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/*-
* Copyright (c) 1983, 1993
* The Regents of the University of California. All rights reserved.
*
* 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.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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/types.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/exec_elf.h>
#include <err.h>
#include <fcntl.h>
#include <string.h>
#include <unistd.h>
#include "gprof.h"
static bool wantsym(const Elf_Sym *, const char *);
/* Things which get -E excluded by default. */
static char *excludes[] = { ".mcount", "_mcleanup", NULL };
int
getnfile(const char *filename, char ***defaultEs)
{
int fd;
Elf_Ehdr h;
struct stat s;
void *mapbase;
const char *base;
const Elf_Shdr *shdrs;
const Elf_Shdr *sh_symtab;
const Elf_Shdr *sh_strtab;
const char *strtab;
const Elf_Sym *symtab;
int symtabct;
int i;
if ((fd = open(filename, O_RDONLY)) == -1)
err(1, "%s", filename);
if (read(fd, &h, sizeof h) != sizeof h || !IS_ELF(h)) {
close(fd);
return -1;
}
if (fstat(fd, &s) == -1)
err(1, "Cannot fstat %s", filename);
if ((mapbase = mmap(0, s.st_size, PROT_READ, MAP_SHARED, fd, 0)) ==
MAP_FAILED)
err(1, "Cannot mmap %s", filename);
close(fd);
base = (const char *)mapbase;
shdrs = (const Elf_Shdr *)(base + h.e_shoff);
/* Find the symbol table and associated string table section. */
for (i = 1; i < h.e_shnum; i++)
if (shdrs[i].sh_type == SHT_SYMTAB)
break;
if (i == h.e_shnum)
errx(1, "%s has no symbol table", filename);
sh_symtab = &shdrs[i];
sh_strtab = &shdrs[sh_symtab->sh_link];
symtab = (const Elf_Sym *)(base + sh_symtab->sh_offset);
symtabct = sh_symtab->sh_size / sh_symtab->sh_entsize;
strtab = (const char *)(base + sh_strtab->sh_offset);
/* Count the symbols that we're interested in. */
nname = 0;
for (i = 1; i < symtabct; i++)
if (wantsym(&symtab[i], strtab))
nname++;
#ifdef DEBUG
if (debug & ELFDEBUG) {
printf("[getnfile] symtab at %p, strtab at %p\n", symtab, strtab);
printf("[getnfile] %d of %d symbols wanted\n", nname, symtabct);
}
#endif
/* Allocate memory for them, plus a terminating entry. */
if ((nl = calloc(nname + 1, sizeof(nltype))) == NULL)
errx(1, "Insufficient memory for symbol table");
/* Read them in. */
npe = nl;
for (i = 1; i < symtabct; i++) {
const Elf_Sym *sym = &symtab[i];
if (wantsym(sym, strtab)) {
npe->value = sym->st_value;
npe->name = strtab + sym->st_name;
#ifdef DEBUG
if (debug & ELFDEBUG)
printf("[getnfile] symbol %d: %s -> %lx\n", i,
npe->name ? npe->name : "(none)", npe->value);
#endif
npe++;
}
}
npe->value = -1;
*defaultEs = excludes;
return 0;
}
static bool
wantsym(const Elf_Sym *sym, const char *strtab)
{
int type;
int bind;
type = ELF_ST_TYPE(sym->st_info);
bind = ELF_ST_BIND(sym->st_info);
if (type != STT_FUNC || (aflag && bind == STB_LOCAL))
#if 0
||
(uflag && strchr(strtab + sym->st_name, '.') != NULL))
#endif
return 0;
#ifdef __arm__
/* ignore what gas calls "mapping symbols" */
{
const char *c = strtab + sym->st_name;
if (c[0] == '$')
return 0;
}
#endif
return 1;
}
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