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>

1 files changed, 1 insertions, 0 deletions

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>