On Mon, Mar 13, 2017 at 10:37:24AM -0700, Andrei Vagin wrote:
Here is one question inline.
Acked-by: Andrei Vagin <redacted>
Thanks!
quoted
+
+ files = get_files_struct(task2);
+ if (!files)
+ return -EBADF;
+
+ spin_lock(&files->file_lock);
+ filp_epoll = fcheck_files(files, slot.efd);
+ if (filp_epoll)
+ get_file(filp_epoll);
+ else
+ filp_tgt = ERR_PTR(-EBADF);
+ spin_unlock(&files->file_lock);
+ put_files_struct(files);
Why can we not use fget here ^^^^ ?
Because it's not @current's file table but foreigner process.
So we make sure there is no expand_fdtable in progress and
we test for file descriptor which is being freed.