1041 lines
28 KiB
C
1041 lines
28 KiB
C
/*-
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* Copyright (c) 2007-2013 Kai Wang
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* All rights reserved.
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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 AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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#include <sys/param.h>
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#include <err.h>
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#include <fnmatch.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include "elfcopy.h"
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ELFTC_VCSID("$Id: symbols.c 2971 2013-12-01 15:22:21Z kaiwang27 $");
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/* Symbol table buffer structure. */
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struct symbuf {
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Elf32_Sym *l32; /* 32bit local symbol */
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Elf32_Sym *g32; /* 32bit global symbol */
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Elf64_Sym *l64; /* 64bit local symbol */
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Elf64_Sym *g64; /* 64bit global symbol */
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size_t ngs, nls; /* number of each kind */
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size_t gcap, lcap; /* buffer capacities. */
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};
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/* String table buffer structure. */
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struct strbuf {
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char *l; /* local symbol string table */
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char *g; /* global symbol string table */
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size_t lsz, gsz; /* size of each kind */
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size_t gcap, lcap; /* buffer capacities. */
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};
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static int is_debug_symbol(unsigned char st_info);
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static int is_global_symbol(unsigned char st_info);
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static int is_local_symbol(unsigned char st_info);
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static int is_local_label(const char *name);
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static int is_needed_symbol(struct elfcopy *ecp, int i, GElf_Sym *s);
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static int is_remove_symbol(struct elfcopy *ecp, size_t sc, int i,
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GElf_Sym *s, const char *name);
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static int is_weak_symbol(unsigned char st_info);
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static int lookup_exact_string(const char *buf, size_t sz, const char *s);
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static int generate_symbols(struct elfcopy *ecp);
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static void mark_symbols(struct elfcopy *ecp, size_t sc);
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static int match_wildcard(const char *name, const char *pattern);
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/* Convenient bit vector operation macros. */
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#define BIT_SET(v, n) (v[(n)>>3] |= 1U << ((n) & 7))
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#define BIT_CLR(v, n) (v[(n)>>3] &= ~(1U << ((n) & 7)))
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#define BIT_ISSET(v, n) (v[(n)>>3] & (1U << ((n) & 7)))
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static int
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is_debug_symbol(unsigned char st_info)
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{
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if (GELF_ST_TYPE(st_info) == STT_SECTION ||
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GELF_ST_TYPE(st_info) == STT_FILE)
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return (1);
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return (0);
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}
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static int
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is_global_symbol(unsigned char st_info)
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{
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if (GELF_ST_BIND(st_info) == STB_GLOBAL)
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return (1);
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return (0);
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}
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static int
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is_weak_symbol(unsigned char st_info)
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{
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if (GELF_ST_BIND(st_info) == STB_WEAK)
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return (1);
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return (0);
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}
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static int
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is_local_symbol(unsigned char st_info)
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{
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if (GELF_ST_BIND(st_info) == STB_LOCAL)
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return (1);
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return (0);
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}
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static int
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is_local_label(const char *name)
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{
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/* Compiler generated local symbols that start with .L */
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if (name[0] == '.' && name[1] == 'L')
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return (1);
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return (0);
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}
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/*
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* Symbols related to relocation are needed.
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*/
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static int
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is_needed_symbol(struct elfcopy *ecp, int i, GElf_Sym *s)
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{
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/* If symbol involves relocation, it is needed. */
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if (BIT_ISSET(ecp->v_rel, i))
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return (1);
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/*
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* For relocatable files (.o files), global and weak symbols
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* are needed.
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*/
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if (ecp->flags & RELOCATABLE) {
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if (is_global_symbol(s->st_info) || is_weak_symbol(s->st_info))
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return (1);
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}
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return (0);
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}
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static int
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is_remove_symbol(struct elfcopy *ecp, size_t sc, int i, GElf_Sym *s,
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const char *name)
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{
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GElf_Sym sym0 = {
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0, /* st_name */
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0, /* st_value */
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0, /* st_size */
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0, /* st_info */
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0, /* st_other */
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SHN_UNDEF, /* st_shndx */
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};
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if (lookup_symop_list(ecp, name, SYMOP_KEEP) != NULL)
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return (0);
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if (lookup_symop_list(ecp, name, SYMOP_STRIP) != NULL)
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return (1);
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/*
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* Keep the first symbol if it is the special reserved symbol.
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* XXX Should we generate one if it's missing?
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*/
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if (i == 0 && !memcmp(s, &sym0, sizeof(GElf_Sym)))
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return (0);
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/* Remove the symbol if the section it refers to was removed. */
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if (s->st_shndx != SHN_UNDEF && s->st_shndx < SHN_LORESERVE &&
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ecp->secndx[s->st_shndx] == 0)
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return (1);
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if (ecp->strip == STRIP_ALL)
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return (1);
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if (ecp->v_rel == NULL)
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mark_symbols(ecp, sc);
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if (is_needed_symbol(ecp, i, s))
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return (0);
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if (ecp->strip == STRIP_UNNEEDED)
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return (1);
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if ((ecp->flags & DISCARD_LOCAL) && is_local_symbol(s->st_info) &&
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!is_debug_symbol(s->st_info))
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return (1);
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if ((ecp->flags & DISCARD_LLABEL) && is_local_symbol(s->st_info) &&
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!is_debug_symbol(s->st_info) && is_local_label(name))
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return (1);
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if (ecp->strip == STRIP_DEBUG && is_debug_symbol(s->st_info))
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return (1);
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return (0);
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}
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/*
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* Mark symbols refered by relocation entries.
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*/
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static void
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mark_symbols(struct elfcopy *ecp, size_t sc)
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{
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const char *name;
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Elf_Data *d;
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Elf_Scn *s;
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GElf_Rel r;
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GElf_Rela ra;
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GElf_Shdr sh;
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size_t n, indx;
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int elferr, i, len;
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ecp->v_rel = calloc((sc + 7) / 8, 1);
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if (ecp->v_rel == NULL)
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err(EXIT_FAILURE, "calloc failed");
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if (elf_getshstrndx(ecp->ein, &indx) == 0)
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errx(EXIT_FAILURE, "elf_getshstrndx failed: %s",
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elf_errmsg(-1));
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s = NULL;
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while ((s = elf_nextscn(ecp->ein, s)) != NULL) {
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if (gelf_getshdr(s, &sh) != &sh)
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errx(EXIT_FAILURE, "elf_getshdr failed: %s",
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elf_errmsg(-1));
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if (sh.sh_type != SHT_REL && sh.sh_type != SHT_RELA)
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continue;
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/*
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* Skip if this reloc section won't appear in the
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* output object.
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*/
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if ((name = elf_strptr(ecp->ein, indx, sh.sh_name)) == NULL)
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errx(EXIT_FAILURE, "elf_strptr failed: %s",
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elf_errmsg(-1));
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if (is_remove_section(ecp, name) ||
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is_remove_reloc_sec(ecp, sh.sh_info))
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continue;
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/* Skip if it's not for .symtab */
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if (sh.sh_link != elf_ndxscn(ecp->symtab->is))
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continue;
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d = NULL;
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n = 0;
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while (n < sh.sh_size && (d = elf_getdata(s, d)) != NULL) {
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len = d->d_size / sh.sh_entsize;
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for (i = 0; i < len; i++) {
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if (sh.sh_type == SHT_REL) {
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if (gelf_getrel(d, i, &r) != &r)
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errx(EXIT_FAILURE,
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"elf_getrel failed: %s",
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elf_errmsg(-1));
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n = GELF_R_SYM(r.r_info);
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} else {
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if (gelf_getrela(d, i, &ra) != &ra)
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errx(EXIT_FAILURE,
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"elf_getrela failed: %s",
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elf_errmsg(-1));
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n = GELF_R_SYM(ra.r_info);
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}
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if (n > 0 && n < sc)
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BIT_SET(ecp->v_rel, n);
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else if (n != 0)
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warnx("invalid symbox index");
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}
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}
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elferr = elf_errno();
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if (elferr != 0)
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errx(EXIT_FAILURE, "elf_getdata failed: %s",
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elf_errmsg(elferr));
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}
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elferr = elf_errno();
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if (elferr != 0)
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errx(EXIT_FAILURE, "elf_nextscn failed: %s",
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elf_errmsg(elferr));
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}
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static int
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generate_symbols(struct elfcopy *ecp)
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{
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struct section *s;
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struct symop *sp;
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struct symbuf *sy_buf;
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struct strbuf *st_buf;
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const char *name;
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char *newname;
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unsigned char *gsym;
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GElf_Shdr ish;
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GElf_Sym sym;
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Elf_Data* id;
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Elf_Scn *is;
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size_t ishstrndx, namelen, ndx, nsyms, sc, symndx;
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int ec, elferr, i;
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if (elf_getshstrndx(ecp->ein, &ishstrndx) == 0)
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errx(EXIT_FAILURE, "elf_getshstrndx failed: %s",
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elf_errmsg(-1));
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if ((ec = gelf_getclass(ecp->eout)) == ELFCLASSNONE)
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errx(EXIT_FAILURE, "gelf_getclass failed: %s",
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elf_errmsg(-1));
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/* Create buffers for .symtab and .strtab. */
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if ((sy_buf = calloc(1, sizeof(*sy_buf))) == NULL)
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err(EXIT_FAILURE, "calloc failed");
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if ((st_buf = calloc(1, sizeof(*st_buf))) == NULL)
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err(EXIT_FAILURE, "calloc failed");
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sy_buf->gcap = sy_buf->lcap = 64;
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st_buf->gcap = 256;
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st_buf->lcap = 64;
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st_buf->lsz = 1; /* '\0' at start. */
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st_buf->gsz = 0;
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nsyms = 0;
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ecp->symtab->sz = 0;
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ecp->strtab->sz = 0;
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ecp->symtab->buf = sy_buf;
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ecp->strtab->buf = st_buf;
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/*
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* Create bit vector v_secsym, which is used to mark sections
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* that already have corresponding STT_SECTION symbols.
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*/
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ecp->v_secsym = calloc((ecp->nos + 7) / 8, 1);
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if (ecp->v_secsym == NULL)
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err(EXIT_FAILURE, "calloc failed");
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/* Locate .strtab of input object. */
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symndx = 0;
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name = NULL;
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is = NULL;
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while ((is = elf_nextscn(ecp->ein, is)) != NULL) {
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if (gelf_getshdr(is, &ish) != &ish)
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errx(EXIT_FAILURE, "elf_getshdr failed: %s",
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elf_errmsg(-1));
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if ((name = elf_strptr(ecp->ein, ishstrndx, ish.sh_name)) ==
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NULL)
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errx(EXIT_FAILURE, "elf_strptr failed: %s",
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elf_errmsg(-1));
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if (strcmp(name, ".strtab") == 0) {
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symndx = elf_ndxscn(is);
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break;
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}
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}
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elferr = elf_errno();
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if (elferr != 0)
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errx(EXIT_FAILURE, "elf_nextscn failed: %s",
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elf_errmsg(elferr));
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/* Symbol table should exist if this function is called. */
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if (symndx == 0) {
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warnx("can't find .strtab section");
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return (0);
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}
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/* Locate .symtab of input object. */
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is = NULL;
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while ((is = elf_nextscn(ecp->ein, is)) != NULL) {
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if (gelf_getshdr(is, &ish) != &ish)
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errx(EXIT_FAILURE, "elf_getshdr failed: %s",
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elf_errmsg(-1));
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if ((name = elf_strptr(ecp->ein, ishstrndx, ish.sh_name)) ==
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NULL)
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errx(EXIT_FAILURE, "elf_strptr failed: %s",
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elf_errmsg(-1));
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if (strcmp(name, ".symtab") == 0)
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break;
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}
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elferr = elf_errno();
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if (elferr != 0)
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errx(EXIT_FAILURE, "elf_nextscn failed: %s",
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elf_errmsg(elferr));
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if (is == NULL)
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errx(EXIT_FAILURE, "can't find .strtab section");
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/*
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* Create bit vector gsym to mark global symbols, and symndx
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* to keep track of symbol index changes from input object to
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* output object, it is used by update_reloc() later to update
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* relocation information.
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*/
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gsym = NULL;
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sc = ish.sh_size / ish.sh_entsize;
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if (sc > 0) {
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ecp->symndx = calloc(sc, sizeof(*ecp->symndx));
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if (ecp->symndx == NULL)
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err(EXIT_FAILURE, "calloc failed");
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gsym = calloc((sc + 7) / 8, sizeof(*gsym));
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if (gsym == NULL)
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err(EXIT_FAILURE, "calloc failed");
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if ((id = elf_getdata(is, NULL)) == NULL) {
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elferr = elf_errno();
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if (elferr != 0)
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errx(EXIT_FAILURE, "elf_getdata failed: %s",
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elf_errmsg(elferr));
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return (0);
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}
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} else
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return (0);
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/* Copy/Filter each symbol. */
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for (i = 0; (size_t)i < sc; i++) {
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if (gelf_getsym(id, i, &sym) != &sym)
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errx(EXIT_FAILURE, "gelf_getsym failed: %s",
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elf_errmsg(-1));
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if ((name = elf_strptr(ecp->ein, symndx, sym.st_name)) == NULL)
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errx(EXIT_FAILURE, "elf_strptr failed: %s",
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elf_errmsg(-1));
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/* Symbol filtering. */
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if (is_remove_symbol(ecp, sc, i, &sym, name) != 0)
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continue;
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/* Check if we need to change the binding of this symbol. */
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if (is_global_symbol(sym.st_info) ||
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is_weak_symbol(sym.st_info)) {
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/*
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* XXX Binutils objcopy does not weaken certain
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* symbols.
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*/
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if (ecp->flags & WEAKEN_ALL ||
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lookup_symop_list(ecp, name, SYMOP_WEAKEN) != NULL)
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sym.st_info = GELF_ST_INFO(STB_WEAK,
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GELF_ST_TYPE(sym.st_info));
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/* Do not localize undefined symbols. */
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if (sym.st_shndx != SHN_UNDEF &&
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lookup_symop_list(ecp, name, SYMOP_LOCALIZE) !=
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NULL)
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sym.st_info = GELF_ST_INFO(STB_LOCAL,
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GELF_ST_TYPE(sym.st_info));
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if (ecp->flags & KEEP_GLOBAL &&
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sym.st_shndx != SHN_UNDEF &&
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lookup_symop_list(ecp, name, SYMOP_KEEPG) == NULL)
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sym.st_info = GELF_ST_INFO(STB_LOCAL,
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GELF_ST_TYPE(sym.st_info));
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} else {
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/* STB_LOCAL binding. */
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if (lookup_symop_list(ecp, name, SYMOP_GLOBALIZE) !=
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NULL)
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sym.st_info = GELF_ST_INFO(STB_GLOBAL,
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GELF_ST_TYPE(sym.st_info));
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/* XXX We should globalize weak symbol? */
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}
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/* Check if we need to rename this symbol. */
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if ((sp = lookup_symop_list(ecp, name, SYMOP_REDEF)) != NULL)
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name = sp->newname;
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/* Check if we need to prefix the symbols. */
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newname = NULL;
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if (ecp->prefix_sym != NULL && name != NULL && *name != '\0') {
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namelen = strlen(name) + strlen(ecp->prefix_sym) + 1;
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if ((newname = malloc(namelen)) == NULL)
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err(EXIT_FAILURE, "malloc failed");
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snprintf(newname, namelen, "%s%s", ecp->prefix_sym,
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name);
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name = newname;
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}
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/* Copy symbol, mark global/weak symbol and add to index map. */
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|
if (is_global_symbol(sym.st_info) ||
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is_weak_symbol(sym.st_info)) {
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BIT_SET(gsym, i);
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ecp->symndx[i] = sy_buf->ngs;
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} else
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ecp->symndx[i] = sy_buf->nls;
|
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add_to_symtab(ecp, name, sym.st_value, sym.st_size,
|
|
sym.st_shndx, sym.st_info, sym.st_other, 0);
|
|
|
|
if (newname != NULL)
|
|
free(newname);
|
|
|
|
/*
|
|
* If the symbol is a STT_SECTION symbol, mark the section
|
|
* it points to.
|
|
*/
|
|
if (GELF_ST_TYPE(sym.st_info) == STT_SECTION)
|
|
BIT_SET(ecp->v_secsym, ecp->secndx[sym.st_shndx]);
|
|
}
|
|
|
|
/*
|
|
* Give up if there is no real symbols inside the table.
|
|
* XXX The logic here needs to be improved. We need to
|
|
* check if that only local symbol is the reserved symbol.
|
|
*/
|
|
if (sy_buf->nls <= 1 && sy_buf->ngs == 0)
|
|
return (0);
|
|
|
|
/*
|
|
* Create STT_SECTION symbols for sections that do not already
|
|
* got one. However, we do not create STT_SECTION symbol for
|
|
* .symtab, .strtab, .shstrtab and reloc sec of relocatables.
|
|
*/
|
|
TAILQ_FOREACH(s, &ecp->v_sec, sec_list) {
|
|
if (s->pseudo)
|
|
continue;
|
|
if (strcmp(s->name, ".symtab") == 0 ||
|
|
strcmp(s->name, ".strtab") == 0 ||
|
|
strcmp(s->name, ".shstrtab") == 0)
|
|
continue;
|
|
if ((ecp->flags & RELOCATABLE) != 0 &&
|
|
((s->type == SHT_REL) || (s->type == SHT_RELA)))
|
|
continue;
|
|
|
|
if ((ndx = elf_ndxscn(s->os)) == SHN_UNDEF)
|
|
errx(EXIT_FAILURE, "elf_ndxscn failed: %s",
|
|
elf_errmsg(-1));
|
|
|
|
if (!BIT_ISSET(ecp->v_secsym, ndx)) {
|
|
sym.st_name = 0;
|
|
sym.st_value = s->vma;
|
|
sym.st_size = 0;
|
|
sym.st_info = GELF_ST_INFO(STB_LOCAL, STT_SECTION);
|
|
/*
|
|
* Don't let add_to_symtab() touch sym.st_shndx.
|
|
* In this case, we know the index already.
|
|
*/
|
|
add_to_symtab(ecp, NULL, sym.st_value, sym.st_size,
|
|
ndx, sym.st_info, sym.st_other, 1);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Update st_name and index map for global/weak symbols. Note that
|
|
* global/weak symbols are put after local symbols.
|
|
*/
|
|
if (gsym != NULL) {
|
|
for(i = 0; (size_t) i < sc; i++) {
|
|
if (!BIT_ISSET(gsym, i))
|
|
continue;
|
|
|
|
/* Update st_name. */
|
|
if (ec == ELFCLASS32)
|
|
sy_buf->g32[ecp->symndx[i]].st_name +=
|
|
st_buf->lsz;
|
|
else
|
|
sy_buf->g64[ecp->symndx[i]].st_name +=
|
|
st_buf->lsz;
|
|
|
|
/* Update index map. */
|
|
ecp->symndx[i] += sy_buf->nls;
|
|
}
|
|
free(gsym);
|
|
}
|
|
|
|
return (1);
|
|
}
|
|
|
|
void
|
|
create_symtab(struct elfcopy *ecp)
|
|
{
|
|
struct section *s, *sy, *st;
|
|
size_t maxndx, ndx;
|
|
|
|
sy = ecp->symtab;
|
|
st = ecp->strtab;
|
|
|
|
/*
|
|
* Set section index map for .symtab and .strtab. We need to set
|
|
* these map because otherwise symbols which refer to .symtab and
|
|
* .strtab will be removed by symbol filtering unconditionally.
|
|
* And we have to figure out scn index this way (instead of calling
|
|
* elf_ndxscn) because we can not create Elf_Scn before we're certain
|
|
* that .symtab and .strtab will exist in the output object.
|
|
*/
|
|
maxndx = 0;
|
|
TAILQ_FOREACH(s, &ecp->v_sec, sec_list) {
|
|
if (s->os == NULL)
|
|
continue;
|
|
if ((ndx = elf_ndxscn(s->os)) == SHN_UNDEF)
|
|
errx(EXIT_FAILURE, "elf_ndxscn failed: %s",
|
|
elf_errmsg(-1));
|
|
if (ndx > maxndx)
|
|
maxndx = ndx;
|
|
}
|
|
ecp->secndx[elf_ndxscn(sy->is)] = maxndx + 1;
|
|
ecp->secndx[elf_ndxscn(st->is)] = maxndx + 2;
|
|
|
|
/*
|
|
* Generate symbols for output object if SYMTAB_INTACT is not set.
|
|
* If there is no symbol in the input object or all the symbols are
|
|
* stripped, then free all the resouces allotted for symbol table,
|
|
* and clear SYMTAB_EXIST flag.
|
|
*/
|
|
if (((ecp->flags & SYMTAB_INTACT) == 0) && !generate_symbols(ecp)) {
|
|
TAILQ_REMOVE(&ecp->v_sec, ecp->symtab, sec_list);
|
|
TAILQ_REMOVE(&ecp->v_sec, ecp->strtab, sec_list);
|
|
free(ecp->symtab);
|
|
free(ecp->strtab);
|
|
ecp->symtab = NULL;
|
|
ecp->strtab = NULL;
|
|
ecp->flags &= ~SYMTAB_EXIST;
|
|
return;
|
|
}
|
|
|
|
/* Create output Elf_Scn for .symtab and .strtab. */
|
|
if ((sy->os = elf_newscn(ecp->eout)) == NULL ||
|
|
(st->os = elf_newscn(ecp->eout)) == NULL)
|
|
errx(EXIT_FAILURE, "elf_newscn failed: %s",
|
|
elf_errmsg(-1));
|
|
/* Update secndx anyway. */
|
|
ecp->secndx[elf_ndxscn(sy->is)] = elf_ndxscn(sy->os);
|
|
ecp->secndx[elf_ndxscn(st->is)] = elf_ndxscn(st->os);
|
|
|
|
/*
|
|
* Copy .symtab and .strtab section headers from input to output
|
|
* object to start with, these will be overridden later if need.
|
|
*/
|
|
copy_shdr(ecp, sy, ".symtab", 1, 0);
|
|
copy_shdr(ecp, st, ".strtab", 1, 0);
|
|
|
|
/* Copy verbatim if symbol table is intact. */
|
|
if (ecp->flags & SYMTAB_INTACT) {
|
|
copy_data(sy);
|
|
copy_data(st);
|
|
return;
|
|
}
|
|
|
|
create_symtab_data(ecp);
|
|
}
|
|
|
|
void
|
|
free_symtab(struct elfcopy *ecp)
|
|
{
|
|
struct symbuf *sy_buf;
|
|
struct strbuf *st_buf;
|
|
|
|
if (ecp->symtab != NULL && ecp->symtab->buf != NULL) {
|
|
sy_buf = ecp->symtab->buf;
|
|
if (sy_buf->l32 != NULL)
|
|
free(sy_buf->l32);
|
|
if (sy_buf->g32 != NULL)
|
|
free(sy_buf->g32);
|
|
if (sy_buf->l64 != NULL)
|
|
free(sy_buf->l64);
|
|
if (sy_buf->g64 != NULL)
|
|
free(sy_buf->g64);
|
|
}
|
|
|
|
if (ecp->strtab != NULL && ecp->strtab->buf != NULL) {
|
|
st_buf = ecp->strtab->buf;
|
|
if (st_buf->l != NULL)
|
|
free(st_buf->l);
|
|
if (st_buf->g != NULL)
|
|
free(st_buf->g);
|
|
}
|
|
}
|
|
|
|
void
|
|
create_external_symtab(struct elfcopy *ecp)
|
|
{
|
|
struct section *s;
|
|
struct symbuf *sy_buf;
|
|
struct strbuf *st_buf;
|
|
GElf_Shdr sh;
|
|
size_t ndx;
|
|
|
|
if (ecp->oec == ELFCLASS32)
|
|
ecp->symtab = create_external_section(ecp, ".symtab", NULL,
|
|
NULL, 0, 0, SHT_SYMTAB, ELF_T_SYM, 0, 4, 0, 0);
|
|
else
|
|
ecp->symtab = create_external_section(ecp, ".symtab", NULL,
|
|
NULL, 0, 0, SHT_SYMTAB, ELF_T_SYM, 0, 8, 0, 0);
|
|
|
|
ecp->strtab = create_external_section(ecp, ".strtab", NULL, NULL, 0, 0,
|
|
SHT_STRTAB, ELF_T_BYTE, 0, 1, 0, 0);
|
|
|
|
/* Let sh_link field of .symtab section point to .strtab section. */
|
|
if (gelf_getshdr(ecp->symtab->os, &sh) == NULL)
|
|
errx(EXIT_FAILURE, "gelf_getshdr() failed: %s",
|
|
elf_errmsg(-1));
|
|
sh.sh_link = elf_ndxscn(ecp->strtab->os);
|
|
if (!gelf_update_shdr(ecp->symtab->os, &sh))
|
|
errx(EXIT_FAILURE, "gelf_update_shdr() failed: %s",
|
|
elf_errmsg(-1));
|
|
|
|
/* Create buffers for .symtab and .strtab. */
|
|
if ((sy_buf = calloc(1, sizeof(*sy_buf))) == NULL)
|
|
err(EXIT_FAILURE, "calloc failed");
|
|
if ((st_buf = calloc(1, sizeof(*st_buf))) == NULL)
|
|
err(EXIT_FAILURE, "calloc failed");
|
|
sy_buf->gcap = sy_buf->lcap = 64;
|
|
st_buf->gcap = 256;
|
|
st_buf->lcap = 64;
|
|
st_buf->lsz = 1; /* '\0' at start. */
|
|
st_buf->gsz = 0;
|
|
|
|
ecp->symtab->sz = 0;
|
|
ecp->strtab->sz = 0;
|
|
ecp->symtab->buf = sy_buf;
|
|
ecp->strtab->buf = st_buf;
|
|
|
|
/* Always create the special symbol at the symtab beginning. */
|
|
add_to_symtab(ecp, NULL, 0, 0, SHN_UNDEF,
|
|
ELF32_ST_INFO(STB_LOCAL, STT_NOTYPE), 0, 1);
|
|
|
|
/* Create STT_SECTION symbols. */
|
|
TAILQ_FOREACH(s, &ecp->v_sec, sec_list) {
|
|
if (s->pseudo)
|
|
continue;
|
|
if (strcmp(s->name, ".symtab") == 0 ||
|
|
strcmp(s->name, ".strtab") == 0 ||
|
|
strcmp(s->name, ".shstrtab") == 0)
|
|
continue;
|
|
(void) elf_errno();
|
|
if ((ndx = elf_ndxscn(s->os)) == SHN_UNDEF) {
|
|
warnx("elf_ndxscn failed: %s",
|
|
elf_errmsg(-1));
|
|
continue;
|
|
}
|
|
add_to_symtab(ecp, NULL, 0, 0, ndx,
|
|
GELF_ST_INFO(STB_LOCAL, STT_SECTION), 0, 1);
|
|
}
|
|
}
|
|
|
|
void
|
|
add_to_symtab(struct elfcopy *ecp, const char *name, uint64_t st_value,
|
|
uint64_t st_size, uint16_t st_shndx, unsigned char st_info,
|
|
unsigned char st_other, int ndx_known)
|
|
{
|
|
struct symbuf *sy_buf;
|
|
struct strbuf *st_buf;
|
|
int pos;
|
|
|
|
/*
|
|
* Convenient macro for copying global/local 32/64 bit symbols
|
|
* from input object to the buffer created for output object.
|
|
* It handles buffer growing, st_name calculating and st_shndx
|
|
* updating for symbols with non-special section index.
|
|
*/
|
|
#define _ADDSYM(B, SZ) do { \
|
|
if (sy_buf->B##SZ == NULL) { \
|
|
sy_buf->B##SZ = malloc(sy_buf->B##cap * \
|
|
sizeof(Elf##SZ##_Sym)); \
|
|
if (sy_buf->B##SZ == NULL) \
|
|
err(EXIT_FAILURE, "malloc failed"); \
|
|
} else if (sy_buf->n##B##s >= sy_buf->B##cap) { \
|
|
sy_buf->B##cap *= 2; \
|
|
sy_buf->B##SZ = realloc(sy_buf->B##SZ, sy_buf->B##cap * \
|
|
sizeof(Elf##SZ##_Sym)); \
|
|
if (sy_buf->B##SZ == NULL) \
|
|
err(EXIT_FAILURE, "realloc failed"); \
|
|
} \
|
|
sy_buf->B##SZ[sy_buf->n##B##s].st_info = st_info; \
|
|
sy_buf->B##SZ[sy_buf->n##B##s].st_other = st_other; \
|
|
sy_buf->B##SZ[sy_buf->n##B##s].st_value = st_value; \
|
|
sy_buf->B##SZ[sy_buf->n##B##s].st_size = st_size; \
|
|
if (ndx_known) \
|
|
sy_buf->B##SZ[sy_buf->n##B##s].st_shndx = st_shndx; \
|
|
else if (st_shndx == SHN_UNDEF || st_shndx >= SHN_LORESERVE) \
|
|
sy_buf->B##SZ[sy_buf->n##B##s].st_shndx = st_shndx; \
|
|
else \
|
|
sy_buf->B##SZ[sy_buf->n##B##s].st_shndx = \
|
|
ecp->secndx[st_shndx]; \
|
|
if (st_buf->B == NULL) { \
|
|
st_buf->B = calloc(st_buf->B##cap, sizeof(*st_buf->B)); \
|
|
if (st_buf->B == NULL) \
|
|
err(EXIT_FAILURE, "malloc failed"); \
|
|
} \
|
|
if (name != NULL && *name != '\0') { \
|
|
pos = lookup_exact_string(st_buf->B, \
|
|
st_buf->B##sz, name); \
|
|
if (pos != -1) \
|
|
sy_buf->B##SZ[sy_buf->n##B##s].st_name = pos; \
|
|
else { \
|
|
sy_buf->B##SZ[sy_buf->n##B##s].st_name = \
|
|
st_buf->B##sz; \
|
|
while (st_buf->B##sz + strlen(name) >= \
|
|
st_buf->B##cap - 1) { \
|
|
st_buf->B##cap *= 2; \
|
|
st_buf->B = realloc(st_buf->B, \
|
|
st_buf->B##cap); \
|
|
if (st_buf->B == NULL) \
|
|
err(EXIT_FAILURE, \
|
|
"realloc failed"); \
|
|
} \
|
|
strncpy(&st_buf->B[st_buf->B##sz], name, \
|
|
strlen(name)); \
|
|
st_buf->B[st_buf->B##sz + strlen(name)] = '\0'; \
|
|
st_buf->B##sz += strlen(name) + 1; \
|
|
} \
|
|
} else \
|
|
sy_buf->B##SZ[sy_buf->n##B##s].st_name = 0; \
|
|
sy_buf->n##B##s++; \
|
|
} while (0)
|
|
|
|
sy_buf = ecp->symtab->buf;
|
|
st_buf = ecp->strtab->buf;
|
|
|
|
if (ecp->oec == ELFCLASS32) {
|
|
if (is_local_symbol(st_info))
|
|
_ADDSYM(l, 32);
|
|
else
|
|
_ADDSYM(g, 32);
|
|
} else {
|
|
if (is_local_symbol(st_info))
|
|
_ADDSYM(l, 64);
|
|
else
|
|
_ADDSYM(g, 64);
|
|
}
|
|
|
|
/* Update section size. */
|
|
ecp->symtab->sz = (sy_buf->nls + sy_buf->ngs) *
|
|
(ecp->oec == ELFCLASS32 ? sizeof(Elf32_Sym) : sizeof(Elf64_Sym));
|
|
ecp->strtab->sz = st_buf->lsz + st_buf->gsz;
|
|
|
|
#undef _ADDSYM
|
|
}
|
|
|
|
void
|
|
finalize_external_symtab(struct elfcopy *ecp)
|
|
{
|
|
struct symbuf *sy_buf;
|
|
struct strbuf *st_buf;
|
|
int i;
|
|
|
|
/*
|
|
* Update st_name for global/weak symbols. (global/weak symbols
|
|
* are put after local symbols)
|
|
*/
|
|
sy_buf = ecp->symtab->buf;
|
|
st_buf = ecp->strtab->buf;
|
|
for (i = 0; (size_t) i < sy_buf->ngs; i++) {
|
|
if (ecp->oec == ELFCLASS32)
|
|
sy_buf->g32[i].st_name += st_buf->lsz;
|
|
else
|
|
sy_buf->g64[i].st_name += st_buf->lsz;
|
|
}
|
|
}
|
|
|
|
void
|
|
create_symtab_data(struct elfcopy *ecp)
|
|
{
|
|
struct section *sy, *st;
|
|
struct symbuf *sy_buf;
|
|
struct strbuf *st_buf;
|
|
Elf_Data *gsydata, *lsydata, *gstdata, *lstdata;
|
|
GElf_Shdr shy, sht;
|
|
|
|
sy = ecp->symtab;
|
|
st = ecp->strtab;
|
|
|
|
if (gelf_getshdr(sy->os, ­) == NULL)
|
|
errx(EXIT_FAILURE, "gelf_getshdr() failed: %s",
|
|
elf_errmsg(-1));
|
|
if (gelf_getshdr(st->os, &sht) == NULL)
|
|
errx(EXIT_FAILURE, "gelf_getshdr() failed: %s",
|
|
elf_errmsg(-1));
|
|
|
|
/*
|
|
* Create two Elf_Data for .symtab section of output object, one
|
|
* for local symbols and another for global symbols. Note that
|
|
* local symbols appear first in the .symtab.
|
|
*/
|
|
sy_buf = sy->buf;
|
|
if (sy_buf->nls > 0) {
|
|
if ((lsydata = elf_newdata(sy->os)) == NULL)
|
|
errx(EXIT_FAILURE, "elf_newdata() failed: %s.",
|
|
elf_errmsg(-1));
|
|
if (ecp->oec == ELFCLASS32) {
|
|
lsydata->d_align = 4;
|
|
lsydata->d_off = 0;
|
|
lsydata->d_buf = sy_buf->l32;
|
|
lsydata->d_size = sy_buf->nls *
|
|
sizeof(Elf32_Sym);
|
|
lsydata->d_type = ELF_T_SYM;
|
|
lsydata->d_version = EV_CURRENT;
|
|
} else {
|
|
lsydata->d_align = 8;
|
|
lsydata->d_off = 0;
|
|
lsydata->d_buf = sy_buf->l64;
|
|
lsydata->d_size = sy_buf->nls *
|
|
sizeof(Elf64_Sym);
|
|
lsydata->d_type = ELF_T_SYM;
|
|
lsydata->d_version = EV_CURRENT;
|
|
}
|
|
}
|
|
if (sy_buf->ngs > 0) {
|
|
if ((gsydata = elf_newdata(sy->os)) == NULL)
|
|
errx(EXIT_FAILURE, "elf_newdata() failed: %s.",
|
|
elf_errmsg(-1));
|
|
if (ecp->oec == ELFCLASS32) {
|
|
gsydata->d_align = 4;
|
|
gsydata->d_off = sy_buf->nls *
|
|
sizeof(Elf32_Sym);
|
|
gsydata->d_buf = sy_buf->g32;
|
|
gsydata->d_size = sy_buf->ngs *
|
|
sizeof(Elf32_Sym);
|
|
gsydata->d_type = ELF_T_SYM;
|
|
gsydata->d_version = EV_CURRENT;
|
|
} else {
|
|
gsydata->d_align = 8;
|
|
gsydata->d_off = sy_buf->nls *
|
|
sizeof(Elf64_Sym);
|
|
gsydata->d_buf = sy_buf->g64;
|
|
gsydata->d_size = sy_buf->ngs *
|
|
sizeof(Elf64_Sym);
|
|
gsydata->d_type = ELF_T_SYM;
|
|
gsydata->d_version = EV_CURRENT;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Create two Elf_Data for .strtab, one for local symbol name
|
|
* and another for globals. Same as .symtab, local symbol names
|
|
* appear first.
|
|
*/
|
|
st_buf = st->buf;
|
|
if ((lstdata = elf_newdata(st->os)) == NULL)
|
|
errx(EXIT_FAILURE, "elf_newdata() failed: %s.",
|
|
elf_errmsg(-1));
|
|
lstdata->d_align = 1;
|
|
lstdata->d_off = 0;
|
|
lstdata->d_buf = st_buf->l;
|
|
lstdata->d_size = st_buf->lsz;
|
|
lstdata->d_type = ELF_T_BYTE;
|
|
lstdata->d_version = EV_CURRENT;
|
|
|
|
if (st_buf->gsz > 0) {
|
|
if ((gstdata = elf_newdata(st->os)) == NULL)
|
|
errx(EXIT_FAILURE, "elf_newdata() failed: %s.",
|
|
elf_errmsg(-1));
|
|
gstdata->d_align = 1;
|
|
gstdata->d_off = lstdata->d_size;
|
|
gstdata->d_buf = st_buf->g;
|
|
gstdata->d_size = st_buf->gsz;
|
|
gstdata->d_type = ELF_T_BYTE;
|
|
gstdata->d_version = EV_CURRENT;
|
|
}
|
|
|
|
shy.sh_addr = 0;
|
|
shy.sh_addralign = (ecp->oec == ELFCLASS32 ? 4 : 8);
|
|
shy.sh_size = sy->sz;
|
|
shy.sh_type = SHT_SYMTAB;
|
|
shy.sh_flags = 0;
|
|
shy.sh_entsize = gelf_fsize(ecp->eout, ELF_T_SYM, 1,
|
|
EV_CURRENT);
|
|
/*
|
|
* According to SYSV abi, here sh_info is one greater than
|
|
* the symbol table index of the last local symbol(binding
|
|
* STB_LOCAL).
|
|
*/
|
|
shy.sh_info = sy_buf->nls;
|
|
|
|
sht.sh_addr = 0;
|
|
sht.sh_addralign = 1;
|
|
sht.sh_size = st->sz;
|
|
sht.sh_type = SHT_STRTAB;
|
|
sht.sh_flags = 0;
|
|
sht.sh_entsize = 0;
|
|
sht.sh_info = 0;
|
|
sht.sh_link = 0;
|
|
|
|
if (!gelf_update_shdr(sy->os, ­))
|
|
errx(EXIT_FAILURE, "gelf_update_shdr() failed: %s",
|
|
elf_errmsg(-1));
|
|
if (!gelf_update_shdr(st->os, &sht))
|
|
errx(EXIT_FAILURE, "gelf_update_shdr() failed: %s",
|
|
elf_errmsg(-1));
|
|
}
|
|
|
|
void
|
|
add_to_symop_list(struct elfcopy *ecp, const char *name, const char *newname,
|
|
unsigned int op)
|
|
{
|
|
struct symop *s;
|
|
|
|
if ((s = lookup_symop_list(ecp, name, ~0U)) == NULL) {
|
|
if ((s = calloc(1, sizeof(*s))) == NULL)
|
|
errx(EXIT_FAILURE, "not enough memory");
|
|
s->name = name;
|
|
if (op == SYMOP_REDEF)
|
|
s->newname = newname;
|
|
}
|
|
|
|
s->op |= op;
|
|
STAILQ_INSERT_TAIL(&ecp->v_symop, s, symop_list);
|
|
}
|
|
|
|
static int
|
|
match_wildcard(const char *name, const char *pattern)
|
|
{
|
|
int reverse, match;
|
|
|
|
reverse = 0;
|
|
if (*pattern == '!') {
|
|
reverse = 1;
|
|
pattern++;
|
|
}
|
|
|
|
match = 0;
|
|
if (!fnmatch(pattern, name, 0)) {
|
|
match = 1;
|
|
printf("string '%s' match to pattern '%s'\n", name, pattern);
|
|
}
|
|
|
|
return (reverse ? !match : match);
|
|
}
|
|
|
|
struct symop *
|
|
lookup_symop_list(struct elfcopy *ecp, const char *name, unsigned int op)
|
|
{
|
|
struct symop *s;
|
|
|
|
STAILQ_FOREACH(s, &ecp->v_symop, symop_list) {
|
|
if (name == NULL || !strcmp(name, s->name) ||
|
|
((ecp->flags & WILDCARD) && match_wildcard(name, s->name)))
|
|
if ((s->op & op) != 0)
|
|
return (s);
|
|
}
|
|
|
|
return (NULL);
|
|
}
|
|
|
|
static int
|
|
lookup_exact_string(const char *buf, size_t sz, const char *s)
|
|
{
|
|
const char *b;
|
|
size_t slen;
|
|
|
|
slen = strlen(s);
|
|
for (b = buf; b < buf + sz; b += strlen(b) + 1) {
|
|
if (strlen(b) != slen)
|
|
continue;
|
|
if (!strcmp(b, s))
|
|
return (b - buf);
|
|
}
|
|
|
|
return (-1);
|
|
}
|