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24#include <linux/file.h>
25#include <linux/mm.h>
26#include <linux/workqueue.h>
27#include <linux/notifier.h>
28#include <linux/dcookies.h>
29#include <linux/profile.h>
30#include <linux/module.h>
31#include <linux/fs.h>
32#include <linux/oprofile.h>
33#include <linux/sched.h>
34#include <linux/gfp.h>
35
36#include "oprofile_stats.h"
37#include "event_buffer.h"
38#include "cpu_buffer.h"
39#include "buffer_sync.h"
40
41static LIST_HEAD(dying_tasks);
42static LIST_HEAD(dead_tasks);
43static cpumask_var_t marked_cpus;
44static DEFINE_SPINLOCK(task_mortuary);
45static void process_task_mortuary(void);
46
47
48
49
50
51
52
53
54static int
55task_free_notify(struct notifier_block *self, unsigned long val, void *data)
56{
57 unsigned long flags;
58 struct task_struct *task = data;
59 spin_lock_irqsave(&task_mortuary, flags);
60 list_add(&task->tasks, &dying_tasks);
61 spin_unlock_irqrestore(&task_mortuary, flags);
62 return NOTIFY_OK;
63}
64
65
66
67
68
69static int
70task_exit_notify(struct notifier_block *self, unsigned long val, void *data)
71{
72
73
74
75 sync_buffer(raw_smp_processor_id());
76 return 0;
77}
78
79
80
81
82
83
84
85static int
86munmap_notify(struct notifier_block *self, unsigned long val, void *data)
87{
88 unsigned long addr = (unsigned long)data;
89 struct mm_struct *mm = current->mm;
90 struct vm_area_struct *mpnt;
91
92 down_read(&mm->mmap_sem);
93
94 mpnt = find_vma(mm, addr);
95 if (mpnt && mpnt->vm_file && (mpnt->vm_flags & VM_EXEC)) {
96 up_read(&mm->mmap_sem);
97
98
99
100 sync_buffer(raw_smp_processor_id());
101 return 0;
102 }
103
104 up_read(&mm->mmap_sem);
105 return 0;
106}
107
108
109
110
111
112static int
113module_load_notify(struct notifier_block *self, unsigned long val, void *data)
114{
115#ifdef CONFIG_MODULES
116 if (val != MODULE_STATE_COMING)
117 return 0;
118
119
120 mutex_lock(&buffer_mutex);
121 add_event_entry(ESCAPE_CODE);
122 add_event_entry(MODULE_LOADED_CODE);
123 mutex_unlock(&buffer_mutex);
124#endif
125 return 0;
126}
127
128
129static struct notifier_block task_free_nb = {
130 .notifier_call = task_free_notify,
131};
132
133static struct notifier_block task_exit_nb = {
134 .notifier_call = task_exit_notify,
135};
136
137static struct notifier_block munmap_nb = {
138 .notifier_call = munmap_notify,
139};
140
141static struct notifier_block module_load_nb = {
142 .notifier_call = module_load_notify,
143};
144
145static void free_all_tasks(void)
146{
147
148 process_task_mortuary();
149 process_task_mortuary();
150}
151
152int sync_start(void)
153{
154 int err;
155
156 if (!zalloc_cpumask_var(&marked_cpus, GFP_KERNEL))
157 return -ENOMEM;
158
159 err = task_handoff_register(&task_free_nb);
160 if (err)
161 goto out1;
162 err = profile_event_register(PROFILE_TASK_EXIT, &task_exit_nb);
163 if (err)
164 goto out2;
165 err = profile_event_register(PROFILE_MUNMAP, &munmap_nb);
166 if (err)
167 goto out3;
168 err = register_module_notifier(&module_load_nb);
169 if (err)
170 goto out4;
171
172 start_cpu_work();
173
174out:
175 return err;
176out4:
177 profile_event_unregister(PROFILE_MUNMAP, &munmap_nb);
178out3:
179 profile_event_unregister(PROFILE_TASK_EXIT, &task_exit_nb);
180out2:
181 task_handoff_unregister(&task_free_nb);
182 free_all_tasks();
183out1:
184 free_cpumask_var(marked_cpus);
185 goto out;
186}
187
188
189void sync_stop(void)
190{
191 end_cpu_work();
192 unregister_module_notifier(&module_load_nb);
193 profile_event_unregister(PROFILE_MUNMAP, &munmap_nb);
194 profile_event_unregister(PROFILE_TASK_EXIT, &task_exit_nb);
195 task_handoff_unregister(&task_free_nb);
196 barrier();
197
198 flush_cpu_work();
199
200 free_all_tasks();
201 free_cpumask_var(marked_cpus);
202}
203
204
205
206
207
208
209static inline unsigned long fast_get_dcookie(struct path *path)
210{
211 unsigned long cookie;
212
213 if (path->dentry->d_flags & DCACHE_COOKIE)
214 return (unsigned long)path->dentry;
215 get_dcookie(path, &cookie);
216 return cookie;
217}
218
219
220
221
222
223
224
225static unsigned long get_exec_dcookie(struct mm_struct *mm)
226{
227 unsigned long cookie = NO_COOKIE;
228 struct file *exe_file;
229
230 if (!mm)
231 goto done;
232
233 exe_file = get_mm_exe_file(mm);
234 if (!exe_file)
235 goto done;
236
237 cookie = fast_get_dcookie(&exe_file->f_path);
238 fput(exe_file);
239done:
240 return cookie;
241}
242
243
244
245
246
247
248
249
250
251static unsigned long
252lookup_dcookie(struct mm_struct *mm, unsigned long addr, off_t *offset)
253{
254 unsigned long cookie = NO_COOKIE;
255 struct vm_area_struct *vma;
256
257 down_read(&mm->mmap_sem);
258 for (vma = find_vma(mm, addr); vma; vma = vma->vm_next) {
259
260 if (addr < vma->vm_start || addr >= vma->vm_end)
261 continue;
262
263 if (vma->vm_file) {
264 cookie = fast_get_dcookie(&vma->vm_file->f_path);
265 *offset = (vma->vm_pgoff << PAGE_SHIFT) + addr -
266 vma->vm_start;
267 } else {
268
269 *offset = addr;
270 }
271
272 break;
273 }
274
275 if (!vma)
276 cookie = INVALID_COOKIE;
277 up_read(&mm->mmap_sem);
278
279 return cookie;
280}
281
282static unsigned long last_cookie = INVALID_COOKIE;
283
284static void add_cpu_switch(int i)
285{
286 add_event_entry(ESCAPE_CODE);
287 add_event_entry(CPU_SWITCH_CODE);
288 add_event_entry(i);
289 last_cookie = INVALID_COOKIE;
290}
291
292static void add_kernel_ctx_switch(unsigned int in_kernel)
293{
294 add_event_entry(ESCAPE_CODE);
295 if (in_kernel)
296 add_event_entry(KERNEL_ENTER_SWITCH_CODE);
297 else
298 add_event_entry(KERNEL_EXIT_SWITCH_CODE);
299}
300
301static void
302add_user_ctx_switch(struct task_struct const *task, unsigned long cookie)
303{
304 add_event_entry(ESCAPE_CODE);
305 add_event_entry(CTX_SWITCH_CODE);
306 add_event_entry(task->pid);
307 add_event_entry(cookie);
308
309 add_event_entry(ESCAPE_CODE);
310 add_event_entry(CTX_TGID_CODE);
311 add_event_entry(task->tgid);
312}
313
314
315static void add_cookie_switch(unsigned long cookie)
316{
317 add_event_entry(ESCAPE_CODE);
318 add_event_entry(COOKIE_SWITCH_CODE);
319 add_event_entry(cookie);
320}
321
322
323static void add_trace_begin(void)
324{
325 add_event_entry(ESCAPE_CODE);
326 add_event_entry(TRACE_BEGIN_CODE);
327}
328
329static void add_data(struct op_entry *entry, struct mm_struct *mm)
330{
331 unsigned long code, pc, val;
332 unsigned long cookie;
333 off_t offset;
334
335 if (!op_cpu_buffer_get_data(entry, &code))
336 return;
337 if (!op_cpu_buffer_get_data(entry, &pc))
338 return;
339 if (!op_cpu_buffer_get_size(entry))
340 return;
341
342 if (mm) {
343 cookie = lookup_dcookie(mm, pc, &offset);
344
345 if (cookie == NO_COOKIE)
346 offset = pc;
347 if (cookie == INVALID_COOKIE) {
348 atomic_inc(&oprofile_stats.sample_lost_no_mapping);
349 offset = pc;
350 }
351 if (cookie != last_cookie) {
352 add_cookie_switch(cookie);
353 last_cookie = cookie;
354 }
355 } else
356 offset = pc;
357
358 add_event_entry(ESCAPE_CODE);
359 add_event_entry(code);
360 add_event_entry(offset);
361
362 while (op_cpu_buffer_get_data(entry, &val))
363 add_event_entry(val);
364}
365
366static inline void add_sample_entry(unsigned long offset, unsigned long event)
367{
368 add_event_entry(offset);
369 add_event_entry(event);
370}
371
372
373
374
375
376
377
378static int
379add_sample(struct mm_struct *mm, struct op_sample *s, int in_kernel)
380{
381 unsigned long cookie;
382 off_t offset;
383
384 if (in_kernel) {
385 add_sample_entry(s->eip, s->event);
386 return 1;
387 }
388
389
390
391 if (!mm) {
392 atomic_inc(&oprofile_stats.sample_lost_no_mm);
393 return 0;
394 }
395
396 cookie = lookup_dcookie(mm, s->eip, &offset);
397
398 if (cookie == INVALID_COOKIE) {
399 atomic_inc(&oprofile_stats.sample_lost_no_mapping);
400 return 0;
401 }
402
403 if (cookie != last_cookie) {
404 add_cookie_switch(cookie);
405 last_cookie = cookie;
406 }
407
408 add_sample_entry(offset, s->event);
409
410 return 1;
411}
412
413
414static void release_mm(struct mm_struct *mm)
415{
416 if (!mm)
417 return;
418 mmput(mm);
419}
420
421static inline int is_code(unsigned long val)
422{
423 return val == ESCAPE_CODE;
424}
425
426
427
428
429
430
431
432
433static void process_task_mortuary(void)
434{
435 unsigned long flags;
436 LIST_HEAD(local_dead_tasks);
437 struct task_struct *task;
438 struct task_struct *ttask;
439
440 spin_lock_irqsave(&task_mortuary, flags);
441
442 list_splice_init(&dead_tasks, &local_dead_tasks);
443 list_splice_init(&dying_tasks, &dead_tasks);
444
445 spin_unlock_irqrestore(&task_mortuary, flags);
446
447 list_for_each_entry_safe(task, ttask, &local_dead_tasks, tasks) {
448 list_del(&task->tasks);
449 free_task(task);
450 }
451}
452
453
454static void mark_done(int cpu)
455{
456 int i;
457
458 cpumask_set_cpu(cpu, marked_cpus);
459
460 for_each_online_cpu(i) {
461 if (!cpumask_test_cpu(i, marked_cpus))
462 return;
463 }
464
465
466
467
468 process_task_mortuary();
469
470 cpumask_clear(marked_cpus);
471}
472
473
474
475
476
477
478typedef enum {
479 sb_bt_ignore = -2,
480 sb_buffer_start,
481 sb_bt_start,
482 sb_sample_start,
483} sync_buffer_state;
484
485
486
487
488
489
490
491void sync_buffer(int cpu)
492{
493 struct mm_struct *mm = NULL;
494 struct mm_struct *oldmm;
495 unsigned long val;
496 struct task_struct *new;
497 unsigned long cookie = 0;
498 int in_kernel = 1;
499 sync_buffer_state state = sb_buffer_start;
500 unsigned int i;
501 unsigned long available;
502 unsigned long flags;
503 struct op_entry entry;
504 struct op_sample *sample;
505
506 mutex_lock(&buffer_mutex);
507
508 add_cpu_switch(cpu);
509
510 op_cpu_buffer_reset(cpu);
511 available = op_cpu_buffer_entries(cpu);
512
513 for (i = 0; i < available; ++i) {
514 sample = op_cpu_buffer_read_entry(&entry, cpu);
515 if (!sample)
516 break;
517
518 if (is_code(sample->eip)) {
519 flags = sample->event;
520 if (flags & TRACE_BEGIN) {
521 state = sb_bt_start;
522 add_trace_begin();
523 }
524 if (flags & KERNEL_CTX_SWITCH) {
525
526 in_kernel = flags & IS_KERNEL;
527 if (state == sb_buffer_start)
528 state = sb_sample_start;
529 add_kernel_ctx_switch(flags & IS_KERNEL);
530 }
531 if (flags & USER_CTX_SWITCH
532 && op_cpu_buffer_get_data(&entry, &val)) {
533
534 new = (struct task_struct *)val;
535 oldmm = mm;
536 release_mm(oldmm);
537 mm = get_task_mm(new);
538 if (mm != oldmm)
539 cookie = get_exec_dcookie(mm);
540 add_user_ctx_switch(new, cookie);
541 }
542 if (op_cpu_buffer_get_size(&entry))
543 add_data(&entry, mm);
544 continue;
545 }
546
547 if (state < sb_bt_start)
548
549 continue;
550
551 if (add_sample(mm, sample, in_kernel))
552 continue;
553
554
555 if (state == sb_bt_start) {
556 state = sb_bt_ignore;
557 atomic_inc(&oprofile_stats.bt_lost_no_mapping);
558 }
559 }
560 release_mm(mm);
561
562 mark_done(cpu);
563
564 mutex_unlock(&buffer_mutex);
565}
566
567
568
569
570
571
572void oprofile_put_buff(unsigned long *buf, unsigned int start,
573 unsigned int stop, unsigned int max)
574{
575 int i;
576
577 i = start;
578
579 mutex_lock(&buffer_mutex);
580 while (i != stop) {
581 add_event_entry(buf[i++]);
582
583 if (i >= max)
584 i = 0;
585 }
586
587 mutex_unlock(&buffer_mutex);
588}
589
590