ima: return d_name.name if d_path fails

This is a small refactoring so ima_d_path() returns dentry name
if path reconstruction fails. It simplifies callers actions
and removes code duplication.
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

security/integrity/ima/ima_api.c

@@ -332,5 +332,5 @@ const char *ima_d_path(struct path *path, char **pathbuf)
 			pathname = NULL;
 		}
 	}
-	return pathname;
+	return pathname ?: (const char *)path->dentry->d_name.name;
 }

security/integrity/ima/ima_main.c

@@ -79,7 +79,6 @@ __setup("ima_hash=", hash_setup);
  */
 static void ima_rdwr_violation_check(struct file *file)
 {
-	struct dentry *dentry = file->f_path.dentry;
 	struct inode *inode = file_inode(file);
 	fmode_t mode = file->f_mode;
 	int must_measure;
@@ -111,8 +110,6 @@ static void ima_rdwr_violation_check(struct file *file)
 		return;
 
 	pathname = ima_d_path(&file->f_path, &pathbuf);
-	if (!pathname || strlen(pathname) > IMA_EVENT_NAME_LEN_MAX)
-		pathname = dentry->d_name.name;
 
 	if (send_tomtou)
 		ima_add_violation(file, pathname, "invalid_pcr", "ToMToU");
@@ -220,9 +217,7 @@ static int process_measurement(struct file *file, const char *filename,
 	if (rc != 0)
 		goto out_digsig;
 
-	pathname = !filename ? ima_d_path(&file->f_path, &pathbuf) : filename;
-	if (!pathname)
-		pathname = (const char *)file->f_dentry->d_name.name;
+	pathname = filename ?: ima_d_path(&file->f_path, &pathbuf);
 
 	if (action & IMA_MEASURE)
 		ima_store_measurement(iint, file, pathname,