Kacper Piwiński [Thu, 9 Mar 2023 10:38:59 +0000 (11:38 +0100)]
linux: fix ntp_gettime abi break (BZ# 30156)
Between versions v2.11 and v2.12 struct ntptimeval got new fields.
That wasn't a problem because new function ntp_gettimex was created
(and made default) to support new struct. Old ntp_gettime was not
using new fields so it was safe to call with old struct
definition. Then commits 5613afe9e3dff and b6ad64b907a (added for
64 bit time_t support), ntp_gettime start setting new fields.
Sets fields manually to maintain compatibility with v2.11 struct
definition.
Arsen Arsenović [Tue, 7 Mar 2023 10:29:35 +0000 (11:29 +0100)]
elf: Add missing dependency between resolvfail and testobj1.so
It was possible to run this test individually and have it fail because
it can't find testobj1.so. This patch adds that dependency, to prevent
such issues.
Wilco Dijkstra [Fri, 3 Mar 2023 16:10:55 +0000 (16:10 +0000)]
Benchtests: Remove simple_str(r)chr
Instead of benchmarking slow byte oriented loops, include the optimized generic
strchr and strrchr implementation. Adjust iteration count to reduce benchmark
time.
Wilco Dijkstra [Fri, 3 Mar 2023 13:03:19 +0000 (13:03 +0000)]
Benchtests: Remove simple_strcspn/strpbrk/strsep
Remove simple_strcspn/strpbrk/strsep which are significantly slower than the
generic implementations. Also remove oldstrsep and oldstrtok since they are
practically identical to the generic implementation. Adjust iteration count
to reduce benchmark time.
Wilco Dijkstra [Fri, 3 Mar 2023 12:57:49 +0000 (12:57 +0000)]
Benchtests: Remove memchr_strnlen
Remove memchr_strnlen since it is now the same as generic_strnlen. Adjust
iteration count to reduce benchmark time. Keep memchr_strlen since the
generic strlen does not use memchr.
Wilco Dijkstra [Fri, 3 Mar 2023 12:54:45 +0000 (12:54 +0000)]
Benchtests: Remove simple_mem(r)chr
Instead of benchmarking slow byte oriented loops, include the optimized
generic memchr/memrchr implementation. Adjust iteration count to reduce
benchmark time.
Wilco Dijkstra [Fri, 3 Mar 2023 12:40:22 +0000 (12:40 +0000)]
Benchtests: Remove simple_str(n)cmp
Instead of benchmarking slow byte oriented loops, include the optimized generic
strcmp/strncmp implementation. Adjust iteration count to reduce benchmark time.
Robert Morell [Tue, 7 Mar 2023 13:14:45 +0000 (10:14 -0300)]
malloc: Fix transposed arguments in sysmalloc_mmap_fallback call
git commit 0849eed45daa ("malloc: Move MORECORE fallback mmap to
sysmalloc_mmap_fallback") moved a block of code from sysmalloc to a
new helper function sysmalloc_mmap_fallback(), but 'pagesize' is used
for the 'minsize' argument and 'MMAP_AS_MORECORE_SIZE' for the
'pagesize' argument.
Fixes: 0849eed45daa ("malloc: Move MORECORE fallback mmap to sysmalloc_mmap_fallback") Signed-off-by: Robert Morell <rmorell@nvidia.com> Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Adam Yi [Wed, 8 Mar 2023 08:11:47 +0000 (03:11 -0500)]
hurd: fix build of tst-system.c
We made tst-system.c depend on pthread, but that requires linking with
$(shared-thread-library). It does not fail under Linux because the
variable expands to nothing under Linux, but it fails for Hurd.
I tested verified via cross-compiling that "make check" now works
for Hurd.
Signed-off-by: Adam Yi <ayi@janestreet.com> Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
caiyinyu [Tue, 28 Feb 2023 08:21:41 +0000 (16:21 +0800)]
x86: Fix bug about glibc.cpu.hwcaps.
Recorded in [BZ #30183]:
1. export GLIBC_TUNABLES=glibc.cpu.hwcaps=-AVX512
2. Add _dl_printf("p -- %s\n", p); just before switch(nl) in
sysdeps/x86/cpu-tunables.c
3. compiled and run ./testrun.sh /usr/bin/ls
you will get:
p -- -AVX512
p -- LC_ADDRESS=en_US.UTF-8
p -- LC_NUMERIC=C
...
The function, TUNABLE_CALLBACK (set_hwcaps)
(tunable_val_t *valp), checks far more than it should and it
should stop at end of "-AVX512".
Adam Yi [Tue, 7 Mar 2023 12:30:02 +0000 (07:30 -0500)]
posix: Fix system blocks SIGCHLD erroneously [BZ #30163]
Fix bug that SIGCHLD is erroneously blocked forever in the following
scenario:
1. Thread A calls system but hasn't returned yet
2. Thread B calls another system but returns
SIGCHLD would be blocked forever in thread B after its system() returns,
even after the system() in thread A returns.
Although POSIX does not require, glibc system implementation aims to be
thread and cancellation safe. This bug was introduced in 5fb7fc96350575c9adb1316833e48ca11553be49 when we moved reverting signal
mask to happen when the last concurrently running system returns,
despite that signal mask is per thread. This commit reverts this logic
and adds a test.
Signed-off-by: Adam Yi <ayi@janestreet.com> Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Before this change, sgetsgent_r did not set errno to ERANGE, but
sgetsgent only check errno, not the return value from sgetsgent_r.
Consequently, sgetsgent did not detect any error, and reported
success to the caller, without initializing the struct sgrp object
whose address was returned.
This commit changes sgetsgent_r to set errno as well. This avoids
similar issues in applications which only change errno.
Joseph Myers [Mon, 6 Mar 2023 15:13:22 +0000 (15:13 +0000)]
Update kernel version to 6.2 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 6.2. (There are no new
constants covered by these tests in 6.2 that need any other header
changes, and the removed MAP_VARIABLE for hppa was addressed
separately.)
arm: Remove __builtin_arm_uqsub8 usage on string-fza.h
The __builtin_arm_uqsub8 is an internal GCC builtin which might change
in future release (the correct way is to include "arm_acle.h" and use
__uqsub8 ()). Since not all compilers support it, just use the
inline assembler instead.
Checked on armv7a-linux-gnueabihf. Reviewed-by: Wilco Dijkstra <Wilco.Dijkstra@arm.com>
The default, and power7 implementation just adds word aligned
access when inputs have the same aligment. The unaligned case
is still done by byte operations.
This is already covered by the generic implementation, which also add
the unaligned input optimization.
Checked on powerpc64-linux-gnu built without multi-arch for powerpc64,
power7, power8, and power9 (build for le). Reviewed-by: Rajalakshmi Srinivasaraghavan <rajis@linux.ibm.com>
The default, power4, and power7 implementation just adds word aligned
access when inputs have the same aligment. The unaligned case
is still done by byte operations.
This is already covered by the generic implementation, which also add
the unaligned input optimization.
Checked on powerpc-linux-gnu built without multi-arch for powerpc,
power4, and power7. Reviewed-by: Rajalakshmi Srinivasaraghavan <rajis@linux.ibm.com>
Joseph Myers [Thu, 2 Mar 2023 19:10:37 +0000 (19:10 +0000)]
C2x scanf binary constant handling
C2x adds binary integer constants starting with 0b or 0B, and supports
those constants for the %i scanf format (in addition to the %b format,
which isn't yet implemented for scanf in glibc). Implement that scanf
support for glibc.
As with the strtol support, this is incompatible with previous C
standard versions, in that such an input string starting with 0b or 0B
was previously required to be parsed as 0 (with the rest of the input
potentially matching subsequent parts of the scanf format string).
Thus this patch adds 12 new __isoc23_* functions per long double
format (12, 24 or 36 depending on how many long double formats the
glibc configuration supports), with appropriate header redirection
support (generally very closely following that for the __isoc99_*
scanf functions - note that __GLIBC_USE (DEPRECATED_SCANF) takes
precedence over __GLIBC_USE (C2X_STRTOL), so the case of GNU
extensions to C89 continues to get old-style GNU %a and does not get
this new feature). The function names would remain as __isoc23_* even
if C2x ends up published in 2024 rather than 2023.
When scanf %b support is added, I think it will be appropriate for all
versions of scanf to follow C2x rules for inputs to the %b format
(given that there are no compatibility concerns for a new format).
Tested for x86_64 (full glibc testsuite). The first version was also
tested for powerpc (32-bit) and powerpc64le (stdio-common/ and wcsmbs/
tests), and with build-many-glibcs.py.
Stefan Liebler [Tue, 28 Feb 2023 12:37:35 +0000 (13:37 +0100)]
nis: Fix stringop-truncation warning with -O3 in nis_local_host.
When building with -O3 on s390x/x86_64, I get this stringop-truncation warning
which leads to a build fail:
In function ‘nis_local_host’,
inlined from ‘nis_local_host’ at nis_local_names.c:147:1:
nis_local_names.c:171:11: error: ‘strncpy’ output may be truncated copying between 0 and 1023 bytes from a string of length 1024 [-Werror=stringop-truncation]
171 | strncpy (cp, nis_local_directory (), NIS_MAXNAMELEN - len -1);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
We can just ignore this warning as the hostname + '.' + directory-name + '\0' always fits
in __nishostname with length of (NIS_MAXNAMELEN + 1) as there is the runtime check above.
Furthermore as we already know the length of the directory-name, we can also just use
memcpy to copy the directory-name inclusive the NUL-termination.
Xi Ruoyao [Mon, 27 Feb 2023 11:08:09 +0000 (19:08 +0800)]
LoongArch: Further refine the condition to enable static PIE
Before GCC r13-2728, it would produce a normal dynamic-linked executable
with -static-pie. I mistakely believed it would produce a static-linked
executable, so failed to detect the breakage. Then with Binutils 2.40
and (vanilla) GCC 12, libc_cv_static_pie_on_loongarch is mistakenly
enabled and cause a building failure with "undefined reference to
_DYNAMIC".
Fix the issue by disabling static PIE if -static-pie creates something
with a INTERP header.
Sergey Bugaev [Wed, 1 Mar 2023 16:23:54 +0000 (19:23 +0300)]
hurd: Remove the ecx kludge
"We don't need it any more"
The INTR_MSG_TRAP macro in intr-msg.h used to play little trick with
the stack pointer: it would temporarily save the "real" stack pointer
into ecx, while setting esp to point to just before the message buffer,
and then invoke the mach_msg trap. This way, INTR_MSG_TRAP reused the
on-stack arguments laid out for the containing call of
_hurd_intr_rpc_mach_msg (), passing them to the mach_msg trap directly.
This, however, required special support in hurdsig.c and trampoline.c,
since they now had to recognize when a thread is inside the piece of
code where esp doesn't point to the real tip of the stack, and handle
this situation specially.
Commit 1d20f33ff4fb634310f27493b7b87d0b20f4a0b0 has removed the actual
temporary change of esp by actually re-pushing mach_msg arguments onto
the stack, and popping them back at end. It did not, however, deal with
the rest of "the ecx kludge" code in other files, resulting in potential
crashes if a signal arrives in the middle of pushing arguments onto the
stack.
Fix that by removing "the ecx kludge". Instead, when we want a thread
to skip the RPC, but cannot make just make it jump to after the trap
since it's not done adjusting the stack yet, set the SYSRETURN register
to MACH_SEND_INTERRUPTED (as we do anyway), and rely on the thread
itself for detecting this case and skipping the RPC.
This simplifies things somewhat and paves the way for a future x86_64
port of this code.
crypt: Remove invalid end of page test badsalttest
The input argument passes an invalid string without a NUL terminator
on crypt settings inputs, which might lead to invalid OOB on strncmp.
Implementations only assume there is a NUL terminator if the string is
shorter than the specified size, so strings don't need to always be NUL
terminated (stratcliff.c has tests for this).
Andreas Arnez [Tue, 28 Feb 2023 12:48:06 +0000 (13:48 +0100)]
S390: Fix _FPU_SETCW/GETCW when compiling with Clang [BZ #30130]
The _FPU_SETCW and _FPU_GETCW macros are defined with inline assemblies.
They use the sfpc and efpc instructions, respectively. But both contain
a spurious second operand that leads to a compile error with Clang.
Removing this operand works both with gcc/gas (since binutils 2.18) as
well as with clang/llvm.
Joseph Myers [Tue, 28 Feb 2023 00:07:59 +0000 (00:07 +0000)]
Add Arm HWCAP values from Linux 6.2 to bits/hwcap.h
Linux 6.2 adds six new Arm HWCAP values and two new HWCAP2 values; add
them to glibc's Arm bits/hwcap.h, with corresponding dl-procinfo.c and
dl-procinfo.h updates.
Tested with build-many-glibcs.py for arm-linux-gnueabi.
The Linux kernel upstream commit 71bdea6f798b ("parisc: Align parisc
MADV_XXX constants with all other architectures") dropped the
parisc-specific MADV_* values in favour of the same constants as
other architectures. In the same commit a wrapper was added which
translates the old values to the standard MADV_* values to avoid
breakage of existing programs.
This upstream patch has been downported to all stable kernel trees as
well.
This patch now drops the parisc specific constants from glibc to
allow newly compliled programs to use the standard MADV_* constants.
v2: Added NEWS section, based on feedback from Florian Weimer
Crossing 2GB boundaries with indirect calls and jumps can use more
branch prediction resources on Intel Golden Cove CPU (see the
"Misprediction for Branches >2GB" section in Intel 64 and IA-32
Architectures Optimization Reference Manual.) There is visible
performance improvement on workloads with many PLT calls when executable
and shared libraries are mmapped below 2GB. Add the Prefer_MAP_32BIT_EXEC
bit so that mmap will try to map executable or denywrite pages in shared
libraries with MAP_32BIT first.
NB: Prefer_MAP_32BIT_EXEC reduces bits available for address space
layout randomization (ASLR), which is always disabled for SUID programs
and can only be enabled by the tunable, glibc.cpu.prefer_map_32bit_exec,
or the environment variable, LD_PREFER_MAP_32BIT_EXEC. This works only
between shared libraries or between shared libraries and executables with
addresses below 2GB. PIEs are usually loaded at a random address above
4GB by the kernel.
Simon Kissane [Fri, 10 Feb 2023 21:58:02 +0000 (08:58 +1100)]
gmon: fix memory corruption issues [BZ# 30101]
V2 of this patch fixes an issue in V1, where the state was changed to ON not
OFF at end of _mcleanup. I hadn't noticed that (counterintuitively) ON=0 and
OFF=3, hence zeroing the buffer turned it back on. So set the state to OFF
after the memset.
1. Prevent double free, and reads from unallocated memory, when
_mcleanup is (incorrectly) called two or more times in a row,
without an intervening call to __monstartup; with this patch, the
second and subsequent calls effectively become no-ops instead.
While setting tos=NULL is minimal fix, safest action is to zero the
whole gmonparam buffer.
2. Prevent memory leak when __monstartup is (incorrectly) called two
or more times in a row, without an intervening call to _mcleanup;
with this patch, the second and subsequent calls effectively become
no-ops instead.
3. After _mcleanup, treat __moncontrol(1) as __moncontrol(0) instead.
With zeroing of gmonparam buffer in _mcleanup, this stops the
state incorrectly being changed to GMON_PROF_ON despite profiling
actually being off. If we'd just done the minimal fix to _mcleanup
of setting tos=NULL, there is risk of far worse memory corruption:
kcount would point to deallocated memory, and the __profil syscall
would make the kernel write profiling data into that memory,
which could have since been reallocated to something unrelated.
4. Ensure __moncontrol(0) still turns off profiling even in error
state. Otherwise, if mcount overflows and sets state to
GMON_PROF_ERROR, when _mcleanup calls __moncontrol(0), the __profil
syscall to disable profiling will not be invoked. _mcleanup will
free the buffer, but the kernel will still be writing profiling
data into it, potentially corrupted arbitrary memory.
Also adds a test case for (1). Issues (2)-(4) are not feasible to test.
Signed-off-by: Simon Kissane <skissane@gmail.com> Reviewed-by: DJ Delorie <dj@redhat.com>
When mcount overflows, no gmon.out file is generated, but no message is printed
to the user, leaving the user with no idea why, and thinking maybe there is
some bug - which is how BZ 27576 ended up being logged. Print a message to
stderr in this case so the user knows what is going on.
As a comment in sys/gmon.h acknowledges, the hardcoded MAXARCS value is too
small for some large applications, including the test case in that BZ. Rather
than increase it, add tunables to enable MINARCS and MAXARCS to be overridden
at runtime (glibc.gmon.minarcs and glibc.gmon.maxarcs). So if a user gets the
mcount overflow error, they can try increasing maxarcs (they might need to
increase minarcs too if the heuristic is wrong in their case.)
Note setting minarcs/maxarcs too large can cause monstartup to fail with an
out of memory error. If you set them large enough, it can cause an integer
overflow in calculating the buffer size. I haven't done anything to defend
against that - it would not generally be a security vulnerability, since these
tunables will be ignored in suid/sgid programs (due to the SXID_ERASE default),
and if you can set GLIBC_TUNABLES in the environment of a process, you can take
it over anyway (LD_PRELOAD, LD_LIBRARY_PATH, etc). I thought about modifying
the code of monstartup to defend against integer overflows, but doing so is
complicated, and I realise the existing code is susceptible to them even prior
to this change (e.g. try passing a pathologically large highpc argument to
monstartup), so I decided just to leave that possibility in-place.
Add a test case which demonstrates mcount overflow and the tunables.
Document the new tunables in the manual.
Signed-off-by: Simon Kissane <skissane@gmail.com> Reviewed-by: DJ Delorie <dj@redhat.com>
The `__monstartup()` allocates a buffer used to store all the data
accumulated by the monitor.
The size of this buffer depends on the size of the internal structures
used and the address range for which the monitor is activated, as well
as on the maximum density of call instructions and/or callable functions
that could be potentially on a segment of executable code.
In particular a hash table of arcs is placed at the end of this buffer.
The size of this hash table is calculated in bytes as
p->fromssize = p->textsize / HASHFRACTION;
but actually should be
p->fromssize = ROUNDUP(p->textsize / HASHFRACTION, sizeof(*p->froms));
This results in writing beyond the end of the allocated buffer when an
added arc corresponds to a call near from the end of the monitored
address range, since `_mcount()` check the incoming caller address for
monitored range but not the intermediate result hash-like index that
uses to write into the table.
It should be noted that when the results are output to `gmon.out`, the
table is read to the last element calculated from the allocated size in
bytes, so the arcs stored outside the buffer boundary did not fall into
`gprof` for analysis. Thus this "feature" help me to found this bug
during working with https://sourceware.org/bugzilla/show_bug.cgi?id=29438
Just in case, I will explicitly note that the problem breaks the
`make test t=gmon/tst-gmon-dso` added for Bug 29438.
There, the arc of the `f3()` call disappears from the output, since in
the DSO case, the call to `f3` is located close to the end of the
monitored range.
Signed-off-by: Леонид Юрьев (Leonid Yuriev) <leo@yuriev.ru>
Another minor error seems a related typo in the calculation of
`kcountsize`, but since kcounts are smaller than froms, this is
actually to align the p->froms data.
Co-authored-by: DJ Delorie <dj@redhat.com> Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Joseph Myers [Wed, 22 Feb 2023 21:36:34 +0000 (21:36 +0000)]
Ignore MAP_VARIABLE in tst-mman-consts.py
Linux 6.2 removed the hppa compatibility MAP_VARIABLE define. That
means that, whether or not we remove it in glibc, it needs to be
ignored in tst-mman-consts.py (since this macro comparison
infrastructure expects that new kernel header versions only add new
macros, not remove old ones).
Tested with build-many-glibcs.py for hppa-linux-gnu (Linux 6.2
headers).
Fix the computation to allow for cntfrq_el0 being larger than 1GHz.
Assume cntfrq_el0 is a multiple of 1MHz to increase the maximum
interval (1024 seconds at 1GHz).
The default Linux implementation already handled the Linux generic
ABIs interface used on newer architectures, so there is no need to
Imply the generic any longer.
Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
And remove redundant entries on other architectures Version. The
version for fallocate64 was supposed to be 2.10, but it was then
added to 32-bit platforms in 2.11 because it mistakenly wasn't
exported for them in 2.10 (see the commit message for 1f3615a1c97a030bca59f728f998947f852679b9).
The linux/generic did not exist before 2.15, i.e. when the tile
ports were added (and microblaze did not exist before 2.18), which
explains those differences but also illustrates that "2.11 for 32-bit,
2.10 for 64-bit" should be sufficient since versions older than the
minimum for the architecture are automatically adjusted.
Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
While cleaning up old libc version support, the deprecated libc4 code was
accidentally kept in `implicit_soname`, instead of the libc6 code.
This causes additional symlinks to be created by `ldconfig` for libraries
without a soname, e.g. a library `libsomething.123.456.789` without a soname
will create a `libsomething.123` -> `libsomething.123.456.789` symlink.
As the libc6 version of the `implicit_soname` code is a trivial `xstrdup`,
just inline it and remove `implicit_soname` altogether.
Some further simplification looks possible (e.g. the call to `create_links`
looks like a no-op if `soname == NULL`, other than the verbose printfs), but
logic is kept as-is for now.
Fixes: BZ #30125 Fixes: 8ee878592c4a ("Assume only FLAG_ELF_LIBC6 suport") Signed-off-by: Joan Bruguera <joanbrugueram@gmail.com> Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Vitaly Buka [Sat, 18 Feb 2023 20:53:41 +0000 (12:53 -0800)]
stdlib: Undo post review change to 16adc58e73f3 [BZ #27749]
Post review removal of "goto restart" from
https://sourceware.org/pipermail/libc-alpha/2021-April/125470.html
introduced a bug when some atexit handers skipped.
Sergey Bugaev [Sat, 18 Feb 2023 20:37:14 +0000 (23:37 +0300)]
mach: Use PAGE_SIZE
The PAGE_SIZE from the Mach headers statically defines the machine's
page size. There's no need to query it dynamically; furthermore, the
implementation of the vm_statistics () RPC unconditionally fills in
pagesize = PAGE_SIZE;
Not doing the extra RPC shaves off 2 RPCs from the start-up of every
process!
Pavel Kozlov [Tue, 17 Jan 2023 12:12:23 +0000 (16:12 +0400)]
ARC:fpu: add extra capability check before use of sqrt and fma builtins
Add extra check for compiler definitions to ensure that compiler provides
sqrt and fma hw fpu instructions else use software implementation.
As divide/sqrt and FMA hw support from CPU side is optional,
the compiler can be configured by options to generate hw FPU instructions,
but without use of FDDIV, FDSQRT, FSDIV, FSSQRT, FDMADD and FSMADD
instructions. In this case __builtin_sqrt and __builtin_sqrtf provided by
compiler can't be used inside the glibc code, as these builtins are used
in implementations of sqrt() and sqrtf() functions but at the same time
these builtins unfold to sqrt() and sqrtf(). So it is possible to receive
code like that:
0001c4b4 <__ieee754_sqrtf>:
1c4b4: 0001 0000 b 0 ;1c4b4 <__ieee754_sqrtf>
The same is also true for __builtin_fma and __builtin_fmaf. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Pavel Kozlov [Wed, 21 Dec 2022 16:19:46 +0000 (20:19 +0400)]
ARC: align child stack in clone
The ARCv2 ABI requires 4 byte stack pointer alignment. Don't allow to
use unaligned child stack in clone. As the stack grows down,
align it down.
This was pointed by misc/tst-misalign-clone-internal and
misc/tst-misalign-clone tests. Stack alignmet fixes these tests
fails. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Use put/get macros __builtin_bswap32 instead. It allows to remove
the unaligned routines, the compiler will generate unaligned access
if the ABI allows it.
Joseph Myers [Fri, 17 Feb 2023 17:23:50 +0000 (17:23 +0000)]
Fix ifunc-impl-list.c build for s390
Builds for s390 recently started failing with:
../sysdeps/s390/multiarch/ifunc-impl-list.c: In function '__libc_ifunc_impl_list':
../sysdeps/s390/multiarch/ifunc-impl-list.c:83:21: error: unused variable 'dl_hwcap' [-Werror=unused-variable]
83 | unsigned long int dl_hwcap = features->hwcap;
| ^~~~~~~~
Joseph Myers [Thu, 16 Feb 2023 23:02:40 +0000 (23:02 +0000)]
C2x strtol binary constant handling
C2x adds binary integer constants starting with 0b or 0B, and supports
those constants in strtol-family functions when the base passed is 0
or 2. Implement that strtol support for glibc.
As discussed at
<https://sourceware.org/pipermail/libc-alpha/2020-December/120414.html>,
this is incompatible with previous C standard versions, in that such
an input string starting with 0b or 0B was previously required to be
parsed as 0 (with the rest of the string unprocessed). Thus, as
proposed there, this patch adds 20 new __isoc23_* functions with
appropriate header redirection support. This patch does *not* do
anything about scanf %i (which will need 12 new functions per long
double variant, so 12, 24 or 36 depending on the glibc configuration),
instead leaving that for a future patch. The function names would
remain as __isoc23_* even if C2x ends up published in 2024 rather than
2023.
Making this change leads to the question of what should happen to
internal uses of these functions in glibc and its tests. The header
redirection (which applies for _GNU_SOURCE or any other feature test
macros enabling C2x features) has the effect of redirecting internal
uses but without those uses then ending up at a hidden alias (see the
comment in include/stdio.h about interaction with libc_hidden_proto).
It seems desirable for the default for internal uses to be the same
versions used by normal code using _GNU_SOURCE, so rather than doing
anything to disable that redirection, similar macro definitions to
those in include/stdio.h are added to the include/ headers for the new
functions.
Given that the default for uses in glibc is for the redirections to
apply, the next question is whether the C2x semantics are correct for
all those uses. Uses with the base fixed to 10, 16 or any other value
other than 0 or 2 can be ignored. I think this leaves the following
internal uses to consider (an important consideration for review of
this patch will be both whether this list is complete and whether my
conclusions on all entries in it are correct):
I think all of these places are OK with the new semantics, except for
resolv/inet_addr.c, where the POSIX semantics of inet_addr do not
allow for binary constants; thus, I changed that file (to use
__strtoul_internal, whose semantics are unchanged) and added a test
for this case. In the case of posix/wordexp.c I think accepting
binary constants is OK since POSIX explicitly allows additional forms
of shell arithmetic expressions, and in stdlib/fmtmsg.c SEV_LEVEL is
not in POSIX so again I think accepting binary constants is OK.
Functions such as __strtol_internal, which are only exported for
compatibility with old binaries from when those were used in inline
functions in headers, have unchanged semantics; the __*_l_internal
versions (purely internal to libc and not exported) have a new
argument to specify whether to accept binary constants.
As well as for the standard functions, the header redirection also
applies to the *_l versions (GNU extensions), and to legacy functions
such as strtoq, to avoid confusing inconsistency (the *q functions
redirect to __isoc23_*ll rather than needing their own __isoc23_*
entry points). For the functions that are only declared with
_GNU_SOURCE, this means the old versions are no longer available for
normal user programs at all. An internal __GLIBC_USE_C2X_STRTOL macro
is used to control the redirections in the headers, and cases in glibc
that wish to avoid the redirections - the function implementations
themselves and the tests of the old versions of the GNU functions -
then undefine and redefine that macro to allow the old versions to be
accessed. (There would of course be greater complexity should we wish
to make any of the old versions into compat symbols / avoid them being
defined at all for new glibc ABIs.)
strtol_l.c has some similarity to strtol.c in gnulib, but has already
diverged some way (and isn't listed at all at
https://sourceware.org/glibc/wiki/SharedSourceFiles unlike strtoll.c
and strtoul.c); I haven't made any attempts at gnulib compatibility in
the changes to that file.
I note incidentally that inttypes.h and wchar.h are missing the
__nonnull present on declarations of this family of functions in
stdlib.h; I didn't make any changes in that regard for the new
declarations added.
Sergey Bugaev [Tue, 14 Feb 2023 17:37:20 +0000 (20:37 +0300)]
hurd: i386 TLS tweaks
* Micro-optimize TLS access using GCC's native support for gs-based
addressing when available;
* Just use THREAD_GETMEM and THREAD_SETMEM instead of more inline
assembly;
* Sync tcbhead_t layout with NPTL, in particular update/fix __private_ss
offset;
* Statically assert that the two offsets that are a part of ABI are what
we expect them to be.