sys_ia32.c

上传linux-jx2410的源代码

	if (!(flags & MAP_ANONYMOUS)) {
		file = fget(a.fd);
		if (!file)
			return -EBADF;
	}

	addr = ia32_do_mmap(file, a.addr, a.len, a.prot, flags, a.offset);

	if (file)
		fput(file);
	return addr;
}

asmlinkage long
sys32_mmap2 (unsigned int addr, unsigned int len, unsigned int prot, unsigned int flags,
	     unsigned int fd, unsigned int pgoff)
{
	struct file *file = NULL;
	unsigned long retval;

	flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
	if (!(flags & MAP_ANONYMOUS)) {
		file = fget(fd);
		if (!file)
			return -EBADF;
	}

	retval = ia32_do_mmap(file, addr, len, prot, flags,
			      (unsigned long) pgoff << IA32_PAGE_SHIFT);

	if (file)
		fput(file);
	return retval;
}

asmlinkage long
sys32_munmap (unsigned int start, unsigned int len)
{
	unsigned int end = start + len;
	long ret;

#if PAGE_SHIFT <= IA32_PAGE_SHIFT
	ret = sys_munmap(start, end - start);
#else
	if (start > end)
		return -EINVAL;

	start = PAGE_ALIGN(start);
	end = PAGE_START(end);

	if (start >= end)
		return 0;

	down(&ia32_mmap_sem);
	{
		ret = sys_munmap(start, end - start);
	}
	up(&ia32_mmap_sem);
#endif
	return ret;
}

#if PAGE_SHIFT > IA32_PAGE_SHIFT

/*
 * When mprotect()ing a partial page, we set the permission to the union of the old
 * settings and the new settings.  In other words, it's only possible to make access to a
 * partial page less restrictive.
 */
static long
mprotect_subpage (unsigned long address, int new_prot)
{
	int old_prot;

	if (new_prot == PROT_NONE)
		return 0;		/* optimize case where nothing changes... */

	old_prot = get_page_prot(address);
	return sys_mprotect(address, PAGE_SIZE, new_prot | old_prot);
}

#endif /* PAGE_SHIFT > IA32_PAGE_SHIFT */

asmlinkage long
sys32_mprotect (unsigned int start, unsigned int len, int prot)
{
	unsigned long end = start + len;
#if PAGE_SHIFT > IA32_PAGE_SHIFT
	long retval = 0;
#endif

	prot = get_prot32(prot);

#if PAGE_SHIFT <= IA32_PAGE_SHIFT
	return sys_mprotect(start, end - start, prot);
#else
	if (OFFSET4K(start))
		return -EINVAL;

	end = IA32_PAGE_ALIGN(end);
	if (end < start)
		return -EINVAL;

	down(&ia32_mmap_sem);
	{
		if (PAGE_OFF(start)) {
			/* start address is 4KB aligned but not page aligned. */
			retval = mprotect_subpage(PAGE_START(start), prot);
			if (retval < 0)
				goto out;

			start = PAGE_ALIGN(start);
			if (start >= end)
				goto out;	/* retval is already zero... */
		}

		if (PAGE_OFF(end)) {
			/* end address is 4KB aligned but not page aligned. */
			retval = mprotect_subpage(PAGE_START(end), prot);
			if (retval < 0)
				return retval;
			end = PAGE_START(end);
		}
		retval = sys_mprotect(start, end - start, prot);
	}
  out:
	up(&ia32_mmap_sem);
	return retval;
#endif
}

asmlinkage long
sys32_pipe (int *fd)
{
	int retval;
	int fds[2];

	retval = do_pipe(fds);
	if (retval)
		goto out;
	if (copy_to_user(fd, fds, sizeof(fds)))
		retval = -EFAULT;
  out:
	return retval;
}

static inline int
put_statfs (struct statfs32 *ubuf, struct statfs *kbuf)
{
	int err;

	if (!access_ok(VERIFY_WRITE, ubuf, sizeof(*ubuf)))
		return -EFAULT;

	err = __put_user(kbuf->f_type, &ubuf->f_type);
	err |= __put_user(kbuf->f_bsize, &ubuf->f_bsize);
	err |= __put_user(kbuf->f_blocks, &ubuf->f_blocks);
	err |= __put_user(kbuf->f_bfree, &ubuf->f_bfree);
	err |= __put_user(kbuf->f_bavail, &ubuf->f_bavail);
	err |= __put_user(kbuf->f_files, &ubuf->f_files);
	err |= __put_user(kbuf->f_ffree, &ubuf->f_ffree);
	err |= __put_user(kbuf->f_namelen, &ubuf->f_namelen);
	err |= __put_user(kbuf->f_fsid.val[0], &ubuf->f_fsid.val[0]);
	err |= __put_user(kbuf->f_fsid.val[1], &ubuf->f_fsid.val[1]);
	return err;
}

extern asmlinkage long sys_statfs(const char * path, struct statfs * buf);

asmlinkage long
sys32_statfs (const char *path, struct statfs32 *buf)
{
	int ret;
	struct statfs s;
	mm_segment_t old_fs = get_fs();

	set_fs(KERNEL_DS);
	ret = sys_statfs(path, &s);
	set_fs(old_fs);
	if (put_statfs(buf, &s))
		return -EFAULT;
	return ret;
}

extern asmlinkage long sys_fstatfs(unsigned int fd, struct statfs * buf);

asmlinkage long
sys32_fstatfs (unsigned int fd, struct statfs32 *buf)
{
	int ret;
	struct statfs s;
	mm_segment_t old_fs = get_fs();

	set_fs(KERNEL_DS);
	ret = sys_fstatfs(fd, &s);
	set_fs(old_fs);
	if (put_statfs(buf, &s))
		return -EFAULT;
	return ret;
}

struct timeval32
{
    int tv_sec, tv_usec;
};

struct itimerval32
{
    struct timeval32 it_interval;
    struct timeval32 it_value;
};

static inline long
get_tv32 (struct timeval *o, struct timeval32 *i)
{
	return (!access_ok(VERIFY_READ, i, sizeof(*i)) ||
		(__get_user(o->tv_sec, &i->tv_sec) | __get_user(o->tv_usec, &i->tv_usec)));
}

static inline long
put_tv32 (struct timeval32 *o, struct timeval *i)
{
	return (!access_ok(VERIFY_WRITE, o, sizeof(*o)) ||
		(__put_user(i->tv_sec, &o->tv_sec) | __put_user(i->tv_usec, &o->tv_usec)));
}

static inline long
get_it32 (struct itimerval *o, struct itimerval32 *i)
{
	return (!access_ok(VERIFY_READ, i, sizeof(*i)) ||
		(__get_user(o->it_interval.tv_sec, &i->it_interval.tv_sec) |
		 __get_user(o->it_interval.tv_usec, &i->it_interval.tv_usec) |
		 __get_user(o->it_value.tv_sec, &i->it_value.tv_sec) |
		 __get_user(o->it_value.tv_usec, &i->it_value.tv_usec)));
}

static inline long
put_it32 (struct itimerval32 *o, struct itimerval *i)
{
	return (!access_ok(VERIFY_WRITE, o, sizeof(*o)) ||
		(__put_user(i->it_interval.tv_sec, &o->it_interval.tv_sec) |
		 __put_user(i->it_interval.tv_usec, &o->it_interval.tv_usec) |
		 __put_user(i->it_value.tv_sec, &o->it_value.tv_sec) |
		 __put_user(i->it_value.tv_usec, &o->it_value.tv_usec)));
}

extern int do_getitimer (int which, struct itimerval *value);

asmlinkage long
sys32_getitimer (int which, struct itimerval32 *it)
{
	struct itimerval kit;
	int error;

	error = do_getitimer(which, &kit);
	if (!error && put_it32(it, &kit))
		error = -EFAULT;

	return error;
}

extern int do_setitimer (int which, struct itimerval *, struct itimerval *);

asmlinkage long
sys32_setitimer (int which, struct itimerval32 *in, struct itimerval32 *out)
{
	struct itimerval kin, kout;
	int error;

	if (in) {
		if (get_it32(&kin, in))
			return -EFAULT;
	} else
		memset(&kin, 0, sizeof(kin));

	error = do_setitimer(which, &kin, out ? &kout : NULL);
	if (error || !out)
		return error;
	if (put_it32(out, &kout))
		return -EFAULT;

	return 0;

}

asmlinkage unsigned long
sys32_alarm (unsigned int seconds)
{
	struct itimerval it_new, it_old;
	unsigned int oldalarm;

	it_new.it_interval.tv_sec = it_new.it_interval.tv_usec = 0;
	it_new.it_value.tv_sec = seconds;
	it_new.it_value.tv_usec = 0;
	do_setitimer(ITIMER_REAL, &it_new, &it_old);
	oldalarm = it_old.it_value.tv_sec;
	/* ehhh.. We can't return 0 if we have an alarm pending.. */
	/* And we'd better return too much than too little anyway */
	if (it_old.it_value.tv_usec)
		oldalarm++;
	return oldalarm;
}

/* Translations due to time_t size differences.  Which affects all
   sorts of things, like timeval and itimerval.  */

struct utimbuf_32 {
	int	atime;
	int	mtime;
};

extern asmlinkage long sys_utimes(char * filename, struct timeval * utimes);
extern asmlinkage long sys_gettimeofday (struct timeval *tv, struct timezone *tz);

asmlinkage long
sys32_utime (char *filename, struct utimbuf_32 *times32)
{
	mm_segment_t old_fs = get_fs();
	struct timeval tv[2], *tvp;
	long ret;

	if (times32) {
		if (get_user(tv[0].tv_sec, &times32->atime))
			return -EFAULT;
		tv[0].tv_usec = 0;
		if (get_user(tv[1].tv_sec, &times32->mtime))
			return -EFAULT;
		tv[1].tv_usec = 0;
		set_fs(KERNEL_DS);
		tvp = tv;
	} else
		tvp = NULL;
	ret = sys_utimes(filename, tvp);
	set_fs(old_fs);
	return ret;
}

extern struct timezone sys_tz;
extern int do_sys_settimeofday (struct timeval *tv, struct timezone *tz);

asmlinkage long
sys32_gettimeofday (struct timeval32 *tv, struct timezone *tz)
{
	if (tv) {
		struct timeval ktv;
		do_gettimeofday(&ktv);
		if (put_tv32(tv, &ktv))
			return -EFAULT;
	}
	if (tz) {
		if (copy_to_user(tz, &sys_tz, sizeof(sys_tz)))
			return -EFAULT;
	}
	return 0;
}

asmlinkage long
sys32_settimeofday (struct timeval32 *tv, struct timezone *tz)
{
	struct timeval ktv;
	struct timezone ktz;

	if (tv) {
		if (get_tv32(&ktv, tv))
			return -EFAULT;
	}
	if (tz) {
		if (copy_from_user(&ktz, tz, sizeof(ktz)))
			return -EFAULT;
	}

	return do_sys_settimeofday(tv ? &ktv : NULL, tz ? &ktz : NULL);
}

struct getdents32_callback {
	struct linux32_dirent * current_dir;
	struct linux32_dirent * previous;
	int count;
	int error;
};

struct readdir32_callback {
	struct old_linux32_dirent * dirent;
	int count;
};

static int
filldir32 (void *__buf, const char *name, int namlen, loff_t offset, ino_t ino,
	   unsigned int d_type)
{
	struct linux32_dirent * dirent;
	struct getdents32_callback * buf = (struct getdents32_callback *) __buf;
	int reclen = ROUND_UP(NAME_OFFSET(dirent) + namlen + 1, 4);

	buf->error = -EINVAL;	/* only used if we fail.. */
	if (reclen > buf->count)
		return -EINVAL;
	buf->error = -EFAULT;	/* only used if we fail.. */
	dirent = buf->previous;
	if (dirent)
		if (put_user(offset, &dirent->d_off))
			return -EFAULT;
	dirent = buf->current_dir;
	buf->previous = dirent;
	if (put_user(ino, &dirent->d_ino)
	    || put_user(reclen, &dirent->d_reclen)
	    || copy_to_user(dirent->d_name, name, namlen)
	    || put_user(0, dirent->d_name + namlen))
		return -EFAULT;
	((char *) dirent) += reclen;
	buf->current_dir = dirent;
	buf->count -= reclen;
	return 0;
}

asmlinkage long
sys32_getdents (unsigned int fd, struct linux32_dirent *dirent, unsigned int count)
{
	struct file * file;
	struct linux32_dirent * lastdirent;
	struct getdents32_callback buf;
	int error;

	error = -EBADF;
	file = fget(fd);
	if (!file)
		goto out;

	buf.current_dir = dirent;
	buf.previous = NULL;
	buf.count = count;
	buf.error = 0;

	error = vfs_readdir(file, filldir32, &buf);
	if (error < 0)
		goto out_putf;
	error = buf.error;
	lastdirent = buf.previous;
	if (lastdirent) {
		error = -EINVAL;
		if (put_user(file->f_pos, &lastdirent->d_off))
			goto out_putf;
		error = count - buf.count;
	}

out_putf:
	fput(file);
out:
	return error;
}

static int
fillonedir32 (void * __buf, const char * name, int namlen, loff_t offset, ino_t ino,
	      unsigned int d_type)
{
	struct readdir32_callback * buf = (struct readdir32_callback *) __buf;
	struct old_linux32_dirent * dirent;

	if (buf->count)
		return -EINVAL;
	buf->count++;
	dirent = buf->dirent;
	if (put_user(ino, &dirent->d_ino)
	    || put_user(offset, &dirent->d_offset)
	    || put_user(namlen, &dirent->d_namlen)
	    || copy_to_user(dirent->d_name, name, namlen)
	    || put_user(0, dirent->d_name + namlen))
		return -EFAULT;
	return 0;
}

asmlinkage long
sys32_readdir (unsigned int fd, void *dirent, unsigned int count)
{
	int error;
	struct file * file;
	struct readdir32_callback buf;

	error = -EBADF;
	file = fget(fd);
	if (!file)
		goto out;

	buf.count = 0;
	buf.dirent = dirent;

	error = vfs_readdir(file, fillonedir32, &buf);
	if (error >= 0)
		error = buf.count;
	fput(file);
out:
	return error;
}

/*
 * We can actually return ERESTARTSYS instead of EINTR, but I'd
 * like to be certain this leads to no problems. So I return
 * EINTR just for safety.
 *
 * Update: ERESTARTSYS breaks at least the xview clock binary, so
 * I'm trying ERESTARTNOHAND which restart only when you want to.
 */
#define MAX_SELECT_SECONDS \
	((unsigned long) (MAX_SCHEDULE_TIMEOUT / HZ)-1)