GCC Code Coverage Report
Directory: ./ Exec Total Coverage
File: usr.bin/gprof/elf.c Lines: 0 43 0.0 %
Date: 2016-12-06 Branches: 0 30 0.0 %

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