OpenSolaris_b135/uts/sparc/dtrace/sdt.c
/*
* 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.
*/
#include <sys/modctl.h>
#include <sys/sunddi.h>
#include <sys/dtrace.h>
#include <sys/kobj.h>
#include <sys/stat.h>
#include <sys/conf.h>
#include <vm/seg_kmem.h>
#include <sys/stack.h>
#include <sys/sdt_impl.h>
static dev_info_t *sdt_devi;
int sdt_verbose = 0;
#define SDT_REG_G0 0
#define SDT_REG_O0 8
#define SDT_REG_O1 9
#define SDT_REG_O2 10
#define SDT_REG_O3 11
#define SDT_REG_O4 12
#define SDT_REG_O5 13
#define SDT_REG_I0 24
#define SDT_REG_I1 25
#define SDT_REG_I2 26
#define SDT_REG_I3 27
#define SDT_REG_I4 28
#define SDT_REG_I5 29
#define SDT_SIMM13_MASK 0x1fff
#define SDT_SIMM13_MAX ((int32_t)0xfff)
#define SDT_CALL(from, to) (((uint32_t)1 << 30) | \
(((uintptr_t)(to) - (uintptr_t)(from) >> 2) & \
0x3fffffff))
#define SDT_SAVE (0x9de3a000 | (-SA(MINFRAME) & SDT_SIMM13_MASK))
#define SDT_RET 0x81c7e008
#define SDT_RESTORE 0x81e80000
#define SDT_OP_SETHI 0x1000000
#define SDT_OP_OR 0x80100000
#define SDT_FMT2_RD_SHIFT 25
#define SDT_IMM22_SHIFT 10
#define SDT_IMM22_MASK 0x3fffff
#define SDT_IMM10_MASK 0x3ff
#define SDT_FMT3_RD_SHIFT 25
#define SDT_FMT3_RS1_SHIFT 14
#define SDT_FMT3_RS2_SHIFT 0
#define SDT_FMT3_IMM (1 << 13)
#define SDT_MOV(rs, rd) \
(SDT_OP_OR | (SDT_REG_G0 << SDT_FMT3_RS1_SHIFT) | \
((rs) << SDT_FMT3_RS2_SHIFT) | ((rd) << SDT_FMT3_RD_SHIFT))
#define SDT_ORLO(rs, val, rd) \
(SDT_OP_OR | ((rs) << SDT_FMT3_RS1_SHIFT) | \
((rd) << SDT_FMT3_RD_SHIFT) | SDT_FMT3_IMM | ((val) & SDT_IMM10_MASK))
#define SDT_ORSIMM13(rs, val, rd) \
(SDT_OP_OR | ((rs) << SDT_FMT3_RS1_SHIFT) | \
((rd) << SDT_FMT3_RD_SHIFT) | SDT_FMT3_IMM | ((val) & SDT_SIMM13_MASK))
#define SDT_SETHI(val, reg) \
(SDT_OP_SETHI | (reg << SDT_FMT2_RD_SHIFT) | \
((val >> SDT_IMM22_SHIFT) & SDT_IMM22_MASK))
#define SDT_ENTRY_SIZE (11 * sizeof (uint32_t))
static void
sdt_initialize(sdt_probe_t *sdp, uint32_t **trampoline)
{
uint32_t *instr = *trampoline;
*instr++ = SDT_SAVE;
if (sdp->sdp_id > (uint32_t)SDT_SIMM13_MAX) {
*instr++ = SDT_SETHI(sdp->sdp_id, SDT_REG_O0);
*instr++ = SDT_ORLO(SDT_REG_O0, sdp->sdp_id, SDT_REG_O0);
} else {
*instr++ = SDT_ORSIMM13(SDT_REG_G0, sdp->sdp_id, SDT_REG_O0);
}
*instr++ = SDT_MOV(SDT_REG_I0, SDT_REG_O1);
*instr++ = SDT_MOV(SDT_REG_I1, SDT_REG_O2);
*instr++ = SDT_MOV(SDT_REG_I2, SDT_REG_O3);
*instr++ = SDT_MOV(SDT_REG_I3, SDT_REG_O4);
*instr = SDT_CALL(instr, dtrace_probe);
instr++;
*instr++ = SDT_MOV(SDT_REG_I4, SDT_REG_O5);
*instr++ = SDT_RET;
*instr++ = SDT_RESTORE;
*trampoline = instr;
}
/*ARGSUSED*/
static void
sdt_provide_module(void *arg, struct modctl *ctl)
{
struct module *mp = ctl->mod_mp;
char *modname = ctl->mod_modname;
int primary, nprobes = 0;
sdt_probedesc_t *sdpd;
sdt_probe_t *sdp, *old;
uint32_t *tab;
sdt_provider_t *prov;
int len;
/*
* One for all, and all for one: if we haven't yet registered all of
* our providers, we'll refuse to provide anything.
*/
for (prov = sdt_providers; prov->sdtp_name != NULL; prov++) {
if (prov->sdtp_id == DTRACE_PROVNONE)
return;
}
if (mp->sdt_nprobes != 0 || (sdpd = mp->sdt_probes) == NULL)
return;
kobj_textwin_alloc(mp);
/*
* Hack to identify unix/genunix/krtld.
*/
primary = vmem_contains(heap_arena, (void *)ctl,
sizeof (struct modctl)) == 0;
/*
* If there hasn't been an sdt table allocated, we'll do so now.
*/
if (mp->sdt_tab == NULL) {
for (; sdpd != NULL; sdpd = sdpd->sdpd_next) {
nprobes++;
}
/*
* We could (should?) determine precisely the size of the
* table -- but a reasonable maximum will suffice.
*/
mp->sdt_size = nprobes * SDT_ENTRY_SIZE;
mp->sdt_tab = kobj_texthole_alloc(mp->text, mp->sdt_size);
if (mp->sdt_tab == NULL) {
cmn_err(CE_WARN, "couldn't allocate SDT table "
"for module %s", modname);
return;
}
}
tab = (uint32_t *)mp->sdt_tab;
for (sdpd = mp->sdt_probes; sdpd != NULL; sdpd = sdpd->sdpd_next) {
char *name = sdpd->sdpd_name, *func, *nname;
int i, j;
sdt_provider_t *prov;
ulong_t offs;
dtrace_id_t id;
for (prov = sdt_providers; prov->sdtp_prefix != NULL; prov++) {
char *prefix = prov->sdtp_prefix;
if (strncmp(name, prefix, strlen(prefix)) == 0) {
name += strlen(prefix);
break;
}
}
nname = kmem_alloc(len = strlen(name) + 1, KM_SLEEP);
for (i = 0, j = 0; name[j] != '\0'; i++) {
if (name[j] == '_' && name[j + 1] == '_') {
nname[i] = '-';
j += 2;
} else {
nname[i] = name[j++];
}
}
nname[i] = '\0';
sdp = kmem_zalloc(sizeof (sdt_probe_t), KM_SLEEP);
sdp->sdp_loadcnt = ctl->mod_loadcnt;
sdp->sdp_primary = primary;
sdp->sdp_ctl = ctl;
sdp->sdp_name = nname;
sdp->sdp_namelen = len;
sdp->sdp_provider = prov;
func = kobj_searchsym(mp, sdpd->sdpd_offset +
(uintptr_t)mp->text, &offs);
if (func == NULL)
func = "<unknown>";
/*
* We have our provider. Now create the probe.
*/
if ((id = dtrace_probe_lookup(prov->sdtp_id, modname,
func, nname)) != DTRACE_IDNONE) {
old = dtrace_probe_arg(prov->sdtp_id, id);
ASSERT(old != NULL);
sdp->sdp_next = old->sdp_next;
sdp->sdp_id = id;
old->sdp_next = sdp;
} else {
sdp->sdp_id = dtrace_probe_create(prov->sdtp_id,
modname, func, nname, 1, sdp);
mp->sdt_nprobes++;
}
sdp->sdp_patchval = SDT_CALL((uintptr_t)mp->text +
sdpd->sdpd_offset, tab);
sdp->sdp_patchpoint = (uint32_t *)((uintptr_t)mp->textwin +
sdpd->sdpd_offset);
sdp->sdp_savedval = *sdp->sdp_patchpoint;
sdt_initialize(sdp, &tab);
}
}
/*ARGSUSED*/
static void
sdt_destroy(void *arg, dtrace_id_t id, void *parg)
{
sdt_probe_t *sdp = parg, *old;
struct modctl *ctl = sdp->sdp_ctl;
if (ctl != NULL && ctl->mod_loadcnt == sdp->sdp_loadcnt) {
if ((ctl->mod_loadcnt == sdp->sdp_loadcnt &&
ctl->mod_loaded) || sdp->sdp_primary) {
((struct module *)(ctl->mod_mp))->sdt_nprobes--;
}
}
while (sdp != NULL) {
old = sdp;
kmem_free(sdp->sdp_name, sdp->sdp_namelen);
sdp = sdp->sdp_next;
kmem_free(old, sizeof (sdt_probe_t));
}
}
/*ARGSUSED*/
static int
sdt_enable(void *arg, dtrace_id_t id, void *parg)
{
sdt_probe_t *sdp = parg;
struct modctl *ctl = sdp->sdp_ctl;
ctl->mod_nenabled++;
/*
* If this module has disappeared since we discovered its probes,
* refuse to enable it.
*/
if (!sdp->sdp_primary && !ctl->mod_loaded) {
if (sdt_verbose) {
cmn_err(CE_NOTE, "sdt is failing for probe %s "
"(module %s unloaded)",
sdp->sdp_name, ctl->mod_modname);
}
goto err;
}
/*
* Now check that our modctl has the expected load count. If it
* doesn't, this module must have been unloaded and reloaded -- and
* we're not going to touch it.
*/
if (ctl->mod_loadcnt != sdp->sdp_loadcnt) {
if (sdt_verbose) {
cmn_err(CE_NOTE, "sdt is failing for probe %s "
"(module %s reloaded)",
sdp->sdp_name, ctl->mod_modname);
}
goto err;
}
while (sdp != NULL) {
*sdp->sdp_patchpoint = sdp->sdp_patchval;
sdp = sdp->sdp_next;
}
err:
return (0);
}
/*ARGSUSED*/
static void
sdt_disable(void *arg, dtrace_id_t id, void *parg)
{
sdt_probe_t *sdp = parg;
struct modctl *ctl = sdp->sdp_ctl;
ASSERT(ctl->mod_nenabled > 0);
ctl->mod_nenabled--;
if ((!sdp->sdp_primary && !ctl->mod_loaded) ||
(ctl->mod_loadcnt != sdp->sdp_loadcnt))
goto err;
while (sdp != NULL) {
*sdp->sdp_patchpoint = sdp->sdp_savedval;
sdp = sdp->sdp_next;
}
err:
;
}
static dtrace_pops_t sdt_pops = {
NULL,
sdt_provide_module,
sdt_enable,
sdt_disable,
NULL,
NULL,
sdt_getargdesc,
NULL,
NULL,
sdt_destroy
};
static int
sdt_attach(dev_info_t *devi, ddi_attach_cmd_t cmd)
{
sdt_provider_t *prov;
switch (cmd) {
case DDI_ATTACH:
break;
case DDI_RESUME:
return (DDI_SUCCESS);
default:
return (DDI_FAILURE);
}
if (ddi_create_minor_node(devi, "sdt", S_IFCHR, 0,
DDI_PSEUDO, NULL) == DDI_FAILURE) {
ddi_remove_minor_node(devi, NULL);
return (DDI_FAILURE);
}
ddi_report_dev(devi);
sdt_devi = devi;
for (prov = sdt_providers; prov->sdtp_name != NULL; prov++) {
if (dtrace_register(prov->sdtp_name, prov->sdtp_attr,
DTRACE_PRIV_KERNEL, NULL,
&sdt_pops, prov, &prov->sdtp_id) != 0) {
cmn_err(CE_WARN, "failed to register sdt provider %s",
prov->sdtp_name);
}
}
return (DDI_SUCCESS);
}
static int
sdt_detach(dev_info_t *devi, ddi_detach_cmd_t cmd)
{
sdt_provider_t *prov;
switch (cmd) {
case DDI_DETACH:
break;
case DDI_SUSPEND:
return (DDI_SUCCESS);
default:
return (DDI_FAILURE);
}
for (prov = sdt_providers; prov->sdtp_name != NULL; prov++) {
if (prov->sdtp_id != DTRACE_PROVNONE) {
if (dtrace_unregister(prov->sdtp_id) != 0)
return (DDI_FAILURE);
prov->sdtp_id = DTRACE_PROVNONE;
}
}
ddi_remove_minor_node(devi, NULL);
return (DDI_SUCCESS);
}
/*ARGSUSED*/
static int
sdt_info(dev_info_t *dip, ddi_info_cmd_t infocmd, void *arg, void **result)
{
int error;
switch (infocmd) {
case DDI_INFO_DEVT2DEVINFO:
*result = (void *)sdt_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
sdt_open(dev_t *devp, int flag, int otyp, cred_t *cred_p)
{
return (0);
}
static struct cb_ops sdt_cb_ops = {
sdt_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 sdt_ops = {
DEVO_REV, /* devo_rev, */
0, /* refcnt */
sdt_info, /* get_dev_info */
nulldev, /* identify */
nulldev, /* probe */
sdt_attach, /* attach */
sdt_detach, /* detach */
nodev, /* reset */
&sdt_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) */
"Statically Defined Tracing", /* name of module */
&sdt_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));
}