Florian Weimer [Thu, 3 Jun 2021 06:26:04 +0000 (08:26 +0200)]
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.
Florian Weimer [Thu, 3 Jun 2021 06:26:04 +0000 (08:26 +0200)]
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.
Florian Weimer [Thu, 3 Jun 2021 06:26:04 +0000 (08:26 +0200)]
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.
Sunil K Pandey [Mon, 31 May 2021 18:08:12 +0000 (11:08 -0700)]
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.
Florian Weimer [Wed, 2 Jun 2021 05:32:20 +0000 (07:32 +0200)]
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.
Florian Weimer [Wed, 2 Jun 2021 05:32:19 +0000 (07:32 +0200)]
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.
Florian Weimer [Wed, 2 Jun 2021 05:32:19 +0000 (07:32 +0200)]
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).
Florian Weimer [Wed, 2 Jun 2021 05:32:19 +0000 (07:32 +0200)]
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.
Florian Weimer [Tue, 1 Jun 2021 15:51:41 +0000 (17:51 +0200)]
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.
Joseph Myers [Tue, 1 Jun 2021 14:22:06 +0000 (14:22 +0000)]
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).
Florian Weimer [Tue, 1 Jun 2021 14:00:48 +0000 (16:00 +0200)]
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.
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>
nptl: Add pthread_attr_setaffinity_np failure test
It checks whether an invalid affinity mask does return an error,
similar to what sysdeps/pthread/tst-bad-schedattr.c does for
pthread_attr_setschedparam.
The 'create_thread' function is moved to pthread_create.c. It removes
the START_THREAD_DEFN and START_THREAD_SELF macros and make the
lock usage more clear (no need to cross-reference multiple files).
Florian Weimer [Thu, 27 May 2021 13:37:35 +0000 (15:37 +0200)]
nptl: Install SIGSETXID handler with SA_ONSTACK [BZ #27914]
The signal is sent to all threads, some of which may have switched
to very small stacks. If they have also installed an alternate
signal stack, SA_ONSTACK makes this work. The Go runtime needs this:
runtime: C.setuid/C.setgid smashes Go stack
<https://github.com/golang/go/issues/9400>
Doing this for SIGCANCEL is less obviously beneficial and needs further
testing.
Naohiro Tamura [Thu, 27 May 2021 07:44:12 +0000 (07:44 +0000)]
aarch64: Added optimized memset for A64FX
This patch optimizes the performance of memset for A64FX [1] which
implements ARMv8-A SVE and has L1 64KB cache per core and L2 8MB cache
per NUMA node.
The performance optimization makes use of Scalable Vector Register
with several techniques such as loop unrolling, memory access
alignment, cache zero fill and prefetch.
SVE assembler code for memset is implemented as Vector Length Agnostic
code so theoretically it can be run on any SOC which supports ARMv8-A
SVE standard.
We confirmed that all testcases have been passed by running 'make
check' and 'make xcheck' not only on A64FX but also on ThunderX2.
And also we confirmed that the SVE 512 bit vector register performance
is roughly 4 times better than Advanced SIMD 128 bit register and 8
times better than scalar 64 bit register by running 'make bench'.
[1] https://github.com/fujitsu/A64FX
Reviewed-by: Wilco Dijkstra <Wilco.Dijkstra@arm.com> Reviewed-by: Szabolcs Nagy <Szabolcs.Nagy@arm.com>
Naohiro Tamura [Thu, 27 May 2021 07:42:35 +0000 (07:42 +0000)]
aarch64: Added optimized memcpy and memmove for A64FX
This patch optimizes the performance of memcpy/memmove for A64FX [1]
which implements ARMv8-A SVE and has L1 64KB cache per core and L2 8MB
cache per NUMA node.
The performance optimization makes use of Scalable Vector Register
with several techniques such as loop unrolling, memory access
alignment, cache zero fill, and software pipelining.
SVE assembler code for memcpy/memmove is implemented as Vector Length
Agnostic code so theoretically it can be run on any SOC which supports
ARMv8-A SVE standard.
We confirmed that all testcases have been passed by running 'make
check' and 'make xcheck' not only on A64FX but also on ThunderX2.
And also we confirmed that the SVE 512 bit vector register performance
is roughly 4 times better than Advanced SIMD 128 bit register and 8
times better than scalar 64 bit register by running 'make bench'.
[1] https://github.com/fujitsu/A64FX
Reviewed-by: Wilco Dijkstra <Wilco.Dijkstra@arm.com> Reviewed-by: Szabolcs Nagy <Szabolcs.Nagy@arm.com>
Naohiro Tamura [Wed, 12 May 2021 09:27:20 +0000 (09:27 +0000)]
aarch64: define BTI_C and BTI_J macros as NOP unless HAVE_AARCH64_BTI
This patch defines BTI_C and BTI_J macros conditionally for
performance.
If HAVE_AARCH64_BTI is true, BTI_C and BTI_J are defined as HINT
instruction for ARMv8.5 BTI (Branch Target Identification).
If HAVE_AARCH64_BTI is false, both BTI_C and BTI_J are defined as
NOP.
Yang Xu [Thu, 18 Feb 2021 02:56:33 +0000 (10:56 +0800)]
tst-mallinfo2.c: Use correct multiple for total variable
Since test uses 160 multiple for malloc size, we should also use 160 multiple
for total variable instead of 16, then comparison is meaningful. So fix it.
Also change the ">" to ">=" so that the test is technically valid.
The testrun.sh --help message was missing the "container" option.
Besides just adding the missing option I decide to rewrite it in the
same layout as other tools.
Nicholas Piggin [Thu, 20 May 2021 14:00:36 +0000 (11:00 -0300)]
powerpc: Fix handling of scv return error codes [BZ #27892]
When using scv for templated ASM syscalls, current code interprets any
negative return value as error, but the only valid error codes are in
the range -4095..-1 according to the ABI.
This commit also fixes 'signal.gen.test' strace test, where the issue
was first identified.
2. Add TEST_STACK_ALIGN_INIT to TEST_STACK_ALIGN.
3. Add a common TEST_STACK_ALIGN_INIT to check 16-byte stack alignment
for both i386 and x86-64.
4. Update powerpc to use TEST_STACK_ALIGN_INIT.
Noah Goldstein [Sun, 23 May 2021 23:43:24 +0000 (19:43 -0400)]
x86: Improve memmove-vec-unaligned-erms.S
This patch changes the condition for copy 4x VEC so that if length is
exactly equal to 4 * VEC_SIZE it will use the 4x VEC case instead of
8x VEC case.
Results For Skylake memcpy-avx2-erms
size, al1 , al2 , Cur T , New T , Win , New / Cur
128 , 0 , 0 , 9.137 , 6.873 , New , 75.22
128 , 7 , 0 , 12.933 , 7.732 , New , 59.79
128 , 0 , 7 , 11.852 , 6.76 , New , 57.04
128 , 7 , 7 , 12.587 , 6.808 , New , 54.09
Results For Icelake memcpy-evex-erms
size, al1 , al2 , Cur T , New T , Win , New / Cur
128 , 0 , 0 , 9.963 , 5.416 , New , 54.36
128 , 7 , 0 , 16.467 , 8.061 , New , 48.95
128 , 0 , 7 , 14.388 , 7.644 , New , 53.13
128 , 7 , 7 , 14.546 , 7.642 , New , 52.54
Results For Tigerlake memcpy-evex-erms
size, al1 , al2 , Cur T , New T , Win , New / Cur
128 , 0 , 0 , 8.979 , 4.95 , New , 55.13
128 , 7 , 0 , 14.245 , 7.122 , New , 50.0
128 , 0 , 7 , 12.668 , 6.675 , New , 52.69
128 , 7 , 7 , 13.042 , 6.802 , New , 52.15
Results For Skylake memmove-avx2-erms
size, al1 , al2 , Cur T , New T , Win , New / Cur
128 , 0 , 32 , 6.181 , 5.691 , New , 92.07
128 , 32 , 0 , 6.165 , 5.752 , New , 93.3
128 , 0 , 7 , 13.923 , 9.37 , New , 67.3
128 , 7 , 0 , 12.049 , 10.182 , New , 84.5
Results For Icelake memmove-evex-erms
size, al1 , al2 , Cur T , New T , Win , New / Cur
128 , 0 , 32 , 5.479 , 4.889 , New , 89.23
128 , 32 , 0 , 5.127 , 4.911 , New , 95.79
128 , 0 , 7 , 18.885 , 13.547 , New , 71.73
128 , 7 , 0 , 15.565 , 14.436 , New , 92.75
Results For Tigerlake memmove-evex-erms
size, al1 , al2 , Cur T , New T , Win , New / Cur
128 , 0 , 32 , 5.275 , 4.815 , New , 91.28
128 , 32 , 0 , 5.376 , 4.565 , New , 84.91
128 , 0 , 7 , 19.426 , 14.273 , New , 73.47
128 , 7 , 0 , 15.924 , 14.951 , New , 93.89
Noah Goldstein [Sun, 23 May 2021 23:36:36 +0000 (19:36 -0400)]
Bench: Add support for choose direction of memcpy in benchtests
This patch adds support for testing memcpy with both dst > src and dst
< src. Since memcpy is implemented as memmove which has seperate
control flows for certain sizes depending on dst > src it seems like
1) information that should be provided in the benchtest output and a
variable that can be controlled for the benchmarks.
Florian Weimer [Fri, 21 May 2021 20:35:00 +0000 (22:35 +0200)]
nptl: Move pthread_create, thrd_create into libc
The symbols were moved using scripts/move-symbol-to-libc.py.
The libpthread placeholder symbols need some changes because some
symbol versions have gone away completely. But
__errno_location@@GLIBC_2.0 still exists, so the GLIBC_2.0 version
is still there.
The internal __pthread_create symbol now points to the correct
function, so the sysdeps/nptl/thrd_create.c override is no longer
necessary.
There was an issue how the hidden alias of pthread_getattr_default_np
was defined, so this commit cleans up that aspects and removes the
GLIBC_PRIVATE export altogether.
Florian Weimer [Fri, 21 May 2021 20:35:00 +0000 (22:35 +0200)]
nptl: Eliminate the __static_tls_size, __static_tls_align_m1 variables
Use the __nptl_tls_static_size_for_stack inline function instead,
and the GLRO (dl_tls_static_align) value directly.
The computation of GLRO (dl_tls_static_align) in
_dl_determine_tlsoffset ensures that the alignment is at least
TLS_TCB_ALIGN, which at least STACK_ALIGN (see allocate_stack).
Therefore, the additional rounding-up step is removed.
ALso move the initialization of the default stack size from
__pthread_initialize_minimal_internal to __pthread_early_init.
This introduces an extra system call during single-threaded startup,
but this simplifies the initialization sequence. No locking is
needed around the writes to __default_pthread_attr because the
process is single-threaded at this point.
Florian Weimer [Fri, 21 May 2021 20:35:00 +0000 (22:35 +0200)]
nptl: Perform signal initialization upon pthread_create
Install signal handlers and unblock signals before pthread_create
creates the first thread.
create_thread in sysdeps/unix/sysv/linux/createthread.c can send
SIGCANCEL to the current thread, so the SIGCANCEL handler is currently
needed even if pthread_cancel is never called. (The way timer_create
uses SIGCANCEL does not need a signal handler; both SIG_DFL and SIG_IGN
dispositions should work.)
Noah Goldstein [Thu, 20 May 2021 17:13:51 +0000 (13:13 -0400)]
x86: Improve memset-vec-unaligned-erms.S
No bug. This commit makes a few small improvements to
memset-vec-unaligned-erms.S. The changes are 1) only aligning to 64
instead of 128. Either alignment will perform equally well in a loop
and 128 just increases the odds of having to do an extra iteration
which can be significant overhead for small values. 2) Align some
targets and the loop. 3) Remove an ALU from the alignment process. 4)
Reorder the last 4x VEC so that they are stored after the loop. 5)
Move the condition for leq 8x VEC to before the alignment
process. test-memset and test-wmemset are both passing.
Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com> Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
Noah Goldstein [Mon, 17 May 2021 17:57:24 +0000 (13:57 -0400)]
x86: Optimize memcmp-evex-movbe.S
No bug. This commit optimizes memcmp-evex.S. The optimizations include
adding a new vec compare path for small sizes, reorganizing the entry
control flow, removing some unnecissary ALU instructions from the main
loop, and most importantly replacing the heavy use of vpcmp + kand
logic with vpxor + vptern. test-memcmp and test-wmemcmp are both
passing.
Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com> Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
Noah Goldstein [Mon, 17 May 2021 17:56:52 +0000 (13:56 -0400)]
x86: Optimize memcmp-avx2-movbe.S
No bug. This commit optimizes memcmp-avx2.S. The optimizations include
adding a new vec compare path for small sizes, reorganizing the entry
control flow, and removing some unnecissary ALU instructions from the
main loop. test-memcmp and test-wmemcmp are both passing.
Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com> Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
Noah Goldstein [Mon, 17 May 2021 17:56:17 +0000 (13:56 -0400)]
x86: Expand bench-memcmp.c and test-memcmp.c
No bug. This commit adds some additional performance test cases to
bench-memcmp.c and test-memcmp.c. The new benchtests include some
medium range sizes, as well as small sizes near page cross. The new
correctness tests correspond with the new benchtests though add some
additional cases for checking the page cross logic.
Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com> Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
Joseph Myers [Tue, 18 May 2021 19:47:49 +0000 (19:47 +0000)]
Do not declare asctime_r and ctime_r for C2X
ISO C2X added the asctime_r, ctime_r, gmtime_r and localtime_r
functions from POSIX. It's now removed asctime_r and ctime_r again,
reflecting that they are marked obsolescent in POSIX; update glibc's
time.h accordingly.
The same change that removed those two functions from C2X also marked
asctime and ctime as deprecated (reflecting how POSIX shows them as
obsolescent), i.e. using the [[deprecated]] attribute in the
prototypes shown in C2X. It's less clear if we should explicitly
deprecate those functions like that in the glibc headers; this patch
does nothing regarding such a deprecation (there's no normative
requirement from C2X showing the functions as deprecated).
Stefan Liebler [Mon, 17 May 2021 14:19:36 +0000 (16:19 +0200)]
Fix stringop-overflow warning in bug-regex19.c.
Starting with commit 26492c0a14966c32c43cd6ca1d0dca5e62c6cfef
"Annotate additional APIs with GCC attribute access.",
gcc emits this warning on s390x:
In function 'do_one_test',
inlined from 'do_mb_tests' at bug-regex19.c:385:11:
bug-regex19.c:271:9: error: 're_search' specified size 18446744073709551615 exceeds maximum object size 9223372036854775807 [-Werror=stringop-overflow=]
271 | res = re_search (®buf, test->string, strlen (test->string),
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
272 | test->start, strlen (test->string) - test->start, NULL);
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from ../include/regex.h:2,
from bug-regex19.c:22:
bug-regex19.c: In function 'do_mb_tests':
../posix/regex.h:554:17: note: in a call to function 're_search' declared with attribute 'read_only (2, 3)'
554 | extern regoff_t re_search (struct re_pattern_buffer *__buffer,
| ^~~~~~~~~
...
The function do_one_test is inlined into do_mb_tests on s390x (at least with
gcc 10). If do_one_test is marked with __attribute__ ((noinline)), there are
no warnings on s390x. If do_one_test is marked with
__attribute__ ((always_inline)), there are the same warnings on x86_64.
test->string points to a variable length array on stack of do_mb_tests
and the content is generated based on the passed test struct.
According to Martin Sebor, this is a false positive caused by the same bug as
the one in nss/makedb.c. It's fixed in GCC 11 and will also be available in
the next GCC 10.4 release.
elf/cache.c: Fix resource leaks identified by static analyzers
A coverity run identified a number of resource leaks in cache.c.
There are a couple of simple memory leaks where a local allocation is
not freed before function return. Then there is a mmap leak and a
file descriptor leak where a map is not unmapped in the error case and
a file descriptor remains open respectively.
Joseph Myers [Mon, 17 May 2021 20:55:21 +0000 (20:55 +0000)]
Add C2X timespec_getres
ISO C2X adds a timespec_getres function alongside the C11
timespec_get, with functionality similar to that of POSIX clock_getres
(including allowing a NULL pointer to be passed to the function).
Implement this function for glibc, similarly to the implementation of
timespec_get.
This includes a basic test like that of timespec_get, but no
documentation in the manual, given that TIME_UTC and timespec_get
aren't documented in the manual at all. The handling of 64-bit time
follows that in timespec_get; people maintaining patch series for
64-bit time will need to update them accordingly (to export
__timespec_getres64, redirect calls in time.h and run the test for
_TIME_BITS=64).
Tested for x86_64 and x86, and (previous version; only testcase
differs) with build-many-glibcs.py.
Andreas Schwab [Mon, 17 May 2021 12:00:19 +0000 (14:00 +0200)]
Missing ENOMEM in realloc_check wrapper (bug 27870)
When MALLOC_CHECK_ is non-zero, the realloc hook missed to set errno to
ENOMEM when called with too big size. Run the test tst-malloc-too-large
also with MALLOC_CHECK_=3 to catch that.
Matheus Castanho [Wed, 12 May 2021 14:27:16 +0000 (11:27 -0300)]
benchtests: Use JSON for bench-rawmemchr output
Convert the output of benchtests/bench-rawmemchr to JSON like other string
benchmarks. This makes the output more parseable and allows usage of
compare_strings.py, for example.
Reviewed-by: Lucas A. M. Magalhaes <lamm@linux.ibm.com>
Matheus Castanho [Tue, 11 May 2021 20:53:07 +0000 (17:53 -0300)]
powerpc: Add optimized rawmemchr for POWER10
Reuse code for optimized strlen to implement a faster version of rawmemchr.
This takes advantage of the same benefits provided by the strlen implementation,
but needs some extra steps. __strlen_power10 code should be unchanged after this
change.
rawmemchr returns a pointer to the char found, while strlen returns only the
length, so we have to take that into account when preparing the return value.
To quickly check 64B, the loop on __strlen_power10 merges the whole block into
16B by using unsigned minimum vector operations (vminub) and checks if there are
any \0 on the resulting vector. The same code is used by rawmemchr if the char c
is 0. However, this approach does not work when c != 0. We first need to
subtract each byte by c, so that the value we are looking for is converted to a
0, then taking the minimum and checking for nulls works again.
The new code branches after it has compared ~256 bytes and chooses which of the
two strategies above will be used in the main loop, based on the char c. This
extra branch adds some overhead (~5%) for length ~256, but is quickly amortized
by the faster loop for larger sizes.
Compared to __rawmemchr_power9, this version is ~20% faster for length < 256.
Because of the optimized main loop, the improvement becomes ~35% for c != 0
and ~50% for c = 0 for strings longer than 256.
Reviewed-by: Lucas A. M. Magalhaes <lamm@linux.ibm.com> Reviewed-by: Raphael M Zinsly <rzinsly@linux.ibm.com>
Florian Weimer [Mon, 17 May 2021 07:59:14 +0000 (09:59 +0200)]
nptl: Move pthread_getcpuclockid into libc
The symbol was moved using scripts/move-symbol-to-libc.py.
__libpthread_version_placeholder@@GLIBC_2.2 is needed by this change;
the Versions entry for GLIBC_2.2 in libpthread had leftover symbols
due to an error in a previous conflict resolution. The condition
for the placeholder symbol is complicated because some architectures
have earlier symbols at the GLIBC_2.2 symbol versions, so the
placeholder is not required there (yet).
Florian Weimer [Mon, 17 May 2021 07:59:14 +0000 (09:59 +0200)]
nptl: Move pthread_getattr_default_np into libc
The symbol was moved using scripts/move-symbol-to-libc.py.
A new placeholder symbol __libpthread_version_placeholder@GLIBC_2.18
is needed to keep the GLIBC_2.18 symbol version in libpthread.
The __pthread_getattr_default_np@@GLIBC_PRIVATE export is used
from pthread_create.
Florian Weimer [Mon, 17 May 2021 07:59:14 +0000 (09:59 +0200)]
elf: Partially initialize ld.so after static dlopen (bug 20802)
After static dlopen, a copy of ld.so is loaded into the inner
namespace, but that copy is not initialized at all. Some
architectures run into serious problems as result, which is why the
_dl_var_init mechanism was invented. With libpthread moving into
libc and parts into ld.so, more architectures impacted, so it makes
sense to switch to a generic mechanism which performs the partial
initialization.
As a result, getauxval now works after static dlopen (bug 20802).
Florian Weimer [Mon, 17 May 2021 07:59:14 +0000 (09:59 +0200)]
nptl: Move __nptl_create_event, __nptl_death_event into libc
In libthread_db, use the exported GLIBC_PRIVATE symbols directly
instead of relying on _thread_db_* variables in libpthread
(which used to be created by the DB_FUNCTION macros).
Florian Weimer [Mon, 17 May 2021 07:59:14 +0000 (09:59 +0200)]
nptl: Move __nptl_initial_report_events into ld.so/startup code
The initialization of the report_events TCB field is now performed
in __tls_init_tp instead of __pthread_initialize_minimal_internal
(in libpthread).
The events interface is difficult to test because GDB stopped using it
in 2015. The td_thr_get_info change to ignore lookup issues is enough
to support GDB with this change.
Martin Sebor [Sun, 16 May 2021 21:21:18 +0000 (15:21 -0600)]
Enable support for GCC 11 -Wmismatched-dealloc.
To help detect common kinds of memory (and other resource) management
bugs, GCC 11 adds support for the detection of mismatched calls to
allocation and deallocation functions. At each call site to a known
deallocation function GCC checks the set of allocation functions
the former can be paired with and, if the two don't match, issues
a -Wmismatched-dealloc warning (something similar happens in C++
for mismatched calls to new and delete). GCC also uses the same
mechanism to detect attempts to deallocate objects not allocated
by any allocation function (or pointers past the first byte into
allocated objects) by -Wfree-nonheap-object.
This support is enabled for built-in functions like malloc and free.
To extend it beyond those, GCC extends attribute malloc to designate
a deallocation function to which pointers returned from the allocation
function may be passed to deallocate the allocated objects. Another,
optional argument designates the positional argument to which
the pointer must be passed.
This change is the first step in enabling this extended support for
Glibc.
nptl: Fix tst-pthread-gdb-attach for ptrace_scope equal 1
This is similar to the fix for elf/tst-pldd (2f9046fb059e94fe25):
it checks ptrace_scope value (values higher than 2 are too restrictive
to allow the test to run) and it rearranges the spawned processes
to make the target process the gdb child.
Checked on x86_64-linux-gnu with ptrace_scope set to 1.
stdlib: Fix data race in __run_exit_handlers [BZ #27749]
Keep __exit_funcs_lock almost all the time and unlock it only to execute
callbacks. This fixed two issues.
1. f->func.cxa was modified outside the lock with rare data race like:
thread 0: __run_exit_handlers unlock __exit_funcs_lock
thread 1: __internal_atexit locks __exit_funcs_lock
thread 0: f->flavor = ef_free;
thread 1: sees ef_free and use it as new
thread 1: new->func.cxa.fn = (void (*) (void *, int)) func;
thread 1: new->func.cxa.arg = arg;
thread 1: new->flavor = ef_cxa;
thread 0: cxafct = f->func.cxa.fn; // it's wrong fn!
thread 0: cxafct (f->func.cxa.arg, status); // it's wrong arg!
thread 0: goto restart;
thread 0: call the same exit_function again as it's ef_cxa
2. Don't unlock in main while loop after *listp = cur->next. If *listp
is NULL and __exit_funcs_done is false another thread may fail in
__new_exitfn on assert (l != NULL):
thread 0: *listp = cur->next; // It can be the last: *listp = NULL.
thread 0: __libc_lock_unlock
thread 1: __libc_lock_lock in __on_exit
thread 1: __new_exitfn
thread 1: if (__exit_funcs_done) // false: thread 0 isn't there yet.
thread 1: l = *listp
thread 1: moves one and crashes on assert (l != NULL);
The test needs multiple iterations to consistently fail without the fix.
git://sourceware.org / glibc.git / log