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

   1 /* Copyright (C) 1995,1997,1998,2000,2003,2006 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, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <errno.h>
  20 #include <sys/shm.h>
  21 #include <ipc_priv.h>
  22
  23 #include <sysdep.h>
  24 #include <string.h>
  25 #include <sys/syscall.h>
  26 #include <bits/wordsize.h>
  27 #include <bp-checks.h>
  28
  29 #include <kernel-features.h>
  30
  31 struct __old_shmid_ds
  32 {
  33   struct __old_ipc_perm shm_perm;       /* operation permission struct */
  34   int shm_segsz;                        /* size of segment in bytes */
  35   __time_t shm_atime;                   /* time of last shmat() */
  36   __time_t shm_dtime;                   /* time of last shmdt() */
  37   __time_t shm_ctime;                   /* time of last change by shmctl() */
  38   __ipc_pid_t shm_cpid;                 /* pid of creator */
  39   __ipc_pid_t shm_lpid;                 /* pid of last shmop */
  40   unsigned short int shm_nattch;        /* number of current attaches */
  41   unsigned short int __shm_npages;      /* size of segment (pages) */
  42   unsigned long int *__unbounded __shm_pages; /* array of ptrs to frames -> SHMMAX */
  43   struct vm_area_struct *__unbounded __attaches; /* descriptors for attaches */
  44 };
  45
  46 struct __old_shminfo
  47 {
  48   int shmmax;
  49   int shmmin;
  50   int shmmni;
  51   int shmseg;
  52   int shmall;
  53 };
  54
  55 /* Provide operations to control over shared memory segments.  */
  56 int __new_shmctl (int, int, struct shmid_ds *);
  57
  58 int
  59 __new_shmctl (int shmid, int cmd, struct shmid_ds *buf)
  60 {
  61 #if __ASSUME_32BITUIDS > 0
  62   return INLINE_SYSCALL (shmctl, 3, shmid, cmd | __IPC_64, CHECK_1 (buf));
  63 #else
  64   switch (cmd) {
  65     case SHM_STAT:
  66     case IPC_STAT:
  67     case IPC_SET:
  68     case IPC_INFO:
  69       break;
  70     default:
  71       return INLINE_SYSCALL (shmctl, 3, shmid, cmd, CHECK_1 (buf));
  72   }
  73
  74   {
  75     int save_errno = errno, result;
  76     struct __old_shmid_ds old;
  77
  78     /* Unfortunately there is no way how to find out for sure whether
  79        we should use old or new shmctl.  */
  80     result = INLINE_SYSCALL (shmctl, 3, shmid, cmd | __IPC_64, CHECK_1 (buf));
  81     if (result != -1 || errno != EINVAL)
  82       return result;
  83
  84     __set_errno(save_errno);
  85     if (cmd == IPC_SET)
  86       {
  87         old.shm_perm.uid = buf->shm_perm.uid;
  88         old.shm_perm.gid = buf->shm_perm.gid;
  89         old.shm_perm.mode = buf->shm_perm.mode;
  90         if (old.shm_perm.uid != buf->shm_perm.uid ||
  91             old.shm_perm.gid != buf->shm_perm.gid)
  92           {
  93             __set_errno (EINVAL);
  94             return -1;
  95           }
  96       }
  97     result = INLINE_SYSCALL (shmctl, 3, shmid, cmd, __ptrvalue (&old));
  98     if (result != -1 && (cmd == SHM_STAT || cmd == IPC_STAT))
  99       {
 100         memset(buf, 0, sizeof(*buf));
 101         buf->shm_perm.__key = old.shm_perm.__key;
 102         buf->shm_perm.uid = old.shm_perm.uid;
 103         buf->shm_perm.gid = old.shm_perm.gid;
 104         buf->shm_perm.cuid = old.shm_perm.cuid;
 105         buf->shm_perm.cgid = old.shm_perm.cgid;
 106         buf->shm_perm.mode = old.shm_perm.mode;
 107         buf->shm_perm.__seq = old.shm_perm.__seq;
 108         buf->shm_atime = old.shm_atime;
 109         buf->shm_dtime = old.shm_dtime;
 110         buf->shm_ctime = old.shm_ctime;
 111         buf->shm_segsz = old.shm_segsz;
 112         buf->shm_nattch = old.shm_nattch;
 113         buf->shm_cpid = old.shm_cpid;
 114         buf->shm_lpid = old.shm_lpid;
 115       }
 116     else if (result != -1 && cmd == IPC_INFO)
 117       {
 118         struct __old_shminfo *oldi = (void *)&old;
 119         struct shminfo *i = (struct shminfo *)buf;
 120
 121         memset(i, 0, sizeof(*i));
 122         i->shmmax = oldi->shmmax;
 123         i->shmmin = oldi->shmmin;
 124         i->shmmni = oldi->shmmni;
 125         i->shmseg = oldi->shmseg;
 126         i->shmall = oldi->shmall;
 127       }
 128     return result;
 129   }
 130 #endif
 131 }
 132
 133 #include <shlib-compat.h>
 134 versioned_symbol (libc, __new_shmctl, shmctl, GLIBC_2_2);