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 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 	strncpy(stats->ac_comm, tsk->comm, sizeof(stats->ac_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  */
xacct_add_tsk(struct taskstats * stats,struct task_struct * p)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 
__acct_update_integrals(struct task_struct * tsk,u64 utime,u64 stime)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  */
acct_update_integrals(struct task_struct * tsk)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  */
acct_account_cputime(struct task_struct * tsk)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  */
acct_clear_integrals(struct task_struct * tsk)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