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1da177e4 LT |
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 | ||
1da177e4 LT |
46 | #include <linux/mm.h> |
47 | #include <linux/slab.h> | |
48 | #include <linux/acct.h> | |
c59ede7b | 49 | #include <linux/capability.h> |
1da177e4 LT |
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> | |
7b7b1ace | 57 | #include <linux/mount.h> |
7153e402 | 58 | #include <linux/uaccess.h> |
1da177e4 LT |
59 | #include <asm/div64.h> |
60 | #include <linux/blkdev.h> /* sector_div */ | |
5f7b703f | 61 | #include <linux/pid_namespace.h> |
efb170c2 | 62 | #include <linux/fs_pin.h> |
1da177e4 LT |
63 | |
64 | /* | |
65 | * These constants control the amount of freespace that suspend and | |
66 | * resume the process accounting system, and the time delay between | |
67 | * each check. | |
68 | * Turned into sysctl-controllable parameters. AV, 12/11/98 | |
69 | */ | |
70 | ||
71 | int acct_parm[3] = {4, 2, 30}; | |
72 | #define RESUME (acct_parm[0]) /* >foo% free space - resume */ | |
73 | #define SUSPEND (acct_parm[1]) /* <foo% free space - suspend */ | |
74 | #define ACCT_TIMEOUT (acct_parm[2]) /* foo second timeout between checks */ | |
75 | ||
76 | /* | |
77 | * External references and all of the globals. | |
78 | */ | |
b8f00e6b | 79 | static void do_acct_process(struct bsd_acct_struct *acct); |
1da177e4 | 80 | |
1629d0eb AV |
81 | struct bsd_acct_struct { |
82 | struct fs_pin pin; | |
b8f00e6b | 83 | struct mutex lock; |
32dc7308 AV |
84 | int active; |
85 | unsigned long needcheck; | |
1da177e4 | 86 | struct file *file; |
5f7b703f | 87 | struct pid_namespace *ns; |
17c0a5aa AV |
88 | struct work_struct work; |
89 | struct completion done; | |
1da177e4 LT |
90 | }; |
91 | ||
1da177e4 LT |
92 | /* |
93 | * Check the amount of free space and suspend/resume accordingly. | |
94 | */ | |
54a4d58a | 95 | static int check_free_space(struct bsd_acct_struct *acct) |
1da177e4 LT |
96 | { |
97 | struct kstatfs sbuf; | |
1da177e4 | 98 | |
54a4d58a | 99 | if (time_is_before_jiffies(acct->needcheck)) |
1da177e4 | 100 | goto out; |
1da177e4 LT |
101 | |
102 | /* May block */ | |
54a4d58a | 103 | if (vfs_statfs(&acct->file->f_path, &sbuf)) |
1da177e4 | 104 | goto out; |
1da177e4 | 105 | |
6248b1b3 | 106 | if (acct->active) { |
54a4d58a AV |
107 | u64 suspend = sbuf.f_blocks * SUSPEND; |
108 | do_div(suspend, 100); | |
109 | if (sbuf.f_bavail <= suspend) { | |
6248b1b3 | 110 | acct->active = 0; |
1da177e4 LT |
111 | printk(KERN_INFO "Process accounting paused\n"); |
112 | } | |
113 | } else { | |
54a4d58a AV |
114 | u64 resume = sbuf.f_blocks * RESUME; |
115 | do_div(resume, 100); | |
116 | if (sbuf.f_bavail >= resume) { | |
6248b1b3 | 117 | acct->active = 1; |
1da177e4 LT |
118 | printk(KERN_INFO "Process accounting resumed\n"); |
119 | } | |
120 | } | |
121 | ||
32dc7308 | 122 | acct->needcheck = jiffies + ACCT_TIMEOUT*HZ; |
1da177e4 | 123 | out: |
54a4d58a | 124 | return acct->active; |
1da177e4 LT |
125 | } |
126 | ||
215752fc | 127 | static struct bsd_acct_struct *acct_get(struct pid_namespace *ns) |
b8f00e6b AV |
128 | { |
129 | struct bsd_acct_struct *res; | |
b8f00e6b | 130 | again: |
2798d4ce AV |
131 | smp_rmb(); |
132 | rcu_read_lock(); | |
133 | res = ACCESS_ONCE(ns->bacct); | |
134 | if (!res) { | |
135 | rcu_read_unlock(); | |
215752fc | 136 | return NULL; |
1da177e4 | 137 | } |
efb170c2 AV |
138 | if (!atomic_long_inc_not_zero(&res->pin.count)) { |
139 | rcu_read_unlock(); | |
140 | cpu_relax(); | |
215752fc | 141 | goto again; |
efb170c2 AV |
142 | } |
143 | rcu_read_unlock(); | |
144 | mutex_lock(&res->lock); | |
145 | if (!res->ns) { | |
146 | mutex_unlock(&res->lock); | |
147 | pin_put(&res->pin); | |
148 | goto again; | |
149 | } | |
b8f00e6b AV |
150 | return res; |
151 | } | |
152 | ||
17c0a5aa AV |
153 | static void close_work(struct work_struct *work) |
154 | { | |
155 | struct bsd_acct_struct *acct = container_of(work, struct bsd_acct_struct, work); | |
156 | struct file *file = acct->file; | |
17c0a5aa AV |
157 | if (file->f_op->flush) |
158 | file->f_op->flush(file, NULL); | |
159 | __fput_sync(file); | |
160 | complete(&acct->done); | |
161 | } | |
162 | ||
b8f00e6b AV |
163 | static void acct_kill(struct bsd_acct_struct *acct, |
164 | struct bsd_acct_struct *new) | |
165 | { | |
166 | if (acct) { | |
b8f00e6b | 167 | struct pid_namespace *ns = acct->ns; |
2798d4ce | 168 | do_acct_process(acct); |
17c0a5aa AV |
169 | INIT_WORK(&acct->work, close_work); |
170 | init_completion(&acct->done); | |
171 | schedule_work(&acct->work); | |
172 | wait_for_completion(&acct->done); | |
efb170c2 | 173 | pin_remove(&acct->pin); |
b8f00e6b | 174 | ns->bacct = new; |
b8f00e6b | 175 | acct->ns = NULL; |
1629d0eb | 176 | atomic_long_dec(&acct->pin.count); |
b8f00e6b | 177 | mutex_unlock(&acct->lock); |
1629d0eb | 178 | pin_put(&acct->pin); |
1da177e4 LT |
179 | } |
180 | } | |
181 | ||
efb170c2 AV |
182 | static void acct_pin_kill(struct fs_pin *pin) |
183 | { | |
184 | struct bsd_acct_struct *acct; | |
185 | acct = container_of(pin, struct bsd_acct_struct, pin); | |
186 | mutex_lock(&acct->lock); | |
187 | if (!acct->ns) { | |
188 | mutex_unlock(&acct->lock); | |
189 | pin_put(pin); | |
190 | acct = NULL; | |
191 | } | |
192 | acct_kill(acct, NULL); | |
193 | } | |
194 | ||
669abf4e | 195 | static int acct_on(struct filename *pathname) |
7b7b1ace AV |
196 | { |
197 | struct file *file; | |
3064c356 | 198 | struct vfsmount *mnt, *internal; |
b8f00e6b AV |
199 | struct pid_namespace *ns = task_active_pid_ns(current); |
200 | struct bsd_acct_struct *acct, *old; | |
3064c356 | 201 | int err; |
b8f00e6b AV |
202 | |
203 | acct = kzalloc(sizeof(struct bsd_acct_struct), GFP_KERNEL); | |
204 | if (!acct) | |
205 | return -ENOMEM; | |
7b7b1ace AV |
206 | |
207 | /* Difference from BSD - they don't do O_APPEND */ | |
669abf4e | 208 | file = file_open_name(pathname, O_WRONLY|O_APPEND|O_LARGEFILE, 0); |
b8f00e6b AV |
209 | if (IS_ERR(file)) { |
210 | kfree(acct); | |
7b7b1ace | 211 | return PTR_ERR(file); |
b8f00e6b | 212 | } |
7b7b1ace | 213 | |
496ad9aa | 214 | if (!S_ISREG(file_inode(file)->i_mode)) { |
b8f00e6b | 215 | kfree(acct); |
7b7b1ace AV |
216 | filp_close(file, NULL); |
217 | return -EACCES; | |
218 | } | |
219 | ||
220 | if (!file->f_op->write) { | |
b8f00e6b | 221 | kfree(acct); |
7b7b1ace AV |
222 | filp_close(file, NULL); |
223 | return -EIO; | |
224 | } | |
3064c356 AV |
225 | internal = mnt_clone_internal(&file->f_path); |
226 | if (IS_ERR(internal)) { | |
227 | kfree(acct); | |
228 | filp_close(file, NULL); | |
229 | return PTR_ERR(internal); | |
230 | } | |
231 | err = mnt_want_write(internal); | |
232 | if (err) { | |
233 | mntput(internal); | |
234 | kfree(acct); | |
235 | filp_close(file, NULL); | |
236 | return err; | |
237 | } | |
238 | mnt = file->f_path.mnt; | |
239 | file->f_path.mnt = internal; | |
7b7b1ace | 240 | |
1629d0eb | 241 | atomic_long_set(&acct->pin.count, 1); |
efb170c2 | 242 | acct->pin.kill = acct_pin_kill; |
b8f00e6b AV |
243 | acct->file = file; |
244 | acct->needcheck = jiffies; | |
245 | acct->ns = ns; | |
246 | mutex_init(&acct->lock); | |
efb170c2 AV |
247 | mutex_lock_nested(&acct->lock, 1); /* nobody has seen it yet */ |
248 | pin_insert(&acct->pin, mnt); | |
0b6b030f | 249 | |
215752fc | 250 | old = acct_get(ns); |
efb170c2 | 251 | if (old) |
b8f00e6b | 252 | acct_kill(old, acct); |
efb170c2 | 253 | else |
0b6b030f | 254 | ns->bacct = acct; |
efb170c2 | 255 | mutex_unlock(&acct->lock); |
3064c356 AV |
256 | mnt_drop_write(mnt); |
257 | mntput(mnt); | |
7b7b1ace AV |
258 | return 0; |
259 | } | |
260 | ||
9df7fa16 AV |
261 | static DEFINE_MUTEX(acct_on_mutex); |
262 | ||
417ef531 RD |
263 | /** |
264 | * sys_acct - enable/disable process accounting | |
265 | * @name: file name for accounting records or NULL to shutdown accounting | |
266 | * | |
267 | * Returns 0 for success or negative errno values for failure. | |
268 | * | |
269 | * sys_acct() is the only system call needed to implement process | |
270 | * accounting. It takes the name of the file where accounting records | |
271 | * should be written. If the filename is NULL, accounting will be | |
272 | * shutdown. | |
1da177e4 | 273 | */ |
b290ebe2 | 274 | SYSCALL_DEFINE1(acct, const char __user *, name) |
1da177e4 | 275 | { |
05b90496 | 276 | int error = 0; |
1da177e4 LT |
277 | |
278 | if (!capable(CAP_SYS_PACCT)) | |
279 | return -EPERM; | |
280 | ||
281 | if (name) { | |
91a27b2a | 282 | struct filename *tmp = getname(name); |
7b7b1ace | 283 | if (IS_ERR(tmp)) |
46c0a8ca | 284 | return PTR_ERR(tmp); |
9df7fa16 | 285 | mutex_lock(&acct_on_mutex); |
669abf4e | 286 | error = acct_on(tmp); |
9df7fa16 | 287 | mutex_unlock(&acct_on_mutex); |
1da177e4 | 288 | putname(tmp); |
7b7b1ace | 289 | } else { |
215752fc | 290 | acct_kill(acct_get(task_active_pid_ns(current)), NULL); |
1da177e4 | 291 | } |
05b90496 | 292 | |
7b7b1ace AV |
293 | return error; |
294 | } | |
1da177e4 | 295 | |
0b6b030f PE |
296 | void acct_exit_ns(struct pid_namespace *ns) |
297 | { | |
215752fc | 298 | acct_kill(acct_get(ns), NULL); |
1da177e4 LT |
299 | } |
300 | ||
301 | /* | |
302 | * encode an unsigned long into a comp_t | |
303 | * | |
304 | * This routine has been adopted from the encode_comp_t() function in | |
305 | * the kern_acct.c file of the FreeBSD operating system. The encoding | |
306 | * is a 13-bit fraction with a 3-bit (base 8) exponent. | |
307 | */ | |
308 | ||
309 | #define MANTSIZE 13 /* 13 bit mantissa. */ | |
310 | #define EXPSIZE 3 /* Base 8 (3 bit) exponent. */ | |
311 | #define MAXFRACT ((1 << MANTSIZE) - 1) /* Maximum fractional value. */ | |
312 | ||
313 | static comp_t encode_comp_t(unsigned long value) | |
314 | { | |
315 | int exp, rnd; | |
316 | ||
317 | exp = rnd = 0; | |
318 | while (value > MAXFRACT) { | |
319 | rnd = value & (1 << (EXPSIZE - 1)); /* Round up? */ | |
320 | value >>= EXPSIZE; /* Base 8 exponent == 3 bit shift. */ | |
321 | exp++; | |
322 | } | |
323 | ||
324 | /* | |
6ae965cd DW |
325 | * If we need to round up, do it (and handle overflow correctly). |
326 | */ | |
1da177e4 LT |
327 | if (rnd && (++value > MAXFRACT)) { |
328 | value >>= EXPSIZE; | |
329 | exp++; | |
330 | } | |
331 | ||
332 | /* | |
6ae965cd DW |
333 | * Clean it up and polish it off. |
334 | */ | |
1da177e4 LT |
335 | exp <<= MANTSIZE; /* Shift the exponent into place */ |
336 | exp += value; /* and add on the mantissa. */ | |
337 | return exp; | |
338 | } | |
339 | ||
340 | #if ACCT_VERSION==1 || ACCT_VERSION==2 | |
341 | /* | |
342 | * encode an u64 into a comp2_t (24 bits) | |
343 | * | |
344 | * Format: 5 bit base 2 exponent, 20 bits mantissa. | |
345 | * The leading bit of the mantissa is not stored, but implied for | |
346 | * non-zero exponents. | |
347 | * Largest encodable value is 50 bits. | |
348 | */ | |
349 | ||
350 | #define MANTSIZE2 20 /* 20 bit mantissa. */ | |
351 | #define EXPSIZE2 5 /* 5 bit base 2 exponent. */ | |
352 | #define MAXFRACT2 ((1ul << MANTSIZE2) - 1) /* Maximum fractional value. */ | |
353 | #define MAXEXP2 ((1 <<EXPSIZE2) - 1) /* Maximum exponent. */ | |
354 | ||
355 | static comp2_t encode_comp2_t(u64 value) | |
356 | { | |
6ae965cd DW |
357 | int exp, rnd; |
358 | ||
359 | exp = (value > (MAXFRACT2>>1)); | |
360 | rnd = 0; | |
361 | while (value > MAXFRACT2) { | |
362 | rnd = value & 1; | |
363 | value >>= 1; | |
364 | exp++; | |
365 | } | |
366 | ||
367 | /* | |
368 | * If we need to round up, do it (and handle overflow correctly). | |
369 | */ | |
370 | if (rnd && (++value > MAXFRACT2)) { | |
371 | value >>= 1; | |
372 | exp++; | |
373 | } | |
374 | ||
375 | if (exp > MAXEXP2) { | |
376 | /* Overflow. Return largest representable number instead. */ | |
377 | return (1ul << (MANTSIZE2+EXPSIZE2-1)) - 1; | |
378 | } else { | |
379 | return (value & (MAXFRACT2>>1)) | (exp << (MANTSIZE2-1)); | |
380 | } | |
1da177e4 LT |
381 | } |
382 | #endif | |
383 | ||
384 | #if ACCT_VERSION==3 | |
385 | /* | |
386 | * encode an u64 into a 32 bit IEEE float | |
387 | */ | |
388 | static u32 encode_float(u64 value) | |
389 | { | |
390 | unsigned exp = 190; | |
391 | unsigned u; | |
392 | ||
393 | if (value==0) return 0; | |
394 | while ((s64)value > 0){ | |
395 | value <<= 1; | |
396 | exp--; | |
397 | } | |
398 | u = (u32)(value >> 40) & 0x7fffffu; | |
399 | return u | (exp << 23); | |
400 | } | |
401 | #endif | |
402 | ||
403 | /* | |
404 | * Write an accounting entry for an exiting process | |
405 | * | |
406 | * The acct_process() call is the workhorse of the process | |
407 | * accounting system. The struct acct is built here and then written | |
408 | * into the accounting file. This function should only be called from | |
bcbe4a07 | 409 | * do_exit() or when switching to a different output file. |
1da177e4 LT |
410 | */ |
411 | ||
cdd37e23 | 412 | static void fill_ac(acct_t *ac) |
1da177e4 | 413 | { |
0e464814 | 414 | struct pacct_struct *pacct = ¤t->signal->pacct; |
ccbf62d8 | 415 | u64 elapsed, run_time; |
24ec839c | 416 | struct tty_struct *tty; |
1da177e4 LT |
417 | |
418 | /* | |
419 | * Fill the accounting struct with the needed info as recorded | |
420 | * by the different kernel functions. | |
421 | */ | |
cdd37e23 | 422 | memset(ac, 0, sizeof(acct_t)); |
1da177e4 | 423 | |
cdd37e23 AV |
424 | ac->ac_version = ACCT_VERSION | ACCT_BYTEORDER; |
425 | strlcpy(ac->ac_comm, current->comm, sizeof(ac->ac_comm)); | |
1da177e4 LT |
426 | |
427 | /* calculate run_time in nsec*/ | |
ccbf62d8 TG |
428 | run_time = ktime_get_ns(); |
429 | run_time -= current->group_leader->start_time; | |
1da177e4 LT |
430 | /* convert nsec -> AHZ */ |
431 | elapsed = nsec_to_AHZ(run_time); | |
432 | #if ACCT_VERSION==3 | |
cdd37e23 | 433 | ac->ac_etime = encode_float(elapsed); |
1da177e4 | 434 | #else |
cdd37e23 | 435 | ac->ac_etime = encode_comp_t(elapsed < (unsigned long) -1l ? |
1da177e4 LT |
436 | (unsigned long) elapsed : (unsigned long) -1l); |
437 | #endif | |
438 | #if ACCT_VERSION==1 || ACCT_VERSION==2 | |
439 | { | |
440 | /* new enlarged etime field */ | |
441 | comp2_t etime = encode_comp2_t(elapsed); | |
cdd37e23 AV |
442 | ac->ac_etime_hi = etime >> 16; |
443 | ac->ac_etime_lo = (u16) etime; | |
1da177e4 LT |
444 | } |
445 | #endif | |
446 | do_div(elapsed, AHZ); | |
cdd37e23 AV |
447 | ac->ac_btime = get_seconds() - elapsed; |
448 | #if ACCT_VERSION==2 | |
449 | ac->ac_ahz = AHZ; | |
450 | #endif | |
451 | ||
452 | spin_lock_irq(¤t->sighand->siglock); | |
453 | tty = current->signal->tty; /* Safe as we hold the siglock */ | |
454 | ac->ac_tty = tty ? old_encode_dev(tty_devnum(tty)) : 0; | |
455 | ac->ac_utime = encode_comp_t(jiffies_to_AHZ(cputime_to_jiffies(pacct->ac_utime))); | |
456 | ac->ac_stime = encode_comp_t(jiffies_to_AHZ(cputime_to_jiffies(pacct->ac_stime))); | |
457 | ac->ac_flag = pacct->ac_flag; | |
458 | ac->ac_mem = encode_comp_t(pacct->ac_mem); | |
459 | ac->ac_minflt = encode_comp_t(pacct->ac_minflt); | |
460 | ac->ac_majflt = encode_comp_t(pacct->ac_majflt); | |
461 | ac->ac_exitcode = pacct->ac_exitcode; | |
462 | spin_unlock_irq(¤t->sighand->siglock); | |
463 | } | |
464 | /* | |
465 | * do_acct_process does all actual work. Caller holds the reference to file. | |
466 | */ | |
b8f00e6b | 467 | static void do_acct_process(struct bsd_acct_struct *acct) |
cdd37e23 AV |
468 | { |
469 | acct_t ac; | |
470 | unsigned long flim; | |
471 | const struct cred *orig_cred; | |
b8f00e6b AV |
472 | struct pid_namespace *ns = acct->ns; |
473 | struct file *file = acct->file; | |
cdd37e23 AV |
474 | |
475 | /* | |
476 | * Accounting records are not subject to resource limits. | |
477 | */ | |
478 | flim = current->signal->rlim[RLIMIT_FSIZE].rlim_cur; | |
479 | current->signal->rlim[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY; | |
480 | /* Perform file operations on behalf of whoever enabled accounting */ | |
481 | orig_cred = override_creds(file->f_cred); | |
482 | ||
483 | /* | |
484 | * First check to see if there is enough free_space to continue | |
485 | * the process accounting system. | |
486 | */ | |
54a4d58a | 487 | if (!check_free_space(acct)) |
cdd37e23 AV |
488 | goto out; |
489 | ||
490 | fill_ac(&ac); | |
1da177e4 | 491 | /* we really need to bite the bullet and change layout */ |
f8f3d4de EB |
492 | ac.ac_uid = from_kuid_munged(file->f_cred->user_ns, orig_cred->uid); |
493 | ac.ac_gid = from_kgid_munged(file->f_cred->user_ns, orig_cred->gid); | |
1da177e4 LT |
494 | #if ACCT_VERSION==1 || ACCT_VERSION==2 |
495 | /* backward-compatible 16 bit fields */ | |
76aac0e9 DH |
496 | ac.ac_uid16 = ac.ac_uid; |
497 | ac.ac_gid16 = ac.ac_gid; | |
1da177e4 LT |
498 | #endif |
499 | #if ACCT_VERSION==3 | |
5f7b703f | 500 | ac.ac_pid = task_tgid_nr_ns(current, ns); |
a846a195 | 501 | rcu_read_lock(); |
5f7b703f | 502 | ac.ac_ppid = task_tgid_nr_ns(rcu_dereference(current->real_parent), ns); |
a846a195 | 503 | rcu_read_unlock(); |
1da177e4 | 504 | #endif |
5ae98f15 JK |
505 | /* |
506 | * Get freeze protection. If the fs is frozen, just skip the write | |
507 | * as we could deadlock the system otherwise. | |
508 | */ | |
ed44724b AV |
509 | if (file_start_write_trylock(file)) { |
510 | /* it's been opened O_APPEND, so position is irrelevant */ | |
511 | loff_t pos = 0; | |
512 | __kernel_write(file, (char *)&ac, sizeof(acct_t), &pos); | |
513 | file_end_write(file); | |
514 | } | |
d8e180dc | 515 | out: |
ed44724b | 516 | current->signal->rlim[RLIMIT_FSIZE].rlim_cur = flim; |
d8e180dc | 517 | revert_creds(orig_cred); |
1da177e4 LT |
518 | } |
519 | ||
0e464814 KK |
520 | /** |
521 | * acct_collect - collect accounting information into pacct_struct | |
f6ec29a4 KK |
522 | * @exitcode: task exit code |
523 | * @group_dead: not 0, if this thread is the last one in the process. | |
0e464814 | 524 | */ |
f6ec29a4 | 525 | void acct_collect(long exitcode, int group_dead) |
0e464814 KK |
526 | { |
527 | struct pacct_struct *pacct = ¤t->signal->pacct; | |
6fac4829 | 528 | cputime_t utime, stime; |
0e464814 KK |
529 | unsigned long vsize = 0; |
530 | ||
f6ec29a4 | 531 | if (group_dead && current->mm) { |
0e464814 KK |
532 | struct vm_area_struct *vma; |
533 | down_read(¤t->mm->mmap_sem); | |
534 | vma = current->mm->mmap; | |
535 | while (vma) { | |
536 | vsize += vma->vm_end - vma->vm_start; | |
537 | vma = vma->vm_next; | |
538 | } | |
539 | up_read(¤t->mm->mmap_sem); | |
540 | } | |
541 | ||
77787bfb | 542 | spin_lock_irq(¤t->sighand->siglock); |
f6ec29a4 KK |
543 | if (group_dead) |
544 | pacct->ac_mem = vsize / 1024; | |
545 | if (thread_group_leader(current)) { | |
546 | pacct->ac_exitcode = exitcode; | |
547 | if (current->flags & PF_FORKNOEXEC) | |
548 | pacct->ac_flag |= AFORK; | |
549 | } | |
550 | if (current->flags & PF_SUPERPRIV) | |
551 | pacct->ac_flag |= ASU; | |
552 | if (current->flags & PF_DUMPCORE) | |
553 | pacct->ac_flag |= ACORE; | |
554 | if (current->flags & PF_SIGNALED) | |
555 | pacct->ac_flag |= AXSIG; | |
6fac4829 FW |
556 | task_cputime(current, &utime, &stime); |
557 | pacct->ac_utime += utime; | |
558 | pacct->ac_stime += stime; | |
77787bfb KK |
559 | pacct->ac_minflt += current->min_flt; |
560 | pacct->ac_majflt += current->maj_flt; | |
561 | spin_unlock_irq(¤t->sighand->siglock); | |
0e464814 KK |
562 | } |
563 | ||
e25ff11f | 564 | static void slow_acct_process(struct pid_namespace *ns) |
1da177e4 | 565 | { |
e25ff11f | 566 | for ( ; ns; ns = ns->parent) { |
215752fc | 567 | struct bsd_acct_struct *acct = acct_get(ns); |
b8f00e6b AV |
568 | if (acct) { |
569 | do_acct_process(acct); | |
570 | mutex_unlock(&acct->lock); | |
1629d0eb | 571 | pin_put(&acct->pin); |
e25ff11f | 572 | } |
e25ff11f | 573 | } |
1da177e4 | 574 | } |
7d1e1350 PE |
575 | |
576 | /** | |
e25ff11f | 577 | * acct_process |
7d1e1350 PE |
578 | * |
579 | * handles process accounting for an exiting task | |
580 | */ | |
581 | void acct_process(void) | |
582 | { | |
583 | struct pid_namespace *ns; | |
584 | ||
0c18d7a5 PE |
585 | /* |
586 | * This loop is safe lockless, since current is still | |
587 | * alive and holds its namespace, which in turn holds | |
588 | * its parent. | |
589 | */ | |
e25ff11f | 590 | for (ns = task_active_pid_ns(current); ns != NULL; ns = ns->parent) { |
b8f00e6b | 591 | if (ns->bacct) |
e25ff11f AV |
592 | break; |
593 | } | |
594 | if (unlikely(ns)) | |
595 | slow_acct_process(ns); | |
7d1e1350 | 596 | } |