[1/7] sysv: linux: Add 64-bit time_t variant for semctl

Message ID 20200630192441.3299710-1-adhemerval.zanella@linaro.org
State Committed
Headers
Series [1/7] sysv: linux: Add 64-bit time_t variant for semctl |

Commit Message

Adhemerval Zanella June 30, 2020, 7:24 p.m. UTC
  Different than others 64-bit time_t syscalls, the SysIPC interface
does not provide a new set of syscall for y2038 safeness.  Instead it
uses ununsed fields in semid_ds structure the return the high bits for
the timestamps.

To provide a y2038 safe interface a new symbol __semctl64 is added
and __semctl is change to call it instead (it adds some extra buffer
copy for the 32 bit time_t implementation).

Two two new structures are added:

  1. kernel_semid64_ds: used internally only on 32-bit architectures
     to issue the syscall.  A handful architectures (hppa, i386, mips,
     powerpc32, sparc32) requires specific implementation due its
     specific kernel ABI.

  2. semid_ds64: this is only for __TIMESIZE != 64 to use along with
     the 64-bit semctl.  It is different than the kernel one because
     the exported 64-bit time_t might require different alignment
     depending of the architecture ABI.

So the resulting implementation does:

  1. For 64-bit architectures it assumes semid_ds already contains
     64-bit time_t fields it will result in just the __semctl symbol
     using the __semctl64 code.  The semid_ds argument is passed as-is
     to the syscall.

  2. For 32-bit architectures with default 64-bit time_t (newer ABIs
     such riscv32 or arc), it will also result in only one exported
     symbol but with the required high/low handling.

     It might be possible to optimize it further to avoid the
     kernel_semid64_ds to semun transformation if the exported ABI
     for the architectures matches the expected kernel ABI, but the
     implementation is already complex enough and don't think this
     should be a hotspot in any case.

  3. Finally for 32-bit architecture with both 32-bit and 64-bit time_t
     support we follow the already set way to provide one symbol with
     64-bit time_t support and implement the 32-bit time_t support on
     basis of the 64-bit one.

     The default 32-bit symbol will allocate and copy the semid_ds
     over multiple buffers, but this should be deprecated in favor
     of the __semctl64 anyway.

Checked on i686-linux-gnu and x86_64-linux-gnu.  I also did some sniff
tests on powerpc, powerpc64, mips, mips64, armhf, sparcv9, and
sparc64.
---
 include/sys/sem.h                             |   7 +
 .../sysv/linux/bits/types/struct_semid64_ds.h |  33 +++
 .../sysv/linux/bits/types/struct_semid_ds.h   |  21 +-
 .../linux/hppa/bits/types/struct_semid_ds.h   |   6 +-
 .../linux/hppa/struct_kernel_semid64_ds.h     |  12 +
 .../linux/i386/struct_kernel_semid64_ds.h     |  12 +
 sysdeps/unix/sysv/linux/ipc_priv.h            |  10 +
 .../linux/mips/bits/types/struct_semid_ds.h   |   4 +-
 .../linux/mips/struct_kernel_semid64_ds.h     |  10 +
 .../powerpc/bits/types/struct_semid_ds.h      |   4 +-
 .../powerpc32/struct_kernel_semid64_ds.h      |  12 +
 sysdeps/unix/sysv/linux/semctl.c              | 261 +++++++++++++++---
 .../linux/sparc/bits/types/struct_semid_ds.h  |   4 +-
 .../sparc/sparc32/struct_kernel_semid64_ds.h  |  12 +
 .../sysv/linux/struct_kernel_semid64_ds.h     |  12 +
 .../linux/x86/bits/types/struct_semid_ds.h    |   4 +-
 16 files changed, 359 insertions(+), 65 deletions(-)
 create mode 100644 sysdeps/unix/sysv/linux/bits/types/struct_semid64_ds.h
 create mode 100644 sysdeps/unix/sysv/linux/hppa/struct_kernel_semid64_ds.h
 create mode 100644 sysdeps/unix/sysv/linux/i386/struct_kernel_semid64_ds.h
 create mode 100644 sysdeps/unix/sysv/linux/mips/struct_kernel_semid64_ds.h
 create mode 100644 sysdeps/unix/sysv/linux/powerpc/powerpc32/struct_kernel_semid64_ds.h
 create mode 100644 sysdeps/unix/sysv/linux/sparc/sparc32/struct_kernel_semid64_ds.h
 create mode 100644 sysdeps/unix/sysv/linux/struct_kernel_semid64_ds.h
  

Comments

Alistair Francis July 2, 2020, 7:01 p.m. UTC | #1
On Tue, Jun 30, 2020 at 12:26 PM Adhemerval Zanella via Libc-alpha
<libc-alpha@sourceware.org> wrote:
>
> Different than others 64-bit time_t syscalls, the SysIPC interface
> does not provide a new set of syscall for y2038 safeness.  Instead it
> uses ununsed fields in semid_ds structure the return the high bits for
> the timestamps.
>
> To provide a y2038 safe interface a new symbol __semctl64 is added
> and __semctl is change to call it instead (it adds some extra buffer
> copy for the 32 bit time_t implementation).
>
> Two two new structures are added:
>
>   1. kernel_semid64_ds: used internally only on 32-bit architectures
>      to issue the syscall.  A handful architectures (hppa, i386, mips,
>      powerpc32, sparc32) requires specific implementation due its
>      specific kernel ABI.
>
>   2. semid_ds64: this is only for __TIMESIZE != 64 to use along with
>      the 64-bit semctl.  It is different than the kernel one because
>      the exported 64-bit time_t might require different alignment
>      depending of the architecture ABI.
>
> So the resulting implementation does:
>
>   1. For 64-bit architectures it assumes semid_ds already contains
>      64-bit time_t fields it will result in just the __semctl symbol
>      using the __semctl64 code.  The semid_ds argument is passed as-is
>      to the syscall.
>
>   2. For 32-bit architectures with default 64-bit time_t (newer ABIs
>      such riscv32 or arc), it will also result in only one exported
>      symbol but with the required high/low handling.
>
>      It might be possible to optimize it further to avoid the
>      kernel_semid64_ds to semun transformation if the exported ABI
>      for the architectures matches the expected kernel ABI, but the
>      implementation is already complex enough and don't think this
>      should be a hotspot in any case.
>
>   3. Finally for 32-bit architecture with both 32-bit and 64-bit time_t
>      support we follow the already set way to provide one symbol with
>      64-bit time_t support and implement the 32-bit time_t support on
>      basis of the 64-bit one.
>
>      The default 32-bit symbol will allocate and copy the semid_ds
>      over multiple buffers, but this should be deprecated in favor
>      of the __semctl64 anyway.
>
> Checked on i686-linux-gnu and x86_64-linux-gnu.  I also did some sniff
> tests on powerpc, powerpc64, mips, mips64, armhf, sparcv9, and
> sparc64.

This looks good.

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>

Alistair

> ---
>  include/sys/sem.h                             |   7 +
>  .../sysv/linux/bits/types/struct_semid64_ds.h |  33 +++
>  .../sysv/linux/bits/types/struct_semid_ds.h   |  21 +-
>  .../linux/hppa/bits/types/struct_semid_ds.h   |   6 +-
>  .../linux/hppa/struct_kernel_semid64_ds.h     |  12 +
>  .../linux/i386/struct_kernel_semid64_ds.h     |  12 +
>  sysdeps/unix/sysv/linux/ipc_priv.h            |  10 +
>  .../linux/mips/bits/types/struct_semid_ds.h   |   4 +-
>  .../linux/mips/struct_kernel_semid64_ds.h     |  10 +
>  .../powerpc/bits/types/struct_semid_ds.h      |   4 +-
>  .../powerpc32/struct_kernel_semid64_ds.h      |  12 +
>  sysdeps/unix/sysv/linux/semctl.c              | 261 +++++++++++++++---
>  .../linux/sparc/bits/types/struct_semid_ds.h  |   4 +-
>  .../sparc/sparc32/struct_kernel_semid64_ds.h  |  12 +
>  .../sysv/linux/struct_kernel_semid64_ds.h     |  12 +
>  .../linux/x86/bits/types/struct_semid_ds.h    |   4 +-
>  16 files changed, 359 insertions(+), 65 deletions(-)
>  create mode 100644 sysdeps/unix/sysv/linux/bits/types/struct_semid64_ds.h
>  create mode 100644 sysdeps/unix/sysv/linux/hppa/struct_kernel_semid64_ds.h
>  create mode 100644 sysdeps/unix/sysv/linux/i386/struct_kernel_semid64_ds.h
>  create mode 100644 sysdeps/unix/sysv/linux/mips/struct_kernel_semid64_ds.h
>  create mode 100644 sysdeps/unix/sysv/linux/powerpc/powerpc32/struct_kernel_semid64_ds.h
>  create mode 100644 sysdeps/unix/sysv/linux/sparc/sparc32/struct_kernel_semid64_ds.h
>  create mode 100644 sysdeps/unix/sysv/linux/struct_kernel_semid64_ds.h
>
> diff --git a/include/sys/sem.h b/include/sys/sem.h
> index 69fdf1f752..a9151e057d 100644
> --- a/include/sys/sem.h
> +++ b/include/sys/sem.h
> @@ -5,5 +5,12 @@
>
>  __typeof__ (semtimedop) __semtimedop attribute_hidden;
>
> +#if __TIMESIZE == 64
> +# define __semctl64 __semctl
> +#else
> +extern int __semctl64 (int semid, int semnum, int cmd, ...);
> +libc_hidden_proto (__semctl64);
> +#endif
> +
>  # endif
>  #endif
> diff --git a/sysdeps/unix/sysv/linux/bits/types/struct_semid64_ds.h b/sysdeps/unix/sysv/linux/bits/types/struct_semid64_ds.h
> new file mode 100644
> index 0000000000..bda9eb4469
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/bits/types/struct_semid64_ds.h
> @@ -0,0 +1,33 @@
> +/* Generic implementation of the semaphore struct semid64_ds.
> +   Copyright (C) 2020 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
> +   <https://www.gnu.org/licenses/>.  */
> +
> +#ifndef _SYS_SEM_H
> +# error "Never include <bits/types/struct_semid_ds.h> directly; use <sys/sem.h> instead."
> +#endif
> +
> +#if __TIMESIZE == 64
> +# define __semid64_ds semid_ds
> +#else
> +struct __semid64_ds
> +{
> +  struct ipc_perm sem_perm;            /* operation permission struct */
> +  __time64_t sem_otime;                        /* last semop() time */
> +  __time64_t sem_ctime;                        /* last time changed by semctl() */
> +  __syscall_ulong_t sem_nsems;         /* number of semaphores in set */
> +};
> +#endif
> diff --git a/sysdeps/unix/sysv/linux/bits/types/struct_semid_ds.h b/sysdeps/unix/sysv/linux/bits/types/struct_semid_ds.h
> index 4222e6a59f..bc26d8be08 100644
> --- a/sysdeps/unix/sysv/linux/bits/types/struct_semid_ds.h
> +++ b/sysdeps/unix/sysv/linux/bits/types/struct_semid_ds.h
> @@ -21,26 +21,19 @@
>  #endif
>
>  /* Data structure describing a set of semaphores.  */
> -#if __TIMESIZE == 32
>  struct semid_ds
>  {
>    struct ipc_perm sem_perm;        /* operation permission struct */
> +#if __TIMESIZE == 32
>    __time_t sem_otime;              /* last semop() time */
> -  __syscall_ulong_t __glibc_reserved1;
> +  __syscall_ulong_t __sem_otime_high;
>    __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;
> -};
> +  __syscall_ulong_t __sem_ctime_high;
>  #else
> -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() */
> -  __syscall_ulong_t sem_nsems;         /* number of semaphores in set */
> +  __time_t sem_otime;
> +  __time_t sem_ctime;
> +#endif
> +  __syscall_ulong_t sem_nsems;    /* number of semaphores in set */
>    __syscall_ulong_t __glibc_reserved3;
>    __syscall_ulong_t __glibc_reserved4;
>  };
> -#endif
> diff --git a/sysdeps/unix/sysv/linux/hppa/bits/types/struct_semid_ds.h b/sysdeps/unix/sysv/linux/hppa/bits/types/struct_semid_ds.h
> index d4c50b5ef8..68f9eca24c 100644
> --- a/sysdeps/unix/sysv/linux/hppa/bits/types/struct_semid_ds.h
> +++ b/sysdeps/unix/sysv/linux/hppa/bits/types/struct_semid_ds.h
> @@ -21,16 +21,14 @@
>  #endif
>
>  /* Data structure describing a set of semaphores.  */
> -#if __TIMESIZE == 32
>  struct semid_ds
>  {
>    struct ipc_perm sem_perm;   /* operation permission struct */
> -  __syscall_ulong_t __glibc_reserved1;
> +  __syscall_ulong_t __sem_otime_high;
>    __time_t sem_otime;         /* last semop() time */
> -  __syscall_ulong_t __glibc_reserved2;
> +  __syscall_ulong_t __sem_ctime_high;
>    __time_t sem_ctime;         /* 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;
>  };
> -#endif
> diff --git a/sysdeps/unix/sysv/linux/hppa/struct_kernel_semid64_ds.h b/sysdeps/unix/sysv/linux/hppa/struct_kernel_semid64_ds.h
> new file mode 100644
> index 0000000000..2871030d0d
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/hppa/struct_kernel_semid64_ds.h
> @@ -0,0 +1,12 @@
> +/* Analogous to kernel struct semid64_ds used on semctl.  */
> +struct kernel_semid64_ds
> +{
> +  struct ipc_perm sem_perm;
> +  unsigned long sem_otime_high;
> +  unsigned long sem_otime;
> +  unsigned long sem_ctime_high;
> +  unsigned long sem_ctime;
> +  unsigned long sem_nsems;
> +  unsigned long __ununsed1;
> +  unsigned long __ununsed2;
> +};
> diff --git a/sysdeps/unix/sysv/linux/i386/struct_kernel_semid64_ds.h b/sysdeps/unix/sysv/linux/i386/struct_kernel_semid64_ds.h
> new file mode 100644
> index 0000000000..bab9cf63ba
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/i386/struct_kernel_semid64_ds.h
> @@ -0,0 +1,12 @@
> +/* Analogous to kernel struct semid64_ds used on semctl.  */
> +struct kernel_semid64_ds
> +{
> +  struct ipc_perm sem_perm;
> +  unsigned long sem_otime;
> +  unsigned long sem_otime_high;
> +  unsigned long sem_ctime;
> +  unsigned long sem_ctime_high;
> +  __syscall_ulong_t sem_nsems;
> +  __syscall_ulong_t __unused3;
> +  __syscall_ulong_t __unused4;
> +};
> diff --git a/sysdeps/unix/sysv/linux/ipc_priv.h b/sysdeps/unix/sysv/linux/ipc_priv.h
> index 15a6e683a4..93a6e5cb24 100644
> --- a/sysdeps/unix/sysv/linux/ipc_priv.h
> +++ b/sysdeps/unix/sysv/linux/ipc_priv.h
> @@ -53,4 +53,14 @@ struct __old_ipc_perm
>  #define SEMTIMEDOP_IPC_ARGS(__nsops, __sops, __timeout) \
>    (__nsops), 0, (__sops), (__timeout)
>
> +/* Linux SysV ipc does not provide new syscalls for 64-bit time support on
> +   32-bit architectures, but rather split the timestamps on previous unused
> +   fields.  */
> +#if (__WORDSIZE == 32 \
> +     && (!defined __SYSCALL_WORDSIZE || __SYSCALL_WORDSIZE == 32))
> +# define __IPC_TIME64 1
> +#else
> +# define __IPC_TIME64 0
> +#endif
> +
>  #include <ipc_ops.h>
> diff --git a/sysdeps/unix/sysv/linux/mips/bits/types/struct_semid_ds.h b/sysdeps/unix/sysv/linux/mips/bits/types/struct_semid_ds.h
> index 8954209a29..eec4a18cae 100644
> --- a/sysdeps/unix/sysv/linux/mips/bits/types/struct_semid_ds.h
> +++ b/sysdeps/unix/sysv/linux/mips/bits/types/struct_semid_ds.h
> @@ -27,6 +27,6 @@ struct semid_ds
>    __time_t sem_otime;  /* last semop() time */
>    __time_t sem_ctime;  /* 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;
> +  __syscall_ulong_t __sem_otime_high;
> +  __syscall_ulong_t __sem_ctime_high;
>  };
> diff --git a/sysdeps/unix/sysv/linux/mips/struct_kernel_semid64_ds.h b/sysdeps/unix/sysv/linux/mips/struct_kernel_semid64_ds.h
> new file mode 100644
> index 0000000000..76a9d83ea5
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/mips/struct_kernel_semid64_ds.h
> @@ -0,0 +1,10 @@
> +/* Analogous to kernel struct semid64_ds used on semctl.  */
> +struct kernel_semid64_ds
> +{
> +  struct ipc_perm sem_perm;
> +  unsigned long sem_otime;
> +  unsigned long sem_ctime;
> +  unsigned long sem_nsems;
> +  unsigned long sem_otime_high;
> +  unsigned long sem_ctime_high;
> +};
> diff --git a/sysdeps/unix/sysv/linux/powerpc/bits/types/struct_semid_ds.h b/sysdeps/unix/sysv/linux/powerpc/bits/types/struct_semid_ds.h
> index 300a9b98e9..d382d93c52 100644
> --- a/sysdeps/unix/sysv/linux/powerpc/bits/types/struct_semid_ds.h
> +++ b/sysdeps/unix/sysv/linux/powerpc/bits/types/struct_semid_ds.h
> @@ -25,9 +25,9 @@ struct semid_ds
>  {
>    struct ipc_perm sem_perm;   /* operation permission struct */
>  #if __TIMESIZE == 32
> -  __syscall_ulong_t __glibc_reserved1;
> +  __syscall_ulong_t __sem_otime_high;
>    __time_t sem_otime;         /* last semop() time */
> -  __syscall_ulong_t __glibc_reserved2;
> +  __syscall_ulong_t __sem_ctime_high;
>    __time_t sem_ctime;        /* last time changed by semctl() */
>  #else
>    __time_t sem_otime;         /* last semop() time */
> diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/struct_kernel_semid64_ds.h b/sysdeps/unix/sysv/linux/powerpc/powerpc32/struct_kernel_semid64_ds.h
> new file mode 100644
> index 0000000000..7fa4ef6424
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/struct_kernel_semid64_ds.h
> @@ -0,0 +1,12 @@
> +/* Analogous to kernel struct semid64_ds used on semctl.  */
> +struct kernel_semid64_ds
> +{
> +  struct ipc_perm sem_perm;
> +  unsigned long sem_otime_high;
> +  unsigned long sem_otime;
> +  unsigned long sem_ctime_high;
> +  unsigned long sem_ctime;
> +  unsigned long sem_nsems;
> +  unsigned long __unused3;
> +  unsigned long __unused4;
> +};
> diff --git a/sysdeps/unix/sysv/linux/semctl.c b/sysdeps/unix/sysv/linux/semctl.c
> index 30571af49f..3a06270242 100644
> --- a/sysdeps/unix/sysv/linux/semctl.c
> +++ b/sysdeps/unix/sysv/linux/semctl.c
> @@ -21,10 +21,13 @@
>  #include <ipc_priv.h>
>  #include <sysdep.h>
>  #include <shlib-compat.h>
> -#include <errno.h>
> -#include <linux/posix_types.h>  /* For __kernel_mode_t.  */
> +#include <bits/types/struct_semid64_ds.h>  /* For __semid64_ds.  */
> +#include <linux/posix_types.h>             /* For __kernel_mode_t.  */
>
> -/* Define a `union semun' suitable for Linux here.  */
> +/* The struct used to issue the syscall.  For architecture that assume
> +   64-bit time as default (!__ASSUME_TIME64_SYSCALLS) the syscall will
> +   split the resulting 64-bit sem_{o,c}time in two fields (__sem_{o,c}time
> +   and __sem_{o,c}time_hi).  */
>  union semun
>  {
>    int val;                     /* value for SETVAL */
> @@ -33,16 +36,89 @@ union semun
>    struct seminfo *__buf;       /* buffer for IPC_INFO */
>  };
>
> -#ifndef DEFAULT_VERSION
> -# ifndef __ASSUME_SYSVIPC_BROKEN_MODE_T
> -#  define DEFAULT_VERSION GLIBC_2_2
> +#if __IPC_TIME64 == 0
> +# define semun64 semun
> +typedef union semun semctl_arg_t;
> +#else
> +# include <struct_kernel_semid64_ds.h>
> +
> +union ksemun64
> +{
> +  int val;
> +  struct kernel_semid64_ds *buf;
> +  unsigned short int *array;
> +  struct seminfo *__buf;
> +};
> +
> +# if __TIMESIZE == 64
> +#  define semun64 semun
>  # else
> -#  define DEFAULT_VERSION GLIBC_2_31
> +/* The struct used when __semctl64 is called.  */
> +union semun64
> +{
> +  int val;
> +  struct __semid64_ds *buf;
> +  unsigned short int *array;
> +  struct seminfo *__buf;
> +};
>  # endif
> +
> +static void
> +semid64_to_ksemid64 (const struct __semid64_ds *semid64,
> +                    struct kernel_semid64_ds *ksemid)
> +{
> +  ksemid->sem_perm       = semid64->sem_perm;
> +  ksemid->sem_otime      = semid64->sem_otime;
> +  ksemid->sem_otime_high = semid64->sem_otime >> 32;
> +  ksemid->sem_ctime      = semid64->sem_ctime;
> +  ksemid->sem_ctime_high = semid64->sem_ctime >> 32;
> +  ksemid->sem_nsems      = semid64->sem_nsems;
> +}
> +
> +static void
> +ksemid64_to_semid64 (const struct kernel_semid64_ds *ksemid,
> +                    struct __semid64_ds *semid64)
> +{
> +  semid64->sem_perm  = ksemid->sem_perm;
> +  semid64->sem_otime = ksemid->sem_otime
> +                      | ((__time64_t) ksemid->sem_otime_high << 32);
> +  semid64->sem_ctime = ksemid->sem_ctime
> +                      | ((__time64_t) ksemid->sem_ctime_high << 32);
> +  semid64->sem_nsems = ksemid->sem_nsems;
> +}
> +
> +static union ksemun64
> +semun64_to_ksemun64 (int cmd, union semun64 semun64,
> +                    struct kernel_semid64_ds *buf)
> +{
> +  union ksemun64 r = { 0 };
> +  switch (cmd)
> +    {
> +    case SETVAL:
> +      r.val = semun64.val;
> +      break;
> +    case GETALL:
> +    case SETALL:
> +      r.array = semun64.array;
> +      break;
> +    case IPC_STAT:
> +    case IPC_SET:
> +      r.buf = buf;
> +      semid64_to_ksemid64 (semun64.buf, r.buf);
> +      break;
> +    case IPC_INFO:
> +    case SEM_INFO:
> +      r.__buf = semun64.__buf;
> +      break;
> +    }
> +  return r;
> +}
> +
> +typedef union ksemun64 semctl_arg_t;
>  #endif
>
>  static int
> -semctl_syscall (int semid, int semnum, int cmd, union semun arg)
> +semctl_syscall (int semid, int semnum, int cmd, semctl_arg_t arg)
>  {
>  #ifdef __ASSUME_DIRECT_SYSVIPC_SYSCALLS
>    return INLINE_SYSCALL_CALL (semctl, semid, semnum, cmd | __IPC_64,
> @@ -53,15 +129,15 @@ semctl_syscall (int semid, int semnum, int cmd, union semun arg)
>  #endif
>  }
>
> +/* POSIX states ipc_perm mode should have type of mode_t.  */
> +_Static_assert (sizeof ((struct semid_ds){0}.sem_perm.mode)
> +               == sizeof (mode_t),
> +               "sizeof (msqid_ds.msg_perm.mode) != sizeof (mode_t)");
> +
>  int
> -__new_semctl (int semid, int semnum, int cmd, ...)
> +__semctl64 (int semid, int semnum, int cmd, ...)
>  {
> -  /* POSIX states ipc_perm mode should have type of mode_t.  */
> -  _Static_assert (sizeof ((struct semid_ds){0}.sem_perm.mode)
> -                 == sizeof (mode_t),
> -                 "sizeof (msqid_ds.msg_perm.mode) != sizeof (mode_t)");
> -
> -  union semun arg = { 0 };
> +  union semun64 arg64 = { 0 };
>    va_list ap;
>
>    /* Get the argument only if required.  */
> @@ -76,44 +152,151 @@ __new_semctl (int semid, int semnum, int cmd, ...)
>      case IPC_INFO:      /* arg.__buf */
>      case SEM_INFO:
>        va_start (ap, cmd);
> -      arg = va_arg (ap, union semun);
> +      arg64 = va_arg (ap, union semun64);
>        va_end (ap);
>        break;
>      }
>
> -#ifdef __ASSUME_SYSVIPC_BROKEN_MODE_T
> -  struct semid_ds tmpds;
> -  if (cmd == IPC_SET)
> -    {
> -      tmpds = *arg.buf;
> -      tmpds.sem_perm.mode *= 0x10000U;
> -      arg.buf = &tmpds;
> -    }
> +#if __IPC_TIME64
> +  struct kernel_semid64_ds ksemid;
> +  union ksemun64 ksemun = semun64_to_ksemun64 (cmd, arg64, &ksemid);
> +  union ksemun64 arg = ksemun;
> +#else
> +  union semun arg = arg64;
>  #endif
>
>    int ret = semctl_syscall (semid, semnum, cmd, arg);
> +  if (ret < 0)
> +    return ret;
>
> -  if (ret >= 0)
> +  switch (cmd)
>      {
> -      switch (cmd)
> -       {
> -        case IPC_STAT:
> -        case SEM_STAT:
> -        case SEM_STAT_ANY:
> +    case IPC_STAT:
> +    case SEM_STAT:
> +    case SEM_STAT_ANY:
>  #ifdef __ASSUME_SYSVIPC_BROKEN_MODE_T
> -          arg.buf->sem_perm.mode >>= 16;
> +      arg.buf->sem_perm.mode >>= 16;
>  #else
> -         /* Old Linux kernel versions might not clear the mode padding.  */
> -         if (sizeof ((struct semid_ds){0}.sem_perm.mode)
> -             != sizeof (__kernel_mode_t))
> -           arg.buf->sem_perm.mode &= 0xFFFF;
> +      /* Old Linux kernel versions might not clear the mode padding.  */
> +      if (sizeof ((struct semid_ds){0}.sem_perm.mode)
> +         != sizeof (__kernel_mode_t))
> +       arg.buf->sem_perm.mode &= 0xFFFF;
>  #endif
> -       }
> +
> +#if __IPC_TIME64
> +      ksemid64_to_semid64 (arg.buf, arg64.buf);
> +#endif
> +    }
> +
> +  return ret;
> +}
> +#if __TIMESIZE != 64
> +libc_hidden_def (__semctl64)
> +
> +
> +/* The 64-bit time_t semid_ds version might have a different layout and
> +   internal field alignment.  */
> +static void
> +semid64_ds_to_semid_ds (struct semid_ds *ds, const struct __semid64_ds *ds64)
> +{
> +  ds->sem_perm = ds64->sem_perm;
> +  ds->sem_otime = ds64->sem_otime;
> +  ds->sem_ctime = ds64->sem_ctime;
> +  ds->sem_nsems = ds64->sem_nsems;
> +}
> +
> +static void
> +semid_ds_to_semid64_ds (struct __semid64_ds *ds64, const struct semid_ds *ds)
> +{
> +  ds64->sem_perm = ds->sem_perm;
> +  ds64->sem_otime = ds->sem_otime
> +                   | ((__time64_t) ds->__sem_otime_high << 32);
> +  ds64->sem_ctime = ds->sem_ctime
> +                   | ((__time64_t) ds->__sem_ctime_high << 32);
> +  ds64->sem_nsems = ds->sem_nsems;
> +}
> +
> +static union semun64
> +semun_to_semun64 (int cmd, union semun semun, struct __semid64_ds *semid64)
> +{
> +  union semun64 r = { 0 };
> +  switch (cmd)
> +    {
> +    case SETVAL:
> +      r.val = semun.val;
> +      break;
> +    case GETALL:
> +    case SETALL:
> +      r.array = semun.array;
> +      break;
> +    case IPC_STAT:
> +    case IPC_SET:
> +      r.buf = semid64;
> +      semid_ds_to_semid64_ds (r.buf, semun.buf);
> +# ifdef __ASSUME_SYSVIPC_BROKEN_MODE_T
> +      if (cmd == IPC_SET)
> +       r.buf->sem_perm.mode *= 0x10000U;
> +# endif
> +      break;
> +    case IPC_INFO:
> +    case SEM_INFO:
> +      r.__buf = semun.__buf;
> +      break;
> +    }
> +  return r;
> +}
> +
> +int
> +__semctl (int semid, int semnum, int cmd, ...)
> +{
> +  union semun arg = { 0 };
> +
> +  va_list ap;
> +
> +  /* Get the argument only if required.  */
> +  switch (cmd)
> +    {
> +    case SETVAL:        /* arg.val */
> +    case GETALL:        /* arg.array */
> +    case SETALL:
> +    case IPC_STAT:      /* arg.buf */
> +    case IPC_SET:
> +    case SEM_STAT:
> +    case IPC_INFO:      /* arg.__buf */
> +    case SEM_INFO:
> +      va_start (ap, cmd);
> +      arg = va_arg (ap, union semun);
> +      va_end (ap);
> +      break;
> +    }
> +
> +  struct __semid64_ds semid64;
> +  union semun64 arg64 = semun_to_semun64 (cmd, arg, &semid64);
> +
> +  int ret = __semctl64 (semid, semnum, cmd, arg64);
> +  if (ret < 0)
> +    return ret;
> +
> +  switch (cmd)
> +    {
> +    case IPC_STAT:
> +    case SEM_STAT:
> +    case SEM_STAT_ANY:
> +      semid64_ds_to_semid_ds (arg.buf, arg64.buf);
>      }
>
>    return ret;
>  }
> -versioned_symbol (libc, __new_semctl, semctl, DEFAULT_VERSION);
> +#endif
> +
> +#ifndef DEFAULT_VERSION
> +# ifndef __ASSUME_SYSVIPC_BROKEN_MODE_T
> +#  define DEFAULT_VERSION GLIBC_2_2
> +# else
> +#  define DEFAULT_VERSION GLIBC_2_31
> +# endif
> +#endif
> +versioned_symbol (libc, __semctl, semctl, DEFAULT_VERSION);
>
>  #if defined __ASSUME_SYSVIPC_BROKEN_MODE_T \
>      && SHLIB_COMPAT (libc, GLIBC_2_2, GLIBC_2_31)
> @@ -121,7 +304,7 @@ int
>  attribute_compat_text_section
>  __semctl_mode16 (int semid, int semnum, int cmd, ...)
>  {
> -  union semun arg = { 0 };
> +  semctl_arg_t arg = { 0 };
>    va_list ap;
>
>    /* Get the argument only if required.  */
> @@ -136,7 +319,7 @@ __semctl_mode16 (int semid, int semnum, int cmd, ...)
>      case IPC_INFO:      /* arg.__buf */
>      case SEM_INFO:
>        va_start (ap, cmd);
> -      arg = va_arg (ap, union semun);
> +      arg = va_arg (ap, semctl_arg_t);
>        va_end (ap);
>        break;
>      }
> diff --git a/sysdeps/unix/sysv/linux/sparc/bits/types/struct_semid_ds.h b/sysdeps/unix/sysv/linux/sparc/bits/types/struct_semid_ds.h
> index 46fcd79fb6..0110c1a940 100644
> --- a/sysdeps/unix/sysv/linux/sparc/bits/types/struct_semid_ds.h
> +++ b/sysdeps/unix/sysv/linux/sparc/bits/types/struct_semid_ds.h
> @@ -25,9 +25,9 @@ struct semid_ds
>  {
>    struct ipc_perm sem_perm;   /* operation permission struct */
>  #if __TIMESIZE == 32
> -  __syscall_ulong_t __glibc_reserved1;
> +  __syscall_ulong_t __sem_otime_high;
>    __time_t sem_otime;         /* last semop() time */
> -  __syscall_ulong_t __glibc_reserved2;
> +  __syscall_ulong_t __sem_ctime_high;
>    __time_t sem_ctime;        /* last time changed by semctl() */
>  #else
>    __time_t sem_otime;         /* last semop() time */
> diff --git a/sysdeps/unix/sysv/linux/sparc/sparc32/struct_kernel_semid64_ds.h b/sysdeps/unix/sysv/linux/sparc/sparc32/struct_kernel_semid64_ds.h
> new file mode 100644
> index 0000000000..8c4697f9ab
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/sparc/sparc32/struct_kernel_semid64_ds.h
> @@ -0,0 +1,12 @@
> +/* Analogous to kernel struct semid64_ds used on semctl.  */
> +struct kernel_semid64_ds
> +{
> +  struct ipc_perm sem_perm;
> +  unsigned long sem_otime_high;
> +  unsigned long sem_otime;
> +  unsigned long sem_ctime_high;
> +  unsigned long sem_ctime;
> +  unsigned long sem_nsems;
> +  unsigned long __unused1;
> +  unsigned long __unused2;
> +};
> diff --git a/sysdeps/unix/sysv/linux/struct_kernel_semid64_ds.h b/sysdeps/unix/sysv/linux/struct_kernel_semid64_ds.h
> new file mode 100644
> index 0000000000..f9edf0f76f
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/struct_kernel_semid64_ds.h
> @@ -0,0 +1,12 @@
> +/* Analogous to kernel struct semid64_ds used on semctl.  */
> +struct kernel_semid64_ds
> +{
> +  struct ipc_perm sem_perm;
> +  unsigned long sem_otime;
> +  unsigned long sem_otime_high;
> +  unsigned long sem_ctime;
> +  unsigned long sem_ctime_high;
> +  unsigned long sem_nsems;
> +  unsigned long __unused1;
> +  unsigned long __unused2;
> +};
> diff --git a/sysdeps/unix/sysv/linux/x86/bits/types/struct_semid_ds.h b/sysdeps/unix/sysv/linux/x86/bits/types/struct_semid_ds.h
> index f7ec89d115..c3f2fde9fd 100644
> --- a/sysdeps/unix/sysv/linux/x86/bits/types/struct_semid_ds.h
> +++ b/sysdeps/unix/sysv/linux/x86/bits/types/struct_semid_ds.h
> @@ -25,9 +25,9 @@ struct semid_ds
>  {
>    struct ipc_perm sem_perm;   /* operation permission struct */
>    __time_t sem_otime;  /* last semop() time */
> -  __syscall_ulong_t __glibc_reserved1;
> +  __syscall_ulong_t __sem_otime_high;
>    __time_t sem_ctime;  /* last time changed by semctl() */
> -  __syscall_ulong_t __glibc_reserved2;
> +  __syscall_ulong_t __sem_ctime_high;
>    __syscall_ulong_t sem_nsems;    /* number of semaphores in set */
>    __syscall_ulong_t __glibc_reserved3;
>    __syscall_ulong_t __glibc_reserved4;
> --
> 2.25.1
>
  
Carlos O'Donell July 7, 2020, 3:32 a.m. UTC | #2
On 6/30/20 3:24 PM, Adhemerval Zanella via Libc-alpha wrote:

OK for master with comment cleanups. Very clean, very easy to understand
patch. I should finish the other 6 patches tomorrow morning.

No regressions on x86_64 or i686 (I did see the new rseq regression
for posix/tst-affinity-static though).

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>

> Different than others 64-bit time_t syscalls, the SysIPC interface
> does not provide a new set of syscall for y2038 safeness.  Instead it
> uses ununsed fields in semid_ds structure the return the high bits for

s/ununsed/unused/g
s/the return/to return/g

> the timestamps.
> 
> To provide a y2038 safe interface a new symbol __semctl64 is added
> and __semctl is change to call it instead (it adds some extra buffer
> copy for the 32 bit time_t implementation).

OK.

> 
> Two two new structures are added:

s/Two two/Two/g

> 
>   1. kernel_semid64_ds: used internally only on 32-bit architectures
>      to issue the syscall.  A handful architectures (hppa, i386, mips,

s/handful/handful of/g

>      powerpc32, sparc32) requires specific implementation due its
>      specific kernel ABI.

Suggest:

require specific implementations due to their kernel ABI.

> 
>   2. semid_ds64: this is only for __TIMESIZE != 64 to use along with
>      the 64-bit semctl.  It is different than the kernel one because

s/one/struct/g

>      the exported 64-bit time_t might require different alignment
>      depending of the architecture ABI.

OK.

> 
> So the resulting implementation does:
> 
>   1. For 64-bit architectures it assumes semid_ds already contains
>      64-bit time_t fields it will result in just the __semctl symbol

s/it/and/g

>      using the __semctl64 code.  The semid_ds argument is passed as-is
>      to the syscall.
> 
>   2. For 32-bit architectures with default 64-bit time_t (newer ABIs
>      such riscv32 or arc), it will also result in only one exported
>      symbol but with the required high/low handling.

OK.
 
>      It might be possible to optimize it further to avoid the
>      kernel_semid64_ds to semun transformation if the exported ABI
>      for the architectures matches the expected kernel ABI, but the
>      implementation is already complex enough and don't think this
>      should be a hotspot in any case.

OK. Agreed. If we see a hotspot here we can discuss.

>   3. Finally for 32-bit architecture with both 32-bit and 64-bit time_t
>      support we follow the already set way to provide one symbol with
>      64-bit time_t support and implement the 32-bit time_t support on
>      basis of the 64-bit one.

s/on basis of/using/g
s/one/time_t/g
 
>      The default 32-bit symbol will allocate and copy the semid_ds
>      over multiple buffers, but this should be deprecated in favor
>      of the __semctl64 anyway.

OK.

> 
> Checked on i686-linux-gnu and x86_64-linux-gnu.  I also did some sniff
> tests on powerpc, powerpc64, mips, mips64, armhf, sparcv9, and
> sparc64.

OK.

> ---
>  include/sys/sem.h                             |   7 +
>  .../sysv/linux/bits/types/struct_semid64_ds.h |  33 +++
>  .../sysv/linux/bits/types/struct_semid_ds.h   |  21 +-
>  .../linux/hppa/bits/types/struct_semid_ds.h   |   6 +-
>  .../linux/hppa/struct_kernel_semid64_ds.h     |  12 +
>  .../linux/i386/struct_kernel_semid64_ds.h     |  12 +
>  sysdeps/unix/sysv/linux/ipc_priv.h            |  10 +
>  .../linux/mips/bits/types/struct_semid_ds.h   |   4 +-
>  .../linux/mips/struct_kernel_semid64_ds.h     |  10 +
>  .../powerpc/bits/types/struct_semid_ds.h      |   4 +-
>  .../powerpc32/struct_kernel_semid64_ds.h      |  12 +
>  sysdeps/unix/sysv/linux/semctl.c              | 261 +++++++++++++++---
>  .../linux/sparc/bits/types/struct_semid_ds.h  |   4 +-
>  .../sparc/sparc32/struct_kernel_semid64_ds.h  |  12 +
>  .../sysv/linux/struct_kernel_semid64_ds.h     |  12 +
>  .../linux/x86/bits/types/struct_semid_ds.h    |   4 +-
>  16 files changed, 359 insertions(+), 65 deletions(-)
>  create mode 100644 sysdeps/unix/sysv/linux/bits/types/struct_semid64_ds.h
>  create mode 100644 sysdeps/unix/sysv/linux/hppa/struct_kernel_semid64_ds.h
>  create mode 100644 sysdeps/unix/sysv/linux/i386/struct_kernel_semid64_ds.h
>  create mode 100644 sysdeps/unix/sysv/linux/mips/struct_kernel_semid64_ds.h
>  create mode 100644 sysdeps/unix/sysv/linux/powerpc/powerpc32/struct_kernel_semid64_ds.h
>  create mode 100644 sysdeps/unix/sysv/linux/sparc/sparc32/struct_kernel_semid64_ds.h
>  create mode 100644 sysdeps/unix/sysv/linux/struct_kernel_semid64_ds.h
> 
> diff --git a/include/sys/sem.h b/include/sys/sem.h
> index 69fdf1f752..a9151e057d 100644
> --- a/include/sys/sem.h
> +++ b/include/sys/sem.h
> @@ -5,5 +5,12 @@
>  
>  __typeof__ (semtimedop) __semtimedop attribute_hidden;
>  
> +#if __TIMESIZE == 64
> +# define __semctl64 __semctl
> +#else
> +extern int __semctl64 (int semid, int semnum, int cmd, ...);
> +libc_hidden_proto (__semctl64);

OK.

> +#endif
> +
>  # endif
>  #endif
> diff --git a/sysdeps/unix/sysv/linux/bits/types/struct_semid64_ds.h b/sysdeps/unix/sysv/linux/bits/types/struct_semid64_ds.h
> new file mode 100644
> index 0000000000..bda9eb4469
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/bits/types/struct_semid64_ds.h
> @@ -0,0 +1,33 @@
> +/* Generic implementation of the semaphore struct semid64_ds.
> +   Copyright (C) 2020 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
> +   <https://www.gnu.org/licenses/>.  */
> +
> +#ifndef _SYS_SEM_H
> +# error "Never include <bits/types/struct_semid_ds.h> directly; use <sys/sem.h> instead."
> +#endif
> +
> +#if __TIMESIZE == 64
> +# define __semid64_ds semid_ds
> +#else
> +struct __semid64_ds
> +{
> +  struct ipc_perm sem_perm;		/* operation permission struct */

OK.

> +  __time64_t sem_otime;			/* last semop() time */
> +  __time64_t sem_ctime;			/* last time changed by semctl() */
> +  __syscall_ulong_t sem_nsems;		/* number of semaphores in set */

OK.

> +};
> +#endif
> diff --git a/sysdeps/unix/sysv/linux/bits/types/struct_semid_ds.h b/sysdeps/unix/sysv/linux/bits/types/struct_semid_ds.h
> index 4222e6a59f..bc26d8be08 100644
> --- a/sysdeps/unix/sysv/linux/bits/types/struct_semid_ds.h
> +++ b/sysdeps/unix/sysv/linux/bits/types/struct_semid_ds.h
> @@ -21,26 +21,19 @@
>  #endif
>  
>  /* Data structure describing a set of semaphores.  */
> -#if __TIMESIZE == 32
>  struct semid_ds
>  {
>    struct ipc_perm sem_perm;        /* operation permission struct */
> +#if __TIMESIZE == 32
>    __time_t sem_otime;              /* last semop() time */
> -  __syscall_ulong_t __glibc_reserved1;
> +  __syscall_ulong_t __sem_otime_high;

OK.

>    __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;
> -};
> +  __syscall_ulong_t __sem_ctime_high;

OK.

>  #else
> -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() */
> -  __syscall_ulong_t sem_nsems;		/* number of semaphores in set */
> +  __time_t sem_otime;
> +  __time_t sem_ctime;

OK.

> +#endif
> +  __syscall_ulong_t sem_nsems;    /* number of semaphores in set */

OK.

>    __syscall_ulong_t __glibc_reserved3;
>    __syscall_ulong_t __glibc_reserved4;
>  };
> -#endif
> diff --git a/sysdeps/unix/sysv/linux/hppa/bits/types/struct_semid_ds.h b/sysdeps/unix/sysv/linux/hppa/bits/types/struct_semid_ds.h
> index d4c50b5ef8..68f9eca24c 100644
> --- a/sysdeps/unix/sysv/linux/hppa/bits/types/struct_semid_ds.h
> +++ b/sysdeps/unix/sysv/linux/hppa/bits/types/struct_semid_ds.h
> @@ -21,16 +21,14 @@
>  #endif
>  
>  /* Data structure describing a set of semaphores.  */
> -#if __TIMESIZE == 32
>  struct semid_ds
>  {
>    struct ipc_perm sem_perm;   /* operation permission struct */
> -  __syscall_ulong_t __glibc_reserved1;
> +  __syscall_ulong_t __sem_otime_high;
>    __time_t sem_otime;         /* last semop() time */
> -  __syscall_ulong_t __glibc_reserved2;
> +  __syscall_ulong_t __sem_ctime_high;

OK.

>    __time_t sem_ctime;         /* 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;
>  };
> -#endif
> diff --git a/sysdeps/unix/sysv/linux/hppa/struct_kernel_semid64_ds.h b/sysdeps/unix/sysv/linux/hppa/struct_kernel_semid64_ds.h
> new file mode 100644
> index 0000000000..2871030d0d
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/hppa/struct_kernel_semid64_ds.h
> @@ -0,0 +1,12 @@
> +/* Analogous to kernel struct semid64_ds used on semctl.  */
> +struct kernel_semid64_ds
> +{
> +  struct ipc_perm sem_perm;
> +  unsigned long sem_otime_high;
> +  unsigned long sem_otime;
> +  unsigned long sem_ctime_high;
> +  unsigned long sem_ctime;

OK. Matches where the reserved entries were for hppa.

> +  unsigned long sem_nsems;
> +  unsigned long __ununsed1;
> +  unsigned long __ununsed2;
> +};
> diff --git a/sysdeps/unix/sysv/linux/i386/struct_kernel_semid64_ds.h b/sysdeps/unix/sysv/linux/i386/struct_kernel_semid64_ds.h
> new file mode 100644
> index 0000000000..bab9cf63ba
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/i386/struct_kernel_semid64_ds.h
> @@ -0,0 +1,12 @@
> +/* Analogous to kernel struct semid64_ds used on semctl.  */
> +struct kernel_semid64_ds
> +{
> +  struct ipc_perm sem_perm;
> +  unsigned long sem_otime;
> +  unsigned long sem_otime_high;
> +  unsigned long sem_ctime;
> +  unsigned long sem_ctime_high;

OK.

> +  __syscall_ulong_t sem_nsems;
> +  __syscall_ulong_t __unused3;
> +  __syscall_ulong_t __unused4;
> +};
> diff --git a/sysdeps/unix/sysv/linux/ipc_priv.h b/sysdeps/unix/sysv/linux/ipc_priv.h
> index 15a6e683a4..93a6e5cb24 100644
> --- a/sysdeps/unix/sysv/linux/ipc_priv.h
> +++ b/sysdeps/unix/sysv/linux/ipc_priv.h
> @@ -53,4 +53,14 @@ struct __old_ipc_perm
>  #define SEMTIMEDOP_IPC_ARGS(__nsops, __sops, __timeout) \
>    (__nsops), 0, (__sops), (__timeout)
>  
> +/* Linux SysV ipc does not provide new syscalls for 64-bit time support on
> +   32-bit architectures, but rather split the timestamps on previous unused
> +   fields.  */

Suggest:

but rather split the timestamp into high and low; storing the high value in
previously unused fields.

> +#if (__WORDSIZE == 32 \
> +     && (!defined __SYSCALL_WORDSIZE || __SYSCALL_WORDSIZE == 32))
> +# define __IPC_TIME64 1
> +#else
> +# define __IPC_TIME64 0
> +#endif

OK.

> +
>  #include <ipc_ops.h>
> diff --git a/sysdeps/unix/sysv/linux/mips/bits/types/struct_semid_ds.h b/sysdeps/unix/sysv/linux/mips/bits/types/struct_semid_ds.h
> index 8954209a29..eec4a18cae 100644
> --- a/sysdeps/unix/sysv/linux/mips/bits/types/struct_semid_ds.h
> +++ b/sysdeps/unix/sysv/linux/mips/bits/types/struct_semid_ds.h
> @@ -27,6 +27,6 @@ struct semid_ds
>    __time_t sem_otime;	/* last semop() time */
>    __time_t sem_ctime;	/* 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;
> +  __syscall_ulong_t __sem_otime_high;
> +  __syscall_ulong_t __sem_ctime_high;

OK.

>  };
> diff --git a/sysdeps/unix/sysv/linux/mips/struct_kernel_semid64_ds.h b/sysdeps/unix/sysv/linux/mips/struct_kernel_semid64_ds.h
> new file mode 100644
> index 0000000000..76a9d83ea5
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/mips/struct_kernel_semid64_ds.h
> @@ -0,0 +1,10 @@
> +/* Analogous to kernel struct semid64_ds used on semctl.  */
> +struct kernel_semid64_ds
> +{
> +  struct ipc_perm sem_perm;
> +  unsigned long sem_otime;
> +  unsigned long sem_ctime;
> +  unsigned long sem_nsems;
> +  unsigned long sem_otime_high;
> +  unsigned long sem_ctime_high;

OK. Matches mips.

> +};
> diff --git a/sysdeps/unix/sysv/linux/powerpc/bits/types/struct_semid_ds.h b/sysdeps/unix/sysv/linux/powerpc/bits/types/struct_semid_ds.h
> index 300a9b98e9..d382d93c52 100644
> --- a/sysdeps/unix/sysv/linux/powerpc/bits/types/struct_semid_ds.h
> +++ b/sysdeps/unix/sysv/linux/powerpc/bits/types/struct_semid_ds.h
> @@ -25,9 +25,9 @@ struct semid_ds
>  {
>    struct ipc_perm sem_perm;   /* operation permission struct */
>  #if __TIMESIZE == 32
> -  __syscall_ulong_t __glibc_reserved1;
> +  __syscall_ulong_t __sem_otime_high;
>    __time_t sem_otime;         /* last semop() time */
> -  __syscall_ulong_t __glibc_reserved2;
> +  __syscall_ulong_t __sem_ctime_high;

OK.

>    __time_t sem_ctime;        /* last time changed by semctl() */
>  #else
>    __time_t sem_otime;         /* last semop() time */
> diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/struct_kernel_semid64_ds.h b/sysdeps/unix/sysv/linux/powerpc/powerpc32/struct_kernel_semid64_ds.h
> new file mode 100644
> index 0000000000..7fa4ef6424
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/struct_kernel_semid64_ds.h
> @@ -0,0 +1,12 @@
> +/* Analogous to kernel struct semid64_ds used on semctl.  */
> +struct kernel_semid64_ds
> +{
> +  struct ipc_perm sem_perm;
> +  unsigned long sem_otime_high;
> +  unsigned long sem_otime;
> +  unsigned long sem_ctime_high;
> +  unsigned long sem_ctime;
> +  unsigned long sem_nsems;
> +  unsigned long __unused3;
> +  unsigned long __unused4;

OK. Matches powerpc32.

> +};
> diff --git a/sysdeps/unix/sysv/linux/semctl.c b/sysdeps/unix/sysv/linux/semctl.c
> index 30571af49f..3a06270242 100644
> --- a/sysdeps/unix/sysv/linux/semctl.c
> +++ b/sysdeps/unix/sysv/linux/semctl.c
> @@ -21,10 +21,13 @@
>  #include <ipc_priv.h>
>  #include <sysdep.h>
>  #include <shlib-compat.h>
> -#include <errno.h>
> -#include <linux/posix_types.h>  /* For __kernel_mode_t.  */
> +#include <bits/types/struct_semid64_ds.h>  /* For __semid64_ds.  */
> +#include <linux/posix_types.h>             /* For __kernel_mode_t.  */

OK.

>  
> -/* Define a `union semun' suitable for Linux here.  */
> +/* The struct used to issue the syscall.  For architecture that assume

s/architecture/architectures/g

> +   64-bit time as default (!__ASSUME_TIME64_SYSCALLS) the syscall will
> +   split the resulting 64-bit sem_{o,c}time in two fields (__sem_{o,c}time

s/__sem_{o,c}time/sem_{o,c}time/g

> +   and __sem_{o,c}time_hi).  */

s/__sem_{o,c}time_hi/__sem{o,c}time_high/g

>  union semun
>  {
>    int val;			/* value for SETVAL */
> @@ -33,16 +36,89 @@ union semun
>    struct seminfo *__buf;	/* buffer for IPC_INFO */
>  };
>  
> -#ifndef DEFAULT_VERSION
> -# ifndef __ASSUME_SYSVIPC_BROKEN_MODE_T
> -#  define DEFAULT_VERSION GLIBC_2_2
> +#if __IPC_TIME64 == 0
> +# define semun64 semun
> +typedef union semun semctl_arg_t;
> +#else
> +# include <struct_kernel_semid64_ds.h>
> +
> +union ksemun64
> +{
> +  int val;
> +  struct kernel_semid64_ds *buf;
> +  unsigned short int *array;
> +  struct seminfo *__buf;
> +};

OK. Kernel side.

> +
> +# if __TIMESIZE == 64
> +#  define semun64 semun
>  # else
> -#  define DEFAULT_VERSION GLIBC_2_31
> +/* The struct used when __semctl64 is called.  */
> +union semun64
> +{
> +  int val;
> +  struct __semid64_ds *buf;
> +  unsigned short int *array;
> +  struct seminfo *__buf;
> +};

OK. User side.

>  # endif
> +
> +static void
> +semid64_to_ksemid64 (const struct __semid64_ds *semid64,
> +		     struct kernel_semid64_ds *ksemid)
> +{
> +  ksemid->sem_perm       = semid64->sem_perm;
> +  ksemid->sem_otime      = semid64->sem_otime;
> +  ksemid->sem_otime_high = semid64->sem_otime >> 32;
> +  ksemid->sem_ctime      = semid64->sem_ctime;
> +  ksemid->sem_ctime_high = semid64->sem_ctime >> 32;
> +  ksemid->sem_nsems      = semid64->sem_nsems;
> +}

OK. Copy to kernel.

> +
> +static void
> +ksemid64_to_semid64 (const struct kernel_semid64_ds *ksemid,
> +		     struct __semid64_ds *semid64)
> +{
> +  semid64->sem_perm  = ksemid->sem_perm;
> +  semid64->sem_otime = ksemid->sem_otime
> +		       | ((__time64_t) ksemid->sem_otime_high << 32);
> +  semid64->sem_ctime = ksemid->sem_ctime
> +		       | ((__time64_t) ksemid->sem_ctime_high << 32);
> +  semid64->sem_nsems = ksemid->sem_nsems;
> +}

OK. Copy to user (full 64-bit wide).

> +
> +static union ksemun64
> +semun64_to_ksemun64 (int cmd, union semun64 semun64,
> +		     struct kernel_semid64_ds *buf)
> +{
> +  union ksemun64 r = { 0 };
> +  switch (cmd)
> +    {
> +    case SETVAL:
> +      r.val = semun64.val;
> +      break;
> +    case GETALL:
> +    case SETALL:
> +      r.array = semun64.array;
> +      break;
> +    case IPC_STAT:
> +    case IPC_SET:
> +      r.buf = buf;
> +      semid64_to_ksemid64 (semun64.buf, r.buf);
> +      break;
> +    case IPC_INFO:
> +    case SEM_INFO:
> +      r.__buf = semun64.__buf;
> +      break;
> +    }
> +  return r;
> +}

OK. Union copy.

> +
> +typedef union ksemun64 semctl_arg_t;
>  #endif
>  
>  static int
> -semctl_syscall (int semid, int semnum, int cmd, union semun arg)
> +semctl_syscall (int semid, int semnum, int cmd, semctl_arg_t arg)
>  {
>  #ifdef __ASSUME_DIRECT_SYSVIPC_SYSCALLS
>    return INLINE_SYSCALL_CALL (semctl, semid, semnum, cmd | __IPC_64,
> @@ -53,15 +129,15 @@ semctl_syscall (int semid, int semnum, int cmd, union semun arg)
>  #endif
>  }
>  
> +/* POSIX states ipc_perm mode should have type of mode_t.  */
> +_Static_assert (sizeof ((struct semid_ds){0}.sem_perm.mode)
> +		== sizeof (mode_t),
> +		"sizeof (msqid_ds.msg_perm.mode) != sizeof (mode_t)");

OK.

> +
>  int
> -__new_semctl (int semid, int semnum, int cmd, ...)
> +__semctl64 (int semid, int semnum, int cmd, ...)
>  {
> -  /* POSIX states ipc_perm mode should have type of mode_t.  */
> -  _Static_assert (sizeof ((struct semid_ds){0}.sem_perm.mode)
> -		  == sizeof (mode_t),
> -		  "sizeof (msqid_ds.msg_perm.mode) != sizeof (mode_t)");
> -
> -  union semun arg = { 0 };
> +  union semun64 arg64 = { 0 };
>    va_list ap;
>  
>    /* Get the argument only if required.  */
> @@ -76,44 +152,151 @@ __new_semctl (int semid, int semnum, int cmd, ...)
>      case IPC_INFO:      /* arg.__buf */
>      case SEM_INFO:
>        va_start (ap, cmd);
> -      arg = va_arg (ap, union semun);
> +      arg64 = va_arg (ap, union semun64);
>        va_end (ap);
>        break;
>      }
>  
> -#ifdef __ASSUME_SYSVIPC_BROKEN_MODE_T
> -  struct semid_ds tmpds;
> -  if (cmd == IPC_SET)
> -    {
> -      tmpds = *arg.buf;
> -      tmpds.sem_perm.mode *= 0x10000U;
> -      arg.buf = &tmpds;
> -    }
> +#if __IPC_TIME64
> +  struct kernel_semid64_ds ksemid;
> +  union ksemun64 ksemun = semun64_to_ksemun64 (cmd, arg64, &ksemid);
> +  union ksemun64 arg = ksemun;
> +#else
> +  union semun arg = arg64;
>  #endif
>  
>    int ret = semctl_syscall (semid, semnum, cmd, arg);
> +  if (ret < 0)
> +    return ret;
>  
> -  if (ret >= 0)
> +  switch (cmd)
>      {
> -      switch (cmd)
> -	{
> -        case IPC_STAT:
> -        case SEM_STAT:
> -        case SEM_STAT_ANY:
> +    case IPC_STAT:
> +    case SEM_STAT:
> +    case SEM_STAT_ANY:
>  #ifdef __ASSUME_SYSVIPC_BROKEN_MODE_T
> -          arg.buf->sem_perm.mode >>= 16;
> +      arg.buf->sem_perm.mode >>= 16;
>  #else
> -	  /* Old Linux kernel versions might not clear the mode padding.  */
> -	  if (sizeof ((struct semid_ds){0}.sem_perm.mode)
> -	      != sizeof (__kernel_mode_t))
> -	    arg.buf->sem_perm.mode &= 0xFFFF;
> +      /* Old Linux kernel versions might not clear the mode padding.  */
> +      if (sizeof ((struct semid_ds){0}.sem_perm.mode)
> +	  != sizeof (__kernel_mode_t))
> +	arg.buf->sem_perm.mode &= 0xFFFF;
>  #endif
> -	}
> +
> +#if __IPC_TIME64
> +      ksemid64_to_semid64 (arg.buf, arg64.buf);
> +#endif
> +    }
> +
> +  return ret;
> +}

OK.

> +#if __TIMESIZE != 64
> +libc_hidden_def (__semctl64)
> +
> +
> +/* The 64-bit time_t semid_ds version might have a different layout and
> +   internal field alignment.  */
> +static void
> +semid64_ds_to_semid_ds (struct semid_ds *ds, const struct __semid64_ds *ds64)
> +{
> +  ds->sem_perm = ds64->sem_perm;
> +  ds->sem_otime = ds64->sem_otime;
> +  ds->sem_ctime = ds64->sem_ctime;
> +  ds->sem_nsems = ds64->sem_nsems;
> +}
> +
> +static void
> +semid_ds_to_semid64_ds (struct __semid64_ds *ds64, const struct semid_ds *ds)
> +{
> +  ds64->sem_perm = ds->sem_perm;
> +  ds64->sem_otime = ds->sem_otime
> +		    | ((__time64_t) ds->__sem_otime_high << 32);
> +  ds64->sem_ctime = ds->sem_ctime
> +		    | ((__time64_t) ds->__sem_ctime_high << 32);
> +  ds64->sem_nsems = ds->sem_nsems;
> +}
> +
> +static union semun64
> +semun_to_semun64 (int cmd, union semun semun, struct __semid64_ds *semid64)
> +{
> +  union semun64 r = { 0 };
> +  switch (cmd)
> +    {
> +    case SETVAL:
> +      r.val = semun.val;
> +      break;
> +    case GETALL:
> +    case SETALL:
> +      r.array = semun.array;
> +      break;
> +    case IPC_STAT:
> +    case IPC_SET:
> +      r.buf = semid64;
> +      semid_ds_to_semid64_ds (r.buf, semun.buf);
> +# ifdef __ASSUME_SYSVIPC_BROKEN_MODE_T
> +      if (cmd == IPC_SET)
> +	r.buf->sem_perm.mode *= 0x10000U;
> +# endif
> +      break;
> +    case IPC_INFO:
> +    case SEM_INFO:
> +      r.__buf = semun.__buf;
> +      break;
> +    }
> +  return r;
> +}

OK.

> +
> +int
> +__semctl (int semid, int semnum, int cmd, ...)
> +{
> +  union semun arg = { 0 };
> +
> +  va_list ap;
> +
> +  /* Get the argument only if required.  */
> +  switch (cmd)
> +    {
> +    case SETVAL:        /* arg.val */
> +    case GETALL:        /* arg.array */
> +    case SETALL:
> +    case IPC_STAT:      /* arg.buf */
> +    case IPC_SET:
> +    case SEM_STAT:
> +    case IPC_INFO:      /* arg.__buf */
> +    case SEM_INFO:
> +      va_start (ap, cmd);
> +      arg = va_arg (ap, union semun);
> +      va_end (ap);
> +      break;
> +    }
> +
> +  struct __semid64_ds semid64;
> +  union semun64 arg64 = semun_to_semun64 (cmd, arg, &semid64);
> +
> +  int ret = __semctl64 (semid, semnum, cmd, arg64);

OK. Implement with __semctl64.

> +  if (ret < 0)
> +    return ret;
> +
> +  switch (cmd)
> +    {
> +    case IPC_STAT:
> +    case SEM_STAT:
> +    case SEM_STAT_ANY:
> +      semid64_ds_to_semid_ds (arg.buf, arg64.buf);
>      }
>  
>    return ret;
>  }
> -versioned_symbol (libc, __new_semctl, semctl, DEFAULT_VERSION);
> +#endif
> +
> +#ifndef DEFAULT_VERSION
> +# ifndef __ASSUME_SYSVIPC_BROKEN_MODE_T
> +#  define DEFAULT_VERSION GLIBC_2_2
> +# else
> +#  define DEFAULT_VERSION GLIBC_2_31
> +# endif
> +#endif
> +versioned_symbol (libc, __semctl, semctl, DEFAULT_VERSION);
>  
>  #if defined __ASSUME_SYSVIPC_BROKEN_MODE_T \
>      && SHLIB_COMPAT (libc, GLIBC_2_2, GLIBC_2_31)
> @@ -121,7 +304,7 @@ int
>  attribute_compat_text_section
>  __semctl_mode16 (int semid, int semnum, int cmd, ...)
>  {
> -  union semun arg = { 0 };
> +  semctl_arg_t arg = { 0 };
>    va_list ap;
>  
>    /* Get the argument only if required.  */
> @@ -136,7 +319,7 @@ __semctl_mode16 (int semid, int semnum, int cmd, ...)
>      case IPC_INFO:      /* arg.__buf */
>      case SEM_INFO:
>        va_start (ap, cmd);
> -      arg = va_arg (ap, union semun);
> +      arg = va_arg (ap, semctl_arg_t);
>        va_end (ap);
>        break;
>      }
> diff --git a/sysdeps/unix/sysv/linux/sparc/bits/types/struct_semid_ds.h b/sysdeps/unix/sysv/linux/sparc/bits/types/struct_semid_ds.h
> index 46fcd79fb6..0110c1a940 100644
> --- a/sysdeps/unix/sysv/linux/sparc/bits/types/struct_semid_ds.h
> +++ b/sysdeps/unix/sysv/linux/sparc/bits/types/struct_semid_ds.h
> @@ -25,9 +25,9 @@ struct semid_ds
>  {
>    struct ipc_perm sem_perm;   /* operation permission struct */
>  #if __TIMESIZE == 32
> -  __syscall_ulong_t __glibc_reserved1;
> +  __syscall_ulong_t __sem_otime_high;
>    __time_t sem_otime;         /* last semop() time */
> -  __syscall_ulong_t __glibc_reserved2;
> +  __syscall_ulong_t __sem_ctime_high;

OK.

>    __time_t sem_ctime;        /* last time changed by semctl() */
>  #else
>    __time_t sem_otime;         /* last semop() time */
> diff --git a/sysdeps/unix/sysv/linux/sparc/sparc32/struct_kernel_semid64_ds.h b/sysdeps/unix/sysv/linux/sparc/sparc32/struct_kernel_semid64_ds.h
> new file mode 100644
> index 0000000000..8c4697f9ab
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/sparc/sparc32/struct_kernel_semid64_ds.h
> @@ -0,0 +1,12 @@
> +/* Analogous to kernel struct semid64_ds used on semctl.  */
> +struct kernel_semid64_ds
> +{
> +  struct ipc_perm sem_perm;
> +  unsigned long sem_otime_high;
> +  unsigned long sem_otime;
> +  unsigned long sem_ctime_high;
> +  unsigned long sem_ctime;

OK. Matches sparc32.

> +  unsigned long sem_nsems;
> +  unsigned long __unused1;
> +  unsigned long __unused2;
> +};
> diff --git a/sysdeps/unix/sysv/linux/struct_kernel_semid64_ds.h b/sysdeps/unix/sysv/linux/struct_kernel_semid64_ds.h
> new file mode 100644
> index 0000000000..f9edf0f76f
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/struct_kernel_semid64_ds.h
> @@ -0,0 +1,12 @@
> +/* Analogous to kernel struct semid64_ds used on semctl.  */
> +struct kernel_semid64_ds
> +{
> +  struct ipc_perm sem_perm;
> +  unsigned long sem_otime;
> +  unsigned long sem_otime_high;
> +  unsigned long sem_ctime;
> +  unsigned long sem_ctime_high;
> +  unsigned long sem_nsems;
> +  unsigned long __unused1;
> +  unsigned long __unused2;
> +};
> diff --git a/sysdeps/unix/sysv/linux/x86/bits/types/struct_semid_ds.h b/sysdeps/unix/sysv/linux/x86/bits/types/struct_semid_ds.h
> index f7ec89d115..c3f2fde9fd 100644
> --- a/sysdeps/unix/sysv/linux/x86/bits/types/struct_semid_ds.h
> +++ b/sysdeps/unix/sysv/linux/x86/bits/types/struct_semid_ds.h
> @@ -25,9 +25,9 @@ struct semid_ds
>  {
>    struct ipc_perm sem_perm;   /* operation permission struct */
>    __time_t sem_otime;  /* last semop() time */
> -  __syscall_ulong_t __glibc_reserved1;
> +  __syscall_ulong_t __sem_otime_high;
>    __time_t sem_ctime;  /* last time changed by semctl() */
> -  __syscall_ulong_t __glibc_reserved2;
> +  __syscall_ulong_t __sem_ctime_high;
>    __syscall_ulong_t sem_nsems;    /* number of semaphores in set */
>    __syscall_ulong_t __glibc_reserved3;
>    __syscall_ulong_t __glibc_reserved4;
> 

OK.
  
Adhemerval Zanella July 7, 2020, 2:09 p.m. UTC | #3
On Tue, Jul 7, 2020 at 12:32 AM Carlos O'Donell <carlos@redhat.com> wrote:
>
> On 6/30/20 3:24 PM, Adhemerval Zanella via Libc-alpha wrote:
>
> OK for master with comment cleanups. Very clean, very easy to understand
> patch. I should finish the other 6 patches tomorrow morning.

Ack, I have included all your comment suggestions changes.

>
> No regressions on x86_64 or i686 (I did see the new rseq regression
> for posix/tst-affinity-static though).
>
> Reviewed-by: Carlos O'Donell <carlos@redhat.com>
> Tested-by: Carlos O'Donell <carlos@redhat.com>

Thanks!
  

Patch

diff --git a/include/sys/sem.h b/include/sys/sem.h
index 69fdf1f752..a9151e057d 100644
--- a/include/sys/sem.h
+++ b/include/sys/sem.h
@@ -5,5 +5,12 @@ 
 
 __typeof__ (semtimedop) __semtimedop attribute_hidden;
 
+#if __TIMESIZE == 64
+# define __semctl64 __semctl
+#else
+extern int __semctl64 (int semid, int semnum, int cmd, ...);
+libc_hidden_proto (__semctl64);
+#endif
+
 # endif
 #endif
diff --git a/sysdeps/unix/sysv/linux/bits/types/struct_semid64_ds.h b/sysdeps/unix/sysv/linux/bits/types/struct_semid64_ds.h
new file mode 100644
index 0000000000..bda9eb4469
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/bits/types/struct_semid64_ds.h
@@ -0,0 +1,33 @@ 
+/* Generic implementation of the semaphore struct semid64_ds.
+   Copyright (C) 2020 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
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef _SYS_SEM_H
+# error "Never include <bits/types/struct_semid_ds.h> directly; use <sys/sem.h> instead."
+#endif
+
+#if __TIMESIZE == 64
+# define __semid64_ds semid_ds
+#else
+struct __semid64_ds
+{
+  struct ipc_perm sem_perm;		/* operation permission struct */
+  __time64_t sem_otime;			/* last semop() time */
+  __time64_t sem_ctime;			/* last time changed by semctl() */
+  __syscall_ulong_t sem_nsems;		/* number of semaphores in set */
+};
+#endif
diff --git a/sysdeps/unix/sysv/linux/bits/types/struct_semid_ds.h b/sysdeps/unix/sysv/linux/bits/types/struct_semid_ds.h
index 4222e6a59f..bc26d8be08 100644
--- a/sysdeps/unix/sysv/linux/bits/types/struct_semid_ds.h
+++ b/sysdeps/unix/sysv/linux/bits/types/struct_semid_ds.h
@@ -21,26 +21,19 @@ 
 #endif
 
 /* Data structure describing a set of semaphores.  */
-#if __TIMESIZE == 32
 struct semid_ds
 {
   struct ipc_perm sem_perm;        /* operation permission struct */
+#if __TIMESIZE == 32
   __time_t sem_otime;              /* last semop() time */
-  __syscall_ulong_t __glibc_reserved1;
+  __syscall_ulong_t __sem_otime_high;
   __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;
-};
+  __syscall_ulong_t __sem_ctime_high;
 #else
-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() */
-  __syscall_ulong_t sem_nsems;		/* number of semaphores in set */
+  __time_t sem_otime;
+  __time_t sem_ctime;
+#endif
+  __syscall_ulong_t sem_nsems;    /* number of semaphores in set */
   __syscall_ulong_t __glibc_reserved3;
   __syscall_ulong_t __glibc_reserved4;
 };
-#endif
diff --git a/sysdeps/unix/sysv/linux/hppa/bits/types/struct_semid_ds.h b/sysdeps/unix/sysv/linux/hppa/bits/types/struct_semid_ds.h
index d4c50b5ef8..68f9eca24c 100644
--- a/sysdeps/unix/sysv/linux/hppa/bits/types/struct_semid_ds.h
+++ b/sysdeps/unix/sysv/linux/hppa/bits/types/struct_semid_ds.h
@@ -21,16 +21,14 @@ 
 #endif
 
 /* Data structure describing a set of semaphores.  */
-#if __TIMESIZE == 32
 struct semid_ds
 {
   struct ipc_perm sem_perm;   /* operation permission struct */
-  __syscall_ulong_t __glibc_reserved1;
+  __syscall_ulong_t __sem_otime_high;
   __time_t sem_otime;         /* last semop() time */
-  __syscall_ulong_t __glibc_reserved2;
+  __syscall_ulong_t __sem_ctime_high;
   __time_t sem_ctime;         /* 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;
 };
-#endif
diff --git a/sysdeps/unix/sysv/linux/hppa/struct_kernel_semid64_ds.h b/sysdeps/unix/sysv/linux/hppa/struct_kernel_semid64_ds.h
new file mode 100644
index 0000000000..2871030d0d
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/hppa/struct_kernel_semid64_ds.h
@@ -0,0 +1,12 @@ 
+/* Analogous to kernel struct semid64_ds used on semctl.  */
+struct kernel_semid64_ds
+{
+  struct ipc_perm sem_perm;
+  unsigned long sem_otime_high;
+  unsigned long sem_otime;
+  unsigned long sem_ctime_high;
+  unsigned long sem_ctime;
+  unsigned long sem_nsems;
+  unsigned long __ununsed1;
+  unsigned long __ununsed2;
+};
diff --git a/sysdeps/unix/sysv/linux/i386/struct_kernel_semid64_ds.h b/sysdeps/unix/sysv/linux/i386/struct_kernel_semid64_ds.h
new file mode 100644
index 0000000000..bab9cf63ba
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/i386/struct_kernel_semid64_ds.h
@@ -0,0 +1,12 @@ 
+/* Analogous to kernel struct semid64_ds used on semctl.  */
+struct kernel_semid64_ds
+{
+  struct ipc_perm sem_perm;
+  unsigned long sem_otime;
+  unsigned long sem_otime_high;
+  unsigned long sem_ctime;
+  unsigned long sem_ctime_high;
+  __syscall_ulong_t sem_nsems;
+  __syscall_ulong_t __unused3;
+  __syscall_ulong_t __unused4;
+};
diff --git a/sysdeps/unix/sysv/linux/ipc_priv.h b/sysdeps/unix/sysv/linux/ipc_priv.h
index 15a6e683a4..93a6e5cb24 100644
--- a/sysdeps/unix/sysv/linux/ipc_priv.h
+++ b/sysdeps/unix/sysv/linux/ipc_priv.h
@@ -53,4 +53,14 @@  struct __old_ipc_perm
 #define SEMTIMEDOP_IPC_ARGS(__nsops, __sops, __timeout) \
   (__nsops), 0, (__sops), (__timeout)
 
+/* Linux SysV ipc does not provide new syscalls for 64-bit time support on
+   32-bit architectures, but rather split the timestamps on previous unused
+   fields.  */
+#if (__WORDSIZE == 32 \
+     && (!defined __SYSCALL_WORDSIZE || __SYSCALL_WORDSIZE == 32))
+# define __IPC_TIME64 1
+#else
+# define __IPC_TIME64 0
+#endif
+
 #include <ipc_ops.h>
diff --git a/sysdeps/unix/sysv/linux/mips/bits/types/struct_semid_ds.h b/sysdeps/unix/sysv/linux/mips/bits/types/struct_semid_ds.h
index 8954209a29..eec4a18cae 100644
--- a/sysdeps/unix/sysv/linux/mips/bits/types/struct_semid_ds.h
+++ b/sysdeps/unix/sysv/linux/mips/bits/types/struct_semid_ds.h
@@ -27,6 +27,6 @@  struct semid_ds
   __time_t sem_otime;	/* last semop() time */
   __time_t sem_ctime;	/* 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;
+  __syscall_ulong_t __sem_otime_high;
+  __syscall_ulong_t __sem_ctime_high;
 };
diff --git a/sysdeps/unix/sysv/linux/mips/struct_kernel_semid64_ds.h b/sysdeps/unix/sysv/linux/mips/struct_kernel_semid64_ds.h
new file mode 100644
index 0000000000..76a9d83ea5
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/mips/struct_kernel_semid64_ds.h
@@ -0,0 +1,10 @@ 
+/* Analogous to kernel struct semid64_ds used on semctl.  */
+struct kernel_semid64_ds
+{
+  struct ipc_perm sem_perm;
+  unsigned long sem_otime;
+  unsigned long sem_ctime;
+  unsigned long sem_nsems;
+  unsigned long sem_otime_high;
+  unsigned long sem_ctime_high;
+};
diff --git a/sysdeps/unix/sysv/linux/powerpc/bits/types/struct_semid_ds.h b/sysdeps/unix/sysv/linux/powerpc/bits/types/struct_semid_ds.h
index 300a9b98e9..d382d93c52 100644
--- a/sysdeps/unix/sysv/linux/powerpc/bits/types/struct_semid_ds.h
+++ b/sysdeps/unix/sysv/linux/powerpc/bits/types/struct_semid_ds.h
@@ -25,9 +25,9 @@  struct semid_ds
 {
   struct ipc_perm sem_perm;   /* operation permission struct */
 #if __TIMESIZE == 32
-  __syscall_ulong_t __glibc_reserved1;
+  __syscall_ulong_t __sem_otime_high;
   __time_t sem_otime;         /* last semop() time */
-  __syscall_ulong_t __glibc_reserved2;
+  __syscall_ulong_t __sem_ctime_high;
   __time_t sem_ctime;        /* last time changed by semctl() */
 #else
   __time_t sem_otime;         /* last semop() time */
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/struct_kernel_semid64_ds.h b/sysdeps/unix/sysv/linux/powerpc/powerpc32/struct_kernel_semid64_ds.h
new file mode 100644
index 0000000000..7fa4ef6424
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/struct_kernel_semid64_ds.h
@@ -0,0 +1,12 @@ 
+/* Analogous to kernel struct semid64_ds used on semctl.  */
+struct kernel_semid64_ds
+{
+  struct ipc_perm sem_perm;
+  unsigned long sem_otime_high;
+  unsigned long sem_otime;
+  unsigned long sem_ctime_high;
+  unsigned long sem_ctime;
+  unsigned long sem_nsems;
+  unsigned long __unused3;
+  unsigned long __unused4;
+};
diff --git a/sysdeps/unix/sysv/linux/semctl.c b/sysdeps/unix/sysv/linux/semctl.c
index 30571af49f..3a06270242 100644
--- a/sysdeps/unix/sysv/linux/semctl.c
+++ b/sysdeps/unix/sysv/linux/semctl.c
@@ -21,10 +21,13 @@ 
 #include <ipc_priv.h>
 #include <sysdep.h>
 #include <shlib-compat.h>
-#include <errno.h>
-#include <linux/posix_types.h>  /* For __kernel_mode_t.  */
+#include <bits/types/struct_semid64_ds.h>  /* For __semid64_ds.  */
+#include <linux/posix_types.h>             /* For __kernel_mode_t.  */
 
-/* Define a `union semun' suitable for Linux here.  */
+/* The struct used to issue the syscall.  For architecture that assume
+   64-bit time as default (!__ASSUME_TIME64_SYSCALLS) the syscall will
+   split the resulting 64-bit sem_{o,c}time in two fields (__sem_{o,c}time
+   and __sem_{o,c}time_hi).  */
 union semun
 {
   int val;			/* value for SETVAL */
@@ -33,16 +36,89 @@  union semun
   struct seminfo *__buf;	/* buffer for IPC_INFO */
 };
 
-#ifndef DEFAULT_VERSION
-# ifndef __ASSUME_SYSVIPC_BROKEN_MODE_T
-#  define DEFAULT_VERSION GLIBC_2_2
+#if __IPC_TIME64 == 0
+# define semun64 semun
+typedef union semun semctl_arg_t;
+#else
+# include <struct_kernel_semid64_ds.h>
+
+union ksemun64
+{
+  int val;
+  struct kernel_semid64_ds *buf;
+  unsigned short int *array;
+  struct seminfo *__buf;
+};
+
+# if __TIMESIZE == 64
+#  define semun64 semun
 # else
-#  define DEFAULT_VERSION GLIBC_2_31
+/* The struct used when __semctl64 is called.  */
+union semun64
+{
+  int val;
+  struct __semid64_ds *buf;
+  unsigned short int *array;
+  struct seminfo *__buf;
+};
 # endif
+
+static void
+semid64_to_ksemid64 (const struct __semid64_ds *semid64,
+		     struct kernel_semid64_ds *ksemid)
+{
+  ksemid->sem_perm       = semid64->sem_perm;
+  ksemid->sem_otime      = semid64->sem_otime;
+  ksemid->sem_otime_high = semid64->sem_otime >> 32;
+  ksemid->sem_ctime      = semid64->sem_ctime;
+  ksemid->sem_ctime_high = semid64->sem_ctime >> 32;
+  ksemid->sem_nsems      = semid64->sem_nsems;
+}
+
+static void
+ksemid64_to_semid64 (const struct kernel_semid64_ds *ksemid,
+		     struct __semid64_ds *semid64)
+{
+  semid64->sem_perm  = ksemid->sem_perm;
+  semid64->sem_otime = ksemid->sem_otime
+		       | ((__time64_t) ksemid->sem_otime_high << 32);
+  semid64->sem_ctime = ksemid->sem_ctime
+		       | ((__time64_t) ksemid->sem_ctime_high << 32);
+  semid64->sem_nsems = ksemid->sem_nsems;
+}
+
+static union ksemun64
+semun64_to_ksemun64 (int cmd, union semun64 semun64,
+		     struct kernel_semid64_ds *buf)
+{
+  union ksemun64 r = { 0 };
+  switch (cmd)
+    {
+    case SETVAL:
+      r.val = semun64.val;
+      break;
+    case GETALL:
+    case SETALL:
+      r.array = semun64.array;
+      break;
+    case IPC_STAT:
+    case IPC_SET:
+      r.buf = buf;
+      semid64_to_ksemid64 (semun64.buf, r.buf);
+      break;
+    case IPC_INFO:
+    case SEM_INFO:
+      r.__buf = semun64.__buf;
+      break;
+    }
+  return r;
+}
+
+typedef union ksemun64 semctl_arg_t;
 #endif
 
 static int
-semctl_syscall (int semid, int semnum, int cmd, union semun arg)
+semctl_syscall (int semid, int semnum, int cmd, semctl_arg_t arg)
 {
 #ifdef __ASSUME_DIRECT_SYSVIPC_SYSCALLS
   return INLINE_SYSCALL_CALL (semctl, semid, semnum, cmd | __IPC_64,
@@ -53,15 +129,15 @@  semctl_syscall (int semid, int semnum, int cmd, union semun arg)
 #endif
 }
 
+/* POSIX states ipc_perm mode should have type of mode_t.  */
+_Static_assert (sizeof ((struct semid_ds){0}.sem_perm.mode)
+		== sizeof (mode_t),
+		"sizeof (msqid_ds.msg_perm.mode) != sizeof (mode_t)");
+
 int
-__new_semctl (int semid, int semnum, int cmd, ...)
+__semctl64 (int semid, int semnum, int cmd, ...)
 {
-  /* POSIX states ipc_perm mode should have type of mode_t.  */
-  _Static_assert (sizeof ((struct semid_ds){0}.sem_perm.mode)
-		  == sizeof (mode_t),
-		  "sizeof (msqid_ds.msg_perm.mode) != sizeof (mode_t)");
-
-  union semun arg = { 0 };
+  union semun64 arg64 = { 0 };
   va_list ap;
 
   /* Get the argument only if required.  */
@@ -76,44 +152,151 @@  __new_semctl (int semid, int semnum, int cmd, ...)
     case IPC_INFO:      /* arg.__buf */
     case SEM_INFO:
       va_start (ap, cmd);
-      arg = va_arg (ap, union semun);
+      arg64 = va_arg (ap, union semun64);
       va_end (ap);
       break;
     }
 
-#ifdef __ASSUME_SYSVIPC_BROKEN_MODE_T
-  struct semid_ds tmpds;
-  if (cmd == IPC_SET)
-    {
-      tmpds = *arg.buf;
-      tmpds.sem_perm.mode *= 0x10000U;
-      arg.buf = &tmpds;
-    }
+#if __IPC_TIME64
+  struct kernel_semid64_ds ksemid;
+  union ksemun64 ksemun = semun64_to_ksemun64 (cmd, arg64, &ksemid);
+  union ksemun64 arg = ksemun;
+#else
+  union semun arg = arg64;
 #endif
 
   int ret = semctl_syscall (semid, semnum, cmd, arg);
+  if (ret < 0)
+    return ret;
 
-  if (ret >= 0)
+  switch (cmd)
     {
-      switch (cmd)
-	{
-        case IPC_STAT:
-        case SEM_STAT:
-        case SEM_STAT_ANY:
+    case IPC_STAT:
+    case SEM_STAT:
+    case SEM_STAT_ANY:
 #ifdef __ASSUME_SYSVIPC_BROKEN_MODE_T
-          arg.buf->sem_perm.mode >>= 16;
+      arg.buf->sem_perm.mode >>= 16;
 #else
-	  /* Old Linux kernel versions might not clear the mode padding.  */
-	  if (sizeof ((struct semid_ds){0}.sem_perm.mode)
-	      != sizeof (__kernel_mode_t))
-	    arg.buf->sem_perm.mode &= 0xFFFF;
+      /* Old Linux kernel versions might not clear the mode padding.  */
+      if (sizeof ((struct semid_ds){0}.sem_perm.mode)
+	  != sizeof (__kernel_mode_t))
+	arg.buf->sem_perm.mode &= 0xFFFF;
 #endif
-	}
+
+#if __IPC_TIME64
+      ksemid64_to_semid64 (arg.buf, arg64.buf);
+#endif
+    }
+
+  return ret;
+}
+#if __TIMESIZE != 64
+libc_hidden_def (__semctl64)
+
+
+/* The 64-bit time_t semid_ds version might have a different layout and
+   internal field alignment.  */
+static void
+semid64_ds_to_semid_ds (struct semid_ds *ds, const struct __semid64_ds *ds64)
+{
+  ds->sem_perm = ds64->sem_perm;
+  ds->sem_otime = ds64->sem_otime;
+  ds->sem_ctime = ds64->sem_ctime;
+  ds->sem_nsems = ds64->sem_nsems;
+}
+
+static void
+semid_ds_to_semid64_ds (struct __semid64_ds *ds64, const struct semid_ds *ds)
+{
+  ds64->sem_perm = ds->sem_perm;
+  ds64->sem_otime = ds->sem_otime
+		    | ((__time64_t) ds->__sem_otime_high << 32);
+  ds64->sem_ctime = ds->sem_ctime
+		    | ((__time64_t) ds->__sem_ctime_high << 32);
+  ds64->sem_nsems = ds->sem_nsems;
+}
+
+static union semun64
+semun_to_semun64 (int cmd, union semun semun, struct __semid64_ds *semid64)
+{
+  union semun64 r = { 0 };
+  switch (cmd)
+    {
+    case SETVAL:
+      r.val = semun.val;
+      break;
+    case GETALL:
+    case SETALL:
+      r.array = semun.array;
+      break;
+    case IPC_STAT:
+    case IPC_SET:
+      r.buf = semid64;
+      semid_ds_to_semid64_ds (r.buf, semun.buf);
+# ifdef __ASSUME_SYSVIPC_BROKEN_MODE_T
+      if (cmd == IPC_SET)
+	r.buf->sem_perm.mode *= 0x10000U;
+# endif
+      break;
+    case IPC_INFO:
+    case SEM_INFO:
+      r.__buf = semun.__buf;
+      break;
+    }
+  return r;
+}
+
+int
+__semctl (int semid, int semnum, int cmd, ...)
+{
+  union semun arg = { 0 };
+
+  va_list ap;
+
+  /* Get the argument only if required.  */
+  switch (cmd)
+    {
+    case SETVAL:        /* arg.val */
+    case GETALL:        /* arg.array */
+    case SETALL:
+    case IPC_STAT:      /* arg.buf */
+    case IPC_SET:
+    case SEM_STAT:
+    case IPC_INFO:      /* arg.__buf */
+    case SEM_INFO:
+      va_start (ap, cmd);
+      arg = va_arg (ap, union semun);
+      va_end (ap);
+      break;
+    }
+
+  struct __semid64_ds semid64;
+  union semun64 arg64 = semun_to_semun64 (cmd, arg, &semid64);
+
+  int ret = __semctl64 (semid, semnum, cmd, arg64);
+  if (ret < 0)
+    return ret;
+
+  switch (cmd)
+    {
+    case IPC_STAT:
+    case SEM_STAT:
+    case SEM_STAT_ANY:
+      semid64_ds_to_semid_ds (arg.buf, arg64.buf);
     }
 
   return ret;
 }
-versioned_symbol (libc, __new_semctl, semctl, DEFAULT_VERSION);
+#endif
+
+#ifndef DEFAULT_VERSION
+# ifndef __ASSUME_SYSVIPC_BROKEN_MODE_T
+#  define DEFAULT_VERSION GLIBC_2_2
+# else
+#  define DEFAULT_VERSION GLIBC_2_31
+# endif
+#endif
+versioned_symbol (libc, __semctl, semctl, DEFAULT_VERSION);
 
 #if defined __ASSUME_SYSVIPC_BROKEN_MODE_T \
     && SHLIB_COMPAT (libc, GLIBC_2_2, GLIBC_2_31)
@@ -121,7 +304,7 @@  int
 attribute_compat_text_section
 __semctl_mode16 (int semid, int semnum, int cmd, ...)
 {
-  union semun arg = { 0 };
+  semctl_arg_t arg = { 0 };
   va_list ap;
 
   /* Get the argument only if required.  */
@@ -136,7 +319,7 @@  __semctl_mode16 (int semid, int semnum, int cmd, ...)
     case IPC_INFO:      /* arg.__buf */
     case SEM_INFO:
       va_start (ap, cmd);
-      arg = va_arg (ap, union semun);
+      arg = va_arg (ap, semctl_arg_t);
       va_end (ap);
       break;
     }
diff --git a/sysdeps/unix/sysv/linux/sparc/bits/types/struct_semid_ds.h b/sysdeps/unix/sysv/linux/sparc/bits/types/struct_semid_ds.h
index 46fcd79fb6..0110c1a940 100644
--- a/sysdeps/unix/sysv/linux/sparc/bits/types/struct_semid_ds.h
+++ b/sysdeps/unix/sysv/linux/sparc/bits/types/struct_semid_ds.h
@@ -25,9 +25,9 @@  struct semid_ds
 {
   struct ipc_perm sem_perm;   /* operation permission struct */
 #if __TIMESIZE == 32
-  __syscall_ulong_t __glibc_reserved1;
+  __syscall_ulong_t __sem_otime_high;
   __time_t sem_otime;         /* last semop() time */
-  __syscall_ulong_t __glibc_reserved2;
+  __syscall_ulong_t __sem_ctime_high;
   __time_t sem_ctime;        /* last time changed by semctl() */
 #else
   __time_t sem_otime;         /* last semop() time */
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc32/struct_kernel_semid64_ds.h b/sysdeps/unix/sysv/linux/sparc/sparc32/struct_kernel_semid64_ds.h
new file mode 100644
index 0000000000..8c4697f9ab
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/sparc/sparc32/struct_kernel_semid64_ds.h
@@ -0,0 +1,12 @@ 
+/* Analogous to kernel struct semid64_ds used on semctl.  */
+struct kernel_semid64_ds
+{
+  struct ipc_perm sem_perm;
+  unsigned long sem_otime_high;
+  unsigned long sem_otime;
+  unsigned long sem_ctime_high;
+  unsigned long sem_ctime;
+  unsigned long sem_nsems;
+  unsigned long __unused1;
+  unsigned long __unused2;
+};
diff --git a/sysdeps/unix/sysv/linux/struct_kernel_semid64_ds.h b/sysdeps/unix/sysv/linux/struct_kernel_semid64_ds.h
new file mode 100644
index 0000000000..f9edf0f76f
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/struct_kernel_semid64_ds.h
@@ -0,0 +1,12 @@ 
+/* Analogous to kernel struct semid64_ds used on semctl.  */
+struct kernel_semid64_ds
+{
+  struct ipc_perm sem_perm;
+  unsigned long sem_otime;
+  unsigned long sem_otime_high;
+  unsigned long sem_ctime;
+  unsigned long sem_ctime_high;
+  unsigned long sem_nsems;
+  unsigned long __unused1;
+  unsigned long __unused2;
+};
diff --git a/sysdeps/unix/sysv/linux/x86/bits/types/struct_semid_ds.h b/sysdeps/unix/sysv/linux/x86/bits/types/struct_semid_ds.h
index f7ec89d115..c3f2fde9fd 100644
--- a/sysdeps/unix/sysv/linux/x86/bits/types/struct_semid_ds.h
+++ b/sysdeps/unix/sysv/linux/x86/bits/types/struct_semid_ds.h
@@ -25,9 +25,9 @@  struct semid_ds
 {
   struct ipc_perm sem_perm;   /* operation permission struct */
   __time_t sem_otime;  /* last semop() time */
-  __syscall_ulong_t __glibc_reserved1;
+  __syscall_ulong_t __sem_otime_high;
   __time_t sem_ctime;  /* last time changed by semctl() */
-  __syscall_ulong_t __glibc_reserved2;
+  __syscall_ulong_t __sem_ctime_high;
   __syscall_ulong_t sem_nsems;    /* number of semaphores in set */
   __syscall_ulong_t __glibc_reserved3;
   __syscall_ulong_t __glibc_reserved4;