usr/src/cmd/sgs/librtld/sparc/_relocate.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 #include        <string.h>
  28 #include        "machdep.h"
  29 #include        "reloc.h"
  30 #include        "_librtld.h"
  31 #include        "_elf.h"
  32
  33 /*
  34  * Undo relocations that have been applied to a memory image.  Basically this
  35  * involves copying the original files relocation offset into the new image
  36  * being created.
  37  */
  38 /* ARGSUSED3 */
  39 void
  40 undo_reloc(void *vrel, uchar_t *oaddr, uchar_t *iaddr, Reloc *reloc)
  41 {
  42         Rela            *rel = vrel;
  43         const Rel_entry *rep;
  44         Xword           rtype = ELF_R_TYPE(rel->r_info, M_MACH);
  45         ulong_t         *_oaddr;
  46         ulong_t         *_iaddr;
  47
  48         switch (rtype) {
  49         case R_SPARC_NONE:
  50                 break;
  51         case R_SPARC_COPY:
  52                 (void) memset((void *)oaddr, 0, (size_t)reloc->r_size);
  53                 break;
  54         case R_SPARC_JMP_SLOT:
  55                 /* LINTED */
  56                 _oaddr = (unsigned long *)oaddr;
  57                 /* LINTED */
  58                 _iaddr = (unsigned long *)iaddr;
  59
  60                 if (_iaddr) {
  61                         *_oaddr++ = *_iaddr++;
  62                         *_oaddr++ = *_iaddr++;
  63                         *_oaddr = *_iaddr;
  64                 } else {
  65                         *_oaddr++ = 0;
  66                         *_oaddr++ = 0;
  67                         *_oaddr = 0;
  68                 }
  69                 break;
  70         default:
  71                 rep = &reloc_table[rtype];
  72                 if (iaddr)
  73                         (void) memcpy(oaddr, iaddr, rep->re_fsize);
  74                 else
  75                         (void) memset(oaddr, 0, rep->re_fsize);
  76         }
  77 }
  78
  79 /*
  80  * Copy a relocation record and increment its value.  The record must reflect
  81  * the new address to which this image is fixed.
  82  */
  83 /* ARGSUSED3 */
  84 void
  85 inc_reloc(void *vnrel, void *vorel, Reloc *reloc, uchar_t *oaddr,
  86     uchar_t *iaddr)
  87 {
  88         Rela    *nrel = vnrel;
  89         Rela    *orel = vorel;
  90
  91         *nrel = *orel;
  92         nrel->r_offset += reloc->r_value;
  93 }
  94
  95 /*
  96  * Clear a relocation record.  The relocation has been applied to the image and
  97  * thus the relocation must not occur again.
  98  */
  99 void
 100 clear_reloc(void *vrel)
 101 {
 102         Rela    *rel = vrel;
 103
 104         rel->r_offset = 0;
 105         rel->r_info = ELF_R_INFO(0, R_SPARC_NONE);
 106         rel->r_addend = 0;
 107 }
 108
 109 /*
 110  * Apply a relocation to an image being built from an input file.  Use the
 111  * runtime linkers routines to do the necessary magic.
 112  */
 113 void
 114 apply_reloc(void *vrel, Reloc *reloc, const char *name, uchar_t *oaddr,
 115     Rt_map *lmp)
 116 {
 117         Rela    *rel = vrel;
 118         Xword   type = ELF_R_TYPE(rel->r_info, M_MACH);
 119         Xword   value = reloc->r_value + rel->r_addend;
 120
 121         if (type == R_SPARC_JMP_SLOT) {
 122                 uintptr_t       addr, vaddr;
 123
 124                 if (FLAGS(lmp) & FLG_RT_FIXED)
 125                         vaddr = 0;
 126                 else
 127                         vaddr = ADDR(lmp);
 128
 129                 addr = (uintptr_t)oaddr - rel->r_offset;
 130                 /* LINTED */
 131                 (void) elf_plt_write((uintptr_t)addr, vaddr, rel,
 132                     (uintptr_t)value, reloc->r_pltndx);
 133
 134         } else if (type == R_SPARC_COPY) {
 135                 (void) memcpy((void *)oaddr, (void *)value,
 136                     (size_t)reloc->r_size);
 137         } else {
 138                 if (IS_EXTOFFSET(type))
 139                         value += ELF_R_TYPE_DATA(rel->r_info);
 140                 (void) do_reloc_rtld(type, oaddr, &value, reloc->r_name, name,
 141                     LIST(lmp));
 142         }
 143 }