The csqrt implementations in glibc can cause spurious underflows in
some cases as a side-effect of the scaling for large arguments (when
underflow is correct for the square root of the argument that was
scaled down to avoid overflow, but not for the original argument).
This patch arranges to avoid the underflowing intermediate computation
(eliminating a multiplication in 0.5 in the problem cases where a
subsequent scaling by 2 would follow).
Tested for x86_64 and x86 and ulps updated accordingly (only needed
for x86).
[BZ #18371]
* math/s_csqrt.c (__csqrt): Avoid multiplication by 0.5 where
intermediate but not final result might underflow.
* math/s_csqrtf.c (__csqrtf): Likewise.
* math/s_csqrtl.c (__csqrtl): Likewise.
* math/auto-libm-test-in: Add more tests of csqrt.
* math/auto-libm-test-out: Regenerated.
* sysdeps/i386/fpu/libm-test-ulps: Update.
The dbl-64 and flt-32 implementations of exp2 functions produce
spurious underflow exceptions. The underlying reason is the same in
both cases: the computation works as (2^a - 1)*2^b + 2^b for suitably
chosen a and b, where a has small magnitude so 2^a - 1 can be computed
with a low-degree polynomial approximation, and (2^a - 1)*2^b can
underflow even when the final result does not. This patch fixes this
by adjusting the threshold for when scaling is used to avoid
intermediate underflow so it works for any possible value of a where
the final result would not underflow.
Tested for x86_64 and x86.
[BZ #18219]
* sysdeps/ieee754/dbl-64/e_exp2.c (__ieee754_exp2): Reduce
threshold on absolute value of exponent for which scaling is used.
* sysdeps/ieee754/flt-32/e_exp2f.c (__ieee754_exp2f): Likewise.
* math/auto-libm-test-in: Add more tests of exp2.
* math/auto-libm-test-out: Regenerated.
When "reorder" resolver option is enabled, threads of a multi-threaded process
could hang in gethostbyaddr_r, gethostbyname_r, or gethostbyname2_r.
Due to a trivial bug in _res_hconf_reorder_addrs, simultaneous
invocations of this function in a multi-threaded process could result to
_res_hconf_reorder_addrs returning without releasing the lock it holds,
causing other threads to block indefinitely while waiting for the lock
that is not going to be released.
[BZ #17977]
* resolv/res_hconf.c (_res_hconf_reorder_addrs): Fix unlocking
when initializing interface list, based on the bug analysis
and the patch proposed by Eric Newton.
* resolv/tst-res_hconf_reorder.c: New test.
* resolv/Makefile [$(have-thread-library) = yes] (tests): Add
tst-res_hconf_reorder.
($(objpfx)tst-res_hconf_reorder): Depend on $(libdl)
and $(shared-thread-library).
(tst-res_hconf_reorder-ENV): New variable.
Similar to various other bugs in this area, some expm1 implementations
do not raise the underflow exception for subnormal arguments, when the
result is tiny and inexact. This patch forces the exception in a
similar way to previous fixes.
(The issue does not apply to the ldbl-* implementations or to those
for x86 / x86_64 long double. The change to
sysdeps/ieee754/dbl-64/wordsize-64/e_cosh.c is one I missed when
previously fixing bug 16354; the bug in that implementation was
previously latent, but the expm1 fixes stopped it being latent and so
required it to be fixed to avoid spurious underflows from cosh.)
Tested for x86_64 and x86.
[BZ #16353]
* sysdeps/i386/fpu/s_expm1.S (dbl_min): New object.
(__expm1): Force underflow exception for arguments with small
absolute value.
* sysdeps/i386/fpu/s_expm1f.S (flt_min): New object.
(__expm1f): Force underflow exception for arguments with small
absolute value.
* sysdeps/ieee754/dbl-64/s_expm1.c: Include <float.h>.
(__expm1): Force underflow exception for arguments with small
absolute value.
* sysdeps/ieee754/flt-32/s_expm1f.c: Include <float.h>.
(__expm1f): Force underflow exception for arguments with small
absolute value.
* sysdeps/ieee754/dbl-64/wordsize-64/e_cosh.c (__ieee754_cosh):
Check for small arguments before calling __expm1.
* math/auto-libm-test-in: Do not mark underflow exceptions as
possibly missing for bug 16353.
* math/auto-libm-test-out: Regenerated.
In the x86 / x86_64 implementations of expm1l, when expm1l's result
should underflow to 0 (argument minus the least subnormal, in some
rounding modes), it can be a zero of the wrong sign. This patch fixes
this by returning the argument with underflow forced in that case
(this is a 1ulp error relative to the correctly rounded result of -0,
which is OK in terms of the documented accuracy goals, whereas a
result with the wrong sign never is).
Tested for x86_64 and x86.
[BZ #18569]
* sysdeps/i386/fpu/e_expl.S (IEEE754_EXPL) [USE_AS_EXPM1L]: Force
underflow and return argument in case of subnormal argument.
* sysdeps/x86_64/fpu/e_expl.S (IEEE754_EXPL) [USE_AS_EXPM1L]:
Likewise.
* math/auto-libm-test-in: Add more tests of expm1.
* math/auto-libm-test-out: Regenerated.
Similar to various other bugs in this area, the x86 and x86_64
implementations of expl / exp10l can fail to produce underflow
exceptions when the unscaled result has trailing 0 bits so the scaling
down to subnormal precision is exact. This patch fixes this by
forcing the exception in the case of tiny results.
Tested for x86_64 and x86.
[BZ #16361]
* sysdeps/i386/fpu/e_expl.S [!USE_AS_EXPM1L] (cmin): New object.
[!USE_AS_EXPM1L] (IEEE754_EXPL): Force underflow exception for
tiny results.
* sysdeps/x86_64/fpu/e_expl.S [!USE_AS_EXPM1L] (cmin): New object.
[!USE_AS_EXPM1L] (IEEE754_EXPL): Force underflow exception for
tiny results.
* math/auto-libm-test-in: Add more tests of exp and exp10. Do not
mark underflow exceptions as possibly missing for bug 16361.
* math/auto-libm-test-out: Regenerated.
conformtest expected pselect for XOPEN2K and POSIX2008 (correctly),
but not for XOPEN2K8 (wrongly). This patch fixes the data to expect
it for XOPEN2K8 as well.
(As for all such fixes based on failures seen from the tests, there is
no guarantee that the data is fully correct for a particular standard
after the fix; headers and data may well have matching bugs. So far
I've only reviewed ISO, ISO99, ISO11 and POSIX data in detail, though
I hope eventually to review the others.)
Tested for x86_64 and x86.
* conform/data/sys/select.h-data [XOPEN2K8] (pselect): Expect.
* conform/Makefile (test-xfail-XOPEN2K8/sys/select.h/conform):
Remove variable.
(test-xfail-XOPEN2K8/sys/time.h/conform): Likewise.
(test-xfail-XOPEN2K8/utmpx.h/conform).
Various conformtest tests fail because of known issues, filed in
Bugzilla, that are hard to fix (requiring new features, kernel
cooperation or involving changing types in ways that may involve care
around padding when interfacing to the kernel). Such an issue has the
effect of making the whole test for the (standard, header) pair fail,
so hiding any other issues with that header for that standard
(possibly regressions or architecture-specific issues).
This patch adds a mechanism for individual conformtest test
expectations to start with xfail-, meaning that a failure of that
particular assertion does not cause the whole test to fail at the
makefile level and so failure at the makefile level can be used to
detect other issues that are likely to be easier to fix. This is
similar to the whitelisted symbols in the linknamespace tests, or the
marking of particular libm tests as allowing spurious or missing
exceptions, for example. The bugs filed in Bugzilla should still be
fixed, and the xfail- markers removed at that point, but xfail-
renders the tests more useful until that happens.
Note that there is no way to add such a marker for the assertion that
a header uses only symbols in the namespace of symbols it's meant to
use. I don't think there's any need for a way to xfail those
namespace tests other than xfailing the whole (standard, header) pair
at the makefile level, since they are generally straightforward to fix
(add appropriate conditionals on the problem definitions).
The xfails in this patch do not necessarily cover all cases of
hard-to-fix header bugs filed in Bugzilla that currently show up in
conformtest failures; there may be more yet to add for existing open
bugs.
Tested for x86_64 and x86.
* conform/conformtest.pl ($xerrors): New variable.
(note_error): New function.
(compiletest): New argument $xfail. Use not_error.
(runtest): Likewise.
(top level): Handle xfail- lines. Update calls to compiletest and
runtest. Handle xfail- and optional- in headers listed with
allow-header.
* conform/data/fcntl.h-data (O_TTY_INIT): Use xfail-.
(O_EXEC): Likewise.
(O_SEARCH): Likewise.
* conform/data/stropts.h-data (ioctl): Likewise.
* conform/data/sys/ipc.h-data (ipc_perm.mode): Likewise.
* conform/data/sys/sem.h-data (semid_ds.sem_nsems): Likewise.
* conform/data/sys/socket.h-data (msghdr.msg_iovlen): Likewise.
(msghdr.msg_controllen): Likewise.
(cmsghdr.cmsg_len): Likewise.
* conform/data/utmpx.h-data (utmpx.ut_tv): Likewise.
* conform/Makefile (test-xfail-XPG3/sys/ipc.h/conform): Remove
variable.
(test-xfail-XPG3/sys/sem.h/conform): Likewise.
(test-xfail-XPG4/stropts.h/conform): Likewise.
(test-xfail-XPG4/sys/ipc.h/conform): Likewise.
(test-xfail-XPG4/sys/sem.h/conform): Likewise.
(test-xfail-XPG4/sys/socket.h/conform): Likewise.
(test-xfail-UNIX98/stropts.h/conform): Likewise.
(test-xfail-UNIX98/sys/ipc.h/conform): Likewise.
(test-xfail-UNIX98/sys/sem.h/conform): Likewise.
(test-xfail-UNIX98/sys/socket.h/conform): Likewise.
(test-xfail-XOPEN2K/stropts.h/conform): Likewise.
(test-xfail-XOPEN2K/sys/ipc.h/conform): Likewise.
(test-xfail-XOPEN2K/sys/sem.h/conform): Likewise.
(test-xfail-XOPEN2K/sys/socket.h/conform): Likewise.
(test-xfail-XOPEN2K/utmpx.h/conform): Likewise.
(test-xfail-POSIX2008/fcntl.h/conform): Likewise.
(test-xfail-POSIX2008/stropts.h/conform): Likewise.
(test-xfail-XOPEN2K8/fcntl.h/conform): Likewise.
(test-xfail-XOPEN2K8/stropts.h/conform): Likewise.
(test-xfail-XOPEN2K8/sys/ipc.h/conform): Likewise.
(test-xfail-XOPEN2K8/sys/sem.h/conform): Likewise.
(test-xfail-XOPEN2K8/sys/socket.h/conform): Likewise.
The Makefile rule is called one time for target %/UTC or %/Universal.
If the tests are run in parallel, UTC or Universal can trigger the rule.
This patch patch generates the second test-result file as a copy of the
generated one.
Thus the testsuite can rely on the existence of the test-result files
regardless of which target has triggered the rule.
ChangeLog:
* timezone/Makefile (%/UTC %/Universal):
Generate test-result files for UTC and Universal.
Similar to various other bugs in this area, some asinh implementations
do not raise the underflow exception for subnormal arguments, when the
result is tiny and inexact. This patch forces the exception in a
similar way to previous fixes.
Tested for x86_64, x86 and mips64.
[BZ #16350]
* sysdeps/i386/fpu/s_asinh.S (__asinh): Force underflow exception
for arguments with small absolute value.
* sysdeps/i386/fpu/s_asinhf.S (__asinhf): Likewise.
* sysdeps/i386/fpu/s_asinhl.S (__asinhl): Likewise.
* sysdeps/ieee754/dbl-64/s_asinh.c: Include <float.h>.
(__asinh): Force underflow exception for arguments with small
absolute value.
* sysdeps/ieee754/flt-32/s_asinhf.c: Include <float.h>.
(__asinhf): Force underflow exception for arguments with small
absolute value.
* sysdeps/ieee754/ldbl-128/s_asinhl.c: Include <float.h>.
(__asinhl): Force underflow exception for arguments with small
absolute value.
* sysdeps/ieee754/ldbl-128ibm/s_asinhl.c: Include <float.h>.
(__asinhl): Force underflow exception for arguments with small
absolute value.
* sysdeps/ieee754/ldbl-96/s_asinhl.c: Include <float.h>.
(__asinhl): Force underflow exception for arguments with small
absolute value.
* math/auto-libm-test-in: Do not mark underflow exceptions as
possibly missing for bug 16350.
* math/auto-libm-test-out: Regenerated.
Ten conformtest failures arise from the internal header
include/bits/ipc.h failing to condition internal declarations, outside
the public namespace of headers including bits/ipc.h, on [!_ISOMAC].
As discussed in
<https://sourceware.org/ml/libc-alpha/2015-06/msg00653.html>, the
internal declarations that are actually relevant are in ipc_priv.h and
so include/bits/ipc.h should not be needed at all; this patch removes
it. (Ten further conformtest failures for other headers including
bits/ipc.h remain because of other conformance issues in those
headers.)
Tested for x86_64 and x86 (testsuite, and that installed stripped
shared libraries are unchanged by the patch).
* include/bits/ipc.h: Remove file.
* conform/Makefile (test-xfail-XPG3/sys/msg.h/conform): Remove
variable.
(test-xfail-XPG3/sys/shm.h/conform): Likewise.
(test-xfail-XPG4/sys/msg.h/conform): Likewise.
(test-xfail-XPG4/sys/shm.h/conform): Likewise.
(test-xfail-UNIX98/sys/msg.h/conform): Likewise.
(test-xfail-UNIX98/sys/shm.h/conform): Likewise.
(test-xfail-XOPEN2K/sys/msg.h/conform): Likewise.
(test-xfail-XOPEN2K/sys/shm.h/conform): Likewise.
(test-xfail-XOPEN2K8/sys/msg.h/conform): Likewise.
(test-xfail-XOPEN2K8/sys/shm.h/conform): Likewise.
I noticed that I'd left a spurious-underflow allowance behind in
auto-libm-test-in for a bug that was fixed some time ago. This patch
removes it.
Tested for x86_64 and x86.
* math/auto-libm-test-in: Remove spurious underflow allowance for
tests of cexp.
* math/auto-libm-test-out: Regenerated.
sysdeps/unix/sysv/linux/bits/in.h (as included in netinet/in.h, and
via that in netdb.h and arpa/inet.h) defines a series of MCAST_*
macros, both under __USE_MISC and then again unconditionally. These
are not POSIX macros, nor in any of the namespaces listed in POSIX as
reserved for this header, so should not be defined unconditionally.
This patch duly removes the unconditional definitions, leaving the
ones conditional on __USE_MISC.
Tested for x86_64 and x86 (testsuite, and that installed stripped
shared libraries are unchanged by the patch).
[BZ #18558]
* sysdeps/unix/sysv/linux/bits/in.h (MCAST_JOIN_GROUP): Remove
unconditional definition.
(MCAST_BLOCK_SOURCE): Likewise.
(MCAST_UNBLOCK_SOURCE): Likewise.
(MCAST_LEAVE_GROUP): Likewise.
(MCAST_JOIN_SOURCE_GROUP): Likewise.
(MCAST_LEAVE_SOURCE_GROUP): Likewise.
(MCAST_MSFILTER): Likewise.
* conform/Makefile (test-xfail-XOPEN2K/arpa/inet.h/conform):
Remove variable.
(test-xfail-XOPEN2K/netdb.h/conform): Likewise.
(test-xfail-XOPEN2K/netinet/in.h/conform): Likewise.
(test-xfail-XOPEN2K8/arpa/inet.h/conform): Likewise.
(test-xfail-XOPEN2K8/netdb.h/conform): Likewise.
(test-xfail-XOPEN2K8/netinet/in.h/conform): Likewise.
sysdeps/ieee754/ldbl-128ibm has its own versions of cprojl, ctanhl and
ctanl.
Having its own versions, where otherwise the math/ copies are
generally used for all floating-point formats, means they are liable
to get out of sync and not benefit from bug fixes to the generic
versions. The substantive differences (not arising from getting out
of sync and slightly different fixes for the same issues) are: long
double compat handling (also done in the ldbl-opt versions, so doesn't
require special versions for ldbl-128ibm); handling of LDBL_EPSILON
(conditionally undefined and redefined in other math/ implementations,
so doesn't justify a special version), and:
/* __gcc_qmul does not respect -0.0 so we need the following fixup. */
if ((__real__ res == 0.0L) && (__real__ x == 0.0L))
__real__ res = __real__ x;
if ((__real__ res == 0.0L) && (__imag__ x == 0.0L))
__imag__ res = __imag__ x;
But if that statement about __gcc_qmul was ever true for an old
version of that libgcc function, it's not the case for any GCC version
now supported to build glibc; there's explicit logic early in that
function (and similarly in __gcc_qdiv) to return an appropriately
signed zero if the product of the high parts is zero. So this patch
adds the special LDBL_EPSILON handling to the generic functions and
removes the ldbl-128ibm versions.
Tested for powerpc32 (compared test-ldouble.out before and after the
changes; there are slight changes to results for ctanl / ctanhl,
arising from divergence of the implementations, but nothing that
affects the overall nature of the issues shown by the testsuite, and
in particular nothing related to signs of zero resutls).
* math/s_ctanhl.c [LDBL_MANT_DIG == 106] (LDBL_EPSILON): Undefine
and redefine.
* math/s_ctanl.c [LDBL_MANT_DIG == 106] (LDBL_EPSILON): Undefine
and redefine.
* sysdeps/ieee754/ldbl-128ibm/s_cprojl.c: Remove file.
* sysdeps/ieee754/ldbl-128ibm/s_ctanhl.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_ctanl.c: Likewise.
nice (XPG3) calls getpriority and setpriority (in XPG4 but not XPG3,
i.e. UX-shaded in XPG4). This patch fixes this by making those
functions into weak aliases of __* functions and calling the __*
versions as needed.
Tested for x86_64 and x86 (testsuite, and that disassembly of
installed shared libraries is unchanged by this patch).
This completes cleaning up the unsorted linknamespace test XFAILs.
[BZ #18553]
* resource/getpriority.c (getpriority): Rename to __getpriority
and define as weak alias of __getpriority.
* resource/setpriority.c (setpriority): Rename to __setpriority
and define as weak alias of __setpriority.
* sysdeps/mach/hurd/getpriority.c (getpriority): Rename to
__getpriority and define as weak alias of __getpriority.
* sysdeps/mach/hurd/setpriority.c (setpriority): Rename to
__setpriority and define as weak alias of __setpriority.
* sysdeps/unix/syscalls.list (getpriority): Use __getpriority as
strong name.
(setpriority): Use __setpriority as strong name.
* sysdeps/unix/sysv/linux/getpriority.c (getpriority): Rename to
__getpriority and define as weak alias of __getpriority.
* include/sys/resource.h (__getpriority): Declare. Use
libc_hidden_proto.
(__setpriority): Likewise.
(getpriority): Don't use libc_hidden_proto.
(setpriority): Likewise.
* sysdeps/posix/nice.c (nice): Call __getpriority instead of
getpriority. Call __setpriority instead of setpriority.
* conform/Makefile (test-xfail-XPG3/unistd.h/linknamespace):
Remove variable.
ttyslot (XPG4) calls the non-XPG4 functions endttyent, getttyent and
setttyent, which in turn bring in references to fgets_unlocked and
getttynam. This patch fixes this by making these functions into weak
aliases and calling the __* names as needed.
Tested for x86_64 and x86 (testsuite, and that disassembly of
installed stripped shared libraries is unchanged by the patch).
[BZ #18547]
* misc/getttyent.c (getttynam): Rename to __getttynam and define
as weak alias of __getttynam. Use prototype function definition.
Call __setttyent, __getttyent and __endttyent instead of
setttyent, getttyent and endttyent.
(getttyent): Rename to __getttyent and define as weak alias of
__getttyent. Call __setttyent instead of setttyent. Call
__fgets_unlocked instead of fgets_unlocked.
(setttyent): Rename to __setttyent and define as weak alias of
__setttyent.
(endttyent): Rename to __endttyent and define as weak alias of
__endttyent.
* include/ttyent.h (__getttyent): Declare. Use libc_hidden_proto.
(__setttyent): Likewise.
(__endttyent): Likewise.
(getttyent): Don't use libc_hidden_proto.
(setttyent): Likewise.
(endttyent): Likewise.
* misc/ttyslot.c (ttyslot): Call __setttyent, __getttyent and
__endttyent instead of setttyent, getttyent and endttyent.
* conform/Makefile (test-xfail-XPG4/unistd.h/linknamespace):
Remove variable.
mq_notify (in the 1996 edition of POSIX) brings in references to recv
and socket (not in POSIX until the 2001 edition). This patch fixes
this by using __recv and __socket, exporting them from libc at version
GLIBC_PRIVATE.
Tested for x86_64 and x86 (testsuite and comparison of installed
stripped shared libraries; PLT / dynamic symbol table changes render
the comparison not particularly useful for libc).
[BZ #18546]
* socket/recv.c (__recv): Use libc_hidden_def.
* socket/socket.c (__socket): Likewise.
* sysdeps/mach/hurd/recv.c (__recv): Likewise.
* sysdeps/mach/hurd/socket.c (__socket): Likewise.
* sysdeps/unix/sysv/linux/generic/recv.c (__recv): Likewise.
* sysdeps/unix/sysv/linux/recv.c (__recv): Use libc_hidden_weak.
* sysdeps/unix/sysv/linux/socket.c (__socket): Use
libc_hidden_def.
* sysdeps/unix/sysv/linux/x86_64/recv.c (__recv): Use
libc_hidden_weak.
* include/sys/socket.h (__socket): Do not use attribute_hidden.
Use libc_hidden_proto.
(__recv): Likewise.
* socket/Versions (libc): Export __recv and __socket at version
GLIBC_PRIVATE.
* sysdeps/unix/sysv/linux/mq_notify.c (helper_thread): Call __recv
instead of recv.
(init_mq_netlink): Call __socket instead of socket.
* conform/Makefile (test-xfail-POSIX/mqueue.h/linknamespace):
Remove variable.
mq_receive calls mq_timedreceive, and mq_send calls mq_timedsend. But
mq_receive and mq_send were in POSIX by 1996, while mq_timed* were
added in the 2001 edition of POSIX. This patch fixes this by making
mq_timed* into weak aliases for __mq_timed* and calling the
__mq_timed* names.
Tested for x86_64 and x86 (testsuite, and that disassembly of
installed shared libraries is unchanged by the patch).
[BZ #18545]
* rt/mq_timedreceive.c (mq_timedreceive): Rename to
__mq_timedreceive and define as alias of __mq_timedreceive. Use
hidden_weak.
* rt/mq_timedsend.c (mq_timedsend): Rename to __mq_timedsend and
define as alias of __mq_timedsend. Use hidden_weak.
* sysdeps/unix/sysv/linux/syscalls.list (mq_timedsend): Use
__mq_timedsend as strong name.
(mq_timedreceive): Use __mq_timedreceive as strong name.
* include/mqueue.h (__mq_timedsend): Declare. Use hidden_proto.
(__mq_timedreceive): Likewise.
* sysdeps/unix/sysv/linux/mq_receive.c (mq_receive): Call
__mq_timedreceive instead of mq_timedreceive.
* sysdeps/unix/sysv/linux/mq_send.c (mq_send): Call __mq_timedsend
instead of mq_timedsend.
* conform/Makefile (test-xfail-UNIX98/mqueue.h/linknamespace):
Remove variable.
The syscall wrappers mechanism automatically creates hidden aliases
for syscalls with libc_hidden_def / libc_hidden_weak. The use of
libc_hidden_* has the side-effect that for syscall wrappers in
non-libc libraries those aliases are not created. In turn, this means
that three mq_* syscalls in sysdeps/unix/sysv/linux/syscalls.list list
the __GI_* names explicitly.
The use of libc_hidden_* dates back to the original introduction of
that support in
2002-08-03 Roland McGrath <roland@redhat.com>
* sysdeps/unix/make-syscalls.sh: Generate libc_hidden_def or
libc_hidden_weak for every system call symbol defined.
(predating the non-libc syscalls in question) and I see no reason for
excluding non-libc syscalls. This patch changes the code to use
hidden_def / hidden_weak (via a wrapper syscall_hidden_def in the case
where the argument is itself a macro, so that the argument gets
expanded before concatenation with __GI_), so avoiding the need to
specify the hidden aliases explicitly in this case.
Tested for x86_64 and x86 (testsuite, and that disassembly of
installed stripped shared libraries is unchanged by the patch; the
mq_* symbols change from weak to strong, which is of no significance
and two of them will shortly change back to weak as part of a fix for
bug 18545).
* sysdeps/unix/make-syscalls.sh (emit_weak_aliases): Use
hidden_def and hidden_weak instead of libc_hidden_def and
libc_hidden_weak.
(top level): Refer to hidden_def in comment.
* sysdeps/unix/syscall-template.S (syscall_hidden_def): New
macro. Use it instead of libc_hidden_def.
* sysdeps/unix/sysv/linux/syscalls.list (mq_timedsend): Do not
specify __GI_* name explicitly.
(mq_timedreceive): Likewise.
(mq_setattr): Likewise.
mq_notify (present in POSIX by 1996) brings in references to
pthread_barrier_init and pthread_barrier_wait (new in the 2001 edition
of POSIX). This patch fixes this by making those functions into weak
aliases of __pthread_barrier_*, exporting the __pthread_barrier_*
names at version GLIBC_PRIVATE and using them in mq_notify.
Tested for x86_64 and x86 (testsuite, and comparison of installed
stripped shared libraries). Changes in addresses from dynamic symbol
table / PLT changes render most comparisons not particularly useful,
but when the addresses of subsequent code don't change there's no sign
of unexpected changes there. This patch does not remove any
linknamespace XFAILs because of other namespace issues remaining with
mqueue.h functions.
[BZ #18544]
* nptl/pthread_barrier_init.c (pthread_barrier_init): Rename to
__pthread_barrier_init and define as weak alias of
__pthread_barrier_init.
* sysdeps/sparc/nptl/pthread_barrier_init.c
(pthread_barrier_init): Likewise.
* nptl/pthread_barrier_wait.c (pthread_barrier_wait): Rename to
__pthread_barrier_wait and define as weak alias of
__pthread_barrier_wait.
* sysdeps/sparc/nptl/pthread_barrier_wait.c
(pthread_barrier_wait): Likewise.
* sysdeps/sparc/sparc32/pthread_barrier_wait.c
(pthread_barrier_wait): Likewise.
* sysdeps/unix/sysv/linux/i386/i486/pthread_barrier_wait.S
(pthread_barrier_wait): Likewise.
* sysdeps/unix/sysv/linux/x86_64/pthread_barrier_wait.S
(pthread_barrier_wait): Likewise.
* nptl/Versions (libpthread): Export __pthread_barrier_init and
__pthread_barrier_wait at version GLIBC_PRIVATE.
* include/pthread.h (__pthread_barrier_init): Declare.
(__pthread_barrier_wait): Likewise.
* sysdeps/unix/sysv/linux/mq_notify.c (notification_function):
Call __pthread_barrier_wait instead of pthread_barrier_wait.
(helper_thread): Likewise.
(init_mq_netlink): Call __pthread_barrier_init instead of
pthread_barrier_init.
swscanf (added in C90 Amendment 1, present in UNIX98) calls vswscanf
(added in C99, not in C90 Amendment 1 or UNIX98). This patch fixes
this by using __vswscanf instead and making vswscanf into a weak
alias.
(I intend to add conform/ test support for C90 Amendment 1 - and
various other standard versions supported by glibc but not yet by
conform/ tests - at some point, once the results for currently tested
standards are cleaner.)
Tested for x86_64 and x86 (testsuite, and that installed stripped
shared libraries are unchanged by the patch).
[BZ #18542]
* libio/iovswscanf.c (__vswscanf): Use libc_hidden_def.
(vswscanf): Use ldbl_weak_alias instead of ldbl_strong_alias
* include/wchar.h (__vswscanf): Declare. Use libc_hidden_proto.
* libio/swscanf.c (__swscanf): Call __vswscanf instead of
vswscanf.
* conform/Makefile (test-xfail-UNIX98/wchar.h/linknamespace):
Remove variable.
The getpass function (XPG3 / XPG4 / UNIX98) calls fflush_unlocked (not
in any of those standards). This patch fixes this by making
fflush_unlocked into a weak alias for __fflush_unlocked and calling
__fflush_unlocked from getpass.
Tested for x86_64 and x86 (testsuite, and that disassembly of
installed stripped shared libraries is unchanged by the patch).
[BZ #18540]
* libio/iofflush.c [!_IO_MTSAFE_IO] (__fflush_unlocked): Define as
strong alias of _IO_fflush. Use libc_hidden_def.
* libio/iofflush_u.c (fflush_unlocked): Rename to
__fflush_unlocked and define as weak alias of __fflush_unlocked.
Use libc_hidden_weak.
* include/stdio.h (__fflush_unlocked): Declare. Use
libc_hidden_proto.
* misc/getpass.c (getpass): Call __fflush_unlocked instead of
fflush_unlocked.
* conform/Makefile (test-xfail-UNIX98/unistd.h/linknamespace):
Remove variable.
Use of fmtmsg (XSI POSIX) brings in addseverity (non-POSIX). This
patch fixes this by making addseverity into a weak alias for
__addseverity.
Tested for x86_64 and x86 (testsuite, and that disassembly of
installed shared libraries is unchanged by the patch).
[BZ #18539]
* stdlib/fmtmsg.c (addseverity): Rename to __addseverity and
define as weak alias of __addseverity.
* conform/Makefile (test-xfail-XPG4/fmtmsg.h/linknamespace):
Remove variable.
(test-xfail-UNIX98/fmtmsg.h/linknamespace): Likewise.
(test-xfail-XOPEN2K/fmtmsg.h/linknamespace): Likewise.
(test-xfail-XOPEN2K8/fmtmsg.h/linknamespace): Likewise.
The sem_* functions bring in references to tdelete, tfind, tsearch and
twalk. But the t* functions are XSI-shaded, while sem_* aren't. This
patch fixes this by using __t* instead, exporting those functions from
libc at version GLIBC_PRIVATE (since sem_* are in libpthread) and
using libc_hidden_* for the benefit of calls within libc.
Tested for x86_64 and x86 (testsuite, and comparison of disassembly of
installed stripped shared libraries). libpthread gets changes from
PLT reordering; addresses in libc change because of PLT / dynamic
symbol table changes.
[BZ #18536]
* misc/tsearch.c (__tsearch): Use libc_hidden_def.
(__tfind): Likewise.
(__tdelete): Likewise.
(__twalk): Likewise.
* misc/Versions (libc): Add __tdelete, __tfind, __tsearch and
__twalk to GLIBC_PRIVATE.
* include/search.h (__tsearch): Use libc_hidden_proto.
(__tfind): Likewise.
(__tdelete): Likewise.
(__twalk): Likewise.
* nptl/sem_close.c (sem_close): Call __twalk instead of twalk.
Call __tdelete instead of tdelete.
* nptl/sem_open.c (check_add_mapping): Call __tfind instead of
tfind. Call __tsearch instead of tsearch.
* sysdeps/sparc/sparc32/sem_open.c (check_add_mapping): Likewise.
* conform/Makefile (test-xfail-POSIX/semaphore.h/linknamespace):
Remove variable.
(test-xfail-POSIX2008/semaphore.h/linknamespace): Likewise.
syslog functions bring in references to dprintf, which wasn't added to
POSIX until the 2008 edition and so isn't in various standards
containing the syslog functions. This patch fixes this by making
dprintf into a weak alias of __dprintf and using __dprintf as
appropriate.
Tested for x86_64 and x86 (testsuite, and that installed stripped
shared libraries are unchanged by the patch).
[BZ #18534]
* stdio-common/dprintf.c (__dprintf): Use libc_hidden_def.
(dprintf): Define as a weak alias of __dprintf, not a strong
alias.
* include/stdio.h (__dprintf): Declare. Use libc_hidden_proto.
* misc/syslog.c (__vsyslog_chk): Call __dprintf instead of
dprintf.
* conform/Makefile (test-xfail-XPG4/syslog.h/linknamespace):
Remove variable.
(test-xfail-UNIX98/syslog.h/linknamespace): Likewise.
(test-xfail-XOPEN2K/syslog.h/linknamespace): Likewise.
syslog functions (in POSIX) bring in the strong symbol vsyslog (not in
POSIX). This patch fixes this by changing this symbol from a strong
alias to a weak alias.
Tested for x86_64 and x86 (testsuite, and that installed stripped
shared libraries are unchanged by the patch). (vsyslog becomes weak
in the static libraries, which is what's needed; the particular macro
sequence in use leaves it as strong in the shared libraries, hence
those libraries being completely unchanged, but it doesn't generally
matter whether symbols exported from the shared libraries are weak or
strong.)
[BZ #18533]
* misc/syslog.c (vsyslog): Define as a weak alias of __vsyslog,
not a strong alias.
* conform/Makefile (test-xfail-XOPEN2K8/syslog.h/linknamespace):
Remove variable.
gethostbyaddr brings in references to in6addr_any and thereby
in6addr_loopback, which aren't in all the standards containing
gethostbyaddr (gethostbyaddr is in XPG4 and UNIX98, in6addr_any and
in6addr_loopback are new in POSIX.1:2001). This patch fixes this by
making those symbols into weak aliases (safe in this case, unlike for
most data symbols, because these data symbols are const).
Tested for x86_64 and x86 (testsuite, and comparison of disassembly of
installed stripped shared libraries). Disassembly is unchanged for
x86_64; for x86, I see some changes of stack offsets, but no other
code generation changes or code size differences.
[BZ #18532]
* inet/in6_addr.c (in6addr_any): Rename to __in6addr_any and
define as weak alias of __in6addr_any. Use libc_hidden_data_weak.
(in6addr_loopback): Rename to __in6addr_loopback and define as
weak alias of __in6addr_loopback. Use libc_hidden_data_weak.
* include/netinet/in.h (__in6addr_loopback): Declare. Use
libc_hidden_proto.
(__in6addr_any): Likewise.
* inet/gethstbyad_r.c (PREPROCESS): Use __in6addr_any instead of
in6addr_any.
* conform/Makefile (test-xfail-XPG4/netdb.h/linknamespace): Remove
variable.
(test-xfail-UNIX98/netdb.h/linknamespace): Likewise.
Some of the cfi annotations used incorrect sign.
* sysdeps/aarch64/dl-tlsdesc.S (_dl_tlsdesc_return_lazy): Fix
cfi_adjust_cfa_offset argument.
(_dl_tlsdesc_undefweak, _dl_tlsdesc_dynamic): Likewise.
(_dl_tlsdesc_resolve_rela, _dl_tlsdesc_resolve_hold): Likewise.
Lazy TLSDESC initialization needs to be synchronized with concurrent TLS
accesses. The TLS descriptor contains a function pointer (entry) and an
argument that is accessed from the entry function. With lazy initialization
the first call to the entry function updates the entry and the argument to
their final value. A final entry function must make sure that it accesses an
initialized argument, this needs synchronization on systems with weak memory
ordering otherwise the writes of the first call can be observed out of order.
There are at least two issues with the current code:
tlsdesc.c (i386, x86_64, arm, aarch64) uses volatile memory accesses on the
write side (in the initial entry function) instead of C11 atomics.
And on systems with weak memory ordering (arm, aarch64) the read side
synchronization is missing from the final entry functions (dl-tlsdesc.S).
This patch only deals with aarch64.
* Write side:
Volatile accesses were replaced with C11 relaxed atomics, and a release
store was used for the initialization of entry so the read side can
synchronize with it.
* Read side:
TLS access generated by the compiler and an entry function code is roughly
ldr x1, [x0] // load the entry
blr x1 // call it
entryfunc:
ldr x0, [x0,#8] // load the arg
ret
Various alternatives were considered to force the ordering in the entry
function between the two loads:
(1) barrier
entryfunc:
dmb ishld
ldr x0, [x0,#8]
(2) address dependency (if the address of the second load depends on the
result of the first one the ordering is guaranteed):
entryfunc:
ldr x1,[x0]
and x1,x1,#8
orr x1,x1,#8
ldr x0,[x0,x1]
(3) load-acquire (ARMv8 instruction that is ordered before subsequent
loads and stores)
entryfunc:
ldar xzr,[x0]
ldr x0,[x0,#8]
Option (1) is the simplest but slowest (note: this runs at every TLS
access), options (2) and (3) do one extra load from [x0] (same address
loads are ordered so it happens-after the load on the call site),
option (2) clobbers x1 which is problematic because existing gcc does
not expect that, so approach (3) was chosen.
A new _dl_tlsdesc_return_lazy entry function was introduced for lazily
relocated static TLS, so non-lazy static TLS can avoid the synchronization
cost.
[BZ #18034]
* sysdeps/aarch64/dl-tlsdesc.h (_dl_tlsdesc_return_lazy): Declare.
* sysdeps/aarch64/dl-tlsdesc.S (_dl_tlsdesc_return_lazy): Define.
(_dl_tlsdesc_undefweak): Guarantee TLSDESC entry and argument load-load
ordering using ldar.
(_dl_tlsdesc_dynamic): Likewise.
(_dl_tlsdesc_return_lazy): Likewise.
* sysdeps/aarch64/tlsdesc.c (_dl_tlsdesc_resolve_rela_fixup): Use
relaxed atomics instead of volatile and synchronize with release store.
(_dl_tlsdesc_resolve_hold_fixup): Use relaxed atomics instead of
volatile.
* elf/tlsdeschtab.h (_dl_tlsdesc_resolve_early_return_p): Likewise.
Some linknamespace test failures turned out to be because the
variables in6addr_any and in6addr_loopback weren't listed in the lists
of extra reserved symbols for the relevant standards (only functions
are handled automatically through -aux-info, data symbols need listing
manually in list-header-symbols.pl). This patch duly adds those
symbols to those lists (there are still failures for older standards
because of references to those symbols being brought in for standards
that didn't reserve them: bug 18532, to be fixed separately).
Tested for x86_64.
* conform/list-header-symbols.pl (%extra_syms): Add in6addr_any
and in6addr_loopback for XOPEN2K, XOPEN2K8 and POSIX2008.
* conform/Makefile (test-xfail-XOPEN2K/netdb.h/linknamespace):
Remove variable.
(test-xfail-POSIX2008/netdb.h/linknamespace): Likewise.
(test-xfail-XOPEN2K8/netdb.h/linknamespace): Likewise.
syslog (XSI POSIX) brings in references to fputs_unlocked (not
POSIX). This patch fixes this by making fputs_unlocked into a weak
alias for __fputs_unlocked and using __fputs_unlocked as needed. (No
linknamespace test XFAILs are removed because there are other failures
from syslog as well.)
Tested for x86_64 and x86 (testsuite, and comparison of disassembly of
installed stripped shared libraries). Disassembly of installed
stripped shared libraries is unchanged on x86_64; on x86, I see some
small changes to instruction ordering and register choice, with no
apparent reason for such changes to be related to this patch, but they
also seem completely harmless with no change to code size.
[BZ #18530]
* libio/iofputs.c [!_IO_MTSAFE_IO] (__fputs_unlocked): Define as
strong alias of _IO_fputs. Use libc_hidden_def.
* libio/iofputs_u.c (fputs_unlocked): Rename to __fputs_unlocked
and define as weak alias of __fputs_unlocked. Use
libc_hidden_weak.
* include/stdio.h (__fputs_unlocked): Declare. Use
libc_hidden_proto.
* misc/syslog.c (__vsyslog_chk): Call __fputs_unlocked instead of
fputs_unlocked.
netdb.h declares interfaces such as getaddrinfo if __USE_POSIX,
i.e. POSIX.1:1990 or later. However, these interfaces were new in the
2001 edition of POSIX, although the header was in XPG4 and UNIX98, so
they should not be declared for XPG4 or UNIX98. (This produces
spurious linknamespace test failures, although there are other
failures for this header as well for the same standards so this patch
doesn't remove any XFAILs.) This patch corrects the condition, and
the conform/ test expectations which were similarly wrong.
Tested for x86_64 and x86 (testsuite, and that installed stripped
shared libraries are unchanged by the patch).
[BZ #18529]
* resolv/netdb.h [__USE_POSIX]: Change condition to
[__USE_XOPEN2K].
* conform/data/netdb.h-data [XPG4 || UNIX98] (struct addrinfo): Do
not expect.
[XPG4 || UNIX98] (AI_PASSIVE): Likewise.
[XPG4 || UNIX98] (AI_CANONNAME): Likewise.
[XPG4 || UNIX98] (AI_NUMERICHOST): Likewise.
[XPG4 || UNIX98] (AI_V4MAPPED): Likewise.
[XPG4 || UNIX98] (AI_ALL): Likewise.
[XPG4 || UNIX98] (AI_ADDRCONFIG): Likewise.
[XPG4 || UNIX98] (AI_NUMERICSERV): Likewise.
[XPG4 || UNIX98] (NI_NOFQDN): Likewise.
[XPG4 || UNIX98] (NI_NUMERICHOST): Likewise.
[XPG4 || UNIX98] (NI_NAMEREQD): Likewise.
[XPG4 || UNIX98] (NI_NUMERICSERV): Likewise.
[XPG4 || UNIX98] (NI_DGRAM): Likewise.
[XPG4 || UNIX98] (EAI_AGAIN): Likewise.
[XPG4 || UNIX98] (EAI_BADFLAGS): Likewise.
[XPG4 || UNIX98] (EAI_FAIL): Likewise.
[XPG4 || UNIX98] (EAI_FAMILY): Likewise.
[XPG4 || UNIX98] (EAI_MEMORY): Likewise.
[XPG4 || UNIX98] (EAI_NONAME): Likewise.
[XPG4 || UNIX98] (EAI_SERVICE): Likewise.
[XPG4 || UNIX98] (EAI_SOCKTYPE): Likewise.
[XPG4 || UNIX98] (EAI_SYSTEM): Likewise.
[XPG4 || UNIX98] (EAI_SYSTEM): Likewise.
[XPG4 || UNIX98] (freeaddrinfo): Likewise.
[XPG4 || UNIX98] (gai_strerror): Likewise.
[XPG4 || UNIX98] (getaddrinfo): Likewise.
[XPG4 || UNIX98] (getnameinfo): Likewise.
grp.h declares endgrent and getgrent if __USE_XOPEN2K8 (i.e. 2008
edition of POSIX, non-XSI). However, the 2013 Technical Corrigendum
corrected the grp.h specification to XSI-shade these functions as in
previous editions (see <http://austingroupbugs.net/view.php?id=24>),
so they should not be declared for non-XSI POSIX. This patch corrects
the conditions - using __USE_MISC || __USE_XOPEN_EXTENDED to match
setgrent - and the conform/ test expectations for this header, thereby
fixing the conform tests for this header for XPG3 (where the
expectations were wrong) and the linknamespace tests for it for
POSIX2008 (where the header bug meant it was wrongly considered a
problem for endgrent to bring in a reference to setgrent).
Tested for x86_64 and x86 (testsuite, and that installed stripped
shared libraries are unchanged by the patch).
[BZ #18528]
* grp/grp.h (endgrent): Condition on [__USE_MISC ||
__USE_XOPEN_EXTENDED], not [__USE_XOPEN_EXTENDED ||
__USE_XOPEN2K8].
(getgrent): Likewise.
* conform/data/grp.h-data [XPG3 || POSIX2008] (getgrent): Do not
expect.
[XPG3 || POSIX2008] (endgrent): Likewise.
[XPG3] (setgrent): Likewise.
* conform/Makefile (test-xfail-XPG3/grp.h/conform): Remove
variable.
(test-xfail-POSIX2008/grp.h/linknamespace): Likewise.
Joseph Myers
Dmitry V. Levin
Andreas Schwab
Leonhard Holz
Andrew Senkevich
Stefan Liebler
Szabolcs Nagy