Reduce kernel-features.h duplication.

This patch reduces duplication between different architectures'
kernel-features.h files by making the architecture-independent file
define various macros unconditionally (instead of only for a
particular list of architectures), with the architecture-specific
files then undefining the macros if necessary.

Specifically, __ASSUME_O_CLOEXEC (O_CLOEXEC flag to open) and
__ASSUME_SOCK_CLOEXEC (SOCK_NONBLOCK and SOCK_CLOEXEC flags to socket)
are supported on all architectures as of 2.6.32 or the minimum kernel
version for the architecture if later.  For __ASSUME_IN_NONBLOCK,
__ASSUME_PIPE2, __ASSUME_EVENTFD2, __ASSUME_SIGNALFD4 and
__ASSUME_DUP3, the relevant syscalls were added for alpha in 2.6.33
but otherwise the features are available as of 2.6.32.  For
__ASSUME_UTIMES, support is everywhere in 2.6.32 except for
asm-generic architectures and hppa.

Although those were the main cases of duplication among
kernel-features.h files, some other cases of unnecessary definitions
were also cleaned up: the hppa file defined various macros that were
either no longer used at all, or defined by the main file by default
anyway, the ia64 file had duplicative definitions of __ASSUME_PSELECT
and __ASSUME_PPOLL, while mips had such a definition of
__ASSUME_IPC64.

Really, rather than being defined in the main file then undefined for
asm-generic architectures, __ASSUME_UTIMES should become an
hppa-specific macro.  Given that __ASSUME_ATFCTS and
__ASSUME_UTIMENSAT are now always true, the only live __ASSUME_UTIMES
conditional is in sysdeps/unix/sysv/linux/utimes.c, which is not used
for asm-generic architectures.  I think the desired state would be an
hppa-specific file (that includes sysdeps/unix/sysv/linux/utimes.c if
__ASSUME_UTIMES, and otherwise has fallback code), with the fallback
code being removed from the main utimes.c.  But I think that's most
reasonably a separate cleanup once __ASSUME_ATFCTS and
__ASSUME_UTIMESAT have both had conditional code cleaned up.

Given this patch, I think it's straightforward to move non-ex-ports
architectures to having their own kernel-features.h files, like
ex-ports architectures, rather than conditionals in the main file
(i.e., such a move won't require the architecture-specific file to
contain anything that isn't genuinely architecture-specific), and
would encourage architecture maintainers to do so.

Tested x86_64 that the installed shared libraries are unchanged by
this patch.  Note that on some architectures this *will* cause
__ASSUME_* macros to be defined in cases where they weren't previously
but should have been (but this is just optimization, not a fix to a
user-visible bug, so doesn't need a bug report in Bugzilla).

	* sysdeps/unix/sysv/linux/kernel-features.h (__ASSUME_UTIMES):
	Define unconditionally.
	(__ASSUME_O_CLOEXEC): Likewise.
	(__ASSUME_SOCK_CLOEXEC): Likewise.
	(__ASSUME_IN_NONBLOCK): Likewise.
	(__ASSUME_PIPE2): Likewise.
	(__ASSUME_EVENTFD2): Likewise.
	(__ASSUME_SIGNALFD4): Likewise.
	(__ASSUME_DUP3): Likewise.
	* sysdeps/unix/sysv/linux/aarch64/kernel-features.h
	(__ASSUME_DUP3): Do not define.
	(__ASSUME_EVENTFD2): Likewise.
	(__ASSUME_IN_NONBLOCK): Likewise.
	(__ASSUME_O_CLOEXEC): Likewise.
	(__ASSUME_PIPE2): Likewise.
	(__ASSUME_SIGNALFD4): Likewise.
	(__ASSUME_SOCK_CLOEXEC): Likewise.
	(__ASSUME_UTIMES): Undefine.
	* sysdeps/unix/sysv/linux/alpha/kernel-features.h
	(__ASSUME_UTIMES): Do not define.
	(__ASSUME_O_CLOEXEC): Likewise.
	(__ASSUME_SOCK_CLOEXEC): Likewise.
	(__ASSUME_IN_NONBLOCK): Undefine if [__LINUX_KERNEL_VERSION <
	0x020621] instead of defining if [__LINUX_KERNEL_VERSION >=
	0x020621].
	(__ASSUME_PIPE2): Likewise.
	(__ASSUME_EVENTFD2): Likewise.
	(__ASSUME_SIGNALFD4): Likewise.
	[__LINUX_KERNEL_VERSION < 0x020621] (__ASSUME_DUP3): Undefine.
	* sysdeps/unix/sysv/linux/arm/kernel-features.h (__ASSUME_UTIMES):
	Do not define.
	(__ASSUME_EVENTFD2): Likewise.
	(__ASSUME_SIGNALFD4): Likewise.
	* sysdeps/unix/sysv/linux/hppa/kernel-features.h
	(__ASSUME_32BITUIDS): Likewise.
	(__ASSUME_TRUNCATE64_SYSCALL): Likewise.
	(__ASSUME_IPC64): Likewise.
	(__ASSUME_ST_INO_64_BIT): Likewise.
	(__ASSUME_GETDENTS64_SYSCALL): Likewise.
	[__LINUX_KERNEL_VERSION < 0x030e00] (__ASSUME_UTIMES): Undefine.
	* sysdeps/unix/sysv/linux/ia64/kernel-features.h
	(__ASSUME_UTIMES): Do not define.
	(__ASSUME_PSELECT): Likewise.
	(__ASSUME_PPOLL): Likewise.
	(__ASSUME_O_CLOEXEC): Likewise.
	(__ASSUME_SOCK_CLOEXEC): Likewise.
	(__ASSUME_IN_NONBLOCK): Likewise.
	(__ASSUME_PIPE2): Likewise.
	(__ASSUME_EVENTFD2): Likewise.
	(__ASSUME_SIGNALFD4): Likewise.
	(__ASSUME_DUP3): Likewise.
	* sysdeps/unix/sysv/linux/m68k/kernel-features.h
	(__ASSUME_UTIMES): Likewise.
	(__ASSUME_O_CLOEXEC): Likewise.
	(__ASSUME_SOCK_CLOEXEC): Likewise.
	(__ASSUME_IN_NONBLOCK): Likewise.
	(__ASSUME_PIPE2): Likewise.
	(__ASSUME_EVENTFD2): Likewise.
	(__ASSUME_SIGNALFD4): Likewise.
	(__ASSUME_DUP3): Likewise.
	* sysdeps/unix/sysv/linux/microblaze/kernel-features.h
	(__ASSUME_UTIMES): Likewise.
	(__ASSUME_O_CLOEXEC): Likewise.
	(__ASSUME_SOCK_CLOEXEC): Likewise.
	(__ASSUME_IN_NONBLOCK): Likewise.
	(__ASSUME_PIPE2): Likewise.
	(__ASSUME_EVENTFD2): Likewise.
	(__ASSUME_SIGNALFD4): Likewise.
	(__ASSUME_DUP3): Likewise.
	* sysdeps/unix/sysv/linux/mips/kernel-features.h (__ASSUME_IPC64):
	Likewise.
	(__ASSUME_UTIMES): Likewise.
	(__ASSUME_EVENTFD2): Likewise.
	(__ASSUME_SIGNALFD4): Likewise.
	* sysdeps/unix/sysv/linux/tile/kernel-features.h
	(__ASSUME_O_CLOEXEC): Likewise.
	(__ASSUME_SOCK_CLOEXEC): Likewise.
	(__ASSUME_IN_NONBLOCK): Likewise.
	(__ASSUME_PIPE2): Likewise.
	(__ASSUME_EVENTFD2): Likewise.
	(__ASSUME_SIGNALFD4): Likewise.
	(__ASSUME_DUP3): Likewise.
	(__ASSUME_UTIMES): Undefine.

10 files changed, 29 insertions, 129 deletions

diff --git a/sysdeps/unix/sysv/linux/aarch64/kernel-features.h b/sysdeps/unix/sysv/linux/aarch64/kernel-features.h
index 53039f9316..bd94fe1c79 100644
--- a/sysdeps/unix/sysv/linux/aarch64/kernel-features.h
+++ b/sysdeps/unix/sysv/linux/aarch64/kernel-features.h
@@ -25,14 +25,10 @@
    features.  */
 
 #define __ASSUME_ACCEPT4_SYSCALL        1
-#define __ASSUME_DUP3                   1
-#define __ASSUME_EVENTFD2		1
-#define __ASSUME_IN_NONBLOCK            1
-#define __ASSUME_O_CLOEXEC              1
-#define __ASSUME_PIPE2                  1
 #define __ASSUME_RECVMMSG_SYSCALL       1
 #define __ASSUME_SENDMMSG_SYSCALL       1
-#define __ASSUME_SIGNALFD4		1
-#define __ASSUME_SOCK_CLOEXEC           1
 
 #include_next <kernel-features.h>
+
+/* asm-generic architectures do not have the utimes syscall.  */
+#undef __ASSUME_UTIMES
diff --git a/sysdeps/unix/sysv/linux/alpha/kernel-features.h b/sysdeps/unix/sysv/linux/alpha/kernel-features.h
index 2e3fc7da39..bea70577f4 100644
--- a/sysdeps/unix/sysv/linux/alpha/kernel-features.h
+++ b/sysdeps/unix/sysv/linux/alpha/kernel-features.h
@@ -20,26 +20,6 @@
 #ifndef _KERNEL_FEATURES_H
 #define _KERNEL_FEATURES_H 1
 
-#define __ASSUME_UTIMES	1
-
-/* Support for the O_CLOEXEC flag was added for alpha in 2.6.23.  */
-#define __ASSUME_O_CLOEXEC    1
-
-/* Support for various CLOEXEC and NONBLOCK flags was added for alpha after
-   2.6.33-rc1.  */
-#if __LINUX_KERNEL_VERSION >= 0x020621
-# define __ASSUME_SOCK_CLOEXEC  1
-# define __ASSUME_IN_NONBLOCK   1
-#endif
-
-/* Support for the pipe2, eventfd2, signalfd4 syscalls was added for alpha
-   after 2.6.33-rc1.  */
-#if __LINUX_KERNEL_VERSION >= 0x020621
-# define __ASSUME_PIPE2     1
-# define __ASSUME_EVENTFD2  1
-# define __ASSUME_SIGNALFD4 1
-#endif
-
 /* Support for recvmmsg was added for alpha in 2.6.33.  */
 #if __LINUX_KERNEL_VERSION >= 0x020621
 # define __ASSUME_RECVMMSG_SYSCALL       1
@@ -67,10 +47,15 @@
 /* Support for fsyncdata was added for alpha after 2.6.21.  */
 #define __ASSUME_FDATASYNC	1
 
-/* Support for preadv and pwritev was added for alpha in 2.6.33.  */
+/* Support for various syscalls was added for alpha in 2.6.33.  */
 #if __LINUX_KERNEL_VERSION < 0x020621
 # undef __ASSUME_PREADV
 # undef __ASSUME_PWRITEV
+# undef __ASSUME_IN_NONBLOCK
+# undef __ASSUME_PIPE2
+# undef __ASSUME_EVENTFD2
+# undef __ASSUME_SIGNALFD4
+# undef __ASSUME_DUP3
 #endif
 
 #endif /* _KERNEL_FEATURES_H */
diff --git a/sysdeps/unix/sysv/linux/arm/kernel-features.h b/sysdeps/unix/sysv/linux/arm/kernel-features.h
index ce0f03ed89..354f2ca2d2 100644
--- a/sysdeps/unix/sysv/linux/arm/kernel-features.h
+++ b/sysdeps/unix/sysv/linux/arm/kernel-features.h
@@ -17,16 +17,9 @@
    License along with the GNU C Library.  If not, see
    <http://www.gnu.org/licenses/>.  */
 
-/* The utimes syscall was added before 2.6.1.  */
-#define __ASSUME_UTIMES	1
-
 /* The signal frame layout changed in 2.6.18.  */
 #define __ASSUME_SIGFRAME_V2	1
 
-/* Support for the eventfd2 and signalfd4 syscalls was added in 2.6.27.  */
-#define __ASSUME_EVENTFD2	1
-#define __ASSUME_SIGNALFD4	1
-
 /* Support for the recvmmsg syscall was added in 2.6.33.  */
 #if __LINUX_KERNEL_VERSION >= 0x020621
 # define __ASSUME_RECVMMSG_SYSCALL	1
diff --git a/sysdeps/unix/sysv/linux/hppa/kernel-features.h b/sysdeps/unix/sysv/linux/hppa/kernel-features.h
index e869c14bdd..25c3e36600 100644
--- a/sysdeps/unix/sysv/linux/hppa/kernel-features.h
+++ b/sysdeps/unix/sysv/linux/hppa/kernel-features.h
@@ -18,15 +18,6 @@
    <http://www.gnu.org/licenses/>.  */
 
 
-/* There are an infinite number of PA-RISC kernel versions numbered
-   2.4.0.  But they've not really been released as such.  We require
-   and expect the final version here.  */
-#define __ASSUME_32BITUIDS		1
-#define __ASSUME_TRUNCATE64_SYSCALL	1
-#define __ASSUME_IPC64			1
-#define __ASSUME_ST_INO_64_BIT		1
-#define __ASSUME_GETDENTS64_SYSCALL	1
-
 /* PA-RISC 2.6.9 kernels had the first LWS CAS support */
 #define __ASSUME_LWS_CAS		1
 
@@ -42,3 +33,8 @@
 #endif
 
 #include_next <kernel-features.h>
+
+/* hppa did not get the utimes syscall until 3.14.  */
+#if __LINUX_KERNEL_VERSION < 0x030e00
+# undef __ASSUME_UTIMES
+#endif
diff --git a/sysdeps/unix/sysv/linux/ia64/kernel-features.h b/sysdeps/unix/sysv/linux/ia64/kernel-features.h
index 471fb88a71..c32789bcc6 100644
--- a/sysdeps/unix/sysv/linux/ia64/kernel-features.h
+++ b/sysdeps/unix/sysv/linux/ia64/kernel-features.h
@@ -20,25 +20,6 @@
 #ifndef _KERNEL_FEATURES_H
 #define _KERNEL_FEATURES_H 1
 
-/* The utimes syscall has been available for some architectures
-   forever.  */
-#define __ASSUME_UTIMES	1
-
-/* pselect/ppoll were introduced just after 2.6.16-rc1.  */
-#define __ASSUME_PSELECT	1
-#define __ASSUME_PPOLL		1
-
-/* Support for various CLOEXEC and NONBLOCK flags was added in 2.6.23.  */
-#define __ASSUME_O_CLOEXEC	1
-
-/* Support for various CLOEXEC and NONBLOCK flags was added in 2.6.27.  */
-#define __ASSUME_SOCK_CLOEXEC	1
-#define __ASSUME_IN_NONBLOCK	1
-#define __ASSUME_PIPE2		1
-#define __ASSUME_EVENTFD2	1
-#define __ASSUME_SIGNALFD4	1
-#define __ASSUME_DUP3		1
-
 /* Support for the recvmmsg syscall was added in 2.6.33.  */
 #if __LINUX_KERNEL_VERSION >= 0x020621
 # define __ASSUME_RECVMMSG_SYSCALL	1
diff --git a/sysdeps/unix/sysv/linux/kernel-features.h b/sysdeps/unix/sysv/linux/kernel-features.h
index 46e16f6e82..026f89fbc5 100644
--- a/sysdeps/unix/sysv/linux/kernel-features.h
+++ b/sysdeps/unix/sysv/linux/kernel-features.h
@@ -76,14 +76,7 @@
    forever.  For x86 it was introduced after 2.5.75, for x86-64,
    ppc, and ppc64 it was introduced in 2.6.0-test3, for s390 it was
    introduced in 2.6.21-rc5.  */
-#if defined __sparc__ \
-    || defined __i386__ \
-    || defined __x86_64__ \
-    || defined __powerpc__ \
-    || defined __sh__ \
-    || defined __s390__
-# define __ASSUME_UTIMES	1
-#endif
+#define __ASSUME_UTIMES	1
 
 /* pselect/ppoll were introduced just after 2.6.16-rc1.  On x86_64 and
    SH this appeared first in 2.6.19-rc1, on ia64 in 2.6.22-rc1.  */
@@ -123,27 +116,21 @@
    only after 2.6.23-rc1.  */
 #define __ASSUME_FALLOCATE	1
 
-/* Support for various CLOEXEC and NONBLOCK flags was added for x86,
-   x86-64, PPC, IA-64, SPARC< and S390 in 2.6.23.  */
-#if (defined __i386__ || defined __x86_64__ || defined __powerpc__ \
-     || defined __sparc__ || defined __s390__)
-# define __ASSUME_O_CLOEXEC	1
-#endif
+/* Support for various CLOEXEC and NONBLOCK flags was added in
+   2.6.23.  */
+#define __ASSUME_O_CLOEXEC	1
 
 /* Support for ADJ_OFFSET_SS_READ was added in 2.6.24.  */
 #define __ASSUME_ADJ_OFFSET_SS_READ	1
 
-/* Support for various CLOEXEC and NONBLOCK flags was added for x86,
-   x86-64, PPC, IA-64, and SPARC in 2.6.27.  */
-#if (defined __i386__ || defined __x86_64__ || defined __powerpc__ \
-     || defined __sparc__ || defined __s390__)
-# define __ASSUME_SOCK_CLOEXEC	1
-# define __ASSUME_IN_NONBLOCK	1
-# define __ASSUME_PIPE2		1
-# define __ASSUME_EVENTFD2	1
-# define __ASSUME_SIGNALFD4	1
-# define __ASSUME_DUP3		1
-#endif
+/* Support for various CLOEXEC and NONBLOCK flags was added in
+   2.6.27.  */
+#define __ASSUME_SOCK_CLOEXEC	1
+#define __ASSUME_IN_NONBLOCK	1
+#define __ASSUME_PIPE2		1
+#define __ASSUME_EVENTFD2	1
+#define __ASSUME_SIGNALFD4	1
+#define __ASSUME_DUP3		1
 
 /* Support for accept4 functionality was added in 2.6.28, but for some
    architectures using a separate syscall rather than socketcall that
diff --git a/sysdeps/unix/sysv/linux/m68k/kernel-features.h b/sysdeps/unix/sysv/linux/m68k/kernel-features.h
index e47fd3b22e..03bcadb285 100644
--- a/sysdeps/unix/sysv/linux/m68k/kernel-features.h
+++ b/sysdeps/unix/sysv/linux/m68k/kernel-features.h
@@ -20,20 +20,6 @@
 /* m68k uses socketcall.  */
 #define __ASSUME_SOCKETCALL	1
 
-/* Many syscalls were added in 2.6.10 for m68k.  */
-#define __ASSUME_UTIMES	1
-
-/* Support for various CLOEXEC and NONBLOCK flags was added 2.6.23.  */
-#define __ASSUME_O_CLOEXEC	1
-
-/* Support for various CLOEXEC and NONBLOCK flags was added in 2.6.27.  */
-#define __ASSUME_SOCK_CLOEXEC	1
-#define __ASSUME_IN_NONBLOCK	1
-#define __ASSUME_PIPE2		1
-#define __ASSUME_EVENTFD2	1
-#define __ASSUME_SIGNALFD4	1
-#define __ASSUME_DUP3		1
-
 #include_next <kernel-features.h>
 
 /* These syscalls were added only in 3.0 for m68k.  */
diff --git a/sysdeps/unix/sysv/linux/microblaze/kernel-features.h b/sysdeps/unix/sysv/linux/microblaze/kernel-features.h
index c7c8c030bd..066c12dd4a 100644
--- a/sysdeps/unix/sysv/linux/microblaze/kernel-features.h
+++ b/sysdeps/unix/sysv/linux/microblaze/kernel-features.h
@@ -19,16 +19,6 @@
 /* MicroBlaze uses socketcall.  */
 #define __ASSUME_SOCKETCALL	1
 
-/* MicroBlaze glibc support starts with 2.6.30, guaranteeing many kernel features.  */
-#define __ASSUME_UTIMES         1
-#define __ASSUME_O_CLOEXEC      1
-#define __ASSUME_SOCK_CLOEXEC   1
-#define __ASSUME_IN_NONBLOCK    1
-#define __ASSUME_PIPE2          1
-#define __ASSUME_EVENTFD2       1
-#define __ASSUME_SIGNALFD4      1
-#define __ASSUME_DUP3           1
-
 /* Support for the accept4 and recvmmsg syscalls was added in 2.6.33.  */
 #if __LINUX_KERNEL_VERSION >= 0x020621
 # define __ASSUME_ACCEPT4_SYSCALL        1
diff --git a/sysdeps/unix/sysv/linux/mips/kernel-features.h b/sysdeps/unix/sysv/linux/mips/kernel-features.h
index a1ebf792f9..b53118d7c6 100644
--- a/sysdeps/unix/sysv/linux/mips/kernel-features.h
+++ b/sysdeps/unix/sysv/linux/mips/kernel-features.h
@@ -19,16 +19,6 @@
 
 #include <sgidefs.h>
 
-/* MIPS platforms had IPC64 all along.  */
-#define __ASSUME_IPC64		1
-
-/* MIPS had the utimes syscall by 2.6.0.  */
-#define __ASSUME_UTIMES		1
-
-/* Support for the eventfd2 and signalfd4 syscalls was added in 2.6.27.  */
-#define __ASSUME_EVENTFD2	1
-#define __ASSUME_SIGNALFD4	1
-
 /* Support for the accept4 syscall was added in 2.6.31.  */
 #define __ASSUME_ACCEPT4_SYSCALL	1
 
diff --git a/sysdeps/unix/sysv/linux/tile/kernel-features.h b/sysdeps/unix/sysv/linux/tile/kernel-features.h
index b028152d43..78aacac8cc 100644
--- a/sysdeps/unix/sysv/linux/tile/kernel-features.h
+++ b/sysdeps/unix/sysv/linux/tile/kernel-features.h
@@ -18,14 +18,7 @@
 
 
 /* TILE glibc support starts with 2.6.36, guaranteeing many kernel features. */
-#define __ASSUME_O_CLOEXEC		1
-#define __ASSUME_SOCK_CLOEXEC		1
-#define __ASSUME_IN_NONBLOCK		1
-#define __ASSUME_PIPE2			1
-#define __ASSUME_EVENTFD2		1
-#define __ASSUME_SIGNALFD4		1
 #define __ASSUME_ACCEPT4_SYSCALL	1
-#define __ASSUME_DUP3			1
 #define __ASSUME_RECVMMSG_SYSCALL	1
 
 /* Support for the sendmmsg syscall was added in 3.0.  */
@@ -35,6 +28,9 @@
 
 #include_next <kernel-features.h>
 
+/* asm-generic architectures do not have the utimes syscall.  */
+#undef __ASSUME_UTIMES
+
 /* Define this if your 32-bit syscall API requires 64-bit register
    pairs to start with an even-number register.  */
 #define __ASSUME_ALIGNED_REGISTER_PAIRS	1