dl-runtime: reloc_{offset,index} now functions arch overide'able

The existing macros are fragile and expect local variables with a
certain name. Fix this by defining them as functions with default
implementation in a new header dl-runtime.h which arches can override
if need be.

This came up during ARC port review, hence the need for argument pltgot
in reloc_index() which is not needed by existing ports.

This patch potentially only affects hppa/x86 ports,
build tested for both those configs and a few more.

Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>

2 files changed, 35 insertions, 9 deletions

diff --git a/sysdeps/x86_64/dl-runtime.c b/sysdeps/x86_64/dl-runtime.c
deleted file mode 100644
index b625d1e882..0000000000
--- a/sysdeps/x86_64/dl-runtime.c
+++ /dev/null
@@ -1,9 +0,0 @@
-/* The ABI calls for the PLT stubs to pass the index of the relocation
-   and not its offset.  In _dl_profile_fixup and _dl_call_pltexit we
-   also use the index.  Therefore it is wasteful to compute the offset
-   in the trampoline just to reverse the operation immediately
-   afterwards.  */
-#define reloc_offset reloc_arg * sizeof (PLTREL)
-#define reloc_index  reloc_arg
-
-#include <elf/dl-runtime.c>
diff --git a/sysdeps/x86_64/dl-runtime.h b/sysdeps/x86_64/dl-runtime.h
new file mode 100644
index 0000000000..3fa61d7a46
--- /dev/null
+++ b/sysdeps/x86_64/dl-runtime.h
@@ -0,0 +1,35 @@
+/* Helpers for On-demand PLT fixup for shared objects.  x86_64 version.
+   Copyright (C) 2020 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, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+/* The ABI calls for the PLT stubs to pass the index of the relocation
+   and not its offset.  In _dl_profile_fixup and _dl_call_pltexit we
+   also use the index.  Therefore it is wasteful to compute the offset
+   in the trampoline just to reverse the operation immediately
+   afterwards.  */
+static inline uintptr_t
+reloc_offset (uintptr_t plt0, uintptr_t pltn)
+{
+  return pltn * sizeof (ElfW(Rela));
+}
+
+static inline uintptr_t
+reloc_index (uintptr_t plt0, uintptr_t pltn, size_t size)
+{
+  return pltn;
+}