1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * tsacct.c - System accounting over taskstats interface
4 *
5 * Copyright (C) Jay Lan, <jlan@sgi.com>
6 */
7
8 #include <linux/kernel.h>
9 #include <linux/sched/signal.h>
10 #include <linux/sched/mm.h>
11 #include <linux/sched/cputime.h>
12 #include <linux/tsacct_kern.h>
13 #include <linux/acct.h>
14 #include <linux/jiffies.h>
15 #include <linux/mm.h>
16
17 /*
18 * fill in basic accounting fields
19 */
bacct_add_tsk(struct user_namespace * user_ns,struct pid_namespace * pid_ns,struct taskstats * stats,struct task_struct * tsk)20 void bacct_add_tsk(struct user_namespace *user_ns,
21 struct pid_namespace *pid_ns,
22 struct taskstats *stats, struct task_struct *tsk)
23 {
24 const struct cred *tcred;
25 u64 utime, stime, utimescaled, stimescaled;
26 u64 delta;
27
28 BUILD_BUG_ON(TS_COMM_LEN < TASK_COMM_LEN);
29
30 /* calculate task elapsed time in nsec */
31 delta = ktime_get_ns() - tsk->start_time;
32 /* Convert to micro seconds */
33 do_div(delta, NSEC_PER_USEC);
34 stats->ac_etime = delta;
35 /* Convert to seconds for btime */
36 do_div(delta, USEC_PER_SEC);
37 stats->ac_btime = get_seconds() - delta;
38 if (thread_group_leader(tsk)) {
39 stats->ac_exitcode = tsk->exit_code;
40 if (tsk->flags & PF_FORKNOEXEC)
41 stats->ac_flag |= AFORK;
42 }
43 if (tsk->flags & PF_SUPERPRIV)
44 stats->ac_flag |= ASU;
45 if (tsk->flags & PF_DUMPCORE)
46 stats->ac_flag |= ACORE;
47 if (tsk->flags & PF_SIGNALED)
48 stats->ac_flag |= AXSIG;
49 stats->ac_nice = task_nice(tsk);
50 stats->ac_sched = tsk->policy;
51 stats->ac_pid = task_pid_nr_ns(tsk, pid_ns);
52 rcu_read_lock();
53 tcred = __task_cred(tsk);
54 stats->ac_uid = from_kuid_munged(user_ns, tcred->uid);
55 stats->ac_gid = from_kgid_munged(user_ns, tcred->gid);
56 stats->ac_ppid = pid_alive(tsk) ?
57 task_tgid_nr_ns(rcu_dereference(tsk->real_parent), pid_ns) : 0;
58 rcu_read_unlock();
59
60 task_cputime(tsk, &utime, &stime);
61 stats->ac_utime = div_u64(utime, NSEC_PER_USEC);
62 stats->ac_stime = div_u64(stime, NSEC_PER_USEC);
63
64 task_cputime_scaled(tsk, &utimescaled, &stimescaled);
65 stats->ac_utimescaled = div_u64(utimescaled, NSEC_PER_USEC);
66 stats->ac_stimescaled = div_u64(stimescaled, NSEC_PER_USEC);
67
68 stats->ac_minflt = tsk->min_flt;
69 stats->ac_majflt = tsk->maj_flt;
70
71 strncpy(stats->ac_comm, tsk->comm, sizeof(stats->ac_comm));
72 }
73
74
75 #ifdef CONFIG_TASK_XACCT
76
77 #define KB 1024
78 #define MB (1024*KB)
79 #define KB_MASK (~(KB-1))
80 /*
81 * fill in extended accounting fields
82 */
xacct_add_tsk(struct taskstats * stats,struct task_struct * p)83 void xacct_add_tsk(struct taskstats *stats, struct task_struct *p)
84 {
85 struct mm_struct *mm;
86
87 /* convert pages-nsec/1024 to Mbyte-usec, see __acct_update_integrals */
88 stats->coremem = p->acct_rss_mem1 * PAGE_SIZE;
89 do_div(stats->coremem, 1000 * KB);
90 stats->virtmem = p->acct_vm_mem1 * PAGE_SIZE;
91 do_div(stats->virtmem, 1000 * KB);
92 mm = get_task_mm(p);
93 if (mm) {
94 /* adjust to KB unit */
95 stats->hiwater_rss = get_mm_hiwater_rss(mm) * PAGE_SIZE / KB;
96 stats->hiwater_vm = get_mm_hiwater_vm(mm) * PAGE_SIZE / KB;
97 mmput(mm);
98 }
99 stats->read_char = p->ioac.rchar & KB_MASK;
100 stats->write_char = p->ioac.wchar & KB_MASK;
101 stats->read_syscalls = p->ioac.syscr & KB_MASK;
102 stats->write_syscalls = p->ioac.syscw & KB_MASK;
103 #ifdef CONFIG_TASK_IO_ACCOUNTING
104 stats->read_bytes = p->ioac.read_bytes & KB_MASK;
105 stats->write_bytes = p->ioac.write_bytes & KB_MASK;
106 stats->cancelled_write_bytes = p->ioac.cancelled_write_bytes & KB_MASK;
107 #else
108 stats->read_bytes = 0;
109 stats->write_bytes = 0;
110 stats->cancelled_write_bytes = 0;
111 #endif
112 }
113 #undef KB
114 #undef MB
115
__acct_update_integrals(struct task_struct * tsk,u64 utime,u64 stime)116 static void __acct_update_integrals(struct task_struct *tsk,
117 u64 utime, u64 stime)
118 {
119 u64 time, delta;
120
121 if (!likely(tsk->mm))
122 return;
123
124 time = stime + utime;
125 delta = time - tsk->acct_timexpd;
126
127 if (delta < TICK_NSEC)
128 return;
129
130 tsk->acct_timexpd = time;
131 /*
132 * Divide by 1024 to avoid overflow, and to avoid division.
133 * The final unit reported to userspace is Mbyte-usecs,
134 * the rest of the math is done in xacct_add_tsk.
135 */
136 tsk->acct_rss_mem1 += delta * get_mm_rss(tsk->mm) >> 10;
137 tsk->acct_vm_mem1 += delta * tsk->mm->total_vm >> 10;
138 }
139
140 /**
141 * acct_update_integrals - update mm integral fields in task_struct
142 * @tsk: task_struct for accounting
143 */
acct_update_integrals(struct task_struct * tsk)144 void acct_update_integrals(struct task_struct *tsk)
145 {
146 u64 utime, stime;
147 unsigned long flags;
148
149 local_irq_save(flags);
150 task_cputime(tsk, &utime, &stime);
151 __acct_update_integrals(tsk, utime, stime);
152 local_irq_restore(flags);
153 }
154
155 /**
156 * acct_account_cputime - update mm integral after cputime update
157 * @tsk: task_struct for accounting
158 */
acct_account_cputime(struct task_struct * tsk)159 void acct_account_cputime(struct task_struct *tsk)
160 {
161 __acct_update_integrals(tsk, tsk->utime, tsk->stime);
162 }
163
164 /**
165 * acct_clear_integrals - clear the mm integral fields in task_struct
166 * @tsk: task_struct whose accounting fields are cleared
167 */
acct_clear_integrals(struct task_struct * tsk)168 void acct_clear_integrals(struct task_struct *tsk)
169 {
170 tsk->acct_timexpd = 0;
171 tsk->acct_rss_mem1 = 0;
172 tsk->acct_vm_mem1 = 0;
173 }
174 #endif
175