commit c6df39a0bd2aafd2a4280a0000ef201f30273bee

Author: Adhemerval Zanella <adhemerval.zanella@linaro.org>

Date:   Mon Oct 11 16:01:49 2021 -0300

    elf: Fix elf_get_dynamic_info definition

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

    [BZ #27220]'), elf_get_dynamic_info() was defined twice on rtld.c: on

    the first dynamic-link.h include and later 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.

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

    instead of defined as a nested function.  So rtld.c defines without

    defining RTLD_BOOTSTRAP and it brokes at least powerpc32.

    This patch fixes by moving the get-dynamic-info.h include out of

    dynamic-link.h, which then the caller can corirectly set the expected

    semantic by defining STATIC_PIE_BOOTSTRAP, RTLD_BOOTSTRAP, and/or

    RESOLVE_MAP.

    It also required to enable some asserts only for the loader bootstrap

    to avoid issues when called from setup_vdso().

    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.

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

    (cherry picked from commit 4af6982e4c9fc465ffb7a54b794aaaa134241f05)

    Resolved conflicts:

            elf/rtld.c

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

index 5c8e51d19ae095d6..d54356dee3f86ae0 100644

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

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

@@ -17,6 +17,7 @@

    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 0976977fbdf21902..eea06629a978aaf3 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>

@@ -1295,7 +1296,7 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd,

   if (l->l_ld != 0)

     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 a52ba8aeb8b573cb..f323b4dd0d5ba279 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 9d0d941000f6114f..61c260ddb81b586c 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 7cc30211649d3820..21cdfc88bbfb89ea 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 15c316b38c05a90c..d169099fbc9897cf 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 ee45657aeac14f3c..352d596dedb42e79 100644

--- a/elf/rtld.c

+++ b/elf/rtld.c

@@ -514,6 +514,7 @@ _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__

@@ -549,7 +550,7 @@ _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 ();

   bootstrap_map.l_ld_readonly = DL_RO_DYN_SECTION;

-  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;

@@ -1653,7 +1654,7 @@ 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 f44748bc9858e5fd..6fdffafcca5e9916 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 7e6761bbe87540d5..86f866ca7c17bd9b 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 78ce890c0ff333ca..fa902612ca8557f9 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 d3fcbb37bf1f4f7c..90c77cfea1de8d63 100644

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

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

@@ -22,6 +22,7 @@

 #define ELF_MACHINE_NAME "x86_64"

+#include <assert.h>

 #include <sys/param.h>

 #include <sysdep.h>

 #include <tls.h>