This patch fixes bug 16789, incorrect sign of (real part) zero result
from clog and clog10 in round-downward mode, arising from that real
part being computed as 0 - 0. To ensure that an underflow exception
occurred, the code used an underflowing value (the next term in the
series for log1p) in arithmetic computing the real part of the result,
yielding the problematic 0 - 0 computation in some cases even when the
mathematical result would be small but positive. The patch changes
this code to use the math_force_eval approach to ensuring that an
underflowing computation actually occurs. Tests of clog and clog10
are enabled in all rounding modes.
Tested x86_64 and x86 and ulps updated accordingly.
[BZ #16789]
* math/s_clog.c (__clog): Use math_force_eval to ensure underflow
instead of using underflowing value in computing result.
* math/s_clog10.c (__clog10): Likewise.
* math/s_clog10f.c (__clog10f): Likewise.
* math/s_clog10l.c (__clog10l): Likewise.
* math/s_clogf.c (__clogf): Likewise.
* math/s_clogl.c (__clogl): Likewise.
* math/libm-test.inc (clog_test): Use ALL_RM_TEST.
(clog10_test): Likewise.
* sysdeps/i386/fpu/libm-test-ulps: Update.
* sysdeps/x86_64/fpu/libm-test-ulps: Likewise.
Fix for values near a power of two, and some tidies.
[BZ #16739]
* sysdeps/ieee754/ldbl-128ibm/s_nextafterl.c (__nextafterl): Correct
output when value is near a power of two. Use int64_t for lx and
remove casts. Use decimal rather than hex exponent constants.
Don't use long double multiplication when double will suffice.
* math/libm-test.inc (nextafter_test_data): Add tests.
* NEWS: Add 16739 and 16786 to bug list.
Without this flag it is possible that the compiler will optimize
away the calls to ffs/ffsll.
ChangeLog:
2014-04-01 Will Newton <will.newton@linaro.org>
* benchtests/Makefile (CFLAGS-bench-ffs.c): Add
-fno-builtin. (CFLAGS-bench-ffsll.c): Likewise.
At this point, we can only abort the process because we have already
switched credentials on other threads. Returning an error would still
leave the process in an inconsistent state.
The new xtest needs root privileges to run.
This patch fixes the default mode of scalb to set errno (bugs 6803 and
6804).
Previously, the _LIB_VERSION == _SVID_ mode would set errno but only
in some relevant cases, and with various peculiarities (such as errno
setting when an exact infinity or zero result arises with an argument
to scalb being an infinity). This patch leaves this mode
bug-compatible, while making the default mode set errno in accordance
with normal practice (so an exact infinity from an infinite argument
is not an error, and nor is an exact zero result). gen-libm-test.pl
is taught new notation such as ERRNO_PLUS_OFLOW to facilitate writing
the tests of errno setting for underflow / overflow in libm-test.inc.
Note that bug 6803 also covers scalbn and scalbln, but this patch only
addresses the scalb parts of that bug (along with the whole of bug
6804).
Tested x86_64 and x86.
[BZ #6803]
[BZ #6804]
* math/w_scalb.c (__scalb): For non-SVID mode, check result and
set errno as appropriate.
* math/w_scalbf.c (__scalbf): Likewise.
* math/w_scalbl.c (__scalbl): Likewise.
* math/gen-libm-test.pl (parse_args): Handle ERRNO_PLUS_OFLOW,
ERRNO_MINUS_OFLOW, ERRNO_PLUS_UFLOW and ERRNO_MINUS_UFLOW.
* math/libm-test.inc (scalb_test_data): Add errno expectations.
Add more NaN tests.
This patch fixes bug 16349, missing errno setting for atan2 underflow,
by adding appropriate checks to the existing wrappers. (As in other
cases, the __kernel_standard support for calling matherr is considered
to be for existing code expecting existing rules for what's considered
an error, even if those don't correspond to a general logical scheme
for what counts as what kind of error, so __set_errno calls are added
directly without any changes to __kernel_standard.)
Tested x86_64 and x86.
[BZ #16349]
* math/w_atan2.c: Include <errno.h>.
(__atan2): Set errno for result underflowing to zero.
* math/w_atan2f.c: Include <errno.h>.
(__atan2f): Set errno for result underflowing to zero.
* math/w_atan2l.c: Include <errno.h>.
(__atan2l): Set errno for result underflowing to zero.
* math/auto-libm-test-in: Don't allow missing errno for some atan2
tests.
* math/auto-libm-test-out: Regenerated.
This patch continues fixing __ASSUME_* issues in preparation for
moving to a 2.6.32 minimum kernel version by addressing assumptions on
robust mutex and PI futex support availability. Those assumptions are
bug 9894, but to be clear this patch does not address all the issues
from that bug about wrong version assumptions, only those still
applicable for --enable-kernel=2.6.32 or later (with the expectation
that the move to that minimum kernel will obsolete the other parts of
the bug). The patch is independent of
<https://sourceware.org/ml/libc-alpha/2014-03/msg00585.html>, my other
pending-review patch preparing for the kernel version change; the two
together complete all the changes I believe are needed in preparation
regarding any macro in sysdeps/unix/sysv/linux/kernel-features.h that
would be affected by such a change. (I have not checked the
correctness of macros whose conditions are unaffected by such a
change, or macros only defined in other kernel-features.h files.)
As discussed in that bug, robust mutexes and PI futexes need
futex_atomic_cmpxchg_inatomic to be implemented, in addition to
certain syscalls needed for robust mutexes (and
architecture-independent kernel pieces for all the features in
question). That is, as I understand it, they need
futex_atomic_cmpxchg_inatomic to *work* (not return an ENOSYS error).
The issues identified in my analysis relate to ARM, M68K, MicroBlaze,
MIPS and SPARC.
On ARM, whether futex_atomic_cmpxchg_inatomic works depends on the
kernel configuration. As of 3.13, the condition for *not* working is
CONFIG_CPU_USE_DOMAINS && CONFIG_SMP. As of 2.6.32 it was simply
CONFIG_SMP that meant the feature was not implemented. I don't know
if there are any circumstances in which we can say "we can assume a
userspace glibc binary built with these options will never run on a
kernel with the problematic configuration", but at least for now I'm
just undefining the relevant __ASSUME_* macros for ARM.
On M68K, two of the three macros are undefined for kernels before
3.10, but as far as I can see __ASSUME_FUTEX_LOCK_PI is in the same
group needing futex_atomic_cmpxchg_inatomic support and so should be
undefined as well.
On MicroBlaze the required support was added in 2.6.33.
On MIPS, the support depends on cpu_has_llsc in the kernel - that is,
actual hardware LL/SC support (GCC and glibc for MIPS GNU/Linux rely
on the instructions being supported in some way, but it may be kernel
emulation; futex_atomic_cmpxchg_inatomic doesn't work with that
emulation). The same condition as in GCC for indicating LL/SC support
may not be available is used for undefining the macros in glibc,
__mips == 1 || defined _MIPS_ARCH_R5900. (Maybe we could in fact
desupport MIPS processors without the hardware support in glibc.)
On SPARC, 32-bit kernels don't support futex_atomic_cmpxchg_inatomic;
__arch64__ || __sparc_v9__ is used as the condition for binaries that
won't run on 32-bit kernels.
This patch is not tested beyond the sanity check of an x86_64 build.
[BZ #9894]
* sysdeps/unix/sysv/linux/kernel-features.h
[__sparc__ && !__arch64__ && !__sparc_v9__]
(__ASSUME_SET_ROBUST_LIST): Do not define.
[__sparc__ && !__arch64__ && !__sparc_v9__]
(__ASSUME_FUTEX_LOCK_PI): Likewise.
[__sparc__ && !__arch64__ && !__sparc_v9__] (__ASSUME_REQUEUE_PI):
Likewise.
* sysdeps/unix/sysv/linux/arm/kernel-features.h
(__ASSUME_FUTEX_LOCK_PI): Undefine.
(__ASSUME_REQUEUE_PI): Likewise.
(__ASSUME_SET_ROBUST_LIST): Likewise.
* sysdeps/unix/sysv/linux/m68k/kernel-features.h
[__LINUX_KERNEL_VERSION < 0x030a00] (__ASSUME_FUTEX_LOCK_PI):
Undefine.
* sysdeps/unix/sysv/linux/microblaze/kernel-features.h
[__LINUX_KERNEL_VERSION < 0x020621] (__ASSUME_FUTEX_LOCK_PI):
Likewise.
[__LINUX_KERNEL_VERSION < 0x020621] (__ASSUME_REQUEUE_PI):
Likewise.
[__LINUX_KERNEL_VERSION < 0x020621] (__ASSUME_SET_ROBUST_LIST):
Likewise.
* sysdeps/unix/sysv/linux/mips/kernel-features.h
[__mips == 1 || _MIPS_ARCH_R5900] (__ASSUME_FUTEX_LOCK_PI):
Undefine.
[__mips == 1 || _MIPS_ARCH_R5900] (__ASSUME_REQUEUE_PI): Likewise.
[__mips == 1 || _MIPS_ARCH_R5900] (__ASSUME_SET_ROBUST_LIST):
Likewise.
Continuing the fixes for __ASSUME_* issues in preparation for moving
to a 2.6.32 minimum kernel version, this *untested* patch fixes bug
16648, the definition of __ASSUME_ATFCTS meaning that the futimesat
syscall is assumed for all MicroBlaze kernels despite not being
present until 2.6.33.
__ASSUME_ATFCTS controls conditionals relating to a lot of different
syscalls in Linux-specific code (fstatat64 faccessat fchmodat fchownat
futimesat newfstatat linkat mkdirat openat readlinkat renameat
symlinkat unlinkat mknodat), where whether newfstatat fstatat64
futimesat are used depends on the architecture, as well as controlling
whether openat64_not_cancel_3 is expected to work in
sysdeps/posix/getcwd.c. The assumptions are all OK as of 2.6.32
except for this MicroBlaze case, and it's generally desirable to get
rid of as many of the __ASSUME_ATFCTS conditionals as possible, to
simplify the code (the fallbacks include potential unbounded dynamic
stack allocations). Thus, rather than the simplest approach of
undefining __ASSUME_ATFCTS for older kernels on MicroBlaze, this patch
takes the approach of using the linux-generic implementation of
futimesat for MicroBlaze kernels before 2.6.33 (all such kernels have
the utimensat syscall).
[BZ #16648]
* sysdeps/unix/sysv/linux/microblaze/kernel-features.h
[__LINUX_KERNEL_VERSION >= 0x020621] (__ASSUME_FUTIMESAT): Define.
* sysdeps/unix/sysv/linux/microblaze/futimesat.c: New file.
Add benchtests for ffs and ffsll. There is no benchtest for ffsl as
it is identical to one of the other functions.
2014-03-31 Will Newton <will.newton@linaro.org>
* benchtests/Makefile (bench): Add ffs and ffsll to list
of tests.
* benchtests/ffs-inputs: New file.
* benchtests/ffsll-inputs: Likewise.
This patch fixes bug 16770, spurious "invalid" exceptions from scalb
when testing whether the second argument is an integer, by inserting
appropriate range checks to determine whether a cast to int is safe.
(Note that invalid_fn is a function that handles both nonintegers and
large integers, distinguishing them reliably using functions such as
__rint; note also that there are no issues with scalb needing to avoid
spurious "inexact" exceptions - it's an old-POSIX XSI function, not a
standard C function bound to an IEEE 754 operation - although the
return value is still fully determined.)
Tested x86_64 and x86.
[BZ #16770]
* math/e_scalb.c (__ieee754_scalb): Check second argument is not
too large before casting to int.
* math/e_scalbf.c (__ieee754_scalbf): Likewise.
* math/e_scalbl.c (__ieee754_scalbl): Likewise.
* math/libm-test.inc (scalb_test_data): Add more tests.
This patch adds an option to get detailed benchmark output for
functions. Invoking the benchmark with 'make DETAILED=1 bench' causes
each benchmark program to store a mean execution time for each input
it works on. This is useful to give a more comprehensive picture of
performance of functions compared to just the single mean figure.
This patch changes the output format of the main benchmark output file
(bench.out) to an extensible format. I chose JSON over XML because in
addition to being extensible, it is also not too verbose.
Additionally it has good support in python.
The significant change I have made in terms of functionality is to put
timing information as an attribute in JSON instead of a string and to
do that, there is a separate program that prints out a JSON snippet
mentioning the type of timing (hp_timing or clock_gettime). The mean
timing has now changed from iterations per unit to actual timing per
iteration.
This patch fixes the imaginary part of clog10 (-0 +/- 0i), which
should be +/-pi / log(10) by analogy with clog (the functions were
wrongly returning a result with imaginary part +/-pi, same as for
clog, and the tests matched the incorrect result, though both
functions and tests were correct for the similar case of clog10 (-inf
+/- 0i)). Tested x86_64 and x86.
[BZ #16362]
* math/s_clog10.c (M_PI_LOG10E): New macro.
(__clog10): Use M_PI_LOG10E instead of M_PI when real and
imaginary parts are 0.
* math/s_clog10f.c (M_PI_LOG10Ef): New macro.
(__clog10f): Use M_PI_LOG10Ef instead of M_PI when real and
imaginary parts are 0.
* math/s_clog10l.c (M_PI_LOG10El): New macro.
(__clog10l): Use M_PI_LOG10El instead of M_PIl when real and
imaginary parts are 0.
* math/libm-test.inc (clog10_test_data): Update expected results
for when real and imaginary parts are 0.
This patch fixes bug 16348, spurious underflows from x86/x86_64 expl
on arguments close to 0. These implementations effectively use expm1
(on the fractional part of the argument) internally, so resulting in
spurious underflows when the result is very close to 1. For arguments
small enough that the round-to-nearest correct result is 1, this patch
uses 1+x instead.
These implementations are also used for exp10l and so the patch fixes
similar issues there (the 0x1p-67 threshold being small enough to be
correct for exp10l as well as expl). But because of spurious
underflows in other exp10 implementations (bug 16560), the tests
aren't added for exp10 at this point - they can be added when the
other exp10 parts of that bug are fixed.
Tested x86_64 and x86; no ulps updates needed.
[BZ #16348]
* sysdeps/i386/fpu/e_expl.S (IEEE754_EXPL) [!USE_AS_EXPM1L]: Use
1+x for argument with exponent below -67.
* sysdeps/x86_64/fpu/e_expl.S (IEEE754_EXPL) [!USE_AS_EXPM1L]:
Likewise.
* math/auto-libm-test-in: Add more tests of exp.
* math/auto-libm-test-out: Regenerated.
getnetgrent is supposed to return NULL for values that are wildcards
in the (host, user, domain) triplet. This works correctly with nscd
disabled, but with it enabled, it returns a blank ("") instead of a
NULL. This is easily seen with the output of `getent netgroup foonet`
for a netgroup foonet defined as follows in /etc/netgroup:
foonet (,foo,)
The output with nscd disabled is:
foonet ( ,foo,)
while with nscd enabled, it is:
foonet (,foo,)
The extra space with nscd disabled is due to the fact that `getent
netgroup` adds it if the return value from getnetgrent is NULL for
either host or user.
Calls to stpcpy from nscd netgroups code will have overlapping source
and destination when all three values in the returned triplet are
non-NULL and in the expected (host,user,domain) order. This is seen
in valgrind as:
==3181== Source and destination overlap in stpcpy(0x19973b48, 0x19973b48)
==3181== at 0x4C2F30A: stpcpy (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==3181== by 0x12567A: addgetnetgrentX (string3.h:111)
==3181== by 0x12722D: addgetnetgrent (netgroupcache.c:665)
==3181== by 0x11114C: nscd_run_worker (connections.c:1338)
==3181== by 0x4E3C102: start_thread (pthread_create.c:309)
==3181== by 0x59B81AC: clone (clone.S:111)
==3181==
Fix this by using memmove instead of stpcpy.
When profiling programs with lock problems with perf record -g dwarf,
libunwind can currently not backtrace through the futex and unlock
functions in pthread. This is because they use out of line sections,
and those are not correctly described in dwarf2 (I believe needs
dwarf3 or 4).
This patch first removes the out of line sections. They only save a
single jump, but cause a lot of pain. Then it converts the now inline
lock code to use the now standard gas .cfi_* commands.
With these changes libunwind/perf can backtrace through the futex
functions now.
Longer term it would be likely better to just use C futex() functions
on x86 like all the other architectures. This would clean the code up
even more.
nscd works correctly when the request in innetgr is a wildcard,
i.e. when one or more of host, user or domain parameters is NULL.
However, it does not work when the the triplet in the netgroup
definition has a wildcard. This is easy to reproduce for a triplet
defined as follows:
foonet (,foo,)
Here, an innetgr call that looks like this:
innetgr ("foonet", "foohost", "foo", NULL);
should succeed and so should:
innetgr ("foonet", NULL, "foo", "foodomain");
It does succeed with nscd disabled, but not with nscd enabled. This
fix adds this additional check for all three parts of the triplet so
that it gives the correct result.
[BZ #16758]
* nscd/netgroupcache.c (addinnetgrX): Succeed if triplet has
blank values.
Bug 16198 is x86_64 fegetenv wrongly masking exceptions for which
traps are enabled, because that's a side-effect of the fnstenv
instruction. This patch fixes it to use fldenv immediately after
fnstenv, like the i386 version. Tested x86_64 and x86.
[BZ #16198]
* sysdeps/x86_64/fpu/fegetenv.c (fegetenv): Use fldenv after
fnstenv.
* math/test-fenv-preserve.c: New file.
* math/Makefile (tests): Add test-fenv-preserve.
This benchmark can take longer than the default 2 seconds on slower
platforms, so increase it to 10 seconds.
ChangeLog:
2014-03-26 Will Newton <will.newton@linaro.org>
* benchtests/bench-strtod.c (TIMEOUT): Define to 10.
GNU_IFUNC are shown by readelf in 'Relocation section' value as
"symbol()" instead of expected hexadecimal value. This causes the
check-localplt script to ignore potential PLT stub begin generated
by wrong IFUNC usage. This patch changes the localplt script to
emit such PLT cases.
gen-auto-libm-tests presently allows but does not require underflow
exceptions for results with magnitude in the range (greatest
subnormal, least normal].
In some cases, the magnitude of the exact result is very slightly
above the least normal, but rounding in the implementation results in
it effectively computing an infinite-precision result that is slightly
below the least normal, so raising an underflow exception. This is in
accordance with the documented accuracy goals, but results in
testsuite failures.
This patch changes the logic to allow underflows when the mathematical
result is up to 0.5ulp above the least normal (so in any case where
the round-to-nearest result is the least normal). Ideally underflows
in all these cases would be accepted only when an underflow with the
actual result is consistent with the rounding mode (in FE_TOWARDZERO
mode, a return value of the least normal implies that the
infinite-precision result did not underflow so there should be no
underflow exception, for example), so as to match the documented goals
more precisely - whereas at present the tests for exceptions are
completely independent of the tests of the returned values. (The same
applies to overflow exceptions as well - they too should be checked
for consistency with the result, as in FE_TOWARDZERO mode a result
1ulp below the largest finite value should be inconsistent with an
overflow exception and cause a failure with overflow rather than
simply being considered a 1ulp error when overflow is expected.) But
the present patch at least deals with the cases causing spurious
failures so that (a) certain existing tests no longer need to be
marked as having spurious exceptions (such markings in
auto-libm-test-in end up applying to more cases than just those they
are needed for) and (b) log1p can be tested in all rounding modes
without introducing more such failures. This patch duly moves tests
of log1p to ALL_RM_TEST.
Tested x86_64 and x86 and ulps updated accordingly.
[BZ #16357]
[BZ #16599]
* math/gen-auto-libm-tests.c (fp_format_desc): Add field
min_plus_half.
(fp_formats): Update initializers.
(init_fp_formats): Initialize new field.
(output_for_one_input_case): Allow underflow for results up to
min_plus_half.
* math/libm-test.inc (log1p_test): Use ALL_RM_TEST.
* math/auto-libm-test-in: Don't mark some underflows from asin and
atanh as spurious.
* math/auto-libm-test-out: Regenerated.
* sysdeps/i386/fpu/libm-test-ulps: Update.
* sysdeps/x86_64/fpu/libm-test-ulps: Likewise.
My recent exp patch introduced warnings about implicit __isinf
declarations in exp because e_exp.c didn't include <math.h>. This
patch fixes this. Because <math.h> can't be included after
<math_private.h> (because of macro definitions of __nan*), it was
necessary to put an include in sysdeps/x86_64/fpu/multiarch/e_exp.c as
well.
Tested x86_64.
* sysdeps/ieee754/dbl-64/e_exp.c: Include <math.h>.
* sysdeps/x86_64/fpu/multiarch/e_exp.c
[HAVE_FMA4_SUPPORT || HAVE_AVX_SUPPORT]: Likewise.
An application that erroneously tries to repeatedly dlopen("a.out", ...)
may hit assertion failure:
Inconsistency detected by ld.so: dl-tls.c: 474: _dl_allocate_tls_init:
Assertion `listp != ((void *)0)' failed!
dlopen() actually fails with "./a.out: cannot dynamically load executable",
but it does so after incrementing dl_tls_max_dtv_idx.
Once we run out of TLS_SLOTINFO_SURPLUS (62), we exit with above assertion
failure.
2014-03-24 Paul Pluzhnikov <ppluzhnikov@google.com>
[BZ #16634]
* elf/dl-load.c (open_verify): Add mode parameter.
Error early when ET_EXEC and mode does not have __RTLD_OPENEXEC.
(open_path): Change from boolean 'secure' to complete flag 'mode'
(_dl_map_object): Adjust.
* elf/Makefile (tests): Add tst-dlopen-aout.
* elf/tst-dlopen-aout.c: New test.
This fixes a bug in the way the results from __nscd_getai are collected:
for every returned result a new entry is first added to the
gaih_addrtuple list, but if that result doesn't match the request this
entry remains uninitialized. So for this non-matching result an extra
result with uninitialized content is returned.
To reproduce (with nscd running):
$ getent ahostsv4 localhost
127.0.0.1 STREAM localhost
127.0.0.1 DGRAM
127.0.0.1 RAW
(null) STREAM
(null) DGRAM
(null) RAW
To reproduce:
# ip li add name dummy0 type dummy
# site_id=$(head -c6 /dev/urandom | od -tx2 -An | tr ' ' ':')
# for ((i = 0; i < 65536; i++)) do
> ip ad ad $(printf fd80$site_id::%04x $i)/128 dev dummy0
> done
# (ulimit -s 900; getent ahosts localhost)
# ip li de dummy0
