Esempio n. 1
0
/*
 * Write out process accounting information, on process exit.
 * Data to be written out is specified in Leffler, et al.
 * and are enumerated below.  (They're also noted in the system
 * "acct.h" header file.)
 */
int
acct_process(struct proc *p)
{
	struct acct acct;
	struct process *pr = p->p_p;
	struct rusage *r;
	struct timeval ut, st, tmp;
	int t;
	struct vnode *vp;
	struct plimit *oplim = NULL;
	int error;

	/* If accounting isn't enabled, don't bother */
	vp = acctp;
	if (vp == NULL)
		return (0);

	/*
	 * Raise the file limit so that accounting can't be stopped by the
	 * user. (XXX - we should think about the cpu limit too).
	 */
	if (pr->ps_limit->p_refcnt > 1) {
		oplim = pr->ps_limit;
		pr->ps_limit = limcopy(pr->ps_limit);
	}
	p->p_rlimit[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY;

	/*
	 * Get process accounting information.
	 */

	/* (1) The name of the command that ran */
	bcopy(p->p_comm, acct.ac_comm, sizeof acct.ac_comm);

	/* (2) The amount of user and system time that was used */
	calcru(&pr->ps_tu, &ut, &st, NULL);
	acct.ac_utime = encode_comp_t(ut.tv_sec, ut.tv_usec);
	acct.ac_stime = encode_comp_t(st.tv_sec, st.tv_usec);

	/* (3) The elapsed time the command ran (and its starting time) */
	acct.ac_btime = pr->ps_start.tv_sec;
	getmicrotime(&tmp);
	timersub(&tmp, &pr->ps_start, &tmp);
	acct.ac_etime = encode_comp_t(tmp.tv_sec, tmp.tv_usec);

	/* (4) The average amount of memory used */
	r = &p->p_ru;
	timeradd(&ut, &st, &tmp);
	t = tmp.tv_sec * hz + tmp.tv_usec / tick;
	if (t)
		acct.ac_mem = (r->ru_ixrss + r->ru_idrss + r->ru_isrss) / t;
	else
		acct.ac_mem = 0;

	/* (5) The number of disk I/O operations done */
	acct.ac_io = encode_comp_t(r->ru_inblock + r->ru_oublock, 0);

	/* (6) The UID and GID of the process */
	acct.ac_uid = p->p_cred->p_ruid;
	acct.ac_gid = p->p_cred->p_rgid;

	/* (7) The terminal from which the process was started */
	if ((pr->ps_flags & PS_CONTROLT) &&
	    pr->ps_pgrp->pg_session->s_ttyp)
		acct.ac_tty = pr->ps_pgrp->pg_session->s_ttyp->t_dev;
	else
		acct.ac_tty = NODEV;

	/* (8) The boolean flags that tell how the process terminated, etc. */
	acct.ac_flag = pr->ps_acflag;

	/*
	 * Now, just write the accounting information to the file.
	 */
	error = vn_rdwr(UIO_WRITE, vp, (caddr_t)&acct, sizeof (acct),
	    (off_t)0, UIO_SYSSPACE, IO_APPEND|IO_UNIT, p->p_ucred, NULL, p);

	if (oplim) {
		limfree(pr->ps_limit);
		pr->ps_limit = oplim;
	}

	return error;
}
Esempio n. 2
0
int
fork1(struct proc *p1, int exitsig, int flags, void *stack, size_t stacksize,
    void (*func)(void *), void *arg, register_t *retval,
    struct proc **rnewprocp)
{
	struct proc *p2;
	uid_t uid;
	struct vmspace *vm;
	int count;
	vaddr_t uaddr;
	int s;
	extern void endtsleep(void *);
	extern void realitexpire(void *);

	/*
	 * Although process entries are dynamically created, we still keep
	 * a global limit on the maximum number we will create. We reserve
	 * the last 5 processes to root. The variable nprocs is the current
	 * number of processes, maxproc is the limit.
	 */
	uid = p1->p_cred->p_ruid;
	if ((nprocs >= maxproc - 5 && uid != 0) || nprocs >= maxproc) {
		static struct timeval lasttfm;

		if (ratecheck(&lasttfm, &fork_tfmrate))
			tablefull("proc");
		return (EAGAIN);
	}
	nprocs++;

	/*
	 * Increment the count of procs running with this uid. Don't allow
	 * a nonprivileged user to exceed their current limit.
	 */
	count = chgproccnt(uid, 1);
	if (uid != 0 && count > p1->p_rlimit[RLIMIT_NPROC].rlim_cur) {
		(void)chgproccnt(uid, -1);
		nprocs--;
		return (EAGAIN);
	}

	uaddr = uvm_km_alloc1(kernel_map, USPACE, USPACE_ALIGN, 1);
	if (uaddr == 0) {
		chgproccnt(uid, -1);
		nprocs--;
		return (ENOMEM);
	}

	/*
	 * From now on, we're committed to the fork and cannot fail.
	 */

	/* Allocate new proc. */
	p2 = pool_get(&proc_pool, PR_WAITOK);

	p2->p_stat = SIDL;			/* protect against others */
	p2->p_exitsig = exitsig;
	p2->p_forw = p2->p_back = NULL;

#ifdef RTHREADS
	if (flags & FORK_THREAD) {
		atomic_setbits_int(&p2->p_flag, P_THREAD);
		p2->p_p = p1->p_p;
		TAILQ_INSERT_TAIL(&p2->p_p->ps_threads, p2, p_thr_link);
	} else {
		process_new(p2, p1);
	}
#else
	process_new(p2, p1);
#endif

	/*
	 * Make a proc table entry for the new process.
	 * Start by zeroing the section of proc that is zero-initialized,
	 * then copy the section that is copied directly from the parent.
	 */
	bzero(&p2->p_startzero,
	    (unsigned) ((caddr_t)&p2->p_endzero - (caddr_t)&p2->p_startzero));
	bcopy(&p1->p_startcopy, &p2->p_startcopy,
	    (unsigned) ((caddr_t)&p2->p_endcopy - (caddr_t)&p2->p_startcopy));

	/*
	 * Initialize the timeouts.
	 */
	timeout_set(&p2->p_sleep_to, endtsleep, p2);
	timeout_set(&p2->p_realit_to, realitexpire, p2);

#if defined(__HAVE_CPUINFO)
	p2->p_cpu = p1->p_cpu;
#endif

	/*
	 * Duplicate sub-structures as needed.
	 * Increase reference counts on shared objects.
	 * The p_stats and p_sigacts substructs are set in vm_fork.
	 */
	p2->p_flag = 0;
	p2->p_emul = p1->p_emul;
	if (p1->p_flag & P_PROFIL)
		startprofclock(p2);
	atomic_setbits_int(&p2->p_flag, p1->p_flag & (P_SUGID | P_SUGIDEXEC));
	if (flags & FORK_PTRACE)
		atomic_setbits_int(&p2->p_flag, p1->p_flag & P_TRACED);
#ifdef RTHREADS
	if (flags & FORK_THREAD) {
		/* nothing */
	} else
#endif
	{
		p2->p_p->ps_cred = pool_get(&pcred_pool, PR_WAITOK);
		bcopy(p1->p_p->ps_cred, p2->p_p->ps_cred, sizeof(*p2->p_p->ps_cred));
		p2->p_p->ps_cred->p_refcnt = 1;
		crhold(p1->p_ucred);
	}

	TAILQ_INIT(&p2->p_selects);

	/* bump references to the text vnode (for procfs) */
	p2->p_textvp = p1->p_textvp;
	if (p2->p_textvp)
		VREF(p2->p_textvp);

	if (flags & FORK_CLEANFILES)
		p2->p_fd = fdinit(p1);
	else if (flags & FORK_SHAREFILES)
		p2->p_fd = fdshare(p1);
	else
		p2->p_fd = fdcopy(p1);

	/*
	 * If ps_limit is still copy-on-write, bump refcnt,
	 * otherwise get a copy that won't be modified.
	 * (If PL_SHAREMOD is clear, the structure is shared
	 * copy-on-write.)
	 */
#ifdef RTHREADS
	if (flags & FORK_THREAD) {
		/* nothing */
	} else
#endif
	{
		if (p1->p_p->ps_limit->p_lflags & PL_SHAREMOD)
			p2->p_p->ps_limit = limcopy(p1->p_p->ps_limit);
		else {
			p2->p_p->ps_limit = p1->p_p->ps_limit;
			p2->p_p->ps_limit->p_refcnt++;
		}
	}

	if (p1->p_session->s_ttyvp != NULL && p1->p_flag & P_CONTROLT)
		atomic_setbits_int(&p2->p_flag, P_CONTROLT);
	if (flags & FORK_PPWAIT)
		atomic_setbits_int(&p2->p_flag, P_PPWAIT);
	p2->p_pptr = p1;
	if (flags & FORK_NOZOMBIE)
		atomic_setbits_int(&p2->p_flag, P_NOZOMBIE);
	LIST_INIT(&p2->p_children);

#ifdef KTRACE
	/*
	 * Copy traceflag and tracefile if enabled.
	 * If not inherited, these were zeroed above.
	 */
	if (p1->p_traceflag & KTRFAC_INHERIT) {
		p2->p_traceflag = p1->p_traceflag;
		if ((p2->p_tracep = p1->p_tracep) != NULL)
			VREF(p2->p_tracep);
	}
#endif

	/*
	 * set priority of child to be that of parent
	 * XXX should move p_estcpu into the region of struct proc which gets
	 * copied.
	 */
	scheduler_fork_hook(p1, p2);

	/*
	 * Create signal actions for the child process.
	 */
	if (flags & FORK_SIGHAND)
		sigactsshare(p1, p2);
	else
		p2->p_sigacts = sigactsinit(p1);

	/*
	 * If emulation has process fork hook, call it now.
	 */
	if (p2->p_emul->e_proc_fork)
		(*p2->p_emul->e_proc_fork)(p2, p1);

	p2->p_addr = (struct user *)uaddr;

	/*
	 * Finish creating the child process.  It will return through a
	 * different path later.
	 */
	uvm_fork(p1, p2, ((flags & FORK_SHAREVM) ? TRUE : FALSE), stack,
	    stacksize, func ? func : child_return, arg ? arg : p2);

	timeout_set(&p2->p_stats->p_virt_to, virttimer_trampoline, p2);
	timeout_set(&p2->p_stats->p_prof_to, proftimer_trampoline, p2);

	vm = p2->p_vmspace;

	if (flags & FORK_FORK) {
		forkstat.cntfork++;
		forkstat.sizfork += vm->vm_dsize + vm->vm_ssize;
	} else if (flags & FORK_VFORK) {
		forkstat.cntvfork++;
		forkstat.sizvfork += vm->vm_dsize + vm->vm_ssize;
	} else if (flags & FORK_RFORK) {
		forkstat.cntrfork++;
		forkstat.sizrfork += vm->vm_dsize + vm->vm_ssize;
	} else {
		forkstat.cntkthread++;
		forkstat.sizkthread += vm->vm_dsize + vm->vm_ssize;
	}

	/* Find an unused pid satisfying 1 <= lastpid <= PID_MAX */
	do {
		lastpid = 1 + (randompid ? arc4random() : lastpid) % PID_MAX;
	} while (pidtaken(lastpid));
	p2->p_pid = lastpid;

	LIST_INSERT_HEAD(&allproc, p2, p_list);
	LIST_INSERT_HEAD(PIDHASH(p2->p_pid), p2, p_hash);
	LIST_INSERT_HEAD(&p1->p_children, p2, p_sibling);
	LIST_INSERT_AFTER(p1, p2, p_pglist);
	if (p2->p_flag & P_TRACED) {
		p2->p_oppid = p1->p_pid;
		if (p2->p_pptr != p1->p_pptr)
			proc_reparent(p2, p1->p_pptr);

		/*
		 * Set ptrace status.
		 */
		if (flags & FORK_FORK) {
			p2->p_ptstat = malloc(sizeof(*p2->p_ptstat),
			    M_SUBPROC, M_WAITOK);
			p1->p_ptstat->pe_report_event = PTRACE_FORK;
			p2->p_ptstat->pe_report_event = PTRACE_FORK;
			p1->p_ptstat->pe_other_pid = p2->p_pid;
			p2->p_ptstat->pe_other_pid = p1->p_pid;
		}
	}

#if NSYSTRACE > 0
	if (ISSET(p1->p_flag, P_SYSTRACE))
		systrace_fork(p1, p2);
#endif

	/*
	 * Make child runnable, set start time, and add to run queue.
	 */
	SCHED_LOCK(s);
 	getmicrotime(&p2->p_stats->p_start);
	p2->p_acflag = AFORK;
	p2->p_stat = SRUN;
	setrunqueue(p2);
	SCHED_UNLOCK(s);

	/*
	 * Notify any interested parties about the new process.
	 */
	KNOTE(&p1->p_klist, NOTE_FORK | p2->p_pid);

	/*
	 * Update stats now that we know the fork was successfull.
	 */
	uvmexp.forks++;
	if (flags & FORK_PPWAIT)
		uvmexp.forks_ppwait++;
	if (flags & FORK_SHAREVM)
		uvmexp.forks_sharevm++;

	/*
	 * Pass a pointer to the new process to the caller.
	 */
	if (rnewprocp != NULL)
		*rnewprocp = p2;

	/*
	 * Preserve synchronization semantics of vfork.  If waiting for
	 * child to exec or exit, set P_PPWAIT on child, and sleep on our
	 * proc (in case of exit).
	 */
	if (flags & FORK_PPWAIT)
		while (p2->p_flag & P_PPWAIT)
			tsleep(p1, PWAIT, "ppwait", 0);

	/*
	 * If we're tracing the child, alert the parent too.
	 */
	if ((flags & FORK_PTRACE) && (p1->p_flag & P_TRACED))
		psignal(p1, SIGTRAP);

	/*
	 * Return child pid to parent process,
	 * marking us as parent via retval[1].
	 */
	if (retval != NULL) {
		retval[0] = p2->p_pid;
		retval[1] = 0;
	}
	return (0);
}