blob: 91e1cfd734d286f922597108e54065ef691d31b2 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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
Linus Torvalds1da177e2005-04-16 15:20:36 -070046#include <linux/mm.h>
47#include <linux/slab.h>
48#include <linux/acct.h>
Randy.Dunlapc59ede72006-01-11 12:17:46 -080049#include <linux/capability.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070050#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>
Al Viro7b7b1ac2005-11-07 17:13:39 -050057#include <linux/mount.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070058#include <asm/uaccess.h>
59#include <asm/div64.h>
60#include <linux/blkdev.h> /* sector_div */
Pavel Emelyanov5f7b7032008-03-24 12:29:53 -070061#include <linux/pid_namespace.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070062
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
70int 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 */
Pavel Emelyanov5f7b7032008-03-24 12:29:53 -070078static void do_acct_process(struct pid_namespace *ns, struct file *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070079
80/*
81 * This structure is used so that all the data protected by lock
82 * can be placed in the same cache line as the lock. This primes
83 * the cache line to have the data after getting the lock.
84 */
85struct acct_glbs {
86 spinlock_t lock;
87 volatile int active;
88 volatile int needcheck;
89 struct file *file;
Pavel Emelyanov5f7b7032008-03-24 12:29:53 -070090 struct pid_namespace *ns;
Linus Torvalds1da177e2005-04-16 15:20:36 -070091 struct timer_list timer;
92};
93
Peter Zijlstra6cfd76a2006-12-06 20:37:22 -080094static struct acct_glbs acct_globals __cacheline_aligned =
95 {__SPIN_LOCK_UNLOCKED(acct_globals.lock)};
Linus Torvalds1da177e2005-04-16 15:20:36 -070096
97/*
98 * Called whenever the timer says to check the free space.
99 */
100static void acct_timeout(unsigned long unused)
101{
102 acct_globals.needcheck = 1;
103}
104
105/*
106 * Check the amount of free space and suspend/resume accordingly.
107 */
108static int check_free_space(struct file *file)
109{
110 struct kstatfs sbuf;
111 int res;
112 int act;
113 sector_t resume;
114 sector_t suspend;
115
116 spin_lock(&acct_globals.lock);
117 res = acct_globals.active;
118 if (!file || !acct_globals.needcheck)
119 goto out;
120 spin_unlock(&acct_globals.lock);
121
122 /* May block */
Josef "Jeff" Sipekf3a43f32006-12-08 02:36:43 -0800123 if (vfs_statfs(file->f_path.dentry, &sbuf))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124 return res;
125 suspend = sbuf.f_blocks * SUSPEND;
126 resume = sbuf.f_blocks * RESUME;
127
128 sector_div(suspend, 100);
129 sector_div(resume, 100);
130
131 if (sbuf.f_bavail <= suspend)
132 act = -1;
133 else if (sbuf.f_bavail >= resume)
134 act = 1;
135 else
136 act = 0;
137
138 /*
139 * If some joker switched acct_globals.file under us we'ld better be
140 * silent and _not_ touch anything.
141 */
142 spin_lock(&acct_globals.lock);
143 if (file != acct_globals.file) {
144 if (act)
145 res = act>0;
146 goto out;
147 }
148
149 if (acct_globals.active) {
150 if (act < 0) {
151 acct_globals.active = 0;
152 printk(KERN_INFO "Process accounting paused\n");
153 }
154 } else {
155 if (act > 0) {
156 acct_globals.active = 1;
157 printk(KERN_INFO "Process accounting resumed\n");
158 }
159 }
160
161 del_timer(&acct_globals.timer);
162 acct_globals.needcheck = 0;
163 acct_globals.timer.expires = jiffies + ACCT_TIMEOUT*HZ;
164 add_timer(&acct_globals.timer);
165 res = acct_globals.active;
166out:
167 spin_unlock(&acct_globals.lock);
168 return res;
169}
170
171/*
Randy Dunlap417ef532005-09-10 00:26:39 -0700172 * Close the old accounting file (if currently open) and then replace
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173 * it with file (if non-NULL).
174 *
175 * NOTE: acct_globals.lock MUST be held on entry and exit.
176 */
177static void acct_file_reopen(struct file *file)
178{
179 struct file *old_acct = NULL;
Pavel Emelyanov5f7b7032008-03-24 12:29:53 -0700180 struct pid_namespace *old_ns = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181
182 if (acct_globals.file) {
183 old_acct = acct_globals.file;
Pavel Emelyanov5f7b7032008-03-24 12:29:53 -0700184 old_ns = acct_globals.ns;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185 del_timer(&acct_globals.timer);
186 acct_globals.active = 0;
187 acct_globals.needcheck = 0;
188 acct_globals.file = NULL;
189 }
190 if (file) {
191 acct_globals.file = file;
Pavel Emelyanov5f7b7032008-03-24 12:29:53 -0700192 acct_globals.ns = get_pid_ns(task_active_pid_ns(current));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193 acct_globals.needcheck = 0;
194 acct_globals.active = 1;
195 /* It's been deleted if it was used before so this is safe */
196 init_timer(&acct_globals.timer);
197 acct_globals.timer.function = acct_timeout;
198 acct_globals.timer.expires = jiffies + ACCT_TIMEOUT*HZ;
199 add_timer(&acct_globals.timer);
200 }
201 if (old_acct) {
Josef "Jeff" Sipekf3a43f32006-12-08 02:36:43 -0800202 mnt_unpin(old_acct->f_path.mnt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203 spin_unlock(&acct_globals.lock);
Pavel Emelyanov5f7b7032008-03-24 12:29:53 -0700204 do_acct_process(old_ns, old_acct);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205 filp_close(old_acct, NULL);
Pavel Emelyanov5f7b7032008-03-24 12:29:53 -0700206 put_pid_ns(old_ns);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207 spin_lock(&acct_globals.lock);
208 }
209}
210
Al Viro7b7b1ac2005-11-07 17:13:39 -0500211static int acct_on(char *name)
212{
213 struct file *file;
214 int error;
215
216 /* Difference from BSD - they don't do O_APPEND */
217 file = filp_open(name, O_WRONLY|O_APPEND|O_LARGEFILE, 0);
218 if (IS_ERR(file))
219 return PTR_ERR(file);
220
Josef "Jeff" Sipekf3a43f32006-12-08 02:36:43 -0800221 if (!S_ISREG(file->f_path.dentry->d_inode->i_mode)) {
Al Viro7b7b1ac2005-11-07 17:13:39 -0500222 filp_close(file, NULL);
223 return -EACCES;
224 }
225
226 if (!file->f_op->write) {
227 filp_close(file, NULL);
228 return -EIO;
229 }
230
231 error = security_acct(file);
232 if (error) {
233 filp_close(file, NULL);
234 return error;
235 }
236
237 spin_lock(&acct_globals.lock);
Josef "Jeff" Sipekf3a43f32006-12-08 02:36:43 -0800238 mnt_pin(file->f_path.mnt);
Al Viro7b7b1ac2005-11-07 17:13:39 -0500239 acct_file_reopen(file);
240 spin_unlock(&acct_globals.lock);
241
Josef "Jeff" Sipekf3a43f32006-12-08 02:36:43 -0800242 mntput(file->f_path.mnt); /* it's pinned, now give up active reference */
Al Viro7b7b1ac2005-11-07 17:13:39 -0500243
244 return 0;
245}
246
Randy Dunlap417ef532005-09-10 00:26:39 -0700247/**
248 * sys_acct - enable/disable process accounting
249 * @name: file name for accounting records or NULL to shutdown accounting
250 *
251 * Returns 0 for success or negative errno values for failure.
252 *
253 * sys_acct() is the only system call needed to implement process
254 * accounting. It takes the name of the file where accounting records
255 * should be written. If the filename is NULL, accounting will be
256 * shutdown.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257 */
258asmlinkage long sys_acct(const char __user *name)
259{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260 int error;
261
262 if (!capable(CAP_SYS_PACCT))
263 return -EPERM;
264
265 if (name) {
Al Viro7b7b1ac2005-11-07 17:13:39 -0500266 char *tmp = getname(name);
267 if (IS_ERR(tmp))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268 return (PTR_ERR(tmp));
Al Viro7b7b1ac2005-11-07 17:13:39 -0500269 error = acct_on(tmp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700270 putname(tmp);
Al Viro7b7b1ac2005-11-07 17:13:39 -0500271 } else {
272 error = security_acct(NULL);
273 if (!error) {
274 spin_lock(&acct_globals.lock);
275 acct_file_reopen(NULL);
276 spin_unlock(&acct_globals.lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700277 }
278 }
Al Viro7b7b1ac2005-11-07 17:13:39 -0500279 return error;
280}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281
Al Viro7b7b1ac2005-11-07 17:13:39 -0500282/**
283 * acct_auto_close - turn off a filesystem's accounting if it is on
284 * @m: vfsmount being shut down
285 *
286 * If the accounting is turned on for a file in the subtree pointed to
287 * to by m, turn accounting off. Done when m is about to die.
288 */
289void acct_auto_close_mnt(struct vfsmount *m)
290{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291 spin_lock(&acct_globals.lock);
Josef "Jeff" Sipekf3a43f32006-12-08 02:36:43 -0800292 if (acct_globals.file && acct_globals.file->f_path.mnt == m)
Al Viro7b7b1ac2005-11-07 17:13:39 -0500293 acct_file_reopen(NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700294 spin_unlock(&acct_globals.lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700295}
296
Randy Dunlap417ef532005-09-10 00:26:39 -0700297/**
298 * acct_auto_close - turn off a filesystem's accounting if it is on
299 * @sb: super block for the filesystem
300 *
301 * If the accounting is turned on for a file in the filesystem pointed
302 * to by sb, turn accounting off.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700303 */
304void acct_auto_close(struct super_block *sb)
305{
306 spin_lock(&acct_globals.lock);
307 if (acct_globals.file &&
Josef "Jeff" Sipekf3a43f32006-12-08 02:36:43 -0800308 acct_globals.file->f_path.mnt->mnt_sb == sb) {
Al Viro7b7b1ac2005-11-07 17:13:39 -0500309 acct_file_reopen(NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700310 }
311 spin_unlock(&acct_globals.lock);
312}
313
314/*
315 * encode an unsigned long into a comp_t
316 *
317 * This routine has been adopted from the encode_comp_t() function in
318 * the kern_acct.c file of the FreeBSD operating system. The encoding
319 * is a 13-bit fraction with a 3-bit (base 8) exponent.
320 */
321
322#define MANTSIZE 13 /* 13 bit mantissa. */
323#define EXPSIZE 3 /* Base 8 (3 bit) exponent. */
324#define MAXFRACT ((1 << MANTSIZE) - 1) /* Maximum fractional value. */
325
326static comp_t encode_comp_t(unsigned long value)
327{
328 int exp, rnd;
329
330 exp = rnd = 0;
331 while (value > MAXFRACT) {
332 rnd = value & (1 << (EXPSIZE - 1)); /* Round up? */
333 value >>= EXPSIZE; /* Base 8 exponent == 3 bit shift. */
334 exp++;
335 }
336
337 /*
Daniel Walker6ae965c2007-10-18 03:06:04 -0700338 * If we need to round up, do it (and handle overflow correctly).
339 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340 if (rnd && (++value > MAXFRACT)) {
341 value >>= EXPSIZE;
342 exp++;
343 }
344
345 /*
Daniel Walker6ae965c2007-10-18 03:06:04 -0700346 * Clean it up and polish it off.
347 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700348 exp <<= MANTSIZE; /* Shift the exponent into place */
349 exp += value; /* and add on the mantissa. */
350 return exp;
351}
352
353#if ACCT_VERSION==1 || ACCT_VERSION==2
354/*
355 * encode an u64 into a comp2_t (24 bits)
356 *
357 * Format: 5 bit base 2 exponent, 20 bits mantissa.
358 * The leading bit of the mantissa is not stored, but implied for
359 * non-zero exponents.
360 * Largest encodable value is 50 bits.
361 */
362
363#define MANTSIZE2 20 /* 20 bit mantissa. */
364#define EXPSIZE2 5 /* 5 bit base 2 exponent. */
365#define MAXFRACT2 ((1ul << MANTSIZE2) - 1) /* Maximum fractional value. */
366#define MAXEXP2 ((1 <<EXPSIZE2) - 1) /* Maximum exponent. */
367
368static comp2_t encode_comp2_t(u64 value)
369{
Daniel Walker6ae965c2007-10-18 03:06:04 -0700370 int exp, rnd;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700371
Daniel Walker6ae965c2007-10-18 03:06:04 -0700372 exp = (value > (MAXFRACT2>>1));
373 rnd = 0;
374 while (value > MAXFRACT2) {
375 rnd = value & 1;
376 value >>= 1;
377 exp++;
378 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700379
Daniel Walker6ae965c2007-10-18 03:06:04 -0700380 /*
381 * If we need to round up, do it (and handle overflow correctly).
382 */
383 if (rnd && (++value > MAXFRACT2)) {
384 value >>= 1;
385 exp++;
386 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387
Daniel Walker6ae965c2007-10-18 03:06:04 -0700388 if (exp > MAXEXP2) {
389 /* Overflow. Return largest representable number instead. */
390 return (1ul << (MANTSIZE2+EXPSIZE2-1)) - 1;
391 } else {
392 return (value & (MAXFRACT2>>1)) | (exp << (MANTSIZE2-1));
393 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394}
395#endif
396
397#if ACCT_VERSION==3
398/*
399 * encode an u64 into a 32 bit IEEE float
400 */
401static u32 encode_float(u64 value)
402{
403 unsigned exp = 190;
404 unsigned u;
405
406 if (value==0) return 0;
407 while ((s64)value > 0){
408 value <<= 1;
409 exp--;
410 }
411 u = (u32)(value >> 40) & 0x7fffffu;
412 return u | (exp << 23);
413}
414#endif
415
416/*
417 * Write an accounting entry for an exiting process
418 *
419 * The acct_process() call is the workhorse of the process
420 * accounting system. The struct acct is built here and then written
421 * into the accounting file. This function should only be called from
Ingo Molnarbcbe4a02007-11-26 21:21:49 +0100422 * do_exit() or when switching to a different output file.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700423 */
424
425/*
426 * do_acct_process does all actual work. Caller holds the reference to file.
427 */
Pavel Emelyanov5f7b7032008-03-24 12:29:53 -0700428static void do_acct_process(struct pid_namespace *ns, struct file *file)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429{
KaiGai Kohei0e464812006-06-25 05:49:24 -0700430 struct pacct_struct *pacct = &current->signal->pacct;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700431 acct_t ac;
432 mm_segment_t fs;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700433 unsigned long flim;
434 u64 elapsed;
435 u64 run_time;
436 struct timespec uptime;
Peter Zijlstra24ec8392006-12-08 02:36:04 -0800437 struct tty_struct *tty;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700438
439 /*
440 * First check to see if there is enough free_space to continue
441 * the process accounting system.
442 */
443 if (!check_free_space(file))
444 return;
445
446 /*
447 * Fill the accounting struct with the needed info as recorded
448 * by the different kernel functions.
449 */
450 memset((caddr_t)&ac, 0, sizeof(acct_t));
451
452 ac.ac_version = ACCT_VERSION | ACCT_BYTEORDER;
453 strlcpy(ac.ac_comm, current->comm, sizeof(ac.ac_comm));
454
455 /* calculate run_time in nsec*/
456 do_posix_clock_monotonic_gettime(&uptime);
457 run_time = (u64)uptime.tv_sec*NSEC_PER_SEC + uptime.tv_nsec;
KaiGai Koheibb231fe2006-03-31 02:30:45 -0800458 run_time -= (u64)current->group_leader->start_time.tv_sec * NSEC_PER_SEC
459 + current->group_leader->start_time.tv_nsec;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700460 /* convert nsec -> AHZ */
461 elapsed = nsec_to_AHZ(run_time);
462#if ACCT_VERSION==3
463 ac.ac_etime = encode_float(elapsed);
464#else
465 ac.ac_etime = encode_comp_t(elapsed < (unsigned long) -1l ?
466 (unsigned long) elapsed : (unsigned long) -1l);
467#endif
468#if ACCT_VERSION==1 || ACCT_VERSION==2
469 {
470 /* new enlarged etime field */
471 comp2_t etime = encode_comp2_t(elapsed);
472 ac.ac_etime_hi = etime >> 16;
473 ac.ac_etime_lo = (u16) etime;
474 }
475#endif
476 do_div(elapsed, AHZ);
john stultz2c6b47d2007-07-24 17:47:43 -0700477 ac.ac_btime = get_seconds() - elapsed;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700478 /* we really need to bite the bullet and change layout */
479 ac.ac_uid = current->uid;
480 ac.ac_gid = current->gid;
481#if ACCT_VERSION==2
482 ac.ac_ahz = AHZ;
483#endif
484#if ACCT_VERSION==1 || ACCT_VERSION==2
485 /* backward-compatible 16 bit fields */
486 ac.ac_uid16 = current->uid;
487 ac.ac_gid16 = current->gid;
488#endif
489#if ACCT_VERSION==3
Pavel Emelyanov5f7b7032008-03-24 12:29:53 -0700490 ac.ac_pid = task_tgid_nr_ns(current, ns);
Pavel Emelyanova846a192008-03-24 12:29:52 -0700491 rcu_read_lock();
Pavel Emelyanov5f7b7032008-03-24 12:29:53 -0700492 ac.ac_ppid = task_tgid_nr_ns(rcu_dereference(current->real_parent), ns);
Pavel Emelyanova846a192008-03-24 12:29:52 -0700493 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700494#endif
495
OGAWA Hirofumia4afee02006-07-14 00:24:18 -0700496 spin_lock_irq(&current->sighand->siglock);
Oleg Nesterov7bcfa952006-12-08 02:36:07 -0800497 tty = current->signal->tty;
498 ac.ac_tty = tty ? old_encode_dev(tty_devnum(tty)) : 0;
KaiGai Kohei77787bf2006-06-25 05:49:26 -0700499 ac.ac_utime = encode_comp_t(jiffies_to_AHZ(cputime_to_jiffies(pacct->ac_utime)));
500 ac.ac_stime = encode_comp_t(jiffies_to_AHZ(cputime_to_jiffies(pacct->ac_stime)));
KaiGai Koheif6ec29a2006-06-25 05:49:25 -0700501 ac.ac_flag = pacct->ac_flag;
KaiGai Kohei0e464812006-06-25 05:49:24 -0700502 ac.ac_mem = encode_comp_t(pacct->ac_mem);
KaiGai Kohei77787bf2006-06-25 05:49:26 -0700503 ac.ac_minflt = encode_comp_t(pacct->ac_minflt);
504 ac.ac_majflt = encode_comp_t(pacct->ac_majflt);
KaiGai Koheif6ec29a2006-06-25 05:49:25 -0700505 ac.ac_exitcode = pacct->ac_exitcode;
OGAWA Hirofumia4afee02006-07-14 00:24:18 -0700506 spin_unlock_irq(&current->sighand->siglock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700507 ac.ac_io = encode_comp_t(0 /* current->io_usage */); /* %% */
508 ac.ac_rw = encode_comp_t(ac.ac_io / 1024);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700509 ac.ac_swaps = encode_comp_t(0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700510
511 /*
Daniel Walker6ae965c2007-10-18 03:06:04 -0700512 * Kernel segment override to datasegment and write it
513 * to the accounting file.
514 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700515 fs = get_fs();
516 set_fs(KERNEL_DS);
517 /*
Daniel Walker6ae965c2007-10-18 03:06:04 -0700518 * Accounting records are not subject to resource limits.
519 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700520 flim = current->signal->rlim[RLIMIT_FSIZE].rlim_cur;
521 current->signal->rlim[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY;
522 file->f_op->write(file, (char *)&ac,
523 sizeof(acct_t), &file->f_pos);
524 current->signal->rlim[RLIMIT_FSIZE].rlim_cur = flim;
525 set_fs(fs);
526}
527
Randy Dunlap417ef532005-09-10 00:26:39 -0700528/**
KaiGai Kohei0e464812006-06-25 05:49:24 -0700529 * acct_init_pacct - initialize a new pacct_struct
Randy Dunlap1dbe83c2006-06-27 02:54:01 -0700530 * @pacct: per-process accounting info struct to initialize
KaiGai Kohei0e464812006-06-25 05:49:24 -0700531 */
532void acct_init_pacct(struct pacct_struct *pacct)
533{
534 memset(pacct, 0, sizeof(struct pacct_struct));
KaiGai Kohei77787bf2006-06-25 05:49:26 -0700535 pacct->ac_utime = pacct->ac_stime = cputime_zero;
KaiGai Kohei0e464812006-06-25 05:49:24 -0700536}
537
538/**
539 * acct_collect - collect accounting information into pacct_struct
KaiGai Koheif6ec29a2006-06-25 05:49:25 -0700540 * @exitcode: task exit code
541 * @group_dead: not 0, if this thread is the last one in the process.
KaiGai Kohei0e464812006-06-25 05:49:24 -0700542 */
KaiGai Koheif6ec29a2006-06-25 05:49:25 -0700543void acct_collect(long exitcode, int group_dead)
KaiGai Kohei0e464812006-06-25 05:49:24 -0700544{
545 struct pacct_struct *pacct = &current->signal->pacct;
546 unsigned long vsize = 0;
547
KaiGai Koheif6ec29a2006-06-25 05:49:25 -0700548 if (group_dead && current->mm) {
KaiGai Kohei0e464812006-06-25 05:49:24 -0700549 struct vm_area_struct *vma;
550 down_read(&current->mm->mmap_sem);
551 vma = current->mm->mmap;
552 while (vma) {
553 vsize += vma->vm_end - vma->vm_start;
554 vma = vma->vm_next;
555 }
556 up_read(&current->mm->mmap_sem);
557 }
558
KaiGai Kohei77787bf2006-06-25 05:49:26 -0700559 spin_lock_irq(&current->sighand->siglock);
KaiGai Koheif6ec29a2006-06-25 05:49:25 -0700560 if (group_dead)
561 pacct->ac_mem = vsize / 1024;
562 if (thread_group_leader(current)) {
563 pacct->ac_exitcode = exitcode;
564 if (current->flags & PF_FORKNOEXEC)
565 pacct->ac_flag |= AFORK;
566 }
567 if (current->flags & PF_SUPERPRIV)
568 pacct->ac_flag |= ASU;
569 if (current->flags & PF_DUMPCORE)
570 pacct->ac_flag |= ACORE;
571 if (current->flags & PF_SIGNALED)
572 pacct->ac_flag |= AXSIG;
KaiGai Kohei77787bf2006-06-25 05:49:26 -0700573 pacct->ac_utime = cputime_add(pacct->ac_utime, current->utime);
574 pacct->ac_stime = cputime_add(pacct->ac_stime, current->stime);
575 pacct->ac_minflt += current->min_flt;
576 pacct->ac_majflt += current->maj_flt;
577 spin_unlock_irq(&current->sighand->siglock);
KaiGai Kohei0e464812006-06-25 05:49:24 -0700578}
579
580/**
Linus Torvalds1da177e2005-04-16 15:20:36 -0700581 * acct_process - now just a wrapper around do_acct_process
Randy Dunlap417ef532005-09-10 00:26:39 -0700582 * @exitcode: task exit code
583 *
584 * handles process accounting for an exiting task
Linus Torvalds1da177e2005-04-16 15:20:36 -0700585 */
Randy Dunlap7f32a252006-06-27 02:53:25 -0700586void acct_process(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700587{
588 struct file *file = NULL;
Pavel Emelyanov5f7b7032008-03-24 12:29:53 -0700589 struct pid_namespace *ns;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700590
591 /*
592 * accelerate the common fastpath:
593 */
594 if (!acct_globals.file)
595 return;
596
597 spin_lock(&acct_globals.lock);
598 file = acct_globals.file;
599 if (unlikely(!file)) {
600 spin_unlock(&acct_globals.lock);
601 return;
602 }
603 get_file(file);
Pavel Emelyanov5f7b7032008-03-24 12:29:53 -0700604 ns = get_pid_ns(acct_globals.ns);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700605 spin_unlock(&acct_globals.lock);
606
Pavel Emelyanov5f7b7032008-03-24 12:29:53 -0700607 do_acct_process(ns, file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700608 fput(file);
Pavel Emelyanov5f7b7032008-03-24 12:29:53 -0700609 put_pid_ns(ns);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700610}