1 /* 2 * linux/arch/arm/kernel/sys_arm.c 3 * 4 * Copyright (C) People who wrote linux/arch/i386/kernel/sys_i386.c 5 * Copyright (C) 1995, 1996 Russell King. 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License version 2 as 9 * published by the Free Software Foundation. 10 * 11 * This file contains various random system calls that 12 * have a non-standard calling sequence on the Linux/arm 13 * platform. 14 */ 15 #include <linux/module.h> 16 #include <linux/errno.h> 17 #include <linux/sched.h> 18 #include <linux/slab.h> 19 #include <linux/mm.h> 20 #include <linux/sem.h> 21 #include <linux/msg.h> 22 #include <linux/shm.h> 23 #include <linux/stat.h> 24 #include <linux/syscalls.h> 25 #include <linux/mman.h> 26 #include <linux/fs.h> 27 #include <linux/file.h> 28 #include <linux/utsname.h> 29 30 #include <asm/uaccess.h> 31 #include <asm/ipc.h> 32 33 extern unsigned long do_mremap(unsigned long addr, unsigned long old_len, 34 unsigned long new_len, unsigned long flags, 35 unsigned long new_addr); 36 37 /* 38 * sys_pipe() is the normal C calling standard for creating 39 * a pipe. It's not the way unix traditionally does this, though. 40 */ 41 asmlinkage int sys_pipe(unsigned long __user *fildes) 42 { 43 int fd[2]; 44 int error; 45 46 error = do_pipe(fd); 47 if (!error) { 48 if (copy_to_user(fildes, fd, 2*sizeof(int))) 49 error = -EFAULT; 50 } 51 return error; 52 } 53 54 /* common code for old and new mmaps */ 55 inline long do_mmap2( 56 unsigned long addr, unsigned long len, 57 unsigned long prot, unsigned long flags, 58 unsigned long fd, unsigned long pgoff) 59 { 60 int error = -EINVAL; 61 struct file * file = NULL; 62 63 flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE); 64 65 if (flags & MAP_FIXED && addr < FIRST_USER_ADDRESS) 66 goto out; 67 68 error = -EBADF; 69 if (!(flags & MAP_ANONYMOUS)) { 70 file = fget(fd); 71 if (!file) 72 goto out; 73 } 74 75 down_write(¤t->mm->mmap_sem); 76 error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff); 77 up_write(¤t->mm->mmap_sem); 78 79 if (file) 80 fput(file); 81 out: 82 return error; 83 } 84 85 struct mmap_arg_struct { 86 unsigned long addr; 87 unsigned long len; 88 unsigned long prot; 89 unsigned long flags; 90 unsigned long fd; 91 unsigned long offset; 92 }; 93 94 asmlinkage int old_mmap(struct mmap_arg_struct __user *arg) 95 { 96 int error = -EFAULT; 97 struct mmap_arg_struct a; 98 99 if (copy_from_user(&a, arg, sizeof(a))) 100 goto out; 101 102 error = -EINVAL; 103 if (a.offset & ~PAGE_MASK) 104 goto out; 105 106 error = do_mmap2(a.addr, a.len, a.prot, a.flags, a.fd, a.offset >> PAGE_SHIFT); 107 out: 108 return error; 109 } 110 111 asmlinkage unsigned long 112 sys_arm_mremap(unsigned long addr, unsigned long old_len, 113 unsigned long new_len, unsigned long flags, 114 unsigned long new_addr) 115 { 116 unsigned long ret = -EINVAL; 117 118 if (flags & MREMAP_FIXED && new_addr < FIRST_USER_ADDRESS) 119 goto out; 120 121 down_write(¤t->mm->mmap_sem); 122 ret = do_mremap(addr, old_len, new_len, flags, new_addr); 123 up_write(¤t->mm->mmap_sem); 124 125 out: 126 return ret; 127 } 128 129 /* 130 * Perform the select(nd, in, out, ex, tv) and mmap() system 131 * calls. 132 */ 133 134 struct sel_arg_struct { 135 unsigned long n; 136 fd_set __user *inp, *outp, *exp; 137 struct timeval __user *tvp; 138 }; 139 140 asmlinkage int old_select(struct sel_arg_struct __user *arg) 141 { 142 struct sel_arg_struct a; 143 144 if (copy_from_user(&a, arg, sizeof(a))) 145 return -EFAULT; 146 /* sys_select() does the appropriate kernel locking */ 147 return sys_select(a.n, a.inp, a.outp, a.exp, a.tvp); 148 } 149 150 /* 151 * sys_ipc() is the de-multiplexer for the SysV IPC calls.. 152 * 153 * This is really horribly ugly. 154 */ 155 asmlinkage int sys_ipc(uint call, int first, int second, int third, 156 void __user *ptr, long fifth) 157 { 158 int version, ret; 159 160 version = call >> 16; /* hack for backward compatibility */ 161 call &= 0xffff; 162 163 switch (call) { 164 case SEMOP: 165 return sys_semtimedop (first, (struct sembuf __user *)ptr, second, NULL); 166 case SEMTIMEDOP: 167 return sys_semtimedop(first, (struct sembuf __user *)ptr, second, 168 (const struct timespec __user *)fifth); 169 170 case SEMGET: 171 return sys_semget (first, second, third); 172 case SEMCTL: { 173 union semun fourth; 174 if (!ptr) 175 return -EINVAL; 176 if (get_user(fourth.__pad, (void __user * __user *) ptr)) 177 return -EFAULT; 178 return sys_semctl (first, second, third, fourth); 179 } 180 181 case MSGSND: 182 return sys_msgsnd(first, (struct msgbuf __user *) ptr, 183 second, third); 184 case MSGRCV: 185 switch (version) { 186 case 0: { 187 struct ipc_kludge tmp; 188 if (!ptr) 189 return -EINVAL; 190 if (copy_from_user(&tmp,(struct ipc_kludge __user *)ptr, 191 sizeof (tmp))) 192 return -EFAULT; 193 return sys_msgrcv (first, tmp.msgp, second, 194 tmp.msgtyp, third); 195 } 196 default: 197 return sys_msgrcv (first, 198 (struct msgbuf __user *) ptr, 199 second, fifth, third); 200 } 201 case MSGGET: 202 return sys_msgget ((key_t) first, second); 203 case MSGCTL: 204 return sys_msgctl(first, second, (struct msqid_ds __user *)ptr); 205 206 case SHMAT: 207 switch (version) { 208 default: { 209 ulong raddr; 210 ret = do_shmat(first, (char __user *)ptr, second, &raddr); 211 if (ret) 212 return ret; 213 return put_user(raddr, (ulong __user *)third); 214 } 215 case 1: /* Of course, we don't support iBCS2! */ 216 return -EINVAL; 217 } 218 case SHMDT: 219 return sys_shmdt ((char __user *)ptr); 220 case SHMGET: 221 return sys_shmget (first, second, third); 222 case SHMCTL: 223 return sys_shmctl (first, second, 224 (struct shmid_ds __user *) ptr); 225 default: 226 return -ENOSYS; 227 } 228 } 229 230 /* Fork a new task - this creates a new program thread. 231 * This is called indirectly via a small wrapper 232 */ 233 asmlinkage int sys_fork(struct pt_regs *regs) 234 { 235 return do_fork(SIGCHLD, regs->ARM_sp, regs, 0, NULL, NULL); 236 } 237 238 /* Clone a task - this clones the calling program thread. 239 * This is called indirectly via a small wrapper 240 */ 241 asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp, 242 int __user *parent_tidptr, int tls_val, 243 int __user *child_tidptr, struct pt_regs *regs) 244 { 245 if (!newsp) 246 newsp = regs->ARM_sp; 247 248 return do_fork(clone_flags, newsp, regs, 0, parent_tidptr, child_tidptr); 249 } 250 251 asmlinkage int sys_vfork(struct pt_regs *regs) 252 { 253 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->ARM_sp, regs, 0, NULL, NULL); 254 } 255 256 /* sys_execve() executes a new program. 257 * This is called indirectly via a small wrapper 258 */ 259 asmlinkage int sys_execve(char __user *filenamei, char __user * __user *argv, 260 char __user * __user *envp, struct pt_regs *regs) 261 { 262 int error; 263 char * filename; 264 265 filename = getname(filenamei); 266 error = PTR_ERR(filename); 267 if (IS_ERR(filename)) 268 goto out; 269 error = do_execve(filename, argv, envp, regs); 270 putname(filename); 271 out: 272 return error; 273 } 274 275 long execve(const char *filename, char **argv, char **envp) 276 { 277 struct pt_regs regs; 278 int ret; 279 280 memset(®s, 0, sizeof(struct pt_regs)); 281 ret = do_execve((char *)filename, (char __user * __user *)argv, 282 (char __user * __user *)envp, ®s); 283 if (ret < 0) 284 goto out; 285 286 /* 287 * Save argc to the register structure for userspace. 288 */ 289 regs.ARM_r0 = ret; 290 291 /* 292 * We were successful. We won't be returning to our caller, but 293 * instead to user space by manipulating the kernel stack. 294 */ 295 asm( "add r0, %0, %1\n\t" 296 "mov r1, %2\n\t" 297 "mov r2, %3\n\t" 298 "bl memmove\n\t" /* copy regs to top of stack */ 299 "mov r8, #0\n\t" /* not a syscall */ 300 "mov r9, %0\n\t" /* thread structure */ 301 "mov sp, r0\n\t" /* reposition stack pointer */ 302 "b ret_to_user" 303 : 304 : "r" (current_thread_info()), 305 "Ir" (THREAD_START_SP - sizeof(regs)), 306 "r" (®s), 307 "Ir" (sizeof(regs)) 308 : "r0", "r1", "r2", "r3", "ip", "memory"); 309 310 out: 311 return ret; 312 } 313 EXPORT_SYMBOL(execve); 314