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/ipc.h>
  29 #include <linux/uaccess.h>
  30
  31 extern unsigned long do_mremap(unsigned long addr, unsigned long old_len,
  32                                unsigned long new_len, unsigned long flags,
  33                                unsigned long new_addr);
  34
  35 /* common code for old and new mmaps */
  36 inline long do_mmap2(
  37         unsigned long addr, unsigned long len,
  38         unsigned long prot, unsigned long flags,
  39         unsigned long fd, unsigned long pgoff)
  40 {
  41         int error = -EINVAL;
  42         struct file * file = NULL;
  43
  44         flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
  45
  46         if (flags & MAP_FIXED && addr < FIRST_USER_ADDRESS)
  47                 goto out;
  48
  49         error = -EBADF;
  50         if (!(flags & MAP_ANONYMOUS)) {
  51                 file = fget(fd);
  52                 if (!file)
  53                         goto out;
  54         }
  55
  56         down_write(&current->mm->mmap_sem);
  57         error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
  58         up_write(&current->mm->mmap_sem);
  59
  60         if (file)
  61                 fput(file);
  62 out:
  63         return error;
  64 }
  65
  66 struct mmap_arg_struct {
  67         unsigned long addr;
  68         unsigned long len;
  69         unsigned long prot;
  70         unsigned long flags;
  71         unsigned long fd;
  72         unsigned long offset;
  73 };
  74
  75 asmlinkage int old_mmap(struct mmap_arg_struct __user *arg)
  76 {
  77         int error = -EFAULT;
  78         struct mmap_arg_struct a;
  79
  80         if (copy_from_user(&a, arg, sizeof(a)))
  81                 goto out;
  82
  83         error = -EINVAL;
  84         if (a.offset & ~PAGE_MASK)
  85                 goto out;
  86
  87         error = do_mmap2(a.addr, a.len, a.prot, a.flags, a.fd, a.offset >> PAGE_SHIFT);
  88 out:
  89         return error;
  90 }
  91
  92 asmlinkage unsigned long
  93 sys_arm_mremap(unsigned long addr, unsigned long old_len,
  94                unsigned long new_len, unsigned long flags,
  95                unsigned long new_addr)
  96 {
  97         unsigned long ret = -EINVAL;
  98
  99         if (flags & MREMAP_FIXED && new_addr < FIRST_USER_ADDRESS)
 100                 goto out;
 101
 102         down_write(&current->mm->mmap_sem);
 103         ret = do_mremap(addr, old_len, new_len, flags, new_addr);
 104         up_write(&current->mm->mmap_sem);
 105
 106 out:
 107         return ret;
 108 }
 109
 110 /*
 111  * Perform the select(nd, in, out, ex, tv) and mmap() system
 112  * calls.
 113  */
 114
 115 struct sel_arg_struct {
 116         unsigned long n;
 117         fd_set __user *inp, *outp, *exp;
 118         struct timeval __user *tvp;
 119 };
 120
 121 asmlinkage int old_select(struct sel_arg_struct __user *arg)
 122 {
 123         struct sel_arg_struct a;
 124
 125         if (copy_from_user(&a, arg, sizeof(a)))
 126                 return -EFAULT;
 127         /* sys_select() does the appropriate kernel locking */
 128         return sys_select(a.n, a.inp, a.outp, a.exp, a.tvp);
 129 }
 130
 131 #if !defined(CONFIG_AEABI) || defined(CONFIG_OABI_COMPAT)
 132 /*
 133  * sys_ipc() is the de-multiplexer for the SysV IPC calls..
 134  *
 135  * This is really horribly ugly.
 136  */
 137 asmlinkage int sys_ipc(uint call, int first, int second, int third,
 138                        void __user *ptr, long fifth)
 139 {
 140         int version, ret;
 141
 142         version = call >> 16; /* hack for backward compatibility */
 143         call &= 0xffff;
 144
 145         switch (call) {
 146         case SEMOP:
 147                 return sys_semtimedop (first, (struct sembuf __user *)ptr, second, NULL);
 148         case SEMTIMEDOP:
 149                 return sys_semtimedop(first, (struct sembuf __user *)ptr, second,
 150                                         (const struct timespec __user *)fifth);
 151
 152         case SEMGET:
 153                 return sys_semget (first, second, third);
 154         case SEMCTL: {
 155                 union semun fourth;
 156                 if (!ptr)
 157                         return -EINVAL;
 158                 if (get_user(fourth.__pad, (void __user * __user *) ptr))
 159                         return -EFAULT;
 160                 return sys_semctl (first, second, third, fourth);
 161         }
 162
 163         case MSGSND:
 164                 return sys_msgsnd(first, (struct msgbuf __user *) ptr,
 165                                   second, third);
 166         case MSGRCV:
 167                 switch (version) {
 168                 case 0: {
 169                         struct ipc_kludge tmp;
 170                         if (!ptr)
 171                                 return -EINVAL;
 172                         if (copy_from_user(&tmp,(struct ipc_kludge __user *)ptr,
 173                                            sizeof (tmp)))
 174                                 return -EFAULT;
 175                         return sys_msgrcv (first, tmp.msgp, second,
 176                                            tmp.msgtyp, third);
 177                 }
 178                 default:
 179                         return sys_msgrcv (first,
 180                                            (struct msgbuf __user *) ptr,
 181                                            second, fifth, third);
 182                 }
 183         case MSGGET:
 184                 return sys_msgget ((key_t) first, second);
 185         case MSGCTL:
 186                 return sys_msgctl(first, second, (struct msqid_ds __user *)ptr);
 187
 188         case SHMAT:
 189                 switch (version) {
 190                 default: {
 191                         ulong raddr;
 192                         ret = do_shmat(first, (char __user *)ptr, second, &raddr);
 193                         if (ret)
 194                                 return ret;
 195                         return put_user(raddr, (ulong __user *)third);
 196                 }
 197                 case 1: /* Of course, we don't support iBCS2! */
 198                         return -EINVAL;
 199                 }
 200         case SHMDT:
 201                 return sys_shmdt ((char __user *)ptr);
 202         case SHMGET:
 203                 return sys_shmget (first, second, third);
 204         case SHMCTL:
 205                 return sys_shmctl (first, second,
 206                                    (struct shmid_ds __user *) ptr);
 207         default:
 208                 return -ENOSYS;
 209         }
 210 }
 211 #endif
 212
 213 /* Fork a new task - this creates a new program thread.
 214  * This is called indirectly via a small wrapper
 215  */
 216 asmlinkage int sys_fork(struct pt_regs *regs)
 217 {
 218 #ifdef CONFIG_MMU
 219         return do_fork(SIGCHLD, regs->ARM_sp, regs, 0, NULL, NULL);
 220 #else
 221         /* can not support in nommu mode */
 222         return(-EINVAL);
 223 #endif
 224 }
 225
 226 /* Clone a task - this clones the calling program thread.
 227  * This is called indirectly via a small wrapper
 228  */
 229 asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
 230                          int __user *parent_tidptr, int tls_val,
 231                          int __user *child_tidptr, struct pt_regs *regs)
 232 {
 233         if (!newsp)
 234                 newsp = regs->ARM_sp;
 235
 236         return do_fork(clone_flags, newsp, regs, 0, parent_tidptr, child_tidptr);
 237 }
 238
 239 asmlinkage int sys_vfork(struct pt_regs *regs)
 240 {
 241         return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->ARM_sp, regs, 0, NULL, NULL);
 242 }
 243
 244 /* sys_execve() executes a new program.
 245  * This is called indirectly via a small wrapper
 246  */
 247 asmlinkage int sys_execve(char __user *filenamei, char __user * __user *argv,
 248                           char __user * __user *envp, struct pt_regs *regs)
 249 {
 250         int error;
 251         char * filename;
 252
 253         filename = getname(filenamei);
 254         error = PTR_ERR(filename);
 255         if (IS_ERR(filename))
 256                 goto out;
 257         error = do_execve(filename, argv, envp, regs);
 258         putname(filename);
 259 out:
 260         return error;
 261 }
 262
 263 int kernel_execve(const char *filename, char *const argv[], char *const envp[])
 264 {
 265         struct pt_regs regs;
 266         int ret;
 267
 268         memset(&regs, 0, sizeof(struct pt_regs));
 269         ret = do_execve((char *)filename, (char __user * __user *)argv,
 270                         (char __user * __user *)envp, &regs);
 271         if (ret < 0)
 272                 goto out;
 273
 274         /*
 275          * Save argc to the register structure for userspace.
 276          */
 277         regs.ARM_r0 = ret;
 278
 279         /*
 280          * We were successful.  We won't be returning to our caller, but
 281          * instead to user space by manipulating the kernel stack.
 282          */
 283         asm(    "add    r0, %0, %1\n\t"
 284                 "mov    r1, %2\n\t"
 285                 "mov    r2, %3\n\t"
 286                 "bl     memmove\n\t"    /* copy regs to top of stack */
 287                 "mov    r8, #0\n\t"     /* not a syscall */
 288                 "mov    r9, %0\n\t"     /* thread structure */
 289                 "mov    sp, r0\n\t"     /* reposition stack pointer */
 290                 "b      ret_to_user"
 291                 :
 292                 : "r" (current_thread_info()),
 293                   "Ir" (THREAD_START_SP - sizeof(regs)),
 294                   "r" (&regs),
 295                   "Ir" (sizeof(regs))
 296                 : "r0", "r1", "r2", "r3", "ip", "lr", "memory");
 297
 298  out:
 299         return ret;
 300 }
 301 EXPORT_SYMBOL(kernel_execve);
 302
 303 /*
 304  * Since loff_t is a 64 bit type we avoid a lot of ABI hassle
 305  * with a different argument ordering.
 306  */
 307 asmlinkage long sys_arm_fadvise64_64(int fd, int advice,
 308                                      loff_t offset, loff_t len)
 309 {
 310         return sys_fadvise64_64(fd, offset, len, advice);
 311 }