/**************************************************************************** * arch/arm/src/armv7-a/arm_sigdeliver.c * * Copyright (C) 2013, 2015-2016, 2018 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * 3. Neither the name NuttX nor the names of its contributors may be * used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #include #include #include #include #include #include "sched/sched.h" #include "up_internal.h" #include "up_arch.h" #ifndef CONFIG_DISABLE_SIGNALS /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: up_sigdeliver * * Description: * This is the a signal handling trampoline. When a signal action was * posted. The task context was mucked with and forced to branch to this * location with interrupts disabled. * ****************************************************************************/ void up_sigdeliver(void) { struct tcb_s *rtcb = this_task(); uint32_t regs[XCPTCONTEXT_REGS]; sig_deliver_t sigdeliver; /* Save the errno. This must be preserved throughout the signal handling * so that the user code final gets the correct errno value (probably * EINTR). */ int saved_errno = rtcb->pterrno; board_autoled_on(LED_SIGNAL); sinfo("rtcb=%p sigdeliver=%p sigpendactionq.head=%p\n", rtcb, rtcb->xcp.sigdeliver, rtcb->sigpendactionq.head); ASSERT(rtcb->xcp.sigdeliver != NULL); /* Save the real return state on the stack. */ up_copyfullstate(regs, rtcb->xcp.regs); regs[REG_PC] = rtcb->xcp.saved_pc; regs[REG_CPSR] = rtcb->xcp.saved_cpsr; /* Get a local copy of the sigdeliver function pointer. we do this so that * we can nullify the sigdeliver function pointer in the TCB and accept * more signal deliveries while processing the current pending signals. */ sigdeliver = rtcb->xcp.sigdeliver; rtcb->xcp.sigdeliver = NULL; #ifdef CONFIG_SMP /* In the SMP case, up_schedule_sigaction(0) will have incremented * 'irqcount' in order to force us into a critical section. At a minimum, * we must call leave_critical_section() at least once in order to * compensate for that. */ leave_critical_section(regs[REG_CPSR]); #endif /* CONFIG_SMP */ #ifndef CONFIG_SUPPRESS_INTERRUPTS /* Then make sure that interrupts are enabled. Signal handlers must always * run with interrupts enabled. * * REVISIT: 'irqcount' could still be greater than zero in the SMP case. * This is an issue because (1) global spinlocks are still held and (2) if * the signal handler were to suspend the the critical section would be * re-established when the signal handler resumes. */ up_irq_enable(); #endif /* Deliver the signal */ sigdeliver(rtcb); /* Output any debug messages BEFORE restoring errno (because they may * alter errno), then disable interrupts again and restore the original * errno that is needed by the user logic (it is probably EINTR). * * REVISIT: In SMP mode up_irq_save() probably only disables interrupts * on the local CPU. We do not want to call enter_critical_section() * here, however, because we don't want this state to stick after the * call to up_fullcontextrestore(). * * I would prefer that all interrupts are disabled when * up_fullcontextrestore() is called, but that may not be necessary. */ sinfo("Resuming\n"); (void)up_irq_save(); rtcb->pterrno = saved_errno; /* Then restore the correct state for this thread of execution. */ board_autoled_off(LED_SIGNAL); up_fullcontextrestore(regs); } #endif /* !CONFIG_DISABLE_SIGNALS */