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 <trace/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 trace_array *tr = kmemtrace_array;
  46         struct kmemtrace_alloc_entry *entry;
  47         struct ring_buffer_event *event;
  48
  49         event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry));
  50         if (!event)
  51                 return;
  52
  53         entry = ring_buffer_event_data(event);
  54         tracing_generic_entry_update(&entry->ent, 0, 0);
  55
  56         entry->ent.type         = TRACE_KMEM_ALLOC;
  57         entry->type_id          = type_id;
  58         entry->call_site        = call_site;
  59         entry->ptr              = ptr;
  60         entry->bytes_req        = bytes_req;
  61         entry->bytes_alloc      = bytes_alloc;
  62         entry->gfp_flags        = gfp_flags;
  63         entry->node             = node;
  64
  65         ring_buffer_unlock_commit(tr->buffer, event);
  66
  67         trace_wake_up();
  68 }
  69
  70 static inline void kmemtrace_free(enum kmemtrace_type_id type_id,
  71                                   unsigned long call_site,
  72                                   const void *ptr)
  73 {
  74         struct trace_array *tr = kmemtrace_array;
  75         struct kmemtrace_free_entry *entry;
  76         struct ring_buffer_event *event;
  77
  78         event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry));
  79         if (!event)
  80                 return;
  81         entry   = ring_buffer_event_data(event);
  82         tracing_generic_entry_update(&entry->ent, 0, 0);
  83
  84         entry->ent.type         = TRACE_KMEM_FREE;
  85         entry->type_id          = type_id;
  86         entry->call_site        = call_site;
  87         entry->ptr              = ptr;
  88
  89         ring_buffer_unlock_commit(tr->buffer, event);
  90
  91         trace_wake_up();
  92 }
  93
  94 static void kmemtrace_kmalloc(unsigned long call_site,
  95                               const void *ptr,
  96                               size_t bytes_req,
  97                               size_t bytes_alloc,
  98                               gfp_t gfp_flags)
  99 {
 100         kmemtrace_alloc(KMEMTRACE_TYPE_KMALLOC, call_site, ptr,
 101                         bytes_req, bytes_alloc, gfp_flags, -1);
 102 }
 103
 104 static void kmemtrace_kmem_cache_alloc(unsigned long call_site,
 105                                        const void *ptr,
 106                                        size_t bytes_req,
 107                                        size_t bytes_alloc,
 108                                        gfp_t gfp_flags)
 109 {
 110         kmemtrace_alloc(KMEMTRACE_TYPE_CACHE, call_site, ptr,
 111                         bytes_req, bytes_alloc, gfp_flags, -1);
 112 }
 113
 114 static void kmemtrace_kmalloc_node(unsigned long call_site,
 115                                    const void *ptr,
 116                                    size_t bytes_req,
 117                                    size_t bytes_alloc,
 118                                    gfp_t gfp_flags,
 119                                    int node)
 120 {
 121         kmemtrace_alloc(KMEMTRACE_TYPE_KMALLOC, call_site, ptr,
 122                         bytes_req, bytes_alloc, gfp_flags, node);
 123 }
 124
 125 static void kmemtrace_kmem_cache_alloc_node(unsigned long call_site,
 126                                             const void *ptr,
 127                                             size_t bytes_req,
 128                                             size_t bytes_alloc,
 129                                             gfp_t gfp_flags,
 130                                             int node)
 131 {
 132         kmemtrace_alloc(KMEMTRACE_TYPE_CACHE, call_site, ptr,
 133                         bytes_req, bytes_alloc, gfp_flags, node);
 134 }
 135
 136 static void kmemtrace_kfree(unsigned long call_site, const void *ptr)
 137 {
 138         kmemtrace_free(KMEMTRACE_TYPE_KMALLOC, call_site, ptr);
 139 }
 140
 141 static void kmemtrace_kmem_cache_free(unsigned long call_site, const void *ptr)
 142 {
 143         kmemtrace_free(KMEMTRACE_TYPE_CACHE, call_site, ptr);
 144 }
 145
 146 static int kmemtrace_start_probes(void)
 147 {
 148         int err;
 149
 150         err = register_trace_kmalloc(kmemtrace_kmalloc);
 151         if (err)
 152                 return err;
 153         err = register_trace_kmem_cache_alloc(kmemtrace_kmem_cache_alloc);
 154         if (err)
 155                 return err;
 156         err = register_trace_kmalloc_node(kmemtrace_kmalloc_node);
 157         if (err)
 158                 return err;
 159         err = register_trace_kmem_cache_alloc_node(kmemtrace_kmem_cache_alloc_node);
 160         if (err)
 161                 return err;
 162         err = register_trace_kfree(kmemtrace_kfree);
 163         if (err)
 164                 return err;
 165         err = register_trace_kmem_cache_free(kmemtrace_kmem_cache_free);
 166
 167         return err;
 168 }
 169
 170 static void kmemtrace_stop_probes(void)
 171 {
 172         unregister_trace_kmalloc(kmemtrace_kmalloc);
 173         unregister_trace_kmem_cache_alloc(kmemtrace_kmem_cache_alloc);
 174         unregister_trace_kmalloc_node(kmemtrace_kmalloc_node);
 175         unregister_trace_kmem_cache_alloc_node(kmemtrace_kmem_cache_alloc_node);
 176         unregister_trace_kfree(kmemtrace_kfree);
 177         unregister_trace_kmem_cache_free(kmemtrace_kmem_cache_free);
 178 }
 179
 180 static int kmem_trace_init(struct trace_array *tr)
 181 {
 182         int cpu;
 183         kmemtrace_array = tr;
 184
 185         for_each_cpu_mask(cpu, cpu_possible_map)
 186                 tracing_reset(tr, cpu);
 187
 188         kmemtrace_start_probes();
 189
 190         return 0;
 191 }
 192
 193 static void kmem_trace_reset(struct trace_array *tr)
 194 {
 195         kmemtrace_stop_probes();
 196 }
 197
 198 static void kmemtrace_headers(struct seq_file *s)
 199 {
 200         /* Don't need headers for the original kmemtrace output */
 201         if (!(kmem_tracer_flags.val & TRACE_KMEM_OPT_MINIMAL))
 202                 return;
 203
 204         seq_printf(s, "#\n");
 205         seq_printf(s, "# ALLOC  TYPE  REQ   GIVEN  FLAGS     "
 206                         "      POINTER         NODE    CALLER\n");
 207         seq_printf(s, "# FREE   |      |     |       |       "
 208                         "       |   |            |        |\n");
 209         seq_printf(s, "# |\n\n");
 210 }
 211
 212 /*
 213  * The following functions give the original output from kmemtrace,
 214  * plus the origin CPU, since reordering occurs in-kernel now.
 215  */
 216
 217 #define KMEMTRACE_USER_ALLOC    0
 218 #define KMEMTRACE_USER_FREE     1
 219
 220 struct kmemtrace_user_event {
 221         u8                      event_id;
 222         u8                      type_id;
 223         u16                     event_size;
 224         u32                     cpu;
 225         u64                     timestamp;
 226         unsigned long           call_site;
 227         unsigned long           ptr;
 228 };
 229
 230 struct kmemtrace_user_event_alloc {
 231         size_t                  bytes_req;
 232         size_t                  bytes_alloc;
 233         unsigned                gfp_flags;
 234         int                     node;
 235 };
 236
 237 static enum print_line_t
 238 kmemtrace_print_alloc_user(struct trace_iterator *iter,
 239                            struct kmemtrace_alloc_entry *entry)
 240 {
 241         struct kmemtrace_user_event_alloc *ev_alloc;
 242         struct trace_seq *s = &iter->seq;
 243         struct kmemtrace_user_event *ev;
 244
 245         ev = trace_seq_reserve(s, sizeof(*ev));
 246         if (!ev)
 247                 return TRACE_TYPE_PARTIAL_LINE;
 248
 249         ev->event_id            = KMEMTRACE_USER_ALLOC;
 250         ev->type_id             = entry->type_id;
 251         ev->event_size          = sizeof(*ev) + sizeof(*ev_alloc);
 252         ev->cpu                 = iter->cpu;
 253         ev->timestamp           = iter->ts;
 254         ev->call_site           = entry->call_site;
 255         ev->ptr                 = (unsigned long)entry->ptr;
 256
 257         ev_alloc = trace_seq_reserve(s, sizeof(*ev_alloc));
 258         if (!ev_alloc)
 259                 return TRACE_TYPE_PARTIAL_LINE;
 260
 261         ev_alloc->bytes_req     = entry->bytes_req;
 262         ev_alloc->bytes_alloc   = entry->bytes_alloc;
 263         ev_alloc->gfp_flags     = entry->gfp_flags;
 264         ev_alloc->node          = entry->node;
 265
 266         return TRACE_TYPE_HANDLED;
 267 }
 268
 269 static enum print_line_t
 270 kmemtrace_print_free_user(struct trace_iterator *iter,
 271                           struct kmemtrace_free_entry *entry)
 272 {
 273         struct trace_seq *s = &iter->seq;
 274         struct kmemtrace_user_event *ev;
 275
 276         ev = trace_seq_reserve(s, sizeof(*ev));
 277         if (!ev)
 278                 return TRACE_TYPE_PARTIAL_LINE;
 279
 280         ev->event_id            = KMEMTRACE_USER_FREE;
 281         ev->type_id             = entry->type_id;
 282         ev->event_size          = sizeof(*ev);
 283         ev->cpu                 = iter->cpu;
 284         ev->timestamp           = iter->ts;
 285         ev->call_site           = entry->call_site;
 286         ev->ptr                 = (unsigned long)entry->ptr;
 287
 288         return TRACE_TYPE_HANDLED;
 289 }
 290
 291 /* The two other following provide a more minimalistic output */
 292 static enum print_line_t
 293 kmemtrace_print_alloc_compress(struct trace_iterator *iter,
 294                                         struct kmemtrace_alloc_entry *entry)
 295 {
 296         struct trace_seq *s = &iter->seq;
 297         int ret;
 298
 299         /* Alloc entry */
 300         ret = trace_seq_printf(s, "  +      ");
 301         if (!ret)
 302                 return TRACE_TYPE_PARTIAL_LINE;
 303
 304         /* Type */
 305         switch (entry->type_id) {
 306         case KMEMTRACE_TYPE_KMALLOC:
 307                 ret = trace_seq_printf(s, "K   ");
 308                 break;
 309         case KMEMTRACE_TYPE_CACHE:
 310                 ret = trace_seq_printf(s, "C   ");
 311                 break;
 312         case KMEMTRACE_TYPE_PAGES:
 313                 ret = trace_seq_printf(s, "P   ");
 314                 break;
 315         default:
 316                 ret = trace_seq_printf(s, "?   ");
 317         }
 318
 319         if (!ret)
 320                 return TRACE_TYPE_PARTIAL_LINE;
 321
 322         /* Requested */
 323         ret = trace_seq_printf(s, "%4zu   ", entry->bytes_req);
 324         if (!ret)
 325                 return TRACE_TYPE_PARTIAL_LINE;
 326
 327         /* Allocated */
 328         ret = trace_seq_printf(s, "%4zu   ", entry->bytes_alloc);
 329         if (!ret)
 330                 return TRACE_TYPE_PARTIAL_LINE;
 331
 332         /* Flags
 333          * TODO: would be better to see the name of the GFP flag names
 334          */
 335         ret = trace_seq_printf(s, "%08x   ", entry->gfp_flags);
 336         if (!ret)
 337                 return TRACE_TYPE_PARTIAL_LINE;
 338
 339         /* Pointer to allocated */
 340         ret = trace_seq_printf(s, "0x%tx   ", (ptrdiff_t)entry->ptr);
 341         if (!ret)
 342                 return TRACE_TYPE_PARTIAL_LINE;
 343
 344         /* Node */
 345         ret = trace_seq_printf(s, "%4d   ", entry->node);
 346         if (!ret)
 347                 return TRACE_TYPE_PARTIAL_LINE;
 348
 349         /* Call site */
 350         ret = seq_print_ip_sym(s, entry->call_site, 0);
 351         if (!ret)
 352                 return TRACE_TYPE_PARTIAL_LINE;
 353
 354         if (!trace_seq_printf(s, "\n"))
 355                 return TRACE_TYPE_PARTIAL_LINE;
 356
 357         return TRACE_TYPE_HANDLED;
 358 }
 359
 360 static enum print_line_t
 361 kmemtrace_print_free_compress(struct trace_iterator *iter,
 362                               struct kmemtrace_free_entry *entry)
 363 {
 364         struct trace_seq *s = &iter->seq;
 365         int ret;
 366
 367         /* Free entry */
 368         ret = trace_seq_printf(s, "  -      ");
 369         if (!ret)
 370                 return TRACE_TYPE_PARTIAL_LINE;
 371
 372         /* Type */
 373         switch (entry->type_id) {
 374         case KMEMTRACE_TYPE_KMALLOC:
 375                 ret = trace_seq_printf(s, "K     ");
 376                 break;
 377         case KMEMTRACE_TYPE_CACHE:
 378                 ret = trace_seq_printf(s, "C     ");
 379                 break;
 380         case KMEMTRACE_TYPE_PAGES:
 381                 ret = trace_seq_printf(s, "P     ");
 382                 break;
 383         default:
 384                 ret = trace_seq_printf(s, "?     ");
 385         }
 386
 387         if (!ret)
 388                 return TRACE_TYPE_PARTIAL_LINE;
 389
 390         /* Skip requested/allocated/flags */
 391         ret = trace_seq_printf(s, "                       ");
 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         /* Skip node */
 401         ret = trace_seq_printf(s, "       ");
 402         if (!ret)
 403                 return TRACE_TYPE_PARTIAL_LINE;
 404
 405         /* Call site */
 406         ret = seq_print_ip_sym(s, entry->call_site, 0);
 407         if (!ret)
 408                 return TRACE_TYPE_PARTIAL_LINE;
 409
 410         if (!trace_seq_printf(s, "\n"))
 411                 return TRACE_TYPE_PARTIAL_LINE;
 412
 413         return TRACE_TYPE_HANDLED;
 414 }
 415
 416 static enum print_line_t kmemtrace_print_line(struct trace_iterator *iter)
 417 {
 418         struct trace_entry *entry = iter->ent;
 419
 420         switch (entry->type) {
 421         case TRACE_KMEM_ALLOC: {
 422                 struct kmemtrace_alloc_entry *field;
 423
 424                 trace_assign_type(field, entry);
 425                 if (kmem_tracer_flags.val & TRACE_KMEM_OPT_MINIMAL)
 426                         return kmemtrace_print_alloc_compress(iter, field);
 427                 else
 428                         return kmemtrace_print_alloc_user(iter, field);
 429         }
 430
 431         case TRACE_KMEM_FREE: {
 432                 struct kmemtrace_free_entry *field;
 433
 434                 trace_assign_type(field, entry);
 435                 if (kmem_tracer_flags.val & TRACE_KMEM_OPT_MINIMAL)
 436                         return kmemtrace_print_free_compress(iter, field);
 437                 else
 438                         return kmemtrace_print_free_user(iter, field);
 439         }
 440
 441         default:
 442                 return TRACE_TYPE_UNHANDLED;
 443         }
 444 }
 445
 446 static struct tracer kmem_tracer __read_mostly = {
 447         .name                   = "kmemtrace",
 448         .init                   = kmem_trace_init,
 449         .reset                  = kmem_trace_reset,
 450         .print_line             = kmemtrace_print_line,
 451         .print_header           = kmemtrace_headers,
 452         .flags                  = &kmem_tracer_flags
 453 };
 454
 455 void kmemtrace_init(void)
 456 {
 457         /* earliest opportunity to start kmem tracing */
 458 }
 459
 460 static int __init init_kmem_tracer(void)
 461 {
 462         return register_tracer(&kmem_tracer);
 463 }
 464 device_initcall(init_kmem_tracer);