tsacct.c

  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 */
 20void 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	stats->ac_ppid	 = task_ppid_nr_ns(tsk, pid_ns);
 61	rcu_read_lock();
 62	tcred = __task_cred(tsk);
 63	stats->ac_uid	 = from_kuid_munged(user_ns, tcred->uid);
 64	stats->ac_gid	 = from_kgid_munged(user_ns, tcred->gid);
 65	rcu_read_unlock();
 66
 67	task_cputime(tsk, &utime, &stime);
 68	stats->ac_utime = div_u64(utime, NSEC_PER_USEC);
 69	stats->ac_stime = div_u64(stime, NSEC_PER_USEC);
 70
 71	task_cputime_scaled(tsk, &utimescaled, &stimescaled);
 72	stats->ac_utimescaled = div_u64(utimescaled, NSEC_PER_USEC);
 73	stats->ac_stimescaled = div_u64(stimescaled, NSEC_PER_USEC);
 74
 75	stats->ac_minflt = tsk->min_flt;
 76	stats->ac_majflt = tsk->maj_flt;
 77
 78	strscpy_pad(stats->ac_comm, tsk->comm);
 79}
 80
 81
 82#ifdef CONFIG_TASK_XACCT
 83
 84#define KB 1024
 85#define MB (1024*KB)
 86#define KB_MASK (~(KB-1))
 87/*
 88 * fill in extended accounting fields
 89 */
 90void xacct_add_tsk(struct taskstats *stats, struct task_struct *p)
 91{
 92	struct mm_struct *mm;
 93
 94	/* convert pages-nsec/1024 to Mbyte-usec, see __acct_update_integrals */
 95	stats->coremem = p->acct_rss_mem1 * PAGE_SIZE;
 96	do_div(stats->coremem, 1000 * KB);
 97	stats->virtmem = p->acct_vm_mem1 * PAGE_SIZE;
 98	do_div(stats->virtmem, 1000 * KB);
 99	mm = get_task_mm(p);
100	if (mm) {
101		/* adjust to KB unit */
102		stats->hiwater_rss   = get_mm_hiwater_rss(mm) * PAGE_SIZE / KB;
103		stats->hiwater_vm    = get_mm_hiwater_vm(mm)  * PAGE_SIZE / KB;
104		mmput(mm);
105	}
106	stats->read_char	= p->ioac.rchar & KB_MASK;
107	stats->write_char	= p->ioac.wchar & KB_MASK;
108	stats->read_syscalls	= p->ioac.syscr & KB_MASK;
109	stats->write_syscalls	= p->ioac.syscw & KB_MASK;
110#ifdef CONFIG_TASK_IO_ACCOUNTING
111	stats->read_bytes	= p->ioac.read_bytes & KB_MASK;
112	stats->write_bytes	= p->ioac.write_bytes & KB_MASK;
113	stats->cancelled_write_bytes = p->ioac.cancelled_write_bytes & KB_MASK;
114#else
115	stats->read_bytes	= 0;
116	stats->write_bytes	= 0;
117	stats->cancelled_write_bytes = 0;
118#endif
119}
120#undef KB
121#undef MB
122
123static void __acct_update_integrals(struct task_struct *tsk,
124				    u64 utime, u64 stime)
125{
126	u64 time, delta;
127
128	if (!likely(tsk->mm))
129		return;
130
131	time = stime + utime;
132	delta = time - tsk->acct_timexpd;
133
134	if (delta < TICK_NSEC)
135		return;
136
137	tsk->acct_timexpd = time;
138	/*
139	 * Divide by 1024 to avoid overflow, and to avoid division.
140	 * The final unit reported to userspace is Mbyte-usecs,
141	 * the rest of the math is done in xacct_add_tsk.
142	 */
143	tsk->acct_rss_mem1 += delta * get_mm_rss(tsk->mm) >> 10;
144	tsk->acct_vm_mem1 += delta * READ_ONCE(tsk->mm->total_vm) >> 10;
145}
146
147/**
148 * acct_update_integrals - update mm integral fields in task_struct
149 * @tsk: task_struct for accounting
150 */
151void acct_update_integrals(struct task_struct *tsk)
152{
153	u64 utime, stime;
154	unsigned long flags;
155
156	local_irq_save(flags);
157	task_cputime(tsk, &utime, &stime);
158	__acct_update_integrals(tsk, utime, stime);
159	local_irq_restore(flags);
160}
161
162/**
163 * acct_account_cputime - update mm integral after cputime update
164 * @tsk: task_struct for accounting
165 */
166void acct_account_cputime(struct task_struct *tsk)
167{
168	__acct_update_integrals(tsk, tsk->utime, tsk->stime);
169}
170
171/**
172 * acct_clear_integrals - clear the mm integral fields in task_struct
173 * @tsk: task_struct whose accounting fields are cleared
174 */
175void acct_clear_integrals(struct task_struct *tsk)
176{
177	tsk->acct_timexpd = 0;
178	tsk->acct_rss_mem1 = 0;
179	tsk->acct_vm_mem1 = 0;
180}
181#endif