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         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  */
  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
 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  */
 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  */
 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  */
 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