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Commit | Line | Data |
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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> |
215752fc | 62 | #include <../fs/mount.h> /* will go away when we refactor */ |
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 | |
081e4c8a | 81 | struct bsd_acct_struct { |
2798d4ce AV |
82 | atomic_long_t count; |
83 | union { | |
84 | struct { | |
85 | struct hlist_node s_list; | |
86 | struct hlist_node m_list; | |
87 | }; | |
88 | struct rcu_head rcu; | |
89 | }; | |
b8f00e6b | 90 | struct mutex lock; |
32dc7308 AV |
91 | int active; |
92 | unsigned long needcheck; | |
1da177e4 | 93 | struct file *file; |
5f7b703f | 94 | struct pid_namespace *ns; |
17c0a5aa AV |
95 | struct work_struct work; |
96 | struct completion done; | |
1da177e4 LT |
97 | }; |
98 | ||
2798d4ce AV |
99 | static void acct_free_rcu(struct rcu_head *head) |
100 | { | |
101 | kfree(container_of(head, struct bsd_acct_struct, rcu)); | |
102 | } | |
103 | ||
a75d9797 PE |
104 | static DEFINE_SPINLOCK(acct_lock); |
105 | ||
1da177e4 LT |
106 | /* |
107 | * Check the amount of free space and suspend/resume accordingly. | |
108 | */ | |
54a4d58a | 109 | static int check_free_space(struct bsd_acct_struct *acct) |
1da177e4 LT |
110 | { |
111 | struct kstatfs sbuf; | |
1da177e4 | 112 | |
54a4d58a | 113 | if (time_is_before_jiffies(acct->needcheck)) |
1da177e4 | 114 | goto out; |
1da177e4 LT |
115 | |
116 | /* May block */ | |
54a4d58a | 117 | if (vfs_statfs(&acct->file->f_path, &sbuf)) |
1da177e4 | 118 | goto out; |
1da177e4 | 119 | |
6248b1b3 | 120 | if (acct->active) { |
54a4d58a AV |
121 | u64 suspend = sbuf.f_blocks * SUSPEND; |
122 | do_div(suspend, 100); | |
123 | if (sbuf.f_bavail <= suspend) { | |
6248b1b3 | 124 | acct->active = 0; |
1da177e4 LT |
125 | printk(KERN_INFO "Process accounting paused\n"); |
126 | } | |
127 | } else { | |
54a4d58a AV |
128 | u64 resume = sbuf.f_blocks * RESUME; |
129 | do_div(resume, 100); | |
130 | if (sbuf.f_bavail >= resume) { | |
6248b1b3 | 131 | acct->active = 1; |
1da177e4 LT |
132 | printk(KERN_INFO "Process accounting resumed\n"); |
133 | } | |
134 | } | |
135 | ||
32dc7308 | 136 | acct->needcheck = jiffies + ACCT_TIMEOUT*HZ; |
1da177e4 | 137 | out: |
54a4d58a | 138 | return acct->active; |
1da177e4 LT |
139 | } |
140 | ||
b8f00e6b | 141 | static void acct_put(struct bsd_acct_struct *p) |
1da177e4 | 142 | { |
2798d4ce AV |
143 | if (atomic_long_dec_and_test(&p->count)) |
144 | call_rcu(&p->rcu, acct_free_rcu); | |
b8f00e6b AV |
145 | } |
146 | ||
215752fc AV |
147 | static struct bsd_acct_struct *__acct_get(struct bsd_acct_struct *res) |
148 | { | |
2798d4ce AV |
149 | if (!atomic_long_inc_not_zero(&res->count)) { |
150 | rcu_read_unlock(); | |
151 | cpu_relax(); | |
152 | return NULL; | |
153 | } | |
154 | rcu_read_unlock(); | |
215752fc AV |
155 | mutex_lock(&res->lock); |
156 | if (!res->ns) { | |
157 | mutex_unlock(&res->lock); | |
2798d4ce | 158 | acct_put(res); |
215752fc AV |
159 | return NULL; |
160 | } | |
161 | return res; | |
162 | } | |
163 | ||
164 | static struct bsd_acct_struct *acct_get(struct pid_namespace *ns) | |
b8f00e6b AV |
165 | { |
166 | struct bsd_acct_struct *res; | |
b8f00e6b | 167 | again: |
2798d4ce AV |
168 | smp_rmb(); |
169 | rcu_read_lock(); | |
170 | res = ACCESS_ONCE(ns->bacct); | |
171 | if (!res) { | |
172 | rcu_read_unlock(); | |
215752fc | 173 | return NULL; |
1da177e4 | 174 | } |
2798d4ce | 175 | res = __acct_get(res); |
215752fc AV |
176 | if (!res) |
177 | goto again; | |
b8f00e6b AV |
178 | return res; |
179 | } | |
180 | ||
17c0a5aa AV |
181 | static void close_work(struct work_struct *work) |
182 | { | |
183 | struct bsd_acct_struct *acct = container_of(work, struct bsd_acct_struct, work); | |
184 | struct file *file = acct->file; | |
185 | mnt_unpin(file->f_path.mnt); | |
186 | if (file->f_op->flush) | |
187 | file->f_op->flush(file, NULL); | |
188 | __fput_sync(file); | |
189 | complete(&acct->done); | |
190 | } | |
191 | ||
b8f00e6b AV |
192 | static void acct_kill(struct bsd_acct_struct *acct, |
193 | struct bsd_acct_struct *new) | |
194 | { | |
195 | if (acct) { | |
b8f00e6b | 196 | struct pid_namespace *ns = acct->ns; |
2798d4ce | 197 | do_acct_process(acct); |
17c0a5aa AV |
198 | INIT_WORK(&acct->work, close_work); |
199 | init_completion(&acct->done); | |
200 | schedule_work(&acct->work); | |
201 | wait_for_completion(&acct->done); | |
b8f00e6b | 202 | spin_lock(&acct_lock); |
215752fc AV |
203 | hlist_del(&acct->m_list); |
204 | hlist_del(&acct->s_list); | |
a75d9797 | 205 | spin_unlock(&acct_lock); |
b8f00e6b AV |
206 | ns->bacct = new; |
207 | if (new) { | |
215752fc | 208 | struct vfsmount *m = new->file->f_path.mnt; |
2798d4ce | 209 | spin_lock(&acct_lock); |
215752fc AV |
210 | hlist_add_head(&new->s_list, &m->mnt_sb->s_pins); |
211 | hlist_add_head(&new->m_list, &real_mount(m)->mnt_pins); | |
2798d4ce AV |
212 | spin_unlock(&acct_lock); |
213 | mutex_unlock(&new->lock); | |
b8f00e6b AV |
214 | } |
215 | acct->ns = NULL; | |
2798d4ce | 216 | atomic_long_dec(&acct->count); |
b8f00e6b | 217 | mutex_unlock(&acct->lock); |
2798d4ce | 218 | acct_put(acct); |
1da177e4 LT |
219 | } |
220 | } | |
221 | ||
669abf4e | 222 | static int acct_on(struct filename *pathname) |
7b7b1ace AV |
223 | { |
224 | struct file *file; | |
df279ca8 | 225 | struct vfsmount *mnt; |
b8f00e6b AV |
226 | struct pid_namespace *ns = task_active_pid_ns(current); |
227 | struct bsd_acct_struct *acct, *old; | |
228 | ||
229 | acct = kzalloc(sizeof(struct bsd_acct_struct), GFP_KERNEL); | |
230 | if (!acct) | |
231 | return -ENOMEM; | |
7b7b1ace AV |
232 | |
233 | /* Difference from BSD - they don't do O_APPEND */ | |
669abf4e | 234 | file = file_open_name(pathname, O_WRONLY|O_APPEND|O_LARGEFILE, 0); |
b8f00e6b AV |
235 | if (IS_ERR(file)) { |
236 | kfree(acct); | |
7b7b1ace | 237 | return PTR_ERR(file); |
b8f00e6b | 238 | } |
7b7b1ace | 239 | |
496ad9aa | 240 | if (!S_ISREG(file_inode(file)->i_mode)) { |
b8f00e6b | 241 | kfree(acct); |
7b7b1ace AV |
242 | filp_close(file, NULL); |
243 | return -EACCES; | |
244 | } | |
245 | ||
246 | if (!file->f_op->write) { | |
b8f00e6b | 247 | kfree(acct); |
7b7b1ace AV |
248 | filp_close(file, NULL); |
249 | return -EIO; | |
250 | } | |
251 | ||
2798d4ce | 252 | atomic_long_set(&acct->count, 1); |
b8f00e6b AV |
253 | acct->file = file; |
254 | acct->needcheck = jiffies; | |
255 | acct->ns = ns; | |
256 | mutex_init(&acct->lock); | |
257 | mnt = file->f_path.mnt; | |
215748e6 | 258 | mnt_pin(mnt); |
0b6b030f | 259 | |
215752fc | 260 | old = acct_get(ns); |
2798d4ce | 261 | mutex_lock_nested(&acct->lock, 1); /* nobody has seen it yet */ |
b8f00e6b AV |
262 | if (old) { |
263 | acct_kill(old, acct); | |
264 | } else { | |
0b6b030f | 265 | ns->bacct = acct; |
2798d4ce | 266 | spin_lock(&acct_lock); |
215752fc AV |
267 | hlist_add_head(&acct->s_list, &mnt->mnt_sb->s_pins); |
268 | hlist_add_head(&acct->m_list, &real_mount(mnt)->mnt_pins); | |
b8f00e6b | 269 | spin_unlock(&acct_lock); |
2798d4ce | 270 | mutex_unlock(&acct->lock); |
0b6b030f | 271 | } |
df279ca8 | 272 | mntput(mnt); /* it's pinned, now give up active reference */ |
7b7b1ace AV |
273 | return 0; |
274 | } | |
275 | ||
9df7fa16 AV |
276 | static DEFINE_MUTEX(acct_on_mutex); |
277 | ||
417ef531 RD |
278 | /** |
279 | * sys_acct - enable/disable process accounting | |
280 | * @name: file name for accounting records or NULL to shutdown accounting | |
281 | * | |
282 | * Returns 0 for success or negative errno values for failure. | |
283 | * | |
284 | * sys_acct() is the only system call needed to implement process | |
285 | * accounting. It takes the name of the file where accounting records | |
286 | * should be written. If the filename is NULL, accounting will be | |
287 | * shutdown. | |
1da177e4 | 288 | */ |
b290ebe2 | 289 | SYSCALL_DEFINE1(acct, const char __user *, name) |
1da177e4 | 290 | { |
05b90496 | 291 | int error = 0; |
1da177e4 LT |
292 | |
293 | if (!capable(CAP_SYS_PACCT)) | |
294 | return -EPERM; | |
295 | ||
296 | if (name) { | |
91a27b2a | 297 | struct filename *tmp = getname(name); |
7b7b1ace | 298 | if (IS_ERR(tmp)) |
46c0a8ca | 299 | return PTR_ERR(tmp); |
9df7fa16 | 300 | mutex_lock(&acct_on_mutex); |
669abf4e | 301 | error = acct_on(tmp); |
9df7fa16 | 302 | mutex_unlock(&acct_on_mutex); |
1da177e4 | 303 | putname(tmp); |
7b7b1ace | 304 | } else { |
215752fc | 305 | acct_kill(acct_get(task_active_pid_ns(current)), NULL); |
1da177e4 | 306 | } |
05b90496 | 307 | |
7b7b1ace AV |
308 | return error; |
309 | } | |
1da177e4 | 310 | |
215752fc | 311 | void acct_auto_close_mnt(struct hlist_head *list) |
7b7b1ace | 312 | { |
2798d4ce | 313 | rcu_read_lock(); |
215752fc | 314 | while (1) { |
2798d4ce AV |
315 | struct hlist_node *p = ACCESS_ONCE(list->first); |
316 | if (!p) | |
215752fc | 317 | break; |
2798d4ce | 318 | acct_kill(__acct_get(hlist_entry(p, |
215752fc AV |
319 | struct bsd_acct_struct, |
320 | m_list)), NULL); | |
2798d4ce | 321 | rcu_read_lock(); |
215752fc | 322 | } |
2798d4ce | 323 | rcu_read_unlock(); |
1da177e4 LT |
324 | } |
325 | ||
215752fc | 326 | void acct_auto_close(struct hlist_head *list) |
1da177e4 | 327 | { |
2798d4ce | 328 | rcu_read_lock(); |
215752fc | 329 | while (1) { |
2798d4ce AV |
330 | struct hlist_node *p = ACCESS_ONCE(list->first); |
331 | if (!p) | |
215752fc | 332 | break; |
2798d4ce | 333 | acct_kill(__acct_get(hlist_entry(p, |
215752fc AV |
334 | struct bsd_acct_struct, |
335 | s_list)), NULL); | |
2798d4ce | 336 | rcu_read_lock(); |
215752fc | 337 | } |
2798d4ce | 338 | rcu_read_unlock(); |
0b6b030f PE |
339 | } |
340 | ||
341 | void acct_exit_ns(struct pid_namespace *ns) | |
342 | { | |
215752fc | 343 | acct_kill(acct_get(ns), NULL); |
1da177e4 LT |
344 | } |
345 | ||
346 | /* | |
347 | * encode an unsigned long into a comp_t | |
348 | * | |
349 | * This routine has been adopted from the encode_comp_t() function in | |
350 | * the kern_acct.c file of the FreeBSD operating system. The encoding | |
351 | * is a 13-bit fraction with a 3-bit (base 8) exponent. | |
352 | */ | |
353 | ||
354 | #define MANTSIZE 13 /* 13 bit mantissa. */ | |
355 | #define EXPSIZE 3 /* Base 8 (3 bit) exponent. */ | |
356 | #define MAXFRACT ((1 << MANTSIZE) - 1) /* Maximum fractional value. */ | |
357 | ||
358 | static comp_t encode_comp_t(unsigned long value) | |
359 | { | |
360 | int exp, rnd; | |
361 | ||
362 | exp = rnd = 0; | |
363 | while (value > MAXFRACT) { | |
364 | rnd = value & (1 << (EXPSIZE - 1)); /* Round up? */ | |
365 | value >>= EXPSIZE; /* Base 8 exponent == 3 bit shift. */ | |
366 | exp++; | |
367 | } | |
368 | ||
369 | /* | |
6ae965cd DW |
370 | * If we need to round up, do it (and handle overflow correctly). |
371 | */ | |
1da177e4 LT |
372 | if (rnd && (++value > MAXFRACT)) { |
373 | value >>= EXPSIZE; | |
374 | exp++; | |
375 | } | |
376 | ||
377 | /* | |
6ae965cd DW |
378 | * Clean it up and polish it off. |
379 | */ | |
1da177e4 LT |
380 | exp <<= MANTSIZE; /* Shift the exponent into place */ |
381 | exp += value; /* and add on the mantissa. */ | |
382 | return exp; | |
383 | } | |
384 | ||
385 | #if ACCT_VERSION==1 || ACCT_VERSION==2 | |
386 | /* | |
387 | * encode an u64 into a comp2_t (24 bits) | |
388 | * | |
389 | * Format: 5 bit base 2 exponent, 20 bits mantissa. | |
390 | * The leading bit of the mantissa is not stored, but implied for | |
391 | * non-zero exponents. | |
392 | * Largest encodable value is 50 bits. | |
393 | */ | |
394 | ||
395 | #define MANTSIZE2 20 /* 20 bit mantissa. */ | |
396 | #define EXPSIZE2 5 /* 5 bit base 2 exponent. */ | |
397 | #define MAXFRACT2 ((1ul << MANTSIZE2) - 1) /* Maximum fractional value. */ | |
398 | #define MAXEXP2 ((1 <<EXPSIZE2) - 1) /* Maximum exponent. */ | |
399 | ||
400 | static comp2_t encode_comp2_t(u64 value) | |
401 | { | |
6ae965cd DW |
402 | int exp, rnd; |
403 | ||
404 | exp = (value > (MAXFRACT2>>1)); | |
405 | rnd = 0; | |
406 | while (value > MAXFRACT2) { | |
407 | rnd = value & 1; | |
408 | value >>= 1; | |
409 | exp++; | |
410 | } | |
411 | ||
412 | /* | |
413 | * If we need to round up, do it (and handle overflow correctly). | |
414 | */ | |
415 | if (rnd && (++value > MAXFRACT2)) { | |
416 | value >>= 1; | |
417 | exp++; | |
418 | } | |
419 | ||
420 | if (exp > MAXEXP2) { | |
421 | /* Overflow. Return largest representable number instead. */ | |
422 | return (1ul << (MANTSIZE2+EXPSIZE2-1)) - 1; | |
423 | } else { | |
424 | return (value & (MAXFRACT2>>1)) | (exp << (MANTSIZE2-1)); | |
425 | } | |
1da177e4 LT |
426 | } |
427 | #endif | |
428 | ||
429 | #if ACCT_VERSION==3 | |
430 | /* | |
431 | * encode an u64 into a 32 bit IEEE float | |
432 | */ | |
433 | static u32 encode_float(u64 value) | |
434 | { | |
435 | unsigned exp = 190; | |
436 | unsigned u; | |
437 | ||
438 | if (value==0) return 0; | |
439 | while ((s64)value > 0){ | |
440 | value <<= 1; | |
441 | exp--; | |
442 | } | |
443 | u = (u32)(value >> 40) & 0x7fffffu; | |
444 | return u | (exp << 23); | |
445 | } | |
446 | #endif | |
447 | ||
448 | /* | |
449 | * Write an accounting entry for an exiting process | |
450 | * | |
451 | * The acct_process() call is the workhorse of the process | |
452 | * accounting system. The struct acct is built here and then written | |
453 | * into the accounting file. This function should only be called from | |
bcbe4a07 | 454 | * do_exit() or when switching to a different output file. |
1da177e4 LT |
455 | */ |
456 | ||
cdd37e23 | 457 | static void fill_ac(acct_t *ac) |
1da177e4 | 458 | { |
0e464814 | 459 | struct pacct_struct *pacct = ¤t->signal->pacct; |
ccbf62d8 | 460 | u64 elapsed, run_time; |
24ec839c | 461 | struct tty_struct *tty; |
1da177e4 LT |
462 | |
463 | /* | |
464 | * Fill the accounting struct with the needed info as recorded | |
465 | * by the different kernel functions. | |
466 | */ | |
cdd37e23 | 467 | memset(ac, 0, sizeof(acct_t)); |
1da177e4 | 468 | |
cdd37e23 AV |
469 | ac->ac_version = ACCT_VERSION | ACCT_BYTEORDER; |
470 | strlcpy(ac->ac_comm, current->comm, sizeof(ac->ac_comm)); | |
1da177e4 LT |
471 | |
472 | /* calculate run_time in nsec*/ | |
ccbf62d8 TG |
473 | run_time = ktime_get_ns(); |
474 | run_time -= current->group_leader->start_time; | |
1da177e4 LT |
475 | /* convert nsec -> AHZ */ |
476 | elapsed = nsec_to_AHZ(run_time); | |
477 | #if ACCT_VERSION==3 | |
cdd37e23 | 478 | ac->ac_etime = encode_float(elapsed); |
1da177e4 | 479 | #else |
cdd37e23 | 480 | ac->ac_etime = encode_comp_t(elapsed < (unsigned long) -1l ? |
1da177e4 LT |
481 | (unsigned long) elapsed : (unsigned long) -1l); |
482 | #endif | |
483 | #if ACCT_VERSION==1 || ACCT_VERSION==2 | |
484 | { | |
485 | /* new enlarged etime field */ | |
486 | comp2_t etime = encode_comp2_t(elapsed); | |
cdd37e23 AV |
487 | ac->ac_etime_hi = etime >> 16; |
488 | ac->ac_etime_lo = (u16) etime; | |
1da177e4 LT |
489 | } |
490 | #endif | |
491 | do_div(elapsed, AHZ); | |
cdd37e23 AV |
492 | ac->ac_btime = get_seconds() - elapsed; |
493 | #if ACCT_VERSION==2 | |
494 | ac->ac_ahz = AHZ; | |
495 | #endif | |
496 | ||
497 | spin_lock_irq(¤t->sighand->siglock); | |
498 | tty = current->signal->tty; /* Safe as we hold the siglock */ | |
499 | ac->ac_tty = tty ? old_encode_dev(tty_devnum(tty)) : 0; | |
500 | ac->ac_utime = encode_comp_t(jiffies_to_AHZ(cputime_to_jiffies(pacct->ac_utime))); | |
501 | ac->ac_stime = encode_comp_t(jiffies_to_AHZ(cputime_to_jiffies(pacct->ac_stime))); | |
502 | ac->ac_flag = pacct->ac_flag; | |
503 | ac->ac_mem = encode_comp_t(pacct->ac_mem); | |
504 | ac->ac_minflt = encode_comp_t(pacct->ac_minflt); | |
505 | ac->ac_majflt = encode_comp_t(pacct->ac_majflt); | |
506 | ac->ac_exitcode = pacct->ac_exitcode; | |
507 | spin_unlock_irq(¤t->sighand->siglock); | |
508 | } | |
509 | /* | |
510 | * do_acct_process does all actual work. Caller holds the reference to file. | |
511 | */ | |
b8f00e6b | 512 | static void do_acct_process(struct bsd_acct_struct *acct) |
cdd37e23 AV |
513 | { |
514 | acct_t ac; | |
515 | unsigned long flim; | |
516 | const struct cred *orig_cred; | |
b8f00e6b AV |
517 | struct pid_namespace *ns = acct->ns; |
518 | struct file *file = acct->file; | |
cdd37e23 AV |
519 | |
520 | /* | |
521 | * Accounting records are not subject to resource limits. | |
522 | */ | |
523 | flim = current->signal->rlim[RLIMIT_FSIZE].rlim_cur; | |
524 | current->signal->rlim[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY; | |
525 | /* Perform file operations on behalf of whoever enabled accounting */ | |
526 | orig_cred = override_creds(file->f_cred); | |
527 | ||
528 | /* | |
529 | * First check to see if there is enough free_space to continue | |
530 | * the process accounting system. | |
531 | */ | |
54a4d58a | 532 | if (!check_free_space(acct)) |
cdd37e23 AV |
533 | goto out; |
534 | ||
535 | fill_ac(&ac); | |
1da177e4 | 536 | /* we really need to bite the bullet and change layout */ |
f8f3d4de EB |
537 | ac.ac_uid = from_kuid_munged(file->f_cred->user_ns, orig_cred->uid); |
538 | ac.ac_gid = from_kgid_munged(file->f_cred->user_ns, orig_cred->gid); | |
1da177e4 LT |
539 | #if ACCT_VERSION==1 || ACCT_VERSION==2 |
540 | /* backward-compatible 16 bit fields */ | |
76aac0e9 DH |
541 | ac.ac_uid16 = ac.ac_uid; |
542 | ac.ac_gid16 = ac.ac_gid; | |
1da177e4 LT |
543 | #endif |
544 | #if ACCT_VERSION==3 | |
5f7b703f | 545 | ac.ac_pid = task_tgid_nr_ns(current, ns); |
a846a195 | 546 | rcu_read_lock(); |
5f7b703f | 547 | ac.ac_ppid = task_tgid_nr_ns(rcu_dereference(current->real_parent), ns); |
a846a195 | 548 | rcu_read_unlock(); |
1da177e4 | 549 | #endif |
5ae98f15 JK |
550 | /* |
551 | * Get freeze protection. If the fs is frozen, just skip the write | |
552 | * as we could deadlock the system otherwise. | |
553 | */ | |
ed44724b AV |
554 | if (file_start_write_trylock(file)) { |
555 | /* it's been opened O_APPEND, so position is irrelevant */ | |
556 | loff_t pos = 0; | |
557 | __kernel_write(file, (char *)&ac, sizeof(acct_t), &pos); | |
558 | file_end_write(file); | |
559 | } | |
d8e180dc | 560 | out: |
ed44724b | 561 | current->signal->rlim[RLIMIT_FSIZE].rlim_cur = flim; |
d8e180dc | 562 | revert_creds(orig_cred); |
1da177e4 LT |
563 | } |
564 | ||
0e464814 KK |
565 | /** |
566 | * acct_collect - collect accounting information into pacct_struct | |
f6ec29a4 KK |
567 | * @exitcode: task exit code |
568 | * @group_dead: not 0, if this thread is the last one in the process. | |
0e464814 | 569 | */ |
f6ec29a4 | 570 | void acct_collect(long exitcode, int group_dead) |
0e464814 KK |
571 | { |
572 | struct pacct_struct *pacct = ¤t->signal->pacct; | |
6fac4829 | 573 | cputime_t utime, stime; |
0e464814 KK |
574 | unsigned long vsize = 0; |
575 | ||
f6ec29a4 | 576 | if (group_dead && current->mm) { |
0e464814 KK |
577 | struct vm_area_struct *vma; |
578 | down_read(¤t->mm->mmap_sem); | |
579 | vma = current->mm->mmap; | |
580 | while (vma) { | |
581 | vsize += vma->vm_end - vma->vm_start; | |
582 | vma = vma->vm_next; | |
583 | } | |
584 | up_read(¤t->mm->mmap_sem); | |
585 | } | |
586 | ||
77787bfb | 587 | spin_lock_irq(¤t->sighand->siglock); |
f6ec29a4 KK |
588 | if (group_dead) |
589 | pacct->ac_mem = vsize / 1024; | |
590 | if (thread_group_leader(current)) { | |
591 | pacct->ac_exitcode = exitcode; | |
592 | if (current->flags & PF_FORKNOEXEC) | |
593 | pacct->ac_flag |= AFORK; | |
594 | } | |
595 | if (current->flags & PF_SUPERPRIV) | |
596 | pacct->ac_flag |= ASU; | |
597 | if (current->flags & PF_DUMPCORE) | |
598 | pacct->ac_flag |= ACORE; | |
599 | if (current->flags & PF_SIGNALED) | |
600 | pacct->ac_flag |= AXSIG; | |
6fac4829 FW |
601 | task_cputime(current, &utime, &stime); |
602 | pacct->ac_utime += utime; | |
603 | pacct->ac_stime += stime; | |
77787bfb KK |
604 | pacct->ac_minflt += current->min_flt; |
605 | pacct->ac_majflt += current->maj_flt; | |
606 | spin_unlock_irq(¤t->sighand->siglock); | |
0e464814 KK |
607 | } |
608 | ||
e25ff11f | 609 | static void slow_acct_process(struct pid_namespace *ns) |
1da177e4 | 610 | { |
e25ff11f | 611 | for ( ; ns; ns = ns->parent) { |
215752fc | 612 | struct bsd_acct_struct *acct = acct_get(ns); |
b8f00e6b AV |
613 | if (acct) { |
614 | do_acct_process(acct); | |
615 | mutex_unlock(&acct->lock); | |
616 | acct_put(acct); | |
e25ff11f | 617 | } |
e25ff11f | 618 | } |
1da177e4 | 619 | } |
7d1e1350 PE |
620 | |
621 | /** | |
e25ff11f | 622 | * acct_process |
7d1e1350 PE |
623 | * |
624 | * handles process accounting for an exiting task | |
625 | */ | |
626 | void acct_process(void) | |
627 | { | |
628 | struct pid_namespace *ns; | |
629 | ||
0c18d7a5 PE |
630 | /* |
631 | * This loop is safe lockless, since current is still | |
632 | * alive and holds its namespace, which in turn holds | |
633 | * its parent. | |
634 | */ | |
e25ff11f | 635 | for (ns = task_active_pid_ns(current); ns != NULL; ns = ns->parent) { |
b8f00e6b | 636 | if (ns->bacct) |
e25ff11f AV |
637 | break; |
638 | } | |
639 | if (unlikely(ns)) | |
640 | slow_acct_process(ns); | |
7d1e1350 | 641 | } |