arch/arm26/kernel/sys_arm.c

   1 /*
   2  *  linux/arch/arm26/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 Ian Molton.
   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 * 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         /*
  67          * If we are doing a fixed mapping, and address < FIRST_USER_ADDRESS,
  68          * then deny it.
  69          */
  70         if (flags & MAP_FIXED && addr < FIRST_USER_ADDRESS)
  71                 goto out;
  72
  73         error = -EBADF;
  74         if (!(flags & MAP_ANONYMOUS)) {
  75                 file = fget(fd);
  76                 if (!file)
  77                         goto out;
  78         }
  79
  80         down_write(&current->mm->mmap_sem);
  81         error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
  82         up_write(&current->mm->mmap_sem);
  83
  84         if (file)
  85                 fput(file);
  86 out:
  87         return error;
  88 }
  89
  90 struct mmap_arg_struct {
  91         unsigned long addr;
  92         unsigned long len;
  93         unsigned long prot;
  94         unsigned long flags;
  95         unsigned long fd;
  96         unsigned long offset;
  97 };
  98
  99 asmlinkage int old_mmap(struct mmap_arg_struct *arg)
 100 {
 101         int error = -EFAULT;
 102         struct mmap_arg_struct a;
 103
 104         if (copy_from_user(&a, arg, sizeof(a)))
 105                 goto out;
 106
 107         error = -EINVAL;
 108         if (a.offset & ~PAGE_MASK)
 109                 goto out;
 110
 111         error = do_mmap2(a.addr, a.len, a.prot, a.flags, a.fd, a.offset >> PAGE_SHIFT);
 112 out:
 113         return error;
 114 }
 115
 116 asmlinkage unsigned long
 117 sys_arm_mremap(unsigned long addr, unsigned long old_len,
 118                unsigned long new_len, unsigned long flags,
 119                unsigned long new_addr)
 120 {
 121         unsigned long ret = -EINVAL;
 122
 123         /*
 124          * If we are doing a fixed mapping, and address < FIRST_USER_ADDRESS,
 125          * then deny it.
 126          */
 127         if (flags & MREMAP_FIXED && new_addr < FIRST_USER_ADDRESS)
 128                 goto out;
 129
 130         down_write(&current->mm->mmap_sem);
 131         ret = do_mremap(addr, old_len, new_len, flags, new_addr);
 132         up_write(&current->mm->mmap_sem);
 133
 134 out:
 135         return ret;
 136 }
 137
 138 /*
 139  * Perform the select(nd, in, out, ex, tv) and mmap() system
 140  * calls.
 141  */
 142
 143 struct sel_arg_struct {
 144         unsigned long n;
 145         fd_set *inp, *outp, *exp;
 146         struct timeval *tvp;
 147 };
 148
 149 asmlinkage int old_select(struct sel_arg_struct *arg)
 150 {
 151         struct sel_arg_struct a;
 152
 153         if (copy_from_user(&a, arg, sizeof(a)))
 154                 return -EFAULT;
 155         /* sys_select() does the appropriate kernel locking */
 156         return sys_select(a.n, a.inp, a.outp, a.exp, a.tvp);
 157 }
 158
 159 /*
 160  * sys_ipc() is the de-multiplexer for the SysV IPC calls..
 161  *
 162  * This is really horribly ugly.
 163  */
 164 asmlinkage int sys_ipc (uint call, int first, int second, int third, void *ptr, long fifth)
 165 {
 166         int version, ret;
 167
 168         version = call >> 16; /* hack for backward compatibility */
 169         call &= 0xffff;
 170
 171         switch (call) {
 172         case SEMOP:
 173                 return sys_semop (first, (struct sembuf *)ptr, second);
 174         case SEMGET:
 175                 return sys_semget (first, second, third);
 176         case SEMCTL: {
 177                 union semun fourth;
 178                 if (!ptr)
 179                         return -EINVAL;
 180                 if (get_user(fourth.__pad, (void **) ptr))
 181                         return -EFAULT;
 182                 return sys_semctl (first, second, third, fourth);
 183         }
 184
 185         case MSGSND:
 186                 return sys_msgsnd (first, (struct msgbuf *) ptr,
 187                                    second, third);
 188         case MSGRCV:
 189                 switch (version) {
 190                 case 0: {
 191                         struct ipc_kludge tmp;
 192                         if (!ptr)
 193                                 return -EINVAL;
 194                         if (copy_from_user(&tmp,(struct ipc_kludge *) ptr,
 195                                            sizeof (tmp)))
 196                                 return -EFAULT;
 197                         return sys_msgrcv (first, tmp.msgp, second,
 198                                            tmp.msgtyp, third);
 199                 }
 200                 default:
 201                         return sys_msgrcv (first,
 202                                            (struct msgbuf *) ptr,
 203                                            second, fifth, third);
 204                 }
 205         case MSGGET:
 206                 return sys_msgget ((key_t) first, second);
 207         case MSGCTL:
 208                 return sys_msgctl (first, second, (struct msqid_ds *) ptr);
 209
 210         case SHMAT:
 211                 switch (version) {
 212                 default: {
 213                         ulong raddr;
 214                         ret = do_shmat (first, (char *) ptr, second, &raddr);
 215                         if (ret)
 216                                 return ret;
 217                         return put_user (raddr, (ulong *) third);
 218                 }
 219                 case 1: /* iBCS2 emulator entry point */
 220                         if (!segment_eq(get_fs(), get_ds()))
 221                                 return -EINVAL;
 222                         return do_shmat (first, (char *) ptr,
 223                                           second, (ulong *) third);
 224                 }
 225         case SHMDT:
 226                 return sys_shmdt ((char *)ptr);
 227         case SHMGET:
 228                 return sys_shmget (first, second, third);
 229         case SHMCTL:
 230                 return sys_shmctl (first, second,
 231                                    (struct shmid_ds *) ptr);
 232         default:
 233                 return -EINVAL;
 234         }
 235 }
 236
 237 /* Fork a new task - this creates a new program thread.
 238  * This is called indirectly via a small wrapper
 239  */
 240 asmlinkage int sys_fork(struct pt_regs *regs)
 241 {
 242         return do_fork(SIGCHLD, regs->ARM_sp, regs, 0, NULL, NULL);
 243 }
 244
 245 /* Clone a task - this clones the calling program thread.
 246  * This is called indirectly via a small wrapper
 247  */
 248 asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp, struct pt_regs *regs)
 249 {
 250         /*
 251          * We don't support SETTID / CLEARTID  (FIXME!!! (nicked from arm32))
 252          */
 253         if (clone_flags & (CLONE_PARENT_SETTID | CLONE_CHILD_CLEARTID))
 254                 return -EINVAL;
 255
 256         if (!newsp)
 257                 newsp = regs->ARM_sp;
 258
 259         return do_fork(clone_flags, newsp, regs, 0, NULL, NULL);
 260 }
 261
 262 asmlinkage int sys_vfork(struct pt_regs *regs)
 263 {
 264         return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->ARM_sp, regs, 0, NULL, NULL);
 265 }
 266
 267 /* sys_execve() executes a new program.
 268  * This is called indirectly via a small wrapper
 269  */
 270 asmlinkage int sys_execve(char *filenamei, char **argv, char **envp, struct pt_regs *regs)
 271 {
 272         int error;
 273         char * filename;
 274
 275         filename = getname(filenamei);
 276         error = PTR_ERR(filename);
 277         if (IS_ERR(filename))
 278                 goto out;
 279         error = do_execve(filename, argv, envp, regs);
 280         putname(filename);
 281 out:
 282         return error;
 283 }
 284
 285 /* FIXME - see if this is correct for arm26 */
 286 long execve(const char *filename, char **argv, char **envp)
 287 {
 288         struct pt_regs regs;
 289         int ret;
 290          memset(&regs, 0, sizeof(struct pt_regs));
 291         ret = do_execve((char *)filename, (char __user * __user *)argv,                         (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_SIZE - 8 - sizeof(regs)),
 315                   "r" (&regs),
 316                   "Ir" (sizeof(regs))
 317                 : "r0", "r1", "r2", "r3", "ip", "memory");
 318
 319  out:
 320         return ret;
 321 }
 322
 323 EXPORT_SYMBOL(execve);