ipc/syscall.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * sys_ipc() is the old de-multiplexer for the SysV IPC calls.
   4  *
   5  * This is really horribly ugly, and new architectures should just wire up
   6  * the individual syscalls instead.
   7  */
   8 #include <linux/unistd.h>
   9 #include <linux/syscalls.h>
  10 #include <linux/security.h>
  11 #include <linux/ipc_namespace.h>
  12 #include "util.h"
  13
  14 #ifdef __ARCH_WANT_SYS_IPC
  15 #include <linux/errno.h>
  16 #include <linux/ipc.h>
  17 #include <linux/shm.h>
  18 #include <linux/uaccess.h>
  19
  20 SYSCALL_DEFINE6(ipc, unsigned int, call, int, first, unsigned long, second,
  21                 unsigned long, third, void __user *, ptr, long, fifth)
  22 {
  23         int version, ret;
  24
  25         version = call >> 16; /* hack for backward compatibility */
  26         call &= 0xffff;
  27
  28         switch (call) {
  29         case SEMOP:
  30                 return ksys_semtimedop(first, (struct sembuf __user *)ptr,
  31                                        second, NULL);
  32         case SEMTIMEDOP:
  33                 return ksys_semtimedop(first, (struct sembuf __user *)ptr,
  34                                        second,
  35                                        (const struct timespec __user *)fifth);
  36
  37         case SEMGET:
  38                 return ksys_semget(first, second, third);
  39         case SEMCTL: {
  40                 unsigned long arg;
  41                 if (!ptr)
  42                         return -EINVAL;
  43                 if (get_user(arg, (unsigned long __user *) ptr))
  44                         return -EFAULT;
  45                 return ksys_semctl(first, second, third, arg);
  46         }
  47
  48         case MSGSND:
  49                 return ksys_msgsnd(first, (struct msgbuf __user *) ptr,
  50                                   second, third);
  51         case MSGRCV:
  52                 switch (version) {
  53                 case 0: {
  54                         struct ipc_kludge tmp;
  55                         if (!ptr)
  56                                 return -EINVAL;
  57
  58                         if (copy_from_user(&tmp,
  59                                            (struct ipc_kludge __user *) ptr,
  60                                            sizeof(tmp)))
  61                                 return -EFAULT;
  62                         return ksys_msgrcv(first, tmp.msgp, second,
  63                                            tmp.msgtyp, third);
  64                 }
  65                 default:
  66                         return ksys_msgrcv(first,
  67                                            (struct msgbuf __user *) ptr,
  68                                            second, fifth, third);
  69                 }
  70         case MSGGET:
  71                 return ksys_msgget((key_t) first, second);
  72         case MSGCTL:
  73                 return ksys_msgctl(first, second,
  74                                    (struct msqid_ds __user *)ptr);
  75
  76         case SHMAT:
  77                 switch (version) {
  78                 default: {
  79                         unsigned long raddr;
  80                         ret = do_shmat(first, (char __user *)ptr,
  81                                        second, &raddr, SHMLBA);
  82                         if (ret)
  83                                 return ret;
  84                         return put_user(raddr, (unsigned long __user *) third);
  85                 }
  86                 case 1:
  87                         /*
  88                          * This was the entry point for kernel-originating calls
  89                          * from iBCS2 in 2.2 days.
  90                          */
  91                         return -EINVAL;
  92                 }
  93         case SHMDT:
  94                 return ksys_shmdt((char __user *)ptr);
  95         case SHMGET:
  96                 return ksys_shmget(first, second, third);
  97         case SHMCTL:
  98                 return ksys_shmctl(first, second,
  99                                    (struct shmid_ds __user *) ptr);
 100         default:
 101                 return -ENOSYS;
 102         }
 103 }
 104 #endif
 105
 106 #ifdef CONFIG_COMPAT
 107 #include <linux/compat.h>
 108
 109 #ifndef COMPAT_SHMLBA
 110 #define COMPAT_SHMLBA   SHMLBA
 111 #endif
 112
 113 struct compat_ipc_kludge {
 114         compat_uptr_t msgp;
 115         compat_long_t msgtyp;
 116 };
 117
 118 #ifdef CONFIG_ARCH_WANT_OLD_COMPAT_IPC
 119 COMPAT_SYSCALL_DEFINE6(ipc, u32, call, int, first, int, second,
 120         u32, third, compat_uptr_t, ptr, u32, fifth)
 121 {
 122         int version;
 123         u32 pad;
 124
 125         version = call >> 16; /* hack for backward compatibility */
 126         call &= 0xffff;
 127
 128         switch (call) {
 129         case SEMOP:
 130                 /* struct sembuf is the same on 32 and 64bit :)) */
 131                 return ksys_semtimedop(first, compat_ptr(ptr), second, NULL);
 132         case SEMTIMEDOP:
 133                 return compat_ksys_semtimedop(first, compat_ptr(ptr), second,
 134                                                 compat_ptr(fifth));
 135         case SEMGET:
 136                 return ksys_semget(first, second, third);
 137         case SEMCTL:
 138                 if (!ptr)
 139                         return -EINVAL;
 140                 if (get_user(pad, (u32 __user *) compat_ptr(ptr)))
 141                         return -EFAULT;
 142                 return compat_ksys_semctl(first, second, third, pad);
 143
 144         case MSGSND:
 145                 return compat_ksys_msgsnd(first, ptr, second, third);
 146
 147         case MSGRCV: {
 148                 void __user *uptr = compat_ptr(ptr);
 149
 150                 if (first < 0 || second < 0)
 151                         return -EINVAL;
 152
 153                 if (!version) {
 154                         struct compat_ipc_kludge ipck;
 155                         if (!uptr)
 156                                 return -EINVAL;
 157                         if (copy_from_user(&ipck, uptr, sizeof(ipck)))
 158                                 return -EFAULT;
 159                         return compat_ksys_msgrcv(first, ipck.msgp, second,
 160                                                  ipck.msgtyp, third);
 161                 }
 162                 return compat_ksys_msgrcv(first, ptr, second, fifth, third);
 163         }
 164         case MSGGET:
 165                 return ksys_msgget(first, second);
 166         case MSGCTL:
 167                 return compat_ksys_msgctl(first, second, compat_ptr(ptr));
 168
 169         case SHMAT: {
 170                 int err;
 171                 unsigned long raddr;
 172
 173                 if (version == 1)
 174                         return -EINVAL;
 175                 err = do_shmat(first, compat_ptr(ptr), second, &raddr,
 176                                COMPAT_SHMLBA);
 177                 if (err < 0)
 178                         return err;
 179                 return put_user(raddr, (compat_ulong_t __user *)compat_ptr(third));
 180         }
 181         case SHMDT:
 182                 return ksys_shmdt(compat_ptr(ptr));
 183         case SHMGET:
 184                 return ksys_shmget(first, (unsigned int)second, third);
 185         case SHMCTL:
 186                 return compat_ksys_shmctl(first, second, compat_ptr(ptr));
 187         }
 188
 189         return -ENOSYS;
 190 }
 191 #endif
 192 #endif