Commit Graph

37542 Commits

Author SHA1 Message Date
Adhemerval Zanella
d8e4a3baca linux: mips: Split libanl.abilist in n32 and n64
The n32 will require the 64-bit time symbols for y2038 support.

Reviewed-by: Lukasz Majewski <lukma@denx.de>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2021-06-14 16:17:24 -03:00
Adhemerval Zanella
078daa35fb linux: mips: Split librt.abilist in n32 and n64
The n32 will require the 64-bit time symbols for y2038 support.

Reviewed-by: Lukasz Majewski <lukma@denx.de>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2021-06-14 16:17:10 -03:00
Siddhesh Poyarekar
06a1b79407 Reinstate gconv-modules as the default configuration file
Reinstate gconv-modules as the main file so that the configuration
files in gconv-modules.d/ become add-on configuration.  With this, the
effective user visible change is that GCONV_PATH can now have
supplementary configuration in GCONV_PATH/gconv-modules.d/ in addition
to the main GCONV_PATH/gconv-modules file.
2021-06-14 18:38:09 +05:30
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
Florian Weimer
acc85ea1eb io: Fix sporadic test failures in io/tst-stat
support_stat_nanoseconds cannot restore the ctime time, and
this may lead to sporadic test failures.  Therefore, probe for
nanoseconds support before the initial statx call.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-06-10 13:48:26 +02:00
Adhemerval Zanella
8fe503f74e nptl: Avoid async cancellation to wrongly update __nptl_nthreads (BZ #19366)
The testcase provided on BZ#19366 may update __nptl_nthreads in a wrong
order, triggering an early process exit because the thread decrement
the value twice.

The issue is once the thread exits without acting on cancellation,
it decreaments '__nptl_nthreads' and then atomically set
 'cancelhandling' with EXITING_BIT (thus preventing further cancellation
handler to act).  The issue happens if a SIGCANCEL is received between
checking '__ntpl_nthreads' and setting EXITING_BIT.  To avoid it, the
'__nptl_nthreads' decrement is moved after EXITING_BIT.

It does fully follow the POSIX XSH 2.9.5 Thread Cancellation under
the heading Thread Cancellation Cleanup Handlers that states that
when a cancellation request is acted upon, or when a thread calls
pthread_exit(), the thread first disables cancellation by setting its
cancelability state to PTHREAD_CANCEL_DISABLE and its cancelability type
to PTHREAD_CANCEL_DEFERRED.  The issue is '__pthread_enable_asynccancel'
explicit enabled assynchrnous cancellation, so an interrupted syscall
within the cancellation cleanup handlers might see an invalid cancelling
type (a possible fix might be possible with my proposed solution to
BZ#12683).

Trying to come up with a test is quite hard since it requires to
mimic the timing issue described below, however I see that the
bug report reproducer does not early exit anymore.

Checked on x86_64-linux-gnu.
2021-06-09 15:16:45 -03:00
Adhemerval Zanella
a6c813d0ad nptl: Use pthread_kill on pthread_cancel
It consolidates the tgkill call and it is the first step of making
pthread_cancel async-signal-safe.  It also fix a possible issue
where the 'struct pthread' tid is not read atomically, which might
send an invalid cancellation signal (similar to what
db988e50a8 fixed for pthread_join).

Checked on x86_64-linux-gnu and aarch64-linux-gnu.
2021-06-09 15:16:45 -03:00
Adhemerval Zanella
f779b1efb3 nptl: Implement raise in terms of pthread_kill
Now that pthread_kill is provided by libc.so it is possible to
implement the generic POSIX implementation as
'pthread_kill(pthread_self(), sig)'.

For Linux implementation, pthread_kill read the targeting TID from
the TCB.  For raise, this it not possible because it would make raise
fail when issue after vfork (where creates the resulting process
has a different TID from the parent, but its TCB is not updated as
for pthread_create).  To make raise use pthread_kill, it is make
usable from vfork by getting the target thread id through gettid
syscall.

Checked on x86_64-linux-gnu and aarch64-linux-gnu.
2021-06-09 15:16:45 -03:00
Adhemerval Zanella
8c1c0aae20 nptl: Move cancel type out of cancelhandling
Now that the thread cancellation type is not accessed concurrently
anymore, it is possible to move it out the cancelhandling.

By removing the cancel state out of the internal thread cancel handling
state there is no need to check if cancelled bit was set in CAS
operation.

It allows simplifing the cancellation wrappers and the
CANCEL_CANCELED_AND_ASYNCHRONOUS is removed.

Checked on x86_64-linux-gnu and aarch64-linux-gnu.
2021-06-09 15:16:45 -03:00
Adhemerval Zanella
2b51742531 nptl: Move cancel state out of cancelhandling
Now that thread cancellation state is not accessed concurrently anymore,
it is possible to move it out the 'cancelhandling'.

The code is also simplified: CANCELLATION_P is replaced with a
internal pthread_testcancel call and the CANCELSTATE_BIT{MASK} is
removed.

With this behavior pthread_setcancelstate does not require to act on
cancellation if cancel type is asynchronous (is already handled either
by pthread_setcanceltype or by the signal handler).

Checked on x86_64-linux-gnu and aarch64-linux-gnu.
2021-06-09 15:16:45 -03:00
Adhemerval Zanella
26cfbb7162 nptl: Remove CANCELING_BITMASK
The CANCELING_BITMASK is used as an optimization to avoid sending
the signal when pthread_cancel is called in a concurrent manner.

This requires then to put both the cancellation state and type on a
shared state (cancelhandling), since 'pthread_cancel' checks whether
cancellation is enabled and asynchrnous to either cancel itself of
 sending the signal.

It also requires handle the CANCELING_BITMASK on
__pthread_disable_asynccancel, however this incurs in the same issues
described on BZ#12683: the cancellation is acted upon even *after*
syscall returns with user visible side-effects.

This patch removes this optimization and simplifies the pthread
cancellation implementation: pthread_cancel now first checks if
cancellation is already pending and if not always, sends a signal
if the target is not itself.  The SIGCANCEL handler is also simpified
since there is not need to setup a CAS loop.

It also allows to move both the cancellation state and mode out of
'cancelhadling' (it is done in subsequent patches).

Checked on x86_64-linux-gnu and aarch64-linux-gnu.
2021-06-09 15:16:45 -03:00
Adhemerval Zanella
41c7295617 nptl: Install cancellation handler on pthread_cancel
Now that cancellation is not used anymore to handle thread setup
creation failure, the sighandle can be installed only when
pthread_cancel is actually used.

Checked on x86_64-linux-gnu and aarch64-linux-gnu.
2021-06-09 15:16:45 -03:00
Adhemerval Zanella
02189e8fb0 nptl: Deallocate the thread stack on setup failure (BZ #19511)
To setup either the thread scheduling parameters or affinity,
pthread_create enforce synchronization on created thread to wait until
its parent either release PD ownership or send a cancellation signal if
a failure occurs.

However, cancelling the thread does not deallocate the newly created
stack since cancellation expects that a pthread_join to deallocate any
allocated thread resouces (threads stack or TLS).

This patch changes on how the thread resource is deallocate in case of
failure to be synchronous, where the creating thread will signal the
created thread to exit early so it could be joined.  The creating thread
will be reponsible for the resource cleanup before returning to the
caller.

To signal the creating thread that a failure has occured, an unused
'struct pthread' member, parent_cancelhandling_unsed, now indicates
whether the setup has failed so creating thread can proper exit.

This strategy also simplifies by not using thread cancellation and
thus not running libgcc_so load in the signal handler (which is
avoided in thread cancellation since 'pthread_cancel' is the one
responsible to dlopen libgcc_s).  Another advantage is since the
early exit is move to first step at thread creation, the signal
mask is not already set and thus it can not act on change ID setxid
handler.

Checked on x86_64-linux-gnu and aarch64-linux-gnu.
2021-06-09 15:16:45 -03:00
Florian Weimer
699361795f Remove stale references to libdl.a
Since commit 0c1c3a771e
("dlfcn: Move dlopen into libc") libdl.a is empty, so linking
against it is no longer necessary.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-06-09 19:14:02 +02:00
Stefan Liebler
51a3df5e35 Fix elf/tst-tls9-static after libdl cleanups.
The testcase elf/tst-tls9-static sometimes fails with:
cannot open 'tst-tlsmod5.so': tst-tlsmod5.so: cannot open shared object file: No such file or directory
cannot open 'tst-tlsmod6.so': tst-tlsmod6.so: cannot open shared object file: No such file or directory

After recent commit
6f1c701026
"dlfcn: Cleanups after -ldl is no longer required"
the libdl variable is not set anymore and thus the
dependencies were missing.
2021-06-09 13:38:41 +02:00
Siddhesh Poyarekar
5a5b481365 iconvdata: Split out non-essential gconv module configuration
Split module configuration so that only the bare minimum charsets,
i.e. ANSI_X3.110, ISO8859-15, ISO8859-1, CP1252, UNICODE, UTF-16,
UTF-32 and UTF-7 are configured in gconv-modules.conf.  The remaining
module configurations are now in gconv-modules-extra.conf.

Reviewed-by: DJ Delorie <dj@redhat.com>
2021-06-09 09:47:16 +05:30
Siddhesh Poyarekar
fc5bfade69 iconvdata: Move gconv-modules configuration to gconv-modules.conf
Move all gconv-modules configuration files to gconv-modules.conf.
That is, the S390 extensions now become gconv-modules-s390.conf.  Move
both configuration files into gconv-modules.d.

Now GCONV_PATH/gconv-modules is read only for backward compatibility
for third-party gconv modules directories.

Reviewed-by: DJ Delorie <dj@redhat.com>
2021-06-09 09:47:16 +05:30
Siddhesh Poyarekar
b17d29b390 gconv_conf: Read configuration files in gconv-modules.d
Read configuration files with names ending in .conf in
GCONV_PATH/gconv-modules.d to mirror configuration flexibility in
iconvconfig into the iconv program and function.

Reviewed-by: DJ Delorie <dj@redhat.com>
2021-06-09 09:47:16 +05:30
Siddhesh Poyarekar
3979c3e1ba iconvconfig: Read configuration from gconv-modules.d subdirectory
In addition to GCONV_PATH/gconv-modules, also read module
configuration from *.conf files in GCONV_PATH/gconv-modules.d.  This
allows a single gconv directory to have multiple sets of gconv modules
but at the same time, a single modules cache.

With this feature, one could separate the glibc supported gconv
modules into a minimal essential set (ISO-8859-*, UTF, etc.) from the
remaining modules.  In future, these could be further segregated into
langpack-associated sets with their own
gconv-modules.d/someconfig.conf.

Reviewed-by: DJ Delorie <dj@redhat.com>
2021-06-09 09:47:16 +05:30
Siddhesh Poyarekar
0c78b0bb78 iconvconfig: Make file handling more general purpose
Split out configuration file handling code from handle_dir into its
own function so that it can be reused for multiple configuration
files.

Reviewed-by: DJ Delorie <dj@redhat.com>
2021-06-09 09:47:16 +05:30
Wilco Dijkstra
6a86bc0992 AArch64: Add support for roundeven[f]
Add inline assembler for the roundeven functions.
Passes GLIBC regression.  Note GCC does not inline the builtin (PR100966),
so this cannot be used for now.
2021-06-08 13:33:09 +01:00
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
57094e576a libio: Assume _IO_lock_inexpensive
It is already set by both Linux and Hurd.
2021-06-04 09:54:52 -03:00
Adhemerval Zanella
eaa53d0f77 nptl: Remove exit-thread.h
No function change.  The code is used only for Linux, besides
being included in generic code.
2021-06-04 09:52:28 -03:00
Sunil K Pandey
642213e043 Improve test coverage of strnlen function
This patch covers the following condition:

Strings start with different alignments and end with length less than or
equal to 512 byte.

Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
2021-06-03 11:16:51 -07:00
Florian Weimer
466c1ea15f dlfcn: Rework static dlopen hooks
Consolidate all hooks structures into a single one.  There are
no static dlopen ABI concerns because glibc 2.34 already comes
with substantial ABI-incompatible changes in this area.  (Static
dlopen requires the exact same dynamic glibc version that was used
for static linking.)

The new approach uses a pointer to the hooks structure into
_rtld_global_ro and initalizes it in __rtld_static_init.  This avoids
a back-and-forth with various callback functions.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-06-03 09:12:05 +02:00
Florian Weimer
9c76debc98 dlfcn: Eliminate GLIBC_PRIVATE dependency from tststatic2
The test appears to use _dlfcn_hook@@GLIBC_PRIVATE as a way to
test dlvsym without having to know the appropriate symbol version.
With <first-versions.h>, we can use a public symbol and the symbol
version at which it was defined first.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-06-03 09:12:05 +02:00
Florian Weimer
6f1c701026 dlfcn: Cleanups after -ldl is no longer required
This commit removes the ELF constructor and internal variables from
dlfcn/dlfcn.c.  The file now serves the same purpose as
nptl/libpthread-compat.c, so it is renamed to dlfcn/libdl-compat.c.
The use of libdl-shared-only-routines ensures that libdl.a is empty.

This commit adjusts the test suite not to use $(libdl).  The libdl.so
symbolic link is no longer installed.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-06-03 09:11:45 +02:00
Florian Weimer
0c1c3a771e dlfcn: Move dlopen into libc
The symbol was moved using scripts/move-symbol-to-libc.py.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-06-03 08:26:04 +02:00
Florian Weimer
add8d7ea01 dlfcn: Move dlvsym into libc
The symbol was moved using scripts/move-symbol-to-libc.py.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-06-03 08:26:04 +02:00
Florian Weimer
6dfc0207eb dlfcn: Move dlinfo into libc
The symbol was moved using scripts/move-symbol-to-libc.py.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-06-03 08:26:04 +02:00
Florian Weimer
492560a32e dlfcn: Move dladdr1 into libc
The symbol was moved using scripts/move-symbol-to-libc.py.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-06-03 08:26:04 +02:00
Florian Weimer
6a1ed32789 dlfcn: Move dlmopen into libc
The symbol was moved using scripts/move-symbol-to-libc.py.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-06-03 08:26:04 +02:00
Florian Weimer
77f876c0e3 dlfcn: Move dlsym into libc
The symbol was moved using scripts/move-symbol-to-libc.py.

In elf/Makefile, remove the $(libdl) dependency from testobj1.so
because it the unused libdl DSO now causes elf/tst-unused-deps to
fail.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-06-03 08:26:04 +02:00
Florian Weimer
602252b553 dlfcn: Move dladdr into libc
The symbol was moved using scripts/move-symbol-to-libc.py.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-06-03 08:26:04 +02:00
Florian Weimer
d8cce17d2a dlfcn: Move dlclose into libc
The symbol was moved using scripts/move-symbol-to-libc.py.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-06-03 08:26:04 +02:00
Sunil K Pandey
c9ff9cf66a Improve test coverage of strlen function
This patch covers the following conditions:

- Strings start with different alignments and end at the page boundary
  with less than 64 byte length.
- Strings starts with different alignments and cross page boundary with
  fixed length.

Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
2021-06-02 05:37:43 -07:00
Xeonacid
5295172e20 fix typo
"accomodate" should be "accommodate"
Reviewed-by: Paul Zimmermann <Paul.Zimmermann@inria.fr>
2021-06-02 12:16:49 +02:00
Florian Weimer
a23c28ec0d dlfcn: Move dlerror into libc
The symbol was moved using scripts/move-symbol-to-libc.py.

There is a minor functionality enhancement: dlerror now sets
errno if it was set as part of the exception.  (This is the result
of using %m in asprintf, to avoid the strerror PLT call.) The
previous errno value upon function return was unpredictable.
Documenting this as a feature is premature; we need to make sure
that the error codes are meaningful when they are set by the dynamic
loader.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-06-02 09:06:10 +02:00
Florian Weimer
c44838ebf8 Add libc ABI extension kludge for baseline-violating libdl symbols
Some targets have a GLIBC_2.0 baseline for libdl, while using
GLIBC_2.2 for libc.  This means that the generated libc.map file
does not have any version nodes for GLIBC_2.0 or GLIBC_2.1.  However,
moving symbols from libdl into libc needs such version nodes.
(Future symbol moves from librt will need this as well.)

This kludge is only necessary for symbols predating GLIBC_2.2 because
the affected targets use GLIBC_2.2 as the baseline for libc.  Given
the small number and fixed set of affected architectures, no generic
mechanism is implemented, and instead the map file fragment is
hard-coded in scripts/versions.mk.

The compat_symbol macro already emits the appropriate version strings,
so no adjustments are needed there.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-06-02 07:34:24 +02:00
Florian Weimer
d32ee64df7 scripts/versions.awk: Add local: * to all version nodes
This requires that all exported symbol versions are listed in
Versions files.  It results in more consistent behavior across
architectures because previously, symbols could be exported
via explicit versioned_symbol and compat_symbol macros if the
version node existed in some Versions file (without listing the
symbol), and it was not the base version for the library (which
already had the local: * directive).

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-06-02 07:32:44 +02:00
Florian Weimer
186cd80b1e Add missing symbols to Version files
Some symbols have explicit versioned_symbol or compat_symbol markers
in the sources, but no corresponding entry in the Versions files.
This presently works because the local: * directive is only applied
to the base version.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-06-02 07:32:19 +02:00
Florian Weimer
217b6dc298 Fix use of __pthread_attr_copy in mq_notify (bug 27896)
__pthread_attr_copy can fail and does not initialize the attribute
structure in that case.

If __pthread_attr_copy is never called and there is no allocated
attribute, pthread_attr_destroy should not be called, otherwise
there is a null pointer dereference in rt/tst-mqueue6.

Fixes commit 42d3593505
("Use __pthread_attr_copy in mq_notify (bug 27896)").

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2021-06-02 07:12:18 +02:00
Andreas Schwab
42d3593505 Use __pthread_attr_copy in mq_notify (bug 27896)
Make a deep copy of the pthread attribute object to remove a potential
use-after-free issue.
2021-06-01 17:12:33 +02:00
Joseph Myers
858045ad1c Update floating-point feature test macro handling for C2X
ISO C2X has made some changes to the handling of feature test macros
related to features from the floating-point TSes, and to exactly what
such features are present in what headers, that require corresponding
changes in glibc.

* For the few features that were controlled by
  __STDC_WANT_IEC_60559_BFP_EXT__ (and the corresponding DFP macro) in
  C2X, there is now instead a new feature test macro
  __STDC_WANT_IEC_60559_EXT__ covering both binary and decimal FP.
  This controls CR_DECIMAL_DIG in <float.h> (provided by GCC; I
  implemented support for the new feature test macro for GCC 11) and
  the totalorder and payload functions in <math.h>.  C2X no longer
  says anything about __STDC_WANT_IEC_60559_BFP_EXT__ (so it's
  appropriate for that macro to continue to enable exactly the
  features from TS 18661-1).

* The SNAN macros for each floating-point type have moved to <float.h>
  (and been renamed in the process).  Thus, the copies in <math.h>
  should only be defined for __STDC_WANT_IEC_60559_BFP_EXT__, not for
  C2X.

* The fmaxmag and fminmag functions have been removed (replaced by new
  functions for the new min/max operations in IEEE 754-2019).  Thus
  those should also only be declared for
  __STDC_WANT_IEC_60559_BFP_EXT__.

* The _FloatN / _FloatNx handling for the last two points in glibc is
  trickier, since __STDC_WANT_IEC_60559_TYPES_EXT__ is still in C2X
  (the integration of TS 18661-3 as an Annex, that is, which hasn't
  yet been merged into the C standard git repository but has been
  accepted by WG14), so C2X with that macro should not declare some
  things that are declared for older standards with that macro.  The
  approach taken here is to provide the declarations (when
  __STDC_WANT_IEC_60559_TYPES_EXT__ is enabled) only when (defined
  __USE_GNU || !__GLIBC_USE (ISOC2X)), so if C2X features are enabled
  then those declarations (that are only in TS 18661-3 and not in C2X)
  will only be provided if _GNU_SOURCE is defined as well.  Thus
  _GNU_SOURCE remains a superset of the TS features as well as of C2X.

Some other somewhat related changes in C2X are not addressed here.
There's an open proposal not to include the fmin and fmax functions
for the _FloatN / _FloatNx types, given the new min/max operations,
which could be handled like the previous point if adopted.  And the
fromfp functions have been changed to return a result in floating type
rather than intmax_t / uintmax_t; my inclination there is to treat
that like that change of totalorder type (new symbol versions etc. for
the ABI change; old versions become compat symbols and are no longer
supported as an API).

Tested for x86_64 and x86.
2021-06-01 14:22:06 +00:00
Florian Weimer
c8a11c5867 stdio-common: Remove _IO_vfwscanf
The symbol has never been exported, so no compatibility symbol is
needed.  Removing this file prevents ld from creation an exported
symbol in case GLIBC_2_0 expands to a symbol version which
does not have a local: *; directive in the symbol version map file.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-06-01 16:00:52 +02:00
Szabolcs Nagy
3842ba4949 aarch64: align stack in clone [BZ #27939]
The AArch64 PCS requires 16 byte aligned stack.  Previously if the
caller passed an unaligned stack to clone then the child crashed.

Fixes bug 27939.
2021-06-01 09:47:48 +01:00
Lucas A. M. Magalhaes
a55e2da270 powerpc: Optimized memcmp for power10
This patch was based on the __memcmp_power8 and the recent
__strlen_power10.

Improvements from __memcmp_power8:

1. Don't need alignment code.

   On POWER10 lxvp and lxvl do not generate alignment interrupts, so
they are safe for use on caching-inhibited memory.  Notice that the
comparison on the main loop will wait for both VSR to be ready.
Therefore aligning one of the input address does not improve
performance.  In order to align both registers a vperm is necessary
which add too much overhead.

2. Uses new POWER10 instructions

   This code uses lxvp to decrease contention on load by loading 32 bytes
per instruction.
   The vextractbm is used to have a smaller tail code for calculating the
return value.

3. Performance improvement

   This version has around 35% better performance on average. I saw no
performance regressions for any length or alignment.

Thanks Matheus for helping me out with some details.

Co-authored-by: Matheus Castanho <msc@linux.ibm.com>
Reviewed-by: Raphael M Zinsly <rzinsly@linux.ibm.com>
2021-05-31 18:00:20 -03:00
H.J. Lu
92a7d13439 x86-64: Align child stack to 16 bytes [BZ #27902]
In the x86-64 clone wrapper, align child stack to 16 bytes per the
x86-64 psABI.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2021-05-31 12:03:36 -07:00
Adhemerval Zanella
271ec55d0a support: Do not build xpthread_attr_setaffinity_np for hurd
It does not provide pthread_attr_setaffinity_np extension.
2021-05-28 16:00:19 -03:00