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1 | /* |
2 | * linux/kernel/acct.c |
3 | * |
4 | * BSD Process Accounting for Linux |
5 | * |
6 | * Author: Marco van Wieringen <mvw@planets.elm.net> |
7 | * |
8 | * Some code based on ideas and code from: |
9 | * Thomas K. Dyas <tdyas@eden.rutgers.edu> |
10 | * |
11 | * This file implements BSD-style process accounting. Whenever any |
12 | * process exits, an accounting record of type "struct acct" is |
13 | * written to the file specified with the acct() system call. It is |
14 | * up to user-level programs to do useful things with the accounting |
15 | * log. The kernel just provides the raw accounting information. |
16 | * |
17 | * (C) Copyright 1995 - 1997 Marco van Wieringen - ELM Consultancy B.V. |
18 | * |
19 | * Plugged two leaks. 1) It didn't return acct_file into the free_filps if |
20 | * the file happened to be read-only. 2) If the accounting was suspended |
21 | * due to the lack of space it happily allowed to reopen it and completely |
22 | * lost the old acct_file. 3/10/98, Al Viro. |
23 | * |
24 | * Now we silently close acct_file on attempt to reopen. Cleaned sys_acct(). |
25 | * XTerms and EMACS are manifestations of pure evil. 21/10/98, AV. |
26 | * |
27 | * Fixed a nasty interaction with with sys_umount(). If the accointing |
28 | * was suspeneded we failed to stop it on umount(). Messy. |
29 | * Another one: remount to readonly didn't stop accounting. |
30 | * Question: what should we do if we have CAP_SYS_ADMIN but not |
31 | * CAP_SYS_PACCT? Current code does the following: umount returns -EBUSY |
32 | * unless we are messing with the root. In that case we are getting a |
33 | * real mess with do_remount_sb(). 9/11/98, AV. |
34 | * |
35 | * Fixed a bunch of races (and pair of leaks). Probably not the best way, |
36 | * but this one obviously doesn't introduce deadlocks. Later. BTW, found |
37 | * one race (and leak) in BSD implementation. |
38 | * OK, that's better. ANOTHER race and leak in BSD variant. There always |
39 | * is one more bug... 10/11/98, AV. |
40 | * |
41 | * Oh, fsck... Oopsable SMP race in do_process_acct() - we must hold |
42 | * ->mmap_sem to walk the vma list of current->mm. Nasty, since it leaks |
43 | * a struct file opened for write. Fixed. 2/6/2000, AV. |
44 | */ |
45 | |
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> /* sector_div */ |
61 | #include <linux/pid_namespace.h> |
62 | |
63 | /* |
64 | * These constants control the amount of freespace that suspend and |
65 | * resume the process accounting system, and the time delay between |
66 | * each check. |
67 | * Turned into sysctl-controllable parameters. AV, 12/11/98 |
68 | */ |
69 | |
70 | int acct_parm[3] = {4, 2, 30}; |
71 | #define RESUME (acct_parm[0]) /* >foo% free space - resume */ |
72 | #define SUSPEND (acct_parm[1]) /* <foo% free space - suspend */ |
73 | #define ACCT_TIMEOUT (acct_parm[2]) /* foo second timeout between checks */ |
74 | |
75 | /* |
76 | * External references and all of the globals. |
77 | */ |
78 | static void do_acct_process(struct bsd_acct_struct *acct, |
79 | struct pid_namespace *ns, struct file *); |
80 | |
81 | /* |
82 | * This structure is used so that all the data protected by lock |
83 | * can be placed in the same cache line as the lock. This primes |
84 | * the cache line to have the data after getting the lock. |
85 | */ |
86 | struct 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 | |
94 | static DEFINE_SPINLOCK(acct_lock); |
95 | static LIST_HEAD(acct_list); |
96 | |
97 | /* |
98 | * Check the amount of free space and suspend/resume accordingly. |
99 | */ |
100 | static 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 | /* May block */ |
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 | * If some joker switched acct->file under us we'ld better be |
132 | * silent and _not_ touch anything. |
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; |
155 | out: |
156 | spin_unlock(&acct_lock); |
157 | return res; |
158 | } |
159 | |
160 | /* |
161 | * Close the old accounting file (if currently open) and then replace |
162 | * it with file (if non-NULL). |
163 | * |
164 | * NOTE: acct_lock MUST be held on entry and exit. |
165 | */ |
166 | static 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 | |
196 | static 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 | /* Difference from BSD - they don't do O_APPEND */ |
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); /* it's pinned, now give up active reference */ |
239 | kfree(acct); |
240 | |
241 | return 0; |
242 | } |
243 | |
244 | /** |
245 | * sys_acct - enable/disable process accounting |
246 | * @name: file name for accounting records or NULL to shutdown accounting |
247 | * |
248 | * Returns 0 for success or negative errno values for failure. |
249 | * |
250 | * sys_acct() is the only system call needed to implement process |
251 | * accounting. It takes the name of the file where accounting records |
252 | * should be written. If the filename is NULL, accounting will be |
253 | * shutdown. |
254 | */ |
255 | SYSCALL_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 | * acct_auto_close - turn off a filesystem's accounting if it is on |
285 | * @m: vfsmount being shut down |
286 | * |
287 | * If the accounting is turned on for a file in the subtree pointed to |
288 | * to by m, turn accounting off. Done when m is about to die. |
289 | */ |
290 | void acct_auto_close_mnt(struct vfsmount *m) |
291 | { |
292 | struct bsd_acct_struct *acct; |
293 | |
294 | spin_lock(&acct_lock); |
295 | restart: |
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 | * acct_auto_close - turn off a filesystem's accounting if it is on |
306 | * @sb: super block for the filesystem |
307 | * |
308 | * If the accounting is turned on for a file in the filesystem pointed |
309 | * to by sb, turn accounting off. |
310 | */ |
311 | void acct_auto_close(struct super_block *sb) |
312 | { |
313 | struct bsd_acct_struct *acct; |
314 | |
315 | spin_lock(&acct_lock); |
316 | restart: |
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 | |
325 | void 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 | * encode an unsigned long into a comp_t |
342 | * |
343 | * This routine has been adopted from the encode_comp_t() function in |
344 | * the kern_acct.c file of the FreeBSD operating system. The encoding |
345 | * is a 13-bit fraction with a 3-bit (base 8) exponent. |
346 | */ |
347 | |
348 | #define MANTSIZE 13 /* 13 bit mantissa. */ |
349 | #define EXPSIZE 3 /* Base 8 (3 bit) exponent. */ |
350 | #define MAXFRACT ((1 << MANTSIZE) - 1) /* Maximum fractional value. */ |
351 | |
352 | static 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)); /* Round up? */ |
359 | value >>= EXPSIZE; /* Base 8 exponent == 3 bit shift. */ |
360 | exp++; |
361 | } |
362 | |
363 | /* |
364 | * If we need to round up, do it (and handle overflow correctly). |
365 | */ |
366 | if (rnd && (++value > MAXFRACT)) { |
367 | value >>= EXPSIZE; |
368 | exp++; |
369 | } |
370 | |
371 | /* |
372 | * Clean it up and polish it off. |
373 | */ |
374 | exp <<= MANTSIZE; /* Shift the exponent into place */ |
375 | exp += value; /* and add on the mantissa. */ |
376 | return exp; |
377 | } |
378 | |
379 | #if ACCT_VERSION==1 || ACCT_VERSION==2 |
380 | /* |
381 | * encode an u64 into a comp2_t (24 bits) |
382 | * |
383 | * Format: 5 bit base 2 exponent, 20 bits mantissa. |
384 | * The leading bit of the mantissa is not stored, but implied for |
385 | * non-zero exponents. |
386 | * Largest encodable value is 50 bits. |
387 | */ |
388 | |
389 | #define MANTSIZE2 20 /* 20 bit mantissa. */ |
390 | #define EXPSIZE2 5 /* 5 bit base 2 exponent. */ |
391 | #define MAXFRACT2 ((1ul << MANTSIZE2) - 1) /* Maximum fractional value. */ |
392 | #define MAXEXP2 ((1 <<EXPSIZE2) - 1) /* Maximum exponent. */ |
393 | |
394 | static 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 | * If we need to round up, do it (and handle overflow correctly). |
408 | */ |
409 | if (rnd && (++value > MAXFRACT2)) { |
410 | value >>= 1; |
411 | exp++; |
412 | } |
413 | |
414 | if (exp > MAXEXP2) { |
415 | /* Overflow. Return largest representable number instead. */ |
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 | * encode an u64 into a 32 bit IEEE float |
426 | */ |
427 | static 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 | /* |
443 | * Write an accounting entry for an exiting process |
444 | * |
445 | * The acct_process() call is the workhorse of the process |
446 | * accounting system. The struct acct is built here and then written |
447 | * into the accounting file. This function should only be called from |
448 | * do_exit() or when switching to a different output file. |
449 | */ |
450 | |
451 | /* |
452 | * do_acct_process does all actual work. Caller holds the reference to file. |
453 | */ |
454 | static 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 | /* Perform file operations on behalf of whoever enabled accounting */ |
468 | orig_cred = override_creds(file->f_cred); |
469 | |
470 | /* |
471 | * First check to see if there is enough free_space to continue |
472 | * the process accounting system. |
473 | */ |
474 | if (!check_free_space(acct, file)) |
475 | goto out; |
476 | |
477 | /* |
478 | * Fill the accounting struct with the needed info as recorded |
479 | * by the different kernel functions. |
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 | /* calculate run_time in nsec*/ |
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 | /* convert nsec -> AHZ */ |
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 | /* new enlarged etime field */ |
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 | /* we really need to bite the bullet and change layout */ |
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 | /* backward-compatible 16 bit fields */ |
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; /* Safe as we hold the siglock */ |
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 /* current->io_usage */); /* %% */ |
539 | ac.ac_rw = encode_comp_t(ac.ac_io / 1024); |
540 | ac.ac_swaps = encode_comp_t(0); |
541 | |
542 | /* |
543 | * Get freeze protection. If the fs is frozen, just skip the write |
544 | * as we could deadlock the system otherwise. |
545 | */ |
546 | if (!file_start_write_trylock(file)) |
547 | goto out; |
548 | /* |
549 | * Kernel segment override to datasegment and write it |
550 | * to the accounting file. |
551 | */ |
552 | fs = get_fs(); |
553 | set_fs(KERNEL_DS); |
554 | /* |
555 | * Accounting records are not subject to resource limits. |
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); |
564 | out: |
565 | revert_creds(orig_cred); |
566 | } |
567 | |
568 | /** |
569 | * acct_collect - collect accounting information into pacct_struct |
570 | * @exitcode: task exit code |
571 | * @group_dead: not 0, if this thread is the last one in the process. |
572 | */ |
573 | void 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 | |
612 | static 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 | * accelerate the common fastpath: |
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 | * acct_process - now just a wrapper around acct_process_in_ns, |
639 | * which in turn is a wrapper around do_acct_process. |
640 | * |
641 | * handles process accounting for an exiting task |
642 | */ |
643 | void acct_process(void) |
644 | { |
645 | struct pid_namespace *ns; |
646 | |
647 | /* |
648 | * This loop is safe lockless, since current is still |
649 | * alive and holds its namespace, which in turn holds |
650 | * its parent. |
651 | */ |
652 | for (ns = task_active_pid_ns(current); ns != NULL; ns = ns->parent) |
653 | acct_process_in_ns(ns); |
654 | } |
655 |
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ben-wpan
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javiroman/ks7010
jz-2.6.34
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Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9