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 */
55
56#if   defined(__x86_64__)
57typedef kern_return_t (*perfCallback)(int, struct savearea_t *, uintptr_t *, __unused int);
58extern perfCallback tempDTraceTrapHook;
59extern kern_return_t fbt_perfCallback(int, struct savearea_t *, uintptr_t *, __unused int);
60#else
61#error Unknown architecture
62#endif
63
64#define	FBT_ADDR2NDX(addr)	((((uintptr_t)(addr)) >> 4) & fbt_probetab_mask)
65#define	FBT_PROBETAB_SIZE	0x8000		/* 32k entries -- 128K total */
66
67static dev_info_t		*fbt_devi;
68static int				fbt_probetab_size;
69dtrace_provider_id_t	fbt_id;
70fbt_probe_t				**fbt_probetab;
71int						fbt_probetab_mask;
72static int				fbt_verbose = 0;
73
74void fbt_init( void );
75
76/*ARGSUSED*/
77static void
78fbt_destroy(void *arg, dtrace_id_t id, void *parg)
79{
80#pragma unused(arg,id)
81	fbt_probe_t *fbt = parg, *next, *hash, *last;
82	int ndx;
83
84	do {
85		/*
86		 * Now we need to remove this probe from the fbt_probetab.
87		 */
88		ndx = FBT_ADDR2NDX(fbt->fbtp_patchpoint);
89		last = NULL;
90		hash = fbt_probetab[ndx];
91
92		while (hash != fbt) {
93			ASSERT(hash != NULL);
94			last = hash;
95			hash = hash->fbtp_hashnext;
96		}
97
98		if (last != NULL) {
99			last->fbtp_hashnext = fbt->fbtp_hashnext;
100		} else {
101			fbt_probetab[ndx] = fbt->fbtp_hashnext;
102		}
103
104		next = fbt->fbtp_next;
105		kmem_free(fbt, sizeof (fbt_probe_t));
106
107		fbt = next;
108	} while (fbt != NULL);
109}
110
111/*ARGSUSED*/
112int
113fbt_enable(void *arg, dtrace_id_t id, void *parg)
114{
115#pragma unused(arg,id)
116	fbt_probe_t *fbt = parg;
117	struct modctl *ctl = NULL;
118
119    for (; fbt != NULL; fbt = fbt->fbtp_next) {
120
121	ctl = fbt->fbtp_ctl;
122
123	if (!ctl->mod_loaded) {
124		if (fbt_verbose) {
125			cmn_err(CE_NOTE, "fbt is failing for probe %s "
126			    "(module %s unloaded)",
127			    fbt->fbtp_name, ctl->mod_modname);
128		}
129
130		continue;
131	}
132
133	/*
134	 * Now check that our modctl has the expected load count.  If it
135	 * doesn't, this module must have been unloaded and reloaded -- and
136	 * we're not going to touch it.
137	 */
138	if (ctl->mod_loadcnt != fbt->fbtp_loadcnt) {
139		if (fbt_verbose) {
140			cmn_err(CE_NOTE, "fbt is failing for probe %s "
141			    "(module %s reloaded)",
142			    fbt->fbtp_name, ctl->mod_modname);
143		}
144
145		continue;
146	}
147
148	dtrace_casptr(&tempDTraceTrapHook, NULL, fbt_perfCallback);
149	if (tempDTraceTrapHook != (perfCallback)fbt_perfCallback) {
150		if (fbt_verbose) {
151			cmn_err(CE_NOTE, "fbt_enable is failing for probe %s "
152			    "in module %s: tempDTraceTrapHook already occupied.",
153			    fbt->fbtp_name, ctl->mod_modname);
154		}
155		continue;
156	}
157
158	if (fbt->fbtp_currentval != fbt->fbtp_patchval) {
159		(void)ml_nofault_copy( (vm_offset_t)&fbt->fbtp_patchval, (vm_offset_t)fbt->fbtp_patchpoint,
160								sizeof(fbt->fbtp_patchval));
161                fbt->fbtp_currentval = fbt->fbtp_patchval;
162		ctl->mod_nenabled++;
163	}
164
165    }
166
167    dtrace_membar_consumer();
168
169    return (0);
170}
171
172/*ARGSUSED*/
173static void
174fbt_disable(void *arg, dtrace_id_t id, void *parg)
175{
176#pragma unused(arg,id)
177	fbt_probe_t *fbt = parg;
178	struct modctl *ctl = NULL;
179
180	for (; fbt != NULL; fbt = fbt->fbtp_next) {
181	    ctl = fbt->fbtp_ctl;
182
183	    if (!ctl->mod_loaded || (ctl->mod_loadcnt != fbt->fbtp_loadcnt))
184		continue;
185
186	    if (fbt->fbtp_currentval != fbt->fbtp_savedval) {
187		(void)ml_nofault_copy( (vm_offset_t)&fbt->fbtp_savedval, (vm_offset_t)fbt->fbtp_patchpoint,
188								sizeof(fbt->fbtp_savedval));
189		fbt->fbtp_currentval = fbt->fbtp_savedval;
190		ASSERT(ctl->mod_nenabled > 0);
191		ctl->mod_nenabled--;
192	    }
193	}
194	dtrace_membar_consumer();
195}
196
197/*ARGSUSED*/
198static void
199fbt_suspend(void *arg, dtrace_id_t id, void *parg)
200{
201#pragma unused(arg,id)
202	fbt_probe_t *fbt = parg;
203	struct modctl *ctl = NULL;
204
205	for (; fbt != NULL; fbt = fbt->fbtp_next) {
206	    ctl = fbt->fbtp_ctl;
207
208	    ASSERT(ctl->mod_nenabled > 0);
209	    if (!ctl->mod_loaded || (ctl->mod_loadcnt != fbt->fbtp_loadcnt))
210		continue;
211
212	    (void)ml_nofault_copy( (vm_offset_t)&fbt->fbtp_savedval, (vm_offset_t)fbt->fbtp_patchpoint,
213								sizeof(fbt->fbtp_savedval));
214
215
216	    fbt->fbtp_currentval = fbt->fbtp_savedval;
217	}
218
219	dtrace_membar_consumer();
220}
221
222/*ARGSUSED*/
223static void
224fbt_resume(void *arg, dtrace_id_t id, void *parg)
225{
226#pragma unused(arg,id)
227	fbt_probe_t *fbt = parg;
228	struct modctl *ctl = NULL;
229
230	for (; fbt != NULL; fbt = fbt->fbtp_next) {
231	    ctl = fbt->fbtp_ctl;
232
233	    ASSERT(ctl->mod_nenabled > 0);
234	    if (!ctl->mod_loaded || (ctl->mod_loadcnt != fbt->fbtp_loadcnt))
235		continue;
236
237	    dtrace_casptr(&tempDTraceTrapHook, NULL, fbt_perfCallback);
238	    if (tempDTraceTrapHook != (perfCallback)fbt_perfCallback) {
239		if (fbt_verbose) {
240			cmn_err(CE_NOTE, "fbt_resume is failing for probe %s "
241			    "in module %s: tempDTraceTrapHook already occupied.",
242			    fbt->fbtp_name, ctl->mod_modname);
243		}
244		return;
245	    }
246
247	    (void)ml_nofault_copy( (vm_offset_t)&fbt->fbtp_patchval, (vm_offset_t)fbt->fbtp_patchpoint,
248								sizeof(fbt->fbtp_patchval));
249
250
251  	    fbt->fbtp_currentval = fbt->fbtp_patchval;
252	}
253
254	dtrace_membar_consumer();
255}
256
257/*
258 * APPLE NOTE: fbt_getargdesc not implemented
259 */
260#if !defined(__APPLE__)
261/*ARGSUSED*/
262static void
263fbt_getargdesc(void *arg, dtrace_id_t id, void *parg, dtrace_argdesc_t *desc)
264{
265	fbt_probe_t *fbt = parg;
266	struct modctl *ctl = fbt->fbtp_ctl;
267	struct module *mp = ctl->mod_mp;
268	ctf_file_t *fp = NULL, *pfp;
269	ctf_funcinfo_t f;
270	int error;
271	ctf_id_t argv[32], type;
272	int argc = sizeof (argv) / sizeof (ctf_id_t);
273	const char *parent;
274
275	if (!ctl->mod_loaded || (ctl->mod_loadcnt != fbt->fbtp_loadcnt))
276		goto err;
277
278	if (fbt->fbtp_roffset != 0 && desc->dtargd_ndx == 0) {
279		(void) strlcpy(desc->dtargd_native, "int",
280			       sizeof(desc->dtargd_native));
281		return;
282	}
283
284	if ((fp = ctf_modopen(mp, &error)) == NULL) {
285		/*
286		 * We have no CTF information for this module -- and therefore
287		 * no args[] information.
288		 */
289		goto err;
290	}
291
292	/*
293	 * If we have a parent container, we must manually import it.
294	 */
295	if ((parent = ctf_parent_name(fp)) != NULL) {
296		struct modctl *mp = &modules;
297		struct modctl *mod = NULL;
298
299		/*
300		 * We must iterate over all modules to find the module that
301		 * is our parent.
302		 */
303		do {
304			if (strcmp(mp->mod_modname, parent) == 0) {
305				mod = mp;
306				break;
307			}
308		} while ((mp = mp->mod_next) != &modules);
309
310		if (mod == NULL)
311			goto err;
312
313		if ((pfp = ctf_modopen(mod->mod_mp, &error)) == NULL) {
314			goto err;
315		}
316
317		if (ctf_import(fp, pfp) != 0) {
318			ctf_close(pfp);
319			goto err;
320		}
321
322		ctf_close(pfp);
323	}
324
325	if (ctf_func_info(fp, fbt->fbtp_symndx, &f) == CTF_ERR)
326		goto err;
327
328	if (fbt->fbtp_roffset != 0) {
329		if (desc->dtargd_ndx > 1)
330			goto err;
331
332		ASSERT(desc->dtargd_ndx == 1);
333		type = f.ctc_return;
334	} else {
335		if (desc->dtargd_ndx + 1 > f.ctc_argc)
336			goto err;
337
338		if (ctf_func_args(fp, fbt->fbtp_symndx, argc, argv) == CTF_ERR)
339			goto err;
340
341		type = argv[desc->dtargd_ndx];
342	}
343
344	if (ctf_type_name(fp, type, desc->dtargd_native,
345	    DTRACE_ARGTYPELEN) != NULL) {
346		ctf_close(fp);
347		return;
348	}
349err:
350	if (fp != NULL)
351		ctf_close(fp);
352
353	desc->dtargd_ndx = DTRACE_ARGNONE;
354}
355#endif /* __APPLE__ */
356
357static dtrace_pattr_t fbt_attr = {
358{ DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_ISA },
359{ DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_UNKNOWN },
360{ DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_UNKNOWN },
361{ DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_ISA },
362{ DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_ISA },
363};
364
365static dtrace_pops_t fbt_pops = {
366	NULL,
367	fbt_provide_module,
368	fbt_enable,
369	fbt_disable,
370	fbt_suspend,
371	fbt_resume,
372	NULL, /*  APPLE NOTE: fbt_getargdesc not implemented */
373	NULL,
374	NULL,
375	fbt_destroy
376};
377
378static void
379fbt_cleanup(dev_info_t *devi)
380{
381	dtrace_invop_remove(fbt_invop);
382	ddi_remove_minor_node(devi, NULL);
383	kmem_free(fbt_probetab, fbt_probetab_size * sizeof (fbt_probe_t *));
384	fbt_probetab = NULL;
385	fbt_probetab_mask = 0;
386}
387
388static int
389fbt_attach(dev_info_t *devi, ddi_attach_cmd_t cmd)
390{
391	switch (cmd) {
392	case DDI_ATTACH:
393		break;
394	case DDI_RESUME:
395		return (DDI_SUCCESS);
396	default:
397		return (DDI_FAILURE);
398	}
399
400	if (fbt_probetab_size == 0)
401		fbt_probetab_size = FBT_PROBETAB_SIZE;
402
403	fbt_probetab_mask = fbt_probetab_size - 1;
404	fbt_probetab =
405	    kmem_zalloc(fbt_probetab_size * sizeof (fbt_probe_t *), KM_SLEEP);
406
407	dtrace_invop_add(fbt_invop);
408
409	if (ddi_create_minor_node(devi, "fbt", S_IFCHR, 0,
410	    DDI_PSEUDO, 0) == DDI_FAILURE ||
411	    dtrace_register("fbt", &fbt_attr, DTRACE_PRIV_KERNEL, NULL,
412	    &fbt_pops, NULL, &fbt_id) != 0) {
413		fbt_cleanup(devi);
414		return (DDI_FAILURE);
415	}
416
417	ddi_report_dev(devi);
418	fbt_devi = devi;
419
420	return (DDI_SUCCESS);
421}
422
423static d_open_t _fbt_open;
424
425static int
426_fbt_open(dev_t dev, int flags, int devtype, struct proc *p)
427{
428#pragma unused(dev,flags,devtype,p)
429	return 0;
430}
431
432#define FBT_MAJOR  -24 /* let the kernel pick the device number */
433
434/*
435 * A struct describing which functions will get invoked for certain
436 * actions.
437 */
438static struct cdevsw fbt_cdevsw =
439{
440	_fbt_open,		/* open */
441	eno_opcl,			/* close */
442	eno_rdwrt,			/* read */
443	eno_rdwrt,			/* write */
444	eno_ioctl,			/* ioctl */
445	(stop_fcn_t *)nulldev, /* stop */
446	(reset_fcn_t *)nulldev, /* reset */
447	NULL,				/* tty's */
448	eno_select,			/* select */
449	eno_mmap,			/* mmap */
450	eno_strat,			/* strategy */
451	eno_getc,			/* getc */
452	eno_putc,			/* putc */
453	0					/* type */
454};
455
456int gIgnoreFBTBlacklist = 0;
457static int gFBTInited = 0;
458#undef kmem_alloc /* from its binding to dt_kmem_alloc glue */
459#undef kmem_free /* from its binding to dt_kmem_free glue */
460#include <vm/vm_kern.h>
461
462void
463fbt_init( void )
464{
465	if (0 == gFBTInited)
466	{
467		int majdevno = cdevsw_add(FBT_MAJOR, &fbt_cdevsw);
468
469		if (majdevno < 0) {
470			printf("fbt_init: failed to allocate a major number!\n");
471			return;
472		}
473
474		PE_parse_boot_argn("IgnoreFBTBlacklist", &gIgnoreFBTBlacklist, sizeof (gIgnoreFBTBlacklist));
475
476		fbt_attach( (dev_info_t	*)(uintptr_t)majdevno, DDI_ATTACH );
477
478		gFBTInited = 1; /* Ensure this initialization occurs just one time. */
479	}
480	else
481		panic("fbt_init: called twice!\n");
482}
483#undef FBT_MAJOR
484