The elision interfaces are closely aligned between the targets that
implement them, so declare them in the generic <lowlevellock.h>
file.
Empty .c stubs are provided, so that fewer makefile updates
under sysdeps are needed. Also simplify initialization via
__libc_early_init.
The symbols __lll_clocklock_elision, __lll_lock_elision,
__lll_trylock_elision, __lll_unlock_elision, __pthread_force_elision
move into libc. For the time being, non-hidden references are used
from libpthread to access them, but once that part of libpthread
is moved into libc, hidden symbols will be used again. (Hidden
references seem desirable to reduce the likelihood of transactions
aborts.)
This moves __futex_abstimed_wait64 and
__futex_abstimed_wait_cancelable64 and exports these functions as
GLIBC_PRIVATE.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
And sort the lines lexicographically. This will make it easier to review
patches which move symbols from libpthread to libc.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
The internal semaphore list code is moved to a specific file,
sem_routine.c, and the internal usage is simplified to only two
functions (one to insert a new semaphore and one to remove it
from the internal list). There is no need to expose the
internal locking, neither how the semaphore mapping is implemented.
No functional or semantic change is expected, tested on
x86_64-linux-gnu.
Previously, glibc would pick an arbitrary tmpfs file system from
/proc/mounts if /dev/shm was not available. This could lead to
an unsuitable file system being picked for the backing storage for
shm_open, sem_open, and related functions.
This patch introduces a new function, __shm_get_name, which builds
the file name under the appropriate (now hard-coded) directory. It is
called from the various shm_* and sem_* function. Unlike the
SHM_GET_NAME macro it replaces, the callers handle the return values
and errno updates. shm-directory.c is moved directly into the posix
subdirectory because it can be implemented directly using POSIX
functionality. It resides in libc because it is needed by both
librt and nptl/htl.
In the sem_open implementation, tmpfname is initialized directly
from a string constant. This happens to remove one alloca call.
Checked on x86_64-linux-gnu.
I've updated copyright dates in glibc for 2021. This is the patch for
the changes not generated by scripts/update-copyrights and subsequent
build / regeneration of generated files. As well as the usual annual
updates, mainly dates in --version output (minus csu/version.c which
previously had to be handled manually but is now successfully updated
by update-copyrights), there is a small change to the copyright notice
in NEWS which should let NEWS get updated automatically next year.
Please remember to include 2021 in the dates for any new files added
in future (which means updating any existing uncommitted patches you
have that add new files to use the new copyright dates in them).
I used these shell commands:
../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")
and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 6694 files FOO.
I then removed trailing white space from benchtests/bench-pthread-locks.c
and iconvdata/tst-iconv-big5-hkscs-to-2ucs4.c, to work around this
diagnostic from Savannah:
remote: *** pre-commit check failed ...
remote: *** error: lines with trailing whitespace found
remote: error: hook declined to update refs/heads/master
The earlier implementation of this, __lll_clocklock, calls lll_clockwait
that doesn't return the futex syscall error codes. It always tries again
if that fails.
However in the current implementation, when the futex returns EAGAIN,
__futex_clocklock64 will also return EGAIN, even if the futex is taken.
This patch fixes the EAGAIN issue and also adds a check for EINTR. As
futex syscall can return EINTR if the thread is interrupted by a signal.
In this case I'm assuming the function should continue trying to lock as
there is no mention to about it on POSIX. Also add a test for both
scenarios.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
The aio_suspend function has been converted to support 64 bit time.
This change uses (in aio_misc.h):
- __futex_abstimed_wait64 (instead of futex_reltimed_wait)
- __futex_abstimed_wait_cancellable64
(instead of futex_reltimed_wait_cancellable)
from ./sysdeps/nptl/futex-helpers.h
The aio_suspend() accepts relative timeout, which then is converted to
absolute one.
The i686-gnu port (HURD) do not define DONT_NEED_AIO_MISC_COND and as it
doesn't (yet) support 64 bit time it uses not converted
pthread_cond_timedwait().
The __aio_suspend() is supposed to be run on ports with __TIMESIZE !=64 and
__WORDSIZE==32. It internally utilizes __aio_suspend_time64() and hence the
conversion from 32 bit struct timespec to 64 bit one is required.
For ports supporting 64 bit time the __aio_suspend_time64() will be used
either via alias (to __aio_suspend when __TIMESIZE==64) or redirection
(when -D_TIME_BITS=64 is passed).
Build tests:
./src/scripts/build-many-glibcs.py glibcs
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Some futex-internal calls require additional check for EOVERFLOW (as
indicated by [1] [2] [3]). For both mutex and rwlock code, EOVERFLOW is
handle as ETIMEDOUT; since it indicate to the caller that the blocking
operation could not be issued.
For mutex it avoids a possible issue where PTHREAD_MUTEX_ROBUST_* might
assume EOVERFLOW indicate futex has succeed, and for PTHREAD_MUTEX_PP_*
it avoid a potential busy infinite loop. For rwlock and semaphores, it
also avoids potential busy infinite loops.
Checked on x86_64-linux-gnu and i686-linux-gnu, although EOVERFLOW
won't be possible with current usage (since all timeouts on 32-bit
architectures with 32-bit time_t support will be in the range of
32-bit time_t).
[1] https://sourceware.org/pipermail/libc-alpha/2020-November/120079.html
[2] https://sourceware.org/pipermail/libc-alpha/2020-November/120080.html
[3] https://sourceware.org/pipermail/libc-alpha/2020-November/120127.html
The 878fe624d4 changed lll_futex_timed_wait, which expects a relative
timeout, with a __futex_abstimed_wait64, which expects an absolute
timeout. However the code still passes a relative timeout.
Also, the PTHREAD_PRIO_PROTECT support for clocks different than
CLOCK_REALTIME was broken since the inclusion of
pthread_mutex_clocklock (9d20e22e46) since lll_futex_timed_wait
always use CLOCK_REALTIME.
This patch fixes by removing the relative time calculation. It
also adds some xtests that tests both thread and inter-process
usage.
Checked on x86_64-linux-gnu.
The align the GNU extension with the others one that accept specify
which clock to wait for (such as pthread_mutex_clocklock).
Check on x86_64-linux-gnu.
Reviewed-by: Lukasz Majewski <lukma@denx.de>
Linux futex FUTEX_LOCK_PI operation only supports CLOCK_REALTIME,
so pthread_mutex_clocklock operation with priority aware mutexes
may fail depending of the input timeout.
Also, it is not possible to convert a CLOCK_MONOTONIC to a
CLOCK_REALTIME due the possible wall clock time change which might
invalid the requested timeout.
Checked on x86_64-linux-gnu and i686-linux-gnu.
Reviewed-by: Lukasz Majewski <lukma@denx.de>
The idea is to make NPTL implementation to use on the functions
provided by futex-internal.h.
Checked on x86_64-linux-gnu and i686-linux-gnu.
Reviewed-by: Lukasz Majewski <lukma@denx.de>
The idea is to make NPTL implementation to use on the functions
provided by futex-internal.h.
Checked on x86_64-linux-gnu and i686-linux-gnu.
Reviewed-by: Lukasz Majewski <lukma@denx.de>
The idea is to make NPTL implementation to use on the functions
provided by futex-internal.h.
Checked on x86_64-linux-gnu and i686-linux-gnu.
Reviewed-by: Lukasz Majewski <lukma@denx.de>
For non null timeouts, the __futex_clocklock_wait64 creates an a
relative timeout by subtracting the current time from the input
argument. The same behavior can be obtained with FUTEX_WAIT_BITSET
without the need to calculate the relative timeout. Besides consolidate
the code it also avoid the possible relative timeout issues [1].
The __futex_abstimed_wait64 needs also to return EINVAL syscall
errors.
Checked on x86_64-linux-gnu and i686-linux-gnu.
[1] https://sourceware.org/pipermail/libc-alpha/2020-November/119881.html
Reviewed-by: Lukasz Majewski <lukma@denx.de>
It can be replaced with a __futex_abstimed_wait_cancelable64 call,
with the advantage that there is no need to further clock adjustments
to create a absolute timeout. It allows to remove the now ununsed
futex_timed_wait_cancel64 internal function.
Checked on x86_64-linux-gnu and i686-linux-gnu.
Reviewed-by: Lukasz Majewski <lukma@denx.de>
It is used solely on __pthread_cond_wait_common and the call can be
replaced by a __futex_abstimed_wait_cancelable64 one.
Checked on x86_64-linux-gnu and i686-linux-gnu.
Reviewed-by: Lukasz Majewski <lukma@denx.de>
The __futex_abstimed_wait usage was remove with 3102e28bd1 and the
__futex_abstimed_wait_cancelable by 323592fdc9 and b8d3e8fbaa.
The futex_lock_pi can be replaced by a futex_lock_pi64.
Checked on x86_64-linux-gnu and i686-linux-gnu.
Reviewed-by: Lukasz Majewski <lukma@denx.de>
On GNU/Hurd we not only need $(common-objpfx) in LD_LIBRARY_PATH when loading
dynamic objects, but also $(common-objpfx)/mach and $(common-objpfx)/hurd. This
adds an ld-library-path variable to be used as LD_LIBRARY_PATH basis in
Makefiles, and a sysdep-ld-library-path variable for sysdeps to add some
more paths, here mach/ and hurd/.
Now __thread_gscope_wait (the function behind THREAD_GSCOPE_WAIT,
formerly __wait_lookup_done) can be implemented directly in ld.so,
eliminating the unprotected GL (dl_wait_lookup_done) function
pointer.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Most systems are SMP, so optimizing for the UP case is no longer
approriate. A dynamic check based on the kernel identification
has been only implemented for i386 anyway.
To disable adaptive mutexes on sh, define DEFAULT_ADAPTIVE_COUNT
as zero for this architecture.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
commit def674652e
Author: Florian Weimer <fweimer@redhat.com>
Date: Mon Apr 27 15:00:14 2020 +0200
nptl/tst-setuid1-static: Improve isolation from system objects
Static dlopen needs an LD_LIBRARY_PATH setting to avoid loading system
libraries.
missed $(common-objpfx)nss. Add $(common-objpfx)nss to LD_LIBRARY_PATH
for tst-setuid1-static to support
struct passwd *pwd = getpwnam ("nobody");
in nptl/tst-setuid1.c.
Building glibc with GCC 11 fails with (among other warnings) spurious
-Wstringop-overflow warnings from calls to setjmp and longjmp with a
pointer to a pthread_unwind_buf that is smaller than jmp_buf. As
discussed in bug 26647, the warning in libc-start.c is a false
positive, because setjmp and longjmp do not access anything (the
signal mask) beyond the common prefix of the two structures, so this
patch disables the warning for that call to setjmp, as well as for two
calls in NPTL code that produce the same warning and look like false
positives for the same reason.
Tested with build-many-glibcs.py for arm-linux-gnueabi, where this
allows the build to get further.
Reviewed-by: DJ Delorie <dj@redhat.com>
The commit:
"y2038: nptl: Convert pthread_mutex_{clock|timed}lock to support 64 bit"
SHA1: 29e9874a04
introduced support for 64 bit timeouts. Unfortunately, it was missing the
code for bitset - i.e. lll_futex_clock_wait_bitset C preprocessor macro
was used. As a result the 64 bit struct __timespec64 was coerced to 32
bit struct timespec and regression visible as timeout was observed
(nptl/tst-robust10 on s390).
Reported-by: Stefan Liebler <stli@linux.ibm.com>
Tested-by: Stefan Liebler <stli@linux.ibm.com>
The pthread_mutex_clocklock and pthread_mutex_timedlock have been converted
to support 64 bit time.
This change uses:
- New __futex_clocklock_wait64 (instead of lll_timedwait)
from ./sysdeps/nptl/futex-helpers.c and
- New __futex_clocklock64 function (instead of lll_clocklock)
- New futex_lock_pi64
defined in sysdeps/nptl/futex-internal.h
The pthread_mutex_{clock|timed}lock only accepts absolute time.
Moreover, there is no need to check for NULL passed as *abstime pointer to the
syscalls as those calls have exported symbols marked with __nonull attribute
for abstime.
Some architectures - namely x86, powerpc and s390 - do support lock elision.
For those - adjustments have been made in arch specific elision-*.c files
to use __futex_clocklock64 instead of lll_clocklock.
The __lll_lock_elision (aliased to __lll_clocklock_elision in e.g.
sysdeps/unix/sysv/linux/s390/elision-timed.c) just uses, in this patch
provided, __futex_clocklock64.
For systems with __TIMESIZE != 64 && __WORDSIZE == 32:
- Conversions between 64 bit time to 32 bit are necessary
- Redirection to pthread_mutex_{clock|timed}lock will provide support for 64
bit time
Build tests:
./src/scripts/build-many-glibcs.py glibcs
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
The pthread_rwlock_clockrdlock, pthread_rwlock_clockwrlock,
pthread_rwlock_timedrdlock and pthread_rwlock_timedwrlock have been converted
to support 64 bit time.
This change uses new futex_abstimed_wait64 function in
./sysdeps/nptl/futex-helpers.c, which uses futex_time64 where possible.
The pthread_rwlock_{clock|timed}{rd|wr}lock only accepts absolute time.
Moreover, there is no need to check for NULL passed as *abstime pointer to the
syscalls as those calls have exported symbols marked with __nonull attribute
for abstime.
For systems with __TIMESIZE != 64 && __WORDSIZE == 32:
- Conversions between 64 bit time to 32 bit are necessary
- Redirection to pthread_rwlock_{clock|timed}{rd|wr}lock will provide support
for 64 bit time
Build tests:
./src/scripts/build-many-glibcs.py glibcs
Run-time tests:
- Run specific tests on ARM/x86 32bit systems (qemu):
https://github.com/lmajewski/meta-y2038 and run tests:
https://github.com/lmajewski/y2038-tests/commits/master
Above tests were performed with Y2038 redirection applied as well as without
to test the proper usage of both __pthread_rwlock_{clock|timed}{rd|wr}lock64
and __pthread_rwlock_{clock|timed}{rd|wr}lock.
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
There are several compiler implementations that allow large stack
allocations to jump over the guard page at the end of the stack and
corrupt memory beyond that. See CVE-2017-1000364.
Compilers can emit code to probe the stack such that the guard page
cannot be skipped, but on aarch64 the probe interval is 64K by default
instead of the minimum supported page size (4K).
This patch enforces at least 64K guard on aarch64 unless the guard
is disabled by setting its size to 0. For backward compatibility
reasons the increased guard is not reported, so it is only observable
by exhausting the address space or parsing /proc/self/maps on linux.
On other targets the patch has no effect. If the stack probe interval
is larger than a page size on a target then ARCH_MIN_GUARD_SIZE can
be defined to get large enough stack guard on libc allocated stacks.
The patch does not affect threads with user allocated stacks.
Fixes bug 26691.
The sem_clockwait and sem_timedwait have been converted to support 64 bit time.
This change reuses futex_abstimed_wait_cancelable64 function introduced earlier.
The sem_{clock|timed}wait only accepts absolute time. Moreover, there is no
need to check for NULL passed as *abstime pointer to the syscalls as both calls
have exported symbols marked with __nonull attribute for abstime.
For systems with __TIMESIZE != 64 && __WORDSIZE == 32:
- Conversion from 32 bit time to 64 bit struct __timespec64 was necessary
- Redirection to __sem_{clock|timed}wait64 will provide support for 64 bit
time
Build tests:
./src/scripts/build-many-glibcs.py glibcs
Run-time tests:
- Run specific tests on ARM/x86 32bit systems (qemu):
https://github.com/lmajewski/meta-y2038 and run tests:
https://github.com/lmajewski/y2038-tests/commits/master
Above tests were performed with Y2038 redirection applied as well as without
to test the proper usage of both __sem_{clock|timed}wait64 and
__sem_{clock|timed}wait.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
It replaces the internal usage of __{f,l}xstat{at}{64} with the
__{f,l}stat{at}{64}. It should not change the generate code since
sys/stat.h explicit defines redirections to internal calls back to
xstat* symbols.
Checked with a build for all affected ABIs. I also check on
x86_64-linux-gnu and i686-linux-gnu.
Reviewed-by: Lukasz Majewski <lukma@denx.de>
The pthread_cond_clockwait and pthread_cond_timedwait have been converted
to support 64 bit time.
This change introduces new futex_abstimed_wait_cancelable64 function in
./sysdeps/nptl/futex-helpers.c, which uses futex_time64 where possible
and tries to replace low-level preprocessor macros from
lowlevellock-futex.h
The pthread_cond_{clock|timed}wait only accepts absolute time. Moreover,
there is no need to check for NULL passed as *abstime pointer as
__pthread_cond_wait_common() always passes non-NULL struct __timespec64
pointer to futex_abstimed_wait_cancellable64().
For systems with __TIMESIZE != 64 && __WORDSIZE == 32:
- Conversions between 64 bit time to 32 bit are necessary
- Redirection to __pthread_cond_{clock|timed}wait64 will provide support
for 64 bit time
The futex_abstimed_wait_cancelable64 function has been put into a separate
file on the purpose - to avoid issues apparent on the m68k architecture
related to small number of available registers (there is not enough
registers to put all necessary arguments in them if the above function
would be added to futex-internal.h with __always_inline attribute).
In fact - new function - namely __futex_abstimed_wait_cancellable32 is
used to reduce number of needed registers (as some in-register values are
stored on the stack when function call is made).
Build tests:
./src/scripts/build-many-glibcs.py glibcs
Run-time tests:
- Run specific tests on ARM/x86 32bit systems (qemu):
https://github.com/lmajewski/meta-y2038 and run tests:
https://github.com/lmajewski/y2038-tests/commits/master
Above tests were performed with Y2038 redirection applied as well as without
to test the proper usage of both __pthread_cond_{clock|timed}wait64 and
__pthread_cond_{clock|timed}wait.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
The pthread_clockjoin_np and pthread_timedjoin_np have been converted to
support 64 bit time.
This change introduces new futex_timed_wait_cancel64 function in
./sysdeps/nptl/futex-internal.h, which uses futex_time64 where possible
and tries to replace low-level preprocessor macros from
lowlevellock-futex.h
The pthread_{timed|clock}join_np only accept absolute time. Moreover,
there is no need to check for NULL passed as *abstime pointer as
clockwait_tid() always passes struct __timespec64.
For systems with __TIMESIZE != 64 && __WORDSIZE == 32:
- Conversions between 64 bit time to 32 bit are necessary
- Redirection to __pthread_{clock|timed}join_np64 will provide support
for 64 bit time
Build tests:
./src/scripts/build-many-glibcs.py glibcs
Run-time tests:
- Run specific tests on ARM/x86 32bit systems (qemu):
https://github.com/lmajewski/meta-y2038 and run tests:
https://github.com/lmajewski/y2038-tests/commits/master
Above tests were performed with Y2038 redirection applied as well as without
to test the proper usage of both __pthread_{timed|clock}join_np64 and
__pthread_{timed|clock}join_np.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
nptl has
/* Opcodes and data types for communication with the signal handler to
change user/group IDs. */
struct xid_command
{
int syscall_no;
long int id[3];
volatile int cntr;
volatile int error;
};
/* This must be last, otherwise the current thread might not have
permissions to send SIGSETXID syscall to the other threads. */
result = INTERNAL_SYSCALL_NCS (cmdp->syscall_no, 3,
cmdp->id[0], cmdp->id[1], cmdp->id[2]);
But the second argument of setgroups syscal is a pointer:
int setgroups (size_t size, const gid_t *list);
But on x32, pointers passed to syscall must have pointer type so that
they will be zero-extended. The kernel XID arguments are unsigned and
do not require sign extension. Change xid_command to
struct xid_command
{
int syscall_no;
unsigned long int id[3];
volatile int cntr;
volatile int error;
};
so that all arguments are zero-extended. A testcase is added for x32 and
setgroups returned with EFAULT when running as root without the fix.
The kernel ABI is not finalized, and there are now various proposals
to change the size of struct rseq, which would make the glibc ABI
dependent on the version of the kernels used for building glibc.
This is of course not acceptable.
This reverts commit 48699da1c4 ("elf:
Support at least 32-byte alignment in static dlopen"), commit
8f4632deb3 ("Linux: rseq registration
tests"), commit 6e29cb3f61 ("Linux: Use
rseq in sched_getcpu if available"), and commit
0c76fc3c2b ("Linux: Perform rseq
registration at C startup and thread creation"), resolving the conflicts
introduced by the ARC port and the TLS static surplus changes.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
The per-thread state is refactored two use two strategies:
1. The default one uses a TLS structure, which will be placed in the
static TLS space (using __thread keyword).
2. Linux allocates via struct pthread and access it through THREAD_*
macros.
The default strategy has the disadvantage of increasing libc.so static
TLS consumption and thus decreasing the possible surplus used in
some scenarios (which might be mitigated by BZ#25051 fix).
It is used only on Hurd, where accessing the thread storage in the in
single thread case is not straightforward (afaiu, Hurd developers could
correct me here).
The fallback static allocation used for allocation failure is also
removed: defining its size is problematic without synchronizing with
translated messages (to avoid partial translation) and the resulting
usage is not thread-safe.
Checked on x86-64-linux-gnu, i686-linux-gnu, powerpc64le-linux-gnu,
and s390x-linux-gnu.
Tested-by: Carlos O'Donell <carlos@redhat.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
