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Diffstat (limited to 'nuttx/arch/arm/src/cortexm3/up_schedulesigaction.c')
| -rw-r--r-- | nuttx/arch/arm/src/cortexm3/up_schedulesigaction.c | 208 |
1 files changed, 208 insertions, 0 deletions
diff --git a/nuttx/arch/arm/src/cortexm3/up_schedulesigaction.c b/nuttx/arch/arm/src/cortexm3/up_schedulesigaction.c new file mode 100644 index 000000000..31219874b --- /dev/null +++ b/nuttx/arch/arm/src/cortexm3/up_schedulesigaction.c @@ -0,0 +1,208 @@ +/**************************************************************************** + * arch/arm/src/cortexm3/up_schedulesigaction.c + * + * Copyright (C) 2009 Gregory Nutt. All rights reserved. + * Author: Gregory Nutt <spudmonkey@racsa.co.cr> + * + * 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 <nuttx/config.h> + +#include <sys/types.h> +#include <sched.h> +#include <debug.h> + +#include <nuttx/arch.h> + +#include "psr.h" +#include "os_internal.h" +#include "up_internal.h" +#include "up_arch.h" + +#ifndef CONFIG_DISABLE_SIGNALS + +/**************************************************************************** + * Private Definitions + ****************************************************************************/ + +/**************************************************************************** + * Private Data + ****************************************************************************/ + +/**************************************************************************** + * Private Functions + ****************************************************************************/ + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: up_schedule_sigaction + * + * Description: + * This function is called by the OS when one or more + * signal handling actions have been queued for execution. + * The architecture specific code must configure things so + * that the 'igdeliver' callback is executed on the thread + * specified by 'tcb' as soon as possible. + * + * This function may be called from interrupt handling logic. + * + * This operation should not cause the task to be unblocked + * nor should it cause any immediate execution of sigdeliver. + * Typically, a few cases need to be considered: + * + * (1) This function may be called from an interrupt handler + * During interrupt processing, all xcptcontext structures + * should be valid for all tasks. That structure should + * be modified to invoke sigdeliver() either on return + * from (this) interrupt or on some subsequent context + * switch to the recipient task. + * (2) If not in an interrupt handler and the tcb is NOT + * the currently executing task, then again just modify + * the saved xcptcontext structure for the recipient + * task so it will invoke sigdeliver when that task is + * later resumed. + * (3) If not in an interrupt handler and the tcb IS the + * currently executing task -- just call the signal + * handler now. + * + ****************************************************************************/ + +void up_schedule_sigaction(_TCB *tcb, sig_deliver_t sigdeliver) +{ + /* Refuse to handle nested signal actions */ + + sdbg("tcb=0x%p sigdeliver=0x%p\n", tcb, sigdeliver); + + if (!tcb->xcp.sigdeliver) + { + irqstate_t flags; + + /* Make sure that interrupts are disabled */ + + flags = irqsave(); + + /* First, handle some special cases when the signal is + * being delivered to the currently executing task. + */ + + sdbg("rtcb=0x%p current_regs=0x%p\n", g_readytorun.head, current_regs); + + if (tcb == (_TCB*)g_readytorun.head) + { + /* CASE 1: We are not in an interrupt handler and + * a task is signalling itself for some reason. + */ + + if (!current_regs) + { + /* In this case just deliver the signal now. */ + + sigdeliver(tcb); + } + + /* CASE 2: We are in an interrupt handler AND the + * interrupted task is the same as the one that + * must receive the signal, then we will have to modify + * the return state as well as the state in the TCB. + * + * Hmmm... there looks like a latent bug here: The following + * logic would fail in the strange case where we are in an + * interrupt handler, the thread is signalling itself, but + * a context switch to another task has occurred so that + * current_regs does not refer to the thread at g_readytorun.head! + */ + + else + { + /* Save the return lr and cpsr and one scratch register + * These will be restored by the signal trampoline after + * the signals have been delivered. + */ + + tcb->xcp.sigdeliver = sigdeliver; + tcb->xcp.saved_pc = current_regs[REG_PC]; + tcb->xcp.saved_primask = current_regs[REG_PRIMASK]; + tcb->xcp.saved_xpsr = current_regs[REG_XPSR]; + + /* Then set up to vector to the trampoline with interrupts + * disabled + */ + + current_regs[REG_PC] = (uint32)up_sigdeliver; + current_regs[REG_PRIMASK] = 1; + current_regs[REG_XPSR] = CORTEXM3_XPSR_T; + + /* And make sure that the saved context in the TCB + * is the same as the interrupt return context. + */ + + up_savestate(tcb->xcp.regs); + } + } + + /* Otherwise, we are (1) signaling a task is not running + * from an interrupt handler or (2) we are not in an + * interrupt handler and the running task is signalling + * some non-running task. + */ + + else + { + /* Save the return lr and cpsr and one scratch register + * These will be restored by the signal trampoline after + * the signals have been delivered. + */ + + tcb->xcp.sigdeliver = sigdeliver; + tcb->xcp.saved_pc = tcb->xcp.regs[REG_PC]; + tcb->xcp.saved_primask = tcb->xcp.regs[REG_PRIMASK]; + tcb->xcp.saved_xpsr = tcb->xcp.regs[REG_XPSR]; + + /* Then set up to vector to the trampoline with interrupts + * disabled + */ + + tcb->xcp.regs[REG_PC] = (uint32)up_sigdeliver; + tcb->xcp.regs[REG_PRIMASK] = 1; + tcb->xcp.regs[REG_XPSR] = CORTEXM3_XPSR_T; + } + + irqrestore(flags); + } +} + +#endif /* !CONFIG_DISABLE_SIGNALS */ |