1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21/*
22 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
23 * Use is subject to license terms.
24 */
25
26/* #pragma ident	"@(#)fbt.c	1.18	07/01/10 SMI" */
27
28#ifdef KERNEL
29#ifndef _KERNEL
30#define _KERNEL /* Solaris vs. Darwin */
31#endif
32#endif
33
34#include <mach-o/loader.h>
35#include <libkern/kernel_mach_header.h>
36
37#include <sys/param.h>
38#include <sys/systm.h>
39#include <sys/errno.h>
40#include <sys/stat.h>
41#include <sys/ioctl.h>
42#include <sys/conf.h>
43#include <sys/fcntl.h>
44#include <miscfs/devfs/devfs.h>
45#include <pexpert/pexpert.h>
46
47#include <sys/dtrace.h>
48#include <sys/dtrace_impl.h>
49#include <sys/fbt.h>
50
51#include <sys/dtrace_glue.h>
52
53/* #include <machine/trap.h> */
54struct savearea_t; /* Used anonymously */
55typedef kern_return_t (*perfCallback)(int, struct savearea_t *, uintptr_t *, int);
56
57extern perfCallback tempDTraceTrapHook;
58extern kern_return_t fbt_perfCallback(int, struct savearea_t *, uintptr_t *);
59
60#define	FBT_ADDR2NDX(addr)	((((uintptr_t)(addr)) >> 4) & fbt_probetab_mask)
61#define	FBT_PROBETAB_SIZE	0x8000		/* 32k entries -- 128K total */
62
63static dev_info_t		*fbt_devi;
64static int				fbt_probetab_size;
65dtrace_provider_id_t	fbt_id;
66fbt_probe_t				**fbt_probetab;
67int						fbt_probetab_mask;
68static int				fbt_verbose = 0;
69
70void fbt_init( void );
71
72/*ARGSUSED*/
73static void
74fbt_destroy(void *arg, dtrace_id_t id, void *parg)
75{
76#pragma unused(arg,id)
77	fbt_probe_t *fbt = parg, *next, *hash, *last;
78	int ndx;
79
80	do {
81		/*
82		 * Now we need to remove this probe from the fbt_probetab.
83		 */
84		ndx = FBT_ADDR2NDX(fbt->fbtp_patchpoint);
85		last = NULL;
86		hash = fbt_probetab[ndx];
87
88		while (hash != fbt) {
89			ASSERT(hash != NULL);
90			last = hash;
91			hash = hash->fbtp_hashnext;
92		}
93
94		if (last != NULL) {
95			last->fbtp_hashnext = fbt->fbtp_hashnext;
96		} else {
97			fbt_probetab[ndx] = fbt->fbtp_hashnext;
98		}
99
100		next = fbt->fbtp_next;
101		kmem_free(fbt, sizeof (fbt_probe_t));
102
103		fbt = next;
104	} while (fbt != NULL);
105}
106
107/*ARGSUSED*/
108int
109fbt_enable(void *arg, dtrace_id_t id, void *parg)
110{
111#pragma unused(arg,id)
112	fbt_probe_t *fbt = parg;
113	struct modctl *ctl = NULL;
114
115    for (; fbt != NULL; fbt = fbt->fbtp_next) {
116
117	ctl = fbt->fbtp_ctl;
118
119	if (!ctl->mod_loaded) {
120		if (fbt_verbose) {
121			cmn_err(CE_NOTE, "fbt is failing for probe %s "
122			    "(module %s unloaded)",
123			    fbt->fbtp_name, ctl->mod_modname);
124		}
125
126		continue;
127	}
128
129	/*
130	 * Now check that our modctl has the expected load count.  If it
131	 * doesn't, this module must have been unloaded and reloaded -- and
132	 * we're not going to touch it.
133	 */
134	if (ctl->mod_loadcnt != fbt->fbtp_loadcnt) {
135		if (fbt_verbose) {
136			cmn_err(CE_NOTE, "fbt is failing for probe %s "
137			    "(module %s reloaded)",
138			    fbt->fbtp_name, ctl->mod_modname);
139		}
140
141		continue;
142	}
143
144	dtrace_casptr(&tempDTraceTrapHook, NULL, fbt_perfCallback);
145	if (tempDTraceTrapHook != (perfCallback)fbt_perfCallback) {
146		if (fbt_verbose) {
147			cmn_err(CE_NOTE, "fbt_enable is failing for probe %s "
148			    "in module %s: tempDTraceTrapHook already occupied.",
149			    fbt->fbtp_name, ctl->mod_modname);
150		}
151		continue;
152	}
153
154	if (fbt->fbtp_currentval != fbt->fbtp_patchval) {
155		(void)ml_nofault_copy( (vm_offset_t)&fbt->fbtp_patchval, (vm_offset_t)fbt->fbtp_patchpoint,
156								sizeof(fbt->fbtp_patchval));
157                fbt->fbtp_currentval = fbt->fbtp_patchval;
158		ctl->mod_nenabled++;
159	}
160
161    }
162
163    dtrace_membar_consumer();
164
165    return (0);
166}
167
168/*ARGSUSED*/
169static void
170fbt_disable(void *arg, dtrace_id_t id, void *parg)
171{
172#pragma unused(arg,id)
173	fbt_probe_t *fbt = parg;
174	struct modctl *ctl = NULL;
175
176	for (; fbt != NULL; fbt = fbt->fbtp_next) {
177	    ctl = fbt->fbtp_ctl;
178
179	    if (!ctl->mod_loaded || (ctl->mod_loadcnt != fbt->fbtp_loadcnt))
180		continue;
181
182	    if (fbt->fbtp_currentval != fbt->fbtp_savedval) {
183		(void)ml_nofault_copy( (vm_offset_t)&fbt->fbtp_savedval, (vm_offset_t)fbt->fbtp_patchpoint,
184								sizeof(fbt->fbtp_savedval));
185		fbt->fbtp_currentval = fbt->fbtp_savedval;
186		ASSERT(ctl->mod_nenabled > 0);
187		ctl->mod_nenabled--;
188	    }
189	}
190	dtrace_membar_consumer();
191}
192
193/*ARGSUSED*/
194static void
195fbt_suspend(void *arg, dtrace_id_t id, void *parg)
196{
197#pragma unused(arg,id)
198	fbt_probe_t *fbt = parg;
199	struct modctl *ctl = NULL;
200
201	for (; fbt != NULL; fbt = fbt->fbtp_next) {
202	    ctl = fbt->fbtp_ctl;
203
204	    ASSERT(ctl->mod_nenabled > 0);
205	    if (!ctl->mod_loaded || (ctl->mod_loadcnt != fbt->fbtp_loadcnt))
206		continue;
207
208	    (void)ml_nofault_copy( (vm_offset_t)&fbt->fbtp_savedval, (vm_offset_t)fbt->fbtp_patchpoint,
209								sizeof(fbt->fbtp_savedval));
210	    fbt->fbtp_currentval = fbt->fbtp_savedval;
211	}
212
213	dtrace_membar_consumer();
214}
215
216/*ARGSUSED*/
217static void
218fbt_resume(void *arg, dtrace_id_t id, void *parg)
219{
220#pragma unused(arg,id)
221	fbt_probe_t *fbt = parg;
222	struct modctl *ctl = NULL;
223
224	for (; fbt != NULL; fbt = fbt->fbtp_next) {
225	    ctl = fbt->fbtp_ctl;
226
227	    ASSERT(ctl->mod_nenabled > 0);
228	    if (!ctl->mod_loaded || (ctl->mod_loadcnt != fbt->fbtp_loadcnt))
229		continue;
230
231	    dtrace_casptr(&tempDTraceTrapHook, NULL, fbt_perfCallback);
232	    if (tempDTraceTrapHook != (perfCallback)fbt_perfCallback) {
233		if (fbt_verbose) {
234			cmn_err(CE_NOTE, "fbt_resume is failing for probe %s "
235			    "in module %s: tempDTraceTrapHook already occupied.",
236			    fbt->fbtp_name, ctl->mod_modname);
237		}
238		return;
239	    }
240
241	    (void)ml_nofault_copy( (vm_offset_t)&fbt->fbtp_patchval, (vm_offset_t)fbt->fbtp_patchpoint,
242								sizeof(fbt->fbtp_patchval));
243  	    fbt->fbtp_currentval = fbt->fbtp_patchval;
244	}
245
246	dtrace_membar_consumer();
247}
248
249#if !defined(__APPLE__)
250/*ARGSUSED*/
251static void
252fbt_getargdesc(void *arg, dtrace_id_t id, void *parg, dtrace_argdesc_t *desc)
253{
254	fbt_probe_t *fbt = parg;
255	struct modctl *ctl = fbt->fbtp_ctl;
256	struct module *mp = ctl->mod_mp;
257	ctf_file_t *fp = NULL, *pfp;
258	ctf_funcinfo_t f;
259	int error;
260	ctf_id_t argv[32], type;
261	int argc = sizeof (argv) / sizeof (ctf_id_t);
262	const char *parent;
263
264	if (!ctl->mod_loaded || (ctl->mod_loadcnt != fbt->fbtp_loadcnt))
265		goto err;
266
267	if (fbt->fbtp_roffset != 0 && desc->dtargd_ndx == 0) {
268		(void) strlcpy(desc->dtargd_native, "int",
269			       sizeof(desc->dtargd_native));
270		return;
271	}
272
273	if ((fp = ctf_modopen(mp, &error)) == NULL) {
274		/*
275		 * We have no CTF information for this module -- and therefore
276		 * no args[] information.
277		 */
278		goto err;
279	}
280
281	/*
282	 * If we have a parent container, we must manually import it.
283	 */
284	if ((parent = ctf_parent_name(fp)) != NULL) {
285		struct modctl *mp = &modules;
286		struct modctl *mod = NULL;
287
288		/*
289		 * We must iterate over all modules to find the module that
290		 * is our parent.
291		 */
292		do {
293			if (strcmp(mp->mod_modname, parent) == 0) {
294				mod = mp;
295				break;
296			}
297		} while ((mp = mp->mod_next) != &modules);
298
299		if (mod == NULL)
300			goto err;
301
302		if ((pfp = ctf_modopen(mod->mod_mp, &error)) == NULL) {
303			goto err;
304		}
305
306		if (ctf_import(fp, pfp) != 0) {
307			ctf_close(pfp);
308			goto err;
309		}
310
311		ctf_close(pfp);
312	}
313
314	if (ctf_func_info(fp, fbt->fbtp_symndx, &f) == CTF_ERR)
315		goto err;
316
317	if (fbt->fbtp_roffset != 0) {
318		if (desc->dtargd_ndx > 1)
319			goto err;
320
321		ASSERT(desc->dtargd_ndx == 1);
322		type = f.ctc_return;
323	} else {
324		if (desc->dtargd_ndx + 1 > f.ctc_argc)
325			goto err;
326
327		if (ctf_func_args(fp, fbt->fbtp_symndx, argc, argv) == CTF_ERR)
328			goto err;
329
330		type = argv[desc->dtargd_ndx];
331	}
332
333	if (ctf_type_name(fp, type, desc->dtargd_native,
334	    DTRACE_ARGTYPELEN) != NULL) {
335		ctf_close(fp);
336		return;
337	}
338err:
339	if (fp != NULL)
340		ctf_close(fp);
341
342	desc->dtargd_ndx = DTRACE_ARGNONE;
343}
344#endif /* __APPLE__ */
345
346static dtrace_pattr_t fbt_attr = {
347{ DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_ISA },
348{ DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_UNKNOWN },
349{ DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_UNKNOWN },
350{ DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_ISA },
351{ DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_ISA },
352};
353
354static dtrace_pops_t fbt_pops = {
355	NULL,
356	fbt_provide_module,
357	fbt_enable,
358	fbt_disable,
359	fbt_suspend,
360	fbt_resume,
361#if !defined(__APPLE__)
362	fbt_getargdesc,
363#else
364	NULL, /* FIXME: where to look for xnu? */
365#endif /* __APPLE__ */
366	NULL,
367	NULL,
368	fbt_destroy
369};
370
371static void
372fbt_cleanup(dev_info_t *devi)
373{
374	dtrace_invop_remove(fbt_invop);
375	ddi_remove_minor_node(devi, NULL);
376	kmem_free(fbt_probetab, fbt_probetab_size * sizeof (fbt_probe_t *));
377	fbt_probetab = NULL;
378	fbt_probetab_mask = 0;
379}
380
381static int
382fbt_attach(dev_info_t *devi, ddi_attach_cmd_t cmd)
383{
384	switch (cmd) {
385	case DDI_ATTACH:
386		break;
387	case DDI_RESUME:
388		return (DDI_SUCCESS);
389	default:
390		return (DDI_FAILURE);
391	}
392
393	if (fbt_probetab_size == 0)
394		fbt_probetab_size = FBT_PROBETAB_SIZE;
395
396	fbt_probetab_mask = fbt_probetab_size - 1;
397	fbt_probetab =
398	    kmem_zalloc(fbt_probetab_size * sizeof (fbt_probe_t *), KM_SLEEP);
399
400	dtrace_invop_add(fbt_invop);
401
402#if !defined(__APPLE__)
403	if (ddi_create_minor_node(devi, "fbt", S_IFCHR, 0,
404	    DDI_PSEUDO, NULL) == DDI_FAILURE ||
405	    dtrace_register("fbt", &fbt_attr, DTRACE_PRIV_KERNEL, NULL,
406	    &fbt_pops, NULL, &fbt_id) != 0) {
407		fbt_cleanup(devi);
408		return (DDI_FAILURE);
409	}
410#else
411	if (ddi_create_minor_node(devi, "fbt", S_IFCHR, 0,
412	    DDI_PSEUDO, 0) == DDI_FAILURE ||
413	    dtrace_register("fbt", &fbt_attr, DTRACE_PRIV_KERNEL, NULL,
414	    &fbt_pops, NULL, &fbt_id) != 0) {
415		fbt_cleanup(devi);
416		return (DDI_FAILURE);
417	}
418#endif /* __APPLE__ */
419
420	ddi_report_dev(devi);
421	fbt_devi = devi;
422
423	return (DDI_SUCCESS);
424}
425
426static d_open_t _fbt_open;
427
428static int
429_fbt_open(dev_t dev, int flags, int devtype, struct proc *p)
430{
431#pragma unused(dev,flags,devtype,p)
432	return 0;
433}
434
435#define FBT_MAJOR  -24 /* let the kernel pick the device number */
436
437/*
438 * A struct describing which functions will get invoked for certain
439 * actions.
440 */
441static struct cdevsw fbt_cdevsw =
442{
443	_fbt_open,		/* open */
444	eno_opcl,			/* close */
445	eno_rdwrt,			/* read */
446	eno_rdwrt,			/* write */
447	eno_ioctl,			/* ioctl */
448	(stop_fcn_t *)nulldev, /* stop */
449	(reset_fcn_t *)nulldev, /* reset */
450	NULL,				/* tty's */
451	eno_select,			/* select */
452	eno_mmap,			/* mmap */
453	eno_strat,			/* strategy */
454	eno_getc,			/* getc */
455	eno_putc,			/* putc */
456	0					/* type */
457};
458
459int gIgnoreFBTBlacklist = 0;
460static int gFBTInited = 0;
461#undef kmem_alloc /* from its binding to dt_kmem_alloc glue */
462#undef kmem_free /* from its binding to dt_kmem_free glue */
463#include <vm/vm_kern.h>
464
465void
466fbt_init( void )
467{
468	if (0 == gFBTInited)
469	{
470		int majdevno = cdevsw_add(FBT_MAJOR, &fbt_cdevsw);
471
472		if (majdevno < 0) {
473			printf("fbt_init: failed to allocate a major number!\n");
474			return;
475		}
476
477		PE_parse_boot_argn("IgnoreFBTBlacklist", &gIgnoreFBTBlacklist, sizeof (gIgnoreFBTBlacklist));
478
479		fbt_attach( (dev_info_t	*)(uintptr_t)majdevno, DDI_ATTACH );
480
481		gFBTInited = 1; /* Ensure this initialization occurs just one time. */
482	}
483	else
484		panic("fbt_init: called twice!\n");
485}
486#undef FBT_MAJOR
487