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authorjake <jake@FreeBSD.org>2002-03-13 02:40:39 +0000
committerjake <jake@FreeBSD.org>2002-03-13 02:40:39 +0000
commitf8145a14d23551ac784c0d7c751ee687979dfc00 (patch)
tree6877c84a23fe8a58f84fcb8d17aa3998059ecab7 /libexec/rtld-elf/sparc64/reloc.c
parent4ff830618672fdf2a2864c71864aea5adc8d03e8 (diff)
downloadFreeBSD-src-f8145a14d23551ac784c0d7c751ee687979dfc00.zip
FreeBSD-src-f8145a14d23551ac784c0d7c751ee687979dfc00.tar.gz
rtld support for sparc64.
Largely obtained from: netbsd Submitted by: jake, tmm
Diffstat (limited to 'libexec/rtld-elf/sparc64/reloc.c')
-rw-r--r--libexec/rtld-elf/sparc64/reloc.c693
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);
+}
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