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NetBSD/sys/kern/exec_macho.c

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/* $NetBSD: exec_macho.c,v 1.2 2001/07/14 03:05:31 christos 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the NetBSD
* Foundation, Inc. and its contributors.
* 4. Neither the name of The NetBSD Foundation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* 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/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 proc *, struct exec_package *,
struct exec_macho_dylinker_command *, u_long *);
static int exec_macho_load_dylib(struct proc *, struct exec_package *,
struct exec_macho_dylib_command *);
static u_long exec_macho_load_thread(struct exec_macho_thread_command *);
static int exec_macho_load_file(struct proc *, struct exec_package *,
const char *, u_long *, int);
static int exec_macho_load_vnode(struct proc *, struct exec_package *,
struct vnode *, struct exec_macho_fat_header *, u_long *, 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", be32toh(arch->offset));
printf("arch.size %d\n", be32toh(arch->size));
printf("arch.align 0x%x\n", 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;
u_long addr = trunc_page(ls->vmaddr), size = round_page(ls->filesize);
if (type != MACHO_MOH_DYLIB)
flags = VMCMD_BASE;
else
flags = VMCMD_RELATIVE;
#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, "__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);
}
if (strcmp(ls->segname, "__DATA") == 0) {
epp->ep_daddr = addr;
epp->ep_dsize = round_page(ls->vmsize);
}
}
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 proc *p, struct exec_package *epp,
struct exec_macho_dylinker_command *dy, u_long *entry)
{
const char *name = ((const char *)dy) + dy->name.offset;
char path[MAXPATHLEN];
int error;
#ifdef DEBUG_MACHO
exec_macho_print_dylinker_command(dy);
#endif
(void)snprintf(path, sizeof(path), "%s%s",
(const char *)epp->ep_emul_arg, name);
DPRINTF(("loading linker %s\n", path));
if ((error = exec_macho_load_file(p, epp, path, entry,
MACHO_MOH_DYLINKER)) != 0)
return error;
return 0;
}
static int
exec_macho_load_dylib(struct proc *p, struct exec_package *epp,
struct exec_macho_dylib_command *dy) {
#ifdef notyet
const char *name = ((const char *)dy) + dy->dylib.name.offset;
char path[MAXPATHLEN];
int error;
u_long entry;
#endif
#ifdef DEBUG_MACHO
exec_macho_print_dylib_command(dy);
#endif
#ifdef notyet
(void)snprintf(path, sizeof(path), "%s%s",
(const char *)epp->ep_emul_arg, name);
DPRINTF(("loading library %s\n", path));
if ((error = exec_macho_load_file(p, epp, path, &entry,
MACHO_MOH_DYLIB)) != 0)
return error;
#endif
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.
*
* XXX: We should be checking for recursive depth, because
* one can construct a binary that crashes the kernel, by
* using a self referential dynamic linker section.
*/
static int
exec_macho_load_file(struct proc *p, struct exec_package *epp,
const char *path, u_long *entry, int type)
{
int error;
struct nameidata nd;
struct vnode *vp;
struct vattr attr;
struct exec_macho_fat_header fat;
/*
* 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, p);
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;
}
/*
* check if vnode is in open for writing, because we want to
* demand-page out of it. if it is, don't do it, for various
* reasons
*/
if (vp->v_writecount != 0) {
#ifdef DIAGNOSTIC
if (vp->v_flag & VTEXT)
panic("exec: a VTEXT vnode has writecount != 0\n");
#endif
error = ETXTBSY;
goto badunlock;
}
if ((error = VOP_ACCESS(vp, VEXEC, p->p_ucred, p)) != 0)
goto badunlock;
/* get attributes */
if ((error = VOP_GETATTR(vp, &attr, p->p_ucred, p)) != 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(p, vp, 0, &fat, sizeof(fat))) != 0)
goto bad;
if ((error = exec_macho_load_vnode(p, epp, vp, &fat, entry, type)) != 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 proc *p, struct exec_package *epp,
struct vnode *vp, struct exec_macho_fat_header *fat, u_long *entry,
int type)
{
u_long aoffs, offs;
struct exec_macho_fat_arch arch;
struct exec_macho_object_header hdr;
struct exec_macho_load_command lc;
int error = ENOEXEC, i;
size_t size;
void *buf = &lc;
if (be32toh(fat->magic) != MACHO_FAT_MAGIC) {
DPRINTF(("bad exec_macho fat magic %x\n", fat->magic));
goto bad;
}
#ifdef DEBUG_MACHO
exec_macho_print_fat_header(fat);
#endif
for (i = 0; i < be32toh(fat->nfat_arch); i++, arch) {
if ((error = exec_read_from(p, vp, sizeof(*fat) +
sizeof(arch) * i, &arch, sizeof(arch))) != 0)
goto bad;
#ifdef DEBUG_MACHO
exec_macho_print_fat_arch(&arch);
#endif
switch (be32toh(arch.cputype)) {
MACHO_MACHDEP_CASES
}
}
DPRINTF(("This MACH-O binary does not support your cpu"));
goto bad;
done:
if ((error = exec_read_from(p, 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:
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(p, 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 (buf != &lc)
free(buf, M_TEMP);
buf = malloc(size = lc.cmdsize, M_TEMP, M_WAITOK);
}
if ((error = exec_read_from(p, vp, offs, buf, lc.cmdsize)) != 0)
goto bad;
switch (lc.cmd) {
case MACHO_LC_SEGMENT:
if ((error = exec_macho_load_segment(epp, vp, aoffs,
(struct exec_macho_segment_command *)buf,
type)) != 0) {
DPRINTF(("load segment failed\n"));
goto bad;
}
break;
case MACHO_LC_LOAD_DYLINKER:
if ((error = exec_macho_load_dylinker(p, epp,
(struct exec_macho_dylinker_command *)buf,
entry)) != 0) {
DPRINTF(("load linker failed\n"));
goto bad;
}
break;
case MACHO_LC_LOAD_DYLIB:
if ((error = exec_macho_load_dylib(p, epp,
(struct exec_macho_dylib_command *)buf)) != 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 *)buf);
} else {
(void)exec_macho_load_thread(
(struct exec_macho_thread_command *)buf);
}
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 (buf != &lc)
free(buf, 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 proc *p, struct exec_package *epp)
{
struct exec_macho_fat_header *fat = epp->ep_hdr;
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);
/*
* check if vnode is in open for writing, because we want to
* demand-page out of it. if it is, don't do it, for various
* reasons
*/
if (epp->ep_vp->v_writecount != 0) {
#ifdef DIAGNOSTIC
if (epp->ep_vp->v_flag & VTEXT)
panic("exec: a VTEXT vnode has writecount != 0\n");
#endif
return ETXTBSY;
}
if (!epp->ep_esch->u.mach_probe_func)
epp->ep_emul_arg = "/";
else {
if ((error = (*epp->ep_esch->u.mach_probe_func)((char **)
&epp->ep_emul_arg)) != 0)
return error;
}
if ((error = exec_macho_load_vnode(p, epp, epp->ep_vp, fat,
&epp->ep_entry, MACHO_MOH_EXECUTE)) != 0)
goto bad;
vn_marktext(epp->ep_vp);
return exec_macho_setup_stack(p, epp);
bad:
kill_vmcmds(&epp->ep_vmcmds);
return error;
}
/*
* exec_macho_setup_stack(): Set up the stack segment for a exec_macho
* executable.
*
* Note that the ep_ssize parameter must be set to be the current stack
* limit; this is adjusted in the body of execve() to yield the
* appropriate stack segment usage once the argument length is
* calculated.
*
* This function returns an int for uniformity with other (future) formats'
* stack setup functions. They might have errors to return.
*/
int
exec_macho_setup_stack(struct proc *p, struct exec_package *epp)
{
epp->ep_maxsaddr = USRSTACK - MAXSSIZ;
epp->ep_minsaddr = USRSTACK;
epp->ep_ssize = p->p_rlimit[RLIMIT_STACK].rlim_cur;
/*
* set up commands for stack. note that this takes *two*, one to
* map the part of the stack which we can access, and one to map
* the part which we can't.
*
* arguably, it could be made into one, but that would require the
* addition of another mapping proc, which is unnecessary
*
* note that in memory, things assumed to be: 0 ... ep_maxsaddr
* <stack> ep_minsaddr
*/
NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero,
((epp->ep_minsaddr - epp->ep_ssize) - epp->ep_maxsaddr),
epp->ep_maxsaddr, NULLVP, 0, VM_PROT_NONE);
NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, epp->ep_ssize,
(epp->ep_minsaddr - epp->ep_ssize), NULLVP, 0,
VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
return 0;
}
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