Commit Graph

695 Commits

Author SHA1 Message Date
Adhemerval Zanella
3d53d18fc7 elf: Enable TLS descriptor tests on aarch64
The aarch64 uses 'trad' for traditional tls and 'desc' for tls
descriptors, but unlike other targets it defaults to 'desc'.  The
gnutls2 configure check does not set aarch64 as an ABI that uses
TLS descriptors, which then disable somes stests.

Also rename the internal machinery fron gnu2 to tls descriptors.

Checked on aarch64-linux-gnu.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
2024-03-19 14:53:30 -03:00
Adhemerval Zanella
968b0ca944 Ignore undefined symbols for -mtls-dialect=gnu2
So it does not fail for arm config that defaults to -mtp=soft (which
issues a call to __aeabi_read_tp).
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
2024-03-19 14:53:30 -03:00
Paul Eggert
dff8da6b3e Update copyright dates with scripts/update-copyrights 2024-01-01 10:53:40 -08:00
Adhemerval Zanella
e6e3c66688 crypt: Remove libcrypt support
All the crypt related functions, cryptographic algorithms, and
make requirements are removed,  with only the exception of md5
implementation which is moved to locale folder since it is
required by localedef for integrity protection (libc's
locale-reading code does not check these, but localedef does
generate them).

Besides thec code itself, both internal documentation and the
manual is also adjusted.  This allows to remove both --enable-crypt
and --enable-nss-crypt configure options.

Checked with a build for all affected ABIs.

Co-authored-by: Zack Weinberg <zack@owlfolio.org>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2023-10-30 13:03:59 -03:00
Adhemerval Zanella Netto
78ceef25d6 configure: Remove --enable-all-warnings option
The option is not activelly tested and has bitrotten, to fix it
would require a lot of work and multiple fixes.  A better option
would to evaluate each option and enable the warning if it makes
sense.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2023-08-01 15:35:25 -03:00
Adhemerval Zanella
a3090c2c98 scripts: Fix fortify checks if compiler does not support _FORTIFY_SOURCE=3
The 30379efad1 added _FORTIFY_SOURCE checks without check if compiler
does support all used fortify levels.  This patch fixes it by first
checking at configure time the maximum support fortify level and using
it instead of a pre-defined one.

Checked on x86_64 with gcc 11, 12, and 13.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Tested-by: Florian Weimer <fweimer@redhat.com>
2023-07-20 17:58:26 -03:00
Siddhesh Poyarekar
6c85c5a177
configure: Disable building libcrypt by default
We mentioned eventual dropping of libcrypt in the 2.28 NEWS.  Actually
put that plan in motion by first disabling building libcrypt by default.
note in NEWS that the library will be dropped completely in a future
release.

Also add a couple of builds into build-many-glibcs.py.

Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Reviewed-by: Andreas K. Hüttel <dilfridge@gentoo.org>
2023-07-20 20:38:13 +02:00
Siddhesh Poyarekar
c6cb8783b5 configure: Use autoconf 2.71
Bump autoconf requirement to 2.71 to allow regenerating configure on
more recent distributions.  autoconf 2.71 has been in Fedora since F36
and is the current version in Debian stable (bookworm).  It appears to
be current in Gentoo as well.

All sysdeps configure and preconfigure scripts have also been
regenerated; all changes are trivial transformations that do not affect
functionality.

Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2023-07-17 10:08:10 -04:00
Frédéric Bérat
64d9580cdf Allow glibc to be built with _FORTIFY_SOURCE
Add --enable-fortify-source option.

It is now possible to enable fortification through a configure option.
The level may be given as parameter, if none is provided, the configure
script will determine what is the highest level possible that can be set
considering GCC built-ins availability and set it.
If level is explicitly set to 3, configure checks if the compiler
supports the built-in function necessary for it or raise an error if it
isn't.

If the configure option isn't explicitly enabled, it _FORTIFY_SOURCE is
forcibly undefined (and therefore disabled).

The result of the configure checks are new variables, ${fortify_source}
and ${no_fortify_source} that can be used to appropriately populate
CFLAGS.

A dedicated patch will follow to make use of this variable in Makefiles
when necessary.

Updated NEWS and INSTALL.

Adding dedicated x86_64 variant that enables the configuration.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2023-07-05 16:59:34 +02:00
Adhemerval Zanella Netto
33237fe83d Remove --enable-tunables configure option
And make always supported.  The configure option was added on glibc 2.25
and some features require it (such as hwcap mask, huge pages support, and
lock elisition tuning).  It also simplifies the build permutations.

Changes from v1:
 * Remove glibc.rtld.dynamic_sort changes, it is orthogonal and needs
   more discussion.
 * Cleanup more code.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2023-03-29 14:33:06 -03:00
Adhemerval Zanella
6384171fa0 Remove --disable-experimental-malloc option
It is the default since 2.26 and it has bitrotten over the years,
By using it multiple malloc tests fails:

  FAIL: malloc/tst-memalign-2
  FAIL: malloc/tst-memalign-2-malloc-hugetlb1
  FAIL: malloc/tst-memalign-2-malloc-hugetlb2
  FAIL: malloc/tst-memalign-2-mcheck
  FAIL: malloc/tst-mxfast-malloc-hugetlb1
  FAIL: malloc/tst-mxfast-malloc-hugetlb2
  FAIL: malloc/tst-tcfree2
  FAIL: malloc/tst-tcfree2-malloc-hugetlb1
  FAIL: malloc/tst-tcfree2-malloc-hugetlb2

Checked on x86_64-linux-gnu.

Reviewed-by: DJ Delorie <dj@redhat.com>
2023-03-29 14:33:06 -03:00
Adhemerval Zanella Netto
91fc5b9990 Remove --with-default-link configure option
Now that there is no need to use a special linker script to hardening
internal data structures, remove the --with-default-link configure
option and associated definitions.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2023-03-27 13:57:55 -03:00
Adhemerval Zanella
02abdab0d1 configure: Move nm, objdump, and readelf to LIBC_PROG_BINUTILS
Allow the variables to be overriden or have the defaults come
from the compiler currently in use.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2023-01-12 09:05:09 -03:00
Adhemerval Zanella
2d2d7e1a8f configure: Allow user override LD, AR, OBJCOPY, and GPROF
The only way to override LD, AR, OBJCOPY, and GPROF is through
--with-binutils (setting the environments variables on configure is
overridden by LIBC_PROG_BINUTILS).

The build-many-glibcs.py (bmg) glibcs option generates a working config,
but not fully concise (some tools will be set from environment variable,
while other will be set from $CC --print-prog-name).  So remove the
environment variable set to always use the "$CC --print-prog-name".
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2023-01-11 17:51:17 -03:00
Adhemerval Zanella
2b0da5028d configure: Remove AS check
The assembler is not issued directly, but rather always through CC
wrapper.  The binutils version check if done with LD instead.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2022-12-06 09:40:19 -03:00
Adhemerval Zanella
6cfc50f40a configure: Remove check if ld is GNU
Assume linker has gnu argument input style.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2022-12-06 09:40:19 -03:00
Adhemerval Zanella
f35b7ce02f configure: Remove check if as is GNU
It is not used in any place.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2022-12-06 09:40:19 -03:00
Adhemerval Zanella
43ecc41dda configure: Move locale tools early
When using --with-binutils, the configure might not use the specified
linker or assembler while checking for expected support.  Move the
tools check early, before any compiler usage test.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2022-12-06 09:40:19 -03:00
Adhemerval Zanella
596183a1ee Rewrite find_cxx_header config configure.ac
With clang if the main file is <stdin>, the first non-main-file
dependency is not listed in the -MP output.  Although it was fixed
on clang-16 [1], this change adds portability for older version.

[1] ff9576f745

Reviewed-by: Fangrui Song <maskray@google.com>
2022-11-07 10:40:17 -03:00
Adhemerval Zanella
8d98c7c00f configure: Use -Wno-ignored-attributes if compiler warns about multiple aliases
clang emits an warning when a double alias redirection is used, to warn
the the original symbol will be used even when weak definition is
overridden.  However, this is a common pattern for weak_alias, where
multiple alias are set to same symbol.

Reviewed-by: Fangrui Song <maskray@google.com>
2022-11-01 09:51:06 -03:00
Adhemerval Zanella
5c5a8b99cf Disable use of -fsignaling-nans if compiler does not support it
Reviewed-by: Fangrui Song <maskray@google.com>
2022-11-01 09:46:08 -03:00
Ludovic Courtès
361d6454c0 Correctly determine libc.so 'OUTPUT_FORMAT' when cross-compiling.
Commit 87d583c6e8 replaces the sed script
with an "objdump -f" invocation to determine the 'OUTPUT_FORMAT' bit of
the libc.so linker script.

However, when cross-compiling, for example from x86_64-linux-gnu to
aarch64-linux-gnu, "objdump -f" would report the wrong
format ("elf64-little").  Conversely, "aarch64-linux-gnu-objdump -f"
reports "elf64-littleaarch64" as expected.

This patch changes 'configure.ac' to use AC_CHECK_TOOL rather than
'$CC -print-prog-name=objdump' to determine the value of the OBJDUMP
variable.  That way, OBJDUMP is set to TRIPLET-objdump when
cross-compiling for TRIPLET.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2022-10-28 17:19:02 -04:00
Florian Weimer
89baed0b93 Revert "Detect ld.so and libc.so version inconsistency during startup"
This reverts commit 6f85dbf102.

Once this change hits the release branches, it will require relinking
of all statically linked applications before static dlopen works
again, for the majority of updates on release branches: The NEWS file
is regularly updated with bug references, so the __libc_early_init
suffix changes, and static dlopen cannot find the function anymore.

While this ABI check is still technically correct (we do require
rebuilding & relinking after glibc updates to keep static dlopen
working), it is too drastic for stable release branches.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2022-08-25 18:46:43 +02:00
Florian Weimer
6f85dbf102 Detect ld.so and libc.so version inconsistency during startup
The files NEWS, include/link.h, and sysdeps/generic/ldsodefs.h
contribute to the version fingerprint used for detection.  The
fingerprint can be further refined using the --with-extra-version-id
configure argument.

_dl_call_libc_early_init is replaced with _dl_lookup_libc_early_init.
The new function is used store a pointer to libc.so's
__libc_early_init function in the libc_map_early_init member of the
ld.so namespace structure.  This function pointer can then be called
directly, so the separate invocation function is no longer needed.

The versioned symbol lookup needs the symbol versioning data
structures, so the initialization of libc_map and libc_map_early_init
is now done from _dl_check_map_versions, after this information
becomes available.  (_dl_map_object_from_fd does not set this up
in time, so the initialization code had to be moved from there.)
This means that the separate initialization code can be removed from
dl_main because _dl_check_map_versions covers all maps, including
the initial executable loaded by the kernel.  The lookup still happens
before relocation and the invocation of IFUNC resolvers, so IFUNC
resolvers are protected from ABI mismatch.

The __libc_early_init function pointer is not protected because
so little code runs between the pointer write and the invocation
(only dynamic linker code and IFUNC resolvers).

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2022-08-24 17:35:57 +02:00
Adhemerval Zanella
f39ff483f3 Remove configure fno_unit_at_a_time
Since it is not used any longer.

Reviewed-by: Fangrui Song <maskray@google.com>
2022-05-13 10:54:41 -03:00
Florian Weimer
e47de5cb2d Do not use --hash-style=both for building glibc shared objects
The comment indicates that --hash-style=both was used to maintain
compatibility with static dlopen, but we had many internal ABI
changes since then, so this compatiblity does not add value anymore.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2022-04-29 16:37:51 +02:00
Fangrui Song
e895cff59a elf: Support DT_RELR relative relocation format [BZ #27924]
PIE and shared objects usually have many relative relocations. In
2017/2018, SHT_RELR/DT_RELR was proposed on
https://groups.google.com/g/generic-abi/c/bX460iggiKg/m/GxjM0L-PBAAJ
("Proposal for a new section type SHT_RELR") and is a pre-standard. RELR
usually takes 3% or smaller space than R_*_RELATIVE relocations. The
virtual memory size of a mostly statically linked PIE is typically 5~10%
smaller.

---

Notes I will not include in the submitted commit:

Available on https://sourceware.org/git/?p=glibc.git;a=shortlog;h=refs/heads/maskray/relr

"pre-standard": even Solaris folks are happy with the refined generic-abi
proposal. Cary Coutant will apply the change
https://sourceware.org/pipermail/libc-alpha/2021-October/131781.html

This patch is simpler than Chrome OS's glibc patch and makes ELF_DYNAMIC_DO_RELR
available to all ports. I don't think the current glibc implementation
supports ia64 in an ELFCLASS32 container. That said, the style I used is
works with an ELFCLASS32 container for 64-bit machine if ElfW(Addr) is
64-bit.

* Chrome OS folks have carried a local patch since 2018 (latest version:
  https://chromium.googlesource.com/chromiumos/overlays/chromiumos-overlay/+/refs/heads/main/sys-libs/glibc/files/local/glibc-2.32).
  I.e. this feature has been battle tested.
* Android bionic supports 2018 and switched to DT_RELR==36 in 2020.
* The Linux kernel has supported CONFIG_RELR since 2019-08
  (https://git.kernel.org/linus/5cf896fb6be3effd9aea455b22213e27be8bdb1d).
* A musl patch (by me) exists but is not applied:
  https://www.openwall.com/lists/musl/2019/03/06/3
* rtld-elf from FreeBSD 14 will support DT_RELR.

I believe upstream glibc should support DT_RELR to benefit all Linux
distributions. I filed some feature requests to get their attention:

* Gentoo: https://bugs.gentoo.org/818376
* Arch Linux: https://bugs.archlinux.org/task/72433
* Debian https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=996598
* Fedora https://bugzilla.redhat.com/show_bug.cgi?id=2014699

As of linker support (to the best of my knowledge):

* LLD support DT_RELR.
* https://chromium.googlesource.com/chromiumos/overlays/chromiumos-overlay/+/refs/heads/main/sys-devel/binutils/files/
  has a gold patch.
* GNU ld feature request https://sourceware.org/bugzilla/show_bug.cgi?id=27923

Changes from the original patch:

1. Check the linker option, -z pack-relative-relocs, which add a
GLIBC_ABI_DT_RELR symbol version dependency on the shared C library if
it provides a GLIBC_2.XX symbol version.
2. Change make variale to have-dt-relr.
3. Rename tst-relr-no-pie to tst-relr-pie for --disable-default-pie.
4. Use TEST_VERIFY in tst-relr.c.
5. Add the check-tst-relr-pie.out test to check for linker generated
libc.so version dependency on GLIBC_ABI_DT_RELR.
6. Move ELF_DYNAMIC_DO_RELR before ELF_DYNAMIC_DO_REL.
2022-04-26 10:16:11 -07:00
Florian Weimer
198abcbb94 Default to --with-default-link=no (bug 25812)
This is necessary to place the libio vtables into the RELRO segment.
New tests elf/tst-relro-ldso and elf/tst-relro-libc are added to
verify that this is what actually happens.

The new tests fail on ia64 due to lack of (default) RELRO support
inbutils, so they are XFAILed there.
2022-04-22 10:59:03 +02:00
Fangrui Song
3ee318c923 Remove -z combreloc and HAVE_Z_COMBRELOC
-z combreloc has been the default regadless of the architecture since
binutils commit f4d733664aabd7bd78c82895e030ec9779a92809 (2002). The
configure check added in commit fdde83499a (2001) has long been
unneeded.

We can therefore treat HAVE_Z_COMBRELOC as always 1 and delete dead code
paths in dl-machine.h files (many were copied from commit a711b01d34
and ee0cb67ec2).

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2022-04-04 17:19:07 -07:00
Sam James
cb7b1c9014 configure.ac: fix bashisms in configure.ac
configure scripts need to be runnable with a POSIX-compliant /bin/sh.

On many (but not all!) systems, /bin/sh is provided by Bash, so errors
like this aren't spotted. Notably Debian defaults to /bin/sh provided
by dash which doesn't tolerate such bashisms as '=='.

This retains compatibility with bash.

Fixes configure warnings/errors like:
```
checking if compiler warns about alias for function with incompatible types... yes
/var/tmp/portage/sys-libs/glibc-2.34-r10/work/glibc-2.34/configure: 4209: test: xyes: unexpected operator
```

Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Signed-off-by: Sam James <sam@gentoo.org>
2022-03-22 21:53:43 -04:00
Andreas Schwab
e8faf48321 Regenerate configure 2022-02-03 09:35:38 +01:00
Carlos O'Donell
e0beb0c9f1 Regenerate configure. 2022-02-03 00:10:03 -05:00
H.J. Lu
ded3aeb202 Properly handle --disable-default-pie [BZ #28780]
When --disable-default-pie is used, all glibc programs and the testsuite
should be built as position dependent executables (non-PIE), regardless
if the build compiler supports PIE or static PIE.

When --disable-default-pie is used, don't build static PIE by default.

This fixes BZ #28780.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2022-01-17 07:27:25 -08:00
Florian Weimer
9ba202c78f Add --with-rtld-early-cflags configure option
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2022-01-14 20:17:15 +01:00
H.J. Lu
bd1616c6be Properly check linker option in LIBC_LINKER_FEATURE [BZ #28738]
Update LIBC_LINKER_FEATURE to also check linker warning message since
unknown linker -z option may be ignored by linker:

$ touch x.c
$ gcc -shared -Wl,-z,foobar x.c
/usr/bin/ld: warning: -z foobar ignored
$ echo $?
0
$

This fixes BZ #28738.

Reviewed-by: Florian Weimer <fweimer@redhat.com>
2022-01-03 05:12:34 -08:00
Siddhesh Poyarekar
23645707f1 Replace --enable-static-pie with --disable-default-pie
Build glibc programs and tests as PIE by default and enable static-pie
automatically if the architecture and toolchain supports it.

Also add a new configuration option --disable-default-pie to prevent
building programs as PIE.

Only the following architectures now have PIE disabled by default
because they do not work at the moment.  hppa, ia64, alpha and csky
don't work because the linker is unable to handle a pcrel relocation
generated from PIE objects.  The microblaze compiler is currently
failing with an ICE.  GNU hurd tries to enable static-pie, which does
not work and hence fails.  All these targets have default PIE disabled
at the moment and I have left it to the target maintainers to enable PIE
on their targets.

build-many-glibcs runs clean for all targets.  I also tested x86_64 on
Fedora and Ubuntu, to verify that the default build as well as
--disable-default-pie work as expected with both system toolchains.

Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2021-12-13 08:08:59 +05:30
H.J. Lu
bada2e312a Add --with-timeoutfactor=NUM to specify TIMEOUTFACTOR
On Ice Lake and Tiger Lake laptops, some test programs timeout when there
are 3 "make check -j8" runs in parallel.  Add --with-timeoutfactor=NUM to
specify an integer to scale the timeout of test programs, which can be
overriden by TIMEOUTFACTOR environment variable.

Reviewed-by: Florian Weimer <fweimer@redhat.com>
2021-12-04 12:58:28 -08:00
Adhemerval Zanella
04e8169f1d Check if linker also support -mtls-dialect=gnu2
Since some linkers (for instance lld for i386) does not support it
for all architectures.

Checked on i686-linux-gnu.

Reviewed-by: Fangrui Song <maskray@google.com>
2021-10-29 09:21:37 -03:00
Adhemerval Zanella
3d5ecb6246 Fix LIBC_PROG_BINUTILS for -fuse-ld=lld
GCC does not print the correct linker when -fuse-ld=lld is used with
the -print-prog-name=ld:

  $ gcc -v 2>&1 | tail -n 1
  gcc version 11.2.0 (Ubuntu 11.2.0-7ubuntu2)
  $ gcc
  ld

This is different than for gold:

  $ gcc -fuse-ld=gold -print-prog-name=ld
  ld.gold

Using ld.lld as the static linker name prints the expected result.

This is only required when -fuse-ld=lld is used, if lld is used as
the 'ld' programs (through a symlink) LIBC_PROG_BINUTILS works
as expected.

Checked on x86_64-linux-gnu.

Reviewed-by: Fangrui Song <maskray@google.com>
2021-10-29 09:21:37 -03:00
Fangrui Song
8438135d34 configure: Don't check LD -v --help for LIBC_LINKER_FEATURE
When LIBC_LINKER_FEATURE is used to check a linker option with the equal
sign, it will likely fail because the LD -v --help output may look like
`-z lam-report=[none|warning|error]` while the needle is something like
`-z lam-report=warning`.

The LD -v --help filter doesn't save much time, so just remove it.
2021-10-25 13:17:44 -07:00
Fangrui Song
5f07d47e4b configure: Fix check for INSERT in linker script
GCC/Clang use local access when referencing a const variable,
so the conftest.so may have no dynamic relocation.
LLD reports `error: unable to insert .foo after .rela.dyn` when the
destination section does not exist.

Use a non-const int to ensure that .rela.dyn exists.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2021-09-13 12:39:20 -07:00
Fangrui Song
224edada60 configure: Allow LD to be LLD 13.0.0 or above [BZ #26558]
When using LLD (LLVM linker) as the linker, configure prints a confusing
message.

    *** These critical programs are missing or too old: GNU ld

LLD>=13.0.0 can build glibc --enable-static-pie. (8.0.0 needs one
workaround for -Wl,-defsym=_begin=0. 9.0.0 works with
--disable-static-pie).

XFAIL two tests sysdeps/x86/tst-ifunc-isa-* which have the BZ #28154
issue (LLD follows the PowerPC port of GNU ld for ifunc by placing
IRELATIVE relocations in .rela.dyn, triggering a glibc ifunc fragility).

The set of dynamic symbols is the same with GNU ld and LLD,
modulo unused SHN_ABS version node symbols.

For comparison, gold does not support --enable-static-pie
yet (--no-dynamic-linker is unsupported BZ #22221), yet
has 6 failures more than LLD. gold linked libc.so has
larger .dynsym differences with GNU ld and LLD
(non-default version symbols are changed to default versions
by a version script BZ #28196).
2021-08-31 20:23:34 -07:00
Fangrui Song
9926f6e2ee elf: Skip tst-auditlogmod-* if the linker doesn't support --depaudit [BZ #28151]
gold and ld.lld do not support --audit or --depaudit.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-08-24 09:35:32 -07:00
Fangrui Song
302247c891 elf: Unconditionally use __ehdr_start
We can consider __ehdr_start (from binutils 2.23 onwards)
unconditionally supported, since configure.ac requires binutils>=2.25.

The configure.ac check is related to an ia64 bug fixed by binutils 2.24.
See https://sourceware.org/pipermail/libc-alpha/2014-August/053503.html

Tested on x86_64-linux-gnu. Tested build-many-glibcs.py with
aarch64-linux-gnu and s390x-linux-gnu.

Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
2021-08-10 11:04:56 -07:00
Matheus Castanho
ebae2f5a6f Add build option to disable usage of scv on powerpc
Commit 68ab82f566 added support for the scv
syscall ABI on powerpc.  Since then systems that have kernel and processor
support started using scv.  However adding the proper support for a new syscall
ABI requires changes to several other projects (e.g. qemu, valgrind, strace,
kernel), which are gradually receiving support.

Meanwhile, having a way to disable scv on glibc at build time can be useful for
distros that may encounter conflicts with projects that still do not support the
scv ABI, buying time until proper support is added.

This commit adds a --disable-scv option that disables scv support and uses sc
for all syscalls, like before commit 68ab82f566.

Reviewed-by: Raphael M Zinsly <rzinsly@linux.ibm.com>
2021-06-10 16:23:25 -03:00
Naohiro Tamura
b190bccc8a configure: Replaced obsolete AC_TRY_COMPILE
This patch replaced obsolete AC_TRY_COMPILE to AC_COMPILE_IFELSE or
AC_PREPROC_IFELSE.
It has been confirmed that GNU 'autoconf' 2.69 suppressed obsolete
warnings, updated the following files:
  - configure
  - sysdeps/mach/configure
  - sysdeps/mach/hurd/configure
  - sysdeps/s390/configure
  - sysdeps/unix/sysv/linux/configure
and didn't change the following files:
  - sysdeps/ieee754/ldbl-opt/configure
  - sysdeps/unix/sysv/linux/powerpc/configure

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-06-04 10:16:00 -03:00
Adhemerval Zanella
f294306ba1 Remove --enable-stackguard-randomization (BZ #27872)
Last ENABLE_STACKGUARD_RANDOMIZE usage was removed by 4a103975c4.
2021-05-19 10:22:19 -03:00
Florian Weimer
ad201afe5c Add pthread-in-libc, libpthread-routines-var, librt-routines-var
These make variables can be used to add routines to different
libraries for the Hurd and Linux builds.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2021-05-03 08:13:32 +02:00
Fangrui Song
cd6ae7ea54 Set the retain attribute on _elf_set_element if CC supports [BZ #27492]
So that text_set_element/data_set_element/bss_set_element defined
variables will be retained by the linker.

Note: 'used' and 'retain' are orthogonal: 'used' makes sure the variable
will not be optimized out; 'retain' prevents section garbage collection
if the linker support SHF_GNU_RETAIN.

GNU ld 2.37 and LLD 13 will support -z start-stop-gc which allow C
identifier name sections to be GCed even if there are live
__start_/__stop_ references.

Without the change, there are some static linking problems, e.g.
_IO_cleanup (libio/genops.c) may be discarded by ld --gc-sections, so
stdout is not flushed on exit.

Note: GCC may warning 'retain' attribute ignored while __has_attribute(retain)
is 1 (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99587).

Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
2021-04-16 11:26:39 -07:00
Florian Weimer
0923f74ada Support for multiple versions in versioned_symbol, compat_symbol
This essentially folds compat_symbol_unique functionality into
compat_symbol.

This change eliminates the need for intermediate aliases for defining
multiple symbol versions, for both compat_symbol and versioned_symbol.
Some binutils versions do not suport multiple versions per symbol on
some targets, so aliases are automatically introduced, similar to what
compat_symbol_unique did.  To reduce symbol table sizes, a configure
check is added to avoid these aliases if they are not needed.

The new mechanism works with data symbols as well as function symbols,
due to the way an assembler-level redirect is used.  It is not
compatible with weak symbols for old binutils versions, which is why
the definition of __malloc_initialize_hook had to be changed.  This
is not a loss of functionality because weak symbols do not matter
to dynamic linking.

The placeholder symbol needs repeating in nptl/libpthread-compat.c
now that compat_symbol is used, but that seems more obvious than
introducing yet another macro.

A subtle difference was that compat_symbol_unique made the symbol
global automatically.  compat_symbol does not do this, so static
had to be removed from the definition of
__libpthread_version_placeholder.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-03-25 12:33:02 +01:00