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 */
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 now_ns, 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 now_ns = ktime_get_ns();
33 /* store whole group time first */
34 delta = now_ns - tsk->group_leader->start_time;
35 /* Convert to micro seconds */
36 do_div(delta, NSEC_PER_USEC);
37 stats->ac_tgetime = delta;
38 delta = now_ns - tsk->start_time;
39 do_div(delta, NSEC_PER_USEC);
40 stats->ac_etime = delta;
41 /* Convert to seconds for btime (note y2106 limit) */
42 btime = ktime_get_real_seconds() - div_u64(delta, USEC_PER_SEC);
43 stats->ac_btime = clamp_t(time64_t, btime, 0, U32_MAX);
44 stats->ac_btime64 = btime;
45
46 if (tsk->flags & PF_EXITING)
47 stats->ac_exitcode = tsk->exit_code;
48 if (thread_group_leader(tsk) && (tsk->flags & PF_FORKNOEXEC))
49 stats->ac_flag |= AFORK;
50 if (tsk->flags & PF_SUPERPRIV)
51 stats->ac_flag |= ASU;
52 if (tsk->flags & PF_DUMPCORE)
53 stats->ac_flag |= ACORE;
54 if (tsk->flags & PF_SIGNALED)
55 stats->ac_flag |= AXSIG;
56 stats->ac_nice = task_nice(tsk);
57 stats->ac_sched = tsk->policy;
58 stats->ac_pid = task_pid_nr_ns(tsk, pid_ns);
59 stats->ac_tgid = task_tgid_nr_ns(tsk, pid_ns);
60 rcu_read_lock();
61 tcred = __task_cred(tsk);
62 stats->ac_uid = from_kuid_munged(user_ns, tcred->uid);
63 stats->ac_gid = from_kgid_munged(user_ns, tcred->gid);
64 stats->ac_ppid = pid_alive(tsk) ?
65 task_tgid_nr_ns(rcu_dereference(tsk->real_parent), pid_ns) : 0;
66 rcu_read_unlock();
67
68 task_cputime(tsk, &utime, &stime);
69 stats->ac_utime = div_u64(utime, NSEC_PER_USEC);
70 stats->ac_stime = div_u64(stime, NSEC_PER_USEC);
71
72 task_cputime_scaled(tsk, &utimescaled, &stimescaled);
73 stats->ac_utimescaled = div_u64(utimescaled, NSEC_PER_USEC);
74 stats->ac_stimescaled = div_u64(stimescaled, NSEC_PER_USEC);
75
76 stats->ac_minflt = tsk->min_flt;
77 stats->ac_majflt = tsk->maj_flt;
78
79 strscpy_pad(stats->ac_comm, tsk->comm);
80 }
81
82
83 #ifdef CONFIG_TASK_XACCT
84
85 #define KB 1024
86 #define MB (1024*KB)
87 #define KB_MASK (~(KB-1))
88 /*
89 * fill in extended accounting fields
90 */
91 void xacct_add_tsk(struct taskstats *stats, struct task_struct *p)
92 {
93 struct mm_struct *mm;
94
95 /* convert pages-nsec/1024 to Mbyte-usec, see __acct_update_integrals */
96 stats->coremem = p->acct_rss_mem1 * PAGE_SIZE;
97 do_div(stats->coremem, 1000 * KB);
98 stats->virtmem = p->acct_vm_mem1 * PAGE_SIZE;
99 do_div(stats->virtmem, 1000 * KB);
100 mm = get_task_mm(p);
101 if (mm) {
102 /* adjust to KB unit */
103 stats->hiwater_rss = get_mm_hiwater_rss(mm) * PAGE_SIZE / KB;
104 stats->hiwater_vm = get_mm_hiwater_vm(mm) * PAGE_SIZE / KB;
105 mmput(mm);
106 }
107 stats->read_char = p->ioac.rchar & KB_MASK;
108 stats->write_char = p->ioac.wchar & KB_MASK;
109 stats->read_syscalls = p->ioac.syscr & KB_MASK;
110 stats->write_syscalls = p->ioac.syscw & KB_MASK;
111 #ifdef CONFIG_TASK_IO_ACCOUNTING
112 stats->read_bytes = p->ioac.read_bytes & KB_MASK;
113 stats->write_bytes = p->ioac.write_bytes & KB_MASK;
114 stats->cancelled_write_bytes = p->ioac.cancelled_write_bytes & KB_MASK;
115 #else
116 stats->read_bytes = 0;
117 stats->write_bytes = 0;
118 stats->cancelled_write_bytes = 0;
119 #endif
120 }
121 #undef KB
122 #undef MB
123
124 static void __acct_update_integrals(struct task_struct *tsk,
125 u64 utime, u64 stime)
126 {
127 u64 time, delta;
128
129 if (!likely(tsk->mm))
130 return;
131
132 time = stime + utime;
133 delta = time - tsk->acct_timexpd;
134
135 if (delta < TICK_NSEC)
136 return;
137
138 tsk->acct_timexpd = time;
139 /*
140 * Divide by 1024 to avoid overflow, and to avoid division.
141 * The final unit reported to userspace is Mbyte-usecs,
142 * the rest of the math is done in xacct_add_tsk.
143 */
144 tsk->acct_rss_mem1 += delta * get_mm_rss(tsk->mm) >> 10;
145 tsk->acct_vm_mem1 += delta * READ_ONCE(tsk->mm->total_vm) >> 10;
146 }
147
148 /**
149 * acct_update_integrals - update mm integral fields in task_struct
150 * @tsk: task_struct for accounting
151 */
152 void acct_update_integrals(struct task_struct *tsk)
153 {
154 u64 utime, stime;
155 unsigned long flags;
156
157 local_irq_save(flags);
158 task_cputime(tsk, &utime, &stime);
159 __acct_update_integrals(tsk, utime, stime);
160 local_irq_restore(flags);
161 }
162
163 /**
164 * acct_account_cputime - update mm integral after cputime update
165 * @tsk: task_struct for accounting
166 */
167 void acct_account_cputime(struct task_struct *tsk)
168 {
169 __acct_update_integrals(tsk, tsk->utime, tsk->stime);
170 }
171
172 /**
173 * acct_clear_integrals - clear the mm integral fields in task_struct
174 * @tsk: task_struct whose accounting fields are cleared
175 */
176 void acct_clear_integrals(struct task_struct *tsk)
177 {
178 tsk->acct_timexpd = 0;
179 tsk->acct_rss_mem1 = 0;
180 tsk->acct_vm_mem1 = 0;
181 }
182 #endif
183
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