xref: /titanic_50/usr/src/cmd/sgs/rtld/sparc/sparc_elf.c (revision 7c478bd95313f5f23a4c958a745db2134aa03244)
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 (c) 1988 AT&T
24  *	  All Rights Reserved
25  *
26  *
27  *	Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
28  *	Use is subject to license terms.
29  */
30 #pragma ident	"%Z%%M%	%I%	%E% SMI"
31 
32 /*
33  * SPARC machine dependent and ELF file class dependent functions.
34  * Contains routines for performing function binding and symbol relocations.
35  */
36 #include	"_synonyms.h"
37 
38 #include	<stdio.h>
39 #include	<sys/elf.h>
40 #include	<sys/elf_SPARC.h>
41 #include	<sys/mman.h>
42 #include	<dlfcn.h>
43 #include	<synch.h>
44 #include	<string.h>
45 #include	"_rtld.h"
46 #include	"_audit.h"
47 #include	"_elf.h"
48 #include	"msg.h"
49 #include	"debug.h"
50 #include	"reloc.h"
51 #include	"conv.h"
52 
53 
54 extern void	iflush_range(caddr_t, size_t);
55 extern void	plt_full_range(uintptr_t, uintptr_t);
56 
57 
58 int
59 elf_mach_flags_check(Rej_desc *rej, Ehdr *ehdr)
60 {
61 	/*
62 	 * Check machine type and flags.
63 	 */
64 	if (ehdr->e_machine != EM_SPARC) {
65 		if (ehdr->e_machine != EM_SPARC32PLUS) {
66 			rej->rej_type = SGS_REJ_MACH;
67 			rej->rej_info = (uint_t)ehdr->e_machine;
68 			return (0);
69 		}
70 		if ((ehdr->e_flags & EF_SPARC_32PLUS) == 0) {
71 			rej->rej_type = SGS_REJ_MISFLAG;
72 			rej->rej_info = (uint_t)ehdr->e_flags;
73 			return (0);
74 		}
75 		if ((ehdr->e_flags & ~at_flags) & EF_SPARC_32PLUS_MASK) {
76 			rej->rej_type = SGS_REJ_BADFLAG;
77 			rej->rej_info = (uint_t)ehdr->e_flags;
78 			return (0);
79 		}
80 	} else if ((ehdr->e_flags & ~EF_SPARCV9_MM) != 0) {
81 		rej->rej_type = SGS_REJ_BADFLAG;
82 		rej->rej_info = (uint_t)ehdr->e_flags;
83 		return (0);
84 	}
85 	return (1);
86 }
87 
88 void
89 ldso_plt_init(Rt_map * lmp)
90 {
91 	/*
92 	 * There is no need to analyze ld.so because we don't map in any of
93 	 * its dependencies.  However we may map these dependencies in later
94 	 * (as if ld.so had dlopened them), so initialize the plt and the
95 	 * permission information.
96 	 */
97 	if (PLTGOT(lmp))
98 		elf_plt_init((PLTGOT(lmp)), (caddr_t)lmp);
99 }
100 
101 /*
102  * elf_plt_write() will test to see how far away our destination
103  *	address lies.  If it is close enough that a branch can
104  *	be used instead of a jmpl - we will fill the plt in with
105  * 	single branch.  The branches are much quicker then
106  *	a jmpl instruction - see bug#4356879 for further
107  *	details.
108  *
109  *	NOTE: we pass in both a 'pltaddr' and a 'vpltaddr' since
110  *		librtld/dldump update PLT's who's physical
111  *		address is not the same as the 'virtual' runtime
112  *		address.
113  */
114 Pltbindtype
115 /* ARGSUSED4 */
116 elf_plt_write(uintptr_t addr, uintptr_t vaddr, void *rptr, uintptr_t symval,
117 	Xword pltndx)
118 {
119 	Rela		*rel = (Rela *)rptr;
120 	uintptr_t	vpltaddr, pltaddr;
121 	long		disp;
122 
123 
124 	pltaddr = addr + rel->r_offset;
125 	vpltaddr = vaddr + rel->r_offset;
126 	disp = symval - vpltaddr - 4;
127 
128 	/*
129 	 * Test if the destination address is close enough to use
130 	 * a ba,a... instruction to reach it.
131 	 */
132 	if (S_INRANGE(disp, 23) && !(rtld_flags & RT_FL_NOBAPLT)) {
133 		uint_t		*pltent, bainstr;
134 		Pltbindtype	rc;
135 
136 		pltent = (uint_t *)pltaddr;
137 		/*
138 		 * The
139 		 *
140 		 *	ba,a,pt %icc, <dest>
141 		 *
142 		 * is the most efficient of the PLT's.  If we
143 		 * are within +-20 bits *and* running on a
144 		 * v8plus architecture - use that branch.
145 		 */
146 		if ((at_flags & EF_SPARC_32PLUS) &&
147 		    S_INRANGE(disp, 20)) {
148 			bainstr = M_BA_A_PT;	/* ba,a,pt %icc,<dest> */
149 			bainstr |= (S_MASK(19) & (disp >> 2));
150 			rc = PLT_T_21D;
151 			DBG_CALL(pltcnt21d++);
152 		} else {
153 			/*
154 			 * Otherwise - we fall back to the good old
155 			 *
156 			 *	ba,a	<dest>
157 			 *
158 			 * Which still beats a jmpl instruction.
159 			 */
160 			bainstr = M_BA_A;		/* ba,a <dest> */
161 			bainstr |= (S_MASK(22) & (disp >> 2));
162 			rc = PLT_T_24D;
163 			DBG_CALL(pltcnt24d++);
164 		}
165 
166 		pltent[2] = M_NOP;		/* nop instr */
167 		pltent[1] = bainstr;
168 
169 		iflush_range((char *)(&pltent[1]), 4);
170 		pltent[0] = M_NOP;		/* nop instr */
171 		iflush_range((char *)(&pltent[0]), 4);
172 		return (rc);
173 	}
174 
175 	/*
176 	 * The PLT destination is not in reach of
177 	 * a branch instruction - so we fall back
178 	 * to a 'jmpl' sequence.
179 	 */
180 	plt_full_range(pltaddr, symval);
181 	DBG_CALL(pltcntfull++);
182 	return (PLT_T_FULL);
183 }
184 
185 
186 /*
187  * Local storage space created on the stack created for this glue
188  * code includes space for:
189  *		0x4	pointer to dyn_data
190  *		0x4	size prev stack frame
191  */
192 static const uchar_t dyn_plt_template[] = {
193 /* 0x00 */	0x80, 0x90, 0x00, 0x1e,	/* tst   %fp */
194 /* 0x04 */	0x02, 0x80, 0x00, 0x04, /* be    0x14 */
195 /* 0x08 */	0x82, 0x27, 0x80, 0x0e,	/* sub   %sp, %fp, %g1 */
196 /* 0x0c */	0x10, 0x80, 0x00, 0x03, /* ba	 0x20 */
197 /* 0x10 */	0x01, 0x00, 0x00, 0x00, /* nop */
198 /* 0x14 */	0x82, 0x10, 0x20, 0x60, /* mov	0x60, %g1 */
199 /* 0x18 */	0x9d, 0xe3, 0xbf, 0x98,	/* save	%sp, -0x68, %sp */
200 /* 0x1c */	0xc2, 0x27, 0xbf, 0xf8,	/* st	%g1, [%fp + -0x8] */
201 /* 0x20 */	0x03, 0x00, 0x00, 0x00,	/* sethi %hi(val), %g1 */
202 /* 0x24 */	0x82, 0x10, 0x60, 0x00, /* or	 %g1, %lo(val), %g1 */
203 /* 0x28 */	0x40, 0x00, 0x00, 0x00,	/* call  <rel_addr> */
204 /* 0x2c */	0xc2, 0x27, 0xbf, 0xfc	/* st    %g1, [%fp + -0x4] */
205 };
206 
207 int	dyn_plt_ent_size = sizeof (dyn_plt_template) +
208 		sizeof (uintptr_t) +	/* reflmp */
209 		sizeof (uintptr_t) +	/* deflmp */
210 		sizeof (ulong_t) +	/* symndx */
211 		sizeof (ulong_t) +	/* sb_flags */
212 		sizeof (Sym);		/* symdef */
213 
214 /*
215  * the dynamic plt entry is:
216  *
217  *	tst	%fp
218  *	be	1f
219  *	nop
220  *	sub	%sp, %fp, %g1
221  *	ba	2f
222  *	nop
223  * 1:
224  *	mov	SA(MINFRAME), %g1	! if %fp is null this is the
225  *					!   'minimum stack'.  %fp is null
226  *					!   on the initial stack frame
227  * 2:
228  *	save	%sp, -(SA(MINFRAME) + 2 * CLONGSIZE), %sp
229  *	st	%g1, [%fp + -0x8] ! store prev_stack size in [%fp - 8]
230  *	sethi	%hi(dyn_data), %g1
231  *	or	%g1, %lo(dyn_data), %g1
232  *	call	elf_plt_trace
233  *	st	%g1, [%fp + -0x4] ! store dyn_data ptr in [%fp - 4]
234  * dyn data:
235  *	uintptr_t	reflmp
236  *	uintptr_t	deflmp
237  *	ulong_t		symndx
238  *	ulong_t		sb_flags
239  *	Sym		symdef
240  */
241 static caddr_t
242 elf_plt_trace_write(caddr_t addr, Rela *rptr, Rt_map *rlmp, Rt_map *dlmp,
243     Sym *sym, ulong_t symndx, ulong_t pltndx, caddr_t to, ulong_t sb_flags,
244     int *fail)
245 {
246 	extern ulong_t	elf_plt_trace();
247 	uintptr_t	dyn_plt;
248 	uintptr_t	*dyndata;
249 
250 	/*
251 	 * If both pltenter & pltexit have been disabled there
252 	 * there is no reason to even create the glue code.
253 	 */
254 	if ((sb_flags & (LA_SYMB_NOPLTENTER | LA_SYMB_NOPLTEXIT)) ==
255 	    (LA_SYMB_NOPLTENTER | LA_SYMB_NOPLTEXIT)) {
256 		(void) elf_plt_write((uintptr_t)addr, (uintptr_t)addr,
257 		    rptr, (uintptr_t)to, pltndx);
258 		return (to);
259 	}
260 
261 	/*
262 	 * We only need to add the glue code if there is an auditing
263 	 * library that is interested in this binding.
264 	 */
265 	dyn_plt = (uintptr_t)AUDINFO(rlmp)->ai_dynplts +
266 		(pltndx * dyn_plt_ent_size);
267 
268 	/*
269 	 * Have we initialized this dynamic plt entry yet?  If we haven't do it
270 	 * now.  Otherwise this function has been called before, but from a
271 	 * different plt (ie. from another shared object).  In that case
272 	 * we just set the plt to point to the new dyn_plt.
273 	 */
274 	if (*(uint_t *)dyn_plt == 0) {
275 		Sym *	symp;
276 		Xword	symvalue;
277 
278 		(void) memcpy((void *)dyn_plt, dyn_plt_template,
279 		    sizeof (dyn_plt_template));
280 		dyndata = (uintptr_t *)(dyn_plt + sizeof (dyn_plt_template));
281 
282 		/*
283 		 * relocating:
284 		 *	sethi	%hi(dyndata), %g1
285 		 */
286 		symvalue = (Xword)dyndata;
287 		if (do_reloc(R_SPARC_HI22, (uchar_t *)(dyn_plt + 0x20),
288 		    &symvalue, MSG_ORIG(MSG_SYM_LADYNDATA),
289 		    MSG_ORIG(MSG_SPECFIL_DYNPLT)) == 0) {
290 			*fail = 1;
291 			return (0);
292 		}
293 
294 		/*
295 		 * relocating:
296 		 *	or	%g1, %lo(dyndata), %g1
297 		 */
298 		symvalue = (Xword)dyndata;
299 		if (do_reloc(R_SPARC_LO10, (uchar_t *)(dyn_plt + 0x24),
300 		    &symvalue, MSG_ORIG(MSG_SYM_LADYNDATA),
301 		    MSG_ORIG(MSG_SPECFIL_DYNPLT)) == 0) {
302 			*fail = 1;
303 			return (0);
304 		}
305 
306 		/*
307 		 * relocating:
308 		 *	call	elf_plt_trace
309 		 */
310 		symvalue = (Xword)((uintptr_t)&elf_plt_trace -
311 			(dyn_plt + 0x28));
312 		if (do_reloc(R_SPARC_WDISP30, (uchar_t *)(dyn_plt + 0x28),
313 		    &symvalue, MSG_ORIG(MSG_SYM_ELFPLTTRACE),
314 		    MSG_ORIG(MSG_SPECFIL_DYNPLT)) == 0) {
315 			*fail = 1;
316 			return (0);
317 		}
318 
319 		*dyndata++ = (uintptr_t)rlmp;
320 		*dyndata++ = (uintptr_t)dlmp;
321 		*(ulong_t *)dyndata++ = symndx;
322 		*(ulong_t *)dyndata++ = sb_flags;
323 		symp = (Sym *)dyndata;
324 		*symp = *sym;
325 		symp->st_name += (Word)STRTAB(dlmp);
326 		symp->st_value = (Addr)to;
327 
328 		iflush_range((void *)dyn_plt, sizeof (dyn_plt_template));
329 	}
330 
331 	(void) elf_plt_write((uintptr_t)addr, (uintptr_t)addr,
332 		rptr, (uintptr_t)dyn_plt, 0);
333 	return ((caddr_t)dyn_plt);
334 }
335 
336 
337 /*
338  * Function binding routine - invoked on the first call to a function through
339  * the procedure linkage table;
340  * passes first through an assembly language interface.
341  *
342  * Takes the address of the PLT entry where the call originated,
343  * the offset into the relocation table of the associated
344  * relocation entry and the address of the link map (rt_private_map struct)
345  * for the entry.
346  *
347  * Returns the address of the function referenced after re-writing the PLT
348  * entry to invoke the function directly.
349  *
350  * On error, causes process to terminate with a signal.
351  */
352 ulong_t
353 elf_bndr(Rt_map *lmp, ulong_t pltoff, caddr_t from)
354 {
355 	Rt_map		*nlmp, *llmp;
356 	ulong_t		addr, vaddr, reloff, symval, rsymndx;
357 	char		*name;
358 	Rela		*rptr;
359 	Sym		*sym, *nsym;
360 	Xword		pltndx;
361 	uint_t		binfo, sb_flags = 0;
362 	Slookup		sl;
363 	Pltbindtype	pbtype;
364 	int		entry, dbg_save, lmflags;
365 
366 	/*
367 	 * For compatibility with libthread (TI_VERSION 1) we track the entry
368 	 * value.  A zero value indicates we have recursed into ld.so.1 to
369 	 * further process a locking request.  Under this recursion we disable
370 	 * tsort and cleanup activities.
371 	 */
372 	entry = enter();
373 
374 	if ((lmflags = LIST(lmp)->lm_flags) & LML_FLG_RTLDLM) {
375 		dbg_save = dbg_mask;
376 		dbg_mask = 0;
377 	}
378 
379 	/*
380 	 * Must calculate true plt relocation address from reloc.
381 	 * Take offset, subtract number of reserved PLT entries, and divide
382 	 * by PLT entry size, which should give the index of the plt
383 	 * entry (and relocation entry since they have been defined to be
384 	 * in the same order).  Then we must multiply by the size of
385 	 * a relocation entry, which will give us the offset of the
386 	 * plt relocation entry from the start of them given by JMPREL(lm).
387 	 */
388 	addr = pltoff - M_PLT_RESERVSZ;
389 	pltndx = addr / M_PLT_ENTSIZE;
390 
391 	/*
392 	 * Perform some basic sanity checks.  If we didn't get a load map
393 	 * or the plt offset is invalid then its possible someone has walked
394 	 * over the plt entries or jumped to plt0 out of the blue.
395 	 */
396 	if (!lmp || ((addr % M_PLT_ENTSIZE) != 0)) {
397 		eprintf(ERR_FATAL, MSG_INTL(MSG_REL_PLTREF),
398 		    conv_reloc_SPARC_type_str(R_SPARC_JMP_SLOT),
399 		    EC_XWORD(lmp), EC_XWORD(pltoff), EC_ADDR(from));
400 		rtldexit(LIST(lmp), 1);
401 	}
402 	reloff = pltndx * sizeof (Rela);
403 
404 	/*
405 	 * Use relocation entry to get symbol table entry and symbol name.
406 	 */
407 	addr = (ulong_t)JMPREL(lmp);
408 	rptr = (Rela *)(addr + reloff);
409 	rsymndx = ELF_R_SYM(rptr->r_info);
410 	sym = (Sym *)((ulong_t)SYMTAB(lmp) + (rsymndx * SYMENT(lmp)));
411 	name = (char *)(STRTAB(lmp) + sym->st_name);
412 
413 	/*
414 	 * Determine the last link-map of this list, this'll be the starting
415 	 * point for any tsort() processing.
416 	 */
417 	llmp = LIST(lmp)->lm_tail;
418 
419 	/*
420 	 * Find definition for symbol.
421 	 */
422 	sl.sl_name = name;
423 	sl.sl_cmap = lmp;
424 	sl.sl_imap = LIST(lmp)->lm_head;
425 	sl.sl_hash = 0;
426 	sl.sl_rsymndx = rsymndx;
427 	sl.sl_flags = LKUP_DEFT;
428 
429 	if ((nsym = lookup_sym(&sl, &nlmp, &binfo)) == 0) {
430 		eprintf(ERR_FATAL, MSG_INTL(MSG_REL_NOSYM), NAME(lmp),
431 		    demangle(name));
432 		rtldexit(LIST(lmp), 1);
433 	}
434 
435 	symval = nsym->st_value;
436 	if (!(FLAGS(nlmp) & FLG_RT_FIXED) &&
437 	    (nsym->st_shndx != SHN_ABS))
438 		symval += ADDR(nlmp);
439 	if ((lmp != nlmp) && ((FLAGS1(nlmp) & FL1_RT_NOINIFIN) == 0)) {
440 		/*
441 		 * Record that this new link map is now bound to the caller.
442 		 */
443 		if (bind_one(lmp, nlmp, BND_REFER) == 0)
444 			rtldexit(LIST(lmp), 1);
445 	}
446 
447 	if ((LIST(lmp)->lm_tflags | FLAGS1(lmp)) & LML_TFLG_AUD_SYMBIND) {
448 		ulong_t	symndx = (((uintptr_t)nsym -
449 			(uintptr_t)SYMTAB(nlmp)) / SYMENT(nlmp));
450 
451 		symval = audit_symbind(lmp, nlmp, nsym, symndx, symval,
452 			&sb_flags);
453 	}
454 
455 	if (FLAGS(lmp) & FLG_RT_FIXED)
456 		vaddr = 0;
457 	else
458 		vaddr = ADDR(lmp);
459 
460 	pbtype = PLT_T_NONE;
461 	if (!(rtld_flags & RT_FL_NOBIND)) {
462 		if (((LIST(lmp)->lm_tflags | FLAGS1(lmp)) &
463 		    (LML_TFLG_AUD_PLTENTER | LML_TFLG_AUD_PLTEXIT)) &&
464 		    AUDINFO(lmp)->ai_dynplts) {
465 			int	fail = 0;
466 			ulong_t	symndx = (((uintptr_t)nsym -
467 				(uintptr_t)SYMTAB(nlmp)) / SYMENT(nlmp));
468 
469 			symval = (ulong_t)elf_plt_trace_write((caddr_t)vaddr,
470 			    rptr, lmp, nlmp, nsym, symndx, pltndx,
471 			    (caddr_t)symval, sb_flags, &fail);
472 			if (fail)
473 				rtldexit(LIST(lmp), 1);
474 		} else {
475 			/*
476 			 * Write standard PLT entry to jump directly
477 			 * to newly bound function.
478 			 */
479 			pbtype = elf_plt_write((uintptr_t)vaddr,
480 				(uintptr_t)vaddr, rptr, symval, pltndx);
481 		}
482 	}
483 
484 	/*
485 	 * Print binding information and rebuild PLT entry.
486 	 */
487 	DBG_CALL(Dbg_bind_global(NAME(lmp), from, from - ADDR(lmp), pltndx,
488 	    pbtype, NAME(nlmp), (caddr_t)symval, (caddr_t)nsym->st_value,
489 	    name, binfo));
490 
491 	/*
492 	 * Complete any processing for newly loaded objects.  Note we don't
493 	 * know exactly where any new objects are loaded (we know the object
494 	 * that supplied the symbol, but others may have been loaded lazily as
495 	 * we searched for the symbol), so sorting starts from the last
496 	 * link-map know on entry to this routine.
497 	 */
498 	if (entry)
499 		load_completion(llmp, lmp);
500 
501 	/*
502 	 * Some operations like dldump() or dlopen()'ing a relocatable object
503 	 * result in objects being loaded on rtld's link-map, make sure these
504 	 * objects are initialized also.
505 	 */
506 	if ((LIST(nlmp)->lm_flags & LML_FLG_RTLDLM) && LIST(nlmp)->lm_init)
507 		load_completion(nlmp, 0);
508 
509 	/*
510 	 * If the object we've bound to is in the process of being initialized
511 	 * by another thread, determine whether we should block.
512 	 */
513 	is_dep_ready(nlmp, lmp, DBG_WAIT_SYMBOL);
514 
515 	/*
516 	 * Make sure the object to which we've bound has had it's .init fired.
517 	 * Cleanup before return to user code.
518 	 */
519 	if (entry) {
520 		is_dep_init(nlmp, lmp);
521 		leave(LIST(lmp));
522 	}
523 
524 	if (lmflags & LML_FLG_RTLDLM)
525 		dbg_mask = dbg_save;
526 
527 	return (symval);
528 }
529 
530 
531 /*
532  * Read and process the relocations for one link object, we assume all
533  * relocation sections for loadable segments are stored contiguously in
534  * the file.
535  */
536 int
537 elf_reloc(Rt_map *lmp, uint_t plt)
538 {
539 	ulong_t		relbgn, relend, relsiz, basebgn, pltbgn, pltend;
540 	ulong_t		roffset, rsymndx, psymndx = 0, etext = ETEXT(lmp);
541 	ulong_t		emap, dsymndx, pltndx;
542 	uchar_t		rtype;
543 	long		reladd, value, pvalue;
544 	Sym		*symref, *psymref, *symdef, *psymdef;
545 	char		*name, *pname;
546 	Rt_map		*_lmp, *plmp;
547 	int		textrel = 0, ret = 1, noplt = 0;
548 	long		relacount = RELACOUNT(lmp);
549 	Rela		*rel;
550 	Pltbindtype	pbtype;
551 	uint_t		binfo, pbinfo;
552 	Alist		*bound = 0;
553 
554 	/*
555 	 * If an object has any DT_REGISTER entries associated with
556 	 * it, they are processed now.
557 	 */
558 	if ((plt == 0) && (FLAGS(lmp) & FLG_RT_REGSYMS)) {
559 		if (elf_regsyms(lmp) == 0)
560 			return (0);
561 	}
562 
563 	/*
564 	 * Although only necessary for lazy binding, initialize the first
565 	 * procedure linkage table entry to go to elf_rtbndr().  dbx(1) seems
566 	 * to find this useful.
567 	 */
568 	if ((plt == 0) && PLTGOT(lmp)) {
569 		if ((ulong_t)PLTGOT(lmp) < etext) {
570 			if (elf_set_prot(lmp, PROT_WRITE) == 0)
571 				return (0);
572 			textrel = 1;
573 		}
574 		elf_plt_init(PLTGOT(lmp), (caddr_t)lmp);
575 	}
576 
577 	/*
578 	 * Initialize the plt start and end addresses.
579 	 */
580 	if ((pltbgn = (ulong_t)JMPREL(lmp)) != 0)
581 		pltend = pltbgn + (ulong_t)(PLTRELSZ(lmp));
582 
583 	/*
584 	 * If we've been called upon to promote an RTLD_LAZY object to an
585 	 * RTLD_NOW then we're only interested in scaning the .plt table.
586 	 */
587 	if (plt) {
588 		relbgn = pltbgn;
589 		relend = pltend;
590 	} else {
591 		/*
592 		 * The relocation sections appear to the run-time linker as a
593 		 * single table.  Determine the address of the beginning and end
594 		 * of this table.  There are two different interpretations of
595 		 * the ABI at this point:
596 		 *
597 		 *   o	The REL table and its associated RELSZ indicate the
598 		 *	concatenation of *all* relocation sections (this is the
599 		 *	model our link-editor constructs).
600 		 *
601 		 *   o	The REL table and its associated RELSZ indicate the
602 		 *	concatenation of all *but* the .plt relocations.  These
603 		 *	relocations are specified individually by the JMPREL and
604 		 *	PLTRELSZ entries.
605 		 *
606 		 * Determine from our knowledege of the relocation range and
607 		 * .plt range, the range of the total relocation table.  Note
608 		 * that one other ABI assumption seems to be that the .plt
609 		 * relocations always follow any other relocations, the
610 		 * following range checking drops that assumption.
611 		 */
612 		relbgn = (ulong_t)(REL(lmp));
613 		relend = relbgn + (ulong_t)(RELSZ(lmp));
614 		if (pltbgn) {
615 			if (!relbgn || (relbgn > pltbgn))
616 				relbgn = pltbgn;
617 			if (!relbgn || (relend < pltend))
618 				relend = pltend;
619 		}
620 	}
621 	if (!relbgn || (relbgn == relend)) {
622 		DBG_CALL(Dbg_reloc_run(NAME(lmp), 0, plt, DBG_REL_NONE));
623 		return (1);
624 	}
625 
626 	relsiz = (ulong_t)(RELENT(lmp));
627 	basebgn = ADDR(lmp);
628 	emap = ADDR(lmp) + MSIZE(lmp);
629 
630 	DBG_CALL(Dbg_reloc_run(NAME(lmp), M_REL_SHT_TYPE, plt, DBG_REL_START));
631 
632 	/*
633 	 * If we're processing in lazy mode there is no need to scan the
634 	 * .rela.plt table.
635 	 */
636 	if (pltbgn && ((MODE(lmp) & RTLD_NOW) == 0))
637 		noplt = 1;
638 
639 	/*
640 	 * Loop through relocations.
641 	 */
642 	while (relbgn < relend) {
643 		Addr		vaddr;
644 		uint_t		sb_flags = 0;
645 
646 		rtype = ELF_R_TYPE(((Rela *)relbgn)->r_info);
647 
648 		/*
649 		 * If this is a RELATIVE relocation in a shared object (the
650 		 * common case), and if we are not debugging, then jump into a
651 		 * tighter relocation loop (elf_reloc_relative).  Only make the
652 		 * jump if we've been given a hint on the number of relocations.
653 		 */
654 		if ((rtype == R_SPARC_RELATIVE) &&
655 		    !(FLAGS(lmp) & FLG_RT_FIXED) && !dbg_mask) {
656 			/*
657 			 * It's possible that the relative relocation block
658 			 * has relocations against the text segment as well
659 			 * as the data segment.  Since our optimized relocation
660 			 * engine does not check which segment the relocation
661 			 * is against - just mprotect it now if it's been
662 			 * marked as containing TEXTREL's.
663 			 */
664 			if ((textrel == 0) && (FLAGS1(lmp) & FL1_RT_TEXTREL)) {
665 				if (elf_set_prot(lmp, PROT_WRITE) == 0) {
666 					ret = 0;
667 					break;
668 				}
669 				textrel = 1;
670 			}
671 			if (relacount) {
672 				relbgn = elf_reloc_relacount(relbgn, relacount,
673 				    relsiz, basebgn);
674 				relacount = 0;
675 			} else {
676 				relbgn = elf_reloc_relative(relbgn, relend,
677 				    relsiz, basebgn, etext, emap);
678 			}
679 			if (relbgn >= relend)
680 				break;
681 			rtype = ELF_R_TYPE(((Rela *)relbgn)->r_info);
682 		}
683 
684 		roffset = ((Rela *)relbgn)->r_offset;
685 
686 		reladd = (long)(((Rela *)relbgn)->r_addend);
687 		rsymndx = ELF_R_SYM(((Rela *)relbgn)->r_info);
688 
689 		rel = (Rela *)relbgn;
690 		relbgn += relsiz;
691 
692 		/*
693 		 * Optimizations.
694 		 */
695 		if (rtype == R_SPARC_NONE)
696 			continue;
697 		if (noplt && ((ulong_t)rel >= pltbgn) &&
698 		    ((ulong_t)rel < pltend)) {
699 			relbgn = pltend;
700 			continue;
701 		}
702 
703 		if (rtype != R_SPARC_REGISTER) {
704 			/*
705 			 * If this is a shared object, add the base address
706 			 * to offset.
707 			 */
708 			if (!(FLAGS(lmp) & FLG_RT_FIXED))
709 				roffset += basebgn;
710 
711 			/*
712 			 * If this relocation is not against part of the image
713 			 * mapped into memory we skip it.
714 			 */
715 			if ((roffset < ADDR(lmp)) || (roffset > (ADDR(lmp) +
716 			    MSIZE(lmp)))) {
717 				elf_reloc_bad(lmp, (void *)rel, rtype, roffset,
718 				    rsymndx);
719 				continue;
720 			}
721 		}
722 
723 		/*
724 		 * If we're promoting plts determine if this one has already
725 		 * been written. An uninitialized plts' second instruction is a
726 		 * branch.
727 		 */
728 		if (plt) {
729 			ulong_t	*_roffset = (ulong_t *)roffset;
730 
731 			_roffset++;
732 			if ((*_roffset & (~(S_MASK(22)))) != M_BA_A)
733 				continue;
734 		}
735 
736 		binfo = 0;
737 		pltndx = (ulong_t)-1;
738 		pbtype = PLT_T_NONE;
739 		/*
740 		 * If a symbol index is specified then get the symbol table
741 		 * entry, locate the symbol definition, and determine its
742 		 * address.
743 		 */
744 		if (rsymndx) {
745 			/*
746 			 * Get the local symbol table entry.
747 			 */
748 			symref = (Sym *)((ulong_t)SYMTAB(lmp) +
749 			    (rsymndx * SYMENT(lmp)));
750 
751 			/*
752 			 * If this is a local symbol, just use the base address.
753 			 * (we should have no local relocations in the
754 			 * executable).
755 			 */
756 			if (ELF_ST_BIND(symref->st_info) == STB_LOCAL) {
757 				value = basebgn;
758 				name = (char *)0;
759 
760 				/*
761 				 * TLS relocation - value for DTPMOD relocation
762 				 * is the TLS modid.
763 				 */
764 				if (rtype == M_R_DTPMOD)
765 					value = TLSMODID(lmp);
766 			} else {
767 				/*
768 				 * If the symbol index is equal to the previous
769 				 * symbol index relocation we processed then
770 				 * reuse the previous values. (Note that there
771 				 * have been cases where a relocation exists
772 				 * against a copy relocation symbol, our ld(1)
773 				 * should optimize this away, but make sure we
774 				 * don't use the same symbol information should
775 				 * this case exist).
776 				 */
777 				if ((rsymndx == psymndx) &&
778 				    (rtype != R_SPARC_COPY)) {
779 					/* LINTED */
780 					if (psymdef == 0) {
781 						DBG_CALL(Dbg_bind_weak(
782 						    NAME(lmp), (caddr_t)roffset,
783 						    (caddr_t)
784 						    (roffset - basebgn), name));
785 						continue;
786 					}
787 					/* LINTED */
788 					value = pvalue;
789 					/* LINTED */
790 					name = pname;
791 					symdef = psymdef;
792 					/* LINTED */
793 					symref = psymref;
794 					/* LINTED */
795 					_lmp = plmp;
796 					/* LINTED */
797 					binfo = pbinfo;
798 
799 					if ((LIST(_lmp)->lm_tflags |
800 					    FLAGS1(_lmp)) &
801 					    LML_TFLG_AUD_SYMBIND) {
802 						value = audit_symbind(lmp, _lmp,
803 						    /* LINTED */
804 						    symdef, dsymndx, value,
805 						    &sb_flags);
806 					}
807 				} else {
808 					Slookup		sl;
809 					uchar_t		bind;
810 
811 					/*
812 					 * Lookup the symbol definition.
813 					 */
814 					name = (char *)(STRTAB(lmp) +
815 					    symref->st_name);
816 
817 					sl.sl_name = name;
818 					sl.sl_cmap = lmp;
819 					sl.sl_imap = 0;
820 					sl.sl_hash = 0;
821 					sl.sl_rsymndx = rsymndx;
822 
823 					if (rtype == R_SPARC_COPY)
824 						sl.sl_flags = LKUP_COPY;
825 					else
826 						sl.sl_flags = LKUP_DEFT;
827 
828 					sl.sl_flags |= LKUP_ALLCNTLIST;
829 
830 					if (rtype != R_SPARC_JMP_SLOT)
831 						sl.sl_flags |= LKUP_SPEC;
832 
833 					bind = ELF_ST_BIND(symref->st_info);
834 					if (bind == STB_WEAK)
835 						sl.sl_flags |= LKUP_WEAK;
836 
837 					symdef = lookup_sym(&sl, &_lmp, &binfo);
838 
839 					/*
840 					 * If the symbol is not found and the
841 					 * reference was not to a weak symbol,
842 					 * report an error.  Weak references
843 					 * may be unresolved.
844 					 */
845 					if (symdef == 0) {
846 					    if (bind != STB_WEAK) {
847 						if (LIST(lmp)->lm_flags &
848 						    LML_FLG_IGNRELERR) {
849 						    continue;
850 						} else if (LIST(lmp)->lm_flags &
851 						    LML_FLG_TRC_WARN) {
852 						    (void) printf(MSG_INTL(
853 							MSG_LDD_SYM_NFOUND),
854 							demangle(name),
855 							NAME(lmp));
856 						    continue;
857 						} else {
858 						    eprintf(ERR_FATAL,
859 							MSG_INTL(MSG_REL_NOSYM),
860 							NAME(lmp),
861 							demangle(name));
862 						    ret = 0;
863 						    break;
864 						}
865 					    } else {
866 						psymndx = rsymndx;
867 						psymdef = 0;
868 
869 						DBG_CALL(Dbg_bind_weak(
870 						    NAME(lmp), (caddr_t)roffset,
871 						    (caddr_t)
872 						    (roffset - basebgn), name));
873 						continue;
874 					    }
875 					}
876 
877 					/*
878 					 * If symbol was found in an object
879 					 * other than the referencing object
880 					 * then record the binding.
881 					 */
882 					if ((lmp != _lmp) && ((FLAGS1(_lmp) &
883 					    FL1_RT_NOINIFIN) == 0)) {
884 						if (alist_test(&bound, _lmp,
885 						    sizeof (Rt_map *),
886 						    AL_CNT_RELBIND) == 0) {
887 							ret = 0;
888 							break;
889 						}
890 					}
891 
892 					/*
893 					 * Calculate the location of definition;
894 					 * symbol value plus base address of
895 					 * containing shared object.
896 					 */
897 					value = symdef->st_value;
898 					if (!(FLAGS(_lmp) & FLG_RT_FIXED) &&
899 					    (symdef->st_shndx != SHN_ABS) &&
900 					    (ELF_ST_TYPE(symdef->st_info) !=
901 					    STT_TLS))
902 						value += ADDR(_lmp);
903 
904 					/*
905 					 * Retain this symbol index and the
906 					 * value in case it can be used for the
907 					 * subsequent relocations.
908 					 */
909 					if (rtype != R_SPARC_COPY) {
910 						psymndx = rsymndx;
911 						pvalue = value;
912 						pname = name;
913 						psymdef = symdef;
914 						psymref = symref;
915 						plmp = _lmp;
916 						pbinfo = binfo;
917 					}
918 					if ((LIST(_lmp)->lm_tflags |
919 					    FLAGS1(_lmp)) &
920 					    LML_TFLG_AUD_SYMBIND) {
921 						dsymndx = (((uintptr_t)symdef -
922 						    (uintptr_t)SYMTAB(_lmp)) /
923 						    SYMENT(_lmp));
924 						value = audit_symbind(lmp, _lmp,
925 						    symdef, dsymndx, value,
926 						    &sb_flags);
927 					}
928 				}
929 
930 				/*
931 				 * If relocation is PC-relative, subtract
932 				 * offset address.
933 				 */
934 				if (IS_PC_RELATIVE(rtype))
935 					value -= roffset;
936 
937 				/*
938 				 * TLS relocation - value for DTPMOD relocation
939 				 * is the TLS modid.
940 				 */
941 				if (rtype == M_R_DTPMOD)
942 					value = TLSMODID(_lmp);
943 				else if (rtype == M_R_TPOFF)
944 					value = -(TLSSTATOFF(_lmp) - value);
945 			}
946 		} else {
947 			/*
948 			 * Special cases, a register symbol associated with
949 			 * symbol index 0 is initialized (i.e. relocated) to
950 			 * a constant in the r_addend field rather than to a
951 			 * symbol value.
952 			 *
953 			 * A DTPMOD relocation is a local binding to a TLS
954 			 * symbol.  Fill in the TLSMODID for the current object.
955 			 */
956 			if (rtype == R_SPARC_REGISTER)
957 				value = 0;
958 			else if (rtype == M_R_DTPMOD)
959 				value = TLSMODID(lmp);
960 			else
961 				value = basebgn;
962 			name = (char *)0;
963 		}
964 
965 		/*
966 		 * If this object has relocations in the text segment, turn
967 		 * off the write protect.
968 		 */
969 		if ((rtype != R_SPARC_REGISTER) && (roffset < etext) &&
970 		    (textrel == 0)) {
971 			if (elf_set_prot(lmp, PROT_WRITE) == 0) {
972 				ret = 0;
973 				break;
974 			}
975 			textrel = 1;
976 		}
977 
978 		/*
979 		 * Call relocation routine to perform required relocation.
980 		 */
981 		DBG_CALL(Dbg_reloc_in(M_MACH, M_REL_SHT_TYPE, rel, name, NULL));
982 
983 		switch (rtype) {
984 		case R_SPARC_REGISTER:
985 			/*
986 			 * The v9 ABI 4.2.4 says that system objects may,
987 			 * but are not required to, use register symbols
988 			 * to inidcate how they use global registers. Thus
989 			 * at least %g6, %g7 must be allowed in addition
990 			 * to %g2 and %g3.
991 			 */
992 			value += reladd;
993 			if (roffset == STO_SPARC_REGISTER_G1) {
994 				set_sparc_g1(value);
995 			} else if (roffset == STO_SPARC_REGISTER_G2) {
996 				set_sparc_g2(value);
997 			} else if (roffset == STO_SPARC_REGISTER_G3) {
998 				set_sparc_g3(value);
999 			} else if (roffset == STO_SPARC_REGISTER_G4) {
1000 				set_sparc_g4(value);
1001 			} else if (roffset == STO_SPARC_REGISTER_G5) {
1002 				set_sparc_g5(value);
1003 			} else if (roffset == STO_SPARC_REGISTER_G6) {
1004 				set_sparc_g6(value);
1005 			} else if (roffset == STO_SPARC_REGISTER_G7) {
1006 				set_sparc_g7(value);
1007 			} else {
1008 				eprintf(ERR_FATAL, MSG_INTL(MSG_REL_BADREG),
1009 				    NAME(lmp), EC_ADDR(roffset));
1010 				ret = 0;
1011 				break;
1012 			}
1013 
1014 			DBG_CALL(Dbg_reloc_reg_apply((Xword)roffset,
1015 				(Xword)value));
1016 			break;
1017 		case R_SPARC_COPY:
1018 			if (elf_copy_reloc(name, symref, lmp, (void *)roffset,
1019 			    symdef, _lmp, (const void *)value) == 0)
1020 				ret = 0;
1021 			break;
1022 		case R_SPARC_JMP_SLOT:
1023 			pltndx = ((ulong_t)rel -
1024 				(uintptr_t)JMPREL(lmp)) / relsiz;
1025 
1026 			if (FLAGS(lmp) & FLG_RT_FIXED)
1027 				vaddr = 0;
1028 			else
1029 				vaddr = ADDR(lmp);
1030 
1031 			if (((LIST(lmp)->lm_tflags | FLAGS1(lmp)) &
1032 			    (LML_TFLG_AUD_PLTENTER | LML_TFLG_AUD_PLTEXIT)) &&
1033 			    AUDINFO(lmp)->ai_dynplts) {
1034 				int	fail = 0;
1035 				ulong_t	symndx = (((uintptr_t)symdef -
1036 					(uintptr_t)SYMTAB(_lmp)) /
1037 					SYMENT(_lmp));
1038 
1039 				(void) elf_plt_trace_write((caddr_t)vaddr,
1040 				    (Rela *)rel, lmp, _lmp, symdef, symndx,
1041 				    pltndx, (caddr_t)value, sb_flags, &fail);
1042 				if (fail)
1043 					ret = 0;
1044 			} else {
1045 				/*
1046 				 * Write standard PLT entry to jump directly
1047 				 * to newly bound function.
1048 				 */
1049 				DBG_CALL(Dbg_reloc_apply((Xword)roffset,
1050 				    (Xword)value));
1051 				pbtype = elf_plt_write((uintptr_t)vaddr,
1052 				    (uintptr_t)vaddr, (void *)rel, value,
1053 				    pltndx);
1054 			}
1055 			break;
1056 		default:
1057 			value += reladd;
1058 
1059 			/*
1060 			 * Write the relocation out.  If this relocation is a
1061 			 * common basic write, skip the doreloc() engine.
1062 			 */
1063 			if ((rtype == R_SPARC_GLOB_DAT) ||
1064 			    (rtype == R_SPARC_32)) {
1065 				if (roffset & 0x3) {
1066 					eprintf(ERR_FATAL,
1067 					    MSG_INTL(MSG_REL_NONALIGN),
1068 					    conv_reloc_SPARC_type_str(rtype),
1069 					    NAME(lmp), demangle(name),
1070 					    EC_OFF(roffset));
1071 					ret = 0;
1072 				} else
1073 					*(uint_t *)roffset += value;
1074 			} else {
1075 				if (do_reloc(rtype, (uchar_t *)roffset,
1076 				    (Xword *)&value, name, NAME(lmp)) == 0)
1077 					ret = 0;
1078 			}
1079 
1080 			/*
1081 			 * The value now contains the 'bit-shifted' value that
1082 			 * was or'ed into memory (this was set by do_reloc()).
1083 			 */
1084 			DBG_CALL(Dbg_reloc_apply((Xword)roffset,
1085 			    (Xword)value));
1086 
1087 			/*
1088 			 * If this relocation is against a text segment, make
1089 			 * sure that the instruction cache is flushed.
1090 			 */
1091 			if (textrel)
1092 				iflush_range((caddr_t)roffset, 0x4);
1093 		}
1094 
1095 		if ((ret == 0) &&
1096 		    ((LIST(lmp)->lm_flags & LML_FLG_TRC_WARN) == 0))
1097 			break;
1098 
1099 		if (binfo) {
1100 			DBG_CALL(Dbg_bind_global(NAME(lmp), (caddr_t)roffset,
1101 			    (caddr_t)(roffset - basebgn), pltndx, pbtype,
1102 			    NAME(_lmp), (caddr_t)value,
1103 			    (caddr_t)symdef->st_value, name, binfo));
1104 		}
1105 	}
1106 
1107 	return (relocate_finish(lmp, bound, textrel, ret));
1108 }
1109 
1110 /*
1111  * Provide a machine specific interface to the conversion routine.  By calling
1112  * the machine specific version, rather than the generic version, we insure that
1113  * the data tables/strings for all known machine versions aren't dragged into
1114  * ld.so.1.
1115  */
1116 const char *
1117 _conv_reloc_type_str(uint_t rel)
1118 {
1119 	return (conv_reloc_SPARC_type_str(rel));
1120 }
1121