/* $NetBSD: subr_evcnt.c,v 1.13 2018/11/24 17:40:37 maxv 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 1.13 2018/11/24 17:40:37 maxv 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>
/* 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);
}
struct xevcnt_sysctl {
struct evcnt_sysctl evs;
char ev_strings[2*EVCNT_STRING_MAX];
};
static size_t
sysctl_fillevcnt(const struct evcnt *ev, struct xevcnt_sysctl *xevs,
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 (xevs != NULL) {
xevs->evs.ev_count = ev->ev_count;
COND_SET_VALUE(xevs->evs.ev_addr, PTRTOUINT64(ev), allowaddr);
COND_SET_VALUE(xevs->evs.ev_parent, PTRTOUINT64(ev->ev_parent),
allowaddr);
xevs->evs.ev_type = ev->ev_type;
xevs->evs.ev_grouplen = ev->ev_grouplen;
xevs->evs.ev_namelen = ev->ev_namelen;
xevs->evs.ev_len = len / sizeof(uint64_t);
strcpy(xevs->evs.ev_strings, ev->ev_group);
strcpy(xevs->evs.ev_strings + ev->ev_grouplen + 1, ev->ev_name);
}
*copylenp = copylen;
return len;
}
static int
sysctl_doevcnt(SYSCTLFN_ARGS)
{
struct xevcnt_sysctl *xevs0 = NULL, *xevs;
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 && xevs0 == NULL)
xevs0 = kmem_zalloc(sizeof(*xevs0), KM_SLEEP);
retries = 100;
retry:
dp = oldp;
len = (oldp != NULL) ? *oldlenp : 0;
xevs = xevs0;
error = 0;
needed = 0;
mutex_enter(&evcnt_lock);
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 xevs is NULL, fillevcnt will just
* how big the item is.
*/
size_t copylen;
const size_t elem_size = sysctl_fillevcnt(ev, xevs, ©len);
needed += elem_size;
if (len < elem_size) {
xevs = NULL;
continue;
}
KASSERT(xevs != NULL);
KASSERT(xevs->evs.ev_grouplen != 0);
KASSERT(xevs->evs.ev_namelen != 0);
KASSERT(xevs->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(xevs, 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 (xevs0 != NULL)
kmem_free(xevs0, sizeof(*xevs0));
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);
}