Commit 0584df9c authored by Marco Elver's avatar Marco Elver Committed by Ingo Molnar
Browse files

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: default avatarMarco Elver <elver@google.com>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200729110916.3920464-1-elver@google.com


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 859247d3

include/linux/irqflags.h

+13 −0
Original line number Diff line number Diff line
@@ -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);

include/linux/sched.h

+2 −9
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ 
#include <linux/mutex.h>

#include <linux/plist.h>

#include <linux/hrtimer.h>

#include <linux/irqflags.h>

#include <linux/seccomp.h>

#include <linux/nodemask.h>

#include <linux/rcupdate.h>
@@ -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;

kernel/fork.c

+5 −11
Original line number Diff line number Diff line
@@ -2035,16 +2035,10 @@ 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;

	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_enable_ip = _THIS_IP_;

	p->softirq_enable_event = 0;

	p->softirq_disable_ip = 0;

	p->softirq_disable_event = 0;

	p->softirq_context		= 0;

#endif

kernel/locking/lockdep.c

+30 −28
Original line number Diff line number Diff line
@@ -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 = &current->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 = &current->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 = &current->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 = &current->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?

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