fbt.c

Sun Solaris 10 中的 DTrace 组件的源代码。请参看: http://www.sun.com/software/solaris/observability.jsp

	int ndx;

	do {
		if (ctl != NULL && ctl->mod_loadcnt == fbt->fbtp_loadcnt) {
			if ((ctl->mod_loadcnt == fbt->fbtp_loadcnt &&
			    ctl->mod_loaded)) {
				((struct module *)
				    (ctl->mod_mp))->fbt_nentries--;
			}
		}

		/*
		 * Now we need to remove this probe from the fbt_probetab.
		 */
		ndx = FBT_ADDR2NDX(fbt->fbtp_patchpoint);
		last = NULL;
		hash = fbt_probetab[ndx];

		while (hash != fbt) {
			ASSERT(hash != NULL);
			last = hash;
			hash = hash->fbtp_hashnext;
		}

		if (last != NULL) {
			last->fbtp_hashnext = fbt->fbtp_hashnext;
		} else {
			fbt_probetab[ndx] = fbt->fbtp_hashnext;
		}

		next = fbt->fbtp_next;
		kmem_free(fbt, sizeof (fbt_probe_t));

		fbt = next;
	} while (fbt != NULL);
}

/*ARGSUSED*/
static void
fbt_enable(void *arg, dtrace_id_t id, void *parg)
{
	fbt_probe_t *fbt = parg;
	struct modctl *ctl = fbt->fbtp_ctl;

	ctl->mod_nenabled++;

	if (!ctl->mod_loaded) {
		if (fbt_verbose) {
			cmn_err(CE_NOTE, "fbt is failing for probe %s "
			    "(module %s unloaded)",
			    fbt->fbtp_name, ctl->mod_modname);
		}

		return;
	}

	/*
	 * 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 != fbt->fbtp_loadcnt) {
		if (fbt_verbose) {
			cmn_err(CE_NOTE, "fbt is failing for probe %s "
			    "(module %s reloaded)",
			    fbt->fbtp_name, ctl->mod_modname);
		}

		return;
	}

	for (; fbt != NULL; fbt = fbt->fbtp_next)
		*fbt->fbtp_patchpoint = fbt->fbtp_patchval;
}

/*ARGSUSED*/
static void
fbt_disable(void *arg, dtrace_id_t id, void *parg)
{
	fbt_probe_t *fbt = parg;
	struct modctl *ctl = fbt->fbtp_ctl;

	ASSERT(ctl->mod_nenabled > 0);
	ctl->mod_nenabled--;

	if (!ctl->mod_loaded || (ctl->mod_loadcnt != fbt->fbtp_loadcnt))
		return;

	for (; fbt != NULL; fbt = fbt->fbtp_next)
		*fbt->fbtp_patchpoint = fbt->fbtp_savedval;
}

/*ARGSUSED*/
static void
fbt_suspend(void *arg, dtrace_id_t id, void *parg)
{
	fbt_probe_t *fbt = parg;
	struct modctl *ctl = fbt->fbtp_ctl;

	ASSERT(ctl->mod_nenabled > 0);

	if (!ctl->mod_loaded || (ctl->mod_loadcnt != fbt->fbtp_loadcnt))
		return;

	for (; fbt != NULL; fbt = fbt->fbtp_next)
		*fbt->fbtp_patchpoint = fbt->fbtp_savedval;
}

/*ARGSUSED*/
static void
fbt_resume(void *arg, dtrace_id_t id, void *parg)
{
	fbt_probe_t *fbt = parg;
	struct modctl *ctl = fbt->fbtp_ctl;

	ASSERT(ctl->mod_nenabled > 0);

	if (!ctl->mod_loaded || (ctl->mod_loadcnt != fbt->fbtp_loadcnt))
		return;

	for (; fbt != NULL; fbt = fbt->fbtp_next)
		*fbt->fbtp_patchpoint = fbt->fbtp_patchval;
}

/*ARGSUSED*/
static void
fbt_getargdesc(void *arg, dtrace_id_t id, void *parg, dtrace_argdesc_t *desc)
{
	fbt_probe_t *fbt = parg;
	struct modctl *ctl = fbt->fbtp_ctl;
	struct module *mp = ctl->mod_mp;
	ctf_file_t *fp = NULL, *pfp;
	ctf_funcinfo_t f;
	int error;
	ctf_id_t argv[32], type;
	int argc = sizeof (argv) / sizeof (ctf_id_t);
	const char *parent;

	if (!ctl->mod_loaded || (ctl->mod_loadcnt != fbt->fbtp_loadcnt))
		goto err;

	if (fbt->fbtp_roffset != 0 && desc->dtargd_ndx == 0) {
		(void) strcpy(desc->dtargd_native, "int");
		return;
	}

	if ((fp = ctf_modopen(mp, &error)) == NULL) {
		/*
		 * We have no CTF information for this module -- and therefore
		 * no args[] information.
		 */
		goto err;
	}

	/*
	 * If we have a parent container, we must manually import it.
	 */
	if ((parent = ctf_parent_name(fp)) != NULL) {
		struct modctl *mod;

		/*
		 * We must iterate over all modules to find the module that
		 * is our parent.
		 */
		for (mod = &modules; mod != NULL; mod = mod->mod_next) {
			if (strcmp(mod->mod_filename, parent) == 0)
				break;
		}

		if (mod == NULL)
			goto err;

		if ((pfp = ctf_modopen(mod->mod_mp, &error)) == NULL)
			goto err;

		if (ctf_import(fp, pfp) != 0) {
			ctf_close(pfp);
			goto err;
		}

		ctf_close(pfp);
	}

	if (ctf_func_info(fp, fbt->fbtp_symndx, &f) == CTF_ERR)
		goto err;

	if (fbt->fbtp_roffset != 0) {
		if (desc->dtargd_ndx > 1)
			goto err;

		ASSERT(desc->dtargd_ndx == 1);
		type = f.ctc_return;
	} else {
		if (desc->dtargd_ndx + 1 > f.ctc_argc)
			goto err;

		if (ctf_func_args(fp, fbt->fbtp_symndx, argc, argv) == CTF_ERR)
			goto err;

		type = argv[desc->dtargd_ndx];
	}

	if (ctf_type_name(fp, type, desc->dtargd_native,
	    DTRACE_ARGTYPELEN) != NULL) {
		ctf_close(fp);
		return;
	}
err:
	if (fp != NULL)
		ctf_close(fp);

	desc->dtargd_ndx = DTRACE_ARGNONE;
}

static dtrace_pattr_t fbt_attr = {
{ DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_ISA },
{ DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_UNKNOWN },
{ DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_UNKNOWN },
{ DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_ISA },
{ DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_ISA },
};

static dtrace_pops_t fbt_pops = {
	NULL,
	fbt_provide_module,
	fbt_enable,
	fbt_disable,
	fbt_suspend,
	fbt_resume,
	fbt_getargdesc,
	NULL,
	NULL,
	fbt_destroy
};

static void
fbt_cleanup(dev_info_t *devi)
{
	dtrace_invop_remove(fbt_invop);
	ddi_remove_minor_node(devi, NULL);
	kmem_free(fbt_probetab, fbt_probetab_size * sizeof (fbt_probe_t *));
	fbt_probetab = NULL;
	fbt_probetab_mask = 0;
}

static int
fbt_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 (fbt_probetab_size == 0)
		fbt_probetab_size = FBT_PROBETAB_SIZE;

	fbt_probetab_mask = fbt_probetab_size - 1;
	fbt_probetab =
	    kmem_zalloc(fbt_probetab_size * sizeof (fbt_probe_t *), KM_SLEEP);

	dtrace_invop_add(fbt_invop);

	if (ddi_create_minor_node(devi, "fbt", S_IFCHR, 0,
	    DDI_PSEUDO, NULL) == DDI_FAILURE ||
	    dtrace_register("fbt", &fbt_attr, DTRACE_PRIV_KERNEL, 0,
	    &fbt_pops, NULL, &fbt_id) != 0) {
		fbt_cleanup(devi);
		return (DDI_FAILURE);
	}

	ddi_report_dev(devi);
	fbt_devi = devi;

	return (DDI_SUCCESS);
}

static int
fbt_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(fbt_id) != 0)
		return (DDI_FAILURE);

	fbt_cleanup(devi);

	return (DDI_SUCCESS);
}

/*ARGSUSED*/
static int
fbt_info(dev_info_t *dip, ddi_info_cmd_t infocmd, void *arg, void **result)
{
	int error;

	switch (infocmd) {
	case DDI_INFO_DEVT2DEVINFO:
		*result = (void *)fbt_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
fbt_open(dev_t *devp, int flag, int otyp, cred_t *cred_p)
{
	return (0);
}

static struct cb_ops fbt_cb_ops = {
	fbt_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 fbt_ops = {
	DEVO_REV,		/* devo_rev */
	0,			/* refcnt */
	fbt_info,		/* get_dev_info */
	nulldev,		/* identify */
	nulldev,		/* probe */
	fbt_attach,		/* attach */
	fbt_detach,		/* detach */
	nodev,			/* reset */
	&fbt_cb_ops,		/* driver operations */
	NULL,			/* bus operations */
	nodev			/* dev power */
};

/*
 * Module linkage information for the kernel.
 */
static struct modldrv modldrv = {
	&mod_driverops,		/* module type (this is a pseudo driver) */
	"Function Boundary Tracing",	/* name of module */
	&fbt_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));
}