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- /*
- * 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 <pzijlstr@redhat.com>
- *
- * Code for /proc/lockdep and /proc/lockdep_stats:
- *
- */
- #include <linux/module.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 <asm/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[128];
- 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", class->ops);
- #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,
- };
- static int lockdep_open(struct inode *inode, struct file *file)
- {
- return seq_open(file, &lockdep_ops);
- }
- static const struct file_operations proc_lockdep_operations = {
- .open = lockdep_open,
- .read = seq_read,
- .llseek = seq_lseek,
- .release = seq_release,
- };
- #ifdef CONFIG_PROVE_LOCKING
- static void *lc_start(struct seq_file *m, loff_t *pos)
- {
- if (*pos == 0)
- return SEQ_START_TOKEN;
- if (*pos - 1 < nr_lock_chains)
- return lock_chains + (*pos - 1);
- return NULL;
- }
- static void *lc_next(struct seq_file *m, void *v, loff_t *pos)
- {
- (*pos)++;
- 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) {
- 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,
- };
- static int lockdep_chains_open(struct inode *inode, struct file *file)
- {
- return seq_open(file, &lockdep_chains_ops);
- }
- static const struct file_operations proc_lockdep_chains_operations = {
- .open = lockdep_chains_open,
- .read = seq_read,
- .llseek = seq_lseek,
- .release = seq_release,
- };
- #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, " 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)
- {
- struct lock_class *class;
- 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;
- 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++;
- #ifdef CONFIG_PROVE_LOCKING
- sum_forward_deps += lockdep_count_forward_deps(class);
- #endif
- }
- #ifdef CONFIG_DEBUG_LOCKDEP
- DEBUG_LOCKS_WARN_ON(debug_atomic_read(nr_unused_locks) != nr_unused);
- #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",
- nr_lock_chains, 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;
- }
- static int lockdep_stats_open(struct inode *inode, struct file *file)
- {
- return single_open(file, lockdep_stats_show, NULL);
- }
- static const struct file_operations proc_lockdep_stats_operations = {
- .open = lockdep_stats_open,
- .read = seq_read,
- .llseek = seq_lseek,
- .release = single_release,
- };
- #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);
- }
- static void seq_stats(struct seq_file *m, struct lock_stat_data *data)
- {
- char name[39];
- struct lock_class *class;
- struct lock_class_stats *stats;
- int i, namelen;
- class = data->class;
- stats = &data->stats;
- namelen = 38;
- if (class->name_version > 1)
- namelen -= 2; /* XXX truncates versions > 9 */
- if (class->subclass)
- namelen -= 2;
- if (!class->name) {
- char str[KSYM_NAME_LEN];
- const char *key_name;
- key_name = __get_key_name(class->key, str);
- snprintf(name, namelen, "%s", key_name);
- } else {
- snprintf(name, namelen, "%s", class->name);
- }
- 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]);
- seq_printf(m, "%40s %14lu %29s %pS\n",
- name, stats->contending_point[i],
- ip, (void *)class->contending_point[i]);
- }
- if (i) {
- seq_puts(m, "\n");
- seq_line(m, '.', 0, 40 + 1 + 10 * (14 + 1));
- seq_puts(m, "\n");
- }
- }
- static void seq_header(struct seq_file *m)
- {
- seq_printf(m, "lock_stat version 0.3\n");
- if (unlikely(!debug_locks))
- seq_printf(m, "*WARNING* lock debugging disabled!! - possibly due to a lockdep warning\n");
- seq_line(m, '-', 0, 40 + 1 + 10 * (14 + 1));
- seq_printf(m, "%40s %14s %14s %14s %14s %14s %14s %14s %14s "
- "%14s %14s\n",
- "class name",
- "con-bounces",
- "contentions",
- "waittime-min",
- "waittime-max",
- "waittime-total",
- "acq-bounces",
- "acquisitions",
- "holdtime-min",
- "holdtime-max",
- "holdtime-total");
- seq_line(m, '-', 0, 40 + 1 + 10 * (14 + 1));
- seq_printf(m, "\n");
- }
- static void *ls_start(struct seq_file *m, loff_t *pos)
- {
- struct lock_stat_seq *data = m->private;
- struct lock_stat_data *iter;
- if (*pos == 0)
- return SEQ_START_TOKEN;
- iter = data->stats + (*pos - 1);
- if (iter >= data->iter_end)
- iter = NULL;
- return iter;
- }
- static void *ls_next(struct seq_file *m, void *v, loff_t *pos)
- {
- (*pos)++;
- return ls_start(m, pos);
- }
- static void ls_stop(struct seq_file *m, void *v)
- {
- }
- static int ls_show(struct seq_file *m, void *v)
- {
- if (v == SEQ_START_TOKEN)
- seq_header(m);
- else
- seq_stats(m, v);
- return 0;
- }
- static const struct seq_operations lockstat_ops = {
- .start = ls_start,
- .next = ls_next,
- .stop = ls_stop,
- .show = ls_show,
- };
- static int lock_stat_open(struct inode *inode, struct file *file)
- {
- int res;
- struct lock_class *class;
- struct lock_stat_seq *data = vmalloc(sizeof(struct lock_stat_seq));
- if (!data)
- return -ENOMEM;
- res = seq_open(file, &lockstat_ops);
- if (!res) {
- struct lock_stat_data *iter = data->stats;
- struct seq_file *m = file->private_data;
- list_for_each_entry(class, &all_lock_classes, lock_entry) {
- iter->class = class;
- iter->stats = lock_stats(class);
- iter++;
- }
- data->iter_end = iter;
- sort(data->stats, data->iter_end - data->stats,
- sizeof(struct lock_stat_data),
- lock_stat_cmp, NULL);
- m->private = data;
- } else
- vfree(data);
- return res;
- }
- static ssize_t lock_stat_write(struct file *file, const char __user *buf,
- size_t count, loff_t *ppos)
- {
- struct lock_class *class;
- char c;
- if (count) {
- if (get_user(c, buf))
- return -EFAULT;
- if (c != '0')
- return count;
- list_for_each_entry(class, &all_lock_classes, lock_entry)
- clear_lock_stats(class);
- }
- return count;
- }
- static int lock_stat_release(struct inode *inode, struct file *file)
- {
- struct seq_file *seq = file->private_data;
- vfree(seq->private);
- return seq_release(inode, file);
- }
- static const struct file_operations proc_lock_stat_operations = {
- .open = lock_stat_open,
- .write = lock_stat_write,
- .read = seq_read,
- .llseek = seq_lseek,
- .release = lock_stat_release,
- };
- #endif /* CONFIG_LOCK_STAT */
- static int __init lockdep_proc_init(void)
- {
- proc_create("lockdep", S_IRUSR, NULL, &proc_lockdep_operations);
- #ifdef CONFIG_PROVE_LOCKING
- proc_create("lockdep_chains", S_IRUSR, NULL,
- &proc_lockdep_chains_operations);
- #endif
- proc_create("lockdep_stats", S_IRUSR, NULL,
- &proc_lockdep_stats_operations);
- #ifdef CONFIG_LOCK_STAT
- proc_create("lock_stat", S_IRUSR | S_IWUSR, NULL,
- &proc_lock_stat_operations);
- #endif
- return 0;
- }
- __initcall(lockdep_proc_init);
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