NetBSD-5.0.2/sys/kern/exec_macho.c
/* $NetBSD: exec_macho.c,v 1.42 2008/04/28 20:24:02 martin Exp $ */
/*-
* Copyright (c) 2001 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Christos Zoulas.
*
* 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.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: exec_macho.c,v 1.42 2008/04/28 20:24:02 martin Exp $");
#include <sys/param.h>
#include <sys/proc.h>
#include <sys/malloc.h>
#include <sys/namei.h>
#include <sys/vnode.h>
#include <sys/exec.h>
#include <sys/exec_macho.h>
#include <sys/syscall.h>
#include <sys/signalvar.h>
#include <sys/resourcevar.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <uvm/uvm.h>
#ifdef DEBUG_MACHO
#define DPRINTF(a) printf a
#else
#define DPRINTF(a)
#endif
static int exec_macho_load_segment(struct exec_package *, struct vnode *,
u_long, struct exec_macho_segment_command *, int);
static int exec_macho_load_dylinker(struct lwp *, struct exec_package *,
struct exec_macho_dylinker_command *, u_long *, int);
static int exec_macho_load_dylib(struct lwp *, struct exec_package *,
struct exec_macho_dylib_command *, int);
static u_long exec_macho_load_thread(struct exec_macho_thread_command *);
static int exec_macho_load_file(struct lwp *, struct exec_package *,
const char *, u_long *, int, int, int);
static int exec_macho_load_vnode(struct lwp *, struct exec_package *,
struct vnode *, struct exec_macho_fat_header *, u_long *, int, int, int);
#ifdef DEBUG_MACHO
static void
exec_macho_print_segment_command(struct exec_macho_segment_command *ls)
{
printf("ls.cmd 0x%lx\n", ls->cmd);
printf("ls.cmdsize 0x%ld\n", ls->cmdsize);
printf("ls.segname %s\n", ls->segname);
printf("ls.vmaddr 0x%lx\n", ls->vmaddr);
printf("ls.vmsize %ld\n", ls->vmsize);
printf("ls.fileoff 0x%lx\n", ls->fileoff);
printf("ls.filesize %ld\n", ls->filesize);
printf("ls.maxprot 0x%x\n", ls->maxprot);
printf("ls.initprot 0x%x\n", ls->initprot);
printf("ls.nsects %ld\n", ls->nsects);
printf("ls.flags 0x%lx\n", ls->flags);
}
static void
exec_macho_print_fat_header(struct exec_macho_fat_header *fat)
{
printf("fat.magic 0x%x\n", be32toh(fat->magic));
printf("fat.nfat_arch %d\n", be32toh(fat->nfat_arch));
}
static void
exec_macho_print_fat_arch(struct exec_macho_fat_arch *arch)
{
printf("arch.cputype %x\n", be32toh(arch->cputype));
printf("arch.cpusubtype %d\n", be32toh(arch->cpusubtype));
printf("arch.offset 0x%x\n", (int32_t)be32toh(arch->offset));
printf("arch.size %d\n", (int32_t)be32toh(arch->size));
printf("arch.align 0x%x\n", (int32_t)be32toh(arch->align));
}
static void
exec_macho_print_object_header(struct exec_macho_object_header *hdr)
{
printf("hdr.magic 0x%lx\n", hdr->magic);
printf("hdr.cputype %x\n", hdr->cputype);
printf("hdr.cpusubtype %d\n", hdr->cpusubtype);
printf("hdr.filetype 0x%lx\n", hdr->filetype);
printf("hdr.ncmds %ld\n", hdr->ncmds);
printf("hdr.sizeofcmds %ld\n", hdr->sizeofcmds);
printf("hdr.flags 0x%lx\n", hdr->flags);
}
static void
exec_macho_print_load_command(struct exec_macho_load_command *lc)
{
printf("lc.cmd %lx\n", lc->cmd);
printf("lc.cmdsize %ld\n", lc->cmdsize);
}
static void
exec_macho_print_dylinker_command(struct exec_macho_dylinker_command *dy)
{
printf("dy.cmd %lx\n", dy->cmd);
printf("dy.cmdsize %ld\n", dy->cmdsize);
printf("dy.name.offset 0x%lx\n", dy->name.offset);
printf("dy.name %s\n", ((char *)dy) + dy->name.offset);
}
static void
exec_macho_print_dylib_command(struct exec_macho_dylib_command *dy)
{
printf("dy.cmd %lx\n", dy->cmd);
printf("dy.cmdsize %ld\n", dy->cmdsize);
printf("dy.dylib.name.offset 0x%lx\n", dy->dylib.name.offset);
printf("dy.dylib.name %s\n", ((char *)dy) + dy->dylib.name.offset);
printf("dy.dylib.timestamp %ld\n", dy->dylib.timestamp);
printf("dy.dylib.current_version %ld\n", dy->dylib.current_version);
printf("dy.dylib.compatibility_version %ld\n",
dy->dylib.compatibility_version);
}
static void
exec_macho_print_thread_command(struct exec_macho_thread_command *th)
{
printf("th.cmd %lx\n", th->cmd);
printf("th.cmdsize %ld\n", th->cmdsize);
printf("th.flavor %ld\n", th->flavor);
printf("th.count %ld\n", th->count);
}
#endif /* DEBUG_MACHO */
static int
exec_macho_load_segment(struct exec_package *epp, struct vnode *vp,
u_long foff, struct exec_macho_segment_command *ls, int type)
{
int flags;
struct exec_macho_emul_arg *emea;
u_long addr = trunc_page(ls->vmaddr), size = round_page(ls->filesize);
emea = (struct exec_macho_emul_arg *)epp->ep_emul_arg;
flags = VMCMD_BASE;
#ifdef DEBUG_MACHO
exec_macho_print_segment_command(ls);
#endif
if (strcmp(ls->segname, "__PAGEZERO") == 0)
return 0;
if (strcmp(ls->segname, "__TEXT") != 0 &&
strcmp(ls->segname, "__DATA") != 0 &&
strcmp(ls->segname, "__LOCK") != 0 &&
strcmp(ls->segname, "__OBJC") != 0 &&
strcmp(ls->segname, "__CGSERVER") != 0 &&
strcmp(ls->segname, "__IMAGE") != 0 &&
strcmp(ls->segname, "__LINKEDIT") != 0) {
DPRINTF(("Unknown exec_macho segment %s\n", ls->segname));
return ENOEXEC;
}
if (type == MACHO_MOH_EXECUTE) {
if (strcmp(ls->segname, "__TEXT") == 0) {
epp->ep_taddr = addr;
epp->ep_tsize = round_page(ls->vmsize);
emea->macho_hdr =
(struct exec_macho_object_header *)addr;
}
if ((strcmp(ls->segname, "__DATA") == 0) ||
(strcmp(ls->segname, "__OBJC") == 0) ||
(strcmp(ls->segname, "__IMAGE") == 0) ||
(strcmp(ls->segname, "__CGSERVER") == 0)) {
epp->ep_daddr = addr;
epp->ep_dsize = round_page(ls->vmsize);
}
}
/*
* Some libraries do not have a load base address. The Darwin
* kernel seems to skip them, and dyld will do the job.
*/
if (addr == 0)
return ENOMEM;
if (ls->filesize > 0) {
NEW_VMCMD2(&epp->ep_vmcmds, vmcmd_map_pagedvn, size,
addr, vp, (off_t)(ls->fileoff + foff),
ls->initprot, flags);
DPRINTF(("map(0x%lx, 0x%lx, %o, fd@ 0x%lx)\n",
addr, size, ls->initprot,
ls->fileoff + foff));
}
if (ls->vmsize > size) {
addr += size;
size = round_page(ls->vmsize - size);
NEW_VMCMD2(&epp->ep_vmcmds, vmcmd_map_zero, size,
addr, vp, (off_t)(ls->fileoff + foff),
ls->initprot, flags);
DPRINTF(("mmap(0x%lx, 0x%lx, %o, zero)\n",
ls->vmaddr + ls->filesize, ls->vmsize - ls->filesize,
ls->initprot));
}
return 0;
}
static int
exec_macho_load_dylinker(struct lwp *l, struct exec_package *epp,
struct exec_macho_dylinker_command *dy, u_long *entry, int depth)
{
struct exec_macho_emul_arg *emea;
const char *name = ((const char *)dy) + dy->name.offset;
char path[MAXPATHLEN];
int error;
#ifdef DEBUG_MACHO
exec_macho_print_dylinker_command(dy);
#endif
emea = (struct exec_macho_emul_arg *)epp->ep_emul_arg;
(void)snprintf(path, sizeof(path), "%s%s", emea->path, name);
DPRINTF(("loading linker %s\n", path));
if ((error = exec_macho_load_file(l, epp, path, entry,
MACHO_MOH_DYLINKER, 1, depth)) != 0)
return error;
return 0;
}
static int
exec_macho_load_dylib(struct lwp *l, struct exec_package *epp,
struct exec_macho_dylib_command *dy, int depth)
{
struct exec_macho_emul_arg *emea;
const char *name = ((const char *)dy) + dy->dylib.name.offset;
char path[MAXPATHLEN];
int error;
u_long entry;
#ifdef DEBUG_MACHO
exec_macho_print_dylib_command(dy);
#endif
emea = (struct exec_macho_emul_arg *)epp->ep_emul_arg;
(void)snprintf(path, sizeof(path), "%s%s", emea->path, name);
DPRINTF(("loading library %s\n", path));
if ((error = exec_macho_load_file(l, epp, path, &entry,
MACHO_MOH_DYLIB, 0, depth)) != 0)
return error;
return 0;
}
static u_long
exec_macho_load_thread(struct exec_macho_thread_command *th)
{
#ifdef DEBUG_MACHO
exec_macho_print_thread_command(th);
#endif
return exec_macho_thread_entry(th);
}
/*
* exec_macho_load_file(): Load a macho-binary. This is used
* for the dynamic linker and library recursive loading.
*/
static int
exec_macho_load_file(struct lwp *l, struct exec_package *epp,
const char *path, u_long *entry, int type, int recursive, int depth)
{
int error;
struct nameidata nd;
struct vnode *vp;
struct vattr attr;
struct exec_macho_fat_header fat;
/*
* Check for excessive rercursive loading
*/
if (depth++ > 6)
return E2BIG;
/*
* 1. open file
* 2. read filehdr
* 3. map text, data, and bss out of it using VM_*
*/
NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, path);
if ((error = namei(&nd)) != 0)
return error;
vp = nd.ni_vp;
/*
* Similarly, if it's not marked as executable, or it's not a regular
* file, we don't allow it to be used.
*/
if (vp->v_type != VREG) {
error = EACCES;
goto badunlock;
}
error = vn_marktext(vp);
if (error)
return (error);
if ((error = VOP_ACCESS(vp, VEXEC, l->l_cred)) != 0)
goto badunlock;
/* get attributes */
if ((error = VOP_GETATTR(vp, &attr, l->l_cred)) != 0)
goto badunlock;
#ifdef notyet /* XXX cgd 960926 */
XXX cgd 960926: (maybe) VOP_OPEN it (and VOP_CLOSE in copyargs?)
#endif
VOP_UNLOCK(vp, 0);
if ((error = exec_read_from(l, vp, 0, &fat, sizeof(fat))) != 0)
goto bad;
if ((error = exec_macho_load_vnode(l, epp, vp, &fat,
entry, type, recursive, depth)) != 0)
goto bad;
vrele(vp);
return 0;
badunlock:
VOP_UNLOCK(vp, 0);
bad:
#ifdef notyet /* XXX cgd 960926 */
(maybe) VOP_CLOSE it
#endif
vrele(vp);
return error;
}
/*
* exec_macho_load_vnode(): Map a file from the given vnode.
* The fat signature is checked,
* and it will return the address of the entry point in entry.
* The type determines what we are loading, a dynamic linker,
* a dynamic library, or a binary. We use that to guess at
* the entry point.
*/
static int
exec_macho_load_vnode(struct lwp *l, struct exec_package *epp,
struct vnode *vp, struct exec_macho_fat_header *fat, u_long *entry,
int type, int recursive, int depth)
{
u_long aoffs, offs;
struct exec_macho_fat_arch arch;
struct exec_macho_object_header hdr;
struct exec_macho_load_command lc;
struct exec_macho_emul_arg *emea;
int error = ENOEXEC, i;
size_t size;
void *bf = &lc;
uint32_t *sc = NULL;
#ifdef DEBUG_MACHO
exec_macho_print_fat_header(fat);
#endif
switch (fat->magic) {
case MACHO_FAT_MAGIC:
for (i = 0; i < be32toh(fat->nfat_arch); i++, arch) {
if ((error = exec_read_from(l, vp, sizeof(*fat) +
sizeof(arch) * i, &arch, sizeof(arch))) != 0)
goto bad;
#ifdef DEBUG_MACHO
exec_macho_print_fat_arch(&arch);
#endif
for (sc = exec_macho_supported_cpu; *sc; sc++)
if (*sc == be32toh(arch.cputype))
break;
if (sc != NULL)
break;
}
if (sc == NULL || *sc == 0) {
DPRINTF(("CPU %d not supported by this binary",
be32toh(arch.cputype)));
goto bad;
}
break;
case MACHO_MOH_MAGIC:
/*
* This is not a FAT Mach-O binary, the file starts
* with the object header.
*/
arch.offset = 0;
break;
default:
DPRINTF(("bad exec_macho magic %x\n", fat->magic));
goto bad;
break;
}
if ((error = exec_read_from(l, vp, be32toh(arch.offset), &hdr,
sizeof(hdr))) != 0)
goto bad;
if (hdr.magic != MACHO_MOH_MAGIC) {
DPRINTF(("bad exec_macho header magic %lx\n", hdr.magic));
goto bad;
}
#ifdef DEBUG_MACHO
exec_macho_print_object_header(&hdr);
#endif
switch (hdr.filetype) {
case MACHO_MOH_PRELOAD:
case MACHO_MOH_EXECUTE:
case MACHO_MOH_DYLINKER:
case MACHO_MOH_DYLIB:
case MACHO_MOH_BUNDLE:
break;
default:
DPRINTF(("Unsupported exec_macho filetype 0x%lx\n",
hdr.filetype));
goto bad;
}
aoffs = be32toh(arch.offset);
offs = aoffs + sizeof(hdr);
size = sizeof(lc);
for (i = 0; i < hdr.ncmds; i++) {
if ((error = exec_read_from(l, vp, offs, &lc, sizeof(lc))) != 0)
goto bad;
#ifdef DEBUG_MACHO
exec_macho_print_load_command(&lc);
#endif
if (size < lc.cmdsize) {
if (lc.cmdsize > 4096) {
DPRINTF(("Bad command size %ld\n", lc.cmdsize));
goto bad;
}
if (bf != &lc)
free(bf, M_TEMP);
bf = malloc(size = lc.cmdsize, M_TEMP, M_WAITOK);
}
if ((error = exec_read_from(l, vp, offs, bf, lc.cmdsize)) != 0)
goto bad;
switch (lc.cmd) {
case MACHO_LC_SEGMENT:
error = exec_macho_load_segment(epp, vp, aoffs,
(struct exec_macho_segment_command *)bf, type);
switch(error) {
case ENOMEM: /* Just skip, dyld will load it */
DPRINTF(("load segment failed, skipping\n"));
i = hdr.ncmds;
break;
case 0: /* No error, carry on loading file */
break;
default: /* Abort file load */
DPRINTF(("load segment failed, aborting\n"));
goto bad;
break;
}
break;
case MACHO_LC_LOAD_DYLINKER:
if ((error = exec_macho_load_dylinker(l, epp,
(struct exec_macho_dylinker_command *)bf,
entry, depth)) != 0) {
DPRINTF(("load linker failed\n"));
goto bad;
}
emea = (struct exec_macho_emul_arg *)epp->ep_emul_arg;
emea->dynamic = 1;
break;
case MACHO_LC_LOAD_DYLIB:
/*
* We should only load libraries required by the
* binary we want to load, not libraries required
* by theses libraries.
*/
if (recursive == 0)
break;
if ((error = exec_macho_load_dylib(l, epp,
(struct exec_macho_dylib_command *)bf,
depth)) != 0) {
DPRINTF(("load dylib failed\n"));
goto bad;
}
break;
case MACHO_LC_THREAD:
case MACHO_LC_UNIXTHREAD:
if (type == MACHO_MOH_DYLINKER || *entry == 0) {
*entry = exec_macho_load_thread(
(struct exec_macho_thread_command *)bf);
} else {
(void)exec_macho_load_thread(
(struct exec_macho_thread_command *)bf);
}
break;
case MACHO_LC_ID_DYLINKER:
case MACHO_LC_ID_DYLIB:
case MACHO_LC_SYMTAB:
case MACHO_LC_DYSYMTAB:
break;
default:
DPRINTF(("Unhandled exec_macho command 0x%lx\n",
lc.cmd));
break;
}
offs += lc.cmdsize;
}
error = 0;
bad:
if (bf != &lc)
free(bf, M_TEMP);
return error;
}
/*
* exec_macho_makecmds(): Prepare an Mach-O binary's exec package
*
* First, set of the various offsets/lengths in the exec package.
*
* Then, mark the text image busy (so it can be demand paged) or error
* out if this is not possible. Finally, set up vmcmds for the
* text, data, bss, and stack segments.
*/
int
exec_macho_makecmds(struct lwp *l, struct exec_package *epp)
{
struct exec_macho_fat_header *fat = epp->ep_hdr;
struct exec_macho_emul_arg *emea;
int error;
if (epp->ep_hdrvalid < sizeof(*fat))
return ENOEXEC;
/*
* Check mount point. Though we're not trying to exec this binary,
* we will be executing code from it, so if the mount point
* disallows execution or set-id-ness, we punt or kill the set-id.
*/
if (epp->ep_vp->v_mount->mnt_flag & MNT_NOEXEC)
return EACCES;
if (epp->ep_vp->v_mount->mnt_flag & MNT_NOSUID)
epp->ep_vap->va_mode &= ~(S_ISUID | S_ISGID);
error = vn_marktext(epp->ep_vp);
if (error)
return (error);
emea = malloc(sizeof(struct exec_macho_emul_arg), M_TEMP, M_WAITOK);
epp->ep_emul_arg = (void *)emea;
emea->dynamic = 0;
if (!epp->ep_esch->u.mach_probe_func)
emea->path = "/";
else {
if ((error = (*epp->ep_esch->u.mach_probe_func)(&emea->path)) != 0)
goto bad2;
}
/*
* Make sure the underlying functions will not get
* a random value here. 0 means that no entry point
* has been found yet.
*/
epp->ep_entry = 0;
if ((error = exec_macho_load_vnode(l, epp, epp->ep_vp, fat,
&epp->ep_entry, MACHO_MOH_EXECUTE, 1, 0)) != 0)
goto bad;
/*
* stash a copy of the program name in epp->ep_emul_arg because
* we will need it later.
*/
if ((error = copyinstr(epp->ep_name, emea->filename,
MAXPATHLEN, NULL)) != 0) {
DPRINTF(("Copyinstr %p failed\n", epp->ep_name));
goto bad;
}
return (*epp->ep_esch->es_setup_stack)(l, epp);
bad:
kill_vmcmds(&epp->ep_vmcmds);
bad2:
free(emea, M_TEMP);
return error;
}