UBUNTU: [Config] CONFIG_SENSORS_IR35221=m

[mirror_ubuntu-artful-kernel.git] / kernel / locking / lockdep_proc.c

/*
 * 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", 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) {
                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,
};

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);
        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]);
                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 + 12 * (14 + 1));
                seq_puts(m, "\n");
        }
}

static void seq_header(struct seq_file *m)
{
        seq_puts(m, "lock_stat version 0.4\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 + 12 * (14 + 1));
        seq_printf(m, "%40s %14s %14s %14s %14s %14s %14s %14s %14s %14s %14s "
                        "%14s %14s\n",
                        "class name",
                        "con-bounces",
                        "contentions",
                        "waittime-min",
                        "waittime-max",
                        "waittime-total",
                        "waittime-avg",
                        "acq-bounces",
                        "acquisitions",
                        "holdtime-min",
                        "holdtime-max",
                        "holdtime-total",
                        "holdtime-avg");
        seq_line(m, '-', 0, 40 + 1 + 12 * (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);