09a06e7fce
This commit is intended to solve the bug caused by #7159. It will fixed data abort issue when task restart in wait sem status. If delete waitobj in the sem recover function, then we will get the wrong task list when remove the task from task list.
109 lines
3.8 KiB
C
109 lines
3.8 KiB
C
/****************************************************************************
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* sched/semaphore/sem_recover.c
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*
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* Licensed to the Apache Software Foundation (ASF) under one or more
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* contributor license agreements. See the NOTICE file distributed with
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* this work for additional information regarding copyright ownership. The
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* ASF licenses this file to you under the Apache License, Version 2.0 (the
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* "License"); you may not use this file except in compliance with the
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* License. You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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* License for the specific language governing permissions and limitations
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* under the License.
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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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#include <assert.h>
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#include <nuttx/irq.h>
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#include <nuttx/arch.h>
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#include <nuttx/sched.h>
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#include "semaphore/semaphore.h"
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* Name: nxsem_recover
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*
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* Description:
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* This function is called from nxtask_recover() when a task is deleted via
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* task_delete() or via pthread_cancel(). It current only checks on the
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* case where a task is waiting for semaphore at the time that is was
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* killed.
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*
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* REVISIT: A more complete implementation would release counts on all
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* semaphores held by the thread. That would, however, require some
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* significant extension to the semaphore data structures because given
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* only the task, there is not mechanism to traverse all of the semaphores
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* with counts held by the task.
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*
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* Input Parameters:
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* tcb - The TCB of the terminated task or thread
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*
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* Returned Value:
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* None.
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*
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* Assumptions:
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* This function is called from task deletion logic in a safe context.
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*
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****************************************************************************/
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void nxsem_recover(FAR struct tcb_s *tcb)
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{
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irqstate_t flags;
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/* The task is being deleted. If it is waiting for a semaphore, then
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* increment the count on the semaphores. This logic is almost identical
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* to what you see in nxsem_wait_irq() except that no attempt is made to
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* restart the exiting task.
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*
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* NOTE: In the case that the task is waiting we can assume: (1) That the
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* task state is TSTATE_WAIT_SEM and (2) that the 'waitobj' in the TCB is
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* non-null. If we get here via pthread_cancel() or via task_delete(),
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* then the task state should be preserved; it will be altered in other
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* cases but in those cases waitobj should be NULL anyway (but we do not
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* enforce that here).
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*/
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flags = enter_critical_section();
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if (tcb->task_state == TSTATE_WAIT_SEM)
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{
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FAR sem_t *sem = tcb->waitobj;
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DEBUGASSERT(sem != NULL && sem->semcount < 0);
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/* Restore the correct priority of all threads that hold references
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* to this semaphore.
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*/
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nxsem_canceled(tcb, sem);
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/* And increment the count on the semaphore. This releases the count
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* that was taken by sem_wait(). This count decremented the semaphore
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* count to negative and caused the thread to be blocked in the first
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* place.
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*/
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sem->semcount++;
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}
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/* Release all semphore holders for the task */
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nxsem_release_all(tcb);
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leave_critical_section(flags);
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}
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