140 lines
4.5 KiB
C
140 lines
4.5 KiB
C
/****************************************************************************
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* sched/environ/env_dup.c
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*
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* Copyright (C) 2007, 2009, 2011, 2013, 2017 Gregory Nutt. All rights reserved.
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* Author: Gregory Nutt <gnutt@nuttx.org>
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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* 3. Neither the name NuttX nor the names of its contributors may be
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* used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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****************************************************************************/
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <nuttx/config.h>
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#ifndef CONFIG_DISABLE_ENVIRON
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#include <sys/types.h>
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#include <sched.h>
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#include <string.h>
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#include <errno.h>
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#include <nuttx/kmalloc.h>
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#include "sched/sched.h"
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#include "environ/environ.h"
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* Name: env_dup
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*
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* Description:
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* Copy the internal environment structure of a task. This is the action
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* that is performed when a new task is created: The new task has a private,
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* exact duplicate of the parent task's environment.
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*
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* Input Parameters:
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* group - The child task group to receive the newly allocated copy of the
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* parent task groups environment structure.
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*
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* Returned Value:
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* zero on success
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*
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* Assumptions:
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* Not called from an interrupt handler.
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*
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****************************************************************************/
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int env_dup(FAR struct task_group_s *group)
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{
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FAR struct tcb_s *ptcb = this_task();
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FAR char *envp = NULL;
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size_t envlen;
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int ret = OK;
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DEBUGASSERT(group != NULL && ptcb != NULL && ptcb->group != NULL);
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/* Pre-emption must be disabled throughout the following because the
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* environment may be shared.
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*/
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sched_lock();
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/* Does the parent task have an environment? */
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if (ptcb->group != NULL && ptcb->group->tg_envp != NULL)
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{
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/* Yes.. The parent task has an environment allocation. */
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envlen = ptcb->group->tg_envsize;
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envp = NULL;
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/* A special case is that the parent has an "empty" environment
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* allocation, i.e., there is an allocation in place but it
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* contains no variable definitions and, hence, envlen == 0.
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*/
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if (envlen > 0)
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{
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/* There is an environment, duplicate it */
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envp = (FAR char *)kumm_malloc(envlen);
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if (envp == NULL)
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{
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/* The parent's environment can not be inherited due to a
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* failure in the allocation of the child environment.
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*/
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envlen = 0;
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ret = -ENOMEM;
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}
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else
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{
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/* Duplicate the parent environment. */
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memcpy(envp, ptcb->group->tg_envp, envlen);
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}
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}
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/* Save the size and child environment allocation. */
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group->tg_envsize = envlen;
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group->tg_envp = envp;
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}
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sched_unlock();
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return ret;
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}
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#endif /* CONFIG_DISABLE_ENVIRON */
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