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 /*
  55  * This is the lowest virtual address we can permit any user space
  56  * mapping to be mapped at.  This is particularly important for
  57  * non-high vector CPUs.
  58  */
  59 #define MIN_MAP_ADDR    (PAGE_SIZE)
  60
  61 /* common code for old and new mmaps */
  62 inline long do_mmap2(
  63         unsigned long addr, unsigned long len,
  64         unsigned long prot, unsigned long flags,
  65         unsigned long fd, unsigned long pgoff)
  66 {
  67         int error = -EINVAL;
  68         struct file * file = NULL;
  69
  70         flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
  71
  72         if (flags & MAP_FIXED && addr < MIN_MAP_ADDR)
  73                 goto out;
  74
  75         error = -EBADF;
  76         if (!(flags & MAP_ANONYMOUS)) {
  77                 file = fget(fd);
  78                 if (!file)
  79                         goto out;
  80         }
  81
  82         down_write(&current->mm->mmap_sem);
  83         error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
  84         up_write(&current->mm->mmap_sem);
  85
  86         if (file)
  87                 fput(file);
  88 out:
  89         return error;
  90 }
  91
  92 struct mmap_arg_struct {
  93         unsigned long addr;
  94         unsigned long len;
  95         unsigned long prot;
  96         unsigned long flags;
  97         unsigned long fd;
  98         unsigned long offset;
  99 };
 100
 101 asmlinkage int old_mmap(struct mmap_arg_struct __user *arg)
 102 {
 103         int error = -EFAULT;
 104         struct mmap_arg_struct a;
 105
 106         if (copy_from_user(&a, arg, sizeof(a)))
 107                 goto out;
 108
 109         error = -EINVAL;
 110         if (a.offset & ~PAGE_MASK)
 111                 goto out;
 112
 113         error = do_mmap2(a.addr, a.len, a.prot, a.flags, a.fd, a.offset >> PAGE_SHIFT);
 114 out:
 115         return error;
 116 }
 117
 118 asmlinkage unsigned long
 119 sys_arm_mremap(unsigned long addr, unsigned long old_len,
 120                unsigned long new_len, unsigned long flags,
 121                unsigned long new_addr)
 122 {
 123         unsigned long ret = -EINVAL;
 124
 125         if (flags & MREMAP_FIXED && new_addr < MIN_MAP_ADDR)
 126                 goto out;
 127
 128         down_write(&current->mm->mmap_sem);
 129         ret = do_mremap(addr, old_len, new_len, flags, new_addr);
 130         up_write(&current->mm->mmap_sem);
 131
 132 out:
 133         return ret;
 134 }
 135
 136 /*
 137  * Perform the select(nd, in, out, ex, tv) and mmap() system
 138  * calls.
 139  */
 140
 141 struct sel_arg_struct {
 142         unsigned long n;
 143         fd_set __user *inp, *outp, *exp;
 144         struct timeval __user *tvp;
 145 };
 146
 147 asmlinkage int old_select(struct sel_arg_struct __user *arg)
 148 {
 149         struct sel_arg_struct a;
 150
 151         if (copy_from_user(&a, arg, sizeof(a)))
 152                 return -EFAULT;
 153         /* sys_select() does the appropriate kernel locking */
 154         return sys_select(a.n, a.inp, a.outp, a.exp, a.tvp);
 155 }
 156
 157 /*
 158  * sys_ipc() is the de-multiplexer for the SysV IPC calls..
 159  *
 160  * This is really horribly ugly.
 161  */
 162 asmlinkage int sys_ipc(uint call, int first, int second, int third,
 163                        void __user *ptr, long fifth)
 164 {
 165         int version, ret;
 166
 167         version = call >> 16; /* hack for backward compatibility */
 168         call &= 0xffff;
 169
 170         switch (call) {
 171         case SEMOP:
 172                 return sys_semtimedop (first, (struct sembuf __user *)ptr, second, NULL);
 173         case SEMTIMEDOP:
 174                 return sys_semtimedop(first, (struct sembuf __user *)ptr, second,
 175                                         (const struct timespec __user *)fifth);
 176
 177         case SEMGET:
 178                 return sys_semget (first, second, third);
 179         case SEMCTL: {
 180                 union semun fourth;
 181                 if (!ptr)
 182                         return -EINVAL;
 183                 if (get_user(fourth.__pad, (void __user * __user *) ptr))
 184                         return -EFAULT;
 185                 return sys_semctl (first, second, third, fourth);
 186         }
 187
 188         case MSGSND:
 189                 return sys_msgsnd(first, (struct msgbuf __user *) ptr,
 190                                   second, third);
 191         case MSGRCV:
 192                 switch (version) {
 193                 case 0: {
 194                         struct ipc_kludge tmp;
 195                         if (!ptr)
 196                                 return -EINVAL;
 197                         if (copy_from_user(&tmp,(struct ipc_kludge __user *)ptr,
 198                                            sizeof (tmp)))
 199                                 return -EFAULT;
 200                         return sys_msgrcv (first, tmp.msgp, second,
 201                                            tmp.msgtyp, third);
 202                 }
 203                 default:
 204                         return sys_msgrcv (first,
 205                                            (struct msgbuf __user *) ptr,
 206                                            second, fifth, third);
 207                 }
 208         case MSGGET:
 209                 return sys_msgget ((key_t) first, second);
 210         case MSGCTL:
 211                 return sys_msgctl(first, second, (struct msqid_ds __user *)ptr);
 212
 213         case SHMAT:
 214                 switch (version) {
 215                 default: {
 216                         ulong raddr;
 217                         ret = do_shmat(first, (char __user *)ptr, second, &raddr);
 218                         if (ret)
 219                                 return ret;
 220                         return put_user(raddr, (ulong __user *)third);
 221                 }
 222                 case 1: /* Of course, we don't support iBCS2! */
 223                         return -EINVAL;
 224                 }
 225         case SHMDT:
 226                 return sys_shmdt ((char __user *)ptr);
 227         case SHMGET:
 228                 return sys_shmget (first, second, third);
 229         case SHMCTL:
 230                 return sys_shmctl (first, second,
 231                                    (struct shmid_ds __user *) ptr);
 232         default:
 233                 return -ENOSYS;
 234         }
 235 }
 236
 237 asmlinkage long sys_shmat(int shmid, char __user *shmaddr, int shmflg,
 238                           unsigned long __user *addr)
 239 {
 240         unsigned long ret;
 241         long err;
 242
 243         err = do_shmat(shmid, shmaddr, shmflg, &ret);
 244         if (err == 0)
 245                 err = put_user(ret, addr);
 246         return err;
 247 }
 248
 249 /* Fork a new task - this creates a new program thread.
 250  * This is called indirectly via a small wrapper
 251  */
 252 asmlinkage int sys_fork(struct pt_regs *regs)
 253 {
 254         return do_fork(SIGCHLD, regs->ARM_sp, regs, 0, NULL, NULL);
 255 }
 256
 257 /* Clone a task - this clones the calling program thread.
 258  * This is called indirectly via a small wrapper
 259  */
 260 asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
 261                          int __user *parent_tidptr, int tls_val,
 262                          int __user *child_tidptr, struct pt_regs *regs)
 263 {
 264         if (!newsp)
 265                 newsp = regs->ARM_sp;
 266
 267         return do_fork(clone_flags, newsp, regs, 0, parent_tidptr, child_tidptr);
 268 }
 269
 270 asmlinkage int sys_vfork(struct pt_regs *regs)
 271 {
 272         return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->ARM_sp, regs, 0, NULL, NULL);
 273 }
 274
 275 /* sys_execve() executes a new program.
 276  * This is called indirectly via a small wrapper
 277  */
 278 asmlinkage int sys_execve(char __user *filenamei, char __user * __user *argv,
 279                           char __user * __user *envp, struct pt_regs *regs)
 280 {
 281         int error;
 282         char * filename;
 283
 284         filename = getname(filenamei);
 285         error = PTR_ERR(filename);
 286         if (IS_ERR(filename))
 287                 goto out;
 288         error = do_execve(filename, argv, envp, regs);
 289         putname(filename);
 290 out:
 291         return error;
 292 }
 293
 294 long execve(const char *filename, char **argv, char **envp)
 295 {
 296         struct pt_regs regs;
 297         int ret;
 298
 299         memset(&regs, 0, sizeof(struct pt_regs));
 300         ret = do_execve((char *)filename, (char __user * __user *)argv,
 301                         (char __user * __user *)envp, &regs);
 302         if (ret < 0)
 303                 goto out;
 304
 305         /*
 306          * Save argc to the register structure for userspace.
 307          */
 308         regs.ARM_r0 = ret;
 309
 310         /*
 311          * We were successful.  We won't be returning to our caller, but
 312          * instead to user space by manipulating the kernel stack.
 313          */
 314         asm(    "add    r0, %0, %1\n\t"
 315                 "mov    r1, %2\n\t"
 316                 "mov    r2, %3\n\t"
 317                 "bl     memmove\n\t"    /* copy regs to top of stack */
 318                 "mov    r8, #0\n\t"     /* not a syscall */
 319                 "mov    r9, %0\n\t"     /* thread structure */
 320                 "mov    sp, r0\n\t"     /* reposition stack pointer */
 321                 "b      ret_to_user"
 322                 :
 323                 : "r" (current_thread_info()),
 324                   "Ir" (THREAD_SIZE - 8 - sizeof(regs)),
 325                   "r" (&regs),
 326                   "Ir" (sizeof(regs))
 327                 : "r0", "r1", "r2", "r3", "ip", "memory");
 328
 329  out:
 330         return ret;
 331 }
 332 EXPORT_SYMBOL(execve);