Implement _dl_catch_error, _dl_signal_error in libc.so [BZ #16628]

This change moves the main implementation of _dl_catch_error,
_dl_signal_error to libc.so, where TLS variables can be used
directly.  This removes a writable function pointer from the
rtld_global variable.

For use during initial relocation, minimal implementations of these
functions are provided in ld.so.  These are eventually interposed
by the libc.so implementations.  This is implemented by compiling
elf/dl-error-skeleton.c twice, via elf/dl-error.c and
elf/dl-error-minimal.c.

As a side effect of this change, the static version of dl-error.c
no longer includes support for the
_dl_signal_cerror/_dl_receive_error mechanism because it is only
used in ld.so.

1 files changed, 0 insertions, 53 deletions

diff --git a/elf/dl-tsd.c b/elf/dl-tsd.c
deleted file mode 100644
index 7181e1c9e0..0000000000
--- a/elf/dl-tsd.c
+++ /dev/null
@@ -1,53 +0,0 @@
-/* Thread-local data used by error handling for runtime dynamic linker.
-   Copyright (C) 2002-2016 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
-   <http://www.gnu.org/licenses/>.  */
-
-#ifdef _LIBC_REENTRANT
-
-# include <ldsodefs.h>
-# include <tls.h>
-
-# ifndef SHARED
-
-/* _dl_error_catch_tsd points to this for the single-threaded case.
-   It's reset by the thread library for multithreaded programs
-   if we're not using __thread.  */
-void ** __attribute__ ((const))
-_dl_initial_error_catch_tsd (void)
-{
-  static __thread void *data;
-  return &data;
-}
-void **(*_dl_error_catch_tsd) (void) __attribute__ ((const))
-     = &_dl_initial_error_catch_tsd;
-
-# else
-
-/* libpthread sets _dl_error_catch_tsd to point to this function.
-   We define it here instead of in libpthread so that it doesn't
-   need to have a TLS segment of its own just for this one pointer.  */
-
-void ** __attribute__ ((const))
-__libc_dl_error_tsd (void)
-{
-  static __thread void *data attribute_tls_model_ie;
-  return &data;
-}
-
-# endif	/* SHARED */
-
-#endif /* _LIBC_REENTRANT */