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