[PATCH] sysv: linux: Pass 64-bit version of semctl syscall

Lukasz Majewski lukma@denx.de
Sat Feb 1 14:09:00 GMT 2020


Hi Alistair,

> Adjust the semctl syscall to match what the kernel expects. That is
> pass a version with a *_high version of sem_otime and sem_ctime in
> the order that the kernel expects.

The change seems to be not a trivial one. Would it be possible to
elaborate the commit message a bit?

> ---
>  include/sys/sem.h                             | 35
> +++++++++++++++++++ sysdeps/unix/sysv/linux/bits/sem-pad.h        |
> 1 + sysdeps/unix/sysv/linux/hppa/bits/sem-pad.h   |  1 +
>  sysdeps/unix/sysv/linux/mips/bits/sem-pad.h   |  2 ++
>  .../unix/sysv/linux/powerpc/bits/sem-pad.h    |  2 ++
>  sysdeps/unix/sysv/linux/semctl.c              | 30 +++++++++++++---
>  sysdeps/unix/sysv/linux/sparc/bits/sem-pad.h  |  2 ++
>  sysdeps/unix/sysv/linux/x86/bits/sem-pad.h    |  1 +
>  8 files changed, 70 insertions(+), 4 deletions(-)
> 
> diff --git a/include/sys/sem.h b/include/sys/sem.h
> index 69fdf1f752..70b83127cb 100644
> --- a/include/sys/sem.h
> +++ b/include/sys/sem.h
> @@ -5,5 +5,40 @@
>  
>  __typeof__ (semtimedop) __semtimedop attribute_hidden;
>  
> +# endif
> +
> +# ifdef __SEMID_DS_HIGH
> +#  if defined (__SEMID_DS_HIGH_END)
> +struct __semid_ds32 {
> +  struct ipc_perm sem_perm;             /* permissions .. see ipc.h
> */
> +  __syscall_ulong_t   sem_otime;          /* last semop time */
> +  __syscall_ulong_t   sem_ctime;          /* last change time */
> +  __syscall_ulong_t   sem_nsems;          /* no. of semaphores in
> array */
> +  __syscall_ulong_t   sem_otime_high;
> +  __syscall_ulong_t   sem_ctime_high;
> +};
> +#  elif defined (__SEMID_DS_HIGH_SWAP)
> +struct __semid_ds32 {
> +  struct ipc_perm sem_perm;              /* operation permission
> struct */
> +  __syscall_ulong_t   sem_otime_high;    /* last semop() time high */
> +  __syscall_ulong_t   sem_otime;         /* last semop() time */
> +  __syscall_ulong_t   sem_ctime_high;    /* last time changed by
> semctl() high */
> +  __syscall_ulong_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;
> +};
> +#  else
> +struct __semid_ds32 {
> +  struct ipc_perm sem_perm;              /* operation permission
> struct */
> +  __syscall_ulong_t   sem_otime;         /* last semop() time */
> +  __syscall_ulong_t   sem_otime_high;    /* last semop() time high */
> +  __syscall_ulong_t   sem_ctime;         /* last time changed by
> semctl() */
> +  __syscall_ulong_t   sem_ctime_high;    /* last time changed by
> semctl() high */
> +  __syscall_ulong_t   sem_nsems;         /* number of semaphores in
> set */
> +  __syscall_ulong_t   __glibc_reserved3;
> +  __syscall_ulong_t   __glibc_reserved4;
> +};
> +#  endif
>  # endif
>  #endif
> diff --git a/sysdeps/unix/sysv/linux/bits/sem-pad.h
> b/sysdeps/unix/sysv/linux/bits/sem-pad.h index 566ce039cc..18235e56df
> 100644 --- a/sysdeps/unix/sysv/linux/bits/sem-pad.h
> +++ b/sysdeps/unix/sysv/linux/bits/sem-pad.h
> @@ -31,3 +31,4 @@
>  
>  #define __SEM_PAD_AFTER_TIME (__TIMESIZE == 32)
>  #define __SEM_PAD_BEFORE_TIME 0
> +#define __SEMID_DS_HIGH (__WORDSIZE == 32)
> diff --git a/sysdeps/unix/sysv/linux/hppa/bits/sem-pad.h
> b/sysdeps/unix/sysv/linux/hppa/bits/sem-pad.h index
> ee0332325b..7e112018a6 100644 ---
> a/sysdeps/unix/sysv/linux/hppa/bits/sem-pad.h +++
> b/sysdeps/unix/sysv/linux/hppa/bits/sem-pad.h @@ -24,3 +24,4 @@
>  
>  #define __SEM_PAD_AFTER_TIME 0
>  #define __SEM_PAD_BEFORE_TIME (__TIMESIZE == 32)
> +#define __SEMID_DS_HIGH (__WORDSIZE == 32)
> diff --git a/sysdeps/unix/sysv/linux/mips/bits/sem-pad.h
> b/sysdeps/unix/sysv/linux/mips/bits/sem-pad.h index
> 4c581f7694..12f2bd9c62 100644 ---
> a/sysdeps/unix/sysv/linux/mips/bits/sem-pad.h +++
> b/sysdeps/unix/sysv/linux/mips/bits/sem-pad.h @@ -22,3 +22,5 @@
>  
>  #define __SEM_PAD_AFTER_TIME 0
>  #define __SEM_PAD_BEFORE_TIME 0
> +#define __SEMID_DS_HIGH (__WORDSIZE == 32)
> +#define __SEMID_DS_HIGH_END (__WORDSIZE == 32)
> diff --git a/sysdeps/unix/sysv/linux/powerpc/bits/sem-pad.h
> b/sysdeps/unix/sysv/linux/powerpc/bits/sem-pad.h index
> 42d8827906..a13ca5f6bd 100644 ---
> a/sysdeps/unix/sysv/linux/powerpc/bits/sem-pad.h +++
> b/sysdeps/unix/sysv/linux/powerpc/bits/sem-pad.h @@ -24,3 +24,5 @@
>  
>  #define __SEM_PAD_AFTER_TIME 0
>  #define __SEM_PAD_BEFORE_TIME (__TIMESIZE == 32)
> +#define __SEMID_DS_HIGH (__WORDSIZE == 32)
> +#define __SEMID_DS_HIGH_SWAP (__WORDSIZE == 32)
> diff --git a/sysdeps/unix/sysv/linux/semctl.c
> b/sysdeps/unix/sysv/linux/semctl.c index 0c3eb0932f..34d3125fc3 100644
> --- a/sysdeps/unix/sysv/linux/semctl.c
> +++ b/sysdeps/unix/sysv/linux/semctl.c
> @@ -28,6 +28,7 @@ union semun
>  {
>    int val;			/* value for SETVAL */
>    struct semid_ds *buf;		/* buffer for IPC_STAT &
> IPC_SET */
> +  struct __semid_ds32 *buf32;
>    unsigned short int *array;	/* array for GETALL & SETALL */
>    struct seminfo *__buf;	/* buffer for IPC_INFO */
>  };
> @@ -43,12 +44,33 @@ union semun
>  static int
>  semctl_syscall (int semid, int semnum, int cmd, union semun arg)
>  {
> -#ifdef __ASSUME_DIRECT_SYSVIPC_SYSCALLS
> -  return INLINE_SYSCALL_CALL (semctl, semid, semnum, cmd | __IPC_64,
> -			      arg.array);
> +#ifdef __SEMID_DS_HIGH
> +  int ret;
> +# ifdef __ASSUME_DIRECT_SYSVIPC_SYSCALLS
> +  ret = INLINE_SYSCALL_CALL (semctl, semid, semnum, cmd | __IPC_64,
> +			     arg.array);
> +# else
> +  ret = INLINE_SYSCALL_CALL (ipc, IPCOP_semctl, semid, semnum, cmd |
> __IPC_64,
> +			     SEMCTL_ARG_ADDRESS (arg));
> +# endif
> +/* If we aren't going to overflow the time_t sem_ctime/sem_otime set
> it  */ +#  if __TIMESIZE == 64 && __WORDSIZE == 32

I guess that this is for RV32? Please correct me if I'm wrong, but
there shouldn't be need any extra code to support ARM32 without Y2038
support?

> +  if (ret == 0)
> +    {
> +      arg.buf->sem_ctime = arg.buf32->sem_ctime | ((time_t)
> arg.buf32->sem_ctime_high << 32);
> +      arg.buf->sem_otime = arg.buf32->sem_otime | ((time_t)
> arg.buf32->sem_otime_high << 32);
> +    }
> +#  endif
> +  return ret;
>  #else
> +# ifdef __ASSUME_DIRECT_SYSVIPC_SYSCALLS
> +  return INLINE_SYSCALL_CALL (semctl, semid, semnum, cmd | __IPC_64,
> +                              arg.array);
> +# else
>    return INLINE_SYSCALL_CALL (ipc, IPCOP_semctl, semid, semnum, cmd
> | __IPC_64,
> -			      SEMCTL_ARG_ADDRESS (arg));
> +                              SEMCTL_ARG_ADDRESS (arg));
> +# endif
> +
>  #endif
>  }
>  
> diff --git a/sysdeps/unix/sysv/linux/sparc/bits/sem-pad.h
> b/sysdeps/unix/sysv/linux/sparc/bits/sem-pad.h index
> 5f4e214d12..79655b8149 100644 ---
> a/sysdeps/unix/sysv/linux/sparc/bits/sem-pad.h +++
> b/sysdeps/unix/sysv/linux/sparc/bits/sem-pad.h @@ -24,3 +24,5 @@
>  
>  #define __SEM_PAD_AFTER_TIME 0
>  #define __SEM_PAD_BEFORE_TIME (__TIMESIZE == 32)
> +#define __SEMID_DS_HIGH (__WORDSIZE == 32)
> +#define __SEMID_DS_HIGH_SWAP (__WORDSIZE == 32)
> diff --git a/sysdeps/unix/sysv/linux/x86/bits/sem-pad.h
> b/sysdeps/unix/sysv/linux/x86/bits/sem-pad.h index
> 102e226997..db397857e7 100644 ---
> a/sysdeps/unix/sysv/linux/x86/bits/sem-pad.h +++
> b/sysdeps/unix/sysv/linux/x86/bits/sem-pad.h @@ -22,3 +22,4 @@
>  
>  #define __SEM_PAD_AFTER_TIME 1
>  #define __SEM_PAD_BEFORE_TIME 0
> +#define __SEMID_DS_HIGH 1

I do guess that this is a unification for existing archs/ports (with no
support for Y2038).

Just informative - there is already available semtimedop_time64 in
Linux 5.1+, which seems to be tricky to support.
(There was a discussion previously about syscalls not eligible for
__ASSUME_TIME64_SYSCALLS flag and semtimedop was one of them).


Best regards,

Lukasz Majewski

--

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HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-59 Fax: (+49)-8142-66989-80 Email: lukma@denx.de
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