nuttx/sched/task/task_setcancelstate.c
Ville Juven df1d7dd480 libc/exit: Purge calls to userspace API exit() from kernel
Remove calls to the userspace API exit() from the kernel. The problem
with doing such calls is that the exit functions are called with kernel
mode privileges which is a big security no-no.
2023-02-17 23:07:17 +08:00

140 lines
4.2 KiB
C

/****************************************************************************
* sched/task/task_setcancelstate.c
*
* 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 <pthread.h>
#include <sched.h>
#include <errno.h>
#include "sched/sched.h"
#include "task/task.h"
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: task_setcancelstate
*
* Description:
* The task_setcancelstate() function atomically both sets the calling
* task's cancellability state to the indicated state and returns the
* previous cancellability state at the location referenced by oldstate.
* Legal values for state are TASK_CANCEL_ENABLE and TASK_CANCEL_DISABLE.
*
* The cancellability state and type of any newly created tasks are
* TASK_CANCEL_ENABLE and TASK_CANCEL_DEFERRED respectively.
*
* Input Parameters:
* state - the new cancellability state, either TASK_CANCEL_ENABLE or
* TASK_CANCEL_DISABLE
* oldstate - The location to return the old cancellability state.
*
* Returned Value:
* Zero (OK) on success; ERROR is returned on any failure with the
* errno value set appropriately.
*
****************************************************************************/
int task_setcancelstate(int state, FAR int *oldstate)
{
FAR struct tcb_s *tcb = this_task();
int ret = OK;
/* Suppress context changes for a bit so that the flags are stable. (the
* flags should not change in interrupt handling).
*/
sched_lock();
/* Return the current state if so requested */
if (oldstate != NULL)
{
if ((tcb->flags & TCB_FLAG_NONCANCELABLE) != 0)
{
*oldstate = TASK_CANCEL_DISABLE;
}
else
{
*oldstate = TASK_CANCEL_ENABLE;
}
}
/* Set the new cancellation state */
if (state == TASK_CANCEL_ENABLE)
{
/* Clear the non-cancelable flag */
tcb->flags &= ~TCB_FLAG_NONCANCELABLE;
/* Check if a cancellation was pending */
if ((tcb->flags & TCB_FLAG_CANCEL_PENDING) != 0)
{
#ifdef CONFIG_CANCELLATION_POINTS
/* If we are using deferred cancellation? */
if ((tcb->flags & TCB_FLAG_CANCEL_DEFERRED) == 0)
#endif
{
/* No.. We are using asynchronous cancellation. If the
* cancellation was pending in this case, then just exit.
*/
tcb->flags &= ~TCB_FLAG_CANCEL_PENDING;
#ifndef CONFIG_DISABLE_PTHREAD
if ((tcb->flags & TCB_FLAG_TTYPE_MASK) ==
TCB_FLAG_TTYPE_PTHREAD)
{
pthread_exit(PTHREAD_CANCELED);
}
else
#endif
{
_exit(EXIT_FAILURE);
}
}
}
}
else if (state == TASK_CANCEL_DISABLE)
{
/* Set the non-cancelable state */
tcb->flags |= TCB_FLAG_NONCANCELABLE;
}
else
{
set_errno(EINVAL);
ret = ERROR;
}
sched_unlock();
return ret;
}