[PATCH] ppc64: crash during firmware flash update

This patch is from Linas Vepstas <linas@austin.ibm.com>.

Race conditions during system shutdown after a firmware flash can sometimes
lead to an invalid pointer deref (deref to freed memory).  This patch fixes
this.  In addition, it makes sure that the proc entries created by the
firmware flash module are removed when the module is unloaded. 
Signed-off-by: Linas Vepstas <linas@linas.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/ppc64/kernel/rtas_flash.c

@@ -562,6 +562,7 @@ static int validate_flash_release(struct inode *inode, struct file *file)
 		validate_flash(args_buf);
 	}
 
+	/* The matching atomic_inc was in rtas_excl_open() */
 	atomic_dec(&dp->count);
 
 	return 0;
@@ -572,7 +573,8 @@ static void remove_flash_pde(struct proc_dir_entry *dp)
 	if (dp) {
 		if (dp->data != NULL)
 			kfree(dp->data);
-		remove_proc_entry(dp->name, NULL);
+		dp->owner = NULL;
+		remove_proc_entry(dp->name, dp->parent);
 	}
 }