dl_mcount F
 GLIBC_2.3 __tls_get_addr F
 GLIBC_2.4 __stack_chk_guard D 0x4
+GLIBC_DEBUG __r_debug_location F
diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n32/ld.abilist b/sysdeps/unix/sysv/linux/mips/mips64/n32/ld.abilist
index be09641a48..a25c73d95d 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/n32/ld.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n32/ld.abilist
@@ -3,3 +3,4 @@  GLIBC_2.2 __libc_stack_end D 0x4
 GLIBC_2.2 _dl_mcount F
 GLIBC_2.3 __tls_get_addr F
 GLIBC_2.4 __stack_chk_guard D 0x4
+GLIBC_DEBUG __r_debug_location F
diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n64/ld.abilist b/sysdeps/unix/sysv/linux/mips/mips64/n64/ld.abilist
index 1ea36e13f2..0c93ebf0ca 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/n64/ld.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n64/ld.abilist
@@ -3,3 +3,4 @@  GLIBC_2.2 __libc_stack_end D 0x8
 GLIBC_2.2 _dl_mcount F
 GLIBC_2.3 __tls_get_addr F
 GLIBC_2.4 __stack_chk_guard D 0x8
+GLIBC_DEBUG __r_debug_location F
diff --git a/sysdeps/unix/sysv/linux/nios2/ld.abilist b/sysdeps/unix/sysv/linux/nios2/ld.abilist
index 52178802dd..63bef92e76 100644
--- a/sysdeps/unix/sysv/linux/nios2/ld.abilist
+++ b/sysdeps/unix/sysv/linux/nios2/ld.abilist
@@ -3,3 +3,4 @@  GLIBC_2.21 __stack_chk_guard D 0x4
 GLIBC_2.21 __tls_get_addr F
 GLIBC_2.21 _dl_mcount F
 GLIBC_2.21 _r_debug D 0x14
+GLIBC_DEBUG __r_debug_location F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/ld.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc32/ld.abilist
index 4bbfba7a61..9ddccbe46e 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/ld.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/ld.abilist
@@ -4,3 +4,4 @@  GLIBC_2.1 _dl_mcount F
 GLIBC_2.22 __tls_get_addr_opt F
 GLIBC_2.23 __parse_hwcap_and_convert_at_platform F
 GLIBC_2.3 __tls_get_addr F
+GLIBC_DEBUG __r_debug_location F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/ld.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/ld.abilist
index 283fb4510b..cf503ddbbf 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/ld.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/ld.abilist
@@ -4,3 +4,4 @@  GLIBC_2.3 __libc_stack_end D 0x8
 GLIBC_2.3 __tls_get_addr F
 GLIBC_2.3 _dl_mcount F
 GLIBC_2.3 _r_debug D 0x28
+GLIBC_DEBUG __r_debug_location F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/ld.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/ld.abilist
index b1f313c7cd..80c12fbf9d 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/ld.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/ld.abilist
@@ -4,3 +4,4 @@  GLIBC_2.17 _dl_mcount F
 GLIBC_2.17 _r_debug D 0x28
 GLIBC_2.22 __tls_get_addr_opt F
 GLIBC_2.23 __parse_hwcap_and_convert_at_platform F
+GLIBC_DEBUG __r_debug_location F
diff --git a/sysdeps/unix/sysv/linux/riscv/rv32/ld.abilist b/sysdeps/unix/sysv/linux/riscv/rv32/ld.abilist
index 94ca64c43d..8758f252b1 100644
--- a/sysdeps/unix/sysv/linux/riscv/rv32/ld.abilist
+++ b/sysdeps/unix/sysv/linux/riscv/rv32/ld.abilist
@@ -3,3 +3,4 @@  GLIBC_2.33 __stack_chk_guard D 0x4
 GLIBC_2.33 __tls_get_addr F
 GLIBC_2.33 _dl_mcount F
 GLIBC_2.33 _r_debug D 0x14
+GLIBC_DEBUG __r_debug_location F
diff --git a/sysdeps/unix/sysv/linux/riscv/rv64/ld.abilist b/sysdeps/unix/sysv/linux/riscv/rv64/ld.abilist
index 845f356c3c..57c5fab0e1 100644
--- a/sysdeps/unix/sysv/linux/riscv/rv64/ld.abilist
+++ b/sysdeps/unix/sysv/linux/riscv/rv64/ld.abilist
@@ -3,3 +3,4 @@  GLIBC_2.27 __stack_chk_guard D 0x8
 GLIBC_2.27 __tls_get_addr F
 GLIBC_2.27 _dl_mcount F
 GLIBC_2.27 _r_debug D 0x28
+GLIBC_DEBUG __r_debug_location F
diff --git a/sysdeps/unix/sysv/linux/s390/s390-32/ld.abilist b/sysdeps/unix/sysv/linux/s390/s390-32/ld.abilist
index b56f005beb..71f9172261 100644
--- a/sysdeps/unix/sysv/linux/s390/s390-32/ld.abilist
+++ b/sysdeps/unix/sysv/linux/s390/s390-32/ld.abilist
@@ -2,3 +2,4 @@  GLIBC_2.0 _r_debug D 0x14
 GLIBC_2.1 __libc_stack_end D 0x4
 GLIBC_2.1 _dl_mcount F
 GLIBC_2.3 __tls_get_offset F
+GLIBC_DEBUG __r_debug_location F
diff --git a/sysdeps/unix/sysv/linux/s390/s390-64/ld.abilist b/sysdeps/unix/sysv/linux/s390/s390-64/ld.abilist
index 6f788a086d..cc7fd7acf7 100644
--- a/sysdeps/unix/sysv/linux/s390/s390-64/ld.abilist
+++ b/sysdeps/unix/sysv/linux/s390/s390-64/ld.abilist
@@ -2,3 +2,4 @@  GLIBC_2.2 __libc_stack_end D 0x8
 GLIBC_2.2 _dl_mcount F
 GLIBC_2.2 _r_debug D 0x28
 GLIBC_2.3 __tls_get_offset F
+GLIBC_DEBUG __r_debug_location F
diff --git a/sysdeps/unix/sysv/linux/sh/be/ld.abilist b/sysdeps/unix/sysv/linux/sh/be/ld.abilist
index d155a59843..04eddb99b4 100644
--- a/sysdeps/unix/sysv/linux/sh/be/ld.abilist
+++ b/sysdeps/unix/sysv/linux/sh/be/ld.abilist
@@ -3,3 +3,4 @@  GLIBC_2.2 _dl_mcount F
 GLIBC_2.2 _r_debug D 0x14
 GLIBC_2.3 __tls_get_addr F
 GLIBC_2.4 __stack_chk_guard D 0x4
+GLIBC_DEBUG __r_debug_location F
diff --git a/sysdeps/unix/sysv/linux/sh/le/ld.abilist b/sysdeps/unix/sysv/linux/sh/le/ld.abilist
index d155a59843..04eddb99b4 100644
--- a/sysdeps/unix/sysv/linux/sh/le/ld.abilist
+++ b/sysdeps/unix/sysv/linux/sh/le/ld.abilist
@@ -3,3 +3,4 @@  GLIBC_2.2 _dl_mcount F
 GLIBC_2.2 _r_debug D 0x14
 GLIBC_2.3 __tls_get_addr F
 GLIBC_2.4 __stack_chk_guard D 0x4
+GLIBC_DEBUG __r_debug_location F
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc32/ld.abilist b/sysdeps/unix/sysv/linux/sparc/sparc32/ld.abilist
index 0c6610e3c2..7e4b112260 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc32/ld.abilist
+++ b/sysdeps/unix/sysv/linux/sparc/sparc32/ld.abilist
@@ -2,3 +2,4 @@  GLIBC_2.0 _r_debug D 0x14
 GLIBC_2.1 __libc_stack_end D 0x4
 GLIBC_2.1 _dl_mcount F
 GLIBC_2.3 __tls_get_addr F
+GLIBC_DEBUG __r_debug_location F
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/ld.abilist b/sysdeps/unix/sysv/linux/sparc/sparc64/ld.abilist
index 33f91199bf..60753bba7b 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc64/ld.abilist
+++ b/sysdeps/unix/sysv/linux/sparc/sparc64/ld.abilist
@@ -2,3 +2,4 @@  GLIBC_2.2 __libc_stack_end D 0x8
 GLIBC_2.2 _dl_mcount F
 GLIBC_2.2 _r_debug D 0x28
 GLIBC_2.3 __tls_get_addr F
+GLIBC_DEBUG __r_debug_location F
diff --git a/sysdeps/unix/sysv/linux/x86_64/64/ld.abilist b/sysdeps/unix/sysv/linux/x86_64/64/ld.abilist
index d3cdf7611e..dd92378ae1 100644
--- a/sysdeps/unix/sysv/linux/x86_64/64/ld.abilist
+++ b/sysdeps/unix/sysv/linux/x86_64/64/ld.abilist
@@ -2,3 +2,4 @@  GLIBC_2.2.5 __libc_stack_end D 0x8
 GLIBC_2.2.5 _dl_mcount F
 GLIBC_2.2.5 _r_debug D 0x28
 GLIBC_2.3 __tls_get_addr F
+GLIBC_DEBUG __r_debug_location F
diff --git a/sysdeps/unix/sysv/linux/x86_64/x32/ld.abilist b/sysdeps/unix/sysv/linux/x86_64/x32/ld.abilist
index c70bccf782..14d41ebcd9 100644
--- a/sysdeps/unix/sysv/linux/x86_64/x32/ld.abilist
+++ b/sysdeps/unix/sysv/linux/x86_64/x32/ld.abilist
@@ -2,3 +2,4 @@  GLIBC_2.16 __libc_stack_end D 0x4
 GLIBC_2.16 __tls_get_addr F
 GLIBC_2.16 _dl_mcount F
 GLIBC_2.16 _r_debug D 0x14
+GLIBC_DEBUG __r_debug_location F