In short: __tls_get_addr checks the global generation counter and if
the current dtv is older then _dl_update_slotinfo updates dtv up to the
generation of the accessed module. So if the global generation is newer
than generation of the module then __tls_get_addr keeps hitting the
slow dtv update path. The dtv update path includes a number of checks
to see if any update is needed and this already causes measurable tls
access slow down after dlopen.
It may be possible to detect up-to-date dtv faster. But if there are
many modules loaded (> TLS_SLOTINFO_SURPLUS) then this requires at
least walking the slotinfo list.
This patch tries to update the dtv to the global generation instead, so
after a dlopen the tls access slow path is only hit once. The modules
with larger generation than the accessed one were not necessarily
synchronized before, so additional synchronization is needed.
This patch uses acquire/release synchronization when accessing the
generation counter.
Note: in the x86_64 version of dl-tls.c the generation is only loaded
once, since relaxed mo is not faster than acquire mo load.
I have not benchmarked this. Tested by Adhemerval Zanella on aarch64,
powerpc, sparc, x86 who reported that it fixes the performance issue
of bug 19924.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
(cherry picked from commit d2123d6827)
The old Intel software developer manual specified that the low byte of
EAX of CPUID leaf 2 returned 1 which indicated the number of rounds of
CPUDID leaf 2 was needed to retrieve the complete cache information. The
newer Intel manual has been changed to that it should always return 1
and be ignored. If the lower byte isn't 1, CPUID leaf 2 can't be used.
In this case, we ignore CPUID leaf 2 and use CPUID leaf 4 instead. If
CPUID leaf 4 doesn't contain the cache information, cache information
isn't available at all. This addresses BZ #30643.
(cherry picked from commit 1493622f4f)
On Skylake, it changes log1p bench performance by:
Before After Improvement
max 63.349 58.347 8%
min 4.448 5.651 -30%
mean 12.0674 10.336 14%
The minimum code path is
if (hx < 0x3FDA827A) /* x < 0.41422 */
{
if (__glibc_unlikely (ax >= 0x3ff00000)) /* x <= -1.0 */
{
...
}
if (__glibc_unlikely (ax < 0x3e200000)) /* |x| < 2**-29 */
{
math_force_eval (two54 + x); /* raise inexact */
if (ax < 0x3c900000) /* |x| < 2**-54 */
{
...
}
else
return x - x * x * 0.5;
FMA and non-FMA code sequences look similar. Non-FMA version is slightly
faster. Since log1p is called by asinh and atanh, it improves asinh
performance by:
Before After Improvement
max 75.645 63.135 16%
min 10.074 10.071 0%
mean 15.9483 14.9089 6%
and improves atanh performance by:
Before After Improvement
max 91.768 75.081 18%
min 15.548 13.883 10%
mean 18.3713 16.8011 8%
(cherry picked from commit a8ecb126d4)
On Skylake, it improves expm1 bench performance by:
Before After Improvement
max 70.204 68.054 3%
min 20.709 16.2 22%
mean 22.1221 16.7367 24%
NB: Add
extern long double __expm1l (long double);
extern long double __expm1f128 (long double);
for __typeof (__expm1l) and __typeof (__expm1f128) when __expm1 is
defined since __expm1 may be expanded in their declarations which
causes the build failure.
(cherry picked from commit 1b214630ce)
On Skylake, it improves log2 bench performance by:
Before After Improvement
max 208.779 63.827 69%
min 9.977 6.55 34%
mean 10.366 6.8191 34%
(cherry picked from commit f6b10ed8e9)
Sort Makefile variables using scripts/sort-makefile-lines.py.
No code generation changes observed in libm. No regressions on x86_64.
(cherry picked from commit 881546979d)
Some hypervisors report 1 TiB L3 cache size. This results
in some variables incorrectly getting zeroed, causing crashes
in memcpy/memmove because invariants are violated.
(cherry picked from commit 61c3450db9)
When adding explicit initialization of rseq fields prior to
registration, I glossed over the fact that 'cpu_id_start' is also
documented as initialized by user-space.
While current kernels don't validate the content of this field on
registration, future ones could.
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
(cherry picked from commit d9f40387d3)
Per the rseq syscall documentation, 3 fields are required to be
initialized by userspace prior to registration, they are 'cpu_id',
'rseq_cs' and 'flags'. Since we have no guarantee that 'struct pthread'
is cleared on all architectures, explicitly set those 3 fields prior to
registration.
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Reviewed-by: Florian Weimer <fweimer@redhat.com>
(cherry picked from commit 97f60abd25)
In commit c628c22963 (elf: Remove
ldconfig kernel version check), the layout of auxcache entries
changed because the osversion field was removed from
struct aux_cache_file_entry. However, AUX_CACHEMAGIC was not
changed, so existing files are still used, potentially leading
to unintended ldconfig behavior. This commit changes AUX_CACHEMAGIC,
so that the file is regenerated.
Reported-by: DJ Delorie <dj@redhat.com>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
(cherry picked from commit 0a536f6e2f)
Starting from glibc 2.1, crt1.o contains _IO_stdin_used which is checked
by _IO_check_libio to provide binary compatibility for glibc 2.0. Add
crt1-2.0.o for tests against glibc 2.0. Define tests-2.0 for glibc 2.0
compatibility tests. Add and update glibc 2.0 compatibility tests for
stderr, matherr and pthread_kill.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
(cherry picked from commit 5f245f3bfb)
_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>
(cherry picked from commit ae4d44b1d5)
Remove local FAIL macro in favor to FAIL_EXIT1 from <support/check.h>,
which provides equivalent reporting, with the name of the file and the
line number within of the failure site additionally included. Remove
FAIL_ERR altogether and include ": %m" explicitly with the format string
supplied to FAIL_EXIT1 as there seems little value to have a separate
macro just for this.
Reviewed-by: DJ Delorie <dj@redhat.com>
(cherry picked from commit 8c98195af6)
Remove local FAIL macro in favor to FAIL_RET from <support/check.h>,
which provides equivalent reporting, with the name of the file of the
failure site additionally included, for the tst-truncate-common core
shared between the tst-truncate and tst-truncate64 tests.
Reviewed-by: DJ Delorie <dj@redhat.com>
(cherry picked from commit fe47595504)
If a file descriptor is left unclosed and is cleaned up by _IO_cleanup
on exit, its backup buffer remains unfreed, registering as a leak in
valgrind. This is not strictly an issue since (1) the program should
ideally be closing the stream once it's not in use and (2) the program
is about to exit anyway, so keeping the backup buffer around a wee bit
longer isn't a real problem. Free it anyway to keep valgrind happy
when the streams in question are the standard ones, i.e. stdout, stdin
or stderr.
Also, the _IO_have_backup macro checks for _IO_save_base,
which is a roundabout way to check for a backup buffer instead of
directly looking for _IO_backup_base. The roundabout check breaks when
the main get area has not been used and user pushes a char into the
backup buffer with ungetc. Fix this to use the _IO_backup_base
directly.
Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
(cherry picked from commit 3e1d8d1d1d)
When ungetc is called on an unused stream, the backup buffer is
allocated without the main get area being present. This results in
every subsequent ungetc (as the stream remains in the backup area)
checking uninitialized memory in the backup buffer when trying to put a
character back into the stream.
Avoid comparing the input character with buffer contents when in backup
to avoid this uninitialized read. The uninitialized read is harmless in
this context since the location is promptly overwritten with the input
character, thus fulfilling ungetc functionality.
Also adjust wording in the manual to drop the paragraph that says glibc
cannot do multiple ungetc back to back since with this change, ungetc
can actually do this.
Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
(cherry picked from commit cdf0f88f97)
Complement commit b03e4d7bd2 ("stdio: fix vfscanf with matches longer
than INT_MAX (bug 27650)") and add a test case for the issue, inspired
by the reproducer provided with the bug report.
This has been verified to succeed as from the commit referred and fail
beforehand.
As the test requires 2GiB of data to be passed around its performance
has been evaluated using a choice of systems and the execution time
determined to be respectively in the range of 9s for POWER9@2.166GHz,
24s for FU740@1.2GHz, and 40s for 74Kf@950MHz. As this is on the verge
of and beyond the default timeout it has been increased by the factor of
8. Regardless, following recent practice the test has been added to the
standard rather than extended set.
Reviewed-by: DJ Delorie <dj@redhat.com>
(cherry picked from commit 89cddc8a70)
Add a FAIL test failure helper analogous to FAIL_RET, that does not
cause the current function to return, providing a standardized way to
report a test failure with a message supplied while permitting the
caller to continue executing, for further reporting, cleaning up, etc.
Update existing test cases that provide a conflicting definition of FAIL
by removing the local FAIL definition and then as follows:
- tst-fortify-syslog: provide a meaningful message in addition to the
file name already added by <support/check.h>; 'support_record_failure'
is already called by 'support_print_failure_impl' invoked by the new
FAIL test failure helper.
- tst-ctype: no update to FAIL calls required, with the name of the file
and the line number within of the failure site additionally included
by the new FAIL test failure helper, and error counting plus count
reporting upon test program termination also already provided by
'support_record_failure' and 'support_report_failure' respectively,
called by 'support_print_failure_impl' and 'adjust_exit_status' also
respectively. However in a number of places 'printf' is called and
the error count adjusted by hand, so update these places to make use
of FAIL instead. And last but not least adjust the final summary just
to report completion, with any error count following as reported by
the test driver.
- test-tgmath2: no update to FAIL calls required, with the name of the
file of the failure site additionally included by the new FAIL test
failure helper. Also there is no need to track the return status by
hand as any call to FAIL will eventually cause the test case to return
an unsuccesful exit status regardless of the return status from the
test function, via a call to 'adjust_exit_status' made by the test
driver.
Reviewed-by: DJ Delorie <dj@redhat.com>
(cherry picked from commit 1b97a9f23b)
Issue was we were expecting not matches with CHAR before the start of
the string in the page cross case.
The check code in the page cross case:
```
and $0xffffffffffffffc0,%rax
vmovdqa64 (%rax),%zmm17
vpcmpneqb %zmm17,%zmm16,%k1
vptestmb %zmm17,%zmm17,%k0{%k1}
kmovq %k0,%rax
inc %rax
shr %cl,%rax
je L(continue)
```
expects that all characters that neither match null nor CHAR will be
1s in `rax` prior to the `inc`. Then the `inc` will overflow all of
the 1s where no relevant match was found.
This is incorrect in the page-cross case, as the
`vmovdqa64 (%rax),%zmm17` loads from before the start of the input
string.
If there are matches with CHAR before the start of the string, `rax`
won't properly overflow.
The fix is quite simple. Just replace:
```
inc %rax
shr %cl,%rax
```
With:
```
sar %cl,%rax
inc %rax
```
The arithmetic shift will clear any matches prior to the start of the
string while maintaining the signbit so the 1s can properly overflow
to zero in the case of no matches.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
(cherry picked from commit 7da0886247)
Rename the identifier sz to __sz everywhere.
Fixes: a643f60c53 ("Make sure that the fortified function conditionals are constant")
(cherry picked from commit 39ca997ab3)
(redone from scratch because of many conflicts)
Previous GCC versions do not support the C23 change that
allows labels on declarations.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
(cherry picked from commit ec119972cb)
Linux 6.5 has one new syscall, cachestat, and also enables the
cacheflush syscall for hppa. Update syscall-names.list and regenerate
the arch-syscall.h headers with build-many-glibcs.py update-syscalls.
Tested with build-many-glibcs.py.
(cherry picked from commit 72511f539c)
Add tests for MREMAP_MAYMOVE and MREMAP_FIXED. On Linux, also test
MREMAP_DONTUNMAP.
Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
(cherry picked from commit ff0320bec2)
Update the mremap C implementation to support the optional argument for
MREMAP_DONTUNMAP added in Linux 5.7 since it may not always be correct
to implement a variadic function as a non-variadic function on all Linux
targets. Return MAP_FAILED and set errno to EINVAL for unknown flag bits.
This fixes BZ #31968.
Note: A test must be added when a new flag bit is introduced.
Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
(cherry picked from commit 6c40cb0e9f)
This avoids changing _res.options, which inteferes with change
detection as part of automatic reloading of /etc/resolv.conf.
Reviewed-by: DJ Delorie <dj@redhat.com>
(cherry picked from commit 868ab8923a)
In single-request mode, there is no second response after an error
because the second query has not been sent yet. Waiting for it
introduces an unnecessary timeout.
Reviewed-by: DJ Delorie <dj@redhat.com>
(cherry picked from commit af625987d6)
The __rseq_size value is now the active area of struct rseq
(so 20 initially), not the full struct size including padding
at the end (32 initially).
Update misc/tst-rseq to print some additional diagnostics.
Reviewed-by: Michael Jeanson <mjeanson@efficios.com>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
(cherry picked from commit 2e456ccf0c)
While working on a patch to add support for the extensible rseq ABI, we
came across an issue where a new 'const' variable would be merged with
the existing '__rseq_size' variable. We tracked this to the use of
'-fmerge-all-constants' which allows the compiler to merge identical
constant variables. This means that all 'const' variables in a compile
unit that are of the same size and are initialized to the same value can
be merged.
In this specific case, on 32 bit systems 'unsigned int' and 'ptrdiff_t'
are both 4 bytes and initialized to 0 which should trigger the merge.
However for reasons we haven't delved into when the attribute 'section
(".data.rel.ro")' is added to the mix, only variables of the same exact
types are merged. As far as we know this behavior is not specified
anywhere and could change with a new compiler version, hence this patch.
Move the definitions of these variables into an assembler file and add
hidden writable aliases for internal use. This has the added bonus of
removing the asm workaround to set the values on rseq registration.
Tested on Debian 12 with GCC 12.2.
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Reviewed-by: Florian Weimer <fweimer@redhat.com>
(cherry picked from commit 2b92982e23)
The z13/vector-optimized wcsncmp implementation segfaults if n=1
and there is only one character (equal on both strings) before
the page end. Then it loads and compares one character and misses
to check n again. The following load fails.
This patch removes the extra load and compare of the first character
and just start with the loop which uses vector-load-to-block-boundary.
This code-path also checks n.
With this patch both tests are passing:
- the simplified one mentioned in the bugzilla 31934
- the full one in Florian Weimer's patch:
"manual: Document a GNU extension for strncmp/wcsncmp"
(https://patchwork.sourceware.org/project/glibc/patch/874j9eml6y.fsf@oldenburg.str.redhat.com/):
On s390x-linux-gnu (z16), the new wcsncmp test fails due to bug 31934.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
(cherry picked from commit 9b76514103)
In Linux 6.9 a new flag is added to allow for Per-io operations to
disable append mode even if a file was opened with the flag O_APPEND.
This is done with the new RWF_NOAPPEND flag.
This caused two test failures as these tests expected the flag 0x00000020
to be unused. Adding the flag definition now fixes these tests on Linux
6.9 (v6.9-rc1).
FAIL: misc/tst-preadvwritev2
FAIL: misc/tst-preadvwritev64v2
This patch adds the flag, adjusts the test and adds details to
documentation.
Link: https://lore.kernel.org/all/20200831153207.GO3265@brightrain.aerifal.cx/
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
(cherry picked from commit 3db9d208dd)
On Fedora 40/x86-64, linker enables --enable-new-dtags by default which
generates DT_RUNPATH instead of DT_RPATH. Unlike DT_RPATH, DT_RUNPATH
only applies to DT_NEEDED entries in the executable and doesn't applies
to DT_NEEDED entries in shared libraries which are loaded via DT_NEEDED
entries in the executable. Some glibc tests have libstdc++.so.6 in
DT_NEEDED, which has libm.so.6 in DT_NEEDED. When DT_RUNPATH is generated,
/lib64/libm.so.6 is loaded for such tests. If the newly built glibc is
older than glibc 2.36, these tests fail with
assert/tst-assert-c++: /export/build/gnu/tools-build/glibc-gitlab-release/build-x86_64-linux/libc.so.6: version `GLIBC_2.36' not found (required by /lib64/libm.so.6)
assert/tst-assert-c++: /export/build/gnu/tools-build/glibc-gitlab-release/build-x86_64-linux/libc.so.6: version `GLIBC_ABI_DT_RELR' not found (required by /lib64/libm.so.6)
Pass -Wl,--disable-new-dtags to linker when building glibc tests with
--enable-hardcoded-path-in-tests. This fixes BZ #31719.
Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
(cherry picked from commit 2dcaf70643)
Using int may give false results for future dates (timeouts after the
year 2028).
Fixes commit 04a21e050d64a1193a6daab872bca2528bda44b ("CVE-2024-33601,
CVE-2024-33602: nscd: netgroup: Use two buffers in addgetnetgrentX
(bug 31680)").
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
(cherry picked from commit 4bbca1a446)
Also compile dl-misc.os with $(rtld-early-cflags) to avoid
Program received signal SIGILL, Illegal instruction.
0x00007ffff7fd36ea in _dl_strtoul (nptr=nptr@entry=0x7fffffffe2c9 "2",
endptr=endptr@entry=0x7fffffffd728) at dl-misc.c:156
156 bool positive = true;
(gdb) bt
#0 0x00007ffff7fd36ea in _dl_strtoul (nptr=nptr@entry=0x7fffffffe2c9 "2",
endptr=endptr@entry=0x7fffffffd728) at dl-misc.c:156
#1 0x00007ffff7fdb1a9 in tunable_initialize (
cur=cur@entry=0x7ffff7ffbc00 <tunable_list+2176>,
strval=strval@entry=0x7fffffffe2c9 "2", len=len@entry=1)
at dl-tunables.c:131
#2 0x00007ffff7fdb3a2 in parse_tunables (valstring=<optimized out>)
at dl-tunables.c:258
#3 0x00007ffff7fdb5d9 in __GI___tunables_init (envp=0x7fffffffdd58)
at dl-tunables.c:288
#4 0x00007ffff7fe44c3 in _dl_sysdep_start (
start_argptr=start_argptr@entry=0x7fffffffdcb0,
dl_main=dl_main@entry=0x7ffff7fe5f80 <dl_main>)
at ../sysdeps/unix/sysv/linux/dl-sysdep.c:110
#5 0x00007ffff7fe5cae in _dl_start_final (arg=0x7fffffffdcb0) at rtld.c:494
#6 _dl_start (arg=0x7fffffffdcb0) at rtld.c:581
#7 0x00007ffff7fe4b38 in _start ()
(gdb)
when setting GLIBC_TUNABLES in glibc compiled with APX.
Reviewed-by: Florian Weimer <fweimer@redhat.com>
(cherry picked from commit 049b7684c9)
This avoids potential memory corruption when the underlying NSS
callback function does not use the buffer space to store all strings
(e.g., for constant strings).
Instead of custom buffer management, two scratch buffers are used.
This increases stack usage somewhat.
Scratch buffer allocation failure is handled by return -1
(an invalid timeout value) instead of terminating the process.
This fixes bug 31679.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
(cherry picked from commit c04a21e050)
The addgetnetgrentX call in addinnetgrX may have failed to produce
a result, so the result variable in addinnetgrX can be NULL.
Use db->negtimeout as the fallback value if there is no result data;
the timeout is also overwritten below.
Also avoid sending a second not-found response. (The client
disconnects after receiving the first response, so the data stream did
not go out of sync even without this fix.) It is still beneficial to
add the negative response to the mapping, so that the client can get
it from there in the future, instead of going through the socket.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
(cherry picked from commit b048a482f0)
If we failed to add a not-found response to the cache, the dataset
point can be null, resulting in a null pointer dereference.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
(cherry picked from commit 7835b00dbc)
Using alloca matches what other caches do. The request length is
bounded by MAXKEYLEN.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
(cherry picked from commit 87801a8fd0)
Fall back to ppoll if ppoll_time64 fails with ENOSYS.
Fixes commit 370da8a121 ("nptl: Fix
tst-cancel30 on sparc64").
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
(cherry picked from commit f4724843ad)
These structs describe file formats under /var/log, and should not
depend on the definition of _TIME_BITS. This is achieved by
defining __WORDSIZE_TIME64_COMPAT32 to 1 on 32-bit ports that
support 32-bit time_t values (where __time_t is 32 bits).
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
(cherry picked from commit 9abdae94c7)
The default <utmp-size.h> is for ports with a 64-bit time_t.
Ports with a 32-bit time_t or with __WORDSIZE_TIME64_COMPAT32=1
need to override it.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
(cherry picked from commit 4d4da5aab9)
ISO-2022-CN-EXT uses escape sequences to indicate character set changes
(as specified by RFC 1922). While the SOdesignation has the expected
bounds checks, neither SS2designation nor SS3designation have its;
allowing a write overflow of 1, 2, or 3 bytes with fixed values:
'$+I', '$+J', '$+K', '$+L', '$+M', or '$*H'.
Checked on aarch64-linux-gnu.
Co-authored-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
(cherry picked from commit f9dc609e06)
This seems to have stopped working with some GCC 14 versions,
which clobber r2. With other compilers, the kernel-provided
r2 value is still available at this point.
Reviewed-by: Peter Bergner <bergner@linux.ibm.com>
(cherry picked from commit 14e56bd4ce)
Szabolcs Nagy
H.J. Lu
Florian Weimer
Michael Jeanson
Siddhesh Poyarekar
Maciej W. Rozycki
Noah Goldstein
Andreas Schwab
Joseph Myers
Adhemerval Zanella
Stefan Liebler
Stafford Horne
Sunil K Pandey
John David Anglin
Charles Fol