1 // SPDX-License-Identifier: GPL-2.0 <<
2 /* 1 /*
3 * linux/kernel/acct.c 2 * linux/kernel/acct.c
4 * 3 *
5 * BSD Process Accounting for Linux 4 * BSD Process Accounting for Linux
6 * 5 *
7 * Author: Marco van Wieringen <mvw@planets.e 6 * Author: Marco van Wieringen <mvw@planets.elm.net>
8 * 7 *
9 * Some code based on ideas and code from: 8 * Some code based on ideas and code from:
10 * Thomas K. Dyas <tdyas@eden.rutgers.edu> 9 * Thomas K. Dyas <tdyas@eden.rutgers.edu>
11 * 10 *
12 * This file implements BSD-style process acc 11 * This file implements BSD-style process accounting. Whenever any
13 * process exits, an accounting record of typ 12 * process exits, an accounting record of type "struct acct" is
14 * written to the file specified with the acc 13 * written to the file specified with the acct() system call. It is
15 * up to user-level programs to do useful thi 14 * up to user-level programs to do useful things with the accounting
16 * log. The kernel just provides the raw acco 15 * log. The kernel just provides the raw accounting information.
17 * 16 *
18 * (C) Copyright 1995 - 1997 Marco van Wiering 17 * (C) Copyright 1995 - 1997 Marco van Wieringen - ELM Consultancy B.V.
19 * 18 *
20 * Plugged two leaks. 1) It didn't return acc 19 * Plugged two leaks. 1) It didn't return acct_file into the free_filps if
21 * the file happened to be read-only. 2) If t 20 * the file happened to be read-only. 2) If the accounting was suspended
22 * due to the lack of space it happily allowe 21 * due to the lack of space it happily allowed to reopen it and completely
23 * lost the old acct_file. 3/10/98, Al Viro. 22 * lost the old acct_file. 3/10/98, Al Viro.
24 * 23 *
25 * Now we silently close acct_file on attempt 24 * Now we silently close acct_file on attempt to reopen. Cleaned sys_acct().
26 * XTerms and EMACS are manifestations of pur 25 * XTerms and EMACS are manifestations of pure evil. 21/10/98, AV.
27 * 26 *
28 * Fixed a nasty interaction with sys_umount( !! 27 * Fixed a nasty interaction with with sys_umount(). If the accointing
29 * was suspeneded we failed to stop it on umo 28 * was suspeneded we failed to stop it on umount(). Messy.
30 * Another one: remount to readonly didn't st 29 * Another one: remount to readonly didn't stop accounting.
31 * Question: what should we do if we have 30 * Question: what should we do if we have CAP_SYS_ADMIN but not
32 * CAP_SYS_PACCT? Current code does the follo 31 * CAP_SYS_PACCT? Current code does the following: umount returns -EBUSY
33 * unless we are messing with the root. In th 32 * unless we are messing with the root. In that case we are getting a
34 * real mess with do_remount_sb(). 9/11/98, A 33 * real mess with do_remount_sb(). 9/11/98, AV.
35 * 34 *
36 * Fixed a bunch of races (and pair of leaks) 35 * Fixed a bunch of races (and pair of leaks). Probably not the best way,
37 * but this one obviously doesn't introduce d 36 * but this one obviously doesn't introduce deadlocks. Later. BTW, found
38 * one race (and leak) in BSD implementation. 37 * one race (and leak) in BSD implementation.
39 * OK, that's better. ANOTHER race and leak i 38 * OK, that's better. ANOTHER race and leak in BSD variant. There always
40 * is one more bug... 10/11/98, AV. 39 * is one more bug... 10/11/98, AV.
41 * 40 *
42 * Oh, fsck... Oopsable SMP race in do_pr 41 * Oh, fsck... Oopsable SMP race in do_process_acct() - we must hold
43 * ->mmap_lock to walk the vma list of current !! 42 * ->mmap_sem to walk the vma list of current->mm. Nasty, since it leaks
44 * a struct file opened for write. Fixed. 2/6/ 43 * a struct file opened for write. Fixed. 2/6/2000, AV.
45 */ 44 */
46 45
47 #include <linux/mm.h> 46 #include <linux/mm.h>
48 #include <linux/slab.h> 47 #include <linux/slab.h>
49 #include <linux/acct.h> 48 #include <linux/acct.h>
50 #include <linux/capability.h> 49 #include <linux/capability.h>
51 #include <linux/file.h> 50 #include <linux/file.h>
52 #include <linux/tty.h> 51 #include <linux/tty.h>
53 #include <linux/security.h> 52 #include <linux/security.h>
54 #include <linux/vfs.h> 53 #include <linux/vfs.h>
55 #include <linux/jiffies.h> 54 #include <linux/jiffies.h>
56 #include <linux/times.h> 55 #include <linux/times.h>
57 #include <linux/syscalls.h> 56 #include <linux/syscalls.h>
58 #include <linux/mount.h> 57 #include <linux/mount.h>
59 #include <linux/uaccess.h> 58 #include <linux/uaccess.h>
60 #include <linux/sched/cputime.h> 59 #include <linux/sched/cputime.h>
61 60
62 #include <asm/div64.h> 61 #include <asm/div64.h>
>> 62 #include <linux/blkdev.h> /* sector_div */
63 #include <linux/pid_namespace.h> 63 #include <linux/pid_namespace.h>
64 #include <linux/fs_pin.h> 64 #include <linux/fs_pin.h>
65 65
66 /* 66 /*
67 * These constants control the amount of frees 67 * These constants control the amount of freespace that suspend and
68 * resume the process accounting system, and t 68 * resume the process accounting system, and the time delay between
69 * each check. 69 * each check.
70 * Turned into sysctl-controllable parameters. 70 * Turned into sysctl-controllable parameters. AV, 12/11/98
71 */ 71 */
72 72
73 static int acct_parm[3] = {4, 2, 30}; !! 73 int acct_parm[3] = {4, 2, 30};
74 #define RESUME (acct_parm[0]) /* >fo 74 #define RESUME (acct_parm[0]) /* >foo% free space - resume */
75 #define SUSPEND (acct_parm[1]) /* <fo 75 #define SUSPEND (acct_parm[1]) /* <foo% free space - suspend */
76 #define ACCT_TIMEOUT (acct_parm[2]) /* foo 76 #define ACCT_TIMEOUT (acct_parm[2]) /* foo second timeout between checks */
77 77
78 #ifdef CONFIG_SYSCTL <<
79 static struct ctl_table kern_acct_table[] = { <<
80 { <<
81 .procname = "acct", <<
82 .data = &acct_parm, <<
83 .maxlen = 3*sizeof(int <<
84 .mode = 0644, <<
85 .proc_handler = proc_dointve <<
86 }, <<
87 }; <<
88 <<
89 static __init int kernel_acct_sysctls_init(voi <<
90 { <<
91 register_sysctl_init("kernel", kern_ac <<
92 return 0; <<
93 } <<
94 late_initcall(kernel_acct_sysctls_init); <<
95 #endif /* CONFIG_SYSCTL */ <<
96 <<
97 /* 78 /*
98 * External references and all of the globals. 79 * External references and all of the globals.
99 */ 80 */
100 81
101 struct bsd_acct_struct { 82 struct bsd_acct_struct {
102 struct fs_pin pin; 83 struct fs_pin pin;
103 atomic_long_t count; 84 atomic_long_t count;
104 struct rcu_head rcu; 85 struct rcu_head rcu;
105 struct mutex lock; 86 struct mutex lock;
106 int active; 87 int active;
107 unsigned long needcheck; 88 unsigned long needcheck;
108 struct file *file; 89 struct file *file;
109 struct pid_namespace *ns; 90 struct pid_namespace *ns;
110 struct work_struct work; 91 struct work_struct work;
111 struct completion done; 92 struct completion done;
112 }; 93 };
113 94
114 static void do_acct_process(struct bsd_acct_st 95 static void do_acct_process(struct bsd_acct_struct *acct);
115 96
116 /* 97 /*
117 * Check the amount of free space and suspend/ 98 * Check the amount of free space and suspend/resume accordingly.
118 */ 99 */
119 static int check_free_space(struct bsd_acct_st 100 static int check_free_space(struct bsd_acct_struct *acct)
120 { 101 {
121 struct kstatfs sbuf; 102 struct kstatfs sbuf;
122 103
123 if (time_is_after_jiffies(acct->needch !! 104 if (time_is_before_jiffies(acct->needcheck))
124 goto out; 105 goto out;
125 106
126 /* May block */ 107 /* May block */
127 if (vfs_statfs(&acct->file->f_path, &s 108 if (vfs_statfs(&acct->file->f_path, &sbuf))
128 goto out; 109 goto out;
129 110
130 if (acct->active) { 111 if (acct->active) {
131 u64 suspend = sbuf.f_blocks * 112 u64 suspend = sbuf.f_blocks * SUSPEND;
132 do_div(suspend, 100); 113 do_div(suspend, 100);
133 if (sbuf.f_bavail <= suspend) 114 if (sbuf.f_bavail <= suspend) {
134 acct->active = 0; 115 acct->active = 0;
135 pr_info("Process accou 116 pr_info("Process accounting paused\n");
136 } 117 }
137 } else { 118 } else {
138 u64 resume = sbuf.f_blocks * R 119 u64 resume = sbuf.f_blocks * RESUME;
139 do_div(resume, 100); 120 do_div(resume, 100);
140 if (sbuf.f_bavail >= resume) { 121 if (sbuf.f_bavail >= resume) {
141 acct->active = 1; 122 acct->active = 1;
142 pr_info("Process accou 123 pr_info("Process accounting resumed\n");
143 } 124 }
144 } 125 }
145 126
146 acct->needcheck = jiffies + ACCT_TIMEO 127 acct->needcheck = jiffies + ACCT_TIMEOUT*HZ;
147 out: 128 out:
148 return acct->active; 129 return acct->active;
149 } 130 }
150 131
151 static void acct_put(struct bsd_acct_struct *p 132 static void acct_put(struct bsd_acct_struct *p)
152 { 133 {
153 if (atomic_long_dec_and_test(&p->count 134 if (atomic_long_dec_and_test(&p->count))
154 kfree_rcu(p, rcu); 135 kfree_rcu(p, rcu);
155 } 136 }
156 137
157 static inline struct bsd_acct_struct *to_acct( 138 static inline struct bsd_acct_struct *to_acct(struct fs_pin *p)
158 { 139 {
159 return p ? container_of(p, struct bsd_ 140 return p ? container_of(p, struct bsd_acct_struct, pin) : NULL;
160 } 141 }
161 142
162 static struct bsd_acct_struct *acct_get(struct 143 static struct bsd_acct_struct *acct_get(struct pid_namespace *ns)
163 { 144 {
164 struct bsd_acct_struct *res; 145 struct bsd_acct_struct *res;
165 again: 146 again:
166 smp_rmb(); 147 smp_rmb();
167 rcu_read_lock(); 148 rcu_read_lock();
168 res = to_acct(READ_ONCE(ns->bacct)); !! 149 res = to_acct(ACCESS_ONCE(ns->bacct));
169 if (!res) { 150 if (!res) {
170 rcu_read_unlock(); 151 rcu_read_unlock();
171 return NULL; 152 return NULL;
172 } 153 }
173 if (!atomic_long_inc_not_zero(&res->co 154 if (!atomic_long_inc_not_zero(&res->count)) {
174 rcu_read_unlock(); 155 rcu_read_unlock();
175 cpu_relax(); 156 cpu_relax();
176 goto again; 157 goto again;
177 } 158 }
178 rcu_read_unlock(); 159 rcu_read_unlock();
179 mutex_lock(&res->lock); 160 mutex_lock(&res->lock);
180 if (res != to_acct(READ_ONCE(ns->bacct !! 161 if (res != to_acct(ACCESS_ONCE(ns->bacct))) {
181 mutex_unlock(&res->lock); 162 mutex_unlock(&res->lock);
182 acct_put(res); 163 acct_put(res);
183 goto again; 164 goto again;
184 } 165 }
185 return res; 166 return res;
186 } 167 }
187 168
188 static void acct_pin_kill(struct fs_pin *pin) 169 static void acct_pin_kill(struct fs_pin *pin)
189 { 170 {
190 struct bsd_acct_struct *acct = to_acct 171 struct bsd_acct_struct *acct = to_acct(pin);
191 mutex_lock(&acct->lock); 172 mutex_lock(&acct->lock);
192 do_acct_process(acct); 173 do_acct_process(acct);
193 schedule_work(&acct->work); 174 schedule_work(&acct->work);
194 wait_for_completion(&acct->done); 175 wait_for_completion(&acct->done);
195 cmpxchg(&acct->ns->bacct, pin, NULL); 176 cmpxchg(&acct->ns->bacct, pin, NULL);
196 mutex_unlock(&acct->lock); 177 mutex_unlock(&acct->lock);
197 pin_remove(pin); 178 pin_remove(pin);
198 acct_put(acct); 179 acct_put(acct);
199 } 180 }
200 181
201 static void close_work(struct work_struct *wor 182 static void close_work(struct work_struct *work)
202 { 183 {
203 struct bsd_acct_struct *acct = contain 184 struct bsd_acct_struct *acct = container_of(work, struct bsd_acct_struct, work);
204 struct file *file = acct->file; 185 struct file *file = acct->file;
205 if (file->f_op->flush) 186 if (file->f_op->flush)
206 file->f_op->flush(file, NULL); 187 file->f_op->flush(file, NULL);
207 __fput_sync(file); 188 __fput_sync(file);
208 complete(&acct->done); 189 complete(&acct->done);
209 } 190 }
210 191
211 static int acct_on(struct filename *pathname) 192 static int acct_on(struct filename *pathname)
212 { 193 {
213 struct file *file; 194 struct file *file;
214 struct vfsmount *mnt, *internal; 195 struct vfsmount *mnt, *internal;
215 struct pid_namespace *ns = task_active 196 struct pid_namespace *ns = task_active_pid_ns(current);
216 struct bsd_acct_struct *acct; 197 struct bsd_acct_struct *acct;
217 struct fs_pin *old; 198 struct fs_pin *old;
218 int err; 199 int err;
219 200
220 acct = kzalloc(sizeof(struct bsd_acct_ 201 acct = kzalloc(sizeof(struct bsd_acct_struct), GFP_KERNEL);
221 if (!acct) 202 if (!acct)
222 return -ENOMEM; 203 return -ENOMEM;
223 204
224 /* Difference from BSD - they don't do 205 /* Difference from BSD - they don't do O_APPEND */
225 file = file_open_name(pathname, O_WRON 206 file = file_open_name(pathname, O_WRONLY|O_APPEND|O_LARGEFILE, 0);
226 if (IS_ERR(file)) { 207 if (IS_ERR(file)) {
227 kfree(acct); 208 kfree(acct);
228 return PTR_ERR(file); 209 return PTR_ERR(file);
229 } 210 }
230 211
231 if (!S_ISREG(file_inode(file)->i_mode) 212 if (!S_ISREG(file_inode(file)->i_mode)) {
232 kfree(acct); 213 kfree(acct);
233 filp_close(file, NULL); 214 filp_close(file, NULL);
234 return -EACCES; 215 return -EACCES;
235 } 216 }
236 217
237 if (!(file->f_mode & FMODE_CAN_WRITE)) 218 if (!(file->f_mode & FMODE_CAN_WRITE)) {
238 kfree(acct); 219 kfree(acct);
239 filp_close(file, NULL); 220 filp_close(file, NULL);
240 return -EIO; 221 return -EIO;
241 } 222 }
242 internal = mnt_clone_internal(&file->f 223 internal = mnt_clone_internal(&file->f_path);
243 if (IS_ERR(internal)) { 224 if (IS_ERR(internal)) {
244 kfree(acct); 225 kfree(acct);
245 filp_close(file, NULL); 226 filp_close(file, NULL);
246 return PTR_ERR(internal); 227 return PTR_ERR(internal);
247 } 228 }
248 err = mnt_get_write_access(internal); !! 229 err = mnt_want_write(internal);
249 if (err) { 230 if (err) {
250 mntput(internal); 231 mntput(internal);
251 kfree(acct); 232 kfree(acct);
252 filp_close(file, NULL); 233 filp_close(file, NULL);
253 return err; 234 return err;
254 } 235 }
255 mnt = file->f_path.mnt; 236 mnt = file->f_path.mnt;
256 file->f_path.mnt = internal; 237 file->f_path.mnt = internal;
257 238
258 atomic_long_set(&acct->count, 1); 239 atomic_long_set(&acct->count, 1);
259 init_fs_pin(&acct->pin, acct_pin_kill) 240 init_fs_pin(&acct->pin, acct_pin_kill);
260 acct->file = file; 241 acct->file = file;
261 acct->needcheck = jiffies; 242 acct->needcheck = jiffies;
262 acct->ns = ns; 243 acct->ns = ns;
263 mutex_init(&acct->lock); 244 mutex_init(&acct->lock);
264 INIT_WORK(&acct->work, close_work); 245 INIT_WORK(&acct->work, close_work);
265 init_completion(&acct->done); 246 init_completion(&acct->done);
266 mutex_lock_nested(&acct->lock, 1); 247 mutex_lock_nested(&acct->lock, 1); /* nobody has seen it yet */
267 pin_insert(&acct->pin, mnt); 248 pin_insert(&acct->pin, mnt);
268 249
269 rcu_read_lock(); 250 rcu_read_lock();
270 old = xchg(&ns->bacct, &acct->pin); 251 old = xchg(&ns->bacct, &acct->pin);
271 mutex_unlock(&acct->lock); 252 mutex_unlock(&acct->lock);
272 pin_kill(old); 253 pin_kill(old);
273 mnt_put_write_access(mnt); !! 254 mnt_drop_write(mnt);
274 mntput(mnt); 255 mntput(mnt);
275 return 0; 256 return 0;
276 } 257 }
277 258
278 static DEFINE_MUTEX(acct_on_mutex); 259 static DEFINE_MUTEX(acct_on_mutex);
279 260
280 /** 261 /**
281 * sys_acct - enable/disable process accountin 262 * sys_acct - enable/disable process accounting
282 * @name: file name for accounting records or 263 * @name: file name for accounting records or NULL to shutdown accounting
283 * 264 *
>> 265 * Returns 0 for success or negative errno values for failure.
>> 266 *
284 * sys_acct() is the only system call needed t 267 * sys_acct() is the only system call needed to implement process
285 * accounting. It takes the name of the file w 268 * accounting. It takes the name of the file where accounting records
286 * should be written. If the filename is NULL, 269 * should be written. If the filename is NULL, accounting will be
287 * shutdown. 270 * shutdown.
288 * <<
289 * Returns: 0 for success or negative errno va <<
290 */ 271 */
291 SYSCALL_DEFINE1(acct, const char __user *, nam 272 SYSCALL_DEFINE1(acct, const char __user *, name)
292 { 273 {
293 int error = 0; 274 int error = 0;
294 275
295 if (!capable(CAP_SYS_PACCT)) 276 if (!capable(CAP_SYS_PACCT))
296 return -EPERM; 277 return -EPERM;
297 278
298 if (name) { 279 if (name) {
299 struct filename *tmp = getname 280 struct filename *tmp = getname(name);
300 281
301 if (IS_ERR(tmp)) 282 if (IS_ERR(tmp))
302 return PTR_ERR(tmp); 283 return PTR_ERR(tmp);
303 mutex_lock(&acct_on_mutex); 284 mutex_lock(&acct_on_mutex);
304 error = acct_on(tmp); 285 error = acct_on(tmp);
305 mutex_unlock(&acct_on_mutex); 286 mutex_unlock(&acct_on_mutex);
306 putname(tmp); 287 putname(tmp);
307 } else { 288 } else {
308 rcu_read_lock(); 289 rcu_read_lock();
309 pin_kill(task_active_pid_ns(cu 290 pin_kill(task_active_pid_ns(current)->bacct);
310 } 291 }
311 292
312 return error; 293 return error;
313 } 294 }
314 295
315 void acct_exit_ns(struct pid_namespace *ns) 296 void acct_exit_ns(struct pid_namespace *ns)
316 { 297 {
317 rcu_read_lock(); 298 rcu_read_lock();
318 pin_kill(ns->bacct); 299 pin_kill(ns->bacct);
319 } 300 }
320 301
321 /* 302 /*
322 * encode an u64 into a comp_t !! 303 * encode an unsigned long into a comp_t
323 * 304 *
324 * This routine has been adopted from the enc 305 * This routine has been adopted from the encode_comp_t() function in
325 * the kern_acct.c file of the FreeBSD operat 306 * the kern_acct.c file of the FreeBSD operating system. The encoding
326 * is a 13-bit fraction with a 3-bit (base 8) 307 * is a 13-bit fraction with a 3-bit (base 8) exponent.
327 */ 308 */
328 309
329 #define MANTSIZE 13 310 #define MANTSIZE 13 /* 13 bit mantissa. */
330 #define EXPSIZE 3 311 #define EXPSIZE 3 /* Base 8 (3 bit) exponent. */
331 #define MAXFRACT ((1 << MANTSIZE) - 1) 312 #define MAXFRACT ((1 << MANTSIZE) - 1) /* Maximum fractional value. */
332 313
333 static comp_t encode_comp_t(u64 value) !! 314 static comp_t encode_comp_t(unsigned long value)
334 { 315 {
335 int exp, rnd; 316 int exp, rnd;
336 317
337 exp = rnd = 0; 318 exp = rnd = 0;
338 while (value > MAXFRACT) { 319 while (value > MAXFRACT) {
339 rnd = value & (1 << (EXPSIZE - 320 rnd = value & (1 << (EXPSIZE - 1)); /* Round up? */
340 value >>= EXPSIZE; /* Bas 321 value >>= EXPSIZE; /* Base 8 exponent == 3 bit shift. */
341 exp++; 322 exp++;
342 } 323 }
343 324
344 /* 325 /*
345 * If we need to round up, do it (and 326 * If we need to round up, do it (and handle overflow correctly).
346 */ 327 */
347 if (rnd && (++value > MAXFRACT)) { 328 if (rnd && (++value > MAXFRACT)) {
348 value >>= EXPSIZE; 329 value >>= EXPSIZE;
349 exp++; 330 exp++;
350 } 331 }
351 332
352 if (exp > (((comp_t) ~0U) >> MANTSIZE) <<
353 return (comp_t) ~0U; <<
354 /* 333 /*
355 * Clean it up and polish it off. 334 * Clean it up and polish it off.
356 */ 335 */
357 exp <<= MANTSIZE; /* Shi 336 exp <<= MANTSIZE; /* Shift the exponent into place */
358 exp += value; /* and 337 exp += value; /* and add on the mantissa. */
359 return exp; 338 return exp;
360 } 339 }
361 340
362 #if ACCT_VERSION == 1 || ACCT_VERSION == 2 341 #if ACCT_VERSION == 1 || ACCT_VERSION == 2
363 /* 342 /*
364 * encode an u64 into a comp2_t (24 bits) 343 * encode an u64 into a comp2_t (24 bits)
365 * 344 *
366 * Format: 5 bit base 2 exponent, 20 bits mant 345 * Format: 5 bit base 2 exponent, 20 bits mantissa.
367 * The leading bit of the mantissa is not stor 346 * The leading bit of the mantissa is not stored, but implied for
368 * non-zero exponents. 347 * non-zero exponents.
369 * Largest encodable value is 50 bits. 348 * Largest encodable value is 50 bits.
370 */ 349 */
371 350
372 #define MANTSIZE2 20 351 #define MANTSIZE2 20 /* 20 bit mantissa. */
373 #define EXPSIZE2 5 352 #define EXPSIZE2 5 /* 5 bit base 2 exponent. */
374 #define MAXFRACT2 ((1ul << MANTSIZE2) - 353 #define MAXFRACT2 ((1ul << MANTSIZE2) - 1) /* Maximum fractional value. */
375 #define MAXEXP2 ((1 << EXPSIZE2) - 1) 354 #define MAXEXP2 ((1 << EXPSIZE2) - 1) /* Maximum exponent. */
376 355
377 static comp2_t encode_comp2_t(u64 value) 356 static comp2_t encode_comp2_t(u64 value)
378 { 357 {
379 int exp, rnd; 358 int exp, rnd;
380 359
381 exp = (value > (MAXFRACT2>>1)); 360 exp = (value > (MAXFRACT2>>1));
382 rnd = 0; 361 rnd = 0;
383 while (value > MAXFRACT2) { 362 while (value > MAXFRACT2) {
384 rnd = value & 1; 363 rnd = value & 1;
385 value >>= 1; 364 value >>= 1;
386 exp++; 365 exp++;
387 } 366 }
388 367
389 /* 368 /*
390 * If we need to round up, do it (and 369 * If we need to round up, do it (and handle overflow correctly).
391 */ 370 */
392 if (rnd && (++value > MAXFRACT2)) { 371 if (rnd && (++value > MAXFRACT2)) {
393 value >>= 1; 372 value >>= 1;
394 exp++; 373 exp++;
395 } 374 }
396 375
397 if (exp > MAXEXP2) { 376 if (exp > MAXEXP2) {
398 /* Overflow. Return largest re 377 /* Overflow. Return largest representable number instead. */
399 return (1ul << (MANTSIZE2+EXPS 378 return (1ul << (MANTSIZE2+EXPSIZE2-1)) - 1;
400 } else { 379 } else {
401 return (value & (MAXFRACT2>>1) 380 return (value & (MAXFRACT2>>1)) | (exp << (MANTSIZE2-1));
402 } 381 }
403 } 382 }
404 #elif ACCT_VERSION == 3 !! 383 #endif
>> 384
>> 385 #if ACCT_VERSION == 3
405 /* 386 /*
406 * encode an u64 into a 32 bit IEEE float 387 * encode an u64 into a 32 bit IEEE float
407 */ 388 */
408 static u32 encode_float(u64 value) 389 static u32 encode_float(u64 value)
409 { 390 {
410 unsigned exp = 190; 391 unsigned exp = 190;
411 unsigned u; 392 unsigned u;
412 393
413 if (value == 0) 394 if (value == 0)
414 return 0; 395 return 0;
415 while ((s64)value > 0) { 396 while ((s64)value > 0) {
416 value <<= 1; 397 value <<= 1;
417 exp--; 398 exp--;
418 } 399 }
419 u = (u32)(value >> 40) & 0x7fffffu; 400 u = (u32)(value >> 40) & 0x7fffffu;
420 return u | (exp << 23); 401 return u | (exp << 23);
421 } 402 }
422 #endif 403 #endif
423 404
424 /* 405 /*
425 * Write an accounting entry for an exiting p 406 * Write an accounting entry for an exiting process
426 * 407 *
427 * The acct_process() call is the workhorse o 408 * The acct_process() call is the workhorse of the process
428 * accounting system. The struct acct is buil 409 * accounting system. The struct acct is built here and then written
429 * into the accounting file. This function sh 410 * into the accounting file. This function should only be called from
430 * do_exit() or when switching to a different 411 * do_exit() or when switching to a different output file.
431 */ 412 */
432 413
433 static void fill_ac(acct_t *ac) 414 static void fill_ac(acct_t *ac)
434 { 415 {
435 struct pacct_struct *pacct = ¤t- 416 struct pacct_struct *pacct = ¤t->signal->pacct;
436 u64 elapsed, run_time; 417 u64 elapsed, run_time;
437 time64_t btime; <<
438 struct tty_struct *tty; 418 struct tty_struct *tty;
439 419
440 /* 420 /*
441 * Fill the accounting struct with the 421 * Fill the accounting struct with the needed info as recorded
442 * by the different kernel functions. 422 * by the different kernel functions.
443 */ 423 */
444 memset(ac, 0, sizeof(acct_t)); 424 memset(ac, 0, sizeof(acct_t));
445 425
446 ac->ac_version = ACCT_VERSION | ACCT_B 426 ac->ac_version = ACCT_VERSION | ACCT_BYTEORDER;
447 strscpy(ac->ac_comm, current->comm, si !! 427 strlcpy(ac->ac_comm, current->comm, sizeof(ac->ac_comm));
448 428
449 /* calculate run_time in nsec*/ 429 /* calculate run_time in nsec*/
450 run_time = ktime_get_ns(); 430 run_time = ktime_get_ns();
451 run_time -= current->group_leader->sta 431 run_time -= current->group_leader->start_time;
452 /* convert nsec -> AHZ */ 432 /* convert nsec -> AHZ */
453 elapsed = nsec_to_AHZ(run_time); 433 elapsed = nsec_to_AHZ(run_time);
454 #if ACCT_VERSION == 3 434 #if ACCT_VERSION == 3
455 ac->ac_etime = encode_float(elapsed); 435 ac->ac_etime = encode_float(elapsed);
456 #else 436 #else
457 ac->ac_etime = encode_comp_t(elapsed < 437 ac->ac_etime = encode_comp_t(elapsed < (unsigned long) -1l ?
458 (unsigned long 438 (unsigned long) elapsed : (unsigned long) -1l);
459 #endif 439 #endif
460 #if ACCT_VERSION == 1 || ACCT_VERSION == 2 440 #if ACCT_VERSION == 1 || ACCT_VERSION == 2
461 { 441 {
462 /* new enlarged etime field */ 442 /* new enlarged etime field */
463 comp2_t etime = encode_comp2_t 443 comp2_t etime = encode_comp2_t(elapsed);
464 444
465 ac->ac_etime_hi = etime >> 16; 445 ac->ac_etime_hi = etime >> 16;
466 ac->ac_etime_lo = (u16) etime; 446 ac->ac_etime_lo = (u16) etime;
467 } 447 }
468 #endif 448 #endif
469 do_div(elapsed, AHZ); 449 do_div(elapsed, AHZ);
470 btime = ktime_get_real_seconds() - ela !! 450 ac->ac_btime = get_seconds() - elapsed;
471 ac->ac_btime = clamp_t(time64_t, btime !! 451 #if ACCT_VERSION==2
472 #if ACCT_VERSION == 2 <<
473 ac->ac_ahz = AHZ; 452 ac->ac_ahz = AHZ;
474 #endif 453 #endif
475 454
476 spin_lock_irq(¤t->sighand->siglo 455 spin_lock_irq(¤t->sighand->siglock);
477 tty = current->signal->tty; /* Saf 456 tty = current->signal->tty; /* Safe as we hold the siglock */
478 ac->ac_tty = tty ? old_encode_dev(tty_ 457 ac->ac_tty = tty ? old_encode_dev(tty_devnum(tty)) : 0;
479 ac->ac_utime = encode_comp_t(nsec_to_A 458 ac->ac_utime = encode_comp_t(nsec_to_AHZ(pacct->ac_utime));
480 ac->ac_stime = encode_comp_t(nsec_to_A 459 ac->ac_stime = encode_comp_t(nsec_to_AHZ(pacct->ac_stime));
481 ac->ac_flag = pacct->ac_flag; 460 ac->ac_flag = pacct->ac_flag;
482 ac->ac_mem = encode_comp_t(pacct->ac_m 461 ac->ac_mem = encode_comp_t(pacct->ac_mem);
483 ac->ac_minflt = encode_comp_t(pacct->a 462 ac->ac_minflt = encode_comp_t(pacct->ac_minflt);
484 ac->ac_majflt = encode_comp_t(pacct->a 463 ac->ac_majflt = encode_comp_t(pacct->ac_majflt);
485 ac->ac_exitcode = pacct->ac_exitcode; 464 ac->ac_exitcode = pacct->ac_exitcode;
486 spin_unlock_irq(¤t->sighand->sig 465 spin_unlock_irq(¤t->sighand->siglock);
487 } 466 }
488 /* 467 /*
489 * do_acct_process does all actual work. Call 468 * do_acct_process does all actual work. Caller holds the reference to file.
490 */ 469 */
491 static void do_acct_process(struct bsd_acct_st 470 static void do_acct_process(struct bsd_acct_struct *acct)
492 { 471 {
493 acct_t ac; 472 acct_t ac;
494 unsigned long flim; 473 unsigned long flim;
495 const struct cred *orig_cred; 474 const struct cred *orig_cred;
496 struct file *file = acct->file; 475 struct file *file = acct->file;
497 476
498 /* 477 /*
499 * Accounting records are not subject 478 * Accounting records are not subject to resource limits.
500 */ 479 */
501 flim = rlimit(RLIMIT_FSIZE); !! 480 flim = current->signal->rlim[RLIMIT_FSIZE].rlim_cur;
502 current->signal->rlim[RLIMIT_FSIZE].rl 481 current->signal->rlim[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY;
503 /* Perform file operations on behalf o 482 /* Perform file operations on behalf of whoever enabled accounting */
504 orig_cred = override_creds(file->f_cre 483 orig_cred = override_creds(file->f_cred);
505 484
506 /* 485 /*
507 * First check to see if there is enou 486 * First check to see if there is enough free_space to continue
508 * the process accounting system. 487 * the process accounting system.
509 */ 488 */
510 if (!check_free_space(acct)) 489 if (!check_free_space(acct))
511 goto out; 490 goto out;
512 491
513 fill_ac(&ac); 492 fill_ac(&ac);
514 /* we really need to bite the bullet a 493 /* we really need to bite the bullet and change layout */
515 ac.ac_uid = from_kuid_munged(file->f_c 494 ac.ac_uid = from_kuid_munged(file->f_cred->user_ns, orig_cred->uid);
516 ac.ac_gid = from_kgid_munged(file->f_c 495 ac.ac_gid = from_kgid_munged(file->f_cred->user_ns, orig_cred->gid);
517 #if ACCT_VERSION == 1 || ACCT_VERSION == 2 496 #if ACCT_VERSION == 1 || ACCT_VERSION == 2
518 /* backward-compatible 16 bit fields * 497 /* backward-compatible 16 bit fields */
519 ac.ac_uid16 = ac.ac_uid; 498 ac.ac_uid16 = ac.ac_uid;
520 ac.ac_gid16 = ac.ac_gid; 499 ac.ac_gid16 = ac.ac_gid;
521 #elif ACCT_VERSION == 3 !! 500 #endif
>> 501 #if ACCT_VERSION == 3
522 { 502 {
523 struct pid_namespace *ns = acc 503 struct pid_namespace *ns = acct->ns;
524 504
525 ac.ac_pid = task_tgid_nr_ns(cu 505 ac.ac_pid = task_tgid_nr_ns(current, ns);
526 rcu_read_lock(); 506 rcu_read_lock();
527 ac.ac_ppid = task_tgid_nr_ns(r 507 ac.ac_ppid = task_tgid_nr_ns(rcu_dereference(current->real_parent),
528 n 508 ns);
529 rcu_read_unlock(); 509 rcu_read_unlock();
530 } 510 }
531 #endif 511 #endif
532 /* 512 /*
533 * Get freeze protection. If the fs is 513 * Get freeze protection. If the fs is frozen, just skip the write
534 * as we could deadlock the system oth 514 * as we could deadlock the system otherwise.
535 */ 515 */
536 if (file_start_write_trylock(file)) { 516 if (file_start_write_trylock(file)) {
537 /* it's been opened O_APPEND, 517 /* it's been opened O_APPEND, so position is irrelevant */
538 loff_t pos = 0; 518 loff_t pos = 0;
539 __kernel_write(file, &ac, size !! 519 __kernel_write(file, (char *)&ac, sizeof(acct_t), &pos);
540 file_end_write(file); 520 file_end_write(file);
541 } 521 }
542 out: 522 out:
543 current->signal->rlim[RLIMIT_FSIZE].rl 523 current->signal->rlim[RLIMIT_FSIZE].rlim_cur = flim;
544 revert_creds(orig_cred); 524 revert_creds(orig_cred);
545 } 525 }
546 526
547 /** 527 /**
548 * acct_collect - collect accounting informati 528 * acct_collect - collect accounting information into pacct_struct
549 * @exitcode: task exit code 529 * @exitcode: task exit code
550 * @group_dead: not 0, if this thread is the l 530 * @group_dead: not 0, if this thread is the last one in the process.
551 */ 531 */
552 void acct_collect(long exitcode, int group_dea 532 void acct_collect(long exitcode, int group_dead)
553 { 533 {
554 struct pacct_struct *pacct = ¤t- 534 struct pacct_struct *pacct = ¤t->signal->pacct;
555 u64 utime, stime; 535 u64 utime, stime;
556 unsigned long vsize = 0; 536 unsigned long vsize = 0;
557 537
558 if (group_dead && current->mm) { 538 if (group_dead && current->mm) {
559 struct mm_struct *mm = current <<
560 VMA_ITERATOR(vmi, mm, 0); <<
561 struct vm_area_struct *vma; 539 struct vm_area_struct *vma;
562 540
563 mmap_read_lock(mm); !! 541 down_read(¤t->mm->mmap_sem);
564 for_each_vma(vmi, vma) !! 542 vma = current->mm->mmap;
>> 543 while (vma) {
565 vsize += vma->vm_end - 544 vsize += vma->vm_end - vma->vm_start;
566 mmap_read_unlock(mm); !! 545 vma = vma->vm_next;
>> 546 }
>> 547 up_read(¤t->mm->mmap_sem);
567 } 548 }
568 549
569 spin_lock_irq(¤t->sighand->siglo 550 spin_lock_irq(¤t->sighand->siglock);
570 if (group_dead) 551 if (group_dead)
571 pacct->ac_mem = vsize / 1024; 552 pacct->ac_mem = vsize / 1024;
572 if (thread_group_leader(current)) { 553 if (thread_group_leader(current)) {
573 pacct->ac_exitcode = exitcode; 554 pacct->ac_exitcode = exitcode;
574 if (current->flags & PF_FORKNO 555 if (current->flags & PF_FORKNOEXEC)
575 pacct->ac_flag |= AFOR 556 pacct->ac_flag |= AFORK;
576 } 557 }
577 if (current->flags & PF_SUPERPRIV) 558 if (current->flags & PF_SUPERPRIV)
578 pacct->ac_flag |= ASU; 559 pacct->ac_flag |= ASU;
579 if (current->flags & PF_DUMPCORE) 560 if (current->flags & PF_DUMPCORE)
580 pacct->ac_flag |= ACORE; 561 pacct->ac_flag |= ACORE;
581 if (current->flags & PF_SIGNALED) 562 if (current->flags & PF_SIGNALED)
582 pacct->ac_flag |= AXSIG; 563 pacct->ac_flag |= AXSIG;
583 564
584 task_cputime(current, &utime, &stime); 565 task_cputime(current, &utime, &stime);
585 pacct->ac_utime += utime; 566 pacct->ac_utime += utime;
586 pacct->ac_stime += stime; 567 pacct->ac_stime += stime;
587 pacct->ac_minflt += current->min_flt; 568 pacct->ac_minflt += current->min_flt;
588 pacct->ac_majflt += current->maj_flt; 569 pacct->ac_majflt += current->maj_flt;
589 spin_unlock_irq(¤t->sighand->sig 570 spin_unlock_irq(¤t->sighand->siglock);
590 } 571 }
591 572
592 static void slow_acct_process(struct pid_names 573 static void slow_acct_process(struct pid_namespace *ns)
593 { 574 {
594 for ( ; ns; ns = ns->parent) { 575 for ( ; ns; ns = ns->parent) {
595 struct bsd_acct_struct *acct = 576 struct bsd_acct_struct *acct = acct_get(ns);
596 if (acct) { 577 if (acct) {
597 do_acct_process(acct); 578 do_acct_process(acct);
598 mutex_unlock(&acct->lo 579 mutex_unlock(&acct->lock);
599 acct_put(acct); 580 acct_put(acct);
600 } 581 }
601 } 582 }
602 } 583 }
603 584
604 /** 585 /**
605 * acct_process - handles process accounting f !! 586 * acct_process
>> 587 *
>> 588 * handles process accounting for an exiting task
606 */ 589 */
607 void acct_process(void) 590 void acct_process(void)
608 { 591 {
609 struct pid_namespace *ns; 592 struct pid_namespace *ns;
610 593
611 /* 594 /*
612 * This loop is safe lockless, since c 595 * This loop is safe lockless, since current is still
613 * alive and holds its namespace, whic 596 * alive and holds its namespace, which in turn holds
614 * its parent. 597 * its parent.
615 */ 598 */
616 for (ns = task_active_pid_ns(current); 599 for (ns = task_active_pid_ns(current); ns != NULL; ns = ns->parent) {
617 if (ns->bacct) 600 if (ns->bacct)
618 break; 601 break;
619 } 602 }
620 if (unlikely(ns)) 603 if (unlikely(ns))
621 slow_acct_process(ns); 604 slow_acct_process(ns);
622 } 605 }
623 606
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