x86/speculation/l1tf: Exempt zeroed PTEs from inversion
[muen/linux.git] / 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                 if (IS_ENABLED(CONFIG_64BIT) || !IS_ENABLED(CONFIG_64BIT_TIME))
34                         return ksys_semtimedop(first, ptr, second,
35                                 (const struct __kernel_timespec __user *)fifth);
36                 else if (IS_ENABLED(CONFIG_COMPAT_32BIT_TIME))
37                         return compat_ksys_semtimedop(first, ptr, second,
38                                 (const struct compat_timespec __user *)fifth);
39                 else
40                         return -ENOSYS;
41
42         case SEMGET:
43                 return ksys_semget(first, second, third);
44         case SEMCTL: {
45                 unsigned long arg;
46                 if (!ptr)
47                         return -EINVAL;
48                 if (get_user(arg, (unsigned long __user *) ptr))
49                         return -EFAULT;
50                 return ksys_semctl(first, second, third, arg);
51         }
52
53         case MSGSND:
54                 return ksys_msgsnd(first, (struct msgbuf __user *) ptr,
55                                   second, third);
56         case MSGRCV:
57                 switch (version) {
58                 case 0: {
59                         struct ipc_kludge tmp;
60                         if (!ptr)
61                                 return -EINVAL;
62
63                         if (copy_from_user(&tmp,
64                                            (struct ipc_kludge __user *) ptr,
65                                            sizeof(tmp)))
66                                 return -EFAULT;
67                         return ksys_msgrcv(first, tmp.msgp, second,
68                                            tmp.msgtyp, third);
69                 }
70                 default:
71                         return ksys_msgrcv(first,
72                                            (struct msgbuf __user *) ptr,
73                                            second, fifth, third);
74                 }
75         case MSGGET:
76                 return ksys_msgget((key_t) first, second);
77         case MSGCTL:
78                 return ksys_msgctl(first, second,
79                                    (struct msqid_ds __user *)ptr);
80
81         case SHMAT:
82                 switch (version) {
83                 default: {
84                         unsigned long raddr;
85                         ret = do_shmat(first, (char __user *)ptr,
86                                        second, &raddr, SHMLBA);
87                         if (ret)
88                                 return ret;
89                         return put_user(raddr, (unsigned long __user *) third);
90                 }
91                 case 1:
92                         /*
93                          * This was the entry point for kernel-originating calls
94                          * from iBCS2 in 2.2 days.
95                          */
96                         return -EINVAL;
97                 }
98         case SHMDT:
99                 return ksys_shmdt((char __user *)ptr);
100         case SHMGET:
101                 return ksys_shmget(first, second, third);
102         case SHMCTL:
103                 return ksys_shmctl(first, second,
104                                    (struct shmid_ds __user *) ptr);
105         default:
106                 return -ENOSYS;
107         }
108 }
109 #endif
110
111 #ifdef CONFIG_COMPAT
112 #include <linux/compat.h>
113
114 #ifndef COMPAT_SHMLBA
115 #define COMPAT_SHMLBA   SHMLBA
116 #endif
117
118 struct compat_ipc_kludge {
119         compat_uptr_t msgp;
120         compat_long_t msgtyp;
121 };
122
123 #ifdef CONFIG_ARCH_WANT_OLD_COMPAT_IPC
124 COMPAT_SYSCALL_DEFINE6(ipc, u32, call, int, first, int, second,
125         u32, third, compat_uptr_t, ptr, u32, fifth)
126 {
127         int version;
128         u32 pad;
129
130         version = call >> 16; /* hack for backward compatibility */
131         call &= 0xffff;
132
133         switch (call) {
134         case SEMOP:
135                 /* struct sembuf is the same on 32 and 64bit :)) */
136                 return ksys_semtimedop(first, compat_ptr(ptr), second, NULL);
137         case SEMTIMEDOP:
138                 if (!IS_ENABLED(CONFIG_COMPAT_32BIT_TIME))
139                         return -ENOSYS;
140                 return compat_ksys_semtimedop(first, compat_ptr(ptr), second,
141                                                 compat_ptr(fifth));
142         case SEMGET:
143                 return ksys_semget(first, second, third);
144         case SEMCTL:
145                 if (!ptr)
146                         return -EINVAL;
147                 if (get_user(pad, (u32 __user *) compat_ptr(ptr)))
148                         return -EFAULT;
149                 return compat_ksys_semctl(first, second, third, pad);
150
151         case MSGSND:
152                 return compat_ksys_msgsnd(first, ptr, second, third);
153
154         case MSGRCV: {
155                 void __user *uptr = compat_ptr(ptr);
156
157                 if (first < 0 || second < 0)
158                         return -EINVAL;
159
160                 if (!version) {
161                         struct compat_ipc_kludge ipck;
162                         if (!uptr)
163                                 return -EINVAL;
164                         if (copy_from_user(&ipck, uptr, sizeof(ipck)))
165                                 return -EFAULT;
166                         return compat_ksys_msgrcv(first, ipck.msgp, second,
167                                                  ipck.msgtyp, third);
168                 }
169                 return compat_ksys_msgrcv(first, ptr, second, fifth, third);
170         }
171         case MSGGET:
172                 return ksys_msgget(first, second);
173         case MSGCTL:
174                 return compat_ksys_msgctl(first, second, compat_ptr(ptr));
175
176         case SHMAT: {
177                 int err;
178                 unsigned long raddr;
179
180                 if (version == 1)
181                         return -EINVAL;
182                 err = do_shmat(first, compat_ptr(ptr), second, &raddr,
183                                COMPAT_SHMLBA);
184                 if (err < 0)
185                         return err;
186                 return put_user(raddr, (compat_ulong_t __user *)compat_ptr(third));
187         }
188         case SHMDT:
189                 return ksys_shmdt(compat_ptr(ptr));
190         case SHMGET:
191                 return ksys_shmget(first, (unsigned int)second, third);
192         case SHMCTL:
193                 return compat_ksys_shmctl(first, second, compat_ptr(ptr));
194         }
195
196         return -ENOSYS;
197 }
198 #endif
199 #endif