This is required when building for powerpc64le POWER8 with GCC 8
at least.

Fixes commit cbd9fd236981717d3d4ee942986ea912e9707c32 ("Consolidate
TLS block allocation for static binaries with ld.so").

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

This reverts commit b62759db04b8ed7f829c06f1d7c3b8fb70616493.

Reason for revert: Incompatible with “env -i” and coreutils (bug 32588).

Reviewed-by: H.J. Lu <hjl.tools@gmail.com>

Some applications set environ to a heap-allocated pointer, call
setenv (expecting it to call realloc), free environ, and then
restore the original environ pointer.  This breaks after
commit 7a61e7f557a97ab597d6fca5e2d1f13f65685c61 ("stdlib: Make
getenv thread-safe in more cases") because after the setenv call,
the environ pointer does not point to the start of a heap allocation.
Instead, setenv creates a separate allocation and changes environ
to point into that.  This means that the free call in the application
results in heap corruption.

The interim approach was more compatible with other libcs because
it does not assume that the incoming environ pointer is allocated
as if by malloc (if it was written by the application).  However,
it seems to be more important to stay compatible with previous
glibc version: assume the incoming pointer is heap allocated,
and preserve this property after setenv calls.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>

Use the same code to compute the TLS block size and its alignment.
The code in elf/dl-tls.c is linked in anyway for all binaries
due to the reference to _dl_tls_static_surplus_init.

It is not possible to call _dl_allocate_tls_storage directly
because malloc is not available in the static case.  (The
dynamic linker uses the minimal malloc at this stage.)  Therefore,
split _dl_tls_block_size_with_pre and _dl_tls_block_align from
_dl_allocate_tls_storage, and call those new functions from
__libc_setup_tls.

This fixes extra TLS allocation for the static case, and apparently
some pre-existing bugs as well (the independent recomputation of
TLS block sizes in init_static_tls looks rather suspect).

Fixes commit 0e411c5d3098982d67cd2d7a233eaa6c977a1869 ("Add generic
'extra TLS'").

Add the logic to append an 'extra TLS' block in the TLS block allocator
with a generic stub implementation. The duplicated code in
'csu/libc-tls.c' and 'elf/dl-tls.c' is to handle both statically linked
applications and the ELF dynamic loader.

Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Reviewed-by: Florian Weimer <fweimer@redhat.com>

Starting from glibc 2.1, crt1.o contains _IO_stdin_used which is checked
by _IO_check_libio to provide binary compatibility for glibc 2.0.  Add
crt1-2.0.o for tests against glibc 2.0.  Define tests-2.0 for glibc 2.0
compatibility tests.  Add and update glibc 2.0 compatibility tests for
stderr, matherr and pthread_kill.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>

Reflow and sort Makefile.

Code generation changes present due to link order changes.

No regressions on x86_64 and i686.