Ingo Molnar | a8f24a3 | 2006-07-03 00:24:52 -0700 | [diff] [blame] | 1 | /* |
| 2 | * kernel/lockdep_proc.c |
| 3 | * |
| 4 | * Runtime locking correctness validator |
| 5 | * |
| 6 | * Started by Ingo Molnar: |
| 7 | * |
| 8 | * Copyright (C) 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com> |
| 9 | * |
| 10 | * Code for /proc/lockdep and /proc/lockdep_stats: |
| 11 | * |
| 12 | */ |
| 13 | #include <linux/sched.h> |
| 14 | #include <linux/module.h> |
| 15 | #include <linux/proc_fs.h> |
| 16 | #include <linux/seq_file.h> |
| 17 | #include <linux/kallsyms.h> |
| 18 | #include <linux/debug_locks.h> |
| 19 | |
| 20 | #include "lockdep_internals.h" |
| 21 | |
| 22 | static void *l_next(struct seq_file *m, void *v, loff_t *pos) |
| 23 | { |
| 24 | struct lock_class *class = v; |
| 25 | |
| 26 | (*pos)++; |
| 27 | |
| 28 | if (class->lock_entry.next != &all_lock_classes) |
| 29 | class = list_entry(class->lock_entry.next, struct lock_class, |
| 30 | lock_entry); |
| 31 | else |
| 32 | class = NULL; |
| 33 | m->private = class; |
| 34 | |
| 35 | return class; |
| 36 | } |
| 37 | |
| 38 | static void *l_start(struct seq_file *m, loff_t *pos) |
| 39 | { |
| 40 | struct lock_class *class = m->private; |
| 41 | |
| 42 | if (&class->lock_entry == all_lock_classes.next) |
| 43 | seq_printf(m, "all lock classes:\n"); |
| 44 | |
| 45 | return class; |
| 46 | } |
| 47 | |
| 48 | static void l_stop(struct seq_file *m, void *v) |
| 49 | { |
| 50 | } |
| 51 | |
| 52 | static unsigned long count_forward_deps(struct lock_class *class) |
| 53 | { |
| 54 | struct lock_list *entry; |
| 55 | unsigned long ret = 1; |
| 56 | |
| 57 | /* |
| 58 | * Recurse this class's dependency list: |
| 59 | */ |
| 60 | list_for_each_entry(entry, &class->locks_after, entry) |
| 61 | ret += count_forward_deps(entry->class); |
| 62 | |
| 63 | return ret; |
| 64 | } |
| 65 | |
| 66 | static unsigned long count_backward_deps(struct lock_class *class) |
| 67 | { |
| 68 | struct lock_list *entry; |
| 69 | unsigned long ret = 1; |
| 70 | |
| 71 | /* |
| 72 | * Recurse this class's dependency list: |
| 73 | */ |
| 74 | list_for_each_entry(entry, &class->locks_before, entry) |
| 75 | ret += count_backward_deps(entry->class); |
| 76 | |
| 77 | return ret; |
| 78 | } |
| 79 | |
| 80 | static int l_show(struct seq_file *m, void *v) |
| 81 | { |
| 82 | unsigned long nr_forward_deps, nr_backward_deps; |
| 83 | struct lock_class *class = m->private; |
| 84 | char str[128], c1, c2, c3, c4; |
| 85 | const char *name; |
| 86 | |
| 87 | seq_printf(m, "%p", class->key); |
| 88 | #ifdef CONFIG_DEBUG_LOCKDEP |
| 89 | seq_printf(m, " OPS:%8ld", class->ops); |
| 90 | #endif |
| 91 | nr_forward_deps = count_forward_deps(class); |
| 92 | seq_printf(m, " FD:%5ld", nr_forward_deps); |
| 93 | |
| 94 | nr_backward_deps = count_backward_deps(class); |
| 95 | seq_printf(m, " BD:%5ld", nr_backward_deps); |
| 96 | |
| 97 | get_usage_chars(class, &c1, &c2, &c3, &c4); |
| 98 | seq_printf(m, " %c%c%c%c", c1, c2, c3, c4); |
| 99 | |
| 100 | name = class->name; |
| 101 | if (!name) { |
| 102 | name = __get_key_name(class->key, str); |
| 103 | seq_printf(m, ": %s", name); |
| 104 | } else{ |
| 105 | seq_printf(m, ": %s", name); |
| 106 | if (class->name_version > 1) |
| 107 | seq_printf(m, "#%d", class->name_version); |
| 108 | if (class->subclass) |
| 109 | seq_printf(m, "/%d", class->subclass); |
| 110 | } |
| 111 | seq_puts(m, "\n"); |
| 112 | |
| 113 | return 0; |
| 114 | } |
| 115 | |
| 116 | static struct seq_operations lockdep_ops = { |
| 117 | .start = l_start, |
| 118 | .next = l_next, |
| 119 | .stop = l_stop, |
| 120 | .show = l_show, |
| 121 | }; |
| 122 | |
| 123 | static int lockdep_open(struct inode *inode, struct file *file) |
| 124 | { |
| 125 | int res = seq_open(file, &lockdep_ops); |
| 126 | if (!res) { |
| 127 | struct seq_file *m = file->private_data; |
| 128 | |
| 129 | if (!list_empty(&all_lock_classes)) |
| 130 | m->private = list_entry(all_lock_classes.next, |
| 131 | struct lock_class, lock_entry); |
| 132 | else |
| 133 | m->private = NULL; |
| 134 | } |
| 135 | return res; |
| 136 | } |
| 137 | |
| 138 | static struct file_operations proc_lockdep_operations = { |
| 139 | .open = lockdep_open, |
| 140 | .read = seq_read, |
| 141 | .llseek = seq_lseek, |
| 142 | .release = seq_release, |
| 143 | }; |
| 144 | |
| 145 | static void lockdep_stats_debug_show(struct seq_file *m) |
| 146 | { |
| 147 | #ifdef CONFIG_DEBUG_LOCKDEP |
| 148 | unsigned int hi1 = debug_atomic_read(&hardirqs_on_events), |
| 149 | hi2 = debug_atomic_read(&hardirqs_off_events), |
| 150 | hr1 = debug_atomic_read(&redundant_hardirqs_on), |
| 151 | hr2 = debug_atomic_read(&redundant_hardirqs_off), |
| 152 | si1 = debug_atomic_read(&softirqs_on_events), |
| 153 | si2 = debug_atomic_read(&softirqs_off_events), |
| 154 | sr1 = debug_atomic_read(&redundant_softirqs_on), |
| 155 | sr2 = debug_atomic_read(&redundant_softirqs_off); |
| 156 | |
| 157 | seq_printf(m, " chain lookup misses: %11u\n", |
| 158 | debug_atomic_read(&chain_lookup_misses)); |
| 159 | seq_printf(m, " chain lookup hits: %11u\n", |
| 160 | debug_atomic_read(&chain_lookup_hits)); |
| 161 | seq_printf(m, " cyclic checks: %11u\n", |
| 162 | debug_atomic_read(&nr_cyclic_checks)); |
| 163 | seq_printf(m, " cyclic-check recursions: %11u\n", |
| 164 | debug_atomic_read(&nr_cyclic_check_recursions)); |
| 165 | seq_printf(m, " find-mask forwards checks: %11u\n", |
| 166 | debug_atomic_read(&nr_find_usage_forwards_checks)); |
| 167 | seq_printf(m, " find-mask forwards recursions: %11u\n", |
| 168 | debug_atomic_read(&nr_find_usage_forwards_recursions)); |
| 169 | seq_printf(m, " find-mask backwards checks: %11u\n", |
| 170 | debug_atomic_read(&nr_find_usage_backwards_checks)); |
| 171 | seq_printf(m, " find-mask backwards recursions:%11u\n", |
| 172 | debug_atomic_read(&nr_find_usage_backwards_recursions)); |
| 173 | |
| 174 | seq_printf(m, " hardirq on events: %11u\n", hi1); |
| 175 | seq_printf(m, " hardirq off events: %11u\n", hi2); |
| 176 | seq_printf(m, " redundant hardirq ons: %11u\n", hr1); |
| 177 | seq_printf(m, " redundant hardirq offs: %11u\n", hr2); |
| 178 | seq_printf(m, " softirq on events: %11u\n", si1); |
| 179 | seq_printf(m, " softirq off events: %11u\n", si2); |
| 180 | seq_printf(m, " redundant softirq ons: %11u\n", sr1); |
| 181 | seq_printf(m, " redundant softirq offs: %11u\n", sr2); |
| 182 | #endif |
| 183 | } |
| 184 | |
| 185 | static int lockdep_stats_show(struct seq_file *m, void *v) |
| 186 | { |
| 187 | struct lock_class *class; |
| 188 | unsigned long nr_unused = 0, nr_uncategorized = 0, |
| 189 | nr_irq_safe = 0, nr_irq_unsafe = 0, |
| 190 | nr_softirq_safe = 0, nr_softirq_unsafe = 0, |
| 191 | nr_hardirq_safe = 0, nr_hardirq_unsafe = 0, |
| 192 | nr_irq_read_safe = 0, nr_irq_read_unsafe = 0, |
| 193 | nr_softirq_read_safe = 0, nr_softirq_read_unsafe = 0, |
| 194 | nr_hardirq_read_safe = 0, nr_hardirq_read_unsafe = 0, |
| 195 | sum_forward_deps = 0, factor = 0; |
| 196 | |
| 197 | list_for_each_entry(class, &all_lock_classes, lock_entry) { |
| 198 | |
| 199 | if (class->usage_mask == 0) |
| 200 | nr_unused++; |
| 201 | if (class->usage_mask == LOCKF_USED) |
| 202 | nr_uncategorized++; |
| 203 | if (class->usage_mask & LOCKF_USED_IN_IRQ) |
| 204 | nr_irq_safe++; |
| 205 | if (class->usage_mask & LOCKF_ENABLED_IRQS) |
| 206 | nr_irq_unsafe++; |
| 207 | if (class->usage_mask & LOCKF_USED_IN_SOFTIRQ) |
| 208 | nr_softirq_safe++; |
| 209 | if (class->usage_mask & LOCKF_ENABLED_SOFTIRQS) |
| 210 | nr_softirq_unsafe++; |
| 211 | if (class->usage_mask & LOCKF_USED_IN_HARDIRQ) |
| 212 | nr_hardirq_safe++; |
| 213 | if (class->usage_mask & LOCKF_ENABLED_HARDIRQS) |
| 214 | nr_hardirq_unsafe++; |
| 215 | if (class->usage_mask & LOCKF_USED_IN_IRQ_READ) |
| 216 | nr_irq_read_safe++; |
| 217 | if (class->usage_mask & LOCKF_ENABLED_IRQS_READ) |
| 218 | nr_irq_read_unsafe++; |
| 219 | if (class->usage_mask & LOCKF_USED_IN_SOFTIRQ_READ) |
| 220 | nr_softirq_read_safe++; |
| 221 | if (class->usage_mask & LOCKF_ENABLED_SOFTIRQS_READ) |
| 222 | nr_softirq_read_unsafe++; |
| 223 | if (class->usage_mask & LOCKF_USED_IN_HARDIRQ_READ) |
| 224 | nr_hardirq_read_safe++; |
| 225 | if (class->usage_mask & LOCKF_ENABLED_HARDIRQS_READ) |
| 226 | nr_hardirq_read_unsafe++; |
| 227 | |
| 228 | sum_forward_deps += count_forward_deps(class); |
| 229 | } |
| 230 | #ifdef CONFIG_LOCKDEP_DEBUG |
| 231 | DEBUG_LOCKS_WARN_ON(debug_atomic_read(&nr_unused_locks) != nr_unused); |
| 232 | #endif |
| 233 | seq_printf(m, " lock-classes: %11lu [max: %lu]\n", |
| 234 | nr_lock_classes, MAX_LOCKDEP_KEYS); |
| 235 | seq_printf(m, " direct dependencies: %11lu [max: %lu]\n", |
| 236 | nr_list_entries, MAX_LOCKDEP_ENTRIES); |
| 237 | seq_printf(m, " indirect dependencies: %11lu\n", |
| 238 | sum_forward_deps); |
| 239 | |
| 240 | /* |
| 241 | * Total number of dependencies: |
| 242 | * |
| 243 | * All irq-safe locks may nest inside irq-unsafe locks, |
| 244 | * plus all the other known dependencies: |
| 245 | */ |
| 246 | seq_printf(m, " all direct dependencies: %11lu\n", |
| 247 | nr_irq_unsafe * nr_irq_safe + |
| 248 | nr_hardirq_unsafe * nr_hardirq_safe + |
| 249 | nr_list_entries); |
| 250 | |
| 251 | /* |
| 252 | * Estimated factor between direct and indirect |
| 253 | * dependencies: |
| 254 | */ |
| 255 | if (nr_list_entries) |
| 256 | factor = sum_forward_deps / nr_list_entries; |
| 257 | |
| 258 | seq_printf(m, " dependency chains: %11lu [max: %lu]\n", |
| 259 | nr_lock_chains, MAX_LOCKDEP_CHAINS); |
| 260 | |
| 261 | #ifdef CONFIG_TRACE_IRQFLAGS |
| 262 | seq_printf(m, " in-hardirq chains: %11u\n", |
| 263 | nr_hardirq_chains); |
| 264 | seq_printf(m, " in-softirq chains: %11u\n", |
| 265 | nr_softirq_chains); |
| 266 | #endif |
| 267 | seq_printf(m, " in-process chains: %11u\n", |
| 268 | nr_process_chains); |
| 269 | seq_printf(m, " stack-trace entries: %11lu [max: %lu]\n", |
| 270 | nr_stack_trace_entries, MAX_STACK_TRACE_ENTRIES); |
| 271 | seq_printf(m, " combined max dependencies: %11u\n", |
| 272 | (nr_hardirq_chains + 1) * |
| 273 | (nr_softirq_chains + 1) * |
| 274 | (nr_process_chains + 1) |
| 275 | ); |
| 276 | seq_printf(m, " hardirq-safe locks: %11lu\n", |
| 277 | nr_hardirq_safe); |
| 278 | seq_printf(m, " hardirq-unsafe locks: %11lu\n", |
| 279 | nr_hardirq_unsafe); |
| 280 | seq_printf(m, " softirq-safe locks: %11lu\n", |
| 281 | nr_softirq_safe); |
| 282 | seq_printf(m, " softirq-unsafe locks: %11lu\n", |
| 283 | nr_softirq_unsafe); |
| 284 | seq_printf(m, " irq-safe locks: %11lu\n", |
| 285 | nr_irq_safe); |
| 286 | seq_printf(m, " irq-unsafe locks: %11lu\n", |
| 287 | nr_irq_unsafe); |
| 288 | |
| 289 | seq_printf(m, " hardirq-read-safe locks: %11lu\n", |
| 290 | nr_hardirq_read_safe); |
| 291 | seq_printf(m, " hardirq-read-unsafe locks: %11lu\n", |
| 292 | nr_hardirq_read_unsafe); |
| 293 | seq_printf(m, " softirq-read-safe locks: %11lu\n", |
| 294 | nr_softirq_read_safe); |
| 295 | seq_printf(m, " softirq-read-unsafe locks: %11lu\n", |
| 296 | nr_softirq_read_unsafe); |
| 297 | seq_printf(m, " irq-read-safe locks: %11lu\n", |
| 298 | nr_irq_read_safe); |
| 299 | seq_printf(m, " irq-read-unsafe locks: %11lu\n", |
| 300 | nr_irq_read_unsafe); |
| 301 | |
| 302 | seq_printf(m, " uncategorized locks: %11lu\n", |
| 303 | nr_uncategorized); |
| 304 | seq_printf(m, " unused locks: %11lu\n", |
| 305 | nr_unused); |
| 306 | seq_printf(m, " max locking depth: %11u\n", |
| 307 | max_lockdep_depth); |
| 308 | seq_printf(m, " max recursion depth: %11u\n", |
| 309 | max_recursion_depth); |
| 310 | lockdep_stats_debug_show(m); |
| 311 | seq_printf(m, " debug_locks: %11u\n", |
| 312 | debug_locks); |
| 313 | |
| 314 | return 0; |
| 315 | } |
| 316 | |
| 317 | static int lockdep_stats_open(struct inode *inode, struct file *file) |
| 318 | { |
| 319 | return single_open(file, lockdep_stats_show, NULL); |
| 320 | } |
| 321 | |
| 322 | static struct file_operations proc_lockdep_stats_operations = { |
| 323 | .open = lockdep_stats_open, |
| 324 | .read = seq_read, |
| 325 | .llseek = seq_lseek, |
| 326 | .release = seq_release, |
| 327 | }; |
| 328 | |
| 329 | static int __init lockdep_proc_init(void) |
| 330 | { |
| 331 | struct proc_dir_entry *entry; |
| 332 | |
| 333 | entry = create_proc_entry("lockdep", S_IRUSR, NULL); |
| 334 | if (entry) |
| 335 | entry->proc_fops = &proc_lockdep_operations; |
| 336 | |
| 337 | entry = create_proc_entry("lockdep_stats", S_IRUSR, NULL); |
| 338 | if (entry) |
| 339 | entry->proc_fops = &proc_lockdep_stats_operations; |
| 340 | |
| 341 | return 0; |
| 342 | } |
| 343 | |
| 344 | __initcall(lockdep_proc_init); |
| 345 | |