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