elf: Fix elf_get_dynamic_info definition

Message ID 20211011191859.509946-1-adhemerval.zanella@linaro.org
State New
Headers show
Series
  • elf: Fix elf_get_dynamic_info definition
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Commit Message

Sunil K Pandey via Libc-alpha Oct. 11, 2021, 7:18 p.m.
Before 490e6c62aa31a8a ('elf: Avoid nested functions in the loader
[BZ #27220]') elf_get_dynamic_info were defined as 'auto' for
!RESOLVE_MAP (the default case).  Also, the function adds extra asserts
depending on whether is defined or not RTLD_BOOTSTRAP.

With the commit change, the function is now included and defined once
instead of defined as a nested function.  So rtld.c defines it when
including 'dynamic-link.h' without defining RTLD_BOOTSTRAP and it
brokes at least powerpc.

This patch fixes by defining iff get-dynamic-info.h, which then the
caller can corectly set the expected semantic by STATIC_PIE_BOOTSTRAP,
RTLD_BOOTSTRAP, and/or RESOLVE_MAP.

It also requires to enable some asserts only for the loader bootstrap
since the function is now define once.

As a side note, this is another issues with nested functions: it is
not clear from pre-processed output (-E -dD) how the function will
be build and its semantic (since nested function will be local and
extra C defines may change it).

I checked on x86_64-linux-gnu (w/o --enable-static-pie),
i686-linux-gnu, powerpc64-linux-gnu, powerpc-linux-gnu-power4,
aarch64-linux-gnu, arm-linux-gnu, sparc64-linux-gnu, and
s390x-linux-gnu.
---
 elf/dl-conflict.c           |  1 +
 elf/dl-load.c               |  3 ++-
 elf/dl-reloc-static-pie.c   |  3 ++-
 elf/dl-runtime.c            |  1 +
 elf/dynamic-link.h          |  1 -
 elf/get-dynamic-info.h      | 25 ++++++++++++++-----------
 elf/rtld.c                  |  5 +++--
 elf/setup-vdso.h            |  2 +-
 sysdeps/arm/dl-machine.h    |  1 +
 sysdeps/i386/dl-machine.h   |  1 +
 sysdeps/x86_64/dl-machine.h |  1 +
 11 files changed, 27 insertions(+), 17 deletions(-)

-- 
2.30.2

Comments

Sunil K Pandey via Libc-alpha Oct. 11, 2021, 7:55 p.m. | #1
On 2021-10-11, Adhemerval Zanella wrote:
>Before 490e6c62aa31a8a ('elf: Avoid nested functions in the loader

>[BZ #27220]') elf_get_dynamic_info were defined as 'auto' for

>!RESOLVE_MAP (the default case).  Also, the function adds extra asserts

>depending on whether is defined or not RTLD_BOOTSTRAP.

>

>With the commit change, the function is now included and defined once

>instead of defined as a nested function.  So rtld.c defines it when

>including 'dynamic-link.h' without defining RTLD_BOOTSTRAP and it

>brokes at least powerpc.

>

>This patch fixes by defining iff get-dynamic-info.h, which then the

>caller can corectly set the expected semantic by STATIC_PIE_BOOTSTRAP,

>RTLD_BOOTSTRAP, and/or RESOLVE_MAP.

>

>It also requires to enable some asserts only for the loader bootstrap

>since the function is now define once.

>

>As a side note, this is another issues with nested functions: it is

>not clear from pre-processed output (-E -dD) how the function will

>be build and its semantic (since nested function will be local and

>extra C defines may change it).

>

>I checked on x86_64-linux-gnu (w/o --enable-static-pie),

>i686-linux-gnu, powerpc64-linux-gnu, powerpc-linux-gnu-power4,

>aarch64-linux-gnu, arm-linux-gnu, sparc64-linux-gnu, and

>s390x-linux-gnu.


Thank you for the fix!

hppa and ia64 build as well.

Reviewed-by: Fangrui Song <maskray@google.com>


>---

> elf/dl-conflict.c           |  1 +

> elf/dl-load.c               |  3 ++-

> elf/dl-reloc-static-pie.c   |  3 ++-

> elf/dl-runtime.c            |  1 +

> elf/dynamic-link.h          |  1 -

> elf/get-dynamic-info.h      | 25 ++++++++++++++-----------

> elf/rtld.c                  |  5 +++--

> elf/setup-vdso.h            |  2 +-

> sysdeps/arm/dl-machine.h    |  1 +

> sysdeps/i386/dl-machine.h   |  1 +

> sysdeps/x86_64/dl-machine.h |  1 +

> 11 files changed, 27 insertions(+), 17 deletions(-)

>

>diff --git a/elf/dl-conflict.c b/elf/dl-conflict.c

>index b58929cc5d..fb501e0373 100644

>--- a/elf/dl-conflict.c

>+++ b/elf/dl-conflict.c

>@@ -16,6 +16,7 @@

>    License along with the GNU C Library; see the file COPYING.LIB.  If

>    not, see <https://www.gnu.org/licenses/>.  */

>

>+#include <assert.h>

> #include <errno.h>

> #include <libintl.h>

> #include <stdlib.h>

>diff --git a/elf/dl-load.c b/elf/dl-load.c

>index 99c5ab83b3..335c79fad5 100644

>--- a/elf/dl-load.c

>+++ b/elf/dl-load.c

>@@ -58,6 +58,7 @@ struct filebuf

> };

>

> #include "dynamic-link.h"

>+#include "get-dynamic-info.h"

> #include <abi-tag.h>

> #include <stackinfo.h>

> #include <sysdep.h>

>@@ -1297,7 +1298,7 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd,

>   else

>     l->l_ld = (ElfW(Dyn) *) ((ElfW(Addr)) l->l_ld + l->l_addr);

>

>-  elf_get_dynamic_info (l);

>+  elf_get_dynamic_info (l, false);

>

>   /* Make sure we are not dlopen'ing an object that has the

>      DF_1_NOOPEN flag set, or a PIE object.  */

>diff --git a/elf/dl-reloc-static-pie.c b/elf/dl-reloc-static-pie.c

>index 4007580453..8a99c4995b 100644

>--- a/elf/dl-reloc-static-pie.c

>+++ b/elf/dl-reloc-static-pie.c

>@@ -28,6 +28,7 @@

> #define STATIC_PIE_BOOTSTRAP

> #define RESOLVE_MAP(map, scope, sym, version, flags) map

> #include "dynamic-link.h"

>+#include "get-dynamic-info.h"

>

> /* Relocate static executable with PIE.  */

>

>@@ -51,7 +52,7 @@ _dl_relocate_static_pie (void)

> 	break;

>       }

>

>-  elf_get_dynamic_info (main_map);

>+  elf_get_dynamic_info (main_map, false);

>

> # ifdef ELF_MACHINE_BEFORE_RTLD_RELOC

>   ELF_MACHINE_BEFORE_RTLD_RELOC (main_map, main_map->l_info);

>diff --git a/elf/dl-runtime.c b/elf/dl-runtime.c

>index 9d0d941000..61c260ddb8 100644

>--- a/elf/dl-runtime.c

>+++ b/elf/dl-runtime.c

>@@ -19,6 +19,7 @@

> #define IN_DL_RUNTIME 1		/* This can be tested in dl-machine.h.  */

>

> #include <alloca.h>

>+#include <assert.h>

> #include <stdlib.h>

> #include <unistd.h>

> #include <sys/param.h>

>diff --git a/elf/dynamic-link.h b/elf/dynamic-link.h

>index 7cc3021164..21cdfc88bb 100644

>--- a/elf/dynamic-link.h

>+++ b/elf/dynamic-link.h

>@@ -93,7 +93,6 @@ elf_machine_lazy_rel (struct link_map *map, struct r_scope_elem *scope[],

>

> #include <dl-machine.h>

>

>-#include "get-dynamic-info.h"

>

> #ifdef RESOLVE_MAP

>

>diff --git a/elf/get-dynamic-info.h b/elf/get-dynamic-info.h

>index 15c316b38c..d169099fbc 100644

>--- a/elf/get-dynamic-info.h

>+++ b/elf/get-dynamic-info.h

>@@ -25,7 +25,7 @@

> #include <libc-diag.h>

>

> static inline void __attribute__ ((unused, always_inline))

>-elf_get_dynamic_info (struct link_map *l)

>+elf_get_dynamic_info (struct link_map *l, bool check)

> {

> #if __ELF_NATIVE_CLASS == 32

>   typedef Elf32_Word d_tag_utype;

>@@ -112,16 +112,19 @@ elf_get_dynamic_info (struct link_map *l)

>     assert (info[DT_RELENT]->d_un.d_val == sizeof (ElfW(Rel)));

> #endif

> #ifdef RTLD_BOOTSTRAP

>-  /* Only the bind now flags are allowed.  */

>-  assert (info[VERSYMIDX (DT_FLAGS_1)] == NULL

>-	  || (info[VERSYMIDX (DT_FLAGS_1)]->d_un.d_val & ~DF_1_NOW) == 0);

>-  /* Flags must not be set for ld.so.  */

>-  assert (info[DT_FLAGS] == NULL

>-	  || (info[DT_FLAGS]->d_un.d_val & ~DF_BIND_NOW) == 0);

>-#endif

>-#if defined RTLD_BOOTSTRAP || defined STATIC_PIE_BOOTSTRAP

>-  assert (info[DT_RUNPATH] == NULL);

>-  assert (info[DT_RPATH] == NULL);

>+  if (check)

>+    {

>+      /* Only the bind now flags are allowed.  */

>+      assert (info[VERSYMIDX (DT_FLAGS_1)] == NULL

>+	      || (info[VERSYMIDX (DT_FLAGS_1)]->d_un.d_val & ~DF_1_NOW) == 0);

>+      /* Flags must not be set for ld.so.  */

>+      assert (info[DT_FLAGS] == NULL

>+	      || (info[DT_FLAGS]->d_un.d_val & ~DF_BIND_NOW) == 0);

>+# ifdef STATIC_PIE_BOOTSTRAP

>+      assert (info[DT_RUNPATH] == NULL);

>+      assert (info[DT_RPATH] == NULL);

>+# endif

>+    }

> #else

>   if (info[DT_FLAGS] != NULL)

>     {

>diff --git a/elf/rtld.c b/elf/rtld.c

>index 5eee9e1091..fe5ee9ec4d 100644

>--- a/elf/rtld.c

>+++ b/elf/rtld.c

>@@ -513,6 +513,7 @@ _dl_start_final (void *arg, struct dl_start_final_info *info)

>      is trivial: always the map of ld.so itself.  */

> #define RTLD_BOOTSTRAP

> #define RESOLVE_MAP(map, scope, sym, version, flags) map

>+#include "get-dynamic-info.h"

> #include "dynamic-link.h"

>

> static ElfW(Addr) __attribute_used__

>@@ -547,7 +548,7 @@ _dl_start (void *arg)

>

>   /* Read our own dynamic section and fill in the info array.  */

>   bootstrap_map.l_ld = (void *) bootstrap_map.l_addr + elf_machine_dynamic ();

>-  elf_get_dynamic_info (&bootstrap_map);

>+  elf_get_dynamic_info (&bootstrap_map, true);

>

> #if NO_TLS_OFFSET != 0

>   bootstrap_map.l_tls_offset = NO_TLS_OFFSET;

>@@ -1615,7 +1616,7 @@ dl_main (const ElfW(Phdr) *phdr,

>   if (! rtld_is_main)

>     {

>       /* Extract the contents of the dynamic section for easy access.  */

>-      elf_get_dynamic_info (main_map);

>+      elf_get_dynamic_info (main_map, false);

>

>       /* If the main map is libc.so, update the base namespace to

> 	 refer to this map.  If libc.so is loaded later, this happens

>diff --git a/elf/setup-vdso.h b/elf/setup-vdso.h

>index f44748bc98..6fdffafcca 100644

>--- a/elf/setup-vdso.h

>+++ b/elf/setup-vdso.h

>@@ -64,7 +64,7 @@ setup_vdso (struct link_map *main_map __attribute__ ((unused)),

>       l->l_map_end += l->l_addr;

>       l->l_text_end += l->l_addr;

>       l->l_ld = (void *) ((ElfW(Addr)) l->l_ld + l->l_addr);

>-      elf_get_dynamic_info (l);

>+      elf_get_dynamic_info (l, false);

>       _dl_setup_hash (l);

>       l->l_relocated = 1;

>

>diff --git a/sysdeps/arm/dl-machine.h b/sysdeps/arm/dl-machine.h

>index 68a0b4b476..dfa05eee44 100644

>--- a/sysdeps/arm/dl-machine.h

>+++ b/sysdeps/arm/dl-machine.h

>@@ -21,6 +21,7 @@

>

> #define ELF_MACHINE_NAME "ARM"

>

>+#include <assert.h>

> #include <sys/param.h>

> #include <tls.h>

> #include <dl-tlsdesc.h>

>diff --git a/sysdeps/i386/dl-machine.h b/sysdeps/i386/dl-machine.h

>index 9f578e536a..78bed03eee 100644

>--- a/sysdeps/i386/dl-machine.h

>+++ b/sysdeps/i386/dl-machine.h

>@@ -21,6 +21,7 @@

>

> #define ELF_MACHINE_NAME "i386"

>

>+#include <assert.h>

> #include <sys/param.h>

> #include <sysdep.h>

> #include <tls.h>

>diff --git a/sysdeps/x86_64/dl-machine.h b/sysdeps/x86_64/dl-machine.h

>index 9c0182d597..20afb0b4bc 100644

>--- a/sysdeps/x86_64/dl-machine.h

>+++ b/sysdeps/x86_64/dl-machine.h

>@@ -21,6 +21,7 @@

>

> #define ELF_MACHINE_NAME "x86_64"

>

>+#include <assert.h>

> #include <sys/param.h>

> #include <sysdep.h>

> #include <tls.h>

>-- 

>2.30.2

>
Florian Weimer Oct. 12, 2021, 6:35 a.m. | #2
* Adhemerval Zanella via Libc-alpha:

> +  if (check)

> +    {

> +      /* Only the bind now flags are allowed.  */

> +      assert (info[VERSYMIDX (DT_FLAGS_1)] == NULL

> +	      || (info[VERSYMIDX (DT_FLAGS_1)]->d_un.d_val & ~DF_1_NOW) == 0);

> +      /* Flags must not be set for ld.so.  */

> +      assert (info[DT_FLAGS] == NULL

> +	      || (info[DT_FLAGS]->d_un.d_val & ~DF_BIND_NOW) == 0);

> +# ifdef STATIC_PIE_BOOTSTRAP

> +      assert (info[DT_RUNPATH] == NULL);

> +      assert (info[DT_RPATH] == NULL);

> +# endif

> +    }


Why is a conditional check required?  Is this an optimization?
Sunil K Pandey via Libc-alpha Oct. 12, 2021, 11:34 a.m. | #3
On 12/10/2021 03:35, Florian Weimer wrote:
> * Adhemerval Zanella via Libc-alpha:

> 

>> +  if (check)

>> +    {

>> +      /* Only the bind now flags are allowed.  */

>> +      assert (info[VERSYMIDX (DT_FLAGS_1)] == NULL

>> +	      || (info[VERSYMIDX (DT_FLAGS_1)]->d_un.d_val & ~DF_1_NOW) == 0);

>> +      /* Flags must not be set for ld.so.  */

>> +      assert (info[DT_FLAGS] == NULL

>> +	      || (info[DT_FLAGS]->d_un.d_val & ~DF_BIND_NOW) == 0);

>> +# ifdef STATIC_PIE_BOOTSTRAP

>> +      assert (info[DT_RUNPATH] == NULL);

>> +      assert (info[DT_RPATH] == NULL);

>> +# endif

>> +    }

> 

> Why is a conditional check required?  Is this an optimization?

> 


Because these asserts are only meaningful for the loader itself, but 
this function is used by setup_vdso() as well.  Enabling it regardless
leads to:

--
$ cat test.c
int main (int argc, char *argv[])
{
  return 0;
}
$ gcc -Wall test.c 
$ ./testrun.sh ./a.out 
Inconsistency detected by ld.so: get-dynamic-info.h: 121: elf_get_dynamic_info: Assertion `info[DT_FLAGS] == NULL || (info[DT_FLAGS]->d_un.d_val & ~DF_BIND_NOW) == 0' failed!
--

Previously to 490e6c62aa31a8a, elf_get_dynamic_info() was defined twice
on rtld.c: first with the "dynamic-link.h" include at line 35 and later
at line 519 within _dl_start.  The former definition did not define
DONT_USE_BOOTSTRAP_MAP and it is used on setup_vdso() (since it is a
global definition), while the former does define DONT_USE_BOOTSTRAP_MAP
and it is used on loader self-relocation.

For rtld.c we must define DONT_USE_BOOTSTRAP_MAP, so I added this test
to handle setup_vdso().

This is another complexity that nested function with 'auto' brings,
which only make the code more convoluted.
Sunil K Pandey via Libc-alpha Oct. 12, 2021, 11:35 a.m. | #4
On 11/10/2021 16:55, Fangrui Song wrote:
> On 2021-10-11, Adhemerval Zanella wrote:

>> Before 490e6c62aa31a8a ('elf: Avoid nested functions in the loader

>> [BZ #27220]') elf_get_dynamic_info were defined as 'auto' for

>> !RESOLVE_MAP (the default case).  Also, the function adds extra asserts

>> depending on whether is defined or not RTLD_BOOTSTRAP.

>>

>> With the commit change, the function is now included and defined once

>> instead of defined as a nested function.  So rtld.c defines it when

>> including 'dynamic-link.h' without defining RTLD_BOOTSTRAP and it

>> brokes at least powerpc.

>>

>> This patch fixes by defining iff get-dynamic-info.h, which then the

>> caller can corectly set the expected semantic by STATIC_PIE_BOOTSTRAP,

>> RTLD_BOOTSTRAP, and/or RESOLVE_MAP.

>>

>> It also requires to enable some asserts only for the loader bootstrap

>> since the function is now define once.

>>

>> As a side note, this is another issues with nested functions: it is

>> not clear from pre-processed output (-E -dD) how the function will

>> be build and its semantic (since nested function will be local and

>> extra C defines may change it).

>>

>> I checked on x86_64-linux-gnu (w/o --enable-static-pie),

>> i686-linux-gnu, powerpc64-linux-gnu, powerpc-linux-gnu-power4,

>> aarch64-linux-gnu, arm-linux-gnu, sparc64-linux-gnu, and

>> s390x-linux-gnu.

> 

> Thank you for the fix!

> 

> hppa and ia64 build as well.

> 

> Reviewed-by: Fangrui Song <maskray@google.com>


And I just checked on ia64 and hppa and I saw no regressions.
Florian Weimer Oct. 13, 2021, 3:18 p.m. | #5
* Adhemerval Zanella:

> On 12/10/2021 03:35, Florian Weimer wrote:

>> * Adhemerval Zanella via Libc-alpha:

>> 

>>> +  if (check)

>>> +    {

>>> +      /* Only the bind now flags are allowed.  */

>>> +      assert (info[VERSYMIDX (DT_FLAGS_1)] == NULL

>>> +	      || (info[VERSYMIDX (DT_FLAGS_1)]->d_un.d_val & ~DF_1_NOW) == 0);

>>> +      /* Flags must not be set for ld.so.  */

>>> +      assert (info[DT_FLAGS] == NULL

>>> +	      || (info[DT_FLAGS]->d_un.d_val & ~DF_BIND_NOW) == 0);

>>> +# ifdef STATIC_PIE_BOOTSTRAP

>>> +      assert (info[DT_RUNPATH] == NULL);

>>> +      assert (info[DT_RPATH] == NULL);

>>> +# endif

>>> +    }

>> 

>> Why is a conditional check required?  Is this an optimization?

>> 

>

> Because these asserts are only meaningful for the loader itself, but 

> this function is used by setup_vdso() as well.  Enabling it regardless

> leads to:


Please add a comment mentioning this.

In the long run, we should replace these asserts with a build-time
check.  I hesitate to add more tests based on readelf output, though.

Patch

diff --git a/elf/dl-conflict.c b/elf/dl-conflict.c
index b58929cc5d..fb501e0373 100644
--- a/elf/dl-conflict.c
+++ b/elf/dl-conflict.c
@@ -16,6 +16,7 @@ 
    License along with the GNU C Library; see the file COPYING.LIB.  If
    not, see <https://www.gnu.org/licenses/>.  */
 
+#include <assert.h>
 #include <errno.h>
 #include <libintl.h>
 #include <stdlib.h>
diff --git a/elf/dl-load.c b/elf/dl-load.c
index 99c5ab83b3..335c79fad5 100644
--- a/elf/dl-load.c
+++ b/elf/dl-load.c
@@ -58,6 +58,7 @@  struct filebuf
 };
 
 #include "dynamic-link.h"
+#include "get-dynamic-info.h"
 #include <abi-tag.h>
 #include <stackinfo.h>
 #include <sysdep.h>
@@ -1297,7 +1298,7 @@  _dl_map_object_from_fd (const char *name, const char *origname, int fd,
   else
     l->l_ld = (ElfW(Dyn) *) ((ElfW(Addr)) l->l_ld + l->l_addr);
 
-  elf_get_dynamic_info (l);
+  elf_get_dynamic_info (l, false);
 
   /* Make sure we are not dlopen'ing an object that has the
      DF_1_NOOPEN flag set, or a PIE object.  */
diff --git a/elf/dl-reloc-static-pie.c b/elf/dl-reloc-static-pie.c
index 4007580453..8a99c4995b 100644
--- a/elf/dl-reloc-static-pie.c
+++ b/elf/dl-reloc-static-pie.c
@@ -28,6 +28,7 @@ 
 #define STATIC_PIE_BOOTSTRAP
 #define RESOLVE_MAP(map, scope, sym, version, flags) map
 #include "dynamic-link.h"
+#include "get-dynamic-info.h"
 
 /* Relocate static executable with PIE.  */
 
@@ -51,7 +52,7 @@  _dl_relocate_static_pie (void)
 	break;
       }
 
-  elf_get_dynamic_info (main_map);
+  elf_get_dynamic_info (main_map, false);
 
 # ifdef ELF_MACHINE_BEFORE_RTLD_RELOC
   ELF_MACHINE_BEFORE_RTLD_RELOC (main_map, main_map->l_info);
diff --git a/elf/dl-runtime.c b/elf/dl-runtime.c
index 9d0d941000..61c260ddb8 100644
--- a/elf/dl-runtime.c
+++ b/elf/dl-runtime.c
@@ -19,6 +19,7 @@ 
 #define IN_DL_RUNTIME 1		/* This can be tested in dl-machine.h.  */
 
 #include <alloca.h>
+#include <assert.h>
 #include <stdlib.h>
 #include <unistd.h>
 #include <sys/param.h>
diff --git a/elf/dynamic-link.h b/elf/dynamic-link.h
index 7cc3021164..21cdfc88bb 100644
--- a/elf/dynamic-link.h
+++ b/elf/dynamic-link.h
@@ -93,7 +93,6 @@  elf_machine_lazy_rel (struct link_map *map, struct r_scope_elem *scope[],
 
 #include <dl-machine.h>
 
-#include "get-dynamic-info.h"
 
 #ifdef RESOLVE_MAP
 
diff --git a/elf/get-dynamic-info.h b/elf/get-dynamic-info.h
index 15c316b38c..d169099fbc 100644
--- a/elf/get-dynamic-info.h
+++ b/elf/get-dynamic-info.h
@@ -25,7 +25,7 @@ 
 #include <libc-diag.h>
 
 static inline void __attribute__ ((unused, always_inline))
-elf_get_dynamic_info (struct link_map *l)
+elf_get_dynamic_info (struct link_map *l, bool check)
 {
 #if __ELF_NATIVE_CLASS == 32
   typedef Elf32_Word d_tag_utype;
@@ -112,16 +112,19 @@  elf_get_dynamic_info (struct link_map *l)
     assert (info[DT_RELENT]->d_un.d_val == sizeof (ElfW(Rel)));
 #endif
 #ifdef RTLD_BOOTSTRAP
-  /* Only the bind now flags are allowed.  */
-  assert (info[VERSYMIDX (DT_FLAGS_1)] == NULL
-	  || (info[VERSYMIDX (DT_FLAGS_1)]->d_un.d_val & ~DF_1_NOW) == 0);
-  /* Flags must not be set for ld.so.  */
-  assert (info[DT_FLAGS] == NULL
-	  || (info[DT_FLAGS]->d_un.d_val & ~DF_BIND_NOW) == 0);
-#endif
-#if defined RTLD_BOOTSTRAP || defined STATIC_PIE_BOOTSTRAP
-  assert (info[DT_RUNPATH] == NULL);
-  assert (info[DT_RPATH] == NULL);
+  if (check)
+    {
+      /* Only the bind now flags are allowed.  */
+      assert (info[VERSYMIDX (DT_FLAGS_1)] == NULL
+	      || (info[VERSYMIDX (DT_FLAGS_1)]->d_un.d_val & ~DF_1_NOW) == 0);
+      /* Flags must not be set for ld.so.  */
+      assert (info[DT_FLAGS] == NULL
+	      || (info[DT_FLAGS]->d_un.d_val & ~DF_BIND_NOW) == 0);
+# ifdef STATIC_PIE_BOOTSTRAP
+      assert (info[DT_RUNPATH] == NULL);
+      assert (info[DT_RPATH] == NULL);
+# endif
+    }
 #else
   if (info[DT_FLAGS] != NULL)
     {
diff --git a/elf/rtld.c b/elf/rtld.c
index 5eee9e1091..fe5ee9ec4d 100644
--- a/elf/rtld.c
+++ b/elf/rtld.c
@@ -513,6 +513,7 @@  _dl_start_final (void *arg, struct dl_start_final_info *info)
      is trivial: always the map of ld.so itself.  */
 #define RTLD_BOOTSTRAP
 #define RESOLVE_MAP(map, scope, sym, version, flags) map
+#include "get-dynamic-info.h"
 #include "dynamic-link.h"
 
 static ElfW(Addr) __attribute_used__
@@ -547,7 +548,7 @@  _dl_start (void *arg)
 
   /* Read our own dynamic section and fill in the info array.  */
   bootstrap_map.l_ld = (void *) bootstrap_map.l_addr + elf_machine_dynamic ();
-  elf_get_dynamic_info (&bootstrap_map);
+  elf_get_dynamic_info (&bootstrap_map, true);
 
 #if NO_TLS_OFFSET != 0
   bootstrap_map.l_tls_offset = NO_TLS_OFFSET;
@@ -1615,7 +1616,7 @@  dl_main (const ElfW(Phdr) *phdr,
   if (! rtld_is_main)
     {
       /* Extract the contents of the dynamic section for easy access.  */
-      elf_get_dynamic_info (main_map);
+      elf_get_dynamic_info (main_map, false);
 
       /* If the main map is libc.so, update the base namespace to
 	 refer to this map.  If libc.so is loaded later, this happens
diff --git a/elf/setup-vdso.h b/elf/setup-vdso.h
index f44748bc98..6fdffafcca 100644
--- a/elf/setup-vdso.h
+++ b/elf/setup-vdso.h
@@ -64,7 +64,7 @@  setup_vdso (struct link_map *main_map __attribute__ ((unused)),
       l->l_map_end += l->l_addr;
       l->l_text_end += l->l_addr;
       l->l_ld = (void *) ((ElfW(Addr)) l->l_ld + l->l_addr);
-      elf_get_dynamic_info (l);
+      elf_get_dynamic_info (l, false);
       _dl_setup_hash (l);
       l->l_relocated = 1;
 
diff --git a/sysdeps/arm/dl-machine.h b/sysdeps/arm/dl-machine.h
index 68a0b4b476..dfa05eee44 100644
--- a/sysdeps/arm/dl-machine.h
+++ b/sysdeps/arm/dl-machine.h
@@ -21,6 +21,7 @@ 
 
 #define ELF_MACHINE_NAME "ARM"
 
+#include <assert.h>
 #include <sys/param.h>
 #include <tls.h>
 #include <dl-tlsdesc.h>
diff --git a/sysdeps/i386/dl-machine.h b/sysdeps/i386/dl-machine.h
index 9f578e536a..78bed03eee 100644
--- a/sysdeps/i386/dl-machine.h
+++ b/sysdeps/i386/dl-machine.h
@@ -21,6 +21,7 @@ 
 
 #define ELF_MACHINE_NAME "i386"
 
+#include <assert.h>
 #include <sys/param.h>
 #include <sysdep.h>
 #include <tls.h>
diff --git a/sysdeps/x86_64/dl-machine.h b/sysdeps/x86_64/dl-machine.h
index 9c0182d597..20afb0b4bc 100644
--- a/sysdeps/x86_64/dl-machine.h
+++ b/sysdeps/x86_64/dl-machine.h
@@ -21,6 +21,7 @@ 
 
 #define ELF_MACHINE_NAME "x86_64"
 
+#include <assert.h>
 #include <sys/param.h>
 #include <sysdep.h>
 #include <tls.h>