elf: Fix dynamic-link.h usage on rtld.c

The 4af6982e4c fix does not fully handle RTLD_BOOTSTRAP usage on
rtld.c due two issues:

  1. RTLD_BOOTSTRAP is also used on dl-machine.h on various
     architectures and it changes the semantics of various machine
     relocation functions.

  2. The elf_get_dynamic_info() change was done sideways, previously
     to 490e6c62aa get-dynamic-info.h was included by the first
     dynamic-link.h include *without* RTLD_BOOTSTRAP being defined.
     It means that the code within elf_get_dynamic_info() that uses
     RTLD_BOOTSTRAP is in fact unused.

To fix 1. this patch now includes dynamic-link.h only once with
RTLD_BOOTSTRAP defined.  The ELF_DYNAMIC_RELOCATE call will now have
the relocation fnctions with the expected semantics for the loader.

And to fix 2. part of 4af6982e4c is reverted (the check argument
elf_get_dynamic_info() is not required) and the RTLD_BOOTSTRAP
pieces are removed.

To reorganize the includes the static TLS definition is moved to
its own header to avoid a circular dependency (it is defined on
dynamic-link.h and dl-machine.h requires it at same time other
dynamic-link.h definition requires dl-machine.h defitions).

Also ELF_MACHINE_NO_REL, ELF_MACHINE_NO_RELA, and ELF_MACHINE_PLT_REL
are moved to its own header.  Only ancient ABIs need special values
(arm, i386, and mips), so a generic one is used as default.

The powerpc Elf64_FuncDesc is also moved to its own header, since
csu code required its definition (which would require either include
elf/ folder or add a full path with elf/).

Checked on x86_64, i686, aarch64, armhf, powerpc64, powerpc32,
and powerpc64le.

Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>

3 files changed, 38 insertions, 17 deletions

diff --git a/sysdeps/powerpc/powerpc64/dl-funcdesc.h b/sysdeps/powerpc/powerpc64/dl-funcdesc.h
new file mode 100644
index 0000000000..b2d1f76ce0
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/dl-funcdesc.h
@@ -0,0 +1,34 @@
+/* PowerPC ELFv1 function descriptor definition.
+   Copyright (C) 2009-2021 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/>.  */
+
+#ifndef _DL_FUNCDESC_H
+#define _DL_FUNCDESC_H
+
+#if _CALL_ELF != 2
+/* A PowerPC64 function descriptor.  The .plt (procedure linkage
+   table) and .opd (official procedure descriptor) sections are
+   arrays of these.  */
+typedef struct
+{
+  Elf64_Addr fd_func;
+  Elf64_Addr fd_toc;
+  Elf64_Addr fd_aux;
+} Elf64_FuncDesc;
+#endif
+
+#endif
diff --git a/sysdeps/powerpc/powerpc64/dl-irel.h b/sysdeps/powerpc/powerpc64/dl-irel.h
index 0e11b7ff64..aa9a2dca71 100644
--- a/sysdeps/powerpc/powerpc64/dl-irel.h
+++ b/sysdeps/powerpc/powerpc64/dl-irel.h
@@ -23,7 +23,7 @@
 #include <stdio.h>
 #include <unistd.h>
 #include <ldsodefs.h>
-#include <dl-machine.h>
+#include <dl-funcdesc.h>
 
 #define ELF_MACHINE_IRELA	1
 
diff --git a/sysdeps/powerpc/powerpc64/dl-machine.h b/sysdeps/powerpc/powerpc64/dl-machine.h
index 3f92fbb369..3a4a21a412 100644
--- a/sysdeps/powerpc/powerpc64/dl-machine.h
+++ b/sysdeps/powerpc/powerpc64/dl-machine.h
@@ -28,23 +28,14 @@
 #include <sysdep.h>
 #include <hwcapinfo.h>
 #include <cpu-features.c>
+#include <dl-static-tls.h>
+#include <dl-funcdesc.h>
+#include <dl-machine-rel.h>
 
 /* Translate a processor specific dynamic tag to the index
    in l_info array.  */
 #define DT_PPC64(x) (DT_PPC64_##x - DT_LOPROC + DT_NUM)
 
-#if _CALL_ELF != 2
-/* A PowerPC64 function descriptor.  The .plt (procedure linkage
-   table) and .opd (official procedure descriptor) sections are
-   arrays of these.  */
-typedef struct
-{
-  Elf64_Addr fd_func;
-  Elf64_Addr fd_toc;
-  Elf64_Addr fd_aux;
-} Elf64_FuncDesc;
-#endif
-
 #define ELF_MULT_MACHINES_SUPPORTED
 
 /* Return nonzero iff ELF header is compatible with the running host.  */
@@ -292,10 +283,6 @@ BODY_PREFIX "_dl_start_user:\n"						\
 /* A reloc type used for ld.so cmdline arg lookups to reject PLT entries.  */
 #define ELF_MACHINE_JMP_SLOT	R_PPC64_JMP_SLOT
 
-/* The PowerPC never uses REL relocations.  */
-#define ELF_MACHINE_NO_REL 1
-#define ELF_MACHINE_NO_RELA 0
-
 /* We define an initialization function to initialize HWCAP/HWCAP2 and
    platform data so it can be copied into the TCB later.  This is called
    very early in _dl_sysdep_start for dynamically linked binaries.  */