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Diffstat (limited to 'kernel/softirq.c')
-rw-r--r--kernel/softirq.c37
1 files changed, 25 insertions, 12 deletions
diff --git a/kernel/softirq.c b/kernel/softirq.c
index dcab1d3fb53d..b24988353458 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -29,7 +29,6 @@
#define CREATE_TRACE_POINTS
#include <trace/events/irq.h>
-#include <asm/irq.h>
/*
- No shared variables, all the data are CPU local.
- If a softirq needs serialization, let it serialize itself
@@ -134,7 +133,6 @@ EXPORT_SYMBOL(local_bh_disable);
static void __local_bh_enable(unsigned int cnt)
{
- WARN_ON_ONCE(in_irq());
WARN_ON_ONCE(!irqs_disabled());
if (softirq_count() == cnt)
@@ -149,6 +147,7 @@ static void __local_bh_enable(unsigned int cnt)
*/
void _local_bh_enable(void)
{
+ WARN_ON_ONCE(in_irq());
__local_bh_enable(SOFTIRQ_DISABLE_OFFSET);
}
@@ -171,8 +170,13 @@ static inline void _local_bh_enable_ip(unsigned long ip)
*/
preempt_count_sub(SOFTIRQ_DISABLE_OFFSET - 1);
- if (unlikely(!in_interrupt() && local_softirq_pending()))
+ if (unlikely(!in_interrupt() && local_softirq_pending())) {
+ /*
+ * Run softirq if any pending. And do it in its own stack
+ * as we may be calling this deep in a task call stack already.
+ */
do_softirq();
+ }
preempt_count_dec();
#ifdef CONFIG_TRACE_IRQFLAGS
@@ -280,10 +284,11 @@ restart:
account_irq_exit_time(current);
__local_bh_enable(SOFTIRQ_OFFSET);
+ WARN_ON_ONCE(in_interrupt());
tsk_restore_flags(current, old_flags, PF_MEMALLOC);
}
-#ifndef __ARCH_HAS_DO_SOFTIRQ
+
asmlinkage void do_softirq(void)
{
@@ -298,13 +303,11 @@ asmlinkage void do_softirq(void)
pending = local_softirq_pending();
if (pending)
- __do_softirq();
+ do_softirq_own_stack();
local_irq_restore(flags);
}
-#endif
-
/*
* Enter an interrupt context.
*/
@@ -329,15 +332,21 @@ void irq_enter(void)
static inline void invoke_softirq(void)
{
if (!force_irqthreads) {
+#ifdef CONFIG_HAVE_IRQ_EXIT_ON_IRQ_STACK
/*
* We can safely execute softirq on the current stack if
* it is the irq stack, because it should be near empty
- * at this stage. But we have no way to know if the arch
- * calls irq_exit() on the irq stack. So call softirq
- * in its own stack to prevent from any overrun on top
- * of a potentially deep task stack.
+ * at this stage.
*/
- do_softirq();
+ __do_softirq();
+#else
+ /*
+ * Otherwise, irq_exit() is called on the task stack that can
+ * be potentially deep already. So call softirq in its own stack
+ * to prevent from any overrun.
+ */
+ do_softirq_own_stack();
+#endif
} else {
wakeup_softirqd();
}
@@ -771,6 +780,10 @@ static void run_ksoftirqd(unsigned int cpu)
{
local_irq_disable();
if (local_softirq_pending()) {
+ /*
+ * We can safely run softirq on inline stack, as we are not deep
+ * in the task stack here.
+ */
__do_softirq();
rcu_note_context_switch(cpu);
local_irq_enable();