This patch adds several new tunables to control the behavior of
elision on supported platforms[1]. Since elision now depends
on tunables, we should always *compile* with elision enabled,
and leave the code disabled, but available for runtime
selection. This gives us *much* better compile-time testing of
the existing code to avoid bit-rot[2].
Tested on ppc, ppc64, ppc64le, s390x and x86_64.
[1] This part of the patch was initially proposed by
Paul Murphy but was "staled" because the framework have changed
since the patch was originally proposed:
https://patchwork.sourceware.org/patch/10342/
[2] This part of the patch was inititally proposed as a RFC by
Carlos O'Donnell. Make sense to me integrate this on the patch:
https://sourceware.org/ml/libc-alpha/2017-05/msg00335.html
* elf/dl-tunables.list: Add elision parameters.
* manual/tunables.texi: Add entries about elision tunable.
* sysdeps/unix/sysv/linux/powerpc/elision-conf.c:
Add callback functions to dynamically enable/disable elision.
Add multiple callbacks functions to set elision parameters.
Deleted __libc_enable_secure check.
* sysdeps/unix/sysv/linux/s390/elision-conf.c: Likewise.
* sysdeps/unix/sysv/linux/x86/elision-conf.c: Likewise.
* configure: Regenerated.
* configure.ac: Option enable_lock_elision was deleted.
* config.h.in: ENABLE_LOCK_ELISION flag was deleted.
* config.make.in: Remove references to enable_lock_elision.
* manual/install.texi: Elision configure option was removed.
* INSTALL: Regenerated to remove enable_lock_elision.
* nptl/Makefile:
Disable elision so it can verify error case for destroying a mutex.
* sysdeps/powerpc/nptl/elide.h:
Cleanup ENABLE_LOCK_ELISION check.
Deleted macros for the case when ENABLE_LOCK_ELISION was not defined.
* sysdeps/s390/configure: Regenerated.
* sysdeps/s390/configure.ac: Remove references to enable_lock_elision..
* nptl/tst-mutex8.c:
Deleted all #ifndef ENABLE_LOCK_ELISION from the test.
* sysdeps/powerpc/powerpc32/sysdep.h:
Deleted all ENABLE_LOCK_ELISION checks.
* sysdeps/powerpc/powerpc64/sysdep.h: Likewise.
* sysdeps/powerpc/sysdep.h: Likewise.
* sysdeps/s390/nptl/bits/pthreadtypes-arch.h: Likewise.
* sysdeps/unix/sysv/linux/powerpc/force-elision.h: Likewise.
* sysdeps/unix/sysv/linux/s390/elision-conf.h: Likewise.
* sysdeps/unix/sysv/linux/s390/force-elision.h: Likewise.
* sysdeps/unix/sysv/linux/s390/lowlevellock.h: Likewise.
* sysdeps/unix/sysv/linux/s390/Makefile: Remove references to
enable-lock-elision.
Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.vnet.ibm.com>
There is a subtle non-determinism when building glibc.
This depends on whether the glibc is built using the distibuted
file intl/plural.c or built using the generated file intl/plural.c.
These two files (intl/plural.c generated vs. distributed) are slightly
different, hence we may end up with slightly different libraries.
Originally, having "bison" installed was optional. So if "bison" was
not present, we always built libraries with the distributed plural.c.
If bison was installed, we *** may have *** replaced the distributed
file plural.c with a new plural.c generated from plural.y. if the
timestamps triggered this rule:
plural.c plural.y
$(BISON) $(BISONFLAGS) $@ $^
Given that timestamps are not preserved in GIT repositories, the above
rule is not reliable without explicitly touching plural.c or plural.y.
In other words, the rule may or may not have fired.
In summary: there are two distinct sources of non-determinism:
1. Having "bison" installed or not
2. Having "bison" installed but timestamps poorly defined.
This patch fixes this by requiring "bison" being installed
and by always generating intl/plural.c from intl/plural.y.
(This is achieved by simply removing checked-in intl/plural.c)
[BZ #22432]
* configure.ac (BISON): Require to be present.
* configure: Regenerated.
* intl/Makefile (generated): Add plural.c.
[$(BISON) != no]: Make code unconditional.
(plural.c): Change rule to $(objpfx)plural.c.
($(objpfx)plural.o): Depend on $(objpfx)plural.c.
* intl/plural.c: Remove.
* manual/install.texi (Tools for Compilation): Document bison as
required.
* INSTALL: Regenerated.
Update all sourceware links to https. The website redirects
everything to https anyway so let the web server do a bit less work.
The only reference that remains unchanged is the one in the old
ChangeLog, since it didn't seem worth changing it.
* NEWS: Update sourceware link to https.
* configure.ac: Likewise.
* crypt/md5test-giant.c: Likewise.
* dlfcn/bug-atexit1.c: Likewise.
* dlfcn/bug-atexit2.c: Likewise.
* localedata/README: Likewise.
* malloc/tst-mallocfork.c: Likewise.
* manual/install.texi: Likewise.
* nptl/tst-pthread-getattr.c: Likewise.
* stdio-common/tst-fgets.c: Likewise.
* stdio-common/tst-fwrite.c: Likewise.
* sunrpc/Makefile: Likewise.
* sysdeps/arm/armv7/multiarch/memcpy_impl.S: Likewise.
* wcsmbs/tst-mbrtowc2.c: Likewise.
* configure: Regenerate.
* INSTALL: Regenerate.
When multi-lib GCC is used to build glibc, the search order of GCC driver
for crt*.o is -B*/`gcc -print-multi-directory`, the installed diretory,
-B*/. This patch adds multi-lib support to csu/Makefile so that
-B/glibc-build-directory/csu/ will pick up the newly built crt*.o.
Tested on x86-64 for i686 and x32.
[BZ #22362]
* Makerules (make-link-multidir): New.
* config.make.in (multidir): New.
* configure.ac (libc_cv_multidir): New. AC_SUBST.
* configure: Regenerated.
* csu/Makefile [$(multidir) != .](multilib-extra-objs): New.
[$(multidir) != .](extra-objs): Add $(multilib-extra-objs).
[$(multidir) != .]($(addprefix $(objpfx)$(multidir)/, $(install-lib))):
New target.
GCC 8 emits an warning for alias for functions with incompatible types
and it is used extensivelly for ifunc resolvers implementations in C
(for instance on weak_alias with the internal symbol name to the
external one or with the libc_hidden_def to set ifunc for internal
usage).
This breaks the build when the ifunc resolver is not defined using
gcc attribute extensions (HAVE_GCC_IFUNC being 0). Although for
all currently architectures that have multiarch support this compiler
options is enabled for default, there is still the option where the
user might try build glibc with a compiler without support for such
extension. In this case this patch just disable the multiarch folder
in sysdeps selections.
GCC 7 and before still builds IFUNCs regardless of compiler support
(although for the lack of attribute support debug information would
be optimal).
Checked with a build on multiarch support architectures (aarch64,
arm, sparc, s390, powerpc, x86_64, i386) with multiarch enable
and disable and with GCC 7 and GCC 8.
* configure.ac (libc_cv_gcc_incompatbile_alias): New define:
indicates whether compiler emits an warning for alias for
functions with incompatible types.
glibc has an add-ons mechanism to allow additional software to be
integrated into the glibc build. Such add-ons may be within the glibc
source tree, or outside it at a path passed to the --enable-add-ons
configure option.
localedata and crypt were once add-ons, distributed in separate
release tarballs, but long since stopped using that mechanism.
Linuxthreads was always an add-on. Ports spent some time as an add-on
with separate release tarballs, then was first moved into the glibc
source tree, then had its sysdeps files moved into the main sysdeps
hierarchy so the add-ons mechanism was no longer used. NPTL spent
some time as an add-on in the main glibc tree before stopping using
the add-on mechanism. libidn used to have separate release tarballs
but no longer does so, but still uses the add-ons mechanism within the
glibc source tree. Various other software has supported building with
the add-ons mechanism at times in the past, but I don't think any is
still widely used.
Add-ons involve significant, little-used complexity in the glibc build
system, and make it hard to understand what the space of possible
glibc configurations is. This patch removes the add-ons mechanism.
libidn is now built via the Subdirs mechanism to cause any
configuration using sysdeps/unix/inet to build libidn; HAVE_LIBIDN
(which effectively means shared libraries are available) is now
defined via sysdeps/unix/inet/configure. Various references to
add-ons around the source tree are removed (in the case of maint.texi,
the example list of sysdeps directories is still very out of date).
Externally maintained ports should now put their files in the normal
sysdeps directory structure rather than being arranged as add-ons;
they probably need to change e.g. elf.h anyway, rather than actually
being able to work just as a drop-in subtree. Hurd libpthread should
be arranged similarly to NPTL, so some files might go in a
hurd-pthreads (or similar) top-level directory in glibc, while sysdeps
files should go in the normal sysdeps directory structure (possibly in
hurd or hurd-pthreads subdirectories, just as there are nptl
subdirectories in the sysdeps tree).
Tested for x86_64, and with build-many-glibcs.py.
* configure.ac (--enable-add-ons): Remove option.
(machine): Do not mention add-ons in comment.
(LIBC_PRECONFIGURE): Likewise.
(add_ons): Remove variable and sanity checks and logic to locate
add-ons.
(add_ons_automatic): Remove variable.
(configured_add_ons): Likewise.
(add_ons_sfx): Likewise.
(add_ons_pfx): Likewise.
(add_on_subdirs): Likewise.
(sysnames_add_ons): Likewise. Remove loop over add-ons and
consideration of add-ons in Implies handling.
(sysdeps_add_ons): Likewise.
* configure: Regenerated.
* libidn/configure.ac: Remove.
* libidn/configure: Likewise.
* sysdeps/unix/inet/configure.ac: New file.
* sysdeps/unix/inet/configure: New generated file.
* sysdeps/unix/inet/Subdirs: Add libidn.
* Makeconfig (sysdeps-srcdirs): Remove variable.
(+sysdep_dirs): Do not include $(sysdeps-srcdirs).
($(common-objpfx)config.status): Do not depend on add-on files.
($(common-objpfx)shlib-versions.v.i): Do not mention add-ons in
comment.
(all-subdirs): Do not include $(add-on-subdirs).
* Makefile (dist-prepare): Do not use $(sysdeps-add-ons).
* config.make.in (add-ons): Remove variable.
(add-on-subdirs): Likewise.
(sysdeps-add-ons): Likewise.
* manual/Makefile (add-chapters): Remove.
($(objpfx)texis): Do not depend on $(add-chapters).
(nonexamples): Do not handle $(add-chapters).
(examples): Do not handle $(add-ons).
(chapters.% top-menu.%): Do not pass '$(add-chapters)' to
libc-texinfo.sh.
* manual/install.texi (Installation): Do not mention add-ons.
(--enable-add-ons): Do not document configure option.
* INSTALL: Regenerated.
* manual/libc-texinfo.sh: Do not handle $2 add-ons argument.
* manual/maint.texi (Hierarchy Conventions): Do not mention
add-ons.
* scripts/build-many-glibcs.py (Glibc.build_glibc): Do not use
--enable-add-ons.
* scripts/gen-sorted.awk: Do not handle Subdirs files from
add-ons.
* scripts/test-installation.pl: Do not handle glibc-compat add-on.
* sysdeps/nptl/Makeconfig: Do not mention add-ons in comment.
When configuring and building GNU libc using the Mozilla NSS library
for cryptography (--enable-nss-crypt option), also include the
NSPR header files along with the Mozilla NSS library header files.
Finally, when running the check-local-headers test, ignore the
Mozilla NSPR library header files (used by the Mozilla NSS library).
Commit 073e8fa773 requires binutils 2.25
or later to build glibc:
* configure.ac (AS): Require binutils 2.25 or later.
(LD): Likewise.
But it only updated LD version check in configure.ac. This patch adds
the missing AS version check.
* configure.ac (AS): Require binutils 2.25 or later.
* configure: Regenerated.
Since gold doesn't support INSERT in linker script:
https://sourceware.org/bugzilla/show_bug.cgi?id=21676
tst-split-dynreloc fails to link with gold. Check if linker supports
INSERT in linker script before using it.
* config.make.in (have-insert): New.
* configure.ac (libc_cv_insert): New. Set to yes if linker
supports INSERT in linker script.
(AC_SUBST(libc_cv_insert): New.
* configure: Regenerated.
* sysdeps/x86_64/Makefile (tests): Add tst-split-dynreloc only
if $(have-insert) == yes.
This patch implements a requirement of binutils >= 2.25 (up from 2.22)
to build glibc. Tests for 2.24 or later on x86_64 and s390 are
removed. It was already the case, as indicated by buildbot results,
that 2.24 was too old for building tests for 32-bit x86 (produced
internal linker errors linking elf/tst-gnu2-tls1mod.so). I don't know
if any configure tests for binutils features are obsolete given the
increased version requirement.
Tested for x86_64.
* configure.ac (AS): Require binutils 2.25 or later.
(LD): Likewise.
* configure: Regenerated.
* sysdeps/s390/configure.ac (AS): Remove version check.
* sysdeps/s390/configure: Regenerated.
* sysdeps/x86_64/configure.ac (AS): Remove version check.
* sysdeps/x86_64/configure: Regenerated.
* manual/install.texi (Tools for Compilation): Document
requirement for binutils 2.25 or later.
* INSTALL: Regenerated.
This patch makes configure require GCC 4.9 or later for building
glibc, and documents that requirement. Requiring GCC 4.9 or later
allows use of _Generic (as in tzcode). It would allow <stdatomic.h>
and _Atomic to be used as well if desired, although we need to avoid
any libatomic dependencies on any platforms. This patch is explicitly
the minimum to implement a new version requirement, with any
consequent cleanups of conditional code (not in installed headers or
files shared with gnulib etc.) to be done separately.
Tested for x86_64.
* configure.ac (libc_cv_compiler_ok): Require GCC 4.9 or later.
* configure: Regenerated.
* manual/install.texi (Tools for Compilation): Document
requirement for GCC 4.9 or later.
* INSTALL: Regenerated.
All of the major architectures are adopting tunables as a way to add
tuning to the library, from hwcap_mask for aarch64 to HLE for s390 and
ifunc and cache geometry for x86. Given this adoption and the fact
that we don't want additional tuning knobs to be added outside of
tunables, it makes sense to enable tunables by default using this
trivial patch.
Smoke tested on x86 to ensure that tunables code was built without
specifying it as a configure flag. I have kept it as --enabled and
not changed it to --disable since we want to still keep the option of
different kinds of front-ends for tunables.
* configure.ac(--enable-tunables): Enable by default.
* configure: Regenerate.
* NEWS: Mention change.
* manual/install.texi (enable-tunables): Adjust documentation.
* INSTALL: Regenerate.
<bits/std_abs.h> from GCC 7 will include /usr/include/stdlib.h from
"#include_next" (instead of stdlib/stdlib.h in the glibc source
directory), and this turns up as a make dependency. Also make a copy
of <bits/std_abs.h> to prevent it from including /usr/include/stdlib.h.
[BZ #21573]
* Makerules [$(c++-bits-std_abs-h) != ""] (before-compile): Add
$(common-objpfx)bits/std_abs.h.
[$(c++-bits-std_abs-h) != ""] ($(common-objpfx)bits/std_abs.h):
New target.
* config.make.in (c++-bits-std_abs-h): New.
* configure.ac (find_cxx_header): Use "\,$1," with sed.
(CXX_BITS_STD_ABS_H): New.
(AC_SUBST(CXX_BITS_STD_ABS_H)): Likewise.
* configure: Regenerated.
The test for "-z combreloc" fails when cross-compiling on a machine
that uses BSD grep (e.g. on macos). grep complains about empty
subexpression and exits with non-zero status, which is interpreted
by configure as "not found". As a result, support for "-z combreloc"
(HAVE_Z_COMBRELOC) is not detected, leading to link failure on SPARC.
While there, replace fgrep with 'grep -F', as fgrep is non-POSIX.
* configure.ac: Avoid empty subexpression in grep.
Signed-off-by: Alexey Neyman <stilor@att.net>
At the GNU Tools Cauldron 2016, the state of the current tunables
patchset was considered OK with the addition of a way to select the
frontend to be used for the tunables. That is, to avoid being locked
in to one type of frontend initially, it should be possible to build
tunables with a different frontend with something as simple as a
configure switch.
To that effect, this patch enhances the --enable-tunables option to
accept more values than just 'yes' or 'no'. The current frontend (and
default when enable-tunables is 'yes') is called 'valstring', to
select the frontend where a single environment variable is set to a
colon-separated value string. More such frontends can be added in
future.
* Makeconfig (have-tunables): Check for non-negative instead
of positive.
* configure.ac: Add 'valstring' as a valid value for
--enable-tunables.
* configure: Regenerate.
* elf/Makefile (have-tunables): Check for non-negative instead
of positive.
(CPPFLAGS-dl-tunables.c): Define TUNABLES_FRONTEND for
dl-tunables.c.
* elf/dl-tunables.c (GLIBC_TUNABLES): Define only when
TUNABLES_FRONTEND == TUNABLES_FRONTEND_valstring.
(tunables_strdup): Likewise.
(disable_tunables): Likewise.
(parse_tunables): Likewise.
(__tunables_init): Process GLIBC_TUNABLES envvar only when.
TUNABLES_FRONTEND == TUNABLES_FRONTEND_valstring.
* elf/dl-tunables.h (TUNABLES_FRONTEND_valstring): New macro.
(TUNABLES_FRONTEND_yes): New macro, define as
TUNABLES_FRONTEND_valstring by default.
* manual/install.texi: Document new acceptable values for
--enable-tunables.
* INSTALL: Regenerate.
The tunables framework allows us to uniformly manage and expose global
variables inside glibc as switches to users. tunables/README has
instructions for glibc developers to add new tunables.
Tunables support can be enabled by passing the --enable-tunables
configure flag to the configure script. This patch only adds a
framework and does not pose any limitations on how tunable values are
read from the user. It also adds environment variables used in malloc
behaviour tweaking to the tunables framework as a PoC of the
compatibility interface.
* manual/install.texi: Add --enable-tunables option.
* INSTALL: Regenerate.
* README.tunables: New file.
* Makeconfig (CPPFLAGS): Define TOP_NAMESPACE.
(before-compile): Generate dl-tunable-list.h early.
* config.h.in: Add HAVE_TUNABLES.
* config.make.in: Add have-tunables.
* configure.ac: Add --enable-tunables option.
* configure: Regenerate.
* csu/init-first.c (__libc_init_first): Move
__libc_init_secure earlier...
* csu/init-first.c (LIBC_START_MAIN):... to here.
Include dl-tunables.h, libc-internal.h.
(LIBC_START_MAIN) [!SHARED]: Initialize tunables for static
binaries.
* elf/Makefile (dl-routines): Add dl-tunables.
* elf/Versions (ld): Add __tunable_set_val to GLIBC_PRIVATE
namespace.
* elf/dl-support (_dl_nondynamic_init): Unset MALLOC_CHECK_
only when !HAVE_TUNABLES.
* elf/rtld.c (process_envvars): Likewise.
* elf/dl-sysdep.c [HAVE_TUNABLES]: Include dl-tunables.h
(_dl_sysdep_start): Call __tunables_init.
* elf/dl-tunable-types.h: New file.
* elf/dl-tunables.c: New file.
* elf/dl-tunables.h: New file.
* elf/dl-tunables.list: New file.
* malloc/tst-malloc-usable-static.c: New test case.
* malloc/Makefile (tests-static): Add it.
* malloc/arena.c [HAVE_TUNABLES]: Include dl-tunables.h.
Define TUNABLE_NAMESPACE.
(DL_TUNABLE_CALLBACK (set_mallopt_check)): New function.
(DL_TUNABLE_CALLBACK_FNDECL): New macro. Use it to define
callback functions.
(ptmalloc_init): Set tunable values.
* scripts/gen-tunables.awk: New file.
* sysdeps/mach/hurd/dl-sysdep.c: Include dl-tunables.h.
(_dl_sysdep_start): Call __tunables_init.
With all the machinery we just added, we can easily arrange to work even
when the compiler passes in -fstack-protector automatically: all the
necessary bits of glibc are always compiled with -fno-stack-protector
now.
So tear out the check in configure, and add appropriate calls to
-fno-stack-protector in tests that need them (largely those that use
-nostdlib), since we don't yet have a __stack_chk_fail that those
tests can rely upon. (GCC often provides one, but we cannot rely on
this, especially not when bootstrapping.)
When stack protection is disabled, explicitly pass -fno-stack-protector
to everything, to stop a compiler hacked to enable it from inserting
calls to __stack_chk_fail via the PLT in every object file.
When dynamically linking, ifunc resolvers are called before TLS is
initialized, so they cannot be safely stack-protected.
We avoid disabling stack-protection on large numbers of files by
using __attribute__ ((__optimize__ ("-fno-stack-protector")))
to turn it off just for the resolvers themselves. (We provide
the attribute even when statically linking, because we will later
use it elsewhere too.)
This adds =all and =strong, with obvious semantics, defaulting to off.
We don't validate the value of the option yet: that's in a later patch.
Nor do we use it for anything at this stage.
We differentiate between 'the compiler understands -fstack-protector'
and 'the user wanted -fstack-protector' so that we can pass
-fno-stack-protector in appropriate places even if the user didn't want
to turn on -fstack-protector for other parts. (This helps us overcome
another existing limitation, that glibc doesn't work with GCCs hacked
to pass in -fstack-protector by default.)
We also arrange to set the STACK_PROTECTOR_LEVEL #define to a value
appropriate for the stack-protection level in use for each file in
particular.
Add a configure check that looks for python3 and python in that order
since we had agreed in the past to prefer python3 over python in all
our code. The patch also adjusts invocations through the various
Makefiles to use the set variable.
* configure.ac: Check for python3 or python.
* configure: Regenerated.
* config.make.in (PYTHON): New variable.
* benchtests/Makefile: Don't define PYTHON.
(bench): Define target only if PYTHON was defined.
* Rules: Don't define PYTHON.
Define pretty printer targets only if PYTHON was defined.
(tests-printers): Add to tests-unsupported if PYTHON is not
found.
(python-flags, python-invoke): Remove.
(tests-printers-out): Use PYTHON instead of python-invoke.
Some configurations may use NSS cryptographic routines but have no
static library for those routines. The following changes allow glibc to
be built and tested with --enable-nss-crypt, but without having a static
NSS library. At a high level the change does two things:
(1) Detect at configure time if static NSS crypto libraries are
available. Assumes libfreebl3.a (instead of the existing Fedora
libfreebl.a which is incomplete) which matches libfreebl3.so.
(2) If static NSS crypto libraries are _not_ available then adjust the
way in which we build tst-linkall-static. This includes excluding a
reference to crypt and not linking against libcrypt.a, all of which
will fail otherwise.
Testing assumptions:
* Static library is named libfreebl3.a (not libfreebl.a as is currently
provided in Fedora), matching libfreebl3.so shared link name.
Tested on x86_64 on Fedora with:
(a) --enable-nss-crypt, with no static NSS library support: PASS
(previous FAIL)
(b) --enable-nss-crypt, with faked static NSS library support: PASS
(unsupported)
* Requires changing elf/Makefile to include a stub
/lib64/libfreebl3.a for testing purposes.
(c) --disable-nss-crypt: PASS
(default)
No regressions on x86_64.
For details see:
https://www.sourceware.org/ml/libc-alpha/2016-11/msg00647.html
When glibc is compiled with gcc 6.2 that has been configured with
--enable-default-pie and --enable-default-ssp, the configure script
fails to detect that the compiler has ssp turned on by default when
being built for i686-linux-gnu.
This is because gcc is emitting __stack_chk_fail_local but the
script is only looking for __stack_chk_fail. Support both.
Example output:
checking whether x86_64-pc-linux-gnu-gcc -m32 -Wl,-O1 -Wl,--as-needed
implicitly enables -fstack-protector... no
This patch adds a configure check to test if gcc supports attribute ifunc.
The support can either be enabled in <gcc-src>/gcc/config.gcc for one
architecture in general by setting default_gnu_indirect_function variable to yes
or by configuring gcc with --enable-gnu-indirect-function.
The next patch rewrites libc_ifunc macro to use gcc attribute ifunc instead
of inline assembly to generate the IFUNC symbols due to false debuginfo.
If gcc does not support attribute ifunc, the old approach for generating
ifunc'ed symbols is used. Then the debug-information is false. Thus it is
recommended to use a gcc with indirect function support (See notes in INSTALL).
After this patch-series these inline assemblies for ifunc-handling are not
scattered in multiple files but are used only indirect via ifunc-macros
and can simply removed in libc-symbols.h in future.
If glibc is configured with --enable-multi-arch and gcc does not support
attribute ifunc, a configure warning is dumped!
ChangeLog:
* config.h.in (HAVE_GCC_IFUNC): New undef.
* configure.ac: Add check if gcc supports attribute ifunc feature.
* configure: Regenerated.
* manual/install.texi: Add recommendation for gcc with
indirect-function support.
* INSTALL: Regenerated.
Since _dl_tlsdesc_dynamic is called via PLT, we need to add 8 bytes for
push in the PLT entry to align the stack.
[BZ #20309]
* configure.ac (have-mtls-dialect-gnu2): Set to yes if
-mtls-dialect=gnu2 works.
* configure: Regenerated.
* elf/Makefile [have-mtls-dialect-gnu2 = yes]
(tests): Add tst-gnu2-tls1.
(modules-names): Add tst-gnu2-tls1mod.
($(objpfx)tst-gnu2-tls1): New.
(tst-gnu2-tls1mod.so-no-z-defs): Likewise.
(CFLAGS-tst-gnu2-tls1mod.c): Likewise.
* elf/tst-gnu2-tls1.c: New file.
* elf/tst-gnu2-tls1mod.c: Likewise.
* sysdeps/x86_64/dl-tlsdesc.S (_dl_tlsdesc_dynamic): Add 8
bytes for push in the PLT entry to align the stack.
When --enable-bind-now is used to configure glibc build, we can avoid
an extra branch to the PLT entry by using indirect branch via the GOT
slot instead, which is similar to the first instructuon in the PLT
entry. Changes in the shared library sizes in text sections:
Shared library Before (bytes) After (bytes)
libm.so 1060813 1060797
libmvec.so 160881 160805
libpthread.so 94992 94984
librt.so 25064 25048
* config.h.in (BIND_NOW): New.
* configure.ac (BIND_NOW): New. Defined for --enable-bind-now.
* configure: Regenerated.
* sysdeps/x86_64/sysdep.h (JUMPTARGET)[BIND_NOW]: Defined to
indirect branch via the GOT slot.
In preparation to fix the --localedir configure argument we must
move the existing conflicting definition of localedir to a more
appropriate name. Given that all current internal uses of localedir
relate to the compiled locales we rename to complocaledir.
There are configure tests for the linker -z nodelete, -z nodlopen and
-z initfirst options. These options were added in binutils 2.11, so
the tests are obsolete; this patch removes them.
Tested for x86_64 and x86 (testsuite, and that installed shared
libraries are unchanged by the patch).
* configure.ac (libc_cv_z_nodelete): Remove configure test.
(libc_cv_z_nodlopen): Likewise.
(libc_cv_z_initfirst): Likewise.
* configure: Regenerated.
There is a configure test for the --no-whole-archive linker option.
This option was added in binutils 2.7, so the test is obsolete; this
patch removes it.
Tested for x86_64 and x86 (testsuite, and that installed shared
libraries are unchanged by the patch).
* configure.ac (libc_cv_ld_no_whole_archive): Remove configure
test.
* configure: Regenerated.
There is a configure test "for .preinit_array/.init_array/.fini_array
support". Support for this feature was added in binutils 2.13, so the
configure test is obsolete; this patch removes it.
Tested for x86_64 and x86 (testsuite, and that installed shared
libraries are unchanged by the patch).
* configure.ac (libc_cv_initfini_array): Remove configure test.
* configure: Regenerated.
There are various configure tests for visibility support in the
compiler and assember.
GCC support for visibility attributes was added in GCC 3.3. I don't
know what specific fix was intended by the test "for broken
__attribute__((visibility())", but it was added by
<https://sourceware.org/ml/libc-hacker/2002-08/msg00030.html>, and GCC
3.3 appears not to have that breakage, so I suspect it was only ever
in development versions before 3.3 was released. The assembler
support was added in binutils 2.10.
This patch removes the tests in question as obsolete. Two tests that
were formerly conditional on "if test $libc_cv_visibility_attribute =
yes", including the one for linker support for protected data, are now
unconditional.
Tested for x86_64 and x86 (testsuite, and that installed shared
libraries are unchanged by the patch).
* configure.ac (libc_cv_asm_protected_directive): Remove configure
test.
(libc_cv_visibility_attribute): Likewise.
(libc_cv_protected_data): Test unconditionally.
(libc_cv_broken_visibility_attribute): Remove configure test.
(libc_cv_have_sdata_section): Test unconditionally.
* configure: Regenerated.
Now that GCC 4.7 or later is required to build glibc, this patch moves
the build from using -std=gnu99 to -std=gnu11 (option added in 4.7).
This allows use of C11 features from GCC's headers, such as new
float.h macros and max_align_t.
Tested for x86_64 and x86 (testsuite; installed stripped shared
libraries are unchanged by the patch on x86_64, while I see some
slight code reordering of no significance on x86).
* Makeconfig (CFLAGS): Use -std=gnu11 instead of -std=gnu99.
* Makefile ($(objpfx)c++-types-check.out): Filter out -std=gnu11
instead of -std=gnu99.
* configure.ac (systemtap): Test with -std=gnu11 instead of
-std=gnu99.
* configure: Regenerated.
* math/gen-auto-libm-tests.c: Use -std=gnu11 instead of -std=gnu99
in compilation command in comment.
sysdeps/nptl/configure.ac tests for forced unwind support and the C
cleanup attribute, giving errors if either is unsupported. It does
nothing beyond running those two tests.
Both the attribute, and _Unwind_GetCFA which is used in the forced
unwind test, were added in GCC 3.3. Thus these tests are long
obsolete, and this patch removes the configure fragment running them,
along with associated conditionals.
Tested for x86_64 and x86 (testsuite, and that installed stripped
shared libraries are unchanged by the patch).
* sysdeps/nptl/configure.ac: Remove file.
* sysdeps/nptl/configure: Remove generated file.
* configure.ac (libc_cv_forced_unwind): Do not substitute.
* configure: Regenerated.
* config.h.in (HAVE_FORCED_UNWIND): Remove #undef.
* config.make.in (have-forced-unwind): Remove variable.
* nptl/Makefile [$(have-forced-unwind) = yes]: Make code
unconditional.
* nptl/descr.h [HAVE_FORCED_UNWIND]: Likewise.
* nptl/unwind.c [HAVE_FORCED_UNWIND]: Likewise.
(__pthread_unwind) [!HAVE_FORCED_UNWIND]: Remove conditional code.
* nptl/version.c [HAVE_FORCED_UNWIND]: Make code unconditional.
* sysdeps/nptl/Makefile [$(have-forced-unwind) = yes]: Make code
unconditional.
This patch implements a requirement of GCC 4.7 or later to build
glibc.
This was discussed in the thread starting at
<https://sourceware.org/ml/libc-alpha/2015-08/msg00851.html>.
Concerns were expressed by Mike and David. At
<https://sourceware.org/ml/libc-alpha/2015-10/msg00453.html> I have
provided a 14-patch series showing in outline the cleanups facilitated
by this version requirement, as requested by Mike (this patch is the
first in that series, with the addition of a NEWS entry). Given the
absence of further concerns or alternative proposals for criteria for
updates to this version requirement as requested in
<https://sourceware.org/ml/libc-alpha/2015-10/msg00065.html>, I am
interpreting this as "absence of sustained opposition" under Carlos's
definition at <https://sourceware.org/glibc/wiki/Consensus> and
proposing this patch for inclusion in glibc. I'd like to remind
people testing with 4.6 that if they move to testing with GCC 5 then
it will probably be about four years before they need to update the
compiler they use to test glibc again.
Although on the principles of time-based updates I think a move to
requiring binutils 2.23 would be reasonable, I'm not currently aware
of any cleanups that would facilitate so am not proposing that at this
time (but would expect to propose a move to requiring binutils 2.24 in
a year's time, as that brings features such as AVX512 support that
should allow some conditionals to be cleaned up). If someone thinks a
move to requiring 2.23 would help clean things up for their
architecture, please speak up. (And in general, I suspect there are
lots of architecture-specific configure tests that could be removed on
the basis of current GCC and binutils version requirements, given how
I've found architecture-independent tests obsolete on the basis of
version requirements going back 20 years.)
Tested for x86_64 and x86 (testsuite, and that installed shared
libraries are unchanged by the patch).
* configure.ac (libc_cv_compiler_ok): Require GCC 4.7 or later.
* configure: Regenerated.
* manual/install.texi (Tools for Compilation): Document
requirement for GCC 4.7 or later.
* INSTALL: Regenerated.
There seemed to be support in response to
<https://sourceware.org/ml/libc-alpha/2015-10/msg00510.html> for
removing configure tests that exist only to produce errors, where we
expect that tool versions failing the tests would also fail the tests
of minimum GCC / binutils versions.
This patch removes the tests for TLS support as one instance of such
tests. Since the addition of TLS emulation support in GCC 4.3, I
don't think these tests would have failed even if proper TLS support
(as required by glibc) was missing in that architecture's GCC back
end, so any new glibc ports wanting a substantive test (if there are
actual GCC or binutils versions for those architectures, with
supported version numbers, missing TLS support) would have needed an
architecture-specific test anyway.
Tested for x86_64 and x86 (testsuite, and that installed shared
libraries are unchanged by the patch).
* configure.ac (libc_cv_gcc___thread): Remove configure test.
(libc_cv_gcc_tls_model_attr): Likewise.
* configure: Regenerated.
There is a configure test for "whether we need to use -P to assemble
.S files".
I think this test is long obsolete. I don't have a specific reference
to a binutils change or version that obsoleted this test, but: (a) we
only support GNU binutils; (b) it looks like every architecture
supported by glibc has '#' as a line comment character in its gas
port; (c) in any case, if the (compiler, assembler) combination in use
cannot compile a .S file without special options, that would clearly
be a substantially broken combination, which I don't think we need to
allow for at all.
The test in question was added by:
Thu Jan 27 16:46:03 1994 Roland McGrath (roland@churchy.gnu.ai.mit.edu)
* configure.in (asm-CPPFLAGS): Add new check to see if assembling
a .S file loses without -P. If so, set asm-CPPFLAGS=-P in config.make.
This patch removes the test and the reference to this issue in the
comment on the default empty definition of asm-CPPFLAGS. (Various
other settings of asm-CPPFLAGS remain in sysdeps Makefile fragments.)
Tested for x86_64 and x86 (testsuite, and that installed shared
libraries are unchanged by the patch).
* configure.ac (libc_cv_need_minus_P): Remove configure test.
* configure: Regenerated.
* Makeconfig (asm-CPPFLAGS): Remove reference to -P in comment.
There is a configure test for the presence of glibc 2.0 headers (that
were renamed / no longer installed in glibc 2.1) and associated
support for removing them on "make install".
Normal practice for subsequent removal / renaming of installed files
has been not to do anything special about removing them; if you want
installed files from an old installation removed reliably, you need to
use a packaging system that tracks what files were installed by a
previous glibc package (via installing in an intermediate directory
with install_root). I think it's been long enough since 2.0 that it's
not particularly useful to have that special logic for those old
headers either; this patch removes it.
Tested for x86_64 and x86 (testsuite, and that installed shared
libraries are unchanged by the patch).
* configure.ac (old_glibc_headers): Remove configure test.
* configure: Regenerated.
* config.make.in (old-glibc-headers): Remove variable.
* Makefile [!$(install_root) && $(old-glibc-headers) = yes]
(install): Remove dependency on remove-old-headers.
(headers2_0): Remove variable.
(remove-old-headers): Remove rule.
There is a configure test for assembler support for the .text
directive.
I suppose this test must have been aimed at some non-ELF platform or
non-GNU assembler. Certainly the GNU assembler has had ELF-specific
architecture-independent handling for .text since version 2.2, and
generic non-ELF-specific support predates that.
This patch removes this test as obsolete.
Tested for x86_64 and x86 (testsuite, and that installed shared
libraries are unchanged by the patch).
* configure.ac (libc_cv_dot_text): Remove configure test.
(libc_cv_asm_set_directive): Use .text instead of
${libc_cv_dot_text} in configure test.
* configure: Regenerated.
There is a configure test for assembler support for the
gnu_unique_object symbol type. This support was added in binutils
2.20, so is present in all versions supported for building glibc.
Thus, I think the configure test can be removed; this patch does so.
Now, there is a caveat that the gas NEWS entry refers to this as a
feature for GNU/Linux targets. But the condition is use of
ELFOSABI_GNU or ELFOSABI_NONE. ELFOSABI_GNU covers Hurd as well as
GNU/Linux (as was the case with the older ELFOSABI_LINUX name), and
ELFOSABI_NONE means this is effectively OS-independent. Furthermore,
I think a correct binutils port for any glibc target ought to support
this feature for use with glibc; glibc supports this as an
OS-independent feature (the configure test is only about glibc
testcases).
Tested for x86_64 (testsuite, and that installed shared libraries are
unchanged by the patch).
* configure.ac (libc_cv_asm_unique_object): Remove configure test.
* configure: Regenerated.
* config.h.in (HAVE_ASM_UNIQUE_OBJECT): Remove #undef.
* elf/tst-unique1.c (do_test) [HAVE_ASM_UNIQUE_OBJECT]: Make code
unconditional.
* elf/tst-unique1mod1.c [HAVE_ASM_UNIQUE_OBJECT]: Likewise.
* elf/tst-unique1mod2.c [HAVE_ASM_UNIQUE_OBJECT]: Likewise.
* elf/tst-unique2.c (do_test) [HAVE_ASM_UNIQUE_OBJECT]: Likewise.
(do_test) [!HAVE_ASM_UNIQUE_OBJECT]: Remove conditional code.
* elf/tst-unique2mod1.c [HAVE_ASM_UNIQUE_OBJECT]: Make code
unconditional.
* elf/tst-unique2mod2.c [HAVE_ASM_UNIQUE_OBJECT]: Likewise.
With gcc-4.9, a new -fstack-protector-strong flag is available that is
between -fstack-protector (pretty weak) and -fstack-protector-all (pretty
strong) that provides good trade-offs between overhead but still providing
good coverage. Update the places in glibc that use ssp to use this flag
when it's available.
This also kills off the indirection of hardcoding the flag name in the
Makefiles and adding it based on a have-ssp boolean. Instead, the build
always expands the $(stack-protector) variable to the best ssp setting.
This makes the build logic a bit simpler and allows people to easily set
to a diff flag like:
make stack-protector=-fstack-protector-all
