sysdeps/unix/sysv/linux/alpha/shmctl.c

   1 /* Copyright (C) 1995, 1997, 1998, 2000, 2003 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@gnu.ai.mit.edu>, August 1995.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #include <errno.h>
  21 #include <sys/shm.h>
  22 #include <ipc_priv.h>
  23
  24 #include <sysdep.h>
  25 #include <string.h>
  26 #include <sys/syscall.h>
  27 #include <bits/wordsize.h>
  28 #include <bp-checks.h>
  29
  30 #include "kernel-features.h"
  31
  32 struct __old_shmid_ds
  33 {
  34   struct __old_ipc_perm shm_perm;       /* operation permission struct */
  35   int shm_segsz;                        /* size of segment in bytes */
  36   __time_t shm_atime;                   /* time of last shmat() */
  37   __time_t shm_dtime;                   /* time of last shmdt() */
  38   __time_t shm_ctime;                   /* time of last change by shmctl() */
  39   __ipc_pid_t shm_cpid;                 /* pid of creator */
  40   __ipc_pid_t shm_lpid;                 /* pid of last shmop */
  41   unsigned short int shm_nattch;        /* number of current attaches */
  42   unsigned short int __shm_npages;      /* size of segment (pages) */
  43   unsigned long int *__unbounded __shm_pages; /* array of ptrs to frames -> SHMMAX */
  44   struct vm_area_struct *__unbounded __attaches; /* descriptors for attaches */
  45 };
  46
  47 struct __old_shminfo
  48 {
  49   int shmmax;
  50   int shmmin;
  51   int shmmni;
  52   int shmseg;
  53   int shmall;
  54 };
  55
  56 /* Provide operations to control over shared memory segments.  */
  57 int __new_shmctl (int, int, struct shmid_ds *);
  58
  59 int
  60 __new_shmctl (int shmid, int cmd, struct shmid_ds *buf)
  61 {
  62 #if __ASSUME_32BITUIDS > 0
  63   return INLINE_SYSCALL (shmctl, 3, shmid, cmd | __IPC_64, CHECK_1 (buf));
  64 #else
  65   switch (cmd) {
  66     case SHM_STAT:
  67     case IPC_STAT:
  68     case IPC_SET:
  69     case IPC_INFO:
  70       break;
  71     default:
  72       return INLINE_SYSCALL (shmctl, 3, shmid, cmd, CHECK_1 (buf));
  73   }
  74
  75   {
  76     int save_errno = errno, result;
  77     struct __old_shmid_ds old;
  78
  79     /* Unfortunately there is no way how to find out for sure whether
  80        we should use old or new shmctl.  */
  81     result = INLINE_SYSCALL (shmctl, 3, shmid, cmd | __IPC_64, CHECK_1 (buf));
  82     if (result != -1 || errno != EINVAL)
  83       return result;
  84
  85     __set_errno(save_errno);
  86     if (cmd == IPC_SET)
  87       {
  88         old.shm_perm.uid = buf->shm_perm.uid;
  89         old.shm_perm.gid = buf->shm_perm.gid;
  90         old.shm_perm.mode = buf->shm_perm.mode;
  91         if (old.shm_perm.uid != buf->shm_perm.uid ||
  92             old.shm_perm.gid != buf->shm_perm.gid)
  93           {
  94             __set_errno (EINVAL);
  95             return -1;
  96           }
  97       }
  98     result = INLINE_SYSCALL (shmctl, 3, shmid, cmd, __ptrvalue (&old));
  99     if (result != -1 && (cmd == SHM_STAT || cmd == IPC_STAT))
 100       {
 101         memset(buf, 0, sizeof(*buf));
 102         buf->shm_perm.__key = old.shm_perm.__key;
 103         buf->shm_perm.uid = old.shm_perm.uid;
 104         buf->shm_perm.gid = old.shm_perm.gid;
 105         buf->shm_perm.cuid = old.shm_perm.cuid;
 106         buf->shm_perm.cgid = old.shm_perm.cgid;
 107         buf->shm_perm.mode = old.shm_perm.mode;
 108         buf->shm_perm.__seq = old.shm_perm.__seq;
 109         buf->shm_atime = old.shm_atime;
 110         buf->shm_dtime = old.shm_dtime;
 111         buf->shm_ctime = old.shm_ctime;
 112         buf->shm_segsz = old.shm_segsz;
 113         buf->shm_nattch = old.shm_nattch;
 114         buf->shm_cpid = old.shm_cpid;
 115         buf->shm_lpid = old.shm_lpid;
 116       }
 117     else if (result != -1 && cmd == IPC_INFO)
 118       {
 119         struct __old_shminfo *oldi = (void *)&old;
 120         struct shminfo *i = (struct shminfo *)buf;
 121
 122         memset(i, 0, sizeof(*i));
 123         i->shmmax = oldi->shmmax;
 124         i->shmmin = oldi->shmmin;
 125         i->shmmni = oldi->shmmni;
 126         i->shmseg = oldi->shmseg;
 127         i->shmall = oldi->shmall;
 128       }
 129     return result;
 130   }
 131 #endif
 132 }
 133
 134 #include <shlib-compat.h>
 135 versioned_symbol (libc, __new_shmctl, shmctl, GLIBC_2_2);