示例#1
0
/**
 * zfcp_unit_enqueue - enqueue unit to unit list of a port.
 * @port: pointer to port where unit is added
 * @fcp_lun: FCP LUN of unit to be enqueued
 * Returns: pointer to enqueued unit on success, ERR_PTR on error
 *
 * Sets up some unit internal structures and creates sysfs entry.
 */
struct zfcp_unit *zfcp_unit_enqueue(struct zfcp_port *port, u64 fcp_lun)
{
	struct zfcp_unit *unit;
	int retval = -ENOMEM;

	get_device(&port->dev);

	unit = zfcp_get_unit_by_lun(port, fcp_lun);
	if (unit) {
		put_device(&unit->dev);
		retval = -EEXIST;
		goto err_out;
	}

	unit = kzalloc(sizeof(struct zfcp_unit), GFP_KERNEL);
	if (!unit)
		goto err_out;

	unit->port = port;
	unit->fcp_lun = fcp_lun;
	unit->dev.parent = &port->dev;
	unit->dev.release = zfcp_unit_release;

	if (dev_set_name(&unit->dev, "0x%016llx",
			 (unsigned long long) fcp_lun)) {
		kfree(unit);
		goto err_out;
	}
	retval = -EINVAL;

	INIT_WORK(&unit->scsi_work, zfcp_scsi_scan);

	spin_lock_init(&unit->latencies.lock);
	unit->latencies.write.channel.min = 0xFFFFFFFF;
	unit->latencies.write.fabric.min = 0xFFFFFFFF;
	unit->latencies.read.channel.min = 0xFFFFFFFF;
	unit->latencies.read.fabric.min = 0xFFFFFFFF;
	unit->latencies.cmd.channel.min = 0xFFFFFFFF;
	unit->latencies.cmd.fabric.min = 0xFFFFFFFF;

	if (device_register(&unit->dev)) {
		put_device(&unit->dev);
		goto err_out;
	}

	if (sysfs_create_group(&unit->dev.kobj, &zfcp_sysfs_unit_attrs))
		goto err_out_put;

	write_lock_irq(&port->unit_list_lock);
	list_add_tail(&unit->list, &port->unit_list);
	write_unlock_irq(&port->unit_list_lock);

	atomic_set_mask(ZFCP_STATUS_COMMON_RUNNING, &unit->status);

	return unit;

err_out_put:
	device_unregister(&unit->dev);
err_out:
	put_device(&port->dev);
	return ERR_PTR(retval);
}
示例#2
0
static int ptrace_attach(struct task_struct *task)
{
	bool wait_trap = false;
	int retval;

	audit_ptrace(task);

	retval = -EPERM;
	if (unlikely(task->flags & PF_KTHREAD))
		goto out;
	if (same_thread_group(task, current))
		goto out;

	/*
	 * Protect exec's credential calculations against our interference;
	 * interference; SUID, SGID and LSM creds get determined differently
	 * under ptrace.
	 */
	retval = -ERESTARTNOINTR;
	if (mutex_lock_interruptible(&task->signal->cred_guard_mutex))
		goto out;

	task_lock(task);
	retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH);
	task_unlock(task);
	if (retval)
		goto unlock_creds;

	write_lock_irq(&tasklist_lock);
	retval = -EPERM;
	if (unlikely(task->exit_state))
		goto unlock_tasklist;
	if (task->ptrace)
		goto unlock_tasklist;

	task->ptrace = PT_PTRACED;
	if (task_ns_capable(task, CAP_SYS_PTRACE))
		task->ptrace |= PT_PTRACE_CAP;

	__ptrace_link(task, current);
	send_sig_info(SIGSTOP, SEND_SIG_FORCED, task);

	spin_lock(&task->sighand->siglock);

	/*
	 * If the task is already STOPPED, set GROUP_STOP_PENDING and
	 * TRAPPING, and kick it so that it transits to TRACED.  TRAPPING
	 * will be cleared if the child completes the transition or any
	 * event which clears the group stop states happens.  We'll wait
	 * for the transition to complete before returning from this
	 * function.
	 *
	 * This hides STOPPED -> RUNNING -> TRACED transition from the
	 * attaching thread but a different thread in the same group can
	 * still observe the transient RUNNING state.  IOW, if another
	 * thread's WNOHANG wait(2) on the stopped tracee races against
	 * ATTACH, the wait(2) may fail due to the transient RUNNING.
	 *
	 * The following task_is_stopped() test is safe as both transitions
	 * in and out of STOPPED are protected by siglock.
	 */
	if (task_is_stopped(task)) {
		task->group_stop |= GROUP_STOP_PENDING | GROUP_STOP_TRAPPING;
		signal_wake_up(task, 1);
		wait_trap = true;
	}

	spin_unlock(&task->sighand->siglock);

	retval = 0;
unlock_tasklist:
	write_unlock_irq(&tasklist_lock);
unlock_creds:
	mutex_unlock(&task->signal->cred_guard_mutex);
out:
	if (wait_trap)
		wait_event(current->signal->wait_chldexit,
			   !(task->group_stop & GROUP_STOP_TRAPPING));
	return retval;
}
示例#3
0
/*-------------------------------------------------------------------------
 *  bproc_masq_wait
 */
int masq_wait(pid_t pid, int options, struct siginfo *infop,
	      unsigned int * stat_addr, struct rusage * ru) {
    int result, lpid, status;
    struct bproc_krequest_t *req;
    struct bproc_rsyscall_msg_t *msg;
    struct bproc_wait_resp_t *resp_msg;
    struct task_struct *child;

    /* XXX to be 100% semantically correct, we need to verify_area
     * here on stat_addr and ru here... */
    req = bpr_rsyscall1(BPROC_SYS_WAIT);
    if (!req){
	printk("bproc: masq: sys_wait: out of memory.\n");
	return -ENOMEM;
    }
    msg = (struct bproc_rsyscall_msg_t *) bproc_msg(req);
    msg->arg[0] = pid;
    msg->arg[1] = options;

    if (bpr_rsyscall2(BPROC_MASQ_MASTER(current), req, 1) != 0) {
	bproc_put_req(req);
	return -EIO;
    }

    resp_msg = bproc_msg(req->response);

    result = resp_msg->hdr.result;
    status = resp_msg->status;
    if (stat_addr) put_user(status, stat_addr);
    if (ru) {
	/* Only a few elements of the rusage structure are provided by
	 * Linux.  Also, convert the times back to the HZ
	 * representation. */
	struct rusage ru_tmp;
	memset(&ru_tmp, 0, sizeof(ru_tmp));
	ru_tmp.ru_utime.tv_sec  =  resp_msg->utime/HZ;
	ru_tmp.ru_utime.tv_usec = (resp_msg->utime*(1000000/HZ))%1000000;
	ru_tmp.ru_stime.tv_sec  =  resp_msg->stime/HZ;
	ru_tmp.ru_stime.tv_usec = (resp_msg->stime*(1000000/HZ))%1000000;
	ru_tmp.ru_minflt        =  resp_msg->minflt;
	ru_tmp.ru_majflt        =  resp_msg->majflt;
	ru_tmp.ru_nswap         =  resp_msg->nswap;
	copy_to_user(ru, &ru_tmp, sizeof(ru_tmp));
    }
    bproc_put_req(req);

    if (result > 0 && (status & 0xff) != 0x7f) {
	/* It's possible that the process we waited on was actually
	 * local.  We need to make sure and get it out of this process
	 * tree too.  If it's not, we need to down the non local child
	 * count by one... */
	write_lock_irq(&tasklist_lock);
	child = masq_find_task_by_pid(BPROC_MASQ_MASTER(current), result);
	if (child)
	    lpid = child->pid;
	else {
	    lpid = 0;
	    current->bproc.nlchild--;
	}
	write_unlock_irq(&tasklist_lock);
	if (lpid) {
	    /* Do all of this as a kernel call to avoid re-entering
	     * this whole mess... */
	    set_bit(BPROC_FLAG_KCALL, &current->bproc.flag);
	    if (k_wait4(lpid, options & ~WNOHANG, NULL, NULL, NULL) == -1) {
		printk(KERN_ERR "bproc: masq: local wait failed on %d (%d)\n",
		       lpid, result);
#if 0
		/* This probably isn't correct.  If we fail to wait,
		 * that probably means that somebody else picked it
		 * up. */
		write_lock_irq(&tasklist_lock);
		current->bproc.nlchild--;
		write_unlock_irq(&tasklist_lock);
#endif
	    }
	}
    }
    return result;
}
示例#4
0
文件: exit.c 项目: benbee/Learning
/*
 * Send signals to all our closest relatives so that they know
 * to properly mourn us..
 */
static void exit_notify(void)
{
	struct task_struct * p, *t;

	forget_original_parent(current);
	/*
	 * Check to see if any process groups have become orphaned
	 * as a result of our exiting, and if they have any stopped
	 * jobs, send them a SIGHUP and then a SIGCONT.  (POSIX 3.2.2.2)
	 *
	 * Case i: Our father is in a different pgrp than we are
	 * and we were the only connection outside, so our pgrp
	 * is about to become orphaned.
	 */
	 
	t = current->p_pptr;
	
	if ((t->pgrp != current->pgrp) &&
	    (t->session == current->session) &&
	    will_become_orphaned_pgrp(current->pgrp, current) &&
	    has_stopped_jobs(current->pgrp)) {
		kill_pg(current->pgrp,SIGHUP,1);
		kill_pg(current->pgrp,SIGCONT,1);
	}

	/* Let father know we died 
	 *
	 * Thread signals are configurable, but you aren't going to use
	 * that to send signals to arbitary processes. 
	 * That stops right now.
	 *
	 * If the parent exec id doesn't match the exec id we saved
	 * when we started then we know the parent has changed security
	 * domain.
	 *
	 * If our self_exec id doesn't match our parent_exec_id then
	 * we have changed execution domain as these two values started
	 * the same after a fork.
	 *	
	 */
	
	if(current->exit_signal != SIGCHLD &&
	    ( current->parent_exec_id != t->self_exec_id  ||
	      current->self_exec_id != current->parent_exec_id) 
	    && !capable(CAP_KILL))
		current->exit_signal = SIGCHLD;

	notify_parent(current, current->exit_signal);

	/*
	 * This loop does two things:
	 *
  	 * A.  Make init inherit all the child processes
	 * B.  Check to see if any process groups have become orphaned
	 *	as a result of our exiting, and if they have any stopped
	 *	jobs, send them a SIGHUP and then a SIGCONT.  (POSIX 3.2.2.2)
	 */

	write_lock_irq(&tasklist_lock);
	while (current->p_cptr != NULL) {
		p = current->p_cptr;
		current->p_cptr = p->p_osptr;
		p->p_ysptr = NULL;
		p->flags &= ~(PF_PTRACED|PF_TRACESYS);

		p->p_pptr = p->p_opptr;
		p->p_osptr = p->p_pptr->p_cptr;
		if (p->p_osptr)
			p->p_osptr->p_ysptr = p;
		p->p_pptr->p_cptr = p;
		if (p->state == TASK_ZOMBIE)
			notify_parent(p, p->exit_signal);
		/*
		 * process group orphan check
		 * Case ii: Our child is in a different pgrp
		 * than we are, and it was the only connection
		 * outside, so the child pgrp is now orphaned.
		 */
		if ((p->pgrp != current->pgrp) &&
		    (p->session == current->session)) {
			int pgrp = p->pgrp;

			write_unlock_irq(&tasklist_lock);
			if (is_orphaned_pgrp(pgrp) && has_stopped_jobs(pgrp)) {
				kill_pg(pgrp,SIGHUP,1);
				kill_pg(pgrp,SIGCONT,1);
			}
			write_lock_irq(&tasklist_lock);
		}
	}
	write_unlock_irq(&tasklist_lock);

	if (current->leader)
		disassociate_ctty(1);
}
示例#5
0
unsigned long hp_sdc_put(void)
{
	hp_sdc_transaction *curr;
	uint8_t act;
	int idx, curridx;

	int limit = 0;

	write_lock(&hp_sdc.lock);

	/* If i8042 buffers are full, we cannot do anything that
	   requires output, so we skip to the administrativa. */
	if (hp_sdc.ibf) {
		hp_sdc_status_in8();
		if (hp_sdc.ibf)
			goto finish;
	}

 anew:
	/* See if we are in the middle of a sequence. */
	if (hp_sdc.wcurr < 0)
		hp_sdc.wcurr = 0;
	read_lock_irq(&hp_sdc.rtq_lock);
	if (hp_sdc.rcurr == hp_sdc.wcurr)
		hp_sdc.wcurr++;
	read_unlock_irq(&hp_sdc.rtq_lock);
	if (hp_sdc.wcurr >= HP_SDC_QUEUE_LEN)
		hp_sdc.wcurr = 0;
	curridx = hp_sdc.wcurr;

	if (hp_sdc.tq[curridx] != NULL)
		goto start;

	while (++curridx != hp_sdc.wcurr) {
		if (curridx >= HP_SDC_QUEUE_LEN) {
			curridx = -1; /* Wrap to top */
			continue;
		}
		read_lock_irq(&hp_sdc.rtq_lock);
		if (hp_sdc.rcurr == curridx) {
			read_unlock_irq(&hp_sdc.rtq_lock);
			continue;
		}
		read_unlock_irq(&hp_sdc.rtq_lock);
		if (hp_sdc.tq[curridx] != NULL)
			break; /* Found one. */
	}
	if (curridx == hp_sdc.wcurr) { /* There's nothing queued to do. */
		curridx = -1;
	}
	hp_sdc.wcurr = curridx;

 start:

	/* Check to see if the interrupt mask needs to be set. */
	if (hp_sdc.set_im) {
		hp_sdc_status_out8(hp_sdc.im | HP_SDC_CMD_SET_IM);
		hp_sdc.set_im = 0;
		goto finish;
	}

	if (hp_sdc.wcurr == -1)
		goto done;

	curr = hp_sdc.tq[curridx];
	idx = curr->actidx;

	if (curr->actidx >= curr->endidx) {
		hp_sdc.tq[curridx] = NULL;
		/* Interleave outbound data between the transactions. */
		hp_sdc.wcurr++;
		if (hp_sdc.wcurr >= HP_SDC_QUEUE_LEN)
			hp_sdc.wcurr = 0;
		goto finish;
	}

	act = curr->seq[idx];
	idx++;

	if (curr->idx >= curr->endidx) {
		if (act & HP_SDC_ACT_DEALLOC)
			kfree(curr);
		hp_sdc.tq[curridx] = NULL;
		/* Interleave outbound data between the transactions. */
		hp_sdc.wcurr++;
		if (hp_sdc.wcurr >= HP_SDC_QUEUE_LEN)
			hp_sdc.wcurr = 0;
		goto finish;
	}

	while (act & HP_SDC_ACT_PRECMD) {
		if (curr->idx != idx) {
			idx++;
			act &= ~HP_SDC_ACT_PRECMD;
			break;
		}
		hp_sdc_status_out8(curr->seq[idx]);
		curr->idx++;
		/* act finished? */
		if ((act & HP_SDC_ACT_DURING) == HP_SDC_ACT_PRECMD)
			goto actdone;
		/* skip quantity field if data-out sequence follows. */
		if (act & HP_SDC_ACT_DATAOUT)
			curr->idx++;
		goto finish;
	}
	if (act & HP_SDC_ACT_DATAOUT) {
		int qty;

		qty = curr->seq[idx];
		idx++;
		if (curr->idx - idx < qty) {
			hp_sdc_data_out8(curr->seq[curr->idx]);
			curr->idx++;
			/* act finished? */
			if (curr->idx - idx >= qty &&
			    (act & HP_SDC_ACT_DURING) == HP_SDC_ACT_DATAOUT)
				goto actdone;
			goto finish;
		}
		idx += qty;
		act &= ~HP_SDC_ACT_DATAOUT;
	} else
	    while (act & HP_SDC_ACT_DATAREG) {
		int mask;
		uint8_t w7[4];

		mask = curr->seq[idx];
		if (idx != curr->idx) {
			idx++;
			idx += !!(mask & 1);
			idx += !!(mask & 2);
			idx += !!(mask & 4);
			idx += !!(mask & 8);
			act &= ~HP_SDC_ACT_DATAREG;
			break;
		}

		w7[0] = (mask & 1) ? curr->seq[++idx] : hp_sdc.r7[0];
		w7[1] = (mask & 2) ? curr->seq[++idx] : hp_sdc.r7[1];
		w7[2] = (mask & 4) ? curr->seq[++idx] : hp_sdc.r7[2];
		w7[3] = (mask & 8) ? curr->seq[++idx] : hp_sdc.r7[3];

		if (hp_sdc.wi > 0x73 || hp_sdc.wi < 0x70 ||
		    w7[hp_sdc.wi - 0x70] == hp_sdc.r7[hp_sdc.wi - 0x70]) {
			int i = 0;

			/* Need to point the write index register */
			while (i < 4 && w7[i] == hp_sdc.r7[i])
				i++;

			if (i < 4) {
				hp_sdc_status_out8(HP_SDC_CMD_SET_D0 + i);
				hp_sdc.wi = 0x70 + i;
				goto finish;
			}

			idx++;
			if ((act & HP_SDC_ACT_DURING) == HP_SDC_ACT_DATAREG)
				goto actdone;

			curr->idx = idx;
			act &= ~HP_SDC_ACT_DATAREG;
			break;
		}

		hp_sdc_data_out8(w7[hp_sdc.wi - 0x70]);
		hp_sdc.r7[hp_sdc.wi - 0x70] = w7[hp_sdc.wi - 0x70];
		hp_sdc.wi++; /* write index register autoincrements */
		{
			int i = 0;

			while ((i < 4) && w7[i] == hp_sdc.r7[i])
				i++;
			if (i >= 4) {
				curr->idx = idx + 1;
				if ((act & HP_SDC_ACT_DURING) ==
				    HP_SDC_ACT_DATAREG)
					goto actdone;
			}
		}
		goto finish;
	}
	/* We don't go any further in the command if there is a pending read,
	   because we don't want interleaved results. */
	read_lock_irq(&hp_sdc.rtq_lock);
	if (hp_sdc.rcurr >= 0) {
		read_unlock_irq(&hp_sdc.rtq_lock);
		goto finish;
	}
	read_unlock_irq(&hp_sdc.rtq_lock);


	if (act & HP_SDC_ACT_POSTCMD) {
		uint8_t postcmd;

		/* curr->idx should == idx at this point. */
		postcmd = curr->seq[idx];
		curr->idx++;
		if (act & HP_SDC_ACT_DATAIN) {

			/* Start a new read */
			hp_sdc.rqty = curr->seq[curr->idx];
			do_gettimeofday(&hp_sdc.rtv);
			curr->idx++;
			/* Still need to lock here in case of spurious irq. */
			write_lock_irq(&hp_sdc.rtq_lock);
			hp_sdc.rcurr = curridx;
			write_unlock_irq(&hp_sdc.rtq_lock);
			hp_sdc_status_out8(postcmd);
			goto finish;
		}
		hp_sdc_status_out8(postcmd);
		goto actdone;
	}

 actdone:
	if (act & HP_SDC_ACT_SEMAPHORE)
		up(curr->act.semaphore);
	else if (act & HP_SDC_ACT_CALLBACK)
		curr->act.irqhook(0,NULL,0,0);

	if (curr->idx >= curr->endidx) { /* This transaction is over. */
		if (act & HP_SDC_ACT_DEALLOC)
			kfree(curr);
		hp_sdc.tq[curridx] = NULL;
	} else {
		curr->actidx = idx + 1;
		curr->idx = idx + 2;
	}
	/* Interleave outbound data between the transactions. */
	hp_sdc.wcurr++;
	if (hp_sdc.wcurr >= HP_SDC_QUEUE_LEN)
		hp_sdc.wcurr = 0;

 finish:
	/* If by some quirk IBF has cleared and our ISR has run to
	   see that that has happened, do it all again. */
	if (!hp_sdc.ibf && limit++ < 20)
		goto anew;

 done:
	if (hp_sdc.wcurr >= 0)
		tasklet_schedule(&hp_sdc.task);
	write_unlock(&hp_sdc.lock);

	return 0;
}
示例#6
0
/*
 * This creates a new process as a copy of the old one,
 * but does not actually start it yet.
 *
 * It copies the registers, and all the appropriate
 * parts of the process environment (as per the clone
 * flags). The actual kick-off is left to the caller.
 */
struct task_struct *copy_process(unsigned long clone_flags,
				 unsigned long stack_start,
				 struct pt_regs *regs,
				 unsigned long stack_size,
				 int __user *parent_tidptr,
				 int __user *child_tidptr)
{
	int retval;
	struct task_struct *p = NULL;

	if ((clone_flags & (CLONE_NEWNS|CLONE_FS)) == (CLONE_NEWNS|CLONE_FS))
		return ERR_PTR(-EINVAL);

	/*
	 * Thread groups must share signals as well, and detached threads
	 * can only be started up within the thread group.
	 */
	if ((clone_flags & CLONE_THREAD) && !(clone_flags & CLONE_SIGHAND))
		return ERR_PTR(-EINVAL);

	/*
	 * Shared signal handlers imply shared VM. By way of the above,
	 * thread groups also imply shared VM. Blocking this case allows
	 * for various simplifications in other code.
	 */
	if ((clone_flags & CLONE_SIGHAND) && !(clone_flags & CLONE_VM))
		return ERR_PTR(-EINVAL);

	retval = security_task_create(clone_flags);
	if (retval)
		goto fork_out;

	retval = -ENOMEM;
	p = dup_task_struct(current);
	if (!p)
		goto fork_out;

	retval = -EAGAIN;
	if (atomic_read(&p->user->processes) >=
			p->rlim[RLIMIT_NPROC].rlim_cur) {
		if (!capable(CAP_SYS_ADMIN) && !capable(CAP_SYS_RESOURCE) &&
				p->user != &root_user)
			goto bad_fork_free;
	}

	atomic_inc(&p->user->__count);
	atomic_inc(&p->user->processes);
	get_group_info(p->group_info);

	/*
	 * If multiple threads are within copy_process(), then this check
	 * triggers too late. This doesn't hurt, the check is only there
	 * to stop root fork bombs.
	 */
	if (nr_threads >= max_threads)
		goto bad_fork_cleanup_count;

	if (!try_module_get(p->thread_info->exec_domain->module))
		goto bad_fork_cleanup_count;

	if (p->binfmt && !try_module_get(p->binfmt->module))
		goto bad_fork_cleanup_put_domain;

	p->did_exec = 0;
	copy_flags(clone_flags, p);
	if (clone_flags & CLONE_IDLETASK)
		p->pid = 0;
	else {
		p->pid = alloc_pidmap();
		if (p->pid == -1)
			goto bad_fork_cleanup;
	}
	retval = -EFAULT;
	if (clone_flags & CLONE_PARENT_SETTID)
		if (put_user(p->pid, parent_tidptr))
			goto bad_fork_cleanup;

	p->proc_dentry = NULL;

	INIT_LIST_HEAD(&p->children);
	INIT_LIST_HEAD(&p->sibling);
	init_waitqueue_head(&p->wait_chldexit);
	p->vfork_done = NULL;
	spin_lock_init(&p->alloc_lock);
	spin_lock_init(&p->proc_lock);

	clear_tsk_thread_flag(p, TIF_SIGPENDING);
	init_sigpending(&p->pending);

	p->it_real_value = p->it_virt_value = p->it_prof_value = 0;
	p->it_real_incr = p->it_virt_incr = p->it_prof_incr = 0;
	init_timer(&p->real_timer);
	p->real_timer.data = (unsigned long) p;

	p->utime = p->stime = 0;
	p->cutime = p->cstime = 0;
	p->lock_depth = -1;		/* -1 = no lock */
	p->start_time = get_jiffies_64();
	p->security = NULL;
	p->io_context = NULL;
	p->audit_context = NULL;
#ifdef CONFIG_NUMA
 	p->mempolicy = mpol_copy(p->mempolicy);
 	if (IS_ERR(p->mempolicy)) {
 		retval = PTR_ERR(p->mempolicy);
 		p->mempolicy = NULL;
 		goto bad_fork_cleanup;
 	}
#endif

	retval = -ENOMEM;
	if ((retval = security_task_alloc(p)))
		goto bad_fork_cleanup_policy;
	if ((retval = audit_alloc(p)))
		goto bad_fork_cleanup_security;
	/* copy all the process information */
	if ((retval = copy_semundo(clone_flags, p)))
		goto bad_fork_cleanup_audit;
	if ((retval = copy_files(clone_flags, p)))
		goto bad_fork_cleanup_semundo;
	if ((retval = copy_fs(clone_flags, p)))
		goto bad_fork_cleanup_files;
	if ((retval = copy_sighand(clone_flags, p)))
		goto bad_fork_cleanup_fs;
	if ((retval = copy_signal(clone_flags, p)))
		goto bad_fork_cleanup_sighand;
	if ((retval = copy_mm(clone_flags, p)))
		goto bad_fork_cleanup_signal;
	if ((retval = copy_namespace(clone_flags, p)))
		goto bad_fork_cleanup_mm;
	retval = copy_thread(0, clone_flags, stack_start, stack_size, p, regs);
	if (retval)
		goto bad_fork_cleanup_namespace;

	p->set_child_tid = (clone_flags & CLONE_CHILD_SETTID) ? child_tidptr : NULL;
	/*
	 * Clear TID on mm_release()?
	 */
	p->clear_child_tid = (clone_flags & CLONE_CHILD_CLEARTID) ? child_tidptr: NULL;

	/*
	 * Syscall tracing should be turned off in the child regardless
	 * of CLONE_PTRACE.
	 */
	clear_tsk_thread_flag(p, TIF_SYSCALL_TRACE);

	/* Our parent execution domain becomes current domain
	   These must match for thread signalling to apply */
	   
	p->parent_exec_id = p->self_exec_id;

	/* ok, now we should be set up.. */
	p->exit_signal = (clone_flags & CLONE_THREAD) ? -1 : (clone_flags & CSIGNAL);
	p->pdeath_signal = 0;

	/* Perform scheduler related setup */
	sched_fork(p);

	/*
	 * Ok, make it visible to the rest of the system.
	 * We dont wake it up yet.
	 */
	p->tgid = p->pid;
	p->group_leader = p;
	INIT_LIST_HEAD(&p->ptrace_children);
	INIT_LIST_HEAD(&p->ptrace_list);

	/* Need tasklist lock for parent etc handling! */
	write_lock_irq(&tasklist_lock);
	/*
	 * Check for pending SIGKILL! The new thread should not be allowed
	 * to slip out of an OOM kill. (or normal SIGKILL.)
	 */
	if (sigismember(&current->pending.signal, SIGKILL)) {
		write_unlock_irq(&tasklist_lock);
		retval = -EINTR;
		goto bad_fork_cleanup_namespace;
	}

	/* CLONE_PARENT re-uses the old parent */
	if (clone_flags & CLONE_PARENT)
		p->real_parent = current->real_parent;
	else
		p->real_parent = current;
	p->parent = p->real_parent;

	if (clone_flags & CLONE_THREAD) {
		spin_lock(&current->sighand->siglock);
		/*
		 * Important: if an exit-all has been started then
		 * do not create this new thread - the whole thread
		 * group is supposed to exit anyway.
		 */
		if (current->signal->group_exit) {
			spin_unlock(&current->sighand->siglock);
			write_unlock_irq(&tasklist_lock);
			retval = -EAGAIN;
			goto bad_fork_cleanup_namespace;
		}
		p->tgid = current->tgid;
		p->group_leader = current->group_leader;

		if (current->signal->group_stop_count > 0) {
			/*
			 * There is an all-stop in progress for the group.
			 * We ourselves will stop as soon as we check signals.
			 * Make the new thread part of that group stop too.
			 */
			current->signal->group_stop_count++;
			set_tsk_thread_flag(p, TIF_SIGPENDING);
		}

		spin_unlock(&current->sighand->siglock);
	}

	SET_LINKS(p);
	if (p->ptrace & PT_PTRACED)
		__ptrace_link(p, current->parent);

	attach_pid(p, PIDTYPE_PID, p->pid);
	if (thread_group_leader(p)) {
		attach_pid(p, PIDTYPE_TGID, p->tgid);
		attach_pid(p, PIDTYPE_PGID, process_group(p));
		attach_pid(p, PIDTYPE_SID, p->signal->session);
		if (p->pid)
			__get_cpu_var(process_counts)++;
	} else
		link_pid(p, p->pids + PIDTYPE_TGID, &p->group_leader->pids[PIDTYPE_TGID].pid);

	nr_threads++;
	write_unlock_irq(&tasklist_lock);
	retval = 0;

fork_out:
	if (retval)
		return ERR_PTR(retval);
	return p;

bad_fork_cleanup_namespace:
	exit_namespace(p);
bad_fork_cleanup_mm:
	exit_mm(p);
	if (p->active_mm)
		mmdrop(p->active_mm);
bad_fork_cleanup_signal:
	exit_signal(p);
bad_fork_cleanup_sighand:
	exit_sighand(p);
bad_fork_cleanup_fs:
	exit_fs(p); /* blocking */
bad_fork_cleanup_files:
	exit_files(p); /* blocking */
bad_fork_cleanup_semundo:
	exit_sem(p);
bad_fork_cleanup_audit:
	audit_free(p);
bad_fork_cleanup_security:
	security_task_free(p);
bad_fork_cleanup_policy:
#ifdef CONFIG_NUMA
	mpol_free(p->mempolicy);
#endif
bad_fork_cleanup:
	if (p->pid > 0)
		free_pidmap(p->pid);
	if (p->binfmt)
		module_put(p->binfmt->module);
bad_fork_cleanup_put_domain:
	module_put(p->thread_info->exec_domain->module);
bad_fork_cleanup_count:
	put_group_info(p->group_info);
	atomic_dec(&p->user->processes);
	free_uid(p->user);
bad_fork_free:
	free_task(p);
	goto fork_out;
}
示例#7
0
static void vcc_remove_socket(struct sock *sk)
{
	write_lock_irq(&vcc_sklist_lock);
	sk_del_node_init(sk);
	write_unlock_irq(&vcc_sklist_lock);
}
static struct task_struct *copy_process(unsigned long clone_flags,
					unsigned long stack_start,
					struct pt_regs *regs,
					unsigned long stack_size,
					int __user *child_tidptr,
					struct pid *pid,
					int trace)
{
	int retval;
	struct task_struct *p;
	int cgroup_callbacks_done = 0;

	if ((clone_flags & (CLONE_NEWNS|CLONE_FS)) == (CLONE_NEWNS|CLONE_FS))
		return ERR_PTR(-EINVAL);

	if ((clone_flags & CLONE_THREAD) && !(clone_flags & CLONE_SIGHAND))
		return ERR_PTR(-EINVAL);

	if ((clone_flags & CLONE_SIGHAND) && !(clone_flags & CLONE_VM))
		return ERR_PTR(-EINVAL);

	if ((clone_flags & CLONE_PARENT) &&
				current->signal->flags & SIGNAL_UNKILLABLE)
		return ERR_PTR(-EINVAL);

	retval = security_task_create(clone_flags);
	if (retval)
		goto fork_out;

	retval = -ENOMEM;
	p = dup_task_struct(current);
	if (!p)
		goto fork_out;

	ftrace_graph_init_task(p);

	rt_mutex_init_task(p);

#ifdef CONFIG_PROVE_LOCKING
	DEBUG_LOCKS_WARN_ON(!p->hardirqs_enabled);
	DEBUG_LOCKS_WARN_ON(!p->softirqs_enabled);
#endif
	retval = -EAGAIN;
	if (atomic_read(&p->real_cred->user->processes) >=
			task_rlimit(p, RLIMIT_NPROC)) {
		if (!capable(CAP_SYS_ADMIN) && !capable(CAP_SYS_RESOURCE) &&
		    p->real_cred->user != INIT_USER)
			goto bad_fork_free;
	}
	current->flags &= ~PF_NPROC_EXCEEDED;

	retval = copy_creds(p, clone_flags);
	if (retval < 0)
		goto bad_fork_free;

	retval = -EAGAIN;
	if (nr_threads >= max_threads)
		goto bad_fork_cleanup_count;

	if (!try_module_get(task_thread_info(p)->exec_domain->module))
		goto bad_fork_cleanup_count;

	p->did_exec = 0;
	delayacct_tsk_init(p);	
	copy_flags(clone_flags, p);
	INIT_LIST_HEAD(&p->children);
	INIT_LIST_HEAD(&p->sibling);
	rcu_copy_process(p);
	p->vfork_done = NULL;
	spin_lock_init(&p->alloc_lock);

	init_sigpending(&p->pending);

	p->utime = p->stime = p->gtime = 0;
	p->utimescaled = p->stimescaled = 0;
#ifndef CONFIG_VIRT_CPU_ACCOUNTING
	p->prev_utime = p->prev_stime = 0;
#endif
#if defined(SPLIT_RSS_COUNTING)
	memset(&p->rss_stat, 0, sizeof(p->rss_stat));
#endif

	p->default_timer_slack_ns = current->timer_slack_ns;

	task_io_accounting_init(&p->ioac);
	acct_clear_integrals(p);

	posix_cpu_timers_init(p);

	do_posix_clock_monotonic_gettime(&p->start_time);
	p->real_start_time = p->start_time;
	monotonic_to_bootbased(&p->real_start_time);
	p->io_context = NULL;
	p->audit_context = NULL;
	if (clone_flags & CLONE_THREAD)
		threadgroup_change_begin(current);
	cgroup_fork(p);
#ifdef CONFIG_NUMA
	p->mempolicy = mpol_dup(p->mempolicy);
	if (IS_ERR(p->mempolicy)) {
		retval = PTR_ERR(p->mempolicy);
		p->mempolicy = NULL;
		goto bad_fork_cleanup_cgroup;
	}
	mpol_fix_fork_child_flag(p);
#endif
#ifdef CONFIG_CPUSETS
	p->cpuset_mem_spread_rotor = NUMA_NO_NODE;
	p->cpuset_slab_spread_rotor = NUMA_NO_NODE;
	seqcount_init(&p->mems_allowed_seq);
#endif
#ifdef CONFIG_TRACE_IRQFLAGS
	p->irq_events = 0;
#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
	p->hardirqs_enabled = 1;
#else
	p->hardirqs_enabled = 0;
#endif
	p->hardirq_enable_ip = 0;
	p->hardirq_enable_event = 0;
	p->hardirq_disable_ip = _THIS_IP_;
	p->hardirq_disable_event = 0;
	p->softirqs_enabled = 1;
	p->softirq_enable_ip = _THIS_IP_;
	p->softirq_enable_event = 0;
	p->softirq_disable_ip = 0;
	p->softirq_disable_event = 0;
	p->hardirq_context = 0;
	p->softirq_context = 0;
#endif
#ifdef CONFIG_LOCKDEP
	p->lockdep_depth = 0; 
	p->curr_chain_key = 0;
	p->lockdep_recursion = 0;
#endif

#ifdef CONFIG_DEBUG_MUTEXES
	
	p->blocked_on = NULL;
	p->blocked_by = NULL;
	p->blocked_since = 0;
#endif
#ifdef CONFIG_CGROUP_MEM_RES_CTLR
	p->memcg_batch.do_batch = 0;
	p->memcg_batch.memcg = NULL;
#endif

	
	sched_fork(p);

	retval = perf_event_init_task(p);
	if (retval)
		goto bad_fork_cleanup_policy;
	retval = audit_alloc(p);
	if (retval)
		goto bad_fork_cleanup_policy;
	
	retval = copy_semundo(clone_flags, p);
	if (retval)
		goto bad_fork_cleanup_audit;
	retval = copy_files(clone_flags, p);
	if (retval)
		goto bad_fork_cleanup_semundo;
	retval = copy_fs(clone_flags, p);
	if (retval)
		goto bad_fork_cleanup_files;
	retval = copy_sighand(clone_flags, p);
	if (retval)
		goto bad_fork_cleanup_fs;
	retval = copy_signal(clone_flags, p);
	if (retval)
		goto bad_fork_cleanup_sighand;
	retval = copy_mm(clone_flags, p);
	if (retval)
		goto bad_fork_cleanup_signal;
	retval = copy_namespaces(clone_flags, p);
	if (retval)
		goto bad_fork_cleanup_mm;
	retval = copy_io(clone_flags, p);
	if (retval)
		goto bad_fork_cleanup_namespaces;
	retval = copy_thread(clone_flags, stack_start, stack_size, p, regs);
	if (retval)
		goto bad_fork_cleanup_io;

	if (pid != &init_struct_pid) {
		retval = -ENOMEM;
		pid = alloc_pid(p->nsproxy->pid_ns);
		if (!pid)
			goto bad_fork_cleanup_io;
	}

	p->pid = pid_nr(pid);
	p->tgid = p->pid;
	if (clone_flags & CLONE_THREAD)
		p->tgid = current->tgid;

	p->set_child_tid = (clone_flags & CLONE_CHILD_SETTID) ? child_tidptr : NULL;
	p->clear_child_tid = (clone_flags & CLONE_CHILD_CLEARTID) ? child_tidptr : NULL;
#ifdef CONFIG_BLOCK
	p->plug = NULL;
#endif
#ifdef CONFIG_FUTEX
	p->robust_list = NULL;
#ifdef CONFIG_COMPAT
	p->compat_robust_list = NULL;
#endif
	INIT_LIST_HEAD(&p->pi_state_list);
	p->pi_state_cache = NULL;
#endif
	if ((clone_flags & (CLONE_VM|CLONE_VFORK)) == CLONE_VM)
		p->sas_ss_sp = p->sas_ss_size = 0;

	user_disable_single_step(p);
	clear_tsk_thread_flag(p, TIF_SYSCALL_TRACE);
#ifdef TIF_SYSCALL_EMU
	clear_tsk_thread_flag(p, TIF_SYSCALL_EMU);
#endif
	clear_all_latency_tracing(p);

	
	if (clone_flags & CLONE_THREAD)
		p->exit_signal = -1;
	else if (clone_flags & CLONE_PARENT)
		p->exit_signal = current->group_leader->exit_signal;
	else
		p->exit_signal = (clone_flags & CSIGNAL);

	p->pdeath_signal = 0;
	p->exit_state = 0;

	p->nr_dirtied = 0;
	p->nr_dirtied_pause = 128 >> (PAGE_SHIFT - 10);
	p->dirty_paused_when = 0;

	p->group_leader = p;
	INIT_LIST_HEAD(&p->thread_group);

	cgroup_fork_callbacks(p);
	cgroup_callbacks_done = 1;

	
	write_lock_irq(&tasklist_lock);

	
	if (clone_flags & (CLONE_PARENT|CLONE_THREAD)) {
		p->real_parent = current->real_parent;
		p->parent_exec_id = current->parent_exec_id;
	} else {
		p->real_parent = current;
		p->parent_exec_id = current->self_exec_id;
	}

	spin_lock(&current->sighand->siglock);

	recalc_sigpending();
	if (signal_pending(current)) {
		spin_unlock(&current->sighand->siglock);
		write_unlock_irq(&tasklist_lock);
		retval = -ERESTARTNOINTR;
		goto bad_fork_free_pid;
	}

	if (clone_flags & CLONE_THREAD) {
		current->signal->nr_threads++;
		atomic_inc(&current->signal->live);
		atomic_inc(&current->signal->sigcnt);
		p->group_leader = current->group_leader;
		list_add_tail_rcu(&p->thread_group, &p->group_leader->thread_group);
	}

	if (likely(p->pid)) {
		ptrace_init_task(p, (clone_flags & CLONE_PTRACE) || trace);

		if (thread_group_leader(p)) {
			if (is_child_reaper(pid))
				p->nsproxy->pid_ns->child_reaper = p;

			p->signal->leader_pid = pid;
			p->signal->tty = tty_kref_get(current->signal->tty);
			attach_pid(p, PIDTYPE_PGID, task_pgrp(current));
			attach_pid(p, PIDTYPE_SID, task_session(current));
			list_add_tail(&p->sibling, &p->real_parent->children);
			list_add_tail_rcu(&p->tasks, &init_task.tasks);
			__this_cpu_inc(process_counts);
		}
		attach_pid(p, PIDTYPE_PID, pid);
		nr_threads++;
	}

	total_forks++;
	spin_unlock(&current->sighand->siglock);
	write_unlock_irq(&tasklist_lock);
	proc_fork_connector(p);
	cgroup_post_fork(p);
	if (clone_flags & CLONE_THREAD)
		threadgroup_change_end(current);
	perf_event_fork(p);

	trace_task_newtask(p, clone_flags);

	return p;

bad_fork_free_pid:
	if (pid != &init_struct_pid)
		free_pid(pid);
bad_fork_cleanup_io:
	if (p->io_context)
		exit_io_context(p);
bad_fork_cleanup_namespaces:
	if (unlikely(clone_flags & CLONE_NEWPID))
		pid_ns_release_proc(p->nsproxy->pid_ns);
	exit_task_namespaces(p);
bad_fork_cleanup_mm:
	if (p->mm)
		mmput(p->mm);
bad_fork_cleanup_signal:
	if (!(clone_flags & CLONE_THREAD))
		free_signal_struct(p->signal);
bad_fork_cleanup_sighand:
	__cleanup_sighand(p->sighand);
bad_fork_cleanup_fs:
	exit_fs(p); 
bad_fork_cleanup_files:
	exit_files(p); 
bad_fork_cleanup_semundo:
	exit_sem(p);
bad_fork_cleanup_audit:
	audit_free(p);
bad_fork_cleanup_policy:
	perf_event_free_task(p);
#ifdef CONFIG_NUMA
	mpol_put(p->mempolicy);
bad_fork_cleanup_cgroup:
#endif
	if (clone_flags & CLONE_THREAD)
		threadgroup_change_end(current);
	cgroup_exit(p, cgroup_callbacks_done);
	delayacct_tsk_free(p);
	module_put(task_thread_info(p)->exec_domain->module);
bad_fork_cleanup_count:
	atomic_dec(&p->cred->user->processes);
	exit_creds(p);
bad_fork_free:
	free_task(p);
fork_out:
	return ERR_PTR(retval);
}
示例#9
0
文件: exit.c 项目: nhanh0/hah
asmlinkage long sys_wait4(pid_t pid,unsigned int * stat_addr, int options, struct rusage * ru)
{
	int flag, retval;
	DECLARE_WAITQUEUE(wait, current);
	struct task_struct *tsk;

	if (options & ~(WNOHANG|WUNTRACED|__WNOTHREAD|__WCLONE|__WALL))
		return -EINVAL;

	add_wait_queue(&current->wait_chldexit,&wait);
repeat:
	flag = 0;
	current->state = TASK_INTERRUPTIBLE;
	read_lock(&tasklist_lock);
	tsk = current;
	do {
		struct task_struct *p;
	 	for (p = tsk->p_cptr ; p ; p = p->p_osptr) {
			if (pid>0) {
				if (p->pid != pid)
					continue;
			} else if (!pid) {
				if (p->pgrp != current->pgrp)
					continue;
			} else if (pid != -1) {
				if (p->pgrp != -pid)
					continue;
			}
			/* Wait for all children (clone and not) if __WALL is set;
			 * otherwise, wait for clone children *only* if __WCLONE is
			 * set; otherwise, wait for non-clone children *only*.  (Note:
			 * A "clone" child here is one that reports to its parent
			 * using a signal other than SIGCHLD.) */
			if (((p->exit_signal != SIGCHLD) ^ ((options & __WCLONE) != 0))
			    && !(options & __WALL))
				continue;
			flag = 1;
			switch (p->state) {
			case TASK_STOPPED:
				if (!p->exit_code)
					continue;
				if (!(options & WUNTRACED) && !(p->ptrace & PT_PTRACED))
					continue;
				read_unlock(&tasklist_lock);
				retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0; 
				if (!retval && stat_addr) 
					retval = put_user((p->exit_code << 8) | 0x7f, stat_addr);
				if (!retval) {
					p->exit_code = 0;
					retval = p->pid;
				}
				goto end_wait4;
			case TASK_ZOMBIE:
				current->times.tms_cutime += p->times.tms_utime + p->times.tms_cutime;
				current->times.tms_cstime += p->times.tms_stime + p->times.tms_cstime;
				read_unlock(&tasklist_lock);
				retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0;
				if (!retval && stat_addr)
					retval = put_user(p->exit_code, stat_addr);
				if (retval)
					goto end_wait4; 
				retval = p->pid;
				if (p->p_opptr != p->p_pptr) {
					write_lock_irq(&tasklist_lock);
					REMOVE_LINKS(p);
					p->p_pptr = p->p_opptr;
					SET_LINKS(p);
					do_notify_parent(p, SIGCHLD);
					write_unlock_irq(&tasklist_lock);
				} else
					release_task(p);
				goto end_wait4;
			default:
				continue;
			}
		}
		if (options & __WNOTHREAD)
			break;
		tsk = next_thread(tsk);
	} while (tsk != current);
	read_unlock(&tasklist_lock);
	if (flag) {
		retval = 0;
		if (options & WNOHANG)
			goto end_wait4;
		retval = -ERESTARTSYS;
		if (signal_pending(current))
			goto end_wait4;
		schedule();
		goto repeat;
	}
	retval = -ECHILD;
end_wait4:
	current->state = TASK_RUNNING;
	remove_wait_queue(&current->wait_chldexit,&wait);
	return retval;
}
示例#10
0
文件: cache.c 项目: 3null/fastsocket
static void ib_cache_update(struct ib_device *device,
			    u8                port)
{
	struct ib_port_attr       *tprops = NULL;
	struct ib_pkey_cache      *pkey_cache = NULL, *old_pkey_cache;
	struct ib_gid_cache       *gid_cache = NULL, *old_gid_cache;
	int                        i, j;
	int                        ret;
	union ib_gid		   gid, empty_gid;
	u16			   pkey;

	tprops = kmalloc(sizeof *tprops, GFP_KERNEL);
	if (!tprops)
		return;

	ret = ib_query_port(device, port, tprops);
	if (ret) {
		printk(KERN_WARNING "ib_query_port failed (%d) for %s\n",
		       ret, device->name);
		goto err;
	}

	pkey_cache = kmalloc(sizeof *pkey_cache + tprops->pkey_tbl_len *
			     sizeof *pkey_cache->entry, GFP_KERNEL);
	if (!pkey_cache)
		goto err;

	pkey_cache->table_len = 0;

	gid_cache = kmalloc(sizeof *gid_cache + tprops->gid_tbl_len *
			    sizeof *gid_cache->entry, GFP_KERNEL);
	if (!gid_cache)
		goto err;

	gid_cache->table_len = 0;

	for (i = 0, j = 0; i < tprops->pkey_tbl_len; ++i) {
		ret = ib_query_pkey(device, port, i, &pkey);
		if (ret) {
			printk(KERN_WARNING "ib_query_pkey failed (%d) for %s (index %d)\n",
			       ret, device->name, i);
			goto err;
		}
		/* pkey 0xffff must be the default pkeyand 0x0000 must be the invalid
		 * pkey per IBTA spec */
		if (pkey) {
			pkey_cache->entry[j].index = i;
			pkey_cache->entry[j++].pkey = pkey;
		}
	}
	pkey_cache->table_len = j;

	memset(&empty_gid, 0, sizeof empty_gid);
	for (i = 0, j = 0; i < tprops->gid_tbl_len; ++i) {
		ret = ib_query_gid(device, port, i, &gid);
		if (ret) {
			printk(KERN_WARNING "ib_query_gid failed (%d) for %s (index %d)\n",
			       ret, device->name, i);
			goto err;
		}
		/* if the lower 8 bytes the device GID entry is all 0,
		 * our entry is a blank, invalid entry...
		 * depending on device, the upper 8 bytes might or might
		 * not be prefilled with a valid subnet prefix, so
		 * don't rely on them for determining a valid gid
		 * entry
		 */
		if (memcmp(&gid + 8, &empty_gid + 8, sizeof gid - 8)) {
			gid_cache->entry[j].index = i;
			gid_cache->entry[j++].gid = gid;
		}
	}
	gid_cache->table_len = j;

	old_pkey_cache = pkey_cache;
	pkey_cache = kmalloc(sizeof *pkey_cache + old_pkey_cache->table_len *
			     sizeof *pkey_cache->entry, GFP_KERNEL);
	if (!pkey_cache)
		pkey_cache = old_pkey_cache;
	else {
		pkey_cache->table_len = old_pkey_cache->table_len;
		memcpy(&pkey_cache->entry[0], &old_pkey_cache->entry[0],
		       pkey_cache->table_len * sizeof *pkey_cache->entry);
		kfree(old_pkey_cache);
	}

	old_gid_cache = gid_cache;
	gid_cache = kmalloc(sizeof *gid_cache + old_gid_cache->table_len *
			    sizeof *gid_cache->entry, GFP_KERNEL);
	if (!gid_cache)
		gid_cache = old_gid_cache;
	else {
		gid_cache->table_len = old_gid_cache->table_len;
		memcpy(&gid_cache->entry[0], &old_gid_cache->entry[0],
		       gid_cache->table_len * sizeof *gid_cache->entry);
		kfree(old_gid_cache);
	}

	write_lock_irq(&device->cache.lock);

	old_pkey_cache = device->cache.pkey_cache[port - start_port(device)];
	old_gid_cache  = device->cache.gid_cache [port - start_port(device)];

	device->cache.pkey_cache[port - start_port(device)] = pkey_cache;
	device->cache.gid_cache [port - start_port(device)] = gid_cache;

	device->cache.lmc_cache[port - start_port(device)] = tprops->lmc;

	write_unlock_irq(&device->cache.lock);

	kfree(old_pkey_cache);
	kfree(old_gid_cache);
	kfree(tprops);
	return;

err:
	kfree(pkey_cache);
	kfree(gid_cache);
	kfree(tprops);
}
示例#11
0
文件: time.c 项目: FoXPeeD/OS-bwis
/*
 * Adjust the time obtained from the CMOS to be UTC time instead of
 * local time.
 * 
 * This is ugly, but preferable to the alternatives.  Otherwise we
 * would either need to write a program to do it in /etc/rc (and risk
 * confusion if the program gets run more than once; it would also be 
 * hard to make the program warp the clock precisely n hours)  or
 * compile in the timezone information into the kernel.  Bad, bad....
 *
 *              				- TYT, 1992-01-01
 *
 * The best thing to do is to keep the CMOS clock in universal time (UTC)
 * as real UNIX machines always do it. This avoids all headaches about
 * daylight saving times and warping kernel clocks.
 */
inline static void warp_clock(void)
{
	write_lock_irq(&xtime_lock);
	xtime.tv_sec += sys_tz.tz_minuteswest * 60;
	write_unlock_irq(&xtime_lock);
}
示例#12
0
/*
 * This creates a new process as a copy of the old one,
 * but does not actually start it yet.
 *
 * It copies the registers, and all the appropriate
 * parts of the process environment (as per the clone
 * flags). The actual kick-off is left to the caller.
 */
static task_t *copy_process(unsigned long clone_flags,
				 unsigned long stack_start,
				 struct pt_regs *regs,
				 unsigned long stack_size,
				 int __user *parent_tidptr,
				 int __user *child_tidptr,
				 int pid)
{
	int retval;
	struct task_struct *p = NULL;

	if ((clone_flags & (CLONE_NEWNS|CLONE_FS)) == (CLONE_NEWNS|CLONE_FS))
		return ERR_PTR(-EINVAL);

	/*
	 * Thread groups must share signals as well, and detached threads
	 * can only be started up within the thread group.
	 */
	if ((clone_flags & CLONE_THREAD) && !(clone_flags & CLONE_SIGHAND))
		return ERR_PTR(-EINVAL);

	/*
	 * Shared signal handlers imply shared VM. By way of the above,
	 * thread groups also imply shared VM. Blocking this case allows
	 * for various simplifications in other code.
	 */
	if ((clone_flags & CLONE_SIGHAND) && !(clone_flags & CLONE_VM))
		return ERR_PTR(-EINVAL);

	retval = security_task_create(clone_flags);
	if (retval)
		goto fork_out;

	retval = -ENOMEM;
	p = dup_task_struct(current);
	if (!p)
		goto fork_out;

	retval = -EAGAIN;
	if (atomic_read(&p->user->processes) >=
			p->signal->rlim[RLIMIT_NPROC].rlim_cur) {
		if (!capable(CAP_SYS_ADMIN) && !capable(CAP_SYS_RESOURCE) &&
				p->user != &root_user)
			goto bad_fork_free;
	}

	atomic_inc(&p->user->__count);
	atomic_inc(&p->user->processes);
	get_group_info(p->group_info);

	/*
	 * If multiple threads are within copy_process(), then this check
	 * triggers too late. This doesn't hurt, the check is only there
	 * to stop root fork bombs.
	 */
	if (nr_threads >= max_threads)
		goto bad_fork_cleanup_count;

	if (!try_module_get(p->thread_info->exec_domain->module))
		goto bad_fork_cleanup_count;

	if (p->binfmt && !try_module_get(p->binfmt->module))
		goto bad_fork_cleanup_put_domain;

	p->did_exec = 0;
	copy_flags(clone_flags, p);
	p->pid = pid;
	retval = -EFAULT;
	if (clone_flags & CLONE_PARENT_SETTID)
		if (put_user(p->pid, parent_tidptr))
			goto bad_fork_cleanup;

	p->proc_dentry = NULL;

	INIT_LIST_HEAD(&p->children);
	INIT_LIST_HEAD(&p->sibling);
	p->vfork_done = NULL;
	spin_lock_init(&p->alloc_lock);
	spin_lock_init(&p->proc_lock);

	clear_tsk_thread_flag(p, TIF_SIGPENDING);
	init_sigpending(&p->pending);

	p->utime = cputime_zero;
	p->stime = cputime_zero;
 	p->sched_time = 0;
	p->rchar = 0;		/* I/O counter: bytes read */
	p->wchar = 0;		/* I/O counter: bytes written */
	p->syscr = 0;		/* I/O counter: read syscalls */
	p->syscw = 0;		/* I/O counter: write syscalls */
	acct_clear_integrals(p);

 	p->it_virt_expires = cputime_zero;
	p->it_prof_expires = cputime_zero;
 	p->it_sched_expires = 0;
 	INIT_LIST_HEAD(&p->cpu_timers[0]);
 	INIT_LIST_HEAD(&p->cpu_timers[1]);
 	INIT_LIST_HEAD(&p->cpu_timers[2]);

	p->lock_depth = -1;		/* -1 = no lock */
	do_posix_clock_monotonic_gettime(&p->start_time);
	p->security = NULL;
	p->io_context = NULL;
	p->io_wait = NULL;
	p->audit_context = NULL;
#ifdef CONFIG_NUMA
 	p->mempolicy = mpol_copy(p->mempolicy);
 	if (IS_ERR(p->mempolicy)) {
 		retval = PTR_ERR(p->mempolicy);
 		p->mempolicy = NULL;
 		goto bad_fork_cleanup;
 	}
#endif

	p->tgid = p->pid;
	if (clone_flags & CLONE_THREAD)
		p->tgid = current->tgid;

	if ((retval = security_task_alloc(p)))
		goto bad_fork_cleanup_policy;
	if ((retval = audit_alloc(p)))
		goto bad_fork_cleanup_security;
	/* copy all the process information */
	if ((retval = copy_semundo(clone_flags, p)))
		goto bad_fork_cleanup_audit;
	if ((retval = copy_files(clone_flags, p)))
		goto bad_fork_cleanup_semundo;
	if ((retval = copy_fs(clone_flags, p)))
		goto bad_fork_cleanup_files;
	if ((retval = copy_sighand(clone_flags, p)))
		goto bad_fork_cleanup_fs;
	if ((retval = copy_signal(clone_flags, p)))
		goto bad_fork_cleanup_sighand;
	if ((retval = copy_mm(clone_flags, p)))
		goto bad_fork_cleanup_signal;
	if ((retval = copy_keys(clone_flags, p)))
		goto bad_fork_cleanup_mm;
	if ((retval = copy_namespace(clone_flags, p)))
		goto bad_fork_cleanup_keys;
	retval = copy_thread(0, clone_flags, stack_start, stack_size, p, regs);
	if (retval)
		goto bad_fork_cleanup_namespace;

	p->set_child_tid = (clone_flags & CLONE_CHILD_SETTID) ? child_tidptr : NULL;
	/*
	 * Clear TID on mm_release()?
	 */
	p->clear_child_tid = (clone_flags & CLONE_CHILD_CLEARTID) ? child_tidptr: NULL;

	/*
	 * Syscall tracing should be turned off in the child regardless
	 * of CLONE_PTRACE.
	 */
	clear_tsk_thread_flag(p, TIF_SYSCALL_TRACE);

	/* Our parent execution domain becomes current domain
	   These must match for thread signalling to apply */
	   
	p->parent_exec_id = p->self_exec_id;

	/* ok, now we should be set up.. */
	p->exit_signal = (clone_flags & CLONE_THREAD) ? -1 : (clone_flags & CSIGNAL);
	p->pdeath_signal = 0;
	p->exit_state = 0;

	/* Perform scheduler related setup */
	sched_fork(p);

	/*
	 * Ok, make it visible to the rest of the system.
	 * We dont wake it up yet.
	 */
	p->group_leader = p;
	INIT_LIST_HEAD(&p->ptrace_children);
	INIT_LIST_HEAD(&p->ptrace_list);

	/* Need tasklist lock for parent etc handling! */
	write_lock_irq(&tasklist_lock);

	/*
	 * The task hasn't been attached yet, so cpus_allowed mask cannot
	 * have changed. The cpus_allowed mask of the parent may have
	 * changed after it was copied first time, and it may then move to
	 * another CPU - so we re-copy it here and set the child's CPU to
	 * the parent's CPU. This avoids alot of nasty races.
	 */
	p->cpus_allowed = current->cpus_allowed;
	set_task_cpu(p, smp_processor_id());

	/*
	 * Check for pending SIGKILL! The new thread should not be allowed
	 * to slip out of an OOM kill. (or normal SIGKILL.)
	 */
	if (sigismember(&current->pending.signal, SIGKILL)) {
		write_unlock_irq(&tasklist_lock);
		retval = -EINTR;
		goto bad_fork_cleanup_namespace;
	}

	/* CLONE_PARENT re-uses the old parent */
	if (clone_flags & (CLONE_PARENT|CLONE_THREAD))
		p->real_parent = current->real_parent;
	else
		p->real_parent = current;
	p->parent = p->real_parent;

	if (clone_flags & CLONE_THREAD) {
		spin_lock(&current->sighand->siglock);
		/*
		 * Important: if an exit-all has been started then
		 * do not create this new thread - the whole thread
		 * group is supposed to exit anyway.
		 */
		if (current->signal->flags & SIGNAL_GROUP_EXIT) {
			spin_unlock(&current->sighand->siglock);
			write_unlock_irq(&tasklist_lock);
			retval = -EAGAIN;
			goto bad_fork_cleanup_namespace;
		}
		p->group_leader = current->group_leader;

		if (current->signal->group_stop_count > 0) {
			/*
			 * There is an all-stop in progress for the group.
			 * We ourselves will stop as soon as we check signals.
			 * Make the new thread part of that group stop too.
			 */
			current->signal->group_stop_count++;
			set_tsk_thread_flag(p, TIF_SIGPENDING);
		}

		if (!cputime_eq(current->signal->it_virt_expires,
				cputime_zero) ||
		    !cputime_eq(current->signal->it_prof_expires,
				cputime_zero) ||
		    current->signal->rlim[RLIMIT_CPU].rlim_cur != RLIM_INFINITY ||
		    !list_empty(&current->signal->cpu_timers[0]) ||
		    !list_empty(&current->signal->cpu_timers[1]) ||
		    !list_empty(&current->signal->cpu_timers[2])) {
			/*
			 * Have child wake up on its first tick to check
			 * for process CPU timers.
			 */
			p->it_prof_expires = jiffies_to_cputime(1);
		}

		spin_unlock(&current->sighand->siglock);
	}

	SET_LINKS(p);
	if (unlikely(p->ptrace & PT_PTRACED))
		__ptrace_link(p, current->parent);

	cpuset_fork(p);

	attach_pid(p, PIDTYPE_PID, p->pid);
	attach_pid(p, PIDTYPE_TGID, p->tgid);
	if (thread_group_leader(p)) {
		attach_pid(p, PIDTYPE_PGID, process_group(p));
		attach_pid(p, PIDTYPE_SID, p->signal->session);
		if (p->pid)
			__get_cpu_var(process_counts)++;
	}

	nr_threads++;
	total_forks++;
	write_unlock_irq(&tasklist_lock);
	retval = 0;

fork_out:
	if (retval)
		return ERR_PTR(retval);
	return p;

bad_fork_cleanup_namespace:
	exit_namespace(p);
bad_fork_cleanup_keys:
	exit_keys(p);
bad_fork_cleanup_mm:
	if (p->mm)
		mmput(p->mm);
bad_fork_cleanup_signal:
	exit_signal(p);
bad_fork_cleanup_sighand:
	exit_sighand(p);
bad_fork_cleanup_fs:
	exit_fs(p); /* blocking */
bad_fork_cleanup_files:
	exit_files(p); /* blocking */
bad_fork_cleanup_semundo:
	exit_sem(p);
bad_fork_cleanup_audit:
	audit_free(p);
bad_fork_cleanup_security:
	security_task_free(p);
bad_fork_cleanup_policy:
#ifdef CONFIG_NUMA
	mpol_free(p->mempolicy);
#endif
bad_fork_cleanup:
	if (p->binfmt)
		module_put(p->binfmt->module);
bad_fork_cleanup_put_domain:
	module_put(p->thread_info->exec_domain->module);
bad_fork_cleanup_count:
	put_group_info(p->group_info);
	atomic_dec(&p->user->processes);
	free_uid(p->user);
bad_fork_free:
	free_task(p);
	goto fork_out;
}
示例#13
0
long sys_ptrace(long request, pid_t pid, long addr, long data)
{
	struct task_struct *child;
	long ret;

	lock_kernel();
	ret = -EPERM;
	if (request == PTRACE_TRACEME) {
		/* are we already being traced? */
		if (current->ptrace & PT_PTRACED)
			goto out;
		/* set the ptrace bit in the process flags. */
		current->ptrace |= PT_PTRACED;
		ret = 0;
		goto out;
	}

	ret = -ESRCH;
	read_lock(&tasklist_lock);
	child = find_task_by_pid(pid);
	if (child)
		get_task_struct(child);
	read_unlock(&tasklist_lock);
	if (!child)
		goto out;
	ret = -EPERM;
	if (pid == 1)		/* no messing around with init! */
		goto out_tsk;

	if (request == PTRACE_ATTACH) {
		if (child == current)
			goto out_tsk;
		if ((!child->dumpable ||
		    (current->uid != child->euid) ||
		    (current->uid != child->suid) ||
		    (current->uid != child->uid) ||
	 	    (current->gid != child->egid) ||
	 	    (current->gid != child->sgid) ||
	 	    (!cap_issubset(child->cap_permitted, current->cap_permitted)) ||
	 	    (current->gid != child->gid)) && !capable(CAP_SYS_PTRACE))
			goto out_tsk;
		/* the same process cannot be attached many times */
		if (child->ptrace & PT_PTRACED)
			goto out_tsk;
		child->ptrace |= PT_PTRACED;
		if (child->p_pptr != current) {
			unsigned long flags;

			write_lock_irqsave(&tasklist_lock, flags);
			REMOVE_LINKS(child);
			child->p_pptr = current;
			SET_LINKS(child);
			write_unlock_irqrestore(&tasklist_lock, flags);
		}
		send_sig(SIGSTOP, child, 1);
		ret = 0;
		goto out_tsk;
	}
	ret = -ESRCH;
	if (!(child->ptrace & PT_PTRACED))
		goto out_tsk;
	if (child->state != TASK_STOPPED) {
		if (request != PTRACE_KILL)
			goto out_tsk;
	}
	if (child->p_pptr != current)
		goto out_tsk;

	switch (request) {
	case PTRACE_PEEKTEXT: /* read word at location addr. */ 
	case PTRACE_PEEKDATA: {
		unsigned long tmp;
		int copied;

		copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
		ret = -EIO;
		if (copied != sizeof(tmp))
			goto out_tsk;
		ret = put_user(tmp,(unsigned long *) data);
		goto out_tsk;
	}

	/* when I and D space are separate, this will have to be fixed. */
	case PTRACE_POKETEXT: /* write the word at location addr. */
	case PTRACE_POKEDATA:
		ret = 0;
		if (access_process_vm(child, addr, &data, sizeof(data), 1) == sizeof(data))
			goto out_tsk;
		ret = -EIO;
		goto out_tsk;

	/* Read the word at location addr in the USER area.  This will need
	   to change when the kernel no longer saves all regs on a syscall. */
	case PTRACE_PEEKUSR: {
		unsigned long tmp;

		ret = -EIO;
		if ((addr & 3) || (unsigned long) addr >= sizeof(struct pt_regs))
			goto out_tsk;

		tmp = *(unsigned long *) ((char *) task_regs(child) + addr);
		ret = put_user(tmp, (unsigned long *) data);
		goto out_tsk;
	}

	/* Write the word at location addr in the USER area.  This will need
	   to change when the kernel no longer saves all regs on a syscall.
	   FIXME.  There is a problem at the moment in that r3-r18 are only
	   saved if the process is ptraced on syscall entry, and even then
	   those values are overwritten by actual register values on syscall
	   exit. */
	case PTRACE_POKEUSR:
		ret = -EIO;
		if ((addr & 3) || (unsigned long) addr >= sizeof(struct pt_regs))
			goto out_tsk;
		/* XXX This test probably needs adjusting.  We probably want to
		 * allow writes to some bits of PSW, and may want to block writes
		 * to (some) space registers.  Some register values written here
		 * may be ignored in entry.S:syscall_restore_rfi; e.g. iaoq is
		 * written with r31/r31+4, and not with the values in pt_regs.
		 */
		/* Allow writing of gr1-gr31, fr*, sr*, iasq*, iaoq*, sar */
		if (addr == PT_PSW || (addr > PT_IAOQ1 && addr != PT_SAR))
			goto out_tsk;

		*(unsigned long *) ((char *) task_regs(child) + addr) = data;
		ret = 0;
		goto out_tsk;

	case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
	case PTRACE_CONT:
		ret = -EIO;
		if ((unsigned long) data > _NSIG)
			goto out_tsk;
		child->ptrace &= ~(PT_SINGLESTEP|PT_BLOCKSTEP);
		if (request == PTRACE_SYSCALL)
			child->ptrace |= PT_TRACESYS;
		else
			child->ptrace &= ~PT_TRACESYS;
		child->exit_code = data;
		goto out_wake_notrap;

	case PTRACE_KILL:
		/*
		 * make the child exit.  Best I can do is send it a
		 * sigkill.  perhaps it should be put in the status
		 * that it wants to exit.
		 */
		if (child->state == TASK_ZOMBIE)	/* already dead */
			goto out_tsk;
		child->exit_code = SIGKILL;
		goto out_wake_notrap;

	case PTRACE_SINGLEBLOCK:
		ret = -EIO;
		if ((unsigned long) data > _NSIG)
			goto out_tsk;
		child->ptrace &= ~(PT_TRACESYS|PT_SINGLESTEP);
		child->ptrace |= PT_BLOCKSTEP;
		child->exit_code = data;

		/* Enable taken branch trap. */
		pa_psw(child)->r = 0;
		pa_psw(child)->t = 1;
		pa_psw(child)->h = 0;
		pa_psw(child)->l = 0;
		goto out_wake;

	case PTRACE_SINGLESTEP:
		ret = -EIO;
		if ((unsigned long) data > _NSIG)
			goto out_tsk;
		child->ptrace &= ~(PT_TRACESYS|PT_BLOCKSTEP);
		child->ptrace |= PT_SINGLESTEP;
		child->exit_code = data;

		if (pa_psw(child)->n) {
			struct siginfo si;

			/* Nullified, just crank over the queue. */
			task_regs(child)->iaoq[0] = task_regs(child)->iaoq[1];
			task_regs(child)->iasq[0] = task_regs(child)->iasq[1];
			task_regs(child)->iaoq[1] = task_regs(child)->iaoq[0] + 4;
			pa_psw(child)->n = 0;
			pa_psw(child)->x = 0;
			pa_psw(child)->y = 0;
			pa_psw(child)->z = 0;
			pa_psw(child)->b = 0;
			pa_psw(child)->r = 0;
			pa_psw(child)->t = 0;
			pa_psw(child)->h = 0;
			pa_psw(child)->l = 0;
			/* Don't wake up the child, but let the
			   parent know something happened. */
			si.si_code = TRAP_TRACE;
			si.si_addr = (void *) (task_regs(child)->iaoq[0] & ~3);
			si.si_signo = SIGTRAP;
			si.si_errno = 0;
			force_sig_info(SIGTRAP, &si, child);
			//notify_parent(child, SIGCHLD);
			//ret = 0;
			goto out_wake;
		}

		/* Enable recovery counter traps.  The recovery counter
		 * itself will be set to zero on a task switch.  If the
		 * task is suspended on a syscall then the syscall return
		 * path will overwrite the recovery counter with a suitable
		 * value such that it traps once back in user space.  We
		 * disable interrupts in the childs PSW here also, to avoid
		 * interrupts while the recovery counter is decrementing.
		 */
		pa_psw(child)->r = 1;
		pa_psw(child)->t = 0;
		pa_psw(child)->h = 0;
		pa_psw(child)->l = 0;
		/* give it a chance to run. */
		goto out_wake;

	case PTRACE_DETACH:
		ret = -EIO;
		if ((unsigned long) data > _NSIG)
			goto out_tsk;
		child->ptrace &= ~(PT_PTRACED|PT_TRACESYS|PT_SINGLESTEP|PT_BLOCKSTEP);
		child->exit_code = data;
		write_lock_irq(&tasklist_lock);
		REMOVE_LINKS(child);
		child->p_pptr = child->p_opptr;
		SET_LINKS(child);
		write_unlock_irq(&tasklist_lock);
		goto out_wake_notrap;

	default:
		ret = -EIO;
		goto out_tsk;
	}

out_wake_notrap:
	/* make sure the trap bits are not set */
	pa_psw(child)->r = 0;
	pa_psw(child)->t = 0;
	pa_psw(child)->h = 0;
	pa_psw(child)->l = 0;
out_wake:
	wake_up_process(child);
	ret = 0;
out_tsk:
	free_task_struct(child);
out:
	unlock_kernel();
	return ret;
}
示例#14
0
/**
 * zfcp_adapter_enqueue - enqueue a new adapter to the list
 * @ccw_device: pointer to the struct cc_device
 *
 * Returns:	0             if a new adapter was successfully enqueued
 *		-ENOMEM       if alloc failed
 * Enqueues an adapter at the end of the adapter list in the driver data.
 * All adapter internal structures are set up.
 * Proc-fs entries are also created.
 * locks:	config_sema must be held to serialise changes to the adapter list
 */
int zfcp_adapter_enqueue(struct ccw_device *ccw_device)
{
	struct zfcp_adapter *adapter;

	/*
	 * Note: It is safe to release the list_lock, as any list changes
	 * are protected by the config_sema, which must be held to get here
	 */

	adapter = kzalloc(sizeof(struct zfcp_adapter), GFP_KERNEL);
	if (!adapter)
		return -ENOMEM;

	ccw_device->handler = NULL;
	adapter->ccw_device = ccw_device;
	atomic_set(&adapter->refcount, 0);

	if (zfcp_qdio_allocate(adapter))
		goto qdio_allocate_failed;

	if (zfcp_allocate_low_mem_buffers(adapter))
		goto failed_low_mem_buffers;

	if (zfcp_reqlist_alloc(adapter))
		goto failed_low_mem_buffers;

	if (zfcp_adapter_debug_register(adapter))
		goto debug_register_failed;

	init_waitqueue_head(&adapter->remove_wq);
	init_waitqueue_head(&adapter->erp_thread_wqh);
	init_waitqueue_head(&adapter->erp_done_wqh);

	INIT_LIST_HEAD(&adapter->port_list_head);
	INIT_LIST_HEAD(&adapter->erp_ready_head);
	INIT_LIST_HEAD(&adapter->erp_running_head);

	spin_lock_init(&adapter->req_list_lock);

	spin_lock_init(&adapter->hba_dbf_lock);
	spin_lock_init(&adapter->san_dbf_lock);
	spin_lock_init(&adapter->scsi_dbf_lock);
	spin_lock_init(&adapter->rec_dbf_lock);
	spin_lock_init(&adapter->req_q_lock);

	rwlock_init(&adapter->erp_lock);
	rwlock_init(&adapter->abort_lock);

	sema_init(&adapter->erp_ready_sem, 0);

	INIT_WORK(&adapter->stat_work, _zfcp_status_read_scheduler);
	INIT_WORK(&adapter->scan_work, _zfcp_scan_ports_later);

	/* mark adapter unusable as long as sysfs registration is not complete */
	atomic_set_mask(ZFCP_STATUS_COMMON_REMOVE, &adapter->status);

	dev_set_drvdata(&ccw_device->dev, adapter);

	if (sysfs_create_group(&ccw_device->dev.kobj,
			       &zfcp_sysfs_adapter_attrs))
		goto sysfs_failed;

	write_lock_irq(&zfcp_data.config_lock);
	atomic_clear_mask(ZFCP_STATUS_COMMON_REMOVE, &adapter->status);
	list_add_tail(&adapter->list, &zfcp_data.adapter_list_head);
	write_unlock_irq(&zfcp_data.config_lock);

	zfcp_fc_nameserver_init(adapter);

	return 0;

sysfs_failed:
	zfcp_adapter_debug_unregister(adapter);
debug_register_failed:
	dev_set_drvdata(&ccw_device->dev, NULL);
	kfree(adapter->req_list);
failed_low_mem_buffers:
	zfcp_free_low_mem_buffers(adapter);
qdio_allocate_failed:
	zfcp_qdio_free(adapter);
	kfree(adapter);
	return -ENOMEM;
}
示例#15
0
/**
 * zfcp_port_enqueue - enqueue port to port list of adapter
 * @adapter: adapter where remote port is added
 * @wwpn: WWPN of the remote port to be enqueued
 * @status: initial status for the port
 * @d_id: destination id of the remote port to be enqueued
 * Returns: pointer to enqueued port on success, ERR_PTR on error
 *
 * All port internal structures are set up and the sysfs entry is generated.
 * d_id is used to enqueue ports with a well known address like the Directory
 * Service for nameserver lookup.
 */
struct zfcp_port *zfcp_port_enqueue(struct zfcp_adapter *adapter, u64 wwpn,
				     u32 status, u32 d_id)
{
	struct zfcp_port *port;
	int retval = -ENOMEM;

	kref_get(&adapter->ref);

	port = zfcp_get_port_by_wwpn(adapter, wwpn);
	if (port) {
		put_device(&port->dev);
		retval = -EEXIST;
		goto err_out;
	}

	port = kzalloc(sizeof(struct zfcp_port), GFP_KERNEL);
	if (!port)
		goto err_out;

	rwlock_init(&port->unit_list_lock);
	INIT_LIST_HEAD(&port->unit_list);

	INIT_WORK(&port->gid_pn_work, zfcp_fc_port_did_lookup);
	INIT_WORK(&port->test_link_work, zfcp_fc_link_test_work);
	INIT_WORK(&port->rport_work, zfcp_scsi_rport_work);

	port->adapter = adapter;
	port->d_id = d_id;
	port->wwpn = wwpn;
	port->rport_task = RPORT_NONE;
	port->dev.parent = &adapter->ccw_device->dev;
	port->dev.release = zfcp_port_release;

	if (dev_set_name(&port->dev, "0x%016llx", (unsigned long long)wwpn)) {
		kfree(port);
		goto err_out;
	}
	retval = -EINVAL;

	if (device_register(&port->dev)) {
		put_device(&port->dev);
		goto err_out;
	}

	if (sysfs_create_group(&port->dev.kobj,
			       &zfcp_sysfs_port_attrs))
		goto err_out_put;

	write_lock_irq(&adapter->port_list_lock);
	list_add_tail(&port->list, &adapter->port_list);
	write_unlock_irq(&adapter->port_list_lock);

	atomic_set_mask(status | ZFCP_STATUS_COMMON_RUNNING, &port->status);

	return port;

err_out_put:
	device_unregister(&port->dev);
err_out:
	zfcp_ccw_adapter_put(adapter);
	return ERR_PTR(retval);
}
示例#16
0
文件: cache.c 项目: chunyenho/RTS-hw2
static void ib_cache_update(struct ib_device *device,
                            u8                port)
{
    struct ib_port_attr       *tprops = NULL;
    struct ib_pkey_cache      *pkey_cache = NULL, *old_pkey_cache;
    struct ib_gid_cache       *gid_cache = NULL, *old_gid_cache;
    int                        i;
    int                        ret;

    tprops = kmalloc(sizeof *tprops, GFP_KERNEL);
    if (!tprops)
        return;

    ret = ib_query_port(device, port, tprops);
    if (ret) {
        printk(KERN_WARNING "ib_query_port failed (%d) for %s\n",
               ret, device->name);
        goto err;
    }

    pkey_cache = kmalloc(sizeof *pkey_cache + tprops->pkey_tbl_len *
                         sizeof *pkey_cache->table, GFP_KERNEL);
    if (!pkey_cache)
        goto err;

    pkey_cache->table_len = tprops->pkey_tbl_len;

    gid_cache = kmalloc(sizeof *gid_cache + tprops->gid_tbl_len *
                        sizeof *gid_cache->table, GFP_KERNEL);
    if (!gid_cache)
        goto err;

    gid_cache->table_len = tprops->gid_tbl_len;

    for (i = 0; i < pkey_cache->table_len; ++i) {
        ret = ib_query_pkey(device, port, i, pkey_cache->table + i);
        if (ret) {
            printk(KERN_WARNING "ib_query_pkey failed (%d) for %s (index %d)\n",
                   ret, device->name, i);
            goto err;
        }
    }

    for (i = 0; i < gid_cache->table_len; ++i) {
        ret = ib_query_gid(device, port, i, gid_cache->table + i);
        if (ret) {
            printk(KERN_WARNING "ib_query_gid failed (%d) for %s (index %d)\n",
                   ret, device->name, i);
            goto err;
        }
    }

    write_lock_irq(&device->cache.lock);

    old_pkey_cache = device->cache.pkey_cache[port - start_port(device)];
    old_gid_cache  = device->cache.gid_cache [port - start_port(device)];

    device->cache.pkey_cache[port - start_port(device)] = pkey_cache;
    device->cache.gid_cache [port - start_port(device)] = gid_cache;

    device->cache.lmc_cache[port - start_port(device)] = tprops->lmc;

    write_unlock_irq(&device->cache.lock);

    kfree(old_pkey_cache);
    kfree(old_gid_cache);
    kfree(tprops);
    return;

err:
    kfree(pkey_cache);
    kfree(gid_cache);
    kfree(tprops);
}
示例#17
0
/**
 * write_one_page - write out a single page and optionally wait on I/O
 * @page: the page to write
 * @wait: if true, wait on writeout
 *
 * The page must be locked by the caller and will be unlocked upon return.
 *
 * write_one_page() returns a negative error code if I/O failed.
 */
int write_one_page(struct page *page, int wait)
{
	struct address_space *mapping = page->mapping;
	int ret = 0;
	struct writeback_control wbc = {
		.sync_mode = WB_SYNC_ALL,
		.nr_to_write = 1,
	};

	BUG_ON(!PageLocked(page));

	if (wait)
		wait_on_page_writeback(page);

	if (clear_page_dirty_for_io(page)) {
		page_cache_get(page);
		ret = mapping->a_ops->writepage(page, &wbc);
		if (ret == 0 && wait) {
			wait_on_page_writeback(page);
			if (PageError(page))
				ret = -EIO;
		}
		page_cache_release(page);
	} else {
		unlock_page(page);
	}
	return ret;
}
EXPORT_SYMBOL(write_one_page);

/*
 * For address_spaces which do not use buffers nor write back.
 */
int __set_page_dirty_no_writeback(struct page *page)
{
	if (!PageDirty(page))
		SetPageDirty(page);
	return 0;
}

/*
 * For address_spaces which do not use buffers.  Just tag the page as dirty in
 * its radix tree.
 *
 * This is also used when a single buffer is being dirtied: we want to set the
 * page dirty in that case, but not all the buffers.  This is a "bottom-up"
 * dirtying, whereas __set_page_dirty_buffers() is a "top-down" dirtying.
 *
 * Most callers have locked the page, which pins the address_space in memory.
 * But zap_pte_range() does not lock the page, however in that case the
 * mapping is pinned by the vma's ->vm_file reference.
 *
 * We take care to handle the case where the page was truncated from the
 * mapping by re-checking page_mapping() insode tree_lock.
 */
int __set_page_dirty_nobuffers(struct page *page)
{
	if (!TestSetPageDirty(page)) {
		struct address_space *mapping = page_mapping(page);
		struct address_space *mapping2;

		if (!mapping)
			return 1;

		write_lock_irq(&mapping->tree_lock);
		mapping2 = page_mapping(page);
		if (mapping2) { /* Race with truncate? */
			BUG_ON(mapping2 != mapping);
			WARN_ON_ONCE(!PagePrivate(page) && !PageUptodate(page));
			if (mapping_cap_account_dirty(mapping)) {
				__inc_zone_page_state(page, NR_FILE_DIRTY);
				task_io_account_write(PAGE_CACHE_SIZE);
			}
			radix_tree_tag_set(&mapping->page_tree,
				page_index(page), PAGECACHE_TAG_DIRTY);
		}
		write_unlock_irq(&mapping->tree_lock);
		if (mapping->host) {
			/* !PageAnon && !swapper_space */
			__mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
		}
		return 1;
	}
	return 0;
}
EXPORT_SYMBOL(__set_page_dirty_nobuffers);

/*
 * When a writepage implementation decides that it doesn't want to write this
 * page for some reason, it should redirty the locked page via
 * redirty_page_for_writepage() and it should then unlock the page and return 0
 */
int redirty_page_for_writepage(struct writeback_control *wbc, struct page *page)
{
	wbc->pages_skipped++;
	return __set_page_dirty_nobuffers(page);
}
示例#18
0
asmlinkage long sys_setpgid(pid_t pid, pid_t pgid)
{
	struct task_struct *p;
	int err = -EINVAL;

	if (!pid)
		pid = current->pid;
	if (!pgid)
		pgid = pid;
	if (pgid < 0)
		return -EINVAL;

	/* From this point forward we keep holding onto the tasklist lock
	 * so that our parent does not change from under us. -DaveM
	 */
	write_lock_irq(&tasklist_lock);

	err = -ESRCH;
	p = find_task_by_pid(pid);
	if (!p)
		goto out;

	err = -EINVAL;
	if (!thread_group_leader(p))
		goto out;

	if (p->parent == current || p->real_parent == current) {
		err = -EPERM;
		if (p->signal->session != current->signal->session)
			goto out;
		err = -EACCES;
		if (p->did_exec)
			goto out;
	} else {
		err = -ESRCH;
		if (p != current)
			goto out;
	}

	err = -EPERM;
	if (p->signal->leader)
		goto out;

	if (pgid != pid) {
		struct task_struct *p;

		do_each_task_pid(pgid, PIDTYPE_PGID, p) {
			if (p->signal->session == current->signal->session)
				goto ok_pgid;
		} while_each_task_pid(pgid, PIDTYPE_PGID, p);
		goto out;
	}

ok_pgid:
	err = security_task_setpgid(p, pgid);
	if (err)
		goto out;

	if (process_group(p) != pgid) {
		detach_pid(p, PIDTYPE_PGID);
		p->signal->pgrp = pgid;
		attach_pid(p, PIDTYPE_PGID, pgid);
	}

	err = 0;
out:
	/* All paths lead to here, thus we are safe. -DaveM */
	write_unlock_irq(&tasklist_lock);
	return err;
}
示例#19
0
void vcc_insert_socket(struct sock *sk)
{
	write_lock_irq(&vcc_sklist_lock);
	__vcc_insert_socket(sk);
	write_unlock_irq(&vcc_sklist_lock);
}
示例#20
0
/**
 * zfcp_unit_enqueue - enqueue unit to unit list of a port.
 * @port: pointer to port where unit is added
 * @fcp_lun: FCP LUN of unit to be enqueued
 * Returns: pointer to enqueued unit on success, ERR_PTR on error
 * Locks: config_sema must be held to serialize changes to the unit list
 *
 * Sets up some unit internal structures and creates sysfs entry.
 */
struct zfcp_unit *zfcp_unit_enqueue(struct zfcp_port *port, u64 fcp_lun)
{
	struct zfcp_unit *unit;

	unit = kzalloc(sizeof(struct zfcp_unit), GFP_KERNEL);
	if (!unit)
		return ERR_PTR(-ENOMEM);

	atomic_set(&unit->refcount, 0);
	init_waitqueue_head(&unit->remove_wq);

	unit->port = port;
	unit->fcp_lun = fcp_lun;

	dev_set_name(&unit->sysfs_device, "0x%016llx",
		     (unsigned long long) fcp_lun);
	unit->sysfs_device.parent = &port->sysfs_device;
	unit->sysfs_device.release = zfcp_sysfs_unit_release;
	dev_set_drvdata(&unit->sysfs_device, unit);

	/* mark unit unusable as long as sysfs registration is not complete */
	atomic_set_mask(ZFCP_STATUS_COMMON_REMOVE, &unit->status);

	spin_lock_init(&unit->latencies.lock);
	unit->latencies.write.channel.min = 0xFFFFFFFF;
	unit->latencies.write.fabric.min = 0xFFFFFFFF;
	unit->latencies.read.channel.min = 0xFFFFFFFF;
	unit->latencies.read.fabric.min = 0xFFFFFFFF;
	unit->latencies.cmd.channel.min = 0xFFFFFFFF;
	unit->latencies.cmd.fabric.min = 0xFFFFFFFF;

	read_lock_irq(&zfcp_data.config_lock);
	if (zfcp_get_unit_by_lun(port, fcp_lun)) {
		read_unlock_irq(&zfcp_data.config_lock);
		goto err_out_free;
	}
	read_unlock_irq(&zfcp_data.config_lock);

	if (device_register(&unit->sysfs_device))
		goto err_out_free;

	if (sysfs_create_group(&unit->sysfs_device.kobj,
			       &zfcp_sysfs_unit_attrs)) {
		device_unregister(&unit->sysfs_device);
		return ERR_PTR(-EIO);
	}

	zfcp_unit_get(unit);

	write_lock_irq(&zfcp_data.config_lock);
	list_add_tail(&unit->list, &port->unit_list_head);
	atomic_clear_mask(ZFCP_STATUS_COMMON_REMOVE, &unit->status);
	atomic_set_mask(ZFCP_STATUS_COMMON_RUNNING, &unit->status);

	write_unlock_irq(&zfcp_data.config_lock);

	zfcp_port_get(port);

	return unit;

err_out_free:
	kfree(unit);
	return ERR_PTR(-EINVAL);
}
示例#21
0
/*
 * This needs some heavy checking ...
 * I just haven't the stomach for it. I also don't fully
 * understand sessions/pgrp etc. Let somebody who does explain it.
 *
 * OK, I think I have the protection semantics right.... this is really
 * only important on a multi-user system anyway, to make sure one user
 * can't send a signal to a process owned by another.  -TYT, 12/12/91
 *
 * Auch. Had to add the 'did_exec' flag to conform completely to POSIX.
 * LBT 04.03.94
 */
asmlinkage long sys_setpgid(pid_t pid, pid_t pgid)
{
	struct task_struct *p;
	struct task_struct *group_leader = current->group_leader;
	int err = -EINVAL;
	struct pid_namespace *ns;

	if (!pid)
		pid = task_pid_vnr(group_leader);
	if (!pgid)
		pgid = pid;
	if (pgid < 0)
		return -EINVAL;

	/* From this point forward we keep holding onto the tasklist lock
	 * so that our parent does not change from under us. -DaveM
	 */
	ns = current->nsproxy->pid_ns;

	write_lock_irq(&tasklist_lock);

	err = -ESRCH;
	p = find_task_by_pid_ns(pid, ns);
	if (!p)
		goto out;

	err = -EINVAL;
	if (!thread_group_leader(p))
		goto out;

	if (p->real_parent->tgid == group_leader->tgid) {
		err = -EPERM;
		if (task_session(p) != task_session(group_leader))
			goto out;
		err = -EACCES;
		if (p->did_exec)
			goto out;
	} else {
		err = -ESRCH;
		if (p != group_leader)
			goto out;
	}

	err = -EPERM;
	if (p->signal->leader)
		goto out;

	if (pgid != pid) {
		struct task_struct *g;

		g = find_task_by_pid_type_ns(PIDTYPE_PGID, pgid, ns);
		if (!g || task_session(g) != task_session(group_leader))
			goto out;
	}

	err = security_task_setpgid(p, pgid);
	if (err)
		goto out;

	if (task_pgrp_nr_ns(p, ns) != pgid) {
		struct pid *pid;

		detach_pid(p, PIDTYPE_PGID);
		pid = find_vpid(pgid);
		attach_pid(p, PIDTYPE_PGID, pid);
		set_task_pgrp(p, pid_nr(pid));
	}

	err = 0;
out:
	/* All paths lead to here, thus we are safe. -DaveM */
	write_unlock_irq(&tasklist_lock);
	return err;
}
示例#22
0
/**
 * zfcp_port_enqueue - enqueue port to port list of adapter
 * @adapter: adapter where remote port is added
 * @wwpn: WWPN of the remote port to be enqueued
 * @status: initial status for the port
 * @d_id: destination id of the remote port to be enqueued
 * Returns: pointer to enqueued port on success, ERR_PTR on error
 * Locks: config_sema must be held to serialize changes to the port list
 *
 * All port internal structures are set up and the sysfs entry is generated.
 * d_id is used to enqueue ports with a well known address like the Directory
 * Service for nameserver lookup.
 */
struct zfcp_port *zfcp_port_enqueue(struct zfcp_adapter *adapter, u64 wwpn,
				     u32 status, u32 d_id)
{
	struct zfcp_port *port;
	int retval;

	port = kzalloc(sizeof(struct zfcp_port), GFP_KERNEL);
	if (!port)
		return ERR_PTR(-ENOMEM);

	init_waitqueue_head(&port->remove_wq);
	INIT_LIST_HEAD(&port->unit_list_head);
	INIT_WORK(&port->gid_pn_work, zfcp_erp_port_strategy_open_lookup);

	port->adapter = adapter;
	port->d_id = d_id;
	port->wwpn = wwpn;

	/* mark port unusable as long as sysfs registration is not complete */
	atomic_set_mask(status | ZFCP_STATUS_COMMON_REMOVE, &port->status);
	atomic_set(&port->refcount, 0);

	dev_set_name(&port->sysfs_device, "0x%016llx",
		     (unsigned long long)wwpn);
	port->sysfs_device.parent = &adapter->ccw_device->dev;

	port->sysfs_device.release = zfcp_sysfs_port_release;
	dev_set_drvdata(&port->sysfs_device, port);

	read_lock_irq(&zfcp_data.config_lock);
	if (!(status & ZFCP_STATUS_PORT_NO_WWPN))
		if (zfcp_get_port_by_wwpn(adapter, wwpn)) {
			read_unlock_irq(&zfcp_data.config_lock);
			goto err_out_free;
		}
	read_unlock_irq(&zfcp_data.config_lock);

	if (device_register(&port->sysfs_device))
		goto err_out_free;

	retval = sysfs_create_group(&port->sysfs_device.kobj,
				    &zfcp_sysfs_port_attrs);

	if (retval) {
		device_unregister(&port->sysfs_device);
		goto err_out;
	}

	zfcp_port_get(port);

	write_lock_irq(&zfcp_data.config_lock);
	list_add_tail(&port->list, &adapter->port_list_head);
	atomic_clear_mask(ZFCP_STATUS_COMMON_REMOVE, &port->status);
	atomic_set_mask(ZFCP_STATUS_COMMON_RUNNING, &port->status);

	write_unlock_irq(&zfcp_data.config_lock);

	zfcp_adapter_get(adapter);
	return port;

err_out_free:
	kfree(port);
err_out:
	return ERR_PTR(-EINVAL);
}
示例#23
0
文件: exit.c 项目: benbee/Learning
asmlinkage int sys_wait4(pid_t pid,unsigned int * stat_addr, int options, struct rusage * ru)
{
	int flag, retval;
	struct wait_queue wait = { current, NULL };
	struct task_struct *p;

	if (options & ~(WNOHANG|WUNTRACED|__WCLONE))
		return -EINVAL;

	add_wait_queue(&current->wait_chldexit,&wait);
repeat:
	flag = 0;

	/* The interruptible state must be set before looking at the
	   children. This because we want to catch any racy exit from
	   the children as do_exit() may run under us. The following
	   read_lock will enforce SMP ordering at the CPU level. */
	current->state = TASK_INTERRUPTIBLE;

	read_lock(&tasklist_lock);
 	for (p = current->p_cptr ; p ; p = p->p_osptr) {
		if (pid>0) {
			if (p->pid != pid)
				continue;
		} else if (!pid) {
			if (p->pgrp != current->pgrp)
				continue;
		} else if (pid != -1) {
			if (p->pgrp != -pid)
				continue;
		}
		/* wait for cloned processes iff the __WCLONE flag is set */
		if ((p->exit_signal != SIGCHLD) ^ ((options & __WCLONE) != 0))
			continue;
		flag = 1;
		switch (p->state) {
			case TASK_STOPPED:
				if (!p->exit_code)
					continue;
				if (!(options & WUNTRACED) && !(p->flags & PF_PTRACED))
					continue;
				read_unlock(&tasklist_lock);
				current->state = TASK_RUNNING;	/* We *must* do this before touching userspace! */
				retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0; 
				if (!retval && stat_addr) 
					retval = put_user((p->exit_code << 8) | 0x7f, stat_addr);
				if (!retval) {
					p->exit_code = 0;
					retval = p->pid;
				}
				goto end_wait4;
			case TASK_ZOMBIE:
				current->times.tms_cutime += p->times.tms_utime + p->times.tms_cutime;
				current->times.tms_cstime += p->times.tms_stime + p->times.tms_cstime;
				read_unlock(&tasklist_lock);
				current->state = TASK_RUNNING;	/* We *must* do this before touching userspace! */
				retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0;
				if (!retval && stat_addr)
					retval = put_user(p->exit_code, stat_addr);
				if (retval)
					goto end_wait4; 
				retval = p->pid;
				if (p->p_opptr != p->p_pptr) {
					write_lock_irq(&tasklist_lock);
					REMOVE_LINKS(p);
					p->p_pptr = p->p_opptr;
					SET_LINKS(p);
					write_unlock_irq(&tasklist_lock);
					notify_parent(p, SIGCHLD);
				} else
					release(p);
#ifdef DEBUG_PROC_TREE
				audit_ptree();
#endif
				goto end_wait4;
			default:
				continue;
		}
	}
	read_unlock(&tasklist_lock);
	if (flag) {
		retval = 0;
		if (options & WNOHANG)
			goto end_wait4;
		retval = -ERESTARTSYS;
		if (signal_pending(current))
			goto end_wait4;
		schedule();
		goto repeat;
	}
	retval = -ECHILD;
end_wait4:
	remove_wait_queue(&current->wait_chldexit,&wait);
	current->state = TASK_RUNNING;
	return retval;
}
示例#24
0
/* adjtimex mainly allows reading (and writing, if superuser) of
 * kernel time-keeping variables. used by xntpd.
 */
int do_adjtimex(struct timex *txc)
{
        long ltemp, mtemp, save_adjust;
	int result;

	/* In order to modify anything, you gotta be super-user! */
	if (txc->modes && !capable(CAP_SYS_TIME))
		return -EPERM;
		
	/* Now we validate the data before disabling interrupts */

	if ((txc->modes & ADJ_OFFSET_SINGLESHOT) == ADJ_OFFSET_SINGLESHOT)
	  /* singleshot must not be used with any other mode bits */
		if (txc->modes != ADJ_OFFSET_SINGLESHOT)
			return -EINVAL;

	if (txc->modes != ADJ_OFFSET_SINGLESHOT && (txc->modes & ADJ_OFFSET))
	  /* adjustment Offset limited to +- .512 seconds */
		if (txc->offset <= - MAXPHASE || txc->offset >= MAXPHASE )
			return -EINVAL;	

	/* if the quartz is off by more than 10% something is VERY wrong ! */
	if (txc->modes & ADJ_TICK)
		if (txc->tick < 900000/HZ || txc->tick > 1100000/HZ)
			return -EINVAL;

	write_lock_irq(&xtime_lock);
	result = time_state;	/* mostly `TIME_OK' */

	/* Save for later - semantics of adjtime is to return old value */
	save_adjust = time_adjust;

#if 0	/* STA_CLOCKERR is never set yet */
	time_status &= ~STA_CLOCKERR;		/* reset STA_CLOCKERR */
#endif
	/* If there are input parameters, then process them */
	if (txc->modes)
	{
	    if (txc->modes & ADJ_STATUS)	/* only set allowed bits */
		time_status =  (txc->status & ~STA_RONLY) |
			      (time_status & STA_RONLY);

	    if (txc->modes & ADJ_FREQUENCY) {	/* p. 22 */
		if (txc->freq > MAXFREQ || txc->freq < -MAXFREQ) {
		    result = -EINVAL;
		    goto leave;
		}
		time_freq = txc->freq - pps_freq;
	    }

	    if (txc->modes & ADJ_MAXERROR) {
		if (txc->maxerror < 0 || txc->maxerror >= NTP_PHASE_LIMIT) {
		    result = -EINVAL;
		    goto leave;
		}
		time_maxerror = txc->maxerror;
	    }

	    if (txc->modes & ADJ_ESTERROR) {
		if (txc->esterror < 0 || txc->esterror >= NTP_PHASE_LIMIT) {
		    result = -EINVAL;
		    goto leave;
		}
		time_esterror = txc->esterror;
	    }

	    if (txc->modes & ADJ_TIMECONST) {	/* p. 24 */
		if (txc->constant < 0) {	/* NTP v4 uses values > 6 */
		    result = -EINVAL;
		    goto leave;
		}
		time_constant = txc->constant;
	    }

	    if (txc->modes & ADJ_OFFSET) {	/* values checked earlier */
		if (txc->modes == ADJ_OFFSET_SINGLESHOT) {
		    /* adjtime() is independent from ntp_adjtime() */
		    time_adjust = txc->offset;
		}
		else if ( time_status & (STA_PLL | STA_PPSTIME) ) {
		    ltemp = (time_status & (STA_PPSTIME | STA_PPSSIGNAL)) ==
		            (STA_PPSTIME | STA_PPSSIGNAL) ?
		            pps_offset : txc->offset;

		    /*
		     * Scale the phase adjustment and
		     * clamp to the operating range.
		     */
		    if (ltemp > MAXPHASE)
		        time_offset = MAXPHASE << SHIFT_UPDATE;
		    else if (ltemp < -MAXPHASE)
			time_offset = -(MAXPHASE << SHIFT_UPDATE);
		    else
		        time_offset = ltemp << SHIFT_UPDATE;

		    /*
		     * Select whether the frequency is to be controlled
		     * and in which mode (PLL or FLL). Clamp to the operating
		     * range. Ugly multiply/divide should be replaced someday.
		     */

		    if (time_status & STA_FREQHOLD || time_reftime == 0)
		        time_reftime = xtime.tv_sec;
		    mtemp = xtime.tv_sec - time_reftime;
		    time_reftime = xtime.tv_sec;
		    if (time_status & STA_FLL) {
		        if (mtemp >= MINSEC) {
			    ltemp = (time_offset / mtemp) << (SHIFT_USEC -
							      SHIFT_UPDATE);
			    if (ltemp < 0)
			        time_freq -= -ltemp >> SHIFT_KH;
			    else
			        time_freq += ltemp >> SHIFT_KH;
			} else /* calibration interval too short (p. 12) */
				result = TIME_ERROR;
		    } else {	/* PLL mode */
示例#25
0
/*
 * This creates a new process as a copy of the old one,
 * but does not actually start it yet.
 *
 * It copies the registers, and all the appropriate
 * parts of the process environment (as per the clone
 * flags). The actual kick-off is left to the caller.
 */
static struct task_struct *copy_process(unsigned long clone_flags,
					unsigned long stack_start,
					struct pt_regs *regs,
					unsigned long stack_size,
					int __user *parent_tidptr,
					int __user *child_tidptr,
					struct pid *pid)
{
	int retval;
	struct task_struct *p = NULL;

	if ((clone_flags & (CLONE_NEWNS|CLONE_FS)) == (CLONE_NEWNS|CLONE_FS))
		return ERR_PTR(-EINVAL);

	/*
	 * Thread groups must share signals as well, and detached threads
	 * can only be started up within the thread group.
	 */
	if ((clone_flags & CLONE_THREAD) && !(clone_flags & CLONE_SIGHAND))
		return ERR_PTR(-EINVAL);

	/*
	 * Shared signal handlers imply shared VM. By way of the above,
	 * thread groups also imply shared VM. Blocking this case allows
	 * for various simplifications in other code.
	 */
	if ((clone_flags & CLONE_SIGHAND) && !(clone_flags & CLONE_VM))
		return ERR_PTR(-EINVAL);

	retval = security_task_create(clone_flags);
	if (retval)
		goto fork_out;

	retval = -ENOMEM;
	p = dup_task_struct(current);
	if (!p)
		goto fork_out;

	rt_mutex_init_task(p);

#ifdef CONFIG_TRACE_IRQFLAGS
	DEBUG_LOCKS_WARN_ON(!p->hardirqs_enabled);
	DEBUG_LOCKS_WARN_ON(!p->softirqs_enabled);
#endif
	retval = -EAGAIN;
	if (atomic_read(&p->user->processes) >=
			p->signal->rlim[RLIMIT_NPROC].rlim_cur) {
		if (!capable(CAP_SYS_ADMIN) && !capable(CAP_SYS_RESOURCE) &&
				p->user != &root_user)
			goto bad_fork_free;
	}

	atomic_inc(&p->user->__count);
	atomic_inc(&p->user->processes);
	get_group_info(p->group_info);

	/*
	 * If multiple threads are within copy_process(), then this check
	 * triggers too late. This doesn't hurt, the check is only there
	 * to stop root fork bombs.
	 */
	if (nr_threads >= max_threads)
		goto bad_fork_cleanup_count;

	if (!try_module_get(task_thread_info(p)->exec_domain->module))
		goto bad_fork_cleanup_count;

	if (p->binfmt && !try_module_get(p->binfmt->module))
		goto bad_fork_cleanup_put_domain;

	p->did_exec = 0;
	delayacct_tsk_init(p);	/* Must remain after dup_task_struct() */
	copy_flags(clone_flags, p);
	p->pid = pid_nr(pid);
	retval = -EFAULT;
	if (clone_flags & CLONE_PARENT_SETTID)
		if (put_user(p->pid, parent_tidptr))
			goto bad_fork_cleanup_delays_binfmt;

	INIT_LIST_HEAD(&p->children);
	INIT_LIST_HEAD(&p->sibling);
	p->vfork_done = NULL;
	spin_lock_init(&p->alloc_lock);

	clear_tsk_thread_flag(p, TIF_SIGPENDING);
	init_sigpending(&p->pending);

	p->utime = cputime_zero;
	p->stime = cputime_zero;
 	p->sched_time = 0;
#ifdef CONFIG_TASK_XACCT
	p->rchar = 0;		/* I/O counter: bytes read */
	p->wchar = 0;		/* I/O counter: bytes written */
	p->syscr = 0;		/* I/O counter: read syscalls */
	p->syscw = 0;		/* I/O counter: write syscalls */
#endif
	task_io_accounting_init(p);
	acct_clear_integrals(p);

 	p->it_virt_expires = cputime_zero;
	p->it_prof_expires = cputime_zero;
 	p->it_sched_expires = 0;
 	INIT_LIST_HEAD(&p->cpu_timers[0]);
 	INIT_LIST_HEAD(&p->cpu_timers[1]);
 	INIT_LIST_HEAD(&p->cpu_timers[2]);

	p->lock_depth = -1;		/* -1 = no lock */
	do_posix_clock_monotonic_gettime(&p->start_time);
	p->security = NULL;
	p->io_context = NULL;
	p->io_wait = NULL;
	p->audit_context = NULL;
	cpuset_fork(p);
#ifdef CONFIG_NUMA
 	p->mempolicy = mpol_copy(p->mempolicy);
 	if (IS_ERR(p->mempolicy)) {
 		retval = PTR_ERR(p->mempolicy);
 		p->mempolicy = NULL;
 		goto bad_fork_cleanup_cpuset;
 	}
	mpol_fix_fork_child_flag(p);
#endif
#ifdef CONFIG_TRACE_IRQFLAGS
	p->irq_events = 0;
#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
	p->hardirqs_enabled = 1;
#else
	p->hardirqs_enabled = 0;
#endif
	p->hardirq_enable_ip = 0;
	p->hardirq_enable_event = 0;
	p->hardirq_disable_ip = _THIS_IP_;
	p->hardirq_disable_event = 0;
	p->softirqs_enabled = 1;
	p->softirq_enable_ip = _THIS_IP_;
	p->softirq_enable_event = 0;
	p->softirq_disable_ip = 0;
	p->softirq_disable_event = 0;
	p->hardirq_context = 0;
	p->softirq_context = 0;
#endif
#ifdef CONFIG_LOCKDEP
	p->lockdep_depth = 0; /* no locks held yet */
	p->curr_chain_key = 0;
	p->lockdep_recursion = 0;
#endif

#ifdef CONFIG_DEBUG_MUTEXES
	p->blocked_on = NULL; /* not blocked yet */
#endif

	p->tgid = p->pid;
	if (clone_flags & CLONE_THREAD)
		p->tgid = current->tgid;

	if ((retval = security_task_alloc(p)))
		goto bad_fork_cleanup_policy;
	if ((retval = audit_alloc(p)))
		goto bad_fork_cleanup_security;
	/* copy all the process information */
	if ((retval = copy_semundo(clone_flags, p)))
		goto bad_fork_cleanup_audit;
	if ((retval = copy_files(clone_flags, p)))
		goto bad_fork_cleanup_semundo;
	if ((retval = copy_fs(clone_flags, p)))
		goto bad_fork_cleanup_files;
	if ((retval = copy_sighand(clone_flags, p)))
		goto bad_fork_cleanup_fs;
	if ((retval = copy_signal(clone_flags, p)))
		goto bad_fork_cleanup_sighand;
	if ((retval = copy_mm(clone_flags, p)))
		goto bad_fork_cleanup_signal;
	if ((retval = copy_keys(clone_flags, p)))
		goto bad_fork_cleanup_mm;
	if ((retval = copy_namespaces(clone_flags, p)))
		goto bad_fork_cleanup_keys;
	retval = copy_thread(0, clone_flags, stack_start, stack_size, p, regs);
	if (retval)
		goto bad_fork_cleanup_namespaces;

	p->set_child_tid = (clone_flags & CLONE_CHILD_SETTID) ? child_tidptr : NULL;
	/*
	 * Clear TID on mm_release()?
	 */
	p->clear_child_tid = (clone_flags & CLONE_CHILD_CLEARTID) ? child_tidptr: NULL;
	p->robust_list = NULL;
#ifdef CONFIG_COMPAT
	p->compat_robust_list = NULL;
#endif
	INIT_LIST_HEAD(&p->pi_state_list);
	p->pi_state_cache = NULL;

	/*
	 * sigaltstack should be cleared when sharing the same VM
	 */
	if ((clone_flags & (CLONE_VM|CLONE_VFORK)) == CLONE_VM)
		p->sas_ss_sp = p->sas_ss_size = 0;

	/*
	 * Syscall tracing should be turned off in the child regardless
	 * of CLONE_PTRACE.
	 */
	clear_tsk_thread_flag(p, TIF_SYSCALL_TRACE);
#ifdef TIF_SYSCALL_EMU
	clear_tsk_thread_flag(p, TIF_SYSCALL_EMU);
#endif

	/* Our parent execution domain becomes current domain
	   These must match for thread signalling to apply */
	p->parent_exec_id = p->self_exec_id;

	/* ok, now we should be set up.. */
	p->exit_signal = (clone_flags & CLONE_THREAD) ? -1 : (clone_flags & CSIGNAL);
	p->pdeath_signal = 0;
	p->exit_state = 0;

	/*
	 * Ok, make it visible to the rest of the system.
	 * We dont wake it up yet.
	 */
	p->group_leader = p;
	INIT_LIST_HEAD(&p->thread_group);
	INIT_LIST_HEAD(&p->ptrace_children);
	INIT_LIST_HEAD(&p->ptrace_list);

	/* Perform scheduler related setup. Assign this task to a CPU. */
	sched_fork(p, clone_flags);

	/* Need tasklist lock for parent etc handling! */
	write_lock_irq(&tasklist_lock);

	/* for sys_ioprio_set(IOPRIO_WHO_PGRP) */
	p->ioprio = current->ioprio;

	/*
	 * The task hasn't been attached yet, so its cpus_allowed mask will
	 * not be changed, nor will its assigned CPU.
	 *
	 * The cpus_allowed mask of the parent may have changed after it was
	 * copied first time - so re-copy it here, then check the child's CPU
	 * to ensure it is on a valid CPU (and if not, just force it back to
	 * parent's CPU). This avoids alot of nasty races.
	 */
	p->cpus_allowed = current->cpus_allowed;
	if (unlikely(!cpu_isset(task_cpu(p), p->cpus_allowed) ||
			!cpu_online(task_cpu(p))))
		set_task_cpu(p, smp_processor_id());

	/* CLONE_PARENT re-uses the old parent */
	if (clone_flags & (CLONE_PARENT|CLONE_THREAD))
		p->real_parent = current->real_parent;
	else
		p->real_parent = current;
	p->parent = p->real_parent;

	spin_lock(&current->sighand->siglock);

	/*
	 * Process group and session signals need to be delivered to just the
	 * parent before the fork or both the parent and the child after the
	 * fork. Restart if a signal comes in before we add the new process to
	 * it's process group.
	 * A fatal signal pending means that current will exit, so the new
	 * thread can't slip out of an OOM kill (or normal SIGKILL).
 	 */
 	recalc_sigpending();
	if (signal_pending(current)) {
		spin_unlock(&current->sighand->siglock);
		write_unlock_irq(&tasklist_lock);
		retval = -ERESTARTNOINTR;
		goto bad_fork_cleanup_namespaces;
	}

	if (clone_flags & CLONE_THREAD) {
		p->group_leader = current->group_leader;
		list_add_tail_rcu(&p->thread_group, &p->group_leader->thread_group);

		if (!cputime_eq(current->signal->it_virt_expires,
				cputime_zero) ||
		    !cputime_eq(current->signal->it_prof_expires,
				cputime_zero) ||
		    current->signal->rlim[RLIMIT_CPU].rlim_cur != RLIM_INFINITY ||
		    !list_empty(&current->signal->cpu_timers[0]) ||
		    !list_empty(&current->signal->cpu_timers[1]) ||
		    !list_empty(&current->signal->cpu_timers[2])) {
			/*
			 * Have child wake up on its first tick to check
			 * for process CPU timers.
			 */
			p->it_prof_expires = jiffies_to_cputime(1);
		}
	}

	if (likely(p->pid)) {
		add_parent(p);
		if (unlikely(p->ptrace & PT_PTRACED))
			__ptrace_link(p, current->parent);

		if (thread_group_leader(p)) {
			p->signal->tty = current->signal->tty;
			p->signal->pgrp = process_group(current);
			set_signal_session(p->signal, process_session(current));
			attach_pid(p, PIDTYPE_PGID, task_pgrp(current));
			attach_pid(p, PIDTYPE_SID, task_session(current));

			list_add_tail_rcu(&p->tasks, &init_task.tasks);
			__get_cpu_var(process_counts)++;
		}
		attach_pid(p, PIDTYPE_PID, pid);
		nr_threads++;
	}

	total_forks++;
	spin_unlock(&current->sighand->siglock);
	write_unlock_irq(&tasklist_lock);
	proc_fork_connector(p);
	return p;

bad_fork_cleanup_namespaces:
	exit_task_namespaces(p);
bad_fork_cleanup_keys:
	exit_keys(p);
bad_fork_cleanup_mm:
	if (p->mm)
		mmput(p->mm);
bad_fork_cleanup_signal:
	cleanup_signal(p);
bad_fork_cleanup_sighand:
	__cleanup_sighand(p->sighand);
bad_fork_cleanup_fs:
	exit_fs(p); /* blocking */
bad_fork_cleanup_files:
	exit_files(p); /* blocking */
bad_fork_cleanup_semundo:
	exit_sem(p);
bad_fork_cleanup_audit:
	audit_free(p);
bad_fork_cleanup_security:
	security_task_free(p);
bad_fork_cleanup_policy:
#ifdef CONFIG_NUMA
	mpol_free(p->mempolicy);
bad_fork_cleanup_cpuset:
#endif
	cpuset_exit(p);
bad_fork_cleanup_delays_binfmt:
	delayacct_tsk_free(p);
	if (p->binfmt)
		module_put(p->binfmt->module);
bad_fork_cleanup_put_domain:
	module_put(task_thread_info(p)->exec_domain->module);
bad_fork_cleanup_count:
	put_group_info(p->group_info);
	atomic_dec(&p->user->processes);
	free_uid(p->user);
bad_fork_free:
	free_task(p);
fork_out:
	return ERR_PTR(retval);
}
示例#26
0
/*
 * This creates a new process as a copy of the old one,
 * but does not actually start it yet.
 *
 * It copies the registers, and all the appropriate
 * parts of the process environment (as per the clone
 * flags). The actual kick-off is left to the caller.
 */
static struct task_struct *copy_process(unsigned long clone_flags,
					unsigned long stack_start,
					struct pt_regs *regs,
					unsigned long stack_size,
					int __user *child_tidptr,
					struct pid *pid,
					int trace)
{
	int retval;
	struct task_struct *p;
	int cgroup_callbacks_done = 0;

	if ((clone_flags & (CLONE_NEWNS|CLONE_FS)) == (CLONE_NEWNS|CLONE_FS))
		return ERR_PTR(-EINVAL);

	/*
	 * Thread groups must share signals as well, and detached threads
	 * can only be started up within the thread group.
	 */
	if ((clone_flags & CLONE_THREAD) && !(clone_flags & CLONE_SIGHAND))
		return ERR_PTR(-EINVAL);

	/*
	 * Shared signal handlers imply shared VM. By way of the above,
	 * thread groups also imply shared VM. Blocking this case allows
	 * for various simplifications in other code.
	 */
	if ((clone_flags & CLONE_SIGHAND) && !(clone_flags & CLONE_VM))
		return ERR_PTR(-EINVAL);

	retval = security_task_create(clone_flags);
	if (retval)
		goto fork_out;

	retval = -ENOMEM;
	p = dup_task_struct(current);
	if (!p)
		goto fork_out;

	rt_mutex_init_task(p);

#ifdef CONFIG_PROVE_LOCKING
	DEBUG_LOCKS_WARN_ON(!p->hardirqs_enabled);
	DEBUG_LOCKS_WARN_ON(!p->softirqs_enabled);
#endif
	retval = -EAGAIN;
	if (atomic_read(&p->real_cred->user->processes) >=
			p->signal->rlim[RLIMIT_NPROC].rlim_cur) {
		if (!capable(CAP_SYS_ADMIN) && !capable(CAP_SYS_RESOURCE) &&
		    p->real_cred->user != INIT_USER)
			goto bad_fork_free;
	}

	retval = copy_creds(p, clone_flags);
	if (retval < 0)
		goto bad_fork_free;

	/*
	 * If multiple threads are within copy_process(), then this check
	 * triggers too late. This doesn't hurt, the check is only there
	 * to stop root fork bombs.
	 */
	retval = -EAGAIN;
	if (nr_threads >= max_threads)
		goto bad_fork_cleanup_count;

	if (!try_module_get(task_thread_info(p)->exec_domain->module))
		goto bad_fork_cleanup_count;

	if (p->binfmt && !try_module_get(p->binfmt->module))
		goto bad_fork_cleanup_put_domain;

	p->did_exec = 0;
	delayacct_tsk_init(p);	/* Must remain after dup_task_struct() */
	copy_flags(clone_flags, p);
	INIT_LIST_HEAD(&p->children);
	INIT_LIST_HEAD(&p->sibling);
#ifdef CONFIG_PREEMPT_RCU
	p->rcu_read_lock_nesting = 0;
	p->rcu_flipctr_idx = 0;
#endif /* #ifdef CONFIG_PREEMPT_RCU */
	p->vfork_done = NULL;
	spin_lock_init(&p->alloc_lock);

	clear_tsk_thread_flag(p, TIF_SIGPENDING);
	init_sigpending(&p->pending);

	p->utime = cputime_zero;
	p->stime = cputime_zero;
	p->gtime = cputime_zero;
	p->utimescaled = cputime_zero;
	p->stimescaled = cputime_zero;
	p->prev_utime = cputime_zero;
	p->prev_stime = cputime_zero;

	p->default_timer_slack_ns = current->timer_slack_ns;

#ifdef CONFIG_DETECT_SOFTLOCKUP
	p->last_switch_count = 0;
	p->last_switch_timestamp = 0;
#endif

	task_io_accounting_init(&p->ioac);
	acct_clear_integrals(p);

	posix_cpu_timers_init(p);

	p->lock_depth = -1;		/* -1 = no lock */
	do_posix_clock_monotonic_gettime(&p->start_time);
	p->real_start_time = p->start_time;
	monotonic_to_bootbased(&p->real_start_time);
	p->io_context = NULL;
	p->audit_context = NULL;
	cgroup_fork(p);
#ifdef CONFIG_NUMA
	p->mempolicy = mpol_dup(p->mempolicy);
 	if (IS_ERR(p->mempolicy)) {
 		retval = PTR_ERR(p->mempolicy);
 		p->mempolicy = NULL;
 		goto bad_fork_cleanup_cgroup;
 	}
	mpol_fix_fork_child_flag(p);
#endif
#ifdef CONFIG_TRACE_IRQFLAGS
	p->irq_events = 0;
#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
	p->hardirqs_enabled = 1;
#else
	p->hardirqs_enabled = 0;
#endif
	p->hardirq_enable_ip = 0;
	p->hardirq_enable_event = 0;
	p->hardirq_disable_ip = _THIS_IP_;
	p->hardirq_disable_event = 0;
	p->softirqs_enabled = 1;
	p->softirq_enable_ip = _THIS_IP_;
	p->softirq_enable_event = 0;
	p->softirq_disable_ip = 0;
	p->softirq_disable_event = 0;
	p->hardirq_context = 0;
	p->softirq_context = 0;
#endif
#ifdef CONFIG_LOCKDEP
	p->lockdep_depth = 0; /* no locks held yet */
	p->curr_chain_key = 0;
	p->lockdep_recursion = 0;
#endif

#ifdef CONFIG_DEBUG_MUTEXES
	p->blocked_on = NULL; /* not blocked yet */
#endif
	if (unlikely(current->ptrace))
		ptrace_fork(p, clone_flags);

	/* Perform scheduler related setup. Assign this task to a CPU. */
	sched_fork(p, clone_flags);

	if ((retval = audit_alloc(p)))
		goto bad_fork_cleanup_policy;
	/* copy all the process information */
	if ((retval = copy_semundo(clone_flags, p)))
		goto bad_fork_cleanup_audit;
	if ((retval = copy_files(clone_flags, p)))
		goto bad_fork_cleanup_semundo;
	if ((retval = copy_fs(clone_flags, p)))
		goto bad_fork_cleanup_files;
	if ((retval = copy_sighand(clone_flags, p)))
		goto bad_fork_cleanup_fs;
	if ((retval = copy_signal(clone_flags, p)))
		goto bad_fork_cleanup_sighand;
	if ((retval = copy_mm(clone_flags, p)))
		goto bad_fork_cleanup_signal;
	if ((retval = copy_namespaces(clone_flags, p)))
		goto bad_fork_cleanup_mm;
	if ((retval = copy_io(clone_flags, p)))
		goto bad_fork_cleanup_namespaces;
	retval = copy_thread(clone_flags, stack_start, stack_size, p, regs);
	if (retval)
		goto bad_fork_cleanup_io;

	if (pid != &init_struct_pid) {
		retval = -ENOMEM;
		pid = alloc_pid(p->nsproxy->pid_ns);
		if (!pid)
			goto bad_fork_cleanup_io;

		if (clone_flags & CLONE_NEWPID) {
			retval = pid_ns_prepare_proc(p->nsproxy->pid_ns);
			if (retval < 0)
				goto bad_fork_free_pid;
		}
	}

	ftrace_graph_init_task(p);

	p->pid = pid_nr(pid);
	p->tgid = p->pid;
	if (clone_flags & CLONE_THREAD)
		p->tgid = current->tgid;

	if (current->nsproxy != p->nsproxy) {
		retval = ns_cgroup_clone(p, pid);
		if (retval)
			goto bad_fork_free_graph;
	}

	p->set_child_tid = (clone_flags & CLONE_CHILD_SETTID) ? child_tidptr : NULL;
	/*
	 * Clear TID on mm_release()?
	 */
	p->clear_child_tid = (clone_flags & CLONE_CHILD_CLEARTID) ? child_tidptr: NULL;
#ifdef CONFIG_FUTEX
	p->robust_list = NULL;
#ifdef CONFIG_COMPAT
	p->compat_robust_list = NULL;
#endif
	INIT_LIST_HEAD(&p->pi_state_list);
	p->pi_state_cache = NULL;
#endif
	/*
	 * sigaltstack should be cleared when sharing the same VM
	 */
	if ((clone_flags & (CLONE_VM|CLONE_VFORK)) == CLONE_VM)
		p->sas_ss_sp = p->sas_ss_size = 0;

	/*
	 * Syscall tracing should be turned off in the child regardless
	 * of CLONE_PTRACE.
	 */
	clear_tsk_thread_flag(p, TIF_SYSCALL_TRACE);
#ifdef TIF_SYSCALL_EMU
	clear_tsk_thread_flag(p, TIF_SYSCALL_EMU);
#endif
	clear_all_latency_tracing(p);

	/* ok, now we should be set up.. */
	p->exit_signal = (clone_flags & CLONE_THREAD) ? -1 : (clone_flags & CSIGNAL);
	p->pdeath_signal = 0;
	p->exit_state = 0;

	/*
	 * Ok, make it visible to the rest of the system.
	 * We dont wake it up yet.
	 */
	p->group_leader = p;
	INIT_LIST_HEAD(&p->thread_group);

	/* Now that the task is set up, run cgroup callbacks if
	 * necessary. We need to run them before the task is visible
	 * on the tasklist. */
	cgroup_fork_callbacks(p);
	cgroup_callbacks_done = 1;

	/* Need tasklist lock for parent etc handling! */
	write_lock_irq(&tasklist_lock);

	/*
	 * The task hasn't been attached yet, so its cpus_allowed mask will
	 * not be changed, nor will its assigned CPU.
	 *
	 * The cpus_allowed mask of the parent may have changed after it was
	 * copied first time - so re-copy it here, then check the child's CPU
	 * to ensure it is on a valid CPU (and if not, just force it back to
	 * parent's CPU). This avoids alot of nasty races.
	 */
	p->cpus_allowed = current->cpus_allowed;
	p->rt.nr_cpus_allowed = current->rt.nr_cpus_allowed;
	if (unlikely(!cpu_isset(task_cpu(p), p->cpus_allowed) ||
			!cpu_online(task_cpu(p))))
		set_task_cpu(p, smp_processor_id());

	/* CLONE_PARENT re-uses the old parent */
	if (clone_flags & (CLONE_PARENT|CLONE_THREAD)) {
		p->real_parent = current->real_parent;
		p->parent_exec_id = current->parent_exec_id;
	} else {
		p->real_parent = current;
		p->parent_exec_id = current->self_exec_id;
	}

	spin_lock(&current->sighand->siglock);

	/*
	 * Process group and session signals need to be delivered to just the
	 * parent before the fork or both the parent and the child after the
	 * fork. Restart if a signal comes in before we add the new process to
	 * it's process group.
	 * A fatal signal pending means that current will exit, so the new
	 * thread can't slip out of an OOM kill (or normal SIGKILL).
 	 */
	recalc_sigpending();
	if (signal_pending(current)) {
		spin_unlock(&current->sighand->siglock);
		write_unlock_irq(&tasklist_lock);
		retval = -ERESTARTNOINTR;
		goto bad_fork_free_graph;
	}

	if (clone_flags & CLONE_THREAD) {
		p->group_leader = current->group_leader;
		list_add_tail_rcu(&p->thread_group, &p->group_leader->thread_group);
	}

	if (likely(p->pid)) {
		list_add_tail(&p->sibling, &p->real_parent->children);
		tracehook_finish_clone(p, clone_flags, trace);

		if (thread_group_leader(p)) {
			if (clone_flags & CLONE_NEWPID)
				p->nsproxy->pid_ns->child_reaper = p;

			p->signal->leader_pid = pid;
			tty_kref_put(p->signal->tty);
			p->signal->tty = tty_kref_get(current->signal->tty);
			attach_pid(p, PIDTYPE_PGID, task_pgrp(current));
			attach_pid(p, PIDTYPE_SID, task_session(current));
			list_add_tail_rcu(&p->tasks, &init_task.tasks);
			__get_cpu_var(process_counts)++;
		}
		attach_pid(p, PIDTYPE_PID, pid);
		nr_threads++;
	}

#ifdef CONFIG_LTT_LITE
	ltt_lite_ev_process(LTT_LITE_EV_PROCESS_FORK, p);
#endif

	total_forks++;
	spin_unlock(&current->sighand->siglock);
	write_unlock_irq(&tasklist_lock);
	proc_fork_connector(p);
	cgroup_post_fork(p);
	return p;

bad_fork_free_graph:
	ftrace_graph_exit_task(p);
bad_fork_free_pid:
	if (pid != &init_struct_pid)
		free_pid(pid);
bad_fork_cleanup_io:
	put_io_context(p->io_context);
bad_fork_cleanup_namespaces:
	exit_task_namespaces(p);
bad_fork_cleanup_mm:
	if (p->mm)
		mmput(p->mm);
bad_fork_cleanup_signal:
	cleanup_signal(p);
bad_fork_cleanup_sighand:
	__cleanup_sighand(p->sighand);
bad_fork_cleanup_fs:
	exit_fs(p); /* blocking */
bad_fork_cleanup_files:
	exit_files(p); /* blocking */
bad_fork_cleanup_semundo:
	exit_sem(p);
bad_fork_cleanup_audit:
	audit_free(p);
bad_fork_cleanup_policy:
#ifdef CONFIG_NUMA
	mpol_put(p->mempolicy);
bad_fork_cleanup_cgroup:
#endif
	cgroup_exit(p, cgroup_callbacks_done);
	delayacct_tsk_free(p);
	if (p->binfmt)
		module_put(p->binfmt->module);
bad_fork_cleanup_put_domain:
	module_put(task_thread_info(p)->exec_domain->module);
bad_fork_cleanup_count:
	atomic_dec(&p->cred->user->processes);
	put_cred(p->real_cred);
	put_cred(p->cred);
bad_fork_free:
	free_task(p);
fork_out:
	return ERR_PTR(retval);
}
/*
 * This creates a new process as a copy of the old one,
 * but does not actually start it yet.
 *
 * It copies the registers, and all the appropriate
 * parts of the process environment (as per the clone
 * flags). The actual kick-off is left to the caller.
 */
static struct task_struct *copy_process(unsigned long clone_flags,
                                        unsigned long stack_start,
                                        struct pt_regs *regs,
                                        unsigned long stack_size,
                                        int __user *child_tidptr,
                                        struct pid *pid,
                                        int trace)
{
    int retval;
    struct task_struct *p;

    if ((clone_flags & (CLONE_NEWNS|CLONE_FS)) == (CLONE_NEWNS|CLONE_FS))
        return ERR_PTR(-EINVAL);

    /*
     * Thread groups must share signals as well, and detached threads
     * can only be started up within the thread group.
     */
    if ((clone_flags & CLONE_THREAD) && !(clone_flags & CLONE_SIGHAND))
        return ERR_PTR(-EINVAL);

    /*
     * Shared signal handlers imply shared VM. By way of the above,
     * thread groups also imply shared VM. Blocking this case allows
     * for various simplifications in other code.
     */
    if ((clone_flags & CLONE_SIGHAND) && !(clone_flags & CLONE_VM))
        return ERR_PTR(-EINVAL);

    /*
     * Siblings of global init remain as zombies on exit since they are
     * not reaped by their parent (swapper). To solve this and to avoid
     * multi-rooted process trees, prevent global and container-inits
     * from creating siblings.
     */
    if ((clone_flags & CLONE_PARENT) &&
            current->signal->flags & SIGNAL_UNKILLABLE)
        return ERR_PTR(-EINVAL);

    retval = security_task_create(clone_flags);
    if (retval)
        goto fork_out;

    retval = -ENOMEM;
    p = dup_task_struct(current);
    if (!p)
        goto fork_out;

    ftrace_graph_init_task(p);

    rt_mutex_init_task(p);

#ifdef CONFIG_PROVE_LOCKING
    DEBUG_LOCKS_WARN_ON(!p->hardirqs_enabled);
    DEBUG_LOCKS_WARN_ON(!p->softirqs_enabled);
#endif
    retval = -EAGAIN;
    if (atomic_read(&p->real_cred->user->processes) >=
            task_rlimit(p, RLIMIT_NPROC)) {
        if (!capable(CAP_SYS_ADMIN) && !capable(CAP_SYS_RESOURCE) &&
                p->real_cred->user != INIT_USER)
            goto bad_fork_free;
    }
    current->flags &= ~PF_NPROC_EXCEEDED;

    retval = copy_creds(p, clone_flags);
    if (retval < 0)
        goto bad_fork_free;

    /*
     * If multiple threads are within copy_process(), then this check
     * triggers too late. This doesn't hurt, the check is only there
     * to stop root fork bombs.
     */
    retval = -EAGAIN;
    if (nr_threads >= max_threads)
        goto bad_fork_cleanup_count;

    if (!try_module_get(task_thread_info(p)->exec_domain->module))
        goto bad_fork_cleanup_count;

    p->did_exec = 0;
    delayacct_tsk_init(p);	/* Must remain after dup_task_struct() */
    copy_flags(clone_flags, p);
    INIT_LIST_HEAD(&p->children);
    INIT_LIST_HEAD(&p->sibling);
    rcu_copy_process(p);
    p->vfork_done = NULL;
    spin_lock_init(&p->alloc_lock);

    init_sigpending(&p->pending);

    p->utime = p->stime = p->gtime = 0;
    p->utimescaled = p->stimescaled = 0;
#ifndef CONFIG_VIRT_CPU_ACCOUNTING
    p->prev_utime = p->prev_stime = 0;
#endif
#if defined(SPLIT_RSS_COUNTING)
    memset(&p->rss_stat, 0, sizeof(p->rss_stat));
#endif

    p->default_timer_slack_ns = current->timer_slack_ns;

    task_io_accounting_init(&p->ioac);
    acct_clear_integrals(p);

    posix_cpu_timers_init(p);

    do_posix_clock_monotonic_gettime(&p->start_time);
    p->real_start_time = p->start_time;
    monotonic_to_bootbased(&p->real_start_time);
    p->io_context = NULL;
    p->audit_context = NULL;
    if (clone_flags & CLONE_THREAD)
        threadgroup_change_begin(current);
    cgroup_fork(p);
#ifdef CONFIG_NUMA
    p->mempolicy = mpol_dup(p->mempolicy);
    if (IS_ERR(p->mempolicy)) {
        retval = PTR_ERR(p->mempolicy);
        p->mempolicy = NULL;
        goto bad_fork_cleanup_cgroup;
    }
    mpol_fix_fork_child_flag(p);
#endif
#ifdef CONFIG_CPUSETS
    p->cpuset_mem_spread_rotor = NUMA_NO_NODE;
    p->cpuset_slab_spread_rotor = NUMA_NO_NODE;
    seqcount_init(&p->mems_allowed_seq);
#endif
#ifdef CONFIG_TRACE_IRQFLAGS
    p->irq_events = 0;
#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
    p->hardirqs_enabled = 1;
#else
    p->hardirqs_enabled = 0;
#endif
    p->hardirq_enable_ip = 0;
    p->hardirq_enable_event = 0;
    p->hardirq_disable_ip = _THIS_IP_;
    p->hardirq_disable_event = 0;
    p->softirqs_enabled = 1;
    p->softirq_enable_ip = _THIS_IP_;
    p->softirq_enable_event = 0;
    p->softirq_disable_ip = 0;
    p->softirq_disable_event = 0;
    p->hardirq_context = 0;
    p->softirq_context = 0;
#endif
#ifdef CONFIG_LOCKDEP
    p->lockdep_depth = 0; /* no locks held yet */
    p->curr_chain_key = 0;
    p->lockdep_recursion = 0;
#endif

#ifdef CONFIG_DEBUG_MUTEXES
    p->blocked_on = NULL; /* not blocked yet */
#endif
#ifdef CONFIG_CGROUP_MEM_RES_CTLR
    p->memcg_batch.do_batch = 0;
    p->memcg_batch.memcg = NULL;
#endif

    /* Perform scheduler related setup. Assign this task to a CPU. */
    sched_fork(p);

    retval = perf_event_init_task(p);
    if (retval)
        goto bad_fork_cleanup_policy;
    retval = audit_alloc(p);
    if (retval)
        goto bad_fork_cleanup_perf;
    /* copy all the process information */
    retval = copy_semundo(clone_flags, p);
    if (retval)
        goto bad_fork_cleanup_audit;
    retval = copy_files(clone_flags, p);
    if (retval)
        goto bad_fork_cleanup_semundo;
    retval = copy_fs(clone_flags, p);
    if (retval)
        goto bad_fork_cleanup_files;
    retval = copy_sighand(clone_flags, p);
    if (retval)
        goto bad_fork_cleanup_fs;
    retval = copy_signal(clone_flags, p);
    if (retval)
        goto bad_fork_cleanup_sighand;
    retval = copy_mm(clone_flags, p);
    if (retval)
        goto bad_fork_cleanup_signal;
    retval = copy_namespaces(clone_flags, p);
    if (retval)
        goto bad_fork_cleanup_mm;
    retval = copy_io(clone_flags, p);
    if (retval)
        goto bad_fork_cleanup_namespaces;
    retval = copy_thread(clone_flags, stack_start, stack_size, p, regs);
    if (retval)
        goto bad_fork_cleanup_io;

    if (pid != &init_struct_pid) {
        retval = -ENOMEM;
        pid = alloc_pid(p->nsproxy->pid_ns);
        if (!pid)
            goto bad_fork_cleanup_io;
    }

    p->pid = pid_nr(pid);
    p->tgid = p->pid;
    if (clone_flags & CLONE_THREAD)
        p->tgid = current->tgid;

    p->set_child_tid = (clone_flags & CLONE_CHILD_SETTID) ? child_tidptr : NULL;
    /*
     * Clear TID on mm_release()?
     */
    p->clear_child_tid = (clone_flags & CLONE_CHILD_CLEARTID) ? child_tidptr : NULL;
#ifdef CONFIG_BLOCK
    p->plug = NULL;
#endif
#ifdef CONFIG_FUTEX
    p->robust_list = NULL;
#ifdef CONFIG_COMPAT
    p->compat_robust_list = NULL;
#endif
    INIT_LIST_HEAD(&p->pi_state_list);
    p->pi_state_cache = NULL;
#endif
    /*
     * sigaltstack should be cleared when sharing the same VM
     */
    if ((clone_flags & (CLONE_VM|CLONE_VFORK)) == CLONE_VM)
        p->sas_ss_sp = p->sas_ss_size = 0;

    /*
     * Syscall tracing and stepping should be turned off in the
     * child regardless of CLONE_PTRACE.
     */
    user_disable_single_step(p);
    clear_tsk_thread_flag(p, TIF_SYSCALL_TRACE);
#ifdef TIF_SYSCALL_EMU
    clear_tsk_thread_flag(p, TIF_SYSCALL_EMU);
#endif
    clear_all_latency_tracing(p);

    /* ok, now we should be set up.. */
    if (clone_flags & CLONE_THREAD)
        p->exit_signal = -1;
    else if (clone_flags & CLONE_PARENT)
        p->exit_signal = current->group_leader->exit_signal;
    else
        p->exit_signal = (clone_flags & CSIGNAL);

    p->pdeath_signal = 0;
    p->exit_state = 0;

    p->nr_dirtied = 0;
    p->nr_dirtied_pause = 128 >> (PAGE_SHIFT - 10);
    p->dirty_paused_when = 0;

    /*
     * Ok, make it visible to the rest of the system.
     * We dont wake it up yet.
     */
    p->group_leader = p;
    INIT_LIST_HEAD(&p->thread_group);

    /* Need tasklist lock for parent etc handling! */
    write_lock_irq(&tasklist_lock);

    /* CLONE_PARENT re-uses the old parent */
    if (clone_flags & (CLONE_PARENT|CLONE_THREAD)) {
        p->real_parent = current->real_parent;
        p->parent_exec_id = current->parent_exec_id;
    } else {
        p->real_parent = current;
        p->parent_exec_id = current->self_exec_id;
    }

    spin_lock(&current->sighand->siglock);

    /*
     * Process group and session signals need to be delivered to just the
     * parent before the fork or both the parent and the child after the
     * fork. Restart if a signal comes in before we add the new process to
     * it's process group.
     * A fatal signal pending means that current will exit, so the new
     * thread can't slip out of an OOM kill (or normal SIGKILL).
    */
    recalc_sigpending();
    if (signal_pending(current)) {
        spin_unlock(&current->sighand->siglock);
        write_unlock_irq(&tasklist_lock);
        retval = -ERESTARTNOINTR;
        goto bad_fork_free_pid;
    }

    if (likely(p->pid)) {
        ptrace_init_task(p, (clone_flags & CLONE_PTRACE) || trace);

        if (thread_group_leader(p)) {
            if (is_child_reaper(pid))
                p->nsproxy->pid_ns->child_reaper = p;

            p->signal->leader_pid = pid;
            p->signal->tty = tty_kref_get(current->signal->tty);
            attach_pid(p, PIDTYPE_PGID, task_pgrp(current));
            attach_pid(p, PIDTYPE_SID, task_session(current));
            list_add_tail(&p->sibling, &p->real_parent->children);
            list_add_tail_rcu(&p->tasks, &init_task.tasks);
            __this_cpu_inc(process_counts);
        } else {
            current->signal->nr_threads++;
            atomic_inc(&current->signal->live);
            atomic_inc(&current->signal->sigcnt);
            p->group_leader = current->group_leader;
            list_add_tail_rcu(&p->thread_group,
                              &p->group_leader->thread_group);
        }
        attach_pid(p, PIDTYPE_PID, pid);
        nr_threads++;
    }

    total_forks++;
    spin_unlock(&current->sighand->siglock);
    syscall_tracepoint_update(p);
    write_unlock_irq(&tasklist_lock);

    proc_fork_connector(p);
    cgroup_post_fork(p);
    if (clone_flags & CLONE_THREAD)
        threadgroup_change_end(current);
    perf_event_fork(p);

    trace_task_newtask(p, clone_flags);

    return p;

bad_fork_free_pid:
    if (pid != &init_struct_pid)
        free_pid(pid);
bad_fork_cleanup_io:
    if (p->io_context)
        exit_io_context(p);
bad_fork_cleanup_namespaces:
    if (unlikely(clone_flags & CLONE_NEWPID))
        pid_ns_release_proc(p->nsproxy->pid_ns);
    exit_task_namespaces(p);
bad_fork_cleanup_mm:
    if (p->mm)
        mmput(p->mm);
bad_fork_cleanup_signal:
    if (!(clone_flags & CLONE_THREAD))
        free_signal_struct(p->signal);
bad_fork_cleanup_sighand:
    __cleanup_sighand(p->sighand);
bad_fork_cleanup_fs:
    exit_fs(p); /* blocking */
bad_fork_cleanup_files:
    exit_files(p); /* blocking */
bad_fork_cleanup_semundo:
    exit_sem(p);
bad_fork_cleanup_audit:
    audit_free(p);
bad_fork_cleanup_perf:
    perf_event_free_task(p);
bad_fork_cleanup_policy:
#ifdef CONFIG_NUMA
    mpol_put(p->mempolicy);
bad_fork_cleanup_cgroup:
#endif
    if (clone_flags & CLONE_THREAD)
        threadgroup_change_end(current);
    cgroup_exit(p, 0);
    delayacct_tsk_free(p);
    module_put(task_thread_info(p)->exec_domain->module);
bad_fork_cleanup_count:
    atomic_dec(&p->cred->user->processes);
    exit_creds(p);
bad_fork_free:
    free_task(p);
fork_out:
    return ERR_PTR(retval);
}
示例#28
0
/*
 * This creates a new process as a copy of the old one,
 * but does not actually start it yet.
 *
 * It copies the registers, and all the appropriate
 * parts of the process environment (as per the clone
 * flags).  The actual kick-off is left to the caller.
 */
struct task_struct *copy_process(unsigned long clone_flags,
			         unsigned long stack_start,
			         struct pt_regs *regs,
			         unsigned long stack_size,
			         int *parent_tidptr,
			         int *child_tidptr)
{
	int retval;
	struct task_struct *p = NULL;

	if ((clone_flags & (CLONE_NEWNS|CLONE_FS)) == (CLONE_NEWNS|CLONE_FS))
		return ERR_PTR(-EINVAL);

	/*
	 * Thread groups must share signals as well, and detached threads
	 * can only be started up within the thread group.
	 */
	if ((clone_flags & CLONE_THREAD) && !(clone_flags & CLONE_SIGHAND))
		return ERR_PTR(-EINVAL);
	if ((clone_flags & CLONE_DETACHED) && !(clone_flags & CLONE_THREAD))
		return ERR_PTR(-EINVAL);
	if (!(clone_flags & CLONE_DETACHED) && (clone_flags & CLONE_THREAD))
		return ERR_PTR(-EINVAL);

	retval = -ENOMEM;
	p = dup_task_struct(current);
	if (!p)
		goto fork_out;

	p->tux_info = NULL;

	retval = -EAGAIN;

	/*
	 * Increment user->__count before the rlimit test so that it would
	 * be correct if we take the bad_fork_free failure path.
	 */
	atomic_inc(&p->user->__count);
	if (atomic_read(&p->user->processes) >= p->rlim[RLIMIT_NPROC].rlim_cur) {
		if (!capable(CAP_SYS_ADMIN) && !capable(CAP_SYS_RESOURCE))
			goto bad_fork_free;
	}

	atomic_inc(&p->user->processes);

	/*
	 * Counter increases are protected by
	 * the kernel lock so nr_threads can't
	 * increase under us (but it may decrease).
	 */
	if (nr_threads >= max_threads)
		goto bad_fork_cleanup_count;
	
	get_exec_domain(p->exec_domain);

	if (p->binfmt && p->binfmt->module)
		__MOD_INC_USE_COUNT(p->binfmt->module);

	p->did_exec = 0;
	p->swappable = 0;
	p->state = TASK_UNINTERRUPTIBLE;

	copy_flags(clone_flags, p);
	if (clone_flags & CLONE_IDLETASK)
		p->pid = 0;
	else {
		p->pid = alloc_pidmap();
		if (p->pid == -1)
			goto bad_fork_cleanup;
	}
	
	retval = -EFAULT;
	if (clone_flags & CLONE_PARENT_SETTID)
		if (put_user(p->pid, parent_tidptr))
			goto bad_fork_cleanup;

	INIT_LIST_HEAD(&p->run_list);

	INIT_LIST_HEAD(&p->children);
	INIT_LIST_HEAD(&p->sibling);
	init_waitqueue_head(&p->wait_chldexit);
	p->vfork_done = NULL;
	spin_lock_init(&p->alloc_lock);
	spin_lock_init(&p->switch_lock);

	p->sigpending = 0;
	init_sigpending(&p->pending);

	p->it_real_value = p->it_virt_value = p->it_prof_value = 0;
	p->it_real_incr = p->it_virt_incr = p->it_prof_incr = 0;
	init_timer(&p->real_timer);
	p->real_timer.data = (unsigned long) p;

	p->leader = 0;		/* session leadership doesn't inherit */
	p->tty_old_pgrp = 0;
	memset(&p->utime, 0, sizeof(p->utime));
	memset(&p->stime, 0, sizeof(p->stime));
	memset(&p->cutime, 0, sizeof(p->cutime));
	memset(&p->cstime, 0, sizeof(p->cstime));
	memset(&p->group_utime, 0, sizeof(p->group_utime));
	memset(&p->group_stime, 0, sizeof(p->group_stime));
	memset(&p->group_cutime, 0, sizeof(p->group_cutime));
	memset(&p->group_cstime, 0, sizeof(p->group_cstime));

#ifdef CONFIG_SMP
	memset(&p->per_cpu_utime, 0, sizeof(p->per_cpu_utime));
	memset(&p->per_cpu_stime, 0, sizeof(p->per_cpu_stime));
#endif

	memset(&p->timing_state, 0, sizeof(p->timing_state));
	p->timing_state.type = PROCESS_TIMING_USER;
	p->last_sigxcpu = 0;
	p->array = NULL;
	p->lock_depth = -1;		/* -1 = no lock */
	p->start_time = jiffies;

	retval = -ENOMEM;
	/* copy all the process information */
	if (copy_files(clone_flags, p))
		goto bad_fork_cleanup;
	if (copy_fs(clone_flags, p))
		goto bad_fork_cleanup_files;
	if (copy_sighand(clone_flags, p))
		goto bad_fork_cleanup_fs;
	if (copy_signal(clone_flags, p))
		goto bad_fork_cleanup_sighand;
	if (copy_mm(clone_flags, p))
		goto bad_fork_cleanup_signal;
	if (copy_namespace(clone_flags, p))
		goto bad_fork_cleanup_mm;
	retval = copy_thread(0, clone_flags, stack_start, stack_size, p, regs);
	if (retval)
		goto bad_fork_cleanup_namespace;
	p->semundo = NULL;

	p->set_child_tid = (clone_flags & CLONE_CHILD_SETTID)
		? child_tidptr : NULL;
	/*
	 * Clear TID on mm_release()?
	 */
	p->clear_child_tid = (clone_flags & CLONE_CHILD_CLEARTID)
		? child_tidptr : NULL;

	/* Our parent execution domain becomes current domain
	   These must match for thread signalling to apply */
	   
	p->parent_exec_id = p->self_exec_id;

	/* ok, now we should be set up.. */
	p->swappable = 1;
	if (clone_flags & CLONE_DETACHED)
		p->exit_signal = -1;
	else
		p->exit_signal = clone_flags & CSIGNAL;
	p->pdeath_signal = 0;

	/*
	 * Share the timeslice between parent and child, thus the
	 * total amount of pending timeslices in the system doesnt change,
	 * resulting in more scheduling fairness.
	 */
	local_irq_disable();
	p->time_slice = (current->time_slice + 1) >> 1;
	p->first_time_slice = 1;
	/*
	 * The remainder of the first timeslice might be recovered by
	 * the parent if the child exits early enough.
	 */
	current->time_slice >>= 1;
	p->last_run = jiffies;
	if (!current->time_slice) {
		/*
		 * This case is rare, it happens when the parent has only
		 * a single jiffy left from its timeslice. Taking the
		 * runqueue lock is not a problem.
		 */
		current->time_slice = 1;
		scheduler_tick(0 /* don't update the time stats */);
	}
	local_irq_enable();

	if ((int)current->time_slice <= 0)
		BUG();
	if ((int)p->time_slice <= 0)
		BUG();

	/*
	 * Ok, add it to the run-queues and make it
	 * visible to the rest of the system.
	 *
	 * Let it rip!
	 */
	p->tgid = p->pid;
	p->group_leader = p;
	INIT_LIST_HEAD(&p->ptrace_children);
	INIT_LIST_HEAD(&p->ptrace_list);

	/* Need tasklist lock for parent etc handling! */
	write_lock_irq(&tasklist_lock);
	/*
	 * Check for pending SIGKILL! The new thread should not be allowed
	 * to slip out of an OOM kill. (or normal SIGKILL.)
	 */
	if (sigismember(&current->pending.signal, SIGKILL)) {
		write_unlock_irq(&tasklist_lock);
		retval = -EINTR;
		goto bad_fork_cleanup_namespace;
	}

	/* CLONE_PARENT re-uses the old parent */
	if (clone_flags & (CLONE_PARENT|CLONE_THREAD))
		p->real_parent = current->real_parent;
	else
		p->real_parent = current;
	p->parent = p->real_parent;

	if (clone_flags & CLONE_THREAD) {
		spin_lock(&current->sighand->siglock);
		/*
		 * Important: if an exit-all has been started then
		 * do not create this new thread - the whole thread
		 * group is supposed to exit anyway.
		 */
		if (current->signal->group_exit) {
			spin_unlock(&current->sighand->siglock);
			write_unlock_irq(&tasklist_lock);
			retval = -EINTR;
			goto bad_fork_cleanup_namespace;
		}
		p->tgid = current->tgid;
		p->group_leader = current->group_leader;

		if (current->signal->group_stop_count > 0) {
			/*
			 * There is an all-stop in progress for the group.
			 * We ourselves will stop as soon as we check signals.
			 * Make the new thread part of that group stop too.
			 */
			current->signal->group_stop_count++;
			p->sigpending = 1;
		}

		spin_unlock(&current->sighand->siglock);
	}

	SET_LINKS(p);
	if (p->ptrace & PT_PTRACED)
		__ptrace_link(p, current->parent);

	attach_pid(p, PIDTYPE_PID, p->pid);
	if (thread_group_leader(p)) {
		attach_pid(p, PIDTYPE_TGID, p->tgid);
		attach_pid(p, PIDTYPE_PGID, p->pgrp);
		attach_pid(p, PIDTYPE_SID, p->session);
	} else {
		link_pid(p, p->pids + PIDTYPE_TGID,
			&p->group_leader->pids[PIDTYPE_TGID].pid);
	}

	/* clear controlling tty of new task if parent's was just cleared */
	if (!current->tty && p->tty)
		p->tty = NULL;

	nr_threads++;
	write_unlock_irq(&tasklist_lock);
	retval = 0;

fork_out:
	if (retval)
		return ERR_PTR(retval);
	return p;

bad_fork_cleanup_namespace:
	exit_namespace(p);
bad_fork_cleanup_mm:
	exit_mm(p);
	if (p->active_mm)
		mmdrop(p->active_mm);
bad_fork_cleanup_signal:
	exit_signal(p);
bad_fork_cleanup_sighand:
	exit_sighand(p);
bad_fork_cleanup_fs:
	exit_fs(p); /* blocking */
bad_fork_cleanup_files:
	exit_files(p); /* blocking */
bad_fork_cleanup:
	if (p->pid > 0)
		free_pidmap(p->pid);
	put_exec_domain(p->exec_domain);
	if (p->binfmt && p->binfmt->module)
		__MOD_DEC_USE_COUNT(p->binfmt->module);
bad_fork_cleanup_count:
	atomic_dec(&p->user->processes);
bad_fork_free:
	p->state = TASK_ZOMBIE; /* debug */
	atomic_dec(&p->usage);
	put_task_struct(p);
	goto fork_out;
}