eb9030c891
Most tools used for compliance and SBOM generation use SPDX identifiers This change brings us a step closer to an easy SBOM generation. Signed-off-by: Alin Jerpelea <alin.jerpelea@sony.com>
660 lines
19 KiB
C
660 lines
19 KiB
C
/****************************************************************************
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* sched/signal/sig_dispatch.c
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*
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* SPDX-License-Identifier: Apache-2.0
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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 <inttypes.h>
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#include <string.h>
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#include <signal.h>
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#include <unistd.h>
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#include <sched.h>
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#include <assert.h>
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#include <errno.h>
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#include <debug.h>
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#include <nuttx/irq.h>
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#include <nuttx/arch.h>
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#include <nuttx/signal.h>
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#include <nuttx/queue.h>
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#include "sched/sched.h"
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#include "group/group.h"
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#include "semaphore/semaphore.h"
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#include "signal/signal.h"
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#include "mqueue/mqueue.h"
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/****************************************************************************
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* Private Functions
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****************************************************************************/
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/****************************************************************************
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* Name: nxsig_queue_action
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*
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* Description:
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* Queue a signal action for delivery to a task.
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*
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* Returned Value:
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* Returns 0 (OK) on success or a negated errno value on failure.
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*
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****************************************************************************/
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static int nxsig_queue_action(FAR struct tcb_s *stcb, siginfo_t *info)
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{
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FAR sigactq_t *sigact;
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FAR sigq_t *sigq;
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irqstate_t flags;
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int ret = OK;
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sched_lock();
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DEBUGASSERT(stcb != NULL && stcb->group != NULL);
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/* Find the group sigaction associated with this signal */
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sigact = nxsig_find_action(stcb->group, info->si_signo);
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/* Check if a valid signal handler is available and if the signal is
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* unblocked. NOTE: There is no default action.
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*/
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if ((sigact) && (sigact->act.sa_u._sa_sigaction))
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{
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/* Allocate a new element for the signal queue. NOTE:
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* nxsig_alloc_pendingsigaction will force a system crash if it is
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* unable to allocate memory for the signal data.
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*/
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sigq = nxsig_alloc_pendingsigaction();
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if (!sigq)
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{
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ret = -ENOMEM;
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}
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else
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{
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/* Populate the new signal queue element */
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sigq->action.sighandler = sigact->act.sa_u._sa_sigaction;
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sigq->mask = sigact->act.sa_mask;
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if ((sigact->act.sa_flags & SA_NODEFER) == 0)
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{
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sigaddset(&sigq->mask, info->si_signo);
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}
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memcpy(&sigq->info, info, sizeof(siginfo_t));
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sigq->info.si_user = sigact->act.sa_user;
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/* Put it at the end of the pending signals list */
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flags = enter_critical_section();
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sq_addlast((FAR sq_entry_t *)sigq, &(stcb->sigpendactionq));
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/* Then schedule execution of the signal handling action on the
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* recipient's thread. SMP related handling will be done in
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* up_schedule_sigaction()
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*/
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up_schedule_sigaction(stcb, nxsig_deliver);
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leave_critical_section(flags);
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}
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}
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sched_unlock();
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return ret;
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}
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/****************************************************************************
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* Name: nxsig_alloc_pendingsignal
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*
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* Description:
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* Allocate a pending signal list entry
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*
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****************************************************************************/
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static FAR sigpendq_t *nxsig_alloc_pendingsignal(void)
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{
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FAR sigpendq_t *sigpend;
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irqstate_t flags;
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/* Check if we were called from an interrupt handler. */
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if (up_interrupt_context())
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{
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/* Try to get the pending signal structure from the free list */
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sigpend = (FAR sigpendq_t *)sq_remfirst(&g_sigpendingsignal);
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if (!sigpend)
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{
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/* If no pending signal structure is available in the free list,
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* then try the special list of structures reserved for
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* interrupt handlers
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*/
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sigpend = (FAR sigpendq_t *)sq_remfirst(&g_sigpendingirqsignal);
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}
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}
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/* If we were not called from an interrupt handler, then we are
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* free to allocate pending action structures if necessary.
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*/
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else
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{
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/* Try to get the pending signal structure from the free list */
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flags = enter_critical_section();
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sigpend = (FAR sigpendq_t *)sq_remfirst(&g_sigpendingsignal);
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leave_critical_section(flags);
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/* Check if we got one. */
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if (!sigpend)
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{
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/* No... Allocate the pending signal */
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sigpend = kmm_malloc(sizeof(sigpendq_t));
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/* Check if we got an allocated message */
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if (sigpend)
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{
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sigpend->type = SIG_ALLOC_DYN;
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}
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}
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}
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return sigpend;
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}
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/****************************************************************************
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* Name: nxsig_find_pendingsignal
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*
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* Description:
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* Find a specified element in the pending signal list
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*
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****************************************************************************/
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static FAR sigpendq_t *
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nxsig_find_pendingsignal(FAR struct task_group_s *group, int signo)
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{
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FAR sigpendq_t *sigpend = NULL;
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irqstate_t flags;
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DEBUGASSERT(group != NULL);
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/* Determining whether a signal is reliable or unreliable */
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if (SIGRTMIN <= signo && signo <= SIGRTMAX)
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{
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return sigpend;
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}
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/* Pending signals can be added from interrupt level. */
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flags = enter_critical_section();
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/* Search the list for a action pending on this signal */
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for (sigpend = (FAR sigpendq_t *)group->tg_sigpendingq.head;
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(sigpend && sigpend->info.si_signo != signo);
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sigpend = sigpend->flink);
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leave_critical_section(flags);
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return sigpend;
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}
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/****************************************************************************
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* Name: nxsig_dispatch_kernel_action
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****************************************************************************/
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static void nxsig_dispatch_kernel_action(FAR struct tcb_s *stcb,
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FAR siginfo_t *info)
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{
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FAR struct task_group_s *group = stcb->group;
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FAR sigactq_t *sigact;
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sigact = nxsig_find_action(group, info->si_signo);
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if (sigact && (sigact->act.sa_flags & SA_KERNELHAND))
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{
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info->si_user = sigact->act.sa_user;
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(sigact->act.sa_sigaction)(info->si_signo, info, NULL);
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}
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}
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/****************************************************************************
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* Name: nxsig_add_pendingsignal
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*
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* Description:
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* Add the specified signal to the signal pending list. NOTE: This
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* function will queue only one entry for each pending signal. This
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* was done intentionally so that a run-away sender cannot consume
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* all of memory.
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*
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****************************************************************************/
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static void nxsig_add_pendingsignal(FAR struct tcb_s *stcb,
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FAR siginfo_t *info)
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{
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FAR struct task_group_s *group;
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FAR sigpendq_t *sigpend;
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irqstate_t flags;
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DEBUGASSERT(stcb != NULL && stcb->group != NULL);
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group = stcb->group;
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/* Check if the signal is already pending for the group */
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sigpend = nxsig_find_pendingsignal(group, info->si_signo);
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if (sigpend != NULL)
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{
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/* The signal is already pending... retain only one copy */
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memcpy(&sigpend->info, info, sizeof(siginfo_t));
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}
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/* No... There is nothing pending in the group for this signo */
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else
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{
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/* Allocate a new pending signal entry */
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sigpend = nxsig_alloc_pendingsignal();
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if (sigpend != NULL)
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{
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/* Put the signal information into the allocated structure */
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memcpy(&sigpend->info, info, sizeof(siginfo_t));
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/* Add the structure to the group pending signal list */
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flags = enter_critical_section();
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sq_addlast((FAR sq_entry_t *)sigpend, &group->tg_sigpendingq);
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leave_critical_section(flags);
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nxsig_dispatch_kernel_action(stcb, &sigpend->info);
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}
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}
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DEBUGASSERT(sigpend);
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}
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* Name: nxsig_tcbdispatch
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*
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* Description:
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* All signals received the task (whatever the source) go through this
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* function to be processed. This function is responsible for:
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*
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* - Determining if the signal is blocked.
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* - Queuing and dispatching signal actions
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* - Unblocking tasks that are waiting for signals
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* - Queuing pending signals.
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*
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* This function will deliver the signal to the task associated with
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* the specified TCB. This function should *not* typically be used
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* to dispatch signals since it will *not* follow the group signal
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* deliver algorithms.
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*
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* Returned Value:
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* Returns 0 (OK) on success or a negated errno value on failure.
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*
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****************************************************************************/
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int nxsig_tcbdispatch(FAR struct tcb_s *stcb, siginfo_t *info)
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{
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FAR struct tcb_s *rtcb = this_task();
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irqstate_t flags;
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int masked;
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int ret = OK;
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sinfo("TCB=%p pid=%d signo=%d code=%d value=%d masked=%s\n",
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stcb, stcb->pid, info->si_signo, info->si_code,
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info->si_value.sival_int,
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sigismember(&stcb->sigprocmask, info->si_signo) == 1 ? "YES" : "NO");
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DEBUGASSERT(stcb != NULL && info != NULL);
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/* Return ESRCH when thread was in exit processing */
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if ((stcb->flags & TCB_FLAG_EXIT_PROCESSING) != 0)
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{
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return -ESRCH;
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}
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/* Don't actually send a signal for signo 0. */
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if (info->si_signo == 0)
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{
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return OK;
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}
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/************************** MASKED SIGNAL ACTIONS *************************/
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masked = nxsig_ismember(&stcb->sigprocmask, info->si_signo);
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#ifdef CONFIG_LIB_SYSCALL
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/* Check if the signal is masked OR if the signal is received while we are
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* processing a system call -- in either case, it will be added to the
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* list of pending signals. Unmasked user signal actions will be deferred
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* while we process the system call.
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*
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* If a thread calls a blocking system call, the thread will still be
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* unblocked when the signal occurs (see OTHER SIGNAL HANDLING below), but
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* any associated user signal action will be deferred until the system
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* call returns. For example, if the application calls sem_wait(), the
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* following would occur:
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*
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* 1. System call entry logic will block user signal handling and call
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* sem_wait() in kernel mode.
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* 2. sem_wait() will block,
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* 3. The receipt of the signal will cause any signal action to pend
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* but will unblock sem_wait(),
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* 4. The sem_wait() system call will awaken and return EINTR,
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* 5. The pending signal action will occur after the sem_wait() system
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* call returns to user mode.
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*
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* Syscall handlers (and logic-in-general within the OS) should not use
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* signal handlers.
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*/
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if ((masked == 1) || (stcb->flags & TCB_FLAG_SYSCALL) != 0)
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#else
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/* Check if the signal is masked. In that case, it will be added to the
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* list of pending signals.
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*/
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if (masked == 1)
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#endif
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{
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/* Check if the task is waiting for this pending signal. If so, then
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* unblock it. This must be performed in a critical section because
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* signals can be queued from the interrupt level.
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*/
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flags = enter_critical_section();
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if (stcb->task_state == TSTATE_WAIT_SIG &&
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(masked == 0 ||
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nxsig_ismember(&stcb->sigwaitmask, info->si_signo)))
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{
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if (stcb->sigunbinfo != NULL)
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{
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memcpy(stcb->sigunbinfo, info, sizeof(siginfo_t));
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}
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sigemptyset(&stcb->sigwaitmask);
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if (WDOG_ISACTIVE(&stcb->waitdog))
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{
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wd_cancel(&stcb->waitdog);
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}
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/* Remove the task from waitting list */
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dq_rem((FAR dq_entry_t *)stcb, list_waitingforsignal());
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/* Add the task to ready-to-run task list and
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* perform the context switch if one is needed
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*/
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if (nxsched_add_readytorun(stcb))
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{
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up_switch_context(stcb, rtcb);
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}
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leave_critical_section(flags);
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#ifdef CONFIG_LIB_SYSCALL
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/* Must also add signal action if in system call */
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if (masked == 0)
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{
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nxsig_add_pendingsignal(stcb, info);
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}
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#endif
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}
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/* Its not one we are waiting for... Add it to the list of pending
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* signals.
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*/
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else
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{
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leave_critical_section(flags);
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nxsig_add_pendingsignal(stcb, info);
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}
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}
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/************************* UNMASKED SIGNAL ACTIONS ************************/
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else
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{
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/* Queue any sigaction's requested by this task. */
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ret = nxsig_queue_action(stcb, info);
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/* Deliver of the signal must be performed in a critical section */
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flags = enter_critical_section();
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/* Check if the task is waiting for an unmasked signal. If so, then
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* unblock it. This must be performed in a critical section because
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* signals can be queued from the interrupt level.
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*/
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if (stcb->task_state == TSTATE_WAIT_SIG)
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{
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if (stcb->sigunbinfo != NULL)
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{
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memcpy(stcb->sigunbinfo, info, sizeof(siginfo_t));
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}
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sigemptyset(&stcb->sigwaitmask);
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if (WDOG_ISACTIVE(&stcb->waitdog))
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{
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wd_cancel(&stcb->waitdog);
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}
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/* Remove the task from waitting list */
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dq_rem((FAR dq_entry_t *)stcb, list_waitingforsignal());
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/* Add the task to ready-to-run task list and
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* perform the context switch if one is needed
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*/
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if (nxsched_add_readytorun(stcb))
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{
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up_switch_context(stcb, rtcb);
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}
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}
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leave_critical_section(flags);
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/* If the task neither was waiting for the signal nor had a signal
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* handler attached to the signal, then the default action is
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* simply to ignore the signal
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*/
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}
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/************************* OTHER SIGNAL HANDLING **************************/
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/* Performed only if the signal is unmasked. These actions also must
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* happen within a system call.
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*/
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if (masked == 0)
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{
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flags = enter_critical_section();
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/* If the task is blocked waiting for a semaphore, then that task must
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* be unblocked when a signal is received.
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*/
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if (stcb->task_state == TSTATE_WAIT_SEM)
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{
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nxsem_wait_irq(stcb, EINTR);
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}
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#if !defined(CONFIG_DISABLE_MQUEUE) || !defined(CONFIG_DISABLE_MQUEUE_SYSV)
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/* If the task is blocked waiting on a message queue, then that task
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* must be unblocked when a signal is received.
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*/
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else if (stcb->task_state == TSTATE_WAIT_MQNOTEMPTY ||
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stcb->task_state == TSTATE_WAIT_MQNOTFULL)
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{
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nxmq_wait_irq(stcb, EINTR);
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}
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#endif
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#ifdef CONFIG_SIG_SIGSTOP_ACTION
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/* If the task was stopped by SIGSTOP or SIGTSTP, then unblock the task
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* if SIGCONT is received.
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*/
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else if (stcb->task_state == TSTATE_TASK_STOPPED &&
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info->si_signo == SIGCONT)
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{
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#ifdef HAVE_GROUP_MEMBERS
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group_continue(stcb);
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#else
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/* Remove the task from waitting list */
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dq_rem((FAR dq_entry_t *)stcb, list_stoppedtasks());
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/* Add the task to ready-to-run task list and
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* perform the context switch if one is needed
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*/
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if (nxsched_add_readytorun(stcb))
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{
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up_switch_context(stcb, rtcb);
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}
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#endif
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}
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#endif
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leave_critical_section(flags);
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}
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/* In case nxsig_ismember failed due to an invalid signal number */
|
|
|
|
if (masked < 0)
|
|
{
|
|
ret = -EINVAL;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: nxsig_dispatch
|
|
*
|
|
* Description:
|
|
* This is the front-end for nxsig_tcbdispatch that should be typically
|
|
* be used to dispatch a signal. If HAVE_GROUP_MEMBERS is defined,
|
|
* then function will follow the group signal delivery algorithms:
|
|
*
|
|
* This front-end does the following things before calling
|
|
* nxsig_tcbdispatch.
|
|
*
|
|
* With HAVE_GROUP_MEMBERS defined:
|
|
* - Get the TCB associated with the pid.
|
|
* - If the TCB was found, get the group from the TCB.
|
|
* - If the PID has already exited, lookup the group that that was
|
|
* started by this task.
|
|
* - Use the group to pick the TCB to receive the signal
|
|
* - Call nxsig_tcbdispatch with the TCB
|
|
*
|
|
* With HAVE_GROUP_MEMBERS *not* defined
|
|
* - Get the TCB associated with the pid.
|
|
* - Call nxsig_tcbdispatch with the TCB
|
|
*
|
|
* Returned Value:
|
|
* Returns 0 (OK) on success or a negated errno value on failure.
|
|
*
|
|
****************************************************************************/
|
|
|
|
int nxsig_dispatch(pid_t pid, FAR siginfo_t *info)
|
|
{
|
|
#ifdef HAVE_GROUP_MEMBERS
|
|
FAR struct tcb_s *stcb;
|
|
FAR struct task_group_s *group;
|
|
|
|
/* Get the TCB associated with the pid */
|
|
|
|
stcb = nxsched_get_tcb(pid);
|
|
if (stcb != NULL)
|
|
{
|
|
/* The task/thread associated with this PID is still active. Get its
|
|
* task group.
|
|
*/
|
|
|
|
group = stcb->group;
|
|
}
|
|
else
|
|
{
|
|
/* The task/thread associated with this PID has exited. In the normal
|
|
* usage model, the PID should correspond to the PID of the task that
|
|
* created the task group. Try looking it up.
|
|
*/
|
|
|
|
group = task_getgroup(pid);
|
|
}
|
|
|
|
/* Did we locate the group? */
|
|
|
|
if (group != NULL)
|
|
{
|
|
/* Yes.. call group_signal() to send the signal to the correct group
|
|
* member.
|
|
*/
|
|
|
|
return group_signal(group, info);
|
|
}
|
|
else
|
|
{
|
|
return -ESRCH;
|
|
}
|
|
|
|
#else
|
|
FAR struct tcb_s *stcb;
|
|
|
|
/* Get the TCB associated with the pid */
|
|
|
|
stcb = nxsched_get_tcb(pid);
|
|
if (stcb == NULL)
|
|
{
|
|
return -ESRCH;
|
|
}
|
|
|
|
return nxsig_tcbdispatch(stcb, info);
|
|
|
|
#endif
|
|
}
|