Commit Graph

647 Commits

Author SHA1 Message Date
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
Samuel Thibault
16b597807d elf: Fix not compiling ifunc tests that need gcc ifunc support 2021-03-24 01:52:46 +01:00
Naohiro Tamura
3907c7bf0f configure: Remove obsolete AC_CHECK_TOOL_PREFIX
This patch removes obsolete AC_CHECK_TOOL_PREFIX.
It has been confirmed that AC_CHECK_TOOL_PREFIX is defined as NOP in
GNU 'autoconf' 2.69 [1], so we can safely remove it.
The 'configure' file has been deleted one blank line by the 'autoconf'
2.69 command .

   [1] autoconf-2.69/share/autoconf/autoconf/programs.m4
   181 # AC_CHECK_TOOL_PREFIX
   182 # --------------------
   183 AU_DEFUN([AC_CHECK_TOOL_PREFIX])
2021-02-21 18:35:30 -05:00
Szabolcs Nagy
374cef32ac configure: Check for static PIE support
Add SUPPORT_STATIC_PIE that targets can define if they support
static PIE. This requires PI_STATIC_AND_HIDDEN support and various
linker features as described in

  commit 9d7a3741c9
  Add --enable-static-pie configure option to build static PIE [BZ #19574]

Currently defined on x86_64, i386 and aarch64 where static PIE is
known to work.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-01-21 15:54:50 +00:00
Fangrui Song
87d583c6e8 install: Replace scripts/output-format.sed with objdump -f [BZ #26559]
GNU ld and gold have supported --print-output-format since 2011. glibc
requires binutils>=2.25 (2015), so if LD is GNU ld or gold, we can
assume the option is supported.

lld is by default a cross linker supporting multiple targets. It auto
detects the file format and does not need OUTPUT_FORMAT. It does not
support --print-output-format.

By parsing objdump -f, we can support all the three linkers.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-01-11 12:03:36 -08:00
Richard Earnshaw
3378408987 config: Allow memory tagging to be enabled when configuring glibc
This patch adds the configuration machinery to allow memory tagging to be
enabled from the command line via the configure option --enable-memory-tagging.

The current default is off, though in time we may change that once the API
is more stable.
2020-12-21 15:25:25 +00:00
Petr Vorel
5500cdba40 Remove --enable-obsolete-rpc configure flag
Sun RPC was removed from glibc. This includes rpcgen program, librpcsvc,
and Sun RPC headers. Also test for bug #20790 was removed
(test for rpcgen).

Backward compatibility for old programs is kept only for architectures
and ABIs that have been added in or before version 2.28.

libtirpc is mature enough, librpcsvc and rpcgen are provided in
rpcsvc-proto project.

NOTE: libnsl code depends on Sun RPC (installed libnsl headers use
installed Sun RPC headers), thus --enable-obsolete-rpc was a dependency
for --enable-obsolete-nsl (removed in a previous commit).

The arc ABI list file has to be updated because the port was added
with the sunrpc symbols

Tested-by: Carlos O'Donell <carlos@redhat.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2020-07-13 19:36:35 +02:00
Petr Vorel
ae7a94e5e3 Remove --enable-obsolete-nsl configure flag
this means that *always* libnsl is only built as shared library for
backward compatibility and the NSS modules libnss_nis and libnss_nisplus
are not built at all, libnsl's headers aren't installed.

This compatibility is kept only for architectures and ABIs that have
been added in or before version 2.28.

Replacement implementations based on TIRPC, which additionally support
IPv6, are available from <https://github.com/thkukuk/>.

This change does not affect libnss_compat which does not depended
on libnsl since 2.27 and thus can be used without NIS.

libnsl code depends on Sun RPC, e.g. on --enable-obsolete-rpc (installed
libnsl headers use installed Sun RPC headers), which will be removed in
the following commit.
2020-07-08 17:25:57 +02:00
Florian Weimer
ce12fc7113 Remove NO_CTORS_DTORS_SECTIONS macro
This was originally added to support binutils older than version
2.22:

  <https://sourceware.org/ml/libc-alpha/2010-12/msg00051.html>

Since 2.22 is older than the minimum required binutils version
for building glibc, we no longer need this.  (The changes do
not impact the statically linked startup code.)
2020-05-18 15:39:34 +02:00
Adhemerval Zanella
a63189c021 Remove reference of --without-fp on configure 2020-03-06 09:53:24 -03:00
Fangrui Song
87a698a216 Improve IFUNC check [BZ #25506]
GNU ld's RISCV port does not support IFUNC. ld -no-pie produces no
relocation and the test passed incorrectly. Be more rigid by testing
IRELATIVE explicitly.

Tested-by: Aurelien Jarno <aurelien@aurel32.net>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2020-03-05 17:05:05 -03:00
Florian Weimer
9fb8139079 x86: Assume --enable-cet if GCC defaults to CET [BZ #25225]
This links in CET support if GCC defaults to CET.  Otherwise, __CET__
is defined, yet CET functionality is not compiled and linked into the
dynamic loader, resulting in a linker failure due to undefined
references to _dl_cet_check and _dl_open_check.
2019-12-03 18:48:18 +01:00
Paul Eggert
02d35f0646 Fix http: URL in 'configure'
* configure.ac: Add URL to AC_INIT so that it generates an
https: URL instead of an http: URL.
* configure: Regenerate.
2019-09-09 14:16:40 -07:00
Paul Eggert
5a82c74822 Prefer https to http for gnu.org and fsf.org URLs
Also, change sources.redhat.com to sourceware.org.
This patch was automatically generated by running the following shell
script, which uses GNU sed, and which avoids modifying files imported
from upstream:

sed -ri '
  s,(http|ftp)(://(.*\.)?(gnu|fsf|sourceware)\.org($|[^.]|\.[^a-z])),https\2,g
  s,(http|ftp)(://(.*\.)?)sources\.redhat\.com($|[^.]|\.[^a-z]),https\2sourceware.org\4,g
' \
  $(find $(git ls-files) -prune -type f \
      ! -name '*.po' \
      ! -name 'ChangeLog*' \
      ! -path COPYING ! -path COPYING.LIB \
      ! -path manual/fdl-1.3.texi ! -path manual/lgpl-2.1.texi \
      ! -path manual/texinfo.tex ! -path scripts/config.guess \
      ! -path scripts/config.sub ! -path scripts/install-sh \
      ! -path scripts/mkinstalldirs ! -path scripts/move-if-change \
      ! -path INSTALL ! -path  locale/programs/charmap-kw.h \
      ! -path po/libc.pot ! -path sysdeps/gnu/errlist.c \
      ! '(' -name configure \
            -execdir test -f configure.ac -o -f configure.in ';' ')' \
      ! '(' -name preconfigure \
            -execdir test -f preconfigure.ac ';' ')' \
      -print)

and then by running 'make dist-prepare' to regenerate files built
from the altered files, and then executing the following to cleanup:

  chmod a+x sysdeps/unix/sysv/linux/riscv/configure
  # Omit irrelevant whitespace and comment-only changes,
  # perhaps from a slightly-different Autoconf version.
  git checkout -f \
    sysdeps/csky/configure \
    sysdeps/hppa/configure \
    sysdeps/riscv/configure \
    sysdeps/unix/sysv/linux/csky/configure
  # Omit changes that caused a pre-commit check to fail like this:
  # remote: *** error: sysdeps/powerpc/powerpc64/ppc-mcount.S: trailing lines
  git checkout -f \
    sysdeps/powerpc/powerpc64/ppc-mcount.S \
    sysdeps/unix/sysv/linux/s390/s390-64/syscall.S
  # Omit change that caused a pre-commit check to fail like this:
  # remote: *** error: sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S: last line does not end in newline
  git checkout -f sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S
2019-09-07 02:43:31 -07:00
H.J. Lu
92ad88fe72 elf/Makefile: Run IFUNC tests if binutils supports IFUNC
We should run IFUNC tests with --disable-multi-arch if the toolchain
supports IFUNCs.  For correctness, --disable-multi-arch must not
remove IFUNC support from the loader.

Tested on x86-64, x32 and i686 with and without --disable-multi-arch.

	* configure.ac (have-ifunc): New LIBC_CONFIG_VAR.
	* configure: Regenerated.
	* elf/Makefile: Run IFUNC tests if binutils supports IFUNC.

Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
2019-02-27 13:21:55 -08:00
Joseph Myers
4dcbbc3b28 Require GCC 6.2 or later to build glibc.
As discussed during development for glibc 2.29, when we increased the
required minimum GCC version for building glibc to GCC 5, working
purely based on the times at which such requirements have been
increased in the past it would be appropriate for glibc 2.30 to
require GCC 6 (matching GCC 4.9 having been required for glibc 2.26).
Naming 6.2 specifically as the minimum version then means a separate
version requirement no longer needs to be specified for powerpc64le.

Thus, this patch increases the minimum to 6.2, removing the
documentation of the separate requirement for powerpc64le.  It does
not remove the powerpc64le configure test, or any __GNUC_PREREQ that
could be removed as not being in installed headers or files shared
with gnulib; I think such cleanups are best done separately.

Tested for x86_64.

	* configure.ac (libc_cv_compiler_ok): Require GCC 6.2 or later.
	* configure: Regenerated.
	* manual/install.texi (Tools for Compilation): Update minimum GCC
	version.
	* INSTALL: Regenerated.
2019-02-01 16:27:44 +00:00
Joseph Myers
192963be49 Require GCC 5 or later to build glibc (bug 23993).
We know that building glibc with GCC 4.9 is broken on various
platforms (bug 23993).  As it's more than a year since we last
increased the minimum GCC version to build glibc, this patch changes
the requirement to be GCC 5 or later (indeed, based on 4.9 having been
required for building 2.26, it would be consistent in terms of timing
to require GCC 6 or later from the 2.30 release onwards).  It
deliberately just updates the configure test and corresponding
documentation, leaving removal of no-longer-needed __GNUC_PREREQ tests
for a separate patch.

In the NEWS entry, the requirement for a newer GCC version for
powerpc64le is reiterated (as in the entry for the 4.9 requirement in
2.26) to avoid suggesting the version requirement there has gone down.
(If that version goes up further as part of support for binary128 long
double, of course the wording would change at that time.)

Tested for x86_64.

	[BZ #23993]
	* configure.ac (libc_cv_compiler_ok): Require GCC 5 or later.
	* configure: Regenerated.
	* manual/install.texi (Tools for Compilation): Update minimum GCC
	version.
	* INSTALL: Regenerated.
2018-12-21 17:53:40 +00:00
Joseph Myers
c6982f7efc Patch to require Python 3.4 or later to build glibc.
This patch makes Python 3.4 or later a required tool for building
glibc, so allowing changes of awk, perl etc. code used in the build
and test to Python code without any such changes needing makefile
conditionals or to handle older Python versions.

This patch makes the configure test for Python check the version and
give an error if Python is missing or too old, and removes makefile
conditionals that are no longer needed.  It does not itself convert
any code from another language to Python, and does not remove any
compatibility with older Python versions from existing scripts.

Tested for x86_64.

	* configure.ac (PYTHON_PROG): Use AC_CHECK_PROG_VER.  Set
	critic_missing for versions before 3.4.
	* configure: Regenerated.
	* manual/install.texi (Tools for Compilation): Document
	requirement for Python to build glibc.
	* INSTALL: Regenerated.
	* Rules [PYTHON]: Make code unconditional.
	* benchtests/Makefile [PYTHON]: Likewise.
	* conform/Makefile [PYTHON]: Likewise.
	* manual/Makefile [PYTHON]: Likewise.
	* math/Makefile [PYTHON]: Likewise.
2018-10-29 15:28:05 +00:00
Adhemerval Zanella
b5c45e8375 Fix ifunc support with DT_TEXTREL segments (BZ#20480)
Currently, DT_TEXTREL is incompatible with IFUNC.  When DT_TEXTREL or
DF_TEXTREL is seen, the dynamic linker calls __mprotect on the segments
with PROT_READ|PROT_WRITE before applying dynamic relocations. It leads
to segfault when performing IFUNC resolution (which requires PROT_EXEC
as well for the IFUNC resolver).

This patch makes it call __mprotect with extra PROT_WRITE bit, which
will keep the PROT_EXEC bit if exists, and thus fixes the segfault.
FreeBSD rtld libexec/rtld-elf/rtld.c (reloc_textrel_prot) does the same.

Checked on x86_64-linux-gnu, i686-linux-gnu, aarch64-linux-gnu,
sparc64-linux-gnu, sparcv9-linux-gnu, and armv8-linux-gnueabihf.

	Adam J. Richte  <adam_richter2004@yahoo.com>
	Adhemerval Zanella  <adhemerval.zanella@linaro.org>
	Fangrui Song  <maskray@google.com>

	[BZ #20480]
	* config.h.in (CAN_TEXTREL_IFUNC): New define.
	* configure.ac: Add check if linker supports textrel relocation with
	ifunc.
	* elf/dl-reloc.c (_dl_relocate_object): Use all required flags on
	DT_TEXTREL segments, not only PROT_READ and PROT_WRITE.
	* elf/Makefile (ifunc-pie-tests): Add tst-ifunc-textrel.
	(CFLAGS-tst-ifunc-textrel.c): New rule.
	* elf/tst-ifunc-textrel.c: New file.
2018-09-25 16:27:50 -03:00
Florian Weimer
6413fcde4f Add --with-nonshared-cflags option to configure 2018-08-17 11:44:39 +02:00
H.J. Lu
f753fa7dea x86: Support IBT and SHSTK in Intel CET [BZ #21598]
Intel Control-flow Enforcement Technology (CET) instructions:

https://software.intel.com/sites/default/files/managed/4d/2a/control-flow-en
forcement-technology-preview.pdf

includes Indirect Branch Tracking (IBT) and Shadow Stack (SHSTK).

GNU_PROPERTY_X86_FEATURE_1_IBT is added to GNU program property to
indicate that all executable sections are compatible with IBT when
ENDBR instruction starts each valid target where an indirect branch
instruction can land.  Linker sets GNU_PROPERTY_X86_FEATURE_1_IBT on
output only if it is set on all relocatable inputs.

On an IBT capable processor, the following steps should be taken:

1. When loading an executable without an interpreter, enable IBT and
lock IBT if GNU_PROPERTY_X86_FEATURE_1_IBT is set on the executable.
2. When loading an executable with an interpreter, enable IBT if
GNU_PROPERTY_X86_FEATURE_1_IBT is set on the interpreter.
  a. If GNU_PROPERTY_X86_FEATURE_1_IBT isn't set on the executable,
     disable IBT.
  b. Lock IBT.
3. If IBT is enabled, when loading a shared object without
GNU_PROPERTY_X86_FEATURE_1_IBT:
  a. If legacy interwork is allowed, then mark all pages in executable
     PT_LOAD segments in legacy code page bitmap.  Failure of legacy code
     page bitmap allocation causes an error.
  b. If legacy interwork isn't allowed, it causes an error.

GNU_PROPERTY_X86_FEATURE_1_SHSTK is added to GNU program property to
indicate that all executable sections are compatible with SHSTK where
return address popped from shadow stack always matches return address
popped from normal stack.  Linker sets GNU_PROPERTY_X86_FEATURE_1_SHSTK
on output only if it is set on all relocatable inputs.

On a SHSTK capable processor, the following steps should be taken:

1. When loading an executable without an interpreter, enable SHSTK if
GNU_PROPERTY_X86_FEATURE_1_SHSTK is set on the executable.
2. When loading an executable with an interpreter, enable SHSTK if
GNU_PROPERTY_X86_FEATURE_1_SHSTK is set on interpreter.
  a. If GNU_PROPERTY_X86_FEATURE_1_SHSTK isn't set on the executable
     or any shared objects loaded via the DT_NEEDED tag, disable SHSTK.
  b. Otherwise lock SHSTK.
3. After SHSTK is enabled, it is an error to load a shared object
without GNU_PROPERTY_X86_FEATURE_1_SHSTK.

To enable CET support in glibc, --enable-cet is required to configure
glibc.  When CET is enabled, both compiler and assembler must support
CET.  Otherwise, it is a configure-time error.

To support CET run-time control,

1. _dl_x86_feature_1 is added to the writable ld.so namespace to indicate
if IBT or SHSTK are enabled at run-time.  It should be initialized by
init_cpu_features.
2. For dynamic executables:
   a. A l_cet field is added to struct link_map to indicate if IBT or
      SHSTK is enabled in an ELF module.  _dl_process_pt_note or
      _rtld_process_pt_note is called to process PT_NOTE segment for
      GNU program property and set l_cet.
   b. _dl_open_check is added to check IBT and SHSTK compatibilty when
      dlopening a shared object.
3. Replace i386 _dl_runtime_resolve and _dl_runtime_profile with
_dl_runtime_resolve_shstk and _dl_runtime_profile_shstk, respectively if
SHSTK is enabled.

CET run-time control can be changed via GLIBC_TUNABLES with

$ export GLIBC_TUNABLES=glibc.tune.x86_shstk=[permissive|on|off]
$ export GLIBC_TUNABLES=glibc.tune.x86_ibt=[permissive|on|off]

1. permissive: SHSTK is disabled when dlopening a legacy ELF module.
2. on: IBT or SHSTK are always enabled, regardless if there are IBT or
SHSTK bits in GNU program property.
3. off: IBT or SHSTK are always disabled, regardless if there are IBT or
SHSTK bits in GNU program property.

<cet.h> from CET-enabled GCC is automatically included by assembly codes
to add GNU_PROPERTY_X86_FEATURE_1_IBT and GNU_PROPERTY_X86_FEATURE_1_SHSTK
to GNU program property.  _CET_ENDBR is added at the entrance of all
assembly functions whose address may be taken.  _CET_NOTRACK is used to
insert NOTRACK prefix with indirect jump table to support IBT.  It is
defined as notrack when _CET_NOTRACK is defined in <cet.h>.

	 [BZ #21598]
	* configure.ac: Add --enable-cet.
	* configure: Regenerated.
	* elf/Makefille (all-built-dso): Add a comment.
	* elf/dl-load.c (filebuf): Moved before "dynamic-link.h".
	Include <dl-prop.h>.
	(_dl_map_object_from_fd): Call _dl_process_pt_note on PT_NOTE
	segment.
	* elf/dl-open.c: Include <dl-prop.h>.
	(dl_open_worker): Call _dl_open_check.
	* elf/rtld.c: Include <dl-prop.h>.
	(dl_main): Call _rtld_process_pt_note on PT_NOTE segment.  Call
	_rtld_main_check.
	* sysdeps/generic/dl-prop.h: New file.
	* sysdeps/i386/dl-cet.c: Likewise.
	* sysdeps/unix/sysv/linux/x86/cpu-features.c: Likewise.
	* sysdeps/unix/sysv/linux/x86/dl-cet.h: Likewise.
	* sysdeps/x86/cet-tunables.h: Likewise.
	* sysdeps/x86/check-cet.awk: Likewise.
	* sysdeps/x86/configure: Likewise.
	* sysdeps/x86/configure.ac: Likewise.
	* sysdeps/x86/dl-cet.c: Likewise.
	* sysdeps/x86/dl-procruntime.c: Likewise.
	* sysdeps/x86/dl-prop.h: Likewise.
	* sysdeps/x86/libc-start.h: Likewise.
	* sysdeps/x86/link_map.h: Likewise.
	* sysdeps/i386/dl-trampoline.S (_dl_runtime_resolve): Add
	_CET_ENDBR.
	(_dl_runtime_profile): Likewise.
	(_dl_runtime_resolve_shstk): New.
	(_dl_runtime_profile_shstk): Likewise.
	* sysdeps/linux/x86/Makefile (sysdep-dl-routines): Add dl-cet
	if CET is enabled.
	(CFLAGS-.o): Add -fcf-protection if CET is enabled.
	(CFLAGS-.os): Likewise.
	(CFLAGS-.op): Likewise.
	(CFLAGS-.oS): Likewise.
	(asm-CPPFLAGS): Add -fcf-protection -include cet.h if CET
	is enabled.
	(tests-special): Add $(objpfx)check-cet.out.
	(cet-built-dso): New.
	(+$(cet-built-dso:=.note)): Likewise.
	(common-generated): Add $(cet-built-dso:$(common-objpfx)%=%.note).
	($(objpfx)check-cet.out): New.
	(generated): Add check-cet.out.
	* sysdeps/x86/cpu-features.c: Include <dl-cet.h> and
	<cet-tunables.h>.
	(TUNABLE_CALLBACK (set_x86_ibt)): New prototype.
	(TUNABLE_CALLBACK (set_x86_shstk)): Likewise.
	(init_cpu_features): Call get_cet_status to check CET status
	and update dl_x86_feature_1 with CET status.  Call
	TUNABLE_CALLBACK (set_x86_ibt) and TUNABLE_CALLBACK
	(set_x86_shstk).  Disable and lock CET in libc.a.
	* sysdeps/x86/cpu-tunables.c: Include <cet-tunables.h>.
	(TUNABLE_CALLBACK (set_x86_ibt)): New function.
	(TUNABLE_CALLBACK (set_x86_shstk)): Likewise.
	* sysdeps/x86/sysdep.h (_CET_NOTRACK): New.
	(_CET_ENDBR): Define if not defined.
	(ENTRY): Add _CET_ENDBR.
	* sysdeps/x86/dl-tunables.list (glibc.tune): Add x86_ibt and
	x86_shstk.
	* sysdeps/x86_64/dl-trampoline.h (_dl_runtime_resolve): Add
	_CET_ENDBR.
	(_dl_runtime_profile): Likewise.
2018-07-16 14:08:27 -07:00
Florian Weimer
f2873d2da0 testrun.sh: Implement --tool=strace, --tool=valgrind
$(file …) appears to be the only convenient way to create files
with newlines and make substitution variables.  This needs make 4.0
(released in 2013), so update the requirement to match.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2018-07-04 15:30:45 +02:00
Zack Weinberg
e69d994a63 New configure option --disable-crypt.
Some Linux distributions are experimenting with a new, separately
maintained and hopefully more agile implementation of the crypt
API.  To facilitate this, add a configure option which disables
glibc's embedded libcrypt.  When this option is given, libcrypt.*
and crypt.h will not be built nor installed.
2018-06-29 16:53:47 +02:00
H.J. Lu
00c714df39 Pass -no-pie to GCC only if GCC defaults to PIE [BZ #22614]
After --enable-static-pie is added to configure, libc_cv_pie_default is
set to yes when either --enable-static-pie is used to configure glibc
or GCC defaults to PIE.  We should set no-pie-ldflag to -no-pie, which
is supported on GCC 6 and later, only if GCC defaults to PIE, not when
--enable-static-pie is used to configure glibc.

Tested on x32 with --enable-static-pie using GCC 5 and without
--enable-static-pie using GCC 7.

	[BZ #22614]
	* Makeconfig (no-pie-ldflag): Set to -no-pie only if
	$(cc-pie-default) == yes.
	* config.make.in (cc-pie-default): New.
	* configure.ac (libc_cv_pie_default): Renamed to ...
	(libc_cv_cc_pie_default): This.
	(libc_cv_pie_default): Set to $libc_cv_cc_pie_default.
	* configure: Regenerated.
2017-12-18 12:24:38 -08:00
H.J. Lu
9d7a3741c9 Add --enable-static-pie configure option to build static PIE [BZ #19574]
Static PIE extends address space layout randomization to static
executables.  It provides additional security hardening benefits at
the cost of some memory and performance.

Dynamic linker, ld.so, is a standalone program which can be loaded at
any address.  This patch adds a configure option, --enable-static-pie,
to embed the part of ld.so in static executable to create static position
independent executable (static PIE).  A static PIE is similar to static
executable, but can be loaded at any address without help from a dynamic
linker.  When --enable-static-pie is used to configure glibc, libc.a is
built as PIE and all static executables, including tests, are built as
static PIE.  The resulting libc.a can be used together with GCC 8 or
above to build static PIE with the compiler option, -static-pie.  But
GCC 8 isn't required to build glibc with --enable-static-pie.  Only GCC
with PIE support is needed.  When an older GCC is used to build glibc
with --enable-static-pie, proper input files are passed to linker to
create static executables as static PIE, together with "-z text" to
prevent dynamic relocations in read-only segments, which are not allowed
in static PIE.

The following changes are made for static PIE:

1. Add a new function, _dl_relocate_static_pie, to:
   a. Get the run-time load address.
   b. Read the dynamic section.
   c. Perform dynamic relocations.
Dynamic linker also performs these steps.  But static PIE doesn't load
any shared objects.
2. Call _dl_relocate_static_pie at entrance of LIBC_START_MAIN in
libc.a.  crt1.o, which is used to create dynamic and non-PIE static
executables, is updated to include a dummy _dl_relocate_static_pie.
rcrt1.o is added to create static PIE, which will link in the real
_dl_relocate_static_pie.  grcrt1.o is also added to create static PIE
with -pg.  GCC 8 has been updated to support rcrt1.o and grcrt1.o for
static PIE.

Static PIE can work on all architectures which support PIE, provided:

1. Target must support accessing of local functions without dynamic
relocations, which is needed in start.S to call __libc_start_main with
function addresses of __libc_csu_init, __libc_csu_fini and main.  All
functions in static PIE are local functions.  If PIE start.S can't reach
main () defined in a shared object, the code sequence:

	pass address of local_main to __libc_start_main
	...

local_main:
	tail call to main via PLT

can be used.
2. start.S is updated to check PIC instead SHARED for PIC code path and
avoid dynamic relocation, when PIC is defined and SHARED isn't defined,
to support static PIE.
3. All assembly codes are updated check PIC instead SHARED for PIC code
path to avoid dynamic relocations in read-only sections.
4. All assembly codes are updated check SHARED instead PIC for static
symbol name.
5. elf_machine_load_address in dl-machine.h are updated to support static
PIE.
6. __brk works without TLS nor dynamic relocations in read-only section
so that it can be used by __libc_setup_tls to initializes TLS in static
PIE.

NB: When glibc is built with GCC defaulted to PIE, libc.a is compiled
with -fPIE, regardless if --enable-static-pie is used to configure glibc.
When glibc is configured with --enable-static-pie, libc.a is compiled
with -fPIE, regardless whether GCC defaults to PIE or not.  The same
libc.a can be used to build both static executable and static PIE.
There is no need for separate PIE copy of libc.a.

On x86-64, the normal static sln:

   text	   data	    bss	    dec	    hex	filename
 625425	   8284	   5456	 639165	  9c0bd	elf/sln

the static PIE sln:

   text	   data	    bss	    dec	    hex	filename
 657626	  20636	   5392	 683654	  a6e86	elf/sln

The code size is increased by 5% and the binary size is increased by 7%.

Linker requirements to build glibc with --enable-static-pie:

1. Linker supports --no-dynamic-linker to remove PT_INTERP segment from
static PIE.
2. Linker can create working static PIE.  The x86-64 linker needs the
fix for

https://sourceware.org/bugzilla/show_bug.cgi?id=21782

The i386 linker needs to be able to convert "movl main@GOT(%ebx), %eax"
to "leal main@GOTOFF(%ebx), %eax" if main is defined locally.

Binutils 2.29 or above are OK for i686 and x86-64.  But linker status for
other targets need to be verified.

3. Linker should resolve undefined weak symbols to 0 in static PIE:

https://sourceware.org/bugzilla/show_bug.cgi?id=22269

4. Many ELF backend linkers incorrectly check bfd_link_pic for TLS
relocations, which should check bfd_link_executable instead:

https://sourceware.org/bugzilla/show_bug.cgi?id=22263

Tested on aarch64, i686 and x86-64.

Using GCC 7 and binutils master branch, build-many-glibcs.py with
--enable-static-pie with all patches for static PIE applied have the
following build successes:

PASS: glibcs-aarch64_be-linux-gnu build
PASS: glibcs-aarch64-linux-gnu build
PASS: glibcs-armeb-linux-gnueabi-be8 build
PASS: glibcs-armeb-linux-gnueabi build
PASS: glibcs-armeb-linux-gnueabihf-be8 build
PASS: glibcs-armeb-linux-gnueabihf build
PASS: glibcs-arm-linux-gnueabi build
PASS: glibcs-arm-linux-gnueabihf build
PASS: glibcs-arm-linux-gnueabihf-v7a build
PASS: glibcs-arm-linux-gnueabihf-v7a-disable-multi-arch build
PASS: glibcs-m68k-linux-gnu build
PASS: glibcs-microblazeel-linux-gnu build
PASS: glibcs-microblaze-linux-gnu build
PASS: glibcs-mips64el-linux-gnu-n32 build
PASS: glibcs-mips64el-linux-gnu-n32-nan2008 build
PASS: glibcs-mips64el-linux-gnu-n32-nan2008-soft build
PASS: glibcs-mips64el-linux-gnu-n32-soft build
PASS: glibcs-mips64el-linux-gnu-n64 build
PASS: glibcs-mips64el-linux-gnu-n64-nan2008 build
PASS: glibcs-mips64el-linux-gnu-n64-nan2008-soft build
PASS: glibcs-mips64el-linux-gnu-n64-soft build
PASS: glibcs-mips64-linux-gnu-n32 build
PASS: glibcs-mips64-linux-gnu-n32-nan2008 build
PASS: glibcs-mips64-linux-gnu-n32-nan2008-soft build
PASS: glibcs-mips64-linux-gnu-n32-soft build
PASS: glibcs-mips64-linux-gnu-n64 build
PASS: glibcs-mips64-linux-gnu-n64-nan2008 build
PASS: glibcs-mips64-linux-gnu-n64-nan2008-soft build
PASS: glibcs-mips64-linux-gnu-n64-soft build
PASS: glibcs-mipsel-linux-gnu build
PASS: glibcs-mipsel-linux-gnu-nan2008 build
PASS: glibcs-mipsel-linux-gnu-nan2008-soft build
PASS: glibcs-mipsel-linux-gnu-soft build
PASS: glibcs-mips-linux-gnu build
PASS: glibcs-mips-linux-gnu-nan2008 build
PASS: glibcs-mips-linux-gnu-nan2008-soft build
PASS: glibcs-mips-linux-gnu-soft build
PASS: glibcs-nios2-linux-gnu build
PASS: glibcs-powerpc64le-linux-gnu build
PASS: glibcs-powerpc64-linux-gnu build
PASS: glibcs-tilegxbe-linux-gnu-32 build
PASS: glibcs-tilegxbe-linux-gnu build
PASS: glibcs-tilegx-linux-gnu-32 build
PASS: glibcs-tilegx-linux-gnu build
PASS: glibcs-tilepro-linux-gnu build

and the following build failures:

FAIL: glibcs-alpha-linux-gnu build

elf/sln is failed to link due to:

assertion fail bfd/elf64-alpha.c:4125

This is caused by linker bug and/or non-PIC code in PIE libc.a.

FAIL: glibcs-hppa-linux-gnu build

elf/sln is failed to link due to:

collect2: fatal error: ld terminated with signal 11 [Segmentation fault]

https://sourceware.org/bugzilla/show_bug.cgi?id=22537

FAIL: glibcs-ia64-linux-gnu build

elf/sln is failed to link due to:

collect2: fatal error: ld terminated with signal 11 [Segmentation fault]

FAIL: glibcs-powerpc-linux-gnu build
FAIL: glibcs-powerpc-linux-gnu-soft build
FAIL: glibcs-powerpc-linux-gnuspe build
FAIL: glibcs-powerpc-linux-gnuspe-e500v1 build

elf/sln is failed to link due to:

ld: read-only segment has dynamic relocations.

This is caused by linker bug and/or non-PIC code in PIE libc.a.  See:

https://sourceware.org/bugzilla/show_bug.cgi?id=22264

FAIL: glibcs-powerpc-linux-gnu-power4 build

elf/sln is failed to link due to:

findlocale.c:96:(.text+0x22c): @local call to ifunc memchr

This is caused by linker bug and/or non-PIC code in PIE libc.a.

FAIL: glibcs-s390-linux-gnu build

elf/sln is failed to link due to:

collect2: fatal error: ld terminated with signal 11 [Segmentation fault], core dumped

assertion fail bfd/elflink.c:14299

This is caused by linker bug and/or non-PIC code in PIE libc.a.

FAIL: glibcs-sh3eb-linux-gnu build
FAIL: glibcs-sh3-linux-gnu build
FAIL: glibcs-sh4eb-linux-gnu build
FAIL: glibcs-sh4eb-linux-gnu-soft build
FAIL: glibcs-sh4-linux-gnu build
FAIL: glibcs-sh4-linux-gnu-soft build

elf/sln is failed to link due to:

ld: read-only segment has dynamic relocations.

This is caused by linker bug and/or non-PIC code in PIE libc.a.  See:

https://sourceware.org/bugzilla/show_bug.cgi?id=22263

Also TLS code sequence in SH assembly syscalls in glibc doesn't match TLS
code sequence expected by ld:

https://sourceware.org/bugzilla/show_bug.cgi?id=22270

FAIL: glibcs-sparc64-linux-gnu build
FAIL: glibcs-sparcv9-linux-gnu build
FAIL: glibcs-tilegxbe-linux-gnu build
FAIL: glibcs-tilegxbe-linux-gnu-32 build
FAIL: glibcs-tilegx-linux-gnu build
FAIL: glibcs-tilegx-linux-gnu-32 build
FAIL: glibcs-tilepro-linux-gnu build

elf/sln is failed to link due to:

ld: read-only segment has dynamic relocations.

This is caused by linker bug and/or non-PIC code in PIE libc.a.  See:

https://sourceware.org/bugzilla/show_bug.cgi?id=22263

	[BZ #19574]
	* INSTALL: Regenerated.
	* Makeconfig (real-static-start-installed-name): New.
	(pic-default): Updated for --enable-static-pie.
	(pie-default): New for --enable-static-pie.
	(default-pie-ldflag): Likewise.
	(+link-static-before-libc): Replace $(DEFAULT-LDFLAGS-$(@F))
	with $(if $($(@F)-no-pie),$(no-pie-ldflag),$(default-pie-ldflag)).
	Replace $(static-start-installed-name) with
	$(real-static-start-installed-name).
	(+prectorT): Updated for --enable-static-pie.
	(+postctorT): Likewise.
	(CFLAGS-.o): Add $(pie-default).
	(CFLAGS-.op): Likewise.
	* NEWS: Mention --enable-static-pie.
	* config.h.in (ENABLE_STATIC_PIE): New.
	* configure.ac (--enable-static-pie): New configure option.
	(have-no-dynamic-linker): New LIBC_CONFIG_VAR.
	(have-static-pie): Likewise.
	Enable static PIE if linker supports --no-dynamic-linker.
	(ENABLE_STATIC_PIE): New AC_DEFINE.
	(enable-static-pie): New LIBC_CONFIG_VAR.
	* configure: Regenerated.
	* csu/Makefile (omit-deps): Add r$(start-installed-name) and
	gr$(start-installed-name) for --enable-static-pie.
	(extra-objs): Likewise.
	(install-lib): Likewise.
	(extra-objs): Add static-reloc.o and static-reloc.os
	($(objpfx)$(start-installed-name)): Also depend on
	$(objpfx)static-reloc.o.
	($(objpfx)r$(start-installed-name)): New.
	($(objpfx)g$(start-installed-name)): Also depend on
	$(objpfx)static-reloc.os.
	($(objpfx)gr$(start-installed-name)): New.
	* csu/libc-start.c (LIBC_START_MAIN): Call _dl_relocate_static_pie
	in libc.a.
	* csu/libc-tls.c (__libc_setup_tls): Add main_map->l_addr to
	initimage.
	* csu/static-reloc.c: New file.
	* elf/Makefile (routines): Add dl-reloc-static-pie.
	(elide-routines.os): Likewise.
	(DEFAULT-LDFLAGS-tst-tls1-static-non-pie): Removed.
	(tst-tls1-static-non-pie-no-pie): New.
	* elf/dl-reloc-static-pie.c: New file.
	* elf/dl-support.c (_dl_get_dl_main_map): New function.
	* elf/dynamic-link.h (ELF_DURING_STARTUP): Also check
	STATIC_PIE_BOOTSTRAP.
	* elf/get-dynamic-info.h (elf_get_dynamic_info): Likewise.
	* gmon/Makefile (tests): Add tst-gmon-static-pie.
	(tests-static): Likewise.
	(DEFAULT-LDFLAGS-tst-gmon-static): Removed.
	(tst-gmon-static-no-pie): New.
	(CFLAGS-tst-gmon-static-pie.c): Likewise.
	(CRT-tst-gmon-static-pie): Likewise.
	(tst-gmon-static-pie-ENV): Likewise.
	(tests-special): Likewise.
	($(objpfx)tst-gmon-static-pie.out): Likewise.
	(clean-tst-gmon-static-pie-data): Likewise.
	($(objpfx)tst-gmon-static-pie-gprof.out): Likewise.
	* gmon/tst-gmon-static-pie.c: New file.
	* manual/install.texi: Document --enable-static-pie.
	* sysdeps/generic/ldsodefs.h (_dl_relocate_static_pie): New.
	(_dl_get_dl_main_map): Likewise.
	* sysdeps/i386/configure.ac: Check if linker supports static PIE.
	* sysdeps/x86_64/configure.ac: Likewise.
	* sysdeps/i386/configure: Regenerated.
	* sysdeps/x86_64/configure: Likewise.
	* sysdeps/mips/Makefile (ASFLAGS-.o): Add $(pie-default).
	(ASFLAGS-.op): Likewise.
2017-12-15 17:12:14 -08:00
Joseph Myers
8df5d34720 Remove --with-fp / --without-fp.
There is a configure option --without-fp that specifies that nofpu
sysdeps directories should be used instead of fpu directories.

For most glibc configurations, this option is of no use: either there
is no valid nofpu variant of that configuration, or there are no fpu
or nofpu sysdeps directories for that processor and so the option does
nothing.  For a few configurations, if you are using a soft-float
compiler this option is required, and failing to use it generally
results in compilation errors from inline asm using unavailable
floating-point instructions.

We're moving away from --with-cpu to configuring glibc based on how
the compiler generates code, and it is natural to do so for
--without-fp as well; in most cases the soft-float and hard-float ABIs
are incompatible so you have no hope of building a working glibc with
an inappropriately configured compiler or libgcc.

This patch eliminates --without-fp, replacing it entirely by automatic
configuration based on the compiler.  Configurations for which this is
relevant (coldfire / mips / powerpc32 / sh) define a variable
with_fp_cond in their preconfigure fragments (under the same
conditions under which those fragments do anything); this is a
preprocessor conditional which the toplevel configure script then uses
in a test to determine which sysdeps directories to use.

The config.make with-fp variable remains.  It's used only by powerpc
(sysdeps/powerpc/powerpc32/Makefile) to add -mhard-float to various
flags variables.  For powerpc, -mcpu= options can imply use of
soft-float.  That could be an issue if you want to build for
e.g. 476fp, but are using --with-cpu=476 because there isn't a 476fp
sysdeps directory.  If in future we eliminate --with-cpu and replace
it entirely by testing the compiler, it would be natural at that point
to eliminate that code as well (as the user should then just use a
compiler defaulting to 476fp and the 476 sysdeps directory would be
used automatically).

Tested for x86_64, and tested with build-many-glibcs.py that installed
shared libraries are unchanged by this patch.

	* configure.ac (--with-fp): Remove configure option.
	(with_fp_cond): New variable.
	(libc_cv_with_fp): New configure test.  Use this variable instead
	of with_fp.
	* configure: Regenerated.
	* config.make.in (with-fp): Use @libc_cv_with_fp@.
	* manual/install.texi (Configuring and compiling): Remove
	--without-fp.
	* INSTALL: Regenerated.
	* sysdeps/m68k/preconfigure (with_fp_cond): Define for ColdFire.
	* sysdeps/mips/preconfigure (with_fp_cond): Define.
	* sysdeps/powerpc/preconfigure (with_fp_cond): Define for 32-bit.
	* sysdeps/sh/preconfigure (with_fp_cond): Define.
	* scripts/build-many-glibcs.py (Context.add_all_configs): Do not
	use --without-fp to configure glibc.
2017-12-12 13:56:47 +00:00
Rogerio Alves
07ed18d26a Add elision tunables
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>
2017-12-05 17:48:48 -02:00
Juro Bystricky
1faaf7035c plural.c: improve reproducibility
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.
2017-11-30 21:21:15 +00:00
Siddhesh Poyarekar
a306c790a8 Prefer https for Sourceware links
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.
2017-11-16 11:49:26 +05:30
H.J. Lu
abcb584d0e Use newly built crt*.o files to build shared objects [BZ #22362]
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.
2017-11-06 08:29:57 -08:00
Adhemerval Zanella
8f6f536272 Avoid build multiarch if compiler warns about mismatched alias
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.
2017-10-20 16:54:27 -02:00
Joseph Myers
644d38570a Remove add-ons mechanism.
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.
2017-10-05 15:58:13 +00:00
Guido Trentalancia
57b4af1955 crypt: Use NSPR header files in addition to NSS header files [BZ #17956]
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).
2017-10-04 15:02:35 +02:00
H.J. Lu
b4396163aa Update configure.ac for binutils 2.25
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.
2017-09-25 18:01:34 -07:00
Florian Weimer
6014c65de2 gmon: Add test for basic mcount/gprof functionality 2017-08-15 15:49:45 +02:00
H.J. Lu
19f1a11e7e Check linker support for INSERT in linker script
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.
2017-08-04 12:17:30 -07:00
DJ Delorie
d5c3fafc43 Add per-thread cache to malloc
* config.make.in: Enable experimental malloc option.
* configure.ac: Likewise.
* configure: Regenerate.
* manual/install.texi: Document it.
* INSTALL: Regenerate.
* malloc/Makefile: Likewise.
* malloc/malloc.c: Add per-thread cache (tcache).
(tcache_put): New.
(tcache_get): New.
(tcache_thread_freeres): New.
(tcache_init): New.
(__libc_malloc): Use cached chunks if available.
(__libc_free): Initialize tcache if needed.
(__libc_realloc): Likewise.
(__libc_calloc): Likewise.
(_int_malloc): Prefill tcache when appropriate.
(_int_free): Likewise.
(do_set_tcache_max): New.
(do_set_tcache_count): New.
(do_set_tcache_unsorted_limit): New.
* manual/probes.texi: Document new probes.
* malloc/arena.c: Add new tcache tunables.
* elf/dl-tunables.list: Likewise.
* manual/tunables.texi: Document them.
* NEWS: Mention the per-thread cache.
2017-07-06 13:37:30 -04:00
Joseph Myers
073e8fa773 Require binutils 2.25 or later to build glibc.
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.
2017-06-28 11:31:50 +00:00
H.J. Lu
f300dc7358 Support building glibc with gold 1.14 or above [BZ #14995]
This patch changes configure.ac to allow gold 1.14 or above to be used
to configire glibc so that gold glibc bugs can be fixed.  Tested with

CC="gcc -fuse-ld=gold" CXX="g++ -fuse-ld=gold"

on Fedora 25 with gold 1.14 (20170623).  Gold 1.14 was first released
in binutils 2.28.

On x86-64, for "make check", I got

Error in `/export/build/gnu/glibc-gold/build-x86_64-linux/elf/constload1': double free or corruption (fasttop): 0x00000000008755f0 ***
======= Backtrace: =========
/export/build/gnu/glibc-gold/build-x86_64-linux/libc.so.6(+0x772fb)[0x7f85225b52fb]
/export/build/gnu/glibc-gold/build-x86_64-linux/libc.so.6(+0x7d6c6)[0x7f85225bb6c6]
/export/build/gnu/glibc-gold/build-x86_64-linux/libc.so.6(+0x7df0e)[0x7f85225bbf0e]
/export/build/gnu/glibc-gold/build-x86_64-linux/dlfcn/libdl.so.2(+0x182d)[0x7f85226e682d]
/export/build/gnu/glibc-gold/build-x86_64-linux/dlfcn/libdl.so.2(dlclose+0x1f)[0x7f85226e623f]
/export/build/gnu/glibc-gold/build-x86_64-linux/elf/constload2.so(+0x933)[0x7f8522539933]
/export/build/gnu/glibc-gold/build-x86_64-linux/elf/ld.so(+0xfd1a)[0x7f85226fbd1a]
/export/build/gnu/glibc-gold/build-x86_64-linux/libc.so.6(+0x3c5e0)[0x7f852257a5e0]
/export/build/gnu/glibc-gold/build-x86_64-linux/libc.so.6(+0x3c63a)[0x7f852257a63a]
/export/build/gnu/glibc-gold/build-x86_64-linux/elf/constload2.so(+0x9aa)[0x7f85225399aa]
/export/build/gnu/glibc-gold/build-x86_64-linux/elf/ld.so(+0xf74a)[0x7f85226fb74a]
/export/build/gnu/glibc-gold/build-x86_64-linux/elf/ld.so(+0xf85b)[0x7f85226fb85b]
/export/build/gnu/glibc-gold/build-x86_64-linux/elf/ld.so(+0x13e98)[0x7f85226ffe98]
/export/build/gnu/glibc-gold/build-x86_64-linux/libc.so.6(_dl_catch_error+0x71)[0x7f85226643c1]
/export/build/gnu/glibc-gold/build-x86_64-linux/elf/ld.so(+0x13639)[0x7f85226ff639]
/export/build/gnu/glibc-gold/build-x86_64-linux/dlfcn/libdl.so.2(+0x1156)[0x7f85226e6156]
/export/build/gnu/glibc-gold/build-x86_64-linux/libc.so.6(_dl_catch_error+0x71)[0x7f85226643c1]
/export/build/gnu/glibc-gold/build-x86_64-linux/dlfcn/libdl.so.2(+0x1789)[0x7f85226e6789]
/export/build/gnu/glibc-gold/build-x86_64-linux/dlfcn/libdl.so.2(dlopen+0x32)[0x7f85226e61e2]
/export/build/gnu/glibc-gold/build-x86_64-linux/elf/constload1[0x4009ca]
/export/build/gnu/glibc-gold/build-x86_64-linux/libc.so.6(__libc_start_main+0xf1)[0x7f8522565231]
/export/build/gnu/glibc-gold/build-x86_64-linux/elf/constload1[0x400a5a]
======= Memory map: ========
00400000-00401000 r-xp 00000000 08:11 26334965                           /export/build/gnu/glibc-gold/build-x86_64-linux/elf/constload1
00401000-00402000 r--p 00000000 08:11 26334965                           /export/build/gnu/glibc-gold/build-x86_64-linux/elf/constload1
00402000-00403000 rw-p 00001000 08:11 26334965                           /export/build/gnu/glibc-gold/build-x86_64-linux/elf/constload1
00875000-00896000 rw-p 00000000 00:00 0                                  [heap]
7f851c000000-7f851c021000 rw-p 00000000 00:00 0
7f851c021000-7f8520000000 ---p 00000000 00:00 0
7f85222f3000-7f8522309000 r-xp 00000000 08:02 136658                     /usr/lib64/libgcc_s-6.3.1-20170216.so.1
7f8522309000-7f8522508000 ---p 00016000 08:02 136658                     /usr/lib64/libgcc_s-6.3.1-20170216.so.1
7f8522508000-7f8522509000 r--p 00015000 08:02 136658                     /usr/lib64/libgcc_s-6.3.1-20170216.so.1
7f8522509000-7f852250a000 rw-p 00016000 08:02 136658                     /usr/lib64/libgcc_s-6.3.1-20170216.so.1
7f8522539000-7f852253a000 r-xp 00000000 08:11 26334619                   /export/build/gnu/glibc-gold/build-x86_64-linux/elf/constload2.so
7f852253a000-7f852253b000 r--p 00000000 08:11 26334619                   /export/build/gnu/glibc-gold/build-x86_64-linux/elf/constload2.so
7f852253b000-7f852253c000 rw-p 00001000 08:11 26334619                   /export/build/gnu/glibc-gold/build-x86_64-linux/elf/constload2.so
7f852253c000-7f852253e000 rw-p 00000000 00:00 0
7f852253e000-7f85226da000 r-xp 00000000 08:11 26309973                   /export/build/gnu/glibc-gold/build-x86_64-linux/libc.so
7f85226da000-7f85226db000 ---p 0019c000 08:11 26309973                   /export/build/gnu/glibc-gold/build-x86_64-linux/libc.so
7f85226db000-7f85226de000 r--p 0019c000 08:11 26309973                   /export/build/gnu/glibc-gold/build-x86_64-linux/libc.so
7f85226de000-7f85226e1000 rw-p 0019f000 08:11 26309973                   /export/build/gnu/glibc-gold/build-x86_64-linux/libc.so
7f85226e1000-7f85226e5000 rw-p 00000000 00:00 0
7f85226e5000-7f85226e8000 r-xp 00000000 08:11 26313777                   /export/build/gnu/glibc-gold/build-x86_64-linux/dlfcn/libdl.so
7f85226e8000-7f85226e9000 r--p 00002000 08:11 26313777                   /export/build/gnu/glibc-gold/build-x86_64-linux/dlfcn/libdl.so
7f85226e9000-7f85226ea000 rw-p 00003000 08:11 26313777                   /export/build/gnu/glibc-gold/build-x86_64-linux/dlfcn/libdl.so
7f85226ea000-7f85226ec000 rw-p 00000000 00:00 0
7f85226ec000-7f8522711000 r-xp 00000000 08:11 26309972                   /export/build/gnu/glibc-gold/build-x86_64-linux/elf/ld.so
7f8522711000-7f8522712000 rw-p 00000000 00:00 0
7f8522712000-7f8522713000 r--p 00025000 08:11 26309972                   /export/build/gnu/glibc-gold/build-x86_64-linux/elf/ld.so
7f8522713000-7f8522714000 rw-p 00026000 08:11 26309972                   /export/build/gnu/glibc-gold/build-x86_64-linux/elf/ld.so
7f8522714000-7f8522715000 rw-p 00000000 00:00 0
7ffc5a2bd000-7ffc5a2df000 rw-p 00000000 00:00 0                          [stack]
7ffc5a32c000-7ffc5a32e000 r--p 00000000 00:00 0                          [vvar]
7ffc5a32e000-7ffc5a330000 r-xp 00000000 00:00 0                          [vdso]
ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0                  [vsyscall]

and

make[4]: *** [/export/build/gnu/glibc-gold/build-x86_64-linux/elf/vismain] Error 1

This is because gold doesn't support protected data symbols:

configure:5672: checking linker support for protected data symbol
configure:5682: gcc -fuse-ld=gold -nostdlib -nostartfiles -fno-stack-protector -fPIC -shared conftest.c -o conftest.so
configure:5685: $? = 0
configure:5692: gcc -fuse-ld=gold -nostdlib -nostartfiles -fno-stack-protector conftest.c -o conftest conftest.so
/usr/local/bin/ld.gold: error: /tmp/ccXWoofs.o: cannot make copy relocation for protected symbol 'bar', defined in conftest.so
collect2: error: ld returned 1 exit status

make[4]: *** [/export/build/gnu/glibc-gold/build-x86_64-linux/elf/tst-split-dynreloc] Error 1

This is because gold doesn't support INSERT in linker script:

https://sourceware.org/bugzilla/show_bug.cgi?id=21676

The total failures are

FAIL: dlfcn/bug-dl-leaf
FAIL: elf/constload1
FAIL: elf/global
FAIL: elf/ifuncmain1
FAIL: elf/ifuncmain1pic
FAIL: elf/ifuncmain1pie
FAIL: elf/ifuncmain1vis
FAIL: elf/ifuncmain1vispic
FAIL: elf/ifuncmain1vispie
FAIL: elf/ifuncmain3
FAIL: elf/initfirst
FAIL: elf/preloadtest
FAIL: elf/tst-audit11
FAIL: elf/tst-audit12
FAIL: elf/tst-audit4
FAIL: elf/tst-audit5
FAIL: elf/tst-audit6
FAIL: elf/tst-audit7
FAIL: elf/tst-dlmodcount
FAIL: elf/tst-dlmopen1
FAIL: elf/tst-dlmopen3
FAIL: elf/tst-dlopenrpath
FAIL: elf/tst-latepthread
FAIL: elf/tst-leaks1-mem
FAIL: elf/tst-nodelete-dlclose
FAIL: elf/unload6
FAIL: nss/test-netdb
FAIL: nss/tst-nss-test1
FAIL: posix/tst-getaddrinfo5

	[BZ #14995]
	* configure.ac: Allow gold 1.14 or above to configire glibc
	* configure: Regenerated.
2017-06-28 04:03:57 -07:00
Joseph Myers
4add86749a Require GCC 4.9 or later for building glibc.
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.
2017-06-19 16:34:05 +00:00
Siddhesh Poyarekar
2c0b90ab44 Enable tunables by default
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.
2017-06-15 15:12:54 +05:30
Florian Weimer
c2528fef3b configure: Suppress expected compiler error message 2017-06-13 22:24:38 +02:00
H.J. Lu
a65ea28d18 Make copy of <bits/std_abs.h> from GCC 7 [BZ #21573]
<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.
2017-06-13 10:53:45 -07:00
Thorsten Kukuk
1e4d83f6fe Deprecate libnsl by default (only shared library will be
build for backward compatibility, no linking possible) and disable building
of libnss_compat, libnss_nis and libnss_nisplus, except --enable-obsolete-nsl
option is given to configure.

        * config.h.in: Add LINK_OBSOLETE_NSL.
        * config.make.in: Add build-obsolete-nsl.
        * configure.ac: Add obsolete-nsl option.
        * include/libc-symbols.h: Define libnsl_hidden_nolink_def.
        * include/rpcsvc/yp.h: Add missing functions as libnsl_hidden_proto.
        * include/rpcsvc/nislib.h: Likewise.
        * include/rpcsvc/ypclnt.h: Likewise.
        * manual/install.texi: Document --enable-obsolete-nsl.
        * nis/Makefile: Build only libnsl by default (add build-obsolete-nsl).
        * nis/nis_add.c: Replace libnsl_hidden_def with
        libnsl_hidden_nolink_def.
        * nis/nis_addmember.c: Likewise.
        * nis/nis_call.c: Likewise.
        * nis/nis_clone_obj.c: Likewise.
        * nis/nis_defaults.c: Likeise.
        * nis/nis_domain_of_r.c: Likewise.
        * nis/nis_error.c: Likewise.
        * nis/nis_file.c: Likewise.
        * nis/nis_free.c: Likewise.
        * nis_local_names.c: Likewise.
        * nis/nis_lookup.c: Likewise.
        * nis/nis_modify.c: Likewise.
        * nis/nis_print.c: Likewise.
        * nis/nis_remove.c: Likewise.
        * nis/nis_table.c: Likewise.
        * nis/nis_util.c: Likewise.
        * nis/nis_xdr.c: Likewise.
        * nis/yp_xdr.c: Likewise.
        * nis/ypclnt.c: Likewise.
        * nis/ypupdate_xdr.c: Likewise.
        * nis/nis_checkpoint.c: Add libnsl_hidden_nolink_def to all functions.
        * nis/nis_clone_dir.c: Likewise.
        * nis/nis_clone_res.c: Likewise.
        * nis/nis_creategroup.c: Likewise.
        * nis/nis_destroygroup.c: Likewise.
        * nis/nis_domain_of.c: Likewise.
        * nis/nis_getservlist.c: Likewise.
        * nis/nis_ismember.c: Likewise.
        * nis/nis_mkdir.c: Likewise.
        * nis/nis_ping.c: Likewise.
        * nis/nis_print_group_entry.c: Likewise.
        * nis/nis_removemember.c: Likewise.
        * nis/nis_rmdir.c: Likewise.
        * nis/nis_server.c: Likewise.
        * nis/nis_subr.c: Likewise.
        * nis/nis_verifygroup.c: Likewise.

Signed-off-by: Thorsten Kukuk <kukuk@suse.com>
2017-03-21 15:14:27 +01:00
Alexey Neyman
e37fc4aa68 Fix combreloc test with BSD grep
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>
2017-03-15 13:26:13 -07:00
Siddhesh Poyarekar
6765d5d34d Enhance --enable-tunables to select tunables frontend at build time
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.
2016-12-31 23:49:24 +05:30
Siddhesh Poyarekar
67e58f3941 Add framework for tunables
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.
2016-12-31 23:49:24 +05:30
Nick Alcock
66a704c43c Work even with compilers which enable -fstack-protector by default [BZ #7065]
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.
2016-12-26 10:10:58 +01:00
Nick Alcock
de6591238b Do not stack-protect ifunc resolvers [BZ #7065]
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.)
2016-12-26 10:08:41 +01:00