[PATCH] get rid of corner case in dup3() entirely

Since Ulrich is OK with getting rid of dup3(fd, fd, flags) completely,
to hell the damn thing goes.  Corner case for dup2() is handled in
sys_dup2() (complete with -EBADF if dup2(fd, fd) is called with fd
that is not open), the rest is done in dup3().

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/fcntl.c b/fs/fcntl.c
index ce12a68851154d43bec75641592dd8378ddea4e6..3deec98870893a763ad708c73e1a10f7c39ea866 100644 (file)
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -135,18 +135,12 @@ asmlinkage long sys_dup3(unsigned int oldfd, unsigned int newfd, int flags)
        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 (unlikely(newfd == oldfd)) {
-               if (flags & O_CLOEXEC) {
-                       fdt = files_fdtable(files);
-                       FD_SET(newfd, fdt->close_on_exec);
-               }
-               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 */
@@ -194,6 +188,14 @@ out_fput:
 
 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);
 }