http://sourceware.org/ml/libc-alpha/2013-08/msg00092.html
Use conditional form of branch and link to avoid destroying the cpu
link stack used to predict blr return addresses.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/makecontext.S: Use
conditional form of branch and link when obtaining pc.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/makecontext.S: Likewise.
http://sourceware.org/ml/libc-alpha/2013-08/msg00091.html
More LE support, correcting word accesses to _dl_hwcap.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/getcontext-common.S: Use
HIWORD/LOWORD.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/setcontext-common.S: Ditto.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/swapcontext-common.S: Ditto.
http://sourceware.org/ml/libc-alpha/2013-08/msg00090.html
This patch fixes symbol versioning in setjmp/longjmp. The existing
code uses raw versions, which results in wrong symbol versioning when
you want to build glibc with a base version of 2.19 for LE.
Note that the merging the 64-bit and 32-bit versions in novmx-lonjmp.c
and pt-longjmp.c doesn't result in GLIBC_2.0 versions for 64-bit, due
to the base in shlib_versions.
* sysdeps/powerpc/longjmp.c: Use proper symbol versioning macros.
* sysdeps/powerpc/novmx-longjmp.c: Likewise.
* sysdeps/powerpc/powerpc32/bsd-_setjmp.S: Likewise.
* sysdeps/powerpc/powerpc32/bsd-setjmp.S: Likewise.
* sysdeps/powerpc/powerpc32/fpu/__longjmp.S: Likewise.
* sysdeps/powerpc/powerpc32/fpu/setjmp.S: Likewise.
* sysdeps/powerpc/powerpc32/mcount.c: Likewise.
* sysdeps/powerpc/powerpc32/setjmp.S: Likewise.
* sysdeps/powerpc/powerpc64/setjmp.S: Likewise.
* nptl/sysdeps/unix/sysv/linux/powerpc/pt-longjmp.c: Likewise.
http://sourceware.org/ml/libc-alpha/2013-08/msg00089.html
Little-endian fixes for setjmp/longjmp. When writing these I noticed
the setjmp code corrupts the non volatile VMX registers when using an
unaligned buffer. Anton fixed this, and also simplified it quite a
bit.
The current code uses boilerplate for the case where we want to store
16 bytes to an unaligned address. For that we have to do a
read/modify/write of two aligned 16 byte quantities. In our case we
are storing a bunch of back to back data (consective VMX registers),
and only the start and end of the region need the read/modify/write.
[BZ #15723]
* sysdeps/powerpc/jmpbuf-offsets.h: Comment fix.
* sysdeps/powerpc/powerpc32/fpu/__longjmp-common.S: Correct
_dl_hwcap access for little-endian.
* sysdeps/powerpc/powerpc32/fpu/setjmp-common.S: Likewise. Don't
destroy vmx regs when saving unaligned.
* sysdeps/powerpc/powerpc64/__longjmp-common.S: Correct CR load.
* sysdeps/powerpc/powerpc64/setjmp-common.S: Likewise CR save. Don't
destroy vmx regs when saving unaligned.
http://sourceware.org/ml/libc-alpha/2013-08/msg00088.html
* sysdeps/powerpc/powerpc32/fpu/s_roundf.S: Increase alignment of
constants to usual value for .cst8 section, and remove redundant
high address load.
* sysdeps/powerpc/powerpc32/power4/fpu/s_llround.S: Use float
constant for 0x1p52. Load little-endian words of double from
correct stack offsets.
http://sourceware.org/ml/libc-alpha/2013-07/msg00201.html
These two functions oddly test x+1>0 when a double x is >= 0.0, and
similarly when x is negative. I don't see the point of that since the
test should always be true. I also don't see any need to convert x+1
to integer rather than simply using xr+1. Note that the standard
allows these functions to return any value when the input is outside
the range of long long, but it's not too hard to prevent xr+1
overflowing so that's what I've done.
(With rounding mode FE_UPWARD, x+1 can be a lot more than what you
might naively expect, but perhaps that situation was covered by the
x - xrf < 1.0 test.)
* sysdeps/powerpc/fpu/s_llround.c (__llround): Rewrite.
* sysdeps/powerpc/fpu/s_llroundf.c (__llroundf): Rewrite.
http://sourceware.org/ml/libc-alpha/2013-07/msg00200.html
This works around the fact that vsx is disabled in current
little-endian gcc. Also, float constants take 4 bytes in memory
vs. 16 bytes for vector constants, and we don't need to write one lot
of masks for double (register format) and another for float (mem
format).
* sysdeps/powerpc/fpu/s_float_bitwise.h (__float_and_test28): Don't
use vector int constants.
(__float_and_test24, __float_and8, __float_get_exp): Likewise.
http://sourceware.org/ml/libc-alpha/2013-07/msg00197.html
A rewrite to make this code correct for little-endian.
* sysdeps/ieee754/ldbl-128ibm/e_sqrtl.c (mynumber): Replace
union 32-bit int array member with 64-bit int array.
(t515, tm256): Double rather than long double.
(__ieee754_sqrtl): Rewrite using 64-bit arithmetic.
http://sourceware.org/ml/libc-alpha/2013-08/msg00085.html
Rid ourselves of ieee854.
* sysdeps/ieee754/ldbl-128ibm/ieee754.h (union ieee854_long_double):
Delete.
(IEEE854_LONG_DOUBLE_BIAS): Delete.
* sysdeps/ieee754/ldbl-128ibm/math_ldbl.h: Don't include ieee854
version of math_ldbl.h.
http://sourceware.org/ml/libc-alpha/2013-08/msg00084.html
Another batch of ieee854 macros and union replacement. These four
files also have bugs fixed with this patch. The fact that the two
doubles in an IBM long double may have different signs means that
negation and absolute value operations can't just twiddle one sign bit
as you can with ieee864 style extended double. fmodl, remainderl,
erfl and erfcl all had errors of this type. erfl also returned +1 for
large magnitude negative input where it should return -1. The hypotl
error is innocuous since the value adjusted twice is only used as a
flag. The e_hypotl.c tests for large "a" and small "b" are mutually
exclusive because we've already exited when x/y > 2**120. That allows
some further small simplifications.
[BZ #15734], [BZ #15735]
* sysdeps/ieee754/ldbl-128ibm/e_fmodl.c (__ieee754_fmodl): Rewrite
all uses of ieee875 long double macros and unions. Simplify test
for 0.0L. Correct |x|<|y| and |x|=|y| test. Use
ldbl_extract_mantissa value for ix,iy exponents. Properly
normalize after ldbl_extract_mantissa, and don't add hidden bit
already handled. Don't treat low word of ieee854 mantissa like
low word of IBM long double and mask off bit when testing for
zero.
* sysdeps/ieee754/ldbl-128ibm/e_hypotl.c (__ieee754_hypotl): Rewrite
all uses of ieee875 long double macros and unions. Simplify tests
for 0.0L and inf. Correct double adjustment of k. Delete dead code
adjusting ha,hb. Simplify code setting kld. Delete two600 and
two1022, instead use their values. Recognise that tests for large
"a" and small "b" are mutually exclusive. Rename vars. Comment.
* sysdeps/ieee754/ldbl-128ibm/e_remainderl.c (__ieee754_remainderl):
Rewrite all uses of ieee875 long double macros and unions. Simplify
test for 0.0L and nan. Correct negation.
* sysdeps/ieee754/ldbl-128ibm/s_erfl.c (__erfl): Rewrite all uses of
ieee875 long double macros and unions. Correct output for large
magnitude x. Correct absolute value calculation.
(__erfcl): Likewise.
* math/libm-test.inc: Add tests for errors discovered in IBM long
double versions of fmodl, remainderl, erfl and erfcl.
http://sourceware.org/ml/libc-alpha/2013-08/msg00083.html
Further replacement of ieee854 macros and unions. These files also
have some optimisations for comparison against 0.0L, infinity and nan.
Since the ABI specifies that the high double of an IBM long double
pair is the value rounded to double, a high double of 0.0 means the
low double must also be 0.0. The ABI also says that infinity and
nan are encoded in the high double, with the low double unspecified.
This means that tests for 0.0L, +/-Infinity and +/-NaN need only check
the high double.
* sysdeps/ieee754/ldbl-128ibm/e_atan2l.c (__ieee754_atan2l): Rewrite
all uses of ieee854 long double macros and unions. Simplify tests
for long doubles that are fully specified by the high double.
* sysdeps/ieee754/ldbl-128ibm/e_gammal_r.c (__ieee754_gammal_r):
Likewise.
* sysdeps/ieee754/ldbl-128ibm/e_ilogbl.c (__ieee754_ilogbl): Likewise.
Remove dead code too.
* sysdeps/ieee754/ldbl-128ibm/e_jnl.c (__ieee754_jnl): Likewise.
(__ieee754_ynl): Likewise.
* sysdeps/ieee754/ldbl-128ibm/e_log10l.c (__ieee754_log10l): Likewise.
* sysdeps/ieee754/ldbl-128ibm/e_logl.c (__ieee754_logl): Likewise.
* sysdeps/ieee754/ldbl-128ibm/e_powl.c (__ieee754_powl): Likewise.
Remove dead code too.
* sysdeps/ieee754/ldbl-128ibm/k_tanl.c (__kernel_tanl): Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_expm1l.c (__expm1l): Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_frexpl.c (__frexpl): Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_isinf_nsl.c (__isinf_nsl): Likewise.
Simplify.
* sysdeps/ieee754/ldbl-128ibm/s_isinfl.c (___isinfl): Likewise.
Simplify.
* sysdeps/ieee754/ldbl-128ibm/s_log1pl.c (__log1pl): Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_modfl.c (__modfl): Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_nextafterl.c (__nextafterl): Likewise.
Comment on variable precision.
* sysdeps/ieee754/ldbl-128ibm/s_nexttoward.c (__nexttoward): Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_nexttowardf.c (__nexttowardf):
Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_remquol.c (__remquol): Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_scalblnl.c (__scalblnl): Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_scalbnl.c (__scalbnl): Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_tanhl.c (__tanhl): Likewise.
* sysdeps/powerpc/fpu/libm-test-ulps: Adjust tan_towardzero ulps.
http://sourceware.org/ml/libc-alpha/2013-08/msg00081.html
This is the first of a series of patches to ban ieee854_long_double
and the ieee854_long_double macros when using IBM long double. union
ieee854_long_double just isn't correct for IBM long double, especially
when little-endian, and pretending it is OK has allowed a number of
bugs to remain undetected in sysdeps/ieee754/ldbl-128ibm/.
This changes the few places in generic code that use it.
* stdio-common/printf_size.c (__printf_size): Don't use
union ieee854_long_double in fpnum union.
* stdio-common/printf_fphex.c (__printf_fphex): Likewise. Use
signbit macro to retrieve sign from long double.
* stdio-common/printf_fp.c (___printf_fp): Use signbit macro to
retrieve sign from long double.
* sysdeps/ieee754/ldbl-128ibm/printf_fphex.c: Adjust for fpnum change.
* sysdeps/ieee754/ldbl-128/printf_fphex.c: Likewise.
* sysdeps/ieee754/ldbl-96/printf_fphex.c: Likewise.
* sysdeps/x86_64/fpu/printf_fphex.c: Likewise.
* math/test-misc.c (main): Don't use union ieee854_long_double.
ports/
* sysdeps/ia64/fpu/printf_fphex.c: Adjust for fpnum change.
http://sourceware.org/ml/libc-alpha/2013-06/msg00919.html
I discovered a number of places where denormals and other corner cases
were being handled wrongly.
- printf_fphex.c: Testing for the low double exponent being zero is
unnecessary. If the difference in exponents is less than 53 then the
high double exponent must be nearing the low end of its range, and the
low double exponent hit rock bottom.
- ldbl2mpn.c: A denormal (ie. exponent of zero) value is treated as
if the exponent was one, so shift mantissa left by one. Code handling
normalisation of the low double mantissa lacked a test for shift count
greater than bits in type being shifted, and lacked anything to handle
the case where the difference in exponents is less than 53 as in
printf_fphex.c.
- math_ldbl.h (ldbl_extract_mantissa): Same as above, but worse, with
code testing for exponent > 1 for some reason, probably a typo for >= 1.
- math_ldbl.h (ldbl_insert_mantissa): Round the high double as per
mpn2ldbl.c (hi is odd or explicit mantissas non-zero) so that the
number we return won't change when applying ldbl_canonicalize().
Add missing overflow checks and normalisation of high mantissa.
Correct misleading comment: "The hidden bit of the lo mantissa is
zero" is not always true as can be seen from the code rounding the hi
mantissa. Also by inspection, lzcount can never be less than zero so
remove that test. Lastly, masking bitfields to their widths can be
left to the compiler.
- mpn2ldbl.c: The overflow checks here on rounding of high double were
just plain wrong. Incrementing the exponent must be accompanied by a
shift right of the mantissa to keep the value unchanged. Above notes
for ldbl_insert_mantissa are also relevant.
[BZ #15680]
* sysdeps/ieee754/ldbl-128ibm/e_rem_pio2l.c: Comment fix.
* sysdeps/ieee754/ldbl-128ibm/printf_fphex.c
(PRINT_FPHEX_LONG_DOUBLE): Tidy code by moving -53 into ediff
calculation. Remove unnecessary test for denormal exponent.
* sysdeps/ieee754/ldbl-128ibm/ldbl2mpn.c (__mpn_extract_long_double):
Correct handling of denormals. Avoid undefined shift behaviour.
Correct normalisation of low mantissa when low double is denormal.
* sysdeps/ieee754/ldbl-128ibm/math_ldbl.h
(ldbl_extract_mantissa): Likewise. Comment. Use uint64_t* for hi64.
(ldbl_insert_mantissa): Make both hi64 and lo64 parms uint64_t.
Correct normalisation of low mantissa. Test for overflow of high
mantissa and normalise.
(ldbl_nearbyint): Use more readable constant for two52.
* sysdeps/ieee754/ldbl-128ibm/mpn2ldbl.c
(__mpn_construct_long_double): Fix test for overflow of high
mantissa and correct normalisation. Avoid undefined shift.
http://sourceware.org/ml/libc-alpha/2013-07/msg00001.html
This patch starts the process of supporting powerpc64 little-endian
long double in glibc. IBM long double is an array of two ieee
doubles, so making union ibm_extended_long_double reflect this fact is
the correct way to access fields of the doubles.
* sysdeps/ieee754/ldbl-128ibm/ieee754.h
(union ibm_extended_long_double): Define as an array of ieee754_double.
(IBM_EXTENDED_LONG_DOUBLE_BIAS): Delete.
* sysdeps/ieee754/ldbl-128ibm/printf_fphex.c: Update all references
to ibm_extended_long_double and IBM_EXTENDED_LONG_DOUBLE_BIAS.
* sysdeps/ieee754/ldbl-128ibm/e_exp10l.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/e_expl.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/ldbl2mpn.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/math_ldbl.h: Likewise.
* sysdeps/ieee754/ldbl-128ibm/mpn2ldbl.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_nearbyintl.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/strtold_l.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/x2y2m1l.c: Likewise.
sysdeps/unix/make-syscalls.sh and sysdeps/unix/Makefile use GNU Bash's
${parameter/pattern/string} parameter expansion. Non-Bash shells (e.g.
dash or BusyBox ash when built with CONFIG_ASH_BASH_COMPAT disabled)
don't support this expansion syntax. So glibc will fail to build when
$(SHELL) expands to a path that isn't provided by Bash.
An example build failure:
for dir in [...]; do \
test -f $dir/syscalls.list && \
{ sysdirs='[...]' \
asm_CPP='gcc -c -I[...] -D_LIBC_REENTRANT -include include/libc-symbols.h -DASSEMBLER -g -Wa,--noexecstack -E -x assembler-with-cpp' \
/bin/sh sysdeps/unix/make-syscalls.sh $dir || exit 1; }; \
test $dir = sysdeps/unix && break; \
done > [build-dir]/sysd-syscallsT
sysdeps/unix/make-syscalls.sh: line 273: syntax error: bad substitution
This patch simply replaces the three instances of the Bash-only syntax
in these files with an echo and sed command substitution.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
This define was removed from the rest of the tree eight years ago.
ChangeLog:
2013-09-24 Will Newton <will.newton@linaro.org>
* sysdeps/mach/hurd/i386/tls.h (TLS_INIT_TP_EXPENSIVE): Remove
macro.
Statically built binaries use __pointer_chk_guard_local,
while dynamically built binaries use __pointer_chk_guard.
Provide the right definition depending on the test case
we are building.
The pointer guard used for pointer mangling was not initialized for
static applications resulting in the security feature being disabled.
The pointer guard is now correctly initialized to a random value for
static applications. Existing static applications need to be
recompiled to take advantage of the fix.
The test tst-ptrguard1-static and tst-ptrguard1 add regression
coverage to ensure the pointer guards are sufficiently random
and initialized to a default value.
It has been a long practice for software using IEEE 754 floating-point
arithmetic run on MIPS processors to use an encoding of Not-a-Number
(NaN) data different to one used by software run on other processors.
And as of IEEE 754-2008 revision [1] this encoding does not follow one
recommended in the standard, as specified in section 6.2.1, where it
is stated that quiet NaNs should have the first bit (d1) of their
significand set to 1 while signalling NaNs should have that bit set to
0, but MIPS software interprets the two bits in the opposite manner.
As from revision 3.50 [2][3] the MIPS Architecture provides for
processors that support the IEEE 754-2008 preferred NaN encoding format.
As the two formats (further referred to as "legacy NaN" and "2008 NaN")
are incompatible to each other, tools have to provide support for the
two formats to help people avoid using incompatible binary modules.
The change is comprised of two functional groups of features, both of
which are required for correct support.
1. Dynamic linker support.
To enforce the NaN encoding requirement in dynamic linking a new ELF
file header flag has been defined. This flag is set for 2008-NaN
shared modules and executables and clear for legacy-NaN ones. The
dynamic linker silently ignores any incompatible modules it
encounters in dependency processing.
To avoid unnecessary processing of incompatible modules in the
presence of a shared module cache, a set of new cache flags has been
defined to mark 2008-NaN modules for the three ABIs supported.
Changes to sysdeps/unix/sysv/linux/mips/readelflib.c have been made
following an earlier code quality suggestion made here:
http://sourceware.org/ml/libc-ports/2009-03/msg00036.html
and are therefore a little bit more extensive than the minimum
required.
Finally a new name has been defined for the dynamic linker so that
2008-NaN and legacy-NaN binaries can coexist on a single system that
supports dual-mode operation and that a legacy dynamic linker that
does not support verifying the 2008-NaN ELF file header flag is not
chosen to interpret a 2008-NaN binary by accident.
2. Floating environment support.
IEEE 754-2008 features are controlled in the Floating-Point Control
and Status (FCSR) register and updates are needed to floating
environment support so that the 2008-NaN flag is set correctly and
the kernel default, inferred from the 2008-NaN ELF file header flag
at the time an executable is loaded, respected.
As the NaN encoding format is a property of GCC code generation that is
both a user-selected GCC configuration default and can be overridden
with GCC options, code that needs to know what NaN encoding standard it
has been configured for checks for the __mips_nan2008 macro that is
defined internally by GCC whenever the 2008-NaN mode has been selected.
This mode is determined at the glibc configuration time and therefore a
few consistency checks have been added to catch cases where compilation
flags have been overridden by the user.
The 2008 NaN set of features relies on kernel support as the in-kernel
floating-point emulator needs to be aware of the NaN encoding used even
on hard-float processors and configure the FPU context according to the
value of the 2008 NaN ELF file header flag of the executable being
started. As at this time work on kernel support is still in progress
and the relevant changes have not made their way yet to linux.org master
repository.
Therefore the minimum version supported has been artificially set to
10.0.0 so that 2008-NaN code is not accidentally run on a Linux kernel
that does not suppport it. It is anticipated that the version is
adjusted later on to the actual initial linux.org kernel version to
support this feature. Legacy NaN encoding support is unaffected, older
kernel versions remain supported.
[1] "IEEE Standard for Floating-Point Arithmetic", IEEE Computer
Society, IEEE Std 754-2008, 29 August 2008
[2] "MIPS Architecture For Programmers, Volume I-A: Introduction to the
MIPS32 Architecture", MIPS Technologies, Inc., Document Number:
MD00082, Revision 3.50, September 20, 2012
[3] "MIPS Architecture For Programmers, Volume I-A: Introduction to the
MIPS64 Architecture", MIPS Technologies, Inc., Document Number:
MD00083, Revision 3.50, September 20, 2012
This change synchronizes the glibc headers with the Linux kernel
headers and arranges to coordinate the definition of structures
already defined the Linux kernel UAPI headers.
It is now safe to include glibc's netinet/in.h or Linux's linux/in6.h
in any order in a userspace application and you will get the same
ABI. The ABI is guaranteed by UAPI and glibc.
Since fanotify_init requires CAP_SYS_ADMIN in order to work (which usually
means running as root), we need to handle that error case too.
Reported-by: Andreas Jaeger <aj@suse.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
This patch fixes backtrace for PPC32 and PPC64 to correctly handle
signal trampolines. The 'debug/tst-backtrace6.c' also check for
SA_SIGINFO handling, where is triggers another vDSO symbols for PPC32.
This patch fixes dlfcn/tststatic5 for PowerPC where pagesize
variable was not properly initialized in certain cases. This patch
is based on other architecture code.
The helper binary pt_chown tricked into granting access to another
user's pseudo-terminal.
Pre-conditions for the attack:
* Attacker with local user account
* Kernel with FUSE support
* "user_allow_other" in /etc/fuse.conf
* Victim with allocated slave in /dev/pts
Using the setuid installed pt_chown and a weak check on whether a file
descriptor is a tty, an attacker could fake a pty check using FUSE and
trick pt_chown to grant ownership of a pty descriptor that the current
user does not own. It cannot access /dev/pts/ptmx however.
In most modern distributions pt_chown is not needed because devpts
is enabled by default. The fix for this CVE is to disable building
and using pt_chown by default. We still provide a configure option
to enable hte use of pt_chown but distributions do so at their own
risk.
The generated header is compiled with `-ffreestanding' to avoid any
circular dependencies against the installed implementation headers.
Such a dependency would require the implementation header to be
installed before the generated header could be built (See bug 15711).
In current practice the generated header dependencies do not include
any of the implementation headers removed by the use of `-ffreestanding'.
---
2013-07-15 Carlos O'Donell <carlos@redhat.com>
[BZ #15711]
* sysdeps/unix/sysv/linux/Makefile ($(objpfx)bits/syscall%h):
Avoid system header dependency with -ffreestanding.
($(objpfx)bits/syscall%d): Likewise.
Many Linux arches require fixed mmaps to be aligned higher than pagesize,
so use the SHMLBA define as it represents this quantity exactly.
This fixes spurious errors seen on those arches like:
cannot map archive header: Invalid argument
URL: http://sourceware.org/bugzilla/show_bug.cgi?id=10283
Reported-by: CHIKAMA Masaki <masaki.chikama@gmail.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
This patch introduces two new convenience functions to set the default
thread attributes used for creating threads. This allows a programmer
to set the default thread attributes just once in a process and then
run pthread_create without additional attributes.
GCC 4.8 enables -ftree-loop-distribute-patterns at -O3 by default and
this optimization may transform loops into memset/memmove calls. Without
proper handling this may generate unexpected PLT calls on GLIBC.
This patch fixes by create memset/memmove alias to internal GLIBC
__GI_memset/__GI_memmove symbols.
The most common use case of math functions is with default rounding
mode, i.e. rounding to nearest. Setting and restoring rounding mode
is an unnecessary overhead for this, so I've added support for a
context, which does the set/restore only if the FP status needs a
change. The code is written such that only x86 uses these. Other
architectures should be unaffected by it, but would definitely benefit
if the set/restore has as much overhead relative to the rest of the
code, as the x86 bits do.
Here's a summary of the performance improvement due to these
improvements; I've only mentioned functions that use the set/restore
and have benchmark inputs for x86_64:
Before:
cos(): ITERS:4.69335e+08: TOTAL:28884.6Mcy, MAX:4080.28cy, MIN:57.562cy, 16248.6 calls/Mcy
exp(): ITERS:4.47604e+08: TOTAL:28796.2Mcy, MAX:207.721cy, MIN:62.385cy, 15543.9 calls/Mcy
pow(): ITERS:1.63485e+08: TOTAL:28879.9Mcy, MAX:362.255cy, MIN:172.469cy, 5660.86 calls/Mcy
sin(): ITERS:3.89578e+08: TOTAL:28900Mcy, MAX:704.859cy, MIN:47.583cy, 13480.2 calls/Mcy
tan(): ITERS:7.0971e+07: TOTAL:28902.2Mcy, MAX:1357.79cy, MIN:388.58cy, 2455.55 calls/Mcy
After:
cos(): ITERS:6.0014e+08: TOTAL:28875.9Mcy, MAX:364.283cy, MIN:45.716cy, 20783.4 calls/Mcy
exp(): ITERS:5.48578e+08: TOTAL:28764.9Mcy, MAX:191.617cy, MIN:51.011cy, 19071.1 calls/Mcy
pow(): ITERS:1.70013e+08: TOTAL:28873.6Mcy, MAX:689.522cy, MIN:163.989cy, 5888.18 calls/Mcy
sin(): ITERS:4.64079e+08: TOTAL:28891.5Mcy, MAX:6959.3cy, MIN:36.189cy, 16062.8 calls/Mcy
tan(): ITERS:7.2354e+07: TOTAL:28898.9Mcy, MAX:1295.57cy, MIN:380.698cy, 2503.7 calls/Mcy
So the improvements are:
cos: 27.9089%
exp: 22.6919%
pow: 4.01564%
sin: 19.1585%
tan: 1.96086%
The downside of the change is that it will have an adverse performance
impact on non-default rounding modes, but I think the tradeoff is
justified.
__clock_gettime and other __clock_* functions could result in an extra
PLT reference within libc.so if it actually gets used. None of the
code currently uses them, which is why this probably went unnoticed.
Resolves: #15465
The program name may be unavailable if the user application tampers
with argc and argv[]. Some parts of the dynamic linker caters for
this while others don't, so this patch consolidates the check and
fallback into a single macro and updates all users.
Fixes BZ #15339.
NSS_STATUS_UNAVAIL may mean that a necessary input resource is not
available. This could occur in a number of cases including when the
network is down, system runs out of file descriptors, etc. The
correct differentiator in such a case is the h_errno, which gives the
nature of failure. In case of failures other than a simple 'not
found', we set h_errno as NETDB_INTERNAL and let errno be the
identifier for the exact error.
This implementation speed up memset in several ways. First is avoiding
expensive computed jump. Second is using fact that arguments of memset
are most of time aligned to 8 bytes.
Benchmark results on:
kam.mff.cuni.cz/~ondra/benchmark_string/memset_profile_result27_04_13.tar.bz2
We add new memcpy version that uses unaligned loads which are fast
on modern processors. This allows second improvement which is avoiding
computed jump which is relatively expensive operation.
Tests available here:
http://kam.mff.cuni.cz/~ondra/memcpy_profile_result27_04_13.tar.bz2
[BZ #15442] This adds support for the inverse interpretation of the
quiet bit of IEEE 754 floating-point NaN data that some processors
use. This includes in particular MIPS architecture processors; the
payload used for the canonical qNaN encoding is updated accordingly
so as not to interfere with the quiet bit.
The EXTRACT_WORDS64 and INSERT_WORDS64 macros use movd for a 64-bit
operation. Somehow gcc manages to turn this into movq, but LLVM won't.
2013-05-15 Peter Collingbourne <pcc@google.com>
* sysdeps/x86_64/fpu/math_private.h (MOVQ): New macro.
(EXTRACT_WORDS64) Use where appropriate.
(INSERT_WORDS64) Likewise.
While these instructions accept memory operands, only one operand
may be a memory operand. Giving two operands xm constraints gives
the compiler the option of using memory for both operands, which
would result in invalid assembly code. Using x for all operands is
more appropriate, as most x86_64 calling conventions will pass the
arguments in registers anyway.
2013-05-15 Peter Collingbourne <pcc@google.com>
* sysdeps/x86_64/fpu/multiarch/s_fma.c (__fma_fma4): Replace xm
constraints with x constraints.
* sysdeps/x86_64/fpu/multiarch/s_fmaf.c (__fmaf_fma4): Likewise.
PowerPC kernel now provides a vDSO implementation for time syscall
(commit fcb41a2030abe0eb716ef0798035ef9562097f42). This patch changes
time syscall wrapper to use the vDSO when available. It also changes
the default non vDSO time on PowerPC to use sysdeps/posix/time.c
(since gettimeofday is a vDSO call).
* sysdeps/gnu/netinet/tcp.h (TCP_TIMESTAMP): New value, from
Linux 3.9.
* sysdeps/unix/sysv/linux/bits/socket.h (PF_VSOCK, AF_VSOCK):
Add.
(PF_MAX): Adjust for VSOCK change.
This patch fix the 3c0265394d commits
by correctly setting minimum architecture for modf PPC optimization
to power5+ instead of power5 (since only on power5+ round/ceil will
be inline to inline assembly).
Kay Sievers reported that coreutils' stat tool has a problem with
s390's statfs[64] definition:
> The definition of struct statfs::f_type needs a fix. s390 is the only
> architecture in the kernel that uses an int and expects magic
> constants lager than INT_MAX to fit into.
>
> A fix is needed to make Fedora boot on s390, it currently fails to do
> so. Userspace does not want to add code to paper-over this issue.
[...]
> Even coreutils cannot handle it:
> #define RAMFS_MAGIC 0x858458f6
> # stat -f -c%t /
> ffffffff858458f6
>
> #define BTRFS_SUPER_MAGIC 0x9123683E
> # stat -f -c%t /mnt
> ffffffff9123683e
The bug is caused by an implicit sign extension within the stat tool:
out_uint_x (pformat, prefix_len, statfsbuf->f_type);
where the format finally will be "%lx".
A similar problem can be found in the 'tail' tool.
s390 is the only architecture which has an int type f_type member in
struct statfs[64]. Other architectures have either unsigned ints or
long values, so that the problem doesn't occur there.
Therefore change the type of the f_type member to unsigned int, so
that we get zero extension instead sign extension when assignment to
a long value happens.
Reported-by: Kay Sievers <kay@vrfy.org>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
We no longer support configuring for i386, nor do we
elide such a configuration to i686. Configuring with
i386-* is a failure, and we provide an example of
how to fix that.
---
2013-04-17 Carlos O'Donell <carlos@redhat.com>
* configure.in: Remove i386 configure warning. Remove i386 case.
* configure: Regenerate.
* sysdeps/i386/configure.in: Raise error if config_machine is i386.
Add example to error message.
* sysdeps/i386/configure: Regenerate.
The value of PI is never exactly PI in any floating point representation,
and the value of PI/2 is never PI/2. It is wrong to expect cos(M_PI_2l)
to return 0, instead it will return an answer that is non-zero because
M_PI_2l doesn't round to exactly PI/2 in the type used.
That is to say that the correct answer is to do the following:
* Take PI or PI/2.
* Round to the floating point representation.
* Take the rounded value and compute an infinite precision cos or sin.
* Use the rounded result of the infinite precision cos or sin as the
answer to the test.
I used printf to do the type rounding, and Wolfram's Alpha to do the
infinite precision cos calculations.
The following changes bring x86-64 and x86 to 1/2 ulp for two tests.
It shows that the x86 cos implementation is quite good, and that
our test are flawed.
Unfortunately given that the rounding errors are type dependent we
need to fix this for each type. No regressions on x86-64 or x86.
---
2013-04-11 Carlos O'Donell <carlos@redhat.com>
* math/libm-test.inc (cos_test): Fix PI/2 test.
(sincos_test): Likewise.
* sysdeps/x86_64/fpu/libm-test-ulps: Regenerate.
* sysdeps/i386/fpu/libm-test-ulps: Regenerate.
This change does two things:
* Treats a target i386-* as if it were i686.
* Fails configure if the user is generating code
for i386.
We no longer support i386 code-generation because the i386
lacks the atomic operations we need in glibc.
You can still configure for i386-*, but you get i686 code.
You can't build with --march=i386, --mtune=i386 or a compiler
that defaults to i386 code-generation.
I've added two i386 entries in the master todo list to discuss
merging and renaming:
http://sourceware.org/glibc/wiki/Development_Todo/Master#i386
The failure modes are fail-safe here. You compile for i386,
get i686, and try to run on i386 and it fails. The configure
log has a warning saying we elided to i686. There is no situation
that I can see where we run into any serious problems.
The patch makes the current state better in that we get less
confused users and we build successfully in more default
configurations.
The next enhancement would be to add --march=i?86
as suggested in #c20 of BZ#10062 for any i?86-* builds, which
would solve the problem of a 32-bit compiler that defaults to
i386 code-gen and glibc configured for i686-* target. Which
previously failed at build time, and now will fail at configure
time (requires adding --march=i686).
Updated NEWS with BZ #10060 and #10062.
No regressions.
---
2013-04-06 Carlos O'Donell <carlos@redhat.com>
[BZ #10060, #10062]
* aclocal.m4 (LIBC_COMPILER_BUILTIN_INLINED): New macro.
* sysdeps/i386/configure.in: Use LIBC_COMPILER_BUILTIN_INLINED and
fail configure if __sync_val_compare_and_swap is not inlined.
* sysdeps/i386/configure: Regenerate.
* configure.in: Build for i686 when configured for i386.
* configure: Regenerate.
* README: Remove i386 reference.
The s390 and s390x sysdep.h files include the more generic sysdep.h.
The more generic sysdep.h defines PSEUDO. This causes an annoying
CPP warning saying the PSEUDO was redefined. This patch removes the
warning by undefining PSEUDO before the redefinition. This is in line
with what all the other machines do.
---
2013-04-06 Carlos O'Donell <carlos@redhat.com>
* sysdeps/s390/s390-32/sysdep.h: Undefine PSEUDO before redefinition.
* sysdeps/s390/s390-64/sysdep.h: Likewise.
Fix BZ #15305.
On kernel versions earlier than 2.6.29, the Linux kernel exported a
sysctl called restrict_chown for xfs, which could be used to allow
chown to users other than the owner. 2.6.29 removed this support,
causing the open_not_cancel_2 to fail and thus modify errno. The fix
is to save and restore errno so that the caller sees it as unmodified.
Additionally, since the code to check the sysctl is not useful on
newer kernels, we add an ifdef so that in future the code block gets
rmeoved completely.
The branch prediction hints is actually hurts performance in this case.
The assembly implementation make two assumptions: 1. 'fabs (x) < 2^52'
is unlikely and 2. 'x > 0.0' is unlike (if 1. is true). Since it a
general floating point function, expected input is not bounded and then
it is better to let the hardware handle the branches.
The compiler is smart enough to convert those into double for powerpc,
but if we put them as doubles, it adds overhead by performing those
operations in floating point mode.
The mantissa of mp_no is intended to take only integral values. This
is a relatively good choice for powerpc due to its 4 fpus, but not for
other architectures, which suffer due to this choice. This change
makes the default mantissa a long integer and allows powerpc to
override it. Additionally, some operations have been optimized for
integer manipulation, resulting in a significant improvement in
performance.
The patch increase the high value to check if expl overflows. Current
high mark value is not really correct, the algorithm accepts high values.
It also adds a correct wrapper function to check for overflow and underflow.
Due to a typo repeated several times, this bug hasn't been fixed yet,
despite being marked as resolved in glibc 2.12.
* sysdeps/x86_64/strcmp.S: Replace all occurrences of NOT_IN_lib
with NOT_IN_libc.
Fixes BZ #12723
The variable pipe buffer size does nothing to the value of PIPE_BUF,
since the number of bytes that are atomically written is still
PIPE_BUF on Linux.
* sysdeps/unix/sysv/linux/bits/mman-linux.h (MAP_ANONYMOUS):
Allow definition via __MAP_ANONYMOUS.
* sysdeps/unix/sysv/linux/mips/bits/mman.h: Remove all defines
provided by bits/mman-linux.h and include <bits/mman-linux.h>.
(__MAP_ANONYMOUS): Define.
* sysdeps/unix/sysv/linux/s390/bits/mman.h: Include
<bits/mman-linux.h>.
(MCL_CURRENT, MCL_FUTURE): Do not define here, the generic value
is fine.
* sysdeps/unix/sysv/linux/sh/bits/mman.h: Move include of
<bits/mman-linux.h> to end of file.
(MCL_CURRENT, MCL_FUTURE): Do not define here, the generic value
is fine.
* sysdeps/unix/sysv/linux/x86/bits/mman.h: Move include of
<bits/mman-linux.h> to end of file.
(MCL_CURRENT, MCL_FUTURE): Do not define here, the generic value
is fine.
* sysdeps/unix/sysv/linux/sparc/bits/mman.h: Move include of
<bits/mman-linux.h> to end of file.
* sysdeps/unix/sysv/linux/bits/mman-linux.h [!MCL_CURRENT]
(MCL_CURRENT, MCL_FUTURE): Define here.
* sysdeps/unix/sysv/linux/bits/mman-linux.h: New file, with
Linux common definitions.
* sysdeps/unix/sysv/linux/sh/bits/mman.h: Remove all defines
provided by bits/mman-linux.h and include <bits/mman-linux.h>.
* sysdeps/unix/sysv/linux/x86/bits/mman.h: Likewise.
* sysdeps/unix/sysv/linux/s390/bits/mman.h: Likewise.
* sysdeps/unix/sysv/linux/powerpc/bits/mman.h: Likewise.
* sysdeps/unix/sysv/linux/sh/bits/mman.h: Likewise.
* sysdeps/unix/sysv/linux/sparc/bits/mman.h: Likewise.
Using long throughout like powerpc does is beneficial since it reduces
the need to switch to 32-bit instructions. It gives a very minor
performance improvement.
These prototypes are duplicated in many places. Add a dedicated
header for holding prototypes for program-specific functions to
avoid that.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
This feature is specifically for the C++ compiler to offload calling
thread_local object destructors on thread program exit, to glibc.
This is to overcome the possible complication of destructors of
thread_local objects getting called after the DSO in which they're
defined is unloaded by the dynamic linker. The DSO is marked as
'unloadable' if it has a constructed thread_local object and marked as
'unloadable' again when all the constructed thread_local objects
defined in it are destroyed.
ARM now supports loading unmarked objects from
the dynamic loader cache. Unmarked objects can
be used with the hard-float or soft-float ABI.
We must support loading unmarked objects during
the transition period from a binutils that does
not mark objects to one that does mark them with
the correct ELF flags.
Signed-off-by: Carlos O'Donell <carlos@redhat.com>
* sysdeps/sparc/sparc32/sparcv9/bits/atomic.h
(__arch_compare_and_exchange_val_32_acq): Use %g0 as second
argument of CAS if possible.
* sysdeps/sparc/sparc64/bits/atomic.h
(__arch_compare_and_exchange_val_32_acq): Likewise.
(__arch_compare_and_exchange_val_64_acq): Likewise.
The bsd implementation of ulimit produces wrong return values, so remove it
in favour of the posix implementation.
The only regression for non-Linux implementations using bsd sysdeps and not
providing an own ulimit is that the __UL_GETMAXBRK case (which is non-standard)
is left unimplemented (giving EINVAL).
In order for the __kernel_get_tbfreq vDSO call to work the
INTERNAL_VSYSCALL_NCS macro needed to be updated to prevent it from
assuming an integer return type (since the timebase frequency is a 64-bit
value) by specifying the type of the return type as a macro parameter. The
macro then specifically declares the return value as a 'register' (or
implied pair) of the denoted type. The compiler is then informed that this
register (or implied pair) is to be used for the return value.
