libs/libc/stdlib/lib_getprogname.c

/****************************************************************************
 * libs/libc/stdlib/lib_getprogname.c
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.  The
 * ASF licenses this file to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance with the
 * License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
 * License for the specific language governing permissions and limitations
 * under the License.
 *
 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <nuttx/config.h>

#include <stdlib.h>
#include <nuttx/sched.h>

/****************************************************************************
 * Public Functions
 ****************************************************************************/

/****************************************************************************
 * Name: getprogname
 *
 * Note that previous impl returns address in the stack of main thread when
 * used from a pthread, that is dangerous as main thread may end earlier.
 ****************************************************************************/

FAR const char *getprogname(void)
{
  struct stackinfo_s si;
  FAR struct tls_info_s *ti = tls_get_info();
  uintptr_t ret = ti ? (uintptr_t)ti + ti->tl_size : 0;
  int rc = nxsched_get_stackinfo(0, &si);

  return (rc >= 0 && ret && ((uintptr_t)si.stack_base_ptr) > ret) ?
           ((FAR char **)ret)[0] : NULL;
}