AT_EMPTY_PATH is a requirement to implement fstat over fstatat,
however it does not prevent the kernel to read the path argument.
It is not an issue, but on x86-64 with SMAP-capable CPUs the kernel is
forced to perform expensive user memory access. After that regular
lookup is performed which adds even more overhead.
Instead, issue the fstat syscall directly on LFS fstat implementation
(32 bit architectures will still continue to use statx, which is
required to have 64 bit time_t support). it should be even a
small performance gain on non x86_64, since there is no need
to handle the path argument.
Checked on x86_64-linux-gnu.
During the review of a GCC analyzer test case, we found most stdio
functions accepting a FILE * argument expect it to be nonnull and just
segfault when the argument is NULL. Add nonnull attribute for them.
fflush and fflush_unlocked are well defined when __stream is NULL so
they are not touched.
For fputs, fgets, fread, fwrite, fprintf, vfprintf, and their unlocked
version, if __stream is empty but there is nothing to read or write,
they did not segfault. But the standard disallow __stream to be empty
here, so nonnull attribute is also added for them. Note that this may
blow up some old code already subtly broken.
Also add __nonnull for _chk variants and __fortify_function versions for
them.
Signed-off-by: Xi Ruoyao <xry111@xry111.site>
Reviewed-by: Alejandro Colomar <alx@kernel.org>
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Remove the unnecessary extra checks for sin (-0.0) from vector sin/sinf,
improving performance. Passes regress.
Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
I made it to agree as much as possible with the rules from CLDR (see:
https://github.com/unicode-org/cldr/blob/main/common/collation/th.xml).
It seems to be impossible to follow the CLDR rules
&[before 1]๚<ฯ # should be "variable"
and
&๛<ๆ # should be "variable"
exactly though. These ask for a primary difference in punctuation
characters whose primary weight should be "IGNORE". But using a
secondary differnence instead still sorts the test data correctly and
the previously used collation in th_TH used tertiary differences for
these characters.
There was old localedata/th_TH.in test data in TIS-620 encoding which
was not used (it was not in the localedata/Makefile). I converted this
to UTF-8 and moved it to localedata/th_TH.UTF-8.in and added it to
localedata/Makefile.
Using the existing collation rules in the th_TH locale did not sort that
test file completely correct, I think my new collation rules based on
iso14651_t1 are better.
This patch updates the kernel version in the tests tst-mman-consts.py
and tst-pidfd-consts.py to 6.5. (There are no new constants covered
by these tests in 6.5 that need any other header changes;
tst-mount-consts.py was updated separately along with a header
constant addition.)
Tested with build-many-glibcs.py.
Add support for a no-mathvec flag to gen-auto-libm-tests.c.
Update input test sin (-0.0) to be skipped in vector math libraries and
regenerate testcases.
Reviewed-By: Paul Zimmermann <Paul.Zimmermann@inria.fr>
Unicode 15.1.0 Support: Character encoding, character type info, and
transliteration tables are all updated to Unicode 15.1.0, using
the generator scripts contributed by Mike FABIAN (Red Hat).
Total removed characters in newly generated CHARMAP: 0
Total changed characters in newly generated CHARMAP: 0
Total added characters in newly generated CHARMAP: 627
Total removed characters in newly generated WIDTH: 0
Total changed characters in newly generated WIDTH: 0
Total added characters in newly generated WIDTH: 627
alpha: Added 622 characters in new ctype which were not in old ctype
graph: Added 627 characters in new ctype which were not in old ctype
print: Added 627 characters in new ctype which were not in old ctype
punct: Added 5 characters in new ctype which were not in old ctype
The five characters added to punct are:
2FFC;IDEOGRAPHIC DESCRIPTION CHARACTER SURROUND FROM RIGHT;So;0;ON;;;;;N;;;;;
2FFD;IDEOGRAPHIC DESCRIPTION CHARACTER SURROUND FROM LOWER RIGHT;So;0;ON;;;;;N;;;;;
2FFE;IDEOGRAPHIC DESCRIPTION CHARACTER HORIZONTAL REFLECTION;So;0;ON;;;;;N;;;;;
2FFF;IDEOGRAPHIC DESCRIPTION CHARACTER ROTATION;So;0;ON;;;;;N;;;;;
31EF;IDEOGRAPHIC DESCRIPTION CHARACTER SUBTRACTION;So;0;ON;;;;;N;;;;;
The Unicode announcement blog entry says "[...] adds 627
characters, [...] additions include 622 CJK unified ideographs in
a new block, [...]", so that looks OK. The Unicode
blog mentions "six completely new emoji" but they don't appear here as
they are all sequences and not single code points.
Resolves: BZ #30854
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
When an NSS plugin only implements the _gethostbyname2_r and
_getcanonname_r callbacks, getaddrinfo could use memory that was freed
during tmpbuf resizing, through h_name in a previous query response.
The backing store for res->at->name when doing a query with
gethostbyname3_r or gethostbyname2_r is tmpbuf, which is reallocated in
gethosts during the query. For AF_INET6 lookup with AI_ALL |
AI_V4MAPPED, gethosts gets called twice, once for a v6 lookup and second
for a v4 lookup. In this case, if the first call reallocates tmpbuf
enough number of times, resulting in a malloc, th->h_name (that
res->at->name refers to) ends up on a heap allocated storage in tmpbuf.
Now if the second call to gethosts also causes the plugin callback to
return NSS_STATUS_TRYAGAIN, tmpbuf will get freed, resulting in a UAF
reference in res->at->name. This then gets dereferenced in the
getcanonname_r plugin call, resulting in the use after free.
Fix this by copying h_name over and freeing it at the end. This
resolves BZ #30843, which is assigned CVE-2023-4806.
Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
According to glibc strrchr microbenchmark test results, this implementation
could reduce the runtime time as following:
Name Percent of rutime reduced
strrchr-lasx 10%-50%
strrchr-lsx 0%-50%
strrchr-aligned 5%-50%
Generic strrchr is implemented by function strlen + memrchr, the lasx version
will compare with generic strrchr implemented by strlen-lasx + memrchr-lasx,
the lsx version will compare with generic strrchr implemented by strlen-lsx +
memrchr-lsx, the aligned version will compare with generic strrchr implemented
by strlen-aligned + memrchr-generic.
According to glibc strcpy and stpcpy microbenchmark test results(changed
to use generic_strcpy and generic_stpcpy instead of strlen + memcpy),
comparing with the generic version, this implementation could reduce the
runtime as following:
Name Percent of rutime reduced
strcpy-aligned 8%-45%
strcpy-unaligned 8%-48%, comparing with the aligned version, unaligned
version takes less instructions to copy the tail of data
which length is less than 8. it also has better performance
in case src and dest cannot be both aligned with 8bytes
strcpy-lsx 20%-80%
strcpy-lasx 15%-86%
stpcpy-aligned 6%-43%
stpcpy-unaligned 8%-48%
stpcpy-lsx 10%-80%
stpcpy-lasx 10%-87%
This patch adds the MOVE_MOUNT_BENEATH constant from Linux 6.5 to
glibc's sys/mount.h and updates tst-mount-consts.py to reflect these
constants being up to date with that Linux kernel version.
Tested with build-many-glibcs.py.
Without passing alt_dns_packet_buffer, __res_context_search can only
store 2048 bytes (what fits into dns_packet_buffer). However,
the function returns the total packet size, and the subsequent
DNS parsing code in _nss_dns_gethostbyname4_r reads beyond the end
of the stack-allocated buffer.
Fixes commit f282cdbe7f ("resolv: Implement no-aaaa
stub resolver option") and bug 30842.
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.
Needed since gcc-10 enabled -fno-common by default.
[In use in Gentoo since gcc-10, no problems observed.
Also discussed with and reviewed by Jessica Clarke from
Debian. Andreas]
Bug: https://bugs.gentoo.org/723268
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Signed-off-by: Sergei Trofimovich <slyich@gmail.com>
Signed-off-by: Andreas K. Hüttel <dilfridge@gentoo.org>
Use a fixed size array instead. The maximum number of arguments
is set by macro tricks.
Co-authored-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
IO_VTABLES_LEN is the size of the struct array in bytes, not the number
of __IO_jump_t's in the array. Drops just under 384kb from .rodata on
LP64 machines.
Fixes: 3020f72618 ("libio: Remove the usage of __libc_IO_vtables")
Signed-off-by: Adam Jackson <ajax@redhat.com>
Reviewed-by: Florian Weimer <fweimer@redhat.com>
Tested-by: Florian Weimer <fweimer@redhat.com>
It is a left-over from commit 52a01100ad
("elf: Remove ad-hoc restrictions on dlopen callers [BZ #22787]").
When backporting commmit 6985865bc3
("elf: Always call destructors in reverse constructor order
(bug 30785)"), we can move the l_init_called_next field to this
place, so that the internal GLIBC_PRIVATE ABI does not change.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
The current implementation of dlclose (and process exit) re-sorts the
link maps before calling ELF destructors. Destructor order is not the
reverse of the constructor order as a result: The second sort takes
relocation dependencies into account, and other differences can result
from ambiguous inputs, such as cycles. (The force_first handling in
_dl_sort_maps is not effective for dlclose.) After the changes in
this commit, there is still a required difference due to
dlopen/dlclose ordering by the application, but the previous
discrepancies went beyond that.
A new global (namespace-spanning) list of link maps,
_dl_init_called_list, is updated right before ELF constructors are
called from _dl_init.
In dl_close_worker, the maps variable, an on-stack variable length
array, is eliminated. (VLAs are problematic, and dlclose should not
call malloc because it cannot readily deal with malloc failure.)
Marking still-used objects uses the namespace list directly, with
next and next_idx replacing the done_index variable.
After marking, _dl_init_called_list is used to call the destructors
of now-unused maps in reverse destructor order. These destructors
can call dlopen. Previously, new objects do not have l_map_used set.
This had to change: There is no copy of the link map list anymore,
so processing would cover newly opened (and unmarked) mappings,
unloading them. Now, _dl_init (indirectly) sets l_map_used, too.
(dlclose is handled by the existing reentrancy guard.)
After _dl_init_called_list traversal, two more loops follow. The
processing order changes to the original link map order in the
namespace. Previously, dependency order was used. The difference
should not matter because relocation dependencies could already
reorder link maps in the old code.
The changes to _dl_fini remove the sorting step and replace it with
a traversal of _dl_init_called_list. The l_direct_opencount
decrement outside the loader lock is removed because it appears
incorrect: the counter manipulation could race with other dynamic
loader operations.
tst-audit23 needs adjustments to the changes in LA_ACT_DELETE
notifications. The new approach for checking la_activity should
make it clearer that la_activty calls come in pairs around namespace
updates.
The dependency sorting test cases need updates because the destructor
order is always the opposite order of constructor order, even with
relocation dependencies or cycles present.
There is a future cleanup opportunity to remove the now-constant
force_first and for_fini arguments from the _dl_sort_maps function.
Fixes commit 1df71d32fe ("elf: Implement
force_first handling in _dl_sort_maps_dfs (bug 28937)").
Reviewed-by: DJ Delorie <dj@redhat.com>
Commit 5f828ff824 ("io: Fix F_GETLK, F_SETLK, and F_SETLKW for
powerpc64") fixed an issue with the value of the lock constants on
powerpc64 when not using __USE_FILE_OFFSET64, but it ended-up also
changing the value when using __USE_FILE_OFFSET64 causing an API change.
Fix that by also checking that define, restoring the pre
4d0fe291ae commit values:
Default values:
- F_GETLK: 5
- F_SETLK: 6
- F_SETLKW: 7
With -D_FILE_OFFSET_BITS=64:
- F_GETLK: 12
- F_SETLK: 13
- F_SETLKW: 14
At the same time, it has been noticed that there was no test for io lock
with __USE_FILE_OFFSET64, so just add one.
Tested on x86_64-linux-gnu, i686-linux-gnu and
powerpc64le-unknown-linux-gnu.
Resolves: BZ #30804.
Co-authored-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
And shorten the section/node names a bit, so that the menu
entries become easier to read.
Texinfo 6.5 fails to process the previous structure:
./dynlink.texi:56: warning: node `Dynamic Linker Introspection' is
next for `Dynamic Linker Diagnostics' in sectioning but not in menu
./dynlink.texi:56: warning: node up `Dynamic Linker Diagnostics'
in menu `Dynamic Linker Invocation' and
in sectioning `Dynamic Linker' differ
./dynlink.texi:1: node `Dynamic Linker' lacks menu item for
`Dynamic Linker Diagnostics' despite being its Up target
./dynlink.texi:226: warning: node prev `Dynamic Linker Introspection' in menu `Dynamic Linker Invocation'
and in sectioning `Dynamic Linker Diagnostics' differ
Texinfo 7.0.2 does not report an error.
This fixes commit f21962ddfc
("manual: Document ld.so --list-diagnostics output").
Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
XTheadBb has similar instructions like Zbb, which allow optimized
string processing:
* th.ff0: find-first zero is a CLZ instruction.
* th.tstnbz: Similar like orc.b, but with a bit-inverted result.
The instructions are documented here:
https://github.com/T-head-Semi/thead-extension-spec/tree/master/xtheadbb
These instructions can be found in the T-Head C906 and the C910.
Tested with the string tests.
Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
This code is generally unused in practice since there don't seem to be
any NSS modules that only implement _nss_MOD_gethostbyname2_r and not
_nss_MOD_gethostbyname3_r.
Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
This interface allows to obtain the associated process ID from the
process file descriptor. It is done by parsing the procps fdinfo
information. Its prototype is:
pid_t pidfd_getpid (int fd)
It returns the associated pid or -1 in case of an error and sets the
errno accordingly. The possible errno values are those from open, read,
and close (used on procps parsing), along with:
- EBADF if the FD is negative, does not have a PID associated, or if
the fdinfo fields contain a value larger than pid_t.
- EREMOTE if the PID is in a separate namespace.
- ESRCH if the process is already terminated.
Checked on x86_64-linux-gnu on Linux 4.15 (no CLONE_PIDFD or waitid
support), Linux 5.4 (full support), and Linux 6.2.
Reviewed-by: Florian Weimer <fweimer@redhat.com>
Returning a pidfd allows a process to keep a race-free handle for a
child process, otherwise, the caller will need to either use pidfd_open
(which still might be subject to TOCTOU) or keep the old racy interface
base on pid_t.
To correct use pifd_spawn, the kernel must support not only returning
the pidfd with clone/clone3 but also waitid (P_PIDFD) (added on Linux
5.4). If kernel does not support the waitid, pidfd return ENOSYS.
It avoids the need to racy workarounds, such as reading the procfs
fdinfo to get the pid to use along with other wait interfaces.
These interfaces are similar to the posix_spawn and posix_spawnp, with
the only difference being it returns a process file descriptor (int)
instead of a process ID (pid_t). Their prototypes are:
int pidfd_spawn (int *restrict pidfd,
const char *restrict file,
const posix_spawn_file_actions_t *restrict facts,
const posix_spawnattr_t *restrict attrp,
char *const argv[restrict],
char *const envp[restrict])
int pidfd_spawnp (int *restrict pidfd,
const char *restrict path,
const posix_spawn_file_actions_t *restrict facts,
const posix_spawnattr_t *restrict attrp,
char *const argv[restrict_arr],
char *const envp[restrict_arr]);
A new symbol is used instead of a posix_spawn extension to avoid
possible issues with language bindings that might track the return
argument lifetime. Although on Linux pid_t and int are interchangeable,
POSIX only states that pid_t should be a signed integer.
Both symbols reuse the posix_spawn posix_spawn_file_actions_t and
posix_spawnattr_t, to void rehash posix_spawn API or add a new one. It
also means that both interfaces support the same attribute and file
actions, and a new flag or file action on posix_spawn is also added
automatically for pidfd_spawn.
Also, using posix_spawn plumbing allows the reusing of most of the
current testing with some changes:
- waitid is used instead of waitpid since it is a more generic
interface.
- tst-posix_spawn-setsid.c is adapted to take into consideration that
the caller can check for session id directly. The test now spawns
itself and writes the session id as a file instead.
- tst-spawn3.c need to know where pidfd_spawn is used so it keeps an
extra file description unused.
Checked on x86_64-linux-gnu on Linux 4.15 (no CLONE_PIDFD or waitid
support), Linux 5.4 (full support), and Linux 6.2.
Reviewed-by: Florian Weimer <fweimer@redhat.com>
These functions allow to posix_spawn and posix_spawnp to use
CLONE_INTO_CGROUP with clone3, allowing the child process to
be created in a different cgroup version 2. These are GNU
extensions that are available only for Linux, and also only
for the architectures that implement clone3 wrapper
(HAVE_CLONE3_WRAPPER).
To create a process on a different cgroupv2, one can use the:
posix_spawnattr_t attr;
posix_spawnattr_init (&attr);
posix_spawnattr_setflags (&attr, POSIX_SPAWN_SETCGROUP);
posix_spawnattr_setcgroup_np (&attr, cgroup);
posix_spawn (...)
Similar to other posix_spawn flags, POSIX_SPAWN_SETCGROUP control
whether the cgroup file descriptor will be used or not with
clone3.
There is no fallback if either clone3 does not support the flag
or if the architecture does not provide the clone3 wrapper, in
this case posix_spawn returns EOPNOTSUPP.
Checked on x86_64-linux-gnu.
Reviewed-by: Florian Weimer <fweimer@redhat.com>
It follows the internal signature:
extern int clone3 (struct clone_args *__cl_args, size_t __size,
int (*__func) (void *__arg), void *__arg);
Checked on mips64el-linux-gnueabihf, mips64el-n32-linux-gnu, and
mipsel-linux-gnu.
It follows the internal signature:
extern int clone3 (struct clone_args *__cl_args, size_t __size,
int (*__func) (void *__arg), void *__arg);
Checked on arm-linux-gnueabihf.
The wiki page https://sourceware.org/glibc/wiki/Proposals/C.UTF-8
says that "Setting LC_ALL=C.UTF-8 will ignore LANGUAGE just like it
does with LC_ALL=C." This patch implements it.
* intl/dcigettext.c (guess_category_value): Treat C.<encoding> locale
like the C locale.
Reviewed-by: Florian Weimer <fweimer@redhat.com>
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>
