This patch removes conditionals on __ASSUME_O_CLOEXEC, and on
O_CLOEXEC being defined, in sysdeps/unix/sysv/linux/, now that
O_CLOEXEC support can be unconditionally assumed.
The patch is conservative in what it changes and further followup
cleanups may be possible. It may be possible to remove dl-opendir.c,
but the patch does not do so, just removing a redundant undefine and
redefine of __ASSUME_O_CLOEXEC. Also, __ASSUME_O_CLOEXEC is defined
unconditionally for Hurd as well as Linux. Thus, if we decide that
O_CLOEXEC support is a required feature of any glibc port, we could
remove __ASSUME_O_CLOEXEC and all conditionals on it throughout glibc,
rather than just cleaning up sysdeps/unix/sysv/linux/.
Tested x86_64 that the disassembly of installed shared libraries is
unchanged by this patch.
* sysdeps/unix/sysv/linux/dl-opendir.c (__ASSUME_O_CLOEXEC): Do
not undefine and redefine.
* sysdeps/unix/sysv/linux/getsysstats.c (__get_nprocs)
[O_CLOEXEC]: Make code unconditional.
(__get_nprocs) [!O_CLOEXEC]: Remove conditional code.
* sysdeps/unix/sysv/linux/shm_open.c: Do not include
<kernel-features.h>.
[O_CLOEXEC && !__ASSUME_O_CLOEXEC] (have_o_cloexec): Remove
conditional variable definition.
(shm_open) [O_CLOEXEC]: Make code unconditional.
(shm_open) [!O_CLOEXEC || !__ASSUME_O_CLOEXEC]: Remove conditional
code.
This patch removes the __ASSUME_XFS_RESTRICTED_CHOWN macro, now it can
be presumed to be defined unconditionally. I'm not sure if what's
left of __statfs_chown_restricted is actually useful (if not, a
followup could remove it), but I left it there to keep the patch
conservative and avoid changing the code generated for glibc.
Tested x86_64 that the disassembly of installed shared libraries is
unchanged by the patch.
* sysdeps/unix/sysv/linux/kernel-features.h
(__ASSUME_XFS_RESTRICTED_CHOWN): Remove macro.
* sysdeps/unix/sysv/linux/pathconf.c (__statfs_chown_restricted)
[__ASSUME_XFS_RESTRICTED_CHOWN]: Make code unconditional.
(__statfs_chown_restricted) [!__ASSUME_XFS_RESTRICTED_CHOWN]:
Remove conditional code.
Add support for the new HWCAP2 values for ARMv8 added in the
3.15 kernel. Tested using QEMU which supports these extensions.
ChangeLog:
2014-06-25 Will Newton <will.newton@linaro.org>
* sysdeps/unix/sysv/linux/arm/dl-procinfo.c
(_dl_arm_cap_flags): Add HWCAP2 values.
* sysdeps/unix/sysv/linux/arm/dl-procinfo.h
(_DL_HWCAP_COUNT): Increase to 37.
(_DL_HWCAP_LAST): New define.
(_DL_HWCAP2_LAST): New define.
(_dl_procinfo): Add support for printing
AT_HWCAP2 entries.
(_dl_string_hwcap): Use _dl_hwcap_string.
This patch removes the __ASSUME_UTIMENSAT macro, now it can be
unconditionally assumed to be true.
This shows that the only live uses of __ASSUME_UTIMES are in utimes.c
and they are only live for hppa. I intend a followup patch to make
__ASSUME_UTIMES into an hppa-specific macro (not used or defined
outside sysdeps/unix/sysv/linux/hppa/).
Tested x86_64 that the disassembly of installed shared libraries is
unchanged by this patch.
* sysdeps/unix/sysv/linux/kernel-features.h (__ASSUME_UTIMENSAT):
Remove macro.
* sysdeps/unix/sysv/linux/futimes.c: Do not include
<kernel-features.h>.
[__NR_utimensat && !__ASSUME_UTIMENSAT] (miss_utimensat): Remove
conditional variable definition.
(__futimes): Update comment.
(__futimes) [__ASSUME_UTIMENSAT]: Make code unconditional.
(__futimes) [!__ASSUME_UTIMENSAT]: Remove conditional code.
This patch removes the __ASSUME_COMPLETE_READV_WRITEV
kernel-features.h macro, now that it can be unconditionally assumed to
be true. (The relevant kernel feature was added some time between 2.0
and 2.2, and this macro is only used in sysdeps/unix/sysv/linux/.)
Tested x86_64 that the disassembly of installed shared libraries is
unchanged by this patch.
* sysdeps/unix/sysv/linux/kernel-features.h
(__ASSUME_COMPLETE_READV_WRITEV): Remove macro.
* sysdeps/unix/sysv/linux/readv.c: Do not include
<kernel-features.h>.
[!__ASSUME_COMPLETE_READV_WRITEV]: Remove conditional code.
[!UIO_FASTIOV] (UIO_FASTIOV): Remove macro.
(__libc_readv) [__ASSUME_COMPLETE_READV_WRITEV]: Make code
unconditional.
(__libc_readv) [!__ASSUME_COMPLETE_READV_WRITEV]: Remove
conditional code.
* sysdeps/unix/sysv/linux/writev.c: Do not include
<kernel-features.h>.
[!__ASSUME_COMPLETE_READV_WRITEV]: Remove conditional code.
[!UIO_FASTIOV] (UIO_FASTIOV): Remove macro.
(__libc_writev) [__ASSUME_COMPLETE_READV_WRITEV]: Make code
unconditional.
(__libc_writev) [!__ASSUME_COMPLETE_READV_WRITEV]: Remove
conditional code.
Continuing the process of making non-ex-ports architectures follow the
preferred sysdeps practices followed by ex-ports architectures - that
is, putting things in architecture-specific sysdeps files rather than
having architecture-specific cases in architecture-independent files -
this patch moves architecture cases out of
sysdeps/unix/sysv/linux/configure.ac into (new or existing) configure
fragments for each architecture. (In the case of the
arch_minimum_kernel setting for x32,
sysdeps/unix/sysv/linux/x86_64/x32/configure already has such a
setting so the setting in sysdeps/unix/sysv/linux/configure.ac was a
duplicate that could just be removed - though I haven't tested for
x32.)
Tested for x86_64 and x86 that the patch causes no changes to the
installed shared libraries or ldd (or any part of the installation
except for the parts that always change because the files contain
timestamps - nscd and static libraries).
* sysdeps/unix/sysv/linux/configure.ac: Remove cases for
individual architectures.
* sysdeps/unix/sysv/linux/configure: Regenerated.
* sysdeps/unix/sysv/linux/i386/configure.ac: New file.
* sysdeps/unix/sysv/linux/i386/configure: New generated file.
* sysdeps/unix/sysv/linux/powerpc/configure.ac
(ldd_rewrite_script): Define variable.
* sysdeps/unix/sysv/linux/powerpc/configure: Regenerated.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/configure.ac: New
file.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/configure: New
generated file.
* sysdeps/unix/sysv/linux/s390/configure.ac: New file.
* sysdeps/unix/sysv/linux/s390/configure: New generated file.
* sysdeps/unix/sysv/linux/sh/configure.ac: New file.
* sysdeps/unix/sysv/linux/sh/configure: New generated file.
* sysdeps/unix/sysv/linux/sparc/configure.ac: New file.
* sysdeps/unix/sysv/linux/sparc/configure: New generated file.
* sysdeps/unix/sysv/linux/x86_64/configure.ac: New file.
* sysdeps/unix/sysv/linux/x86_64/configure: New generated file.
This patch updates glibc headers for changes / new definitions in
Linux 3.15. In the course of my review I noticed that
IPV6_PMTUDISC_INTERFACE was absent from glibc despite the inclusion of
IP_PMTUDISC_INTERFACE; I added it along with IP_PMTUDISC_OMIT and
IPV6_PMTUDISC_OMIT. I did not add FALLOC_FL_NO_HIDE_STALE given the
kernel header comment that it is reserved.
Tested x86_64.
* sysdeps/unix/sysv/linux/bits/fcntl-linux.h [__USE_GNU]
(FALLOC_FL_COLLAPSE_RANGE): New macro.
[__USE_GNU] (FALLOC_FL_ZERO_RANGE): Likewise.
* sysdeps/unix/sysv/linux/bits/in.h (IP_PMTUDISC_OMIT): Likewise.
(IPV6_PMTUDISC_INTERFACE): Likewise.
(IPV6_PMTUDISC_OMIT): Likewise.
This patch removes ARM __ASSUME_SIGFRAME_V2 now that the
2.6.18-and-later signal frame layout can be assumed, renaming the
affected functions accordingly now only one version of them is needed
in glibc. (sigrestorer.S did not in fact include <kernel-features.h>
and it appears that, unlike other such cases, it didn't get the header
indirectly, so the v1 functions would have been compiled in even when
sigaction.c didn't reference them.)
(alpha and hppa also have architecture-specific __ASSUME_* macros that
should now be removed: __ASSUME_FDATASYNC and __ASSUME_LWS_CAS
respectively. I don't have any plans to do anything on that myself.)
Tested on ARM.
* sysdeps/unix/sysv/linux/arm/kernel-features.h
(__ASSUME_SIGFRAME_V2): Remove macro.
* sysdeps/unix/sysv/linux/arm/sigrestorer.S: Update comment.
[!__ASSUME_SIGFRAME_V2]: Remove conditional code.
(__default_sa_restorer_v2): Rename to __default_sa_restorer.
(__default_rt_sa_restorer_v2): Rename to __default_rt_sa_restorer.
* sysdeps/unix/sysv/linux/arm/sigaction.c (__default_sa_restorer):
Declare as function. Remove conditional macro definitions.
(__default_rt_sa_restorer): Likewise.
(__default_sa_restorer_v1): Remove declaration.
(__default_sa_restorer_v2): Likewise.
(__default_rt_sa_restorer_v1): Likewise.
(__default_rt_sa_restorer_v2): Likewise.
* sysdeps/unix/sysv/linux/arm/Versions (GLIBC_PRIVATE): Remove
__default_sa_restorer_v1, __default_rt_sa_restorer_v1,
__default_sa_restorer_v2 and __default_rt_sa_restorer_v2.
This patch removes conditionals on __ASSUME_SOCK_CLOEXEC, and on
SOCK_CLOEXEC being defined, in Linux-specific code, now that all
supported Linux kernel versions can be assumed to have this
functionality. (The macro is also used in OS-independent code and is
not defined for Hurd.)
Tested x86_64 that the disassembly of installed shared libraries is
unchanged by this patch.
* nptl/sysdeps/unix/sysv/linux/mq_notify.c: Do not include
<kernel-features.h>.
(init_mq_netlink): Remove conditional have_sock_cloexec
definitions. Remove code conditional on have_sock_cloexec < 0.
(init_mq_netlink) [!SOCK_CLOEXEC]: Remove conditional code.
(init_mq_netlink) [!__ASSUME_SOCK_CLOEXEC]: Likewise.
* sysdeps/unix/sysv/linux/opensock.c: Do not include
<kernel-features.h>.
(__opensock) [SOCK_CLOEXEC]: Make code unconditional.
(__opensock) [!__ASSUME_SOCK_CLOEXEC]: Remove conditional code.
This patch removes __ASSUME_F_GETOWN_EX now it can be assumed to be
true unconditionally.
Tested x86_64 that disassembly of installed shared libraries is
unchanged by this patch.
* sysdeps/unix/sysv/linux/kernel-features.h
(__ASSUME_F_GETOWN_EX): Remove macro.
* sysdeps/unix/sysv/linux/fcntl.c: Do not include
<kernel-features.h>.
(miss_F_GETOWN_EX): Remove variable or macro.
(do_fcntl): Do not check miss_F_GETOWN_EX.
(do_fcntl) [!__ASSUME_F_GETOWN_EX]: Remove conditional code.
This patch removes __ASSUME_AT_RANDOM now it can be assumed to be true
unconditionally.
Tested x86_64 that the disassembly of installed shared libraries is
unchanged by this patch.
* sysdeps/unix/sysv/linux/kernel-features.h (__ASSUME_AT_RANDOM):
Remove macro.
* sysdeps/unix/sysv/linux/dl-osinfo.h (_dl_setup_stack_chk_guard)
[!__ASSUME_AT_RANDOM]: Remove conditional code.
(_dl_setup_pointer_guard) [!__ASSUME_AT_RANDOM]: Likewise.
This patch removes the __ASSUME_ADJ_OFFSET_SS_READ macro (and
conditionals on whether ADJ_OFFSET_SS_READ is defined), now it can be
unconditionally assumed to be true and ADJ_OFFSET_SS_READ can be
assumed to be defined.
Tested x86_64 that the disassembly of installed shared libraries is
unchanged by this patch.
* sysdeps/unix/sysv/linux/kernel-features.h
(__ASSUME_ADJ_OFFSET_SS_READ): Remove macro.
* sysdeps/unix/sysv/linux/adjtime.c (ADJTIME)
[ADJ_OFFSET_SS_READ]: Make code unconditional.
(ADJTIME) [!ADJ_OFFSET_SS_READ]: Remove conditional code.
This patch cleans up for __ASSUME_ATFCTS now always being true for the
supported Linux kernel versions by removing conditional code in
sysdeps/unix/sysv/linux. Several fchownat.c files that were only
present because of differences in the fallback syscalls used
(depending on the architecture-specific names of chown-related
syscalls for 32-bit uids) are removed. Files that looks like they
could be replaced by syscalls.list entries have the standard "Consider
moving to syscalls.list." comment (see bug 14138) added. Conditionals
on the relevant __NR_* syscall numbers being defined are also removed,
since my analysis indicated that the relevant syscalls are always
defined for all relevant kernel versions using any affected file.
Much of the removed fallback code had unbounded stack allocations, so
this reduces the number of cases to consider for anyone reviewing uses
of alloca and VLAs in glibc.
There remain tests of __ASSUME_ATFCTS in io/openat.c (to determine
whether to define __have_atfcts) and sysdeps/posix/getcwd.c (which
also uses __have_atfcts); thus, the definition of __ASSUME_ATFCTS
remains in kernel-features.h. The logical condition relevant there is
whether openat64_not_cancel_3 is known to work. Hurd doesn't use this
version of getcwd at all, so the conditionals in getcwd.c are always
true in glibc. However, this code is also used in gnulib. So the
best way to deal with the conditionals there may be for gnulib people
to deal with merging all relevant changes in both directions between
the glibc and gnulib versions of this file, at the end of which the
openat conditionals should be in whatever form is best for gnulib, and
hardcoded in the _LIBC case to having openat supported.
Tested by comparing before-and-after disassembly of installed
(stripped) shared libraries, on x86_64 and x86. On x86 the patch made
no change to the disassembly; on x86_64, the only changes were in
readlinkat, where formerly the return value from the readlinkat
syscall was stored in an int variable before being converted to
ssize_t for the return, and now the return value is returned directly
without truncation to int. I think it's clearly correct not to
truncate the return value (although I also think the truncation would
not have been a user-visible bug because the kernel would never have
returned a value it could have affected).
* include/fcntl.h (__atfct_seterrno): Remove prototype.
(__atfct_seterrno_2): Likewise.
* sysdeps/unix/sysv/linux/alpha/dl-fxstatat64.c: Do not include
<kernel-features.h>.
(__ASSUME_ATFCTS): Do not undefine and redefine.
* sysdeps/unix/sysv/linux/alpha/fxstatat.c [__ASSUME_ATFCTS]
(__have_atfcts): Remove conditional definition.
(__fxstatat([__NR_fstatat64]: Make code unconditional.
(__fxstatat) [!__ASSUME_ATFCTS]: Remove conditional code and code
unreachable if [__ASSUME_ATFCTS].
* sysdeps/unix/sysv/linux/dl-fxstatat64.c (__ASSUME_ATFCTS): Do
not undefine and redefine.
* sysdeps/unix/sysv/linux/faccessat.c: Do not include
<kernel-features.h>.
(faccessat) [__NR_faccessat]: Make code unconditional.
(faccessat) [!__ASSUME_ATFCTS]: Remove conditional code.
* sysdeps/unix/sysv/linux/fchmodat.c: Do not include
<kernel-features.h>.
(fchmodat) [__NR_fchmodat]: Make code unconditional.
(fchmodat) [!__ASSUME_ATFCTS]: Remove conditional code.
* sysdeps/unix/sysv/linux/fchownat.c: Do not include
<kernel-features.h>.
(fchownat) [__NR_fchownat]: Make code unconditional.
(fchownat) [!__ASSUME_ATFCTS]: Remove conditional code.
* sysdeps/unix/sysv/linux/futimesat.c: Do not include
<kernel-features.h>.
(futimesat) [__NR_futimesat]: Make code unconditional.
(futimesat) [!__ASSUME_ATFCTS]: Remove conditional code.
* sysdeps/unix/sysv/linux/fxstatat.c: Do not include
<kernel-features.h>.
(__fxstatat) [__NR_newfstatat]: Make code unconditional.
(__fxstatat) [!__ASSUME_ATFCTS]: Remove conditional code.
* sysdeps/unix/sysv/linux/fxstatat64.c: Do not include
<kernel-features.h>.
(__fxstatat64) [__NR_fstatat64]: Make code unconditional.
(__fxstatat64) [!__ASSUME_ATFCTS]: Remove conditional code.
* sysdeps/unix/sysv/linux/i386/fchownat.c: Remove file.
* sysdeps/unix/sysv/linux/i386/fxstatat.c: Do not include
<kernel-features.h>.
(__fxstatat) [__NR_fstatat64]: Make code unconditional.
(__fxstatat) [!__ASSUME_ATFCTS]: Remove conditional code.
* sysdeps/unix/sysv/linux/linkat.c: Do not include
<kernel-features.h>.
(linkat) [__NR_linkat]: Make code unconditional.
(linkat) [!__ASSUME_ATFCTS]: Remove conditional code.
* sysdeps/unix/sysv/linux/m68k/fchownat.c: Remove file.
* sysdeps/unix/sysv/linux/mips/mips64/fxstatat64.c: Do not include
<kernel-features.h>.
(__fxstatat64) [__NR_newfstatat]: Make code unconditional.
(__fxstatat64) [!__ASSUME_ATFCTS]: Remove conditional code.
* sysdeps/unix/sysv/linux/mkdirat.c: Do not include
<kernel-features.h>.
(mkdirat) [__NR_mkdirat]: Make code unconditional.
(mkdirat) [!__ASSUME_ATFCTS]: Remove conditional code.
* sysdeps/unix/sysv/linux/openat.c: Do not include
<kernel-features.h>.
[!__ASSUME_ATFCTS] (__atfct_seterrno): Remove function.
[!__ASSUME_ATFCTS] (__have_atfcts): Remove variable.
(OPENAT_NOT_CANCEL) [__NR_openat]: Make code unconditional.
(OPENAT_NOT_CANCEL) [!__ASSUME_ATFCTS]: Remove conditional code.
* sysdeps/unix/sysv/linux/powerpc/fchownat.c: Remove file.
* sysdeps/unix/sysv/linux/readlinkat.c: Do not include
<kernel-features.h>.
(readlinkat) [__NR_readlinkat]: Make code unconditional.
(readlinkat) [!__ASSUME_ATFCTS]: Remove conditional code. Return
result of INLINE_SYSCALL directly, not via int variable.
* sysdeps/unix/sysv/linux/renameat.c: Do not include
<kernel-features.h>.
[!__ASSUME_ATFCTS] (__atfct_seterrno_2): Remove function.
(renameat) [__NR_renameat]: Make code unconditional.
(renameat) [!__ASSUME_ATFCTS]: Remove conditional code.
* sysdeps/unix/sysv/linux/s390/s390-32/fchownat.c: Remove file.
* sysdeps/unix/sysv/linux/sh/fchownat.c: Remove file.
* sysdeps/unix/sysv/linux/sparc/sparc32/fchownat.c: Remove file.
* sysdeps/unix/sysv/linux/sparc/sparc64/dl-fxstatat64.c
(__ASSUME_ATFCTS): Do not undefine and redefine.
* sysdeps/unix/sysv/linux/symlinkat.c: Do not include
<kernel-features.h>.
(symlinkat) [__NR_symlinkat]: Make code unconditional.
(symlinkat) [!__ASSUME_ATFCTS]: Remove conditional code.
* sysdeps/unix/sysv/linux/unlinkat.c: Do not include
<kernel-features.h>.
(unlinkat) [__NR_unlinkat]: Make code unconditional.
(unlinkat) [!__ASSUME_ATFCTS]: Remove conditional code.
* sysdeps/unix/sysv/linux/wordsize-64/dl-fxstatat64.c
(__ASSUME_ATFCTS): Do not undefine and redefine.
* sysdeps/unix/sysv/linux/wordsize-64/fxstatat.c: Do not include
<kernel-features.h>.
(__fxstatat) [__NR_newfstatat]: Make code unconditional.
(__fxstatat) [!__ASSUME_ATFCTS]: Remove conditional code.
* sysdeps/unix/sysv/linux/xmknodat.c: Do not include
<kernel-features.h>.
(__xmknodat) [__NR_mknodat]: Make code unconditional.
(__xmknodat) [!__ASSUME_ATFCTS]: Remove conditional code.
With the recent tuning the C version of rwlocks is basically the same
performance as the x86 assembler version for uncontended locks (with a
a few cycles near the run-to-run variability). For others it should not
matter anyways.
So remove the assembler code and use the C version like other
architectures.
This patch relies on the C version of the rwlocks posted earlier.
With C rwlocks it is very straight forward to do adaptive elision
using TSX. It is based on the infrastructure added earlier
for mutexes, but uses its own elision macros. The macros
are fairly general purpose and could be used for other
elision purposes too.
This version is much cleaner than the earlier assembler based
version, and in particular implements adaptation which makes
it safer.
I changed the behavior slightly to not require any changes
in the test suite and fully conform to all expected
behaviors (generally at the cost of not eliding in
various situations). In particular this means the timedlock
variants are not elided. Nested trylock aborts.
The implementation of __get_nprocs uses a stactic variable to cache
the value of the current number of processors. The caching breaks when
'time (NULL) == 0':
$ cat nproc.c
#include <stdio.h>
#include <time.h>
#include <sys/time.h>
int main(int argc, char *argv[])
{
time_t t;
struct timeval tv = {0, 0};
printf("settimeofday({0, 0}, NULL) = %d\n", settimeofday(&tv, NULL));
t = time(NULL);
printf("Time: %d, CPUs: %d\n", (unsigned int)t, get_nprocs());
return 0;
}
$ gcc -O3 nproc.c
$ ./a.out
settimeofday({0, 0}, NULL) = -1
Time: 1401311578, CPUs: 4
$ sudo ./a.out
settimeofday({0, 0}, NULL) = 0
Time: 0, CPUs: 0
The problem is with the condition used to check whether a cached
value should be returned or not:
static int cached_result;
static time_t timestamp;
time_t now = time (NULL);
time_t prev = timestamp;
atomic_read_barrier ();
if (now == prev)
return cached_result;
This patch fixes the problem by ensuring that 'cached_result' has
been set at least once before returning it.
The hppa port has no need of a custom lowlevellock.c, it should
use the generic version which is updated and correct. This
similarly fixes bug 15119 for hppa.
