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         int cpu;
 187         kmemtrace_array = tr;
 188
 189         for_each_cpu(cpu, cpu_possible_mask)
 190                 tracing_reset(tr, cpu);
 191
 192         kmemtrace_start_probes();
 193
 194         return 0;
 195 }
 196
 197 static void kmem_trace_reset(struct trace_array *tr)
 198 {
 199         kmemtrace_stop_probes();
 200 }
 201
 202 static void kmemtrace_headers(struct seq_file *s)
 203 {
 204         /* Don't need headers for the original kmemtrace output */
 205         if (!(kmem_tracer_flags.val & TRACE_KMEM_OPT_MINIMAL))
 206                 return;
 207
 208         seq_printf(s, "#\n");
 209         seq_printf(s, "# ALLOC  TYPE  REQ   GIVEN  FLAGS     "
 210                         "      POINTER         NODE    CALLER\n");
 211         seq_printf(s, "# FREE   |      |     |       |       "
 212                         "       |   |            |        |\n");
 213         seq_printf(s, "# |\n\n");
 214 }
 215
 216 /*
 217  * The following functions give the original output from kmemtrace,
 218  * plus the origin CPU, since reordering occurs in-kernel now.
 219  */
 220
 221 #define KMEMTRACE_USER_ALLOC    0
 222 #define KMEMTRACE_USER_FREE     1
 223
 224 struct kmemtrace_user_event {
 225         u8                      event_id;
 226         u8                      type_id;
 227         u16                     event_size;
 228         u32                     cpu;
 229         u64                     timestamp;
 230         unsigned long           call_site;
 231         unsigned long           ptr;
 232 };
 233
 234 struct kmemtrace_user_event_alloc {
 235         size_t                  bytes_req;
 236         size_t                  bytes_alloc;
 237         unsigned                gfp_flags;
 238         int                     node;
 239 };
 240
 241 static enum print_line_t
 242 kmemtrace_print_alloc_user(struct trace_iterator *iter,
 243                            struct kmemtrace_alloc_entry *entry)
 244 {
 245         struct kmemtrace_user_event_alloc *ev_alloc;
 246         struct trace_seq *s = &iter->seq;
 247         struct kmemtrace_user_event *ev;
 248
 249         ev = trace_seq_reserve(s, sizeof(*ev));
 250         if (!ev)
 251                 return TRACE_TYPE_PARTIAL_LINE;
 252
 253         ev->event_id            = KMEMTRACE_USER_ALLOC;
 254         ev->type_id             = entry->type_id;
 255         ev->event_size          = sizeof(*ev) + sizeof(*ev_alloc);
 256         ev->cpu                 = iter->cpu;
 257         ev->timestamp           = iter->ts;
 258         ev->call_site           = entry->call_site;
 259         ev->ptr                 = (unsigned long)entry->ptr;
 260
 261         ev_alloc = trace_seq_reserve(s, sizeof(*ev_alloc));
 262         if (!ev_alloc)
 263                 return TRACE_TYPE_PARTIAL_LINE;
 264
 265         ev_alloc->bytes_req     = entry->bytes_req;
 266         ev_alloc->bytes_alloc   = entry->bytes_alloc;
 267         ev_alloc->gfp_flags     = entry->gfp_flags;
 268         ev_alloc->node          = entry->node;
 269
 270         return TRACE_TYPE_HANDLED;
 271 }
 272
 273 static enum print_line_t
 274 kmemtrace_print_free_user(struct trace_iterator *iter,
 275                           struct kmemtrace_free_entry *entry)
 276 {
 277         struct trace_seq *s = &iter->seq;
 278         struct kmemtrace_user_event *ev;
 279
 280         ev = trace_seq_reserve(s, sizeof(*ev));
 281         if (!ev)
 282                 return TRACE_TYPE_PARTIAL_LINE;
 283
 284         ev->event_id            = KMEMTRACE_USER_FREE;
 285         ev->type_id             = entry->type_id;
 286         ev->event_size          = sizeof(*ev);
 287         ev->cpu                 = iter->cpu;
 288         ev->timestamp           = iter->ts;
 289         ev->call_site           = entry->call_site;
 290         ev->ptr                 = (unsigned long)entry->ptr;
 291
 292         return TRACE_TYPE_HANDLED;
 293 }
 294
 295 /* The two other following provide a more minimalistic output */
 296 static enum print_line_t
 297 kmemtrace_print_alloc_compress(struct trace_iterator *iter,
 298                                         struct kmemtrace_alloc_entry *entry)
 299 {
 300         struct trace_seq *s = &iter->seq;
 301         int ret;
 302
 303         /* Alloc entry */
 304         ret = trace_seq_printf(s, "  +      ");
 305         if (!ret)
 306                 return TRACE_TYPE_PARTIAL_LINE;
 307
 308         /* Type */
 309         switch (entry->type_id) {
 310         case KMEMTRACE_TYPE_KMALLOC:
 311                 ret = trace_seq_printf(s, "K   ");
 312                 break;
 313         case KMEMTRACE_TYPE_CACHE:
 314                 ret = trace_seq_printf(s, "C   ");
 315                 break;
 316         case KMEMTRACE_TYPE_PAGES:
 317                 ret = trace_seq_printf(s, "P   ");
 318                 break;
 319         default:
 320                 ret = trace_seq_printf(s, "?   ");
 321         }
 322
 323         if (!ret)
 324                 return TRACE_TYPE_PARTIAL_LINE;
 325
 326         /* Requested */
 327         ret = trace_seq_printf(s, "%4zu   ", entry->bytes_req);
 328         if (!ret)
 329                 return TRACE_TYPE_PARTIAL_LINE;
 330
 331         /* Allocated */
 332         ret = trace_seq_printf(s, "%4zu   ", entry->bytes_alloc);
 333         if (!ret)
 334                 return TRACE_TYPE_PARTIAL_LINE;
 335
 336         /* Flags
 337          * TODO: would be better to see the name of the GFP flag names
 338          */
 339         ret = trace_seq_printf(s, "%08x   ", entry->gfp_flags);
 340         if (!ret)
 341                 return TRACE_TYPE_PARTIAL_LINE;
 342
 343         /* Pointer to allocated */
 344         ret = trace_seq_printf(s, "0x%tx   ", (ptrdiff_t)entry->ptr);
 345         if (!ret)
 346                 return TRACE_TYPE_PARTIAL_LINE;
 347
 348         /* Node */
 349         ret = trace_seq_printf(s, "%4d   ", entry->node);
 350         if (!ret)
 351                 return TRACE_TYPE_PARTIAL_LINE;
 352
 353         /* Call site */
 354         ret = seq_print_ip_sym(s, entry->call_site, 0);
 355         if (!ret)
 356                 return TRACE_TYPE_PARTIAL_LINE;
 357
 358         if (!trace_seq_printf(s, "\n"))
 359                 return TRACE_TYPE_PARTIAL_LINE;
 360
 361         return TRACE_TYPE_HANDLED;
 362 }
 363
 364 static enum print_line_t
 365 kmemtrace_print_free_compress(struct trace_iterator *iter,
 366                               struct kmemtrace_free_entry *entry)
 367 {
 368         struct trace_seq *s = &iter->seq;
 369         int ret;
 370
 371         /* Free entry */
 372         ret = trace_seq_printf(s, "  -      ");
 373         if (!ret)
 374                 return TRACE_TYPE_PARTIAL_LINE;
 375
 376         /* Type */
 377         switch (entry->type_id) {
 378         case KMEMTRACE_TYPE_KMALLOC:
 379                 ret = trace_seq_printf(s, "K     ");
 380                 break;
 381         case KMEMTRACE_TYPE_CACHE:
 382                 ret = trace_seq_printf(s, "C     ");
 383                 break;
 384         case KMEMTRACE_TYPE_PAGES:
 385                 ret = trace_seq_printf(s, "P     ");
 386                 break;
 387         default:
 388                 ret = trace_seq_printf(s, "?     ");
 389         }
 390
 391         if (!ret)
 392                 return TRACE_TYPE_PARTIAL_LINE;
 393
 394         /* Skip requested/allocated/flags */
 395         ret = trace_seq_printf(s, "                       ");
 396         if (!ret)
 397                 return TRACE_TYPE_PARTIAL_LINE;
 398
 399         /* Pointer to allocated */
 400         ret = trace_seq_printf(s, "0x%tx   ", (ptrdiff_t)entry->ptr);
 401         if (!ret)
 402                 return TRACE_TYPE_PARTIAL_LINE;
 403
 404         /* Skip node */
 405         ret = trace_seq_printf(s, "       ");
 406         if (!ret)
 407                 return TRACE_TYPE_PARTIAL_LINE;
 408
 409         /* Call site */
 410         ret = seq_print_ip_sym(s, entry->call_site, 0);
 411         if (!ret)
 412                 return TRACE_TYPE_PARTIAL_LINE;
 413
 414         if (!trace_seq_printf(s, "\n"))
 415                 return TRACE_TYPE_PARTIAL_LINE;
 416
 417         return TRACE_TYPE_HANDLED;
 418 }
 419
 420 static enum print_line_t kmemtrace_print_line(struct trace_iterator *iter)
 421 {
 422         struct trace_entry *entry = iter->ent;
 423
 424         switch (entry->type) {
 425         case TRACE_KMEM_ALLOC: {
 426                 struct kmemtrace_alloc_entry *field;
 427
 428                 trace_assign_type(field, entry);
 429                 if (kmem_tracer_flags.val & TRACE_KMEM_OPT_MINIMAL)
 430                         return kmemtrace_print_alloc_compress(iter, field);
 431                 else
 432                         return kmemtrace_print_alloc_user(iter, field);
 433         }
 434
 435         case TRACE_KMEM_FREE: {
 436                 struct kmemtrace_free_entry *field;
 437
 438                 trace_assign_type(field, entry);
 439                 if (kmem_tracer_flags.val & TRACE_KMEM_OPT_MINIMAL)
 440                         return kmemtrace_print_free_compress(iter, field);
 441                 else
 442                         return kmemtrace_print_free_user(iter, field);
 443         }
 444
 445         default:
 446                 return TRACE_TYPE_UNHANDLED;
 447         }
 448 }
 449
 450 static struct tracer kmem_tracer __read_mostly = {
 451         .name                   = "kmemtrace",
 452         .init                   = kmem_trace_init,
 453         .reset                  = kmem_trace_reset,
 454         .print_line             = kmemtrace_print_line,
 455         .print_header           = kmemtrace_headers,
 456         .flags                  = &kmem_tracer_flags
 457 };
 458
 459 void kmemtrace_init(void)
 460 {
 461         /* earliest opportunity to start kmem tracing */
 462 }
 463
 464 static int __init init_kmem_tracer(void)
 465 {
 466         return register_tracer(&kmem_tracer);
 467 }
 468 device_initcall(init_kmem_tracer);