common/syscall/tasksys.c

	tasksys.c revision ff19e029e81c950f4e0f40f1f1ee1f7d8f8d8041
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved.
 */


/*
 * System calls for creating and inquiring about tasks and projects
 */

#include <sys/param.h>
#include <sys/types.h>
#include <sys/errno.h>
#include <sys/thread.h>
#include <sys/proc.h>
#include <sys/task.h>
#include <sys/systm.h>
#include <sys/project.h>
#include <sys/cpuvar.h>
#include <sys/policy.h>
#include <sys/zone.h>
#include <sys/rctl.h>

/*
 * Limit projlist to 256k projects.
 */
#define MAX_PROJLIST_BUFSIZE        1048576

typedef struct projlist_walk {
    projid_t    *pw_buf;
    size_t      pw_bufsz;
} projlist_walk_t;

/*
 * taskid_t tasksys_settaskid(projid_t projid, uint_t flags);
 *
 * Overview
 *   Place the calling process in a new task if sufficiently privileged.  If the
 *   present task is finalized, the process may not create a new task.
 *
 * Return values
 *   0 on success, errno on failure.
 */
static long
tasksys_settaskid(projid_t projid, uint_t flags)
{
    proc_t *p = ttoproc(curthread);
    kproject_t *oldpj;
    kproject_t *kpj;
    task_t *tk, *oldtk;
    rctl_entity_p_t e;
    zone_t *zone;
    int rctlfail = 0;

    if (secpolicy_tasksys(CRED()) != 0)
        return (set_errno(EPERM));

    if (projid < 0 || projid > MAXPROJID)
        return (set_errno(EINVAL));

    if (flags & ~TASK_FINAL)
        return (set_errno(EINVAL));

    mutex_enter(&pidlock);
    if (p->p_task->tk_flags & TASK_FINAL) {
        mutex_exit(&pidlock);
        return (set_errno(EACCES));
    }
    mutex_exit(&pidlock);

    /*
     * Try to stop all other lwps in the process while we're changing
     * our project.  This way, curthread doesn't need to grab its own
     * thread_lock to find its project ID (see curprojid()).  If this
     * is the /proc agent lwp, we know that the other lwps are already
     * held.  If we failed to hold all lwps, bail out and return EINTR.
     */
    if (curthread != p->p_agenttp && !holdlwps(SHOLDFORK1))
        return (set_errno(EINTR));
    /*
     * Put a hold on our new project and make sure that nobody is
     * trying to bind it to a pool while we're joining.
     */
    kpj = project_hold_by_id(projid, p->p_zone, PROJECT_HOLD_INSERT);
    e.rcep_p.proj = kpj;
    e.rcep_t = RCENTITY_PROJECT;

    mutex_enter(&p->p_lock);
    oldpj = p->p_task->tk_proj;
    zone = p->p_zone;

    mutex_enter(&zone->zone_nlwps_lock);
    mutex_enter(&zone->zone_mem_lock);

    if (kpj->kpj_nlwps + p->p_lwpcnt > kpj->kpj_nlwps_ctl)
        if (rctl_test_entity(rc_project_nlwps, kpj->kpj_rctls, p, &e,
            p->p_lwpcnt, 0) & RCT_DENY)
            rctlfail = 1;

    if (kpj->kpj_ntasks + 1 > kpj->kpj_ntasks_ctl)
        if (rctl_test_entity(rc_project_ntasks, kpj->kpj_rctls, p, &e,
            1, 0) & RCT_DENY)
            rctlfail = 1;

    if (kpj != proj0p && kpj->kpj_nprocs + 1 > kpj->kpj_nprocs_ctl)
        if (rctl_test_entity(rc_project_nprocs, kpj->kpj_rctls, p, &e,
            1, 0) & RCT_DENY)
            rctlfail = 1;

    if (kpj->kpj_data.kpd_locked_mem + p->p_locked_mem >
        kpj->kpj_data.kpd_locked_mem_ctl)
        if (rctl_test_entity(rc_project_locked_mem, kpj->kpj_rctls, p,
            &e, p->p_locked_mem, 0) & RCT_DENY)
            rctlfail = 1;

    mutex_enter(&(kpj->kpj_data.kpd_crypto_lock));
    if (kpj->kpj_data.kpd_crypto_mem + p->p_crypto_mem >
        kpj->kpj_data.kpd_crypto_mem_ctl)
        if (rctl_test_entity(rc_project_crypto_mem, kpj->kpj_rctls, p,
            &e, p->p_crypto_mem, 0) & RCT_DENY)
            rctlfail = 1;

    if (rctlfail) {
        mutex_exit(&(kpj->kpj_data.kpd_crypto_lock));
        mutex_exit(&zone->zone_mem_lock);
        mutex_exit(&zone->zone_nlwps_lock);
        if (curthread != p->p_agenttp)
            continuelwps(p);
        mutex_exit(&p->p_lock);
        return (set_errno(EAGAIN));
    }
    kpj->kpj_data.kpd_crypto_mem += p->p_crypto_mem;
    mutex_exit(&(kpj->kpj_data.kpd_crypto_lock));
    kpj->kpj_data.kpd_locked_mem += p->p_locked_mem;
    kpj->kpj_nlwps += p->p_lwpcnt;
    kpj->kpj_ntasks++;
    kpj->kpj_nprocs++;

    oldpj->kpj_data.kpd_locked_mem -= p->p_locked_mem;
    mutex_enter(&(oldpj->kpj_data.kpd_crypto_lock));
    oldpj->kpj_data.kpd_crypto_mem -= p->p_crypto_mem;
    mutex_exit(&(oldpj->kpj_data.kpd_crypto_lock));
    oldpj->kpj_nlwps -= p->p_lwpcnt;
    oldpj->kpj_nprocs--;

    mutex_exit(&zone->zone_mem_lock);
    mutex_exit(&zone->zone_nlwps_lock);
    mutex_exit(&p->p_lock);

    mutex_enter(&kpj->kpj_poolbind);
    tk = task_create(projid, curproc->p_zone);
    mutex_enter(&cpu_lock);
    /*
     * Returns with p_lock held.
     */
    oldtk = task_join(tk, flags);
    if (curthread != p->p_agenttp)
        continuelwps(p);
    mutex_exit(&p->p_lock);
    mutex_exit(&cpu_lock);
    mutex_exit(&kpj->kpj_poolbind);
    task_rele(oldtk);
    project_rele(kpj);
    return (tk->tk_tkid);
}

/*
 * taskid_t tasksys_gettaskid(void);
 *
 * Overview
 *   Return the current task ID for this process.
 *
 * Return value
 *   The ID for the task to which the current process belongs.
 */
static long
tasksys_gettaskid()
{
    long ret;
    proc_t *p = ttoproc(curthread);

    mutex_enter(&pidlock);
    ret = p->p_task->tk_tkid;
    mutex_exit(&pidlock);
    return (ret);
}

/*
 * projid_t tasksys_getprojid(void);
 *
 * Overview
 *   Return the current project ID for this process.
 *
 * Return value
 *   The ID for the project to which the current process belongs.
 */
static long
tasksys_getprojid()
{
    long ret;
    proc_t *p = ttoproc(curthread);

    mutex_enter(&pidlock);
    ret = p->p_task->tk_proj->kpj_id;
    mutex_exit(&pidlock);
    return (ret);
}

static int
tasksys_projlist_cb(kproject_t *kp, void *buf)
{
    projlist_walk_t *pw = (projlist_walk_t *)buf;

    if (pw && pw->pw_bufsz >= sizeof (projid_t)) {
        *pw->pw_buf = kp->kpj_id;
        pw->pw_buf++;
        pw->pw_bufsz -= sizeof (projid_t);
    }

    return (0);
}

/*
 * long tasksys_projlist(void *buf, size_t bufsz)
 *
 * Overview
 *   Return a buffer containing the project IDs of all currently active projects
 *   in the current zone.
 *
 * Return values
 *   The minimum size of a buffer sufficiently large to contain all of the
 *   active project IDs, or -1 if an error occurs during copyout.
 */
static long
tasksys_projlist(void *buf, size_t bufsz)
{
    long ret = 0;
    projlist_walk_t pw;
    void *kbuf;

    if (buf == NULL || bufsz == 0)
        return (project_walk_all(getzoneid(), tasksys_projlist_cb,
            NULL));

    if (bufsz > MAX_PROJLIST_BUFSIZE)
        return (set_errno(ENOMEM));

    kbuf = pw.pw_buf = kmem_zalloc(bufsz, KM_SLEEP);
    pw.pw_bufsz = bufsz;

    ret = project_walk_all(getzoneid(), tasksys_projlist_cb, &pw);

    if (copyout(kbuf, buf, bufsz) == -1)
        ret = set_errno(EFAULT);

    kmem_free(kbuf, bufsz);
    return (ret);
}

long
tasksys(int code, projid_t projid, uint_t flags, void *projidbuf, size_t pbufsz)
{
    switch (code) {
    case 0:
        return (tasksys_settaskid(projid, flags));
    case 1:
        return (tasksys_gettaskid());
    case 2:
        return (tasksys_getprojid());
    case 3:
        return (tasksys_projlist(projidbuf, pbufsz));
    default:
        return (set_errno(EINVAL));
    }
}