diff options
Diffstat (limited to 'kernel/softirq.c')
| -rw-r--r-- | kernel/softirq.c | 49 |
1 files changed, 40 insertions, 9 deletions
diff --git a/kernel/softirq.c b/kernel/softirq.c index 9e368ef35f9..8b93b3770f8 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -188,14 +188,48 @@ EXPORT_SYMBOL(__local_bh_enable_ip); #define MAX_SOFTIRQ_TIME msecs_to_jiffies(2) #define MAX_SOFTIRQ_RESTART 10 +#ifdef CONFIG_TRACE_IRQFLAGS +/* + * When we run softirqs from irq_exit() and thus on the hardirq stack we need + * to keep the lockdep irq context tracking as tight as possible in order to + * not miss-qualify lock contexts and miss possible deadlocks. + */ + +static inline bool lockdep_softirq_start(void) +{ + bool in_hardirq = false; + + if (trace_hardirq_context(current)) { + in_hardirq = true; + trace_hardirq_exit(); + } + + lockdep_softirq_enter(); + + return in_hardirq; +} + +static inline void lockdep_softirq_end(bool in_hardirq) +{ + lockdep_softirq_exit(); + + if (in_hardirq) + trace_hardirq_enter(); +} +#else +static inline bool lockdep_softirq_start(void) { return false; } +static inline void lockdep_softirq_end(bool in_hardirq) { } +#endif + asmlinkage void __do_softirq(void) { - struct softirq_action *h; - __u32 pending; unsigned long end = jiffies + MAX_SOFTIRQ_TIME; - int cpu; unsigned long old_flags = current->flags; int max_restart = MAX_SOFTIRQ_RESTART; + struct softirq_action *h; + bool in_hardirq; + __u32 pending; + int cpu; /* * Mask out PF_MEMALLOC s current task context is borrowed for the @@ -208,7 +242,7 @@ asmlinkage void __do_softirq(void) account_irq_enter_time(current); __local_bh_disable_ip(_RET_IP_, SOFTIRQ_OFFSET); - lockdep_softirq_enter(); + in_hardirq = lockdep_softirq_start(); cpu = smp_processor_id(); restart: @@ -255,16 +289,13 @@ restart: wakeup_softirqd(); } - lockdep_softirq_exit(); - + lockdep_softirq_end(in_hardirq); account_irq_exit_time(current); __local_bh_enable(SOFTIRQ_OFFSET); WARN_ON_ONCE(in_interrupt()); tsk_restore_flags(current, old_flags, PF_MEMALLOC); } - - asmlinkage void do_softirq(void) { __u32 pending; @@ -352,13 +383,13 @@ void irq_exit(void) #endif account_irq_exit_time(current); - trace_hardirq_exit(); preempt_count_sub(HARDIRQ_OFFSET); if (!in_interrupt() && local_softirq_pending()) invoke_softirq(); tick_irq_exit(); rcu_irq_exit(); + trace_hardirq_exit(); /* must be last! */ } /* |