scripts: Remove arceb-linux-gnu from build-many-glibcs.py
This was discussed on the hallway track at GNU Tools Cauldron
2024. There are concerns about stability of the big-endian
GCC backend, and Linux removed support for the only big-endian
ARC platform in commit dd7c7ab01a04d645b7e7baa8530bfd81e31a2202
("ARC: [plat-eznps]: Drop support for EZChip NPS platform").
In Linux 6.11, fstat and newfstatat are added back. To avoid the messy
usage of the fstat, newfstatat, and statx system calls, we will continue
using statx only in glibc, maintaining consistency with previous versions of
the LoongArch-specific glibc implementation.
Use the setresuid32 system call if it is available, prefering
it over setresuid. If both system calls exist, setresuid
is the 16-bit variant. This fixes a build failure on
sparcv9-linux-gnu.
elf: Move __rtld_malloc_init_stubs call into _dl_start_final
Calling an extern function in a different translation unit before
self-relocation is brittle. The compiler may load the address
at an earlier point in _dl_start, before self-relocation. In
_dl_start_final, the call is behind a compiler barrier, so this
cannot happen.
elf: Remove version assert in check_match in elf/dl-lookup.c
This case is detected early in the elf/dl-version.c consistency
checks. (These checks could be disabled in the future to allow
the removal of symbol versioning from objects.)
Commit f0b2132b35 ("ld.so: Support moving versioned symbols between
sonames [BZ #24741]) removed another call to _dl_name_match_p. The
_dl_check_caller function no longer exists, and the remaining calls
to _dl_name_match_p happen under the loader lock. This means that
atomic accesses are no longer required for the l_libname list. This
supersedes commit 395be7c218 ("elf: Fix data race in _dl_name_match_p
[BZ #21349]").
iconv: Use $(run-program-prefix) for running iconv (bug 32197)
With --enable-hardcoded-path-in-tests, $(test-program-prefix)
does not redirect to the built glibc, but we need to run
iconv (the program) against the built glibc even with
--enable-hardcoded-path-in-tests, as it is using the ABI
path for the dynamic linker (as an installed program).
Use $(run-program-prefix) instead.
Joe Ramsay [Mon, 23 Sep 2024 14:32:53 +0000 (15:32 +0100)]
AArch64: Improve codegen in users of ADVSIMD expm1f helper
Rearrange operations so MOV is not necessary in reduction or around
the special-case handler. Reduce memory access by using more indexed
MLAs in polynomial.
Joe Ramsay [Mon, 23 Sep 2024 14:32:14 +0000 (15:32 +0100)]
AArch64: Improve codegen in users of AdvSIMD log1pf helper
log1pf is quite register-intensive - use fewer registers for the
polynomial, and make various changes to shorten dependency chains in
parent routines. There is now no spilling with GCC 14. Accuracy moves
around a little - comments adjusted accordingly but does not require
regen-ulps.
Use the helper in log1pf as well, instead of having separate
implementations. The more accurate polynomial means special-casing can
be simplified, and the shorter dependency chain avoids the usual dance
around v0, which is otherwise difficult.
There is a small duplication of vectors containing 1.0f (or 0x3f800000) -
GCC is not currently able to efficiently handle values which fit in FMOV
but not MOVI, and are reinterpreted to integer. There may be potential
for more optimisation if this is fixed.
Joe Ramsay [Mon, 23 Sep 2024 14:30:20 +0000 (15:30 +0100)]
AArch64: Improve codegen in SVE F32 logs
Reduce MOVPRFXs by using unpredicated (non-destructive) instructions
where possible. Similar to the recent change to AdvSIMD F32 logs,
adjust special-case arguments and bounds to allow for more optimal
register usage. For all 3 routines one MOVPRFX remains in the
reduction, which cannot be avoided as immediate AND and ASR are both
destructive.
Joe Ramsay [Mon, 23 Sep 2024 14:26:12 +0000 (15:26 +0100)]
AArch64: Improve codegen in SVE expf & related routines
Reduce MOV and MOVPRFX by improving special-case handling. Use inline
helper to duplicate the entire computation between the special- and
non-special case branches, removing the contention for z0 between x
and the return value.
Also rearrange some MLAs and MLSs - by making the multiplicand the
destination we can avoid a MOVPRFX in several cases. Also change which
constants go in the vector used for lanewise ops - the last lane is no
longer wasted.
Spotted that shift was incorrect in exp2f and exp10f, w.r.t. to the
comment that explains it. Fixed - worst-case ULP for exp2f moves
around but it doesn't change significantly for either routine.
Worst-case error for coshf increases due to passing x to exp rather
than abs(x) - updated the comment, but does not require regen-ulps.
Linux: Use readdir64_r for compat __old_readdir64_r (bug 32128)
It is not necessary to do the conversion at the getdents64
layer for readdir64_r. Doing it piecewise for readdir64
is slightly simpler and allows deleting __old_getdents64.
This fixes bug 32128 because readdir64_r handles the length
check correctly.
The tests check that O_EXCL is used properly, that 0600 is used
as the mode, that the characters used are as expected, and that
the distribution of names generated is reasonably random.
The tests run very slowly on some kernel versions, so make them
xtests.
Add tests of special cases for freopen that were omitted from the more
general tests of different modes and similar issues. The special
cases in the three tests here are logically unconnected, it was simply
convenient to put these tests in one patch.
* Test freopen with a NULL path to the new file, in a chroot. Rather
than asserting that this fails (logically, failure in this case is
an implementation detail; it's not required for freopen to rely on
/proc), verify that either it fails (without memory leaks) or that
it succeeds and behaves as expected on success. There is no check
for file descriptor leaks because the machinery for that also
depends on /proc, so can't be used in a chroot.
* Test that freopen and freopen64 are genuinely different in
configurations with 32-bit off_t by checking for an EFBIG trying to
write past 2GB in a file opened with freopen in such a configuration
but no error with 64-bit off_t or when opening with freopen64.
Joseph Myers [Fri, 20 Sep 2024 23:25:32 +0000 (23:25 +0000)]
Make tst-strtod-underflow type-generic
The test tst-strtod-underflow covers various edge cases close to the
underflow threshold for strtod (especially cases where underflow on
architectures with after-rounding tininess detection depends on the
rounding mode). Make it use the type-generic machinery, with
corresponding test inputs for each supported floating-point format, so
that other functions in the strtod family are tested for underflow
edge cases as well.
Joseph Myers [Fri, 20 Sep 2024 23:24:45 +0000 (23:24 +0000)]
Add tests of more strtod special cases
There is very little test coverage of inputs to strtod-family
functions that don't contain anything that can be parsed as a number
(one test of ".y" in tst-strtod2), and none that I can see of skipping
initial whitespace. Add some tests of these things to tst-strtod2.
Joseph Myers [Fri, 20 Sep 2024 23:24:02 +0000 (23:24 +0000)]
Add more tests of strtod end pointer
Although there are some tests in tst-strtod2 and tst-strtod3 for the
end pointer provided by strtod when it doesn't parse the whole string,
they aren't very thorough. Add tests of more such cases to
tst-strtod2.
Joseph Myers [Fri, 20 Sep 2024 23:23:13 +0000 (23:23 +0000)]
Make tst-strtod2 and tst-strtod5 type-generic
Some of the strtod tests use type-generic machinery in tst-strtod.h to
test the strto* functions for all floating types, while others only
test double even when the tests are in fact meaningful for all
floating types.
Convert tst-strtod2 and tst-strtod5 to use the type-generic machinery
so they test all floating types. I haven't tried to convert them to
use newer test interfaces in other ways, just made the changes
necessary to use the type-generic machinery.
Implement run-built-tests=no for make xcheck, always build xtests
Previously, the second occurrence of the xtests target
expected all xtests to run (as the result of specifying
$(xtests)), but these tests have not been run due to
the the first xtests target is set up for run-built-tests=no:
it only runs tests in $(xtests-special). Consequently,
xtests are reported as UNSUPPORTED with “make xcheck
run-built-tests=no”. The xtests were not built, either.
After this change always, xtests are built regardless
of the $(run-built-tests) variable (except for xtests listed
in $(tests-unsupported)). To fix the UNSUPPORTED issue,
introduce xtests-expected and use that manage test
expectations in the second xtests target.
Add new testcase elf/tst-startup-errno.c which tests that errno is set
to 0 at first ELF constructor execution and at the start of the
program's main function.
Add new file libio/tst-fclose-unopened2.c that tests whether fclose on an
unopened file returns EOF.
This test differs from tst-fclose-unopened.c by ensuring the file's buffer
is allocated prior to double-fclose. A comment in tst-fclose-unopened.c
now clarifies that it is testing a file with an unallocated buffer.
Calling fclose on unopened files normally causes a use-after-free bug,
however the standard streams are an exception since they are not
deallocated by fclose.
iconv: Support in-place conversions (bug 10460, bug 32033)
Check if any of the input files overlaps with the output file, and use
a temporary file in this case, so that the input is no clobbered
before it is read. This fixes bug 10460. It allows to use iconv
more easily as a functional replacement for GNU recode.
The updated output buffer management truncates the output file
if there is no input, fixing bug 32033.
In several converters, a __GCONV_ILLEGAL_INPUT result gets overwritten
with __GCONV_FULL_OUTPUT. As a result, iconv (the function) returns
E2BIG instead of EILSEQ. The iconv program does not see the original
EILSEQ failure, does not recognize the invalid input, and may
incorrectly exit successfully.
To address this, a new __flags bit is used to indicate a sticky input
error state. All __GCONV_ILLEGAL_INPUT results are replaced with a
function call that sets this new __GCONV_ENCOUNTERED_ILLEGAL_INPUT and
returns __GCONV_ILLEGAL_INPUT. The iconv program checks for
__GCONV_ENCOUNTERED_ILLEGAL_INPUT and overrides the exit status.
The converter changes introducing __gconv_mark_illegal_input are
mostly mechanical, except for the res variable initialization in
iconvdata/iso-2022-jp.c: this error gets overwritten with __GCONV_OK
and other results in the following code. If res ==
__GCONV_ILLEGAL_INPUT afterwards, STANDARD_TO_LOOP_ERR_HANDLER below
will handle it.
The __gconv_mark_illegal_input changes do not alter the errno value
set by the iconv function. This is simpler to implement than
reviewing each __GCONV_FULL_OUTPUT result and adjust it not to
override a previous __GCONV_ILLEGAL_INPUT result. Doing it that way
would also change some E2BIG errors in to EILSEQ errors, so it had to
be done conditionally (under a flag set by the iconv program only), to
avoid confusing buffer management in other applications.
iconv: Do not use mmap in iconv (the program) (bug 17703)
On current systems, very large files are needed before
mmap becomes beneficial. Simplify the implementation.
This exposed that inptr was not initialized correctly in
process_fd. Handling multiple input files resulted in
EFAULT in read because a null pointer was passed. This
could be observed previously if an input file was not
mappable and was reported as bug 17703.
Joe Ramsay [Thu, 19 Sep 2024 16:34:02 +0000 (17:34 +0100)]
AArch64: Add vector logp1 alias for log1p
This enables vectorisation of C23 logp1, which is an alias for log1p.
There are no new tests or ulp entries because the new symbols are simply
aliases.
hurd: Avoid file_check_access () RPC for access (F_OK)
A common use case of access () / faccessat () is checking for file
existence, not any specific access permissions. In that case, we can
avoid doing the file_check_access () RPC; whether the given path had
been successfully resolved to a file is all we need to know to answer.
This is prompted by GLib switching to use faccessat (F_OK) to implement
g_file_query_exists () for local files.
https://gitlab.gnome.org/GNOME/glib/-/merge_requests/4272
tst: Extend cross-test-ssh.sh to support passing glibc tunables
This patch adds new flag --glibctunables to the cross-test-ssh.sh script
to pass Glibc tunables to the system on which tests are executed.
The value to pass can be also provided via the GLIBC_TUNABLES environment
variable.
This works similar to the TIMEOUTFACTOR variable.
Sometimes it is useful to cross test glibc with some non-default tunable,
and a global environment variable is the easiest way to inject some
tunable value into most tests. With this patch using cross-test-ssh.sh
script becomes very similar to running a test natively on the local host
when using non-default tunable is important. Reviewed-by: Arjun Shankar <arjun@redhat.com>
Linux: Add the sched_setattr and sched_getattr functions
And struct sched_attr.
In sysdeps/unix/sysv/linux/bits/sched.h, the hack that defines
sched_param around the inclusion of <linux/sched/types.h> is quite
ugly, but the definition of struct sched_param has already been
dropped by the kernel, so there is nothing else we can do and maintain
compatibility of <sched.h> with a wide range of kernel header
versions. (An alternative would involve introducing a separate header
for this functionality, but this seems unnecessary.)
The existing sched_* functions that change scheduler parameters
are already incompatible with PTHREAD_PRIO_PROTECT mutexes, so
there is no harm in adding more functionality in this area.
The documentation mostly defers to the Linux manual pages.
The reading loops did not check for read failures. Addresses
a static analysis report.
Manually tested by compiling a program with the GCC's
-finstrument-functions option, running it with
“LD_PRELOAD=debug/libpcprofile.so PCPROFILE_OUTPUT=output-file”,
and reviewing the output of “debug/pcprofiledump output-file”.
Improve small memsets by avoiding branches and use overlapping stores.
Use DC ZVA for copies over 128 bytes. Remove unnecessary code for ZVA sizes
other than 64 and 128. Performance of random memset benchmark improves by 24%
on Neoverse N1.
Joe Ramsay [Mon, 9 Sep 2024 12:00:01 +0000 (13:00 +0100)]
aarch64: Avoid redundant MOVs in AdvSIMD F32 logs
Since the last operation is destructive, the first argument to the FMA
also has to be the first argument to the special-case in order to
avoid unnecessary MOVs. Reorder arguments and adjust special-case
bounds to facilitate this.
Joseph Myers [Fri, 6 Sep 2024 20:38:23 +0000 (20:38 +0000)]
Document limitations on streams passed to freopen
As recently discussed, document that freopen does not work with
streams opened with functions such as popen, fmemopen, open_memstream
or fopencookie. I've filed
<https://austingroupbugs.net/view.php?id=1855> to clarify this issue
in POSIX.
stdlib: Do not use GLIBC_PRIVATE ABI for errno in libc_nonshared.a
Using TLS directly introduces a GLIBC_PRIVATE ABI dependency
into libc_nonshared.a, and thus indirectly into applications.
Adding the !defined LIBC_NONSHARED condition deactivates direct
TLS access, and libc_nonshared.a code switches to using
__errno_location, like application code.
Currently, this has no effect because there is no code in
libc_nonshared.a that accesses errno.
Sync tzselect, zdump, zic to TZDB 2024b. This patch incorporates the
following TZDB source code changes:
6903dde3 Release 2024b 812aff32 Improve historical transitions in Mexico 1921-1997 52662566 Adjust to mailing list software change 7748036b Mention Internet RFC 9557 339e81d1 Mention Levine’s proposal to replace leap seconds b4e6ad2d No leap second on 2024-12-31 7eb5bf88 Asia/Choibalsan is now an alias for Asia/Ulaanbaatar 43450cbf Improve historical data for Portugal and former possessions. 13d7348b Typo and validation fixes. 3c39cde8 Fix typo for “removed” in a comment 03fd9e45 More documentation updates for POSIX.1-2024 eb3bcceb POSIX.1-2014 is now published 913b0410 tzselect: support POSIX.1-2024 offset range b5318b55 Document POSIX.1-2024 better 837609b7 Fix typo when making .txt man pages d56ae6ee SUPPORT_C89 now defaults to 1, not 0 b1fe113d Port ! to Solaris make 8f1fd321 Avoid crash in Solaris 10 /usr/xpg4/bin/make e0fcfdd6 Use ‘export VAR=VAL’ syntax eba43166 Avoid an awk invocation via $'...' 36479a80 Avoid some subshells in tzselect 7f6cf054 * tzselect.ksh: Assume POSIX.2 awk. a1cf1daf * tzselect.ksh: Assume POSIX.2 $PWD. a9b8e536 Assume POSIX.2 command substitution eaa4ef16 Avoid subshells when possible 9dac9eb7 Prefer $PWD to $(pwd) in Makefile fada6a4c Prefer $(CMD) to `CMD` in Makefile 3e871b9a Assume POSIX.2 and eschew ‘expr’ c5d67805 difftime isn’t pure either 5857c056 * CONTRIBUTING: Document build assumptions. 6822cc82 ‘make check’ no longer depends on curl+Internet cc6eb255 Document GCC bug 114833 and workaround bcbc86bf Scale back on function attribute use c0789e46 C23 [[reproducible]] and [[unsequenced]] fixups bbd88154 More updates to GCC_DEBUG_FLAGS for GCC 14 1a35b7c8 Spelling fixes f71085f2 POSIX.1-2024 removes asctime_r, ctime_r 70856f8e Adjust to refactored location of ctime, ctime_r aacd151d Update GCC_DEBUG_FLAGS for GCC 14 967dcf3b Sub-second history for Maputo and Zurich 782d0826 Make EET, MET and WET links a0b09c02 Mark CET, CST6CDT etc. as obsolescent db7fb40d Document SMPTE timecodes and rolling leaps 97232e18 Don’t be so sure about leap seconds going away 5b6a74fb Update some URLs a75a6251 * zic.8: Tweak for consistency. 1e75b31f Document what %s means before any rule applies 00c96cbb Conform to RFC 8536 section 3.2 for default type 3e944959 Document problems with stripped-down TZif readers 20fc91cf Shanks is likely wrong about Maputo switch to CAT d99589b6 * zic.8: Add missing tab character. 94e6b3b0 Switch to %z in main dataform 2cd57b93 Treat W-Eur like Port when reguarding ad6f6d94 Check that main.zi agrees with sources a43b030f .gitignore: Add .pdf, .ps, .s. Remove obsolete ‘yearistype’. 253ca020 * theory.html: ‘CLT’ → ‘LTC’ (per Michael H Deckers) a3dee8c8 * NEWS: ‘how’ → ‘now’ (thanks to Paul Goyette). ea6341c5 * theory.html: Mention NASA and CLT (per Arthur David Olson). 0dcebe37 America/Scoresbysund matches America/Nuuk from now on b1e07fb0 Update Vzic link (thanks to Allen Winter) a4b05030 Fix wday/mday typo in previous patch 732a4803 Document how to detect mktime failure reliably a64067e9 ziguard.awk: generalize for proposed Portugal patch 59c861fd Line up zdump examples 66c106c9 tzfile.5: srcfix e5553001 Fix .RS/.RE problem in tzfile.5 d647eb01 Add Doctorow book 59d4a1ba Asia/Almaty matches Asia/Tashkent from now on d4d3c3ba * asia: Update Philippine URLs (thanks to Guy Harris). 9fc11a27 Port unlikely overflow check to C23 b52a2969 Fix 2023d NEWS typo e48c5b53 Cite "The NTP Leap Second File" b1dc2122 Update Israel tz-link 6cf4e912 Extrapolate less from the 2022 CGPM resolution.
It fixes glibc build with gcc master [1].
Checked on x86_64-linux-gnu and on i686-linux-gnu.
[1] https://sourceware.org/pipermail/libc-alpha/2024-September/159571.html Reviewed-by: Paul Eggert <eggert@cs.ucla.edu>
Joseph Myers [Thu, 5 Sep 2024 20:08:10 +0000 (20:08 +0000)]
Fix freopen handling of ,ccs= (bug 23675)
As reported in bug 23675 and shown up in the recently added tests of
different cases of freopen (relevant part of the test currently
conditioned under #if 0 to avoid a failure resulting from this bug),
freopen wrongly forces the stream to unoriented even when a mode with
,ccs= is specified, though such a mode is supposed to result in a
wide-oriented stream. Move the clearing of _mode to before the actual
reopening occurs, so that the main fopen implementation can leave a
wide-oriented stream in the ,ccs= case.
powerpc64le: Build new strtod tests with long double ABI flags (bug 32145)
This fixes several test failures:
=====FAIL: stdlib/tst-strtod1i.out=====
Locale tests
all OK
Locale tests
all OK
Locale tests
strtold("1,5") returns -6,38643e+367 and not 1,5
strtold("1.5") returns 1,5 and not 1
strtold("1.500") returns 1 and not 1500
strtold("36.893.488.147.419.103.232") returns 1500 and not 3,68935e+19
Locale tests
all OK
Aaron Merey [Thu, 29 Aug 2024 16:02:25 +0000 (12:02 -0400)]
Test fclose on an unopened file.
Add new file libio/tst-fclosed-unopened.c that tests whether fclose on
an unopened file returns EOF.
Calling fclose on unopened files normally causes a use-after-free bug,
however the standard streams are an exception since they are not
deallocated by fclose.
fclose returning EOF for unopened files is not part of the external
contract but there are dependancies on this behaviour. For example,
gnulib's close_stdout in lib/closeout.c.
Joseph Myers [Thu, 5 Sep 2024 11:16:59 +0000 (11:16 +0000)]
Fix memory leak on freopen error return (bug 32140)
As reported in bug 32140, freopen leaks the FILE object when it
returns NULL: there is no valid use of the FILE * pointer (including
passing to freopen again or to fclose) after such an error return, so
the underlying object should be freed. Add code to free it.
Note 1: while I think it's clear from the relevant standards that the
object should be freed and the FILE * can't be used after the call in
this case (the stream is closed, which ends the lifetime of the FILE),
it's entirely possible that some existing code does in fact try to use
the existing FILE * in some way and could be broken by this change.
(Though the most common case for freopen may be stdin / stdout /
stderr, which _IO_deallocate_file explicitly checks for and does not
deallocate.)
Note 2: the deallocation is only done in the _IO_IS_FILEBUF case.
Other kinds of streams bypass all the freopen logic handling closing
the file, meaning a call to _IO_deallocate_file would neither be safe
(the FILE might still be linked into the list of all open FILEs) nor
sufficient (other internal memory allocations associated with the file
would not have been freed). I think the validity of freopen for any
other kind of stream will need clarifying with the Austin Group, but
if it is valid in any such case (where "valid" means "not undefined
behavior so required to close the stream" rather than "required to
successfully associate the stream with the new file in cases where
fopen would work"), more significant changes would be needed to ensure
the stream gets fully closed.
Joseph Myers [Thu, 5 Sep 2024 11:15:29 +0000 (11:15 +0000)]
Clear flags2 flags set from mode in freopen (bug 32134)
As reported in bug 32134, freopen does not clear the flags set in
fp->_flags2 by the "e", "m" or "c" mode characters. Clear these so
that they can be set or not as appropriate from the mode string passed
to freopen. The relevant test for "e" in tst-freopen2-main.c is
enabled accordingly; "c" is expected to be covered in a separately
written test (and while tst-freopen2-main.c does include transitions
to and from "m", that's not really a semantic flag intended to result
in behaving in an observably different way).
Florian Weimer [Fri, 30 Aug 2024 19:51:46 +0000 (21:51 +0200)]
Bundle <linux/fuse.h> userspace header from Linux 6.10
And include the required licensing information. The only
change is a removed trailing empty line in
LICENSES/exceptions/Linux-syscall-note.
Bundling <linux/fuse.h> is the recommended way to deal with
the evolution of the FUSE userspace interface because
structs change sizes over time. The kernel maintains
compatibility, but source-level compatibility on recompilation
may require additional code that is aware of older struct sizes.
Signed-off-by: Florian Weimer <fweimer@redhat.com> Reviewed-by: DJ Delorie <dj@redhat.com>
Joseph Myers [Wed, 4 Sep 2024 16:32:21 +0000 (16:32 +0000)]
Add more thorough tests of freopen
freopen is rather minimally tested in libio/tst-freopen and
libio/test-freopen. Add some more thorough tests, covering different
cases for change of mode in particular. The tests are run for both
freopen and freopen64 (given that those functions have two separate
copies of much of the code, so any bug fix directly in the freopen
code would probably need applying in both places).
Note that there are two parts of the tests disabled because of bugs
discovered through running the tests, with bug numbers given in
comments. I expect to address those separately. The tests also don't
cover changes to cancellation ("c" in mode); I think that will better
be handled through a separate test. Also to handle separately:
testing on stdin / stdout / stderr; documenting lack of support for
streams opened with popen / fmemopen / open_memstream / fopencookie;
maybe also a chroot test without /proc; maybe also more thorough tests
for large file handling on 32-bit systems (freopen64).
Joseph Myers [Wed, 4 Sep 2024 13:21:23 +0000 (13:21 +0000)]
Do not set errno for overflowing NaN payload in strtod/nan (bug 32045)
As reported in bug 32045, it's incorrect for strtod/nan functions to
set errno based on overflowing payload (strtod should only set errno
for overflow / underflow of its actual result, and potentially if
nothing in the string can be parsed as a number at all; nan should be
a pure function that never sets it). Save and restore errno around
the internal strtoull call and add associated test coverage.
Joseph Myers [Wed, 4 Sep 2024 13:20:18 +0000 (13:20 +0000)]
Improve NaN payload testing
There are two separate sets of tests of NaN payloads in glibc:
* libm-test-{get,set}payload* verify that getpayload, setpayload,
setpayloadsig and __builtin_nan functions are consistent in their
payload handling.
* test-nan-payload verifies that strtod-family functions and the
not-built-in nan functions are consistent in their payload handling.
Nothing, however, connects the two sets of functions (i.e., verifies
that strtod / nan are consistent with getpayload / setpayload /
__builtin_nan).
Improve test-nan-payload to check actual payload value with getpayload
rather than just verifying that the strtod and nan functions produce
the same NaN. Also check that the NaNs produced aren't signaling and
extend the tests to cover _FloatN / _FloatNx.
Florian Weimer [Fri, 30 Aug 2024 18:37:18 +0000 (20:37 +0200)]
io: Add error tests for fchmod
On Linux most descriptors that do not correspond to file system
entities (such as anonymous pipes and sockets) have file permissions
that can be changed. While it is possible to create a custom file
system that returns (say) EINVAL for an fchmod attempt, testing this
does not appear to be useful.
powerpc64: Fix syscall_cancel build for powerpc64le-linux-gnu [BZ #32125]
In __syscall_cancel_arch, there's a tail call to __syscall_do_cancel.
On P10, since the caller uses the TOC and the callee is using
PC-relative addressing, there's only a branch instruction with no NOPs
to restore the TOC, which causes the build error. The fix involves adding
the NOTOC directive to the branch instruction, informing the linker
not to generate a TOC stub, thus resolving the issue.
Joseph Myers [Tue, 27 Aug 2024 20:41:54 +0000 (20:41 +0000)]
Make __strtod_internal tests type-generic
Some of the strtod tests use type-generic machinery in tst-strtod.h to
test the strto* functions for all floating types, while others only
test double even when the tests are in fact meaningful for all
floating types.
Convert the tests of the internal __strtod_internal interface to cover
all floating types. I haven't tried to convert them to use newer test
interfaces in other ways, just made the changes necessary to use the
type-generic machinery. As an internal interface, there are no
aliases for different types with the same ABI (however,
__strtold_internal is defined even if long double has the same ABI as
double), so macros used by the type-generic testing code are redefined
as needed to avoid expecting such aliases to be present.
Joseph Myers [Tue, 27 Aug 2024 12:41:02 +0000 (12:41 +0000)]
Fix strtod subnormal rounding (bug 30220)
As reported in bug 30220, the implementation of strtod-family
functions has a bug in the following case: the input string would,
with infinite exponent range, take one more bit to represent than is
available in the normal precision of the return type; the value
represented is in the subnormal range; and there are no nonzero bits
in the value, below those that can be represented in subnormal
precision, other than the least significant bit and possibly the
0.5ulp bit. In this case, round_and_return ends up discarding the
least significant bit.
Fix by saving that bit to merge into more_bits (it can't be merged in
at the time it's computed, because more_bits mustn't include this bit
in the case of after-rounding tininess detection checking if the
result is still subnormal when rounded to normal precision, so merging
this bit into more_bits needs to take place after that check).
Joseph Myers [Tue, 27 Aug 2024 12:38:01 +0000 (12:38 +0000)]
More thoroughly test underflow / errno in tst-strtod-round
Add tests of underflow in tst-strtod-round, and thus also test for
errno being unchanged when there is neither overflow nor underflow.
The errno setting before the function call to test for being unchanged
is adjusted to set errno to 12345 instead of 0, so that any bugs where
strtod sets errno to 0 would be detected.
This doesn't add any new test inputs for tst-strtod-round, and in
particular doesn't cover the edge cases of underflow the way
tst-strtod-underflow does (none of the existing test inputs for
tst-strtod-round actually exercise cases that have underflow with
before-rounding tininess detection but not with after-rounding
tininess detection), but at least it provides some coverage (as per
the recent discussions) that ordinary non-overflowing non-underflowing
inputs to these functions do not set errno.
Florian Weimer [Wed, 7 Aug 2024 12:57:41 +0000 (14:57 +0200)]
manual: Add Descriptor-Relative Access section
Reference this new section from the O_PATH documentation.
And document the functions openat, openat64, fstatat, fstatat64.
(The safety assessment for fstatat was already obsolete because
current glibc assumes kernel support for the underlying system
call.)
Feifei Wang [Mon, 19 Aug 2024 06:57:54 +0000 (14:57 +0800)]
x86: Add cache information support for Hygon processors
Add hygon branch in dl_init_cacheinfo function to initialize
cache size variables for hygon processors. In the meanwhile,
add handle_hygon() function to get cache information.
Signed-off-by: Feifei Wang <wangfeifei@hygon.cn> Reviewed-by: Jing Li <lijing@hygon.cn> Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
Feifei Wang [Mon, 19 Aug 2024 06:57:53 +0000 (14:57 +0800)]
x86: Add new architecture type for Hygon processors
Add a new architecture type arch_kind_hygon to spilt Hygon branch
from AMD. This is to facilitate the Hygon processors to make settings
that are suitable for its own characteristics.
Signed-off-by: Feifei Wang <wangfeifei@hygon.cn> Reviewed-by: Jing Li <lijing@hygon.cn> Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
Samuel Thibault [Sun, 25 Aug 2024 01:35:29 +0000 (03:35 +0200)]
mach: Fix bogus negative return
One can be very unlucky to call time_now first just before a second switch,
and mach_msg sleep just a bit more enough for the second time_now call to
count one second too many (or even more if scheduling is really unlucky).
So we have to protect against returning a bogus negative value in such case.
Mahesh Bodapati [Fri, 23 Aug 2024 21:48:32 +0000 (16:48 -0500)]
powerpc64: Optimize strcpy and stpcpy for Power9/10
This patch modifies the current Power9 implementation of strcpy and
stpcpy to optimize it for Power9 and Power10.
No new Power10 instructions are used, so the original Power9 strcpy
is modified instead of creating a new implementation for Power10.
The changes also affect stpcpy, which uses the same implementation
with some additional code before returning.
Improvements compared to the old Power9 version:
Use simple comparisons for the first ~512 bytes:
The main loop is good for long strings, but comparing 16B each time is
better for shorter strings. After aligning the address to 16 bytes, we
unroll the loop four times, checking 128 bytes each time. There may be
some overlap with the main loop for unaligned strings, but it is better
for shorter strings.
Loop with 64 bytes for longer bytes:
Use 4 consecutive lxv/stxv instructions.
Showed an average improvement of 13%.
Reviewed-by: Paul E. Murphy <murphyp@linux.ibm.com> Reviewed-by: Peter Bergner <bergner@linux.ibm.com>
nptl: Fix Race conditions in pthread cancellation [BZ#12683]
The current racy approach is to enable asynchronous cancellation
before making the syscall and restore the previous cancellation
type once the syscall returns, and check if cancellation has happen
during the cancellation entrypoint.
As described in BZ#12683, this approach shows 2 problems:
1. Cancellation can act after the syscall has returned from the
kernel, but before userspace saves the return value. It might
result in a resource leak if the syscall allocated a resource or a
side effect (partial read/write), and there is no way to program
handle it with cancellation handlers.
2. If a signal is handled while the thread is blocked at a cancellable
syscall, the entire signal handler runs with asynchronous
cancellation enabled. This can lead to issues if the signal
handler call functions which are async-signal-safe but not
async-cancel-safe.
For the cancellation to work correctly, there are 5 points at which the
cancellation signal could arrive:
[ ... )[ ... )[ syscall ]( ...
1 2 3 4 5
1. Before initial testcancel, e.g. [*... testcancel)
2. Between testcancel and syscall start, e.g. [testcancel...syscall start)
3. While syscall is blocked and no side effects have yet taken
place, e.g. [ syscall ]
4. Same as 3 but with side-effects having occurred (e.g. a partial
read or write).
5. After syscall end e.g. (syscall end...*]
And libc wants to act on cancellation in cases 1, 2, and 3 but not
in cases 4 or 5. For the 4 and 5 cases, the cancellation will eventually
happen in the next cancellable entrypoint without any further external
event.
The proposed solution for each case is:
1. Do a conditional branch based on whether the thread has received
a cancellation request;
2. It can be caught by the signal handler determining that the saved
program counter (from the ucontext_t) is in some address range
beginning just before the "testcancel" and ending with the
syscall instruction.
3. SIGCANCEL can be caught by the signal handler and determine that
the saved program counter (from the ucontext_t) is in the address
range beginning just before "testcancel" and ending with the first
uninterruptable (via a signal) syscall instruction that enters the
kernel.
4. In this case, except for certain syscalls that ALWAYS fail with
EINTR even for non-interrupting signals, the kernel will reset
the program counter to point at the syscall instruction during
signal handling, so that the syscall is restarted when the signal
handler returns. So, from the signal handler's standpoint, this
looks the same as case 2, and thus it's taken care of.
5. For syscalls with side-effects, the kernel cannot restart the
syscall; when it's interrupted by a signal, the kernel must cause
the syscall to return with whatever partial result is obtained
(e.g. partial read or write).
6. The saved program counter points just after the syscall
instruction, so the signal handler won't act on cancellation.
This is similar to 4. since the program counter is past the syscall
instruction.
So The proposed fixes are:
1. Remove the enable_asynccancel/disable_asynccancel function usage in
cancellable syscall definition and instead make them call a common
symbol that will check if cancellation is enabled (__syscall_cancel
at nptl/cancellation.c), call the arch-specific cancellable
entry-point (__syscall_cancel_arch), and cancel the thread when
required.
2. Provide an arch-specific generic system call wrapper function
that contains global markers. These markers will be used in
SIGCANCEL signal handler to check if the interruption has been
called in a valid syscall and if the syscalls has side-effects.
A reference implementation sysdeps/unix/sysv/linux/syscall_cancel.c
is provided. However, the markers may not be set on correct
expected places depending on how INTERNAL_SYSCALL_NCS is
implemented by the architecture. It is expected that all
architectures add an arch-specific implementation.
3. Rewrite SIGCANCEL asynchronous handler to check for both canceling
type and if current IP from signal handler falls between the global
markers and act accordingly.
4. Adjust libc code to replace LIBC_CANCEL_ASYNC/LIBC_CANCEL_RESET to
use the appropriate cancelable syscalls.
5. Adjust 'lowlevellock-futex.h' arch-specific implementations to
provide cancelable futex calls.
Some architectures require specific support on syscall handling:
* On i386 the syscall cancel bridge needs to use the old int80
instruction because the optimized vDSO symbol the resulting PC value
for an interrupted syscall points to an address outside the expected
markers in __syscall_cancel_arch. It has been discussed in LKML [1]
on how kernel could help userland to accomplish it, but afaik
discussion has stalled.
Also, sysenter should not be used directly by libc since its calling
convention is set by the kernel depending of the underlying x86 chip
(check kernel commit 30bfa7b3488bfb1bb75c9f50a5fcac1832970c60).
* mips o32 is the only kABI that requires 7 argument syscall, and to
avoid add a requirement on all architectures to support it, mips
support is added with extra internal defines.
Checked on aarch64-linux-gnu, arm-linux-gnueabihf, powerpc-linux-gnu,
powerpc64-linux-gnu, powerpc64le-linux-gnu, i686-linux-gnu, and
x86_64-linux-gnu.
[1] https://lkml.org/lkml/2016/3/8/1105 Reviewed-by: Carlos O'Donell <carlos@redhat.com>
git://sourceware.org / glibc.git / log