GCC marked OABI obsolete in 4.7 and dropped it in 4.8. So the number
of people this is catching is shrinking every day. At this point,
it's not terribly useful, so just drop it.
This patch removes the configure test for working -z relro.
The use of -z relro in Makeconfig became unconditional with
commit 2e6ab1df44c412bb9d30b26a4d8a679150a7e375
Author: Ulrich Drepper <drepper@redhat.com>
Date: Sat Oct 28 06:44:04 2006 +0000
Remove conditional code which now is unnecessary.
(commit reference from git://repo.or.cz/glibc/history), so since then
the configure test has not controlled anything about how glibc is
built - simply about whether configure succeeds and allows a build to
be attempted. The test for whether the option did something useful
(as opposed to whether it exists - which we can certainly just assume
by now) was originally added in
<https://sourceware.org/ml/libc-hacker/2004-09/msg00069.html> to
disable the option in a case when it did nothing useful on ia64 (as a
result of something deliberate in the linker on ia64). Since 2006
that disabling has been of no effect, and given that the current test
does not set libc_relro_required for ia64, it does nothing whatever
useful for the original motivating case. Also at around the same time
in 2006 the test was made to give an error for missing or broken -z
relro support on various architectures.
So effectively all the test does now is verify that, on certain
architectures, the linker has not been changed deliberately to make
the option ineffective. I see no apparent reason why such a change
should be expected, or why the build should be stopped if it were to
be made (any more than we disallow build on ia64); I think we can
trust binutils patch review to point out the consequences of any
change to COMMONPAGESIZE setting. The only thing that might now make
sense would be disabling the -z relro use on an architecture-specific
basis if there were an architecture-specific reason to consider that
to make sense; it would be for the ia64 maintainer to decide if that
makes sense for ia64 at present, but I think that could be done
through sysdeps Makefiles - no special configure tests needed.
Tested for x86_64 that this patch makes no change to the installed
shared libraries.
Together with
<https://sourceware.org/ml/libc-alpha/2014-06/msg00788.html> (pending
review) this substantially eliminates architecture-specific cases from
architecture-independent configure.ac files. There remains an i386
case in sysdeps/mach/hurd/configure.ac that should properly move to
the i386 subdirectory. (There are also OS-specific cases outside
OS-specific directories; in principle I think should should also
move.)
* configure.ac (libc_commonpagesize): Remove variable.
(libc_relro_required): Likewise.
(libc_cv_z_relro): Remove configure test.
* configure: Regenerated.
* sysdeps/aarch64/preconfigure (libc_commonpagesize): Do not set
variable.
(libc_relro_required): Likewise.
* sysdeps/alpha/preconfigure (libc_commonpagesize): Likewise.
(libc_relro_required): Likewise.
* sysdeps/arm/preconfigure.ac (libc_commonpagesize): Likewise.
(libc_relro_required): Likewise.
* sysdeps/arm/preconfigure: Regenerated.
* sysdeps/ia64/preconfigure: Remove file.
* sysdeps/tile/preconfigure (libc_commonpagesize): Do not set
variable.
(libc_relro_required): Likewise.
Set values for libc_commonpagesize and libc_relro_required for the
ARM port to enable relro by default and suppress a warning at
configure time.
ChangeLog:
2014-05-09 Will Newton <will.newton@linaro.org>
* sysdeps/arm/preconfigure.ac: Set libc_commonpagesize
and libc_relro_required for ARM.
* sysdeps/arm/preconfigure: Regenerate.
I've moved the ARM port from ports to the main sysdeps hierarchy.
Beyond the README update, the move of the files was simply
git mv ports/sysdeps/arm sysdeps/arm
git mv ports/sysdeps/unix/arm sysdeps/unix/arm
git mv ports/sysdeps/unix/sysv/linux/arm sysdeps/unix/sysv/linux/arm
and in addition to the ChangeLog entries here, I put a note at the top
of ports/ChangeLog.arm similar to that at the top of
ChangeLog.powerpc. There is deliberately no NEWS change, as I think
it makes the most sense to put in a general note above all ports
having moved if we can achieve that for 2.20.
Tested that disassembly of installed shared libraries for arm is the
same before and after this patch, except for data (not instructions)
in ld.so (there are assertions in sysdeps/arm/dl-machine.h, and the
path by which that file is found, and so by which it appears in the
assertion message, changes as a result of the move).
* sysdeps/arm: Move directory from ports/sysdeps/arm.
* sysdeps/unix/arm: Move directory from ports/sysdeps/unix/arm.
* sysdeps/unix/sysv/linux/arm: Move directory from
ports/sysdeps/unix/sysv/linux/arm.
* README: Update listing for arm-*-linux-gnueabi.
ports/ChangeLog.arm:
* sysdeps/arm: Move directory to ../sysdeps/arm.
* sysdeps/unix/arm: Move directory to ../sysdeps.arm.
* sysdeps/unix/sysv/linux/arm: Move directory to
../sysdeps/unix/sysv/linux/arm.
Mike Frysinger
Roland McGrath
Joseph Myers
Will Newton