Commit Graph

1727 Commits

Author SHA1 Message Date
H. Peter Anvin (Intel) 5f138519eb termios: add new baud_t interface, defined to be explicitly numeric
Add an explicitly numeric interface for baudrate setting. For glibc,
this only announces what is a fair accompli, but this is a plausible
way forward for standardization, and may be possible to infill on
non-compliant systems. The POSIX committee has stated:

[https://www.austingroupbugs.net/view.php?id=1916#c7135]

	A future version of this standard is expected to add at least
	the following symbolic constants for use as values of objects
	of type speed_t: B57600, B115200, B230400, B460800, and
	B921600.

	Implementations are encouraged to propose additional
	interfaces which will make it possible to set and query a
	wider range of speeds than just those enumerated by the
	constants beginning with B. If a set of common interfaces
	emerges between several implementations, a future version of
	this standard will likely add those interfaces.

This is exactly that interface.

The use of the term "baud" is due to the need to have a term
contrasting "speed", and it is already well established as a legacy
term -- including in the names of the legacy Bxxx
constants. Futhermore, it *is* valid from the point of view that the
termios interface fundamentally emulates an RS-232 serial port as far
as the application software is concerned.

The documentation states that for the current version of glibc,
speed_t == baud_t, but explicitly declares that this may not be the
case in the future.

Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2025-06-17 09:11:38 -03:00
H. Peter Anvin (Intel) c4929eecf7 io: replace local_isatty() with a proper function __isatty_nostatus()
Replace local_isatty() inlined in libio with a proper function
__isatty_nostatus(). This allows simpler system-specific
implementations that don't need to touch errno at all.

Note: I left the prototype in include/unistd.h (the internal header
file.) It didn't much make sense to me to put it in a different header
(not-cancel.h), but perhaps someone can elucidate the need.

Add such an implementation for Linux, with a generic fallback.

Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2025-06-17 09:11:38 -03:00
H. Peter Anvin (Intel) edf7328db2 termios: make __tcsetattr() the internal interface
There is a prototype for an internal __tcsetattr() function in
include/termios.h, but tcsetattr without __ were still declared as the
actual functions.

Make this match the comment and make __tcsetattr() an internal
interface. This will be required to version struct termios for Linux on
MIPS and SPARC.

Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2025-06-17 09:11:38 -03:00
Jonathan Wakely a2d2c62072 Fix comment typo in libc-symbols.h
Reviewed-by: Sam James <sam@gentoo.org>
2025-05-27 11:34:14 +01:00
Florian Weimer e0c0f856f5 Use proper extern declaration for _nl_C_LC_CTYPE_{class,toupper,tolower}
The existing initializers already contain explicit casts.  Keep them
due to int/uint32_t mismatch.

Reviewed-by: Frédéric Bérat <fberat@redhat.com>
2025-05-16 19:53:09 +02:00
Florian Weimer a894f04d87 Optimize __libc_tsd_* thread variable access
These variables are not exported, and libc.so TLS is initial-exec
anyway.  Declare these variables as hidden and use the initial-exec
TLS model.

Reviewed-by: Frédéric Bérat <fberat@redhat.com>
2025-05-16 19:53:09 +02:00
Florian Weimer 10a66a8e42 Remove <libc-tsd.h>
Use __thread variables directly instead.  The macros do not save any
typing.  It seems unlikely that a future port will lack __thread
variable support.

Some of the __libc_tsd_* variables are referenced from assembler
files, so keep their names.  Previously, <libc-tls.h> included
<tls.h>, which in turn included <errno.h>, so a few direct includes
of <errno.h> are now required.

Reviewed-by: Frédéric Bérat <fberat@redhat.com>
2025-05-16 19:53:09 +02:00
Aaron Merey e3a6e85d67 Add _FORTIFY_SOURCE support for inet_pton
Add function __inet_pton_chk which calls __chk_fail when the size of
argument dst is too small.   inet_pton is redirected to __inet_pton_chk
or __inet_pton_warn when _FORTIFY_SOURCE is > 0.

Also add tests to debug/tst-fortify.c, update the abilist with
__inet_pton_chk and mention inet_pton fortification in maint.texi.

Co-authored-by: Frédéric Bérat <fberat@redhat.com>
Reviewed-by: Florian Weimer <fweimer@redhat.com>
2025-03-24 14:43:03 -04:00
Adhemerval Zanella ed6a68bac7 debug: Improve '%n' fortify detection (BZ 30932)
The 7bb8045ec0 path made the '%n' fortify check ignore EMFILE errors
while trying to open /proc/self/maps, and this added a security
issue where EMFILE can be attacker-controlled thus making it
ineffective for some cases.

The EMFILE failure is reinstated but with a different error
message.  Also, to improve the false positive of the hardening for
the cases where no new files can be opened, the
_dl_readonly_area now uses  _dl_find_object to check if the
memory area is within a writable ELF segment.  The procfs method is
still used as fallback.

Checked on x86_64-linux-gnu and i686-linux-gnu.
Reviewed-by: Arjun Shankar <arjun@redhat.com>
2025-03-21 15:46:48 -03:00
Frédéric Bérat 090dfa40a5 Add _FORTIFY_SOURCE support for inet_ntop
- Create the __inet_ntop_chk routine that verifies that the builtin size
of the destination buffer is at least as big as the size given by the
user.
- Redirect calls from inet_ntop to __inet_ntop_chk or __inet_ntop_warn
- Update the abilist for this new routine
- Update the manual to mention the new fortification

Reviewed-by: Florian Weimer <fweimer@redhat.com>
2025-03-21 09:35:42 +01:00
Frédéric Bérat 3cdb99d8bb Add missing guards in include/arpa/inet.h
Add the missing guards in the header, similarly to other headers at the
same level

Reviewed-by: Florian Weimer <fweimer@redhat.com>
2025-03-21 09:35:36 +01:00
Frédéric Bérat 84373ef7b7 Prepare inet_ntop to be fortified
Rename inet_ntop to __inet_ntop and create the inet_ntop weak alias
based on it in order to prepare for disabling fortification when
available.

Reviewed-by: Florian Weimer <fweimer@redhat.com>
2025-03-21 09:35:16 +01:00
Florian Weimer d12cb8e452 elf: Merge __dl_libc_freemem into __rtld_libc_freeres
The functions serve very similar purposes.  The advantage of
__rtld_libc_freeres is that it is located within ld.so, so it is
more natural to poke at link map internals there.

This slightly regresses cleanup capabilities for statically linked
binaries.  If that becomes a problem, we should start calling
__rtld_libc_freeres from __libc_freeres (perhaps after renaming it).
2025-02-02 20:10:09 +01:00
Florian Weimer 96429bcc91 elf: Do not add a copy of _dl_find_object to libc.so
This reduces code size and dependencies on ld.so internals from
libc.so.

Fixes commit f4c142bb9f
("arm: Use _dl_find_object on __gnu_Unwind_Find_exidx (BZ 31405)").

Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2025-02-01 12:37:58 +01:00
Andreas K. Hüttel f46351b491
Bump version to 2.41
Signed-off-by: Andreas K. Hüttel <dilfridge@gentoo.org>
2025-01-28 18:25:13 +01:00
Florian Weimer 36fcdfbbc5 Revert "stdlib: Support malloc-managed environ arrays for compatibility"
This reverts commit b62759db04.

Reason for revert: Incompatible with “env -i” and coreutils (bug 32588).

Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
2025-01-24 12:25:29 +01:00
Florian Weimer b62759db04 stdlib: Support malloc-managed environ arrays for compatibility
Some applications set environ to a heap-allocated pointer, call
setenv (expecting it to call realloc), free environ, and then
restore the original environ pointer.  This breaks after
commit 7a61e7f557 ("stdlib: Make
getenv thread-safe in more cases") because after the setenv call,
the environ pointer does not point to the start of a heap allocation.
Instead, setenv creates a separate allocation and changes environ
to point into that.  This means that the free call in the application
results in heap corruption.

The interim approach was more compatible with other libcs because
it does not assume that the incoming environ pointer is allocated
as if by malloc (if it was written by the application).  However,
it seems to be more important to stay compatible with previous
glibc version: assume the incoming pointer is heap allocated,
and preserve this property after setenv calls.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2025-01-23 17:43:15 +01:00
Samuel Thibault a4c414796a include/string.h: Also redirect calls if not inlined in libpthread
htl's pt-alloc.c calls __mempcpy, which is #defined to
__builtin_mempcpy, but which does not happen to get inlined (the size is
dynamic), and then gcc emits a reference to mempcpy, thus violating
symbol exposition standard. We thus also have to redirect such
references to __mempcpy too.
2025-01-07 20:53:18 +01:00
H.J. Lu e9eea05986 Redirect mempcpy and stpcpy only in libc.a
The mempcpy and stpcpy redirections to __mempcpy and __stpcpy were added
by

commit 939da41143
Author: Joseph Myers <joseph@codesourcery.com>
Date:   Wed Nov 12 22:36:34 2014 +0000

    Fix stpcpy / mempcpy namespace (bug 17573).

to fix the namespace bug since __mempcpy and __stpcpy were defined as
macros in <bits/string2.h>.  These macros call __builtin_mempcpy and
__builtin_stpcpy which may end up calling the C functions mempcpy
and stpcpy.  In libc.so, libc_hidden_builtin_proto ensures that calls
to mempcpy and stpcpy are in turn mapped to call __GI_mempcpy and
__GI_stpcpy.  The redirections were applied outside of libc.so, including
libc.a, to map mempcpy and stpcpy to __mempcpy and __stpcpy.  Since

commit 18b10de7ce
Author: Wilco Dijkstra <wdijkstr@arm.com>
Date:   Mon Jun 12 15:19:38 2017 +0100

    2017-06-12  Wilco Dijkstra  <wdijkstr@arm.com>

    There is no longer a need for string2.h, so remove it and all mention of it.
    Move the redirect for __stpcpy to include/string.h since it is
still required
    until all internal uses have been renamed.
    This fixes several linknamespace/localplt failures when building with -Os.

removed the __mempcpy and __stpcpy macros from the public header file,
limit these redirections to libc.a to avoid Clang error:

In file included from tst-iconv-sticky-input-error.c:22:
In file included from ./gconv_int.h:24:
../include/string.h:182:44: error: attribute declaration must precede definition [-Werror,-Wignored-attributes]
  182 | extern __typeof (mempcpy) mempcpy __asm__ ("__mempcpy");
      |                                            ^
../string/bits/string_fortified.h:42:8: note: previous definition is here
   42 | __NTH (mempcpy (void *__restrict __dest, const void *__restrict __src,
      |        ^

when testing with Clang for fortify build.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Sam James <sam@gentoo.org>
2025-01-03 05:30:44 +08:00
Paul Eggert 2642002380 Update copyright dates with scripts/update-copyrights 2025-01-01 11:22:09 -08:00
Adhemerval Zanella a2b0ff98a0 include/sys/cdefs.h: Add __attribute_optimization_barrier__
Add __attribute_optimization_barrier__ to disable inlining and cloning on a
function.  For Clang, expand it to

__attribute__ ((optnone))

Otherwise, expand it to

__attribute__ ((noinline, clone))

Co-Authored-By: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Sam James <sam@gentoo.org>
2024-12-23 06:28:55 +08:00
H.J. Lu b587e7d45c Fix build without stack protector [BZ #32494]
Without stack protector, inhibit_stack_protector is undefined during build:

In file included from <command-line>:
./../include/libc-symbols.h:665:3: error: expected ';' before '__typeof'
  665 |   __typeof (type_name) *name##_ifunc (__VA_ARGS__)
         \
      |   ^~~~~~~~
./../include/libc-symbols.h:676:3: note: in expansion of macro
'__ifunc_resolver'
  676 |   __ifunc_resolver (type_name, name, expr, init, static, __VA_ARGS__)
      |   ^~~~~~~~~~~~~~~~
./../include/libc-symbols.h:703:3: note: in expansion of macro '__ifunc_args'
  703 |   __ifunc_args (type_name, name, expr, init, arg)
      |   ^~~~~~~~~~~~
./../include/libc-symbols.h:790:3: note: in expansion of macro '__ifunc'
  790 |   __ifunc (redirected_name, name, expr, void, INIT_ARCH)
      |   ^~~~~~~
../sysdeps/x86_64/multiarch/memchr.c:29:1: note: in expansion of macro
'libc_ifunc_redirected'
   29 | libc_ifunc_redirected (__redirect_memchr, memchr, IFUNC_SELECTOR ());
      | ^~~~~~~~~~~~~~~~~~~~~

1. Fix a typo in include/libc-symbols.h to define inhibit_stack_protector
for build.
2. Don't include <config.h> in include/libc-symbols.h since it has been
included in include/libc-misc.h.
3. Change #include "libc-misc.h" to #include <libc-misc.h> in
string/test-string.h.

This fixes BZ #32494.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Sam James <sam@gentoo.org>
2024-12-23 04:51:30 +08:00
Adhemerval Zanella b2556550a0 Add clang specific warning suppression macros
Four new macros are added:

  * DIAG_{PUSH,POP}_NEEDS_COMMENT_CLANG are similar to
    DIAG_{PUSH,POP}_NEEDS_COMMENT, but enable clang specific pragmas to
    handle warnings for options only supported by clang.

  * DIAG_IGNORE_NEEDS_COMMENT_{CLANG,GCC} are similar to
    DIAG_IGNORE_NEEDS_COMMENT, but enable the warning suppression only
    for the referenced compiler.

Reviewed-by: Sam James <sam@gentoo.org>
2024-12-22 13:29:20 +08:00
H.J. Lu 494eb254c3 Add include/libc-misc.h
Add include/libc-misc.h to provide miscellaneous definitions for both
glibc build and test:

1. Move inhibit_stack_protector to libc-misc.h and add Clang support.
2. Add test_inhibit_stack_protector for glibc testing.
3. Move inhibit_loop_to_libcall to libc-misc.h.
4. Add test_cc_inhibit_loop_to_libcall to handle TEST_CC != CC and
replace inhibit_loop_to_libcall with test_cc_inhibit_loop_to_libcall
in glibc tests.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Co-Authored-By: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Reviewed-by: Sam James <sam@gentoo.org>
2024-12-22 13:03:46 +08:00
H.J. Lu 034cd67528 Don't use glibc <tgmath.h> when testing with Clang
Clang has its own <tgmath.h> and doesn't use <tgmath.h> from glibc.  Pass
"-I." to compiler only if $($(<F)-no-include-dot) are undefined.  Define
it to yes for tgmath tests when testing with Clang.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Sam James <sam@gentoo.org>
2024-12-21 05:24:07 +08:00
H.J. Lu ed377c952a include/bits/sigstksz.h: Avoid #elif IS_IN (libsupport)
GCC 4.9 issues an error when generating misc/check-installed-headers-c.out:

In file included from ../signal/signal.h:328:0,
                 from ../include/signal.h:2,
                 from ../misc/sys/param.h:28,
                 from ../include/sys/param.h:1,
                 from /tmp/cih_test_e156ZB.c:10:
../include/bits/sigstksz.h:5:7: error: "IS_IN" is not defined [-Werror=undef]
 #elif IS_IN (libsupport)
       ^

Use "#else" instead.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Sam James <sam@gentoo.org>
2024-12-14 19:30:16 +08:00
H.J. Lu 6bc301672b math: Remove __XXX math functions from installed math.h [BZ #32418]
Since libm doesn't export __XXX math functions, don't declare them in
the installed math.h by adding <bits/mathcalls-macros.h> to declare
__XXX math functions internally for glibc build.  This fixes BZ #32418.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Sam James <sam@gentoo.org>
2024-12-12 16:17:54 +08:00
H.J. Lu 5df09b4448 math: Exclude internal math symbols for tests [BZ #32414]
Since internal tests don't have access to internal symbols in libm,
exclude them for internal tests.  Also make tst-strtod5 and tst-strtod5i
depend on $(libm) to support older versions of GCC which can't inline
copysign family functions.  This fixes BZ #32414.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Sunil K Pandey <skpgkp2@gmail.com>
2024-12-07 13:43:01 -08:00
Lenard Mollenkopf e442e8376d Add feature test macro _ISOC2Y_SOURCE
This patch starts preparation for C2Y support in glibc headers by
adding a feature test macro _ISOC2Y_SOURCE and corresponding
__GLIBC_USE (ISOC2Y). (I mostly copied the work of Joseph Myers
for C2X). As with other such macros, C2Y features are also
enabled by compiling for a standard newer than C23, or by using
_GNU_SOURCE.

This patch does not itself enable anything new in the headers for C2Y;
that is to be done in followup patches. (For example an implementation
of WG14 N3349.)

Once C2Y becomes an actual standard we'll presumably move to using the
actual year in the feature test macro and __GLIBC_USE, with some
period when both macro spellings are accepted, as was done with
_ISOC2X_SOURCE.

Tested for x86_64.

Signed-off-by: Lenard Mollenkopf <glibc@lenardmollenkopf.de>
2024-11-04 22:40:55 +00:00
Adhemerval Zanella d40ac01cbb stdlib: Make abort/_Exit AS-safe (BZ 26275)
The recursive lock used on abort does not synchronize with a new process
creation (either by fork-like interfaces or posix_spawn ones), nor it
is reinitialized after fork().

Also, the SIGABRT unblock before raise() shows another race condition,
where a fork or posix_spawn() call by another thread, just after the
recursive lock release and before the SIGABRT signal, might create
programs with a non-expected signal mask.  With the default option
(without POSIX_SPAWN_SETSIGDEF), the process can see SIG_DFL for
SIGABRT, where it should be SIG_IGN.

To fix the AS-safe, raise() does not change the process signal mask,
and an AS-safe lock is used if a SIGABRT is installed or the process
is blocked or ignored.  With the signal mask change removal,
there is no need to use a recursive loc.  The lock is also taken on
both _Fork() and posix_spawn(), to avoid the spawn process to see the
abort handler as SIG_DFL.

A read-write lock is used to avoid serialize _Fork and posix_spawn
execution.  Both sigaction (SIGABRT) and abort() requires to lock
as writer (since both change the disposition).

The fallback is also simplified: there is no need to use a loop of
ABORT_INSTRUCTION after _exit() (if the syscall does not terminate the
process, the system is broken).

The proposed fix changes how setjmp works on a SIGABRT handler, where
glibc does not save the signal mask.  So usage like the below will now
always abort.

  static volatile int chk_fail_ok;
  static jmp_buf chk_fail_buf;

  static void
  handler (int sig)
  {
    if (chk_fail_ok)
      {
        chk_fail_ok = 0;
        longjmp (chk_fail_buf, 1);
      }
    else
      _exit (127);
  }
  [...]
  signal (SIGABRT, handler);
  [....]
  chk_fail_ok = 1;
  if (! setjmp (chk_fail_buf))
    {
      // Something that can calls abort, like a failed fortify function.
      chk_fail_ok = 0;
      printf ("FAIL\n");
    }

Such cases will need to use sigsetjmp instead.

The _dl_start_profile calls sigaction through _profil, and to avoid
pulling abort() on loader the call is replaced with __libc_sigaction.

Checked on x86_64-linux-gnu and aarch64-linux-gnu.

Reviewed-by: DJ Delorie <dj@redhat.com>
2024-10-08 14:40:12 -03:00
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 eb0e50e9a1 Define __libc_initial for the static libc
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2024-08-09 16:17:14 +02:00
Florian Weimer 5097cd344f elf: Avoid re-initializing already allocated TLS in dlopen (bug 31717)
The old code used l_init_called as an indicator for whether TLS
initialization was complete.  However, it is possible that
TLS for an object is initialized, written to, and then dlopen
for this object is called again, and l_init_called is not true at
this point.  Previously, this resulted in TLS being initialized
twice, discarding any interim writes (technically introducing a
use-after-free bug even).

This commit introduces an explicit per-object flag, l_tls_in_slotinfo.
It indicates whether _dl_add_to_slotinfo has been called for this
object.  This flag is used to avoid double-initialization of TLS.
In update_tls_slotinfo, the first_static_tls micro-optimization
is removed because preserving the initalization flag for subsequent
use by the second loop for static TLS is a bit complicated, and
another per-object flag does not seem to be worth it.  Furthermore,
the l_init_called flag is dropped from the second loop (for static
TLS initialization) because l_need_tls_init on its own prevents
double-initialization.

The remaining l_init_called usage in resize_scopes and update_scopes
is just an optimization due to the use of scope_has_map, so it is
not changed in this commit.

The isupper check ensures that libc.so.6 is TLS is not reverted.
Such a revert happens if l_need_tls_init is not cleared in
_dl_allocate_tls_init for the main_thread case, now that
l_init_called is not checked anymore in update_tls_slotinfo
in elf/dl-open.c.

Reported-by: Jonathon Anderson <janderson@rice.edu>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2024-08-05 18:26:52 +02:00
Andreas K. Hüttel 89d3d815ef
Increase version number to 2.40
Signed-off-by: Andreas K. Hüttel <dilfridge@gentoo.org>
2024-07-21 18:23:25 +02:00
Adhemerval Zanella 686d542025 posix: Sync tempname with gnulib
The gnulib version contains an important change (9ce573cde), which
fixes some problems with multithreading, entropy loss, and ASLR leak
nfo.  It also fixes an issue where getrandom is not being used
on some new files generation (only for __GT_NOCREATE on first try).

The 044bf893ac removed __path_search, which is now moved to another
gnulib shared files (stdio-common/tmpdir.{c,h}).  Tthis patch
also fixes direxists to use __stat64_time64 instead of __xstat64,
and move the include of pathmax.h for !_LIBC (since it is not used
by glibc).  The license is also changed from GPL 3.0 to 2.1, with
permission from the authors (Bruno Haible and Paul Eggert).

The sync also removed the clock fallback, since clock_gettime
with CLOCK_REALTIME is expected to always succeed.

It syncs with gnulib commit 323834962817af7b115187e8c9a833437f8d20ec.

Checked on x86_64-linux-gnu.

Co-authored-by: Bruno Haible <bruno@clisp.org>
Co-authored-by: Paul Eggert <eggert@cs.ucla.edu>
Reviewed-by: Bruno Haible <bruno@clisp.org>
2024-04-10 14:53:39 -03:00
Evan Green a29bb320a1
riscv: Enable multi-arg ifunc resolvers
RISC-V is apparently the first architecture to pass more than one
argument to ifunc resolvers. The helper macros in libc-symbols.h,
__ifunc_resolver(), __ifunc(), and __ifunc_hidden(), are incompatible
with this. These macros have an "arg" (non-final) parameter that
represents the parameter signature of the ifunc resolver. The result is
an inability to pass the required comma through in a single preprocessor
argument.

Rearrange the __ifunc_resolver() macro to be variadic, and pass the
types as those variable parameters. Move the guts of __ifunc() and
__ifunc_hidden() into new macros, __ifunc_args(), and
__ifunc_args_hidden(), that pass the variable arguments down through to
__ifunc_resolver(). Then redefine __ifunc() and __ifunc_hidden(), which
are used in a bunch of places, to simply shuffle the arguments down into
__ifunc_args[_hidden]. Finally, define a riscv-ifunc.h header, which
provides convenience macros to those looking to write ifunc selectors
that use both arguments.

Signed-off-by: Evan Green <evan@rivosinc.com>
Reviewed-by: Florian Weimer <fweimer@redhat.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-03-01 07:14:59 -08:00
Adhemerval Zanella f4c142bb9f arm: Use _dl_find_object on __gnu_Unwind_Find_exidx (BZ 31405)
Instead of __dl_iterate_phdr. On ARM dlfo_eh_frame/dlfo_eh_count
maps to PT_ARM_EXIDX vaddr start / length.

On a Neoverse N1 machine with 160 cores, the following program:

  $ cat test.c
  #include <stdlib.h>
  #include <pthread.h>
  #include <assert.h>

  enum {
    niter = 1024,
    ntimes = 128,
  };

  static void *
  tf (void *arg)
  {
    int a = (int) arg;

    for (int i = 0; i < niter; i++)
      {
        void *p[ntimes];
        for (int j = 0; j < ntimes; j++)
  	p[j] = malloc (a * 128);
        for (int j = 0; j < ntimes; j++)
  	free (p[j]);
      }

    return NULL;
  }

  int main (int argc, char *argv[])
  {
    enum { nthreads = 16 };
    pthread_t t[nthreads];

    for (int i = 0; i < nthreads; i ++)
      assert (pthread_create (&t[i], NULL, tf, (void *) i) == 0);

    for (int i = 0; i < nthreads; i++)
      {
        void *r;
        assert (pthread_join (t[i], &r) == 0);
        assert (r == NULL);
      }

    return 0;
  }
  $ arm-linux-gnueabihf-gcc -fsanitize=address test.c -o test

Improves from ~15s to 0.5s.

Checked on arm-linux-gnueabihf.
2024-02-23 08:50:00 -03:00
Stefan Liebler fa3eb7d5e7 string: Add hidden builtin definition for __strcpy_chk.
Otherwise on at least x86_64 and s390x there is an unwanted PLT entry
in libc.so when configured with --enable-fortify-source=3 and build
with -Os.

This is observed in elf/check-localplt
Extra PLT reference: libc.so: __strcpy_chk

The call to PLT entry is in inet/ruserpass.c.
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2024-02-06 09:17:04 +01:00
Joseph Myers 42cc619dfb Refer to C23 in place of C2X in glibc
WG14 decided to use the name C23 as the informal name of the next
revision of the C standard (notwithstanding the publication date in
2024).  Update references to C2X in glibc to use the C23 name.

This is intended to update everything *except* where it involves
renaming files (the changes involving renaming tests are intended to
be done separately).  In the case of the _ISOC2X_SOURCE feature test
macro - the only user-visible interface involved - support for that
macro is kept for backwards compatibility, while adding
_ISOC23_SOURCE.

Tested for x86_64.
2024-02-01 11:02:01 +00:00
Andreas K. Hüttel 3e941ef87e
version.h, include/features.h: Bump version to 2.39
Signed-off-by: Andreas K. Hüttel <dilfridge@gentoo.org>
2024-01-31 01:29:11 +01:00
Joseph Myers b34b46b880 Implement C23 <stdbit.h>
C23 adds a header <stdbit.h> with various functions and type-generic
macros for bit-manipulation of unsigned integers (plus macro defines
related to endianness).  Implement this header for glibc.

The functions have both inline definitions in the header (referenced
by macros defined in the header) and copies with external linkage in
the library (which are implemented in terms of those macros to avoid
duplication).  They are documented in the glibc manual.  Tests, as
well as verifying results for various inputs (of both the macros and
the out-of-line functions), verify the types of those results (which
showed up a bug in an earlier version with the type-generic macro
stdc_has_single_bit wrongly returning a promoted type), that the
macros can be used at top level in a source file (so don't use ({})),
that they evaluate their arguments exactly once, and that the macros
for the type-specific functions have the expected implicit conversions
to the relevant argument type.

Jakub previously referred to -Wconversion warnings in type-generic
macros, so I've included a test with -Wconversion (but the only
warnings I saw and fixed from that test were actually in inline
functions in the <stdbit.h> header - not anything coming from use of
the type-generic macros themselves).

This implementation of the type-generic macros does not handle
unsigned __int128, or unsigned _BitInt types with a width other than
that of a standard integer type (and C23 doesn't require the header to
handle such types either).  Support for those types, using the new
type-generic built-in functions Jakub's added for GCC 14, can
reasonably be added in a followup (along of course with associated
tests).

This implementation doesn't do anything special to handle C++, or have
any tests of functionality in C++ beyond the existing tests that all
headers can be compiled in C++ code; it's not clear exactly what form
this header should take in C++, but probably not one using macros.

DIS ballot comment AT-107 asks for the word "count" to be added to the
names of the stdc_leading_zeros, stdc_leading_ones,
stdc_trailing_zeros and stdc_trailing_ones functions and macros.  I
don't think it's likely to be accepted (accepting any technical
comments would mean having an FDIS ballot), but if it is accepted at
the WG14 meeting (22-26 January in Strasbourg, starting with DIS
ballot comment handling) then there would still be time to update
glibc for the renaming before the 2.39 release.

The new functions and header are placed in the stdlib/ directory in
glibc, rather than creating a new toplevel stdbit/ or putting them in
string/ alongside ffs.

Tested for x86_64 and x86.
2024-01-03 12:07:14 +00:00
Paul Eggert dff8da6b3e Update copyright dates with scripts/update-copyrights 2024-01-01 10:53:40 -08:00
Joe Ramsay cc0d77ba94 aarch64: Add half-width versions of AdvSIMD f32 libmvec routines
Compilers may emit calls to 'half-width' routines (two-lane
single-precision variants). These have been added in the form of
wrappers around the full-width versions, where the low half of the
vector is simply duplicated. This will perform poorly when one lane
triggers the special-case handler, as there will be a redundant call
to the scalar version, however this is expected to be rare at Ofast.

Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
2023-12-20 08:41:25 +00:00
Adhemerval Zanella 472894d2cf malloc: Use __get_nprocs on arena_get2 (BZ 30945)
This restore the 2.33 semantic for arena_get2.  It was changed by
11a02b035b to avoid arena_get2 call malloc (back when __get_nproc
was refactored to use an scratch_buffer - 903bc7dcc2).  The
__get_nproc was refactored over then and now it also avoid to call
malloc.

The 11a02b035b did not take in consideration any performance
implication, which should have been discussed properly.  The
__get_nprocs_sched is still used as a fallback mechanism if procfs
and sysfs is not acessible.

Checked on x86_64-linux-gnu.
Reviewed-by: DJ Delorie <dj@redhat.com>
2023-11-22 09:39:29 -03:00
Adhemerval Zanella 55f41ef8de elf: Remove LD_PROFILE for static binaries
The _dl_non_dynamic_init does not parse LD_PROFILE, which does not
enable profile for dlopen objects.  Since dlopen is deprecated for
static objects, it is better to remove the support.

It also allows to trim down libc.a of profile support.

Checked on x86_64-linux-gnu.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2023-11-21 16:15:42 -03:00
Adhemerval Zanella 78ed8bdf4f linux: Add PR_SET_VMA_ANON_NAME support
Linux 5.17 added support to naming anonymous virtual memory areas
through the prctl syscall.  The __set_vma_name is a wrapper to avoid
optimizing the prctl call if the kernel does not support it.

If the kernel does not support PR_SET_VMA_ANON_NAME, prctl returns
EINVAL. And it also returns the same error for an invalid argument.
Since it is an internal-only API, it assumes well-formatted input:
aligned START, with (START, START+LEN) being a valid memory range,
and NAME with a limit of 80 characters without an invalid one
("\\`$[]").
Reviewed-by: DJ Delorie <dj@redhat.com>
2023-11-07 10:27:20 -03:00
Adhemerval Zanella 03bf8357e8 stdlib: Remove use of mergesort on qsort (BZ 21719)
This patch removes the mergesort optimization on qsort implementation
and uses the introsort instead.  The mergesort implementation has some
issues:

  - It is as-safe only for certain types sizes (if total size is less
    than 1 KB with large element sizes also forcing memory allocation)
    which contradicts the function documentation.  Although not required
    by the C standard, it is preferable and doable to have an O(1) space
    implementation.

  - The malloc for certain element size and element number adds
    arbitrary latency (might even be worse if malloc is interposed).

  - To avoid trigger swap from memory allocation the implementation
    relies on system information that might be virtualized (for instance
    VMs with overcommit memory) which might lead to potentially use of
    swap even if system advertise more memory than actually has.  The
    check also have the downside of issuing syscalls where none is
    expected (although only once per execution).

  - The mergesort is suboptimal on an already sorted array (BZ#21719).

The introsort implementation is already optimized to use constant extra
space (due to the limit of total number of elements from maximum VM
size) and thus can be used to avoid the malloc usage issues.

Resulting performance is slower due the usage of qsort, specially in the
worst-case scenario (partialy or sorted arrays) and due the fact
mergesort uses a slight improved swap operations.

This change also renders the BZ#21719 fix unrequired (since it is meant
to fix the sorted input performance degradation for mergesort).  The
manual is also updated to indicate the function is now async-cancel
safe.

Checked on x86_64-linux-gnu.
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
2023-10-31 14:18:05 -03:00
Adhemerval Zanella e6e3c66688 crypt: Remove libcrypt support
All the crypt related functions, cryptographic algorithms, and
make requirements are removed,  with only the exception of md5
implementation which is moved to locale folder since it is
required by localedef for integrity protection (libc's
locale-reading code does not check these, but localedef does
generate them).

Besides thec code itself, both internal documentation and the
manual is also adjusted.  This allows to remove both --enable-crypt
and --enable-nss-crypt configure options.

Checked with a build for all affected ABIs.

Co-authored-by: Zack Weinberg <zack@owlfolio.org>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2023-10-30 13:03:59 -03:00
Arjun Shankar 3f7c7ac887 Move 'netgroup' routines from 'inet' into 'nss'
These netgroup routines are entry points for nss functionality.
This commit moves them along with netgroup.h from the 'inet'
subdirectory to 'nss', and adjusts any references accordingly.
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2023-10-24 12:30:59 +02:00
Arjun Shankar 4298586619 Move 'aliases' routines from 'inet' into 'nss'
The aliases routines are entry points for nss functionality.  This
commit moves aliases.h and the aliases routines from the 'inet'
subdirectory to 'nss', and adjusts any external references.
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2023-10-24 12:30:59 +02:00