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46#include <linux/mm.h>
47#include <linux/slab.h>
48#include <linux/acct.h>
49#include <linux/capability.h>
50#include <linux/file.h>
51#include <linux/tty.h>
52#include <linux/security.h>
53#include <linux/vfs.h>
54#include <linux/jiffies.h>
55#include <linux/times.h>
56#include <linux/syscalls.h>
57#include <linux/mount.h>
58#include <asm/uaccess.h>
59#include <asm/div64.h>
60#include <linux/blkdev.h>
61#include <linux/pid_namespace.h>
62
63
64
65
66
67
68
69
70int acct_parm[3] = {4, 2, 30};
71#define RESUME (acct_parm[0])
72#define SUSPEND (acct_parm[1])
73#define ACCT_TIMEOUT (acct_parm[2])
74
75
76
77
78static void do_acct_process(struct bsd_acct_struct *acct,
79 struct pid_namespace *ns, struct file *);
80
81
82
83
84
85
86struct bsd_acct_struct {
87 int active;
88 unsigned long needcheck;
89 struct file *file;
90 struct pid_namespace *ns;
91 struct list_head list;
92};
93
94static DEFINE_SPINLOCK(acct_lock);
95static LIST_HEAD(acct_list);
96
97
98
99
100static int check_free_space(struct bsd_acct_struct *acct, struct file *file)
101{
102 struct kstatfs sbuf;
103 int res;
104 int act;
105 u64 resume;
106 u64 suspend;
107
108 spin_lock(&acct_lock);
109 res = acct->active;
110 if (!file || time_is_before_jiffies(acct->needcheck))
111 goto out;
112 spin_unlock(&acct_lock);
113
114
115 if (vfs_statfs(&file->f_path, &sbuf))
116 return res;
117 suspend = sbuf.f_blocks * SUSPEND;
118 resume = sbuf.f_blocks * RESUME;
119
120 do_div(suspend, 100);
121 do_div(resume, 100);
122
123 if (sbuf.f_bavail <= suspend)
124 act = -1;
125 else if (sbuf.f_bavail >= resume)
126 act = 1;
127 else
128 act = 0;
129
130
131
132
133
134 spin_lock(&acct_lock);
135 if (file != acct->file) {
136 if (act)
137 res = act>0;
138 goto out;
139 }
140
141 if (acct->active) {
142 if (act < 0) {
143 acct->active = 0;
144 printk(KERN_INFO "Process accounting paused\n");
145 }
146 } else {
147 if (act > 0) {
148 acct->active = 1;
149 printk(KERN_INFO "Process accounting resumed\n");
150 }
151 }
152
153 acct->needcheck = jiffies + ACCT_TIMEOUT*HZ;
154 res = acct->active;
155out:
156 spin_unlock(&acct_lock);
157 return res;
158}
159
160
161
162
163
164
165
166static void acct_file_reopen(struct bsd_acct_struct *acct, struct file *file,
167 struct pid_namespace *ns)
168{
169 struct file *old_acct = NULL;
170 struct pid_namespace *old_ns = NULL;
171
172 if (acct->file) {
173 old_acct = acct->file;
174 old_ns = acct->ns;
175 acct->active = 0;
176 acct->file = NULL;
177 acct->ns = NULL;
178 list_del(&acct->list);
179 }
180 if (file) {
181 acct->file = file;
182 acct->ns = ns;
183 acct->needcheck = jiffies + ACCT_TIMEOUT*HZ;
184 acct->active = 1;
185 list_add(&acct->list, &acct_list);
186 }
187 if (old_acct) {
188 mnt_unpin(old_acct->f_path.mnt);
189 spin_unlock(&acct_lock);
190 do_acct_process(acct, old_ns, old_acct);
191 filp_close(old_acct, NULL);
192 spin_lock(&acct_lock);
193 }
194}
195
196static int acct_on(struct filename *pathname)
197{
198 struct file *file;
199 struct vfsmount *mnt;
200 struct pid_namespace *ns;
201 struct bsd_acct_struct *acct = NULL;
202
203
204 file = file_open_name(pathname, O_WRONLY|O_APPEND|O_LARGEFILE, 0);
205 if (IS_ERR(file))
206 return PTR_ERR(file);
207
208 if (!S_ISREG(file_inode(file)->i_mode)) {
209 filp_close(file, NULL);
210 return -EACCES;
211 }
212
213 if (!file->f_op->write) {
214 filp_close(file, NULL);
215 return -EIO;
216 }
217
218 ns = task_active_pid_ns(current);
219 if (ns->bacct == NULL) {
220 acct = kzalloc(sizeof(struct bsd_acct_struct), GFP_KERNEL);
221 if (acct == NULL) {
222 filp_close(file, NULL);
223 return -ENOMEM;
224 }
225 }
226
227 spin_lock(&acct_lock);
228 if (ns->bacct == NULL) {
229 ns->bacct = acct;
230 acct = NULL;
231 }
232
233 mnt = file->f_path.mnt;
234 mnt_pin(mnt);
235 acct_file_reopen(ns->bacct, file, ns);
236 spin_unlock(&acct_lock);
237
238 mntput(mnt);
239 kfree(acct);
240
241 return 0;
242}
243
244
245
246
247
248
249
250
251
252
253
254
255SYSCALL_DEFINE1(acct, const char __user *, name)
256{
257 int error = 0;
258
259 if (!capable(CAP_SYS_PACCT))
260 return -EPERM;
261
262 if (name) {
263 struct filename *tmp = getname(name);
264 if (IS_ERR(tmp))
265 return (PTR_ERR(tmp));
266 error = acct_on(tmp);
267 putname(tmp);
268 } else {
269 struct bsd_acct_struct *acct;
270
271 acct = task_active_pid_ns(current)->bacct;
272 if (acct == NULL)
273 return 0;
274
275 spin_lock(&acct_lock);
276 acct_file_reopen(acct, NULL, NULL);
277 spin_unlock(&acct_lock);
278 }
279
280 return error;
281}
282
283
284
285
286
287
288
289
290void acct_auto_close_mnt(struct vfsmount *m)
291{
292 struct bsd_acct_struct *acct;
293
294 spin_lock(&acct_lock);
295restart:
296 list_for_each_entry(acct, &acct_list, list)
297 if (acct->file && acct->file->f_path.mnt == m) {
298 acct_file_reopen(acct, NULL, NULL);
299 goto restart;
300 }
301 spin_unlock(&acct_lock);
302}
303
304
305
306
307
308
309
310
311void acct_auto_close(struct super_block *sb)
312{
313 struct bsd_acct_struct *acct;
314
315 spin_lock(&acct_lock);
316restart:
317 list_for_each_entry(acct, &acct_list, list)
318 if (acct->file && acct->file->f_path.dentry->d_sb == sb) {
319 acct_file_reopen(acct, NULL, NULL);
320 goto restart;
321 }
322 spin_unlock(&acct_lock);
323}
324
325void acct_exit_ns(struct pid_namespace *ns)
326{
327 struct bsd_acct_struct *acct = ns->bacct;
328
329 if (acct == NULL)
330 return;
331
332 spin_lock(&acct_lock);
333 if (acct->file != NULL)
334 acct_file_reopen(acct, NULL, NULL);
335 spin_unlock(&acct_lock);
336
337 kfree(acct);
338}
339
340
341
342
343
344
345
346
347
348#define MANTSIZE 13
349#define EXPSIZE 3
350#define MAXFRACT ((1 << MANTSIZE) - 1)
351
352static comp_t encode_comp_t(unsigned long value)
353{
354 int exp, rnd;
355
356 exp = rnd = 0;
357 while (value > MAXFRACT) {
358 rnd = value & (1 << (EXPSIZE - 1));
359 value >>= EXPSIZE;
360 exp++;
361 }
362
363
364
365
366 if (rnd && (++value > MAXFRACT)) {
367 value >>= EXPSIZE;
368 exp++;
369 }
370
371
372
373
374 exp <<= MANTSIZE;
375 exp += value;
376 return exp;
377}
378
379#if ACCT_VERSION==1 || ACCT_VERSION==2
380
381
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386
387
388
389#define MANTSIZE2 20
390#define EXPSIZE2 5
391#define MAXFRACT2 ((1ul << MANTSIZE2) - 1)
392#define MAXEXP2 ((1 <<EXPSIZE2) - 1)
393
394static comp2_t encode_comp2_t(u64 value)
395{
396 int exp, rnd;
397
398 exp = (value > (MAXFRACT2>>1));
399 rnd = 0;
400 while (value > MAXFRACT2) {
401 rnd = value & 1;
402 value >>= 1;
403 exp++;
404 }
405
406
407
408
409 if (rnd && (++value > MAXFRACT2)) {
410 value >>= 1;
411 exp++;
412 }
413
414 if (exp > MAXEXP2) {
415
416 return (1ul << (MANTSIZE2+EXPSIZE2-1)) - 1;
417 } else {
418 return (value & (MAXFRACT2>>1)) | (exp << (MANTSIZE2-1));
419 }
420}
421#endif
422
423#if ACCT_VERSION==3
424
425
426
427static u32 encode_float(u64 value)
428{
429 unsigned exp = 190;
430 unsigned u;
431
432 if (value==0) return 0;
433 while ((s64)value > 0){
434 value <<= 1;
435 exp--;
436 }
437 u = (u32)(value >> 40) & 0x7fffffu;
438 return u | (exp << 23);
439}
440#endif
441
442
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445
446
447
448
449
450
451
452
453
454static void do_acct_process(struct bsd_acct_struct *acct,
455 struct pid_namespace *ns, struct file *file)
456{
457 struct pacct_struct *pacct = ¤t->signal->pacct;
458 acct_t ac;
459 mm_segment_t fs;
460 unsigned long flim;
461 u64 elapsed;
462 u64 run_time;
463 struct timespec uptime;
464 struct tty_struct *tty;
465 const struct cred *orig_cred;
466
467
468 orig_cred = override_creds(file->f_cred);
469
470
471
472
473
474 if (!check_free_space(acct, file))
475 goto out;
476
477
478
479
480
481 memset(&ac, 0, sizeof(acct_t));
482
483 ac.ac_version = ACCT_VERSION | ACCT_BYTEORDER;
484 strlcpy(ac.ac_comm, current->comm, sizeof(ac.ac_comm));
485
486
487 do_posix_clock_monotonic_gettime(&uptime);
488 run_time = (u64)uptime.tv_sec*NSEC_PER_SEC + uptime.tv_nsec;
489 run_time -= (u64)current->group_leader->start_time.tv_sec * NSEC_PER_SEC
490 + current->group_leader->start_time.tv_nsec;
491
492 elapsed = nsec_to_AHZ(run_time);
493#if ACCT_VERSION==3
494 ac.ac_etime = encode_float(elapsed);
495#else
496 ac.ac_etime = encode_comp_t(elapsed < (unsigned long) -1l ?
497 (unsigned long) elapsed : (unsigned long) -1l);
498#endif
499#if ACCT_VERSION==1 || ACCT_VERSION==2
500 {
501
502 comp2_t etime = encode_comp2_t(elapsed);
503 ac.ac_etime_hi = etime >> 16;
504 ac.ac_etime_lo = (u16) etime;
505 }
506#endif
507 do_div(elapsed, AHZ);
508 ac.ac_btime = get_seconds() - elapsed;
509
510 ac.ac_uid = from_kuid_munged(file->f_cred->user_ns, orig_cred->uid);
511 ac.ac_gid = from_kgid_munged(file->f_cred->user_ns, orig_cred->gid);
512#if ACCT_VERSION==2
513 ac.ac_ahz = AHZ;
514#endif
515#if ACCT_VERSION==1 || ACCT_VERSION==2
516
517 ac.ac_uid16 = ac.ac_uid;
518 ac.ac_gid16 = ac.ac_gid;
519#endif
520#if ACCT_VERSION==3
521 ac.ac_pid = task_tgid_nr_ns(current, ns);
522 rcu_read_lock();
523 ac.ac_ppid = task_tgid_nr_ns(rcu_dereference(current->real_parent), ns);
524 rcu_read_unlock();
525#endif
526
527 spin_lock_irq(¤t->sighand->siglock);
528 tty = current->signal->tty;
529 ac.ac_tty = tty ? old_encode_dev(tty_devnum(tty)) : 0;
530 ac.ac_utime = encode_comp_t(jiffies_to_AHZ(cputime_to_jiffies(pacct->ac_utime)));
531 ac.ac_stime = encode_comp_t(jiffies_to_AHZ(cputime_to_jiffies(pacct->ac_stime)));
532 ac.ac_flag = pacct->ac_flag;
533 ac.ac_mem = encode_comp_t(pacct->ac_mem);
534 ac.ac_minflt = encode_comp_t(pacct->ac_minflt);
535 ac.ac_majflt = encode_comp_t(pacct->ac_majflt);
536 ac.ac_exitcode = pacct->ac_exitcode;
537 spin_unlock_irq(¤t->sighand->siglock);
538 ac.ac_io = encode_comp_t(0 );
539 ac.ac_rw = encode_comp_t(ac.ac_io / 1024);
540 ac.ac_swaps = encode_comp_t(0);
541
542
543
544
545
546 if (!file_start_write_trylock(file))
547 goto out;
548
549
550
551
552 fs = get_fs();
553 set_fs(KERNEL_DS);
554
555
556
557 flim = current->signal->rlim[RLIMIT_FSIZE].rlim_cur;
558 current->signal->rlim[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY;
559 file->f_op->write(file, (char *)&ac,
560 sizeof(acct_t), &file->f_pos);
561 current->signal->rlim[RLIMIT_FSIZE].rlim_cur = flim;
562 set_fs(fs);
563 file_end_write(file);
564out:
565 revert_creds(orig_cred);
566}
567
568
569
570
571
572
573void acct_collect(long exitcode, int group_dead)
574{
575 struct pacct_struct *pacct = ¤t->signal->pacct;
576 cputime_t utime, stime;
577 unsigned long vsize = 0;
578
579 if (group_dead && current->mm) {
580 struct vm_area_struct *vma;
581 down_read(¤t->mm->mmap_sem);
582 vma = current->mm->mmap;
583 while (vma) {
584 vsize += vma->vm_end - vma->vm_start;
585 vma = vma->vm_next;
586 }
587 up_read(¤t->mm->mmap_sem);
588 }
589
590 spin_lock_irq(¤t->sighand->siglock);
591 if (group_dead)
592 pacct->ac_mem = vsize / 1024;
593 if (thread_group_leader(current)) {
594 pacct->ac_exitcode = exitcode;
595 if (current->flags & PF_FORKNOEXEC)
596 pacct->ac_flag |= AFORK;
597 }
598 if (current->flags & PF_SUPERPRIV)
599 pacct->ac_flag |= ASU;
600 if (current->flags & PF_DUMPCORE)
601 pacct->ac_flag |= ACORE;
602 if (current->flags & PF_SIGNALED)
603 pacct->ac_flag |= AXSIG;
604 task_cputime(current, &utime, &stime);
605 pacct->ac_utime += utime;
606 pacct->ac_stime += stime;
607 pacct->ac_minflt += current->min_flt;
608 pacct->ac_majflt += current->maj_flt;
609 spin_unlock_irq(¤t->sighand->siglock);
610}
611
612static void acct_process_in_ns(struct pid_namespace *ns)
613{
614 struct file *file = NULL;
615 struct bsd_acct_struct *acct;
616
617 acct = ns->bacct;
618
619
620
621 if (!acct || !acct->file)
622 return;
623
624 spin_lock(&acct_lock);
625 file = acct->file;
626 if (unlikely(!file)) {
627 spin_unlock(&acct_lock);
628 return;
629 }
630 get_file(file);
631 spin_unlock(&acct_lock);
632
633 do_acct_process(acct, ns, file);
634 fput(file);
635}
636
637
638
639
640
641
642
643void acct_process(void)
644{
645 struct pid_namespace *ns;
646
647
648
649
650
651
652 for (ns = task_active_pid_ns(current); ns != NULL; ns = ns->parent)
653 acct_process_in_ns(ns);
654}
655