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// SPDX-License-Identifier: GPL-2.0/* * kernel/lockdep_proc.c * * Runtime locking correctness validator * * Started by Ingo Molnar: * *  Copyright (C) 2006,2007 Red Hat, Inc., Ingo Molnar <mingo@redhat.com> *  Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra * * Code for /proc/lockdep and /proc/lockdep_stats: * */#include <linux/export.h>#include <linux/proc_fs.h>#include <linux/seq_file.h>#include <linux/kallsyms.h>#include <linux/debug_locks.h>#include <linux/vmalloc.h>#include <linux/sort.h>#include <linux/uaccess.h>#include <asm/div64.h> #include "lockdep_internals.h" static void *l_next(struct seq_file *m, void *v, loff_t *pos){	return seq_list_next(v, &all_lock_classes, pos);} static void *l_start(struct seq_file *m, loff_t *pos){	return seq_list_start_head(&all_lock_classes, *pos);} static void l_stop(struct seq_file *m, void *v){} static void print_name(struct seq_file *m, struct lock_class *class){	char str[KSYM_NAME_LEN];	const char *name = class->name; 	if (!name) {		name = __get_key_name(class->key, str);		seq_printf(m, "%s", name);	} else{		seq_printf(m, "%s", name);		if (class->name_version > 1)			seq_printf(m, "#%d", class->name_version);		if (class->subclass)			seq_printf(m, "/%d", class->subclass);	}} static int l_show(struct seq_file *m, void *v){	struct lock_class *class = list_entry(v, struct lock_class, lock_entry);	struct lock_list *entry;	char usage[LOCK_USAGE_CHARS]; 	if (v == &all_lock_classes) {		seq_printf(m, "all lock classes:\n");		return 0;	} 	seq_printf(m, "%p", class->key);#ifdef CONFIG_DEBUG_LOCKDEP	seq_printf(m, " OPS:%8ld", debug_class_ops_read(class));#endif#ifdef CONFIG_PROVE_LOCKING	seq_printf(m, " FD:%5ld", lockdep_count_forward_deps(class));	seq_printf(m, " BD:%5ld", lockdep_count_backward_deps(class));#endif 	get_usage_chars(class, usage);	seq_printf(m, " %s", usage); 	seq_printf(m, ": ");	print_name(m, class);	seq_puts(m, "\n"); 	list_for_each_entry(entry, &class->locks_after, entry) {		if (entry->distance == 1) {			seq_printf(m, " -> [%p] ", entry->class->key);			print_name(m, entry->class);			seq_puts(m, "\n");		}	}	seq_puts(m, "\n"); 	return 0;} static const struct seq_operations lockdep_ops = {	.start	= l_start,	.next	= l_next,	.stop	= l_stop,	.show	= l_show,}; #ifdef CONFIG_PROVE_LOCKINGstatic void *lc_start(struct seq_file *m, loff_t *pos){	if (*pos < 0)		return NULL; 	if (*pos == 0)		return SEQ_START_TOKEN; 	return lock_chains + (*pos - 1);} static void *lc_next(struct seq_file *m, void *v, loff_t *pos){	*pos = lockdep_next_lockchain(*pos - 1) + 1;	return lc_start(m, pos);} static void lc_stop(struct seq_file *m, void *v){} static int lc_show(struct seq_file *m, void *v){	struct lock_chain *chain = v;	struct lock_class *class;	int i; 	if (v == SEQ_START_TOKEN) {		if (nr_chain_hlocks > MAX_LOCKDEP_CHAIN_HLOCKS)			seq_printf(m, "(buggered) ");		seq_printf(m, "all lock chains:\n");		return 0;	} 	seq_printf(m, "irq_context: %d\n", chain->irq_context); 	for (i = 0; i < chain->depth; i++) {		class = lock_chain_get_class(chain, i);		if (!class->key)			continue; 		seq_printf(m, "[%p] ", class->key);		print_name(m, class);		seq_puts(m, "\n");	}	seq_puts(m, "\n"); 	return 0;} static const struct seq_operations lockdep_chains_ops = {	.start	= lc_start,	.next	= lc_next,	.stop	= lc_stop,	.show	= lc_show,};#endif /* CONFIG_PROVE_LOCKING */ static void lockdep_stats_debug_show(struct seq_file *m){#ifdef CONFIG_DEBUG_LOCKDEP	unsigned long long hi1 = debug_atomic_read(hardirqs_on_events),			   hi2 = debug_atomic_read(hardirqs_off_events),			   hr1 = debug_atomic_read(redundant_hardirqs_on),			   hr2 = debug_atomic_read(redundant_hardirqs_off),			   si1 = debug_atomic_read(softirqs_on_events),			   si2 = debug_atomic_read(softirqs_off_events),			   sr1 = debug_atomic_read(redundant_softirqs_on),			   sr2 = debug_atomic_read(redundant_softirqs_off); 	seq_printf(m, " chain lookup misses:           %11llu\n",		debug_atomic_read(chain_lookup_misses));	seq_printf(m, " chain lookup hits:             %11llu\n",		debug_atomic_read(chain_lookup_hits));	seq_printf(m, " cyclic checks:                 %11llu\n",		debug_atomic_read(nr_cyclic_checks));	seq_printf(m, " redundant checks:              %11llu\n",		debug_atomic_read(nr_redundant_checks));	seq_printf(m, " redundant links:               %11llu\n",		debug_atomic_read(nr_redundant));	seq_printf(m, " find-mask forwards checks:     %11llu\n",		debug_atomic_read(nr_find_usage_forwards_checks));	seq_printf(m, " find-mask backwards checks:    %11llu\n",		debug_atomic_read(nr_find_usage_backwards_checks)); 	seq_printf(m, " hardirq on events:             %11llu\n", hi1);	seq_printf(m, " hardirq off events:            %11llu\n", hi2);	seq_printf(m, " redundant hardirq ons:         %11llu\n", hr1);	seq_printf(m, " redundant hardirq offs:        %11llu\n", hr2);	seq_printf(m, " softirq on events:             %11llu\n", si1);	seq_printf(m, " softirq off events:            %11llu\n", si2);	seq_printf(m, " redundant softirq ons:         %11llu\n", sr1);	seq_printf(m, " redundant softirq offs:        %11llu\n", sr2);#endif} static int lockdep_stats_show(struct seq_file *m, void *v){	unsigned long nr_unused = 0, nr_uncategorized = 0,		      nr_irq_safe = 0, nr_irq_unsafe = 0,		      nr_softirq_safe = 0, nr_softirq_unsafe = 0,		      nr_hardirq_safe = 0, nr_hardirq_unsafe = 0,		      nr_irq_read_safe = 0, nr_irq_read_unsafe = 0,		      nr_softirq_read_safe = 0, nr_softirq_read_unsafe = 0,		      nr_hardirq_read_safe = 0, nr_hardirq_read_unsafe = 0,		      sum_forward_deps = 0; #ifdef CONFIG_PROVE_LOCKING	struct lock_class *class; 	list_for_each_entry(class, &all_lock_classes, lock_entry) { 		if (class->usage_mask == 0)			nr_unused++;		if (class->usage_mask == LOCKF_USED)			nr_uncategorized++;		if (class->usage_mask & LOCKF_USED_IN_IRQ)			nr_irq_safe++;		if (class->usage_mask & LOCKF_ENABLED_IRQ)			nr_irq_unsafe++;		if (class->usage_mask & LOCKF_USED_IN_SOFTIRQ)			nr_softirq_safe++;		if (class->usage_mask & LOCKF_ENABLED_SOFTIRQ)			nr_softirq_unsafe++;		if (class->usage_mask & LOCKF_USED_IN_HARDIRQ)			nr_hardirq_safe++;		if (class->usage_mask & LOCKF_ENABLED_HARDIRQ)			nr_hardirq_unsafe++;		if (class->usage_mask & LOCKF_USED_IN_IRQ_READ)			nr_irq_read_safe++;		if (class->usage_mask & LOCKF_ENABLED_IRQ_READ)			nr_irq_read_unsafe++;		if (class->usage_mask & LOCKF_USED_IN_SOFTIRQ_READ)			nr_softirq_read_safe++;		if (class->usage_mask & LOCKF_ENABLED_SOFTIRQ_READ)			nr_softirq_read_unsafe++;		if (class->usage_mask & LOCKF_USED_IN_HARDIRQ_READ)			nr_hardirq_read_safe++;		if (class->usage_mask & LOCKF_ENABLED_HARDIRQ_READ)			nr_hardirq_read_unsafe++; 		sum_forward_deps += lockdep_count_forward_deps(class);	}#ifdef CONFIG_DEBUG_LOCKDEP	DEBUG_LOCKS_WARN_ON(debug_atomic_read(nr_unused_locks) != nr_unused);#endif #endif	seq_printf(m, " lock-classes:                  %11lu [max: %lu]\n",			nr_lock_classes, MAX_LOCKDEP_KEYS);	seq_printf(m, " direct dependencies:           %11lu [max: %lu]\n",			nr_list_entries, MAX_LOCKDEP_ENTRIES);	seq_printf(m, " indirect dependencies:         %11lu\n",			sum_forward_deps); 	/*	 * Total number of dependencies:	 *	 * All irq-safe locks may nest inside irq-unsafe locks,	 * plus all the other known dependencies:	 */	seq_printf(m, " all direct dependencies:       %11lu\n",			nr_irq_unsafe * nr_irq_safe +			nr_hardirq_unsafe * nr_hardirq_safe +			nr_list_entries); #ifdef CONFIG_PROVE_LOCKING	seq_printf(m, " dependency chains:             %11lu [max: %lu]\n",			lock_chain_count(), MAX_LOCKDEP_CHAINS);	seq_printf(m, " dependency chain hlocks:       %11d [max: %lu]\n",			nr_chain_hlocks, MAX_LOCKDEP_CHAIN_HLOCKS);#endif #ifdef CONFIG_TRACE_IRQFLAGS	seq_printf(m, " in-hardirq chains:             %11u\n",			nr_hardirq_chains);	seq_printf(m, " in-softirq chains:             %11u\n",			nr_softirq_chains);#endif	seq_printf(m, " in-process chains:             %11u\n",			nr_process_chains);	seq_printf(m, " stack-trace entries:           %11lu [max: %lu]\n",			nr_stack_trace_entries, MAX_STACK_TRACE_ENTRIES);	seq_printf(m, " combined max dependencies:     %11u\n",			(nr_hardirq_chains + 1) *			(nr_softirq_chains + 1) *			(nr_process_chains + 1)	);	seq_printf(m, " hardirq-safe locks:            %11lu\n",			nr_hardirq_safe);	seq_printf(m, " hardirq-unsafe locks:          %11lu\n",			nr_hardirq_unsafe);	seq_printf(m, " softirq-safe locks:            %11lu\n",			nr_softirq_safe);	seq_printf(m, " softirq-unsafe locks:          %11lu\n",			nr_softirq_unsafe);	seq_printf(m, " irq-safe locks:                %11lu\n",			nr_irq_safe);	seq_printf(m, " irq-unsafe locks:              %11lu\n",			nr_irq_unsafe); 	seq_printf(m, " hardirq-read-safe locks:       %11lu\n",			nr_hardirq_read_safe);	seq_printf(m, " hardirq-read-unsafe locks:     %11lu\n",			nr_hardirq_read_unsafe);	seq_printf(m, " softirq-read-safe locks:       %11lu\n",			nr_softirq_read_safe);	seq_printf(m, " softirq-read-unsafe locks:     %11lu\n",			nr_softirq_read_unsafe);	seq_printf(m, " irq-read-safe locks:           %11lu\n",			nr_irq_read_safe);	seq_printf(m, " irq-read-unsafe locks:         %11lu\n",			nr_irq_read_unsafe); 	seq_printf(m, " uncategorized locks:           %11lu\n",			nr_uncategorized);	seq_printf(m, " unused locks:                  %11lu\n",			nr_unused);	seq_printf(m, " max locking depth:             %11u\n",			max_lockdep_depth);#ifdef CONFIG_PROVE_LOCKING	seq_printf(m, " max bfs queue depth:           %11u\n",			max_bfs_queue_depth);#endif	lockdep_stats_debug_show(m);	seq_printf(m, " debug_locks:                   %11u\n",			debug_locks); 	return 0;} #ifdef CONFIG_LOCK_STAT struct lock_stat_data {	struct lock_class *class;	struct lock_class_stats stats;}; struct lock_stat_seq {	struct lock_stat_data *iter_end;	struct lock_stat_data stats[MAX_LOCKDEP_KEYS];}; /* * sort on absolute number of contentions */static int lock_stat_cmp(const void *l, const void *r){	const struct lock_stat_data *dl = l, *dr = r;	unsigned long nl, nr; 	nl = dl->stats.read_waittime.nr + dl->stats.write_waittime.nr;	nr = dr->stats.read_waittime.nr + dr->stats.write_waittime.nr; 	return nr - nl;} static void seq_line(struct seq_file *m, char c, int offset, int length){	int i; 	for (i = 0; i < offset; i++)		seq_puts(m, " ");	for (i = 0; i < length; i++)		seq_printf(m, "%c", c);	seq_puts(m, "\n");} static void snprint_time(char *buf, size_t bufsiz, s64 nr){	s64 div;	s32 rem; 	nr += 5; /* for display rounding */	div = div_s64_rem(nr, 1000, &rem);	snprintf(buf, bufsiz, "%lld.%02d", (long long)div, (int)rem/10);} static void seq_time(struct seq_file *m, s64 time){	char num[15]; 	snprint_time(num, sizeof(num), time);	seq_printf(m, " %14s", num);} static void seq_lock_time(struct seq_file *m, struct lock_time *lt){	seq_printf(m, "%14lu", lt->nr);	seq_time(m, lt->min);	seq_time(m, lt->max);	seq_time(m, lt->total);	seq_time(m, lt->nr ? div_s64(lt->total, lt->nr) : 0);} static void seq_stats(struct seq_file *m, struct lock_stat_data *data){	struct lockdep_subclass_key *ckey;	struct lock_class_stats *stats;	struct lock_class *class;	const char *cname;	int i, namelen;	char name[39]; 	class = data->class;	stats = &data->stats; 	namelen = 38;	if (class->name_version > 1)		namelen -= 2; /* XXX truncates versions > 9 */	if (class->subclass)		namelen -= 2; 	rcu_read_lock_sched();	cname = rcu_dereference_sched(class->name);	ckey  = rcu_dereference_sched(class->key); 	if (!cname && !ckey) {		rcu_read_unlock_sched();		return; 	} else if (!cname) {		char str[KSYM_NAME_LEN];		const char *key_name; 		key_name = __get_key_name(ckey, str);		snprintf(name, namelen, "%s", key_name);	} else {		snprintf(name, namelen, "%s", cname);	}	rcu_read_unlock_sched(); 	namelen = strlen(name);	if (class->name_version > 1) {		snprintf(name+namelen, 3, "#%d", class->name_version);		namelen += 2;	}	if (class->subclass) {		snprintf(name+namelen, 3, "/%d", class->subclass);		namelen += 2;	} 	if (stats->write_holdtime.nr) {		if (stats->read_holdtime.nr)			seq_printf(m, "%38s-W:", name);		else			seq_printf(m, "%40s:", name); 		seq_printf(m, "%14lu ", stats->bounces[bounce_contended_write]);		seq_lock_time(m, &stats->write_waittime);		seq_printf(m, " %14lu ", stats->bounces[bounce_acquired_write]);		seq_lock_time(m, &stats->write_holdtime);		seq_puts(m, "\n");	} 	if (stats->read_holdtime.nr) {		seq_printf(m, "%38s-R:", name);		seq_printf(m, "%14lu ", stats->bounces[bounce_contended_read]);		seq_lock_time(m, &stats->read_waittime);		seq_printf(m, " %14lu ", stats->bounces[bounce_acquired_read]);		seq_lock_time(m, &stats->read_holdtime);		seq_puts(m, "\n");	} 	if (stats->read_waittime.nr + stats->write_waittime.nr == 0)		return; 	if (stats->read_holdtime.nr)		namelen += 2; 	for (i = 0; i < LOCKSTAT_POINTS; i++) {		char ip[32]; 		if (class->contention_point[i] == 0)			break; 		if (!i)			seq_line(m, '-', 40-namelen, namelen); 		snprintf(ip, sizeof(ip), "[<%p>]",				(void *)class->contention_point[i]);		seq_printf(m, "%40s %14lu %29s %pS\n",			   name, stats->contention_point[i],			   ip, (void *)class->contention_point[i]);	}	for (i = 0; i < LOCKSTAT_POINTS; i++) {		char ip[32]; 		if (class->contending_point[i] == 0)			break; 		if (!i)			seq_line(m, '-', 40-namelen, namelen); 		snprintf(ip, sizeof(ip), "[<%p>]",				(void *)class->contending_point[i]);

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