kernel/trace/kmemtrace.c

   1 /*
   2  * Memory allocator tracing
   3  *
   4  * Copyright (C) 2008 Eduard - Gabriel Munteanu
   5  * Copyright (C) 2008 Pekka Enberg <penberg@cs.helsinki.fi>
   6  * Copyright (C) 2008 Frederic Weisbecker <fweisbec@gmail.com>
   7  */
   8
   9 #include <linux/tracepoint.h>
  10 #include <linux/seq_file.h>
  11 #include <linux/debugfs.h>
  12 #include <linux/dcache.h>
  13 #include <linux/fs.h>
  14
  15 #include <linux/kmemtrace.h>
  16
  17 #include "trace_output.h"
  18 #include "trace.h"
  19
  20 /* Select an alternative, minimalistic output than the original one */
  21 #define TRACE_KMEM_OPT_MINIMAL  0x1
  22
  23 static struct tracer_opt kmem_opts[] = {
  24         /* Default disable the minimalistic output */
  25         { TRACER_OPT(kmem_minimalistic, TRACE_KMEM_OPT_MINIMAL) },
  26         { }
  27 };
  28
  29 static struct tracer_flags kmem_tracer_flags = {
  30         .val                    = 0,
  31         .opts                   = kmem_opts
  32 };
  33
  34 static struct trace_array *kmemtrace_array;
  35
  36 /* Trace allocations */
  37 static inline void kmemtrace_alloc(enum kmemtrace_type_id type_id,
  38                                    unsigned long call_site,
  39                                    const void *ptr,
  40                                    size_t bytes_req,
  41                                    size_t bytes_alloc,
  42                                    gfp_t gfp_flags,
  43                                    int node)
  44 {
  45         struct ftrace_event_call *call = &event_kmem_alloc;
  46         struct trace_array *tr = kmemtrace_array;
  47         struct kmemtrace_alloc_entry *entry;
  48         struct ring_buffer_event *event;
  49
  50         event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry));
  51         if (!event)
  52                 return;
  53
  54         entry = ring_buffer_event_data(event);
  55         tracing_generic_entry_update(&entry->ent, 0, 0);
  56
  57         entry->ent.type         = TRACE_KMEM_ALLOC;
  58         entry->type_id          = type_id;
  59         entry->call_site        = call_site;
  60         entry->ptr              = ptr;
  61         entry->bytes_req        = bytes_req;
  62         entry->bytes_alloc      = bytes_alloc;
  63         entry->gfp_flags        = gfp_flags;
  64         entry->node             = node;
  65
  66         if (!filter_check_discard(call, entry, tr->buffer, event))
  67                 ring_buffer_unlock_commit(tr->buffer, event);
  68
  69         trace_wake_up();
  70 }
  71
  72 static inline void kmemtrace_free(enum kmemtrace_type_id type_id,
  73                                   unsigned long call_site,
  74                                   const void *ptr)
  75 {
  76         struct ftrace_event_call *call = &event_kmem_free;
  77         struct trace_array *tr = kmemtrace_array;
  78         struct kmemtrace_free_entry *entry;
  79         struct ring_buffer_event *event;
  80
  81         event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry));
  82         if (!event)
  83                 return;
  84         entry   = ring_buffer_event_data(event);
  85         tracing_generic_entry_update(&entry->ent, 0, 0);
  86
  87         entry->ent.type         = TRACE_KMEM_FREE;
  88         entry->type_id          = type_id;
  89         entry->call_site        = call_site;
  90         entry->ptr              = ptr;
  91
  92         if (!filter_check_discard(call, entry, tr->buffer, event))
  93                 ring_buffer_unlock_commit(tr->buffer, event);
  94
  95         trace_wake_up();
  96 }
  97
  98 static void kmemtrace_kmalloc(void *ignore,
  99                               unsigned long call_site,
 100                               const void *ptr,
 101                               size_t bytes_req,
 102                               size_t bytes_alloc,
 103                               gfp_t gfp_flags)
 104 {
 105         kmemtrace_alloc(KMEMTRACE_TYPE_KMALLOC, call_site, ptr,
 106                         bytes_req, bytes_alloc, gfp_flags, -1);
 107 }
 108
 109 static void kmemtrace_kmem_cache_alloc(void *ignore,
 110                                        unsigned long call_site,
 111                                        const void *ptr,
 112                                        size_t bytes_req,
 113                                        size_t bytes_alloc,
 114                                        gfp_t gfp_flags)
 115 {
 116         kmemtrace_alloc(KMEMTRACE_TYPE_CACHE, call_site, ptr,
 117                         bytes_req, bytes_alloc, gfp_flags, -1);
 118 }
 119
 120 static void kmemtrace_kmalloc_node(void *ignore,
 121                                    unsigned long call_site,
 122                                    const void *ptr,
 123                                    size_t bytes_req,
 124                                    size_t bytes_alloc,
 125                                    gfp_t gfp_flags,
 126                                    int node)
 127 {
 128         kmemtrace_alloc(KMEMTRACE_TYPE_KMALLOC, call_site, ptr,
 129                         bytes_req, bytes_alloc, gfp_flags, node);
 130 }
 131
 132 static void kmemtrace_kmem_cache_alloc_node(void *ignore,
 133                                             unsigned long call_site,
 134                                             const void *ptr,
 135                                             size_t bytes_req,
 136                                             size_t bytes_alloc,
 137                                             gfp_t gfp_flags,
 138                                             int node)
 139 {
 140         kmemtrace_alloc(KMEMTRACE_TYPE_CACHE, call_site, ptr,
 141                         bytes_req, bytes_alloc, gfp_flags, node);
 142 }
 143
 144 static void
 145 kmemtrace_kfree(void *ignore, unsigned long call_site, const void *ptr)
 146 {
 147         kmemtrace_free(KMEMTRACE_TYPE_KMALLOC, call_site, ptr);
 148 }
 149
 150 static void kmemtrace_kmem_cache_free(void *ignore,
 151                                       unsigned long call_site, const void *ptr)
 152 {
 153         kmemtrace_free(KMEMTRACE_TYPE_CACHE, call_site, ptr);
 154 }
 155
 156 static int kmemtrace_start_probes(void)
 157 {
 158         int err;
 159
 160         err = register_trace_kmalloc(kmemtrace_kmalloc, NULL);
 161         if (err)
 162                 return err;
 163         err = register_trace_kmem_cache_alloc(kmemtrace_kmem_cache_alloc, NULL);
 164         if (err)
 165                 return err;
 166         err = register_trace_kmalloc_node(kmemtrace_kmalloc_node, NULL);
 167         if (err)
 168                 return err;
 169         err = register_trace_kmem_cache_alloc_node(kmemtrace_kmem_cache_alloc_node, NULL);
 170         if (err)
 171                 return err;
 172         err = register_trace_kfree(kmemtrace_kfree, NULL);
 173         if (err)
 174                 return err;
 175         err = register_trace_kmem_cache_free(kmemtrace_kmem_cache_free, NULL);
 176
 177         return err;
 178 }
 179
 180 static void kmemtrace_stop_probes(void)
 181 {
 182         unregister_trace_kmalloc(kmemtrace_kmalloc, NULL);
 183         unregister_trace_kmem_cache_alloc(kmemtrace_kmem_cache_alloc, NULL);
 184         unregister_trace_kmalloc_node(kmemtrace_kmalloc_node, NULL);
 185         unregister_trace_kmem_cache_alloc_node(kmemtrace_kmem_cache_alloc_node, NULL);
 186         unregister_trace_kfree(kmemtrace_kfree, NULL);
 187         unregister_trace_kmem_cache_free(kmemtrace_kmem_cache_free, NULL);
 188 }
 189
 190 static int kmem_trace_init(struct trace_array *tr)
 191 {
 192         kmemtrace_array = tr;
 193
 194         tracing_reset_online_cpus(tr);
 195
 196         kmemtrace_start_probes();
 197
 198         return 0;
 199 }
 200
 201 static void kmem_trace_reset(struct trace_array *tr)
 202 {
 203         kmemtrace_stop_probes();
 204 }
 205
 206 static void kmemtrace_headers(struct seq_file *s)
 207 {
 208         /* Don't need headers for the original kmemtrace output */
 209         if (!(kmem_tracer_flags.val & TRACE_KMEM_OPT_MINIMAL))
 210                 return;
 211
 212         seq_printf(s, "#\n");
 213         seq_printf(s, "# ALLOC  TYPE  REQ   GIVEN  FLAGS     "
 214                         "      POINTER         NODE    CALLER\n");
 215         seq_printf(s, "# FREE   |      |     |       |       "
 216                         "       |   |            |        |\n");
 217         seq_printf(s, "# |\n\n");
 218 }
 219
 220 /*
 221  * The following functions give the original output from kmemtrace,
 222  * plus the origin CPU, since reordering occurs in-kernel now.
 223  */
 224
 225 #define KMEMTRACE_USER_ALLOC    0
 226 #define KMEMTRACE_USER_FREE     1
 227
 228 struct kmemtrace_user_event {
 229         u8                      event_id;
 230         u8                      type_id;
 231         u16                     event_size;
 232         u32                     cpu;
 233         u64                     timestamp;
 234         unsigned long           call_site;
 235         unsigned long           ptr;
 236 };
 237
 238 struct kmemtrace_user_event_alloc {
 239         size_t                  bytes_req;
 240         size_t                  bytes_alloc;
 241         unsigned                gfp_flags;
 242         int                     node;
 243 };
 244
 245 static enum print_line_t
 246 kmemtrace_print_alloc(struct trace_iterator *iter, int flags)
 247 {
 248         struct trace_seq *s = &iter->seq;
 249         struct kmemtrace_alloc_entry *entry;
 250         int ret;
 251
 252         trace_assign_type(entry, iter->ent);
 253
 254         ret = trace_seq_printf(s, "type_id %d call_site %pF ptr %lu "
 255             "bytes_req %lu bytes_alloc %lu gfp_flags %lu node %d\n",
 256             entry->type_id, (void *)entry->call_site, (unsigned long)entry->ptr,
 257             (unsigned long)entry->bytes_req, (unsigned long)entry->bytes_alloc,
 258             (unsigned long)entry->gfp_flags, entry->node);
 259
 260         if (!ret)
 261                 return TRACE_TYPE_PARTIAL_LINE;
 262         return TRACE_TYPE_HANDLED;
 263 }
 264
 265 static enum print_line_t
 266 kmemtrace_print_free(struct trace_iterator *iter, int flags)
 267 {
 268         struct trace_seq *s = &iter->seq;
 269         struct kmemtrace_free_entry *entry;
 270         int ret;
 271
 272         trace_assign_type(entry, iter->ent);
 273
 274         ret = trace_seq_printf(s, "type_id %d call_site %pF ptr %lu\n",
 275                                entry->type_id, (void *)entry->call_site,
 276                                (unsigned long)entry->ptr);
 277
 278         if (!ret)
 279                 return TRACE_TYPE_PARTIAL_LINE;
 280         return TRACE_TYPE_HANDLED;
 281 }
 282
 283 static enum print_line_t
 284 kmemtrace_print_alloc_user(struct trace_iterator *iter, int flags)
 285 {
 286         struct trace_seq *s = &iter->seq;
 287         struct kmemtrace_alloc_entry *entry;
 288         struct kmemtrace_user_event *ev;
 289         struct kmemtrace_user_event_alloc *ev_alloc;
 290
 291         trace_assign_type(entry, iter->ent);
 292
 293         ev = trace_seq_reserve(s, sizeof(*ev));
 294         if (!ev)
 295                 return TRACE_TYPE_PARTIAL_LINE;
 296
 297         ev->event_id            = KMEMTRACE_USER_ALLOC;
 298         ev->type_id             = entry->type_id;
 299         ev->event_size          = sizeof(*ev) + sizeof(*ev_alloc);
 300         ev->cpu                 = iter->cpu;
 301         ev->timestamp           = iter->ts;
 302         ev->call_site           = entry->call_site;
 303         ev->ptr                 = (unsigned long)entry->ptr;
 304
 305         ev_alloc = trace_seq_reserve(s, sizeof(*ev_alloc));
 306         if (!ev_alloc)
 307                 return TRACE_TYPE_PARTIAL_LINE;
 308
 309         ev_alloc->bytes_req     = entry->bytes_req;
 310         ev_alloc->bytes_alloc   = entry->bytes_alloc;
 311         ev_alloc->gfp_flags     = entry->gfp_flags;
 312         ev_alloc->node          = entry->node;
 313
 314         return TRACE_TYPE_HANDLED;
 315 }
 316
 317 static enum print_line_t
 318 kmemtrace_print_free_user(struct trace_iterator *iter, int flags)
 319 {
 320         struct trace_seq *s = &iter->seq;
 321         struct kmemtrace_free_entry *entry;
 322         struct kmemtrace_user_event *ev;
 323
 324         trace_assign_type(entry, iter->ent);
 325
 326         ev = trace_seq_reserve(s, sizeof(*ev));
 327         if (!ev)
 328                 return TRACE_TYPE_PARTIAL_LINE;
 329
 330         ev->event_id            = KMEMTRACE_USER_FREE;
 331         ev->type_id             = entry->type_id;
 332         ev->event_size          = sizeof(*ev);
 333         ev->cpu                 = iter->cpu;
 334         ev->timestamp           = iter->ts;
 335         ev->call_site           = entry->call_site;
 336         ev->ptr                 = (unsigned long)entry->ptr;
 337
 338         return TRACE_TYPE_HANDLED;
 339 }
 340
 341 /* The two other following provide a more minimalistic output */
 342 static enum print_line_t
 343 kmemtrace_print_alloc_compress(struct trace_iterator *iter)
 344 {
 345         struct kmemtrace_alloc_entry *entry;
 346         struct trace_seq *s = &iter->seq;
 347         int ret;
 348
 349         trace_assign_type(entry, iter->ent);
 350
 351         /* Alloc entry */
 352         ret = trace_seq_printf(s, "  +      ");
 353         if (!ret)
 354                 return TRACE_TYPE_PARTIAL_LINE;
 355
 356         /* Type */
 357         switch (entry->type_id) {
 358         case KMEMTRACE_TYPE_KMALLOC:
 359                 ret = trace_seq_printf(s, "K   ");
 360                 break;
 361         case KMEMTRACE_TYPE_CACHE:
 362                 ret = trace_seq_printf(s, "C   ");
 363                 break;
 364         case KMEMTRACE_TYPE_PAGES:
 365                 ret = trace_seq_printf(s, "P   ");
 366                 break;
 367         default:
 368                 ret = trace_seq_printf(s, "?   ");
 369         }
 370
 371         if (!ret)
 372                 return TRACE_TYPE_PARTIAL_LINE;
 373
 374         /* Requested */
 375         ret = trace_seq_printf(s, "%4zu   ", entry->bytes_req);
 376         if (!ret)
 377                 return TRACE_TYPE_PARTIAL_LINE;
 378
 379         /* Allocated */
 380         ret = trace_seq_printf(s, "%4zu   ", entry->bytes_alloc);
 381         if (!ret)
 382                 return TRACE_TYPE_PARTIAL_LINE;
 383
 384         /* Flags
 385          * TODO: would be better to see the name of the GFP flag names
 386          */
 387         ret = trace_seq_printf(s, "%08x   ", entry->gfp_flags);
 388         if (!ret)
 389                 return TRACE_TYPE_PARTIAL_LINE;
 390
 391         /* Pointer to allocated */
 392         ret = trace_seq_printf(s, "0x%tx   ", (ptrdiff_t)entry->ptr);
 393         if (!ret)
 394                 return TRACE_TYPE_PARTIAL_LINE;
 395
 396         /* Node and call site*/
 397         ret = trace_seq_printf(s, "%4d   %pf\n", entry->node,
 398                                                  (void *)entry->call_site);
 399         if (!ret)
 400                 return TRACE_TYPE_PARTIAL_LINE;
 401
 402         return TRACE_TYPE_HANDLED;
 403 }
 404
 405 static enum print_line_t
 406 kmemtrace_print_free_compress(struct trace_iterator *iter)
 407 {
 408         struct kmemtrace_free_entry *entry;
 409         struct trace_seq *s = &iter->seq;
 410         int ret;
 411
 412         trace_assign_type(entry, iter->ent);
 413
 414         /* Free entry */
 415         ret = trace_seq_printf(s, "  -      ");
 416         if (!ret)
 417                 return TRACE_TYPE_PARTIAL_LINE;
 418
 419         /* Type */
 420         switch (entry->type_id) {
 421         case KMEMTRACE_TYPE_KMALLOC:
 422                 ret = trace_seq_printf(s, "K     ");
 423                 break;
 424         case KMEMTRACE_TYPE_CACHE:
 425                 ret = trace_seq_printf(s, "C     ");
 426                 break;
 427         case KMEMTRACE_TYPE_PAGES:
 428                 ret = trace_seq_printf(s, "P     ");
 429                 break;
 430         default:
 431                 ret = trace_seq_printf(s, "?     ");
 432         }
 433
 434         if (!ret)
 435                 return TRACE_TYPE_PARTIAL_LINE;
 436
 437         /* Skip requested/allocated/flags */
 438         ret = trace_seq_printf(s, "                       ");
 439         if (!ret)
 440                 return TRACE_TYPE_PARTIAL_LINE;
 441
 442         /* Pointer to allocated */
 443         ret = trace_seq_printf(s, "0x%tx   ", (ptrdiff_t)entry->ptr);
 444         if (!ret)
 445                 return TRACE_TYPE_PARTIAL_LINE;
 446
 447         /* Skip node and print call site*/
 448         ret = trace_seq_printf(s, "       %pf\n", (void *)entry->call_site);
 449         if (!ret)
 450                 return TRACE_TYPE_PARTIAL_LINE;
 451
 452         return TRACE_TYPE_HANDLED;
 453 }
 454
 455 static enum print_line_t kmemtrace_print_line(struct trace_iterator *iter)
 456 {
 457         struct trace_entry *entry = iter->ent;
 458
 459         if (!(kmem_tracer_flags.val & TRACE_KMEM_OPT_MINIMAL))
 460                 return TRACE_TYPE_UNHANDLED;
 461
 462         switch (entry->type) {
 463         case TRACE_KMEM_ALLOC:
 464                 return kmemtrace_print_alloc_compress(iter);
 465         case TRACE_KMEM_FREE:
 466                 return kmemtrace_print_free_compress(iter);
 467         default:
 468                 return TRACE_TYPE_UNHANDLED;
 469         }
 470 }
 471
 472 static struct trace_event kmem_trace_alloc = {
 473         .type                   = TRACE_KMEM_ALLOC,
 474         .trace                  = kmemtrace_print_alloc,
 475         .binary                 = kmemtrace_print_alloc_user,
 476 };
 477
 478 static struct trace_event kmem_trace_free = {
 479         .type                   = TRACE_KMEM_FREE,
 480         .trace                  = kmemtrace_print_free,
 481         .binary                 = kmemtrace_print_free_user,
 482 };
 483
 484 static struct tracer kmem_tracer __read_mostly = {
 485         .name                   = "kmemtrace",
 486         .init                   = kmem_trace_init,
 487         .reset                  = kmem_trace_reset,
 488         .print_line             = kmemtrace_print_line,
 489         .print_header           = kmemtrace_headers,
 490         .flags                  = &kmem_tracer_flags
 491 };
 492
 493 void kmemtrace_init(void)
 494 {
 495         /* earliest opportunity to start kmem tracing */
 496 }
 497
 498 static int __init init_kmem_tracer(void)
 499 {
 500         if (!register_ftrace_event(&kmem_trace_alloc)) {
 501                 pr_warning("Warning: could not register kmem events\n");
 502                 return 1;
 503         }
 504
 505         if (!register_ftrace_event(&kmem_trace_free)) {
 506                 pr_warning("Warning: could not register kmem events\n");
 507                 return 1;
 508         }
 509
 510         if (register_tracer(&kmem_tracer) != 0) {
 511                 pr_warning("Warning: could not register the kmem tracer\n");
 512                 return 1;
 513         }
 514
 515         return 0;
 516 }
 517 device_initcall(init_kmem_tracer);