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