summaryrefslogtreecommitdiffstats
path: root/kernel/trace/kmemtrace.c
blob: 5011f4d91e375c2895cdc074299caafdf058ca38 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
/*
 * Memory allocator tracing
 *
 * Copyright (C) 2008 Eduard - Gabriel Munteanu
 * Copyright (C) 2008 Pekka Enberg <penberg@cs.helsinki.fi>
 * Copyright (C) 2008 Frederic Weisbecker <fweisbec@gmail.com>
 */

#include <linux/tracepoint.h>
#include <linux/seq_file.h>
#include <linux/debugfs.h>
#include <linux/dcache.h>
#include <linux/fs.h>

#include <trace/kmemtrace.h>

#include "trace_output.h"
#include "trace.h"

/* Select an alternative, minimalistic output than the original one */
#define TRACE_KMEM_OPT_MINIMAL	0x1

static struct tracer_opt kmem_opts[] = {
	/* Default disable the minimalistic output */
	{ TRACER_OPT(kmem_minimalistic, TRACE_KMEM_OPT_MINIMAL) },
	{ }
};

static struct tracer_flags kmem_tracer_flags = {
	.val			= 0,
	.opts			= kmem_opts
};

static struct trace_array *kmemtrace_array;

/* Trace allocations */
static inline void kmemtrace_alloc(enum kmemtrace_type_id type_id,
				   unsigned long call_site,
				   const void *ptr,
				   size_t bytes_req,
				   size_t bytes_alloc,
				   gfp_t gfp_flags,
				   int node)
{
	struct trace_array *tr = kmemtrace_array;
	struct kmemtrace_alloc_entry *entry;
	struct ring_buffer_event *event;

	event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry));
	if (!event)
		return;

	entry = ring_buffer_event_data(event);
	tracing_generic_entry_update(&entry->ent, 0, 0);

	entry->ent.type		= TRACE_KMEM_ALLOC;
	entry->type_id		= type_id;
	entry->call_site	= call_site;
	entry->ptr		= ptr;
	entry->bytes_req	= bytes_req;
	entry->bytes_alloc	= bytes_alloc;
	entry->gfp_flags	= gfp_flags;
	entry->node		= node;

	ring_buffer_unlock_commit(tr->buffer, event);

	trace_wake_up();
}

static inline void kmemtrace_free(enum kmemtrace_type_id type_id,
				  unsigned long call_site,
				  const void *ptr)
{
	struct trace_array *tr = kmemtrace_array;
	struct kmemtrace_free_entry *entry;
	struct ring_buffer_event *event;

	event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry));
	if (!event)
		return;
	entry	= ring_buffer_event_data(event);
	tracing_generic_entry_update(&entry->ent, 0, 0);

	entry->ent.type		= TRACE_KMEM_FREE;
	entry->type_id		= type_id;
	entry->call_site	= call_site;
	entry->ptr		= ptr;

	ring_buffer_unlock_commit(tr->buffer, event);

	trace_wake_up();
}

static void kmemtrace_kmalloc(unsigned long call_site,
			      const void *ptr,
			      size_t bytes_req,
			      size_t bytes_alloc,
			      gfp_t gfp_flags)
{
	kmemtrace_alloc(KMEMTRACE_TYPE_KMALLOC, call_site, ptr,
			bytes_req, bytes_alloc, gfp_flags, -1);
}

static void kmemtrace_kmem_cache_alloc(unsigned long call_site,
				       const void *ptr,
				       size_t bytes_req,
				       size_t bytes_alloc,
				       gfp_t gfp_flags)
{
	kmemtrace_alloc(KMEMTRACE_TYPE_CACHE, call_site, ptr,
			bytes_req, bytes_alloc, gfp_flags, -1);
}

static void kmemtrace_kmalloc_node(unsigned long call_site,
				   const void *ptr,
				   size_t bytes_req,
				   size_t bytes_alloc,
				   gfp_t gfp_flags,
				   int node)
{
	kmemtrace_alloc(KMEMTRACE_TYPE_KMALLOC, call_site, ptr,
			bytes_req, bytes_alloc, gfp_flags, node);
}

static void kmemtrace_kmem_cache_alloc_node(unsigned long call_site,
					    const void *ptr,
					    size_t bytes_req,
					    size_t bytes_alloc,
					    gfp_t gfp_flags,
					    int node)
{
	kmemtrace_alloc(KMEMTRACE_TYPE_CACHE, call_site, ptr,
			bytes_req, bytes_alloc, gfp_flags, node);
}

static void kmemtrace_kfree(unsigned long call_site, const void *ptr)
{
	kmemtrace_free(KMEMTRACE_TYPE_KMALLOC, call_site, ptr);
}

static void kmemtrace_kmem_cache_free(unsigned long call_site, const void *ptr)
{
	kmemtrace_free(KMEMTRACE_TYPE_CACHE, call_site, ptr);
}

static int kmemtrace_start_probes(void)
{
	int err;

	err = register_trace_kmalloc(kmemtrace_kmalloc);
	if (err)
		return err;
	err = register_trace_kmem_cache_alloc(kmemtrace_kmem_cache_alloc);
	if (err)
		return err;
	err = register_trace_kmalloc_node(kmemtrace_kmalloc_node);
	if (err)
		return err;
	err = register_trace_kmem_cache_alloc_node(kmemtrace_kmem_cache_alloc_node);
	if (err)
		return err;
	err = register_trace_kfree(kmemtrace_kfree);
	if (err)
		return err;
	err = register_trace_kmem_cache_free(kmemtrace_kmem_cache_free);

	return err;
}

static void kmemtrace_stop_probes(void)
{
	unregister_trace_kmalloc(kmemtrace_kmalloc);
	unregister_trace_kmem_cache_alloc(kmemtrace_kmem_cache_alloc);
	unregister_trace_kmalloc_node(kmemtrace_kmalloc_node);
	unregister_trace_kmem_cache_alloc_node(kmemtrace_kmem_cache_alloc_node);
	unregister_trace_kfree(kmemtrace_kfree);
	unregister_trace_kmem_cache_free(kmemtrace_kmem_cache_free);
}

static int kmem_trace_init(struct trace_array *tr)
{
	int cpu;
	kmemtrace_array = tr;

	for_each_cpu_mask(cpu, cpu_possible_map)
		tracing_reset(tr, cpu);

	kmemtrace_start_probes();

	return 0;
}

static void kmem_trace_reset(struct trace_array *tr)
{
	kmemtrace_stop_probes();
}

static void kmemtrace_headers(struct seq_file *s)
{
	/* Don't need headers for the original kmemtrace output */
	if (!(kmem_tracer_flags.val & TRACE_KMEM_OPT_MINIMAL))
		return;

	seq_printf(s, "#\n");
	seq_printf(s, "# ALLOC  TYPE  REQ   GIVEN  FLAGS     "
			"      POINTER         NODE    CALLER\n");
	seq_printf(s, "# FREE   |      |     |       |       "
			"       |   |            |        |\n");
	seq_printf(s, "# |\n\n");
}

/*
 * The following functions give the original output from kmemtrace,
 * plus the origin CPU, since reordering occurs in-kernel now.
 */

#define KMEMTRACE_USER_ALLOC	0
#define KMEMTRACE_USER_FREE	1

struct kmemtrace_user_event {
	u8			event_id;
	u8			type_id;
	u16			event_size;
	u32			cpu;
	u64			timestamp;
	unsigned long		call_site;
	unsigned long		ptr;
};

struct kmemtrace_user_event_alloc {
	size_t			bytes_req;
	size_t			bytes_alloc;
	unsigned		gfp_flags;
	int			node;
};

static enum print_line_t
kmemtrace_print_alloc_user(struct trace_iterator *iter,
			   struct kmemtrace_alloc_entry *entry)
{
	struct kmemtrace_user_event_alloc *ev_alloc;
	struct trace_seq *s = &iter->seq;
	struct kmemtrace_user_event *ev;

	ev = trace_seq_reserve(s, sizeof(*ev));
	if (!ev)
		return TRACE_TYPE_PARTIAL_LINE;

	ev->event_id		= KMEMTRACE_USER_ALLOC;
	ev->type_id		= entry->type_id;
	ev->event_size		= sizeof(*ev) + sizeof(*ev_alloc);
	ev->cpu			= iter->cpu;
	ev->timestamp		= iter->ts;
	ev->call_site		= entry->call_site;
	ev->ptr			= (unsigned long)entry->ptr;

	ev_alloc = trace_seq_reserve(s, sizeof(*ev_alloc));
	if (!ev_alloc)
		return TRACE_TYPE_PARTIAL_LINE;

	ev_alloc->bytes_req	= entry->bytes_req;
	ev_alloc->bytes_alloc	= entry->bytes_alloc;
	ev_alloc->gfp_flags	= entry->gfp_flags;
	ev_alloc->node		= entry->node;

	return TRACE_TYPE_HANDLED;
}

static enum print_line_t
kmemtrace_print_free_user(struct trace_iterator *iter,
			  struct kmemtrace_free_entry *entry)
{
	struct trace_seq *s = &iter->seq;
	struct kmemtrace_user_event *ev;

	ev = trace_seq_reserve(s, sizeof(*ev));
	if (!ev)
		return TRACE_TYPE_PARTIAL_LINE;

	ev->event_id		= KMEMTRACE_USER_FREE;
	ev->type_id		= entry->type_id;
	ev->event_size		= sizeof(*ev);
	ev->cpu			= iter->cpu;
	ev->timestamp		= iter->ts;
	ev->call_site		= entry->call_site;
	ev->ptr			= (unsigned long)entry->ptr;

	return TRACE_TYPE_HANDLED;
}

/* The two other following provide a more minimalistic output */
static enum print_line_t
kmemtrace_print_alloc_compress(struct trace_iterator *iter,
					struct kmemtrace_alloc_entry *entry)
{
	struct trace_seq *s = &iter->seq;
	int ret;

	/* Alloc entry */
	ret = trace_seq_printf(s, "  +      ");
	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;

	/* Type */
	switch (entry->type_id) {
	case KMEMTRACE_TYPE_KMALLOC:
		ret = trace_seq_printf(s, "K   ");
		break;
	case KMEMTRACE_TYPE_CACHE:
		ret = trace_seq_printf(s, "C   ");
		break;
	case KMEMTRACE_TYPE_PAGES:
		ret = trace_seq_printf(s, "P   ");
		break;
	default:
		ret = trace_seq_printf(s, "?   ");
	}

	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;

	/* Requested */
	ret = trace_seq_printf(s, "%4zu   ", entry->bytes_req);
	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;

	/* Allocated */
	ret = trace_seq_printf(s, "%4zu   ", entry->bytes_alloc);
	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;

	/* Flags
	 * TODO: would be better to see the name of the GFP flag names
	 */
	ret = trace_seq_printf(s, "%08x   ", entry->gfp_flags);
	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;

	/* Pointer to allocated */
	ret = trace_seq_printf(s, "0x%tx   ", (ptrdiff_t)entry->ptr);
	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;

	/* Node */
	ret = trace_seq_printf(s, "%4d   ", entry->node);
	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;

	/* Call site */
	ret = seq_print_ip_sym(s, entry->call_site, 0);
	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;

	if (!trace_seq_printf(s, "\n"))
		return TRACE_TYPE_PARTIAL_LINE;

	return TRACE_TYPE_HANDLED;
}

static enum print_line_t
kmemtrace_print_free_compress(struct trace_iterator *iter,
			      struct kmemtrace_free_entry *entry)
{
	struct trace_seq *s = &iter->seq;
	int ret;

	/* Free entry */
	ret = trace_seq_printf(s, "  -      ");
	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;

	/* Type */
	switch (entry->type_id) {
	case KMEMTRACE_TYPE_KMALLOC:
		ret = trace_seq_printf(s, "K     ");
		break;
	case KMEMTRACE_TYPE_CACHE:
		ret = trace_seq_printf(s, "C     ");
		break;
	case KMEMTRACE_TYPE_PAGES:
		ret = trace_seq_printf(s, "P     ");
		break;
	default:
		ret = trace_seq_printf(s, "?     ");
	}

	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;

	/* Skip requested/allocated/flags */
	ret = trace_seq_printf(s, "                       ");
	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;

	/* Pointer to allocated */
	ret = trace_seq_printf(s, "0x%tx   ", (ptrdiff_t)entry->ptr);
	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;

	/* Skip node */
	ret = trace_seq_printf(s, "       ");
	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;

	/* Call site */
	ret = seq_print_ip_sym(s, entry->call_site, 0);
	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;

	if (!trace_seq_printf(s, "\n"))
		return TRACE_TYPE_PARTIAL_LINE;

	return TRACE_TYPE_HANDLED;
}

static enum print_line_t kmemtrace_print_line(struct trace_iterator *iter)
{
	struct trace_entry *entry = iter->ent;

	switch (entry->type) {
	case TRACE_KMEM_ALLOC: {
		struct kmemtrace_alloc_entry *field;

		trace_assign_type(field, entry);
		if (kmem_tracer_flags.val & TRACE_KMEM_OPT_MINIMAL)
			return kmemtrace_print_alloc_compress(iter, field);
		else
			return kmemtrace_print_alloc_user(iter, field);
	}

	case TRACE_KMEM_FREE: {
		struct kmemtrace_free_entry *field;

		trace_assign_type(field, entry);
		if (kmem_tracer_flags.val & TRACE_KMEM_OPT_MINIMAL)
			return kmemtrace_print_free_compress(iter, field);
		else
			return kmemtrace_print_free_user(iter, field);
	}

	default:
		return TRACE_TYPE_UNHANDLED;
	}
}

static struct tracer kmem_tracer __read_mostly = {
	.name			= "kmemtrace",
	.init			= kmem_trace_init,
	.reset			= kmem_trace_reset,
	.print_line		= kmemtrace_print_line,
	.print_header		= kmemtrace_headers,
	.flags			= &kmem_tracer_flags
};

void kmemtrace_init(void)
{
	/* earliest opportunity to start kmem tracing */
}

static int __init init_kmem_tracer(void)
{
	return register_tracer(&kmem_tracer);
}
device_initcall(init_kmem_tracer);