Commit Graph

1699 Commits

Author SHA1 Message Date
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
Arjun Shankar
c6b577caef Remove 'shadow' and merge into 'nss'
The majority of shadow routines are entry points for nss functionality.
This commit removes the 'shadow' subdirectory and moves all
functionality and tests to 'nss'.  References to shadow/ are accordingly
changed.
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2023-10-24 12:30:59 +02:00
Arjun Shankar
0ac35d181e Remove 'pwd' and merge into 'nss'
The majority of pwd routines are entry points for nss functionality.
This commit removes the 'pwd' subdirectory and moves all functionality
and tests to 'nss'.  References to pwd/ are accordingly changed.
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2023-10-24 12:30:59 +02:00
Arjun Shankar
98b107e308 Remove 'gshadow' and merge into 'nss'
The majority of gshadow routines are entry points for nss functionality.
This commit removes the 'gshadow' subdirectory and moves all
functionality and tests to 'nss'.  References to gshadow/ are
accordingly changed.
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2023-10-24 12:30:59 +02:00
Arjun Shankar
b121fdc552 Remove 'grp' and merge into 'nss' and 'posix'
The majority of grp routines are entry points for nss functionality.
This commit removes the 'grp' subdirectory and moves all nss-relevant
functionality and all tests to 'nss', and the 'setgroups' stub into
'posix' (alongside the 'getgroups' stub).  References to grp/ are
accordingly changed.  In addition, compat-initgroups.c, a fallback
implementation of initgroups is renamed to initgroups-fallback.c so that
the build system does not confuse it for nss_compat/compat-initgroups.c.

Build time improves very slightly; e.g. down from an average of 45.5s to
44.5s on an 8-thread mobile x86_64 CPU.
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2023-10-24 12:30:59 +02:00
Florian Weimer
dd32e1db38 Revert "elf: Always call destructors in reverse constructor order (bug 30785)"
This reverts commit 6985865bc3.

Reason for revert:

The commit changes the order of ELF destructor calls too much relative
to what applications expect or can handle.  In particular, during
process exit and _dl_fini, after the revert commit, we no longer call
the destructors of the main program first; that only happens after
some dlopen'ed objects have been destructed.  This robs applications
of an opportunity to influence destructor order by calling dlclose
explicitly from the main program's ELF destructors.  A couple of
different approaches involving reverse constructor order were tried,
and none of them worked really well.  It seems we need to keep the
dependency sorting in _dl_fini.

There is also an ambiguity regarding nested dlopen calls from ELF
constructors: Should those destructors run before or after the object
that called dlopen?  Commit 6985865bc3 used reverse order
of the start of ELF constructor calls for destructors, but arguably
using completion of constructors is more correct.  However, that alone
is not sufficient to address application compatibility issues (it
does not change _dl_fini ordering at all).
2023-10-18 11:30:38 +02:00
Joe Simmons-Talbott
5f798d38e9 stdio: Remove __libc_message alloca usage
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>
2023-09-11 16:16:49 +00:00
Florian Weimer
53df2ce688 elf: Remove unused l_text_end field from struct link_map
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>
2023-09-08 18:39:20 +02:00
Florian Weimer
6985865bc3 elf: Always call destructors in reverse constructor order (bug 30785)
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>
2023-09-08 12:34:27 +02:00
Adhemerval Zanella Netto
0d6f9f6265 posix: Add pidfd_spawn and pidfd_spawnp (BZ 30349)
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>
2023-09-05 13:08:59 -03:00
Samuel Thibault
6333a6014f __call_tls_dtors: Use call_function_static_weak 2023-09-04 20:03:37 +02:00
Florian Weimer
039ff51ac7 nscd: Do not rebuild getaddrinfo (bug 30709)
The nscd daemon caches hosts data from NSS modules verbatim, without
filtering protocol families or sorting them (otherwise separate caches
would be needed for certain ai_flags combinations).  The cache
implementation is complete separate from the getaddrinfo code.  This
means that rebuilding getaddrinfo is not needed.  The only function
actually used is __bump_nl_timestamp from check_pf.c, and this change
moves it into nscd/connections.c.

Tested on x86_64-linux-gnu with -fexceptions, built with
build-many-glibcs.py.  I also backported this patch into a distribution
that still supports nscd and verified manually that caching still works.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2023-08-11 10:10:16 +02:00
Samuel Thibault
04bf7d2d8a chk: Add and fix hidden builtin definitions for *_chk
Otherwise on gnu-i686 there are unwanted PLT entries in libc.so when
fortification is enabled.

Tested for i686-gnu, x86_64-gnu, i686-linux-gnu and x86_64-linux-gnu
2023-08-03 22:46:48 +02:00
Andreas K. Hüttel
e5da48e5ec
Increase version numbers
Signed-off-by: Andreas K. Hüttel <dilfridge@gentoo.org>
2023-07-30 21:35:28 +02:00
Frédéric Bérat
ba745eff46 misc/bits/syslog.h: Clearly separate declaration from definition
This allows to include bits/syslog-decl.h in include/sys/syslog.h and
therefore be able to create the libc_hidden_builtin_proto (__syslog_chk)
prototype.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2023-07-05 16:59:48 +02:00
Frédéric Bérat
d9a99272d2 misc/bits/select2.h: Clearly separate declaration from definitions
The __fdelt_chk declaration needs to be available so that
libc_hidden_proto can be used while not redefining __FD_ELT.
Thus, misc/bits/select-decl.h is created to hold the corresponding
prototypes.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2023-07-05 16:59:48 +02:00
Frédéric Bérat
b17d65ff92 unistd: Avoid PLT entries with _FORTIFY_SOURCE
The change is meant to avoid unwanted PLT entries for the read_chk,
getdomainname_chk and getlogin_r_chk routines when _FORTIFY_SOURCE is set.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2023-07-05 16:59:48 +02:00
Frédéric Bérat
391f5e9619 posix/bits/unistd.h: Clearly separate declaration from definitions
This change is similar to what was done for bits/wchar2.h.
Routines declaration are moved into a dedicated bits/unistd-decl.h file
which is then included into the bits/unistd.h file.

This will allow to adapt the files so that PLT entries are not created when
_FORTIFY_SOURCE is enabled.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2023-07-05 16:59:48 +02:00
Frédéric Bérat
64f9857507 wchar: Avoid PLT entries with _FORTIFY_SOURCE
The change is meant to avoid unwanted PLT entries for the wmemset and
wcrtomb routines when _FORTIFY_SOURCE is set.

On top of that, ensure that *_chk routines have their hidden builtin
definitions available.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2023-07-05 16:59:48 +02:00
Frédéric Bérat
eea000f6e6 misc/sys/cdefs.h: Create FORTIFY redirects for internal calls
The __REDIRECT* macros are creating aliases which may lead to unwanted
PLT entries when fortification is enabled.
To prevent these entries, the REDIRECT alias should be set to point to the
existing __GI_* aliases.
This is done transparently by creating a __REDIRECT_FORTIFY* version of
these macros, that can be overwritten internally when necessary.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2023-07-05 16:59:48 +02:00
Frédéric Bérat
505c884aeb stdio: Ensure *_chk routines have their hidden builtin definition available
If libc_hidden_builtin_{def,proto} isn't properly set for *_chk routines,
there are unwanted PLT entries in libc.so.

There is a special case with __asprintf_chk:
If ldbl_* macros are used for asprintf, ABI gets broken on s390x,
if it isn't, ppc64le isn't building due to multiple asm redirections.

This is due to the inclusion of bits/stdio-lbdl.h for ppc64le whereas it
isn't for s390x. This header creates redirections, which are not
compatible with the ones generated using libc_hidden_def.
Yet, we can't use libc_hidden_ldbl_proto on s390x since it will not
create a simple strong alias (e.g. as done on x86_64), but a versioned
alias, leading to ABI breakage.

This results in errors on s390x:
/usr/bin/ld: glibc/iconv/../libio/bits/stdio2.h:137: undefined reference
to `__asprintf_chk'

Original __asprintf_chk symbols:
00000000001395b0 T __asprintf_chk
0000000000177e90 T __nldbl___asprintf_chk

__asprintf_chk symbols with ldbl_* macros:
000000000012d590 t ___asprintf_chk
000000000012d590 t __asprintf_chk@@GLIBC_2.4
000000000012d590 t __GI___asprintf_chk
000000000012d590 t __GL____asprintf_chk___asprintf_chk
0000000000172240 T __nldbl___asprintf_chk

__asprintf_chk symbols with the patch:
000000000012d590 t ___asprintf_chk
000000000012d590 T __asprintf_chk
000000000012d590 t __GI___asprintf_chk
0000000000172240 T __nldbl___asprintf_chk

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2023-07-05 16:59:48 +02:00
Frédéric Bérat
dd8486ffc1 string: Ensure *_chk routines have their hidden builtin definition available
If libc_hidden_builtin_{def,proto} isn't properly set for *_chk routines,
there are unwanted PLT entries in libc.so.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2023-07-05 16:59:48 +02:00
Frederic Berat
04d85febb9 wcsmbs/bits/wchar2{, -decl}.h: Clearly separate declaration from definitions
This will enable __REDIRECT_FORTIFY* macros to be used when _FORTIFY_SOURCE
is set.

Routine declarations that were in bits/wchar2.h are moved into the
bits/wchar2-decl.h file.
The file is now included into include/wchar.h irrespectively from
fortification.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2023-06-22 00:21:01 -04:00
Florian Weimer
b54e5d1c92 Add the wcslcpy, wcslcat functions
These functions are about to be added to POSIX, under Austin Group
issue 986.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2023-06-14 18:10:24 +02:00
Florian Weimer
454a20c875 Implement strlcpy and strlcat [BZ #178]
These functions are about to be added to POSIX, under Austin Group
issue 986.

The fortified strlcat implementation does not raise SIGABRT if the
destination buffer does not contain a null terminator, it just
inherits the non-failing regular strlcat behavior.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2023-06-14 18:10:08 +02:00
Frédéric Bérat
200ae471b6 Move {read,write}_all functions to a dedicated header
Since these functions are used in both catgets/gencat.c and
malloc/memusage{,stat}.c, it make sense to move them into a dedicated
header where they can be inlined.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2023-06-06 08:23:53 -04:00
Paul Pluzhnikov
2cbeda847b Fix a few more typos I missed in previous round -- BZ 25337 2023-06-02 23:46:32 +00:00
Paul Pluzhnikov
7f0d9e61f4 Fix all the remaining misspellings -- BZ 25337 2023-06-02 01:39:48 +00:00
Alejandro Colomar
5013f6fc6c Use __nonnull for the epoll_wait(2) family of syscalls
Signed-off-by: Alejandro Colomar <alx@kernel.org>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2023-06-01 14:50:42 -03:00