Patchwork Use single bits/sem.h for all architectures

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Submitter Joseph Myers
Date Oct. 11, 2018, 8:36 p.m.
Message ID <alpine.DEB.2.21.1810112036210.9740@digraph.polyomino.org.uk>
Download mbox | patch
Permalink /patch/29712/
State New
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Joseph Myers - Oct. 11, 2018, 8:36 p.m.
The bits/sem.h headers for architectures using the Linux kernel vary
in a few ways:

* x32 uses __syscall_ulong_t instead of unsigned long int.

* The x86 header uses padding after time fields unconditionally
  (including for both x86_64 ABIs), not just for 32-bit time (unlike
  in msqid_ds where there is only padding for 32-bit time).  Because
  this padding is present for x32, and is __syscall_ulong_t there, it
  does have to be __syscall_ulong_t, not unsigned long int.

* The MIPS header never uses padding around time fields, even when
  32-bit (unlike in msqid_ds where it has endian-dependent padding for
  32-bit time).

* Some older 32-bit big-endian architectures have padding before
  rather than after time fields, although the preferred generic
  approach is padding after the time fields independent of endianness.

(There are also insubstantial differences such as use of unsigned int
for padding instead of unsigned long int, which makes no difference to
layout since the padding fields using unsigned int are only present on
32-bit architectures.)

For the first, __syscall_ulong_t can be used in the generic version as
it's the same as unsigned long int everywhere except x32.  For the
other differences, this patch adds macros __SEM_PAD_BEFORE_TIME and
__SEM_PAD_AFTER_TIME in a new bits/sem-pad.h header, so that header is
the only one needing to be provided on architectures with differences
in this area, and everything else can go in a single common bits/sem.h
header.

Tested for x86_64 and x86, and with build-many-glibcs.py.

2018-10-11  Joseph Myers  <joseph@codesourcery.com>

	* sysdeps/unix/sysv/linux/Makefile (sysdep_headers): Add
	bits/sem-pad.h.
	* sysdeps/unix/sysv/linux/bits/sem.h: Include <bits/sem-pad.h>
	instead of <bits/wordsize.h>.
	(__SEM_PAD_TIME): New macro, depending on [__SEM_PAD_BEFORE_TIME]
	and [__SEM_PAD_AFTER_TIME].
	(struct semid_ds): Define time fields using __SEM_PAD_TIME.  Use
	__syscall_ulong_t instead of unsigned long int.
	* sysdeps/unix/sysv/linux/bits/sem-pad.h: New file.
	* sysdeps/unix/sysv/linux/hppa/bits/sem-pad.h: Likewise.
	* sysdeps/unix/sysv/linux/mips/bits/sem-pad.h: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/bits/sem-pad.h: Likewise.
	* sysdeps/unix/sysv/linux/sparc/bits/sem-pad.h: Likewise.
	* sysdeps/unix/sysv/linux/x86/bits/sem-pad.h: Likewise.
	* sysdeps/unix/sysv/linux/hppa/bits/sem.h: Remove.
	* sysdeps/unix/sysv/linux/mips/bits/sem.h: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/bits/sem.h: Likewise.
	* sysdeps/unix/sysv/linux/sparc/bits/sem.h: Likewise.
	* sysdeps/unix/sysv/linux/x86/bits/sem.h: Likewise.

Patch

diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile
index ff4535cdca..edb1d29bf3 100644
--- a/sysdeps/unix/sysv/linux/Makefile
+++ b/sysdeps/unix/sysv/linux/Makefile
@@ -43,7 +43,7 @@  sysdep_headers += sys/mount.h sys/acct.h sys/sysctl.h \
 		  bits/siginfo-arch.h bits/siginfo-consts-arch.h \
 		  bits/procfs.h bits/procfs-id.h bits/procfs-extra.h \
 		  bits/procfs-prregset.h bits/mman-map-flags-generic.h \
-		  bits/msq-pad.h
+		  bits/msq-pad.h bits/sem-pad.h
 
 tests += tst-clone tst-clone2 tst-clone3 tst-fanotify tst-personality \
 	 tst-quota tst-sync_file_range tst-sysconf-iov_max tst-ttyname \
diff --git a/sysdeps/unix/sysv/linux/bits/sem-pad.h b/sysdeps/unix/sysv/linux/bits/sem-pad.h
new file mode 100644
index 0000000000..77979976bd
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/bits/sem-pad.h
@@ -0,0 +1,31 @@ 
+/* Define where padding goes in struct semid_ds.  Generic version.
+   Copyright (C) 2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef _SYS_SEM_H
+# error "Never use <bits/sem-pad.h> directly; include <sys/sem.h> instead."
+#endif
+
+#include <bits/wordsize.h>
+
+/* On most architectures, padding goes after time fields for 32-bit
+   systems and is omitted for 64-bit systems.  Some architectures pad
+   before time fields instead, or omit padding despite being 32-bit,
+   or include it despite being 64-bit.  */
+
+#define __SEM_PAD_AFTER_TIME (__WORDSIZE == 32)
+#define __SEM_PAD_BEFORE_TIME 0
diff --git a/sysdeps/unix/sysv/linux/bits/sem.h b/sysdeps/unix/sysv/linux/bits/sem.h
index bf6d797080..ad682156b5 100644
--- a/sysdeps/unix/sysv/linux/bits/sem.h
+++ b/sysdeps/unix/sysv/linux/bits/sem.h
@@ -20,7 +20,7 @@ 
 #endif
 
 #include <sys/types.h>
-#include <bits/wordsize.h>
+#include <bits/sem-pad.h>
 
 /* Flags for `semop'.  */
 #define SEM_UNDO	0x1000		/* undo the operation on exit */
@@ -35,21 +35,26 @@ 
 #define SETALL		17		/* set all semval's */
 
 
+#if __SEM_PAD_BEFORE_TIME
+# define __SEM_PAD_TIME(NAME, RES)				\
+  unsigned long int __glibc_reserved ## RES; __time_t NAME
+#elif __SEM_PAD_AFTER_TIME
+# define __SEM_PAD_TIME(NAME, RES)				\
+  __time_t NAME; unsigned long int __glibc_reserved ## RES
+#else
+# define __SEM_PAD_TIME(NAME, RES)		\
+  __time_t NAME
+#endif
+
 /* Data structure describing a set of semaphores.  */
 struct semid_ds
 {
   struct ipc_perm sem_perm;		/* operation permission struct */
-  __time_t sem_otime;			/* last semop() time */
-#if __WORDSIZE == 32
-  unsigned long int __glibc_reserved1;
-#endif
-  __time_t sem_ctime;			/* last time changed by semctl() */
-#if __WORDSIZE == 32
-  unsigned long int __glibc_reserved2;
-#endif
-  unsigned long int sem_nsems;		/* number of semaphores in set */
-  unsigned long int __glibc_reserved3;
-  unsigned long int __glibc_reserved4;
+  __SEM_PAD_TIME (sem_otime, 1);	/* last semop() time */
+  __SEM_PAD_TIME (sem_ctime, 2);	/* last time changed by semctl() */
+  __syscall_ulong_t sem_nsems;		/* number of semaphores in set */
+  __syscall_ulong_t __glibc_reserved3;
+  __syscall_ulong_t __glibc_reserved4;
 };
 
 /* The user should define a union like the following to use it for arguments
diff --git a/sysdeps/unix/sysv/linux/hppa/bits/sem-pad.h b/sysdeps/unix/sysv/linux/hppa/bits/sem-pad.h
new file mode 100644
index 0000000000..a938c2c92b
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/hppa/bits/sem-pad.h
@@ -0,0 +1,26 @@ 
+/* Define where padding goes in struct semid_ds.  HPPA version.
+   Copyright (C) 2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef _SYS_SEM_H
+# error "Never use <bits/sem-pad.h> directly; include <sys/sem.h> instead."
+#endif
+
+#include <bits/wordsize.h>
+
+#define __SEM_PAD_AFTER_TIME 0
+#define __SEM_PAD_BEFORE_TIME (__WORDSIZE == 32)
diff --git a/sysdeps/unix/sysv/linux/hppa/bits/sem.h b/sysdeps/unix/sysv/linux/hppa/bits/sem.h
deleted file mode 100644
index 12b849ae79..0000000000
--- a/sysdeps/unix/sysv/linux/hppa/bits/sem.h
+++ /dev/null
@@ -1,92 +0,0 @@ 
-/* Copyright (C) 1995-2018 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-
-   The GNU C Library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library.  If not, see
-   <http://www.gnu.org/licenses/>.  */
-
-#ifndef _SYS_SEM_H
-# error "Never include <bits/sem.h> directly; use <sys/sem.h> instead."
-#endif
-
-#include <sys/types.h>
-#include <bits/wordsize.h>
-
-/* Flags for `semop'.  */
-#define SEM_UNDO	0x1000		/* undo the operation on exit */
-
-/* Commands for `semctl'.  */
-#define GETPID		11		/* get sempid */
-#define GETVAL		12		/* get semval */
-#define GETALL		13		/* get all semval's */
-#define GETNCNT		14		/* get semncnt */
-#define GETZCNT		15		/* get semzcnt */
-#define SETVAL		16		/* set semval */
-#define SETALL		17		/* set all semval's */
-
-
-/* Data structure describing a set of semaphores.  */
-struct semid_ds
-{
-  struct ipc_perm sem_perm;		/* operation permission struct */
-#if __WORDSIZE == 32
-  unsigned int __pad1;
-#endif
-  __time_t sem_otime;			/* last semop() time */
-#if __WORDSIZE == 32
-  unsigned int __pad2;
-#endif
-  __time_t sem_ctime;			/* last time changed by semctl() */
-  unsigned long int sem_nsems;		/* number of semaphores in set */
-  unsigned long int __glibc_reserved1;
-  unsigned long int __glibc_reserved2;
-};
-
-/* The user should define a union like the following to use it for arguments
-   for `semctl'.
-
-   union semun
-   {
-     int val;				<= value for SETVAL
-     struct semid_ds *buf;		<= buffer for IPC_STAT & IPC_SET
-     unsigned short int *array;		<= array for GETALL & SETALL
-     struct seminfo *__buf;		<= buffer for IPC_INFO
-   };
-
-   Previous versions of this file used to define this union but this is
-   incorrect.  One can test the macro _SEM_SEMUN_UNDEFINED to see whether
-   one must define the union or not.  */
-#define _SEM_SEMUN_UNDEFINED	1
-
-#ifdef __USE_MISC
-
-/* ipcs ctl cmds */
-# define SEM_STAT 18
-# define SEM_INFO 19
-# define SEM_STAT_ANY 20
-
-struct  seminfo
-{
-  int semmap;
-  int semmni;
-  int semmns;
-  int semmnu;
-  int semmsl;
-  int semopm;
-  int semume;
-  int semusz;
-  int semvmx;
-  int semaem;
-};
-
-#endif /* __USE_MISC */
diff --git a/sysdeps/unix/sysv/linux/mips/bits/sem-pad.h b/sysdeps/unix/sysv/linux/mips/bits/sem-pad.h
new file mode 100644
index 0000000000..61f27cbc8f
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/mips/bits/sem-pad.h
@@ -0,0 +1,24 @@ 
+/* Define where padding goes in struct semid_ds.  MIPS version.
+   Copyright (C) 2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef _SYS_SEM_H
+# error "Never use <bits/sem-pad.h> directly; include <sys/sem.h> instead."
+#endif
+
+#define __SEM_PAD_AFTER_TIME 0
+#define __SEM_PAD_BEFORE_TIME 0
diff --git a/sysdeps/unix/sysv/linux/mips/bits/sem.h b/sysdeps/unix/sysv/linux/mips/bits/sem.h
deleted file mode 100644
index d218cf4f92..0000000000
--- a/sysdeps/unix/sysv/linux/mips/bits/sem.h
+++ /dev/null
@@ -1,85 +0,0 @@ 
-/* Copyright (C) 1995-2018 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-
-   The GNU C Library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library.  If not, see
-   <http://www.gnu.org/licenses/>.  */
-
-#ifndef _SYS_SEM_H
-# error "Never include <bits/sem.h> directly; use <sys/sem.h> instead."
-#endif
-
-#include <sys/types.h>
-
-/* Flags for `semop'.  */
-#define SEM_UNDO	0x1000		/* undo the operation on exit */
-
-/* Commands for `semctl'.  */
-#define GETPID		11		/* get sempid */
-#define GETVAL		12		/* get semval */
-#define GETALL		13		/* get all semval's */
-#define GETNCNT		14		/* get semncnt */
-#define GETZCNT		15		/* get semzcnt */
-#define SETVAL		16		/* set semval */
-#define SETALL		17		/* set all semval's */
-
-
-/* Data structure describing a set of semaphores.  */
-struct semid_ds
-{
-  struct ipc_perm sem_perm;		/* operation permission struct */
-  __time_t sem_otime;			/* last semop() time */
-  __time_t sem_ctime;			/* last time changed by semctl() */
-  unsigned long int sem_nsems;		/* number of semaphores in set */
-  unsigned long int __glibc_reserved1;
-  unsigned long int __glibc_reserved2;
-};
-
-/* The user should define a union like the following to use it for arguments
-   for `semctl'.
-
-   union semun
-   {
-     int val;				<= value for SETVAL
-     struct semid_ds *buf;		<= buffer for IPC_STAT & IPC_SET
-     unsigned short int *array;		<= array for GETALL & SETALL
-     struct seminfo *__buf;		<= buffer for IPC_INFO
-   };
-
-   Previous versions of this file used to define this union but this is
-   incorrect.  One can test the macro _SEM_SEMUN_UNDEFINED to see whether
-   one must define the union or not.  */
-#define _SEM_SEMUN_UNDEFINED	1
-
-#ifdef __USE_MISC
-
-/* ipcs ctl cmds */
-# define SEM_STAT 18
-# define SEM_INFO 19
-# define SEM_STAT_ANY 20
-
-struct  seminfo
-{
-  int semmap;
-  int semmni;
-  int semmns;
-  int semmnu;
-  int semmsl;
-  int semopm;
-  int semume;
-  int semusz;
-  int semvmx;
-  int semaem;
-};
-
-#endif /* __USE_MISC */
diff --git a/sysdeps/unix/sysv/linux/powerpc/bits/sem-pad.h b/sysdeps/unix/sysv/linux/powerpc/bits/sem-pad.h
new file mode 100644
index 0000000000..d4c9a93956
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/powerpc/bits/sem-pad.h
@@ -0,0 +1,26 @@ 
+/* Define where padding goes in struct semid_ds.  PowerPC version.
+   Copyright (C) 2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef _SYS_SEM_H
+# error "Never use <bits/sem-pad.h> directly; include <sys/sem.h> instead."
+#endif
+
+#include <bits/wordsize.h>
+
+#define __SEM_PAD_AFTER_TIME 0
+#define __SEM_PAD_BEFORE_TIME (__WORDSIZE == 32)
diff --git a/sysdeps/unix/sysv/linux/powerpc/bits/sem.h b/sysdeps/unix/sysv/linux/powerpc/bits/sem.h
deleted file mode 100644
index 27b026cf61..0000000000
--- a/sysdeps/unix/sysv/linux/powerpc/bits/sem.h
+++ /dev/null
@@ -1,91 +0,0 @@ 
-/* Copyright (C) 1995-2018 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-
-   The GNU C Library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library; if not, see
-   <http://www.gnu.org/licenses/>.  */
-
-#ifndef _SYS_SEM_H
-# error "Never include <bits/sem.h> directly; use <sys/sem.h> instead."
-#endif
-
-#include <sys/types.h>
-
-/* Flags for `semop'.  */
-#define SEM_UNDO       0x1000          /* undo the operation on exit */
-
-/* Commands for `semctl'.  */
-#define GETPID         11              /* get sempid */
-#define GETVAL         12              /* get semval */
-#define GETALL         13              /* get all semval's */
-#define GETNCNT                14              /* get semncnt */
-#define GETZCNT                15              /* get semzcnt */
-#define SETVAL         16              /* set semval */
-#define SETALL         17              /* set all semval's */
-
-
-/* Data structure describing a set of semaphores.  */
-struct semid_ds
-{
-  struct ipc_perm sem_perm;            /* operation permission struct */
-#if __WORDSIZE == 32
-  unsigned int __glibc_reserved1;
-#endif
-  __time_t sem_otime;                  /* last semop() time */
-#if __WORDSIZE == 32
-  unsigned int __glibc_reserved2;
-#endif
-  __time_t sem_ctime;                  /* last time changed by semctl() */
-  unsigned long int sem_nsems;         /* number of semaphores in set */
-  unsigned long __glibc_reserved3;
-  unsigned long __glibc_reserved4;
-};
-
-/* The user should define a union like the following to use it for arguments
-   for `semctl'.
-
-   union semun
-   {
-     int val;                          <= value for SETVAL
-     struct semid_ds *buf;             <= buffer for IPC_STAT & IPC_SET
-     unsigned short int *array;                <= array for GETALL & SETALL
-     struct seminfo *__buf;            <= buffer for IPC_INFO
-   };
-
-   Previous versions of this file used to define this union but this is
-   incorrect.  One can test the macro _SEM_SEMUN_UNDEFINED to see whether
-   one must define the union or not.  */
-#define _SEM_SEMUN_UNDEFINED   1
-
-#ifdef __USE_MISC
-
-/* ipcs ctl cmds */
-# define SEM_STAT 18
-# define SEM_INFO 19
-# define SEM_STAT_ANY 20
-
-struct  seminfo
-{
-  int semmap;
-  int semmni;
-  int semmns;
-  int semmnu;
-  int semmsl;
-  int semopm;
-  int semume;
-  int semusz;
-  int semvmx;
-  int semaem;
-};
-
-#endif /* __USE_MISC */
diff --git a/sysdeps/unix/sysv/linux/sparc/bits/sem-pad.h b/sysdeps/unix/sysv/linux/sparc/bits/sem-pad.h
new file mode 100644
index 0000000000..b85f6b70a2
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/sparc/bits/sem-pad.h
@@ -0,0 +1,26 @@ 
+/* Define where padding goes in struct semid_ds.  SPARC version.
+   Copyright (C) 2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef _SYS_SEM_H
+# error "Never use <bits/sem-pad.h> directly; include <sys/sem.h> instead."
+#endif
+
+#include <bits/wordsize.h>
+
+#define __SEM_PAD_AFTER_TIME 0
+#define __SEM_PAD_BEFORE_TIME (__WORDSIZE == 32)
diff --git a/sysdeps/unix/sysv/linux/sparc/bits/sem.h b/sysdeps/unix/sysv/linux/sparc/bits/sem.h
deleted file mode 100644
index f5b2654eec..0000000000
--- a/sysdeps/unix/sysv/linux/sparc/bits/sem.h
+++ /dev/null
@@ -1,92 +0,0 @@ 
-/* Copyright (C) 1995-2018 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-
-   The GNU C Library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library; if not, see
-   <http://www.gnu.org/licenses/>.  */
-
-#ifndef _SYS_SEM_H
-# error "Never include <bits/sem.h> directly; use <sys/sem.h> instead."
-#endif
-
-#include <sys/types.h>
-#include <bits/wordsize.h>
-
-/* Flags for `semop'.  */
-#define SEM_UNDO	0x1000		/* undo the operation on exit */
-
-/* Commands for `semctl'.  */
-#define GETPID		11		/* get sempid */
-#define GETVAL		12		/* get semval */
-#define GETALL		13		/* get all semval's */
-#define GETNCNT		14		/* get semncnt */
-#define GETZCNT		15		/* get semzcnt */
-#define SETVAL		16		/* set semval */
-#define SETALL		17		/* set all semval's */
-
-
-/* Data structure describing a set of semaphores.  */
-struct semid_ds
-{
-  struct ipc_perm sem_perm;		/* operation permission struct */
-#if __WORDSIZE == 32
-  unsigned int __pad1;
-#endif
-  __time_t sem_otime;			/* last semop() time */
-#if __WORDSIZE == 32
-  unsigned int __pad2;
-#endif
-  __time_t sem_ctime;			/* last time changed by semctl() */
-  unsigned long int sem_nsems;		/* number of semaphores in set */
-  unsigned long int __glibc_reserved1;
-  unsigned long int __glibc_reserved2;
-};
-
-/* The user should define a union like the following to use it for arguments
-   for `semctl'.
-
-   union semun
-   {
-     int val;				<= value for SETVAL
-     struct semid_ds *buf;		<= buffer for IPC_STAT & IPC_SET
-     unsigned short int *array;		<= array for GETALL & SETALL
-     struct seminfo *__buf;		<= buffer for IPC_INFO
-   };
-
-   Previous versions of this file used to define this union but this is
-   incorrect.  One can test the macro _SEM_SEMUN_UNDEFINED to see whether
-   one must define the union or not.  */
-#define _SEM_SEMUN_UNDEFINED	1
-
-#ifdef __USE_MISC
-
-/* ipcs ctl cmds */
-# define SEM_STAT 18
-# define SEM_INFO 19
-# define SEM_STAT_ANY 20
-
-struct  seminfo
-{
-  int semmap;
-  int semmni;
-  int semmns;
-  int semmnu;
-  int semmsl;
-  int semopm;
-  int semume;
-  int semusz;
-  int semvmx;
-  int semaem;
-};
-
-#endif /* __USE_MISC */
diff --git a/sysdeps/unix/sysv/linux/x86/bits/sem-pad.h b/sysdeps/unix/sysv/linux/x86/bits/sem-pad.h
new file mode 100644
index 0000000000..625f8ed21e
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/x86/bits/sem-pad.h
@@ -0,0 +1,24 @@ 
+/* Define where padding goes in struct semid_ds.  x86 version.
+   Copyright (C) 2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef _SYS_SEM_H
+# error "Never use <bits/sem-pad.h> directly; include <sys/sem.h> instead."
+#endif
+
+#define __SEM_PAD_AFTER_TIME 1
+#define __SEM_PAD_BEFORE_TIME 0
diff --git a/sysdeps/unix/sysv/linux/x86/bits/sem.h b/sysdeps/unix/sysv/linux/x86/bits/sem.h
deleted file mode 100644
index 6771966a06..0000000000
--- a/sysdeps/unix/sysv/linux/x86/bits/sem.h
+++ /dev/null
@@ -1,87 +0,0 @@ 
-/* Copyright (C) 2002-2018 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-
-   The GNU C Library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library; if not, see
-   <http://www.gnu.org/licenses/>.  */
-
-#ifndef _SYS_SEM_H
-# error "Never include <bits/sem.h> directly; use <sys/sem.h> instead."
-#endif
-
-#include <sys/types.h>
-
-/* Flags for `semop'.  */
-#define SEM_UNDO	0x1000		/* undo the operation on exit */
-
-/* Commands for `semctl'.  */
-#define GETPID		11		/* get sempid */
-#define GETVAL		12		/* get semval */
-#define GETALL		13		/* get all semval's */
-#define GETNCNT		14		/* get semncnt */
-#define GETZCNT		15		/* get semzcnt */
-#define SETVAL		16		/* set semval */
-#define SETALL		17		/* set all semval's */
-
-
-/* Data structure describing a set of semaphores.  */
-struct semid_ds
-{
-  struct ipc_perm sem_perm;		/* operation permission struct */
-  __time_t sem_otime;			/* last semop() time */
-  __syscall_ulong_t __glibc_reserved1;
-  __time_t sem_ctime;			/* last time changed by semctl() */
-  __syscall_ulong_t __glibc_reserved2;
-  __syscall_ulong_t sem_nsems;		/* number of semaphores in set */
-  __syscall_ulong_t __glibc_reserved3;
-  __syscall_ulong_t __glibc_reserved4;
-};
-
-/* The user should define a union like the following to use it for arguments
-   for `semctl'.
-
-   union semun
-   {
-     int val;				<= value for SETVAL
-     struct semid_ds *buf;		<= buffer for IPC_STAT & IPC_SET
-     unsigned short int *array;		<= array for GETALL & SETALL
-     struct seminfo *__buf;		<= buffer for IPC_INFO
-   };
-
-   Previous versions of this file used to define this union but this is
-   incorrect.  One can test the macro _SEM_SEMUN_UNDEFINED to see whether
-   one must define the union or not.  */
-#define _SEM_SEMUN_UNDEFINED	1
-
-#ifdef __USE_MISC
-
-/* ipcs ctl cmds */
-# define SEM_STAT 18
-# define SEM_INFO 19
-# define SEM_STAT_ANY 20
-
-struct  seminfo
-{
-  int semmap;
-  int semmni;
-  int semmns;
-  int semmnu;
-  int semmsl;
-  int semopm;
-  int semume;
-  int semusz;
-  int semvmx;
-  int semaem;
-};
-
-#endif /* __USE_MISC */