/*
* 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 2009 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/*
* Copyright (c) 2011, Joyent, Inc. All rights reserved.
*/
#include <sys/errno.h>
#include <sys/stat.h>
#include <sys/modctl.h>
#include <sys/conf.h>
#include <sys/systm.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>
#include <sys/cpuvar.h>
#include <sys/kmem.h>
#include <sys/strsubr.h>
#include <sys/dtrace.h>
#include <sys/cyclic.h>
#include <sys/atomic.h>
static dev_info_t *profile_devi;
static dtrace_provider_id_t profile_id;
/*
* Regardless of platform, the stack frames look like this in the case of the
* profile provider:
*
* profile_fire
* cyclic_expire
* cyclic_fire
* [ cbe ]
* [ interrupt code ]
*
* On x86, there are five frames from the generic interrupt code; further, the
* interrupted instruction appears as its own stack frame, giving us a total of
* 10.
*
* On SPARC, the picture is further complicated because the compiler
* optimizes away tail-calls -- so the following frames are optimized away:
*
* profile_fire
* cyclic_expire
*
* This gives three frames. However, on DEBUG kernels, the cyclic_expire
* frame cannot be tail-call eliminated, yielding four frames in this case.
*
* All of the above constraints lead to the mess below. Yes, the profile
* provider should ideally figure this out on-the-fly by hitting one of its own
* probes and then walking its own stack trace. This is complicated, however,
* and the static definition doesn't seem to be overly brittle. Still, we
* allow for a manual override in case we get it completely wrong.
*/
#ifdef __x86
#define PROF_ARTIFICIAL_FRAMES 10
#else
#ifdef __sparc
#ifdef DEBUG
#define PROF_ARTIFICIAL_FRAMES 4
#else
#define PROF_ARTIFICIAL_FRAMES 3
#endif
#endif
#endif
#define PROF_NAMELEN 15
#define PROF_PROFILE 0
#define PROF_TICK 1
#define PROF_PREFIX_PROFILE "profile-"
#define PROF_PREFIX_TICK "tick-"
typedef struct profile_probe {
char prof_name[PROF_NAMELEN];
dtrace_id_t prof_id;
int prof_kind;
hrtime_t prof_interval;
cyclic_id_t prof_cyclic;
} profile_probe_t;
typedef struct profile_probe_percpu {
hrtime_t profc_expected;
hrtime_t profc_interval;
profile_probe_t *profc_probe;
} profile_probe_percpu_t;
hrtime_t profile_interval_min = NANOSEC / 5000; /* 5000 hz */
int profile_aframes = 0; /* override */
static int profile_rates[] = {
97, 199, 499, 997, 1999,
4001, 4999, 0, 0, 0,
0, 0, 0, 0, 0,
0, 0, 0, 0, 0
};
static int profile_ticks[] = {
1, 10, 100, 500, 1000,
5000, 0, 0, 0, 0,
0, 0, 0, 0, 0
};
/*
* profile_max defines the upper bound on the number of profile probes that
* can exist (this is to prevent malicious or clumsy users from exhausing
* system resources by creating a slew of profile probes). At mod load time,
* this gets its value from PROFILE_MAX_DEFAULT or profile-max-probes if it's
* present in the profile.conf file.
*/
#define PROFILE_MAX_DEFAULT 1000 /* default max. number of probes */
static uint32_t profile_max; /* maximum number of profile probes */
static uint32_t profile_total; /* current number of profile probes */
static void
profile_fire(void *arg)
{
profile_probe_percpu_t *pcpu = arg;
profile_probe_t *prof = pcpu->profc_probe;
hrtime_t late;
late = dtrace_gethrtime() - pcpu->profc_expected;
pcpu->profc_expected += pcpu->profc_interval;
dtrace_probe(prof->prof_id, CPU->cpu_profile_pc,
CPU->cpu_profile_upc, late, 0, 0);
}
static void
profile_tick(void *arg)
{
profile_probe_t *prof = arg;
dtrace_probe(prof->prof_id, CPU->cpu_profile_pc,
CPU->cpu_profile_upc, 0, 0, 0);
}
static void
profile_create(hrtime_t interval, const char *name, int kind)
{
profile_probe_t *prof;
int nr_frames = PROF_ARTIFICIAL_FRAMES + dtrace_mach_aframes();
if (profile_aframes)
nr_frames = profile_aframes;
if (interval < profile_interval_min)
return;
if (dtrace_probe_lookup(profile_id, NULL, NULL, name) != 0)
return;
atomic_inc_32(&profile_total);
if (profile_total > profile_max) {
atomic_dec_32(&profile_total);
return;
}
prof = kmem_zalloc(sizeof (profile_probe_t), KM_SLEEP);
(void) strcpy(prof->prof_name, name);
prof->prof_interval = interval;
prof->prof_cyclic = CYCLIC_NONE;
prof->prof_kind = kind;
prof->prof_id = dtrace_probe_create(profile_id,
NULL, NULL, name, nr_frames, prof);
}
/*ARGSUSED*/
static void
profile_provide(void *arg, const dtrace_probedesc_t *desc)
{
int i, j, rate, kind;
hrtime_t val = 0, mult = 1, len;
const char *name, *suffix = NULL;
const struct {
char *prefix;
int kind;
} types[] = {
{ PROF_PREFIX_PROFILE, PROF_PROFILE },
{ PROF_PREFIX_TICK, PROF_TICK },
{ NULL, NULL }
};
const struct {
char *name;
hrtime_t mult;
} suffixes[] = {
{ "ns", NANOSEC / NANOSEC },
{ "nsec", NANOSEC / NANOSEC },
{ "us", NANOSEC / MICROSEC },
{ "usec", NANOSEC / MICROSEC },
{ "ms", NANOSEC / MILLISEC },
{ "msec", NANOSEC / MILLISEC },
{ "s", NANOSEC / SEC },
{ "sec", NANOSEC / SEC },
{ "m", NANOSEC * (hrtime_t)60 },
{ "min", NANOSEC * (hrtime_t)60 },
{ "h", NANOSEC * (hrtime_t)(60 * 60) },
{ "hour", NANOSEC * (hrtime_t)(60 * 60) },
{ "d", NANOSEC * (hrtime_t)(24 * 60 * 60) },
{ "day", NANOSEC * (hrtime_t)(24 * 60 * 60) },
{ "hz", 0 },
{ NULL }
};
if (desc == NULL) {
char n[PROF_NAMELEN];
/*
* If no description was provided, provide all of our probes.
*/
for (i = 0; i < sizeof (profile_rates) / sizeof (int); i++) {
if ((rate = profile_rates[i]) == 0)
continue;
(void) snprintf(n, PROF_NAMELEN, "%s%d",
PROF_PREFIX_PROFILE, rate);
profile_create(NANOSEC / rate, n, PROF_PROFILE);
}
for (i = 0; i < sizeof (profile_ticks) / sizeof (int); i++) {
if ((rate = profile_ticks[i]) == 0)
continue;
(void) snprintf(n, PROF_NAMELEN, "%s%d",
PROF_PREFIX_TICK, rate);
profile_create(NANOSEC / rate, n, PROF_TICK);
}
return;
}
name = desc->dtpd_name;
for (i = 0; types[i].prefix != NULL; i++) {
len = strlen(types[i].prefix);
if (strncmp(name, types[i].prefix, len) != 0)
continue;
break;
}
if (types[i].prefix == NULL)
return;
kind = types[i].kind;
j = strlen(name) - len;
/*
* We need to start before any time suffix.
*/
for (j = strlen(name); j >= len; j--) {
if (name[j] >= '0' && name[j] <= '9')
break;
suffix = &name[j];
}
ASSERT(suffix != NULL);
/*
* Now determine the numerical value present in the probe name.
*/
for (; j >= len; j--) {
if (name[j] < '0' || name[j] > '9')
return;
val += (name[j] - '0') * mult;
mult *= (hrtime_t)10;
}
if (val == 0)
return;
/*
* Look-up the suffix to determine the multiplier.
*/
for (i = 0, mult = 0; suffixes[i].name != NULL; i++) {
if (strcasecmp(suffixes[i].name, suffix) == 0) {
mult = suffixes[i].mult;
break;
}
}
if (suffixes[i].name == NULL && *suffix != '\0')
return;
if (mult == 0) {
/*
* The default is frequency-per-second.
*/
val = NANOSEC / val;
} else {
val *= mult;
}
profile_create(val, name, kind);
}
/*ARGSUSED*/
static void
profile_destroy(void *arg, dtrace_id_t id, void *parg)
{
profile_probe_t *prof = parg;
ASSERT(prof->prof_cyclic == CYCLIC_NONE);
kmem_free(prof, sizeof (profile_probe_t));
ASSERT(profile_total >= 1);
atomic_dec_32(&profile_total);
}
/*ARGSUSED*/
static void
profile_online(void *arg, cpu_t *cpu, cyc_handler_t *hdlr, cyc_time_t *when)
{
profile_probe_t *prof = arg;
profile_probe_percpu_t *pcpu;
pcpu = kmem_zalloc(sizeof (profile_probe_percpu_t), KM_SLEEP);
pcpu->profc_probe = prof;
hdlr->cyh_func = profile_fire;
hdlr->cyh_arg = pcpu;
hdlr->cyh_level = CY_HIGH_LEVEL;
when->cyt_interval = prof->prof_interval;
when->cyt_when = dtrace_gethrtime() + when->cyt_interval;
pcpu->profc_expected = when->cyt_when;
pcpu->profc_interval = when->cyt_interval;
}
/*ARGSUSED*/
static void
profile_offline(void *arg, cpu_t *cpu, void *oarg)
{
profile_probe_percpu_t *pcpu = oarg;
ASSERT(pcpu->profc_probe == arg);
kmem_free(pcpu, sizeof (profile_probe_percpu_t));
}
/*ARGSUSED*/
static int
profile_enable(void *arg, dtrace_id_t id, void *parg)
{
profile_probe_t *prof = parg;
cyc_omni_handler_t omni;
cyc_handler_t hdlr;
cyc_time_t when;
ASSERT(prof->prof_interval != 0);
ASSERT(MUTEX_HELD(&cpu_lock));
if (prof->prof_kind == PROF_TICK) {
hdlr.cyh_func = profile_tick;
hdlr.cyh_arg = prof;
hdlr.cyh_level = CY_HIGH_LEVEL;
when.cyt_interval = prof->prof_interval;
when.cyt_when = dtrace_gethrtime() + when.cyt_interval;
} else {
ASSERT(prof->prof_kind == PROF_PROFILE);
omni.cyo_online = profile_online;
omni.cyo_offline = profile_offline;
omni.cyo_arg = prof;
}
if (prof->prof_kind == PROF_TICK) {
prof->prof_cyclic = cyclic_add(&hdlr, &when);
} else {
prof->prof_cyclic = cyclic_add_omni(&omni);
}
return (0);
}
/*ARGSUSED*/
static void
profile_disable(void *arg, dtrace_id_t id, void *parg)
{
profile_probe_t *prof = parg;
ASSERT(prof->prof_cyclic != CYCLIC_NONE);
ASSERT(MUTEX_HELD(&cpu_lock));
cyclic_remove(prof->prof_cyclic);
prof->prof_cyclic = CYCLIC_NONE;
}
/*ARGSUSED*/
static int
profile_mode(void *arg, dtrace_id_t id, void *parg)
{
profile_probe_t *prof = parg;
int mode;
if (CPU->cpu_profile_pc != 0) {
mode = DTRACE_MODE_KERNEL;
} else {
mode = DTRACE_MODE_USER;
}
if (prof->prof_kind == PROF_TICK) {
mode |= DTRACE_MODE_NOPRIV_RESTRICT;
} else {
ASSERT(prof->prof_kind == PROF_PROFILE);
mode |= DTRACE_MODE_NOPRIV_DROP;
}
return (mode);
}
static dtrace_pattr_t profile_attr = {
{ DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_COMMON },
{ DTRACE_STABILITY_UNSTABLE, DTRACE_STABILITY_UNSTABLE, DTRACE_CLASS_UNKNOWN },
{ DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_UNKNOWN },
{ DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_COMMON },
{ DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_COMMON },
};
static dtrace_pops_t profile_pops = {
profile_provide,
NULL,
profile_enable,
profile_disable,
NULL,
NULL,
NULL,
NULL,
profile_mode,
profile_destroy
};
static int
profile_attach(dev_info_t *devi, ddi_attach_cmd_t cmd)
{
switch (cmd) {
case DDI_ATTACH:
break;
case DDI_RESUME:
return (DDI_SUCCESS);
default:
return (DDI_FAILURE);
}
if (ddi_create_minor_node(devi, "profile", S_IFCHR, 0,
DDI_PSEUDO, NULL) == DDI_FAILURE ||
dtrace_register("profile", &profile_attr,
DTRACE_PRIV_KERNEL | DTRACE_PRIV_USER, NULL,
&profile_pops, NULL, &profile_id) != 0) {
ddi_remove_minor_node(devi, NULL);
return (DDI_FAILURE);
}
profile_max = ddi_getprop(DDI_DEV_T_ANY, devi, DDI_PROP_DONTPASS,
"profile-max-probes", PROFILE_MAX_DEFAULT);
ddi_report_dev(devi);
profile_devi = devi;
return (DDI_SUCCESS);
}
static int
profile_detach(dev_info_t *devi, ddi_detach_cmd_t cmd)
{
switch (cmd) {
case DDI_DETACH:
break;
case DDI_SUSPEND:
return (DDI_SUCCESS);
default:
return (DDI_FAILURE);
}
if (dtrace_unregister(profile_id) != 0)
return (DDI_FAILURE);
ddi_remove_minor_node(devi, NULL);
return (DDI_SUCCESS);
}
/*ARGSUSED*/
static int
profile_info(dev_info_t *dip, ddi_info_cmd_t infocmd, void *arg, void **result)
{
int error;
switch (infocmd) {
case DDI_INFO_DEVT2DEVINFO:
*result = (void *)profile_devi;
error = DDI_SUCCESS;
break;
case DDI_INFO_DEVT2INSTANCE:
*result = (void *)0;
error = DDI_SUCCESS;
break;
default:
error = DDI_FAILURE;
}
return (error);
}
/*ARGSUSED*/
static int
profile_open(dev_t *devp, int flag, int otyp, cred_t *cred_p)
{
return (0);
}
static struct cb_ops profile_cb_ops = {
profile_open, /* open */
nodev, /* close */
nulldev, /* strategy */
nulldev, /* print */
nodev, /* dump */
nodev, /* read */
nodev, /* write */
nodev, /* ioctl */
nodev, /* devmap */
nodev, /* mmap */
nodev, /* segmap */
nochpoll, /* poll */
ddi_prop_op, /* cb_prop_op */
0, /* streamtab */
D_NEW | D_MP /* Driver compatibility flag */
};
static struct dev_ops profile_ops = {
DEVO_REV, /* devo_rev, */
0, /* refcnt */
profile_info, /* get_dev_info */
nulldev, /* identify */
nulldev, /* probe */
profile_attach, /* attach */
profile_detach, /* detach */
nodev, /* reset */
&profile_cb_ops, /* driver operations */
NULL, /* bus operations */
nodev, /* dev power */
ddi_quiesce_not_needed, /* quiesce */
};
/*
* Module linkage information for the kernel.
*/
static struct modldrv modldrv = {
&mod_driverops, /* module type (this is a pseudo driver) */
"Profile Interrupt Tracing", /* name of module */
&profile_ops, /* driver ops */
};
static struct modlinkage modlinkage = {
MODREV_1,
(void *)&modldrv,
NULL
};
int
_init(void)
{
return (mod_install(&modlinkage));
}
int
_info(struct modinfo *modinfop)
{
return (mod_info(&modlinkage, modinfop));
}
int
_fini(void)
{
return (mod_remove(&modlinkage));
}