Commit Graph

41370 Commits

Author SHA1 Message Date
Joe Ramsay
8b09af572b 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.

Reviewed-by: Wilco Dijkstra  <Wilco.Dijkstra@arm.com>
2024-09-09 13:03:49 +01:00
Florian Weimer
43669fcf73 io: Add FUSE-based test for fchmod
Test all mode arguments, and that extra bits are ignored
as required by POSIX.

Reviewed-by: DJ Delorie <dj@redhat.com>
2024-09-09 09:51:50 +02:00
Florian Weimer
f4ae345810 io: Add tst-lstat-nofollow, tst-lstat-nofollow-time64
They verify that lstat, lstat64 do not follow symbolic links.

Reviewed-by: DJ Delorie <dj@redhat.com>
2024-09-09 09:14:22 +02:00
Joseph Myers
a2509a8bc9 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.

Tested with "make info" and "make html".
2024-09-06 20:38:23 +00:00
Florian Weimer
7d6e30b4b4 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.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2024-09-06 14:07:00 +02:00
Florian Weimer
6efd6cd46b manual: Safety annotations for clock_gettime, clock_getres
The annotations are preliminary, for consistency with existing
annotations on gettimeofday etc.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2024-09-06 14:07:00 +02:00
mengqinggang
6252c59f15 LoongArch: Fix macro redefined warning in tls-desc.S
Undef macro to avoid redefined warning.
2024-09-06 15:46:13 +08:00
Adhemerval Zanella
1b171c942e timezone: sync to TZDB 2024b
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>
2024-09-05 20:57:17 +00:00
Florian Weimer
a8c433856f i386: Update ulps
As seen on an AMD Ryzen 9 7950X CPU when building with GCC 14
with SSE2 math.
2024-09-05 22:25:55 +02:00
Joseph Myers
e44ca1c085 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.

Tested for x86_64.
2024-09-05 20:08:10 +00:00
Florian Weimer
cc3e743fc0 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

=====FAIL: stdlib/tst-strtod3.out=====
0: got wrong results -2.5937e+4826, expected 0

=====FAIL: stdlib/tst-strtod4.out=====
0: got wrong results -6,38643e+367, expected 0
1: got wrong results 0, expected 1e+06
2: got wrong results 1e+06, expected 10

=====FAIL: stdlib/tst-strtod5i.out=====
0: got wrong results -6,38643e+367, expected 0
2: got wrong results 0, expected -0
4: got wrong results -0, expected 0
5: got wrong results 0, expected -0
6: got wrong results -0, expected 0
7: got wrong results 0, expected -0
8: got wrong results -0, expected 0
9: got wrong results 0, expected -0
10: got wrong results -0, expected 0
11: got wrong results 0, expected -0
12: got wrong results -0, expected 0
13: got wrong results 0, expected -0
14: got wrong results -0, expected 0
15: got wrong results 0, expected -0
16: got wrong results -0, expected 0
17: got wrong results 0, expected -0
18: got wrong results -0, expected 0
20: got wrong results 0, expected -0
22: got wrong results -0, expected 0
23: got wrong results 0, expected -0
24: got wrong results -0, expected 0
25: got wrong results 0, expected -0
26: got wrong results -0, expected 0
27: got wrong results 0, expected -0

Fixes commit 3fc063dee0
("Make __strtod_internal tests type-generic").

Suggested-by: Joseph Myers <josmyers@redhat.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2024-09-05 22:02:23 +02:00
Aaron Merey
3e4a01870e 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.

Tested for x86_64.

Signed-off-by: Aaron Merey <amerey@redhat.com>
2024-09-05 09:55:27 -04:00
Joseph Myers
9c0d6f7a10 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.

Tested for x86_64.
2024-09-05 11:16:59 +00:00
Joseph Myers
f512634dde 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).

Tested for x86_64.
2024-09-05 11:15:29 +00:00
Florian Weimer
f169509ded support: Add FUSE-based file system test framework to support/
This allows to monitor the exact file system operations
performed by glibc and inject errors.

Hurd does not have <sys/mount.h>.  To get the sources to compile
at least, the same approach as in support/test-container.c is used.

Reviewed-by: DJ Delorie <dj@redhat.com>
2024-09-05 12:05:32 +02:00
Florian Weimer
61f2c2e1d1 Linux: readdir_r needs to report getdents failures (bug 32124)
Upon error, return the errno value set by the __getdents call
in __readdir_unlocked.  Previously, kernel-reported errors
were ignored.

Reviewed-by: DJ Delorie <dj@redhat.com>
2024-09-05 12:05:32 +02:00
Florian Weimer
3b1d321776 support: Add <support/xdirent.h>
Use static functions for readdir/readdir_r, so that
-D_FILE_OFFSET_BITS=64 does not improperly redirect calls to the wrong
implementation.

Reviewed-by: DJ Delorie <dj@redhat.com>
2024-09-05 12:05:32 +02:00
Florian Weimer
b09a520bb6 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>
2024-09-05 11:34:31 +02:00
Florian Weimer
ed416ee402 i386: Update ulps
As seen on an unspecified Intel system with glibc compiled
with GCC 8.
2024-09-05 09:57:25 +02:00
DJ Delorie
4945ffc88a fgets: more tests
Add more tests for unusual situations fgets() might see:

* zero size file
* zero sized buffer
* NULL buffer
* NUL data
* writable stream
* closed stream

Reviewed-by: Florian Weimer <fweimer@redhat.com>
2024-09-04 16:24:12 -04:00
Joseph Myers
ed4bb289cf 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).

Tested for x86_64.
2024-09-04 16:32:21 +00:00
Siddhesh Poyarekar
ae4d44b1d5 libio: Attempt wide backup free only for non-legacy code
_wide_data and _mode are not available in legacy code, so do not attempt
to free the wide backup buffer in legacy code.

Resolves: BZ #32137 and BZ #27821

Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Reviewed-by: Florian Weimer <fweimer@redhat.com>
2024-09-04 09:29:35 -04:00
Joseph Myers
64f62c47e9 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.

Tested for x86_64.
2024-09-04 13:21:23 +00:00
Joseph Myers
be77d5ae41 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.

Tested for x86_64.
2024-09-04 13:20:18 +00:00
Joseph Myers
96d0bf98ca Add support/ code for checking file contents
For use in freopen tests, add various support/ helper interfaces for
use in checking file contents.

Tested for x86_64.
2024-09-03 13:53:01 +00:00
Adhemerval Zanella
1927f718fc linux: mips: Fix syscall_cancell build for __mips_isa_rev >= 6
Use beqzc instead of bnel.

Checked with a mipsisa64r6el-n64-linux-gnu build and some nptl
cancellation tests on qemu.
2024-09-02 12:30:45 -03:00
Florian Weimer
3844cdc330 io: Fix destructive nature of tst-fchmod-errors
We must not change the permissions of /dev/null if running
as root.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2024-08-30 22:30:05 +02:00
Florian Weimer
424d97be50 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.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2024-08-30 21:12:01 +02:00
Jeevitha Palanisamy
29f0db6a2e 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.
2024-08-30 08:50:47 -05:00
Joseph Myers
3fc063dee0 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.

Tested for x86_64.
2024-08-27 20:41:54 +00:00
Joseph Myers
457622c2fa 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).

Tested for x86_64.
2024-08-27 12:41:02 +00:00
Joseph Myers
d73ed2601b 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.

Tested for x86_64.
2024-08-27 12:38:01 +00:00
Florian Weimer
3de73f974f 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.)

Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2024-08-27 10:16:10 +02:00
Feifei Wang
ca90758b2a x86: Enable non-temporal memset for Hygon processors
This patch uses 'Avoid_Non_Temporal_Memset' flag to access
the non-temporal memset implementation for hygon processors.

Test Results:

hygon1 arch
x86_memset_non_temporal_threshold = 8MB
size                          new performance time / old performance time
1MB                           0.994
4MB                           0.996
8MB                           0.670
16MB                          0.343
32MB                          0.355

hygon2 arch
x86_memset_non_temporal_threshold = 8MB
size                          new performance time / old performance time
1MB                           1
4MB                           1
8MB                           1.312
16MB                          0.822
32MB                          0.830

hygon3 arch
x86_memset_non_temporal_threshold = 8MB
size                          new performance time / old performance time
1MB                           1
4MB                           0.990
8MB                           0.737
16MB                          0.390
32MB                          0.401

For hygon arch with this patch, non-temporal stores can improve
performance by 20% - 65%.

Signed-off-by: Feifei Wang <wangfeifei@hygon.cn>
Reviewed-by: Jing Li <lijing@hygon.cn>
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
2024-08-26 10:01:58 -07:00
Feifei Wang
d14aecbffc 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>
2024-08-26 10:01:58 -07:00
Feifei Wang
6b08116b2d 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>
2024-08-26 10:01:58 -07:00
Florian Weimer
34e52acd55 support: Report errno constants in TEST_COMPARE failures
If the expression is errno, decode it as an errno constant
using strerrorname_np.

Reviewed-by: Arjun Shankar <arjun@redhat.com>
2024-08-26 16:46:45 +02:00
Florian Weimer
79f44e1a47 inet: Avoid label at end of compound statement in tst-if_nameindex
This fails to compile with GCC 8.
2024-08-26 16:45:31 +02:00
Samuel Thibault
f071795d80 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.
2024-08-25 03:35:29 +02:00
Mahesh Bodapati
82b5340ebd 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>
2024-08-23 16:48:32 -05:00
Adhemerval Zanella
89b53077d2 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>
2024-08-23 14:27:43 -03:00
Joseph Myers
55cd51d971 Test mkdirat use of mode argument
The test io/tst-mkdirat doesn't verify the permissions on the created
directory (thus, doesn't verify at all anything about how mkdirat uses
the mode argument).  Add checks of this to the existing test.

Tested for x86_64.
2024-08-22 11:25:14 +00:00
Joseph Myers
7f04bb4e49 Add more tests of getline
There is very little test coverage for getline (only a minimal
stdio-common/tstgetln.c which doesn't verify anything about the
results of the getline calls).  Add some more thorough tests
(generally using fopencookie for convenience in testing various cases
for what the input and possible errors / EOF in the file read might
look like).

Note the following regarding testing of error cases:

* Nothing is said in the specifications about what if anything might
  be written into the buffer, and whether it might be reallocated, in
  error cases.  The expectation of the tests (required to avoid memory
  leaks on error) is that at least on error cases, the invariant that
  lineptr points to at least n bytes is maintained.

* The optional EOVERFLOW error case specified in POSIX, "The number of
  bytes to be written into the buffer, including the delimiter
  character (if encountered), would exceed {SSIZE_MAX}.", doesn't seem
  practically testable, as any case reading so many characters (half
  the address space) would also be liable to run into allocation
  failure along (ENOMEM) the way.

* If a read error occurs part way through reading an input line, it
  seems unclear whether a partial line should be returned by getline
  (avoid input getting lost), which is what glibc does at least in the
  fopencookie case used in this test, or whether getline should return
  -1 (error) (so avoiding the program misbehaving by processing a
  truncated line as if it were complete).  (There was a short,
  inconclusive discussion about this on the Austin Group list on 9-10
  November 2014.)

* The POSIX specification of getline inherits errors from fgetc.  I
  didn't try to cover fgetc errors systematically, just one example of
  such an error.

Tested for x86_64 and x86.
2024-08-21 19:58:14 +00:00
Florian Weimer
498ba34ee2 Revert "inet: Avoid label at end of compound statement in tst-if_nameindex"
This reverts commit 26aca73db5.

Reason for revert: Unintended semantic change.
2024-08-21 20:06:33 +02:00
Florian Weimer
26aca73db5 inet: Avoid label at end of compound statement in tst-if_nameindex
This fails to compile with GCC 8.
2024-08-21 19:16:04 +02:00
Samuel Thibault
734e7f91e7 Rules: Also build memcheck tests even when not running them
This will avoid in the future cases like a57cbbd853 ("malloc: Link
threading tests with $(shared-thread-library") missing the memcheck
cases added in 251843e16f ("malloc: Link threading tests with
$(shared-thread-library)")
2024-08-20 16:23:03 +02:00
Samuel Thibault
251843e16f malloc: Link threading tests with $(shared-thread-library)
Fixes build failures on Hurd.
2024-08-20 16:16:25 +02:00
DJ Delorie
2eee835eca inet: test if_nametoindex and if_indextoname
Tests for if_nameindex, if_name2index, and if_index2name

Tests that valid results are consistent.

Tests that invalid parameters fail correctly.

Reviewed-by: Florian Weimer <fweimer@redhat.com>
2024-08-19 17:37:37 -04:00
Adhemerval Zanella
745c3cc10f elf: Make dl-fptr and dl-symaddr hppa specific
With ia64 removal, the function descriptor supports is only used
by HPPA and new architectures do not seem leaning towards this
design.

Reviewed-by: Florian Weimer <fweimer@redhat.com>
2024-08-19 14:54:07 -03:00
Matthew Sterrett
294a892769 x86: Unifies 'strnlen-evex' and 'strnlen-evex512' implementations.
This commit uses a common implementation 'strnlen-evex-base.S' for both
'strnlen-evex' and 'strnlen-evex512'

This patch serves both to reduce the number of implementations, and it also does some small optimizations that benefit strnlen-evex and strnlen-evex512.

All tests pass on x86.

Benchmarks were taken on SKX.
https://www.intel.com/content/www/us/en/products/sku/123613/intel-core-i97900x-xseries-processor-13-75m-cache-up-to-4-30-ghz/specifications.html

Geometric mean for strnlen-evex over all benchmarks (N=10) was (new/old) 0.881
Geometric mean for strnlen-evex512 over all benchmarks (N=10) was (new/old) 0.953

Code Size Changes:
    strnlen-evex       :  +31 bytes
    strnlen-evex512    :  +156 bytes
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
2024-08-19 07:34:02 -07:00