rtld support for sparc64.

Largely obtained from:	netbsd
Submitted by:	jake, tmm

1 files changed, 693 insertions, 0 deletions

diff --git a/libexec/rtld-elf/sparc64/reloc.c b/libexec/rtld-elf/sparc64/reloc.c
new file mode 100644
index 0000000..1a897c3
--- /dev/null
+++ b/libexec/rtld-elf/sparc64/reloc.c
@@ -0,0 +1,693 @@
+/*	$NetBSD: mdreloc.c,v 1.5 2001/04/25 12:24:51 kleink Exp $	*/
+
+/*-
+ * Copyright (c) 2000 Eduardo Horvath.
+ * Copyright (c) 1999 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Paul Kranenburg.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *        This product includes software developed by the NetBSD
+ *        Foundation, Inc. and its contributors.
+ * 4. Neither the name of The NetBSD Foundation nor the names of its
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/stat.h>
+
+#include "debug.h"
+#include "rtld.h"
+
+/*
+ * The following table holds for each relocation type:
+ *	- the width in bits of the memory location the relocation
+ *	  applies to (not currently used)
+ *	- the number of bits the relocation value must be shifted to the
+ *	  right (i.e. discard least significant bits) to fit into
+ *	  the appropriate field in the instruction word.
+ *	- flags indicating whether
+ *		* the relocation involves a symbol
+ *		* the relocation is relative to the current position
+ *		* the relocation is for a GOT entry
+ *		* the relocation is relative to the load address
+ *
+ */
+#define _RF_S		0x80000000		/* Resolve symbol */
+#define _RF_A		0x40000000		/* Use addend */
+#define _RF_P		0x20000000		/* Location relative */
+#define _RF_G		0x10000000		/* GOT offset */
+#define _RF_B		0x08000000		/* Load address relative */
+#define _RF_U		0x04000000		/* Unaligned */
+#define _RF_SZ(s)	(((s) & 0xff) << 8)	/* memory target size */
+#define _RF_RS(s)	( (s) & 0xff)		/* right shift */
+static int reloc_target_flags[] = {
+	0,							/* NONE */
+	_RF_S|_RF_A|		_RF_SZ(8)  | _RF_RS(0),		/* RELOC_8 */
+	_RF_S|_RF_A|		_RF_SZ(16) | _RF_RS(0),		/* RELOC_16 */
+	_RF_S|_RF_A|		_RF_SZ(32) | _RF_RS(0),		/* RELOC_32 */
+	_RF_S|_RF_A|_RF_P|	_RF_SZ(8)  | _RF_RS(0),		/* DISP_8 */
+	_RF_S|_RF_A|_RF_P|	_RF_SZ(16) | _RF_RS(0),		/* DISP_16 */
+	_RF_S|_RF_A|_RF_P|	_RF_SZ(32) | _RF_RS(0),		/* DISP_32 */
+	_RF_S|_RF_A|_RF_P|	_RF_SZ(32) | _RF_RS(2),		/* WDISP_30 */
+	_RF_S|_RF_A|_RF_P|	_RF_SZ(32) | _RF_RS(2),		/* WDISP_22 */
+	_RF_S|_RF_A|		_RF_SZ(32) | _RF_RS(10),	/* HI22 */
+	_RF_S|_RF_A|		_RF_SZ(32) | _RF_RS(0),		/* 22 */
+	_RF_S|_RF_A|		_RF_SZ(32) | _RF_RS(0),		/* 13 */
+	_RF_S|_RF_A|		_RF_SZ(32) | _RF_RS(0),		/* LO10 */
+	_RF_G|			_RF_SZ(32) | _RF_RS(0),		/* GOT10 */
+	_RF_G|			_RF_SZ(32) | _RF_RS(0),		/* GOT13 */
+	_RF_G|			_RF_SZ(32) | _RF_RS(10),	/* GOT22 */
+	_RF_S|_RF_A|_RF_P|	_RF_SZ(32) | _RF_RS(0),		/* PC10 */
+	_RF_S|_RF_A|_RF_P|	_RF_SZ(32) | _RF_RS(10),	/* PC22 */
+	      _RF_A|_RF_P|	_RF_SZ(32) | _RF_RS(2),		/* WPLT30 */
+				_RF_SZ(32) | _RF_RS(0),		/* COPY */
+	_RF_S|_RF_A|		_RF_SZ(64) | _RF_RS(0),		/* GLOB_DAT */
+				_RF_SZ(32) | _RF_RS(0),		/* JMP_SLOT */
+	      _RF_A|	_RF_B|	_RF_SZ(64) | _RF_RS(0),		/* RELATIVE */
+	_RF_S|_RF_A|	_RF_U|	_RF_SZ(32) | _RF_RS(0),		/* UA_32 */
+
+	      _RF_A|		_RF_SZ(32) | _RF_RS(0),		/* PLT32 */
+	      _RF_A|		_RF_SZ(32) | _RF_RS(10),	/* HIPLT22 */
+	      _RF_A|		_RF_SZ(32) | _RF_RS(0),		/* LOPLT10 */
+	      _RF_A|_RF_P|	_RF_SZ(32) | _RF_RS(0),		/* PCPLT32 */
+	      _RF_A|_RF_P|	_RF_SZ(32) | _RF_RS(10),	/* PCPLT22 */
+	      _RF_A|_RF_P|	_RF_SZ(32) | _RF_RS(0),		/* PCPLT10 */
+	_RF_S|_RF_A|		_RF_SZ(32) | _RF_RS(0),		/* 10 */
+	_RF_S|_RF_A|		_RF_SZ(32) | _RF_RS(0),		/* 11 */
+	_RF_S|_RF_A|		_RF_SZ(64) | _RF_RS(0),		/* 64 */
+	_RF_S|_RF_A|/*extra*/	_RF_SZ(32) | _RF_RS(0),		/* OLO10 */
+	_RF_S|_RF_A|		_RF_SZ(32) | _RF_RS(42),	/* HH22 */
+	_RF_S|_RF_A|		_RF_SZ(32) | _RF_RS(32),	/* HM10 */
+	_RF_S|_RF_A|		_RF_SZ(32) | _RF_RS(10),	/* LM22 */
+	_RF_S|_RF_A|_RF_P|	_RF_SZ(32) | _RF_RS(42),	/* PC_HH22 */
+	_RF_S|_RF_A|_RF_P|	_RF_SZ(32) | _RF_RS(32),	/* PC_HM10 */
+	_RF_S|_RF_A|_RF_P|	_RF_SZ(32) | _RF_RS(10),	/* PC_LM22 */
+	_RF_S|_RF_A|_RF_P|	_RF_SZ(32) | _RF_RS(2),		/* WDISP16 */
+	_RF_S|_RF_A|_RF_P|	_RF_SZ(32) | _RF_RS(2),		/* WDISP19 */
+	_RF_S|_RF_A|		_RF_SZ(32) | _RF_RS(0),		/* GLOB_JMP */
+	_RF_S|_RF_A|		_RF_SZ(32) | _RF_RS(0),		/* 7 */
+	_RF_S|_RF_A|		_RF_SZ(32) | _RF_RS(0),		/* 5 */
+	_RF_S|_RF_A|		_RF_SZ(32) | _RF_RS(0),		/* 6 */
+	_RF_S|_RF_A|_RF_P|	_RF_SZ(64) | _RF_RS(0),		/* DISP64 */
+	      _RF_A|		_RF_SZ(64) | _RF_RS(0),		/* PLT64 */
+	_RF_S|_RF_A|		_RF_SZ(32) | _RF_RS(10),	/* HIX22 */
+	_RF_S|_RF_A|		_RF_SZ(32) | _RF_RS(0),		/* LOX10 */
+	_RF_S|_RF_A|		_RF_SZ(32) | _RF_RS(22),	/* H44 */
+	_RF_S|_RF_A|		_RF_SZ(32) | _RF_RS(12),	/* M44 */
+	_RF_S|_RF_A|		_RF_SZ(32) | _RF_RS(0),		/* L44 */
+	_RF_S|_RF_A|		_RF_SZ(64) | _RF_RS(0),		/* REGISTER */
+	_RF_S|_RF_A|	_RF_U|	_RF_SZ(64) | _RF_RS(0),		/* UA64 */
+	_RF_S|_RF_A|	_RF_U|	_RF_SZ(16) | _RF_RS(0),		/* UA16 */
+};
+
+#if 0
+static const char *reloc_names[] = {
+	"NONE", "RELOC_8", "RELOC_16", "RELOC_32", "DISP_8",
+	"DISP_16", "DISP_32", "WDISP_30", "WDISP_22", "HI22",
+	"22", "13", "LO10", "GOT10", "GOT13",
+	"GOT22", "PC10", "PC22", "WPLT30", "COPY",
+	"GLOB_DAT", "JMP_SLOT", "RELATIVE", "UA_32", "PLT32",
+	"HIPLT22", "LOPLT10", "LOPLT10", "PCPLT22", "PCPLT32",
+	"10", "11", "64", "OLO10", "HH22",
+	"HM10", "LM22", "PC_HH22", "PC_HM10", "PC_LM22", 
+	"WDISP16", "WDISP19", "GLOB_JMP", "7", "5", "6",
+	"DISP64", "PLT64", "HIX22", "LOX10", "H44", "M44", 
+	"L44", "REGISTER", "UA64", "UA16"
+};
+#endif
+
+#define RELOC_RESOLVE_SYMBOL(t)		((reloc_target_flags[t] & _RF_S) != 0)
+#define RELOC_PC_RELATIVE(t)		((reloc_target_flags[t] & _RF_P) != 0)
+#define RELOC_BASE_RELATIVE(t)		((reloc_target_flags[t] & _RF_B) != 0)
+#define RELOC_UNALIGNED(t)		((reloc_target_flags[t] & _RF_U) != 0)
+#define RELOC_USE_ADDEND(t)		((reloc_target_flags[t] & _RF_A) != 0)
+#define RELOC_TARGET_SIZE(t)		((reloc_target_flags[t] >> 8) & 0xff)
+#define RELOC_VALUE_RIGHTSHIFT(t)	(reloc_target_flags[t] & 0xff)
+
+static long reloc_target_bitmask[] = {
+#define _BM(x)	(~(-(1ULL << (x))))
+	0,				/* NONE */
+	_BM(8), _BM(16), _BM(32),	/* RELOC_8, _16, _32 */
+	_BM(8), _BM(16), _BM(32),	/* DISP8, DISP16, DISP32 */
+	_BM(30), _BM(22),		/* WDISP30, WDISP22 */
+	_BM(22), _BM(22),		/* HI22, _22 */
+	_BM(13), _BM(10),		/* RELOC_13, _LO10 */
+	_BM(10), _BM(13), _BM(22),	/* GOT10, GOT13, GOT22 */
+	_BM(10), _BM(22),		/* _PC10, _PC22 */  
+	_BM(30), 0,			/* _WPLT30, _COPY */
+	_BM(32), _BM(32), _BM(32),	/* _GLOB_DAT, JMP_SLOT, _RELATIVE */
+	_BM(32), _BM(32),		/* _UA32, PLT32 */
+	_BM(22), _BM(10),		/* _HIPLT22, LOPLT10 */
+	_BM(32), _BM(22), _BM(10),	/* _PCPLT32, _PCPLT22, _PCPLT10 */
+	_BM(10), _BM(11), -1,		/* _10, _11, _64 */
+	_BM(10), _BM(22),		/* _OLO10, _HH22 */
+	_BM(10), _BM(22),		/* _HM10, _LM22 */
+	_BM(22), _BM(10), _BM(22),	/* _PC_HH22, _PC_HM10, _PC_LM22 */
+	_BM(16), _BM(19),		/* _WDISP16, _WDISP19 */
+	-1,				/* GLOB_JMP */
+	_BM(7), _BM(5), _BM(6)		/* _7, _5, _6 */
+	-1, -1,				/* DISP64, PLT64 */
+	_BM(22), _BM(13),		/* HIX22, LOX10 */
+	_BM(22), _BM(10), _BM(13),	/* H44, M44, L44 */
+	-1, -1, _BM(16),		/* REGISTER, UA64, UA16 */
+#undef _BM
+};
+#define RELOC_VALUE_BITMASK(t)	(reloc_target_bitmask[t])
+
+#undef flush
+#define	flush(va, offs)	\
+	__asm __volatile("flush %0 + %1" : : "r" (va), "I" (offs));
+
+static int reloc_nonplt_object(Obj_Entry *obj, const Elf_Rela *rela,
+			       SymCache *cache);
+static void install_plt(Elf_Half *pltgot, Elf_Addr proc);
+
+extern char _rtld_bind_start_0[];
+extern char _rtld_bind_start_1[];
+
+int
+do_copy_relocations(Obj_Entry *dstobj)
+{
+	const Elf_Rela *relalim;
+	const Elf_Rela *rela;
+	const Elf_Sym *dstsym;
+	const Elf_Sym *srcsym;
+	void *dstaddr;
+	const void *srcaddr;
+	Obj_Entry *srcobj;
+	unsigned long hash;
+	const char *name;
+	size_t size;
+
+	assert(dstobj->mainprog);   /* COPY relocations are invalid elsewhere */
+
+	relalim = (const Elf_Rela *)((caddr_t)dstobj->rela + dstobj->relasize);
+	for (rela = dstobj->rela; rela < relalim; rela++) {
+		if (ELF_R_TYPE(rela->r_info) == R_SPARC_COPY) {
+			dstaddr = (void *)(dstobj->relocbase + rela->r_offset);
+			dstsym = dstobj->symtab + ELF_R_SYM(rela->r_info);
+			name = dstobj->strtab + dstsym->st_name;
+			hash = elf_hash(name);
+			size = dstsym->st_size;
+
+			for (srcobj = dstobj->next; srcobj != NULL;
+			    srcobj = srcobj->next)
+				if ((srcsym = symlook_obj(name, hash, srcobj,
+				    false)) != NULL)
+					break;
+
+			if (srcobj == NULL) {
+				_rtld_error("Undefined symbol \"%s\""
+					    "referenced from COPY relocation"
+					    "in %s", name, dstobj->path);
+				return (-1);
+			}
+
+			srcaddr = (const void *)(srcobj->relocbase +
+			    srcsym->st_value);
+			memcpy(dstaddr, srcaddr, size);
+		}
+	}
+
+	return (0);
+}
+
+int
+reloc_non_plt(Obj_Entry *obj, Obj_Entry *obj_rtld)
+{
+	const Elf_Rela *relalim;
+	const Elf_Rela *rela;
+	SymCache *cache;
+
+	cache = (SymCache *)alloca(obj->nchains * sizeof(SymCache));
+	if (cache != NULL)
+		memset(cache, 0, obj->nchains * sizeof(SymCache));
+
+	relalim = (const Elf_Rela *)((caddr_t)obj->rela + obj->relasize);
+	for (rela = obj->rela; rela < relalim; rela++) {
+		if (reloc_nonplt_object(obj, rela, cache) < 0)
+			return (-1);
+	}
+
+	return (0);
+}
+
+static int
+reloc_nonplt_object(Obj_Entry *obj, const Elf_Rela *rela, SymCache *cache)
+{
+	const Obj_Entry *defobj;
+	const Elf_Sym *def;
+	Elf_Addr *where;
+	Elf_Half *where32;
+	Elf_Word type;
+	Elf_Addr value;
+	Elf_Addr mask;
+	
+	where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
+	where32 = (Elf_Half *)where;
+	defobj = NULL;
+	def = NULL;
+
+	type = ELF_R_TYPE(rela->r_info);
+	if (type == R_SPARC_NONE)
+		return (0);
+
+	/* We do JMP_SLOTs below */
+	if (type == R_SPARC_JMP_SLOT)
+		return (0);
+
+	/* COPY relocs are also handled elsewhere */
+	if (type == R_SPARC_COPY)
+		return (0);
+
+	/*
+	 * Note: R_SPARC_UA16 must be numerically largest relocation type.
+	 */
+	if (type > R_SPARC_UA16)
+		return (-1);
+
+	value = rela->r_addend;
+
+	/*
+	 * Handle relative relocs here, because we might not
+	 * be able to access globals yet.
+	 */
+	if (type == R_SPARC_RELATIVE) {
+		/* XXXX -- apparently we ignore the preexisting value */
+		*where = (Elf_Addr)(obj->relocbase + value);
+		return (0);
+	}
+
+	/*
+	 * If we get here while relocating rtld itself, we will crash because
+	 * a non-local variable is accessed.
+	 */
+	if (RELOC_RESOLVE_SYMBOL(type)) {
+
+		/* Find the symbol */
+		def = find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj,
+		    false, cache);
+		if (def == NULL)
+			return (-1);
+
+		/* Add in the symbol's absolute address */
+		value += (Elf_Addr)(defobj->relocbase + def->st_value);
+	}
+
+	if (RELOC_PC_RELATIVE(type))
+		value -= (Elf_Addr)where;
+
+	if (RELOC_BASE_RELATIVE(type)) {
+		/*
+		 * Note that even though sparcs use `Elf_rela' exclusively
+		 * we still need the implicit memory addend in relocations
+		 * referring to GOT entries. Undoubtedly, someone f*cked
+		 * this up in the distant past, and now we're stuck with
+		 * it in the name of compatibility for all eternity..
+		 *
+		 * In any case, the implicit and explicit should be mutually
+		 * exclusive. We provide a check for that here.
+		 */
+		/* XXXX -- apparently we ignore the preexisting value */
+		value += (Elf_Addr)(obj->relocbase);
+	}
+
+	mask = RELOC_VALUE_BITMASK(type);
+	value >>= RELOC_VALUE_RIGHTSHIFT(type);
+	value &= mask;
+
+	if (RELOC_UNALIGNED(type)) {
+		/* Handle unaligned relocations. */
+		Elf_Addr tmp;
+		char *ptr;
+		int size;
+		int i;
+	
+		size = RELOC_TARGET_SIZE(type) / 8;
+		ptr = (char *)where;
+		tmp = 0;
+	
+		/* Read it in one byte at a time. */
+		for (i = 0; i < size; i++)
+			tmp = (tmp << 8) | ptr[i];
+
+		tmp &= ~mask;
+		tmp |= value;
+
+		/* Write it back out. */
+		for (i = 0; i < size; i++)
+			ptr[i] = ((tmp >> (8 * i)) & 0xff);
+	} else if (RELOC_TARGET_SIZE(type) > 32) {
+		*where &= ~mask;
+		*where |= value;
+	} else {
+		*where32 &= ~mask;
+		*where32 |= value;
+	}
+
+	return (0);
+}
+
+int
+reloc_plt(Obj_Entry *obj)
+{
+#if 0
+	const Obj_Entry *defobj;
+	const Elf_Rela *relalim;
+	const Elf_Rela *rela;
+	const Elf_Sym *def;
+	Elf_Addr *where;
+	Elf_Addr value;
+
+	relalim = (const Elf_Rela *)((char *)obj->pltrela + obj->pltrelasize);
+	for (rela = obj->pltrela; rela < relalim; rela++) {
+		if (rela->r_addend == 0)
+			continue;
+		assert(ELF_R_TYPE(rela->r_info) == R_SPARC_JMP_SLOT);
+		where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
+		def = find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj,
+		    true, NULL);
+		value = (Elf_Addr)(defobj->relocbase + def->st_value);
+		*where = value;
+	}
+#endif
+	return (0);
+}
+
+/*
+ * Instruction templates:
+ */
+#define	BAA	0x10400000	/*	ba,a	%xcc, 0 */
+#define	SETHI	0x03000000	/*	sethi	%hi(0), %g1 */
+#define	JMP	0x81c06000	/*	jmpl	%g1+%lo(0), %g0 */
+#define	NOP	0x01000000	/*	sethi	%hi(0), %g0 */
+#define	OR	0x82806000	/*	or	%g1, 0, %g1 */
+#define	XOR	0x82c06000	/*	xor	%g1, 0, %g1 */
+#define	MOV71	0x8283a000	/*	or	%o7, 0, %g1 */
+#define	MOV17	0x9c806000	/*	or	%g1, 0, %o7 */
+#define	CALL	0x40000000	/*	call	0 */
+#define	SLLX	0x8b407000	/*	sllx	%g1, 0, %g1 */
+#define	SETHIG5	0x0b000000	/*	sethi	%hi(0), %g5 */
+#define	ORG5	0x82804005	/*	or	%g1, %g5, %g1 */
+
+
+/* %hi(v) with variable shift */
+#define	HIVAL(v, s)	(((v) >> (s)) &  0x003fffff)
+#define LOVAL(v)	((v) & 0x000003ff)
+
+int
+reloc_jmpslots(Obj_Entry *obj)
+{
+	const Obj_Entry *defobj;
+	const Elf_Rela *relalim;
+	const Elf_Rela *rela;
+	const Elf_Sym *def;
+	Elf_Addr *where;
+	Elf_Addr target;
+
+	relalim = (const Elf_Rela *)((char *)obj->pltrela + obj->pltrelasize);
+	for (rela = obj->pltrela; rela < relalim; rela++) {
+		assert(ELF_R_TYPE(rela->r_info) == R_SPARC_JMP_SLOT);
+		where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
+		def = find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj,
+		    true, NULL);
+		target = (Elf_Addr)(defobj->relocbase + def->st_value);
+		reloc_jmpslot(where, target, defobj);
+	}
+	obj->jmpslots_done = true;
+	return (0);
+}
+
+Elf_Addr
+reloc_jmpslot(Elf_Addr *wherep, Elf_Addr target, const Obj_Entry *obj)
+{
+	Elf_Addr offset;
+	Elf_Half *where;
+
+	/*
+	 * At the PLT entry pointed at by `where', we now construct
+	 * a direct transfer to the now fully resolved function
+	 * address.
+	 *
+	 * A PLT entry is supposed to start by looking like this:
+	 *
+	 *	sethi	%hi(. - .PLT0), %g1
+	 *	ba,a	%xcc, .PLT1
+	 *	nop
+	 *	nop
+	 *	nop
+	 *	nop
+	 *	nop
+	 *	nop
+	 *
+	 * When we replace these entries we start from the second
+	 * entry and do it in reverse order so the last thing we
+	 * do is replace the branch.  That allows us to change this
+	 * atomically.
+	 *
+	 * We now need to find out how far we need to jump.  We
+	 * have a choice of several different relocation techniques
+	 * which are increasingly expensive.
+	 */
+
+	where = (Elf_Half *)wherep;
+	offset = ((Elf_Addr)where) - target;
+	if (offset <= (1L<<20) && offset >= -(1L<<20)) {
+		/* 
+		 * We're within 1MB -- we can use a direct branch insn.
+		 *
+		 * We can generate this pattern:
+		 *
+		 *	sethi	%hi(. - .PLT0), %g1
+		 *	ba,a	%xcc, addr
+		 *	nop
+		 *	nop
+		 *	nop
+		 *	nop
+		 *	nop
+		 *	nop
+		 *
+		 */
+		where[1] = BAA | ((offset >> 2) &0x3fffff);
+		flush(where, 4);
+	} else if (target >= 0 && target < (1L<<32)) {
+		/* 
+		 * We're withing 32-bits of address zero.
+		 *
+		 * The resulting code in the jump slot is:
+		 *
+		 *	sethi	%hi(. - .PLT0), %g1
+		 *	sethi	%hi(addr), %g1
+		 *	jmp	%g1+%lo(addr)
+		 *	nop
+		 *	nop
+		 *	nop
+		 *	nop
+		 *	nop
+		 *
+		 */
+		where[2] = JMP   | LOVAL(target);
+		flush(where, 8);
+		where[1] = SETHI | HIVAL(target, 10);
+		flush(where, 4);
+	} else if (target <= 0 && target > -(1L<<32)) {
+		/* 
+		 * We're withing 32-bits of address -1.
+		 *
+		 * The resulting code in the jump slot is:
+		 *
+		 *	sethi	%hi(. - .PLT0), %g1
+		 *	sethi	%hix(addr), %g1
+		 *	xor	%g1, %lox(addr), %g1
+		 *	jmp	%g1
+		 *	nop
+		 *	nop
+		 *	nop
+		 *	nop
+		 *
+		 */
+		where[3] = JMP;
+		flush(where, 12);
+		where[2] = XOR | ((~target) & 0x00001fff);
+		flush(where, 8);
+		where[1] = SETHI | HIVAL(~target, 10);
+		flush(where, 4);
+	} else if (offset <= (1L<<32) && offset >= -((1L<<32) - 4)) {
+		/* 
+		 * We're withing 32-bits -- we can use a direct call insn 
+		 *
+		 * The resulting code in the jump slot is:
+		 *
+		 *	sethi	%hi(. - .PLT0), %g1
+		 *	mov	%o7, %g1
+		 *	call	(.+offset)
+		 *	 mov	%g1, %o7
+		 *	nop
+		 *	nop
+		 *	nop
+		 *	nop
+		 *
+		 */
+		where[3] = MOV17;
+		flush(where, 12);
+		where[2] = CALL	  | ((offset >> 4) & 0x3fffffff);
+		flush(where, 8);
+		where[1] = MOV71;
+		flush(where, 4);
+	} else if (offset >= 0 && offset < (1L<<44)) {
+		/* 
+		 * We're withing 44 bits.  We can generate this pattern:
+		 *
+		 * The resulting code in the jump slot is:
+		 *
+		 *	sethi	%hi(. - .PLT0), %g1
+		 *	sethi	%h44(addr), %g1
+		 *	or	%g1, %m44(addr), %g1
+		 *	sllx	%g1, 12, %g1	
+		 *	jmp	%g1+%l44(addr)	
+		 *	nop
+		 *	nop
+		 *	nop
+		 *
+		 */
+		where[4] = JMP   | LOVAL(offset);
+		flush(where, 16);
+		where[3] = SLLX  | 12;
+		flush(where, 12);
+		where[2] = OR    | (((offset) >> 12) & 0x00001fff);
+		flush(where, 8);
+		where[1] = SETHI | HIVAL(offset, 22);
+		flush(where, 4);
+	} else if (offset < 0 && offset > -(1L<<44)) {
+		/* 
+		 * We're withing 44 bits.  We can generate this pattern:
+		 *
+		 * The resulting code in the jump slot is:
+		 *
+		 *	sethi	%hi(. - .PLT0), %g1
+		 *	sethi	%h44(-addr), %g1
+		 *	xor	%g1, %m44(-addr), %g1
+		 *	sllx	%g1, 12, %g1	
+		 *	jmp	%g1+%l44(addr)	
+		 *	nop
+		 *	nop
+		 *	nop
+		 *
+		 */
+		where[4] = JMP   | LOVAL(offset);
+		flush(where, 16);
+		where[3] = SLLX  | 12;
+		flush(where, 12);
+		where[2] = XOR   | (((~offset) >> 12) & 0x00001fff);
+		flush(where, 8);
+		where[1] = SETHI | HIVAL(~offset, 22);
+		flush(where, 4);
+	} else {
+		/* 
+		 * We need to load all 64-bits
+		 *
+		 * The resulting code in the jump slot is:
+		 *
+		 *	sethi	%hi(. - .PLT0), %g1
+		 *	sethi	%hh(addr), %g1
+		 *	sethi	%lm(addr), %g5
+		 *	or	%g1, %hm(addr), %g1
+		 *	sllx	%g1, 32, %g1
+		 *	or	%g1, %g5, %g1
+		 *	jmp	%g1+%lo(addr)
+		 *	nop
+		 *
+		 */
+		where[6] = JMP     | LOVAL(target);
+		flush(where, 24);
+		where[5] = ORG5;
+		flush(where, 20);
+		where[4] = SLLX    | 12;
+		flush(where, 16);
+		where[3] = OR      | LOVAL((target) >> 32);
+		flush(where, 12);
+		where[2] = SETHIG5 | HIVAL(target, 10);
+		flush(where, 8);
+		where[1] = SETHI   | HIVAL(target, 42);
+		flush(where, 4);
+	}
+
+	return (target);
+}
+
+/*
+ * Install rtld function call into this PLT slot.
+ */
+#define	SAVE		0x9de3bf50
+#define	SETHI_l0	0x21000000
+#define	SETHI_l1	0x23000000
+#define	OR_l0_l0	0xa0142000
+#define	SLLX_l0_32_l0	0xa12c3020
+#define	OR_l0_l1_l0	0xa0140011
+#define	JMPL_l0_o1	0x93c42000
+#define	MOV_g1_o0	0x90100001
+
+void
+init_pltgot(Obj_Entry *obj)
+{
+	Elf_Half *entry;
+
+	if (obj->pltgot != NULL) {
+		entry = (Elf_Half *)obj->pltgot;
+		install_plt(&entry[0], (Elf_Addr)_rtld_bind_start_0);
+		install_plt(&entry[8], (Elf_Addr)_rtld_bind_start_1);
+		obj->pltgot[8] = (Elf_Addr)obj;
+	}
+}
+
+static void
+install_plt(Elf_Half *pltgot, Elf_Addr proc)
+{
+	pltgot[0] = SAVE;
+	flush(pltgot, 0);
+	pltgot[1] = SETHI_l0 | HIVAL(proc, 42);
+	flush(pltgot, 4);
+	pltgot[2] = SETHI_l1 | HIVAL(proc, 10);
+	flush(pltgot, 8);
+	pltgot[3] = OR_l0_l0 | LOVAL((proc) >> 32);
+	flush(pltgot, 12);
+	pltgot[4] = SLLX_l0_32_l0;
+	flush(pltgot, 16);
+	pltgot[5] = OR_l0_l1_l0;
+	flush(pltgot, 20);
+	pltgot[6] = JMPL_l0_o1 | LOVAL(proc);
+	flush(pltgot, 24);
+	pltgot[7] = MOV_g1_o0;
+	flush(pltgot, 28);
+}