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  *  Copyright (C) 2003, 2004 Hyok S. Choi
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  *
  12  *  This file contains various random system calls that
  13  *  have a non-standard calling sequence on the Linux/arm
  14  *  platform.
  15  */
  16 #include <linux/module.h>
  17 #include <linux/errno.h>
  18 #include <linux/sched.h>
  19 #include <linux/slab.h>
  20 #include <linux/mm.h>
  21 #include <linux/sem.h>
  22 #include <linux/msg.h>
  23 #include <linux/shm.h>
  24 #include <linux/stat.h>
  25 #include <linux/syscalls.h>
  26 #include <linux/mman.h>
  27 #include <linux/fs.h>
  28 #include <linux/file.h>
  29 #include <linux/utsname.h>
  30
  31 #include <asm/uaccess.h>
  32 #include <asm/ipc.h>
  33
  34 extern unsigned long do_mremap(unsigned long addr, unsigned long old_len,
  35                                unsigned long new_len, unsigned long flags,
  36                                unsigned long new_addr);
  37
  38 /*
  39  * sys_pipe() is the normal C calling standard for creating
  40  * a pipe. It's not the way unix traditionally does this, though.
  41  */
  42 asmlinkage int sys_pipe(unsigned long __user *fildes)
  43 {
  44         int fd[2];
  45         int error;
  46
  47         error = do_pipe(fd);
  48         if (!error) {
  49                 if (copy_to_user(fildes, fd, 2*sizeof(int)))
  50                         error = -EFAULT;
  51         }
  52         return error;
  53 }
  54
  55 /* common code for old and new mmaps */
  56 inline long do_mmap2(
  57         unsigned long addr, unsigned long len,
  58         unsigned long prot, unsigned long flags,
  59         unsigned long fd, unsigned long pgoff)
  60 {
  61         int error = -EINVAL;
  62         struct file * file = NULL;
  63
  64         flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
  65
  66         if (flags & MAP_FIXED && addr < FIRST_USER_ADDRESS)
  67                 goto out;
  68
  69         error = -EBADF;
  70         if (!(flags & MAP_ANONYMOUS)) {
  71                 file = fget(fd);
  72                 if (!file)
  73                         goto out;
  74         }
  75
  76         down_write(&current->mm->mmap_sem);
  77         error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
  78         up_write(&current->mm->mmap_sem);
  79
  80         if (file)
  81                 fput(file);
  82 out:
  83         return error;
  84 }
  85
  86 struct mmap_arg_struct {
  87         unsigned long addr;
  88         unsigned long len;
  89         unsigned long prot;
  90         unsigned long flags;
  91         unsigned long fd;
  92         unsigned long offset;
  93 };
  94
  95 asmlinkage int old_mmap(struct mmap_arg_struct __user *arg)
  96 {
  97         int error = -EFAULT;
  98         struct mmap_arg_struct a;
  99
 100         if (copy_from_user(&a, arg, sizeof(a)))
 101                 goto out;
 102
 103         error = -EINVAL;
 104         if (a.offset & ~PAGE_MASK)
 105                 goto out;
 106
 107         error = do_mmap2(a.addr, a.len, a.prot, a.flags, a.fd, a.offset >> PAGE_SHIFT);
 108 out:
 109         return error;
 110 }
 111
 112 asmlinkage unsigned long
 113 sys_arm_mremap(unsigned long addr, unsigned long old_len,
 114                unsigned long new_len, unsigned long flags,
 115                unsigned long new_addr)
 116 {
 117         unsigned long ret = -EINVAL;
 118 #ifdef CONFIG_MMU
 119         if (flags & MREMAP_FIXED && new_addr < FIRST_USER_ADDRESS)
 120                 goto out;
 121
 122         down_write(&current->mm->mmap_sem);
 123         ret = do_mremap(addr, old_len, new_len, flags, new_addr);
 124         up_write(&current->mm->mmap_sem);
 125
 126 out:
 127 #endif
 128         return ret;
 129 }
 130
 131 /*
 132  * Perform the select(nd, in, out, ex, tv) and mmap() system
 133  * calls.
 134  */
 135
 136 struct sel_arg_struct {
 137         unsigned long n;
 138         fd_set __user *inp, *outp, *exp;
 139         struct timeval __user *tvp;
 140 };
 141
 142 asmlinkage int old_select(struct sel_arg_struct __user *arg)
 143 {
 144         struct sel_arg_struct a;
 145
 146         if (copy_from_user(&a, arg, sizeof(a)))
 147                 return -EFAULT;
 148         /* sys_select() does the appropriate kernel locking */
 149         return sys_select(a.n, a.inp, a.outp, a.exp, a.tvp);
 150 }
 151
 152 #if !defined(CONFIG_AEABI) || defined(CONFIG_OABI_COMPAT)
 153 /*
 154  * sys_ipc() is the de-multiplexer for the SysV IPC calls..
 155  *
 156  * This is really horribly ugly.
 157  */
 158 asmlinkage int sys_ipc(uint call, int first, int second, int third,
 159                        void __user *ptr, long fifth)
 160 {
 161         int version, ret;
 162
 163         version = call >> 16; /* hack for backward compatibility */
 164         call &= 0xffff;
 165
 166         switch (call) {
 167         case SEMOP:
 168                 return sys_semtimedop (first, (struct sembuf __user *)ptr, second, NULL);
 169         case SEMTIMEDOP:
 170                 return sys_semtimedop(first, (struct sembuf __user *)ptr, second,
 171                                         (const struct timespec __user *)fifth);
 172
 173         case SEMGET:
 174                 return sys_semget (first, second, third);
 175         case SEMCTL: {
 176                 union semun fourth;
 177                 if (!ptr)
 178                         return -EINVAL;
 179                 if (get_user(fourth.__pad, (void __user * __user *) ptr))
 180                         return -EFAULT;
 181                 return sys_semctl (first, second, third, fourth);
 182         }
 183
 184         case MSGSND:
 185                 return sys_msgsnd(first, (struct msgbuf __user *) ptr,
 186                                   second, third);
 187         case MSGRCV:
 188                 switch (version) {
 189                 case 0: {
 190                         struct ipc_kludge tmp;
 191                         if (!ptr)
 192                                 return -EINVAL;
 193                         if (copy_from_user(&tmp,(struct ipc_kludge __user *)ptr,
 194                                            sizeof (tmp)))
 195                                 return -EFAULT;
 196                         return sys_msgrcv (first, tmp.msgp, second,
 197                                            tmp.msgtyp, third);
 198                 }
 199                 default:
 200                         return sys_msgrcv (first,
 201                                            (struct msgbuf __user *) ptr,
 202                                            second, fifth, third);
 203                 }
 204         case MSGGET:
 205                 return sys_msgget ((key_t) first, second);
 206         case MSGCTL:
 207                 return sys_msgctl(first, second, (struct msqid_ds __user *)ptr);
 208
 209         case SHMAT:
 210                 switch (version) {
 211                 default: {
 212                         ulong raddr;
 213                         ret = do_shmat(first, (char __user *)ptr, second, &raddr);
 214                         if (ret)
 215                                 return ret;
 216                         return put_user(raddr, (ulong __user *)third);
 217                 }
 218                 case 1: /* Of course, we don't support iBCS2! */
 219                         return -EINVAL;
 220                 }
 221         case SHMDT:
 222                 return sys_shmdt ((char __user *)ptr);
 223         case SHMGET:
 224                 return sys_shmget (first, second, third);
 225         case SHMCTL:
 226                 return sys_shmctl (first, second,
 227                                    (struct shmid_ds __user *) ptr);
 228         default:
 229                 return -ENOSYS;
 230         }
 231 }
 232 #endif
 233
 234 /* Fork a new task - this creates a new program thread.
 235  * This is called indirectly via a small wrapper
 236  */
 237 asmlinkage int sys_fork(struct pt_regs *regs)
 238 {
 239 #ifdef CONFIG_MMU
 240         return do_fork(SIGCHLD, regs->ARM_sp, regs, 0, NULL, NULL);
 241 #else
 242         /* can not support in nommu mode */
 243         return(-EINVAL);
 244 #endif
 245 }
 246
 247 /* Clone a task - this clones the calling program thread.
 248  * This is called indirectly via a small wrapper
 249  */
 250 asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
 251                          int __user *parent_tidptr, int tls_val,
 252                          int __user *child_tidptr, struct pt_regs *regs)
 253 {
 254         if (!newsp)
 255                 newsp = regs->ARM_sp;
 256
 257         return do_fork(clone_flags, newsp, regs, 0, parent_tidptr, child_tidptr);
 258 }
 259
 260 asmlinkage int sys_vfork(struct pt_regs *regs)
 261 {
 262         return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->ARM_sp, regs, 0, NULL, NULL);
 263 }
 264
 265 /* sys_execve() executes a new program.
 266  * This is called indirectly via a small wrapper
 267  */
 268 asmlinkage int sys_execve(char __user *filenamei, char __user * __user *argv,
 269                           char __user * __user *envp, struct pt_regs *regs)
 270 {
 271         int error;
 272         char * filename;
 273
 274         filename = getname(filenamei);
 275         error = PTR_ERR(filename);
 276         if (IS_ERR(filename))
 277                 goto out;
 278         error = do_execve(filename, argv, envp, regs);
 279         putname(filename);
 280 out:
 281         return error;
 282 }
 283
 284 int kernel_execve(const char *filename, char *const argv[], char *const envp[])
 285 {
 286         struct pt_regs regs;
 287         int ret;
 288
 289         memset(&regs, 0, sizeof(struct pt_regs));
 290         ret = do_execve((char *)filename, (char __user * __user *)argv,
 291                         (char __user * __user *)envp, &regs);
 292         if (ret < 0)
 293                 goto out;
 294
 295         /*
 296          * Save argc to the register structure for userspace.
 297          */
 298         regs.ARM_r0 = ret;
 299
 300         /*
 301          * We were successful.  We won't be returning to our caller, but
 302          * instead to user space by manipulating the kernel stack.
 303          */
 304         asm(    "add    r0, %0, %1\n\t"
 305                 "mov    r1, %2\n\t"
 306                 "mov    r2, %3\n\t"
 307                 "bl     memmove\n\t"    /* copy regs to top of stack */
 308                 "mov    r8, #0\n\t"     /* not a syscall */
 309                 "mov    r9, %0\n\t"     /* thread structure */
 310                 "mov    sp, r0\n\t"     /* reposition stack pointer */
 311                 "b      ret_to_user"
 312                 :
 313                 : "r" (current_thread_info()),
 314                   "Ir" (THREAD_START_SP - sizeof(regs)),
 315                   "r" (&regs),
 316                   "Ir" (sizeof(regs))
 317                 : "r0", "r1", "r2", "r3", "ip", "lr", "memory");
 318
 319  out:
 320         return ret;
 321 }
 322 EXPORT_SYMBOL(kernel_execve);
 323
 324 /*
 325  * Since loff_t is a 64 bit type we avoid a lot of ABI hastle
 326  * with a different argument ordering.
 327  */
 328 asmlinkage long sys_arm_fadvise64_64(int fd, int advice,
 329                                      loff_t offset, loff_t len)
 330 {
 331         return sys_fadvise64_64(fd, offset, len, advice);
 332 }