forked from Imagelibrary/rtems
293 lines
10 KiB
C
293 lines
10 KiB
C
/*
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* Taken from NetBSD and stripped of the relocations not needed on RTEMS.
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*/
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/* $NetBSD: mdreloc.c,v 1.43 2010/01/13 20:17:22 christos Exp $ */
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/*-
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* Copyright (c) 1999, 2002 The NetBSD Foundation, Inc.
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* All rights reserved.
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*
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* This code is derived from software contributed to The NetBSD Foundation
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* by Paul Kranenburg and by Charles M. Hannum.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
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* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
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* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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#include <stdio.h>
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#include <rtems/rtl/rtl.h>
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#include "rtl-elf.h"
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#include "rtl-error.h"
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#include <rtems/rtl/rtl-trace.h>
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#include "rtl-unwind.h"
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#include "rtl-unwind-dw2.h"
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/*
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* The following table holds for each relocation type:
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* - the width in bits of the memory location the relocation
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* applies to (not currently used)
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* - the number of bits the relocation value must be shifted to the
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* right (i.e. discard least significant bits) to fit into
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* the appropriate field in the instruction word.
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* - flags indicating whether
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* * the relocation involves a symbol
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* * the relocation is relative to the current position
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* * the relocation is for a GOT entry
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* * the relocation is relative to the load address
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*
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*/
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#define _RF_S 0x80000000 /* Resolve symbol */
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#define _RF_A 0x40000000 /* Use addend */
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#define _RF_P 0x20000000 /* Location relative */
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#define _RF_G 0x10000000 /* GOT offset */
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#define _RF_B 0x08000000 /* Load address relative */
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#define _RF_U 0x04000000 /* Unaligned */
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#define _RF_SZ(s) (((s) & 0xff) << 8) /* memory target size */
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#define _RF_RS(s) ( (s) & 0xff) /* right shift */
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static const uint32_t reloc_target_flags[] = {
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0, /* NONE */
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_RF_S|_RF_A| _RF_SZ(8) | _RF_RS(0), /* RELOC_8 */
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_RF_S|_RF_A| _RF_SZ(16) | _RF_RS(0), /* RELOC_16 */
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_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* RELOC_32 */
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_RF_S|_RF_A|_RF_P| _RF_SZ(8) | _RF_RS(0), /* DISP_8 */
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_RF_S|_RF_A|_RF_P| _RF_SZ(16) | _RF_RS(0), /* DISP_16 */
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_RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(0), /* DISP_32 */
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_RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(2), /* WDISP_30 */
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_RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(2), /* WDISP_22 */
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_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(10), /* HI22 */
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_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* 22 */
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_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* 13 */
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_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* LO10 */
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_RF_G| _RF_SZ(32) | _RF_RS(0), /* GOT10 */
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_RF_G| _RF_SZ(32) | _RF_RS(0), /* GOT13 */
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_RF_G| _RF_SZ(32) | _RF_RS(10), /* GOT22 */
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_RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(0), /* PC10 */
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_RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(10), /* PC22 */
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_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(2), /* WPLT30 */
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_RF_SZ(32) | _RF_RS(0), /* COPY */
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_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* GLOB_DAT */
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_RF_SZ(32) | _RF_RS(0), /* JMP_SLOT */
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_RF_A| _RF_B|_RF_SZ(32) | _RF_RS(0), /* RELATIVE */
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_RF_S|_RF_A| _RF_U|_RF_SZ(32) | _RF_RS(0), /* UA_32 */
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};
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#define NOT_CURRENTLY_USED_BUT_MAYBE_USEFUL
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#ifdef NOT_CURRENTLY_USED_BUT_MAYBE_USEFUL
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static const char *reloc_names[] = {
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"NONE", "RELOC_8", "RELOC_16", "RELOC_32", "DISP_8",
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"DISP_16", "DISP_32", "WDISP_30", "WDISP_22", "HI22",
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"22", "13", "LO10", "GOT10", "GOT13",
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"GOT22", "PC10", "PC22", "WPLT30", "COPY",
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"GLOB_DAT", "JMP_SLOT", "RELATIVE", "UA_32"
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};
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#endif
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#define RELOC_RESOLVE_SYMBOL(t) ((reloc_target_flags[t] & _RF_S) != 0)
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#define RELOC_PC_RELATIVE(t) ((reloc_target_flags[t] & _RF_P) != 0)
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#define RELOC_BASE_RELATIVE(t) ((reloc_target_flags[t] & _RF_B) != 0)
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#define RELOC_UNALIGNED(t) ((reloc_target_flags[t] & _RF_U) != 0)
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#define RELOC_USE_ADDEND(t) ((reloc_target_flags[t] & _RF_A) != 0)
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#define RELOC_TARGET_SIZE(t) ((reloc_target_flags[t] >> 8) & 0xff)
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#define RELOC_VALUE_RIGHTSHIFT(t) (reloc_target_flags[t] & 0xff)
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static const int reloc_target_bitmask[] = {
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#define _BM(x) (~(-(1ULL << (x))))
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0, /* NONE */
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_BM(8), _BM(16), _BM(32), /* RELOC_8, _16, _32 */
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_BM(8), _BM(16), _BM(32), /* DISP8, DISP16, DISP32 */
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_BM(30), _BM(22), /* WDISP30, WDISP22 */
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_BM(22), _BM(22), /* HI22, _22 */
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_BM(13), _BM(10), /* RELOC_13, _LO10 */
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_BM(10), _BM(13), _BM(22), /* GOT10, GOT13, GOT22 */
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_BM(10), _BM(22), /* _PC10, _PC22 */
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_BM(30), 0, /* _WPLT30, _COPY */
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-1, -1, -1, /* _GLOB_DAT, JMP_SLOT, _RELATIVE */
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_BM(32) /* _UA32 */
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#undef _BM
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};
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#define RELOC_VALUE_BITMASK(t) (reloc_target_bitmask[t])
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uint32_t
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rtems_rtl_elf_section_flags (const rtems_rtl_obj* obj,
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const Elf_Shdr* shdr)
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{
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return 0;
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}
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bool
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rtems_rtl_elf_rel_resolve_sym (Elf_Word type)
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{
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return RELOC_RESOLVE_SYMBOL (type) ? true : false;
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}
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bool
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rtems_rtl_elf_relocate_rela (const rtems_rtl_obj* obj,
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const Elf_Rela* rela,
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const rtems_rtl_obj_sect* sect,
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const char* symname,
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const Elf_Byte syminfo,
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const Elf_Word symvalue)
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{
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Elf_Addr *where;
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Elf_Word type, value, mask;
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Elf_Addr tmp = 0;
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where = (Elf_Addr *) (sect->base + rela->r_offset);
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type = ELF_R_TYPE(rela->r_info);
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if (type == R_TYPE(NONE))
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return true;
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/* We do JMP_SLOTs in _rtld_bind() below */
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if (type == R_TYPE(JMP_SLOT))
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return true;
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/* COPY relocs are also handled elsewhere */
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if (type == R_TYPE(COPY))
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return true;
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/*
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* We use the fact that relocation types are an `enum'
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* Note: R_SPARC_6 is currently numerically largest.
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*/
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if (type > R_TYPE(6))
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return false;
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value = rela->r_addend;
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/*
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* Handle relative relocs here, as an optimization.
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*/
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if (type == R_TYPE (RELATIVE)) {
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*where += (Elf_Addr)(sect->base + value);
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if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC))
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printf ("rtl: reloc relative in %s --> %p",
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rtems_rtl_obj_oname (obj), (void *)*where);
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return true;
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}
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if (RELOC_RESOLVE_SYMBOL (type)) {
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/* Add in the symbol's absolute address */
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value += symvalue;
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}
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if (RELOC_PC_RELATIVE (type)) {
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value -= (Elf_Word)where;
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}
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if (RELOC_BASE_RELATIVE (type)) {
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/*
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* Note that even though sparcs use `Elf_rela'
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* exclusively we still need the implicit memory addend
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* in relocations referring to GOT entries.
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* Undoubtedly, someone f*cked this up in the distant
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* past, and now we're stuck with it in the name of
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* compatibility for all eternity..
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*
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* In any case, the implicit and explicit should be
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* mutually exclusive. We provide a check for that
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* here.
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*/
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#define DIAGNOSTIC
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#ifdef DIAGNOSTIC
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if (value != 0 && *where != 0) {
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if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC))
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printf("rtl: reloc base_rel(%s): where=%p, *where 0x%lx, "
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"addend=0x%lx, base %p\n",
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rtems_rtl_obj_oname (obj),
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where, *where, rela->r_addend, sect->base);
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}
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#endif
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value += (Elf_Word)(sect->base + *where);
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}
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mask = RELOC_VALUE_BITMASK (type);
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value >>= RELOC_VALUE_RIGHTSHIFT (type);
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value &= mask;
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if (RELOC_UNALIGNED(type)) {
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/*
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* Handle unaligned relocations.
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*/
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char *ptr = (char*) where;
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int i, size = RELOC_TARGET_SIZE (type) / 8;
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/* Read it in one byte at a time. */
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for (i = size - 1; i >= 0; i--)
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tmp = (tmp << 8) | ptr[i];
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tmp &= ~mask;
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tmp |= value;
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/* Write it back out. */
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for (i = size - 1; i >= 0; i--, tmp >>= 8)
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ptr[i] = tmp & 0xff;
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} else {
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*where &= ~mask;
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*where |= value;
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tmp = *where;
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}
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if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC))
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printf ("rtl: %s %p @ %p in %s\n",
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reloc_names[ELF_R_TYPE(rela->r_info)],
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(void *)tmp, where, rtems_rtl_obj_oname (obj));
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return true;
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}
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bool
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rtems_rtl_elf_relocate_rel (const rtems_rtl_obj* obj,
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const Elf_Rel* rel,
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const rtems_rtl_obj_sect* sect,
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const char* symname,
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const Elf_Byte syminfo,
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const Elf_Word symvalue)
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{
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printf ("rtl: rel type record not supported; please report\n");
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return false;
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}
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bool
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rtems_rtl_elf_unwind_parse (const rtems_rtl_obj* obj,
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const char* name,
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uint32_t flags)
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{
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return rtems_rtl_elf_unwind_dw2_parse (obj, name, flags);
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}
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bool
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rtems_rtl_elf_unwind_register (rtems_rtl_obj* obj)
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{
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return rtems_rtl_elf_unwind_dw2_register (obj);
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}
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bool
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rtems_rtl_elf_unwind_deregister (rtems_rtl_obj* obj)
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{
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return rtems_rtl_elf_unwind_dw2_deregister (obj);
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}
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