NSIG is a deprecated symbol only visible under MISC visibility.
_NSIG is used widely instead, and on most systems NSIG is
defined in terms of _NSIG.
Follow suit: Change NSIG to _NSIG throughout and change visiblity
of NSIG to be defined only in __MISC_VISIBLE case.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
This edits licenses held by Berkeley and NetBSD, both of which
have removed the advertising requirement from their licenses.
Signed-off-by: Keith Packard <keithp@keithp.com>
Though our implementation of cpu sets doesn't need it, software from
Linux environments expects this definition to be present. It's
documented on the Linux CPU_SET(3) man page but was left out due to
oversight.
Addresses https://cygwin.com/ml/cygwin/2019-12/msg00248.html
The CPU_SET macros defined in Cygwin's include/sys/cpuset.h must not
be visible in an application's namespace unless _GNU_SOURCE has been
#defined. Internally this means wrapping them in #if __GNU_VISIBLE.
This patch supplies an implementation of the CPU_SET(3) processor
affinity macros as documented on the relevant Linux man page.
There is a mostly superset implementation of cpusets under newlib's
libc/sys/RTEMS/include/sys that has Linux and FreeBSD compatibility
and is built on top of FreeBSD bitsets. This Cygwin implementation
and the RTEMS one could be combined if desired at some future point.
Have sched_getaffinity() interface like glibc's, and provide an
undocumented internal interface __sched_getaffinity_sys() like the Linux
kernel's sched_getaffinity() for benefit of taskset(1).
This patch set implements the Linux syscalls sched_getaffinity,
sched_setaffinity, pthread_getaffinity_np, and pthread_setaffinity_np.
Linux has a straightforward view of the cpu sets used in affinity masks.
They are simply long (1024-bit) bit masks. This code emulates that view
while internally dealing with Windows' distribution of available CPUs among
processor groups.
libX11 provides <X11/Xlocale.h>. The build of libX11 itself adds
include/X11 to the compiler's include path. This results in a name
collision with /usr/include/xlocale.h on case-insensitive filesystems.
Commit 90e35b1eb3 renamed sys/_locale.h to xlocale.h in March 2017 under
the assumption that we should provide the locale_t type in the same file
as on Linux, FreeBSD, and Darwin.
A few weeks later (June 2017), glibc removed the xlocale.h file in favor
of bits/types/locale_t.h, which shouldn't be included directly anyway.
For reference and the reasoning, see
https://sourceware.org/git/?p=glibc.git;a=commit;h=f0be25b6336d
Given the above, revert 90e35b1eb3 and
fix additional usage of xlocale.h.
strace only printed the Windows PID in event output so far.
Especially now that Windows and Cygwin PID are decoupled, the
strace user might like to see the Cygwin pid in event output as
well. However, at process startup, the process might not have
a Cygwin PID yet.
To mitigate this, always print the Windows PID and only add the
Cygwin pid if it exists.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
- feenableexcept,fedisableexcept, fegetexcept are GNU-only
- fegetprec, fesetprec are Solaris, use __MISC_VISIBLE
- _feinitialise is Cygwin-internal only
- Replace self-named FP precision values to values from
http://www.open-std.org/jtc1/sc22//WG14/www/docs/n752.htm
as used by Solaris.
- Change return value of fesetprec to adhere to the above document
and Solaris.
- Document fegetprec, fesetprec as Solaris functions, not as GNU
functions
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Commit c1023ee353 changed the way
path_conv::binmode() works. Rather than returning three states,
O_BINARY, O_TEXT, 0, it only returned 2 states, O_BINARY, O_TEXT. Since
mounts are only binary if they are explicitely mounted binary by setting
the MOUNT_BINARY flag, textmode is default.
This introduced a new bug. When inheriting stdio HANDLEs from native
Windows processes, the fhandler and its path_conv are created from a
device struct only. None of the path or mount flags get set this way.
So the mount flags are 0 and path_conv::binmode() returned 0.
After the path_conv::binmode() change it returned O_TEXT since, as
explained above, the default mount mode is textmode.
Rather than just enforcing binary mode for path_conv's created from
device structs, this patch changes the default mount mode to binary:
Replace MOUNT_BINARY flag with MOUNT_TEXT flag with opposite meaning.
Drop all explicit setting of MOUNT_BINARY. Drop local set_flags
function, it doesn't add any value.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
* Rename cygwin_shared->prefer_forkable_hardlinks to
forkable_hardlink_support, with values
0 for Unknown, 1 for Supported, -1 for Unsupported.
Upon first dll loaded ever, dll_list::forkable_ntnamesize checks the
/var/run/cygfork directory to both exist and reside on NTFS, setting
cygwin_shared->forkable_hardlink_support accordingly.
* Replace enum forkables_needs by bool forkables_created: Set
to True by request_forkables after creating forkable hardlinks.
To avoid the need for each process to check the filesystem to detect
that hardlink creation is impossible or disabled, cache this fact in
shared memory. Removing cygfork directory while in use does disable
hardlinks creation. To (re-)enable hardlinks creation, the cygfork
directory has to exist before the first cygwin process does fork.
* forkable.cc (dll_list::forkable_ntnamesize): Short cut
forkables needs to impossible when disabled via shared memory.
(dll_list::update_forkables_needs): When detecting hardlink
creation as impossible (not on NTFS) while still (we are the
first one checking) enabled via shared memory, disable the
shared memory value.
(dll_list::request_forkables): Disable the shared memory value
when hardlinks creation became disabled, that is when the
cygfork directory was removed.
* include/cygwin/version.h: Bump CYGWIN_VERSION_SHARED_DATA 6.
* shared_info.h (struct shared_info): Add member
prefer_forkable_hardlinks. Update CURR_SHARED_MAGIC.
* shared.cc (shared_info::initialize): Initialize
prefer_forkable_hardlinks to 1 (Yes).
Using the Windows PID as Cygwin PID has a few drawbacks:
- the PIDs on Windows get reused quickly. Some POSIX applications choke
on that, so we need extra code to avoid too quick PID reuse.
- The code to avoid PID reuse keeps parent process handles and
(depending on a build option) child processes open unnecessarily.
- After an execve, the process has a split personality: Its Windows PID
is a new PID, while its Cygwin PID is the PID of the execve caller
process. This requires to keep two procinfo shared sections open, the
second just to redirect process info requests to the first, correct
one.
This patch changes the way Cygwin PIDs are generated:
- Cygwin PIDs are generated independently of the Windows PID, in a way
expected by POSIX processes. The PIDs are created incrementally in
the range between 2 and 65535, round-robin.
- On startup of the first Cygwin process, choose a semi-random start PID
for the first process in the lower PID range to make the PIDs slightly
unpredictable. This may not be necessary but it seems kind of inviting
to know that the first Cygwin process always starts with PID 2.
- Every process not only creates the shared procinfo section, but also a
symlink in the NT namespace, symlinking the Windows PID to the Cygwin
PID. This drops the need for the extra procinfo section after execve.
- Don't keep other process handles around unnecessarily.
- Simplify the code creating/opening the shared procinfo section and
make a clear distinction between interfaces getting a Cygwin PID and
interfaces getting a Windows PID.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
- This simple and official method replaces cyglsa and "create token"
methods. No network share access, same as before.
- lsaauth and create_token are disabled now. If problems crop up,
they can be easily reactivated. If no problems crop up, they
can be removed in a while, together with the lsaauth subdir.
- Bump Cygwin version to 3.0.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
First cut of a timerfd implementation.
Still TODO:
- fork/exec semantics
- timerfd_settime TFD_TIMER_CANCEL_ON_SET flag
- ioctl(TFD_IOC_SET_TICKS)
- bug fixes
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
First cut of a signalfd implementation.
Still TODO: Non-polling select.
This should mostly work as on Linux except for missing support
for some members of struct signalfd_siginfo, namely ssi_fd,
ssi_band (both SIGIO/SIGPOLL, not fully implemented) and ssi_trapno
(HW exception, required HW support).
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
The new proc fd code accidentally allowed to linkat an O_TMPFILE
even if the file has been opened with O_EXCL. This patch fixes it.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
- Remove another unfortunate amalgamation: Mount flags (MOUNT_xxx)
are converted to path_types (PATH_xxx) and mixed with non-mount
path_types flags in the same storage, leading to a tangled,
pell-mell usage of mount flags and path flags in path_conv and
symlink_info.
- There's also the case of PC_NONULLEMPTY. It's used in exactly
one place with a path_conv constructor only used in this single
place, just to override the automatic PC_NULLEMPTY addition
when calling the other path_conv constructors. Crazily,
PC_NONULLEMPTY is a define, no path_types flag, despite its
name.
- It doesn't help that the binary flag exists as mount and path
flag, while the text flag only exists as path flag. This leads
to mount code using path flags to set text/binary. Very confusing
is the fact that a text mount/path flag is not actually required;
the mount code sets the text flag on non binary mounts anyway, so
there are only two states. However, to puzzle people a bit more,
path_conv::binary wrongly implies there's a third, non-binary/non-text
state.
Clean up this mess:
- Store path flags separately from mount flags in path_conv and
symlink_info classes and change all checks and testing inline
methods accordingly.
- Make PC_NONULLEMPTY a simple path_types flag and drop the
redundant path_check constructor.
- Clean up the definition of pathconv_arg, path_types, and mount flags.
Use _BIT expression, newly define in cygwin/bits.h.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
- Drop hires_[nm]s clocks, rename hires.h to clock.h.
- Implement clk_t class as an extensible clock class in new file clock.cc.
- Introduce get_clock(clock_id) returning a pointer to the clk_t instance
for clock_id. Provide the following methods along the lines of the former
hires classes:
void clk_t::nsecs (struct timespec *);
ULONGLONG clk_t::nsecs ();
LONGLONG clk_t::usecs ();
LONGLONG clk_t::msecs ();
void clk_t::resolution (struct timespec *);
- Add CLOCK_REALTIME_COARSE, CLOCK_MONOTONIC_RAW, CLOCK_MONOTONIC_COARSE
and CLOCK_BOOTTIME clocks.
- Allow clock_nanosleep, pthread_condattr_setclock and timer_create to use
all new clocks (both clocks should be usable with a small tweak, though).
- Bump DLL major version to 2.12.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Move common content of the various <sys/dirent.h> and the latest FreeBSD
<dirent.h> to <dirent.h>.
Signed-off-by: Sebastian Huber <sebastian.huber@embedded-brains.de>
This patch follows glibc. Original commit message:
Author: Florian Weimer <fweimer@redhat.com>
Date: Thu, 14 Apr 2016 06:54:57 +0000
Remove union wait [BZ #19613]
The overloading approach in the W* macros was incompatible with
integer expressions of a type different from int. Applications
using union wait and these macros will have to migrate to the
POSIX-specified int status type.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Add __nl_item to <sys/_types.h> for FreeBSD compatibility. Use it in
<langinfo.h> and the Cygwin <nl_types.h>. Make the enum __nl_item in
<langinfo.h> anonymous.
Signed-off-by: Sebastian Huber <sebastian.huber@embedded-brains.de>
By excluding the denormal-operand exception from FE_ALL_EXCEPT, it will not
be possible anymore to UNmask this exception by means of the API defined by
/usr/include/fenv.h
Note: terminology has changed since IEEE Std 854-1987; denormalized numbers
are called subnormal numbers nowadays.
This modification has basically been motivated by the fact that it is also
not possible on Linux to manipulate the denormal-operand exception by means
of the interface as defined by /usr/include/fenv.h. This has been the state
of affairs on Linux since 2001 (Andreas Jaeger).
The exceptions required by the standard (IEEE Std 754), in case they can be
supported by the implementation, are:
FE_INEXACT, FE_UNDERFLOW, FE_OVERFLOW, FE_DIVBYZERO and FE_INVALID.
Although it is allowed to define additional exceptions, there is no reason
to support the "denormal-operand exception" in this case (fenv.h), because
the subnormal numbers can be handled almost as fast the normalized numbers
by the hardware of the x86/x86_64 architecture. Said differently, a reason
to trap on the input of subnormal numbers does not exist. At least that is
what William Kahan and others at Intel asserted around 2000.
(that is William Kahan of the K-C-S draft, the precursor to the standard)
This commit modifies winsup/cygwin/include/fenv.h as follows:
- redefines FE_ALL_EXCEPT from 0x3f to 0x3d
- removes the definition for FE_DENORMAL
- introduces __FE_DENORM (0x2) (enum in Linux also uses __FE_DENORM)
- introduces FE_ALL_EXCEPT_X86 (0x3f), i.e. ALL x86/x86_64 FP exceptions
* create new function __get_cpus_per_group to evaluate # of CPU groups
* Call from format_proc_cpuinfo and sched_getcpu
* Bump API minor version
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Updates to misc files to integrate AIO into the Cygwin source tree.
Much of it has to be done when adding any new syscalls. There are
some updates to limits.h for AIO-specific limits. And some doc mods.
This is the core of the AIO implementation: aio.cc and aio.h. The
latter is used within the Cygwin DLL by aio.cc and the fhandler* modules,
as well as by user programs wanting the AIO functionality.
- Move pthread_join to thread.cc to have all `join' calls in
the same file (pthread_timedjoin_np needs pthread_convert_abstime
which is static inline in thread.cc)
- Bump API version
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
* Rearrange includes and drop unneccessary ones.
* Don't pull in cygwin/socket.h into sys/un.h just to get
sa_family_t. Include sys/types.h and use __sa_family_t instead.
* start including Windows headers using the w32api/ path prefix
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
* Make distinct from AF_LOCAL for testing purposes. This will have
to be reverted as soon as fhandler_socket_unix goes life.
* Move saw_reuseaddr flag back to fhandler_socket status
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
While POSIX mandates that certain socket types shall be defined by the
inclusing of <netinet/in.h>, it also says that this header may also make
visible all <sys/socket.h> symbols. Glibc does this, and without out it,
some packages end up requiring an additional #include <sys/socket.h>.
Signed-off-by: Yaakov Selkowitz <yselkowi@redhat.com>
POSIX does not mention the inclusion of <sys/time.h> in <sys/socket.h>
or <netinet/in.h>, nor is there anything in the latter two that would
require the former.
Signed-off-by: Yaakov Selkowitz <yselkowi@redhat.com>
The first argument of gethostbyaddr needs to accept a generic pointer
to be compatible with e.g. struct in_addr *. This caused an issue
compiling krb5-1.15.
Signed-off-by: Yaakov Selkowitz <yselkowi@redhat.com>
herror etc. are MISC, rcmd etc. are BSD, addrinfo functions are
POSIX.1-2001, except for IDN functionality which is GNU.
Signed-off-by: Yaakov Selkowitz <yselkowi@redhat.com>
In order to avoid the year 2038 problem, define time_t to a signed
integer with at least 64-bits. The type for time_t can be forced to
long with the --enable-newlib-long-time_t configure option or with the
_USE_LONG_TIME_T system configuration define.
Signed-off-by: Sebastian Huber <sebastian.huber@embedded-brains.de>
Always use the __-decorated form of an attribute name in public
headers, as the bareword form is in the user's namespace, and we
don't want compilation to break just because the user defines the
bareword to mean something else.
Signed-off-by: Eric Blake <eblake@redhat.com>
- pthread_mutex::lock now takes a PLARGE_INTEGER timeout pointer
and uses that in the call to cygwait.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
This is copied from musl (MIT license). This is newer and more thorough
than that of FreeBSD currently shipped only on Cygwin.
Signed-off-by: Yaakov Selkowitz <yselkowi@redhat.com>
struct sigaction is POSIX.1-1990 but siginfo_t, which is used by its
sa_sigaction member, is POSIX.1b-1993. Therefore it needs to be guarded
as well, and as part of a union, the struct size is protected.
Signed-off-by: Yaakov Selkowitz <yselkowi@redhat.com>
There are two common sigpause variants, both of which take an int argument.
If you request _XOPEN_SOURCE or _GNU_SOURCE, you get the System V version,
which removes the given signal from the process's signal mask; otherwise
you get the BSD version, which sets the process's signal mask to the given
value.
Signed-off-by: Yaakov Selkowitz <yselkowi@redhat.com>
v2:
autoload PerfDataHelper functions
Keep loadavg in shared memory
Guard loadavg access by a mutex
Initialize loadavg to the current load
v3:
Shared memory version bump isn't needed if we are only extending it
Remove unused autoload
Mark inititalized flags as NO_COPY for correct behaviour in fork child
Signed-off-by: Jon Turney <jon.turney@dronecode.org.uk>
The locale_t type is provided by <xlocale.h> on Linux, FreeBSD, and Darwin.
While, like on some of those systems, it is automatically included by
<locale.h> with the proper feature test macros, its presence under this
particular name is still presumed in real-world software.
Signed-off-by: Yaakov Selkowitz <yselkowi@redhat.com>
Note that this always returns with dli_sname and dli_saddr set to NULL,
indicating no symbol matching addr could be found.
Signed-off-by: Jon Turney <jon.turney@dronecode.org.uk>
Match glibc behaviour to expose the public bswap_* macros only with an
explicity #include <byteswap.h>; #include'ing <endian.h> should not expose
them.
Signed-off-by: Yaakov Selkowitz <yselkowi@redhat.com>
The termios code doesn't handle erasing of multibyte characters
in canonical mode, it always erases a single byte. When entering
a multibyte character and then pressing VERASE, the input ends up
with an invalid character.
Following Linux we introduce the IUTF8 input flag now, set by
default. When this flag is set, VERASE or VWERASE will check
if the just erased input byte is a UTF-8 continuation byte. If
so, it erases another byte and checks again until the entire
UTF-8 character has been removed from the input buffer.
Note that this (just as on Linux) does NOT work with arbitrary
multibyte codesets. This only works with UTF-8.
For a discussion what happens, see
https://cygwin.com/ml/cygwin/2017-01/msg00299.html
Sidenote: The eat_readahead function is now member of fhandler_termios,
not fhandler_base. That's necessary to get access to the terminal's
termios flags.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Provide <memory.h> for all standard Newlib targets and remove
Cygwin-specific header. Most POSIX like systems provide this historic
header.
Signed-off-by: Sebastian Huber <sebastian.huber@embedded-brains.de>
This makes it possible provide operating system specific types for
<pthread.h>. It is in line with the FreeBSD header file structure and
allows a future cleanup of <pthread.h> to not expose unrelated things
via <sys/types.h> and <unistd.h>. Glibc uses the similar
<bits/pthreadtypes.h> for this purpose.
Signed-off-by: Sebastian Huber <sebastian.huber@embedded-brains.de>
Update the getconf utility to support the new flag as well as
_PC_POSIX_PERMISSIONS and _PC_POSIX_SECURITY. These were previously
unsupported, probably as an oversight.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
This patch adds pthread_getname_np and pthread_setname_np.
These were added to glibc in 2.12[1] and are also present in some form on
NetBSD and several UNIXes.
The code is based on NetBSD's implementation with changes to better match
Linux behaviour.
Implementation quirks:
* pthread_setname_np with a NULL pointer segfaults (as linux)
* pthread_setname_np returns ERANGE for names longer than 16 characters (as
linux)
* pthread_getname_np with a NULL pointer returns EFAULT (as linux)
* pthread_getname_np with a buffer length of less than 16 returns ERANGE (as
linux)
* pthread_getname_np truncates the thread name to fit the buffer length.
This guarantees success even when the default thread name is longer than 16
characters, but means there is no way to discover the actual length of the
thread name. (Linux always truncates the thread name to 16 characters)
* Changing program_invocation_short_name changes the default thread name (on
linux, it has no effect on the default thread name)
I'll leave it up to you to decide if any of these matter.
This is implemented via class pthread_attr to make it easier to add
pthread_attr_[gs]etname_np (present in NetBSD and some UNIXes) should it
ever be added to Linux (or we decide we want it anyway).
[1] https://sourceware.org/git/?p=glibc.git;a=blob;f=NEWS
Change nl_langinfo to nl_langinfo_l using locale given as argument.
Remove outdated TRANSITION_PERIOD_HACK. The codeset is stored in
the locale for quite some time now. For !MB_CAPABLE targets, just
return "US_ASCII" as codeset.
Implement nl_langinfo by calling nl_langinfo_l. Export nl_langinfo_l
from Cygwin DLL and bump minor API version number.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Commit 6f3943b erroneously removed the `#ifdef _COMPILING_NEWLIB'
guarding the __getreent inline function. This patch ignored the
fact that config.h is included when building applications, and the
code in question requires internal, auto-generated headers to be
available which are not exposed to user-space.
Reinstantiate defined(_COMPILING_NEWLIB) test and alternatively
check for defined (__INSIDE_CYGWIN__), otherwise we'd have to
reinstantiate the __getreent macro in cygtls.h which is really
confusing.
While testing it turned out that a low number of source codes inside
Cygwin won't see the inline __getreent due to a missing __INSIDE_CYGWIN__
definition. For malloc.cc this was actually deliberate to get different
definitions from including cygmalloc.h. Change this by defining
__INSIDE_CYGWIN__ in malloc.cc but changing the test in cygmalloc.h
to test for defined(DLMALLOC_VERSION). This might need a change if we
ever get around to replace dlmalloc with a newer, more threading-aware
malloc implementation.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
This partially reverts commit 10a30e7 as far as the Cygwin version of
the __getreent function is concerned. Remove _COMPILING_NEWLIB guard
only allowing to use __getreent inline function when building newlib,
since we wan to use it in Cygwin as well.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Signed-off-by: Stefan Assmann <sassmann@redhat.com>
This reverts commit 4de8596. It worked around a problem which was
actually introduced by patch 10a30e7 a few weeks ago. Rather than
adding special code to the newlib version of __getreent, the followup
patch reinstantiates the original, Cygwin-only implementation of
__getreent.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Signed-off-by: Stefan Assmann <sassmann@redhat.com>
So far the lib function __getreent always returned _impure_ptr. On Cygwin
this is only correct after _impure_ptr got initialized. The inline
function in include/cygwin/config.h always returns the right _reent ptr,
though.
After introducing per-thread locales, the __getreent function is called
prior to initialization of _impure_ptr (from dll_crt0_0) to access the
locale pointer, which leads to a crash.
Fix the __getreent lib function for Cygwin to return the correct _reent
pointer all the time. Rename inline function to __inline_getreent
and introduce a macro __getreent calling the inline function. Change
the lib function __getreent to call __inline_getreent on Cygwin.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Add global const __C_locale for reference purposes.
Bump Cygwin API minor number and DLL major version number to 2.6.0.
Signed-off by: Corinna Vinschen <corinna@vinschen.de>
POSIX requires that SSIZE_MAX have the same type as ssize_t, but
on 32-bit, we were defining it as a long even though ssize_t
resolves to an int. It also requires that SSIZE_MAX be usable
via preprocessor #if, so we can't cheat and use a cast.
If this were newlib, I'd have had to hack _intsup.h to probe the
qualities of size_t (via gcc's __SIZE_TYPE__), similar to how we
already probe the qualities of int8_t and friends, then cross our
fingers that ssize_t happens to have the same rank (most systems
do, but POSIX permits a system where they differ such as size_t
being long while ssize_t is int). Unfortunately gcc gives us
neither __SSIZE_TYPE__ nor __SSIZE_MAX__. On the other hand, our
limits.h is specific to cygwin, so we can just shortcut to the
correct results rather than being generic to all possible ABI.
Signed-off-by: Eric Blake <eblake@redhat.com>