This patch adds an optimized POWER8 st{r,p}ncpy using unaligned accesses.
It shows 10%-80% improvement over the optimized POWER7 one that uses
only aligned accesses, specially on unaligned inputs.
The algorithm first read and check 16 bytes (if inputs do not cross a 4K
page size). The it realign source to 16-bytes and issue a 16 bytes read
and compare loop to speedup null byte checks for large strings. Also,
different from POWER7 optimization, the null pad is done inline in the
implementation using possible unaligned accesses, instead of realying on
a memset call. Special case is added for page cross reads.
With 3eb38795db (Simplify strncat) the generic algorithms uses
strlen, strnlen, and memcpy. This is faster than POWER7 current
implementation, especially for unaligned strings (where POWER7 code
uses byte-byte operations).
This patch removes the assembly implementation and uses a multiarch
specialization based on default algorithm calling optimized POWER7
symbols.
This patch adds an optimized POWER8 strcpy using unaligned accesses.
For strings up to 16 bytes the implementation first calculate the
string size, like strlen, and issues a memcpy. For larger strings,
source is first aligned to 16 bytes and then tested over a loop that
reads 16 bytes am combine the cmpb results for speedup. Special case is
added for page cross reads.
It shows 30%-60% improvement over the optimized POWER7 one that uses
only aligned accesses.
The ldbl-96 implementation of scalblnl (used for x86_64 and ia64) uses
a condition k <= -63 to determine when a standard underflowing result
tiny*__copysignl(tiny,x) should be returned. However, that condition
corresponds to values with exponent -16446 or less, and in the case of
-16446, the correct result for round-to-nearest depends on whether the
value is exactly 0x1p-16446 (half the least subnormal) or more than
that. This patch fixes the bug by changing the condition to k <= -64
and accordingly adjusting the exponent by 64 not 63 when converting to
a normal value.
Tested for x86_64.
[BZ #17803]
* sysdeps/ieee754/ldbl-96/s_scalblnl.c (twom63): Rename to
twom64. Adjust value to 0x1p-64L.
(__scalblnl): Only return standard underflowing result for K <=
-64 not K <= -63; adjust exponent for underflowing result by 64
not 63.
* math/libm-test.inc (scalbn_test_data): Add more tests.
(scalbln_test_data): Likewise.
The ldbl-96 implementation of scalblnl (used for x86_64 and ia64) is
incorrect for subnormal arguments (this is a separate bug from bug
17803, which is about underflowing results). There are two problems
with the adjustments of subnormal arguments: the "two63" variable
multiplied by is actually 0x1p52L not 0x1p63L, so is insufficient to
make values normal, and then GET_LDOUBLE_EXP(es,x), used to extract
the new exponent, extracts it into a variable that isn't used, while
the value taken to by the new exponent is wrongly taken from the high
part of the mantissa before the adjustment (hx). This patch fixes
both those problems and adds appropriate tests.
Tested for x86_64.
[BZ #17834]
* sysdeps/ieee754/ldbl-96/s_scalblnl.c (two63): Change value to
0x1p63L.
(__scalblnl): Get new exponent of adjusted subnormal value from ES
not HX.
* math/libm-test.inc (scalbn_test_data): Add more tests.
(scalbln_test_data): Likewise.
Linux 3.15 adds support for clock_gettime, gettimeofday, and time vDSO
(commit id 37c975545ec63320789962bf307f000f08fabd48). This patch adds
GLIBC supports to use such symbol when they are avaiable.
Along with x86 vDSO support, this patch cleanup x86_64 code by moving
all common code to x86 common folder. Only init-first.c is different
between implementations.
Linux kernel powerpc documentation states issuing a syscall inside a
transaction is not recommended and may lead to undefined behavior. It
also states syscalls does not abort transactoin neither they run in
transactional state.
To avoid side-effects being visible outside transactions, GLIBC with
lock elision enabled will issue a transaction abort instruction just
before all syscalls if hardware supports hardware transactions.
This patch adds support for lock elision using ISA 2.07 hardware
transactional memory for rwlocks. The logic is similar to the
one presented in pthread_mutex lock elision.
This patch adds support for lock elision using ISA 2.07 hardware
transactional memory instructions for pthread_mutex primitives.
Similar to s390 version, the for elision logic defined in
'force-elision.h' is only enabled if ENABLE_LOCK_ELISION is defined.
Also, the lock elision code should be able to be built even with
a compiler that does not provide HTM support with builtins.
However I have noted the performance is sub-optimal due scheduling
pressures.
Microblaze apparently has a variable page size (see thread below) and
should not hard-code any page-size related macros.
Also remove macros that are only used for BFD's trad-core support
which is not relavant for microblaze also according to the thread
starting here:
https://sourceware.org/ml/libc-ports/2013-11/msg00028.html
This patch is neither built nor tested but mirrors a MIPS patch that
fixes the same issue.
Thanks,
Matthew
* sysdepsysdeps/unix/sysv/linux/microblaze/sys/user.h
(PAGE_SHIFT, PAGE_SIZE, PAGE_MASK, NBPG, UPAGES): Remove.
(HOST_TEXT_START_ADDR, HOST_STACK_END_ADDR): Remove.
Signed-off-by: David Holsgrove <david.holsgrove@xilinx.com>
2015-01-06 David Holsgrove <david.holsgrove@xilinx.com>
* sysdeps/microblaze/jmpbuf-unwind.h (_jmpbuf_sp): Declare SP as void
pointer and cast to uintptr_t.
Signed-off-by: David Holsgrove <david.holsgrove@xilinx.com>
2015-01-06 David Holsgrove <david.holsgrove@xilinx.com>
* sysdeps/microblaze/nptl/tls.h (TLS_INIT_TP): Use NULL instead
of 0.
Signed-off-by: David Holsgrove <david.holsgrove@xilinx.com>
GCC 5.0 emits an warning when using sizeof on array function parameters
and powerpc internal syscall macros add a check for such cases. More
specifically, on powerpc64 and powerpc32 sysdep.h:
if (__builtin_classify_type (__arg3) != 5 && sizeof (__arg3) > 8) \
__illegally_sized_syscall_arg3 (); \
And for sysdeps/unix/sysv/linux/utimensat.c build GCC emits:
error: ‘sizeof’ on array function parameter ‘tsp’ will return size of
‘const struct timespec *’
This patch uses the address of first struct member instead of the struct
itself in syscall macro.
Concluding the fixes for C90 libm functions calling C99 fe* functions,
this patch fixes the case of feupdateenv by making it a weak alias for
__feupdateenv and making the affected code call __feupdateenv.
Tested for x86_64 (testsuite, and that installed stripped shared
libraries are unchanged by the patch). Also tested for ARM
(soft-float) that the math.h linknamespace tests now pass.
[BZ #17748]
* include/fenv.h (__feupdateenv): Use libm_hidden_proto.
* math/feupdateenv.c (__feupdateenv): Use libm_hidden_def.
* sysdeps/aarch64/fpu/feupdateenv.c (feupdateenv): Rename to
__feupdateenv and define as weak alias of __feupdateenv. Use
libm_hidden_weak.
* sysdeps/alpha/fpu/feupdateenv.c (__feupdateenv): Use
libm_hidden_def.
* sysdeps/arm/feupdateenv.c (feupdateenv): Rename to __feupdateenv
and define as weak alias of __feupdateenv. Use libm_hidden_weak.
* sysdeps/hppa/fpu/feupdateenv.c (feupdateenv): Likewise.
* sysdeps/i386/fpu/feupdateenv.c (__feupdateenv): Use
libm_hidden_def.
* sysdeps/ia64/fpu/feupdateenv.c (feupdateenv): Rename to
__feupdateenv and define as weak alias of __feupdateenv. Use
libm_hidden_weak.
* sysdeps/m68k/fpu/feupdateenv.c (__feupdateenv): Use
libm_hidden_def.
* sysdeps/mips/fpu/feupdateenv.c (feupdateenv): Rename to
__feupdateenv and define as weak alias of __feupdateenv. Use
libm_hidden_weak.
* sysdeps/powerpc/fpu/feupdateenv.c (__feupdateenv): Use
libm_hidden_def.
* sysdeps/powerpc/nofpu/feupdateenv.c (__feupdateenv): Likewise.
* sysdeps/powerpc/powerpc32/e500/nofpu/feupdateenv.c
(__feupdateenv): Likewise.
* sysdeps/s390/fpu/feupdateenv.c (feupdateenv): Rename to
__feupdateenv and define as weak alias of __feupdateenv. Use
libm_hidden_weak.
* sysdeps/sh/sh4/fpu/feupdateenv.c (feupdateenv): Likewise.
* sysdeps/sparc/fpu/feupdateenv.c (__feupdateenv): Use
libm_hidden_def.
* sysdeps/tile/math_private.h (__feupdateenv): New inline
function.
* sysdeps/x86_64/fpu/feupdateenv.c (__feupdateenv): Use
libm_hidden_def.
* sysdeps/generic/math_private.h (default_libc_feupdateenv): Call
__feupdateenv instead of feupdateenv.
(default_libc_feupdateenv_test): Likewise.
(libc_feresetround_ctx): Likewise.
Continuing the fixes for C90 libm functions calling C99 fe* functions,
this patch fixes the case of fesetround by making it a weak alias of
__fesetround and making the affected code call __fesetround. An
existing __fesetround function in fenv_libc.h for powerpc is renamed
to __fesetround_inline.
Tested for x86_64 (testsuite, and that disassembly of installed shared
libraries is unchanged by the patch). Also tested for ARM
(soft-float) that fesetround failures disappear from the linknamespace
test results (feupdateenv remains to be addressed to complete fixing
bug 17748).
[BZ #17748]
* include/fenv.h (__fesetround): Declare. Use libm_hidden_proto.
* math/fesetround.c (fesetround): Rename to __fesetround and
define as weak alias of __fesetround. Use libm_hidden_weak.
* sysdeps/aarch64/fpu/fesetround.c (fesetround): Likewise.
* sysdeps/alpha/fpu/fesetround.c (fesetround): Likewise.
* sysdeps/arm/fesetround.c (fesetround): Likewise.
* sysdeps/hppa/fpu/fesetround.c (fesetround): Likewise.
* sysdeps/i386/fpu/fesetround.c (fesetround): Likewise.
* sysdeps/ia64/fpu/fesetround.c (fesetround): Likewise.
* sysdeps/m68k/fpu/fesetround.c (fesetround): Likewise.
* sysdeps/mips/fpu/fesetround.c (fesetround): Likewise.
* sysdeps/powerpc/fpu/fenv_libc.h (__fesetround): Rename to
__fesetround_inline.
* sysdeps/powerpc/fpu/fenv_private.h (libc_fesetround_ppc): Call
__fesetround_inline instead of __fesetround.
* sysdeps/powerpc/fpu/fesetround.c (fesetround): Rename to
__fesetround and define as weak alias of __fesetround. Use
libm_hidden_weak. Call __fesetround_inline instead of
__fesetround.
* sysdeps/powerpc/nofpu/fesetround.c (fesetround): Rename to
__fesetround and define as weak alias of __fesetround. Use
libm_hidden_weak.
* sysdeps/powerpc/powerpc32/e500/nofpu/fesetround.c (fesetround):
Likewise.
* sysdeps/s390/fpu/fesetround.c (fesetround): Likewise.
* sysdeps/sh/sh4/fpu/fesetround.c (fesetround): Likewise.
* sysdeps/sparc/fpu/fesetround.c (fesetround): Likewise.
* sysdeps/tile/math_private.h (__fesetround): New inline function.
* sysdeps/x86_64/fpu/fesetround.c (fesetround): Rename to
__fesetround and define as weak alias of __fesetround. Use
libm_hidden_weak.
* sysdeps/generic/math_private.h (default_libc_fesetround): Call
__fesetround instead of fesetround.
(default_libc_feholdexcept_setround): Likewise.
(libc_feholdsetround_ctx): Likewise.
(libc_feholdsetround_noex_ctx): Likewise.
Continuing the fixes for C90 libm functions calling C99 fe* functions,
this patch fixes the case of fesetenv by making it a weak alias of
__fesetenv and making the affected code (including various copies of
feupdateenv which also gets called from C90 functions) call
__fesetenv.
Tested for x86_64 (testsuite, and that disassembly of installed shared
libraries is unchanged by the patch). Also tested for ARM
(soft-float) that fesetenv failures disappear from the linknamespace
test results (fsetround and feupdateenv remain to be addressed to
complete fixing bug 17748).
[BZ #17748]
* include/fenv.h (__fesetenv): Use libm_hidden_proto.
* math/fesetenv.c (__fesetenv): Use libm_hidden_def.
* sysdeps/aarch64/fpu/fesetenv.c (fesetenv): Rename to __fesetenv
and define as weak alias of __fesetenv. Use libm_hidden_weak.
* sysdeps/alpha/fpu/fesetenv.c (__fesetenv): Use libm_hidden_def.
* sysdeps/arm/fesetenv.c (fesetenv): Rename to __fesetenv and
define as weak alias of __fesetenv. Use libm_hidden_weak.
* sysdeps/hppa/fpu/fesetenv.c (fesetenv): Likewise.
* sysdeps/i386/fpu/fesetenv.c (__fesetenv): Use libm_hidden_def.
* sysdeps/ia64/fpu/fesetenv.c (fesetenv): Rename to __fesetenv and
define as weak alias of __fesetenv. Use libm_hidden_weak.
* sysdeps/m68k/fpu/fesetenv.c (__fesetenv): Use libm_hidden_def.
* sysdeps/mips/fpu/fesetenv.c (fesetenv): Rename to __fesetenv and
define as weak alias of __fesetenv. Use libm_hidden_weak.
* sysdeps/powerpc/fpu/fesetenv.c (__fesetenv): Use
libm_hidden_def.
* sysdeps/powerpc/nofpu/fesetenv.c (__fesetenv): Likewise.
* sysdeps/powerpc/powerpc32/e500/nofpu/fesetenv.c (__fesetenv):
Likewise.
* sysdeps/s390/fpu/fesetenv.c (fesetenv): Rename to __fesetenv and
define as weak alias of __fesetenv. Use libm_hidden_weak.
* sysdeps/sh/sh4/fpu/fesetenv.c (fesetenv): Likewise.
* sysdeps/sparc/fpu/fesetenv.c (__fesetenv): Use libm_hidden_def.
* sysdeps/tile/math_private.h (__fesetenv): New inline function.
* sysdeps/x86_64/fpu/fesetenv.c (fesetenv): Rename to __fesetenv
and define as weak alias of __fesetenv. Use libm_hidden_weak.
* sysdeps/generic/math_private.h (default_libc_fesetenv): Use
__fesetenv instead of fesetenv.
(libc_feresetround_noex_ctx): Likewise.
* sysdeps/alpha/fpu/feupdateenv.c (__feupdateenv): Likewise.
* sysdeps/hppa/fpu/feupdateenv.c (feupdateenv): Likewise.
* sysdeps/i386/fpu/feupdateenv.c (__feupdateenv): Likewise.
* sysdeps/ia64/fpu/feupdateenv.c (feupdateenv): Likewise.
* sysdeps/m68k/fpu/feupdateenv.c (__feupdateenv): Likewise.
* sysdeps/mips/fpu/feupdateenv.c (feupdateenv): Likewise.
* sysdeps/powerpc/nofpu/feupdateenv.c (__feupdateenv): Likewise.
* sysdeps/powerpc/powerpc32/e500/nofpu/feupdateenv.c
(__feupdateenv): Likewise.
* sysdeps/s390/fpu/feupdateenv.c (feupdateenv): Likewise.
* sysdeps/sh/sh4/fpu/feupdateenv.c (feupdateenv): Likewise.
* sysdeps/sparc/fpu/feupdateenv.c (__feupdateenv): Likewise.
* sysdeps/x86_64/fpu/feupdateenv.c (__feupdateenv): Likewise.
We simplify allocation strategy there so instead of using temporary linked list
and then copying entries to output array we keep them in resizable
array.
C99 specifies that CLOCKS_PER_SEC is an expression with the type clock_t.
This patch adds a generic <bits/time2.h> to define CLOCKS_PER_SEC and
provides the Linux/x86-64 version of <bits/time2.h> to support x32.
[BZ #17797]
* bits/time.h (CLOCKS_PER_SEC): Changed to ((clock_t) 1000000).
* sysdeps/unix/sysv/linux/bits/time.h (CLOCKS_PER_SEC): Likewise.
* sysdeps/unix/sysv/linux/clock.c (clock): _Static_assert
CLOCKS_PER_SEC == 1000000.
* time/clocktest.c (main): Replace %ld with %jd and cast to
intmax_t.
Continuing the fixes for C90 libm functions calling C99 fe* functions,
this patch fixes the case of feholdexcept by making it a weak alias of
__feholdexcept and making the affected code call __feholdexcept.
Tested for x86_64 (testsuite, and that disassembly of installed shared
libraries is unchanged by the patch). Also tested for ARM
(soft-float) that feholdexcept failures disappear from the
linknamespace test failures (fesetenv, fsetround and feupdateenv
remain to be addressed to complete fixing bug 17748).
[BZ #17748]
* include/fenv.h (__feholdexcept): Declare. Use
libm_hidden_proto.
* math/feholdexcpt.c (feholdexcept): Rename to __feholdexcept and
define as weak alias of __feholdexcept. Use libm_hidden_weak.
* sysdeps/aarch64/fpu/feholdexcpt.c (feholdexcept): Likewise.
* sysdeps/alpha/fpu/feholdexcpt.c (feholdexcept): Likewise.
* sysdeps/arm/feholdexcpt.c (feholdexcept): Likewise.
* sysdeps/hppa/fpu/feholdexcpt.c (feholdexcept): Likewise.
* sysdeps/i386/fpu/feholdexcpt.c (feholdexcept): Likewise.
* sysdeps/ia64/fpu/feholdexcpt.c (feholdexcept): Likewise.
* sysdeps/m68k/fpu/feholdexcpt.c (feholdexcept): Likewise.
* sysdeps/mips/fpu/feholdexcpt.c (feholdexcept): Likewise.
* sysdeps/powerpc/fpu/feholdexcpt.c (feholdexcept): Likewise.
* sysdeps/powerpc/nofpu/feholdexcpt.c (feholdexcept): Likewise.
* sysdeps/powerpc/powerpc32/e500/nofpu/feholdexcpt.c
(feholdexcept): Likewise.
* sysdeps/s390/fpu/feholdexcpt.c (feholdexcept): Likewise.
* sysdeps/sh/sh4/fpu/feholdexcpt.c (feholdexcept): Likewise.
* sysdeps/sparc/fpu/feholdexcpt.c (feholdexcept): Likewise.
* sysdeps/x86_64/fpu/feholdexcpt.c (feholdexcept): Likewise.
* sysdeps/generic/math_private.h (default_libc_feholdexcept): Use
__feholdexcept instead of feholdexcept.
(default_libc_feholdexcept_setround): Likewise.
sysdeps/unix/sysv/linux/mips/mips64/n64/posix_fadvise.c defines
posix_fadvise64 as a strong alias for posix_fadvise (for
!SHLIB_COMPAT(libc, GLIBC_2_2, GLIBC_2_3_3) - i.e., for static
linking, which is the case when this matters), but it should be a weak
alias. This patch makes it a weak alias.
Tested for MIPS that this fixes the observed linknamespace test
failures.
[BZ #17796]
* sysdeps/unix/sysv/linux/mips/mips64/n64/posix_fadvise.c
[!SHLIB_COMPAT(libc, GLIBC_2_2, GLIBC_2_3_3)] (posix_fadvise64):
Define as weak alias not strong alias.
The tile vDSO vsyscalls were not properly setting the error value.
Conventionally, tile returns the same "non-negative success, negative
errno" value that x86 does (in r0), but it also returns "zero or positive
errno" in r1, which is what the regular syscall code checks. This change
uses that convention for the vDSO calls as well.
Platforms with 64-bit registers where 32-bit values need to have the
high 32 bits set in a particular way need to have an explicit cast
when using the 64-bit sysdeps/ieee754/dbl-64/wordsize-64 version
of llround() as lround(). This includes tilegx32, and likely MIPS.
x32 does not need this, and AArch64 ILP32 will not either. Require
it to be specified in sysdep.h to be explicit.
ARM posix_fadvise calls __posix_fadvise64_l64, to which
posix_fadvise64 is a strong alias, but posix_fadvise is a POSIX
function and posix_fadvise64 isn't. This patch changes it into a weak
alias.
Tested for ARM that this fixes the corresponding linknamespace test
failures.
[BZ #17793]
* sysdeps/unix/sysv/linux/arm/posix_fadvise64.c (posix_fadvise64):
Define as weak alias not strong alias.
On systems using sysdeps/unix/sysv/linux/wordsize-64, posix_fadvise64
and posix_fallocate64 (non-POSIX) are strong aliases for posix_fadvise
and posix_fallocate (POSIX), meaning references to the latter wrongly
bring in definitions of the former. They should be weak aliases; this
patch makes them so.
Tested for x86_64 (testsuite, and that disassembly of installed shared
libraries is unchanged by the patch).
[BZ #17777]
* sysdeps/unix/sysv/linux/wordsize-64/posix_fadvise.c
(posix_fadvise64): Define as weak alias not strong alias.
* sysdeps/unix/sysv/linux/wordsize-64/posix_fallocate.c
(posix_fallocate64): Likewise.
* conform/Makefile (test-xfail-XOPEN2K/fcntl.h/linknamespace):
Remove variable.
(test-xfail-XOPEN2K/mqueue.h/linknamespace): Likewise.
(test-xfail-POSIX2008/fcntl.h/linknamespace): Likewise.
(test-xfail-POSIX2008/mqueue.h/linknamespace): Likewise.
(test-xfail-XOPEN2K8/fcntl.h/linknamespace): Likewise.
(test-xfail-XOPEN2K8/mqueue.h/linknamespace): Likewise.
MIPS supports a variable page size but glibc defines a constant.
This causes at least two glibc tests to fail when the page size
does not match the hard-coded size:
inet/test-ifaddrs
inet/test_ifindex
[BZ #16191]
* NEWS: Mention bug fix.
* sysdeps/unix/sysv/linux/mips/sys/user.h (PAGE_SHIFT): Remove.
(PAGE_SIZE, PAGE_MASK, NBPG, UPAGES): Likewise.
(HOST_TEXT_START_ADDR, HOST_DATA_START_ADDR): Likewise.
(HOST_STACK_END_ADDR): Likewise.
Continuing the fixes for C90 libm functions calling C99 fe* functions,
this patch fixes the case of fegetround by making it a weak alias of
__fegetround and making the affected code call __fegetround.
Tested for x86_64 (testsuite, and that disassembly of installed shared
libraries is unchanged by the patch). Also tested for ARM
(soft-float) that fegetround failures disappear from the linknamespace
test failures (feholdexcept, fesetenv, fesetround and feupdateenv
remain to be addressed before bug 17748 is fully fixed, although this
patch may suffice to fix the failures in some cases, when the libc_fe*
functions are implemented but there is no architecture-specific sqrt
implementation in use so there were failures from fegetround used by
sqrt but no other such failures).
[BZ #17748]
* include/fenv.h (__fegetround): Declare. Use libm_hidden_proto.
* math/fegetround.c (fegetround): Rename to __fegetround and
define as weak alias of __fegetround. Use libm_hidden_weak.
* sysdeps/aarch64/fpu/fegetround.c (fegetround): Likewise.
* sysdeps/alpha/fpu/fegetround.c (fegetround): Likewise.
* sysdeps/arm/fegetround.c (fegetround): Likewise.
* sysdeps/hppa/fpu/fegetround.c (fegetround): Likewise.
* sysdeps/i386/fpu/fegetround.c (fegetround): Likewise.
* sysdeps/ia64/fpu/fegetround.c (fegetround): Likewise.
* sysdeps/m68k/fpu/fegetround.c (fegetround): Likewise.
* sysdeps/mips/fpu/fegetround.c (fegetround): Likewise.
* sysdeps/powerpc/fpu/fegetround.c (fegetround): Likewise.
Undefine after rather than before function definition; use
parentheses around function name in definition.
(__fegetround): Also undefine macro after function definition.
* sysdeps/powerpc/nofpu/fegetround.c (fegetround): Rename to
__fegetround and define as weak alias of __fegetround. Use
libm_hidden_weak. Do not undefine as macro.
* sysdeps/powerpc/powerpc32/e500/nofpu/fegetround.c (fegetround):
Likewise.
* sysdeps/s390/fpu/fegetround.c (fegetround): Rename to
__fegetround and define as weak alias of __fegetround. Use
libm_hidden_weak.
* sysdeps/sh/sh4/fpu/fegetround.c (fegetround): Likewise.
* sysdeps/sparc/fpu/fegetround.c (fegetround): Likewise.
* sysdeps/tile/math_private.h (__fegetround): New inline function.
* sysdeps/x86_64/fpu/fegetround.c (fegetround): Rename to
__fegetround and define as weak alias of __fegetround. Use
libm_hidden_weak.
* sysdeps/ieee754/dbl-64/e_sqrt.c (__ieee754_sqrt): Use
__fegetround instead of fegetround.
sysdeps/unix/sysv/linux/mips/bits/termios.h defines TIOCSER_TEMT
unconditionally, but it's in the user's namespace. This patch
conditions it on __USE_MISC, as on powerpc. I've filed bug 17783 for
the residual inconsistency in conditions on this macro (sparc defines
it for __USE_GNU only).
[BZ #17782]
* sysdeps/unix/sysv/linux/mips/bits/termios.h (TIOCSER_TEMT):
Condition macro definition on [__USE_MISC].
sysdeps/unix/sysv/linux/mips/bits/sigaction.h gives sa_flags type
unsigned int, but POSIX says it should be signed int. This patch
gives it the correct type (the layout is unchanged, so there are no
ABI issues involved).
[BZ #17781]
* sysdeps/unix/sysv/linux/mips/bits/sigaction.h
(struct sigaction): Change type of sa_flags field to int.
sysdeps/unix/sysv/linux/mips/bits/fcntl.h has a structure field called
pad, which is in the user's namespace. This patch changes it to
__glibc_reserved0.
[BZ #17780]
* sysdeps/unix/sysv/linux/mips/bits/fcntl.h (struct flock)
[!__USE_FILE_OFFSET64 && _MIPS_SIM != _ABI64]: Rename pad field to
__glibc_reserved0.
The default required version of binutils has been increased to 2.22
making this check redundant.
ChangeLog:
2015-01-02 Will Newton <will.newton@linaro.org>
* sysdeps/arm/armv7/configure: Removed.
* sysdeps/arm/armv7/configure.ac: Likewise.
Some C90 libm functions call fegetenv via libc_feholdsetround*
functions in math_private.h. This patch makes them call __fegetenv
instead, making fegetenv into a weak alias for __fegetenv as needed.
Tested for x86_64 (testsuite, and that disassembly of installed shared
libraries is unchanged by the patch). Also tested for ARM
(soft-float) that fegetenv failures disappear from the linknamespace
test failures (however, similar fixes will also be needed for
fegetround, feholdexcept, fesetenv, fesetround and feupdateenv before
this set of namespace issues covered by bug 17748 is fully fixed and
those linknamespace tests start passing).
[BZ #17748]
* include/fenv.h (__fegetenv): Use libm_hidden_proto.
* math/fegetenv.c (__fegetenv): Use libm_hidden_def.
* sysdeps/aarch64/fpu/fegetenv.c (fegetenv): Rename to __fegetenv
and define as weak alias of __fegetenv. Use libm_hidden_weak.
* sysdeps/alpha/fpu/fegetenv.c (__fegetenv): Use libm_hidden_def.
* sysdeps/arm/fegetenv.c (fegetenv): Rename to __fegetenv and
define as weak alias of __fegetenv. Use libm_hidden_weak.
* sysdeps/hppa/fpu/fegetenv.c (fegetenv): Likewise.
* sysdeps/i386/fpu/fegetenv.c (__fegetenv): Use libm_hidden_def.
* sysdeps/ia64/fpu/fegetenv.c (fegetenv): Rename to __fegetenv and
define as weak alias of __fegetenv. Use libm_hidden_weak.
* sysdeps/m68k/fpu/fegetenv.c (__fegetenv): Use libm_hidden_def.
* sysdeps/mips/fpu/fegetenv.c (fegetenv): Rename to __fegetenv and
define as weak alias of __fegetenv. Use libm_hidden_weak.
* sysdeps/powerpc/fpu/fegetenv.c (__fegetenv): Use
libm_hidden_def.
* sysdeps/powerpc/nofpu/fegetenv.c (__fegetenv): Likewise.
* sysdeps/powerpc/powerpc32/e500/nofpu/fegetenv.c (__fegetenv):
Likewise.
* sysdeps/s390/fpu/fegetenv.c (fegetenv): Rename to __fegetenv and
define as weak alias of __fegetenv. Use libm_hidden_weak.
* sysdeps/sh/sh4/fpu/fegetenv.c (fegetenv): Likewise.
* sysdeps/sparc/fpu/fegetenv.c (__fegetenv): Use libm_hidden_def.
* sysdeps/tile/math_private.h (__fegetenv): New inline function.
* sysdeps/x86_64/fpu/fegetenv.c (fegetenv): Rename to __fegetenv
and define as weak alias of __fegetenv. Use libm_hidden_weak.
* sysdeps/generic/math_private.h (libc_feholdsetround_ctx): Use
__fegetenv instead of fegetenv.
(libc_feholdsetround_noex_ctx): Likewise.
This patch optimizes strcpy for ppc64/power7 for unaligned source or
destination address. The source or destination address is aligned
to doubleword and data is shifted based on the alignment and
added with the previous loaded data to be written as a doubleword.
For each load, cmpb instruction is used for faster null check.
The word aligned optimization is also removed, since the new unaligned
code path shows better results handling word-aligned strings.
More combination of unaligned inputs is also added in benchtest
to measure the improvement.The new optimization shows 2 to 80% of
performance improvement for longer string though it does not show
big difference on string size less than 16 due to additional checks.
The natural fix for some linknamespace test failures, where C90 libm
functions call C99 <fenv.h> functions, is to make fe* into weak
aliases for __fe* and call __fe* from within libm as needed.
To do this, the __fe* names need to be available for that purpose -
that is, they must not be used for something other than aliases of
fe*. On powerpc, however, __fegetround is an inline function in
fenv_libc.h, with no corresponding fegetround inline function;
fegetround has an equivalent macro expansion in bits/fenvinline.h, but
that is disabled if __NO_MATH_INLINES (which is defined for building
libm).
I see no need for that disabling; it's not even clear that
__NO_MATH_INLINES should affect <fenv.h>, and the results of
fegetround are completely defined so there is no semantic effect of
that disabling at all outside glibc. The x86 inline feraiseexcept is
conditioned on __USE_EXTERN_INLINES not __NO_MATH_INLINES (but that's
an inline function rather than a macro).
This patch removes the __NO_MATH_INLINES conditional on that
fegetround macro, so resulting in it being expanded inline inside
glibc. In turn, this means that direct calls to __fegetround from C99
functions in ldbl-128ibm can be changed to calls to fegetround, so
that nofpu fenv_libc.h files don't need to define __fegetround at all
and, by changing ldbl-128ibm files to use <fenv.h> not <fenv_libc.h>,
non-e500 nofpu no longer needs an fenv_libc.h file.
The other macros in fenvinline.h are left conditional on
__NO_MATH_INLINES, although since the only case where this should make
a difference is one involving undefined behavior (if the argument to
the function is not a valid exception macro).
The out-of-line definition for fegetround uses __fegetround (the
inline function removed by this patch). So this continues to work,
the fenvinline.h header is made to define __fegetround, and then to
define fegetround to call __fegetround.
Tested for powerpc32 (hard float) that installed stripped shared
libraries are unchanged by this patch; also tested that powerpc-nofpu
build still works. (This patch does not itself fix any bugs; it
simply cleans things up in preparation for separate bug fixes.)
* sysdeps/powerpc/bits/fenvinline.h (fegetround): Rename macro to
__fegetround and redefine to call __fegetround. Remove condition
on [!__NO_MATH_INLINES].
* sysdeps/powerpc/fpu/fenv_libc.h (__fegetround): Remove inline
function.
* sysdeps/powerpc/nofpu/fenv_libc.h: Remove file.
* sysdeps/powerpc/powerpc32/e500/nofpu/fenv_libc.h (__fegetround):
Remove macro.
* sysdeps/ieee754/ldbl-128ibm/s_llrintl.c: Include <fenv.h>
instead of <fenv_libc.h>.
(__llrintl): Call fegetround instead of __fegetround.
* sysdeps/ieee754/ldbl-128ibm/s_llroundl.c: Include <fenv.h>
instead of <fenv_libc.h>.
* sysdeps/ieee754/ldbl-128ibm/s_lrintl.c: Likewise.
(__lrintl): Call fegetround instead of __fegetround.
* sysdeps/ieee754/ldbl-128ibm/s_lroundl.c: Include <fenv.h>
instead of <fenv_libc.h>.
* sysdeps/ieee754/ldbl-128ibm/s_rintl.c: Likewise.
(__rintl): Call fegetround instead of __fegetround.
PI_STATIC_AND_HIDDEN is always defined for i386. There is no need to
check PI_STATIC_AND_HIDDEN in sysdeps/i386/dl-machine.h.
[BZ #17775]
* sysdeps/i386/dl-machine.h (PI_STATIC_AND_HIDDEN): Removed.
(elf_machine_dynamic) [!PI_STATIC_AND_HIDDEN]: Likewise.
(elf_machine_load_address) [!PI_STATIC_AND_HIDDEN]: Likewise.
Fixed 3 "make check" failures on glibc 32bit built by gcc 5.0 due to EBX
was enabled for allocation:
https://gcc.gnu.org/ml/gcc-patches/2014-10/msg00892.html
Tests elf/tst-tls3, elf/tst-execstack-needed, elf/tst-execstack-prog
were failed because EBX was used as PIC register.
* sysdeps/i386/tls-macros.h: Include <features.h>.
(TLS_LE): Use non-PIC version for GCC >= 5.0.
(TLS_IE): Likewise.
(TLS_LD): Likewise.
(TLS_GD): Likewise.
* sysdeps/unix/sysv/linux/i386/sysdep.h (check_consistency): Don't
define for GCC >= 5.0.
Various C90 and UNIX98 libm functions call feraiseexcept, which is not
in those standards. This causes linknamespace test failures - except
on x86 / x86_64, where feraiseexcept is inline (for the relevant
constant arguments) in bits/fenv.h.
This patch fixes this by making those functions call __feraiseexcept
instead. All changes are applied to all architectures rather than
considering the possibility that some might not be needed in some
cases (e.g. x86) as it seems most maintainable to keep architectures
consistent.
Where __feraiseexcept does not exist, it is added, with feraiseexcept
made a weak alias; where it is a strong alias, it is made weak.
libm_hidden_def / libm_hidden_proto are used with __feraiseexcept
(this might in some cases improve code generation for existing calls
to __feraiseexcept in some code on some architectures). Where there
are dummy feraiseexcept macros (on architectures without
floating-point exceptions support, to avoid compile errors from
references to undefined FE_* macros), corresponding dummy
__feraiseexcept macros are added. And on x86, to ensure
__feraiseexcept calls still get inlined, the inline function in
bits/fenv.h is refactored so that most of it can be reused in an
inline __feraiseexcept in a separate include/bits/fenv.h.
Calls are changed in C90/UNIX98 functions, but generally not in
functions missing from those standards. They are also changed in
libc_fe* functions (on the basis that those might be used in any libm
function), and in feupdateenv (on the same basis - may be used, via
default libc_*, in any libm function - of course feupdateenv will need
changing to __feupdateenv in a subsequent patch to make that fully
namespace-clean).
No __feraiseexcept is added corresponding to the feraiseexcept in
powerpc bits/fenvinline.h, because that macro definition is
conditional on !defined __NO_MATH_INLINES, and glibc libm is built
with -D__NO_MATH_INLINES, so changing internal calls to use
__feraiseexcept should make no difference.
Tested for x86_64 (testsuite; the only change in disassembly of
installed shared libraries is a slight code reordering in clog10, of
no apparent significance). Also tested for MIPS, where (in the
configuration tested) it eliminates math.h linknamespace failures for
n32 and n64 (some for o32 remain because of other issues).
[BZ #17723]
* include/fenv.h (__feraiseexcept): Use libm_hidden_proto.
* math/fraiseexcpt.c (__feraiseexcept): Use libm_hidden_def.
* sysdeps/aarch64/fpu/fraiseexcpt.c (feraiseexcept): Rename to
__feraiseexcept and define as weak alias of __feraiseexcept. Use
libm_hidden_weak.
* sysdeps/arm/fraiseexcpt.c (feraiseexcept): Likewise.
* sysdeps/hppa/fpu/fraiseexcpt.c (feraiseexcept): Likewise.
* sysdeps/i386/fpu/fraiseexcpt.c (__feraiseexcept): Use
libm_hidden_def.
* sysdeps/ia64/fpu/fraiseexcpt.c (feraiseexcept): Rename to
__feraiseexcept and define as weak alias of __feraiseexcept. Use
libm_hidden_weak.
* sysdeps/m68k/coldfire/fpu/fraiseexcpt.c (feraiseexcept):
Likewise.
* sysdeps/microblaze/math_private.h (__feraiseexcept): New macro.
* sysdeps/mips/fpu/fraiseexcpt.c (feraiseexcept): Rename to
__feraiseexcept and define as weak alias of __feraiseexcept. Use
libm_hidden_weak.
* sysdeps/powerpc/fpu/fraiseexcpt.c (__feraiseexcept): Use
libm_hidden_def.
* sysdeps/powerpc/nofpu/fraiseexcpt.c (__feraiseexcept): Likewise.
* sysdeps/powerpc/powerpc32/e500/nofpu/fraiseexcpt.c
(__feraiseexcept): Likewise.
* sysdeps/s390/fpu/fraiseexcpt.c (feraiseexcept): Rename to
__feraiseexcept and define as weak alias of __feraiseexcept. Use
libm_hidden_weak.
* sysdeps/sh/sh4/fpu/fraiseexcpt.c (feraiseexcept): Likewise.
* sysdeps/sparc/fpu/fraiseexcpt.c (__feraiseexcept): Use
libm_hidden_def.
* sysdeps/tile/math_private.h (__feraiseexcept): New macro.
* sysdeps/unix/sysv/linux/alpha/fraiseexcpt.S (__feraiseexcept):
Use libm_hidden_def.
* sysdeps/x86_64/fpu/fraiseexcpt.c (__feraiseexcept): Use
libm_hidden_def.
(feraiseexcept): Define as weak not strong alias. Use
libm_hidden_weak.
* sysdeps/x86/fpu/bits/fenv.h (__feraiseexcept_invalid_divbyzero):
New inline function. Factored out of ...
(feraiseexcept): ... here. Use __feraiseexcept_invalid_divbyzero.
* sysdeps/x86/fpu/include/bits/fenv.h: New file.
* math/e_scalb.c (invalid_fn): Call __feraiseexcept instead of
feraiseexcept.
* math/w_acos.c (__acos): Likewise.
* math/w_asin.c (__asin): Likewise.
* math/w_ilogb.c (__ilogb): Likewise.
* math/w_j0.c (y0): Likewise.
* math/w_j1.c (y1): Likewise.
* math/w_jn.c (yn): Likewise.
* math/w_log.c (__log): Likewise.
* math/w_log10.c (__log10): Likewise.
* sysdeps/aarch64/fpu/feupdateenv.c (feupdateenv): Likewise.
* sysdeps/aarch64/fpu/math_private.h
(libc_feupdateenv_test_aarch64): Likewise.
* sysdeps/alpha/fpu/feupdateenv.c (__feupdateenv): Likewise.
* sysdeps/arm/fenv_private.h (libc_feupdateenv_test_vfp): Likewise.
* sysdeps/arm/feupdateenv.c (feupdateenv): Likewise.
* sysdeps/ia64/fpu/feupdateenv.c (feupdateenv): Likewise.
* sysdeps/m68k/fpu/feupdateenv.c (__feupdateenv): Likewise.
* sysdeps/mips/fpu/feupdateenv.c (feupdateenv): Likewise.
* sysdeps/powerpc/fpu/e_sqrt.c (__slow_ieee754_sqrt): Likewise.
* sysdeps/s390/fpu/feupdateenv.c (feupdateenv): Likewise.
* sysdeps/sh/sh4/fpu/feupdateenv.c (feupdateenv): Likewise.
* sysdeps/sparc/fpu/feupdateenv.c (__feupdateenv): Likewise.
These new memcpy functions are the 32-bit version of x86_64 SSE2 unaligned
memcpy. Memcpy average performace benefit is 18% on Silvermont, other
platforms also improved about 35%, benchmarked on Silvermont, Haswell, Ivy
Bridge, Sandy Bridge and Westmere, performance results attached in
https://sourceware.org/ml/libc-alpha/2014-07/msg00157.html
* sysdeps/i386/i686/multiarch/bcopy-sse2-unaligned.S: New file.
* sysdeps/i386/i686/multiarch/memcpy-sse2-unaligned.S: Likewise.
* sysdeps/i386/i686/multiarch/memmove-sse2-unaligned.S: Likewise.
* sysdeps/i386/i686/multiarch/mempcpy-sse2-unaligned.S: Likewise.
* sysdeps/i386/i686/multiarch/bcopy.S: Select the sse2_unaligned
version if bit_Fast_Unaligned_Load is set.
* sysdeps/i386/i686/multiarch/memcpy.S: Likewise.
* sysdeps/i386/i686/multiarch/memcpy_chk.S: Likewise.
* sysdeps/i386/i686/multiarch/memmove.S: Likewise.
* sysdeps/i386/i686/multiarch/memmove_chk.S: Likewise.
* sysdeps/i386/i686/multiarch/mempcpy.S: Likewise.
* sysdeps/i386/i686/multiarch/mempcpy_chk.S: Likewise.
* sysdeps/i386/i686/multiarch/Makefile (sysdep_routines): Add
bcopy-sse2-unaligned, memcpy-sse2-unaligned,
memmove-sse2-unaligned and mempcpy-sse2-unaligned.
* sysdeps/i386/i686/multiarch/ifunc-impl-list.c (MAX_IFUNC): Set
to 4.
(__libc_ifunc_impl_list): Test __bcopy_sse2_unaligned,
__memmove_chk_sse2_unaligned, __memmove_sse2_unaligned,
__memcpy_chk_sse2_unaligned, __memcpy_sse2_unaligned,
__mempcpy_chk_sse2_unaligned, and __mempcpy_sse2_unaligned.
This patch adds support to generate the spec array in getconf from the
conf.list. The generated code is mostly unchanged. the only changes
are due to the change in layout of the spec and val arrays in the ELF.
The val array can also be auto-generated from posix-conf-vars.list
once the remaining macros are added to it.
* posix/posix-conf-vars.list (SPEC:XBS5): Add sysconf prefix.
* posix/confstr.c: Define NEED_SPEC_ARRAY to 0.
* posix/posix-envs.def: Likewise.
* sysdeps/posix/sysconf.c: Likewise.
* posix/getconf.c: Define NEED_SPEC_ARRAY to 1.
(specs): Remove array.
* scripts/gen-posix-conf-vars.awk: Support generation of specs
array.
This fixes the remaining -Wundef warnings. Tested on x86_64.
* posix/posix-conf-vars.list: Add _POSIX sysconf namespace.
* sysdeps/posix/sysconf.c: Include posix-conf-vars.h.
(__sysconf): Use CONF_IS_* macros.
These avoid having tile generate real calls to the no-op
functions, which then causes linknamespace test failures.
It might make sense to factor all of these out into a common
header that can be shared by tile, microblaze, etc., but for
now just fix the test failures.
These definitions were added back before __ASSUME_POSIX_CPU_TIMERS
was removed. There used to be a vsyscall to clock_getres() in
maybe_syscall_settime_cpu(), but that function was removed in commit
26889eac. The presence of the vsyscall definitions means that platforms
that don't provide clock_getres as a vsyscall hit a symbol redefinition
warning in this file, becoming fatal with -Werror. Removing the
vsyscall definitions is the obvious fix.
No change to generated code on x86_64.
The symbol for HAVE_CLOCK_GETTIME_VSYSCALL was being
only conditionally defined under [SHARED]. However, it turns
out this causes a preprocessor symbol redefinition warning
when building clock_gettime.o. Move the symbol definition
down to make it unconditional, like other platforms do.
The _Unwind_GetCFA() routine returns a 64-bit value,
which we interpret as a pointer. Add an intermediate
cast to long so that in ILP32 mode we don't get a warning
about casting a wrong-sized integer to a pointer.
I missed this during the initial port. Some testing shows that
enabling this mode does, unsurprisingly, yield some nice speedups
on the math functions in question.
This patch makes __ASSUME_UTIMES hppa-specific, removing mentions of
the macro from architecture-independent code and code for other
architectures. (All other architectures either have the utimes
syscall in all relevant kernel versions, or use the asm-generic
interface so only have utimensat and won't get the utimes syscall.) A
similar approach is used to that used for futimesat for MicroBlaze: if
the kernel is recent enough that the utimes syscall can be assumed to
be present, use the implementation in terms of the utimes syscall, and
otherwise use the linux/generic implementation in terms of utimensat.
Tested x86_64 that the disassembly of installed shared libraries is
unchanged by the patch. Not tested for hppa.
* sysdeps/unix/sysv/linux/kernel-features.h (__ASSUME_UTIMES): Do
not define.
* sysdeps/unix/sysv/linux/utimes.c: Do not include
<kernel-features.h>.
(__utimes) [__NR_utimes]: Make code unconditional.
(__utimes) [!__ASSUME_UTIMES]: Remove conditional code.
* sysdeps/unix/sysv/linux/aarch64/kernel-features.h
(__ASSUME_UTIMES): Do not undefine.
* sysdeps/unix/sysv/linux/tile/kernel-features.h
(__ASSUME_UTIMES): Likewise.
* sysdeps/unix/sysv/linux/hppa/kernel-features.h
(__ASSUME_UTIMES): Define for [__LINUX_KERNEL_VERSION >= 0x030e00]
instead of undefining for [__LINUX_KERNEL_VERSION < 0x030e00].
* sysdeps/unix/sysv/linux/hppa/utimes.c: New file.
[BZ #17746]
The __builtin_expect() truncated a uint64_t to a 32-bit long
in ILP32 mode, discarding the high 32 bits, and potentially
missing the NUL terminator that we were searching for with SIMD
operations. Explicitly compare to zero to fix the problem.
Bug 17724 reports references to fesetround being brought in by
ldbl-128ibm rintl via references to __rintl from __kernel_standard_l.
Because all three __kernel_standard* functions are in the same file,
this gets brought in even though only the long double version
__kernel_standard_l needs __rintl, and the C90 functions use only
__kernel_standard.
This patch fixes this by splitting the three versions into separate
files; it's fine for long double functions to refer to fe* functions
directly, unless they get called by C90 double functions.
Tested for x86_64 (testsuite; the reordering of code means disassembly
of shared libraries can't usefully be compared). Tested for powerpc
that the relevant issue disappears from the linknamespace test
output.
[BZ #17724]
* sysdeps/ieee754/k_standard.c: Don't include <float.h>.
(__kernel_standard_f): Remove. Moved to k_standardf.c.
(__kernel_standard_l): Remove. Moved to k_standardl.c with
(char *) casts added.
* sysdeps/ieee754/k_standardf.c: New file.
* sysdeps/ieee754/k_standardl.c: Likewise.
* math/Makefile (libm-support): Remove k_standard.
(libm-calls): Add k_standard.
On Linux architectures using socketcall, the resolver ends up bringing
in strong symbols for bind and getsockname, which are not in
POSIX.1-1996. This causes linknamespace test failures:
FAIL: conform/POSIX/pthread.h/linknamespace
FAIL: conform/POSIX/sched.h/linknamespace
FAIL: conform/POSIX/time.h/linknamespace
These functions are defined as strong symbols with __bind and
__getsockname as weak aliases. This patch switches this to the other
way round by removing the NO_WEAK_ALIAS definitions and so letting the
default case in socket.S act; I see no reason for the existing
arrangements.
Tested for x86 (testsuite, and that disassembly of installed shared
libraries is unchanged by the patch).
[BZ #17733]
* sysdeps/unix/sysv/linux/bind.S (NO_WEAK_ALIAS): Do not define.
(__bind): Do not define as weak alias.
* sysdeps/unix/sysv/linux/getsockname.S (NO_WEAK_ALIAS): Do not
define.
(__getsockname): Do not define as weak alias.
__tls_get_addr/___tls_get_addr is always defined in ld.so. There is
no need to call them via PLT inside ld.so. This patch adds the hidden
__tls_get_addr/___tls_get_addr aliases and calls them directly from
_dl_tlsdesc_dynamic. There is no need to set up the EBX register in
i386 _dl_tlsdesc_dynamic when calling the hidden ___tls_get_addr.
* elf/dl-tls.c (__tls_get_addr): Provide the hidden definition
if not defined.
* sysdeps/i386/dl-tls.h (___tls_get_addr): Provide the hidden
definition.
* sysdeps/i386/dl-tlsdesc.S (_dl_tlsdesc_dynamic): Call the
hidden ___tls_get_addr.
* sysdeps/x86_64/dl-tlsdesc.S (_dl_tlsdesc_dynamic): Call the
hidden __tls_get_addr.
* sysdeps/generic/localplt.data (__tls_get_addr): Removed.
* sysdeps/unix/sysv/linux/i386/localplt.data (___tls_get_addr):
Likewise.
_dl_start_user in ld.so calls the local function _dl_init. There is no
need to go through PLT.
* sysdeps/i386/dl-machine.h (_dl_start_user): Remove @PLT
from "call _dl_init@PLT".
* sysdeps/x86_64/dl-machine.h (_dl_start_user): Likewise.
from "call _dl_init@PLT".
The two_way_short_needle() routine included from str-two-way.h
is not used, so mark it so to avoid compiler warnings.
Calling strnlen() breaks linknamespace tests, so change it
to __strnlen().
* sysdeps/mips/sys/asm.h (PTR_ADDU): Use addu on mips32r6/mips64r6.
(PTR_ADDIU): Use addiu for mips32r6/mips64r6.
(PTR_SUBU): Use subu for mips32r6/mips64r6.
(PTR_SUBIU): Use subu for mips32r6/mips64r6 (subiu does not exist).
* sysdeps/mips/machine-gmon.h (PTR_ADDU_STRING) Use addu for
mips32r6/mips64r6.
(PTR_SUBU_STRING) Use subu for mips32r6/mips64r6.
Since x32 returns 32-bit long int and 64-bit long long int in the
same 64-bit register, we make the 32b-bit lround an alias of the
64-bit llround. Add -Wno-error for x32 build to silence the compiler.
X86-64 and x32 use sysdeps/i386/ldbl2mpn.c. res_ptr is a pointer
to mp_limb_t, which is long for i386 and x86-64 and long long for
x32. On x32, I got
../sysdeps/x86_64/../i386/ldbl2mpn.c: In function ‘__mpn_extract_long_double’:
../sysdeps/x86_64/../i386/ldbl2mpn.c:72:4: error: left shift count >= width of type [-Werror]
res_ptr[N - 1] &= ~(1L << ((LDBL_MANT_DIG - 1) % BITS_PER_MP_LIMB));
^
cc1: all warnings being treated as errors
This patch replaces 1L with (mp_limb_t) 1. Verified on x32, i686 and
x86-64 with GCC 4.8.3.
On ARM, where profil_counter is not static, it is brought in by
references to various standard functions, as noted in
<https://sourceware.org/ml/libc-alpha/2014-11/msg00890.html>, although
it is not a standard function itself. I don't know if this also
causes test failures on SPARC, although I see no reason for it not to
do so.
This patch fixes this namespace issue. profil_counter is renamed to
__profil_counter and made a weak alias on ARM and SPARC. Because of
the uses in profil.c / sprofil.c it seems simplest to make the rename
globally, including on the other architectures for which
profil_counter was static and so the change is of no substance. The
variant names profil_counter_* used in sprofil.c are also renamed to
start with __ so that undesired function names do not get exported in
static libc.
As I noted in bug 17726, profil_counter should probably be a compat
symbol on ARM and SPARC, so it wouldn't exist at all in static libc
even as a weak alias. Since defining a compat symbol still requires
an internal name as a target of an alias, this patch still seems
reasonable as an intermediate step towards that goal: it wouldn't be
possible for the function simply to be static profil_counter on ARM
and SPARC with profil_counter also being the exported compat symbol
name, so profil.c / sprofil.c would still need to be prepared to call
the function under another name (here, __profil_counter).
Tested for x86_64 (testsuite, and that stripped installed shared
libraries are unchanged by the patch) and ARM (ABI and linknamespace
tests - this patch reduces the number of linknamespace failures I see
on ARM from 227 to 5, the residue being math.h failures for fe*
functions and for j0l/j1n/jnl/y0l/y1l/ynl aliases).
2014-12-17 Joseph Myers <joseph@codesourcery.com>
[BZ #17725]
* sysdeps/generic/profil-counter.h (profil_counter): Rename to
__profil_counter.
* sysdeps/unix/sysv/linux/hppa/profil-counter.h (profil_counter):
Likewise.
* sysdeps/unix/sysv/linux/i386/profil-counter.h (profil_counter):
Likewise.
* sysdeps/unix/sysv/linux/ia64/profil-counter.h (profil_counter):
Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/profil-counter.h
(profil_counter): Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/profil-counter.h
(profil_counter): Likewise.
* sysdeps/unix/sysv/linux/sh/profil-counter.h (profil_counter):
Likewise.
* sysdeps/unix/sysv/linux/tile/profil-counter.h (profil_counter):
Likewise.
* sysdeps/unix/sysv/linux/x86_64/profil-counter.h
(profil_counter): Likewise.
* sysdeps/unix/sysv/linux/arm/profil-counter.h (profil_counter):
Likewise.
[!__profil_counter] (profil_counter): Define as weak alias of
__profil_counter.
* sysdeps/unix/sysv/linux/sparc/sparc32/profil-counter.h
(profil_counter): Rename to __profil_counter.
[!__profil_counter] (profil_counter): Define as weak alias of
__profil_counter.
* sysdeps/unix/sysv/linux/sparc/sparc64/profil-counter.h
(profil_counter): Rename to __profil_counter.
[!__profil_counter] (profil_counter): Define as weak alias of
__profil_counter.
* sysdeps/posix/profil.c: Update comment referring to
profil_counter.
(__profil): Use __profil_counter instead of profil_counter.
* sysdeps/posix/sprofil.c (profil_counter): Rename to
__profil_counter. Use __profil_counter_ushort and
__profil_counter_uint in definitions.
(__sprofil): Use __profil_counter_uint and __profil_counter_ushort
instead of profil_counter_uint and profil_counter_ushort.
On x86_64, memrchr (not a standard function) is defined as a strong
symbol, instead of a weak alias of __memrchr as on other
architectures. This results in linknamespace test failures from the
use of __memrchr from dirname. (Not a conformance issue because of
the mem* reservation, but contrary to glibc conventions.) This patch
makes x86_64 follow other architectures by defining memrchr as a weak
alias.
Tested for x86_64 (testsuite, and that disassembly of installed shared
libraries is unchanged by the patch).
[BZ #17719]
* sysdeps/x86_64/memrchr.S (memrchr): Rename to __memrchr and
define as weak alias of __memrchr.
(__memrchr): Do not define as strong alias of memrchr.
* conform/Makefile (test-xfail-XPG4/libgen.h/linknamespace):
Remove variable.
(test-xfail-UNIX98/libgen.h/linknamespace): Likewise.
(test-xfail-XOPEN2K/libgen.h/linknamespace): Likewise.
(test-xfail-XOPEN2K8/libgen.h/linknamespace): Likewise.
Resolver code, brought in by pthreads (at least), uses if_* interfaces
that weren't in POSIX before 2001, resulting in linknamespace
failures. This patch changes those interfaces to be weak aliases of
__if_* and makes the resolver use __if_* directly.
Tested for x86_64 (testsuite, and that disassembly of installed shared
libraries is unchanged by this patch).
[BZ #17717]
* inet/if_index.c (if_nametoindex): Rename to __if_nametoindex and
define as weak alias of __if_nametoindex. Use libc_hidden_weak.
(if_indextoname): Rename to __if_indextoname and define as weak
alias of __if_indextoname. Use libc_hidden_weak.
(if_freenameindex): Rename to __if_freenameindex and define as
weak alias of __if_freenameindex.
(if_nameindex): Rename to __if_nameindex and define as weak alias
of __if_nameindex.
* sysdeps/mach/hurd/if_index.c (if_nametoindex): Rename to
__if_nametoindex and define as weak alias of __if_nametoindex.
Use libc_hidden_weak.
(if_freenameindex): Rename to __if_freenameindex and define as
weak alias of __if_freenameindex.
(if_nameindex): Rename to __if_nameindex and define as weak alias
of __if_nameindex.
(if_indextoname): Rename to __if_indextoname and define as weak
alias of __if_indextoname. Use libc_hidden_weak.
* sysdeps/unix/sysv/linux/if_index.c (if_nametoindex): Rename to
__if_nametoindex and define as weak alias of __if_nametoindex.
Use libc_hidden_weak.
(if_freenameindex): Rename to __if_freenameindex and define as
weak alias of __if_freenameindex. Use libc_hidden_weak.
(if_nameindex_netlink): Use __if_freenameindex instead of
if_freenameindex.
(if_nameindex): Rename to __if_nameindex and define as weak alias
of __if_nameindex. Use libc_hidden_weak.
(if_indextoname): Rename to __if_indextoname and define as weak
alias of __if_indextoname. Use libc_hidden_weak.
* include/net/if.h [!_ISOMAC] (__if_nametoindex): Declare and use
libc_hidden_proto.
[!_ISOMAC] (__if_freenameindex): Likewise.
* resolv/res_init.c (__res_vinit): Use __if_nametoindex instead of
if_nametoindex.
* conform/Makefile (test-xfail-XPG4/grp.h/linknamespace): Remove
variable.
(test-xfail-XPG4/pwd.h/linknamespace): Likewise.
(test-xfail-UNIX98/aio.h/linknamespace): Likewise.
(test-xfail-UNIX98/grp.h/linknamespace): Likewise.
(test-xfail-UNIX98/pthread.h/linknamespace): Likewise.
(test-xfail-UNIX98/pwd.h/linknamespace): Likewise.
(test-xfail-UNIX98/sched.h/linknamespace): Likewise.
(test-xfail-UNIX98/time.h/linknamespace): Likewise.
Carlos reported failures in conform/ tests in environments where the
compiler used could only find headers in glibc's source and build
trees, not any previously installed headers
<https://sourceware.org/ml/libc-alpha/2014-09/msg00040.html>.
This patch moves nptl/semaphore.h to sysdeps/pthread/semaphore.h so
that it can be found by builds from all glibc subdirectories; it's not
in any way NPTL-specific. (I left the Makefile setting to install
this header in nptl/, but maybe it should move as well - it's just not
clear to me what ifeq ($(subdir),...) conditional should be used to
select the directory to associate the header with for installation
purposes. The path in the toplevel Makefile used for begin-end-check
also remains hardcoded; it's a known todo issue to rework that test to
run in each subdirectory checking the headers installed from that
subdirectory, rather than a separate hardcoded list.)
Tested for x86_64 (testsuite, and that installed stripped shared
libraries are unchanged by the patch). I did *not* test a
configuration such as that in which Carlos saw failure.
* nptl/semaphore.h: Move to ...
* sysdeps/pthread/semaphore.h: ... here.
* Makefile (installed-headers): Change nptl/semaphore.h to
sysdeps/pthread/semaphore.h.
Without this, on gcc 4.8.2 the built glibc crashes when memcpy
or memset are invoked, since they call themselves recursively.
See commit 85c2e6110c for the generic inhibit_loop_to_libcall.
ldbl-128ibm uses ldbl-128 e_lgammal_r implementation as is, however some
constants definitions overflows for IBM long double range. This patch
suppress the compiler warnings until the ldbl-128ibm implementation is
fixed.
As previously discussed in
<https://sourceware.org/ml/libc-alpha/2012-11/msg00798.html>, MIPS (o32)
waitid has build warnings (now errors) because a function is declared
inline but functions with five-argument syscalls cannot be inlined for
MIPS o32.
This patch disables the -Winline warnings for waitid.c using a
MIPS-specific wrapper file. As it's whole-file disabling, there's no
point in using push and pop, so just DIAG_IGNORE_NEEDS_COMMENT is
used.
* sysdeps/unix/sysv/linux/mips/mips32/waitid.c: New file.
Building MIPS sigaction (for ABIs other than o32) fails because of
"'restore_rt' used but never defined", arising from static functions
being defined in asms and referred to from C code. There is no
corresponding -W option for that warning, so this patch uses
-Wno-error for building sigaction.c.
* sysdeps/unix/sysv/linux/mips/mips64/Makefile
[$(subdir) == signal] (CFLAGS-sigaction.c): New variable.
[$(subdir) == nptl] (CFLAGS-sigaction.c): Likewise.
Use of strftime, a C90 function, ends up bringing in wcschr, which is
not a C90 function. Although not a conformance bug (C90 reserves
wcs*), this is still contrary to glibc practice of avoiding relying on
those reservations; this patch arranges for the internal uses to use
__wcschr instead, with wcschr being a weak alias. This is more
complicated than some such patches because of the various IFUNC
definitions of wcschr (which include code redefining libc_hidden_def
in a way that involves creating __GI_wcschr manually and so also needs
to create __GI___wcschr after the change of internal uses to use
__wcschr).
Tested for x86_64 and 32-bit x86 (testsuite, and that disassembly of
installed shared libraries is unchanged by the patch).
2014-12-10 Joseph Myers <joseph@codesourcery.com>
Adhemerval Zanella <azanella@linux.vnet.ibm.com>
[BZ #17634]
* wcsmbs/wcschr.c [!WCSCHR] (wcschr): Define as __wcschr.
Undefine after defining function. Define as weak alias of
__wcschr. Use libc_hidden_weak.
* include/wchar.h (__wcschr): Declare. Use libc_hidden_proto.
* sysdeps/i386/i686/multiarch/wcschr-c.c [IS_IN (libc) && SHARED]
(libc_hidden_def): Also define __GI___wcschr alias.
* sysdeps/i386/i686/multiarch/wcschr.S (wcschr): Rename to
__wcschr and define as weak alias of __wcschr.
* sysdeps/powerpc/power6/wcschr.c [!WCSCHR] (WCSCHR): Define as
__wcschr.
[!WCSCHR] (DEFAULT_WCSCHR): Define.
[DEFAULT_WCSCHR] (__wcschr): Use libc_hidden_def.
[DEFAULT_WCSCHR] (wcschr): Define as weak alias of __wcschr. Use
libc_hidden_weak. Do not use libc_hidden_def.
* sysdeps/powerpc/powerpc32/power4/multiarch/wcschr-ppc32.c
[IS_IN (libc) && SHARED] (libc_hidden_def): Also define
__GI___wcschr alias.
* sysdeps/powerpc/powerpc32/power4/multiarch/wcschr.c
[IS_IN (libc)] (wcschr): Define as macro expanding to
__redirect_wcschr.
[IS_IN (libc)] (__wcschr_ppc): Use __redirect_wcschr in typeof.
[IS_IN (libc)] (__wcschr_power6): Likewise.
[IS_IN (libc)] (__wcschr_power7): Likewise.
[IS_IN (libc)] (__libc_wcschr): New. Define with libc_ifunc
instead of wcschr.
[IS_IN (libc)] (wcschr): Undefine and define as weak alias of
__libc_wcschr.
[!IS_IN (libc)] (libc_hidden_def): Do not undefine and redefine.
* sysdeps/powerpc/powerpc64/multiarch/wcschr.c (wcschr): Rename to
__wcschr and define as weak alias of __wcschr. Use
libc_hidden_builtin_def.
* sysdeps/x86_64/wcschr.S (wcschr): Rename to __wcschr and define
as weak alias of __wcschr. Use libc_hidden_weak.
* time/alt_digit.c (_nl_get_walt_digit): Use __wcschr instead of
wcschr.
* time/era.c (_nl_init_era_entries): Likewise.
* conform/Makefile (test-xfail-ISO/time.h/linknamespace): Remove
variable.
(test-xfail-XPG3/time.h/linknamespace): Likewise.
(test-xfail-XPG4/time.h/linknamespace): Likewise.
Some pthreads functions use getrlimit and gettimeofday, but these
functions are XSI, not base POSIX; this is a namespace issue for
dynamic linking as well as static linking. This patch makes them use
__getrlimit and __gettimeofday instead - the former needed to be newly
exported from libc.so at GLIBC_PRIVATE (and so now needs
libc_hidden_proto / libc_hidden_def), the latter was already exported.
Tested for x86_64 (testsuite, and that disassembly of installed shared
libraries is unchanged by the patch).
[BZ #17682]
* resource/Versions (libc): Add __getrlimit at GLIBC_PRIVATE.
* resource/getrlimit.c (__getrlimit): Use libc_hidden_def.
* sysdeps/mach/hurd/getrlimit.c (__getrlimit): Likewise.
* include/sys/resource.h (__getrlimit): Use libc_hidden_proto.
* nptl/nptl-init.c (__pthread_initialize_minimal_internal): Use
__getrlimit instead of getrlimit.
* nptl/pthread_cond_timedwait.c (__pthread_cond_timedwait): Use
__gettimeofday instead of gettimeofday.
* nptl/pthread_rwlock_timedrdlock.c (pthread_rwlock_timedrdlock):
Likewise.
* nptl/pthread_rwlock_timedwrlock.c (pthread_rwlock_timedwrlock):
Likewise.
* sysdeps/pthread/aio_misc.c (handle_fildes_io): Likewise.
* conform/Makefile (test-xfail-POSIX2008/aio.h/linknamespace):
Remove variable.
(test-xfail-POSIX2008/pthread.h/linknamespace): Likewise.
(test-xfail-POSIX2008/time.h/linknamespace): Likewise.
Various objects in glibc bring in ifaddrs.o (via references to
__netlink_*) and thereby getifaddrs and freeifaddrs, which are not
part of any standard supported by glibc. These should be weak aliases
of __getifaddrs and __freeifaddrs; this patch makes them so.
(The path by which these functions are brought in is Linux-specific,
but it seems less confusing to make all versions of these functions
weak aliases rather than only the Linux-specific versions that
definitely need it.)
Tested for x86_64 (testsuite, and that disassembly of installed shared
libraries is unchanged by this patch).
[BZ #17668]
* inet/ifaddrs.c (getifaddrs): Rename to __getifaddrs and define
as weak alias of __getifaddrs. Use libc_hidden_weak.
(freeifaddrs): Rename to __freeifaddrs and define as weak alias of
__freeifaddrs. Use libc_hidden_weak.
* sysdeps/gnu/ifaddrs.c (getifaddrs): Rename to __getifaddrs and
define as weak alias of __getifaddrs. Use libc_hidden_weak.
(freeifaddrs): Rename to __freeifaddrs and define as weak alias of
__freeifaddrs. Use libc_hidden_weak.
* sysdeps/unix/sysv/linux/ifaddrs.c (getifaddrs): Rename to
__getifaddrs and define as weak alias of __getifaddrs. Use
libc_hidden_weak.
(freeifaddrs): Rename to __freeifaddrs and define as weak alias of
__freeifaddrs. Use libc_hidden_weak.
* conform/Makefile (test-xfail-XOPEN2K/net/if.h/linknamespace):
Remove variable.
(test-xfail-POSIX2008/net/if.h/linknamespace): Likewise.
(test-xfail-XOPEN2K8/net/if.h/linknamespace): Likewise.
Since __libc_start_main may not be in the same 256MB-aligned region as
the function __start, replace use of jal instruction with la/jalr.
This fixes linker issue reported in:
https://sourceware.org/bugzilla/show_bug.cgi?id=17601
[BZ #17601]
* sysdeps/mips/start.S (__start): Use indirect jump to call
__libc_start_main.
This patch makes the POWER7 optimized strpbrk generic by using
default doubleword stores to zero the hash, instead of VSX
instructions. Performance on POWER7/POWER8 does not change.
This patch makes the POWER7 optimized strcspn generic by using
default doubleword stores to zero the hash, instead of VSX
instructions. Performance on POWER7/POWER8 does not change.
This patch makes the POWER7 optimized strspn generic by using
default doubleword stores to zero the hash, instead of VSX
instructions. Performance on POWER7/POWER8 machines does not changed.
This patch optimizes strtok and strtok_r for POWERPC64.
A table of 256 characters is created and marked based on
the 'accept' argument and used to check for any occurance on
the input string.Loop unrolling is also used to gain improvements.
This patch fixes
../sysdeps/mips/__longjmp.c:27:1: warning: function declaration isn't a prototype [-Wstrict-prototypes]
which arose I think from the MIPS16 changes (renaming the function to
____longjmp with an alias __longjmp, so a prior header prototype for
__longjmp no longer sufficed to prevent a warning). I've made the
function use a prototype definition, which is what we want for all
function definitions in glibc anyway.
Tested for MIPS.
* sysdeps/mips/__longjmp.c (____longjmp): Use prototype
definition.
This patch fixes a warning
../include/features.h:328:4: warning: #warning _FORTIFY_SOURCE requires compiling with optimization (-O) [-Wcpp]
seen when building for ARM. This warning comes from libc-do-syscall.S
being built for nscd: the nscd build uses _FORTIFY_SOURCE, while .S
files aren't built with -O, and the combination produces a warning.
As _FORTIFY_SOURCE doesn't do anything for .S files, undefining it in
libc-do-syscall.S seems the simplest solution.
Tested for ARM.
* sysdeps/unix/sysv/linux/arm/libc-do-syscall.S (_FORTIFY_SOURCE):
Undefine.
This patch fixes bugs in ldbl-128ibm frexpl for 32-bit systems shown
up by warnings:
../sysdeps/ieee754/ldbl-128ibm/s_frexpl.c:82:4: warning: left shift count >= width of type
../sysdeps/ieee754/ldbl-128ibm/s_frexpl.c:129:5: warning: left shift count >= width of type
This did in fact show up in test-ldouble.out (alongside all the other
problems there ... maybe we should again consider running the libm
tests at finer granularity from the makefiles) as already covered by
the testsuite after the previous patch that fixed these bugs for
64-bit systems. The fix is simply using 1LL instead of 1L when
shifting by 52.
Tested for powerpc32 (soft float).
[BZ #16619]
[BZ #16740]
* sysdeps/ieee754/ldbl-128ibm/s_frexpl.c (__frexpl): Use 1LL << 52
instead of 1L << 52.
On powerpc, atomic_exchange_and_add is implemented without any
barriers. This patchs adds the missing instruction and memory barrier
for acquire and release semanthics.
Replace with IS_IN (ldconfig). No change in generated code.
* elf/Makefile (CFLAGS-ldconfig.c): Remove definition of
IS_IN_ldconfig.
* sysdeps/unix/sysv/linux/x86_64/dl-procinfo.c: Use IS_IN.
* sysdeps/unix/sysv/linux/x86_64/dl-procinfo.h: Likewise.
dlopening libraries from a static program would dlopen libc.so,
which thus needs its own initialization, done in posixland_init,
which was missing initializing RPCs so far.
ChangeLog:
2014-11-23 Samuel Thibault <samuel.thibault@ens-lyon.org>
* sysdeps/mach/hurd/i386/init-first.c (posixland_init): Call
__mach_init in dlopened libc.
GCC marked OABI obsolete in 4.7 and dropped it in 4.8. So the number
of people this is catching is shrinking every day. At this point,
it's not terribly useful, so just drop it.
This patch reformats the inline-asm in elf_machine_load_address so it is
easier to change only part of the inline-asm. That is using string
concatenating instead of string continuation.
Also document why this inline-asm works - it depends on the 32bit
relocation being resolved at link time.
ChangeLog:
2014-11-21 Will Newton <will.newton@linaro.org>
Andrew Pinski <andrew.pinski@caviumnetworks.com>
* sysdeps/aarch64/dl-machine.h (elf_machine_load_address):
Refactor inline-asm. Also add comment.
Using the macros for ELF types is required for adding ILP32 support.
In the standard AArch64 configuration this makes no difference to
the types used.
ChangeLog:
2014-11-21 Will Newton <will.newton@linaro.org>
Andrew Pinski <andrew.pinski@caviumnetworks.com>
* sysdeps/aarch64/bits/link.h (la_aarch64_gnu_pltenter): Use
ElfW macro instead of hardcoded Elf64 types.
(la_aarch64_gnu_pltenter): Likewise.
* sysdeps/aarch64/dl-machine.h
(elf_machine_runtime_setup): Use ElfW(Addr).
The latest version of the binutils ELF header defines a new set of
dynamic relocations for ILP32 and renames some to make the naming
more uniform.
ChangeLog:
2014-11-21 Will Newton <will.newton@linaro.org>
Andrew Pinski <andrew.pinski@caviumnetworks.com>
* elf/elf.h (R_AARCH64_P32_ABS32, R_AARCH64_P32_COPY,
R_AARCH64_P32_GLOB_DAT, R_AARCH64_P32_JUMP_SLOT,
R_AARCH64_P32_RELATIVE, R_AARCH64_P32_TLS_DTPMOD,
R_AARCH64_P32_TLS_DTPREL, R_AARCH64_P32_TLS_TPREL,
R_AARCH64_P32_TLSDESC, R_AARCH64_P32_IRELATIVE): Define.
(R_AARCH64_TLS_DTPMOD64): Rename to ..
(R_AARCH64_TLS_DTPMOD): This.
(R_AARCH64_TLS_DTPREL64): Rename to ...
(R_AARCH64_TLS_DTPREL): This.
(R_AARCH64_TLS_TPREL64): Rename to ...
(R_AARCH64_TLS_TPREL): This.
* sysdeps/aarch64/dl-machine.h (elf_machine_type_class): Update
R_AARCH64_TLS_DTPMOD64, R_AARCH64_TLS_DTPREL64, and
R_AARCH64_TLS_TPREL64.
(elf_machine_rela): Likewise.
for ChangeLog
* sysdeps/posix/ctermid.c (ctermid): Return a pointer to a
string literal if not passed a buffer.
* manual/job.texi (ctermid): Update reasoning, note deviation
from posix, suggest mtasurace when not passed a buffer, for
future non-preliminary safety notes.
