835 Commits

Author SHA1 Message Date
Paul Eggert
66f3e9219d Update copyright dates with scripts/update-copyrights 2026-01-01 13:42:29 -08:00
Paul Eggert
a9bf6a2a90 Pass glibc pre-commit checks
This is needed for the next patch which updates copyright dates.
* elf/sprof.c:
* sysdeps/unix/sysv/linux/tst-pidfd_getinfo.c:
Remove trailing white space.
* misc/tst-atomic.c: Remove trailing empty line.
2026-01-01 13:42:03 -08:00
Adhemerval Zanella
2b00b3a890 misc: Enable tst-atomic for clang
The atomic.h macros now uses compiler builtins.

Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
2025-12-22 15:55:30 -03:00
Wilco Dijkstra
9da0585852 atomic: Reinstate HAVE_64B_ATOMICS configure check
Reinstate HAVE_64B_ATOMICS configure check that was reverted by commit
7fec8a5de6 due to BZ #33632.  This was
fixed by 3dd2cbfa35 by only allowing
64-bit atomics on sem_t if its type is 8-byte aligned.  Rebase and add
in cleanups in include/atomic.h that were omitted.

Fix an issue with sparcv8-linux-gnu-leon3 forcing -mcpu=v8 for rtld.c which
overrules -mcpu=leon3 and causes __atomic_always_lock_free (4, 0) to
incorrectly return 0 and trigger asserts in atomics.  Remove this as it
seems to be a workaround for an issue in 1997.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2025-12-17 22:57:00 +00:00
Adhemerval Zanella
6b7067460f Handle clang -Wignored-attributes on weak aliases
Clang issues a warning for double alias redirection, indicating that thei
original symbol is used even if a weak definition attempts to override it.

For instance, in the construction:

  int __internal_impl (...) {}
  weak_alias (__internal_impl, external_impl);
  #if SOMETHING
  weak_alias (external_impl, another_external_impl)
  #endif

Clang warns that another_external_impl always resolves to __internal_impl,
even if external_impl is a weak reference. Using the internal symbol for
both aliases resolves this warning.

This issue also occurs with certain libc_hidden_def usage:

  int __internal_impl (...) {}
  weak_alias (__internal_impl, __internal_alias)
  libc_hidden_weak (__internal_alias)

In this case, using a strong_alias is sufficient to avoid the warning
(since the alias is internal, there is no need to use a weak alias).

However, for the constructions like:

  int __internal_impl (...) {}
  weak_alias (__internal_impl, __internal_alias)
  libc_hidden_def (__internal_alias)
  weak_alias (__internal_impl, external_alias)
  libc_hidden_def (external_alias)

Clang warns that the internal external_alias will always resolve to
__GI___internal_impl, even if a weak definition of __GI_internal_impl is
overridden.  For this case, a new macro named static_weak_alias is used
to create a strong alias for SHARED, or a weak_alias otherwise.

With these changes, there is no need to check and enable the
-Wno-ignored-attributes suppression when using clang.

Checked with a build on affected ABIs, and a full check on aarch64,
armhf, i686, and x86_64.

Reviewed-by: Sam James <sam@gentoo.org>
2025-12-09 08:58:10 -03:00
Adhemerval Zanella
8d26bed1eb Enable --enable-fortify-source with clang
clang generates internal calls for some _chk symbol, so add internal
aliases for them, and stub some with rtld-stubbed-symbols to avoid
ld.so linker issues.

Reviewed-by: Sam James <sam@gentoo.org>
2025-11-21 13:13:11 -03:00
Joseph Myers
cd748a63ab Implement C23 const-preserving standard library macros
C23 makes various standard library functions, that return a pointer
into an input array, into macros that return a pointer to const when
the relevant argument passed to the macro is a pointer to const.  (The
requirement is for macros, with the existing function types applying
when macro expansion is suppressed.  When a null pointer constant is
passed, such as integer 0, that's the same as a pointer to non-const.)

Implement this feature.  This only applies to C, not C++, since such
macros are not an appropriate way of doing this for C++ and all the
affected functions other than bsearch have overloads to implement an
equivalent feature for C++ anyway.  Nothing is done to apply such a
change to any non-C23 functions with the same property of returning a
pointer into an input array.

The feature is also disabled when _LIBC is defined, since there are
various places in glibc that either redefine these identifiers as
macros, or define the functions themselves, and would need changing to
work in the presence of these macro definitions.  A natural question
is whether we should in fact change those places and not disable the
macro definitions for _LIBC.  If so, we'd need a solution for the
places in glibc that define the macro *before* including the relevant
header (in order in effect to disable the header declaration of the
function by renaming that declaration).

One testcase has #undef added to avoid conflicting with this feature
and another has const added; -Wno-discarded-qualifiers is added for
building zic (but could be removed once there's a new upstream tzcode
release that's const-safe with this C23 change and glibc has updated
to code from that new release).  Probably other places in glibc proper
would need const added if we remove the _LIBC conditionals.

Another question would be whether some GCC extension should be added
to support this feature better with macros that only expand each
argument once (as well as reducing duplication of diagnostics for bad
usages such as non-pointer and pointer-to-volatile-qualfied
arguments).

Tested for x86_64.
2025-11-20 19:31:04 +00:00
Adhemerval Zanella
7fec8a5de6 Revert __HAVE_64B_ATOMICS configure check
The 53807741fb added a configure check
for 64-bit atomic operations that were not previously enabled on some
32-bit ABIs.

However, the NPTL semaphore code casts a sem_t to a new_sem and issues
a 64-bit atomic operation for __HAVE_64B_ATOMICS.  Since sem_t has
32-bit alignment on 32-bit architectures, this prevents the use of
64-bit atomics even if the ABI supports them.

Assume 64-bit atomic support from __WORDSIZE, which maps to how glibc
defines it before the broken change.  Also rename __HAVE_64B_ATOMICS
to USE_64B_ATOMICS to define better the flag meaning.

Checked on x86_64-linux-gnu and i686-linux-gnu.

Reviewed-by: Wilco Dijkstra  <Wilco.Dijkstra@arm.com>
2025-11-14 14:05:20 -03:00
Bruno Haible
e06a1962e6 cdefs: Fix some typos in comments.
Reviewed-by: Collin Funk <collin.funk1@gmail.com>
2025-11-11 11:04:29 -08:00
Yury Khrustalev
58a31b4316 posix: Fix invalid flags test for p{write,read}v2
Two tests fail from time to time when a new flag is added for the
p{write,read}v2 functions in a new Linux kernel:

 - misc/tst-preadvwritev2
 - misc/tst-preadvwritev64v2

This disrupts when testing Glibc on a system with a newer kernel
and it seems we can try improve testing for invalid flags setting
all the bits that are not supposed to be supported (rather than
setting only the next unsupported bit).

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2025-11-07 08:57:09 +00:00
Eric Wong
3ac0112b5d cdefs: allow __attribute__ on tcc
According to the tcc (tiny C compiler) Changelog, tcc supports
__attribute__ since 0.9.3.  Looking at history of tcc at
<https://repo.or.cz/tinycc.git>, __attribute__ support was added
in commit 14658993425878be300aae2e879560698e0c6c4c on 2002-01-03,
which also looks like the release of 0.9.3.  While I'm unable to
find release tags for tcc before 0.9.18 (2003-04-14), the next
release (0.9.28) will include __attribute__((cleanup(func)) which
I rely on.

Reviewed-by: Collin Funk <collin.funk1@gmail.com>
2025-10-30 20:03:00 -07:00
Collin Funk
3fe3f62833 Cleanup some recently added whitespace.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
2025-10-30 18:56:58 -07:00
Adhemerval Zanella
970364dac0 Annotate swtich fall-through
The clang default to warning for missing fall-through and it does
not support all comment-like annotation that gcc does.  Use C23
[[fallthrough]] annotation instead.
proper attribute instead.

Reviewed-by: Collin Funk <collin.funk1@gmail.com>
2025-10-29 12:54:01 -03:00
Adhemerval Zanella
6e862a07f7 misc: Fix clang -Wstring-plus-int warnings on syslog
clang issues:

syslog.c:193:9: error: adding 'int' to a string does not append to the string [-Werror,-Wstring-plus-int]
  193 |                       SYSLOG_HEADER (pri, timestamp, &msgoff, pid));
      |                       ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
syslog.c:180:7: note: expanded from macro 'SYSLOG_HEADER'
  180 |   "[" + (pid == 0), pid, "]" + (pid == 0)

Use array indexes instead of string addition (it is simpler than
add a supress warning).
2025-10-22 16:35:39 -03:00
Wilco Dijkstra
210ee29503 atomics: Remove unused atomics
Remove all unused atomics.  Replace uses of catomic_increment and
catomic_decrement with atomic_fetch_add_relaxed which maps to a standard
compiler builtin. Relaxed memory ordering is correct for simple counters
since they only need atomicity.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2025-09-10 09:18:06 +00:00
Xi Ruoyao
3b39822a82 misc: Add support for Linux uio.h RWF_DONTCACHE flag
Linux 6.14 adds the new flag for uncached buffered IO on a filesystem
supporting it.

This caused two test failures as these tests expected the flag
0x00000080 is unused.  Add the flag definition to fix these tests on
Linux >= 6.14:

    FAIL: misc/tst-preadvwritev2
    FAIL: misc/tst-preadvwritev64v2

The test failures were not detected in routine test suite runs because
normally we create the test file in /tmp, where a tmpfs is usually
mounted, and tmpfs does not support this flag.  But it can be reproduced
with TMPDIR set to some directory in an ext4 file system.

Link: https://git.kernel.org/torvalds/c/af6505e5745b
Signed-off-by: Xi Ruoyao <xry111@xry111.site>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2025-09-08 08:22:20 -03:00
Maciej W. Rozycki
5d45da09e6 testsuite: Update tests for 'xfclose' use
Convert (some) tests to use 'xfclose' rather than using plain 'fclose'
call with no error checking or plain missing such a call.

Reviewed-by: Florian Weimer <fweimer@redhat.com>
2025-09-05 11:53:31 +01:00
Maciej W. Rozycki
2d47b01de0 testsuite: Update tests for 'xfmemopen' use
Convert tests to use 'xfmemopen' rather than open-coding error checks
with 'fmemopen' or plain missing them, where 'fmemopen' itself is not
the scope of testing.  Leave 'fmemopen' tests alone.

Reviewed-by: Florian Weimer <fweimer@redhat.com>
2025-09-05 11:53:31 +01:00
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
Sam James
e9be7701e6 mlock, mlock2, munlock: Use __attr_access_none macro
This fixes build failures using GCC 7.5.0 against glibc headers,
see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118194#c5.

Followup to 013106ae67.

Reported-by: vvinayag@arm.com
2025-01-02 17:58:06 +00:00
Paul Eggert
2642002380 Update copyright dates with scripts/update-copyrights 2025-01-01 11:22:09 -08:00
Xi Ruoyao
013106ae67 mlock, mlock2, munlock: Tell the compiler we don't dereference the pointer
Since https://gcc.gnu.org/r11-959, the compiler emits
-Wmaybe-uninitialized if a const pointer to an uninitialized buffer is
passed.  Tell the compiler we don't dereference the pointer to remove
the false alarm.

Link: https://gcc.gnu.org/PR118194
Signed-off-by: Xi Ruoyao <xry111@xry111.site>
Reviewed-by: Sam James <sam@gentoo.org>
2025-01-01 16:08:36 +01:00
H.J. Lu
0813cb5847 Suppress Clang -Wimplicit-fallthrough warnings
Since Clang doesn't properly handle

/* FALLTHROUGH */

in elf/tst-align2.c nor

/* fall through */

in misc/tst-tsearch.c

tst-align2.c💯9: error: unannotated fall-through between switch labels [-Werror,-Wimplicit-fallthrough]
  100 |         case 'A':
      |         ^
tst-align2.c💯9: note: insert '__attribute__((fallthrough));' to silence this warning
  100 |         case 'A':
      |         ^
      |         __attribute__((fallthrough));
tst-align2.c💯9: note: insert 'break;' to avoid fall-through
  100 |         case 'A':
      |         ^
      |         break;

suppress them when compiled with Clang.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Sam James <sam@gentoo.org>
2024-12-23 06:28:55 +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
e5a5229868 tst-atomic.c: Mark as UNSUPPORTED when compiled with Clang
Since Clang can't remove the dead statement and issues an error:

tst-atomic.c:463:7: error: unsupported inline asm: input with type 'int64_t' (aka 'long') matching output with type 'typeof (*&mem)' (aka 'int')
  463 |   if (catomic_exchange_and_add (&mem, 11) != 2
      |       ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../sysdeps/x86/atomic-machine.h:213:3: note: expanded from macro 'catomic_exchange_and_add'
  213 |   __arch_exchange_and_add_body (__arch_exchange_and_add_cprefix, __arch_c,    \
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  214 |                                 mem, value)
      |                                 ~~~~~~~~~~~
../sysdeps/x86/atomic-machine.h:199:12: note: expanded from macro '__arch_exchange_and_add_body'
  198 |                          : "=r" (__result), "=m" (*mem)                       \
      |                                  ~~~~~~~~
  199 |                          : "0" ((int64_t) cast_to_integer (__addval)),     \
      |                                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
tst-atomic.c:487:7: error: unsupported inline asm: input with type 'int64_t' (aka 'long') matching output with type 'typeof (*(&mem))' (aka 'int')
  487 |   if (catomic_increment_val (&mem) != 3)
      |       ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
../include/atomic.h:313:38: note: expanded from macro 'catomic_increment_val'
  313 | # define catomic_increment_val(mem) (catomic_exchange_and_add ((mem), 1) + 1)
      |                                      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../sysdeps/x86/atomic-machine.h:213:3: note: expanded from macro 'catomic_exchange_and_add'
  213 |   __arch_exchange_and_add_body (__arch_exchange_and_add_cprefix, __arch_c,    \
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  214 |                                 mem, value)
      |                                 ~~~~~~~~~~~
../sysdeps/x86/atomic-machine.h:199:12: note: expanded from macro '__arch_exchange_and_add_body'
  198 |                          : "=r" (__result), "=m" (*mem)                       \
      |                                  ~~~~~~~~
  199 |                          : "0" ((int64_t) cast_to_integer (__addval)),     \
      |                                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
tst-atomic.c:501:7: error: unsupported inline asm: input with type 'int64_t' (aka 'long') matching output with type 'typeof (*(&mem))' (aka 'int')
  501 |   if (catomic_decrement_val (&mem) != 15)
      |       ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
../include/atomic.h:340:38: note: expanded from macro 'catomic_decrement_val'
  340 | # define catomic_decrement_val(mem) (catomic_exchange_and_add ((mem), -1) - 1)
      |                                      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../sysdeps/x86/atomic-machine.h:213:3: note: expanded from macro 'catomic_exchange_and_add'
  213 |   __arch_exchange_and_add_body (__arch_exchange_and_add_cprefix, __arch_c,    \
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  214 |                                 mem, value)
      |                                 ~~~~~~~~~~~
../sysdeps/x86/atomic-machine.h:199:12: note: expanded from macro '__arch_exchange_and_add_body'
  198 |                          : "=r" (__result), "=m" (*mem)                       \
      |                                  ~~~~~~~~
  199 |                          : "0" ((int64_t) cast_to_integer (__addval)),     \
      |                                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

mark tst-atomic.c as UNSUPPORTED when compiled with Clang.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Sam James <sam@gentoo.org>
2024-12-22 12:56:49 +08:00
H.J. Lu
07e3eb1774 Use empty initializer to silence GCC 4.9 or older
Use empty initializer to silence GCC 4.9 or older:

getaddrinfo.c: In function ‘gaih_inet’:
getaddrinfo.c:1135:24: error: missing braces around initializer [-Werror=missing-braces]
       / sizeof (struct gaih_typeproto)] = {0};
                        ^

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Sam James <sam@gentoo.org>
2024-12-16 04:06:30 +08:00
H.J. Lu
20f8c5df56 Revert "Add braces in initializers for GCC 4.9 or older"
This reverts commit 8aa2a9e033.

as not all targets need braces.
2024-12-15 18:49:52 +08:00
H.J. Lu
8aa2a9e033 Add braces in initializers for GCC 4.9 or older
Add braces to silence GCC 4.9 or older:

getaddrinfo.c: In function ‘gaih_inet’:
getaddrinfo.c:1135:24: error: missing braces around initializer [-Werror=missing-braces]
       / sizeof (struct gaih_typeproto)] = {0};
                        ^

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Sam James <sam@gentoo.org>
2024-12-14 19:26:45 +08:00
H.J. Lu
1d40170dd3 Return EXIT_UNSUPPORTED if __builtin_mul_overflow unavailable
Since GCC 4.9 doesn't support __builtin_mul_overflow:

tst-fd_to_filename.c: In function ‘check_ranges’:
tst-fd_to_filename.c:51:3: error: implicit declaration of function ‘__builtin_mul_overflow’ [-Werror=implicit-function-declaration]
   while (!__builtin_mul_overflow (power, base, &power));
   ^
cc1: all warnings being treated as errors

return EXIT_UNSUPPORTED for GCC 4.9 or older.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Sam James <sam@gentoo.org>
2024-12-14 19:26:00 +08:00
H.J. Lu
00de38e531 Fix and sort variables in Makefiles
Fix variables in Makefiles:

1. There is a tab, not a space, between "variable" and =, +=, :=.
2. The last entry doesn't have a trailing \.

and sort them.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
2024-12-05 15:36:23 +08:00
Alejandro Colomar
53fcdf5f74 Silence most -Wzero-as-null-pointer-constant diagnostics
Replace 0 by NULL and {0} by {}.

Omit a few cases that aren't so trivial to fix.

Link: <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117059>
Link: <https://software.codidact.com/posts/292718/292759#answer-292759>
Signed-off-by: Alejandro Colomar <alx@kernel.org>
2024-11-25 16:45:59 -03:00
Andreas Schwab
6e7778ecde misc: remove extra va_end in error_tail (bug 32233)
This is an addendum to commit b7b52b9dec ("error, error_at_line: Add
missing va_end calls"), which added the va_end calls in the callers where
they belong.
2024-11-20 14:05:52 +01:00
Adhemerval Zanella
5ffc903216 misc: Add support for Linux uio.h RWF_ATOMIC flag
Linux 6.11 adds the new flag for pwritev2 (commit
c34fc6f26ab86d03a2d47446f42b6cd492dfdc56).

Checked on x86_64-linux-gnu on 6.11 kernel.

Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
2024-10-10 10:28:01 -03:00
Florian Weimer
3ef26b7087 misc: Link tst-mkstemp-fuse-parallel with $(shared-thread-library)
The barrier functions require this on Hurd.
2024-09-24 13:05:52 +02:00
Florian Weimer
e3db0a699c misc: FUSE-based tests for mkstemp
The tests check that O_EXCL is used properly, that 0600 is used
as the mode, that the characters used are as expected, and that
the distribution of names generated is reasonably random.

The tests run very slowly on some kernel versions, so make them
xtests.

Reviewed-by: DJ Delorie <dj@redhat.com>
2024-09-21 19:25:35 +02:00
H.J. Lu
ff0320bec2 Add mremap tests
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>
2024-08-01 05:06:12 -07:00
Carlos O'Donell
a7fe3e805d Fix conditionals on mtrace-based tests (bug 31892)
The conditionals for several mtrace-based tests in catgets, elf, libio,
malloc, misc, nptl, posix, and stdio-common were incorrect leading to
test failures when bootstrapping glibc without perl.

The correct conditional for mtrace-based tests requires three checks:
first checking for run-built-tests, then build-shared, and lastly that
PERL is not equal to "no" (missing perl).
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2024-07-01 17:20:30 +02:00
Florian Weimer
8d7b6b4cb2 socket: Use may_alias on sockaddr structs (bug 19622)
This supports common coding patterns.  The GCC C front end before
version 7 rejects the may_alias attribute on a struct definition
if it was not present in a previous forward declaration, so this
attribute can only be conditionally applied.

This implements the spirit of the change in Austin Group issue 1641.

Suggested-by: Marek Polacek <polacek@redhat.com>
Suggested-by: Jakub Jelinek <jakub@redhat.com>
Reviewed-by: Sam James <sam@gentoo.org>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2024-05-18 09:33:19 +02:00
Stafford Horne
3db9d208dd misc: Add support for Linux uio.h RWF_NOAPPEND flag
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>
2024-04-04 09:41:27 +01:00
Adhemerval Zanella
a4ed0471d7 Always define __USE_TIME_BITS64 when 64 bit time_t is used
It was raised on libc-help [1] that some Linux kernel interfaces expect
the libc to define __USE_TIME_BITS64 to indicate the time_t size for the
kABI.  Different than defined by the initial y2038 design document [2],
the __USE_TIME_BITS64 is only defined for ABIs that support more than
one time_t size (by defining the _TIME_BITS for each module).

The 64 bit time_t redirects are now enabled using a different internal
define (__USE_TIME64_REDIRECTS). There is no expected change in semantic
or code generation.

Checked on x86_64-linux-gnu, i686-linux-gnu, aarch64-linux-gnu, and
arm-linux-gnueabi

[1] https://sourceware.org/pipermail/libc-help/2024-January/006557.html
[2] https://sourceware.org/glibc/wiki/Y2038ProofnessDesign

Reviewed-by: DJ Delorie <dj@redhat.com>
2024-04-02 15:28:36 -03:00
Siddhesh Poyarekar
bf9688e623 cdefs: Drop access attribute for _FORTIFY_SOURCE=3 (BZ #31383)
When passed a pointer to a zero-sized struct, the access attribute
without the third argument misleads -Wstringop-overflow diagnostics to
think that a function is writing 1 byte into the zero-sized structs.
The attribute doesn't add that much value in this context, so drop it
completely for _FORTIFY_SOURCE=3.

Resolves: BZ #31383
Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2024-02-28 08:35:10 -05:00
Adhemerval Zanella
86889e22db debug: Improve fcntl.h fortify warnings with clang
It improves open, open64, openat, and openat64.  The compile and runtime
checks have similar coverage as with GCC.

Checked on aarch64, armhf, x86_64, and i686.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2024-02-27 10:52:59 -03:00
Adhemerval Zanella
471c3c7a47 syslog: Improve fortify with clang
It improve fortify checks for syslog and vsyslog.  The compile
and runtime hecks have similar coverage as with GCC.

The syslog fortify wrapper calls the va_arg version, since clang does
not support __va_arg_pack.

Checked on aarch64, armhf, x86_64, and i686.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2024-02-27 10:52:59 -03:00
Adhemerval Zanella
7a7093615c cdefs.h: Add clang fortify directives
For instance, the read wrapper is currently expanded as:

  extern __inline
  __attribute__((__always_inline__))
  __attribute__((__artificial__))
  __attribute__((__warn_unused_result__))
  ssize_t read (int __fd, void *__buf, size_t __nbytes)
  {
     return __glibc_safe_or_unknown_len (__nbytes,
                                         sizeof (char),
                                         __glibc_objsize0 (__buf))
            ? __read_alias (__fd, __buf, __nbytes)
            : __glibc_unsafe_len (__nbytes,
                                  sizeof (char),
                                  __glibc_objsize0 (__buf))
              ? __read_chk_warn (__fd,
                                 __buf,
                                 __nbytes,
                                 __builtin_object_size (__buf, 0))
              : __read_chk (__fd,
                            __buf,
                            __nbytes,
                            __builtin_object_size (__buf, 0));
  }

The wrapper relies on __builtin_object_size call lowers to a constant at
compile-time and many other operations in the wrapper depends on
having a single, known value for parameters.   Because this is
impossible to have for function parameters, the wrapper depends heavily
on inlining to work and While this is an entirely viable approach on
GCC, it is not fully reliable on clang.  This is because by the time llvm
gets to inlining and optimizing, there is a minimal reliable source and
type-level information available (more information on a more deep
explanation on how to fortify wrapper works on clang [1]).

To allow the wrapper to work reliably and with the same functionality as
with GCC, clang requires a different approach:

  * __attribute__((diagnose_if(c, “str”, “warning”))) which is a function
    level attribute; if the compiler can determine that 'c' is true at
    compile-time, it will emit a warning with the text 'str1'.  If it would
    be better to emit an error, the wrapper can use "error" instead of
    "warning".

  * __attribute__((overloadable)) which is also a function-level attribute;
    and it allows C++-style overloading to occur on C functions.

  * __attribute__((pass_object_size(n))) which is a parameter-level
    attribute; and it makes the compiler evaluate
    __builtin_object_size(param, n) at each call site of the function
    that has the parameter, and passes it in as a hidden parameter.

    This attribute has two side-effects that are key to how FORTIFY works:

    1. It can overload solely on pass_object_size (e.g. there are two
       overloads of foo in

         void foo(char * __attribute__((pass_object_size(0))) c);
         void foo(char *);

      (The one with pass_object_size attribute has precende over the
      default one).

    2. A function with at least one pass_object_size parameter can never
       have its address taken (and overload resolution respects this).

Thus the read wrapper can be implemented as follows, without
hindering any fortify coverage compile and runtime:

  extern __inline
  __attribute__((__always_inline__))
  __attribute__((__artificial__))
  __attribute__((__overloadable__))
  __attribute__((__warn_unused_result__))
  ssize_t read (int __fd,
                 void *const __attribute__((pass_object_size (0))) __buf,
                 size_t __nbytes)
     __attribute__((__diagnose_if__ ((((__builtin_object_size (__buf, 0)) != -1ULL
                                        && (__nbytes) > (__builtin_object_size (__buf, 0)) / (1))),
                                     "read called with bigger length than size of the destination buffer",
                                     "warning")))
  {
    return (__builtin_object_size (__buf, 0) == (size_t) -1)
      ? __read_alias (__fd,
                      __buf,
                      __nbytes)
      : __read_chk (__fd,
                    __buf,
                    __nbytes,
                    __builtin_object_size (__buf, 0));
  }

To avoid changing the current semantic for GCC, a set of macros is
defined to enable the clang required attributes, along with some changes
on internal macros to avoid the need to issue the symbol_chk symbols
(which are done through the __diagnose_if__ attribute for clang).
The read wrapper is simplified as:

  __fortify_function __attribute_overloadable__ __wur
  ssize_t read (int __fd,
                __fortify_clang_overload_arg0 (void *, ,__buf),
                size_t __nbytes)
       __fortify_clang_warning_only_if_bos0_lt (__nbytes, __buf,
                                                "read called with bigger length than "
                                                "size of the destination buffer")

  {
    return __glibc_fortify (read, __nbytes, sizeof (char),
                            __glibc_objsize0 (__buf),
                            __fd, __buf, __nbytes);
  }

There is no expected semantic or code change when using GCC.

Also, clang does not support __va_arg_pack, so variadic functions are
expanded to call va_arg implementations.  The error function must not
have bodies (address takes are expanded to nonfortified calls), and
with the __fortify_function compiler might still create a body with the
C++ mangling name (due to the overload attribute).  In this case, the
function is defined with __fortify_function_error_function macro
instead.

[1] https://docs.google.com/document/d/1DFfZDICTbL7RqS74wJVIJ-YnjQOj1SaoqfhbgddFYSM/edit

Checked on aarch64, armhf, x86_64, and i686.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2024-02-27 10:52:57 -03:00
Arjun Shankar
ddf542da94 syslog: Fix integer overflow in __vsyslog_internal (CVE-2023-6780)
__vsyslog_internal calculated a buffer size by adding two integers, but
did not first check if the addition would overflow.  This commit fixes
that.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2024-01-30 15:53:37 +01:00
Arjun Shankar
7e5a0c286d syslog: Fix heap buffer overflow in __vsyslog_internal (CVE-2023-6779)
__vsyslog_internal used the return value of snprintf/vsnprintf to
calculate buffer sizes for memory allocation.  If these functions (for
any reason) failed and returned -1, the resulting buffer would be too
small to hold output.  This commit fixes that.

All snprintf/vsnprintf calls are checked for negative return values and
the function silently returns upon encountering them.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2024-01-30 15:53:37 +01:00
Arjun Shankar
6bd0e4efcc syslog: Fix heap buffer overflow in __vsyslog_internal (CVE-2023-6246)
__vsyslog_internal did not handle a case where printing a SYSLOG_HEADER
containing a long program name failed to update the required buffer
size, leading to the allocation and overflow of a too-small buffer on
the heap.  This commit fixes that.  It also adds a new regression test
that uses glibc.malloc.check.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2024-01-30 15:53:37 +01:00
Paul Eggert
dff8da6b3e Update copyright dates with scripts/update-copyrights 2024-01-01 10:53:40 -08:00
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
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