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 time64_t btime;
28
29 BUILD_BUG_ON(TS_COMM_LEN < TASK_COMM_LEN);
30
31 /* calculate task elapsed time in nsec */
32 delta = ktime_get_ns() - tsk->start_time;
33 /* Convert to micro seconds */
34 do_div(delta, NSEC_PER_USEC);
35 stats->ac_etime = delta;
36 /* Convert to seconds for btime (note y2106 limit) */
37 btime = ktime_get_real_seconds() - div_u64(delta, USEC_PER_SEC);
38 stats->ac_btime = clamp_t(time64_t, btime, 0, U32_MAX);
39 stats->ac_btime64 = btime;
40
41 if (thread_group_leader(tsk)) {
42 stats->ac_exitcode = tsk->exit_code;
43 if (tsk->flags & PF_FORKNOEXEC)
44 stats->ac_flag |= AFORK;
45 }
46 if (tsk->flags & PF_SUPERPRIV)
47 stats->ac_flag |= ASU;
48 if (tsk->flags & PF_DUMPCORE)
49 stats->ac_flag |= ACORE;
50 if (tsk->flags & PF_SIGNALED)
51 stats->ac_flag |= AXSIG;
52 stats->ac_nice = task_nice(tsk);
53 stats->ac_sched = tsk->policy;
54 stats->ac_pid = task_pid_nr_ns(tsk, pid_ns);
55 rcu_read_lock();
56 tcred = __task_cred(tsk);
57 stats->ac_uid = from_kuid_munged(user_ns, tcred->uid);
58 stats->ac_gid = from_kgid_munged(user_ns, tcred->gid);
59 stats->ac_ppid = pid_alive(tsk) ?
60 task_tgid_nr_ns(rcu_dereference(tsk->real_parent), pid_ns) : 0;
61 rcu_read_unlock();
62
63 task_cputime(tsk, &utime, &stime);
64 stats->ac_utime = div_u64(utime, NSEC_PER_USEC);
65 stats->ac_stime = div_u64(stime, NSEC_PER_USEC);
66
67 task_cputime_scaled(tsk, &utimescaled, &stimescaled);
68 stats->ac_utimescaled = div_u64(utimescaled, NSEC_PER_USEC);
69 stats->ac_stimescaled = div_u64(stimescaled, NSEC_PER_USEC);
70
71 stats->ac_minflt = tsk->min_flt;
72 stats->ac_majflt = tsk->maj_flt;
73
74 strncpy(stats->ac_comm, tsk->comm, sizeof(stats->ac_comm));
75 }
76
77
78 #ifdef CONFIG_TASK_XACCT
79
80 #define KB 1024
81 #define MB (1024*KB)
82 #define KB_MASK (~(KB-1))
83 /*
84 * fill in extended accounting fields
85 */
xacct_add_tsk(struct taskstats * stats,struct task_struct * p)86 void xacct_add_tsk(struct taskstats *stats, struct task_struct *p)
87 {
88 struct mm_struct *mm;
89
90 /* convert pages-nsec/1024 to Mbyte-usec, see __acct_update_integrals */
91 stats->coremem = p->acct_rss_mem1 * PAGE_SIZE;
92 do_div(stats->coremem, 1000 * KB);
93 stats->virtmem = p->acct_vm_mem1 * PAGE_SIZE;
94 do_div(stats->virtmem, 1000 * KB);
95 mm = get_task_mm(p);
96 if (mm) {
97 /* adjust to KB unit */
98 stats->hiwater_rss = get_mm_hiwater_rss(mm) * PAGE_SIZE / KB;
99 stats->hiwater_vm = get_mm_hiwater_vm(mm) * PAGE_SIZE / KB;
100 mmput(mm);
101 }
102 stats->read_char = p->ioac.rchar & KB_MASK;
103 stats->write_char = p->ioac.wchar & KB_MASK;
104 stats->read_syscalls = p->ioac.syscr & KB_MASK;
105 stats->write_syscalls = p->ioac.syscw & KB_MASK;
106 #ifdef CONFIG_TASK_IO_ACCOUNTING
107 stats->read_bytes = p->ioac.read_bytes & KB_MASK;
108 stats->write_bytes = p->ioac.write_bytes & KB_MASK;
109 stats->cancelled_write_bytes = p->ioac.cancelled_write_bytes & KB_MASK;
110 #else
111 stats->read_bytes = 0;
112 stats->write_bytes = 0;
113 stats->cancelled_write_bytes = 0;
114 #endif
115 }
116 #undef KB
117 #undef MB
118
__acct_update_integrals(struct task_struct * tsk,u64 utime,u64 stime)119 static void __acct_update_integrals(struct task_struct *tsk,
120 u64 utime, u64 stime)
121 {
122 u64 time, delta;
123
124 if (!likely(tsk->mm))
125 return;
126
127 time = stime + utime;
128 delta = time - tsk->acct_timexpd;
129
130 if (delta < TICK_NSEC)
131 return;
132
133 tsk->acct_timexpd = time;
134 /*
135 * Divide by 1024 to avoid overflow, and to avoid division.
136 * The final unit reported to userspace is Mbyte-usecs,
137 * the rest of the math is done in xacct_add_tsk.
138 */
139 tsk->acct_rss_mem1 += delta * get_mm_rss(tsk->mm) >> 10;
140 tsk->acct_vm_mem1 += delta * tsk->mm->total_vm >> 10;
141 }
142
143 /**
144 * acct_update_integrals - update mm integral fields in task_struct
145 * @tsk: task_struct for accounting
146 */
acct_update_integrals(struct task_struct * tsk)147 void acct_update_integrals(struct task_struct *tsk)
148 {
149 u64 utime, stime;
150 unsigned long flags;
151
152 local_irq_save(flags);
153 task_cputime(tsk, &utime, &stime);
154 __acct_update_integrals(tsk, utime, stime);
155 local_irq_restore(flags);
156 }
157
158 /**
159 * acct_account_cputime - update mm integral after cputime update
160 * @tsk: task_struct for accounting
161 */
acct_account_cputime(struct task_struct * tsk)162 void acct_account_cputime(struct task_struct *tsk)
163 {
164 __acct_update_integrals(tsk, tsk->utime, tsk->stime);
165 }
166
167 /**
168 * acct_clear_integrals - clear the mm integral fields in task_struct
169 * @tsk: task_struct whose accounting fields are cleared
170 */
acct_clear_integrals(struct task_struct * tsk)171 void acct_clear_integrals(struct task_struct *tsk)
172 {
173 tsk->acct_timexpd = 0;
174 tsk->acct_rss_mem1 = 0;
175 tsk->acct_vm_mem1 = 0;
176 }
177 #endif
178
