From 0584df9c12f449124d0bfef9899e5365604ee7a9 Mon Sep 17 00:00:00 2001 From: Marco Elver Date: Wed, 29 Jul 2020 13:09:15 +0200 Subject: [PATCH] lockdep: Refactor IRQ trace events fields into struct Refactor the IRQ trace events fields, used for printing information about the IRQ trace events, into a separate struct 'irqtrace_events'. This improves readability by separating the information only used in reporting, as well as enables (simplified) storing/restoring of irqtrace_events snapshots. No functional change intended. Signed-off-by: Marco Elver Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20200729110916.3920464-1-elver@google.com Signed-off-by: Ingo Molnar --- include/linux/irqflags.h | 13 +++++++++++ include/linux/sched.h | 11 ++------- kernel/fork.c | 16 +++++-------- kernel/locking/lockdep.c | 58 +++++++++++++++++++++++++----------------------- 4 files changed, 50 insertions(+), 48 deletions(-) diff --git a/include/linux/irqflags.h b/include/linux/irqflags.h index 5811ee8a5cd8..bd5c55755447 100644 --- a/include/linux/irqflags.h +++ b/include/linux/irqflags.h @@ -33,6 +33,19 @@ #ifdef CONFIG_TRACE_IRQFLAGS +/* Per-task IRQ trace events information. */ +struct irqtrace_events { + unsigned int irq_events; + unsigned long hardirq_enable_ip; + unsigned long hardirq_disable_ip; + unsigned int hardirq_enable_event; + unsigned int hardirq_disable_event; + unsigned long softirq_disable_ip; + unsigned long softirq_enable_ip; + unsigned int softirq_disable_event; + unsigned int softirq_enable_event; +}; + DECLARE_PER_CPU(int, hardirqs_enabled); DECLARE_PER_CPU(int, hardirq_context); diff --git a/include/linux/sched.h b/include/linux/sched.h index 8d1de021b315..52e0fdd6a555 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -18,6 +18,7 @@ #include #include #include +#include #include #include #include @@ -980,17 +981,9 @@ struct task_struct { #endif #ifdef CONFIG_TRACE_IRQFLAGS - unsigned int irq_events; + struct irqtrace_events irqtrace; unsigned int hardirq_threaded; - unsigned long hardirq_enable_ip; - unsigned long hardirq_disable_ip; - unsigned int hardirq_enable_event; - unsigned int hardirq_disable_event; u64 hardirq_chain_key; - unsigned long softirq_disable_ip; - unsigned long softirq_enable_ip; - unsigned int softirq_disable_event; - unsigned int softirq_enable_event; int softirqs_enabled; int softirq_context; int irq_config; diff --git a/kernel/fork.c b/kernel/fork.c index 70d9d0a4de2a..56a640799680 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -2035,17 +2035,11 @@ static __latent_entropy struct task_struct *copy_process( seqcount_init(&p->mems_allowed_seq); #endif #ifdef CONFIG_TRACE_IRQFLAGS - p->irq_events = 0; - p->hardirq_enable_ip = 0; - p->hardirq_enable_event = 0; - p->hardirq_disable_ip = _THIS_IP_; - p->hardirq_disable_event = 0; - p->softirqs_enabled = 1; - p->softirq_enable_ip = _THIS_IP_; - p->softirq_enable_event = 0; - p->softirq_disable_ip = 0; - p->softirq_disable_event = 0; - p->softirq_context = 0; + memset(&p->irqtrace, 0, sizeof(p->irqtrace)); + p->irqtrace.hardirq_disable_ip = _THIS_IP_; + p->irqtrace.softirq_enable_ip = _THIS_IP_; + p->softirqs_enabled = 1; + p->softirq_context = 0; #endif p->pagefault_disabled = 0; diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index c9ea05edce25..7b5800374c40 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -3484,19 +3484,21 @@ check_usage_backwards(struct task_struct *curr, struct held_lock *this, void print_irqtrace_events(struct task_struct *curr) { - printk("irq event stamp: %u\n", curr->irq_events); + const struct irqtrace_events *trace = &curr->irqtrace; + + printk("irq event stamp: %u\n", trace->irq_events); printk("hardirqs last enabled at (%u): [<%px>] %pS\n", - curr->hardirq_enable_event, (void *)curr->hardirq_enable_ip, - (void *)curr->hardirq_enable_ip); + trace->hardirq_enable_event, (void *)trace->hardirq_enable_ip, + (void *)trace->hardirq_enable_ip); printk("hardirqs last disabled at (%u): [<%px>] %pS\n", - curr->hardirq_disable_event, (void *)curr->hardirq_disable_ip, - (void *)curr->hardirq_disable_ip); + trace->hardirq_disable_event, (void *)trace->hardirq_disable_ip, + (void *)trace->hardirq_disable_ip); printk("softirqs last enabled at (%u): [<%px>] %pS\n", - curr->softirq_enable_event, (void *)curr->softirq_enable_ip, - (void *)curr->softirq_enable_ip); + trace->softirq_enable_event, (void *)trace->softirq_enable_ip, + (void *)trace->softirq_enable_ip); printk("softirqs last disabled at (%u): [<%px>] %pS\n", - curr->softirq_disable_event, (void *)curr->softirq_disable_ip, - (void *)curr->softirq_disable_ip); + trace->softirq_disable_event, (void *)trace->softirq_disable_ip, + (void *)trace->softirq_disable_ip); } static int HARDIRQ_verbose(struct lock_class *class) @@ -3699,7 +3701,7 @@ EXPORT_SYMBOL_GPL(lockdep_hardirqs_on_prepare); void noinstr lockdep_hardirqs_on(unsigned long ip) { - struct task_struct *curr = current; + struct irqtrace_events *trace = ¤t->irqtrace; if (unlikely(!debug_locks)) return; @@ -3752,8 +3754,8 @@ void noinstr lockdep_hardirqs_on(unsigned long ip) skip_checks: /* we'll do an OFF -> ON transition: */ this_cpu_write(hardirqs_enabled, 1); - curr->hardirq_enable_ip = ip; - curr->hardirq_enable_event = ++curr->irq_events; + trace->hardirq_enable_ip = ip; + trace->hardirq_enable_event = ++trace->irq_events; debug_atomic_inc(hardirqs_on_events); } EXPORT_SYMBOL_GPL(lockdep_hardirqs_on); @@ -3763,8 +3765,6 @@ EXPORT_SYMBOL_GPL(lockdep_hardirqs_on); */ void noinstr lockdep_hardirqs_off(unsigned long ip) { - struct task_struct *curr = current; - if (unlikely(!debug_locks)) return; @@ -3784,12 +3784,14 @@ void noinstr lockdep_hardirqs_off(unsigned long ip) return; if (lockdep_hardirqs_enabled()) { + struct irqtrace_events *trace = ¤t->irqtrace; + /* * We have done an ON -> OFF transition: */ this_cpu_write(hardirqs_enabled, 0); - curr->hardirq_disable_ip = ip; - curr->hardirq_disable_event = ++curr->irq_events; + trace->hardirq_disable_ip = ip; + trace->hardirq_disable_event = ++trace->irq_events; debug_atomic_inc(hardirqs_off_events); } else { debug_atomic_inc(redundant_hardirqs_off); @@ -3802,7 +3804,7 @@ EXPORT_SYMBOL_GPL(lockdep_hardirqs_off); */ void lockdep_softirqs_on(unsigned long ip) { - struct task_struct *curr = current; + struct irqtrace_events *trace = ¤t->irqtrace; if (unlikely(!debug_locks || current->lockdep_recursion)) return; @@ -3814,7 +3816,7 @@ void lockdep_softirqs_on(unsigned long ip) if (DEBUG_LOCKS_WARN_ON(!irqs_disabled())) return; - if (curr->softirqs_enabled) { + if (current->softirqs_enabled) { debug_atomic_inc(redundant_softirqs_on); return; } @@ -3823,9 +3825,9 @@ void lockdep_softirqs_on(unsigned long ip) /* * We'll do an OFF -> ON transition: */ - curr->softirqs_enabled = 1; - curr->softirq_enable_ip = ip; - curr->softirq_enable_event = ++curr->irq_events; + current->softirqs_enabled = 1; + trace->softirq_enable_ip = ip; + trace->softirq_enable_event = ++trace->irq_events; debug_atomic_inc(softirqs_on_events); /* * We are going to turn softirqs on, so set the @@ -3833,7 +3835,7 @@ void lockdep_softirqs_on(unsigned long ip) * enabled too: */ if (lockdep_hardirqs_enabled()) - mark_held_locks(curr, LOCK_ENABLED_SOFTIRQ); + mark_held_locks(current, LOCK_ENABLED_SOFTIRQ); lockdep_recursion_finish(); } @@ -3842,8 +3844,6 @@ void lockdep_softirqs_on(unsigned long ip) */ void lockdep_softirqs_off(unsigned long ip) { - struct task_struct *curr = current; - if (unlikely(!debug_locks || current->lockdep_recursion)) return; @@ -3853,13 +3853,15 @@ void lockdep_softirqs_off(unsigned long ip) if (DEBUG_LOCKS_WARN_ON(!irqs_disabled())) return; - if (curr->softirqs_enabled) { + if (current->softirqs_enabled) { + struct irqtrace_events *trace = ¤t->irqtrace; + /* * We have done an ON -> OFF transition: */ - curr->softirqs_enabled = 0; - curr->softirq_disable_ip = ip; - curr->softirq_disable_event = ++curr->irq_events; + current->softirqs_enabled = 0; + trace->softirq_disable_ip = ip; + trace->softirq_disable_event = ++trace->irq_events; debug_atomic_inc(softirqs_off_events); /* * Whoops, we wanted softirqs off, so why aren't they? -- 2.11.0