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 int ksys_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)) 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 old_timespec32 __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_old_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_old_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_old_shmctl(first, second, 104 (struct shmid_ds __user *) ptr); 105 default: 106 return -ENOSYS; 107 } 108 } 109 110 SYSCALL_DEFINE6(ipc, unsigned int, call, int, first, unsigned long, second, 111 unsigned long, third, void __user *, ptr, long, fifth) 112 { 113 return ksys_ipc(call, first, second, third, ptr, fifth); 114 } 115 #endif 116 117 #ifdef CONFIG_COMPAT 118 #include <linux/compat.h> 119 120 #ifndef COMPAT_SHMLBA 121 #define COMPAT_SHMLBA SHMLBA 122 #endif 123 124 struct compat_ipc_kludge { 125 compat_uptr_t msgp; 126 compat_long_t msgtyp; 127 }; 128 129 #ifdef CONFIG_ARCH_WANT_OLD_COMPAT_IPC 130 int compat_ksys_ipc(u32 call, int first, int second, 131 u32 third, compat_uptr_t ptr, u32 fifth) 132 { 133 int version; 134 u32 pad; 135 136 version = call >> 16; /* hack for backward compatibility */ 137 call &= 0xffff; 138 139 switch (call) { 140 case SEMOP: 141 /* struct sembuf is the same on 32 and 64bit :)) */ 142 return ksys_semtimedop(first, compat_ptr(ptr), second, NULL); 143 case SEMTIMEDOP: 144 if (!IS_ENABLED(CONFIG_COMPAT_32BIT_TIME)) 145 return -ENOSYS; 146 return compat_ksys_semtimedop(first, compat_ptr(ptr), second, 147 compat_ptr(fifth)); 148 case SEMGET: 149 return ksys_semget(first, second, third); 150 case SEMCTL: 151 if (!ptr) 152 return -EINVAL; 153 if (get_user(pad, (u32 __user *) compat_ptr(ptr))) 154 return -EFAULT; 155 return compat_ksys_old_semctl(first, second, third, pad); 156 157 case MSGSND: 158 return compat_ksys_msgsnd(first, ptr, second, third); 159 160 case MSGRCV: { 161 void __user *uptr = compat_ptr(ptr); 162 163 if (first < 0 || second < 0) 164 return -EINVAL; 165 166 if (!version) { 167 struct compat_ipc_kludge ipck; 168 if (!uptr) 169 return -EINVAL; 170 if (copy_from_user(&ipck, uptr, sizeof(ipck))) 171 return -EFAULT; 172 return compat_ksys_msgrcv(first, ipck.msgp, second, 173 ipck.msgtyp, third); 174 } 175 return compat_ksys_msgrcv(first, ptr, second, fifth, third); 176 } 177 case MSGGET: 178 return ksys_msgget(first, second); 179 case MSGCTL: 180 return compat_ksys_old_msgctl(first, second, compat_ptr(ptr)); 181 182 case SHMAT: { 183 int err; 184 unsigned long raddr; 185 186 if (version == 1) 187 return -EINVAL; 188 err = do_shmat(first, compat_ptr(ptr), second, &raddr, 189 COMPAT_SHMLBA); 190 if (err < 0) 191 return err; 192 return put_user(raddr, (compat_ulong_t __user *)compat_ptr(third)); 193 } 194 case SHMDT: 195 return ksys_shmdt(compat_ptr(ptr)); 196 case SHMGET: 197 return ksys_shmget(first, (unsigned int)second, third); 198 case SHMCTL: 199 return compat_ksys_old_shmctl(first, second, compat_ptr(ptr)); 200 } 201 202 return -ENOSYS; 203 } 204 205 COMPAT_SYSCALL_DEFINE6(ipc, u32, call, int, first, int, second, 206 u32, third, compat_uptr_t, ptr, u32, fifth) 207 { 208 return compat_ksys_ipc(call, first, second, third, ptr, fifth); 209 } 210 #endif 211 #endif 212