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enter/leave_critical_section: In SMP configuration, may attempt to access the task lists before they have been initialized

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This commit is contained in:
Gregory Nutt 2016-05-18 08:21:28 -06:00
parent 72de45b7cf
commit 32838fcc2c
3 changed files with 73 additions and 65 deletions
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31
include/nuttx/init.h
View File

@ -65,21 +65,22 @@
enum os_initstate_e
{
OSINIT_POWERUP = 0, /* Power-up. No initialization yet performed.
* Depends on .bss initialization logic for this
* value. */
OSINIT_BOOT = 1, /* Basic boot up initialization is complete. OS
* services and hardware resources are not yet
* available. */
OSINIT_MEMORY = 2, /* The memory manager has been initialized */
OSINIT_HARDWARE = 3, /* MCU-specific hardware is initialized. Hardware
* resources such as timers and device drivers are
* now avaiable. Low-level OS services sufficient
* to support the hardware are also available but
* the OS has not yet completed its full
* initialization. */
OSINIT_OSREADY = 4 /* The OS is fully initialized and multi-tasking is
* active. */
OSINIT_POWERUP = 0, /* Power-up. No initialization yet performed.
* Depends on .bss initialization logic for this
* value. */
OSINIT_BOOT = 1, /* Basic boot up initialization is complete. OS
* services and hardware resources are not yet
* available. */
OSINIT_TASKLISTS = 2, /* Head of ready-to-run/assigned task lists valid */
OSINIT_MEMORY = 3, /* The memory manager has been initialized */
OSINIT_HARDWARE = 4, /* MCU-specific hardware is initialized. Hardware
* resources such as timers and device drivers are
* now avaiable. Low-level OS services sufficient
* to support the hardware are also available but
* the OS has not yet completed its full
* initialization. */
OSINIT_OSREADY = 5 /* The OS is fully initialized and multi-tasking is
* active. */
};
/****************************************************************************

4
sched/init/os_start.c
View File

@ -530,6 +530,10 @@ void os_start(void)
up_initial_state(&g_idletcb[cpu].cmn);
}
/* Task lists are initialized */
g_os_initstate = OSINIT_TASKLISTS;
/* Initialize RTOS facilities *********************************************/
/* Initialize the semaphore facility. This has to be done very early
* because many subsystems depend upon fully functional semaphores.

103
sched/irq/irq_csection.c
View File

@ -41,6 +41,7 @@
#include <sys/types.h>
#include <nuttx/init.h>
#include <nuttx/spinlock.h>
#include <nuttx/sched_note.h>
#include <arch/irq.h>
@ -86,54 +87,50 @@ irqstate_t enter_critical_section(void)
{
FAR struct tcb_s *rtcb;
/* Do nothing if called from an interrupt handler */
/* Check if we were called from an interrupt handler and that the tasks
* lists have been initialized.
*/
if (up_interrupt_context())
if (!up_interrupt_context() && g_os_initstate >= OSINIT_TASKLISTS)
{
/* The value returned does not matter. We assume only that it is a
* scalar here.
*/
/* Do we already have interrupts disabled? */
return (irqstate_t)0;
}
rtcb = this_task();
DEBUGASSERT(rtcb != NULL);
/* Do we already have interrupts disabled? */
if (rtcb->irqcount > 0)
{
/* Yes... make sure that the spinlock is set and increment the IRQ
* lock count.
*/
rtcb = this_task();
DEBUGASSERT(rtcb != NULL);
DEBUGASSERT(g_cpu_irqlock == SP_LOCKED && rtcb->irqcount < INT16_MAX);
rtcb->irqcount++;
}
else
{
/* NO.. Take the spinlock to get exclusive access and set the lock
* count to 1.
*
* We must avoid that case where a context occurs between taking the
* g_cpu_irqlock and disabling interrupts. Also interrupts disables
* must follow a stacked order. We cannot other context switches to
* re-order the enabling/disabling of interrupts.
*
* The scheduler accomplishes this by treating the irqcount like
* lockcount: Both will disable pre-emption.
*/
if (rtcb->irqcount > 0)
{
/* Yes... make sure that the spinlock is set and increment the IRQ
* lock count.
*/
DEBUGASSERT(g_cpu_irqlock == SP_LOCKED && rtcb->irqcount < INT16_MAX);
rtcb->irqcount++;
}
else
{
/* NO.. Take the spinlock to get exclusive access and set the lock
* count to 1.
*
* We must avoid that case where a context occurs between taking the
* g_cpu_irqlock and disabling interrupts. Also interrupts disables
* must follow a stacked order. We cannot other context switches to
* re-order the enabling/disabling of interrupts.
*
* The scheduler accomplishes this by treating the irqcount like
* lockcount: Both will disable pre-emption.
*/
spin_setbit(&g_cpu_irqset, this_cpu(), &g_cpu_irqsetlock,
&g_cpu_irqlock);
rtcb->irqcount = 1;
spin_setbit(&g_cpu_irqset, this_cpu(), &g_cpu_irqsetlock,
&g_cpu_irqlock);
rtcb->irqcount = 1;
#ifdef CONFIG_SCHED_INSTRUMENTATION_CSECTION
/* Note that we have entered the critical section */
/* Note that we have entered the critical section */
sched_note_csection(rtcb, true);
sched_note_csection(rtcb, true);
#endif
}
}
/* Then disable interrupts (they may already be disabled, be we need to
@ -145,9 +142,11 @@ irqstate_t enter_critical_section(void)
#else /* defined(CONFIG_SCHED_INSTRUMENTATION_CSECTION) */
irqstate_t enter_critical_section(void)
{
/* Check if we were called from an interrupt handler */
/* Check if we were called from an interrupt handler and that the tasks
* lists have been initialized.
*/
if (!up_interrupt_context())
if (!up_interrupt_context() && g_os_initstate >= OSINIT_TASKLISTS)
{
FAR struct tcb_s *rtcb = this_task();
DEBUGASSERT(rtcb != NULL);
@ -175,9 +174,11 @@ irqstate_t enter_critical_section(void)
#ifdef CONFIG_SMP
void leave_critical_section(irqstate_t flags)
{
/* Do nothing if called from an interrupt handler */
/* Check if we were called from an interrupt handler and that the tasks
* lists have been initialized.
*/
if (!up_interrupt_context())
if (!up_interrupt_context() && g_os_initstate >= OSINIT_TASKLISTS)
{
FAR struct tcb_s *rtcb = this_task();
DEBUGASSERT(rtcb != 0 && rtcb->irqcount > 0);
@ -229,20 +230,22 @@ void leave_critical_section(irqstate_t flags)
}
}
}
/* Restore the previous interrupt state which may still be interrupts
* disabled (but we don't have a mechanism to verify that now)
*/
up_irq_restore(flags);
}
/* Restore the previous interrupt state which may still be interrupts
* disabled (but we don't have a mechanism to verify that now)
*/
up_irq_restore(flags);
}
#else /* defined(CONFIG_SCHED_INSTRUMENTATION_CSECTION) */
void leave_critical_section(irqstate_t flags)
{
/* Check if we were called from an interrupt handler */
/* Check if we were called from an interrupt handler and that the tasks
* lists have been initialized.
*/
if (!up_interrupt_context())
if (!up_interrupt_context() && g_os_initstate >= OSINIT_TASKLISTS)
{
FAR struct tcb_s *rtcb = this_task();
DEBUGASSERT(rtcb != NULL);