NetBSD-5.0.2/sys/compat/linux/common/linux_exec_elf32.c
/* $NetBSD: linux_exec_elf32.c,v 1.81 2008/04/28 20:23:43 martin Exp $ */
/*-
* Copyright (c) 1995, 1998, 2000, 2001 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Christos Zoulas, Frank van der Linden, Eric Haszlakiewicz and
* Emmanuel Dreyfus.
*
* 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.
*/
/*
* based on exec_aout.c, sunos_exec.c and svr4_exec.c
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: linux_exec_elf32.c,v 1.81 2008/04/28 20:23:43 martin Exp $");
#ifndef ELFSIZE
/* XXX should die */
#define ELFSIZE 32
#endif
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/malloc.h>
#include <sys/namei.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/exec.h>
#include <sys/exec_elf.h>
#include <sys/stat.h>
#include <sys/kauth.h>
#include <sys/mman.h>
#include <sys/syscallargs.h>
#include <sys/cpu.h>
#include <machine/reg.h>
#include <compat/linux/common/linux_types.h>
#include <compat/linux/common/linux_signal.h>
#include <compat/linux/common/linux_util.h>
#include <compat/linux/common/linux_exec.h>
#include <compat/linux/common/linux_machdep.h>
#include <compat/linux/linux_syscallargs.h>
#include <compat/linux/linux_syscall.h>
#ifdef DEBUG_LINUX
#define DPRINTF(a) uprintf a
#else
#define DPRINTF(a)
#endif
#ifdef LINUX_ATEXIT_SIGNATURE
/*
* On the PowerPC, statically linked Linux binaries are not recognized
* by linux_signature nor by linux_gcc_signature. Fortunately, thoses
* binaries features a __libc_atexit ELF section. We therefore assume we
* have a Linux binary if we find this section.
*/
int
ELFNAME2(linux,atexit_signature)(l, epp, eh)
struct lwp *l;
struct exec_package *epp;
Elf_Ehdr *eh;
{
size_t shsize;
int strndx;
size_t i;
static const char signature[] = "__libc_atexit";
char *strtable = NULL;
Elf_Shdr *sh;
int error;
/*
* load the section header table
*/
shsize = eh->e_shnum * sizeof(Elf_Shdr);
sh = (Elf_Shdr *) malloc(shsize, M_TEMP, M_WAITOK);
error = exec_read_from(l, epp->ep_vp, eh->e_shoff, sh, shsize);
if (error)
goto out;
/*
* Now let's find the string table. If it does not exists, give up.
*/
strndx = (int)(eh->e_shstrndx);
if (strndx == SHN_UNDEF) {
error = ENOEXEC;
goto out;
}
/*
* strndx is the index in section header table of the string table
* section get the whole string table in strtable, and then we get access to the names
* s->sh_name is the offset of the section name in strtable.
*/
strtable = malloc(sh[strndx].sh_size, M_TEMP, M_WAITOK);
error = exec_read_from(l, epp->ep_vp, sh[strndx].sh_offset, strtable,
sh[strndx].sh_size);
if (error)
goto out;
for (i = 0; i < eh->e_shnum; i++) {
Elf_Shdr *s = &sh[i];
if (!memcmp((void*)(&(strtable[s->sh_name])), signature,
sizeof(signature))) {
DPRINTF(("linux_atexit_sig=%s\n",
&(strtable[s->sh_name])));
error = 0;
goto out;
}
}
error = ENOEXEC;
out:
free(sh, M_TEMP);
if (strtable)
free(strtable, M_TEMP);
return (error);
}
#endif
#ifdef LINUX_GCC_SIGNATURE
/*
* Take advantage of the fact that all the linux binaries are compiled
* with gcc, and gcc sticks in the comment field a signature. Note that
* on SVR4 binaries, the gcc signature will follow the OS name signature,
* that will not be a problem. We don't bother to read in the string table,
* but we check all the progbits headers.
*
* XXX This only works in the i386. On the alpha (at least)
* XXX we have the same gcc signature which incorrectly identifies
* XXX NetBSD binaries as Linux.
*/
int
ELFNAME2(linux,gcc_signature)(l, epp, eh)
struct lwp *l;
struct exec_package *epp;
Elf_Ehdr *eh;
{
size_t shsize;
size_t i;
static const char signature[] = "\0GCC: (GNU) ";
char tbuf[sizeof(signature) - 1];
Elf_Shdr *sh;
int error;
shsize = eh->e_shnum * sizeof(Elf_Shdr);
sh = (Elf_Shdr *) malloc(shsize, M_TEMP, M_WAITOK);
error = exec_read_from(l, epp->ep_vp, eh->e_shoff, sh, shsize);
if (error)
goto out;
for (i = 0; i < eh->e_shnum; i++) {
Elf_Shdr *s = &sh[i];
/*
* Identify candidates for the comment header;
* Header cannot have a load address, or flags and
* it must be large enough.
*/
if (s->sh_type != SHT_PROGBITS ||
s->sh_addr != 0 ||
s->sh_flags != 0 ||
s->sh_size < sizeof(signature) - 1)
continue;
error = exec_read_from(l, epp->ep_vp, s->sh_offset, tbuf,
sizeof(signature) - 1);
if (error)
continue;
/*
* error is 0, if the signatures match we are done.
*/
DPRINTF(("linux_gcc_sig: sig=%s\n", tbuf));
if (!memcmp(tbuf, signature, sizeof(signature) - 1)) {
error = 0;
goto out;
}
}
error = ENOEXEC;
out:
free(sh, M_TEMP);
return (error);
}
#endif
#ifdef LINUX_DEBUGLINK_SIGNATURE
/*
* Look for a .gnu_debuglink, specific to x86_64 interpeter
*/
int
ELFNAME2(linux,debuglink_signature)(l, epp, eh)
struct lwp *l;
struct exec_package *epp;
Elf_Ehdr *eh;
{
size_t shsize;
int strndx;
size_t i;
static const char signature[] = ".gnu_debuglink";
char *strtable = NULL;
Elf_Shdr *sh;
int error;
/*
* load the section header table
*/
shsize = eh->e_shnum * sizeof(Elf_Shdr);
sh = (Elf_Shdr *) malloc(shsize, M_TEMP, M_WAITOK);
error = exec_read_from(l, epp->ep_vp, eh->e_shoff, sh, shsize);
if (error)
goto out;
/*
* Now let's find the string table. If it does not exists, give up.
*/
strndx = (int)(eh->e_shstrndx);
if (strndx == SHN_UNDEF) {
error = ENOEXEC;
goto out;
}
/*
* strndx is the index in section header table of the string table
* section get the whole string table in strtable, and then we get access to the names
* s->sh_name is the offset of the section name in strtable.
*/
strtable = malloc(sh[strndx].sh_size, M_TEMP, M_WAITOK);
error = exec_read_from(l, epp->ep_vp, sh[strndx].sh_offset, strtable,
sh[strndx].sh_size);
if (error)
goto out;
for (i = 0; i < eh->e_shnum; i++) {
Elf_Shdr *s = &sh[i];
if (!memcmp((void*)(&(strtable[s->sh_name])), signature,
sizeof(signature))) {
DPRINTF(("linux_debuglink_sig=%s\n",
&(strtable[s->sh_name])));
error = 0;
goto out;
}
}
error = ENOEXEC;
out:
free(sh, M_TEMP);
if (strtable)
free(strtable, M_TEMP);
return (error);
}
#endif
int
ELFNAME2(linux,signature)(l, epp, eh, itp)
struct lwp *l;
struct exec_package *epp;
Elf_Ehdr *eh;
char *itp;
{
size_t i;
Elf_Phdr *ph;
size_t phsize;
int error;
static const char linux[] = "Linux";
if (eh->e_ident[EI_OSABI] == 3 ||
memcmp(&eh->e_ident[EI_ABIVERSION], linux, sizeof(linux)) == 0)
return 0;
phsize = eh->e_phnum * sizeof(Elf_Phdr);
ph = (Elf_Phdr *)malloc(phsize, M_TEMP, M_WAITOK);
error = exec_read_from(l, epp->ep_vp, eh->e_phoff, ph, phsize);
if (error)
goto out;
for (i = 0; i < eh->e_phnum; i++) {
Elf_Phdr *ephp = &ph[i];
Elf_Nhdr *np;
u_int32_t *abi;
if (ephp->p_type != PT_NOTE ||
ephp->p_filesz > 1024 ||
ephp->p_filesz < sizeof(Elf_Nhdr) + 20)
continue;
np = (Elf_Nhdr *)malloc(ephp->p_filesz, M_TEMP, M_WAITOK);
error = exec_read_from(l, epp->ep_vp, ephp->p_offset, np,
ephp->p_filesz);
if (error)
goto next;
if (np->n_type != ELF_NOTE_TYPE_ABI_TAG ||
np->n_namesz != ELF_NOTE_ABI_NAMESZ ||
np->n_descsz != ELF_NOTE_ABI_DESCSZ ||
memcmp((void *)(np + 1), ELF_NOTE_ABI_NAME,
ELF_NOTE_ABI_NAMESZ))
goto next;
/* Make sure the OS is Linux. */
abi = (u_int32_t *)((char *)np + sizeof(Elf_Nhdr) +
np->n_namesz);
if (abi[0] == ELF_NOTE_ABI_OS_LINUX)
error = 0;
else
error = ENOEXEC;
free(np, M_TEMP);
goto out;
next:
free(np, M_TEMP);
continue;
}
/* Check for certain intepreter names. */
if (itp) {
if (!strncmp(itp, "/lib/ld-linux", 13) ||
#if (ELFSIZE == 64)
!strncmp(itp, "/lib64/ld-linux", 15) ||
#endif
!strncmp(itp, "/lib/ld.so.", 11))
error = 0;
else
error = ENOEXEC;
goto out;
}
error = ENOEXEC;
out:
free(ph, M_TEMP);
return (error);
}
int
ELFNAME2(linux,probe)(struct lwp *l, struct exec_package *epp, void *eh,
char *itp, vaddr_t *pos)
{
int error;
if (((error = ELFNAME2(linux,signature)(l, epp, eh, itp)) != 0) &&
#ifdef LINUX_GCC_SIGNATURE
((error = ELFNAME2(linux,gcc_signature)(l, epp, eh)) != 0) &&
#endif
#ifdef LINUX_ATEXIT_SIGNATURE
((error = ELFNAME2(linux,atexit_signature)(l, epp, eh)) != 0) &&
#endif
#ifdef LINUX_DEBUGLINK_SIGNATURE
((error = ELFNAME2(linux,debuglink_signature)(l, epp, eh)) != 0) &&
#endif
1) {
DPRINTF(("linux_probe: returning %d\n", error));
return error;
}
if (itp) {
if ((error = emul_find_interp(l, epp, itp)))
return (error);
}
DPRINTF(("linux_probe: returning 0\n"));
return 0;
}
#ifndef LINUX_MACHDEP_ELF_COPYARGS
/*
* Copy arguments onto the stack in the normal way, but add some
* extra information in case of dynamic binding.
*/
int
ELFNAME2(linux,copyargs)(struct lwp *l, struct exec_package *pack,
struct ps_strings *arginfo, char **stackp, void *argp)
{
size_t len;
AuxInfo ai[LINUX_ELF_AUX_ENTRIES], *a;
struct elf_args *ap;
int error;
struct vattr *vap;
if ((error = copyargs(l, pack, arginfo, stackp, argp)) != 0)
return error;
a = ai;
/*
* Push extra arguments used by glibc on the stack.
*/
a->a_type = AT_PAGESZ;
a->a_v = PAGE_SIZE;
a++;
if ((ap = (struct elf_args *)pack->ep_emul_arg)) {
a->a_type = AT_PHDR;
a->a_v = ap->arg_phaddr;
a++;
a->a_type = AT_PHENT;
a->a_v = ap->arg_phentsize;
a++;
a->a_type = AT_PHNUM;
a->a_v = ap->arg_phnum;
a++;
a->a_type = AT_BASE;
a->a_v = ap->arg_interp;
a++;
a->a_type = AT_FLAGS;
a->a_v = 0;
a++;
a->a_type = AT_ENTRY;
a->a_v = ap->arg_entry;
a++;
free(pack->ep_emul_arg, M_TEMP);
pack->ep_emul_arg = NULL;
}
/* Linux-specific items */
a->a_type = LINUX_AT_CLKTCK;
a->a_v = hz;
a++;
vap = pack->ep_vap;
a->a_type = LINUX_AT_UID;
a->a_v = kauth_cred_getuid(l->l_cred);
a++;
a->a_type = LINUX_AT_EUID;
if (vap->va_mode & S_ISUID)
a->a_v = vap->va_uid;
else
a->a_v = kauth_cred_geteuid(l->l_cred);
a++;
a->a_type = LINUX_AT_GID;
a->a_v = kauth_cred_getgid(l->l_cred);
a++;
a->a_type = LINUX_AT_EGID;
if (vap->va_mode & S_ISGID)
a->a_v = vap->va_gid;
else
a->a_v = kauth_cred_getegid(l->l_cred);
a++;
a->a_type = AT_NULL;
a->a_v = 0;
a++;
len = (a - ai) * sizeof(AuxInfo);
if ((error = copyout(ai, *stackp, len)) != 0)
return error;
*stackp += len;
return 0;
}
#endif /* !LINUX_MACHDEP_ELF_COPYARGS */