Add Linux-specific comments about the atomicity of write() and
the POSIX requirements.
2014-10-29 Carlos O'Donell <carlos@redhat.com>
* manual/llio.texi: Add comments discussing why write() may be
considered MT-unsafe on Linux.
During a refactoring pass several repeated blocks of code in dl-load.c
were turned into a call to a local function named local_strdup. There
is no need for local_strdup, and the routines should instead call
__strdup. This change does just that. We call the internal symbol
__strdup because calling strdup is unsafe. The user might be
using a standard that doesn't include strdup and may have defined this
symbol in their application. During a static link we might reference
the user defined symbol and crash if it doesn't implement a standards
conforming strdup. The resulting code is simpler to understand, and
makes it easier to debug.
No regressions on x86_64.
2014-10-28 Carlos O'Donell <carlos@redhat.com>
* dl-load.c (local_strdup): Remove.
(expand_dynamic_string_token): Use __strdup.
(decompose_rpath): Likewise.
(_dl_map_object): Likewise.
Continuing the removal of the obsolete INTDEF / INTUSE mechanism, this
patch replaces its use in unwind-dw2-fde.c with hidden_def and
hidden_proto.
Tested for x86. This patch does result in code generation differences
(for some reason GCC decides to partition __register_frame_info_bases
after the patch).
[BZ #14132]
* sysdeps/generic/unwind-dw2-fde.c
(__register_frame_info_bases_internal): Do not declare.
(__register_frame_info_table_bases_internal): Likewise.
(__deregister_frame_info_bases_internal): Likewise.
(__register_frame_info_bases): Declare and use hidden_proto before
definition. Use hidden_def instead of INTDEF.
(__register_frame_info_table_bases): Likewise.
(__deregister_frame_info_bases): Likewise.
(__register_frame_info): Do not use INTUSE.
(__register_frame): Likewise.
(__register_frame_info_table): Likewise.
(__register_frame_table): Likewise.
(__deregister_frame_info): Likewise.
(__deregister_frame): Likewise.
ARM linux kernels before 3.14.3 may or may not support
futex_atomic_cmpxchg_inatomic depending on the kernel configuration (e.g.
CONFIG_CPU_USE_DOMAINS && CONFIG_SMP configuration was not supported)
Starting with 3.14.3 the linux kernel unconditionally enables support for
ARM, and this re-enables the relevant __ASSUME_* macros.
Tested on ARM both with kernels >= 3.14.3 and older kernels.
* sysdeps/unix/sysv/linux/arm/kernel-features.h
[__LINUX_KERNEL_VERSION >= 0x030E03] (__ASSUME_FUTEX_LOCK_PI): Do
not undefine.
[__LINUX_KERNEL_VERSION >= 0x030E03] (__ASSUME_REQUEUE_PI):
Likewise.
[__LINUX_KERNEL_VERSION >= 0x030E03] (__ASSUME_SET_ROBUST_LIST):
Likewise.
this
will improve performance even on targets which don't have an optimized strlen. It is about twice
as
fast as the original strncat in bench-strncat.
implementation, so this improves performance even on targets which don't have an optimized
strlen and strcpy - it is 25% faster in bench-strcat. On targets which don't provide an
optimized strcat but which do have an optimized strlen and strcpy, performance gain is > 2x.
Continuing the move of syscall definitions to syscalls.list, where the
removal of support for old kernel versions has made this possible,
this patch moves various definitions of chown, lchown and fchown.
In most cases the need for special syscalls.list entries (rather than
existing generic ones) is because these architectures use chown32,
lchown32 and fchown32 as syscall names. Some architectures also have
symbol versioning compatibility for older versions of chown having
been equivalent to lchown.
The aliases specified for s390-32 had the effect of exporting
__chown@@GLIBC_2.1 (but not __chown@GLIBC_2.0) despite it not being
listed in Versions files. (I'm not sure why versioned_symbol but not
compat_symbol were effective like that to create such __chown exports
in the absence of Versions entries.) The natural way to preserve that
versioned export of __chown seems to be to add it in a Versions file,
so I did so. (Maybe actually it should be a compat symbol,
__chown@GLIBC_2.1, unless there's a good reason for that export, but
this patch doesn't change anything there.)
Tested for x86.
[BZ #14138]
* sysdeps/unix/sysv/linux/i386/chown.c: Remove file.
* sysdeps/unix/sysv/linux/i386/fchown.c: Likewise.
* sysdeps/unix/sysv/linux/i386/lchown.c: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/chown.c: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/fchown.c: Remove file.
* sysdeps/unix/sysv/linux/s390/s390-32/lchown.c: Likewise.
* sysdeps/unix/sysv/linux/sh/chown.c: Likewise.
* sysdeps/unix/sysv/linux/sh/fchown.c: Likewise.
* sysdeps/unix/sysv/linux/sh/lchown.c: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc32/chown.c: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc32/fchown.c: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc32/lchown.c: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/Versions (GLIBC_2.1): Add
__chown.
* sysdeps/unix/sysv/linux/i386/syscalls.list (chown): Add syscall.
(lchown): Likewise.
(fchown): Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/syscalls.list (chown):
Likewise.
(lchown): Likewise.
(fchown): Likewise.
* sysdeps/unix/sysv/linux/sh/syscalls.list (chown): Likewise.
(lchown): Likewise.
(fchown): Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc32/syscalls.list (chown):
Likewise.
(lchown): Likewise.
(fchown): Likewise.
In the Linux kernel version 3.17 the signal numbers were rearranged in
order to make hppa like every other arch. Previously we started
__SIGRTMIN at 37, and that meant several pieces of important software,
including systemd, would fail to build. To support systemd we removed
SIGEMT and SIGLOST, and rearranged the others according to expected
values. This is technically an ABI incompatible change, but because
zero applications use SIGSTKFLT, SIGXCPU, SIGXFSZ and SIGSYS nothing
broke. Nothing uses SIGEMT and SIGLOST, and they were present for
HPUX compatibility which is no longer supported. Thus because nothing
breaks we don't do any compatibility work here.
Upstream kernel commit is 1f25df2eff5b25f52c139d3ff31bc883eee9a0ab.
Signed-off-by: Carlos O'Donell <carlos@systemhalted.org>
Signed-off-by: Helge Deller <deller@gmx.de>
2014-10-23 Carlos O'Donell <carlos@systemhalted.org>
Helge Deller <deller@gmx.de>
[BZ #17508]
* sysdeps/unix/sysv/linux/hppa/bits/signum.h: Remove SIGEMT.
Define SIGSTKFLT as 7. Define SIGSYS as 31. Define SIGXCPU as 12.
Remove SIGLOST. Define SIGXFSZ as 30. Define __SIGRTMIN as 32.
Continuing the removal of the obsolete INTDEF / INTUSE mechanism, this
patch removes the use of INTUSE to rename symbols in
sysdeps/powerpc/powerpc32/libgcc-compat.S. As the names in question
are purely internal to this particular object and not used anywhere
else, it doesn't matter at all whether __*_v_glibc20 or __*_internal
is used, so this patch just removes the macros in question.
Tested for powerpc32 that stripped installed shared libraries are
unchanged by this patch.
[BZ #14132]
* sysdeps/powerpc/powerpc32/libgcc-compat.S (__ashldi3_v_glibc20):
Remove macro definition.
(__ashrdi3_v_glibc20): Likewise.
(__lshrdi3_v_glibc20): Likewise.
(__cmpdi2_v_glibc20): Likewise.
(__ucmpdi2_v_glibc20): Likewise.
[!_SOFT_FLOAT && !__NO_FPRS__] (__fixdfdi_v_glibc20): Likewise.
[!_SOFT_FLOAT && !__NO_FPRS__] (__fixsfdi_v_glibc20): Likewise.
[!_SOFT_FLOAT && !__NO_FPRS__] (__fixunsdfdi_v_glibc20): Likewise.
[!_SOFT_FLOAT && !__NO_FPRS__] (__fixunssfdi_v_glibc20): Likewise.
[!_SOFT_FLOAT && !__NO_FPRS__] (__floatdidf_v_glibc20): Likewise.
[!_SOFT_FLOAT && !__NO_FPRS__] (__floatdisf_v_glibc20): Likewise.
This satisfies a symbol reference created with:
.symver __libc_vfork, vfork@GLIBC_2.0
where `__libc_vfork' has not been defined or referenced. In this case
the `vfork@GLIBC_2.0' reference is supposed to be discarded, however a
bug present in GAS since forever causes an undefined symbol table entry
to be created. This in turn triggers a problem in the linker that can
manifest itself by link errors such as:
ld: libpthread.so: invalid string offset 2765592330 >= 5154 for section `.dynstr'
The GAS and linker bugs need to be resolved, but we can avoid them too
by providing a `__libc_vfork' definition just like our other platforms.
[BZ #17485]
* sysdeps/unix/sysv/linux/mips/vfork.S (__libc_vfork): Define.
Continuing the removal of the obsolete INTDEF / INTUSE mechanism, this
patch removes the use of INTDEF for __ldexpf. As far as I can tell,
the resulting alias is completely unused.
Tested for x86_64 that stripped installed shared libraries are
unchanged by this patch.
[BZ #14132]
* math/s_ldexpf.c (__ldexpf): Do not use INTDEF.
Continuing the move of syscall definitions to syscalls.list, where the
removal of support for old kernel versions has made this possible,
this patch moves definitions of readv and writev.
The relevant syscalls.list entries were already in
sysdeps/unix/syscalls.list, but to match the C files they needed to
have the names __libc_readv and __libc_writev added. In fact, I don't
see anything making use of those names - as far as I can tell, these
functions could just be defined as __readv and __writev with aliases
readv and writev. But cleaning up unnecessary aliases for functions
should be a separate matter from cleaning up unnecessary C syscall
wrappers.
Tested for x86_64.
[BZ #14138]
* sysdeps/unix/syscalls.list (readv): Use __libc_readv as strong
name.
(writev): Use __libc_writev as strong name.
* sysdeps/unix/sysv/linux/readv.c: Remove file.
* sysdeps/unix/sysv/linux/writev.c: Likewise.
this is a path that should solve bug 15884. It complains about the performance
of strcoll(). It was found out that the runtime of strcoll() is actually bound
to strlen which is needed for calculating the size of a cache that was
installed to improve the comparison performance.
The idea for this patch was that the cache is only useful in rare cases
(strings of same length and same first-level-chars) and that it would be
better to avoid memory allocation at all. To prove this I wrote a performance
test bench-strcoll.c with test data in benchtests-strcoll.tar.gz. Also
modifications in benchtests/Makefile and localedata/Makefile are necessary to
make it work.
After removing the cache the strcoll method showed the predicted behavior
(getting slightly faster) in all but the test case for hindi word sorting.
This was due the hindi text having much more equal words than the other ones.
For equal strings the performance was worse since all comparison levels were
run through and from the second level on the cache improved the comparison
performance of the original version.
Therefore I added a bytewise test via strcmp iff the first level comparison
found that both strings did match because in this case it is very likely that
equal strings are compared. This solved the problem with the hindi test case
and improved the performance of the others.
Performance comparison:
glibc files -33.77%
vi_VN.UTF-8 -34.12%
en_US.UTF-8 -42.42%
ar_SA.UTF-8 -27.49%
zh_CN.UTF-8 +07.90%
cs_CZ.UTF-8 -29.67%
en_GB.UTF-8 -28.50%
da_DK.UTF-8 -36.57%
pl_PL.UTF-8 -39.31%
fr_FR.UTF-8 -28.57%
pt_PT.UTF-8 -22.82%
el_GR.UTF-8 -26.77%
ru_RU.UTF-8 -35.81%
iw_IL.UTF-8 -35.34%
es_ES.UTF-8 -34.46%
hi_IN.UTF-8 -00.38%
sv_SE.UTF-8 -36.99%
hu_HU.UTF-8 -16.35%
tr_TR.UTF-8 -27.80%
is_IS.UTF-8 -33.24%
it_IT.UTF-8 -24.39%
sr_RS.UTF-8 -37.55%
ja_JP.UTF-8 +02.84%
Continuing the series of patches to clean up conformtest expectations
for "POSIX" (1995/6) based on review of the expectations against the
standard, this patch cleans up expectations for sys/utsname.h and
sys/wait.h. Tested x86_64; a new XFAIL for sys/wait.h is added.
* conform/data/sys/utsname.h-data (*_t): Allow.
* conform/data/sys/wait.h-data [POSIX] (uid_t): Do not define.
[POSIX] (WEXITED): Do not expect constant.
[POSIX] (WSTOPPED): Likewise.
[POSIX] (WNOHANG): Likewise.
[POSIX] (WNOWAIT): Likewise.
[POSIX] (siginfo_t): Do not expect type or elements.
[POSIX] (pid_t): Do not expect type.
[POSIX] (signal.h): Do not allow header.
[POSIX] (sys/resource.h): Likewise.
[POSIX] (si_*): Do not allow pattern.
[POSIX] (W*): Likewise.
[POSIX] (P_*): Likewise.
[POSIX] (BUS_*): Likewise.
[POSIX] (CLD_*): Likewise.
[POSIX] (FPE_*): Likewise.
[POSIX] (ILL_*): Likewise.
[POSIX] (POLL_*): Likewise.
[POSIX] (SEGV_*): Likewise.
[POSIX] (SI_*): Likewise.
[POSIX] (TRAP_*): Likewise.
* conform/Makefile (test-xfail-POSIX/sys/wait.h/conform): New
variable.
The recvmsg could return 0 under some conditions and cause the
make_request function to be stuck in an infinite loop.
Thank you Jim King <jim.king@simplivity.com> for posting Paul's patch
on the list.
As far as I can tell, CANCEL-FCT-WAIVE and CANCEL-FILE-WAIVE are old
notes from the addition of cancellation support to glibc and are not
currently used by any glibc testcases or otherwise in the build
process, and it does not seem useful to me to keep them around. This
patch removes them.
Tested for x86_64.
* CANCEL-FCT-WAIVE: Remove file.
* CANCEL-FILE-WAIVE: Likewise.
Continuing the removal of the obsolete INTDEF / INTVARDEF / INTUSE
mechanism, this patch replaces its use for __libc_enable_secure with
the use of rtld_hidden_data_def and rtld_hidden_proto.
Tested for x86_64 that installed stripped shared libraries are
unchanged by the patch.
[BZ #14132]
* elf/dl-sysdep.c (__libc_enable_secure): Use rtld_hidden_data_def
instead of INTVARDEF.
(_dl_sysdep_start): Do not use INTUSE with __libc_enable_secure.
* sysdeps/mach/hurd/dl-sysdep.c (__libc_enable_secure): Use
rtld_hidden_data_def instead of INTVARDEF.
(_dl_sysdep_start): Do not use INTUSE with __libc_enable_secure.
* elf/dl-deps.c (expand_dst): Likewise.
* elf/dl-load.c (_dl_dst_count): Likewise.
(_dl_dst_substitute): Likewise.
(decompose_rpath): Likewise.
(_dl_init_paths): Likewise.
(open_path): Likewise.
(_dl_map_object): Likewise.
* elf/rtld.c (dl_main): Likewise.
(process_dl_audit): Likewise.
(process_envvars): Likewise.
* include/unistd.h [IS_IN_rtld] (__libc_enable_secure_internal):
Remove declaration.
(__libc_enable_secure): Use rtld_hidden_proto.
Continuing the addition of soft-fp features in the Linux kernel
version, this patch adds _FP_TO_INT support for rsigned == 2 (reduce
overflowing results modulo 2^rsize to fit in the destination, used for
alpha emulation).
The kernel version is buggy; it can left shift by a negative amount
when right shifting is required in an overflow case (the kernel
version also has other bugs fixed long ago in glibc; at least,
spurious exceptions converting to the most negative integer). This
version avoids that by handling overflow (other than to 0) for rsigned
== 2 along with the normal non-overflow case, which already properly
determines the direction in which to shift.
Tested for powerpc-nofpu. Some functions get slightly bigger and some
get slightly smaller, no doubt as a result of the change to where in
the macro "inexact" is raised, but I don't think those changes are
significant. Also tested for powerpc-nofpu with the relevant __fix*
functions changed to use rsigned == 2 (which is after all just as
valid as rsigned == 1 in IEEE terms), including verifying the results
and exceptions for various cases of conversions.
With these seven patches, the one remaining feature to add for the
soft-fp code to have all the features of the kernel version is
_FP_TO_INT_ROUND.
* soft-fp/op-common.h (_FP_TO_INT): Handle rsigned == 2.
