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404 lines
12 KiB
404 lines
12 KiB
/************************************************************************ |
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* sched/sig_received.c |
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* |
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* Copyright (C) 2007, 2009, 2011 Gregory Nutt. All rights reserved. |
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* Author: Gregory Nutt <gnutt@nuttx.org> |
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* |
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* Redistribution and use in source and binary forms, with or without |
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* modification, are permitted provided that the following conditions |
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* are met: |
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* |
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* 1. Redistributions of source code must retain the above copyright |
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* notice, this list of conditions and the following disclaimer. |
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* 2. Redistributions in binary form must reproduce the above copyright |
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* notice, this list of conditions and the following disclaimer in |
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* the documentation and/or other materials provided with the |
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* distribution. |
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* 3. Neither the name NuttX nor the names of its contributors may be |
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* used to endorse or promote products derived from this software |
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* without specific prior written permission. |
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* |
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS |
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE |
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, |
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, |
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS |
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED |
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN |
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
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* POSSIBILITY OF SUCH DAMAGE. |
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* |
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************************************************************************/ |
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/************************************************************************ |
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* Included Files |
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************************************************************************/ |
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#include <nuttx/config.h> |
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#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 <errno.h> |
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#include <debug.h> |
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#include <nuttx/arch.h> |
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#include "os_internal.h" |
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#include "sem_internal.h" |
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#include "sig_internal.h" |
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#include "mq_internal.h" |
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/************************************************************************ |
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* Definitions |
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************************************************************************/ |
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/************************************************************************ |
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* Private Type Declarations |
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************************************************************************/ |
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/************************************************************************ |
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* Global Variables |
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************************************************************************/ |
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/************************************************************************ |
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* Private Variables |
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************************************************************************/ |
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/************************************************************************ |
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* Private Functions |
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************************************************************************/ |
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/************************************************************************ |
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* Name: sig_queueaction |
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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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************************************************************************/ |
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static int sig_queueaction(FAR _TCB *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 saved_state; |
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int ret = OK; |
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sched_lock(); |
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/* Find the sigaction associated with this signal */ |
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sigact = sig_findaction(stcb, 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: sig_allocatependingsigaction |
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* will force a system crash if it is unable to allocate memory for the |
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* signal data */ |
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sigq = sig_allocatependingsigaction(); |
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if (!sigq) ret = ERROR; |
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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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memcpy(&sigq->info, info, sizeof(siginfo_t)); |
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/* Put it at the end of the pending signals list */ |
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saved_state = irqsave(); |
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sq_addlast((FAR sq_entry_t*)sigq, &(stcb->sigpendactionq)); |
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irqrestore(saved_state); |
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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: sig_findpendingsignal |
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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 *sig_findpendingsignal(FAR _TCB *stcb, int signo) |
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{ |
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FAR sigpendq_t *sigpend = NULL; |
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irqstate_t saved_state; |
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/* Verify the caller's sanity */ |
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if (stcb) |
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{ |
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/* Pending sigals can be added from interrupt level. */ |
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saved_state = irqsave(); |
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/* Seach the list for a sigpendion on this signal */ |
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for(sigpend = (FAR sigpendq_t*)stcb->sigpendingq.head; |
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(sigpend && sigpend->info.si_signo != signo); |
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sigpend = sigpend->flink); |
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irqrestore(saved_state); |
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} |
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return sigpend; |
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} |
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/************************************************************************ |
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* Name: sig_allocatependingsignal |
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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 *sig_allocatependingsignal(void) |
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{ |
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FAR sigpendq_t *sigpend; |
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irqstate_t saved_state; |
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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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else |
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{ |
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/* Try to get the pending signal structure from the free list */ |
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saved_state = irqsave(); |
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sigpend = (FAR sigpendq_t*)sq_remfirst(&g_sigpendingsignal); |
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irqrestore(saved_state); |
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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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if (!sigpend) |
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{ |
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sigpend = (FAR sigpendq_t *)kmalloc((sizeof (sigpendq_t))); |
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} |
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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: sig_addpendingsignal |
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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 FAR sigpendq_t *sig_addpendingsignal(FAR _TCB *stcb, |
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siginfo_t *info) |
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{ |
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FAR sigpendq_t *sigpend; |
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irqstate_t saved_state; |
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/* Check if the signal is already pending */ |
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sigpend = sig_findpendingsignal(stcb, info->si_signo); |
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if (sigpend) |
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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 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 = sig_allocatependingsignal(); |
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if (sigpend) |
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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 pending signal list */ |
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saved_state = irqsave(); |
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sq_addlast((FAR sq_entry_t*)sigpend, &stcb->sigpendingq); |
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irqrestore(saved_state); |
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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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* Public Functions |
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************************************************************************/ |
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/************************************************************************ |
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* Name: sig_received |
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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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************************************************************************/ |
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int sig_received(FAR _TCB *stcb, siginfo_t *info) |
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{ |
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irqstate_t saved_state; |
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int ret = ERROR; |
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sdbg("TCB=0x%08x signo=%d code=%d value=%d mask=%08x\n", |
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stcb, info->si_signo, info->si_code, |
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info->si_value.sival_int, stcb->sigprocmask); |
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if (stcb && info) |
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{ |
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ret = OK; |
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/****************** MASKED SIGNAL HANDLING ******************/ |
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/* Check if the signal is masked -- if it is, it will be added to the |
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* list of pending signals. |
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*/ |
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if (sigismember(&stcb->sigprocmask, info->si_signo)) |
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{ |
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/* Check if the task is waiting for this pending signal. If so, |
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* then unblock it. This must be performed in a critical section |
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* because signals can be queued from the interrupt level. |
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*/ |
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saved_state = irqsave(); |
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if (stcb->task_state == TSTATE_WAIT_SIG && |
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sigismember(&stcb->sigwaitmask, info->si_signo)) |
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{ |
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memcpy(&stcb->sigunbinfo, info, sizeof(siginfo_t)); |
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stcb->sigwaitmask = NULL_SIGNAL_SET; |
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up_unblock_task(stcb); |
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irqrestore(saved_state); |
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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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irqrestore(saved_state); |
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if (!sig_addpendingsignal(stcb, info)) |
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{ |
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PANIC(OSERR_FAILEDTOADDSIGNAL); |
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} |
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} |
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} |
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/****************** UNMASKED SIGNAL HANDLING ******************/ |
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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 = sig_queueaction(stcb, info); |
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/* Then schedule execution of the signal handling action on |
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* the recipients thread. |
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*/ |
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up_schedule_sigaction(stcb, sig_deliver); |
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/* Check if the task is waiting for an unmasked signal. If so, |
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* then unblock it. This must be performed in a critical section |
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* because signals can be queued from the interrupt level. |
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*/ |
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saved_state = irqsave(); |
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if (stcb->task_state == TSTATE_WAIT_SIG) |
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{ |
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memcpy(&stcb->sigunbinfo, info, sizeof(siginfo_t)); |
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stcb->sigwaitmask = NULL_SIGNAL_SET; |
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up_unblock_task(stcb); |
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} |
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irqrestore(saved_state); |
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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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/****************** OTHER SIGNAL HANDLING ******************/ |
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/* If the task is blocked waiting for a semaphore, then that |
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* task must 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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sem_waitirq(stcb, EINTR); |
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} |
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/* If the task is blocked waiting on a message queue, then that |
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* task must be unblocked when a signal is received. |
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*/ |
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#ifndef CONFIG_DISABLE_MQUEUE |
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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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mq_waitirq(stcb, EINTR); |
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} |
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#endif |
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} |
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} |
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return ret; |
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}
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