return res;
}
-/*
- * locate_fd finds a free file descriptor in the open_fds fdset,
- * expanding the fd arrays if necessary. Must be called with the
- * file_lock held for write.
- */
-
-static int locate_fd(unsigned int orig_start, int cloexec)
-{
- struct files_struct *files = current->files;
- unsigned int newfd;
- unsigned int start;
- int error;
- struct fdtable *fdt;
-
- spin_lock(&files->file_lock);
-
- error = -EINVAL;
- if (orig_start >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur)
- goto out;
-
-repeat:
- fdt = files_fdtable(files);
- /*
- * Someone might have closed fd's in the range
- * orig_start..fdt->next_fd
- */
- start = orig_start;
- if (start < files->next_fd)
- start = files->next_fd;
-
- newfd = start;
- if (start < fdt->max_fds)
- newfd = find_next_zero_bit(fdt->open_fds->fds_bits,
- fdt->max_fds, start);
-
- error = -EMFILE;
- if (newfd >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur)
- goto out;
-
- error = expand_files(files, newfd);
- if (error < 0)
- goto out;
-
- /*
- * If we needed to expand the fs array we
- * might have blocked - try again.
- */
- if (error)
- goto repeat;
-
- if (start <= files->next_fd)
- files->next_fd = newfd + 1;
-
- FD_SET(newfd, fdt->open_fds);
- if (cloexec)
- FD_SET(newfd, fdt->close_on_exec);
- else
- FD_CLR(newfd, fdt->close_on_exec);
- error = newfd;
-
-out:
- spin_unlock(&files->file_lock);
- return error;
-}
-
-static int dupfd(struct file *file, unsigned int start, int cloexec)
-{
- int fd = locate_fd(start, cloexec);
- if (fd >= 0)
- fd_install(fd, file);
- else
- fput(file);
-
- return fd;
-}
-
-asmlinkage long sys_dup2(unsigned int oldfd, unsigned int newfd)
+asmlinkage long sys_dup3(unsigned int oldfd, unsigned int newfd, int flags)
{
int err = -EBADF;
struct file * file, *tofree;
struct files_struct * files = current->files;
struct fdtable *fdt;
+ if ((flags & ~O_CLOEXEC) != 0)
+ return -EINVAL;
+
+ if (unlikely(oldfd == newfd))
+ return -EINVAL;
+
spin_lock(&files->file_lock);
if (!(file = fcheck(oldfd)))
goto out_unlock;
- err = newfd;
- if (newfd == oldfd)
- goto out_unlock;
- err = -EBADF;
- if (newfd >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur)
- goto out_unlock;
get_file(file); /* We are now finished with oldfd */
err = expand_files(files, newfd);
- if (err < 0)
+ if (unlikely(err < 0)) {
+ if (err == -EMFILE)
+ err = -EBADF;
goto out_fput;
+ }
/* To avoid races with open() and dup(), we will mark the fd as
* in-use in the open-file bitmap throughout the entire dup2()
rcu_assign_pointer(fdt->fd[newfd], file);
FD_SET(newfd, fdt->open_fds);
- FD_CLR(newfd, fdt->close_on_exec);
+ if (flags & O_CLOEXEC)
+ FD_SET(newfd, fdt->close_on_exec);
+ else
+ FD_CLR(newfd, fdt->close_on_exec);
spin_unlock(&files->file_lock);
if (tofree)
goto out;
}
+asmlinkage long sys_dup2(unsigned int oldfd, unsigned int newfd)
+{
+ if (unlikely(newfd == oldfd)) { /* corner case */
+ struct files_struct *files = current->files;
+ rcu_read_lock();
+ if (!fcheck_files(files, oldfd))
+ oldfd = -EBADF;
+ rcu_read_unlock();
+ return oldfd;
+ }
+ return sys_dup3(oldfd, newfd, 0);
+}
+
asmlinkage long sys_dup(unsigned int fildes)
{
int ret = -EBADF;
- struct file * file = fget(fildes);
-
- if (file)
- ret = dupfd(file, 0, 0);
+ struct file *file = fget(fildes);
+
+ if (file) {
+ ret = get_unused_fd();
+ if (ret >= 0)
+ fd_install(ret, file);
+ else
+ fput(file);
+ }
return ret;
}
switch (cmd) {
case F_DUPFD:
case F_DUPFD_CLOEXEC:
- get_file(filp);
- err = dupfd(filp, arg, cmd == F_DUPFD_CLOEXEC);
+ if (arg >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur)
+ break;
+ err = alloc_fd(arg, cmd == F_DUPFD_CLOEXEC ? O_CLOEXEC : 0);
+ if (err >= 0) {
+ get_file(filp);
+ fd_install(err, filp);
+ }
break;
case F_GETFD:
err = get_close_on_exec(fd) ? FD_CLOEXEC : 0;