Some of the x86 string functions create pointers based on input strings
that may be outside of the input strings. When this happens in C code,
the compiler can potentially detect this, leading to warnings in
application code when those string functions are inlined. Perform those
operations in the assembly code instead of the C code to fix this.
since
https://sourceware.org/ml/libc-alpha/2014-04/msg00006.html
setcontext etc is no longer tied to the kernel use of ucontext.
in that patch the ucontext reserved space is not used consistently
with the kernel abi: the d8,d9 pair is saved in the slot of q8.
this is ok (*context functions work together), but probably not
desirable (ucontexts created by the kernel and getcontext are
subtly different).
the fix just replaces dN with qN in the save/restore code, which
does a bit more than needed (saves/restores the top half of qN that
is not callee saved), but this should not be an issue (and avoids
having to deal with endianness).
(kernel fpsimd context layout: the first 64bit contains 0x210 the fpsimd
context size and 0x46508001 the FPSIMD_MAGIC, the second 64bit is for
fpsr and fpcr, and the rest is the 128bit q0..q31 registers).
given d8=8.1, d9=9.1,... d15=15.1, the context created by getcontext is
current:
(gdb) x/40xg ctx.uc_mcontext.__reserved
0x410df0 <ctx+464>: 0x0000021046508001 0x0000000000000000
0x410e00 <ctx+480>: 0x0000000000000000 0x0000000000000000
0x410e10 <ctx+496>: 0x0000000000000000 0x0000000000000000
0x410e20 <ctx+512>: 0x0000000000000000 0x0000000000000000
0x410e30 <ctx+528>: 0x0000000000000000 0x0000000000000000
0x410e40 <ctx+544>: 0x0000000000000000 0x0000000000000000
0x410e50 <ctx+560>: 0x0000000000000000 0x0000000000000000
0x410e60 <ctx+576>: 0x0000000000000000 0x0000000000000000
0x410e70 <ctx+592>: 0x0000000000000000 0x0000000000000000
0x410e80 <ctx+608>: 0x4020333333333333 0x4022333333333333
0x410e90 <ctx+624>: 0x0000000000000000 0x0000000000000000
0x410ea0 <ctx+640>: 0x4024333333333333 0x4026333333333333
0x410eb0 <ctx+656>: 0x0000000000000000 0x0000000000000000
0x410ec0 <ctx+672>: 0x4028333333333333 0x402a333333333333
0x410ed0 <ctx+688>: 0x0000000000000000 0x0000000000000000
0x410ee0 <ctx+704>: 0x402c333333333333 0x402e333333333333
0x410ef0 <ctx+720>: 0x0000000000000000 0x0000000000000000
0x410f00 <ctx+736>: 0x0000000000000000 0x0000000000000000
0x410f10 <ctx+752>: 0x0000000000000000 0x0000000000000000
0x410f20 <ctx+768>: 0x0000000000000000 0x0000000000000000
fixed:
(gdb) x/40xg ctx.uc_mcontext.__reserved
0x410d70 <ctx+464>: 0x0000021046508001 0x0000000000000000
0x410d80 <ctx+480>: 0x0000000000000000 0x0000000000000000
0x410d90 <ctx+496>: 0x0000000000000000 0x0000000000000000
0x410da0 <ctx+512>: 0x0000000000000000 0x0000000000000000
0x410db0 <ctx+528>: 0x0000000000000000 0x0000000000000000
0x410dc0 <ctx+544>: 0x0000000000000000 0x0000000000000000
0x410dd0 <ctx+560>: 0x0000000000000000 0x0000000000000000
0x410de0 <ctx+576>: 0x0000000000000000 0x0000000000000000
0x410df0 <ctx+592>: 0x0000000000000000 0x0000000000000000
0x410e00 <ctx+608>: 0x4020333333333333 0x0000000000000000
0x410e10 <ctx+624>: 0x4022333333333333 0x0000000000000000
0x410e20 <ctx+640>: 0x4024333333333333 0x0000000000000000
0x410e30 <ctx+656>: 0x4026333333333333 0x0000000000000000
0x410e40 <ctx+672>: 0x4028333333333333 0x0000000000000000
0x410e50 <ctx+688>: 0x402a333333333333 0x0000000000000000
0x410e60 <ctx+704>: 0x402c333333333333 0x0000000000000000
0x410e70 <ctx+720>: 0x402e333333333333 0x0000000000000000
0x410e80 <ctx+736>: 0x0000000000000000 0x0000000000000000
0x410e90 <ctx+752>: 0x0000000000000000 0x0000000000000000
0x410ea0 <ctx+768>: 0x0000000000000000 0x0000000000000000
2015-07-06 Szabolcs Nagy <szabolcs.nagy@arm.com>
* sysdeps/unix/sysv/linux/aarch64/getcontext.S (__getcontext): Use q
registers instead of d ones so the layout is kernel abi compatible.
* sysdeps/unix/sysv/linux/aarch64/setcontext.S (__setcontext): Likewise.
* sysdeps/unix/sysv/linux/aarch64/swapcontext.S (__swapcontext):
Likewise.# Please enter the commit message for your changes. Lines starting
In the ldbl-128 implementation of expm1l, when expm1l's result should
underflow to 0 (argument minus the least subnormal, in some rounding
modes), it can be a zero of the wrong sign. This patch fixes this in
the same way previously used for the x86 / x86_64 versions.
Tested for mips64.
[BZ #18619]
* sysdeps/ieee754/ldbl-128/s_expm1l.c (__expm1l): Force underflow
and return argument in case of subnormal argument.
the initialization routine to exit by throwing an exception.
Such an execution, termed exceptional, requires call_once to
propagate the exception to its caller. A program may contain
any number of exceptional executions but only one returning
execution (which, if it exists, must be the last execution
with the same once flag).
On POSIX systems such as Linux, std::call_once is implemented
in terms of pthread_once. However, as discussed in libstdc++
bug 66146 - "call_once not C++11-compliant on ppc64le," GLIBC's
pthread_once hangs when the initialization function exits by
throwing an exception on at least arm and ppc64 (though
apparently not on x86_64). This effectively prevents call_once
from conforming to the C++ requirements since there doesn't
appear to be a thread-safe way to work around this problem in
libstdc++.
This patch changes pthread_once to handle gracefully init
functions that exit by throwing exceptions. It was successfully
tested on ppc64, ppc64le, and x86_64.
[BZ #18435]
* nptl/Makefile: Add tst-once5.cc.
* nptl/pthreadP.h (pthread_cleanup_push, pthread_cleanup_pop):
Remove macro redefinitions.
* nptl/tst-once5.cc: New test.
The probes are not provided on all architectures (and only partially by the
x86 assembly implementation), and we are not aware of actual uses of these
probes.
a need for them.
This patch combines BUSY_WAIT_NOP and atomic_delay into a new
atomic_spin_nop function and adjusts all clients. The new function is
put into atomic.h because what is best done in a spin loop is
architecture-specific, and atomics must be used for spinning. The
function name is meant to tell users that this has no effect on
synchronization semantics but is a performance aid for spinning.
In non-default rounding modes, tgamma can be slightly less accurate
than permitted by glibc's accuracy goals.
Part of the problem is error accumulation, addressed in this patch by
setting round-to-nearest for internal computations. However, there
was also a bug in the code dealing with computing pow (x + n, x + n)
where x + n is not exactly representable, providing another source of
error even in round-to-nearest mode; it was necessary to address both
bugs to get errors for all testcases within glibc's accuracy goals.
Given this second fix, accuracy in round-to-nearest mode is also
improved (hence regeneration of ulps for tgamma should be from scratch
- truncate libm-test-ulps or at least remove existing tgamma entries -
so that the expected ulps can be reduced).
Some additional complications also arose. Certain tgamma tests should
strictly, according to IEEE semantics, overflow or not depending on
the rounding mode; this is beyond the scope of glibc's accuracy goals
for any function without exactly-determined results, but
gen-auto-libm-tests doesn't handle being lax there as it does for
underflow. (libm-test.inc also doesn't handle being lax about whether
the result in cases very close to the overflow threshold is infinity
or a finite value close to overflow, but that doesn't cause problems
in this case though I've seen it cause problems with random test
generation for some functions.) Thus, spurious-overflow markings,
with a comment, are added to auto-libm-test-in (no bug in Bugzilla
because the issue is with the testsuite, not a user-visible bug in
glibc). And on x86, after the patch I saw ERANGE issues as previously
reported by Carlos (see my commentary in
<https://sourceware.org/ml/libc-alpha/2015-01/msg00485.html>), which
needed addressing by ensuring excess range and precision were
eliminated at various points if FLT_EVAL_METHOD != 0.
I also noticed and fixed a cosmetic issue where 1.0f was used in long
double functions and should have been 1.0L.
This completes the move of all functions to testing in all rounding
modes with ALL_RM_TEST, so gen-libm-have-vector-test.sh is updated to
remove the workaround for some functions not using ALL_RM_TEST.
Tested for x86_64, x86, mips64 and powerpc.
[BZ #18613]
* sysdeps/ieee754/dbl-64/e_gamma_r.c (gamma_positive): Take log of
X_ADJ not X when adjusting exponent.
(__ieee754_gamma_r): Do intermediate computations in
round-to-nearest then adjust overflowing and underflowing results
as needed.
* sysdeps/ieee754/flt-32/e_gammaf_r.c (gammaf_positive): Take log
of X_ADJ not X when adjusting exponent.
(__ieee754_gammaf_r): Do intermediate computations in
round-to-nearest then adjust overflowing and underflowing results
as needed.
* sysdeps/ieee754/ldbl-128/e_gammal_r.c (gammal_positive): Take
log of X_ADJ not X when adjusting exponent.
(__ieee754_gammal_r): Do intermediate computations in
round-to-nearest then adjust overflowing and underflowing results
as needed. Use 1.0L not 1.0f as numerator of division.
* sysdeps/ieee754/ldbl-128ibm/e_gammal_r.c (gammal_positive): Take
log of X_ADJ not X when adjusting exponent.
(__ieee754_gammal_r): Do intermediate computations in
round-to-nearest then adjust overflowing and underflowing results
as needed. Use 1.0L not 1.0f as numerator of division.
* sysdeps/ieee754/ldbl-96/e_gammal_r.c (gammal_positive): Take log
of X_ADJ not X when adjusting exponent.
(__ieee754_gammal_r): Do intermediate computations in
round-to-nearest then adjust overflowing and underflowing results
as needed. Use 1.0L not 1.0f as numerator of division.
* math/libm-test.inc (tgamma_test_data): Remove one test. Moved
to auto-libm-test-in.
(tgamma_test): Use ALL_RM_TEST.
* math/auto-libm-test-in: Add one test of tgamma. Mark some other
tests of tgamma with spurious-overflow.
* math/auto-libm-test-out: Regenerated.
* math/gen-libm-have-vector-test.sh: Do not check for START.
* sysdeps/i386/fpu/libm-test-ulps: Update.
* sysdeps/x86_64/fpu/libm-test-ulps: Likewise.
The ldbl-128 implementation of j1l produces spurious underflow
exceptions for some small arguments, as a result of squaring the
argument. This patch fixes it just to use a linear approximation for
sufficiently small arguments, and then to force an underflow exception
only in the cases where it is required.
Tested for mips64.
[BZ #18612]
* sysdeps/ieee754/ldbl-128/e_j1l.c (__ieee754_j1l): For small
arguments, just return 0.5 times the argument, with underflow
forced as needed.
* math/auto-libm-test-in: Add more tests of j1.
* math/auto-libm-test-out: Regenerated.
Similar to various other bugs in this area, j1 and jn implementations
can fail to raise the underflow exception when the internal
computation is exact although the actual function is inexact. This
patch forces the exception in a similar way to other such fixes. (The
ldbl-128 / ldbl-128ibm j1l implementation is different and doesn't
need a change for this until spurious underflows in it are fixed.)
Tested for x86_64, x86, mips64 and powerpc.
[BZ #16559]
* sysdeps/ieee754/dbl-64/e_j1.c: Include <float.h>.
(__ieee754_j1): Force underflow exception for small results.
* sysdeps/ieee754/dbl-64/e_jn.c (__ieee754_jn): Likewise.
* sysdeps/ieee754/flt-32/e_j1f.c: Include <float.h>.
(__ieee754_j1f): Force underflow exception for small results.
* sysdeps/ieee754/flt-32/e_jnf.c (__ieee754_jnf): Likewise.
* sysdeps/ieee754/ldbl-128/e_jnl.c (__ieee754_jnl): Likewise.
* sysdeps/ieee754/ldbl-128ibm/e_jnl.c (__ieee754_jnl): Likewise.
* sysdeps/ieee754/ldbl-96/e_j1l.c: Include <float.h>.
(__ieee754_j1l): Force underflow exception for small results.
* sysdeps/ieee754/ldbl-96/e_jnl.c (__ieee754_jnl): Likewise.
* math/auto-libm-test-in: Add more tests of j1 and jn.
* math/auto-libm-test-out: Regenerated.
This patch updates installed glibc headers for new definitions from
Linux 4.0 and 4.1 that seem relevant to glibc headers. In addition, I
noticed that PF_IB / AF_IB, added in Linux 3.11, were missing for no
obvious reason, so added those as well.
Tested for x86_64 (testsuite, and that installed stripped shared
libraries are unchanged by the patch).
* sysdeps/unix/sysv/linux/bits/in.h (IP_CHECKSUM): New macro.
* sysdeps/unix/sysv/linux/bits/socket.h (PF_IB): Likewise.
(PF_MPLS): Likewise.
(AF_IB): Likewise.
(AF_MPLS): Likewise.
* sysdeps/unix/sysv/linux/sys/mount.h (MS_LAZYTIME): New enum
value and macro.
(MS_RMT_MASK): Include MS_LAZYTIME.
mksquashfs was reported in openSUSE to be causing segmentation faults when
creating installation images. Testing showed that mksquashfs sometimes
failed and could be reproduced within 10 attempts. The core dump looked
like the heap top was corrupted and was pointing to an unmapped area. In
other cases, this has been due to an application corrupting glibc structures
but mksquashfs appears to be fine in this regard.
The problem is that heap_trim is "growing" the top into unmapped space.
If the top chunk == MINSIZE then top_area is -1 and this check does not
behave as expected due to a signed/unsigned comparison
if (top_area <= pad)
return 0;
The next calculation extra = ALIGN_DOWN(top_area - pad, pagesz) calculates
extra as a negative number which also is unnoticed due to a signed/unsigned
comparison. We then call shrink_heap(heap, negative_number) which crashes
later. This patch adds a simple check against MINSIZE to make sure extra
does not become negative. It adds a cast to hint to the reader that this
is a signed vs unsigned issue.
Without the patch, mksquash fails within 10 attempts. With it applied, it
completed 1000 times without error. The standard test suite "make check"
showed no changes in the summary of test results.
This tag allows debugging of MIPS position independent executables
and provides access to shared library information.
* elf/elf.h (DT_MIPS_RLD_MAP_REL): New macro.
(DT_MIPS_NUM): Update.
* sysdeps/mips/dl-machine.h (ELF_MACHINE_DEBUG_SETUP): Handle
DT_MIPS_RLD_MAP_REL.
Some existing jn tests, if run in non-default rounding modes, produce
errors above those accepted in glibc, which causes problems for moving
tests of jn to use ALL_RM_TEST. This patch makes jn set rounding
to-nearest internally, as was done for yn some time ago, then computes
the appropriate underflowing value for results that underflowed to
zero in to-nearest, and moves the tests to ALL_RM_TEST. It does
nothing about the general inaccuracy of Bessel function
implementations in glibc, though it should make jn more accurate on
average in non-default rounding modes through reduced error
accumulation. The recomputation of results that underflowed to zero
should as a side-effect fix some cases of bug 16559, where jn just
used an exact zero, but that is *not* the goal of this patch and other
cases of that bug remain unfixed.
(Most of the changes in the patch are reindentation to add new scopes
for SET_RESTORE_ROUND*.)
Tested for x86_64, x86, powerpc and mips64.
[BZ #16559]
[BZ #18602]
* sysdeps/ieee754/dbl-64/e_jn.c (__ieee754_jn): Set
round-to-nearest internally then recompute results that
underflowed to zero in the original rounding mode.
* sysdeps/ieee754/flt-32/e_jnf.c (__ieee754_jnf): Likewise.
* sysdeps/ieee754/ldbl-128/e_jnl.c (__ieee754_jnl): Likewise.
* sysdeps/ieee754/ldbl-128ibm/e_jnl.c (__ieee754_jnl): Likewise.
* sysdeps/ieee754/ldbl-96/e_jnl.c (__ieee754_jnl): Likewise
* math/libm-test.inc (jn_test): Use ALL_RM_TEST.
* sysdeps/i386/fpu/libm-test-ulps: Update.
* sysdeps/x86_64/fpu/libm-test-ulps: Likewise.
To support building glibc with GCC 6 configured with --enable-default-pie,
which generates PIE by default, we need to build programs as PIE. But
elf/tst-dlopen-aout must not be built as PIE since it tests dlopen on
ET_EXEC file and PIE is ET_DYN.
[BZ #17841]
* Makeconfig (no-pie-ldflag): New.
(+link): Set to $(+link-pie) if default to PIE.
(+link-tests): Set to $(+link-pie-tests) if default to PIE.
* config.make.in (build-pie-default): New.
* configure.ac (libc_cv_pie_default): New. Set to yes if -fPIE
is default. AC_SUBST.
* configure: Regenerated.
* elf/Makefile (LDFLAGS-tst-dlopen-aout): New.
We need to align TCB offset to the maximum alignment for TLS_TCB_AT_TP
targets, as _dl_allocate_tls_storage (in elf/dl-tls.c) does using
__libc_memalign and dl_tls_static_align.
[BZ #18383]
* csu/libc-tls.c (__libc_setup_tls) [TLS_TCB_AT_TP]: Align
TCB_OFFSET to MAX_ALIGN, not just TCBALIGN. Add comment.
* elf/Makefile (test-xfail-tst-tlsalign{,-static}): Remove
comment for i386/x86-64.
(test-xfail-tst-tlsalign-extern-static): Removed.
cexp, ccos, ccosh, csin and csinh have spurious underflows in cases
where they compute sin of the smallest normal, that produces an
underflow exception (depending on which sin implementation is in use)
but the final result does not underflow. ctan and ctanh may also have
such underflows, or they may be latent (the issue there is that
e.g. ctan (DBL_MIN) should, rounded upwards, be the next double value
above DBL_MIN, which under glibc's accuracy goals may not have an
underflow exception, but the intermediate computation of sin (DBL_MIN)
would legitimately underflow on before-rounding architectures).
This patch fixes all those functions so they use plain comparisons (>
DBL_MIN etc.) instead of comparing the result of fpclassify with
FP_SUBNORMAL (in all these cases, we already know the number being
compared is finite). Note that in the case of csin / csinf / csinl,
there is no need for fabs calls in the comparison because the real
part has already been reduced to its absolute value.
As the patch fixes the failures that previously obstructed moving
tests of cexp to use ALL_RM_TEST, those tests are moved to ALL_RM_TEST
by the patch (two functions remain yet to be converted).
Tested for x86_64 and x86 and ulps updated accordingly.
[BZ #18594]
* math/s_ccosh.c (__ccosh): Compare with least normal value
instead of comparing class with FP_SUBNORMAL.
* math/s_ccoshf.c (__ccoshf): Likewise.
* math/s_ccoshl.c (__ccoshl): Likewise.
* math/s_cexp.c (__cexp): Likewise.
* math/s_cexpf.c (__cexpf): Likewise.
* math/s_cexpl.c (__cexpl): Likewise.
* math/s_csin.c (__csin): Likewise.
* math/s_csinf.c (__csinf): Likewise.
* math/s_csinh.c (__csinh): Likewise.
* math/s_csinhf.c (__csinhf): Likewise.
* math/s_csinhl.c (__csinhl): Likewise.
* math/s_csinl.c (__csinl): Likewise.
* math/s_ctan.c (__ctan): Likewise.
* math/s_ctanf.c (__ctanf): Likewise.
* math/s_ctanh.c (__ctanh): Likewise.
* math/s_ctanhf.c (__ctanhf): Likewise.
* math/s_ctanhl.c (__ctanhl): Likewise.
* math/s_ctanl.c (__ctanl): Likewise.
* math/auto-libm-test-in: Add more tests of ccos, ccosh, cexp,
csin, csinh, ctan and ctanh.
* math/auto-libm-test-out: Regenerated.
* math/libm-test.inc (cexp_test): Use ALL_RM_TEST.
* sysdeps/i386/fpu/libm-test-ulps: Update.
* sysdeps/x86_64/fpu/libm-test-ulps: Likewise.
Many packages, including GCC, install Python files for GDB in library
diretory. ldconfig reads them and issue errors since they aren't ELF
files:
ldconfig: /usr/gcc-5.1.1/lib/libstdc++.so.6.0.21-gdb.py is not an ELF file - it has the wrong magic bytes at the start.
ldconfig: /usr/gcc-5.1.1/libx32/libstdc++.so.6.0.21-gdb.py is not an ELF file - it has the wrong magic bytes at the start.
ldconfig: /usr/gcc-5.1.1/lib64/libstdc++.so.6.0.21-gdb.py is not an ELF file - it has the wrong magic bytes at the start.
This patch silences ldconfig on GDB Python files by checking filenames
with -gdb.py suffix.
[BZ #18585]
* elf/readlib.c (is_gdb_python_file): New.
(process_file): Don't issue errors on filenames with -gdb.py
suffix.
This patch moves most tests of csin and csinh with finite inputs from
libm-test.inc to auto-libm-test-in. The remaining two tests of each
function with small arguments are not moved because moving them causes
the time required by gen-auto-libm-tests to go up from under 8 seconds
to over 11 minutes for me. (The current development version of MPC
has had speed improvements for mpc_sin for some time, but there hasn't
been a release containing those improvements yet.)
Tested for x86_64 and x86.
* math/auto-libm-test-in: Add more tests of csin and csinh.
* math/auto-libm-test-out: Regenerated.
* math/libm-test.inc (csin_test_data): Remove tests moved to
auto-libm-test-in.
(csinh_test_data): Likewise.
csin and csinh can produce bad results when overflowing in directed
rounding modes, because a multiplication that can overflow is followed
by a possible negation. This patch fixes this by negating one of the
arguments of the multiplication before the multiplication instead of
negating the result.
The new tests for this issue are added to auto-libm-test-in, starting
use of that file for csin and csinh. The issue was found in the
course of moving existing tests for csin and csinh (existing tests, by
being enabled in more cases than previously, showed the issue for
float and double but not for long double); that move will now be done
separately.
Tested for x86_64 and x86 and ulps updated accordingly.
[BZ #18593]
* math/s_csin.c (__csin): Negate before rather than after possibly
overflowing multiplication.
* math/s_csinf.c (__csinf): Likewise.
* math/s_csinh.c (__csinh): Likewise.
* math/s_csinhf.c (__csinhf): Likewise.
* math/s_csinhl.c (__csinhl): Likewise.
* math/s_csinl.c (__csinl): Likewise.
* math/auto-libm-test-in: Add some tests of csin and csinh.
* math/auto-libm-test-out: Regenerated.
* math/libm-test.inc (csin_test_data): Use AUTO_TESTS_c_c.
(csinh_test_data): Likewise.
* sysdeps/x86_64/fpu/libm-test-ulps: Update.
Similar to various other bugs in this area, the ldbl-128 expl
implementation does not raise the underflow exception for all
subnormal results, if the scaling down is exact although the actual
result is inexact. This patch fixes this by forcing the exception in
this case (the tests that failed before and pass after the test are
already in the testsuite).
Tested for mips64.
[BZ #18586]
* sysdeps/ieee754/ldbl-128/e_expl.c (__ieee754_expl): Force
underflow exception for small results.
Similar to various other bugs in this area, some sin and sincos
implementations do not raise the underflow exception for subnormal
arguments, when the result is tiny and inexact. This patch forces the
exception in a similar way to previous fixes.
Tested for x86_64, x86, mips64 and powerpc.
[BZ #16526]
[BZ #16538]
* sysdeps/ieee754/dbl-64/s_sin.c: Include <float.h>.
(__sin): Force underflow exception for arguments with small
absolute value.
* sysdeps/ieee754/flt-32/k_sinf.c: Include <float.h>.
(__kernel_sinf): Force underflow exception for arguments with
small absolute value.
* sysdeps/ieee754/ldbl-128/k_sincosl.c: Include <float.h>.
(__kernel_sincosl): Force underflow exception for arguments with
small absolute value.
* sysdeps/ieee754/ldbl-128/k_sinl.c: Include <float.h>.
(__kernel_sinl): Force underflow exception for arguments with
small absolute value.
* sysdeps/ieee754/ldbl-128ibm/k_sincosl.c: Include <float.h>.
(__kernel_sincosl): Force underflow exception for arguments with
small absolute value.
* sysdeps/ieee754/ldbl-128ibm/k_sinl.c: Include <float.h>.
(__kernel_sinl): Force underflow exception for arguments with
small absolute value.
* sysdeps/ieee754/ldbl-96/k_sinl.c: Include <float.h>.
(__kernel_sinl): Force underflow exception for arguments with
small absolute value.
* sysdeps/powerpc/fpu/k_sinf.c: Include <float.h>.
(__kernel_sinf): Force underflow exception for arguments with
small absolute value.
* math/auto-libm-test-in: Add more tests of sin and sincos.
* math/auto-libm-test-out: Regenerated.
__kernel_standard_l converts long double arguments to double for use
in SVID "struct exception". This has special-case handling for when
that conversion would overflow or underflow but the original long
double function wouldn't. However, it turns out that "inexact"
exceptions can be spurious here as well, when the function is exactly
determined and __kernel_standard_l is being called for a domain error.
This patch fixes this by using feholdexcept / fesetenv to avoid
exceptions from the conversion, replacing the previous special-case
logic for overflow and underflow (this covers all functions using
__kernel_standard_l, not just those that actually need a change, since
there doesn't seem to be much point in restricting things just to the
functions that mustn't get "inexact" here).
Tested for x86_64 and x86.
[BZ #18245]
[BZ #18583]
* sysdeps/ieee754/k_standardl.c: Include <fenv.h>.
(__kernel_standard_l): Use feholdexcept and fesetenv around
conversion to double instead of special-casing overflow and
underflow.
* math/libm-test.inc (fmod_test_data): Add more tests.
(remainder_test_data): Likewise.
(sqrt_test_data): Likewise.
This fixes BZ #17403 by defining atomic_full_barrier,
atomic_read_barrier, and atomic_write_barrier on x86 and x86_64. A full
barrier is implemented through an atomic idempotent modification to the
stack and not through using mfence because the latter can supposedly be
somewhat slower due to having to provide stronger guarantees wrt.
self-modifying code, for example.
Since the libmvec tests went in I've noticed build failures from
parallel testing in math/, when those tests start building before
libm-test.c has been fully generated. (This only applies if libm test
sources have been modified after the original glibc build, because
otherwise libm-test.stmp was generated during the original build and
doesn't get regenerated during testing.)
Those tests depend on libm-test.stmp, but the dependency uses
$(libmvec-tests), which is set in the sysdeps Makefile fragments, and
appears before the inclusion of ../Rules, which is what includes those
fragments; thus, the dependency does not work and parallel make can
start building the vector tests too soon. This patch moves the
dependency further down so that the required variable is defined when
the dependency is.
Tested for x86_64.
* math/Makefile [$(PERL) != no]
($(addprefix $(objpfx), $(addsuffix .o, $(libm-vec-tests)))): Move
dependency on libm-test.stmp below the inclusion of Rules.
The csqrt implementations in glibc can cause spurious underflows in
some cases as a side-effect of the scaling for large arguments (when
underflow is correct for the square root of the argument that was
scaled down to avoid overflow, but not for the original argument).
This patch arranges to avoid the underflowing intermediate computation
(eliminating a multiplication in 0.5 in the problem cases where a
subsequent scaling by 2 would follow).
Tested for x86_64 and x86 and ulps updated accordingly (only needed
for x86).
[BZ #18371]
* math/s_csqrt.c (__csqrt): Avoid multiplication by 0.5 where
intermediate but not final result might underflow.
* math/s_csqrtf.c (__csqrtf): Likewise.
* math/s_csqrtl.c (__csqrtl): Likewise.
* math/auto-libm-test-in: Add more tests of csqrt.
* math/auto-libm-test-out: Regenerated.
* sysdeps/i386/fpu/libm-test-ulps: Update.
The dbl-64 and flt-32 implementations of exp2 functions produce
spurious underflow exceptions. The underlying reason is the same in
both cases: the computation works as (2^a - 1)*2^b + 2^b for suitably
chosen a and b, where a has small magnitude so 2^a - 1 can be computed
with a low-degree polynomial approximation, and (2^a - 1)*2^b can
underflow even when the final result does not. This patch fixes this
by adjusting the threshold for when scaling is used to avoid
intermediate underflow so it works for any possible value of a where
the final result would not underflow.
Tested for x86_64 and x86.
[BZ #18219]
* sysdeps/ieee754/dbl-64/e_exp2.c (__ieee754_exp2): Reduce
threshold on absolute value of exponent for which scaling is used.
* sysdeps/ieee754/flt-32/e_exp2f.c (__ieee754_exp2f): Likewise.
* math/auto-libm-test-in: Add more tests of exp2.
* math/auto-libm-test-out: Regenerated.
When "reorder" resolver option is enabled, threads of a multi-threaded process
could hang in gethostbyaddr_r, gethostbyname_r, or gethostbyname2_r.
Due to a trivial bug in _res_hconf_reorder_addrs, simultaneous
invocations of this function in a multi-threaded process could result to
_res_hconf_reorder_addrs returning without releasing the lock it holds,
causing other threads to block indefinitely while waiting for the lock
that is not going to be released.
[BZ #17977]
* resolv/res_hconf.c (_res_hconf_reorder_addrs): Fix unlocking
when initializing interface list, based on the bug analysis
and the patch proposed by Eric Newton.
* resolv/tst-res_hconf_reorder.c: New test.
* resolv/Makefile [$(have-thread-library) = yes] (tests): Add
tst-res_hconf_reorder.
($(objpfx)tst-res_hconf_reorder): Depend on $(libdl)
and $(shared-thread-library).
(tst-res_hconf_reorder-ENV): New variable.
Similar to various other bugs in this area, some expm1 implementations
do not raise the underflow exception for subnormal arguments, when the
result is tiny and inexact. This patch forces the exception in a
similar way to previous fixes.
(The issue does not apply to the ldbl-* implementations or to those
for x86 / x86_64 long double. The change to
sysdeps/ieee754/dbl-64/wordsize-64/e_cosh.c is one I missed when
previously fixing bug 16354; the bug in that implementation was
previously latent, but the expm1 fixes stopped it being latent and so
required it to be fixed to avoid spurious underflows from cosh.)
Tested for x86_64 and x86.
[BZ #16353]
* sysdeps/i386/fpu/s_expm1.S (dbl_min): New object.
(__expm1): Force underflow exception for arguments with small
absolute value.
* sysdeps/i386/fpu/s_expm1f.S (flt_min): New object.
(__expm1f): Force underflow exception for arguments with small
absolute value.
* sysdeps/ieee754/dbl-64/s_expm1.c: Include <float.h>.
(__expm1): Force underflow exception for arguments with small
absolute value.
* sysdeps/ieee754/flt-32/s_expm1f.c: Include <float.h>.
(__expm1f): Force underflow exception for arguments with small
absolute value.
* sysdeps/ieee754/dbl-64/wordsize-64/e_cosh.c (__ieee754_cosh):
Check for small arguments before calling __expm1.
* math/auto-libm-test-in: Do not mark underflow exceptions as
possibly missing for bug 16353.
* math/auto-libm-test-out: Regenerated.
