arch/arm/kernel/sys_arm.c

   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(&current->mm->mmap_sem);
  76         error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
  77         up_write(&current->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(&current->mm->mmap_sem);
 122         ret = do_mremap(addr, old_len, new_len, flags, new_addr);
 123         up_write(&current->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(&regs, 0, sizeof(struct pt_regs));
 281         ret = do_execve((char *)filename, (char __user * __user *)argv,
 282                         (char __user * __user *)envp, &regs);
 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" (&regs),
 307                   "Ir" (sizeof(regs))
 308                 : "r0", "r1", "r2", "r3", "ip", "memory");
 309
 310  out:
 311         return ret;
 312 }
 313 EXPORT_SYMBOL(execve);