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