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