linux/arch/x86/kernel/sys_i386_32.c
<<
>>
Prefs
   1/*
   2 * This file contains various random system calls that
   3 * have a non-standard calling sequence on the Linux/i386
   4 * platform.
   5 */
   6
   7#include <linux/errno.h>
   8#include <linux/sched.h>
   9#include <linux/mm.h>
  10#include <linux/fs.h>
  11#include <linux/smp.h>
  12#include <linux/sem.h>
  13#include <linux/msg.h>
  14#include <linux/shm.h>
  15#include <linux/stat.h>
  16#include <linux/syscalls.h>
  17#include <linux/mman.h>
  18#include <linux/file.h>
  19#include <linux/utsname.h>
  20#include <linux/ipc.h>
  21
  22#include <linux/uaccess.h>
  23#include <linux/unistd.h>
  24
  25#include <asm/syscalls.h>
  26
  27asmlinkage long sys_mmap2(unsigned long addr, unsigned long len,
  28                          unsigned long prot, unsigned long flags,
  29                          unsigned long fd, unsigned long pgoff)
  30{
  31        int error = -EBADF;
  32        struct file *file = NULL;
  33        struct mm_struct *mm = current->mm;
  34
  35        flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
  36        if (!(flags & MAP_ANONYMOUS)) {
  37                file = fget(fd);
  38                if (!file)
  39                        goto out;
  40        }
  41
  42        down_write(&mm->mmap_sem);
  43        error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
  44        up_write(&mm->mmap_sem);
  45
  46        if (file)
  47                fput(file);
  48out:
  49        return error;
  50}
  51
  52/*
  53 * Perform the select(nd, in, out, ex, tv) and mmap() system
  54 * calls. Linux/i386 didn't use to be able to handle more than
  55 * 4 system call parameters, so these system calls used a memory
  56 * block for parameter passing..
  57 */
  58
  59struct mmap_arg_struct {
  60        unsigned long addr;
  61        unsigned long len;
  62        unsigned long prot;
  63        unsigned long flags;
  64        unsigned long fd;
  65        unsigned long offset;
  66};
  67
  68asmlinkage int old_mmap(struct mmap_arg_struct __user *arg)
  69{
  70        struct mmap_arg_struct a;
  71        int err = -EFAULT;
  72
  73        if (copy_from_user(&a, arg, sizeof(a)))
  74                goto out;
  75
  76        err = -EINVAL;
  77        if (a.offset & ~PAGE_MASK)
  78                goto out;
  79
  80        err = sys_mmap2(a.addr, a.len, a.prot, a.flags,
  81                        a.fd, a.offset >> PAGE_SHIFT);
  82out:
  83        return err;
  84}
  85
  86
  87struct sel_arg_struct {
  88        unsigned long n;
  89        fd_set __user *inp, *outp, *exp;
  90        struct timeval __user *tvp;
  91};
  92
  93asmlinkage int old_select(struct sel_arg_struct __user *arg)
  94{
  95        struct sel_arg_struct a;
  96
  97        if (copy_from_user(&a, arg, sizeof(a)))
  98                return -EFAULT;
  99        /* sys_select() does the appropriate kernel locking */
 100        return sys_select(a.n, a.inp, a.outp, a.exp, a.tvp);
 101}
 102
 103/*
 104 * sys_ipc() is the de-multiplexer for the SysV IPC calls..
 105 *
 106 * This is really horribly ugly.
 107 */
 108asmlinkage int sys_ipc(uint call, int first, int second,
 109                        int third, void __user *ptr, long fifth)
 110{
 111        int version, ret;
 112
 113        version = call >> 16; /* hack for backward compatibility */
 114        call &= 0xffff;
 115
 116        switch (call) {
 117        case SEMOP:
 118                return sys_semtimedop(first, (struct sembuf __user *)ptr, second, NULL);
 119        case SEMTIMEDOP:
 120                return sys_semtimedop(first, (struct sembuf __user *)ptr, second,
 121                                        (const struct timespec __user *)fifth);
 122
 123        case SEMGET:
 124                return sys_semget(first, second, third);
 125        case SEMCTL: {
 126                union semun fourth;
 127                if (!ptr)
 128                        return -EINVAL;
 129                if (get_user(fourth.__pad, (void __user * __user *) ptr))
 130                        return -EFAULT;
 131                return sys_semctl(first, second, third, fourth);
 132        }
 133
 134        case MSGSND:
 135                return sys_msgsnd(first, (struct msgbuf __user *) ptr,
 136                                   second, third);
 137        case MSGRCV:
 138                switch (version) {
 139                case 0: {
 140                        struct ipc_kludge tmp;
 141                        if (!ptr)
 142                                return -EINVAL;
 143
 144                        if (copy_from_user(&tmp,
 145                                           (struct ipc_kludge __user *) ptr,
 146                                           sizeof(tmp)))
 147                                return -EFAULT;
 148                        return sys_msgrcv(first, tmp.msgp, second,
 149                                           tmp.msgtyp, third);
 150                }
 151                default:
 152                        return sys_msgrcv(first,
 153                                           (struct msgbuf __user *) ptr,
 154                                           second, fifth, third);
 155                }
 156        case MSGGET:
 157                return sys_msgget((key_t) first, second);
 158        case MSGCTL:
 159                return sys_msgctl(first, second, (struct msqid_ds __user *) ptr);
 160
 161        case SHMAT:
 162                switch (version) {
 163                default: {
 164                        ulong raddr;
 165                        ret = do_shmat(first, (char __user *) ptr, second, &raddr);
 166                        if (ret)
 167                                return ret;
 168                        return put_user(raddr, (ulong __user *) third);
 169                }
 170                case 1: /* iBCS2 emulator entry point */
 171                        if (!segment_eq(get_fs(), get_ds()))
 172                                return -EINVAL;
 173                        /* The "(ulong *) third" is valid _only_ because of the kernel segment thing */
 174                        return do_shmat(first, (char __user *) ptr, second, (ulong *) third);
 175                }
 176        case SHMDT:
 177                return sys_shmdt((char __user *)ptr);
 178        case SHMGET:
 179                return sys_shmget(first, second, third);
 180        case SHMCTL:
 181                return sys_shmctl(first, second,
 182                                   (struct shmid_ds __user *) ptr);
 183        default:
 184                return -ENOSYS;
 185        }
 186}
 187
 188/*
 189 * Old cruft
 190 */
 191asmlinkage int sys_uname(struct old_utsname __user *name)
 192{
 193        int err;
 194        if (!name)
 195                return -EFAULT;
 196        down_read(&uts_sem);
 197        err = copy_to_user(name, utsname(), sizeof(*name));
 198        up_read(&uts_sem);
 199        return err? -EFAULT:0;
 200}
 201
 202asmlinkage int sys_olduname(struct oldold_utsname __user *name)
 203{
 204        int error;
 205
 206        if (!name)
 207                return -EFAULT;
 208        if (!access_ok(VERIFY_WRITE, name, sizeof(struct oldold_utsname)))
 209                return -EFAULT;
 210
 211        down_read(&uts_sem);
 212
 213        error = __copy_to_user(&name->sysname, &utsname()->sysname,
 214                               __OLD_UTS_LEN);
 215        error |= __put_user(0, name->sysname + __OLD_UTS_LEN);
 216        error |= __copy_to_user(&name->nodename, &utsname()->nodename,
 217                                __OLD_UTS_LEN);
 218        error |= __put_user(0, name->nodename + __OLD_UTS_LEN);
 219        error |= __copy_to_user(&name->release, &utsname()->release,
 220                                __OLD_UTS_LEN);
 221        error |= __put_user(0, name->release + __OLD_UTS_LEN);
 222        error |= __copy_to_user(&name->version, &utsname()->version,
 223                                __OLD_UTS_LEN);
 224        error |= __put_user(0, name->version + __OLD_UTS_LEN);
 225        error |= __copy_to_user(&name->machine, &utsname()->machine,
 226                                __OLD_UTS_LEN);
 227        error |= __put_user(0, name->machine + __OLD_UTS_LEN);
 228
 229        up_read(&uts_sem);
 230
 231        error = error ? -EFAULT : 0;
 232
 233        return error;
 234}
 235
 236
 237/*
 238 * Do a system call from kernel instead of calling sys_execve so we
 239 * end up with proper pt_regs.
 240 */
 241int kernel_execve(const char *filename, char *const argv[], char *const envp[])
 242{
 243        long __res;
 244        asm volatile ("push %%ebx ; movl %2,%%ebx ; int $0x80 ; pop %%ebx"
 245        : "=a" (__res)
 246        : "0" (__NR_execve), "ri" (filename), "c" (argv), "d" (envp) : "memory");
 247        return __res;
 248}
 249
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.