xnu-1228.7.58.tar.gz

[apple/xnu.git] / bsd / kern / mach_loader.c

/*
 * Copyright (c) 2000-2007 Apple Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 * 
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */
/*
 *      Copyright (C) 1988, 1989,  NeXT, Inc.
 *
 *      File:   kern/mach_loader.c
 *      Author: Avadis Tevanian, Jr.
 *
 *      Mach object file loader (kernel version, for now).
 *
 * 21-Jul-88  Avadis Tevanian, Jr. (avie) at NeXT
 *      Started.
 */

#include <sys/param.h>
#include <sys/vnode_internal.h>
#include <sys/uio.h>
#include <sys/namei.h>
#include <sys/proc_internal.h>
#include <sys/kauth.h>
#include <sys/stat.h>
#include <sys/malloc.h>
#include <sys/mount_internal.h>
#include <sys/fcntl.h>
#include <sys/ubc_internal.h>
#include <sys/imgact.h>

#include <mach/mach_types.h>
#include <mach/vm_map.h>        /* vm_allocate() */
#include <mach/mach_vm.h>       /* mach_vm_allocate() */
#include <mach/vm_statistics.h>
#include <mach/task.h>
#include <mach/thread_act.h>

#include <machine/vmparam.h>
#include <machine/exec.h>

#include <kern/kern_types.h>
#include <kern/cpu_number.h>
#include <kern/mach_loader.h>
#include <kern/kalloc.h>
#include <kern/task.h>
#include <kern/thread.h>

#include <mach-o/fat.h>
#include <mach-o/loader.h>

#include <vm/pmap.h>
#include <vm/vm_map.h>
#include <vm/vm_kern.h>
#include <vm/vm_pager.h>
#include <vm/vnode_pager.h>
#include <vm/vm_protos.h> 

/*
 * XXX vm/pmap.h should not treat these prototypes as MACH_KERNEL_PRIVATE
 * when KERNEL is defined.
 */
extern pmap_t   pmap_create(vm_map_size_t size, boolean_t is_64bit);
extern void     pmap_switch(pmap_t);

/*
 * XXX kern/thread.h should not treat these prototypes as MACH_KERNEL_PRIVATE
 * when KERNEL is defined.
 */
extern kern_return_t    thread_setstatus(thread_t thread, int flavor,
                                thread_state_t tstate,
                                mach_msg_type_number_t count);

extern kern_return_t    thread_state_initialize(thread_t thread);


/* XXX should have prototypes in a shared header file */
extern int      get_map_nentries(vm_map_t);
extern kern_return_t    thread_userstack(thread_t, int, thread_state_t,
                                unsigned int, mach_vm_offset_t *, int *);
extern kern_return_t    thread_entrypoint(thread_t, int, thread_state_t,
                                unsigned int, mach_vm_offset_t *);

extern kern_return_t    memory_object_signed(memory_object_control_t control,
                                             boolean_t is_signed);

/* An empty load_result_t */
static load_result_t load_result_null = {
        .mach_header = MACH_VM_MIN_ADDRESS,
        .entry_point = MACH_VM_MIN_ADDRESS,
        .user_stack = MACH_VM_MIN_ADDRESS,
        .thread_count = 0,
        .unixproc = 0,
        .dynlinker = 0,
        .customstack = 0,
        .csflags = 0
};

/*
 * Prototypes of static functions.
 */
static load_return_t
parse_machfile(
        struct vnode            *vp,
        vm_map_t                map,
        thread_t                thread,
        struct mach_header      *header,
        off_t                   file_offset,
        off_t                   macho_size,
        int                     depth,
        load_result_t           *result
);

static load_return_t
load_segment(
        struct segment_command  *scp,
        void *                                  pager,
        off_t                           pager_offset,
        off_t                           macho_size,
        off_t                           end_of_file,
        vm_map_t                                map,
        load_result_t                   *result
);

static load_return_t
load_segment_64(
        struct segment_command_64       *scp64,
        void                            *pager,
        off_t                           pager_offset,
        off_t                           macho_size,
        off_t                           end_of_file,
        vm_map_t                        map,
        load_result_t                   *result
);

int load_code_signature(
        struct linkedit_data_command    *lcp,
        struct vnode                    *vp,
        off_t                           macho_offset,
        off_t                           macho_size,
        cpu_type_t                      cputype,
        load_result_t                   *result);
        
static load_return_t
load_unixthread(
        struct thread_command   *tcp,
        thread_t                        thread,
        load_result_t                   *result
);

static load_return_t
load_thread(
        struct thread_command   *tcp,
        thread_t                        thread,
        load_result_t                   *result
);

static load_return_t
load_threadstate(
        thread_t                thread,
        unsigned long   *ts,
        unsigned long   total_size
);

static load_return_t
load_threadstack(
        thread_t                thread,
        unsigned long   *ts,
        unsigned long   total_size,
        user_addr_t     *user_stack,
        int                             *customstack
);

static load_return_t
load_threadentry(
        thread_t                thread,
        unsigned long   *ts,
        unsigned long   total_size,
        mach_vm_offset_t        *entry_point
);

static load_return_t
load_dylinker(
        struct dylinker_command *lcp,
        integer_t               archbits,
        vm_map_t                                map,
        thread_t                        thread,
        int                                             depth,
        load_result_t                   *result,
        boolean_t                       is_64bit
);

static load_return_t
get_macho_vnode(
        char                            *path,
        integer_t               archbits,
        struct mach_header      *mach_header,
        off_t                   *file_offset,
        off_t                   *macho_size,
        struct vnode            **vpp
);

load_return_t
load_machfile(
        struct image_params     *imgp,
        struct mach_header      *header,
        thread_t                thread,
        vm_map_t                new_map,
        load_result_t           *result
)
{
        struct vnode            *vp = imgp->ip_vp;
        off_t                   file_offset = imgp->ip_arch_offset;
        off_t                   macho_size = imgp->ip_arch_size;
        
        pmap_t                  pmap = 0;       /* protected by create_map */
        vm_map_t                map;
        vm_map_t                old_map;
        load_result_t           myresult;
        load_return_t           lret;
        boolean_t create_map = TRUE;

        if (new_map != VM_MAP_NULL) {
                create_map = FALSE;
        }

        if (create_map) {
                old_map = current_map();
                pmap = pmap_create((vm_map_size_t) 0, (imgp->ip_flags & IMGPF_IS_64BIT));
                map = vm_map_create(pmap,
                                0,
                                vm_compute_max_offset((imgp->ip_flags & IMGPF_IS_64BIT)),
                                TRUE);
        } else
                map = new_map;

        if ( (header->flags & MH_ALLOW_STACK_EXECUTION) )
                vm_map_disable_NX(map);
                
        if (!result)
                result = &myresult;

        *result = load_result_null;

        lret = parse_machfile(vp, map, thread, header, file_offset, macho_size,
                              0, result);

        if (lret != LOAD_SUCCESS) {
                if (create_map) {
                        vm_map_deallocate(map); /* will lose pmap reference too */
                }
                return(lret);
        }

        /*
         * For 64-bit users, check for presence of a 4GB page zero
         * which will enable the kernel to share the user's address space
         * and hence avoid TLB flushes on kernel entry/exit
         */ 
        if ((imgp->ip_flags & IMGPF_IS_64BIT) &&
             vm_map_has_4GB_pagezero(map))
                vm_map_set_4GB_pagezero(map);

        /*
         *      Commit to new map.  First make sure that the current
         *      users of the task get done with it, and that we clean
         *      up the old contents of IPC and memory.  The task is
         *      guaranteed to be single threaded upon return (us).
         *
         *      Swap the new map for the old, which  consumes our new map
         *      reference but each leaves us responsible for the old_map reference.
         *      That lets us get off the pmap associated with it, and
         *      then we can release it.
         */

         if (create_map) {
                task_halt(current_task());

                old_map = swap_task_map(current_task(), map);
                vm_map_clear_4GB_pagezero(old_map);
                pmap_switch(pmap);      /* Make sure we are using the new pmap */
                vm_map_deallocate(old_map);
        }
        return(LOAD_SUCCESS);
}

/*
 * The file size of a mach-o file is limited to 32 bits; this is because
 * this is the limit on the kalloc() of enough bytes for a mach_header and
 * the contents of its sizeofcmds, which is currently constrained to 32
 * bits in the file format itself.  We read into the kernel buffer the
 * commands section, and then parse it in order to parse the mach-o file
 * format load_command segment(s).  We are only interested in a subset of
 * the total set of possible commands.
 */
static
load_return_t
parse_machfile(
        struct vnode            *vp,       
        vm_map_t                map,
        thread_t                thread,
        struct mach_header      *header,
        off_t                   file_offset,
        off_t                   macho_size,
        int                     depth,
        load_result_t           *result
)
{
        uint32_t                ncmds;
        struct load_command     *lcp;
        struct dylinker_command *dlp = 0;
        integer_t               dlarchbits = 0;
        void *                  pager;
        load_return_t           ret = LOAD_SUCCESS;
        caddr_t                 addr;
        void *                  kl_addr;
        vm_size_t               size,kl_size;
        size_t                  offset;
        size_t                  oldoffset;      /* for overflow check */
        int                     pass;
        proc_t                  p = current_proc();             /* XXXX */
        int                     error;
        int resid=0;
        task_t task;
        size_t                  mach_header_sz = sizeof(struct mach_header);
        boolean_t               abi64;
        boolean_t               got_code_signatures = FALSE;

        if (header->magic == MH_MAGIC_64 ||
            header->magic == MH_CIGAM_64) {
                mach_header_sz = sizeof(struct mach_header_64);
        }

        /*
         *      Break infinite recursion
         */
        if (depth > 6) {
                return(LOAD_FAILURE);
        }

        task = (task_t)get_threadtask(thread);

        depth++;

        /*
         *      Check to see if right machine type.
         */
        if (((cpu_type_t)(header->cputype & ~CPU_ARCH_MASK) != cpu_type()) ||
            !grade_binary(header->cputype, 
                header->cpusubtype & ~CPU_SUBTYPE_MASK))
                return(LOAD_BADARCH);
                
        abi64 = ((header->cputype & CPU_ARCH_ABI64) == CPU_ARCH_ABI64);
                
        switch (header->filetype) {
        
        case MH_OBJECT:
        case MH_EXECUTE:
        case MH_PRELOAD:
                if (depth != 1) {
                        return (LOAD_FAILURE);
                }
                break;
                
        case MH_FVMLIB:
        case MH_DYLIB:
                if (depth == 1) {
                        return (LOAD_FAILURE);
                }
                break;

        case MH_DYLINKER:
                if (depth != 2) {
                        return (LOAD_FAILURE);
                }
                break;
                
        default:
                return (LOAD_FAILURE);
        }

        /*
         *      Get the pager for the file.
         */
        pager = (void *) ubc_getpager(vp);

        /*
         *      Map portion that must be accessible directly into
         *      kernel's map.
         */
        if ((mach_header_sz + header->sizeofcmds) > macho_size)
                return(LOAD_BADMACHO);

        /*
         *      Round size of Mach-O commands up to page boundry.
         */
        size = round_page(mach_header_sz + header->sizeofcmds);
        if (size <= 0)
                return(LOAD_BADMACHO);

        /*
         * Map the load commands into kernel memory.
         */
        addr = 0;
        kl_size = size;
        kl_addr = kalloc(size);
        addr = (caddr_t)kl_addr;
        if (addr == NULL)
                return(LOAD_NOSPACE);

        error = vn_rdwr(UIO_READ, vp, addr, size, file_offset,
            UIO_SYSSPACE32, 0, kauth_cred_get(), &resid, p);
        if (error) {
                if (kl_addr )
                        kfree(kl_addr, kl_size);
                return(LOAD_IOERROR);
        }
        /* (void)ubc_map(vp, PROT_EXEC); */ /* NOT HERE */
        
        /*
         *      Scan through the commands, processing each one as necessary.
         */
        for (pass = 1; pass <= 2; pass++) {
                /*
                 * Loop through each of the load_commands indicated by the
                 * Mach-O header; if an absurd value is provided, we just
                 * run off the end of the reserved section by incrementing
                 * the offset too far, so we are implicitly fail-safe.
                 */
                offset = mach_header_sz;
                ncmds = header->ncmds;
                while (ncmds--) {
                        /*
                         *      Get a pointer to the command.
                         */
                        lcp = (struct load_command *)(addr + offset);
                        oldoffset = offset;
                        offset += lcp->cmdsize;

                        /*
                         * Perform prevalidation of the struct load_command
                         * before we attempt to use its contents.  Invalid
                         * values are ones which result in an overflow, or
                         * which can not possibly be valid commands, or which
                         * straddle or exist past the reserved section at the
                         * start of the image.
                         */
                        if (oldoffset > offset ||
                            lcp->cmdsize < sizeof(struct load_command) ||
                            offset > header->sizeofcmds + mach_header_sz) {
                                ret = LOAD_BADMACHO;
                                break;
                        }

                        /*
                         * Act on struct load_command's for which kernel
                         * intervention is required.
                         */
                        switch(lcp->cmd) {
                        case LC_SEGMENT_64:
                                if (pass != 1)
                                        break;
                                ret = load_segment_64(
                                               (struct segment_command_64 *)lcp,
                                                   pager,
                                                   file_offset,
                                                   macho_size,
                                                   ubc_getsize(vp),
                                                   map,
                                                   result);
                                break;
                        case LC_SEGMENT:
                                if (pass != 1)
                                        break;
                                ret = load_segment(
                                               (struct segment_command *) lcp,
                                                   pager,
                                                   file_offset,
                                                   macho_size,
                                                   ubc_getsize(vp),
                                                   map,
                                                   result);
                                break;
                        case LC_THREAD:
                                if (pass != 2)
                                        break;
                                ret = load_thread((struct thread_command *)lcp,
                                                   thread,
                                                  result);
                                break;
                        case LC_UNIXTHREAD:
                                if (pass != 2)
                                        break;
                                ret = load_unixthread(
                                                 (struct thread_command *) lcp,
                                                   thread,
                                                 result);
                                break;
                        case LC_LOAD_DYLINKER:
                                if (pass != 2)
                                        break;
                                if ((depth == 1) && (dlp == 0)) {
                                        dlp = (struct dylinker_command *)lcp;
                                        dlarchbits = (header->cputype & CPU_ARCH_MASK);
                                } else {
                                        ret = LOAD_FAILURE;
                                }
                                break;
                        case LC_CODE_SIGNATURE:
                                /* CODE SIGNING */
                                if (pass != 2)
                                        break;
                                /* pager -> uip ->
                                   load signatures & store in uip
                                   set VM object "signed_pages"
                                */
                                ret = load_code_signature(
                                        (struct linkedit_data_command *) lcp,
                                        vp,
                                        file_offset,
                                        macho_size,
                                        header->cputype,
                                        (depth == 1) ? result : NULL);
                                if (ret != LOAD_SUCCESS) {
                                        printf("proc %d: load code signature error %d "
                                               "for file \"%s\"\n",
                                               p->p_pid, ret, vp->v_name);
                                        ret = LOAD_SUCCESS; /* ignore error */
                                } else {
                                        got_code_signatures = TRUE;
                                }
                                break;
                        default:
                                /* Other commands are ignored by the kernel */
                                ret = LOAD_SUCCESS;
                                break;
                        }
                        if (ret != LOAD_SUCCESS)
                                break;
                }
                if (ret != LOAD_SUCCESS)
                        break;
        }
        if (ret == LOAD_SUCCESS) { 
            if (! got_code_signatures) {
                    struct cs_blob *blob;
                    /* no embedded signatures: look for detached ones */
                    blob = ubc_cs_blob_get(vp, -1, file_offset);
                    if (blob != NULL) {
                            /* get flags to be applied to the process */
                            result->csflags |= blob->csb_flags;
                    }
            }

            if (dlp != 0)
                        ret = load_dylinker(dlp, dlarchbits, map, thread, depth, result, abi64);

            if(depth == 1) {
                if (result->thread_count == 0) {
                        ret = LOAD_FAILURE;
                } else if ( abi64 ) {
#ifdef __ppc__
                        /* Map in 64-bit commpage */
                        /* LP64todo - make this clean */
                        /*
                         * PPC51: ppc64 is limited to 51-bit addresses.
                         * Memory above that limit is handled specially
                         * at the pmap level.
                         */
                        pmap_map_sharedpage(current_task(), get_map_pmap(map));
#endif /* __ppc__ */
                }
            }
        }

        if (kl_addr )
                kfree(kl_addr, kl_size);

        if (ret == LOAD_SUCCESS)
                (void)ubc_map(vp, PROT_READ | PROT_EXEC);
                
        return(ret);
}

#ifdef __i386__

#define APPLE_UNPROTECTED_HEADER_SIZE   (3 * PAGE_SIZE_64)

static load_return_t
unprotect_segment_64(
        uint64_t        file_off,
        uint64_t        file_size,
        vm_map_t        map,
        vm_map_offset_t map_addr,
        vm_map_size_t   map_size)
{
        kern_return_t   kr;

        /*
         * The first APPLE_UNPROTECTED_HEADER_SIZE bytes (from offset 0 of
         * this part of a Universal binary) are not protected...
         * The rest needs to be "transformed".
         */
        if (file_off <= APPLE_UNPROTECTED_HEADER_SIZE &&
            file_off + file_size <= APPLE_UNPROTECTED_HEADER_SIZE) {
                /* it's all unprotected, nothing to do... */
                kr = KERN_SUCCESS;
        } else {
                if (file_off <= APPLE_UNPROTECTED_HEADER_SIZE) {
                        /*
                         * We start mapping in the unprotected area.
                         * Skip the unprotected part...
                         */
                        vm_map_offset_t delta;

                        delta = APPLE_UNPROTECTED_HEADER_SIZE;
                        delta -= file_off;
                        map_addr += delta;
                        map_size -= delta;
                }
                /* ... transform the rest of the mapping. */
                kr = vm_map_apple_protected(map,
                                            map_addr,
                                            map_addr + map_size);
        }

        if (kr != KERN_SUCCESS) {
                return LOAD_FAILURE;
        }
        return LOAD_SUCCESS;
}
#else   /* __i386__ */
#define unprotect_segment_64(file_off, file_size, map, map_addr, map_size) \
        LOAD_SUCCESS
#endif  /* __i386__ */

static
load_return_t
load_segment(
        struct segment_command  *scp,
        void *                  pager,
        off_t                   pager_offset,
        off_t                   macho_size,
        __unused off_t          end_of_file,
        vm_map_t                map,
        load_result_t           *result
)
{
        kern_return_t           ret;
        vm_offset_t             map_addr, map_offset;
        vm_size_t               map_size, seg_size, delta_size;
        vm_prot_t               initprot;
        vm_prot_t               maxprot;

        /*
         * Make sure what we get from the file is really ours (as specified
         * by macho_size).
         */
        if (scp->fileoff + scp->filesize > macho_size)
                return (LOAD_BADMACHO);
        /*
         * Make sure the segment is page-aligned in the file.
         */
        if ((scp->fileoff & PAGE_MASK) != 0)
                return LOAD_BADMACHO;

        seg_size = round_page(scp->vmsize);
        if (seg_size == 0)
                return(KERN_SUCCESS);

        /*
         *      Round sizes to page size.
         */
        map_size = round_page(scp->filesize);
        map_addr = trunc_page(scp->vmaddr);

#if 0   /* XXX (4596982) this interferes with Rosetta */
        if (map_addr == 0 &&
            map_size == 0 &&
            seg_size != 0 &&
            (scp->initprot & VM_PROT_ALL) == VM_PROT_NONE &&
            (scp->maxprot & VM_PROT_ALL) == VM_PROT_NONE) {
                /*
                 * This is a "page zero" segment:  it starts at address 0,
                 * is not mapped from the binary file and is not accessible.
                 * User-space should never be able to access that memory, so
                 * make it completely off limits by raising the VM map's
                 * minimum offset.
                 */
                ret = vm_map_raise_min_offset(map, (vm_map_offset_t) seg_size);
                if (ret != KERN_SUCCESS) {
                        return LOAD_FAILURE;
                }
                return LOAD_SUCCESS;
        }
#endif

        map_offset = pager_offset + scp->fileoff;

        if (map_size > 0) {
                initprot = (scp->initprot) & VM_PROT_ALL;
                maxprot = (scp->maxprot) & VM_PROT_ALL;
                /*
                 *      Map a copy of the file into the address space.
                 */
                ret = vm_map(map,
                                &map_addr, map_size, (vm_offset_t)0,
                                VM_FLAGS_FIXED, pager, map_offset, TRUE,
                                initprot, maxprot,
                                VM_INHERIT_DEFAULT);
                if (ret != KERN_SUCCESS)
                        return(LOAD_NOSPACE);
        
                /*
                 *      If the file didn't end on a page boundary,
                 *      we need to zero the leftover.
                 */
                delta_size = map_size - scp->filesize;
#if FIXME
                if (delta_size > 0) {
                        vm_offset_t     tmp;
        
                        ret = vm_allocate(kernel_map, &tmp, delta_size, VM_FLAGS_ANYWHERE);
                        if (ret != KERN_SUCCESS)
                                return(LOAD_RESOURCE);
        
                        if (copyout(tmp, map_addr + scp->filesize,
                                                                delta_size)) {
                                (void) vm_deallocate(
                                                kernel_map, tmp, delta_size);
                                return(LOAD_FAILURE);
                        }
                        
                        (void) vm_deallocate(kernel_map, tmp, delta_size);
                }
#endif /* FIXME */
        }

        /*
         *      If the virtual size of the segment is greater
         *      than the size from the file, we need to allocate
         *      zero fill memory for the rest.
         */
        delta_size = seg_size - map_size;
        if (delta_size > 0) {
                vm_offset_t     tmp = map_addr + map_size;

                ret = vm_map(map, &tmp, delta_size, 0, VM_FLAGS_FIXED,
                             NULL, 0, FALSE,
                             scp->initprot, scp->maxprot,
                             VM_INHERIT_DEFAULT);
                if (ret != KERN_SUCCESS)
                        return(LOAD_NOSPACE);
        }

        if ( (scp->fileoff == 0) && (scp->filesize != 0) )
                result->mach_header = map_addr;

        if (scp->flags & SG_PROTECTED_VERSION_1) {
                ret = unprotect_segment_64((uint64_t) scp->fileoff,
                                           (uint64_t) scp->filesize,
                                           map,
                                           (vm_map_offset_t) map_addr,
                                           (vm_map_size_t) map_size);
        } else {
                ret = LOAD_SUCCESS;
        }

        return ret;
}

static
load_return_t
load_segment_64(
        struct segment_command_64       *scp64,
        void *                          pager,
        off_t                           pager_offset,
        off_t                           macho_size,
        __unused off_t                  end_of_file,
        vm_map_t                        map,
        load_result_t           *result
)
{
        kern_return_t           ret;
        mach_vm_offset_t        map_addr, map_offset;
        mach_vm_size_t          map_size, seg_size, delta_size;
        vm_prot_t               initprot;
        vm_prot_t               maxprot;
        
        /*
         * Make sure what we get from the file is really ours (as specified
         * by macho_size).
         */
        if (scp64->fileoff + scp64->filesize > (uint64_t)macho_size)
                return (LOAD_BADMACHO);
        /*
         * Make sure the segment is page-aligned in the file.
         */
        if ((scp64->fileoff & PAGE_MASK_64) != 0)
                return LOAD_BADMACHO;

        seg_size = round_page_64(scp64->vmsize);
        if (seg_size == 0)
                return(KERN_SUCCESS);

        /*
         *      Round sizes to page size.
         */
        map_size = round_page_64(scp64->filesize);      /* limited to 32 bits */
        map_addr = round_page_64(scp64->vmaddr);

        if (map_addr == 0 &&
            map_size == 0 &&
            seg_size != 0 &&
            (scp64->initprot & VM_PROT_ALL) == VM_PROT_NONE &&
            (scp64->maxprot & VM_PROT_ALL) == VM_PROT_NONE) {
                /*
                 * This is a "page zero" segment:  it starts at address 0,
                 * is not mapped from the binary file and is not accessible.
                 * User-space should never be able to access that memory, so
                 * make it completely off limits by raising the VM map's
                 * minimum offset.
                 */
                ret = vm_map_raise_min_offset(map, seg_size);
                if (ret != KERN_SUCCESS) {
                        return LOAD_FAILURE;
                }
                return LOAD_SUCCESS;
        }

        map_offset = pager_offset + scp64->fileoff;     /* limited to 32 bits */

        if (map_size > 0) {
                initprot = (scp64->initprot) & VM_PROT_ALL;
                maxprot = (scp64->maxprot) & VM_PROT_ALL;
                /*
                 *      Map a copy of the file into the address space.
                 */
                ret = mach_vm_map(map,
                                &map_addr, map_size, (mach_vm_offset_t)0,
                                VM_FLAGS_FIXED, pager, map_offset, TRUE,
                                initprot, maxprot,
                                VM_INHERIT_DEFAULT);
                if (ret != KERN_SUCCESS)
                        return(LOAD_NOSPACE);
        
                /*
                 *      If the file didn't end on a page boundary,
                 *      we need to zero the leftover.
                 */
                delta_size = map_size - scp64->filesize;
#if FIXME
                if (delta_size > 0) {
                        mach_vm_offset_t        tmp;
        
                        ret = vm_allocate(kernel_map, &tmp, delta_size, VM_FLAGS_ANYWHERE);
                        if (ret != KERN_SUCCESS)
                                return(LOAD_RESOURCE);
        
                        if (copyout(tmp, map_addr + scp64->filesize,
                                                                delta_size)) {
                                (void) vm_deallocate(
                                                kernel_map, tmp, delta_size);
                                return (LOAD_FAILURE);
                        }
        
                        (void) vm_deallocate(kernel_map, tmp, delta_size);
                }
#endif /* FIXME */
        }

        /*
         *      If the virtual size of the segment is greater
         *      than the size from the file, we need to allocate
         *      zero fill memory for the rest.
         */
        delta_size = seg_size - map_size;
        if (delta_size > 0) {
                mach_vm_offset_t tmp = map_addr + map_size;

                ret = mach_vm_map(map, &tmp, delta_size, 0, VM_FLAGS_FIXED,
                                  NULL, 0, FALSE,
                                  scp64->initprot, scp64->maxprot,
                                  VM_INHERIT_DEFAULT);
                if (ret != KERN_SUCCESS)
                        return(LOAD_NOSPACE);
        }

        if ( (scp64->fileoff == 0) && (scp64->filesize != 0) )
                result->mach_header = map_addr;

        if (scp64->flags & SG_PROTECTED_VERSION_1) {
                ret = unprotect_segment_64(scp64->fileoff,
                                           scp64->filesize,
                                           map,
                                           map_addr,
                                           map_size);
        } else {
                ret = LOAD_SUCCESS;
        }

        return ret;
}

static
load_return_t
load_thread(
        struct thread_command   *tcp,
        thread_t                        thread,
        load_result_t           *result
)
{
        kern_return_t   kret;
        load_return_t   lret;
        task_t                  task;
        int customstack=0;

        task = get_threadtask(thread);

        /* if count is 0; same as thread */
        if (result->thread_count != 0) {
                kret = thread_create(task, &thread);
                if (kret != KERN_SUCCESS)
                        return(LOAD_RESOURCE);
                thread_deallocate(thread);
        }

        lret = load_threadstate(thread,
                       (unsigned long *)(((vm_offset_t)tcp) + 
                                sizeof(struct thread_command)),
                       tcp->cmdsize - sizeof(struct thread_command));
        if (lret != LOAD_SUCCESS)
                return (lret);

        if (result->thread_count == 0) {
                lret = load_threadstack(thread,
                                (unsigned long *)(((vm_offset_t)tcp) + 
                                        sizeof(struct thread_command)),
                                tcp->cmdsize - sizeof(struct thread_command),
                                &result->user_stack,
                                &customstack);
                if (customstack)
                                result->customstack = 1;
                else
                                result->customstack = 0;
                        
                if (lret != LOAD_SUCCESS)
                        return(lret);

                lret = load_threadentry(thread,
                                (unsigned long *)(((vm_offset_t)tcp) + 
                                        sizeof(struct thread_command)),
                                tcp->cmdsize - sizeof(struct thread_command),
                                &result->entry_point);
                if (lret != LOAD_SUCCESS)
                        return(lret);
        }
        /*
         *      Resume thread now, note that this means that the thread
         *      commands should appear after all the load commands to
         *      be sure they don't reference anything not yet mapped.
         */
        else
                thread_resume(thread);
                
        result->thread_count++;

        return(LOAD_SUCCESS);
}

static
load_return_t
load_unixthread(
        struct thread_command   *tcp,
        thread_t                thread,
        load_result_t           *result
)
{
        load_return_t   ret;
        int customstack =0;
        
        if (result->thread_count != 0) {
printf("load_unixthread: already have a thread!");
                return (LOAD_FAILURE);
        }
        
        ret = load_threadstack(thread,
                       (unsigned long *)(((vm_offset_t)tcp) + 
                                sizeof(struct thread_command)),
                       tcp->cmdsize - sizeof(struct thread_command),
                       &result->user_stack,
                           &customstack);
        if (ret != LOAD_SUCCESS)
                return(ret);

        if (customstack)
                        result->customstack = 1;
        else
                        result->customstack = 0;
        ret = load_threadentry(thread,
                       (unsigned long *)(((vm_offset_t)tcp) + 
                                sizeof(struct thread_command)),
                       tcp->cmdsize - sizeof(struct thread_command),
                       &result->entry_point);
        if (ret != LOAD_SUCCESS)
                return(ret);

        ret = load_threadstate(thread,
                       (unsigned long *)(((vm_offset_t)tcp) + 
                                sizeof(struct thread_command)),
                       tcp->cmdsize - sizeof(struct thread_command));
        if (ret != LOAD_SUCCESS)
                return (ret);

        result->unixproc = TRUE;
        result->thread_count++;

        return(LOAD_SUCCESS);
}

static
load_return_t
load_threadstate(
        thread_t        thread,
        unsigned long   *ts,
        unsigned long   total_size
)
{
        kern_return_t   ret;
        unsigned long   size;
        int             flavor;
        unsigned long   thread_size;

    ret = thread_state_initialize( thread );
    if (ret != KERN_SUCCESS) {
        return(LOAD_FAILURE);
    }
    
        /*
         *      Set the new thread state; iterate through the state flavors in
     *  the mach-o file.
         */
        while (total_size > 0) {
                flavor = *ts++;
                size = *ts++;
                thread_size = (size+2)*sizeof(unsigned long);
                if (thread_size > total_size)
                        return(LOAD_BADMACHO);
                total_size -= thread_size;
                /*
                 * Third argument is a kernel space pointer; it gets cast
                 * to the appropriate type in machine_thread_set_state()
                 * based on the value of flavor.
                 */
                ret = thread_setstatus(thread, flavor, (thread_state_t)ts, size);
                if (ret != KERN_SUCCESS) {
                        return(LOAD_FAILURE);
                }
                ts += size;     /* ts is a (unsigned long *) */
        }
        return(LOAD_SUCCESS);
}

static
load_return_t
load_threadstack(
        thread_t        thread,
        unsigned long   *ts,
        unsigned long   total_size,
        user_addr_t     *user_stack,
        int *customstack
)
{
        kern_return_t   ret;
        unsigned long   size;
        int             flavor;
        unsigned long   stack_size;

        while (total_size > 0) {
                flavor = *ts++;
                size = *ts++;
                stack_size = (size+2)*sizeof(unsigned long);
                if (stack_size > total_size)
                        return(LOAD_BADMACHO);
                total_size -= stack_size;

                /*
                 * Third argument is a kernel space pointer; it gets cast
                 * to the appropriate type in thread_userstack() based on
                 * the value of flavor.
                 */
                ret = thread_userstack(thread, flavor, (thread_state_t)ts, size, user_stack, customstack);
                if (ret != KERN_SUCCESS) {
                        return(LOAD_FAILURE);
                }
                ts += size;     /* ts is a (unsigned long *) */
        }
        return(LOAD_SUCCESS);
}

static
load_return_t
load_threadentry(
        thread_t        thread,
        unsigned long   *ts,
        unsigned long   total_size,
        mach_vm_offset_t        *entry_point
)
{
        kern_return_t   ret;
        unsigned long   size;
        int             flavor;
        unsigned long   entry_size;

        /*
         *      Set the thread state.
         */
        *entry_point = MACH_VM_MIN_ADDRESS;
        while (total_size > 0) {
                flavor = *ts++;
                size = *ts++;
                entry_size = (size+2)*sizeof(unsigned long);
                if (entry_size > total_size)
                        return(LOAD_BADMACHO);
                total_size -= entry_size;
                /*
                 * Third argument is a kernel space pointer; it gets cast
                 * to the appropriate type in thread_entrypoint() based on
                 * the value of flavor.
                 */
                ret = thread_entrypoint(thread, flavor, (thread_state_t)ts, size, entry_point);
                if (ret != KERN_SUCCESS) {
                        return(LOAD_FAILURE);
                }
                ts += size;     /* ts is a (unsigned long *) */
        }
        return(LOAD_SUCCESS);
}


static
load_return_t
load_dylinker(
        struct dylinker_command *lcp,
        integer_t               archbits,
        vm_map_t                map,
        thread_t        thread,
        int                     depth,
        load_result_t           *result,
        boolean_t               is_64bit
)
{
        char                    *name;
        char                    *p;
        struct vnode            *vp = NULLVP;   /* set by get_macho_vnode() */
        struct mach_header      header;
        off_t                   file_offset = 0; /* set by get_macho_vnode() */
        off_t                   macho_size = 0; /* set by get_macho_vnode() */
        vm_map_t                copy_map;
        load_result_t           myresult;
        kern_return_t           ret;
        vm_map_copy_t   tmp;
        mach_vm_offset_t        dyl_start, map_addr;
        mach_vm_size_t          dyl_length;

        name = (char *)lcp + lcp->name.offset;
        /*
         *      Check for a proper null terminated string.
         */
        p = name;
        do {
                if (p >= (char *)lcp + lcp->cmdsize)
                        return(LOAD_BADMACHO);
        } while (*p++);

        ret = get_macho_vnode(name, archbits, &header, &file_offset, &macho_size, &vp);
        if (ret)
                return (ret);
                        
        myresult = load_result_null;

        /*
         *      First try to map dyld in directly.  This should work most of
         *      the time since there shouldn't normally be something already
         *      mapped to its address.
         */

        ret = parse_machfile(vp, map, thread, &header, file_offset, macho_size,
                                depth, &myresult);

        /*
         *      If it turned out something was in the way, then we'll take
         *      take this longer path to map dyld into a temporary map and
         *      copy it into destination map at a different address.
         */

        if (ret == LOAD_NOSPACE) {

                /*
                 *      Load the Mach-O.
                 *      Use a temporary map to do the work.
                 */
                copy_map = vm_map_create(pmap_create(vm_map_round_page(macho_size),
                                                     is_64bit),
                                         get_map_min(map), get_map_max(map), TRUE);
                if (VM_MAP_NULL == copy_map) {
                        ret = LOAD_RESOURCE;
                        goto out;
                }
        
                myresult = load_result_null;

                ret = parse_machfile(vp, copy_map, thread, &header,
                                        file_offset, macho_size,
                                        depth, &myresult);
        
                if (ret) {
                        vm_map_deallocate(copy_map);
                        goto out;
                }
        
                if (get_map_nentries(copy_map) > 0) {
        
                        dyl_start = mach_get_vm_start(copy_map);
                        dyl_length = mach_get_vm_end(copy_map) - dyl_start;
        
                        map_addr = dyl_start;
                        ret = mach_vm_allocate(map, &map_addr, dyl_length, VM_FLAGS_ANYWHERE);
        
                        if (ret != KERN_SUCCESS) {
                                vm_map_deallocate(copy_map);
                                ret = LOAD_NOSPACE;
                                goto out;
                        
                        }

                        ret = vm_map_copyin(copy_map,
                                            (vm_map_address_t)dyl_start,
                                            (vm_map_size_t)dyl_length,
                                            TRUE, &tmp);
                        if (ret != KERN_SUCCESS) {
                                (void) vm_map_remove(map,
                                             vm_map_trunc_page(map_addr),
                                             vm_map_round_page(map_addr + dyl_length),
                                             VM_MAP_NO_FLAGS);
                                vm_map_deallocate(copy_map);
                                goto out;
                        }
        
                        ret = vm_map_copy_overwrite(map,
                                             (vm_map_address_t)map_addr,
                                             tmp, FALSE);
                        if (ret != KERN_SUCCESS) {
                                vm_map_copy_discard(tmp);
                                (void) vm_map_remove(map,
                                             vm_map_trunc_page(map_addr),
                                             vm_map_round_page(map_addr + dyl_length),
                                             VM_MAP_NO_FLAGS);
                                vm_map_deallocate(copy_map);
                                goto out;
                        }
        
                        if (map_addr != dyl_start)
                                myresult.entry_point += (map_addr - dyl_start);
                } else {
                        ret = LOAD_FAILURE;
                }

                vm_map_deallocate(copy_map);
        }
        
        if (ret == LOAD_SUCCESS) {              
                result->dynlinker = TRUE;
                result->entry_point = myresult.entry_point;
                (void)ubc_map(vp, PROT_READ | PROT_EXEC);
        }
out:
        vnode_put(vp);
        return (ret);

}

int
load_code_signature(
        struct linkedit_data_command    *lcp,
        struct vnode                    *vp,
        off_t                           macho_offset,
        off_t                           macho_size,
        cpu_type_t                      cputype,
        load_result_t                   *result)
{
        int             ret;
        kern_return_t   kr;
        vm_offset_t     addr;
        int             resid;
        struct cs_blob  *blob;
        int             error;

        addr = 0;
        blob = NULL;

        if (lcp->cmdsize != sizeof (struct linkedit_data_command) ||
            lcp->dataoff + lcp->datasize > macho_size) {
                ret = LOAD_BADMACHO;
                goto out;
        }

        blob = ubc_cs_blob_get(vp, cputype, -1);
        if (blob != NULL) {
                /* we already have a blob for this vnode and cputype */
                if (blob->csb_cpu_type == cputype &&
                    blob->csb_base_offset == macho_offset &&
                    blob->csb_mem_size == lcp->datasize) {
                        /* it matches the blob we want here: we're done */
                        ret = LOAD_SUCCESS;
                } else {
                        /* the blob has changed for this vnode: fail ! */
                        ret = LOAD_BADMACHO;
                }
                goto out;
        }

        kr = kmem_alloc(kernel_map, &addr, round_page(lcp->datasize));
        if (kr != KERN_SUCCESS) {
                ret = LOAD_NOSPACE;
                goto out;
        }
        
        resid = 0;
        error = vn_rdwr(UIO_READ,
                        vp,
                        (caddr_t) addr,
                        lcp->datasize,
                        macho_offset + lcp->dataoff,
                        UIO_SYSSPACE32,
                        0,
                        kauth_cred_get(),
                        &resid,
                        current_proc());
        if (error || resid != 0) {
                ret = LOAD_IOERROR;
                goto out;
        }

        if (ubc_cs_blob_add(vp,
                            cputype,
                            macho_offset,
                            addr,
                            lcp->datasize)) {
                ret = LOAD_FAILURE;
                goto out;
        } else {
                /* ubc_cs_blob_add() has consumed "addr" */
                addr = 0;
        }
                
        blob = ubc_cs_blob_get(vp, cputype, -1);

        ret = LOAD_SUCCESS;
out:
        if (result && ret == LOAD_SUCCESS) {
                result->csflags |= blob->csb_flags;
        }
        if (addr != 0) {
                kmem_free(kernel_map, addr, round_page(lcp->datasize));
                addr = 0;
        }

        return ret;
}

/*
 * This routine exists to support the load_dylinker().
 *
 * This routine has its own, separate, understanding of the FAT file format,
 * which is terrifically unfortunate.
 */
static
load_return_t
get_macho_vnode(
        char                    *path,
        integer_t               archbits,
        struct mach_header      *mach_header,
        off_t                   *file_offset,
        off_t                   *macho_size,
        struct vnode            **vpp
)
{
        struct vnode            *vp;
        vfs_context_t           ctx = vfs_context_current();
        proc_t                  p = vfs_context_proc(ctx);
        kauth_cred_t            kerncred;
        struct nameidata nid, *ndp;
        boolean_t               is_fat;
        struct fat_arch         fat_arch;
        int                     error = LOAD_SUCCESS;
        int resid;
        union {
                struct mach_header      mach_header;
                struct fat_header       fat_header;
                char    pad[512];
        } header;
        off_t fsize = (off_t)0;
        int err2;
        
        /*
         * Capture the kernel credential for use in the actual read of the
         * file, since the user doing the execution may have execute rights
         * but not read rights, but to exec something, we have to either map
         * or read it into the new process address space, which requires
         * read rights.  This is to deal with lack of common credential
         * serialization code which would treat NOCRED as "serialize 'root'".
         */
        kerncred = vfs_context_ucred(vfs_context_kernel());

        ndp = &nid;
        
        /* init the namei data to point the file user's program name */
        NDINIT(ndp, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE32, CAST_USER_ADDR_T(path), ctx);

        if ((error = namei(ndp)) != 0) {
                if (error == ENOENT) {
                        error = LOAD_ENOENT;
                } else {
                        error = LOAD_FAILURE;
                }
                return(error);
        }
        nameidone(ndp);
        vp = ndp->ni_vp;
        
        /* check for regular file */
        if (vp->v_type != VREG) {
                error = LOAD_PROTECT;
                goto bad1;
        }

        /* get size */
        if ((error = vnode_size(vp, &fsize, ctx)) != 0) {
                error = LOAD_FAILURE;
                goto bad1;
        }

        /* Check mount point */
        if (vp->v_mount->mnt_flag & MNT_NOEXEC) {
                error = LOAD_PROTECT;
                goto bad1;
        }

        /* check access */
        if ((error = vnode_authorize(vp, NULL, KAUTH_VNODE_EXECUTE, ctx)) != 0) {
                error = LOAD_PROTECT;
                goto bad1;
        }

        /* try to open it */
        if ((error = VNOP_OPEN(vp, FREAD, ctx)) != 0) {
                error = LOAD_PROTECT;
                goto bad1;
        }

        if ((error = vn_rdwr(UIO_READ, vp, (caddr_t)&header, sizeof(header), 0,
            UIO_SYSSPACE32, IO_NODELOCKED, kerncred, &resid, p)) != 0) {
                error = LOAD_IOERROR;
                goto bad2;
        }
        
        if (header.mach_header.magic == MH_MAGIC ||
            header.mach_header.magic == MH_MAGIC_64)
            is_fat = FALSE;
        else if (header.fat_header.magic == FAT_MAGIC ||
                 header.fat_header.magic == FAT_CIGAM)
            is_fat = TRUE;
        else {
            error = LOAD_BADMACHO;
            goto bad2;
        }

        if (is_fat) {
                /* Look up our architecture in the fat file. */
                error = fatfile_getarch_with_bits(vp, archbits, (vm_offset_t)(&header.fat_header), &fat_arch);
                if (error != LOAD_SUCCESS)
                        goto bad2;

                /* Read the Mach-O header out of it */
                error = vn_rdwr(UIO_READ, vp, (caddr_t)&header.mach_header,
                                sizeof(header.mach_header), fat_arch.offset,
                                UIO_SYSSPACE32, IO_NODELOCKED, kerncred, &resid, p);
                if (error) {
                        error = LOAD_IOERROR;
                        goto bad2;
                }

                /* Is this really a Mach-O? */
                if (header.mach_header.magic != MH_MAGIC &&
                    header.mach_header.magic != MH_MAGIC_64) {
                        error = LOAD_BADMACHO;
                        goto bad2;
                }

                *file_offset = fat_arch.offset;
                *macho_size = fat_arch.size;
        } else {
                /*
                 * Force get_macho_vnode() to fail if the architecture bits
                 * do not match the expected architecture bits.  This in
                 * turn causes load_dylinker() to fail for the same reason,
                 * so it ensures the dynamic linker and the binary are in
                 * lock-step.  This is potentially bad, if we ever add to
                 * the CPU_ARCH_* bits any bits that are desirable but not
                 * required, since the dynamic linker might work, but we will
                 * refuse to load it because of this check.
                 */
                if ((cpu_type_t)(header.mach_header.cputype & CPU_ARCH_MASK) != archbits)
                        return(LOAD_BADARCH);

                *file_offset = 0;
                *macho_size = fsize;
        }

        *mach_header = header.mach_header;
        *vpp = vp;

        ubc_setsize(vp, fsize);
        
        return (error);

bad2:
        err2 = VNOP_CLOSE(vp, FREAD, ctx);
        vnode_put(vp);
        return (error);

bad1:
        vnode_put(vp);
        return(error);
}