source: rtems/cpukit/libdl/rtl-mdreloc-sparc.c @ 990adc5

5
Last change on this file since 990adc5 was 990adc5, checked in by Sebastian Huber <sebastian.huber@…>, on Dec 13, 2017 at 7:20:30 AM

libdl: Include <rtems/rtl/rtl-*.h>

Prepare for header file move to common include directory.

Update #3254.

  • Property mode set to 100644
File size: 10.2 KB
Line 
1/*
2 * Taken from NetBSD and stripped of the relocations not needed on RTEMS.
3 */
4
5/*  $NetBSD: mdreloc.c,v 1.43 2010/01/13 20:17:22 christos Exp $  */
6
7/*-
8 * Copyright (c) 1999, 2002 The NetBSD Foundation, Inc.
9 * All rights reserved.
10 *
11 * This code is derived from software contributed to The NetBSD Foundation
12 * by Paul Kranenburg and by Charles M. Hannum.
13 *
14 * Redistribution and use in source and binary forms, with or without
15 * modification, are permitted provided that the following conditions
16 * are met:
17 * 1. Redistributions of source code must retain the above copyright
18 *    notice, this list of conditions and the following disclaimer.
19 * 2. Redistributions in binary form must reproduce the above copyright
20 *    notice, this list of conditions and the following disclaimer in the
21 *    documentation and/or other materials provided with the distribution.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
24 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
25 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
26 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
27 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
28 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
29 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
30 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
31 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
32 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
33 * POSSIBILITY OF SUCH DAMAGE.
34 */
35
36#include <sys/cdefs.h>
37
38#include <stdio.h>
39
40#include <rtems/rtl/rtl.h>
41#include "rtl-elf.h"
42#include "rtl-error.h"
43#include <rtems/rtl/rtl-trace.h>
44#include "rtl-unwind.h"
45#include "rtl-unwind-dw2.h"
46
47/*
48 * The following table holds for each relocation type:
49 *  - the width in bits of the memory location the relocation
50 *    applies to (not currently used)
51 *  - the number of bits the relocation value must be shifted to the
52 *    right (i.e. discard least significant bits) to fit into
53 *    the appropriate field in the instruction word.
54 *  - flags indicating whether
55 *    * the relocation involves a symbol
56 *    * the relocation is relative to the current position
57 *    * the relocation is for a GOT entry
58 *    * the relocation is relative to the load address
59 *
60 */
61#define _RF_S     0x80000000           /* Resolve symbol */
62#define _RF_A     0x40000000           /* Use addend */
63#define _RF_P     0x20000000           /* Location relative */
64#define _RF_G     0x10000000           /* GOT offset */
65#define _RF_B     0x08000000           /* Load address relative */
66#define _RF_U     0x04000000           /* Unaligned */
67#define _RF_SZ(s) (((s) & 0xff) << 8)  /* memory target size */
68#define _RF_RS(s) ( (s) & 0xff)        /* right shift */
69
70static const uint32_t reloc_target_flags[] = {
71  0,                                             /* NONE */
72  _RF_S|_RF_A|        _RF_SZ(8)  | _RF_RS(0),    /* RELOC_8 */
73  _RF_S|_RF_A|        _RF_SZ(16) | _RF_RS(0),    /* RELOC_16 */
74  _RF_S|_RF_A|        _RF_SZ(32) | _RF_RS(0),    /* RELOC_32 */
75  _RF_S|_RF_A|_RF_P|  _RF_SZ(8)  | _RF_RS(0),    /* DISP_8 */
76  _RF_S|_RF_A|_RF_P|  _RF_SZ(16) | _RF_RS(0),    /* DISP_16 */
77  _RF_S|_RF_A|_RF_P|  _RF_SZ(32) | _RF_RS(0),    /* DISP_32 */
78  _RF_S|_RF_A|_RF_P|  _RF_SZ(32) | _RF_RS(2),    /* WDISP_30 */
79  _RF_S|_RF_A|_RF_P|  _RF_SZ(32) | _RF_RS(2),    /* WDISP_22 */
80  _RF_S|_RF_A|        _RF_SZ(32) | _RF_RS(10),   /* HI22 */
81  _RF_S|_RF_A|        _RF_SZ(32) | _RF_RS(0),    /* 22 */
82  _RF_S|_RF_A|        _RF_SZ(32) | _RF_RS(0),    /* 13 */
83  _RF_S|_RF_A|        _RF_SZ(32) | _RF_RS(0),    /* LO10 */
84  _RF_G|              _RF_SZ(32) | _RF_RS(0),    /* GOT10 */
85  _RF_G|              _RF_SZ(32) | _RF_RS(0),    /* GOT13 */
86  _RF_G|              _RF_SZ(32) | _RF_RS(10),   /* GOT22 */
87  _RF_S|_RF_A|_RF_P|  _RF_SZ(32) | _RF_RS(0),    /* PC10 */
88  _RF_S|_RF_A|_RF_P|  _RF_SZ(32) | _RF_RS(10),   /* PC22 */
89        _RF_A|_RF_P|  _RF_SZ(32) | _RF_RS(2),    /* WPLT30 */
90                      _RF_SZ(32) | _RF_RS(0),    /* COPY */
91  _RF_S|_RF_A|        _RF_SZ(32) | _RF_RS(0),    /* GLOB_DAT */
92                      _RF_SZ(32) | _RF_RS(0),    /* JMP_SLOT */
93        _RF_A|  _RF_B|_RF_SZ(32) | _RF_RS(0),    /* RELATIVE */
94  _RF_S|_RF_A|  _RF_U|_RF_SZ(32) | _RF_RS(0),    /* UA_32 */
95};
96
97#define NOT_CURRENTLY_USED_BUT_MAYBE_USEFUL
98#ifdef NOT_CURRENTLY_USED_BUT_MAYBE_USEFUL
99static const char *reloc_names[] = {
100  "NONE", "RELOC_8", "RELOC_16", "RELOC_32", "DISP_8",
101  "DISP_16", "DISP_32", "WDISP_30", "WDISP_22", "HI22",
102  "22", "13", "LO10", "GOT10", "GOT13",
103  "GOT22", "PC10", "PC22", "WPLT30", "COPY",
104  "GLOB_DAT", "JMP_SLOT", "RELATIVE", "UA_32"
105};
106#endif
107
108#define RELOC_RESOLVE_SYMBOL(t)    ((reloc_target_flags[t] & _RF_S) != 0)
109#define RELOC_PC_RELATIVE(t)       ((reloc_target_flags[t] & _RF_P) != 0)
110#define RELOC_BASE_RELATIVE(t)     ((reloc_target_flags[t] & _RF_B) != 0)
111#define RELOC_UNALIGNED(t)         ((reloc_target_flags[t] & _RF_U) != 0)
112#define RELOC_USE_ADDEND(t)        ((reloc_target_flags[t] & _RF_A) != 0)
113#define RELOC_TARGET_SIZE(t)       ((reloc_target_flags[t] >> 8) & 0xff)
114#define RELOC_VALUE_RIGHTSHIFT(t)  (reloc_target_flags[t] & 0xff)
115
116static const int reloc_target_bitmask[] = {
117#define _BM(x)  (~(-(1ULL << (x))))
118  0,        /* NONE */
119  _BM(8),  _BM(16), _BM(32),  /* RELOC_8, _16, _32 */
120  _BM(8),  _BM(16), _BM(32),  /* DISP8, DISP16, DISP32 */
121  _BM(30), _BM(22),           /* WDISP30, WDISP22 */
122  _BM(22), _BM(22),           /* HI22, _22 */
123  _BM(13), _BM(10),           /* RELOC_13, _LO10 */
124  _BM(10), _BM(13), _BM(22),  /* GOT10, GOT13, GOT22 */
125  _BM(10), _BM(22),           /* _PC10, _PC22 */
126  _BM(30), 0,                 /* _WPLT30, _COPY */
127  -1, -1, -1,                 /* _GLOB_DAT, JMP_SLOT, _RELATIVE */
128  _BM(32)                     /* _UA32 */
129#undef _BM
130};
131#define RELOC_VALUE_BITMASK(t)  (reloc_target_bitmask[t])
132
133uint32_t
134rtems_rtl_elf_section_flags (const rtems_rtl_obj_t* obj,
135                             const Elf_Shdr*        shdr)
136{
137  return 0;
138}
139
140bool
141rtems_rtl_elf_rel_resolve_sym (Elf_Word type)
142{
143  return RELOC_RESOLVE_SYMBOL (type) ? true : false;
144}
145
146bool
147rtems_rtl_elf_relocate_rela (const rtems_rtl_obj_t*      obj,
148                             const Elf_Rela*             rela,
149                             const rtems_rtl_obj_sect_t* sect,
150                             const char*                 symname,
151                             const Elf_Byte              syminfo,
152                             const Elf_Word              symvalue)
153{
154  Elf_Addr *where;
155  Elf_Word type, value, mask;
156  Elf_Addr tmp = 0;
157
158  where = (Elf_Addr *) (sect->base + rela->r_offset);
159
160  type = ELF_R_TYPE(rela->r_info);
161  if (type == R_TYPE(NONE))
162    return true;
163
164  /* We do JMP_SLOTs in _rtld_bind() below */
165  if (type == R_TYPE(JMP_SLOT))
166    return true;
167
168  /* COPY relocs are also handled elsewhere */
169  if (type == R_TYPE(COPY))
170    return true;
171
172  /*
173   * We use the fact that relocation types are an `enum'
174   * Note: R_SPARC_6 is currently numerically largest.
175   */
176  if (type > R_TYPE(6))
177    return false;
178
179  value = rela->r_addend;
180
181  /*
182   * Handle relative relocs here, as an optimization.
183   */
184  if (type == R_TYPE (RELATIVE)) {
185    *where += (Elf_Addr)(sect->base + value);
186    if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC))
187      printf ("rtl: reloc relative in %s --> %p",
188              rtems_rtl_obj_oname (obj), (void *)*where);
189    return true;
190  }
191
192  if (RELOC_RESOLVE_SYMBOL (type)) {
193    /* Add in the symbol's absolute address */
194    value += symvalue;
195  }
196
197  if (RELOC_PC_RELATIVE (type)) {
198    value -= (Elf_Word)where;
199  }
200
201  if (RELOC_BASE_RELATIVE (type)) {
202    /*
203     * Note that even though sparcs use `Elf_rela'
204     * exclusively we still need the implicit memory addend
205     * in relocations referring to GOT entries.
206     * Undoubtedly, someone f*cked this up in the distant
207     * past, and now we're stuck with it in the name of
208     * compatibility for all eternity..
209     *
210     * In any case, the implicit and explicit should be
211     * mutually exclusive. We provide a check for that
212     * here.
213     */
214#define DIAGNOSTIC
215#ifdef DIAGNOSTIC
216    if (value != 0 && *where != 0) {
217      if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC))
218        printf("rtl: reloc base_rel(%s): where=%p, *where 0x%lx, "
219               "addend=0x%lx, base %p\n",
220               rtems_rtl_obj_oname (obj),
221               where, *where, rela->r_addend, sect->base);
222    }
223#endif
224    value += (Elf_Word)(sect->base + *where);
225  }
226
227  mask = RELOC_VALUE_BITMASK (type);
228  value >>= RELOC_VALUE_RIGHTSHIFT (type);
229  value &= mask;
230
231  if (RELOC_UNALIGNED(type)) {
232    /*
233     * Handle unaligned relocations.
234     */
235    char *ptr = (char*) where;
236    int i, size = RELOC_TARGET_SIZE (type) / 8;
237
238    /* Read it in one byte at a time. */
239    for (i = size - 1; i >= 0; i--)
240      tmp = (tmp << 8) | ptr[i];
241
242    tmp &= ~mask;
243    tmp |= value;
244
245    /* Write it back out. */
246    for (i = size - 1; i >= 0; i--, tmp >>= 8)
247      ptr[i] = tmp & 0xff;
248  } else {
249    *where &= ~mask;
250    *where |= value;
251    tmp = *where;
252  }
253
254  if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC))
255    printf ("rtl: %s %p @ %p in %s\n",
256            reloc_names[ELF_R_TYPE(rela->r_info)],
257            (void *)tmp, where, rtems_rtl_obj_oname (obj));
258
259  return true;
260}
261
262bool
263rtems_rtl_elf_relocate_rel (const rtems_rtl_obj_t*      obj,
264                            const Elf_Rel*              rel,
265                            const rtems_rtl_obj_sect_t* sect,
266                            const char*                 symname,
267                            const Elf_Byte              syminfo,
268                            const Elf_Word              symvalue)
269{
270  printf ("rtl: rel type record not supported; please report\n");
271  return false;
272}
273
274bool
275rtems_rtl_elf_unwind_parse (const rtems_rtl_obj_t* obj,
276                            const char*            name,
277                            uint32_t               flags)
278{
279  return rtems_rtl_elf_unwind_dw2_parse (obj, name, flags);
280}
281
282bool
283rtems_rtl_elf_unwind_register (rtems_rtl_obj_t* obj)
284{
285  return rtems_rtl_elf_unwind_dw2_register (obj);
286}
287
288bool
289rtems_rtl_elf_unwind_deregister (rtems_rtl_obj_t* obj)
290{
291  return rtems_rtl_elf_unwind_dw2_deregister (obj);
292}
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