xref: /illumos-gate/usr/src/lib/libdtrace/common/dt_as.c (revision 581cede61ac9c14d8d4ea452562a567189eead78)
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, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 #include <sys/types.h>
30 #include <strings.h>
31 #include <stdlib.h>
32 #include <assert.h>
33 
34 #include <dt_impl.h>
35 #include <dt_parser.h>
36 #include <dt_as.h>
37 
38 void
39 dt_irlist_create(dt_irlist_t *dlp)
40 {
41 	bzero(dlp, sizeof (dt_irlist_t));
42 	dlp->dl_label = 1;
43 }
44 
45 void
46 dt_irlist_destroy(dt_irlist_t *dlp)
47 {
48 	dt_irnode_t *dip, *nip;
49 
50 	for (dip = dlp->dl_list; dip != NULL; dip = nip) {
51 		nip = dip->di_next;
52 		free(dip);
53 	}
54 }
55 
56 void
57 dt_irlist_append(dt_irlist_t *dlp, dt_irnode_t *dip)
58 {
59 	if (dlp->dl_last != NULL)
60 		dlp->dl_last->di_next = dip;
61 	else
62 		dlp->dl_list = dip;
63 
64 	dlp->dl_last = dip;
65 
66 	if (dip->di_label == DT_LBL_NONE || dip->di_instr != DIF_INSTR_NOP)
67 		dlp->dl_len++; /* don't count forward refs in instr count */
68 }
69 
70 uint_t
71 dt_irlist_label(dt_irlist_t *dlp)
72 {
73 	return (dlp->dl_label++);
74 }
75 
76 /*ARGSUSED*/
77 static int
78 dt_countvar(dt_idhash_t *dhp, dt_ident_t *idp, void *data)
79 {
80 	size_t *np = data;
81 
82 	if (idp->di_flags & (DT_IDFLG_DIFR | DT_IDFLG_DIFW))
83 		(*np)++; /* include variable in vartab */
84 
85 	return (0);
86 }
87 
88 /*ARGSUSED*/
89 static int
90 dt_copyvar(dt_idhash_t *dhp, dt_ident_t *idp, void *data)
91 {
92 	dt_pcb_t *pcb = data;
93 	dtrace_difv_t *dvp;
94 	ssize_t stroff;
95 	dt_node_t dn;
96 
97 	if (!(idp->di_flags & (DT_IDFLG_DIFR | DT_IDFLG_DIFW)))
98 		return (0); /* omit variable from vartab */
99 
100 	dvp = &pcb->pcb_difo->dtdo_vartab[pcb->pcb_asvidx++];
101 	stroff = dt_strtab_insert(pcb->pcb_strtab, idp->di_name);
102 
103 	if (stroff == -1L)
104 		longjmp(pcb->pcb_jmpbuf, EDT_NOMEM);
105 	if (stroff > DIF_STROFF_MAX)
106 		longjmp(pcb->pcb_jmpbuf, EDT_STR2BIG);
107 
108 	dvp->dtdv_name = (uint_t)stroff;
109 	dvp->dtdv_id = idp->di_id;
110 	dvp->dtdv_flags = 0;
111 
112 	dvp->dtdv_kind = (idp->di_kind == DT_IDENT_ARRAY) ?
113 	    DIFV_KIND_ARRAY : DIFV_KIND_SCALAR;
114 
115 	if (idp->di_flags & DT_IDFLG_LOCAL)
116 		dvp->dtdv_scope = DIFV_SCOPE_LOCAL;
117 	else if (idp->di_flags & DT_IDFLG_TLS)
118 		dvp->dtdv_scope = DIFV_SCOPE_THREAD;
119 	else
120 		dvp->dtdv_scope = DIFV_SCOPE_GLOBAL;
121 
122 	if (idp->di_flags & DT_IDFLG_DIFR)
123 		dvp->dtdv_flags |= DIFV_F_REF;
124 	if (idp->di_flags & DT_IDFLG_DIFW)
125 		dvp->dtdv_flags |= DIFV_F_MOD;
126 
127 	bzero(&dn, sizeof (dn));
128 	dt_node_type_assign(&dn, idp->di_ctfp, idp->di_type);
129 	dt_node_diftype(pcb->pcb_hdl, &dn, &dvp->dtdv_type);
130 
131 	idp->di_flags &= ~(DT_IDFLG_DIFR | DT_IDFLG_DIFW);
132 	return (0);
133 }
134 
135 static ssize_t
136 dt_copystr(const char *s, size_t n, size_t off, dt_pcb_t *pcb)
137 {
138 	bcopy(s, pcb->pcb_difo->dtdo_strtab + off, n);
139 	return (n);
140 }
141 
142 /*
143  * Rewrite the xlate/xlarg instruction at dtdo_buf[i] so that the instruction's
144  * xltab index reflects the offset 'xi' of the assigned dtdo_xlmtab[] location.
145  * We track the cumulative references to translators and members in the pcb's
146  * pcb_asxrefs[] array, a two-dimensional array of bitmaps indexed by the
147  * global translator id and then by the corresponding translator member id.
148  */
149 static void
150 dt_as_xlate(dt_pcb_t *pcb, dtrace_difo_t *dp,
151     uint_t i, uint_t xi, dt_node_t *dnp)
152 {
153 	dtrace_hdl_t *dtp = pcb->pcb_hdl;
154 	dt_xlator_t *dxp = dnp->dn_membexpr->dn_xlator;
155 
156 	assert(i < dp->dtdo_len);
157 	assert(xi < dp->dtdo_xlmlen);
158 
159 	assert(dnp->dn_kind == DT_NODE_MEMBER);
160 	assert(dnp->dn_membexpr->dn_kind == DT_NODE_XLATOR);
161 
162 	assert(dxp->dx_id < dtp->dt_xlatorid);
163 	assert(dnp->dn_membid < dxp->dx_nmembers);
164 
165 	if (pcb->pcb_asxrefs == NULL) {
166 		pcb->pcb_asxreflen = dtp->dt_xlatorid;
167 		pcb->pcb_asxrefs =
168 		    dt_zalloc(dtp, sizeof (ulong_t *) * pcb->pcb_asxreflen);
169 		if (pcb->pcb_asxrefs == NULL)
170 			longjmp(pcb->pcb_jmpbuf, EDT_NOMEM);
171 	}
172 
173 	if (pcb->pcb_asxrefs[dxp->dx_id] == NULL) {
174 		pcb->pcb_asxrefs[dxp->dx_id] =
175 		    dt_zalloc(dtp, BT_SIZEOFMAP(dxp->dx_nmembers));
176 		if (pcb->pcb_asxrefs[dxp->dx_id] == NULL)
177 			longjmp(pcb->pcb_jmpbuf, EDT_NOMEM);
178 	}
179 
180 	dp->dtdo_buf[i] = DIF_INSTR_XLATE(
181 	    DIF_INSTR_OP(dp->dtdo_buf[i]), xi, DIF_INSTR_RD(dp->dtdo_buf[i]));
182 
183 	BT_SET(pcb->pcb_asxrefs[dxp->dx_id], dnp->dn_membid);
184 	dp->dtdo_xlmtab[xi] = dnp;
185 }
186 
187 static void
188 dt_as_undef(const dt_ident_t *idp, uint_t offset)
189 {
190 	const char *kind, *mark = (idp->di_flags & DT_IDFLG_USER) ? "``" : "`";
191 	const dtrace_syminfo_t *dts = idp->di_data;
192 
193 	if (idp->di_flags & DT_IDFLG_USER)
194 		kind = "user";
195 	else if (idp->di_flags & DT_IDFLG_PRIM)
196 		kind = "primary kernel";
197 	else
198 		kind = "loadable kernel";
199 
200 	yylineno = idp->di_lineno;
201 
202 	xyerror(D_ASRELO, "relocation remains against %s symbol %s%s%s (offset "
203 	    "0x%x)\n", kind, dts->dts_object, mark, dts->dts_name, offset);
204 }
205 
206 dtrace_difo_t *
207 dt_as(dt_pcb_t *pcb)
208 {
209 	dtrace_hdl_t *dtp = pcb->pcb_hdl;
210 	dt_irlist_t *dlp = &pcb->pcb_ir;
211 	uint_t *labels = NULL;
212 	dt_irnode_t *dip;
213 	dtrace_difo_t *dp;
214 	dt_ident_t *idp;
215 
216 	size_t n = 0;
217 	uint_t i;
218 
219 	uint_t kmask, kbits, umask, ubits;
220 	uint_t krel = 0, urel = 0, xlrefs = 0;
221 
222 	/*
223 	 * Select bitmasks based upon the desired symbol linking policy.  We
224 	 * test (di_extern->di_flags & xmask) == xbits to determine if the
225 	 * symbol should have a relocation entry generated in the loop below.
226 	 *
227 	 * DT_LINK_KERNEL = kernel symbols static, user symbols dynamic
228 	 * DT_LINK_PRIMARY = primary kernel symbols static, others dynamic
229 	 * DT_LINK_DYNAMIC = all symbols dynamic
230 	 * DT_LINK_STATIC = all symbols static
231 	 *
232 	 * By 'static' we mean that we use the symbol's value at compile-time
233 	 * in the final DIF.  By 'dynamic' we mean that we create a relocation
234 	 * table entry for the symbol's value so it can be relocated later.
235 	 */
236 	switch (dtp->dt_linkmode) {
237 	case DT_LINK_KERNEL:
238 		kmask = 0;
239 		kbits = -1u;
240 		umask = DT_IDFLG_USER;
241 		ubits = DT_IDFLG_USER;
242 		break;
243 	case DT_LINK_PRIMARY:
244 		kmask = DT_IDFLG_USER | DT_IDFLG_PRIM;
245 		kbits = 0;
246 		umask = DT_IDFLG_USER;
247 		ubits = DT_IDFLG_USER;
248 		break;
249 	case DT_LINK_DYNAMIC:
250 		kmask = DT_IDFLG_USER;
251 		kbits = 0;
252 		umask = DT_IDFLG_USER;
253 		ubits = DT_IDFLG_USER;
254 		break;
255 	case DT_LINK_STATIC:
256 		kmask = umask = 0;
257 		kbits = ubits = -1u;
258 		break;
259 	default:
260 		xyerror(D_UNKNOWN, "internal error -- invalid link mode %u\n",
261 		    dtp->dt_linkmode);
262 	}
263 
264 	assert(pcb->pcb_difo == NULL);
265 	pcb->pcb_difo = dt_zalloc(dtp, sizeof (dtrace_difo_t));
266 
267 	if ((dp = pcb->pcb_difo) == NULL)
268 		longjmp(pcb->pcb_jmpbuf, EDT_NOMEM);
269 
270 	dp->dtdo_buf = dt_alloc(dtp, sizeof (dif_instr_t) * dlp->dl_len);
271 
272 	if (dp->dtdo_buf == NULL)
273 		longjmp(pcb->pcb_jmpbuf, EDT_NOMEM);
274 
275 	if ((labels = dt_alloc(dtp, sizeof (uint_t) * dlp->dl_label)) == NULL)
276 		longjmp(pcb->pcb_jmpbuf, EDT_NOMEM);
277 
278 	/*
279 	 * Make an initial pass through the instruction list, filling in the
280 	 * instruction buffer with valid instructions and skipping labeled nops.
281 	 * While doing this, we also fill in our labels[] translation table
282 	 * and we count up the number of relocation table entries we will need.
283 	 */
284 	for (i = 0, dip = dlp->dl_list; dip != NULL; dip = dip->di_next) {
285 		if (dip->di_label != DT_LBL_NONE)
286 			labels[dip->di_label] = i;
287 
288 		if (dip->di_label == DT_LBL_NONE ||
289 		    dip->di_instr != DIF_INSTR_NOP)
290 			dp->dtdo_buf[i++] = dip->di_instr;
291 
292 		if (dip->di_extern == NULL)
293 			continue; /* no external references needed */
294 
295 		switch (DIF_INSTR_OP(dip->di_instr)) {
296 		case DIF_OP_SETX:
297 			idp = dip->di_extern;
298 			if ((idp->di_flags & kmask) == kbits)
299 				krel++;
300 			else if ((idp->di_flags & umask) == ubits)
301 				urel++;
302 			break;
303 		case DIF_OP_XLATE:
304 		case DIF_OP_XLARG:
305 			xlrefs++;
306 			break;
307 		default:
308 			xyerror(D_UNKNOWN, "unexpected assembler relocation "
309 			    "for opcode 0x%x\n", DIF_INSTR_OP(dip->di_instr));
310 		}
311 	}
312 
313 	assert(i == dlp->dl_len);
314 	dp->dtdo_len = dlp->dl_len;
315 
316 	/*
317 	 * Make a second pass through the instructions, relocating each branch
318 	 * label to the index of the final instruction in the buffer and noting
319 	 * any other instruction-specific DIFO flags such as dtdo_destructive.
320 	 */
321 	for (i = 0; i < dp->dtdo_len; i++) {
322 		dif_instr_t instr = dp->dtdo_buf[i];
323 		uint_t op = DIF_INSTR_OP(instr);
324 
325 		if (op == DIF_OP_CALL) {
326 			if (DIF_INSTR_SUBR(instr) == DIF_SUBR_COPYOUT ||
327 			    DIF_INSTR_SUBR(instr) == DIF_SUBR_COPYOUTSTR)
328 				dp->dtdo_destructive = 1;
329 			continue;
330 		}
331 
332 		if (op >= DIF_OP_BA && op <= DIF_OP_BLEU) {
333 			assert(DIF_INSTR_LABEL(instr) < dlp->dl_label);
334 			dp->dtdo_buf[i] = DIF_INSTR_BRANCH(op,
335 			    labels[DIF_INSTR_LABEL(instr)]);
336 		}
337 	}
338 
339 	dt_free(dtp, labels);
340 	pcb->pcb_asvidx = 0;
341 
342 	/*
343 	 * Allocate memory for the appropriate number of variable records and
344 	 * then fill in each variable record.  As we populate the variable
345 	 * table we insert the corresponding variable names into the strtab.
346 	 */
347 	(void) dt_idhash_iter(dtp->dt_tls, dt_countvar, &n);
348 	(void) dt_idhash_iter(dtp->dt_globals, dt_countvar, &n);
349 	(void) dt_idhash_iter(pcb->pcb_locals, dt_countvar, &n);
350 
351 	if (n != 0) {
352 		dp->dtdo_vartab = dt_alloc(dtp, n * sizeof (dtrace_difv_t));
353 		dp->dtdo_varlen = (uint32_t)n;
354 
355 		if (dp->dtdo_vartab == NULL)
356 			longjmp(pcb->pcb_jmpbuf, EDT_NOMEM);
357 
358 		(void) dt_idhash_iter(dtp->dt_tls, dt_copyvar, pcb);
359 		(void) dt_idhash_iter(dtp->dt_globals, dt_copyvar, pcb);
360 		(void) dt_idhash_iter(pcb->pcb_locals, dt_copyvar, pcb);
361 	}
362 
363 	/*
364 	 * Allocate memory for the appropriate number of relocation table
365 	 * entries based upon our kernel and user counts from the first pass.
366 	 */
367 	if (krel != 0) {
368 		dp->dtdo_kreltab = dt_alloc(dtp,
369 		    krel * sizeof (dof_relodesc_t));
370 		dp->dtdo_krelen = krel;
371 
372 		if (dp->dtdo_kreltab == NULL)
373 			longjmp(pcb->pcb_jmpbuf, EDT_NOMEM);
374 	}
375 
376 	if (urel != 0) {
377 		dp->dtdo_ureltab = dt_alloc(dtp,
378 		    urel * sizeof (dof_relodesc_t));
379 		dp->dtdo_urelen = urel;
380 
381 		if (dp->dtdo_ureltab == NULL)
382 			longjmp(pcb->pcb_jmpbuf, EDT_NOMEM);
383 	}
384 
385 	if (xlrefs != 0) {
386 		dp->dtdo_xlmtab = dt_zalloc(dtp, sizeof (dt_node_t *) * xlrefs);
387 		dp->dtdo_xlmlen = xlrefs;
388 
389 		if (dp->dtdo_xlmtab == NULL)
390 			longjmp(pcb->pcb_jmpbuf, EDT_NOMEM);
391 	}
392 
393 	/*
394 	 * If any relocations are needed, make another pass through the
395 	 * instruction list and fill in the relocation table entries.
396 	 */
397 	if (krel + urel + xlrefs != 0) {
398 		uint_t knodef = pcb->pcb_cflags & DTRACE_C_KNODEF;
399 		uint_t unodef = pcb->pcb_cflags & DTRACE_C_UNODEF;
400 
401 		dof_relodesc_t *krp = dp->dtdo_kreltab;
402 		dof_relodesc_t *urp = dp->dtdo_ureltab;
403 		dt_node_t **xlp = dp->dtdo_xlmtab;
404 
405 		i = 0; /* dtdo_buf[] index */
406 
407 		for (dip = dlp->dl_list; dip != NULL; dip = dip->di_next) {
408 			dof_relodesc_t *rp;
409 			ssize_t soff;
410 			uint_t nodef;
411 
412 			if (dip->di_label != DT_LBL_NONE &&
413 			    dip->di_instr == DIF_INSTR_NOP)
414 				continue; /* skip label declarations */
415 
416 			i++; /* advance dtdo_buf[] index */
417 
418 			if (DIF_INSTR_OP(dip->di_instr) == DIF_OP_XLATE ||
419 			    DIF_INSTR_OP(dip->di_instr) == DIF_OP_XLARG) {
420 				assert(dp->dtdo_buf[i - 1] == dip->di_instr);
421 				dt_as_xlate(pcb, dp, i - 1, (uint_t)
422 				    (xlp++ - dp->dtdo_xlmtab), dip->di_extern);
423 				continue;
424 			}
425 
426 			if ((idp = dip->di_extern) == NULL)
427 				continue; /* no relocation entry needed */
428 
429 			if ((idp->di_flags & kmask) == kbits) {
430 				nodef = knodef;
431 				rp = krp++;
432 			} else if ((idp->di_flags & umask) == ubits) {
433 				nodef = unodef;
434 				rp = urp++;
435 			} else
436 				continue;
437 
438 			if (!nodef)
439 				dt_as_undef(idp, i);
440 
441 			assert(DIF_INSTR_OP(dip->di_instr) == DIF_OP_SETX);
442 			soff = dt_strtab_insert(pcb->pcb_strtab, idp->di_name);
443 
444 			if (soff == -1L)
445 				longjmp(pcb->pcb_jmpbuf, EDT_NOMEM);
446 			if (soff > DIF_STROFF_MAX)
447 				longjmp(pcb->pcb_jmpbuf, EDT_STR2BIG);
448 
449 			rp->dofr_name = (dof_stridx_t)soff;
450 			rp->dofr_type = DOF_RELO_SETX;
451 			rp->dofr_offset = DIF_INSTR_INTEGER(dip->di_instr) *
452 			    sizeof (uint64_t);
453 			rp->dofr_data = 0;
454 		}
455 
456 		assert(krp == dp->dtdo_kreltab + dp->dtdo_krelen);
457 		assert(urp == dp->dtdo_ureltab + dp->dtdo_urelen);
458 		assert(xlp == dp->dtdo_xlmtab + dp->dtdo_xlmlen);
459 		assert(i == dp->dtdo_len);
460 	}
461 
462 	/*
463 	 * Allocate memory for the compiled string table and then copy the
464 	 * chunks from the string table into the final string buffer.
465 	 */
466 	if ((n = dt_strtab_size(pcb->pcb_strtab)) != 0) {
467 		if ((dp->dtdo_strtab = dt_alloc(dtp, n)) == NULL)
468 			longjmp(pcb->pcb_jmpbuf, EDT_NOMEM);
469 
470 		(void) dt_strtab_write(pcb->pcb_strtab,
471 		    (dt_strtab_write_f *)dt_copystr, pcb);
472 		dp->dtdo_strlen = (uint32_t)n;
473 	}
474 
475 	/*
476 	 * Allocate memory for the compiled integer table and then copy the
477 	 * integer constants from the table into the final integer buffer.
478 	 */
479 	if ((n = dt_inttab_size(pcb->pcb_inttab)) != 0) {
480 		if ((dp->dtdo_inttab = dt_alloc(dtp,
481 		    n * sizeof (uint64_t))) == NULL)
482 			longjmp(pcb->pcb_jmpbuf, EDT_NOMEM);
483 
484 		dt_inttab_write(pcb->pcb_inttab, dp->dtdo_inttab);
485 		dp->dtdo_intlen = (uint32_t)n;
486 	}
487 
488 	/*
489 	 * Fill in the DIFO return type from the type associated with the
490 	 * node saved in pcb_dret, and then clear pcb_difo and pcb_dret
491 	 * now that the assembler has completed successfully.
492 	 */
493 	dt_node_diftype(dtp, pcb->pcb_dret, &dp->dtdo_rtype);
494 	pcb->pcb_difo = NULL;
495 	pcb->pcb_dret = NULL;
496 
497 	if (pcb->pcb_cflags & DTRACE_C_DIFV)
498 		dt_dis(dp, stderr);
499 
500 	return (dp);
501 }
502