Re: [PATCH] kernel: in_irq() cleanup

From: Paul E. McKenney
Date: Fri Aug 13 2021 - 22:26:09 EST


On Fri, Aug 13, 2021 at 10:51:01PM +0800, Changbin Du wrote:
> Replace the obsolete and ambiguos macro in_irq() with new
> macro in_hardirq().
>
> Signed-off-by: Changbin Du <changbin.du@xxxxxxxxx>

>From an RCU viewpoint:

Reviewed-by: Paul E. McKenney <paulmck@xxxxxxxxxx>

> ---
> include/linux/lockdep.h | 2 +-
> include/linux/rcutiny.h | 2 +-
> kernel/irq/irqdesc.c | 2 +-
> kernel/rcu/tree.c | 2 +-
> kernel/rcu/tree_plugin.h | 2 +-
> kernel/softirq.c | 10 +++++-----
> kernel/time/timer.c | 4 ++--
> kernel/trace/trace.h | 2 +-
> kernel/trace/trace_functions_graph.c | 2 +-
> lib/locking-selftest.c | 4 ++--
> lib/vsprintf.c | 2 +-
> 11 files changed, 17 insertions(+), 17 deletions(-)
>
> diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
> index 5cf387813754..e7aa0050bfd8 100644
> --- a/include/linux/lockdep.h
> +++ b/include/linux/lockdep.h
> @@ -633,7 +633,7 @@ do { \
> #define lockdep_assert_in_softirq() \
> do { \
> WARN_ON_ONCE(__lockdep_enabled && \
> - (!in_softirq() || in_irq() || in_nmi())); \
> + (!in_softirq() || in_hardirq() || in_nmi())); \
> } while (0)
>
> #else
> diff --git a/include/linux/rcutiny.h b/include/linux/rcutiny.h
> index 953e70fafe38..7fedbd33d5d2 100644
> --- a/include/linux/rcutiny.h
> +++ b/include/linux/rcutiny.h
> @@ -88,7 +88,7 @@ static inline void rcu_irq_enter_irqson(void) { }
> static inline void rcu_irq_exit(void) { }
> static inline void rcu_irq_exit_check_preempt(void) { }
> #define rcu_is_idle_cpu(cpu) \
> - (is_idle_task(current) && !in_nmi() && !in_irq() && !in_serving_softirq())
> + (is_idle_task(current) && !in_nmi() && !in_hardirq() && !in_serving_softirq())
> static inline void exit_rcu(void) { }
> static inline bool rcu_preempt_need_deferred_qs(struct task_struct *t)
> {
> diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c
> index fadb93766020..0ffd6c19259f 100644
> --- a/kernel/irq/irqdesc.c
> +++ b/kernel/irq/irqdesc.c
> @@ -640,7 +640,7 @@ int handle_irq_desc(struct irq_desc *desc)
> return -EINVAL;
>
> data = irq_desc_get_irq_data(desc);
> - if (WARN_ON_ONCE(!in_irq() && handle_enforce_irqctx(data)))
> + if (WARN_ON_ONCE(!in_hardirq() && handle_enforce_irqctx(data)))
> return -EPERM;
>
> generic_handle_irq_desc(desc);
> diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
> index 51f24ecd94b2..18f6658f0713 100644
> --- a/kernel/rcu/tree.c
> +++ b/kernel/rcu/tree.c
> @@ -1510,7 +1510,7 @@ static void rcu_gp_kthread_wake(void)
> {
> struct task_struct *t = READ_ONCE(rcu_state.gp_kthread);
>
> - if ((current == t && !in_irq() && !in_serving_softirq()) ||
> + if ((current == t && !in_hardirq() && !in_serving_softirq()) ||
> !READ_ONCE(rcu_state.gp_flags) || !t)
> return;
> WRITE_ONCE(rcu_state.gp_wake_time, jiffies);
> diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
> index de1dc3bb7f70..953171af6d0c 100644
> --- a/kernel/rcu/tree_plugin.h
> +++ b/kernel/rcu/tree_plugin.h
> @@ -672,7 +672,7 @@ static void rcu_read_unlock_special(struct task_struct *t)
> (IS_ENABLED(CONFIG_RCU_BOOST) && irqs_were_disabled &&
> t->rcu_blocked_node);
> // Need to defer quiescent state until everything is enabled.
> - if (use_softirq && (in_irq() || (expboost && !irqs_were_disabled))) {
> + if (use_softirq && (in_hardirq() || (expboost && !irqs_were_disabled))) {
> // Using softirq, safe to awaken, and either the
> // wakeup is free or there is either an expedited
> // GP in flight or a potential need to deboost.
> diff --git a/kernel/softirq.c b/kernel/softirq.c
> index f3a012179f47..e8c62c4b1e5d 100644
> --- a/kernel/softirq.c
> +++ b/kernel/softirq.c
> @@ -222,7 +222,7 @@ void __local_bh_enable_ip(unsigned long ip, unsigned int cnt)
> u32 pending;
> int curcnt;
>
> - WARN_ON_ONCE(in_irq());
> + WARN_ON_ONCE(in_hardirq());
> lockdep_assert_irqs_enabled();
>
> local_irq_save(flags);
> @@ -305,7 +305,7 @@ void __local_bh_disable_ip(unsigned long ip, unsigned int cnt)
> {
> unsigned long flags;
>
> - WARN_ON_ONCE(in_irq());
> + WARN_ON_ONCE(in_hardirq());
>
> raw_local_irq_save(flags);
> /*
> @@ -352,14 +352,14 @@ static void __local_bh_enable(unsigned int cnt)
> */
> void _local_bh_enable(void)
> {
> - WARN_ON_ONCE(in_irq());
> + WARN_ON_ONCE(in_hardirq());
> __local_bh_enable(SOFTIRQ_DISABLE_OFFSET);
> }
> EXPORT_SYMBOL(_local_bh_enable);
>
> void __local_bh_enable_ip(unsigned long ip, unsigned int cnt)
> {
> - WARN_ON_ONCE(in_irq());
> + WARN_ON_ONCE(in_hardirq());
> lockdep_assert_irqs_enabled();
> #ifdef CONFIG_TRACE_IRQFLAGS
> local_irq_disable();
> @@ -617,7 +617,7 @@ static inline void tick_irq_exit(void)
>
> /* Make sure that timer wheel updates are propagated */
> if ((idle_cpu(cpu) && !need_resched()) || tick_nohz_full_cpu(cpu)) {
> - if (!in_irq())
> + if (!in_hardirq())
> tick_nohz_irq_exit();
> }
> #endif
> diff --git a/kernel/time/timer.c b/kernel/time/timer.c
> index e3d2c23c413d..dfdbb114a43d 100644
> --- a/kernel/time/timer.c
> +++ b/kernel/time/timer.c
> @@ -1369,7 +1369,7 @@ int del_timer_sync(struct timer_list *timer)
> * don't use it in hardirq context, because it
> * could lead to deadlock.
> */
> - WARN_ON(in_irq() && !(timer->flags & TIMER_IRQSAFE));
> + WARN_ON(in_hardirq() && !(timer->flags & TIMER_IRQSAFE));
>
> /*
> * Must be able to sleep on PREEMPT_RT because of the slowpath in
> @@ -1784,7 +1784,7 @@ void update_process_times(int user_tick)
> run_local_timers();
> rcu_sched_clock_irq(user_tick);
> #ifdef CONFIG_IRQ_WORK
> - if (in_irq())
> + if (in_hardirq())
> irq_work_tick();
> #endif
> scheduler_tick();
> diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
> index a180abf76d4e..2ed5b77b60ca 100644
> --- a/kernel/trace/trace.h
> +++ b/kernel/trace/trace.h
> @@ -876,7 +876,7 @@ static inline int ftrace_graph_addr(struct ftrace_graph_ent *trace)
> * is set, and called by an interrupt handler, we still
> * want to trace it.
> */
> - if (in_irq())
> + if (in_hardirq())
> trace_recursion_set(TRACE_IRQ_BIT);
> else
> trace_recursion_clear(TRACE_IRQ_BIT);
> diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
> index 0de6837722da..b08d3923de98 100644
> --- a/kernel/trace/trace_functions_graph.c
> +++ b/kernel/trace/trace_functions_graph.c
> @@ -120,7 +120,7 @@ static inline int ftrace_graph_ignore_irqs(void)
> if (!ftrace_graph_skip_irqs || trace_recursion_test(TRACE_IRQ_BIT))
> return 0;
>
> - return in_irq();
> + return in_hardirq();
> }
>
> int trace_graph_entry(struct ftrace_graph_ent *trace)
> diff --git a/lib/locking-selftest.c b/lib/locking-selftest.c
> index 161108e5d2fe..a4edff9ffc33 100644
> --- a/lib/locking-selftest.c
> +++ b/lib/locking-selftest.c
> @@ -196,7 +196,7 @@ static void init_shared_classes(void)
> local_irq_disable(); \
> __irq_enter(); \
> lockdep_hardirq_threaded(); \
> - WARN_ON(!in_irq());
> + WARN_ON(!in_hardirq());
>
> #define HARDIRQ_EXIT() \
> __irq_exit(); \
> @@ -2456,7 +2456,7 @@ static void hardirq_exit(int *_)
> int notthreaded_hardirq_guard_##name __guard(hardirq_exit); \
> local_irq_disable(); \
> __irq_enter(); \
> - WARN_ON(!in_irq());
> + WARN_ON(!in_hardirq());
>
> static void softirq_exit(int *_)
> {
> diff --git a/lib/vsprintf.c b/lib/vsprintf.c
> index 26c83943748a..2c5b4351330c 100644
> --- a/lib/vsprintf.c
> +++ b/lib/vsprintf.c
> @@ -865,7 +865,7 @@ char *restricted_pointer(char *buf, char *end, const void *ptr,
> * kptr_restrict==1 cannot be used in IRQ context
> * because its test for CAP_SYSLOG would be meaningless.
> */
> - if (in_irq() || in_serving_softirq() || in_nmi()) {
> + if (in_hardirq() || in_serving_softirq() || in_nmi()) {
> if (spec.field_width == -1)
> spec.field_width = 2 * sizeof(ptr);
> return error_string(buf, end, "pK-error", spec);
> --
> 2.30.2
>