592 lines
18 KiB
C
592 lines
18 KiB
C
/****************************************************************************
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* sched/signal/sig_default.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 <sys/wait.h>
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#include <stdint.h>
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#include <stdlib.h>
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#include <string.h>
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#include <pthread.h>
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#include <signal.h>
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#include <assert.h>
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#include <nuttx/sched.h>
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#include <nuttx/spinlock.h>
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#include <nuttx/signal.h>
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#include "group/group.h"
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#include "sched/sched.h"
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#include "task/task.h"
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#include "signal/signal.h"
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/****************************************************************************
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* Pre-processor Definitions
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****************************************************************************/
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#if defined(CONFIG_SIG_SIGUSR1_ACTION) || defined(CONFIG_SIG_SIGUSR2_ACTION) || \
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defined(CONFIG_SIG_SIGALRM_ACTION) || defined(CONFIG_SIG_SIGPOLL_ACTION) || \
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defined(CONFIG_SIG_SIGKILL_ACTION) || defined(CONFIG_SIG_SIGPIPE_ACTION)
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# define HAVE_NXSIG_ABNORMAL_TERMINANTION 1
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#endif
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/* Bit definitions for the struct nxsig_defaction_s 'flags' field */
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#define SIG_FLAG_NOCATCH (1 << 0) /* Signal cannot be caught or ignored */
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/****************************************************************************
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* Private Types
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****************************************************************************/
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/* This type provides the default action associated with a signal */
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struct nxsig_defaction_s
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{
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uint8_t signo; /* Signal number. Range 1..MAX_SIGNO */
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uint8_t flags; /* See SIG_FLAG_ definitions */
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_sa_handler_t action; /* Default signal action */
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};
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/****************************************************************************
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* Private Function Prototypes
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****************************************************************************/
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/* Default actions */
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#ifdef HAVE_NXSIG_ABNORMAL_TERMINANTION
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static void nxsig_abnormal_termination(int signo);
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#endif
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#ifdef CONFIG_SIG_SIGSTOP_ACTION
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static void nxsig_null_action(int signo);
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static void nxsig_stop_task(int signo);
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#endif
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/* Helpers */
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static _sa_handler_t nxsig_default_action(int signo);
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static void nxsig_setup_default_action(FAR struct task_group_s *group,
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FAR const struct nxsig_defaction_s *
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info);
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/****************************************************************************
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* Private Data
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****************************************************************************/
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/* NOTE: Default actions are not currently supported for very many signals.
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* However, this array is set up to support an indefinite number of default
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* signal actions.
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*/
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/* This table is used to make the default action for a signal to the correct
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* signal handler. Signals whose default action is be ignored do not need
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* to be in this table (e.g., SIGCHLD).
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*/
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static const struct nxsig_defaction_s g_defactions[] =
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{
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#ifdef CONFIG_SIG_SIGKILL_ACTION
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{ SIGHUP, 0, nxsig_abnormal_termination },
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{ SIGINT, 0, nxsig_abnormal_termination },
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{ SIGQUIT, 0, nxsig_abnormal_termination },
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{ SIGILL, 0, nxsig_abnormal_termination },
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{ SIGTRAP, 0, nxsig_abnormal_termination },
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{ SIGABRT, 0, nxsig_abnormal_termination },
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{ SIGBUS, 0, nxsig_abnormal_termination },
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{ SIGFPE, 0, nxsig_abnormal_termination },
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{ SIGKILL, SIG_FLAG_NOCATCH, nxsig_abnormal_termination },
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{ SIGSEGV, 0, nxsig_abnormal_termination },
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{ SIGTERM, 0, nxsig_abnormal_termination },
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{ SIGXCPU, 0, nxsig_abnormal_termination },
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{ SIGXFSZ, 0, nxsig_abnormal_termination },
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{ SIGSYS, 0, nxsig_abnormal_termination },
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#endif
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#ifdef CONFIG_SIG_SIGUSR1_ACTION
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{ SIGUSR1, 0, nxsig_abnormal_termination },
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#endif
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#ifdef CONFIG_SIG_SIGUSR2_ACTION
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{ SIGUSR2, 0, nxsig_abnormal_termination },
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#endif
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#ifdef CONFIG_SIG_SIGPIPE_ACTION
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{ SIGPIPE, 0, nxsig_abnormal_termination },
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#endif
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#ifdef CONFIG_SIG_SIGALRM_ACTION
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{ SIGALRM, 0, nxsig_abnormal_termination },
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{ SIGVTALRM, 0, nxsig_abnormal_termination },
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#endif
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#ifdef CONFIG_SIG_SIGSTOP_ACTION
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{ SIGCONT, 0, nxsig_null_action },
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{ SIGSTOP, SIG_FLAG_NOCATCH, nxsig_stop_task },
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{ SIGTSTP, 0, nxsig_stop_task },
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{ SIGTTIN, 0, nxsig_stop_task },
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{ SIGTTOU, 0, nxsig_stop_task },
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#endif
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#ifdef CONFIG_SIG_SIGPROF_ACTION
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{ SIGPROF, 0, nxsig_abnormal_termination },
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#endif
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#ifdef CONFIG_SIG_SIGPOLL_ACTION
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{ SIGPOLL, 0, nxsig_abnormal_termination },
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#endif
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};
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#define NACTIONS (sizeof(g_defactions) / sizeof(struct nxsig_defaction_s))
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/****************************************************************************
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* Private Functions
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****************************************************************************/
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/* TODO: Take into account pthread-specific signal behaviors */
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/* Default Actions:
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*
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* - Abnormal termination of the process. The process is terminated with
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* all the consequences of _exit() except that the status made available
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* to wait() and waitpid() indicates abnormal termination by the
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* specified signal.
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* - Abnormal termination of the process. Additionally with the XSI
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* extension, implementation-defined abnormal termination actions, such
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* as creation of a core file, may occur.
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* - Ignore the signal.
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* - Stop the process.
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* - Continue the process, if it is stopped; otherwise, ignore the signal.
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*/
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/****************************************************************************
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* Name: nxsig_null_action
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*
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* Description:
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* The do-nothing default signal action handler.
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*
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* Input Parameters:
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* Standard signal handler parameters
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*
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* Returned Value:
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* None
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*
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****************************************************************************/
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#ifdef CONFIG_SIG_SIGSTOP_ACTION
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static void nxsig_null_action(int signo)
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{
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}
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#endif
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/****************************************************************************
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* Name: nxsig_abnormal_termination
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*
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* Description:
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* This is the handler for the abnormal termination default action.
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*
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* Input Parameters:
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* Standard signal handler parameters
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*
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* Returned Value:
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* None
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*
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****************************************************************************/
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#ifdef HAVE_NXSIG_ABNORMAL_TERMINANTION
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static void nxsig_abnormal_termination(int signo)
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{
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FAR struct tcb_s *rtcb = this_task();
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/* Careful: In the multi-threaded task, the signal may be handled on a
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* child pthread.
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*/
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#ifdef HAVE_GROUP_MEMBERS
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/* Kill all of the children of the task. This will not kill the currently
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* running task/pthread (this_task). It will kill the main thread of the
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* task group if this_task is a pthread.
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*/
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group_kill_children(rtcb);
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#endif
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#ifndef CONFIG_DISABLE_PTHREAD
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/* Check if the currently running task is actually a pthread */
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if ((rtcb->flags & TCB_FLAG_TTYPE_MASK) == TCB_FLAG_TTYPE_PTHREAD)
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{
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/* Exit the final thread of the task group.
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*
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* REVISIT: This will not work if HAVE_GROUP_MEMBERS is not set.
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*/
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pthread_exit(NULL);
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}
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else
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#endif
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{
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UNUSED(rtcb);
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/* Exit to terminate the task. */
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_exit(EXIT_FAILURE);
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}
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}
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#endif
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/****************************************************************************
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* Name: nxsig_stop_task
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*
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* Description:
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* This is the handler for the stop default action.
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*
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* Input Parameters:
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* Standard signal handler parameters
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*
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* Returned Value:
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* None
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*
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****************************************************************************/
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#ifdef CONFIG_SIG_SIGSTOP_ACTION
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static void nxsig_stop_task(int signo)
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{
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FAR struct tcb_s *rtcb = this_task();
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#if defined(CONFIG_SCHED_WAITPID) && !defined(CONFIG_SCHED_HAVE_PARENT)
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FAR struct task_group_s *group;
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DEBUGASSERT(rtcb != NULL && rtcb->group != NULL);
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group = rtcb->group;
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#endif
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/* Careful: In the multi-threaded task, the signal may be handled on a
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* child pthread.
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*/
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#ifdef HAVE_GROUP_MEMBERS
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/* Suspend all of the children of the task. This will not suspend the
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* currently running task/pthread (this_task). It will suspend the
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* main thread of the task group if this_task is a pthread.
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*/
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group_suspend_children(rtcb);
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#endif
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/* Lock the scheduler so this thread is not pre-empted until after we
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* call nxsched_suspend().
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*/
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sched_lock();
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#if defined(CONFIG_SCHED_WAITPID) && !defined(CONFIG_SCHED_HAVE_PARENT)
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/* Notify via waitpid if any parent is waiting for this task to EXIT
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* or STOP. This action is only performed if WUNTRACED is set in the
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* waitpid flags.
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*/
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if ((group->tg_waitflags & WUNTRACED) != 0)
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{
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/* Return zero for exit status (we are not exiting, however) */
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if (group->tg_statloc != NULL)
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{
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*group->tg_statloc = 0;
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group->tg_statloc = NULL;
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}
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/* tg_waitflags == 0 means that the flags are available to another
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* caller of waitpid().
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*/
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group->tg_waitflags = 0;
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/* Wakeup any tasks waiting for this task to exit or stop. */
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while (group->tg_exitsem.semcount < 0)
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{
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/* Wake up the thread */
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nxsem_post(&group->tg_exitsem);
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}
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}
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#endif
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/* Then, finally, suspend this the final thread of the task group */
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nxsched_suspend(rtcb);
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sched_unlock();
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}
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#endif
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/****************************************************************************
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* Name: nxsig_default_action
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*
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* Description:
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* Look up the default action associated with this signal
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*
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* Input Parameters:
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* signo - The signal number to use in the query
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*
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* Returned Value:
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* The default handler associated with this signal
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*
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****************************************************************************/
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static _sa_handler_t nxsig_default_action(int signo)
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{
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int i;
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/* Search the default action table for the entry associated with this
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* signal.
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*/
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for (i = 0; i < NACTIONS; i++)
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{
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if (g_defactions[i].signo == signo)
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{
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return g_defactions[i].action;
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}
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}
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/* No default action */
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return SIG_IGN;
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}
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/****************************************************************************
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* Name: nxsig_setup_default_action
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*
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* Description:
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* Setup the default action for a signal.
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*
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* This function is called early in task setup, prior to the creation of
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* any pthreads so we should have exclusive access to the group structure.
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*
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* Input Parameters:
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* group - The group that the task belongs in.
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* action - The new default signal action
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* signo - The signal that will produce this default action
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*
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* Returned Value:
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* None
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*
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****************************************************************************/
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static void nxsig_setup_default_action(FAR struct task_group_s *group,
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FAR const struct nxsig_defaction_s *
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info)
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{
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/* Get the address of the handler for this signals default action. */
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if (info->action != SIG_IGN)
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{
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struct sigaction sa;
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/* Attach the signal handler.
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*
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* NOTE: nxsig_action will call nxsig_default(tcb, action, false).
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* Don't be surprised.
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*/
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memset(&sa, 0, sizeof(sa));
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sa.sa_handler = info->action;
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sa.sa_flags = SA_SIGINFO;
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nxsig_action(info->signo, &sa, NULL, true);
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/* Indicate that the default signal handler has been attached */
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nxsig_addset(&group->tg_sigdefault, (int)info->signo);
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}
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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_isdefault
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*
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* Description:
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* Return true if the specified signal is set to the default action.
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*
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* Input Parameters:
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* tcb - Identifies the thread associated with the default handler
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* signo - The signal number to be queried
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*
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* Returned Value:
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* Zero (OK) is returned on success; A negated errno value is returned
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* on failure.
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*
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****************************************************************************/
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bool nxsig_isdefault(FAR struct tcb_s *tcb, int signo)
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{
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FAR struct task_group_s *group;
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int ret;
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DEBUGASSERT(tcb != NULL && tcb->group != NULL && GOOD_SIGNO(signo));
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group = tcb->group;
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/* Return true if the signo is marked as using the default action. Return
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* false in all other cases.
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*/
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ret = nxsig_ismember(&group->tg_sigdefault, signo);
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return ret < 0 ? false : (bool)ret;
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}
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/****************************************************************************
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* Name: nxsig_iscatchable
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*
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* Description:
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* Return true if the specified signal can be caught or ignored.
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*
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* Input Parameters:
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* signo - The signal number to be queried
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*
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* Returned Value:
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* Zero (OK) is returned on success; A negated errno value is returned
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* on failure.
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*
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****************************************************************************/
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bool nxsig_iscatchable(int signo)
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{
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int i;
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/* Search the default action table for the entry associated with this
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* signal.
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*/
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for (i = 0; i < NACTIONS; i++)
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{
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if (g_defactions[i].signo == signo)
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{
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return (g_defactions[i].flags & SIG_FLAG_NOCATCH) == 0;
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}
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}
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/* If it is not in the table, then it is catchable */
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return true;
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}
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/****************************************************************************
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* Name: nxsig_default
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*
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* Description:
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* If 'defaction' is true, then return the default signal handler action
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* for the specified signal and mark that the default signal handler is
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* in place (it is not yet).
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*
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* If 'defaction' is false, then mark that the default signal handler is
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* NOT in place and return SIG_IGN.
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*
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* This function is called form sigaction() to handle actions = SIG_DFL.
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*
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* Input Parameters:
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* tcb - Identifies the thread associated with the default handler
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* signo - The signal number whose behavior will be modified.
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* defaction - True: the default action is in place
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*
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* Returned Value:
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* The address of the default signal action handler is returne on success.
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* SIG_IGN is returned if there is no default action.
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*
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****************************************************************************/
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_sa_handler_t nxsig_default(FAR struct tcb_s *tcb, int signo, bool defaction)
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{
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FAR struct task_group_s *group;
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_sa_handler_t handler = SIG_IGN;
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irqstate_t flags;
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DEBUGASSERT(tcb != NULL && tcb->group != NULL);
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group = tcb->group;
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/* Are we setting or unsetting the default action? */
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if (defaction)
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{
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/* We are setting the default action. Look up the default action
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* associated with signo.
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*/
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handler = nxsig_default_action(signo);
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if (handler != SIG_IGN)
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{
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/* nxsig_addset() is not atomic (but neither is sigaction()) */
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flags = spin_lock_irqsave(NULL);
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nxsig_addset(&group->tg_sigdefault, signo);
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spin_unlock_irqrestore(NULL, flags);
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}
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}
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if (handler == SIG_IGN)
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{
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/* We are unsetting the default action. NOTE that nxsig_delset() is not
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* atomic (but neither is sigaction()).
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*/
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flags = spin_lock_irqsave(NULL);
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nxsig_delset(&group->tg_sigdefault, signo);
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spin_unlock_irqrestore(NULL, flags);
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}
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return handler;
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}
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/****************************************************************************
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* Name: nxsig_default_initialize
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*
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* Description:
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* Set all signals to their default action. This is called from
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* nxtask_start() to configure the newly started task.
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*
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* Input Parameters:
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* tcb - Identifies the thread associated with the default handlers
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*
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* Returned Value:
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* Zero (OK) is returned on success; A negated errno value is returned
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* on failure.
|
|
*
|
|
****************************************************************************/
|
|
|
|
int nxsig_default_initialize(FAR struct tcb_s *tcb)
|
|
{
|
|
FAR struct task_group_s *group;
|
|
int i;
|
|
|
|
DEBUGASSERT(tcb != NULL && tcb->group != NULL);
|
|
group = tcb->group;
|
|
|
|
/* Initialize the set of default signal handlers */
|
|
|
|
sigemptyset(&group->tg_sigdefault);
|
|
|
|
/* Setup the default action for each signal in g_defactions[] */
|
|
|
|
for (i = 0; i < NACTIONS; i++)
|
|
{
|
|
nxsig_setup_default_action(group, &g_defactions[i]);
|
|
}
|
|
|
|
return OK;
|
|
}
|