A recent GCC change to expand floating-point classification built-in
functions inline using integer rather than floating-point arithmetic
in some cases resulted in localplt test failures for nios2 and sparc32
<https://sourceware.org/ml/libc-testresults/2017-q2/msg00320.html>.
This patch updates the localplt.data files in question to mark the
relevant symbols as optional / add a new optional symbol. (The GCC
patch has been reverted because of other problems it caused, but one
can assume it will be applied again, without changes that would affect
the PLT entries generated, once those issues have been resolved.)
Tested with build-many-glibcs.py.
* sysdeps/unix/sysv/linux/nios2/localplt.data (__gtdf2): Mark
libc.so PLT entry optional.
(__gtsf2): Likewise.
(__unorddf2): Likewise.
(__unordsf2): Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc32/localplt.data (_Q_fgt):
New optional libc.so PLT entry.
It is no longer needed since commit 6c444ad6e9
(elf: Do not use memalign for TCB/TLS blocks allocation [BZ #17730]).
Applications do not link against ld.so and will use the definition in
libc.so, so there is no ABI impact.
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.
This patch updates nios2 localplt.data so the localplt test passes in
my compile-only all-ABIs glibc testing. A new PLT entry for
__extendsfdf2 is added.
Tested for nios2.
* sysdeps/unix/sysv/linux/nios2/localplt.data: Add __extendsfdf2
for libc.so.
