GCC Code Coverage Report
Directory: ./ Exec Total Coverage
File: usr.sbin/kvm_mkdb/nlist.c Lines: 0 126 0.0 %
Date: 2017-11-07 Branches: 0 106 0.0 %

Line Branch Exec Source
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/*	$OpenBSD: nlist.c,v 1.50 2016/09/10 05:48:18 jsg Exp $	*/
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/*-
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 * Copyright (c) 1990, 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 <db.h>
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#include <err.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <kvm.h>
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#include <limits.h>
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#include <paths.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 <unistd.h>
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#include "extern.h"
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#include <sys/mman.h>
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#include <sys/stat.h>
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#include <sys/file.h>
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#include <sys/sysctl.h>
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#include <elf_abi.h>
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typedef struct nlist NLIST;
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#define	_strx	n_un.n_strx
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#define	_name	n_un.n_name
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static char *kfile;
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static char *fmterr;
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int	__elf_knlist(int fd, DB *db, int ksyms);
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int
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__elf_knlist(int fd, DB *db, int ksyms)
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{
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	caddr_t strtab = NULL;
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	off_t symstroff, symoff;
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	u_long symsize, symstrsize;
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	u_long kernvma, kernoffs;
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	int i, error = 0;
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	Elf32_Word j;
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	Elf_Sym sbuf;
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	char buf[1024];
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	Elf_Ehdr eh;
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	Elf_Shdr *sh = NULL;
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	DBT data, key;
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	NLIST nbuf;
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	FILE *fp;
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	int usemalloc = 0;
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	if ((fp = fdopen(fd, "r")) == NULL)
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		err(1, "%s", kfile);
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	if (fseek(fp, (off_t)0, SEEK_SET) == -1 ||
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	    fread(&eh, sizeof(eh), 1, fp) != 1 ||
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	    !IS_ELF(eh)) {
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		fclose(fp);
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		return (1);
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	}
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	sh = calloc(sizeof(Elf_Shdr), eh.e_shnum);
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	if (sh == NULL)
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		errx(1, "cannot allocate %zu bytes for symbol header",
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		    sizeof(Elf_Shdr) * eh.e_shnum);
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	if (fseek (fp, eh.e_shoff, SEEK_SET) < 0) {
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		fmterr = "no exec header";
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		error = -1;
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		goto done;
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	}
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	if (fread(sh, sizeof(Elf_Shdr) * eh.e_shnum, 1, fp) != 1) {
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		fmterr = "no exec header";
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		error = -1;
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		goto done;
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	}
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	symstrsize = symsize = 0;
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	kernvma = (u_long)-1;	/* 0 is a valid value (at least on hp300) */
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	for (i = 0; i < eh.e_shnum; i++) {
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		if (sh[i].sh_type == SHT_STRTAB) {
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			for (j = 0; j < eh.e_shnum; j++)
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				if (sh[j].sh_type == SHT_SYMTAB &&
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				    sh[j].sh_link == (unsigned)i) {
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					symstroff = sh[i].sh_offset;
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					symstrsize = sh[i].sh_size;
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			}
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		} else if (sh[i].sh_type == SHT_SYMTAB) {
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			symoff = sh[i].sh_offset;
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			symsize = sh[i].sh_size;
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		} else if (sh[i].sh_type == SHT_PROGBITS &&
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		    (sh[i].sh_flags & SHF_EXECINSTR)) {
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			kernvma = sh[i].sh_addr;
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			kernoffs = sh[i].sh_offset;
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		}
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	}
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	if (symstrsize == 0 || symsize == 0 || kernvma == (u_long)-1) {
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		fmterr = "corrupt file";
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		error = -1;
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		goto done;
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	}
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	/*
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	 * Map string table into our address space.  This gives us
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	 * an easy way to randomly access all the strings, without
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	 * making the memory allocation permanent as with malloc/free
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	 * (i.e., munmap will return it to the system).
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	 *
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	 * XXX - we really want to check if this is a regular file.
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	 *	 then we probably want a MAP_PRIVATE here.
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	 */
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	strtab = mmap(NULL, (size_t)symstrsize, PROT_READ,
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	    MAP_SHARED|MAP_FILE, fileno(fp), symstroff);
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	if (strtab == MAP_FAILED) {
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		usemalloc = 1;
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		if ((strtab = malloc(symstrsize)) == NULL) {
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			fmterr = "out of memory";
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			error = -1;
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			goto done;
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		}
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		if (fseek(fp, symstroff, SEEK_SET) == -1) {
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			fmterr = "corrupt file";
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			error = -1;
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			goto done;
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		}
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		if (fread(strtab, symstrsize, 1, fp) != 1) {
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			fmterr = "corrupt file";
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			error = -1;
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			goto done;
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		}
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	}
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	if (fseek(fp, symoff, SEEK_SET) == -1) {
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		fmterr = "corrupt file";
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		error = -1;
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		goto done;
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	}
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	data.data = (u_char *)&nbuf;
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	data.size = sizeof(NLIST);
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	/* Read each symbol and enter it into the database. */
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	while (symsize > 0) {
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		symsize -= sizeof(Elf_Sym);
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		if (fread((char *)&sbuf, sizeof(sbuf), 1, fp) != 1) {
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			if (feof(fp))
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				fmterr = "corrupted symbol table";
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			else
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				warn("%s", kfile);
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			error = -1;
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			goto done;
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		}
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		if (!sbuf.st_name)
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			continue;
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		nbuf.n_value = sbuf.st_value;
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		/* XXX type conversion is pretty rude... */
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		switch(ELF_ST_TYPE(sbuf.st_info)) {
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		case STT_NOTYPE:
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			switch (sbuf.st_shndx) {
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			case SHN_UNDEF:
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				nbuf.n_type = N_UNDF;
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				break;
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			case SHN_ABS:
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				nbuf.n_type = N_ABS;
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				break;
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			case SHN_COMMON:
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				nbuf.n_type = N_COMM;
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				break;
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			default:
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				nbuf.n_type = N_COMM | N_EXT;
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				break;
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			}
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			break;
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		case STT_FUNC:
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			nbuf.n_type = N_TEXT;
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			break;
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		case STT_OBJECT:
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			nbuf.n_type = N_DATA;
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			break;
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		case STT_FILE:
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			nbuf.n_type = N_FN;
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			break;
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		}
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		if (ELF_ST_BIND(sbuf.st_info) == STB_LOCAL)
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			nbuf.n_type = N_EXT;
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		*buf = '_';
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		strlcpy(buf + 1, strtab + sbuf.st_name, sizeof buf - 1);
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		key.data = (u_char *)buf;
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		key.size = strlen((char *)key.data);
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		if (db->put(db, &key, &data, 0))
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			err(1, "record enter");
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		if (strcmp((char *)key.data, VRS_SYM) == 0) {
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			long cur_off;
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			if (!ksyms) {
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				/*
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				 * Calculate offset to the version string in
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				 * the file. kernvma is where the kernel is
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				 * really loaded; kernoffs is where in the
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				 * file it starts.
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				 */
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				long voff;
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				voff = nbuf.n_value - kernvma + kernoffs;
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				cur_off = ftell(fp);
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				if (fseek(fp, voff, SEEK_SET) == -1) {
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					fmterr = "corrupted string table";
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					error = -1;
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					goto done;
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				}
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				/*
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				 * Read version string up to, and including
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				 * newline. This code assumes that a newline
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				 * terminates the version line.
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				 */
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				if (fgets(buf, sizeof(buf), fp) == NULL) {
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					fmterr = "corrupted string table";
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					error = -1;
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					goto done;
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				}
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			} else {
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				/*
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				 * This is /dev/ksyms or a look alike.
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				 * Use sysctl() to get version since we
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				 * don't have real text or data.
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				 */
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				int mib[2];
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				size_t len;
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				char *p;
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				mib[0] = CTL_KERN;
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				mib[1] = KERN_VERSION;
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				len = sizeof(buf);
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				if (sysctl(mib, 2, buf, &len, NULL, 0) == -1) {
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					err(1, "sysctl can't find kernel "
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					    "version string");
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				}
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				if ((p = strchr(buf, '\n')) != NULL)
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					*(p+1) = '\0';
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			}
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			key.data = (u_char *)VRS_KEY;
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			key.size = sizeof(VRS_KEY) - 1;
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			data.data = (u_char *)buf;
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			data.size = strlen(buf);
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			if (db->put(db, &key, &data, 0))
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				err(1, "record enter");
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284
			/* Restore to original values. */
285
			data.data = (u_char *)&nbuf;
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			data.size = sizeof(NLIST);
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			if (!ksyms && fseek(fp, cur_off, SEEK_SET) == -1) {
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				fmterr = "corrupted string table";
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				error = -1;
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				goto done;
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			}
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		}
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	}
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done:
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	if (strtab) {
296
		if (usemalloc)
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			free(strtab);
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		else
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			munmap(strtab, symstrsize);
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	}
301
	(void)fclose(fp);
302
	free(sh);
303
	return (error);
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}
305
306
int
307
create_knlist(char *name, int fd, DB *db)
308
{
309
	int error, ksyms;
310
311
	if (strcmp(name, _PATH_KSYMS) == 0) {
312
		ksyms = 1;
313
	} else {
314
		ksyms = 0;
315
	}
316
317
	fmterr = NULL;
318
	kfile = name;
319
	/* rval of 1 means wrong executable type */
320
	error = __elf_knlist(fd, db, ksyms);
321
322
	if (fmterr != NULL)
323
		warnc(EFTYPE, "%s: %s", kfile, fmterr);
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325
	return(error);
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}