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                       struct trace_event *event)
 248 {
 249         struct trace_seq *s = &iter->seq;
 250         struct kmemtrace_alloc_entry *entry;
 251         int ret;
 252
 253         trace_assign_type(entry, iter->ent);
 254
 255         ret = trace_seq_printf(s, "type_id %d call_site %pF ptr %lu "
 256             "bytes_req %lu bytes_alloc %lu gfp_flags %lu node %d\n",
 257             entry->type_id, (void *)entry->call_site, (unsigned long)entry->ptr,
 258             (unsigned long)entry->bytes_req, (unsigned long)entry->bytes_alloc,
 259             (unsigned long)entry->gfp_flags, entry->node);
 260
 261         if (!ret)
 262                 return TRACE_TYPE_PARTIAL_LINE;
 263         return TRACE_TYPE_HANDLED;
 264 }
 265
 266 static enum print_line_t
 267 kmemtrace_print_free(struct trace_iterator *iter, int flags,
 268                      struct trace_event *event)
 269 {
 270         struct trace_seq *s = &iter->seq;
 271         struct kmemtrace_free_entry *entry;
 272         int ret;
 273
 274         trace_assign_type(entry, iter->ent);
 275
 276         ret = trace_seq_printf(s, "type_id %d call_site %pF ptr %lu\n",
 277                                entry->type_id, (void *)entry->call_site,
 278                                (unsigned long)entry->ptr);
 279
 280         if (!ret)
 281                 return TRACE_TYPE_PARTIAL_LINE;
 282         return TRACE_TYPE_HANDLED;
 283 }
 284
 285 static enum print_line_t
 286 kmemtrace_print_alloc_user(struct trace_iterator *iter, int flags,
 287                            struct trace_event *event)
 288 {
 289         struct trace_seq *s = &iter->seq;
 290         struct kmemtrace_alloc_entry *entry;
 291         struct kmemtrace_user_event *ev;
 292         struct kmemtrace_user_event_alloc *ev_alloc;
 293
 294         trace_assign_type(entry, iter->ent);
 295
 296         ev = trace_seq_reserve(s, sizeof(*ev));
 297         if (!ev)
 298                 return TRACE_TYPE_PARTIAL_LINE;
 299
 300         ev->event_id            = KMEMTRACE_USER_ALLOC;
 301         ev->type_id             = entry->type_id;
 302         ev->event_size          = sizeof(*ev) + sizeof(*ev_alloc);
 303         ev->cpu                 = iter->cpu;
 304         ev->timestamp           = iter->ts;
 305         ev->call_site           = entry->call_site;
 306         ev->ptr                 = (unsigned long)entry->ptr;
 307
 308         ev_alloc = trace_seq_reserve(s, sizeof(*ev_alloc));
 309         if (!ev_alloc)
 310                 return TRACE_TYPE_PARTIAL_LINE;
 311
 312         ev_alloc->bytes_req     = entry->bytes_req;
 313         ev_alloc->bytes_alloc   = entry->bytes_alloc;
 314         ev_alloc->gfp_flags     = entry->gfp_flags;
 315         ev_alloc->node          = entry->node;
 316
 317         return TRACE_TYPE_HANDLED;
 318 }
 319
 320 static enum print_line_t
 321 kmemtrace_print_free_user(struct trace_iterator *iter, int flags,
 322                           struct trace_event *event)
 323 {
 324         struct trace_seq *s = &iter->seq;
 325         struct kmemtrace_free_entry *entry;
 326         struct kmemtrace_user_event *ev;
 327
 328         trace_assign_type(entry, iter->ent);
 329
 330         ev = trace_seq_reserve(s, sizeof(*ev));
 331         if (!ev)
 332                 return TRACE_TYPE_PARTIAL_LINE;
 333
 334         ev->event_id            = KMEMTRACE_USER_FREE;
 335         ev->type_id             = entry->type_id;
 336         ev->event_size          = sizeof(*ev);
 337         ev->cpu                 = iter->cpu;
 338         ev->timestamp           = iter->ts;
 339         ev->call_site           = entry->call_site;
 340         ev->ptr                 = (unsigned long)entry->ptr;
 341
 342         return TRACE_TYPE_HANDLED;
 343 }
 344
 345 /* The two other following provide a more minimalistic output */
 346 static enum print_line_t
 347 kmemtrace_print_alloc_compress(struct trace_iterator *iter)
 348 {
 349         struct kmemtrace_alloc_entry *entry;
 350         struct trace_seq *s = &iter->seq;
 351         int ret;
 352
 353         trace_assign_type(entry, iter->ent);
 354
 355         /* Alloc entry */
 356         ret = trace_seq_printf(s, "  +      ");
 357         if (!ret)
 358                 return TRACE_TYPE_PARTIAL_LINE;
 359
 360         /* Type */
 361         switch (entry->type_id) {
 362         case KMEMTRACE_TYPE_KMALLOC:
 363                 ret = trace_seq_printf(s, "K   ");
 364                 break;
 365         case KMEMTRACE_TYPE_CACHE:
 366                 ret = trace_seq_printf(s, "C   ");
 367                 break;
 368         case KMEMTRACE_TYPE_PAGES:
 369                 ret = trace_seq_printf(s, "P   ");
 370                 break;
 371         default:
 372                 ret = trace_seq_printf(s, "?   ");
 373         }
 374
 375         if (!ret)
 376                 return TRACE_TYPE_PARTIAL_LINE;
 377
 378         /* Requested */
 379         ret = trace_seq_printf(s, "%4zu   ", entry->bytes_req);
 380         if (!ret)
 381                 return TRACE_TYPE_PARTIAL_LINE;
 382
 383         /* Allocated */
 384         ret = trace_seq_printf(s, "%4zu   ", entry->bytes_alloc);
 385         if (!ret)
 386                 return TRACE_TYPE_PARTIAL_LINE;
 387
 388         /* Flags
 389          * TODO: would be better to see the name of the GFP flag names
 390          */
 391         ret = trace_seq_printf(s, "%08x   ", entry->gfp_flags);
 392         if (!ret)
 393                 return TRACE_TYPE_PARTIAL_LINE;
 394
 395         /* Pointer to allocated */
 396         ret = trace_seq_printf(s, "0x%tx   ", (ptrdiff_t)entry->ptr);
 397         if (!ret)
 398                 return TRACE_TYPE_PARTIAL_LINE;
 399
 400         /* Node and call site*/
 401         ret = trace_seq_printf(s, "%4d   %pf\n", entry->node,
 402                                                  (void *)entry->call_site);
 403         if (!ret)
 404                 return TRACE_TYPE_PARTIAL_LINE;
 405
 406         return TRACE_TYPE_HANDLED;
 407 }
 408
 409 static enum print_line_t
 410 kmemtrace_print_free_compress(struct trace_iterator *iter)
 411 {
 412         struct kmemtrace_free_entry *entry;
 413         struct trace_seq *s = &iter->seq;
 414         int ret;
 415
 416         trace_assign_type(entry, iter->ent);
 417
 418         /* Free entry */
 419         ret = trace_seq_printf(s, "  -      ");
 420         if (!ret)
 421                 return TRACE_TYPE_PARTIAL_LINE;
 422
 423         /* Type */
 424         switch (entry->type_id) {
 425         case KMEMTRACE_TYPE_KMALLOC:
 426                 ret = trace_seq_printf(s, "K     ");
 427                 break;
 428         case KMEMTRACE_TYPE_CACHE:
 429                 ret = trace_seq_printf(s, "C     ");
 430                 break;
 431         case KMEMTRACE_TYPE_PAGES:
 432                 ret = trace_seq_printf(s, "P     ");
 433                 break;
 434         default:
 435                 ret = trace_seq_printf(s, "?     ");
 436         }
 437
 438         if (!ret)
 439                 return TRACE_TYPE_PARTIAL_LINE;
 440
 441         /* Skip requested/allocated/flags */
 442         ret = trace_seq_printf(s, "                       ");
 443         if (!ret)
 444                 return TRACE_TYPE_PARTIAL_LINE;
 445
 446         /* Pointer to allocated */
 447         ret = trace_seq_printf(s, "0x%tx   ", (ptrdiff_t)entry->ptr);
 448         if (!ret)
 449                 return TRACE_TYPE_PARTIAL_LINE;
 450
 451         /* Skip node and print call site*/
 452         ret = trace_seq_printf(s, "       %pf\n", (void *)entry->call_site);
 453         if (!ret)
 454                 return TRACE_TYPE_PARTIAL_LINE;
 455
 456         return TRACE_TYPE_HANDLED;
 457 }
 458
 459 static enum print_line_t kmemtrace_print_line(struct trace_iterator *iter)
 460 {
 461         struct trace_entry *entry = iter->ent;
 462
 463         if (!(kmem_tracer_flags.val & TRACE_KMEM_OPT_MINIMAL))
 464                 return TRACE_TYPE_UNHANDLED;
 465
 466         switch (entry->type) {
 467         case TRACE_KMEM_ALLOC:
 468                 return kmemtrace_print_alloc_compress(iter);
 469         case TRACE_KMEM_FREE:
 470                 return kmemtrace_print_free_compress(iter);
 471         default:
 472                 return TRACE_TYPE_UNHANDLED;
 473         }
 474 }
 475
 476 static struct trace_event_functions kmem_trace_alloc_funcs = {
 477         .trace                  = kmemtrace_print_alloc,
 478         .binary                 = kmemtrace_print_alloc_user,
 479 };
 480
 481 static struct trace_event kmem_trace_alloc = {
 482         .type                   = TRACE_KMEM_ALLOC,
 483         .funcs                  = &kmem_trace_alloc_funcs,
 484 };
 485
 486 static struct trace_event_functions kmem_trace_free_funcs = {
 487         .trace                  = kmemtrace_print_free,
 488         .binary                 = kmemtrace_print_free_user,
 489 };
 490
 491 static struct trace_event kmem_trace_free = {
 492         .type                   = TRACE_KMEM_FREE,
 493         .funcs                  = &kmem_trace_free_funcs,
 494 };
 495
 496 static struct tracer kmem_tracer __read_mostly = {
 497         .name                   = "kmemtrace",
 498         .init                   = kmem_trace_init,
 499         .reset                  = kmem_trace_reset,
 500         .print_line             = kmemtrace_print_line,
 501         .print_header           = kmemtrace_headers,
 502         .flags                  = &kmem_tracer_flags
 503 };
 504
 505 void kmemtrace_init(void)
 506 {
 507         /* earliest opportunity to start kmem tracing */
 508 }
 509
 510 static int __init init_kmem_tracer(void)
 511 {
 512         if (!register_ftrace_event(&kmem_trace_alloc)) {
 513                 pr_warning("Warning: could not register kmem events\n");
 514                 return 1;
 515         }
 516
 517         if (!register_ftrace_event(&kmem_trace_free)) {
 518                 pr_warning("Warning: could not register kmem events\n");
 519                 return 1;
 520         }
 521
 522         if (register_tracer(&kmem_tracer) != 0) {
 523                 pr_warning("Warning: could not register the kmem tracer\n");
 524                 return 1;
 525         }
 526
 527         return 0;
 528 }
 529 device_initcall(init_kmem_tracer);