NetBSD/usr.sbin/kvm_mkdb/nlist_elf32.c

384 lines
9.4 KiB
C

/* $NetBSD: nlist_elf32.c,v 1.15 2003/05/02 16:25:22 ragge Exp $ */
/*
* Copyright (c) 1996 Christopher G. Demetriou
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed for the
* NetBSD Project. See http://www.netbsd.org/ for
* information about NetBSD.
* 4. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*
* <<Id: LICENSE,v 1.2 2000/06/14 15:57:33 cgd Exp>>
*/
#include <sys/cdefs.h>
#ifndef lint
__RCSID("$NetBSD: nlist_elf32.c,v 1.15 2003/05/02 16:25:22 ragge Exp $");
#endif /* not lint */
/* If not included by nlist_elf64.c, ELFSIZE won't be defined. */
#ifndef ELFSIZE
#define ELFSIZE 32
#endif
#include <sys/param.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/sysctl.h>
#include <sys/ioctl.h>
#include <sys/ksyms.h>
#include <a.out.h>
#include <db.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <kvm.h>
#include <limits.h>
#include <paths.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "extern.h"
#if defined(NLIST_ELF32) || defined(NLIST_ELF64)
#include <sys/exec_elf.h>
#endif
#if (defined(NLIST_ELF32) && (ELFSIZE == 32)) || \
(defined(NLIST_ELF64) && (ELFSIZE == 64))
typedef struct nlist NLIST;
#define _strx n_un.n_strx
#define _name n_un.n_name
#define badfmt(str) \
do { \
warnx("%s: %s: %s", kfile, str, strerror(EFTYPE)); \
punt(); \
} while (0)
#define check(off, size) ((off < 0) || (off + size > mappedsize))
#define BAD do { rv = -1; goto out; } while (0)
#define BADUNMAP do { rv = -1; goto unmap; } while (0)
static const char *kfile;
int
ELFNAMEEND(create_knlist)(name, db)
const char *name;
DB *db;
{
struct stat st;
struct nlist nbuf;
DBT key, data;
char *mappedfile, *symname, *fsymname, *tmpcp, *strtab;
size_t mappedsize, symnamesize, fsymnamesize;
Elf_Ehdr *ehdrp;
Elf_Shdr *shdrp, *symshdrp, *symstrshdrp;
Elf_Sym *symp;
Elf_Off shdr_off;
Elf_Word shdr_size;
#if (ELFSIZE == 32)
Elf32_Half nshdr;
#elif (ELFSIZE == 64)
Elf64_Half nshdr;
#endif
unsigned long i, nsyms;
int fd, rv, malloced = 0, isksyms;
rv = -1;
#ifdef __GNUC__
/* fix compiler warnings */
symshdrp = NULL;
symstrshdrp = NULL;
#endif
/*
* Open and map the whole file. If we can't open/stat it,
* something bad is going on so we punt.
*/
kfile = name;
if ((fd = open(name, O_RDONLY, 0)) < 0) {
warn("%s", kfile);
punt();
}
if (fstat(fd, &st) < 0) {
warn("%s", kfile);
punt();
}
if (st.st_size > SIZE_T_MAX)
BAD;
/*
* Map the file in its entirety.
*/
mappedfile = MAP_FAILED;
mappedsize = st.st_size;
isksyms = S_ISCHR(st.st_mode) &&
strncmp(name, _PATH_KSYMS, sizeof(_PATH_KSYMS)) == 0;
if (mappedsize == 0) {
/* if it's a character device, stat returns size 0 */
if (!isksyms)
BAD;
} else {
mappedfile = mmap(NULL, mappedsize, PROT_READ,
MAP_PRIVATE|MAP_FILE, fd, 0);
}
/*
* If mmap failed, try to read the file instead.
*/
if (mappedfile == MAP_FAILED) {
int allocsiz, readsz;
if (isksyms != 0) {
if (ioctl(fd, KIOCGSIZE, &allocsiz) < 0)
BAD;
mappedsize = allocsiz;
} else
allocsiz = mappedsize;
if ((mappedfile = malloc(mappedsize)) == NULL)
BAD;
malloced = 1;
if ((readsz = read(fd, mappedfile, mappedsize)) < 0)
BADUNMAP;
if (readsz != mappedsize) /* Sanity */
BADUNMAP;
}
/*
* Make sure we can access the executable's header
* directly, and make sure the recognize the executable
* as an ELF binary.
*/
if (check(0, sizeof *ehdrp))
BADUNMAP;
ehdrp = (Elf_Ehdr *)&mappedfile[0];
if (memcmp(ehdrp->e_ident, ELFMAG, SELFMAG) != 0 ||
ehdrp->e_ident[EI_CLASS] != ELFCLASS)
BADUNMAP;
switch (ehdrp->e_machine) {
ELFDEFNNAME(MACHDEP_ID_CASES)
default:
BADUNMAP;
}
/*
* We've recognized it as an ELF binary. From here
* on out, all errors are fatal.
*/
/*
* Find the symbol list and string table.
*/
nshdr = ehdrp->e_shnum;
shdr_off = ehdrp->e_shoff;
shdr_size = ehdrp->e_shentsize * nshdr;
if (check(shdr_off, shdr_size) ||
(sizeof *shdrp != ehdrp->e_shentsize))
badfmt("bogus section header table");
shdrp = (Elf_Shdr *)&mappedfile[shdr_off];
for (i = 0; i < nshdr; i++) {
if (shdrp[i].sh_type == SHT_SYMTAB) {
symshdrp = &shdrp[i];
symstrshdrp = &shdrp[shdrp[i].sh_link];
}
}
if (symshdrp == NULL)
badfmt("no symbol section header found");
if (symshdrp->sh_offset == 0)
badfmt("stripped");
if (check(symshdrp->sh_offset, symshdrp->sh_size))
badfmt("bogus symbol section header");
if (check(symstrshdrp->sh_offset, symstrshdrp->sh_size))
badfmt("bogus symbol string section header");
symp = (Elf_Sym *)&mappedfile[symshdrp->sh_offset];
nsyms = symshdrp->sh_size / sizeof(*symp);
strtab = &mappedfile[symstrshdrp->sh_offset];
/*
* Set up the data item, pointing to a nlist structure.
* which we fill in for each symbol.
*/
data.data = (u_char *)&nbuf;
data.size = sizeof(nbuf);
/*
* Create a buffer (to be expanded later, if necessary)
* to hold symbol names after we've added underscores
* to them.
*/
symnamesize = 1024;
if ((symname = malloc(symnamesize)) == NULL) {
warn("malloc");
punt();
}
/*
* Read each symbol and enter it into the database.
*/
for (i = 0; i < nsyms; i++) {
/*
* No symbol name; ignore this symbol.
*/
if (symp[i].st_name == 0)
continue;
/*
* Find symbol name, copy it (with added underscore) to
* temporary buffer, and prepare the database key for
* insertion.
*/
fsymname = &strtab[symp[i].st_name];
fsymnamesize = strlen(fsymname) + 1;
while (symnamesize < fsymnamesize + 1) {
symnamesize *= 2;
if ((symname = realloc(symname, symnamesize)) == NULL) {
warn("malloc");
punt();
}
}
strcpy(symname, "_");
strcat(symname, fsymname);
key.data = symname;
key.size = strlen((char *)key.data);
/*
* Convert the symbol information into an nlist structure,
* as best we can.
*/
nbuf.n_value = symp[i].st_value;
switch (ELFDEFNNAME(ST_TYPE)(symp[i].st_info)) {
default:
case STT_NOTYPE:
nbuf.n_type = N_UNDF;
break;
case STT_OBJECT:
nbuf.n_type = N_DATA;
break;
case STT_FUNC:
nbuf.n_type = N_TEXT;
break;
case STT_FILE:
nbuf.n_type = N_FN;
break;
}
if (ELFDEFNNAME(ST_BIND)(symp[i].st_info) != STB_LOCAL)
nbuf.n_type |= N_EXT;
nbuf.n_desc = 0; /* XXX */
nbuf.n_other = 0; /* XXX */
/*
* Enter the symbol into the database.
*/
if (db->put(db, &key, &data, 0)) {
warn("record enter");
punt();
}
/*
* If it's the kernel version string, we've gotta keep
* some extra data around. Under a separate key,
* we enter the first line (i.e. up to the first newline,
* with the newline replaced by a NUL to terminate the
* entered string) of the version string.
*/
if (strcmp((char *)key.data, VRS_SYM) == 0) {
key.data = (u_char *)VRS_KEY;
key.size = sizeof(VRS_KEY) - 1;
/* Find the version string, relative to its section */
if (isksyms) {
/* reading from /dev/ksyms, use sysctl */
size_t sz;
int mib[2];
char *kv;
mib[0] = CTL_KERN;
mib[1] = KERN_VERSION;
if (sysctl(mib, 2, NULL, &sz, NULL, 0) == -1) {
warn("sysctl version size");
punt();
}
if ((kv = malloc(sz)) == NULL) {
warn("malloc version string");
punt();
}
if (sysctl(mib, 2, kv, &sz, NULL, 0) == -1) {
warn("sysctl version string");
punt();
}
data.data = kv;
} else
data.data = strdup(&mappedfile[nbuf.n_value -
shdrp[symp[i].st_shndx].sh_addr +
shdrp[symp[i].st_shndx].sh_offset]);
/* assumes newline terminates version. */
if ((tmpcp = strchr(data.data, '\n')) != NULL)
*tmpcp = '\0';
data.size = strlen((char *)data.data);
if (db->put(db, &key, &data, 0)) {
warn("record enter");
punt();
}
/* free pointer created by strdup(). */
free(data.data);
/* Restore to original values */
data.data = (u_char *)&nbuf;
data.size = sizeof(nbuf);
}
}
rv = 0;
unmap:
if (malloced)
free(mappedfile);
else
munmap(mappedfile, mappedsize);
out:
return (rv);
}
#endif