irq/core changes for v3.4

index 40fc861..58b7f27 100644
@@ -100,13 +100,8 @@ execute_on_irq_stack(int overflow, struct irq_desc *desc, int irq)
 	irqctx->tinfo.task = curctx->tinfo.task;
 	irqctx->tinfo.previous_esp = current_stack_pointer;
 
-	/*
-	 * Copy the softirq bits in preempt_count so that the
-	 * softirq checks work in the hardirq context.
-	 */
-	irqctx->tinfo.preempt_count =
-		(irqctx->tinfo.preempt_count & ~SOFTIRQ_MASK) |
-		(curctx->tinfo.preempt_count & SOFTIRQ_MASK);
+	/* Copy the preempt_count so that the [soft]irq checks work. */
+	irqctx->tinfo.preempt_count = curctx->tinfo.preempt_count;
 
 	if (unlikely(overflow))
 		call_on_stack(print_stack_overflow, isp);

@@ -196,7 +191,7 @@ bool handle_irq(unsigned irq, struct pt_regs *regs)
 	if (unlikely(!desc))
 		return false;
 
-	if (!execute_on_irq_stack(overflow, desc, irq)) {
+	if (user_mode_vm(regs) || !execute_on_irq_stack(overflow, desc, irq)) {
 		if (unlikely(overflow))
 			print_stack_overflow();
 		desc->handle_irq(irq, desc);

index 0657368..abb67cf 100644
@@ -1319,6 +1319,11 @@ struct task_struct {
 	unsigned sched_reset_on_fork:1;
 	unsigned sched_contributes_to_load:1;
 
+#ifdef CONFIG_GENERIC_HARDIRQS
+	/* IRQ handler threads */
+	unsigned irq_thread:1;
+#endif
+
 	pid_t pid;
 	pid_t tgid;
 

@@ -1427,11 +1432,6 @@ struct task_struct {
  * mempolicy */
 	spinlock_t alloc_lock;
 
-#ifdef CONFIG_GENERIC_HARDIRQS
-	/* IRQ handler threads */
-	struct irqaction *irqaction;
-#endif
-
 	/* Protection of the PI data structures: */
 	raw_spinlock_t pi_lock;
 

index 4b4042f..752d2c0 100644
@@ -935,8 +935,6 @@ void do_exit(long code)
 		schedule();
 	}
 
-	exit_irq_thread();
-
 	exit_signals(tsk);  /* sets PF_EXITING */
 	/*
 	 * tsk->flags are checked in the futex code to protect against

@@ -945,6 +943,8 @@ void do_exit(long code)
 	smp_mb();
 	raw_spin_unlock_wait(&tsk->pi_lock);
 
+	exit_irq_thread();
+
 	if (unlikely(in_atomic()))
 		printk(KERN_INFO "note: %s[%d] exited with preempt_count %d\n",
 				current->comm, task_pid_nr(current),

index fb7db75..25784d6 100644
@@ -61,8 +61,7 @@ int irq_set_irq_type(unsigned int irq, unsigned int type)
 		return -EINVAL;
 
 	type &= IRQ_TYPE_SENSE_MASK;
-	if (type != IRQ_TYPE_NONE)
-		ret = __irq_set_trigger(desc, irq, type);
+	ret = __irq_set_trigger(desc, irq, type);
 	irq_put_desc_busunlock(desc, flags);
 	return ret;
 }

index 470d08c..6ff84e6 100644
@@ -60,7 +60,7 @@ static void irq_wake_thread(struct irq_desc *desc, struct irqaction *action)
 	 * device interrupt, so no irq storm is lurking. If the
 	 * RUNTHREAD bit is already set, nothing to do.
 	 */
-	if (test_bit(IRQTF_DIED, &action->thread_flags) ||
+	if ((action->thread->flags & PF_EXITING) ||
 	    test_and_set_bit(IRQTF_RUNTHREAD, &action->thread_flags))
 		return;
 

@@ -110,6 +110,18 @@ static void irq_wake_thread(struct irq_desc *desc, struct irqaction *action)
 	 * threads_oneshot untouched and runs the thread another time.
 	 */
 	desc->threads_oneshot |= action->thread_mask;
+
+	/*
+	 * We increment the threads_active counter in case we wake up
+	 * the irq thread. The irq thread decrements the counter when
+	 * it returns from the handler or in the exit path and wakes
+	 * up waiters which are stuck in synchronize_irq() when the
+	 * active count becomes zero. synchronize_irq() is serialized
+	 * against this code (hard irq handler) via IRQS_INPROGRESS
+	 * like the finalize_oneshot() code. See comment above.
+	 */
+	atomic_inc(&desc->threads_active);
+
 	wake_up_process(action->thread);
 }
 

index 40378ff..8e5c56b 100644
@@ -20,14 +20,12 @@ extern bool noirqdebug;
 /*
  * Bits used by threaded handlers:
  * IRQTF_RUNTHREAD - signals that the interrupt handler thread should run
- * IRQTF_DIED      - handler thread died
  * IRQTF_WARNED    - warning "IRQ_WAKE_THREAD w/o thread_fn" has been printed
  * IRQTF_AFFINITY  - irq thread is requested to adjust affinity
  * IRQTF_FORCED_THREAD  - irq action is force threaded
  */
 enum {
 	IRQTF_RUNTHREAD,
-	IRQTF_DIED,
 	IRQTF_WARNED,
 	IRQTF_AFFINITY,
 	IRQTF_FORCED_THREAD,

144 lines not on this page · raw message

index 4eb3a0f..c82d95a 100644
@@ -310,31 +310,21 @@ void irq_enter(void)
 	__irq_enter();
 }
 
-#ifdef __ARCH_IRQ_EXIT_IRQS_DISABLED
 static inline void invoke_softirq(void)
 {
-	if (!force_irqthreads)
+	if (!force_irqthreads) {
+#ifdef __ARCH_IRQ_EXIT_IRQS_DISABLED
 		__do_softirq();
-	else {
-		__local_bh_disable((unsigned long)__builtin_return_address(0),
-				SOFTIRQ_OFFSET);
-		wakeup_softirqd();
-		__local_bh_enable(SOFTIRQ_OFFSET);
-	}
-}
 #else
-static inline void invoke_softirq(void)
-{
-	if (!force_irqthreads)
 		do_softirq();
-	else {
+#endif
+	} else {
 		__local_bh_disable((unsigned long)__builtin_return_address(0),
 				SOFTIRQ_OFFSET);
 		wakeup_softirqd();
 		__local_bh_enable(SOFTIRQ_OFFSET);
 	}
 }
-#endif
 
 /*
  * Exit an interrupt context. Process softirqs if needed and possible: