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(unsigned long call_site,
  99                               const void *ptr,
 100                               size_t bytes_req,
 101                               size_t bytes_alloc,
 102                               gfp_t gfp_flags)
 103 {
 104         kmemtrace_alloc(KMEMTRACE_TYPE_KMALLOC, call_site, ptr,
 105                         bytes_req, bytes_alloc, gfp_flags, -1);
 106 }
 107
 108 static void kmemtrace_kmem_cache_alloc(unsigned long call_site,
 109                                        const void *ptr,
 110                                        size_t bytes_req,
 111                                        size_t bytes_alloc,
 112                                        gfp_t gfp_flags)
 113 {
 114         kmemtrace_alloc(KMEMTRACE_TYPE_CACHE, call_site, ptr,
 115                         bytes_req, bytes_alloc, gfp_flags, -1);
 116 }
 117
 118 static void kmemtrace_kmalloc_node(unsigned long call_site,
 119                                    const void *ptr,
 120                                    size_t bytes_req,
 121                                    size_t bytes_alloc,
 122                                    gfp_t gfp_flags,
 123                                    int node)
 124 {
 125         kmemtrace_alloc(KMEMTRACE_TYPE_KMALLOC, call_site, ptr,
 126                         bytes_req, bytes_alloc, gfp_flags, node);
 127 }
 128
 129 static void kmemtrace_kmem_cache_alloc_node(unsigned long call_site,
 130                                             const void *ptr,
 131                                             size_t bytes_req,
 132                                             size_t bytes_alloc,
 133                                             gfp_t gfp_flags,
 134                                             int node)
 135 {
 136         kmemtrace_alloc(KMEMTRACE_TYPE_CACHE, call_site, ptr,
 137                         bytes_req, bytes_alloc, gfp_flags, node);
 138 }
 139
 140 static void kmemtrace_kfree(unsigned long call_site, const void *ptr)
 141 {
 142         kmemtrace_free(KMEMTRACE_TYPE_KMALLOC, call_site, ptr);
 143 }
 144
 145 static void kmemtrace_kmem_cache_free(unsigned long call_site, const void *ptr)
 146 {
 147         kmemtrace_free(KMEMTRACE_TYPE_CACHE, call_site, ptr);
 148 }
 149
 150 static int kmemtrace_start_probes(void)
 151 {
 152         int err;
 153
 154         err = register_trace_kmalloc(kmemtrace_kmalloc);
 155         if (err)
 156                 return err;
 157         err = register_trace_kmem_cache_alloc(kmemtrace_kmem_cache_alloc);
 158         if (err)
 159                 return err;
 160         err = register_trace_kmalloc_node(kmemtrace_kmalloc_node);
 161         if (err)
 162                 return err;
 163         err = register_trace_kmem_cache_alloc_node(kmemtrace_kmem_cache_alloc_node);
 164         if (err)
 165                 return err;
 166         err = register_trace_kfree(kmemtrace_kfree);
 167         if (err)
 168                 return err;
 169         err = register_trace_kmem_cache_free(kmemtrace_kmem_cache_free);
 170
 171         return err;
 172 }
 173
 174 static void kmemtrace_stop_probes(void)
 175 {
 176         unregister_trace_kmalloc(kmemtrace_kmalloc);
 177         unregister_trace_kmem_cache_alloc(kmemtrace_kmem_cache_alloc);
 178         unregister_trace_kmalloc_node(kmemtrace_kmalloc_node);
 179         unregister_trace_kmem_cache_alloc_node(kmemtrace_kmem_cache_alloc_node);
 180         unregister_trace_kfree(kmemtrace_kfree);
 181         unregister_trace_kmem_cache_free(kmemtrace_kmem_cache_free);
 182 }
 183
 184 static int kmem_trace_init(struct trace_array *tr)
 185 {
 186         kmemtrace_array = tr;
 187
 188         tracing_reset_online_cpus(tr);
 189
 190         kmemtrace_start_probes();
 191
 192         return 0;
 193 }
 194
 195 static void kmem_trace_reset(struct trace_array *tr)
 196 {
 197         kmemtrace_stop_probes();
 198 }
 199
 200 static void kmemtrace_headers(struct seq_file *s)
 201 {
 202         /* Don't need headers for the original kmemtrace output */
 203         if (!(kmem_tracer_flags.val & TRACE_KMEM_OPT_MINIMAL))
 204                 return;
 205
 206         seq_printf(s, "#\n");
 207         seq_printf(s, "# ALLOC  TYPE  REQ   GIVEN  FLAGS     "
 208                         "      POINTER         NODE    CALLER\n");
 209         seq_printf(s, "# FREE   |      |     |       |       "
 210                         "       |   |            |        |\n");
 211         seq_printf(s, "# |\n\n");
 212 }
 213
 214 /*
 215  * The following functions give the original output from kmemtrace,
 216  * plus the origin CPU, since reordering occurs in-kernel now.
 217  */
 218
 219 #define KMEMTRACE_USER_ALLOC    0
 220 #define KMEMTRACE_USER_FREE     1
 221
 222 struct kmemtrace_user_event {
 223         u8                      event_id;
 224         u8                      type_id;
 225         u16                     event_size;
 226         u32                     cpu;
 227         u64                     timestamp;
 228         unsigned long           call_site;
 229         unsigned long           ptr;
 230 };
 231
 232 struct kmemtrace_user_event_alloc {
 233         size_t                  bytes_req;
 234         size_t                  bytes_alloc;
 235         unsigned                gfp_flags;
 236         int                     node;
 237 };
 238
 239 static enum print_line_t
 240 kmemtrace_print_alloc(struct trace_iterator *iter, int flags)
 241 {
 242         struct trace_seq *s = &iter->seq;
 243         struct kmemtrace_alloc_entry *entry;
 244         int ret;
 245
 246         trace_assign_type(entry, iter->ent);
 247
 248         ret = trace_seq_printf(s, "type_id %d call_site %pF ptr %lu "
 249             "bytes_req %lu bytes_alloc %lu gfp_flags %lu node %d\n",
 250             entry->type_id, (void *)entry->call_site, (unsigned long)entry->ptr,
 251             (unsigned long)entry->bytes_req, (unsigned long)entry->bytes_alloc,
 252             (unsigned long)entry->gfp_flags, entry->node);
 253
 254         if (!ret)
 255                 return TRACE_TYPE_PARTIAL_LINE;
 256         return TRACE_TYPE_HANDLED;
 257 }
 258
 259 static enum print_line_t
 260 kmemtrace_print_free(struct trace_iterator *iter, int flags)
 261 {
 262         struct trace_seq *s = &iter->seq;
 263         struct kmemtrace_free_entry *entry;
 264         int ret;
 265
 266         trace_assign_type(entry, iter->ent);
 267
 268         ret = trace_seq_printf(s, "type_id %d call_site %pF ptr %lu\n",
 269                                entry->type_id, (void *)entry->call_site,
 270                                (unsigned long)entry->ptr);
 271
 272         if (!ret)
 273                 return TRACE_TYPE_PARTIAL_LINE;
 274         return TRACE_TYPE_HANDLED;
 275 }
 276
 277 static enum print_line_t
 278 kmemtrace_print_alloc_user(struct trace_iterator *iter, int flags)
 279 {
 280         struct trace_seq *s = &iter->seq;
 281         struct kmemtrace_alloc_entry *entry;
 282         struct kmemtrace_user_event *ev;
 283         struct kmemtrace_user_event_alloc *ev_alloc;
 284
 285         trace_assign_type(entry, iter->ent);
 286
 287         ev = trace_seq_reserve(s, sizeof(*ev));
 288         if (!ev)
 289                 return TRACE_TYPE_PARTIAL_LINE;
 290
 291         ev->event_id            = KMEMTRACE_USER_ALLOC;
 292         ev->type_id             = entry->type_id;
 293         ev->event_size          = sizeof(*ev) + sizeof(*ev_alloc);
 294         ev->cpu                 = iter->cpu;
 295         ev->timestamp           = iter->ts;
 296         ev->call_site           = entry->call_site;
 297         ev->ptr                 = (unsigned long)entry->ptr;
 298
 299         ev_alloc = trace_seq_reserve(s, sizeof(*ev_alloc));
 300         if (!ev_alloc)
 301                 return TRACE_TYPE_PARTIAL_LINE;
 302
 303         ev_alloc->bytes_req     = entry->bytes_req;
 304         ev_alloc->bytes_alloc   = entry->bytes_alloc;
 305         ev_alloc->gfp_flags     = entry->gfp_flags;
 306         ev_alloc->node          = entry->node;
 307
 308         return TRACE_TYPE_HANDLED;
 309 }
 310
 311 static enum print_line_t
 312 kmemtrace_print_free_user(struct trace_iterator *iter, int flags)
 313 {
 314         struct trace_seq *s = &iter->seq;
 315         struct kmemtrace_free_entry *entry;
 316         struct kmemtrace_user_event *ev;
 317
 318         trace_assign_type(entry, iter->ent);
 319
 320         ev = trace_seq_reserve(s, sizeof(*ev));
 321         if (!ev)
 322                 return TRACE_TYPE_PARTIAL_LINE;
 323
 324         ev->event_id            = KMEMTRACE_USER_FREE;
 325         ev->type_id             = entry->type_id;
 326         ev->event_size          = sizeof(*ev);
 327         ev->cpu                 = iter->cpu;
 328         ev->timestamp           = iter->ts;
 329         ev->call_site           = entry->call_site;
 330         ev->ptr                 = (unsigned long)entry->ptr;
 331
 332         return TRACE_TYPE_HANDLED;
 333 }
 334
 335 /* The two other following provide a more minimalistic output */
 336 static enum print_line_t
 337 kmemtrace_print_alloc_compress(struct trace_iterator *iter)
 338 {
 339         struct kmemtrace_alloc_entry *entry;
 340         struct trace_seq *s = &iter->seq;
 341         int ret;
 342
 343         trace_assign_type(entry, iter->ent);
 344
 345         /* Alloc entry */
 346         ret = trace_seq_printf(s, "  +      ");
 347         if (!ret)
 348                 return TRACE_TYPE_PARTIAL_LINE;
 349
 350         /* Type */
 351         switch (entry->type_id) {
 352         case KMEMTRACE_TYPE_KMALLOC:
 353                 ret = trace_seq_printf(s, "K   ");
 354                 break;
 355         case KMEMTRACE_TYPE_CACHE:
 356                 ret = trace_seq_printf(s, "C   ");
 357                 break;
 358         case KMEMTRACE_TYPE_PAGES:
 359                 ret = trace_seq_printf(s, "P   ");
 360                 break;
 361         default:
 362                 ret = trace_seq_printf(s, "?   ");
 363         }
 364
 365         if (!ret)
 366                 return TRACE_TYPE_PARTIAL_LINE;
 367
 368         /* Requested */
 369         ret = trace_seq_printf(s, "%4zu   ", entry->bytes_req);
 370         if (!ret)
 371                 return TRACE_TYPE_PARTIAL_LINE;
 372
 373         /* Allocated */
 374         ret = trace_seq_printf(s, "%4zu   ", entry->bytes_alloc);
 375         if (!ret)
 376                 return TRACE_TYPE_PARTIAL_LINE;
 377
 378         /* Flags
 379          * TODO: would be better to see the name of the GFP flag names
 380          */
 381         ret = trace_seq_printf(s, "%08x   ", entry->gfp_flags);
 382         if (!ret)
 383                 return TRACE_TYPE_PARTIAL_LINE;
 384
 385         /* Pointer to allocated */
 386         ret = trace_seq_printf(s, "0x%tx   ", (ptrdiff_t)entry->ptr);
 387         if (!ret)
 388                 return TRACE_TYPE_PARTIAL_LINE;
 389
 390         /* Node and call site*/
 391         ret = trace_seq_printf(s, "%4d   %pf\n", entry->node,
 392                                                  (void *)entry->call_site);
 393         if (!ret)
 394                 return TRACE_TYPE_PARTIAL_LINE;
 395
 396         return TRACE_TYPE_HANDLED;
 397 }
 398
 399 static enum print_line_t
 400 kmemtrace_print_free_compress(struct trace_iterator *iter)
 401 {
 402         struct kmemtrace_free_entry *entry;
 403         struct trace_seq *s = &iter->seq;
 404         int ret;
 405
 406         trace_assign_type(entry, iter->ent);
 407
 408         /* Free entry */
 409         ret = trace_seq_printf(s, "  -      ");
 410         if (!ret)
 411                 return TRACE_TYPE_PARTIAL_LINE;
 412
 413         /* Type */
 414         switch (entry->type_id) {
 415         case KMEMTRACE_TYPE_KMALLOC:
 416                 ret = trace_seq_printf(s, "K     ");
 417                 break;
 418         case KMEMTRACE_TYPE_CACHE:
 419                 ret = trace_seq_printf(s, "C     ");
 420                 break;
 421         case KMEMTRACE_TYPE_PAGES:
 422                 ret = trace_seq_printf(s, "P     ");
 423                 break;
 424         default:
 425                 ret = trace_seq_printf(s, "?     ");
 426         }
 427
 428         if (!ret)
 429                 return TRACE_TYPE_PARTIAL_LINE;
 430
 431         /* Skip requested/allocated/flags */
 432         ret = trace_seq_printf(s, "                       ");
 433         if (!ret)
 434                 return TRACE_TYPE_PARTIAL_LINE;
 435
 436         /* Pointer to allocated */
 437         ret = trace_seq_printf(s, "0x%tx   ", (ptrdiff_t)entry->ptr);
 438         if (!ret)
 439                 return TRACE_TYPE_PARTIAL_LINE;
 440
 441         /* Skip node and print call site*/
 442         ret = trace_seq_printf(s, "       %pf\n", (void *)entry->call_site);
 443         if (!ret)
 444                 return TRACE_TYPE_PARTIAL_LINE;
 445
 446         return TRACE_TYPE_HANDLED;
 447 }
 448
 449 static enum print_line_t kmemtrace_print_line(struct trace_iterator *iter)
 450 {
 451         struct trace_entry *entry = iter->ent;
 452
 453         if (!(kmem_tracer_flags.val & TRACE_KMEM_OPT_MINIMAL))
 454                 return TRACE_TYPE_UNHANDLED;
 455
 456         switch (entry->type) {
 457         case TRACE_KMEM_ALLOC:
 458                 return kmemtrace_print_alloc_compress(iter);
 459         case TRACE_KMEM_FREE:
 460                 return kmemtrace_print_free_compress(iter);
 461         default:
 462                 return TRACE_TYPE_UNHANDLED;
 463         }
 464 }
 465
 466 static struct trace_event kmem_trace_alloc = {
 467         .type                   = TRACE_KMEM_ALLOC,
 468         .trace                  = kmemtrace_print_alloc,
 469         .binary                 = kmemtrace_print_alloc_user,
 470 };
 471
 472 static struct trace_event kmem_trace_free = {
 473         .type                   = TRACE_KMEM_FREE,
 474         .trace                  = kmemtrace_print_free,
 475         .binary                 = kmemtrace_print_free_user,
 476 };
 477
 478 static struct tracer kmem_tracer __read_mostly = {
 479         .name                   = "kmemtrace",
 480         .init                   = kmem_trace_init,
 481         .reset                  = kmem_trace_reset,
 482         .print_line             = kmemtrace_print_line,
 483         .print_header           = kmemtrace_headers,
 484         .flags                  = &kmem_tracer_flags
 485 };
 486
 487 void kmemtrace_init(void)
 488 {
 489         /* earliest opportunity to start kmem tracing */
 490 }
 491
 492 static int __init init_kmem_tracer(void)
 493 {
 494         if (!register_ftrace_event(&kmem_trace_alloc)) {
 495                 pr_warning("Warning: could not register kmem events\n");
 496                 return 1;
 497         }
 498
 499         if (!register_ftrace_event(&kmem_trace_free)) {
 500                 pr_warning("Warning: could not register kmem events\n");
 501                 return 1;
 502         }
 503
 504         if (register_tracer(&kmem_tracer) != 0) {
 505                 pr_warning("Warning: could not register the kmem tracer\n");
 506                 return 1;
 507         }
 508
 509         return 0;
 510 }
 511 device_initcall(init_kmem_tracer);