This is a new implementation for condition variables, required
after http://austingroupbugs.net/view.php?id=609 to fix bug 13165. In
essence, we need to be stricter in which waiters a signal or broadcast
is required to wake up; this couldn't be solved using the old algorithm.
ISO C++ made a similar clarification, so this also fixes a bug in
current libstdc++, for example.
We can't use the old algorithm anymore because futexes do not guarantee
to wake in FIFO order. Thus, when we wake, we can't simply let any
waiter grab a signal, but we need to ensure that one of the waiters
happening before the signal is woken up. This is something the previous
algorithm violated (see bug 13165).
There's another issue specific to condvars: ABA issues on the underlying
futexes. Unlike mutexes that have just three states, or semaphores that
have no tokens or a limited number of them, the state of a condvar is
the *order* of the waiters. A waiter on a semaphore can grab a token
whenever one is available; a condvar waiter must only consume a signal
if it is eligible to do so as determined by the relative order of the
waiter and the signal.
Therefore, this new algorithm maintains two groups of waiters: Those
eligible to consume signals (G1), and those that have to wait until
previous waiters have consumed signals (G2). Once G1 is empty, G2
becomes the new G1. 64b counters are used to avoid ABA issues.
This condvar doesn't yet use a requeue optimization (ie, on a broadcast,
waking just one thread and requeueing all others on the futex of the
mutex supplied by the program). I don't think doing the requeue is
necessarily the right approach (but I haven't done real measurements
yet):
* If a program expects to wake many threads at the same time and make
that scalable, a condvar isn't great anyway because of how it requires
waiters to operate mutually exclusive (due to the mutex usage). Thus, a
thundering herd problem is a scalability problem with or without the
optimization. Using something like a semaphore might be more
appropriate in such a case.
* The scalability problem is actually at the mutex side; the condvar
could help (and it tries to with the requeue optimization), but it
should be the mutex who decides how that is done, and whether it is done
at all.
* Forcing all but one waiter into the kernel-side wait queue of the
mutex prevents/avoids the use of lock elision on the mutex. Thus, it
prevents the only cure against the underlying scalability problem
inherent to condvars.
* If condvars use short critical sections (ie, hold the mutex just to
check a binary flag or such), which they should do ideally, then forcing
all those waiter to proceed serially with kernel-based hand-off (ie,
futex ops in the mutex' contended state, via the futex wait queues) will
be less efficient than just letting a scalable mutex implementation take
care of it. Our current mutex impl doesn't employ spinning at all, but
if critical sections are short, spinning can be much better.
* Doing the requeue stuff requires all waiters to always drive the mutex
into the contended state. This leads to each waiter having to call
futex_wake after lock release, even if this wouldn't be necessary.
[BZ #13165]
* nptl/pthread_cond_broadcast.c (__pthread_cond_broadcast): Rewrite to
use new algorithm.
* nptl/pthread_cond_destroy.c (__pthread_cond_destroy): Likewise.
* nptl/pthread_cond_init.c (__pthread_cond_init): Likewise.
* nptl/pthread_cond_signal.c (__pthread_cond_signal): Likewise.
* nptl/pthread_cond_wait.c (__pthread_cond_wait): Likewise.
(__pthread_cond_timedwait): Move here from pthread_cond_timedwait.c.
(__condvar_confirm_wakeup, __condvar_cancel_waiting,
__condvar_cleanup_waiting, __condvar_dec_grefs,
__pthread_cond_wait_common): New.
(__condvar_cleanup): Remove.
* npt/pthread_condattr_getclock.c (pthread_condattr_getclock): Adapt.
* npt/pthread_condattr_setclock.c (pthread_condattr_setclock):
Likewise.
* npt/pthread_condattr_getpshared.c (pthread_condattr_getpshared):
Likewise.
* npt/pthread_condattr_init.c (pthread_condattr_init): Likewise.
* nptl/tst-cond1.c: Add comment.
* nptl/tst-cond20.c (do_test): Adapt.
* nptl/tst-cond22.c (do_test): Likewise.
* sysdeps/aarch64/nptl/bits/pthreadtypes.h (pthread_cond_t): Adapt
structure.
* sysdeps/arm/nptl/bits/pthreadtypes.h (pthread_cond_t): Likewise.
* sysdeps/ia64/nptl/bits/pthreadtypes.h (pthread_cond_t): Likewise.
* sysdeps/m68k/nptl/bits/pthreadtypes.h (pthread_cond_t): Likewise.
* sysdeps/microblaze/nptl/bits/pthreadtypes.h (pthread_cond_t):
Likewise.
* sysdeps/mips/nptl/bits/pthreadtypes.h (pthread_cond_t): Likewise.
* sysdeps/nios2/nptl/bits/pthreadtypes.h (pthread_cond_t): Likewise.
* sysdeps/s390/nptl/bits/pthreadtypes.h (pthread_cond_t): Likewise.
* sysdeps/sh/nptl/bits/pthreadtypes.h (pthread_cond_t): Likewise.
* sysdeps/tile/nptl/bits/pthreadtypes.h (pthread_cond_t): Likewise.
* sysdeps/unix/sysv/linux/alpha/bits/pthreadtypes.h (pthread_cond_t):
Likewise.
* sysdeps/unix/sysv/linux/powerpc/bits/pthreadtypes.h (pthread_cond_t):
Likewise.
* sysdeps/x86/bits/pthreadtypes.h (pthread_cond_t): Likewise.
* sysdeps/nptl/internaltypes.h (COND_NWAITERS_SHIFT): Remove.
(COND_CLOCK_BITS): Adapt.
* sysdeps/nptl/pthread.h (PTHREAD_COND_INITIALIZER): Adapt.
* nptl/pthreadP.h (__PTHREAD_COND_CLOCK_MONOTONIC_MASK,
__PTHREAD_COND_SHARED_MASK): New.
* nptl/nptl-printers.py (CLOCK_IDS): Remove.
(ConditionVariablePrinter, ConditionVariableAttributesPrinter): Adapt.
* nptl/nptl_lock_constants.pysym: Adapt.
* nptl/test-cond-printers.py: Adapt.
* sysdeps/unix/sysv/linux/hppa/internaltypes.h (cond_compat_clear,
cond_compat_check_and_clear): Adapt.
* sysdeps/unix/sysv/linux/hppa/pthread_cond_timedwait.c: Remove file ...
* sysdeps/unix/sysv/linux/hppa/pthread_cond_wait.c
(__pthread_cond_timedwait): ... and move here.
* nptl/DESIGN-condvar.txt: Remove file.
* nptl/lowlevelcond.sym: Likewise.
* nptl/pthread_cond_timedwait.c: Likewise.
* sysdeps/unix/sysv/linux/i386/i486/pthread_cond_broadcast.S: Likewise.
* sysdeps/unix/sysv/linux/i386/i486/pthread_cond_signal.S: Likewise.
* sysdeps/unix/sysv/linux/i386/i486/pthread_cond_timedwait.S: Likewise.
* sysdeps/unix/sysv/linux/i386/i486/pthread_cond_wait.S: Likewise.
* sysdeps/unix/sysv/linux/i386/i586/pthread_cond_broadcast.S: Likewise.
* sysdeps/unix/sysv/linux/i386/i586/pthread_cond_signal.S: Likewise.
* sysdeps/unix/sysv/linux/i386/i586/pthread_cond_timedwait.S: Likewise.
* sysdeps/unix/sysv/linux/i386/i586/pthread_cond_wait.S: Likewise.
* sysdeps/unix/sysv/linux/i386/i686/pthread_cond_broadcast.S: Likewise.
* sysdeps/unix/sysv/linux/i386/i686/pthread_cond_signal.S: Likewise.
* sysdeps/unix/sysv/linux/i386/i686/pthread_cond_timedwait.S: Likewise.
* sysdeps/unix/sysv/linux/i386/i686/pthread_cond_wait.S: Likewise.
* sysdeps/unix/sysv/linux/x86_64/pthread_cond_broadcast.S: Likewise.
* sysdeps/unix/sysv/linux/x86_64/pthread_cond_signal.S: Likewise.
* sysdeps/unix/sysv/linux/x86_64/pthread_cond_timedwait.S: Likewise.
* sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S: Likewise.
TS 18661-1 defines fromfp functions (fromfp, fromfpx, ufromfp,
ufromfpx, and float and long double variants) to convert from
floating-point to an integer type with any signedness and any given
width up to that of intmax_t, in any of the five IEEE rounding modes
(the usual four for binary floating point, plus rounding to nearest
with ties rounding away from zero), with control of whether in-range
non-integer values should result in the "inexact" exception being
raised. This patch implements these functions for glibc.
These implementations are (apart from raising exceptions) pure integer
implementations; it's entirely possible optimized versions could be
devised for some architectures. A common math/fromfp.h header
provides various common helper code that can readily be shared between
the implementations for different types. For each type, the bulk of
the implementation is also shared between the four functions, with
wrappers that define UNSIGNED and INEXACT macros appropriately before
including the main implementation.
As the functions return intmax_t and uintmax_t without math.h being
allowed to expose those typedef names, they are declared using
__intmax_t and __uintmax_t as obtained from <bits/types.h>.
The FP_INT_* rounding direction macros are defined as ascending
integers in the order the names are listed in the TS; I see no
significant value in allowing architectures to vary the values of
them.
The libm-test machinery is duly adapted to handle unsigned int
arguments, and intmax_t and uintmax_t results. Because each test
input is generally tested for four functions, five rounding modes and
several different widths, the libm-test.inc additions are very large.
Thus, the diffs in the body of this message exclude the libm-test.inc
changes, with the full patch being attached gzipped. The bulk of the
new tests were generated (expanded from a test input plus rounding
results and information about where it lies in the relevant interval
between integers, to libm-test tests for all relevant combinations of
function, rounding direction and width) by a script that's included in
the patch as math/gen-fromfp-tests.py (input data
math/gen-fromfp-tests-inputs); as an ad hoc script that's not really
expected to be rerun, it's not very polished, but it's at least
plausibly useful for adding any further tests for these functions in
future. I may split the libm-test tests up by function in future (so
both libm-test.inc and auto-libm-test-out are split into separate
files, and the tests for each function are also built and run
separately), but not for 2.25.
For no obvious reason, adding tgmath tests for the new functions
resulted in -Wuninitialized errors from test-tgmath.c about the
variable i being used uninitialized. Those errors were correct - the
variable is read by the frexp version in test-tgmath.c (where real
frexp would write through that pointer instead of reading it) - but I
don't know why this patch would result in the pre-existing issue being
newly detected. The patch initializes the variable to avoid those
errors.
With these changes, glibc 2.25 should have all the library features
from TS 18661-1 other than the functions that round result to narrower
type (and constant rounding directions, but I'm considering those
mainly a compiler feature not a library one).
Tested for x86_64, x86, mips64 and powerpc.
* math/bits/mathcalls.h [__GLIBC_USE (IEC_60559_BFP_EXT)]
(fromfp): New declaration.
[__GLIBC_USE (IEC_60559_BFP_EXT)] (fromfpx): Likewise.
[__GLIBC_USE (IEC_60559_BFP_EXT)] (ufromfp): Likewise.
[__GLIBC_USE (IEC_60559_BFP_EXT)] (ufromfpx): Likewise.
* math/tgmath.h (__TGMATH_TERNARY_FIRST_REAL_RET_ONLY): New macro.
[__GLIBC_USE (IEC_60559_BFP_EXT)] (fromfp): Likewise.
[__GLIBC_USE (IEC_60559_BFP_EXT)] (ufromfp): Likewise.
[__GLIBC_USE (IEC_60559_BFP_EXT)] (fromfpx): Likewise.
[__GLIBC_USE (IEC_60559_BFP_EXT)] (ufromfpx): Likewise.
* math/math.h: Include <bits/types.h>.
[__GLIBC_USE (IEC_60559_BFP_EXT)] (FP_INT_UPWARD): New enum
constant and macro.
(FP_INT_DOWNWARD): Likewise.
(FP_INT_TOWARDZERO): Likewise.
(FP_INT_TONEARESTFROMZERO): Likewise.
(FP_INT_TONEAREST): Likewise.
* math/Versions (fromfp): New libm symbol at version GLIBC_2.25.
(fromfpf): Likewise.
(fromfpl): Likewise.
(ufromfp): Likewise.
(ufromfpf): Likewise.
(ufromfpl): Likewise.
(fromfpx): Likewise.
(fromfpxf): Likewise.
(fromfpxl): Likewise.
(ufromfpx): Likewise.
(ufromfpxf): Likewise.
(ufromfpxl): Likewise.
* math/Makefile (libm-calls): Add s_fromfpF, s_ufromfpF,
s_fromfpxF and s_ufromfpxF.
* math/gen-fromfp-tests.py: New file.
* math/gen-fromfp-tests-inputs: Likewise.
* math/libm-test.inc: Include <stdint.h>
(check_intmax_t): New function.
(check_uintmax_t): Likewise.
(struct test_fiu_M_data): New type.
(struct test_fiu_U_data): Likewise.
(RUN_TEST_fiu_M): New macro.
(RUN_TEST_LOOP_fiu_M): Likewise.
(RUN_TEST_fiu_U): Likewise.
(RUN_TEST_LOOP_fiu_U): Likewise.
(fromfp_test_data): New array.
(fromfp_test): New function.
(fromfpx_test_data): New array.
(fromfpx_test): New function.
(ufromfp_test_data): New array.
(ufromfp_test): New function.
(ufromfpx_test_data): New array.
(ufromfpx_test): New function.
(main): Call fromfp_test, fromfpx_test, ufromfp_test and
ufromfpx_test.
* math/gen-libm-test.pl (parse_args): Handle u, M and U descriptor
characters.
* math/test-tgmath-ret.c: Include <stdint.h>.
(rm): New variable.
(width): Likewise.
(CHECK_RET_CONST_TYPE): Take extra arguments and pass them to
called function.
(CHECK_RET_CONST_FLOAT): Take extra arguments and pass them to
CHECK_RET_CONST_TYPE.
(CHECK_RET_CONST_DOUBLE): Likewise.
(CHECK_RET_CONST_LDOUBLE): Likewise.
(CHECK_RET_CONST): Take extra arguments and pass them to calls
macros.
(fromfp): New CHECK_RET_CONST call.
(ufromfp): Likewise.
(fromfpx): Likewise.
(ufromfpx): Likewise.
(do_test): Call check_return_fromfp, check_return_ufromfp,
check_return_fromfpx and check_return_ufromfpx.
* math/test-tgmath.c: Include <stdint.h>
(NCALLS): Increase to 138.
(F(compile_test)): Initialize i. Call fromfp functions.
(F(fromfp)): New function.
(F(fromfpx)): Likewise.
(F(ufromfp)): Likewise.
(F(ufromfpx)): Likewise.
* manual/arith.texi (Rounding Functions): Document FP_INT_UPWARD,
FP_INT_DOWNWARD, FP_INT_TOWARDZERO, FP_INT_TONEARESTFROMZERO,
FP_INT_TONEAREST, fromfp, fromfpf, fromfpl, ufromfp, ufromfpf,
ufromfpl, fromfpx, fromfpxf, fromfpxl, ufromfpx, ufromfpxf and
ufromfpxl.
* manual/libm-err-tab.pl (@all_functions): Add fromfp, fromfpx,
ufromfp and ufromfpx.
* math/fromfp.h: New file.
* sysdeps/ieee754/dbl-64/s_fromfp.c: Likewise.
* sysdeps/ieee754/dbl-64/s_fromfp_main.c: Likewise.
* sysdeps/ieee754/dbl-64/s_fromfpx.c: Likewise.
* sysdeps/ieee754/dbl-64/s_ufromfp.c: Likewise.
* sysdeps/ieee754/dbl-64/s_ufromfpx.c: Likewise.
* sysdeps/ieee754/flt-32/s_fromfpf.c: Likewise.
* sysdeps/ieee754/flt-32/s_fromfpf_main.c: Likewise.
* sysdeps/ieee754/flt-32/s_fromfpxf.c: Likewise.
* sysdeps/ieee754/flt-32/s_ufromfpf.c: Likewise.
* sysdeps/ieee754/flt-32/s_ufromfpxf.c: Likewise.
* sysdeps/ieee754/ldbl-128/s_fromfpl.c: Likewise.
* sysdeps/ieee754/ldbl-128/s_fromfpl_main.c: Likewise.
* sysdeps/ieee754/ldbl-128/s_fromfpxl.c: Likewise.
* sysdeps/ieee754/ldbl-128/s_ufromfpl.c: Likewise.
* sysdeps/ieee754/ldbl-128/s_ufromfpxl.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_fromfpl.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_fromfpl_main.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_fromfpxl.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_ufromfpl.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_ufromfpxl.c: Likewise.
* sysdeps/ieee754/ldbl-96/s_fromfpl.c: Likewise.
* sysdeps/ieee754/ldbl-96/s_fromfpl_main.c: Likewise.
* sysdeps/ieee754/ldbl-96/s_fromfpxl.c: Likewise.
* sysdeps/ieee754/ldbl-96/s_ufromfpl.c: Likewise.
* sysdeps/ieee754/ldbl-96/s_ufromfpxl.c: Likewise.
* sysdeps/ieee754/ldbl-opt/Makefile (libnldbl-calls): Add fromfp,
ufromfp, fromfpx and ufromfpx.
(CFLAGS-nldbl-fromfp.c): New variable.
(CFLAGS-nldbl-fromfpx.c): Likewise.
(CFLAGS-nldbl-ufromfp.c): Likewise.
(CFLAGS-nldbl-ufromfpx.c): Likewise.
* sysdeps/ieee754/ldbl-opt/nldbl-compat.h: Include <stdint.h>.
* sysdeps/ieee754/ldbl-opt/nldbl-fromfp.c: New file.
* sysdeps/ieee754/ldbl-opt/nldbl-fromfpx.c: Likewise.
* sysdeps/ieee754/ldbl-opt/nldbl-ufromfp.c: Likewise.
* sysdeps/ieee754/ldbl-opt/nldbl-ufromfpx.c: Likewise.
* sysdeps/nacl/libm.abilist: Update.
* sysdeps/unix/sysv/linux/aarch64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/alpha/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/arm/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/hppa/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/i386/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/ia64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/m68k/coldfire/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/m68k/m680x0/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/microblaze/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/nios2/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm-le.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sh/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/tile/tilepro/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/x32/libm.abilist: Likewise.
this patch add a direct call to shmget syscall if it is supported by
kernel features.
Checked on x86_64, i686, powerpc64le, aarch64, and armhf.
* sysdeps/unix/sysv/linux/alpha/syscalls.list (shmget): Remove.
* sysdeps/unix/sysv/linux/arm/syscalls.list (shmget): Likewise.
* sysdeps/unix/sysv/linux/generic/syscalls.list (shmget): Likewise.
* sysdeps/unix/sysv/linux/hppa/syscalls.list (shmget): Likewise.
* sysdeps/unix/sysv/linux/ia64/syscalls.list (shmget): Likewise.
* sysdeps/unix/sysv/linux/microblaze/syscalls.list (shmget): Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/syscalls.list (shmget):
Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/syscalls.list (shmget):
Likewise.
* sysdeps/unix/sysv/linux/x86_64/syscalls.list (shmget): Likewise.
* sysdeps/unix/sysv/linux/shmget.c (shmget): Use shmget syscall if it
is defined.
this patch add a direct call to shmdt syscall if it is supported by
kernel features.
hecked on x86_64, i686, powerpc64le, aarch64, and armhf.
* sysdeps/unix/sysv/linux/alpha/syscalls.list (shmdt): Remove.
* sysdeps/unix/sysv/linux/arm/syscalls.list (shmdt): Likewise.
* sysdeps/unix/sysv/linux/generic/syscalls.list (shmdt): Likewise.
* sysdeps/unix/sysv/linux/hppa/syscalls.list (shmdt): Likewise.
* sysdeps/unix/sysv/linux/ia64/syscalls.list (shmdt): Likewise.
* sysdeps/unix/sysv/linux/microblaze/syscalls.list (shmdt): Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/syscalls.list (shmdt):
Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/syscalls.list (shmdt):
Likewise.
* sysdeps/unix/sysv/linux/x86_64/syscalls.list (shmdt): Likewise.
* sysdeps/unix/sysv/linux/shmdt.c (shmdt): Use shmdt syscall if it is
defined.
This patch consolidates the shmctl Linux implementation in only
one default file, sysdeps/unix/sysv/linux/shmctl.c. If tries to use
the direct syscall if it is supported, otherwise will use the old ipc
multiplex mechanism.
The patch also simplify header inclusion and reorganize internal
compat symbol to be built only if old ipc is defined.
Checked on x86_64, i686, powerpc64le, aarch64, and armhf.
* sysdeps/unix/sysv/linux/alpha/Makefile (sysdeps_routines): Remove
oldshmctl.
* sysdeps/unix/sysv/linux/alpha/syscalls.list (shmctl): Remove.
* sysdeps/unix/sysv/linux/arm/syscalls.list (shmctl): Likewise.
* sysdeps/unix/sysv/linux/generic/syscalls.list (shmctl): Likewise.
* sysdeps/unix/sysv/linux/hppa/syscalls.list (shmctl): Likewise.
* sysdeps/unix/sysv/linux/ia64/syscalls.list (shmctl): Likewise.
* sysdeps/unix/sysv/linux/microblaze/syscalls.list (shmctl): Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/syscalls.list (shmctl):
Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/syscalls.list (shmctl):
Likewise.
* sysdeps/unix/sysv/linux/x86_64/syscalls.list (shmctl): Likewise.
* sysdeps/unix/sysv/linux/alpha/shmctl.c: Remove file.
* sysdeps/unix/sysv/linux/arm/shmctl.c: Likewise.
* sysdeps/unix/sysv/linux/microblaze/shmctl.c: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/shmctl.c: Use default
implementation.
* sysdeps/unix/sysv/linux/shmctl.c (__new_shmctl): Use shmctl syscall
if it is defined.
This patch consolidates the semtimedop Linux implementation in only
one default file, sysdeps/unix/sysv/linux/semtimedop.c. If tries to use
the direct syscall if it is supported, otherwise will use the old ipc
multiplex mechanism.
Checked on x86_64, i686, powerpc64le, aarch64, and armhf.
* sysdeps/unix/sysv/linux/alpha/syscalls.list (semtimedop): Remove.
* sysdeps/unix/sysv/linux/arm/syscalls.list (semtimedop): Likewise.
* sysdeps/unix/sysv/linux/generic/syscalls.list (semtimedop):
Likewise.
* sysdeps/unix/sysv/linux/hppa/syscalls.list (semtimedop): Likewise.
* sysdeps/unix/sysv/linux/ia64/syscalls.list (semtimedop): Likewise.
* sysdeps/unix/sysv/linux/microblaze/syscalls.list (semtimedop):
Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/syscalls.list (semtimedop):
Likewise.
* sysdeps/unix/sysv/linux/x86_64/syscalls.list (semtimedop): Likewise.
* sysdeps/unix/sysv/linux/m68k/semtimedop.S: Remove file.
* sysdeps/unix/sysv/linux/s390/semtimedop.c: Reorganize headers and
add a comment about s390 syscall difference from default one.
* sysdeps/unix/sysv/linux/semtimedop.c (semtimedop): Use semtimedop
syscall if it is defined.
This patch add a direct call to semop syscall if it is supported by
kernel headers.
Checked on x86_64, i686, powerpc64le, aarch64, and armhf.
* sysdeps/unix/sysv/linux/alpha/syscalls.list (semop): Remove.
* sysdeps/unix/sysv/linux/arm/syscalls.list (semop): Likewise.
* sysdeps/unix/sysv/linux/generic/syscalls.list (semop): Likewise.
* sysdeps/unix/sysv/linux/hppa/syscalls.list (semop): Likewise.
* sysdeps/unix/sysv/linux/ia64/syscalls.list (semop): Likewise.
* sysdeps/unix/sysv/linux/microblaze/syscalls.list (semop): Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/syscalls.list (semop):
Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/syscalls.list (semop):
Likewise.
* sysdeps/unix/sysv/linux/x86_64/syscalls.list (semop): Likewise.
* sysdeps/unix/sysv/linux/semop.c (semop): Use semop syscall if it is
defined.
This patch add a direct call to semget syscall if it is supported by
kernel features.
hecked on x86_64, i686, powerpc64le, aarch64, and armhf.
* sysdeps/unix/sysv/linux/alpha/syscalls.list (semget): Remove.
* sysdeps/unix/sysv/linux/arm/syscalls.list (semget): Likewise.
* sysdeps/unix/sysv/linux/generic/syscalls.list (semget): Likewise.
* sysdeps/unix/sysv/linux/hppa/syscalls.list (semget): Likewise.
* sysdeps/unix/sysv/linux/ia64/syscalls.list (semget): Likewise.
* sysdeps/unix/sysv/linux/microblaze/syscalls.list (semget): Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/syscalls.list (semget):
Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/syscalls.list (semget):
Likewise.
* sysdeps/unix/sysv/linux/x86_64/syscalls.list (semget): Likewise.
* sysdeps/unix/sysv/linux/semget.c (semget): Use semget syscall
if it is defined.
This patch consolidates the semctl Linux implementation in only
one default file, sysdeps/unix/sysv/linux/semctl.c. If tries to use
the direct syscall if it is supported, otherwise will use the old ipc
multiplex mechanism.
The patch also simplify header inclusion and reorganize internal
compat symbol to be built only if old ipc is defined.
Checked on x86_64, i686, powerpc64le, aarch64, and armhf.
* sysdeps/unix/sysv/linux/alpha/Makefile (sysdeps_routines): Remove
oldsemctl.
* sysdeps/unix/sysv/linux/alpha/semctl.c: Remove file.
* sysdeps/unix/sysv/linux/arm/semctl.c: Likewise.
* sysdeps/unix/sysv/linux/microblaze/semctl.c: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/semctl.c: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/semctl.c: Use defaulf
implementation.
* sysdeps/unix/sysv/linux/semctl.c (__new_semctl): Use semctl
syscall if it is defined.
* sysdeps/unix/sysv/linux/generic/syscalls.list (semctl): Remove.
* sysdeps/unix/sysv/linux/alpha/syscalls.list (semctl): Likewise.
* sysdeps/unix/sysv/linux/hppa/syscalls.list (semctl): Likewise.
* sysdeps/unix/sysv/linux/ia64/syscalls.list (semctl): Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/syscalls.list (semctl):
Likewise.
* sysdeps/unix/sysv/linux/x86_64/syscalls.list (semctl): Likewise.
This patch consolidates the msgrcv Linux implementation in only
one default file, sysdeps/unix/sysv/linux/msgrcv.c. If tries to use
the direct syscall if it is supported, otherwise will use the old ipc
multiplex mechanism.
Checked on x86_64, i686, powerpc64le, aarch64, and armhf.
* sysdeps/unix/sysv/linux/alpha/syscalls.list (msgctl): Remove.
* sysdeps/unix/sysv/linux/arm/syscalls.list (msgctl): Likewise.
* sysdeps/unix/sysv/linux/generic/syscalls.list (msgctl): Likewise.
* sysdeps/unix/sysv/linux/hppa/syscalls.list (msgctl): Likewise.
* sysdeps/unix/sysv/linux/ia64/syscalls.list (msgctl): Likewise.
* sysdeps/unix/sysv/linux/microblaze/syscalls.list (msgctl): Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/syscalls.list (msgctl):
Likewise.
* sysdeps/unix/sysv/linux/x86_64/syscalls.list (msgctl): Likewise,
* sysdeps/unix/sysv/linux/mips/mips64/syscalls.list (msgctl):
Likewise.
* sysdeps/unix/sysv/linux/msgrcv.c (__libc_msgrcv): Use msgrcv syscall
if defined.
* sysdeps/unix/sysv/linux/sparc/sparc64/msgrcv.c: Remove file.
This patch consolidates the msgctl Linux implementation in only
one default file, sysdeps/unix/sysv/linux/msgctl.c. If tries to use
the direct syscall if it is supported, otherwise will use the old ipc
multiplex mechanism.
The patch also simplify header inclusion and reorganize internal
compat symbol to be built only if old ipc is defined.
Checked on x86_64, i686, powerpc64le, aarch64, and armhf.
* sysdeps/unix/sysv/linux/alpha/Makefile (sysdeps_routines): Remove
oldmsgctl.
* sysdeps/unix/sysv/linux/alpha/msgctl.c: Remove file.
* sysdeps/unix/sysv/linux/arm/msgctl.c: Likewise.
* sysdeps/unix/sysv/linux/microblaze/msgctl.c: Likewise.
* sysdeps/unix/sysv/linux/alpha/syscalls.list (oldmsgctl): Remove.
* sysdeps/unix/sysv/linux/generic/syscalls.list (msgctl): Likewise.
* sysdeps/unix/sysv/linux/hppa/syscalls.list (msgctl): Likewise.
* sysdeps/unix/sysv/linux/ia64/syscalls.list (msgctl): Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/syscalls.list (msgctl):
Likewise.
* sysdeps/unix/sysv/linux/x86_64/syscalls.list (msgctl): Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/msgctl.c: Use default
implementation.
* sysdeps/unix/sysv/linux/msgctl.c (__new_msgctl): Use msgctl syscall
if defined.
Some architectures support the old-style IPC and require IPC_64 equal to
0x100 to be passed along SysV IPC syscalls, while new architectures should
default to new IPC version (without the flags being set).
This patch refactor current ipc_priv.h Linux headers in two directions:
- Remove cross platform references (for instance alpha including powerpc
definition) and add required definition for each required port. The
idea is to avoid tie one architecture definition with another and make
platform change independent.
- Move all common definitions (the ipc syscall commands) on a common
header, ipc_ops.h.
* sysdeps/unix/sysv/linux/aarch64/ipc_priv.h: New file.
* sysdeps/unix/sysv/linux/alpha/ipc_priv.h: Avoid included other arch
definition and define its own.
* sysdeps/unix/sysv/linux/ipc_ops.h: New file.
* sysdeps/unix/sysv/linux/x86_64/ipc_priv.h: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/ipc_priv.h: Likewise.
* sysdeps/unix/sysv/linux/mips/ipc_priv.h: Remove file.
* sysdeps/unix/sysv/linux/mips/mips64/ipc_priv.h: New file.
* sysdeps/unix/sysv/linux/ipc_priv.h: Move ipc syscall operation
definitions to common header.
* sysdeps/unix/sysv/linux/powerpc/ipc_priv.h: Use common syscall
operation from ipc_ops.h.
On current minimum supported kernels, the SysV IPC on Linux is provided
by either the ipc syscalls or correspondent wire syscalls. Also, for
architectures that supports wire syscalls all syscalls are supported
in a set (msgct, msgrcv, msgsnd, msgget, semctl, semget, semop, semtimedop,
shmctl, shmat, shmget, shmdt).
The architectures that only supports ipc syscall are:
- i386, m68k, microblaze, mips32, powerpc (powerpc32, powerpc64, and
powerpc64le), s390 (32 and 64 bits), sh, sparc32, and sparc64.
And the architectures that only supports wired syscalls are:
- aarch64, alpha, hppa, ia64, mips64, mips64n32, nios2, tile
(tilepro, tilegx, and tilegx64), and x86_64
Also arm is the only one that supports both wire syscalls and the
ipc, although the ipc one is deprecated.
This patch adds a new define, __ASSUME_DIRECT_SYSVIPC_SYSCALL, that wired
syscalls are supported on the system and the general idea is to use
it where possible.
I also checked the syscall table for all architectures on Linux 4.9
and there is no change on described support for Linux 2.6.32/3.2.
* sysdeps/unix/sysv/linux/kernel-features.h
(__ASSUME_DIRECT_SYSVIPC_SYSCALL): New define.
* sysdeps/unix/sysv/linux/i386/kernel-features.h
(__ASSUME_DIRECT_SYSVIPC_SYSCALL): Undef.
* sysdeps/unix/sysv/linux/m68k/kernel-features.h
(__ASSUME_DIRECT_SYSVIPC_SYSCALL): Likewise.
* sysdeps/unix/sysv/linux/mips/kernel-features.h
(__ASSUME_DIRECT_SYSVIPC_SYSCALL): Likewise.
* sysdeps/unix/sysv/linux/powerpc/kernel-features.h
(__ASSUME_DIRECT_SYSVIPC_SYSCALL): Likewise.
* sysdeps/unix/sysv/linux/s390/kernel-features.h
(__ASSUME_DIRECT_SYSVIPC_SYSCALL): Likewise.
* sysdeps/unix/sysv/linux/sh/kernel-features.h
(__ASSUME_DIRECT_SYSVIPC_SYSCALL): Likewise.
* sysdeps/unix/sysv/linux/sparc/kernel-features.h
(__ASSUME_DIRECT_SYSVIPC_SYSCALL): Likewise.
These are called from the kernel with the stack at a carefully-
chosen location so that the stack frame can be restored: they must not
move the stack pointer lest garbage be restored into the registers.
We explicitly inhibit protection for SPARC and for signal/sigreturn.c:
other arches either define their sigreturn stubs in .S files, or (i386,
x86_64, mips) use macros expanding to top-level asm blocks and explicit
labels in the text section to mock up a "function" without telling the
compiler that one is there at all.
When dynamically linking, ifunc resolvers are called before TLS is
initialized, so they cannot be safely stack-protected.
We avoid disabling stack-protection on large numbers of files by
using __attribute__ ((__optimize__ ("-fno-stack-protector")))
to turn it off just for the resolvers themselves. (We provide
the attribute even when statically linking, because we will later
use it elsewhere too.)
Currently strsep calls strpbrk is is now a veneer to strcspn. Calling
strcspn directly is faster. Since it handles a delimiter string of size
1 as a special case, this is not needed in strsep itself. Although this
means there is a slightly higher overhead if the delimiter size is 1,
all other cases are slightly faster. The overall performance gain is 5-10%
on AArch64.
The string/bits/string2.h header contains optimizations for constant
delimiters of size 1-3. Benchmarking these showed similar performance for
size 1 (since in all cases strchr/strchrnul is used), while size 2 and 3
can give up to 2x speedup for small input strings. However if these cases
are common it seems much better to add this optimization to strcspn.
So move these header optimizations to string-inlines.c.
Improve the strsep benchmark so that it actually benchmarks something.
The current version contains a delimiter character at every position in the
input string, so there is very little work to do, and the extremely inefficent
simple_strsep implementation appears fastest in every case. The new version
has either no match in the input for the fail case and a match halfway in the
input for the success case. The input is then restored so that each iteration
does exactly the same amount of work. Reduce the number of testcases since
simple_strsep takes a lot of time now.
* benchtests/bench-strsep.c (oldstrsep): Add old implementation.
(do_one_test) Restore original string so iteration works.
* string/string-inlines.c (do_test): Create better input strings.
(test_main) Reduce number of testruns.
* string/string-inlines.c (__old_strsep_1c): New function.
(__old_strsep_2c): Likewise.
(__old_strsep_3c): Likewise.
* string/strsep.c (__strsep): Remove case of small delim string.
Call strcspn directly rather than strpbrk.
* string/bits/string2.h (__strsep): Remove define.
(__strsep_1c): Remove.
(__strsep_2c): Remove.
(__strsep_3c): Remove.
(strsep): Remove.
* sysdeps/unix/sysv/linux/internal_statvfs.c
(__statvfs_getflags): Rename to __strsep.
TS 18661-1 defines roundeven functions that round a floating-point
number to the nearest integer, in that floating-point type, with ties
rounding to even (whereas the round functions round ties away from
zero). As with other such functions, they raise no exceptions apart
from "invalid" for signaling NaNs. There was a previous user request
for this functionality in glibc in
<https://sourceware.org/ml/libc-help/2015-02/msg00005.html>.
This patch implements these functions for glibc. The implementations
use integer bit-manipulation (or roundeven on the high and low parts,
in the IBM long double case). It's possible that there may be faster
approaches on some architectures (in particular, on AArch64 the frintn
instruction should do exactly what's required); I'll leave it to
architecture maintainers or others interested to implement such
architecture-specific versions if desired. (Where architectures have
instructions to round to nearest integer in the current rounding mode,
implementations saving and restoring the rounding mode - and dealing
with exceptions if those instructions generate "inexact" - are also
possible, though their performance depends on the cost of manipulating
exceptions / rounding mode state.)
Tested for x86_64, x86, mips64 and powerpc.
* math/bits/mathcalls.h [__GLIBC_USE (IEC_60559_BFP_EXT)]
(roundeven): New declaration.
* math/tgmath.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (roundeven): New
macro.
* math/Versions (roundeven): New libm symbol at version
GLIBC_2.25.
(roundevenf): Likewise.
(roundevenl): Likewise.
* math/Makefile (libm-calls): Add s_roundevenF.
* math/libm-test.inc (roundeven_test_data): New array.
(roundeven_test): New function.
(main): Call roundeven_test.
* math/test-tgmath.c (NCALLS): Increase to 134.
(F(compile_test)): Call roundeven.
(F(roundeven)): New function.
* manual/arith.texi (Rounding Functions): Document roundeven,
roundevenf and roundevenl.
* manual/libm-err-tab.pl (@all_functions): Add roundeven.
* include/math.h (roundeven): Use libm_hidden_proto.
* sysdeps/ieee754/dbl-64/s_roundeven.c: New file.
* sysdeps/ieee754/dbl-64/wordsize-64/s_roundeven.c: Likewise.
* sysdeps/ieee754/flt-32/s_roundevenf.c: Likewise.
* sysdeps/ieee754/ldbl-128/s_roundevenl.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_roundevenl.c: Likewise.
* sysdeps/ieee754/ldbl-96/s_roundevenl.c: Likewise.
* sysdeps/ieee754/ldbl-opt/Makefile (libnldbl-calls): Add
roundeven.
(CFLAGS-nldbl-roundeven.c): New variable.
* sysdeps/ieee754/ldbl-opt/nldbl-roundeven.c: New file.
* sysdeps/nacl/libm.abilist: Update.
* sysdeps/unix/sysv/linux/aarch64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/alpha/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/arm/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/hppa/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/i386/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/ia64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/m68k/coldfire/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/m68k/m680x0/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/microblaze/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/nios2/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm-le.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sh/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/tile/tilepro/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/x32/libm.abilist: Likewise.
This patch decrements the adapt_count while unlocking the futex
instead of before aquiring the futex as it is done on power, too.
Furthermore a transaction is only started if the futex is currently free.
This check is done after starting the transaction, too.
If the futex is not free and the transaction nesting depth is one,
we can simply end the started transaction instead of aborting it.
The implementation of this check was faulty as it always ended the
started transaction. By using the fallback path, the the outermost
transaction was aborted. Now the outermost transaction is aborted
directly.
This patch also adds some commentary and aligns the code in
elision-trylock.c to the code in elision-lock.c as possible.
ChangeLog:
* sysdeps/unix/sysv/linux/s390/lowlevellock.h
(__lll_unlock_elision, lll_unlock_elision): Add adapt_count argument.
* sysdeps/unix/sysv/linux/s390/elision-lock.c:
(__lll_lock_elision): Decrement adapt_count while unlocking
instead of before locking.
* sysdeps/unix/sysv/linux/s390/elision-trylock.c
(__lll_trylock_elision): Likewise.
* sysdeps/unix/sysv/linux/s390/elision-unlock.c:
(__lll_unlock_elision): Likewise.
This patch implements __libc_tbegin_retry macro which is equivalent to
gcc builtin __builtin_tbegin_retry, except the changes which were applied
to __libc_tbegin in the previous patch.
If tbegin aborts with _HTM_TBEGIN_TRANSIENT. Then this macros restores
the fpc, fprs and automatically retries up to retry_cnt tbegins.
Further saving of the state is omitted as it is already saved in the
first round. Before retrying a further transaction, the
transaction-abort-assist instruction is used to support the cpu.
This macro is now used in function __lll_lock_elision.
ChangeLog:
* sysdeps/unix/sysv/linux/s390/htm.h(__libc_tbegin_retry): New macro.
* sysdeps/unix/sysv/linux/s390/elision-lock.c (__lll_lock_elision):
Use __libc_tbegin_retry macro.
This patch defines __libc_tbegin, __libc_tend, __libc_tabort and
__libc_tx_nesting_depth in htm.h which replaces the direct usage of
equivalent gcc builtins.
We have to use an own inline assembly instead of __builtin_tbegin,
as tbegin has to filter program interruptions which can't be done with
the builtin. Before this change, e.g. a segmentation fault within a
transaction, leads to a coredump where the instruction pointer points
behind the tbegin instruction instead of real failing one.
Now the transaction aborts and the code should be reexecuted by the
fallback path without transactions. The segmentation fault will
produce a coredump with the real failing instruction.
The fpc is not saved before starting the transaction. If e.g. the
rounging mode is changed and the transaction is aborting afterwards,
the builtin will not restore the fpc. This is now done with the
__libc_tbegin macro.
Now the call saved fprs have to be saved / restored in the
__libc_tbegin macro. Using the gcc builtin had forced the saving /
restoring of fprs at begin / end of e.g. __lll_lock_elision function.
The new macro saves these fprs before tbegin instruction and only
restores them on a transaction abort. Restoring is not needed on
a successfully started transaction.
The used inline assembly does not clobber the fprs / vrs!
Clobbering the latter ones would force the compiler to save / restore
the call saved fprs as those overlap with the vrs, but they only
need to be restored if the transaction fails. Thus the user of the
tbegin macros has to compile the file / function with -msoft-float.
It prevents gcc from using fprs / vrs.
ChangeLog:
* sysdeps/unix/sysv/linux/s390/Makefile (elision-CFLAGS):
Add -msoft-float.
* sysdeps/unix/sysv/linux/s390/htm.h: New File.
* sysdeps/unix/sysv/linux/s390/elision-lock.c:
Use __libc_t* transaction macros instead of __builtin_t*.
* sysdeps/unix/sysv/linux/s390/elision-trylock.c: Likewise.
* sysdeps/unix/sysv/linux/s390/elision-unlock.c: Likewise.
This uses atomic operations to access lock elision metadata that is accessed
concurrently (ie, adapt_count fields). The size of the data is less than a
word but accessed only with atomic loads and stores.
See also x86 commit ca6e601a9d4a72b3699cca15bad12ac1716bf49a:
"Use C11-like atomics instead of plain memory accesses in x86 lock elision."
ChangeLog:
* sysdeps/unix/sysv/linux/s390/elision-lock.c
(__lll_lock_elision): Use atomics to load / store adapt_count.
* sysdeps/unix/sysv/linux/s390/elision-trylock.c
(__lll_trylock_elision): Likewise.
explicit_bzero(s, n) is the same as memset(s, 0, n), except that the
compiler is not allowed to delete a call to explicit_bzero even if the
memory pointed to by 's' is dead after the call. Right now, this effect
is achieved externally by having explicit_bzero be a function whose
semantics are unknown to the compiler, and internally, with a no-op
asm statement that clobbers memory. This does mean that small
explicit_bzero operations cannot be expanded inline as small memset
operations can, but on the other hand, small memset operations do get
deleted by the compiler. Hopefully full compiler support for
explicit_bzero will happen relatively soon.
There are two new tests: test-explicit_bzero.c verifies the
visible semantics in the same way as the existing test-bzero.c,
and tst-xbzero-opt.c verifies the not-being-optimized-out property.
The latter is conceptually based on a test written by Matthew Dempsky
for the OpenBSD regression suite.
The crypt() implementation has an immediate use for this new feature.
We avoid having to add a GLIBC_PRIVATE alias for explicit_bzero
by running all of libcrypt's calls through the fortified variant,
__explicit_bzero_chk, which is in the impl namespace anyway. Currently
I'm not aware of anything in libc proper that needs this, but the
glue is all in place if it does become necessary. The legacy DES
implementation wasn't bothering to clear its buffers, so I added that,
mostly for consistency's sake.
* string/explicit_bzero.c: New routine.
* string/test-explicit_bzero.c, string/tst-xbzero-opt.c: New tests.
* string/Makefile (routines, strop-tests, tests): Add them.
* string/test-memset.c: Add ifdeffage for testing explicit_bzero.
* string/string.h [__USE_MISC]: Declare explicit_bzero.
* debug/explicit_bzero_chk.c: New routine.
* debug/Makefile (routines): Add it.
* debug/tst-chk1.c: Test fortification of explicit_bzero.
* string/bits/string3.h: Fortify explicit_bzero.
* manual/string.texi: Document explicit_bzero.
* NEWS: Mention addition of explicit_bzero.
* crypt/crypt-entry.c (__crypt_r): Clear key-dependent intermediate
data before returning, using explicit_bzero.
* crypt/md5-crypt.c (__md5_crypt_r): Likewise.
* crypt/sha256-crypt.c (__sha256_crypt_r): Likewise.
* crypt/sha512-crypt.c (__sha512_crypt_r): Likewise.
* include/string.h: Redirect internal uses of explicit_bzero
to __explicit_bzero_chk[_internal].
* string/Versions [GLIBC_2.25]: Add explicit_bzero.
* debug/Versions [GLIBC_2.25]: Add __explicit_bzero_chk.
* sysdeps/arm/nacl/libc.abilist
* sysdeps/unix/sysv/linux/aarch64/libc.abilist
* sysdeps/unix/sysv/linux/alpha/libc.abilist
* sysdeps/unix/sysv/linux/arm/libc.abilist
* sysdeps/unix/sysv/linux/hppa/libc.abilist
* sysdeps/unix/sysv/linux/i386/libc.abilist
* sysdeps/unix/sysv/linux/ia64/libc.abilist
* sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
* sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
* sysdeps/unix/sysv/linux/microblaze/libc.abilist
* sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
* sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
* sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
* sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
* sysdeps/unix/sysv/linux/nios2/libc.abilist
* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist
* sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
* sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
* sysdeps/unix/sysv/linux/sh/libc.abilist
* sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
* sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
* sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist
* sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist
* sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist
* sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
* sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist:
Add entries for explicit_bzero and __explicit_bzero_chk.
Information about whether the ABI of long double is the same as that
of double is split between bits/mathdef.h and bits/wordsize.h.
When the ABIs are the same, bits/mathdef.h defines
__NO_LONG_DOUBLE_MATH. In addition, in the case where the same glibc
binary supports both -mlong-double-64 and -mlong-double-128,
bits/wordsize.h defines __LONG_DOUBLE_MATH_OPTIONAL, along with
__NO_LONG_DOUBLE_MATH if this particular compilation is with
-mlong-double-64.
As part of the refactoring I proposed in
<https://sourceware.org/ml/libc-alpha/2016-11/msg00745.html>, this
patch puts all that information in a single header,
bits/long-double.h. It is included from sys/cdefs.h alongside the
include of bits/wordsize.h, so other headers generally do not need to
include bits/long-double.h directly.
Previously, various bits/mathdef.h headers and bits/wordsize.h headers
had this long double information (including implicitly in some
bits/mathdef.h headers through not having the defines present in the
default version). After the patch, it's all in six bits/long-double.h
headers. Furthermore, most of those new headers are not
architecture-specific. Architectures with optional long double all
use the ldbl-opt sysdeps directory, either in the order (ldbl-64-128,
ldbl-opt, ldbl-128) or (ldbl-128ibm, ldbl-opt). Thus a generic header
for the case where long double = double, and headers in ldbl-128,
ldbl-96 and ldbl-opt, suffices to cover every architecture except for
cases where long double properties vary between different ABIs sharing
a set of installed headers; fortunately all the ldbl-opt cases share a
single compiler-predefined macro __LONG_DOUBLE_128__ that can be used
to tell whether this compilation is -mlong-double-64 or
-mlong-double-128.
The two cases where a set of headers is shared between ABIs with
different long double properties, MIPS (o32 has long double = double,
other ABIs use ldbl-128) and SPARC (32-bit has optional long double,
64-bit has required long double), need their own bits/long-double.h
headers.
As with bits/wordsize.h, multiple-include protection for this header
is generally implicit through the include guards on sys/cdefs.h, and
multiple inclusion is harmless in any case. There is one subtlety:
the header must not define __LONG_DOUBLE_MATH_OPTIONAL if
__NO_LONG_DOUBLE_MATH was defined before its inclusion, because doing
so breaks how sysdeps/ieee754/ldbl-opt/nldbl-compat.h defines
__NO_LONG_DOUBLE_MATH itself before including system headers. Subject
to keeping that working, it would be reasonable to move these macros
from defined/undefined #ifdef to always-defined 1/0 #if semantics, but
this patch does not attempt to do so, just rearranges where the macros
are defined.
After this patch, the only use of bits/mathdef.h is the alpha one for
modifying complex function ABIs for old GCC. Thus, all versions of
the header other than the default and alpha versions are removed, as
is the include from math.h.
Tested for x86_64 and x86. Also did compilation-only testing with
build-many-glibcs.py.
* bits/long-double.h: New file.
* sysdeps/ieee754/ldbl-128/bits/long-double.h: Likewise.
* sysdeps/ieee754/ldbl-96/bits/long-double.h: Likewise.
* sysdeps/ieee754/ldbl-opt/bits/long-double.h: Likewise.
* sysdeps/mips/bits/long-double.h: Likewise.
* sysdeps/unix/sysv/linux/sparc/bits/long-double.h: Likewise.
* math/Makefile (headers): Add bits/long-double.h.
* misc/sys/cdefs.h: Include <bits/long-double.h>.
* stdlib/strtold.c: Include <bits/long-double.h> instead of
<bits/wordsize.h>.
* bits/mathdef.h [!_COMPLEX_H]: Do not allow inclusion.
[!__NO_LONG_DOUBLE_MATH]: Remove conditional code.
* math/math.h: Do not include <bits/mathdef.h>.
* sysdeps/aarch64/bits/mathdef.h: Remove file.
* sysdeps/alpha/bits/mathdef.h [!_COMPLEX_H]: Do not allow
inclusion.
* sysdeps/ia64/bits/mathdef.h: Remove file.
* sysdeps/m68k/m680x0/bits/mathdef.h: Likewise.
* sysdeps/mips/bits/mathdef.h: Likewise.
* sysdeps/powerpc/bits/mathdef.h: Likewise.
* sysdeps/s390/bits/mathdef.h: Likewise.
* sysdeps/sparc/bits/mathdef.h: Likewise.
* sysdeps/x86/bits/mathdef.h: Likewise.
* sysdeps/s390/s390-32/bits/wordsize.h
[!__NO_LONG_DOUBLE_MATH && !__LONG_DOUBLE_MATH_OPTIONAL]: Remove
conditional code.
* sysdeps/s390/s390-64/bits/wordsize.h
[!__NO_LONG_DOUBLE_MATH && !__LONG_DOUBLE_MATH_OPTIONAL]:
Likewise.
* sysdeps/unix/sysv/linux/alpha/bits/wordsize.h
[!__NO_LONG_DOUBLE_MATH && !__LONG_DOUBLE_MATH_OPTIONAL]:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/bits/wordsize.h
[!__NO_LONG_DOUBLE_MATH && !__LONG_DOUBLE_MATH_OPTIONAL]:
Likewise.
* sysdeps/unix/sysv/linux/sparc/bits/wordsize.h
[!__NO_LONG_DOUBLE_MATH && !__LONG_DOUBLE_MATH_OPTIONAL]:
Likewise.
This patch makes bits/fcntl-linux.h include <linux/falloc.h> to define
the FALLOC_* flags under __USE_GNU (linux/falloc.h defines only those
bits, nothing else).
Tested for x86_64 and x86.
* sysdeps/unix/sysv/linux/bits/fcntl-linux.h [__USE_GNU]: Include
<linux/falloc.h>.
(FALLOC_FL_KEEP_SIZE): Remove.
(FALLOC_FL_PUNCH_HOLE): Likewise.
(FALLOC_FL_COLLAPSE_RANGE): Likewise.
(FALLOC_FL_ZERO_RANGE): Likewise.
This patch consolidates the Linux renameat implementation on
sysdeps/unix/sysv/linux/renameat.c. The renameat syscall was
deprecated at b0da6d44 for newer architectures, so using the
auto-generation list may generate wrappers that returns ENOSYS.
Current code try to use __NR_renameat and if it is not define
it uses __NR_renameat2.
Checked on x86_64 and aarch64.
* sysdeps/unix/sysv/linux/renameat.c: New file.
* sysdeps/unix/sysv/linux/syscalls.list: Remove renameat.
This patch consolidates the Linux rename implementation on
sysdeps/unix/sysv/linux/rename.c. Current code try to use
__NR_rename if is defined and apply the same strategy for
__NR_renameat and __NR_renameat2.
Check on x86_64 and aarch64.
* sysdeps/unix/sysv/linux/rename.c: New file.
* sysdeps/unix/sysv/linux/generic/rename.c: Remove file.
The new test driver in <support/test-driver.c> has feature parity with
the old one. The main difference is that its hooking mechanism is
based on functions and function pointers instead of macros. This
commit also implements a new environment variable, TEST_COREDUMPS,
which disables the code which disables coredumps (that is, it enables
them if the invocation environment has not disabled them).
<test-skeleton.c> defines wrapper functions so that it is possible to
use existing macros with the new-style hook functionality.
This commit changes only a few test cases to the new test driver, to
make sure that it works as expected.
This uses atomic operations to access lock elision metadata that is accessed
concurrently (ie, adapt_count fields). The size of the data is less than a
word but accessed only with atomic loads and stores; therefore, we add
support for shorter-size atomic load and stores too.
* include/atomic.h (__atomic_check_size_ls): New.
(atomic_load_relaxed, atomic_load_acquire, atomic_store_relaxed,
atomic_store_release): Use it.
* sysdeps/x86/elide.h (ACCESS_ONCE): Remove.
(elision_adapt, ELIDE_LOCK): Use atomics.
* sysdeps/unix/sysv/linux/x86/elision-lock.c (__lll_lock_elision): Use
atomics and improve code comments.
* sysdeps/unix/sysv/linux/x86/elision-trylock.c
(__lll_trylock_elision): Likewise.
TS 18661-1 defines llogb functions that are like ilogb except that
they return long int instead of int. Corresponding FP_LLOGB* macros
are defined, whose values are required to have the obvious
correspondence to those of the FP_ILOGB* macros.
This patch implements these functions and macros for glibc. llogb
uses the type-generic infrastructure, with an implementation similar
to the wrapper for ilogb but with additional conversion from FP_ILOGB*
to FP_LLOGB*; this approach avoids needing to modify or duplicate any
of the architecture-specific ilogb implementations. Tests are also
based on those for ilogb.
Ideally the llogb functions would alias the ilogb ones when long is
32-bit, but such aliasing requires the associated header declarations
of the different-type alias to be hidden, typically by defining macros
before including the header (see e.g. how
sysdeps/ieee754/dbl-64/wordsize-64/s_llround.c defines lround to
__hidden_lround before including <math.h>). The infrastructure for
type-generic function implementations does not support defining such
macros at present (since C code can't define a macro whose name is
determined by other macros). So this patch leaves them as separate
functions (similar to e.g. scalbln and scalbn being separate in such a
case as well), but with the remapping of FP_ILOGB* to FP_LLOGB*
conditioned out in the case where it would be the identity map.
Tested for x86_64, x86, mips64 and powerpc.
* math/bits/mathcalls.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (llogb):
New declaration.
* math/tgmath.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (llogb): New
macro.
* math/math.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (__FP_LONG_MAX):
New macro.
[__GLIBC_USE (IEC_60559_BFP_EXT)] (FP_LLOGB0): Likewise.
[__GLIBC_USE (IEC_60559_BFP_EXT)] (FP_LLOGBNAN): Likewise.
* math/Versions (llogb): New libm symbol at version GLIBC_2.25.
(llogbf): Likewise.
(llogbl): Likewise.
* math/Makefile (gen-libm-calls): Add w_llogbF.
(tests): Add test-fp-llogb-constants.
* math/w_llogb_template.c: New file. Based on
math/w_ilogb_template.c.
* math/libm-test.inc (llogb_test_data): New array.
(llogb_test): New function.
(main): Call llogb_test.
* math/test-fp-llogb-constants.c: New file. Based on
math/test-fp-ilogb-constants.c.
* math/test-tgmath-ret.c (llogb): New CHECK_RET_CONST call.
(do_test): Call check_return_llogb.
* math/test-tgmath.c (NCALLS): Increase to 126.
(F(compile_test)): Call llogb.
(F(llogb)): New function.
* manual/math.texi (Exponents and Logarithms): Document llogb,
llogbf, llogbl, FP_LLOGB0 and FP_LLOGBNAN.
* manual/libm-err-tab.pl (@all_functions): Add llogb.
* sysdeps/ieee754/ldbl-opt/nldbl-llogb.c: New file.
* sysdeps/ieee754/ldbl-opt/w_llogbl.c: Likewise.
* sysdeps/ieee754/ldbl-opt/Makefile (libnldbl-calls): Add llogb.
(CFLAGS-nldbl-llogb.c): New variable.
* sysdeps/nacl/libm.abilist: Update.
* sysdeps/unix/sysv/linux/aarch64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/alpha/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/arm/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/hppa/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/i386/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/ia64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/m68k/coldfire/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/m68k/m680x0/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/microblaze/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/nios2/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm-le.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sh/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/tile/tilepro/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/x32/libm.abilist: Likewise.
It is no longer needed since commit 6c444ad6e9
(elf: Do not use memalign for TCB/TLS blocks allocation [BZ #17730]).
Applications do not link against ld.so and will use the definition in
libc.so, so there is no ABI impact.
This change moves the main implementation of _dl_catch_error,
_dl_signal_error to libc.so, where TLS variables can be used
directly. This removes a writable function pointer from the
rtld_global variable.
For use during initial relocation, minimal implementations of these
functions are provided in ld.so. These are eventually interposed
by the libc.so implementations. This is implemented by compiling
elf/dl-error-skeleton.c twice, via elf/dl-error.c and
elf/dl-error-minimal.c.
As a side effect of this change, the static version of dl-error.c
no longer includes support for the
_dl_signal_cerror/_dl_receive_error mechanism because it is only
used in ld.so.
* sysdeps/unix/sysv/linux/generic/wordsize-32/fxstat.c: Do not define
fxstat if XSTAT_IS_XSTAT64 is set to non-zero.
* sysdeps/unix/sysv/linux/generic/wordsize-32/fxstatat.c: Ditto for
fxstatat.
* sysdeps/unix/sysv/linux/generic/wordsize-32/lxstat.c: Ditto for
lxstat.
* sysdeps/unix/sysv/linux/generic/wordsize-32/xstat.c: Ditto for xstat.
* sysdeps/unix/sysv/linux/generic/wordsize-32/fxstat64.c: New file.
* sysdeps/unix/sysv/linux/generic/wordsize-32/fxstatat64.c: New file.
* sysdeps/unix/sysv/linux/generic/wordsize-32/lxstat64.c: Make __lxstat
an alias of __lxstat64 if XSTAT_IS_XSTAT64 is set to non-zero.
* sysdeps/unix/sysv/linux/generic/wordsize-32/xstat64.c: Ditto for
__xstat.
The __longjmp symbol was left in accidentally. It is not exported
through a Versions file, but through a .symver assembler directive.
The corresponding exported symbol was removed from the non-fpu
powerpc64 targets in commit 9b9ef82358.
Building tests for IA64 runs into a build failure compiling
stdlib/tst-setcontext2.c:
tst-setcontext2.c: In function 'do_test':
tst-setcontext2.c:210:20: error: passing argument 1 of 'sigismember' from incompatible pointer type [-Werror=incompatible-pointer-types]
if (sigismember (&oldctx.uc_sigmask, SIGUSR2) != 1)
^
Indeed, the IA64 uc_sigmask as unsigned long rather than the larger
userspace sigset_t. Fixing this might be hard; this patch works
around the build failure by making IA64 wrap the test with a version
that #defines sigismember to add a cast (I'd welcome a better approach
for fixing this).
Tested (compilation only) for ia64.
* sysdeps/unix/sysv/linux/ia64/tst-setcontext2.c: New file.
* sysdeps/unix/sysv/linux/fstatfs64.c: Reorder include files,
only alias fstatfs and __fstatfs if STATFS_IS_STATFS64 is non-zero.
* sysdeps/unix/sysv/linux/statfs64.c: Ditto for statfs and __statfs.
The nios2 sys/cachectl.h includes a kernel header asm/cachectl.h,
which does not exist, so causing the check-installed-headers tests to
fail. This patch removes the include of a nonexistent header.
Tested (compilation only) for nios2.
* sysdeps/unix/sysv/linux/nios2/sys/cachectl.h: Do not include
<asm/cachectl.h>.
TS 18661-1 defines functions for manipulating the payloads of NaNs.
This patch implements the setpayloadsig functions for glibc; these are
like the setpayload functions, but produce a signaling NaN instead of
a quiet NaN.
The substance of the implementation was included with the setpayload
implementation, so the new files here just need to wrap the main files
with different defines to build the new functions.
Because the functions store a signaling NaN via a pointer and the
libm-test macros choose a suitable initial value for the variable in
such a case by comparing with the expected value, the relevant macro
needs to clear exceptions after FE_INVALID may have been raised by
that comparison.
Tested for x86_64, x86, mips64 and powerpc.
* math/bits/mathcalls.h [__GLIBC_USE (IEC_60559_BFP_EXT)]
(setpayloadsig): New declaration.
* math/Versions (setpayloadsig): New libm symbol at version
GLIBC_2.25.
(setpayloadsigf): Likewise.
(setpayloadsigl): Likewise.
* math/Makefile (libm-calls): Add s_setpayloadsigF.
* math/libm-test.inc (RUN_TEST_Ff_b1): Call feclearexcept
(FE_ALL_EXCEPT) after initializing EXTRA_VAR.
(setpayloadsig_test_data): New array.
(setpayloadsig_test): New function.
(main): Call setpayloadsig_test.
* manual/arith.texi (FP Bit Twiddling): Document setpayloadsig,
setpayloadsigf and setpayloadsigl.
* manual/libm-err-tab.pl: Update comment on interfaces without
ulps tabulated.
* sysdeps/ieee754/dbl-64/s_setpayloadsig.c: New file.
* sysdeps/ieee754/flt-32/s_setpayloadsigf.c: Likewise.
* sysdeps/ieee754/ldbl-128/s_setpayloadsigl.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_setpayloadsigl.c: Likewise.
* sysdeps/ieee754/ldbl-96/s_setpayloadsigl.c: Likewise.
* sysdeps/ieee754/ldbl-opt/nldbl-setpayloadsig.c: Likewise.
* sysdeps/ieee754/ldbl-opt/Makefile (libnldbl-calls): Add
setpayloadsig.
(CFLAGS-nldbl-setpayloadsig.c): New variable.
* sysdeps/nacl/libm.abilist: Update.
* sysdeps/unix/sysv/linux/aarch64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/alpha/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/arm/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/hppa/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/i386/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/ia64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/m68k/coldfire/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/m68k/m680x0/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/microblaze/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/nios2/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm-le.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sh/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/tile/tilepro/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/x32/libm.abilist: Likewise.
This patch remove the PID cache and usage in current GLIBC code. Current
usage is mainly used a performance optimization to avoid the syscall,
however it adds some issues:
- The exposed clone syscall will try to set pid/tid to make the new
thread somewhat compatible with current GLIBC assumptions. This cause
a set of issue with new workloads and usecases (such as BZ#17214 and
[1]) as well for new internal usage of clone to optimize other algorithms
(such as clone plus CLONE_VM for posix_spawn, BZ#19957).
- The caching complexity also added some bugs in the past [2] [3] and
requires more effort of each port to handle such requirements (for
both clone and vfork implementation).
- Caching performance gain in mainly on getpid and some specific
code paths. The getpid performance leverage is questionable [4],
either by the idea of getpid being a hotspot as for the getpid
implementation itself (if it is indeed a justifiable hotspot a
vDSO symbol could let to a much more simpler solution).
Other usage is mainly for non usual code paths, such as pthread
cancellation signal and handling.
For thread creation (on stack allocation) the code simplification in fact
adds some performance gain due the no need of transverse the stack cache
and invalidate each element pid.
Other thread usages will require a direct getpid syscall, such as
cancellation/setxid signal, thread cancellation, thread fail path (at
create_thread), and thread signal (pthread_kill and pthread_sigqueue).
However these are hardly usual hotspots and I think adding a syscall is
justifiable.
It also simplifies both the clone and vfork arch-specific implementation.
And by review each fork implementation there are some discrepancies that
this patch also solves:
- microblaze clone/vfork does not set/reset the pid/tid field
- hppa uses the default vfork implementation that fallback to fork.
Since vfork is deprecated I do not think we should bother with it.
The patch also removes the TID caching in clone. My understanding for
such semantic is try provide some pthread usage after a user program
issue clone directly (as done by thread creation with CLONE_PARENT_SETTID
and pthread tid member). However, as stated before in multiple discussions
threads, GLIBC provides clone syscalls without further supporting all this
semantics.
I ran a full make check on x86_64, x32, i686, armhf, aarch64, and powerpc64le.
For sparc32, sparc64, and mips I ran the basic fork and vfork tests from
posix/ folder (on a qemu system). So it would require further testing
on alpha, hppa, ia64, m68k, nios2, s390, sh, and tile (I excluded microblaze
because it is already implementing the patch semantic regarding clone/vfork).
[1] https://codereview.chromium.org/800183004/
[2] https://sourceware.org/ml/libc-alpha/2006-07/msg00123.html
[3] https://sourceware.org/bugzilla/show_bug.cgi?id=15368
[4] http://yarchive.net/comp/linux/getpid_caching.html
* sysdeps/nptl/fork.c (__libc_fork): Remove pid cache setting.
* nptl/allocatestack.c (allocate_stack): Likewise.
(__reclaim_stacks): Likewise.
(setxid_signal_thread): Obtain pid through syscall.
* nptl/nptl-init.c (sigcancel_handler): Likewise.
(sighandle_setxid): Likewise.
* nptl/pthread_cancel.c (pthread_cancel): Likewise.
* sysdeps/unix/sysv/linux/pthread_kill.c (__pthread_kill): Likewise.
* sysdeps/unix/sysv/linux/pthread_sigqueue.c (pthread_sigqueue):
Likewise.
* sysdeps/unix/sysv/linux/createthread.c (create_thread): Likewise.
* sysdeps/unix/sysv/linux/getpid.c: Remove file.
* nptl/descr.h (struct pthread): Change comment about pid value.
* nptl/pthread_getattr_np.c (pthread_getattr_np): Remove thread
pid assert.
* sysdeps/unix/sysv/linux/pthread-pids.h (__pthread_initialize_pids):
Do not set pid value.
* nptl_db/td_ta_thr_iter.c (iterate_thread_list): Remove thread
pid cache check.
* nptl_db/td_thr_validate.c (td_thr_validate): Likewise.
* sysdeps/aarch64/nptl/tcb-offsets.sym: Remove pid offset.
* sysdeps/alpha/nptl/tcb-offsets.sym: Likewise.
* sysdeps/arm/nptl/tcb-offsets.sym: Likewise.
* sysdeps/hppa/nptl/tcb-offsets.sym: Likewise.
* sysdeps/i386/nptl/tcb-offsets.sym: Likewise.
* sysdeps/ia64/nptl/tcb-offsets.sym: Likewise.
* sysdeps/m68k/nptl/tcb-offsets.sym: Likewise.
* sysdeps/microblaze/nptl/tcb-offsets.sym: Likewise.
* sysdeps/mips/nptl/tcb-offsets.sym: Likewise.
* sysdeps/nios2/nptl/tcb-offsets.sym: Likewise.
* sysdeps/powerpc/nptl/tcb-offsets.sym: Likewise.
* sysdeps/s390/nptl/tcb-offsets.sym: Likewise.
* sysdeps/sh/nptl/tcb-offsets.sym: Likewise.
* sysdeps/sparc/nptl/tcb-offsets.sym: Likewise.
* sysdeps/tile/nptl/tcb-offsets.sym: Likewise.
* sysdeps/x86_64/nptl/tcb-offsets.sym: Likewise.
* sysdeps/unix/sysv/linux/aarch64/clone.S: Remove pid and tid caching.
* sysdeps/unix/sysv/linux/alpha/clone.S: Likewise.
* sysdeps/unix/sysv/linux/arm/clone.S: Likewise.
* sysdeps/unix/sysv/linux/hppa/clone.S: Likewise.
* sysdeps/unix/sysv/linux/i386/clone.S: Likewise.
* sysdeps/unix/sysv/linux/ia64/clone2.S: Likewise.
* sysdeps/unix/sysv/linux/mips/clone.S: Likewise.
* sysdeps/unix/sysv/linux/nios2/clone.S: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/clone.S: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/clone.S: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/clone.S: Likewise.
* sysdeps/unix/sysv/linux/sh/clone.S: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc32/clone.S: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/clone.S: Likewise.
* sysdeps/unix/sysv/linux/tile/clone.S: Likewise.
* sysdeps/unix/sysv/linux/x86_64/clone.S: Likewise.
* sysdeps/unix/sysv/linux/aarch64/vfork.S: Remove pid set and reset.
* sysdeps/unix/sysv/linux/alpha/vfork.S: Likewise.
* sysdeps/unix/sysv/linux/arm/vfork.S: Likewise.
* sysdeps/unix/sysv/linux/i386/vfork.S: Likewise.
* sysdeps/unix/sysv/linux/ia64/vfork.S: Likewise.
* sysdeps/unix/sysv/linux/m68k/clone.S: Likewise.
* sysdeps/unix/sysv/linux/m68k/vfork.S: Likewise.
* sysdeps/unix/sysv/linux/mips/vfork.S: Likewise.
* sysdeps/unix/sysv/linux/nios2/vfork.S: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/vfork.S: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/vfork.S: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/vfork.S: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/vfork.S: Likewise.
* sysdeps/unix/sysv/linux/sh/vfork.S: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc32/vfork.S: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/vfork.S: Likewise.
* sysdeps/unix/sysv/linux/tile/vfork.S: Likewise.
* sysdeps/unix/sysv/linux/x86_64/vfork.S: Likewise.
* sysdeps/unix/sysv/linux/tst-clone2.c (f): Remove direct pthread
struct access.
(clone_test): Remove function.
(do_test): Rewrite to take in consideration pid is not cached anymore.
* sysdeps/unix/sysv/linux/fstatfs64.c: Hide prototypes for fstatfs
and __fstatfs. Make them aliases of __fstatfs64 if
STATFS_IS_STATFS64 is set to non-zero.
* sysdeps/unix/sysv/linux/statfs64.c: Ditto for __statfs, statfs,
and __statfs64.
* sysdeps/unix/sysv/linux/generic/wordsize-32/fstatfs.c: Do not
define __fstatfs and fstatfs if STATFS_IS_STATFS64 is non-zero.
* sysdeps/unix/sysv/linux/generic/wordsize-32/statfs.c: Ditto
for __statfs and statfs.
* sysdeps/unix/sysv/linux/alpha/kernel_stat.h: Set STATFS_IS_STATFS64
to 0.
* sysdeps/unix/sysv/linux/generic/kernel_stat.h: Ditto.
* sysdeps/unix/sysv/linux/hppa/kernel_stat.h: Ditto.
* sysdeps/unix/sysv/linux/ia64/kernel_stat.h: Ditto.
* sysdeps/unix/sysv/linux/kernel_stat.h: Ditto.
* sysdeps/unix/sysv/linux/microblaze/kernel_stat.h: Ditto.
* sysdeps/unix/sysv/linux/mips/kernel_stat.h: Ditto.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/kernel_stat.h: Ditto.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/kernel_stat.h: Ditto.
* sysdeps/unix/sysv/linux/s390/s390-64/kernel_stat.h: Ditto.
* sysdeps/unix/sysv/linux/sparc/sparc32/kernel_stat.h: Ditto.
* sysdeps/unix/sysv/linux/sparc/sparc64/kernel_stat.h: Ditto.
* sysdeps/unix/sysv/linux/x86_64/kernel_stat.h: Ditto.
TS 18661-1 defines functions for manipulating the payloads of NaNs.
This patch implements the setpayload functions for glibc; these set a
number (pointed to by a function argument) to a quiet NaN with the
given payload, or to +0 if the given payload is not valid. The
implementations are structured to allow the substance of the
implementation to be shared with the setpayloadsig functions when
those are added.
The semantics in the TS are not entirely clear in the case where the
payload passed to the function is zero (see discussion on the WG14
reflector last month). This patch implements what seems the most
sensible interpretation, that -0 is never valid to give as the
payload, but +0 is valid in the case where the kind of NaN being
generated has its high mantissa bit set so payload 0 is actually
possible in such a NaN.
Tested for x86_64, x86, mips64 and powerpc.
* math/bits/mathcalls.h [__GLIBC_USE (IEC_60559_BFP_EXT)]
(setpayload): New declaration.
* math/Versions (setpayload): New libm symbol at version
GLIBC_2.25.
(setpayloadf): Likewise.
(setpayloadl): Likewise.
* math/Makefile (libm-calls): Add s_setpayloadF.
* math/libm-test.inc (struct test_Ffp_b1_data): Rename to struct
test_Ff_b1_data.
(RUN_TEST_Ff_b1): New macro.
(RUN_TEST_LOOP_Ff_b1): Likewise.
(canonicalize_test_data): Update type.
(setpayload_test_data): New array.
(setpayload_test): New function.
(main): Call setpayload_test.
* manual/arith.texi (FP Bit Twiddling): Document setpayload,
setpayloadf and setpayloadl.
* manual/libm-err-tab.pl: Update comment on interfaces without
ulps tabulated.
* sysdeps/ieee754/dbl-64/s_setpayload.c: New file.
* sysdeps/ieee754/dbl-64/s_setpayload_main.c: Likewise.
* sysdeps/ieee754/dbl-64/wordsize-64/s_setpayload_main.c:
Likewise.
* sysdeps/ieee754/flt-32/s_setpayloadf.c: Likewise.
* sysdeps/ieee754/flt-32/s_setpayloadf_main.c: Likewise.
* sysdeps/ieee754/ldbl-128/s_setpayloadl.c: Likewise.
* sysdeps/ieee754/ldbl-128/s_setpayloadl_main.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_setpayloadl.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_setpayloadl_main.c: Likewise.
* sysdeps/ieee754/ldbl-96/s_setpayloadl.c: Likewise.
* sysdeps/ieee754/ldbl-96/s_setpayloadl_main.c: Likewise.
* sysdeps/ieee754/ldbl-opt/nldbl-setpayload.c: Likewise.
* sysdeps/ieee754/ldbl-opt/Makefile (libnldbl-calls): Add
setpayload.
(CFLAGS-nldbl-setpayload.c): New variable.
* sysdeps/nacl/libm.abilist: Update.
* sysdeps/unix/sysv/linux/aarch64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/alpha/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/arm/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/hppa/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/i386/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/ia64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/m68k/coldfire/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/m68k/m680x0/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/microblaze/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/nios2/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm-le.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sh/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/tile/tilepro/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/x32/libm.abilist: Likewise.
The set_dataplane() API in <sys/dataplane.h> originally supported the
Tilera version of Linux as shipped to our customers. Once we started
upstreaming the dataplane support in the kernel, the API changed
to use fcntl() as part of the current task-isolation patch series.
It doesn't seem like continuing to support the old API is useful
for newly-compiled code, and even supporting the old glibc binary
API on an upstream kernel that supports the new task isolation mode
isn't straightforward, since the semantics have changed in ways that
make it hard to map the old semantics precisely to the new ones,
so just return ENOSYS.
Torvald Riegel
Joseph Myers
Adhemerval Zanella
Nick Alcock
Wilco Dijkstra
Stefan Liebler
Zack Weinberg
Florian Weimer
Andreas Schwab
Steve Ellcey
Chris Metcalf