diff options
Diffstat (limited to 'contrib/libexecinfo/symtab.c')
| -rw-r--r-- | contrib/libexecinfo/symtab.c | 193 |
1 files changed, 193 insertions, 0 deletions
diff --git a/contrib/libexecinfo/symtab.c b/contrib/libexecinfo/symtab.c new file mode 100644 index 000000000000..92d92dc20bc5 --- /dev/null +++ b/contrib/libexecinfo/symtab.c @@ -0,0 +1,193 @@ +/* $NetBSD: symtab.c,v 1.2 2013/08/29 15:01:57 christos Exp $ */ + +/*- + * Copyright (c) 2012 The NetBSD Foundation, Inc. + * All rights reserved. + * + * This code is derived from software contributed to The NetBSD Foundation + * by Christos Zoulas. + * + * 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. + * + * 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. + */ +#include <sys/cdefs.h> +__RCSID("$NetBSD: symtab.c,v 1.2 2013/08/29 15:01:57 christos Exp $"); + +#include <stdlib.h> +#include <stdio.h> +#include <string.h> +#include <stdint.h> +#include <err.h> +#include <dlfcn.h> + +#include <libelf.h> +#include <gelf.h> +#ifndef ELF_ST_BIND +#define ELF_ST_BIND(x) ((x) >> 4) +#endif +#ifndef ELF_ST_TYPE +#define ELF_ST_TYPE(x) (((unsigned int)x) & 0xf) +#endif + + +#include "symtab.h" + +struct symbol { + char *st_name; + uintptr_t st_value; + uintptr_t st_info; +}; + +struct symtab { + size_t nsymbols; + struct symbol *symbols; +}; + +static int +address_compare(const void *a, const void *b) +{ + const struct symbol *sa = a; + const struct symbol *sb = b; + return (int)(intmax_t)(sa->st_value - sb->st_value); +} + +void +symtab_destroy(symtab_t *s) +{ + if (s == NULL) + return; + for (size_t i = 0; i < s->nsymbols; i++) + free(s->symbols[i].st_name); + free(s->symbols); + free(s); +} + +symtab_t * +symtab_create(int fd, int bind, int type) +{ + Elf *elf; + symtab_t *st; + Elf_Scn *scn = NULL; + + if (elf_version(EV_CURRENT) == EV_NONE) { + warnx("Elf Library is out of date."); + return NULL; + } + + elf = elf_begin(fd, ELF_C_READ, NULL); + if (elf == NULL) { + warnx("Error opening elf file: %s", elf_errmsg(elf_errno())); + return NULL; + } + st = calloc(1, sizeof(*st)); + if (st == NULL) { + warnx("Error allocating symbol table"); + elf_end(elf); + return NULL; + } + + while ((scn = elf_nextscn(elf, scn)) != NULL) { + GElf_Shdr shdr; + Elf_Data *edata; + size_t ns; + struct symbol *s; + + gelf_getshdr(scn, &shdr); + if(shdr.sh_type != SHT_SYMTAB) + continue; + + edata = elf_getdata(scn, NULL); + ns = shdr.sh_size / shdr.sh_entsize; + s = calloc(ns, sizeof(*s)); + if (s == NULL) { + warn("Cannot allocate %zu symbols", ns); + goto out; + } + st->symbols = s; + + for (size_t i = 0; i < ns; i++) { + GElf_Sym sym; + gelf_getsym(edata, (int)i, &sym); + + if (bind != -1 && + (unsigned)bind != ELF_ST_BIND(sym.st_info)) + continue; + + if (type != -1 && + (unsigned)type != ELF_ST_TYPE(sym.st_info)) + continue; + + s->st_value = sym.st_value; + s->st_info = sym.st_info; + s->st_name = strdup( + elf_strptr(elf, shdr.sh_link, sym.st_name)); + if (s->st_name == NULL) + goto out; + s++; + } + st->nsymbols = s - st->symbols; + if (st->nsymbols == 0) { + warnx("No symbols found"); + goto out; + } + qsort(st->symbols, st->nsymbols, sizeof(*st->symbols), + address_compare); + elf_end(elf); + return st; + } +out: + symtab_destroy(st); + elf_end(elf); + return NULL; +} + + +int +symtab_find(const symtab_t *st, const void *p, Dl_info *dli) +{ + struct symbol *s = st->symbols; + size_t ns = st->nsymbols; + size_t hi = ns; + size_t lo = 0; + size_t mid = ns / 2; + uintptr_t dd, sd, me = (uintptr_t)p; + + for (;;) { + if (s[mid].st_value < me) + lo = mid; + else if (s[mid].st_value > me) + hi = mid; + else + break; + if (hi - lo == 1) { + mid = lo; + break; + } + mid = (hi + lo) / 2; + } + dd = me - (uintptr_t)dli->dli_saddr; + sd = me - s[mid].st_value; + if (dd > sd) { + dli->dli_saddr = (void *)s[mid].st_value; + dli->dli_sname = s[mid].st_name; + } + return 1; +} |