/* $NetBSD: subr_evcnt.c,v 1.17 2021/04/17 00:05:31 mrg Exp $ */

/*
* Copyright (c) 1996, 2000 Christopher G. Demetriou
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
*    must display the following acknowledgement:
*          This product includes software developed for the
*          NetBSD Project.  See http://www.NetBSD.org/ for
*          information about NetBSD.
* 4. The name of the author may not be used to endorse or promote products
*    derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* --(license Id: LICENSE.proto,v 1.1 2000/06/13 21:40:26 cgd Exp )--
*/

/*
* Copyright (c) 1992, 1993
*      The Regents of the University of California.  All rights reserved.
*
* This software was developed by the Computer Systems Engineering group
* at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
* contributed to Berkeley.
*
* All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
*      This product includes software developed by the University of
*      California, Lawrence Berkeley Laboratories.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
*    may be used to endorse or promote products derived from this software
*    without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* from: Header: subr_autoconf.c,v 1.12 93/02/01 19:31:48 torek Exp  (LBL)
*
*      @(#)subr_autoconf.c     8.3 (Berkeley) 5/17/94
*/

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: subr_evcnt.c,v 1.17 2021/04/17 00:05:31 mrg Exp $");

#include <sys/param.h>
#include <sys/evcnt.h>
#include <sys/kmem.h>
#include <sys/mutex.h>
#include <sys/sysctl.h>
#include <sys/systm.h>

/*
* Everything related to __HAVE_LEGACY_INTRCNT can disappear once
* no more ports are using old-style intrcnt/intrnames interrupt
* accounting.  The follow files have __HAVE_LEGACY_INTRCNT code:
*
*   sys/kern/init_main.c
*   sys/kern/subr_evcnt.c
*   sys/sys/evcnt.h
*   sys/arch/<port>/include/types.h
*/
#ifdef _RUMPKERNEL
/* RUMP doesn't need/want to know about intrcnts */
#undef __HAVE_LEGACY_INTRCNT
#endif

#ifdef __HAVE_LEGACY_INTRCNT
static void evcnt_update_intrcnt(void);
#endif

/* list of all events */
struct evcntlist allevents = TAILQ_HEAD_INITIALIZER(allevents);
static kmutex_t evcnt_lock __cacheline_aligned;
static bool init_done;
static uint32_t evcnt_generation;

/*
* We need a dummy object to stuff into the evcnt link set to
* ensure that there always is at least one object in the set.
*/
static struct evcnt dummy_static_evcnt;
__link_set_add_bss(evcnts, dummy_static_evcnt);

/*
* Initialize event counters.  This does the attach procedure for
* each of the static event counters in the "evcnts" link set.
*/
void
evcnt_init(void)
{
       __link_set_decl(evcnts, struct evcnt);
       struct evcnt * const *evp;

       KASSERT(!init_done);

       mutex_init(&evcnt_lock, MUTEX_DEFAULT, IPL_NONE);

       init_done = true;

       __link_set_foreach(evp, evcnts) {
               if (*evp == &dummy_static_evcnt)
                       continue;
               evcnt_attach_static(*evp);
       }
}

/*
* Attach a statically-initialized event.  The type and string pointers
* are already set up.
*/
void
evcnt_attach_static(struct evcnt *ev)
{
       int len;

       KASSERTMSG(init_done,
           "%s: evcnt non initialized: group=<%s> name=<%s>",
           __func__, ev->ev_group, ev->ev_name);

       len = strlen(ev->ev_group);
#ifdef DIAGNOSTIC
       if (len == 0 || len >= EVCNT_STRING_MAX) /* ..._MAX includes NUL */
               panic("evcnt_attach_static: group length (%s)", ev->ev_group);
#endif
       ev->ev_grouplen = len;

       len = strlen(ev->ev_name);
#ifdef DIAGNOSTIC
       if (len == 0 || len >= EVCNT_STRING_MAX) /* ..._MAX includes NUL */
               panic("evcnt_attach_static: name length (%s)", ev->ev_name);
#endif
       ev->ev_namelen = len;

       mutex_enter(&evcnt_lock);
       TAILQ_INSERT_TAIL(&allevents, ev, ev_list);
       mutex_exit(&evcnt_lock);
}

/*
* Attach a dynamically-initialized event.  Zero it, set up the type
* and string pointers and then act like it was statically initialized.
*/
void
evcnt_attach_dynamic_nozero(struct evcnt *ev, int type,
   const struct evcnt *parent, const char *group, const char *name)
{

       ev->ev_type = type;
       ev->ev_parent = parent;
       ev->ev_group = group;
       ev->ev_name = name;
       evcnt_attach_static(ev);
}
/*
* Attach a dynamically-initialized event.  Zero it, set up the type
* and string pointers and then act like it was statically initialized.
*/
void
evcnt_attach_dynamic(struct evcnt *ev, int type, const struct evcnt *parent,
   const char *group, const char *name)
{

       memset(ev, 0, sizeof *ev);
       evcnt_attach_dynamic_nozero(ev, type, parent, group, name);
}

/*
* Detach an event.
*/
void
evcnt_detach(struct evcnt *ev)
{

       mutex_enter(&evcnt_lock);
       TAILQ_REMOVE(&allevents, ev, ev_list);
       evcnt_generation++;
       mutex_exit(&evcnt_lock);
}

typedef char ev_strings[2*EVCNT_STRING_MAX];

static size_t
sysctl_fillevcnt(const struct evcnt *ev, struct evcnt_sysctl *evs,
       size_t *copylenp)
{
       const bool allowaddr = get_expose_address(curproc);
       const size_t copylen = offsetof(struct evcnt_sysctl, ev_strings)
           + ev->ev_grouplen + 1 + ev->ev_namelen + 1;
       const size_t len = roundup2(copylen, sizeof(uint64_t));

       if (evs != NULL) {
               evs->ev_count = ev->ev_count;
               COND_SET_VALUE(evs->ev_addr, PTRTOUINT64(ev), allowaddr);
               COND_SET_VALUE(evs->ev_parent, PTRTOUINT64(ev->ev_parent),
                   allowaddr);
               evs->ev_type = ev->ev_type;
               evs->ev_grouplen = ev->ev_grouplen;
               evs->ev_namelen = ev->ev_namelen;
               evs->ev_len = len / sizeof(uint64_t);
               strcpy(evs->ev_strings, ev->ev_group);
               strcpy(evs->ev_strings + ev->ev_grouplen + 1, ev->ev_name);
       }

       *copylenp = copylen;
       return len;
}

static int
sysctl_doevcnt(SYSCTLFN_ARGS)
{
       struct evcnt_sysctl *evs0 = NULL, *evs;
       const size_t xevcnt_size = sizeof(*evs0) + sizeof(ev_strings);
       const struct evcnt *ev;
       int error;
       int retries;
       size_t needed, len;
       char *dp;

       if (namelen == 1 && name[0] == CTL_QUERY)
               return (sysctl_query(SYSCTLFN_CALL(rnode)));

       if (namelen != 2)
               return (EINVAL);

       /*
        * We can filter on the type of evcnt.
        */
       const int filter = name[0];
       if (filter != EVCNT_TYPE_ANY
           && filter != EVCNT_TYPE_MISC
           && filter != EVCNT_TYPE_INTR
           && filter != EVCNT_TYPE_TRAP)
               return (EINVAL);

       const u_int count = name[1];
       if (count != KERN_EVCNT_COUNT_ANY
           && count != KERN_EVCNT_COUNT_NONZERO)
               return (EINVAL);

       sysctl_unlock();

       if (oldp != NULL)
               evs0 = kmem_zalloc(xevcnt_size, KM_SLEEP);

       retries = 100;
retry:
       dp = oldp;
       len = (oldp != NULL) ? *oldlenp : 0;
       evs = evs0;
       error = 0;
       needed = 0;

       mutex_enter(&evcnt_lock);
#ifdef __HAVE_LEGACY_INTRCNT
       evcnt_update_intrcnt();
#endif
       TAILQ_FOREACH(ev, &allevents, ev_list) {
               if (filter != EVCNT_TYPE_ANY && filter != ev->ev_type)
                       continue;
               if (count == KERN_EVCNT_COUNT_NONZERO && ev->ev_count == 0)
                       continue;

               /*
                * Prepare to copy.  If evs is NULL, fillevcnt will just
                * how big the item is.
                */
               size_t copylen;
               const size_t elem_size = sysctl_fillevcnt(ev, evs, &copylen);
               needed += elem_size;

               if (len < elem_size) {
                       evs = NULL;
                       continue;
               }

               KASSERT(evs != NULL);
               KASSERT(evs->ev_grouplen != 0);
               KASSERT(evs->ev_namelen != 0);
               KASSERT(evs->ev_strings[0] != 0);

               const uint32_t last_generation = evcnt_generation;
               mutex_exit(&evcnt_lock);

               /*
                * Only copy the actual number of bytes, not the rounded
                * number.  If we did the latter we'd have to zero them
                * first or we'd leak random kernel memory.
                */
               error = copyout(evs, dp, copylen);

               mutex_enter(&evcnt_lock);
               if (error)
                       break;

               if (__predict_false(last_generation != evcnt_generation)) {
                       /*
                        * This sysctl node is only for statistics.
                        * Retry; if the queue keeps changing, then
                        * bail out.
                        */
                       if (--retries == 0) {
                               error = EAGAIN;
                               break;
                       }
                       mutex_exit(&evcnt_lock);
                       goto retry;
               }

               /*
                * Now we deal with the pointer/len since we aren't going to
                * toss their values away.
                */
               dp += elem_size;
               len -= elem_size;
       }
       mutex_exit(&evcnt_lock);

       if (evs0 != NULL)
               kmem_free(evs0, xevcnt_size);

       sysctl_relock();

       *oldlenp = needed;
       if (oldp == NULL)
               *oldlenp += 1024;

       return (error);
}



SYSCTL_SETUP(sysctl_evcnt_setup, "sysctl kern.evcnt subtree setup")
{

       sysctl_createv(clog, 0, NULL, NULL,
                      CTLFLAG_PERMANENT,
                      CTLTYPE_STRUCT, "evcnt",
                      SYSCTL_DESCR("Kernel evcnt information"),
                      sysctl_doevcnt, 0, NULL, 0,
                      CTL_KERN, KERN_EVCNT, CTL_EOL);
}

#ifdef __HAVE_LEGACY_INTRCNT
extern u_int intrcnt[], eintrcnt[];
extern char intrnames[];
static size_t nintr;
struct evcnt *intr_evcnts;
/*
* Remove the following when the last intrcnt/intrnames user is cleaned up.
*/
void
evcnt_attach_legacy_intrcnt(void)
{
       size_t i;
       const char *cp;

       nintr = ((intptr_t)eintrcnt - (intptr_t)intrcnt) / sizeof(intrcnt[0]);
       intr_evcnts = kmem_alloc(sizeof(struct evcnt) * nintr, KM_SLEEP);
       for (cp = intrnames, i = 0; i < nintr; i++) {
               evcnt_attach_dynamic(&intr_evcnts[i], EVCNT_TYPE_INTR,
                   NULL, "cpu", cp);
               cp += strlen(cp) + 1;
       }
}

static void
evcnt_update_intrcnt(void)
{
       size_t i;

       KASSERT(nintr > 0);
       KASSERT(intr_evcnts != NULL);

       for (i = 0; i < nintr; i++) {
               intr_evcnts[i].ev_count = intrcnt[i];
       }
}
#endif

You are viewing proxied material from ftp.icm.edu.pl. The copyright of proxied material belongs to its original authors. Any comments or complaints in relation to proxied material should be directed to the original authors of the content concerned. Please see the disclaimer for more details.