Joseph Myers [Mon, 24 Oct 2022 13:43:19 +0000 (13:43 +0000)]
Add ADDRB from Linux 6.0 to bits/termios-c_cflag.h
Linux 6.0 adds a constant ADDRB, a termios c_cflag bit, to its
include/uapi/asm-generic/termbits-common.h.
Add it accordingly to glibc's bits/termios-c_cflag.h headers. As
other constants in these headers are generally in octal, I converted
the value to octal to match. As ADDRB isn't in a POSIX-reserved
namespace, I made it conditional on __USE_MISC.
Noah Goldstein [Thu, 20 Oct 2022 02:15:55 +0000 (19:15 -0700)]
x86: Add support for VEC_SIZE == 64 in strcmp-evex.S impl
Unused at the moment, but evex512 strcmp, strncmp, strcasecmp{l}, and
strncasecmp{l} functions can be added by including strcmp-evex.S with
"x86-evex512-vecs.h" defined.
x86: Optimize strrchr-evex.S and implement with VMM headers
Added `vpcompress{b|d}` to the page-cross logic with is an
AVX512-VBMI2 instruction. This is not supported on SKX. Since the
page-cross logic is relatively cold and the benefit is minimal
revert the page-cross case back to the old logic which is supported
on SKX.
Felix Riemann [Tue, 18 Oct 2022 15:20:44 +0000 (17:20 +0200)]
sysdeps: arm: Fix preconfigure script for ARMv8/v9 targets [BZ #29698]
The ARM preconfigure script tries to detect the capabilities of the
target platform by checking the compiler's predefined architecture
macros. However, if the compiler is tuning for AArch32 on ARMv8/v9 this
step fails:
checking for sysdeps preconfigure fragments... aarch64 alpha arc arm
WARNING: arm/preconfigure: Did not find ARM architecture type; using default
This is because preconfigure.ac doesn't escape the square brackets in
the glob for matching compilers targeting ARMv8. Adding another pair of
brackets to escape the first pair fixes this:
checking for sysdeps preconfigure fragments... aarch64 alpha arc arm
Found compiler is configured for something newer than v7 - using v7
Signed-off-by: Felix Riemann <felix.riemann@sma.de> Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
linux: Avoid shifting a negative signed on POSIX timer interface
The current macros uses pid as signed value, which triggers a compiler
warning for process and thread timers. Replace MAKE_PROCESS_CPUCLOCK
with static inline function that expects the pid as unsigned. These
are similar to what Linux does internally.
Checked on x86_64-linux-gnu. Reviewed-by: Arjun Shankar <arjun@redhat.com>
Noah Goldstein [Wed, 19 Oct 2022 00:44:07 +0000 (17:44 -0700)]
x86: Optimize strrchr-evex.S and implement with VMM headers
Optimization is:
1. Cache latest result in "fast path" loop with `vmovdqu` instead of
`kunpckdq`. This helps if there are more than one matches.
Code Size Changes:
strrchr-evex.S : +30 bytes (Same number of cache lines)
Net perf changes:
Reported as geometric mean of all improvements / regressions from N=10
runs of the benchtests. Value as New Time / Old Time so < 1.0 is
improvement and 1.0 is regression.
strrchr-evex.S : 0.932 (From cases with higher match frequency)
Noah Goldstein [Wed, 19 Oct 2022 00:44:06 +0000 (17:44 -0700)]
x86: Optimize memrchr-evex.S
Optimizations are:
1. Use the fact that lzcnt(0) -> VEC_SIZE for memchr to save a branch
in short string case.
2. Save several instructions in len = [VEC_SIZE, 4 * VEC_SIZE] case.
3. Use more code-size efficient instructions.
- tzcnt ... -> bsf ...
- vpcmpb $0 ... -> vpcmpeq ...
Code Size Changes:
memrchr-evex.S : -29 bytes
Net perf changes:
Reported as geometric mean of all improvements / regressions from N=10
runs of the benchtests. Value as New Time / Old Time so < 1.0 is
improvement and 1.0 is regression.
memrchr-evex.S : 0.949 (Mostly from improvements in small strings)
Noah Goldstein [Wed, 19 Oct 2022 00:44:05 +0000 (17:44 -0700)]
x86: Optimize strnlen-evex.S and implement with VMM headers
Optimizations are:
1. Use the fact that bsf(0) leaves the destination unchanged to save a
branch in short string case.
2. Restructure code so that small strings are given the hot path.
- This is a net-zero on the benchmark suite but in general makes
sense as smaller sizes are far more common.
3. Use more code-size efficient instructions.
- tzcnt ... -> bsf ...
- vpcmpb $0 ... -> vpcmpeq ...
4. Align labels less aggressively, especially if it doesn't save fetch
blocks / causes the basic-block to span extra cache-lines.
The optimizations (especially for point 2) make the strnlen and
strlen code essentially incompatible so split strnlen-evex
to a new file.
Reported as geometric mean of all improvements / regressions from N=10
runs of the benchtests. Value as New Time / Old Time so < 1.0 is
improvement and 1.0 is regression.
strlen-evex.S : 0.992 (No real change)
strnlen-evex.S : 0.947
Noah Goldstein [Wed, 19 Oct 2022 00:44:04 +0000 (17:44 -0700)]
x86: Shrink / minorly optimize strchr-evex and implement with VMM headers
Size Optimizations:
1. Condence hot path for better cache-locality.
- This is most impact for strchrnul where the logic strings with
len <= VEC_SIZE or with a match in the first VEC no fits entirely
in the first cache line.
2. Reuse common targets in first 4x VEC and after the loop.
3. Don't align targets so aggressively if it doesn't change the number
of fetch blocks it will require and put more care in avoiding the
case where targets unnecessarily split cache lines.
4. Align the loop better for DSB/LSD
5. Use more code-size efficient instructions.
- tzcnt ... -> bsf ...
- vpcmpb $0 ... -> vpcmpeq ...
6. Align labels less aggressively, especially if it doesn't save fetch
blocks / causes the basic-block to span extra cache-lines.
Net perf changes:
Reported as geometric mean of all improvements / regressions from N=10
runs of the benchtests. Value as New Time / Old Time so < 1.0 is
improvement and 1.0 is regression.
Noah Goldstein [Wed, 19 Oct 2022 00:44:03 +0000 (17:44 -0700)]
x86: Optimize memchr-evex.S and implement with VMM headers
Optimizations are:
1. Use the fact that tzcnt(0) -> VEC_SIZE for memchr to save a branch
in short string case.
2. Restructure code so that small strings are given the hot path.
- This is a net-zero on the benchmark suite but in general makes
sense as smaller sizes are far more common.
3. Use more code-size efficient instructions.
- tzcnt ... -> bsf ...
- vpcmpb $0 ... -> vpcmpeq ...
4. Align labels less aggressively, especially if it doesn't save fetch
blocks / causes the basic-block to span extra cache-lines.
The optimizations (especially for point 2) make the memchr and
rawmemchr code essentially incompatible so split rawmemchr-evex
to a new file.
Reported as geometric mean of all improvements / regressions from N=10
runs of the benchtests. Value as New Time / Old Time so < 1.0 is
improvement and 1.0 is regression.
Sunil K Pandey [Thu, 18 Aug 2022 13:48:07 +0000 (06:48 -0700)]
x86_64: Implement evex512 version of memchr, rawmemchr and wmemchr
This patch implements following evex512 version of string functions.
evex512 version takes up to 30% less cycle as compared to evex,
depending on length and alignment.
- memchr function using 512 bit vectors.
- rawmemchr function using 512 bit vectors.
- wmemchr function using 512 bit vectors.
Florian Weimer [Tue, 18 Oct 2022 15:00:07 +0000 (17:00 +0200)]
Use PTR_MANGLE and PTR_DEMANGLE unconditionally in C sources
In the future, this will result in a compilation failure if the
macros are unexpectedly undefined (due to header inclusion ordering
or header inclusion missing altogether).
Assembler sources are more difficult to convert. In many cases,
they are hand-optimized for the mangling and no-mangling variants,
which is why they are not converted.
sysdeps/s390/s390-32/__longjmp.c and sysdeps/s390/s390-64/__longjmp.c
are special: These are C sources, but most of the implementation is
in assembler, so the PTR_DEMANGLE macro has to be undefined in some
cases, to match the assembler style.
Florian Weimer [Tue, 18 Oct 2022 15:00:07 +0000 (17:00 +0200)]
Introduce <pointer_guard.h>, extracted from <sysdep.h>
This allows us to define a generic no-op version of PTR_MANGLE and
PTR_DEMANGLE. In the future, we can use PTR_MANGLE and PTR_DEMANGLE
unconditionally in C sources, avoiding an unintended loss of hardening
due to missing include files or unlucky header inclusion ordering.
In i386 and x86_64, we can avoid a <tls.h> dependency in the C
code by using the computed constant from <tcb-offsets.h>. <sysdep.h>
no longer includes these definitions, so there is no cyclic dependency
anymore when computing the <tcb-offsets.h> constants.
Florian Weimer [Tue, 18 Oct 2022 15:00:07 +0000 (17:00 +0200)]
x86-64: Move LP_SIZE definition to its own header
This way, we can define the pointer guard macros without including
<sysdep.h> on x86-64. Other architectures will not have such an
inclusion dependency, and the implied header file inclusion would
create a porting hazard.
Szabolcs Nagy [Thu, 13 Oct 2022 10:10:10 +0000 (11:10 +0100)]
math: Fix asin and acos invalid exception with old gcc
This works around a gcc issue where it const folded inf/inf into nan,
preventing the invalid exception to be signalled.
(x-x)/(x-x) is more robust against optimizations and works for all
out of bounds values including x==nan.
The gcc issue https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95115
should be fixed on release branches starting from gcc-10, but it is
better to change the code in case glibc is built with older gcc.
Noah Goldstein [Sat, 15 Oct 2022 03:00:25 +0000 (22:00 -0500)]
x86: Update VEC macros to complete API for evex/evex512 impls
1) Copy so that backport will be easier.
2) Make section only define if there is not a previous definition
3) Add `VEC_lo` definition for proper reg-width but in the
ymm/zmm0-15 range.
4) Add macros for accessing GPRs based on VEC_SIZE
This is to make it easier to do think like:
```
vpcmpb %VEC(0), %VEC(1), %k0
kmov{d|q} %k0, %{eax|rax}
test %{eax|rax}
```
It adds macro s.t any GPR can get the proper width with:
`V{upcase_GPR_name}`
and any mask insn can get the proper width with:
`{upcase_mask_insn_without_postfix}`
Florian Weimer [Fri, 14 Oct 2022 09:02:25 +0000 (11:02 +0200)]
elf: Do not completely clear reused namespace in dlmopen (bug 29600)
The data in the _ns_debug member must be preserved, otherwise
_dl_debug_initialize enters an infinite loop. To be conservative,
only clear the libc_map member for now, to fix bug 29528.
Florian Weimer [Thu, 13 Oct 2022 03:45:41 +0000 (05:45 +0200)]
malloc: Switch global_max_fast to uint8_t
MAX_FAST_SIZE is 160 at most, so a uint8_t is sufficient. This makes
it harder to use memory corruption, by overwriting global_max_fast
with a large value, to fundamentally alter malloc behavior.
elf: Remove -fno-tree-loop-distribute-patterns usage on dl-support
Besides the option being gcc specific, this approach is still fragile
and not future proof since we do not know if this will be the only
optimization option gcc will add that transforms loops to memset
(or any libcall).
This patch adds a new header, dl-symbol-redir-ifunc.h, that can b
used to redirect the compiler generated libcalls to port the generic
memset implementation if required.
Checked on x86_64-linux-gnu and aarch64-linux-gnu. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Xi Ruoyao [Sun, 2 Oct 2022 14:23:09 +0000 (22:23 +0800)]
LoongArch: Fix the condition to use PC-relative addressing in start.S
A start.o compiled from start.S with -DPIC and no -DSHARED is used by
both crt1.o and rcrt1.o. So the LoongArch static PIE patch
unintentionally introduced PC-relative addressing for main and
__libc_start_main into crt1.o.
While the latest Binutils (trunk, which will be released as 2.40)
supports the PC-relative relocs against an external function by creating
a PLT entry, the 2.39 release branch doesn't (and won't) support this.
An error is raised:
"PLT stub does not represent and symbol not defined."
So, we need the following changes:
1. Check if ld supports the PC-relative relocs against an external
function. If it's not supported, we deem static PIE unsupported.
2. Change start.S. If static PIE is supported, use PC-relative
addressing for main and __libc_start_main and rely on the linker to
create PLT entries. Otherwise, restore the old behavior (using GOT
to address these functions).
An alternative would be adding a new "static-pie-start.S", and some
custom logic into Makefile to build rcrt1.o with it. And, restore
start.S to the state before static PIE change so crt1.o won't contain
PC-relative relocs against external symbols. But I can't see any
benefit of this alternative, so I'd just keep it simple.
Tested by building glibc with the following configurations:
1. Binutils trunk + GCC trunk. Static PIE enabled. All tests
passed.
2. Binutils 2.39 branch + GCC trunk. Static PIE disabled. Tests
related to ifunc failed (it's a known issue). All other tests
passed.
3. Binutils 2.39 branch + GCC 12 branch, cross compilation with
build-many-glibcs.py from x86_64-linux-gnu. Static PIE disabled.
Build succeeded.
And since the function is called prior thread pointer setup, it
triggers a invalid memory access (this is shown with the failure
of elf/tst-tls1-static-non-pie).
Although it might characterizes as compiler issue or missed
optimization, to be safe also disables stack protector on
static-reloc object.
Checked on x86_64-linux-gnu and sparc64-linux-gnu. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Mike FABIAN [Thu, 29 Sep 2022 14:04:42 +0000 (16:04 +0200)]
Update to Unicode 15.0.0 [BZ #29604]
Unicode 15.0.0 Support: Character encoding, character type info, and
transliteration tables are all updated to Unicode 15.0.0, using
the generator scripts contributed by Mike FABIAN (Red Hat).
Total added characters in newly generated CHARMAP: 4489
Total removed characters in newly generated WIDTH: 0
Total changed characters in newly generated WIDTH: 0
Total added characters in newly generated WIDTH: 4257
alpha: Added 4389 characters in new ctype which were not in old ctype
combining: Added 42 characters in new ctype which were not in old ctype
combining_level3: Added 34 characters in new ctype which were not in old ctype
graph: Added 4489 characters in new ctype which were not in old ctype
lower: Added 73 characters in new ctype which were not in old ctype
print: Added 4489 characters in new ctype which were not in old ctype
punct: Missing 5 characters of old ctype in new ctype
punct: Missing: ఄ 0xc04 TELUGU SIGN COMBINING ANUSVARA ABOVE
punct: Missing: ྂ 0xf82 TIBETAN SIGN NYI ZLA NAA DA
punct: Missing: ྃ 0xf83 TIBETAN SIGN SNA LDAN
punct: Missing: 𑂀 0x11080 KAITHI SIGN CANDRABINDU
punct: Missing: 𑂁 0x11081 KAITHI SIGN ANUSVARA
That’s OK, because these are now Alphabetic in DerivedCoreProperties.txt
punct: Added 105 characters in new ctype which were not in old ctype
Resolves: BZ #29604 Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Joseph Myers [Wed, 5 Oct 2022 22:11:27 +0000 (22:11 +0000)]
Update kernel version to 6.0 in header constant tests
This patch updates the kernel version in the tests tst-mman-consts.py,
tst-mount-consts.py and tst-pidfd-consts.py to 6.0. (There are no new
constants covered by these tests in 6.0 that need any other header
changes.)
The compiler might transform __stpcpy calls (which are routed to
__builtin_stpcpy as an optimization) to strcpy and x86_64 strcpy
multiarch implementation does not build any working symbol due
ISA_SHOULD_BUILD not being evaluated for IS_IN(rtld).
Checked on x86_64-linux-gnu. Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
netname.c: In function ‘user2netname’:
netname.c:51:28: error: ‘%s’ directive writing up to 255 bytes into a
region of size between 239 and 249 [-Werror=format-overflow=]
51 | sprintf (netname, "%s.%d@%s", OPSYS, uid, dfltdom);
| ^~ ~~~~~~~
netname.c:51:3: note: ‘sprintf’ output between 8 and 273 bytes into a
destination of size 256
51 | sprintf (netname, "%s.%d@%s", OPSYS, uid, dfltdom);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors
However the code does test prior the sprintf call that dfltdom plus
the required extra space for OPSYS, uid, and extra character will not
overflow and return 0 instead.
Checked on x86_64-linux-gnu and i686-linux-gnu. Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
GCC with -Os warns that the mq_send input may be used uninitialized.
Although for the tests the data content sent is not important, since
both tests checks only if mq_notify was properly set, the warning is
correct and data is indeed uninitialized.
Checked on x86_64-linux-gnu and i686-linux-gnu. Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
Martin Jansa [Wed, 21 Sep 2022 13:51:03 +0000 (10:51 -0300)]
locale: prevent maybe-uninitialized errors with -Os [BZ #19444]
Fixes following error when building with -Os:
| In file included from strcoll_l.c:43:
| strcoll_l.c: In function '__strcoll_l':
| ../locale/weight.h:31:26: error: 'seq2.back_us' may be used
uninitialized in this function [-Werror=maybe-uninitialized]
| int_fast32_t i = table[*(*cpp)++];
| ^~~~~~~~~
| strcoll_l.c:304:18: note: 'seq2.back_us' was declared here
| coll_seq seq1, seq2;
| ^~~~
| In file included from strcoll_l.c:43:
| ../locale/weight.h:31:26: error: 'seq1.back_us' may be used
uninitialized in this function [-Werror=maybe-uninitialized]
| int_fast32_t i = table[*(*cpp)++];
| ^~~~~~~~~
| strcoll_l.c:304:12: note: 'seq1.back_us' was declared here
| coll_seq seq1, seq2;
| ^~~~ Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
Joseph Myers [Wed, 5 Oct 2022 19:21:25 +0000 (19:21 +0000)]
Regenerate sysdeps/mach/hurd/bits/errno.h
This addition to the list of source headers in
sysdeps/mach/hurd/bits/errno.h appears in the source tree after
build-many-glibcs.py runs, I'm guessing resulting from gnumach commit c566ad85a2d6728ebc8ec0f461a3b35df300e96e.
nscd: Drop local address tuple variable [BZ #29607]
When a request needs to be resent (e.g. due to insufficient buffer
space), the references to subsequent tuples in the local variable are
stale and should not be used. This used to work by accident before, but
since 1d495912a it no longer does. Instead of trying to reset it, just
let gethostbyname4_r write into TUMPBUF6 for us, thus maintaining a
consistent state at all times. This is now consistent with what is done
in gaih_inet for getaddrinfo.
Aurelien Jarno [Mon, 3 Oct 2022 21:46:11 +0000 (23:46 +0200)]
x86-64: Require BMI1/BMI2 for AVX2 strrchr and wcsrchr implementations
The AVX2 strrchr and wcsrchr implementation uses the 'blsmsk'
instruction which belongs to the BMI1 CPU feature and the 'shrx'
instruction, which belongs to the BMI2 CPU feature.
Aurelien Jarno [Mon, 3 Oct 2022 21:46:11 +0000 (23:46 +0200)]
x86-64: Require BMI2 and LZCNT for AVX2 memrchr implementation
The AVX2 memrchr implementation uses the 'shlxl' instruction, which
belongs to the BMI2 CPU feature and uses the 'lzcnt' instruction, which
belongs to the LZCNT CPU feature.
Aurelien Jarno [Mon, 3 Oct 2022 21:46:11 +0000 (23:46 +0200)]
x86-64: Require BMI2 for AVX2 wcs(n)cmp implementations
The AVX2 wcs(n)cmp implementations use the 'bzhi' instruction, which
belongs to the BMI2 CPU feature.
NB: It also uses the 'tzcnt' BMI1 instruction, but it is executed as BSF
as BSF if the CPU doesn't support TZCNT, and produces the same result
for non-zero input.
Aurelien Jarno [Mon, 3 Oct 2022 21:46:11 +0000 (23:46 +0200)]
x86-64: Require BMI2 for AVX2 strncmp implementation
The AVX2 strncmp implementations uses the 'bzhi' instruction, which
belongs to the BMI2 CPU feature.
NB: It also uses the 'tzcnt' BMI1 instruction, but it is executed as BSF
as BSF if the CPU doesn't support TZCNT, and produces the same result
for non-zero input.
Aurelien Jarno [Mon, 3 Oct 2022 21:46:11 +0000 (23:46 +0200)]
x86-64: Require BMI2 for AVX2 strcmp implementation
The AVX2 strcmp implementation uses the 'bzhi' instruction, which
belongs to the BMI2 CPU feature.
NB: It also uses the 'tzcnt' BMI1 instruction, but it is executed as BSF
as BSF if the CPU doesn't support TZCNT, and produces the same result
for non-zero input.
Aurelien Jarno [Mon, 3 Oct 2022 21:46:11 +0000 (23:46 +0200)]
x86-64: Require BMI2 for AVX2 str(n)casecmp implementations
The AVX2 str(n)casecmp implementations use the 'bzhi' instruction, which
belongs to the BMI2 CPU feature.
NB: It also uses the 'tzcnt' BMI1 instruction, but it is executed as BSF
as BSF if the CPU doesn't support TZCNT, and produces the same result
for non-zero input.
Noah Goldstein [Sat, 1 Oct 2022 04:13:27 +0000 (21:13 -0700)]
x86: Cleanup pthread_spin_{try}lock.S
Save a jmp on the lock path coming from an initial failure in
pthread_spin_lock.S. This costs 4-bytes of code but since the
function still fits in the same number of 16-byte blocks (default
function alignment) it does not have affect on the total binary size
of libc.so (unchanged after this commit).
pthread_spin_trylock was using a CAS when a simple xchg works which
is often more expensive.
hppa: Fix initialization of dp register [BZ 29635]
After upgrading glibc to Debian 2.35-1, gdb faulted on
startup and dropped core in a function call in the main
application. This was caused by not initializing the
global dp register for the main application early enough.
Restore the code to initialize dp in _dl_start_user.
It was removed when code was added to initialize dp in
elf_machine_runtime_setup.
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Joseph Myers [Fri, 30 Sep 2022 19:36:41 +0000 (19:36 +0000)]
Fix iseqsig for _FloatN and _FloatNx in C++ with GCC 13
With GCC 13, _FloatN and _FloatNx types, when they exist, are distinct
types like they are in C with GCC 7 and later, rather than typedefs
for types such as float, double or long double.
This breaks the templated iseqsig implementation for C++ in <math.h>,
when used with types that were previously implemented as aliases. Add
the necessary definitions for _Float32, _Float64, _Float128 (when the
same format as long double), _Float32x and _Float64x in this case, so
that iseqsig can be used with such types in C++ with GCC 13 as it
could with previous GCC versions.
Also add tests for calling iseqsig in C++ with arguments of such types
(more minimal than existing tests, so that they can work with older
GCC versions and without relying on any C++ library support for the
types or on hardcoding details of their formats). The LDBL_MANT_DIG
!= 106 conditionals on some tests are because the type-generic
comparison macros have undefined behavior when neither argument has a
type whose set of values is a subset of those for the type of the
other argument, which applies when one argument is IBM long double and
the other is an IEEE format wider than binary64.
Tested with build-many-glibcs.py glibcs build for aarch64-linux-gnu
i686-linux-gnu mips-linux-gnu mips64-linux-gnu-n32 powerpc-linux-gnu
powerpc64le-linux-gnu x86_64-linux-gnu.
Xi Ruoyao [Sat, 24 Sep 2022 07:45:34 +0000 (15:45 +0800)]
LoongArch: Add static PIE support
If the compiler is new enough, enable static PIE support. In the static
PIE version of _start (in rcrt1.o), use la.pcrel instead of la.got
because in a static PIE we cannot use GOT entries until the dynamic
relocations for GOT are resolved.
Joseph Myers [Wed, 28 Sep 2022 20:09:34 +0000 (20:09 +0000)]
Update _FloatN header support for C++ in GCC 13
GCC 13 adds support for _FloatN and _FloatNx types in C++, so breaking
the installed glibc headers that assume such support is not present.
GCC mostly works around this with fixincludes, but that doesn't help
for building glibc and its tests (glibc doesn't itself contain C++
code, but there's C++ code built for tests). Update glibc's
bits/floatn-common.h and bits/floatn.h headers to handle the GCC 13
support directly.
In general the changes match those made by fixincludes, though I think
the ones in sysdeps/powerpc/bits/floatn.h, where the header tests
__LDBL_MANT_DIG__ == 113 or uses #elif, wouldn't match the existing
fixincludes patterns.
Some places involving special C++ handling in relation to _FloatN
support are not changed. There's no need to change the
__HAVE_FLOATN_NOT_TYPEDEF definition (also in a form that wouldn't be
matched by the fixincludes fixes) because it's only used in relation
to macro definitions using features not supported for C++
(__builtin_types_compatible_p and _Generic). And there's no need to
change the inline function overloads for issignaling, iszero and
iscanonical in C++ because cases where types have the same format but
are no longer compatible types are handled automatically by the C++
overload resolution rules.
This patch also does not change the overload handling for iseqsig, and
there I think changes *are* needed, beyond those in this patch or made
by fixincludes. The way that overload is defined, via a template
parameter to a structure type, requires overloads whenever the types
are incompatible, even if they have the same format. So I think we
need to add overloads with GCC 13 for every supported _FloatN and
_FloatNx type, rather than just having one for _Float128 when it has a
different ABI to long double as at present (but for older GCC, such
overloads must not be defined for types that end up defined as
typedefs for another type).
Tested with build-many-glibcs.py: compilers build for
aarch64-linux-gnu ia64-linux-gnu mips64-linux-gnu powerpc-linux-gnu
powerpc64le-linux-gnu x86_64-linux-gnu; glibcs build for
aarch64-linux-gnu ia64-linux-gnu i686-linux-gnu mips-linux-gnu
mips64-linux-gnu-n32 powerpc-linux-gnu powerpc64le-linux-gnu
x86_64-linux-gnu.
nss: Use shared prefix in IPv4 address in tst-reload1
Otherwise, sorting based on the longest-matching prefix in
getaddrinfo can reorder the addresses in ways the test does not
expect, depending on the IPv4 address of the host.
Use C11 atomics instead of atomic_decrement_and_test
Replace atomic_decrement_and_test with atomic_fetch_add_relaxed.
These are simple counters which do not protect any shared data from
concurrent accesses. Also remove the unused file cond-perf.c.
Replace atomic_increment and atomic_increment_val with atomic_fetch_add_relaxed.
One case in sem_post.c uses release semantics (see comment above it).
The others are simple counters and do not protect any shared data from
concurrent accesses.
Remove the 4 uses of atomic_and and atomic_or with atomic_fetch_and_acquire
and atomic_fetch_or_acquire. This is preserves existing implied semantics,
however relaxed MO on FUTEX_OWNER_DIED accesses may be correct.
The need to maintain elf/elf.h and scripts/glibcelf.py in parallel
results in a backporting hazard: they need to be kept in sync to
avoid elf/tst-glibcelf consistency check failures. glibcelf (unlike
tst-glibcelf) does not use the C implementation to extract constants.
This applies the additional glibcpp syntax checks to <elf.h>.
This changereplaces the types derived from Python enum types with
custom types _TypedConstant, _IntConstant, and _FlagConstant. These
types have fewer safeguards, but this also allows incremental
construction and greater flexibility for grouping constants among
the types. Architectures-specific named constants are now added
as members into their superclasses (but value-based lookup is
still restricted to generic constants only).
Consequently, check_duplicates in elf/tst-glibcelf has been adjusted
to accept differently-named constants of the same value if their
subtypes are distinct. The ordering check for named constants
has been dropped because they are no longer strictly ordered.
Further test adjustments: Some of the type names are different.
The new types do not support iteration (because it is unclear
whether iteration should cover the all named values (including
architecture-specific constants), or only the generic named values),
so elf/tst-glibcelf now uses by_name explicit (to get all constants).
PF_HP_SBP and PF_PARISC_SBP are now of distinct types (PfHP and
PfPARISC), so they are how both present on the Python side. EM_NUM
and PT_NUM are filtered (which was an oversight in the old
conversion).
The new version of glibcelf should also be compatible with earlier
Python versions because it no longer depends on the enum module and its
advanced features.
git://sourceware.org / glibc.git / log