imgact_elf.c

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/*-
 * Copyright (c) 2000 David O'Brien
 * Copyright (c) 1995-1996 Søren Schmidt
 * Copyright (c) 1996 Peter Wemm
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer
 *    in this position and unchanged.
 * 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. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/cdefs.h>
__FBSDID("$BSDSUniX$");

#include "opt_capsicum.h"
#include "opt_compat.h"
#include "opt_core.h"

#include <sys/param.h>
#include <sys/capability.h>
#include <sys/exec.h>
#include <sys/fcntl.h>
#include <sys/filedesc.h>
#include <sys/imgact.h>
#include <sys/imgact_elf.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/mutex.h>
#include <sys/mman.h>
#include <sys/namei.h>
#include <sys/pioctl.h>
#include <sys/proc.h>
#include <sys/procfs.h>
#include <sys/racct.h>
#include <sys/resourcevar.h>
#include <sys/sbuf.h>
#include <sys/sf_buf.h>
#include <sys/smp.h>
#include <sys/systm.h>
#include <sys/signalvar.h>
#include <sys/stat.h>
#include <sys/sx.h>
#include <sys/syscall.h>
#include <sys/sysctl.h>
#include <sys/sysent.h>
#include <sys/vnode.h>
#include <sys/syslog.h>
#include <sys/eventhandler.h>
#include <sys/user.h>

#include <net/zlib.h>

#include <vm/vm.h>
#include <vm/vm_kern.h>
#include <vm/vm_param.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
#include <vm/vm_object.h>
#include <vm/vm_extern.h>

#include <machine/elf.h>
#include <machine/md_var.h>

#define ELF_NOTE_ROUNDSIZE      4
#define OLD_EI_BRAND    8

static int __elfN(check_header)(const Elf_Ehdr *hdr);
static Elf_Brandinfo *__elfN(get_brandinfo)(struct image_params *imgp,
    const char *interp, int interp_name_len, int32_t *osrel);
static int __elfN(load_file)(struct proc *p, const char *file, u_long *addr,
    u_long *entry, size_t pagesize);
static int __elfN(load_section)(struct vmspace *vmspace, vm_object_t object,
    vm_offset_t offset, caddr_t vmaddr, size_t memsz, size_t filsz,
    vm_prot_t prot, size_t pagesize);
static int __CONCAT(exec_, __elfN(imgact))(struct image_params *imgp);
static boolean_t __elfN(bsdsunix_trans_osrel)(const Elf_Note *note,
    int32_t *osrel);
static boolean_t kbsdsunix_trans_osrel(const Elf_Note *note, int32_t *osrel);
static boolean_t __elfN(check_note)(struct image_params *imgp,
    Elf_Brandnote *checknote, int32_t *osrel);
static vm_prot_t __elfN(trans_prot)(Elf_Word);
static Elf_Word __elfN(untrans_prot)(vm_prot_t);

SYSCTL_NODE(_kern, OID_AUTO, __CONCAT(elf, __ELF_WORD_SIZE), CTLFLAG_RW, 0,
    "");

#ifdef COMPRESS_USER_CORES
static int compress_core(gzFile, char *, char *, unsigned int,
    struct thread * td);
#endif
#define CORE_BUF_SIZE   (16 * 1024)

int __elfN(fallback_brand) = -1;
SYSCTL_INT(__CONCAT(_kern_elf, __ELF_WORD_SIZE), OID_AUTO,
    fallback_brand, CTLFLAG_RW, &__elfN(fallback_brand), 0,
    __XSTRING(__CONCAT(ELF, __ELF_WORD_SIZE)) " brand of last resort");
TUNABLE_INT("kern.elf" __XSTRING(__ELF_WORD_SIZE) ".fallback_brand",
    &__elfN(fallback_brand));

static int elf_legacy_coredump = 0;
SYSCTL_INT(_debug, OID_AUTO, __elfN(legacy_coredump), CTLFLAG_RW, 
    &elf_legacy_coredump, 0, "");

int __elfN(nxstack) =
#if defined(__amd64__) || defined(__powerpc64__) /* both 64 and 32 bit */
        1;
#else
        0;
#endif
SYSCTL_INT(__CONCAT(_kern_elf, __ELF_WORD_SIZE), OID_AUTO,
    nxstack, CTLFLAG_RW, &__elfN(nxstack), 0,
    __XSTRING(__CONCAT(ELF, __ELF_WORD_SIZE)) ": enable non-executable stack");

#if __ELF_WORD_SIZE == 32
#if defined(__amd64__) || defined(__ia64__)
int i386_read_exec = 0;
SYSCTL_INT(_kern_elf32, OID_AUTO, read_exec, CTLFLAG_RW, &i386_read_exec, 0,
    "enable execution from readable segments");
#endif
#endif

static Elf_Brandinfo *elf_brand_list[MAX_BRANDS];

#define trunc_page_ps(va, ps)   ((va) & ~(ps - 1))
#define round_page_ps(va, ps)   (((va) + (ps - 1)) & ~(ps - 1))
#define aligned(a, t)   (trunc_page_ps((u_long)(a), sizeof(t)) == (u_long)(a))

static const char BSDSUNIX_ABI_VENDOR[] = "BSDSUniX";

Elf_Brandnote __elfN(bsdsunix_brandnote) = {
        .hdr.n_namesz   = sizeof(BSDSUNIX_ABI_VENDOR),
        .hdr.n_descsz   = sizeof(int32_t),
        .hdr.n_type     = 1,
        .vendor         = BSDSUNIX_ABI_VENDOR,
        .flags          = BN_TRANSLATE_OSREL,
        .trans_osrel    = __elfN(bsdsunix_trans_osrel)
};

static boolean_t
__elfN(bsdsunix_trans_osrel)(const Elf_Note *note, int32_t *osrel)
{
        uintptr_t p;

        p = (uintptr_t)(note + 1);
        p += roundup2(note->n_namesz, ELF_NOTE_ROUNDSIZE);
        *osrel = *(const int32_t *)(p);

        return (TRUE);
}

static const char GNU_ABI_VENDOR[] = "GNU";
static int GNU_KBSDSUNIX_ABI_DESC = 3;

Elf_Brandnote __elfN(kbsdsunix_brandnote) = {
        .hdr.n_namesz   = sizeof(GNU_ABI_VENDOR),
        .hdr.n_descsz   = 16,   /* XXX at least 16 */
        .hdr.n_type     = 1,
        .vendor         = GNU_ABI_VENDOR,
        .flags          = BN_TRANSLATE_OSREL,
        .trans_osrel    = kbsdsunix_trans_osrel
};

static boolean_t
kbsdsunix_trans_osrel(const Elf_Note *note, int32_t *osrel)
{
        const Elf32_Word *desc;
        uintptr_t p;

        p = (uintptr_t)(note + 1);
        p += roundup2(note->n_namesz, ELF_NOTE_ROUNDSIZE);

        desc = (const Elf32_Word *)p;
        if (desc[0] != GNU_KBSDSUNIX_ABI_DESC)
                return (FALSE);

        /*
         * Debian GNU/kFreeBSD embed the earliest compatible kernel version
         * (__BSDSUniX_version: <major><two digit minor>Rxx) in the LSB way.
         */
        *osrel = desc[1] * 100000 + desc[2] * 1000 + desc[3];

        return (TRUE);
}

int
__elfN(insert_brand_entry)(Elf_Brandinfo *entry)
{
        int i;

        for (i = 0; i < MAX_BRANDS; i++) {
                if (elf_brand_list[i] == NULL) {
                        elf_brand_list[i] = entry;
                        break;
                }
        }
        if (i == MAX_BRANDS) {
                printf("WARNING: %s: could not insert brandinfo entry: %p\n",
                        __func__, entry);
                return (-1);
        }
        return (0);
}

int
__elfN(remove_brand_entry)(Elf_Brandinfo *entry)
{
        int i;

        for (i = 0; i < MAX_BRANDS; i++) {
                if (elf_brand_list[i] == entry) {
                        elf_brand_list[i] = NULL;
                        break;
                }
        }
        if (i == MAX_BRANDS)
                return (-1);
        return (0);
}

int
__elfN(brand_inuse)(Elf_Brandinfo *entry)
{
        struct proc *p;
        int rval = FALSE;

        sx_slock(&allproc_lock);
        FOREACH_PROC_IN_SYSTEM(p) {
                if (p->p_sysent == entry->sysvec) {
                        rval = TRUE;
                        break;
                }
        }
        sx_sunlock(&allproc_lock);

        return (rval);
}

static Elf_Brandinfo *
__elfN(get_brandinfo)(struct image_params *imgp, const char *interp,
    int interp_name_len, int32_t *osrel)
{
        const Elf_Ehdr *hdr = (const Elf_Ehdr *)imgp->image_header;
        Elf_Brandinfo *bi;
        boolean_t ret;
        int i;

        /*
         * We support four types of branding -- (1) the ELF EI_OSABI field
         * that SCO added to the ELF spec, (2) FreeBSD 3.x's traditional string
         * branding w/in the ELF header, (3) path of the `interp_path'
         * field, and (4) the ".note.ABI-tag" ELF section.
         */

        /* Look for an ".note.ABI-tag" ELF section */
        for (i = 0; i < MAX_BRANDS; i++) {
                bi = elf_brand_list[i];
                if (bi == NULL)
                        continue;
                if (hdr->e_machine == bi->machine && (bi->flags &
                    (BI_BRAND_NOTE|BI_BRAND_NOTE_MANDATORY)) != 0) {
                        ret = __elfN(check_note)(imgp, bi->brand_note, osrel);
                        if (ret)
                                return (bi);
                }
        }

        /* If the executable has a brand, search for it in the brand list. */
        for (i = 0; i < MAX_BRANDS; i++) {
                bi = elf_brand_list[i];
                if (bi == NULL || bi->flags & BI_BRAND_NOTE_MANDATORY)
                        continue;
                if (hdr->e_machine == bi->machine &&
                    (hdr->e_ident[EI_OSABI] == bi->brand ||
                    strncmp((const char *)&hdr->e_ident[OLD_EI_BRAND],
                    bi->compat_3_brand, strlen(bi->compat_3_brand)) == 0))
                        return (bi);
        }

        /* Lacking a known brand, search for a recognized interpreter. */
        if (interp != NULL) {
                for (i = 0; i < MAX_BRANDS; i++) {
                        bi = elf_brand_list[i];
                        if (bi == NULL || bi->flags & BI_BRAND_NOTE_MANDATORY)
                                continue;
                        if (hdr->e_machine == bi->machine &&
                            /* ELF image p_filesz includes terminating zero */
                            strlen(bi->interp_path) + 1 == interp_name_len &&
                            strncmp(interp, bi->interp_path, interp_name_len)
                            == 0)
                                return (bi);
                }
        }

        /* Lacking a recognized interpreter, try the default brand */
        for (i = 0; i < MAX_BRANDS; i++) {
                bi = elf_brand_list[i];
                if (bi == NULL || bi->flags & BI_BRAND_NOTE_MANDATORY)
                        continue;
                if (hdr->e_machine == bi->machine &&
                    __elfN(fallback_brand) == bi->brand)
                        return (bi);
        }
        return (NULL);
}

static int
__elfN(check_header)(const Elf_Ehdr *hdr)
{
        Elf_Brandinfo *bi;
        int i;

        if (!IS_ELF(*hdr) ||
            hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||
            hdr->e_ident[EI_DATA] != ELF_TARG_DATA ||
            hdr->e_ident[EI_VERSION] != EV_CURRENT ||
            hdr->e_phentsize != sizeof(Elf_Phdr) ||
            hdr->e_version != ELF_TARG_VER)
                return (ENOEXEC);

        /*
         * Make sure we have at least one brand for this machine.
         */

        for (i = 0; i < MAX_BRANDS; i++) {
                bi = elf_brand_list[i];
                if (bi != NULL && bi->machine == hdr->e_machine)
                        break;
        }
        if (i == MAX_BRANDS)
                return (ENOEXEC);

        return (0);
}

static int
__elfN(map_partial)(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
    vm_offset_t start, vm_offset_t end, vm_prot_t prot)
{
        struct sf_buf *sf;
        int error;
        vm_offset_t off;

        /*
         * Create the page if it doesn't exist yet. Ignore errors.
         */
        vm_map_lock(map);
        vm_map_insert(map, NULL, 0, trunc_page(start), round_page(end),
            VM_PROT_ALL, VM_PROT_ALL, 0);
        vm_map_unlock(map);

        /*
         * Find the page from the underlying object.
         */
        if (object) {
                sf = vm_imgact_map_page(object, offset);
                if (sf == NULL)
                        return (KERN_FAILURE);
                off = offset - trunc_page(offset);
                error = copyout((caddr_t)sf_buf_kva(sf) + off, (caddr_t)start,
                    end - start);
                vm_imgact_unmap_page(sf);
                if (error) {
                        return (KERN_FAILURE);
                }
        }

        return (KERN_SUCCESS);
}

static int
__elfN(map_insert)(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
    vm_offset_t start, vm_offset_t end, vm_prot_t prot, int cow)
{
        struct sf_buf *sf;
        vm_offset_t off;
        vm_size_t sz;
        int error, rv;

        if (start != trunc_page(start)) {
                rv = __elfN(map_partial)(map, object, offset, start,
                    round_page(start), prot);
                if (rv)
                        return (rv);
                offset += round_page(start) - start;
                start = round_page(start);
        }
        if (end != round_page(end)) {
                rv = __elfN(map_partial)(map, object, offset +
                    trunc_page(end) - start, trunc_page(end), end, prot);
                if (rv)
                        return (rv);
                end = trunc_page(end);
        }
        if (end > start) {
                if (offset & PAGE_MASK) {
                        /*
                         * The mapping is not page aligned. This means we have
                         * to copy the data. Sigh.
                         */
                        rv = vm_map_find(map, NULL, 0, &start, end - start,
                            FALSE, prot | VM_PROT_WRITE, VM_PROT_ALL, 0);
                        if (rv)
                                return (rv);
                        if (object == NULL)
                                return (KERN_SUCCESS);
                        for (; start < end; start += sz) {
                                sf = vm_imgact_map_page(object, offset);
                                if (sf == NULL)
                                        return (KERN_FAILURE);
                                off = offset - trunc_page(offset);
                                sz = end - start;
                                if (sz > PAGE_SIZE - off)
                                        sz = PAGE_SIZE - off;
                                error = copyout((caddr_t)sf_buf_kva(sf) + off,
                                    (caddr_t)start, sz);
                                vm_imgact_unmap_page(sf);
                                if (error) {
                                        return (KERN_FAILURE);
                                }
                                offset += sz;
                        }
                        rv = KERN_SUCCESS;
                } else {
                        vm_object_reference(object);
                        vm_map_lock(map);
                        rv = vm_map_insert(map, object, offset, start, end,
                            prot, VM_PROT_ALL, cow);
                        vm_map_unlock(map);
                        if (rv != KERN_SUCCESS)
                                vm_object_deallocate(object);
                }
                return (rv);
        } else {
                return (KERN_SUCCESS);
        }
}

static int
__elfN(load_section)(struct vmspace *vmspace,
        vm_object_t object, vm_offset_t offset,
        caddr_t vmaddr, size_t memsz, size_t filsz, vm_prot_t prot,
        size_t pagesize)
{
        struct sf_buf *sf;
        size_t map_len;
        vm_offset_t map_addr;
        int error, rv, cow;
        size_t copy_len;
        vm_offset_t file_addr;

        /*
         * It's necessary to fail if the filsz + offset taken from the
         * header is greater than the actual file pager object's size.
         * If we were to allow this, then the vm_map_find() below would
         * walk right off the end of the file object and into the ether.
         *
         * While I'm here, might as well check for something else that
         * is invalid: filsz cannot be greater than memsz.
         */
        if ((off_t)filsz + offset > object->un_pager.vnp.vnp_size ||
            filsz > memsz) {
                uprintf("elf_load_section: truncated ELF file\n");
                return (ENOEXEC);
        }

        map_addr = trunc_page_ps((vm_offset_t)vmaddr, pagesize);
        file_addr = trunc_page_ps(offset, pagesize);

        /*
         * We have two choices.  We can either clear the data in the last page
         * of an oversized mapping, or we can start the anon mapping a page
         * early and copy the initialized data into that first page.  We
         * choose the second..
         */
        if (memsz > filsz)
                map_len = trunc_page_ps(offset + filsz, pagesize) - file_addr;
        else
                map_len = round_page_ps(offset + filsz, pagesize) - file_addr;

        if (map_len != 0) {
                /* cow flags: don't dump readonly sections in core */
                cow = MAP_COPY_ON_WRITE | MAP_PREFAULT |
                    (prot & VM_PROT_WRITE ? 0 : MAP_DISABLE_COREDUMP);

                rv = __elfN(map_insert)(&vmspace->vm_map,
                                      object,
                                      file_addr,        /* file offset */
                                      map_addr,         /* virtual start */
                                      map_addr + map_len,/* virtual end */
                                      prot,
                                      cow);
                if (rv != KERN_SUCCESS)
                        return (EINVAL);

                /* we can stop now if we've covered it all */
                if (memsz == filsz) {
                        return (0);
                }
        }


        /*
         * We have to get the remaining bit of the file into the first part
         * of the oversized map segment.  This is normally because the .data
         * segment in the file is extended to provide bss.  It's a neat idea
         * to try and save a page, but it's a pain in the behind to implement.
         */
        copy_len = (offset + filsz) - trunc_page_ps(offset + filsz, pagesize);
        map_addr = trunc_page_ps((vm_offset_t)vmaddr + filsz, pagesize);
        map_len = round_page_ps((vm_offset_t)vmaddr + memsz, pagesize) -
            map_addr;

        /* This had damn well better be true! */
        if (map_len != 0) {
                rv = __elfN(map_insert)(&vmspace->vm_map, NULL, 0, map_addr,
                    map_addr + map_len, VM_PROT_ALL, 0);
                if (rv != KERN_SUCCESS) {
                        return (EINVAL);
                }
        }

        if (copy_len != 0) {
                vm_offset_t off;

                sf = vm_imgact_map_page(object, offset + filsz);
                if (sf == NULL)
                        return (EIO);

                /* send the page fragment to user space */
                off = trunc_page_ps(offset + filsz, pagesize) -
                    trunc_page(offset + filsz);
                error = copyout((caddr_t)sf_buf_kva(sf) + off,
                    (caddr_t)map_addr, copy_len);
                vm_imgact_unmap_page(sf);
                if (error) {
                        return (error);
                }
        }

        /*
         * set it to the specified protection.
         * XXX had better undo the damage from pasting over the cracks here!
         */
        vm_map_protect(&vmspace->vm_map, trunc_page(map_addr),
            round_page(map_addr + map_len),  prot, FALSE);

        return (0);
}

/*
 * Load the file "file" into memory.  It may be either a shared object
 * or an executable.
 *
 * The "addr" reference parameter is in/out.  On entry, it specifies
 * the address where a shared object should be loaded.  If the file is
 * an executable, this value is ignored.  On exit, "addr" specifies
 * where the file was actually loaded.
 *
 * The "entry" reference parameter is out only.  On exit, it specifies
 * the entry point for the loaded file.
 */
static int
__elfN(load_file)(struct proc *p, const char *file, u_long *addr,
        u_long *entry, size_t pagesize)
{
        struct {
                struct nameidata nd;
                struct vattr attr;
                struct image_params image_params;
        } *tempdata;
        const Elf_Ehdr *hdr = NULL;
        const Elf_Phdr *phdr = NULL;
        struct nameidata *nd;
        struct vmspace *vmspace = p->p_vmspace;
        struct vattr *attr;
        struct image_params *imgp;
        vm_prot_t prot;
        u_long rbase;
        u_long base_addr = 0;
        int vfslocked, error, i, numsegs;

#ifdef CAPABILITY_MODE
        /*
         * XXXJA: This check can go away once we are sufficiently confident
         * that the checks in namei() are correct.
         */
        if (IN_CAPABILITY_MODE(curthread))
                return (ECAPMODE);
#endif

        tempdata = malloc(sizeof(*tempdata), M_TEMP, M_WAITOK);
        nd = &tempdata->nd;
        attr = &tempdata->attr;
        imgp = &tempdata->image_params;

        /*
         * Initialize part of the common data
         */
        imgp->proc = p;
        imgp->attr = attr;
        imgp->firstpage = NULL;
        imgp->image_header = NULL;
        imgp->object = NULL;
        imgp->execlabel = NULL;

        NDINIT(nd, LOOKUP, MPSAFE|LOCKLEAF|FOLLOW, UIO_SYSSPACE, file,
            curthread);
        vfslocked = 0;
        if ((error = namei(nd)) != 0) {
                nd->ni_vp = NULL;
                goto fail;
        }
        vfslocked = NDHASGIANT(nd);
        NDFREE(nd, NDF_ONLY_PNBUF);
        imgp->vp = nd->ni_vp;

        /*
         * Check permissions, modes, uid, etc on the file, and "open" it.
         */
        error = exec_check_permissions(imgp);
        if (error)
                goto fail;

        error = exec_map_first_page(imgp);
        if (error)
                goto fail;

        /*
         * Also make certain that the interpreter stays the same, so set
         * its VV_TEXT flag, too.
         */
        VOP_SET_TEXT(nd->ni_vp);

        imgp->object = nd->ni_vp->v_object;

        hdr = (const Elf_Ehdr *)imgp->image_header;
        if ((error = __elfN(check_header)(hdr)) != 0)
                goto fail;
        if (hdr->e_type == ET_DYN)
                rbase = *addr;
        else if (hdr->e_type == ET_EXEC)
                rbase = 0;
        else {
                error = ENOEXEC;
                goto fail;
        }

        /* Only support headers that fit within first page for now      */
        if ((hdr->e_phoff > PAGE_SIZE) ||
            (u_int)hdr->e_phentsize * hdr->e_phnum > PAGE_SIZE - hdr->e_phoff) {
                error = ENOEXEC;
                goto fail;
        }

        phdr = (const Elf_Phdr *)(imgp->image_header + hdr->e_phoff);
        if (!aligned(phdr, Elf_Addr)) {
                error = ENOEXEC;
                goto fail;
        }

        for (i = 0, numsegs = 0; i < hdr->e_phnum; i++) {
                if (phdr[i].p_type == PT_LOAD && phdr[i].p_memsz != 0) {
                        /* Loadable segment */
                        prot = __elfN(trans_prot)(phdr[i].p_flags);
                        if ((error = __elfN(load_section)(vmspace,
                            imgp->object, phdr[i].p_offset,
                            (caddr_t)(uintptr_t)phdr[i].p_vaddr + rbase,
                            phdr[i].p_memsz, phdr[i].p_filesz, prot,
                            pagesize)) != 0)
                                goto fail;
                        /*
                         * Establish the base address if this is the
                         * first segment.
                         */
                        if (numsegs == 0)
                                base_addr = trunc_page(phdr[i].p_vaddr +
                                    rbase);
                        numsegs++;
                }
        }
        *addr = base_addr;
        *entry = (unsigned long)hdr->e_entry + rbase;

fail:
        if (imgp->firstpage)
                exec_unmap_first_page(imgp);

        if (nd->ni_vp)
                vput(nd->ni_vp);

        VFS_UNLOCK_GIANT(vfslocked);
        free(tempdata, M_TEMP);

        return (error);
}

static int
__CONCAT(exec_, __elfN(imgact))(struct image_params *imgp)
{
        const Elf_Ehdr *hdr = (const Elf_Ehdr *)imgp->image_header;
        const Elf_Phdr *phdr;
        Elf_Auxargs *elf_auxargs;
        struct vmspace *vmspace;
        vm_prot_t prot;
        u_long text_size = 0, data_size = 0, total_size = 0;
        u_long text_addr = 0, data_addr = 0;
        u_long seg_size, seg_addr;
        u_long addr, baddr, et_dyn_addr, entry = 0, proghdr = 0;
        int32_t osrel = 0;
        int error = 0, i, n, interp_name_len = 0;
        const char *interp = NULL, *newinterp = NULL;
        Elf_Brandinfo *brand_info;
        char *path;
        struct sysentvec *sv;

        /*
         * Do we have a valid ELF header ?
         *
         * Only allow ET_EXEC & ET_DYN here, reject ET_DYN later
         * if particular brand doesn't support it.
         */
        if (__elfN(check_header)(hdr) != 0 ||
            (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN))
                return (-1);

        /*
         * From here on down, we return an errno, not -1, as we've
         * detected an ELF file.
         */

        if ((hdr->e_phoff > PAGE_SIZE) ||
            (u_int)hdr->e_phentsize * hdr->e_phnum > PAGE_SIZE - hdr->e_phoff) {
                /* Only support headers in first page for now */
                return (ENOEXEC);
        }
        phdr = (const Elf_Phdr *)(imgp->image_header + hdr->e_phoff);
        if (!aligned(phdr, Elf_Addr))
                return (ENOEXEC);
        n = 0;
        baddr = 0;
        for (i = 0; i < hdr->e_phnum; i++) {
                switch (phdr[i].p_type) {
                case PT_LOAD:
                        if (n == 0)
                                baddr = phdr[i].p_vaddr;
                        n++;
                        break;
                case PT_INTERP:
                        /* Path to interpreter */
                        if (phdr[i].p_filesz > MAXPATHLEN ||
                            phdr[i].p_offset > PAGE_SIZE ||
                            phdr[i].p_filesz > PAGE_SIZE - phdr[i].p_offset)
                                return (ENOEXEC);
                        interp = imgp->image_header + phdr[i].p_offset;
                        interp_name_len = phdr[i].p_filesz;
                        break;
                case PT_GNU_STACK:
                        if (__elfN(nxstack))
                                imgp->stack_prot =
                                    __elfN(trans_prot)(phdr[i].p_flags);
                        break;
                }
        }

        brand_info = __elfN(get_brandinfo)(imgp, interp, interp_name_len,
            &osrel);
        if (brand_info == NULL) {
                uprintf("ELF binary type \"%u\" not known.\n",
                    hdr->e_ident[EI_OSABI]);
                return (ENOEXEC);
        }
        if (hdr->e_type == ET_DYN) {
                if ((brand_info->flags & BI_CAN_EXEC_DYN) == 0)
                        return (ENOEXEC);
                /*
                 * Honour the base load address from the dso if it is
                 * non-zero for some reason.
                 */
                if (baddr == 0)
                        et_dyn_addr = ET_DYN_LOAD_ADDR;
                else
                        et_dyn_addr = 0;
        } else
                et_dyn_addr = 0;
        sv = brand_info->sysvec;
        if (interp != NULL && brand_info->interp_newpath != NULL)
                newinterp = brand_info->interp_newpath;

        /*
         * Avoid a possible deadlock if the current address space is destroyed
         * and that address space maps the locked vnode.  In the common case,
         * the locked vnode's v_usecount is decremented but remains greater
         * than zero.  Consequently, the vnode lock is not needed by vrele().
         * However, in cases where the vnode lock is external, such as nullfs,
         * v_usecount may become zero.
         */
        VOP_UNLOCK(imgp->vp, 0);

        error = exec_new_vmspace(imgp, sv);
        imgp->proc->p_sysent = sv;

        vn_lock(imgp->vp, LK_EXCLUSIVE | LK_RETRY);
        if (error)
                return (error);

        vmspace = imgp->proc->p_vmspace;

        for (i = 0; i < hdr->e_phnum; i++) {
                switch (phdr[i].p_type) {
                case PT_LOAD:   /* Loadable segment */
                        if (phdr[i].p_memsz == 0)
                                break;
                        prot = __elfN(trans_prot)(phdr[i].p_flags);
                        if ((error = __elfN(load_section)(vmspace,
                            imgp->object, phdr[i].p_offset,
                            (caddr_t)(uintptr_t)phdr[i].p_vaddr + et_dyn_addr,
                            phdr[i].p_memsz, phdr[i].p_filesz, prot,
                            sv->sv_pagesize)) != 0)
                                return (error);

                        /*
                         * If this segment contains the program headers,
                         * remember their virtual address for the AT_PHDR
                         * aux entry. Static binaries don't usually include
                         * a PT_PHDR entry.
                         */
                        if (phdr[i].p_offset == 0 &&
                            hdr->e_phoff + hdr->e_phnum * hdr->e_phentsize
                                <= phdr[i].p_filesz)
                                proghdr = phdr[i].p_vaddr + hdr->e_phoff +
                                    et_dyn_addr;

                        seg_addr = trunc_page(phdr[i].p_vaddr + et_dyn_addr);
                        seg_size = round_page(phdr[i].p_memsz +
                            phdr[i].p_vaddr + et_dyn_addr - seg_addr);

                        /*
                         * Make the largest executable segment the official
                         * text segment and all others data.
                         *
                         * Note that obreak() assumes that data_addr + 
                         * data_size == end of data load area, and the ELF
                         * file format expects segments to be sorted by
                         * address.  If multiple data segments exist, the
                         * last one will be used.
                         */

                        if (phdr[i].p_flags & PF_X && text_size < seg_size) {
                                text_size = seg_size;
                                text_addr = seg_addr;
                        } else {
                                data_size = seg_size;
                                data_addr = seg_addr;
                        }
                        total_size += seg_size;
                        break;
                case PT_PHDR:   /* Program header table info */
                        proghdr = phdr[i].p_vaddr + et_dyn_addr;
                        break;
                default:
                        break;
                }
        }
        
        if (data_addr == 0 && data_size == 0) {
                data_addr = text_addr;
                data_size = text_size;
        }

        entry = (u_long)hdr->e_entry + et_dyn_addr;

        /*
         * Check limits.  It should be safe to check the
         * limits after loading the segments since we do
         * not actually fault in all the segments pages.
         */
        PROC_LOCK(imgp->proc);
        if (data_size > lim_cur(imgp->proc, RLIMIT_DATA) ||
            text_size > maxtsiz ||
            total_size > lim_cur(imgp->proc, RLIMIT_VMEM) ||
            racct_set(imgp->proc, RACCT_DATA, data_size) != 0 ||
            racct_set(imgp->proc, RACCT_VMEM, total_size) != 0) {
                PROC_UNLOCK(imgp->proc);
                return (ENOMEM);
        }

        vmspace->vm_tsize = text_size >> PAGE_SHIFT;
        vmspace->vm_taddr = (caddr_t)(uintptr_t)text_addr;
        vmspace->vm_dsize = data_size >> PAGE_SHIFT;
        vmspace->vm_daddr = (caddr_t)(uintptr_t)data_addr;

        /*
         * We load the dynamic linker where a userland call
         * to mmap(0, ...) would put it.  The rationale behind this
         * calculation is that it leaves room for the heap to grow to
         * its maximum allowed size.
         */
        addr = round_page((vm_offset_t)imgp->proc->p_vmspace->vm_daddr +
            lim_max(imgp->proc, RLIMIT_DATA));
        PROC_UNLOCK(imgp->proc);

        imgp->entry_addr = entry;

        if (interp != NULL) {
                int have_interp = FALSE;
                VOP_UNLOCK(imgp->vp, 0);
                if (brand_info->emul_path != NULL &&
                    brand_info->emul_path[0] != '\0') {
                        path = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
                        snprintf(path, MAXPATHLEN, "%s%s",
                            brand_info->emul_path, interp);
                        error = __elfN(load_file)(imgp->proc, path, &addr,
                            &imgp->entry_addr, sv->sv_pagesize);
                        free(path, M_TEMP);
                        if (error == 0)
                                have_interp = TRUE;
                }
                if (!have_interp && newinterp != NULL) {
                        error = __elfN(load_file)(imgp->proc, newinterp, &addr,
                            &imgp->entry_addr, sv->sv_pagesize);
                        if (error == 0)
                                have_interp = TRUE;
                }
                if (!have_interp) {
                        error = __elfN(load_file)(imgp->proc, interp, &addr,
                            &imgp->entry_addr, sv->sv_pagesize);
                }
                vn_lock(imgp->vp, LK_EXCLUSIVE | LK_RETRY);
                if (error != 0) {
                        uprintf("ELF interpreter %s not found\n", interp);
                        return (error);
                }
        } else
                addr = et_dyn_addr;

        /*
         * Construct auxargs table (used by the fixup routine)
         */
        elf_auxargs = malloc(sizeof(Elf_Auxargs), M_TEMP, M_WAITOK);
        elf_auxargs->execfd = -1;
        elf_auxargs->phdr = proghdr;
        elf_auxargs->phent = hdr->e_phentsize;
        elf_auxargs->phnum = hdr->e_phnum;
        elf_auxargs->pagesz = PAGE_SIZE;
        elf_auxargs->base = addr;
        elf_auxargs->flags = 0;
        elf_auxargs->entry = entry;

        imgp->auxargs = elf_auxargs;
        imgp->interpreted = 0;
        imgp->reloc_base = addr;
        imgp->proc->p_osrel = osrel;

        return (error);
}

#define suword __CONCAT(suword, __ELF_WORD_SIZE)

int
__elfN(bsdsunix_fixup)(register_t **stack_base, struct image_params *imgp)
{
        Elf_Auxargs *args = (Elf_Auxargs *)imgp->auxargs;
        Elf_Addr *base;
        Elf_Addr *pos;

        base = (Elf_Addr *)*stack_base;
        pos = base + (imgp->args->argc + imgp->args->envc + 2);

        if (args->execfd != -1)
                AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd);
        AUXARGS_ENTRY(pos, AT_PHDR, args->phdr);
        AUXARGS_ENTRY(pos, AT_PHENT, args->phent);
        AUXARGS_ENTRY(pos, AT_PHNUM, args->phnum);
        AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz);
        AUXARGS_ENTRY(pos, AT_FLAGS, args->flags);
        AUXARGS_ENTRY(pos, AT_ENTRY, args->entry);
        AUXARGS_ENTRY(pos, AT_BASE, args->base);
        if (imgp->execpathp != 0)
                AUXARGS_ENTRY(pos, AT_EXECPATH, imgp->execpathp);
        AUXARGS_ENTRY(pos, AT_OSRELDATE, osreldate);
        if (imgp->canary != 0) {
                AUXARGS_ENTRY(pos, AT_CANARY, imgp->canary);
                AUXARGS_ENTRY(pos, AT_CANARYLEN, imgp->canarylen);
        }
        AUXARGS_ENTRY(pos, AT_NCPUS, mp_ncpus);
        if (imgp->pagesizes != 0) {
                AUXARGS_ENTRY(pos, AT_PAGESIZES, imgp->pagesizes);
                AUXARGS_ENTRY(pos, AT_PAGESIZESLEN, imgp->pagesizeslen);
        }
        if (imgp->sysent->sv_timekeep_base != 0) {
                AUXARGS_ENTRY(pos, AT_TIMEKEEP,
                    imgp->sysent->sv_timekeep_base);
        }
        AUXARGS_ENTRY(pos, AT_STACKPROT, imgp->sysent->sv_shared_page_obj
            != NULL && imgp->stack_prot != 0 ? imgp->stack_prot :
            imgp->sysent->sv_stackprot);
        AUXARGS_ENTRY(pos, AT_NULL, 0);

        free(imgp->auxargs, M_TEMP);
        imgp->auxargs = NULL;

        base--;
        suword(base, (long)imgp->args->argc);
        *stack_base = (register_t *)base;
        return (0);
}

/*
 * Code for generating ELF core dumps.
 */

typedef void (*segment_callback)(vm_map_entry_t, void *);

/* Closure for cb_put_phdr(). */
struct phdr_closure {
        Elf_Phdr *phdr;         /* Program header to fill in */
        Elf_Off offset;         /* Offset of segment in core file */
};

/* Closure for cb_size_segment(). */
struct sseg_closure {
        int count;              /* Count of writable segments. */
        size_t size;            /* Total size of all writable segments. */
};

typedef void (*outfunc_t)(void *, struct sbuf *, size_t *);

struct note_info {
        int             type;           /* Note type. */
        outfunc_t       outfunc;        /* Output function. */
        void            *outarg;        /* Argument for the output function. */
        size_t          outsize;        /* Output size. */
        TAILQ_ENTRY(note_info) link;    /* Link to the next note info. */
};

TAILQ_HEAD(note_info_list, note_info);

static void cb_put_phdr(vm_map_entry_t, void *);
static void cb_size_segment(vm_map_entry_t, void *);
static void each_writable_segment(struct thread *, segment_callback, void *);
static int __elfN(corehdr)(struct thread *, struct vnode *, struct ucred *,
    int, void *, size_t, struct note_info_list *, size_t, gzFile);
static void __elfN(prepare_notes)(struct thread *, struct note_info_list *,
    size_t *);
static void __elfN(puthdr)(struct thread *, void *, size_t, int, size_t);
static void __elfN(putnote)(struct note_info *, struct sbuf *);
static size_t register_note(struct note_info_list *, int, outfunc_t, void *);
static int sbuf_drain_core_output(void *, const char *, int);
static int sbuf_drain_count(void *arg, const char *data, int len);

static void __elfN(note_fpregset)(void *, struct sbuf *, size_t *);
static void __elfN(note_prpsinfo)(void *, struct sbuf *, size_t *);
static void __elfN(note_prstatus)(void *, struct sbuf *, size_t *);
static void __elfN(note_threadmd)(void *, struct sbuf *, size_t *);
static void __elfN(note_thrmisc)(void *, struct sbuf *, size_t *);
static void __elfN(note_procstat_auxv)(void *, struct sbuf *, size_t *);
static void __elfN(note_procstat_proc)(void *, struct sbuf *, size_t *);
static void __elfN(note_procstat_psstrings)(void *, struct sbuf *, size_t *);
static void note_procstat_files(void *, struct sbuf *, size_t *);
static void note_procstat_groups(void *, struct sbuf *, size_t *);
static void note_procstat_osrel(void *, struct sbuf *, size_t *);
static void note_procstat_rlimit(void *, struct sbuf *, size_t *);
static void note_procstat_umask(void *, struct sbuf *, size_t *);
static void note_procstat_vmmap(void *, struct sbuf *, size_t *);

#ifdef COMPRESS_USER_CORES
extern int compress_user_cores;
extern int compress_user_cores_gzlevel;
#endif

static int
core_output(struct vnode *vp, void *base, size_t len, off_t offset,
    struct ucred *active_cred, struct ucred *file_cred,
    struct thread *td, char *core_buf, gzFile gzfile) {

        int error;
        if (gzfile) {
#ifdef COMPRESS_USER_CORES
                error = compress_core(gzfile, base, core_buf, len, td);
#else
                panic("shouldn't be here");
#endif
        } else {
                error = vn_rdwr_inchunks(UIO_WRITE, vp, base, len, offset,
                    UIO_USERSPACE, IO_UNIT | IO_DIRECT, active_cred, file_cred,
                    NULL, td);
        }
        return (error);
}

/* Coredump output parameters for sbuf drain routine. */
struct sbuf_drain_core_params {
        off_t           offset;
        struct ucred    *active_cred;
        struct ucred    *file_cred;
        struct thread   *td;
        struct vnode    *vp;
#ifdef COMPRESS_USER_CORES
        gzFile          gzfile;
#endif
};

/*
 * Drain into a core file.
 */
static int
sbuf_drain_core_output(void *arg, const char *data, int len)
{
        struct sbuf_drain_core_params *p;
        int error, locked;

        p = (struct sbuf_drain_core_params *)arg;

        /*
         * Some kern_proc out routines that print to this sbuf may
         * call us with the process lock held. Draining with the
         * non-sleepable lock held is unsafe. The lock is needed for
         * those routines when dumping a live process. In our case we
         * can safely release the lock before draining and acquire
         * again after.
         */
        locked = PROC_LOCKED(p->td->td_proc);
        if (locked)
                PROC_UNLOCK(p->td->td_proc);
#ifdef COMPRESS_USER_CORES
        if (p->gzfile != Z_NULL)
                error = compress_core(p->gzfile, NULL, __DECONST(char *, data),
                    len, p->td);
        else
#endif
                error = vn_rdwr_inchunks(UIO_WRITE, p->vp,
                    __DECONST(void *, data), len, p->offset, UIO_SYSSPACE,
                    IO_UNIT | IO_DIRECT, p->active_cred, p->file_cred, NULL,
                    p->td);
        if (locked)
                PROC_LOCK(p->td->td_proc);
        if (error != 0)
                return (-error);
        p->offset += len;
        return (len);
}

/*
 * Drain into a counter.
 */
static int
sbuf_drain_count(void *arg, const char *data __unused, int len)
{
        size_t *sizep;

        sizep = (size_t *)arg;
        *sizep += len;
        return (len);
}

int
__elfN(coredump)(struct thread *td, struct vnode *vp, off_t limit, int flags)
{
        struct ucred *cred = td->td_ucred;
        int error = 0;
        struct sseg_closure seginfo;
        struct note_info_list notelst;
        struct note_info *ninfo;
        void *hdr;
        size_t hdrsize, notesz, coresize;

        gzFile gzfile = Z_NULL;
        char *core_buf = NULL;
#ifdef COMPRESS_USER_CORES
        char gzopen_flags[8];
        char *p;
        int doing_compress = flags & IMGACT_CORE_COMPRESS;
#endif

        hdr = NULL;
        TAILQ_INIT(&notelst);

#ifdef COMPRESS_USER_CORES
        if (doing_compress) {
                p = gzopen_flags;
                *p++ = 'w';
                if (compress_user_cores_gzlevel >= 0 &&
                    compress_user_cores_gzlevel <= 9)
                        *p++ = '0' + compress_user_cores_gzlevel;
                *p = 0;
                gzfile = gz_open("", gzopen_flags, vp);
                if (gzfile == Z_NULL) {
                        error = EFAULT;
                        goto done;
                }
                core_buf = malloc(CORE_BUF_SIZE, M_TEMP, M_WAITOK | M_ZERO);
                if (!core_buf) {
                        error = ENOMEM;
                        goto done;
                }
        }
#endif

        /* Size the program segments. */
        seginfo.count = 0;
        seginfo.size = 0;
        each_writable_segment(td, cb_size_segment, &seginfo);

        /*
         * Collect info about the core file header area.
         */
        hdrsize = sizeof(Elf_Ehdr) + sizeof(Elf_Phdr) * (1 + seginfo.count);
        __elfN(prepare_notes)(td, &notelst, &notesz);
        coresize = round_page(hdrsize + notesz) + seginfo.size;

#ifdef RACCT
        PROC_LOCK(td->td_proc);
        error = racct_add(td->td_proc, RACCT_CORE, coresize);
        PROC_UNLOCK(td->td_proc);
        if (error != 0) {
                error = EFAULT;
                goto done;
        }
#endif
        if (coresize >= limit) {
                error = EFAULT;
                goto done;
        }

        /*
         * Allocate memory for building the header, fill it up,
         * and write it out following the notes.
         */
        hdr = malloc(hdrsize, M_TEMP, M_WAITOK);
        if (hdr == NULL) {
                error = EINVAL;
                goto done;
        }
        error = __elfN(corehdr)(td, vp, cred, seginfo.count, hdr, hdrsize,
            &notelst, notesz, gzfile);

        /* Write the contents of all of the writable segments. */
        if (error == 0) {
                Elf_Phdr *php;
                off_t offset;
                int i;

                php = (Elf_Phdr *)((char *)hdr + sizeof(Elf_Ehdr)) + 1;
                offset = round_page(hdrsize + notesz);
                for (i = 0; i < seginfo.count; i++) {
                        error = core_output(vp, (caddr_t)(uintptr_t)php->p_vaddr,
                            php->p_filesz, offset, cred, NOCRED, curthread, core_buf, gzfile);
                        if (error != 0)
                                break;
                        offset += php->p_filesz;
                        php++;
                }
        }
        if (error) {
                log(LOG_WARNING,
                    "Failed to write core file for process %s (error %d)\n",
                    curproc->p_comm, error);
        }

done:
#ifdef COMPRESS_USER_CORES
        if (core_buf)
                free(core_buf, M_TEMP);
        if (gzfile)
                gzclose(gzfile);
#endif
        while ((ninfo = TAILQ_FIRST(&notelst)) != NULL) {
                TAILQ_REMOVE(&notelst, ninfo, link);
                free(ninfo, M_TEMP);
        }
        if (hdr != NULL)
                free(hdr, M_TEMP);

        return (error);
}

/*
 * A callback for each_writable_segment() to write out the segment's
 * program header entry.
 */
static void
cb_put_phdr(entry, closure)
        vm_map_entry_t entry;
        void *closure;
{
        struct phdr_closure *phc = (struct phdr_closure *)closure;
        Elf_Phdr *phdr = phc->phdr;

        phc->offset = round_page(phc->offset);

        phdr->p_type = PT_LOAD;
        phdr->p_offset = phc->offset;
        phdr->p_vaddr = entry->start;
        phdr->p_paddr = 0;
        phdr->p_filesz = phdr->p_memsz = entry->end - entry->start;
        phdr->p_align = PAGE_SIZE;
        phdr->p_flags = __elfN(untrans_prot)(entry->protection);

        phc->offset += phdr->p_filesz;
        phc->phdr++;
}

/*
 * A callback for each_writable_segment() to gather information about
 * the number of segments and their total size.
 */
static void
cb_size_segment(entry, closure)
        vm_map_entry_t entry;
        void *closure;
{
        struct sseg_closure *ssc = (struct sseg_closure *)closure;

        ssc->count++;
        ssc->size += entry->end - entry->start;
}

/*
 * For each writable segment in the process's memory map, call the given
 * function with a pointer to the map entry and some arbitrary
 * caller-supplied data.
 */
static void
each_writable_segment(td, func, closure)
        struct thread *td;
        segment_callback func;
        void *closure;
{
        struct proc *p = td->td_proc;
        vm_map_t map = &p->p_vmspace->vm_map;
        vm_map_entry_t entry;
        vm_object_t backing_object, object;
        boolean_t ignore_entry;

        vm_map_lock_read(map);
        for (entry = map->header.next; entry != &map->header;
            entry = entry->next) {
                /*
                 * Don't dump inaccessible mappings, deal with legacy
                 * coredump mode.
                 *
                 * Note that read-only segments related to the elf binary
                 * are marked MAP_ENTRY_NOCOREDUMP now so we no longer
                 * need to arbitrarily ignore such segments.
                 */
                if (elf_legacy_coredump) {
                        if ((entry->protection & VM_PROT_RW) != VM_PROT_RW)
                                continue;
                } else {
                        if ((entry->protection & VM_PROT_ALL) == 0)
                                continue;
                }

                /*
                 * Dont include memory segment in the coredump if
                 * MAP_NOCORE is set in mmap(2) or MADV_NOCORE in
                 * madvise(2).  Do not dump submaps (i.e. parts of the
                 * kernel map).
                 */
                if (entry->eflags & (MAP_ENTRY_NOCOREDUMP|MAP_ENTRY_IS_SUB_MAP))
                        continue;

                if ((object = entry->object.vm_object) == NULL)
                        continue;

                /* Ignore memory-mapped devices and such things. */
                VM_OBJECT_LOCK(object);
                while ((backing_object = object->backing_object) != NULL) {
                        VM_OBJECT_LOCK(backing_object);
                        VM_OBJECT_UNLOCK(object);
                        object = backing_object;
                }
                ignore_entry = object->type != OBJT_DEFAULT &&
                    object->type != OBJT_SWAP && object->type != OBJT_VNODE &&
                    object->type != OBJT_PHYS;
                VM_OBJECT_UNLOCK(object);
                if (ignore_entry)
                        continue;

                (*func)(entry, closure);
        }
        vm_map_unlock_read(map);
}

/*
 * Write the core file header to the file, including padding up to
 * the page boundary.
 */
static int
__elfN(corehdr)(struct thread *td, struct vnode *vp, struct ucred *cred,
    int numsegs, void *hdr, size_t hdrsize, struct note_info_list *notelst,
    size_t notesz, gzFile gzfile)
{
        struct sbuf_drain_core_params params;
        struct note_info *ninfo;
        struct sbuf *sb;
        int error;

        /* Fill in the header. */
        bzero(hdr, hdrsize);
        __elfN(puthdr)(td, hdr, hdrsize, numsegs, notesz);

        params.offset = 0;
        params.active_cred = cred;
        params.file_cred = NOCRED;
        params.td = td;
        params.vp = vp;
#ifdef COMPRESS_USER_CORES
        params.gzfile = gzfile;
#endif
        sb = sbuf_new(NULL, NULL, CORE_BUF_SIZE, SBUF_FIXEDLEN);
        sbuf_set_drain(sb, sbuf_drain_core_output, &params);
        sbuf_start_section(sb, NULL);
        sbuf_bcat(sb, hdr, hdrsize);
        TAILQ_FOREACH(ninfo, notelst, link)
            __elfN(putnote)(ninfo, sb);
        /* Align up to a page boundary for the program segments. */
        sbuf_end_section(sb, -1, PAGE_SIZE, 0);
        error = sbuf_finish(sb);
        sbuf_delete(sb);

        return (error);
}

static void
__elfN(prepare_notes)(struct thread *td, struct note_info_list *list,
    size_t *sizep)
{
        struct proc *p;
        struct thread *thr;
        size_t size;

        p = td->td_proc;
        size = 0;

        size += register_note(list, NT_PRPSINFO, __elfN(note_prpsinfo), p);

        /*
         * To have the debugger select the right thread (LWP) as the initial
         * thread, we dump the state of the thread passed to us in td first.
         * This is the thread that causes the core dump and thus likely to
         * be the right thread one wants to have selected in the debugger.
         */
        thr = td;
        while (thr != NULL) {
                size += register_note(list, NT_PRSTATUS,
                    __elfN(note_prstatus), thr);
                size += register_note(list, NT_FPREGSET,
                    __elfN(note_fpregset), thr);
                size += register_note(list, NT_THRMISC,
                    __elfN(note_thrmisc), thr);
                size += register_note(list, -1,
                    __elfN(note_threadmd), thr);

                thr = (thr == td) ? TAILQ_FIRST(&p->p_threads) :
                    TAILQ_NEXT(thr, td_plist);
                if (thr == td)
                        thr = TAILQ_NEXT(thr, td_plist);
        }

        size += register_note(list, NT_PROCSTAT_PROC,
            __elfN(note_procstat_proc), p);
        size += register_note(list, NT_PROCSTAT_FILES,
            note_procstat_files, p);
        size += register_note(list, NT_PROCSTAT_VMMAP,
            note_procstat_vmmap, p);
        size += register_note(list, NT_PROCSTAT_GROUPS,
            note_procstat_groups, p);
        size += register_note(list, NT_PROCSTAT_UMASK,
            note_procstat_umask, p);
        size += register_note(list, NT_PROCSTAT_RLIMIT,
            note_procstat_rlimit, p);
        size += register_note(list, NT_PROCSTAT_OSREL,
            note_procstat_osrel, p);
        size += register_note(list, NT_PROCSTAT_PSSTRINGS,
            __elfN(note_procstat_psstrings), p);
        size += register_note(list, NT_PROCSTAT_AUXV,
            __elfN(note_procstat_auxv), p);

        *sizep = size;
}

static void
__elfN(puthdr)(struct thread *td, void *hdr, size_t hdrsize, int numsegs,
    size_t notesz)
{
        Elf_Ehdr *ehdr;
        Elf_Phdr *phdr;
        struct phdr_closure phc;

        ehdr = (Elf_Ehdr *)hdr;
        phdr = (Elf_Phdr *)((char *)hdr + sizeof(Elf_Ehdr));

        ehdr->e_ident[EI_MAG0] = ELFMAG0;
        ehdr->e_ident[EI_MAG1] = ELFMAG1;
        ehdr->e_ident[EI_MAG2] = ELFMAG2;
        ehdr->e_ident[EI_MAG3] = ELFMAG3;
        ehdr->e_ident[EI_CLASS] = ELF_CLASS;
        ehdr->e_ident[EI_DATA] = ELF_DATA;
        ehdr->e_ident[EI_VERSION] = EV_CURRENT;
        ehdr->e_ident[EI_OSABI] = ELFOSABI_BSDSUNIX;
        ehdr->e_ident[EI_ABIVERSION] = 0;
        ehdr->e_ident[EI_PAD] = 0;
        ehdr->e_type = ET_CORE;
#if defined(COMPAT_32BIT) && __ELF_WORD_SIZE == 32
        ehdr->e_machine = ELF_ARCH32;
#else
        ehdr->e_machine = ELF_ARCH;
#endif
        ehdr->e_version = EV_CURRENT;
        ehdr->e_entry = 0;
        ehdr->e_phoff = sizeof(Elf_Ehdr);
        ehdr->e_flags = 0;
        ehdr->e_ehsize = sizeof(Elf_Ehdr);
        ehdr->e_phentsize = sizeof(Elf_Phdr);
        ehdr->e_phnum = numsegs + 1;
        ehdr->e_shentsize = sizeof(Elf_Shdr);
        ehdr->e_shnum = 0;
        ehdr->e_shstrndx = SHN_UNDEF;

        /*
         * Fill in the program header entries.
         */

        /* The note segement. */
        phdr->p_type = PT_NOTE;
        phdr->p_offset = hdrsize;
        phdr->p_vaddr = 0;
        phdr->p_paddr = 0;
        phdr->p_filesz = notesz;
        phdr->p_memsz = 0;
        phdr->p_flags = PF_R;
        phdr->p_align = ELF_NOTE_ROUNDSIZE;
        phdr++;

        /* All the writable segments from the program. */
        phc.phdr = phdr;
        phc.offset = round_page(hdrsize + notesz);
        each_writable_segment(td, cb_put_phdr, &phc);
}

static size_t
register_note(struct note_info_list *list, int type, outfunc_t out, void *arg)
{
        struct note_info *ninfo;
        size_t size, notesize;

        size = 0;
        out(arg, NULL, &size);
        ninfo = malloc(sizeof(*ninfo), M_TEMP, M_ZERO | M_WAITOK);
        ninfo->type = type;
        ninfo->outfunc = out;
        ninfo->outarg = arg;
        ninfo->outsize = size;
        TAILQ_INSERT_TAIL(list, ninfo, link);

        if (type == -1)
                return (size);

        notesize = sizeof(Elf_Note) +           /* note header */
            roundup2(9, ELF_NOTE_ROUNDSIZE) +   /* note name ("BSDSUniX") */
            roundup2(size, ELF_NOTE_ROUNDSIZE); /* note description */

        return (notesize);
}

static void
__elfN(putnote)(struct note_info *ninfo, struct sbuf *sb)
{
        Elf_Note note;
        ssize_t old_len;

        if (ninfo->type == -1) {
                ninfo->outfunc(ninfo->outarg, sb, &ninfo->outsize);
                return;
        }

        note.n_namesz = 9; /* strlen("BSDSUniX") + 1 */
        note.n_descsz = ninfo->outsize;
        note.n_type = ninfo->type;

        sbuf_bcat(sb, &note, sizeof(note));
        sbuf_start_section(sb, &old_len);
        sbuf_bcat(sb, "BSDSUniX", note.n_namesz);
        sbuf_end_section(sb, old_len, ELF_NOTE_ROUNDSIZE, 0);
        if (note.n_descsz == 0)
                return;
        sbuf_start_section(sb, &old_len);
        ninfo->outfunc(ninfo->outarg, sb, &ninfo->outsize);
        sbuf_end_section(sb, old_len, ELF_NOTE_ROUNDSIZE, 0);
}

/*
 * Miscellaneous note out functions.
 */

#if defined(COMPAT_32BIT) && __ELF_WORD_SIZE == 32
#include <compat/compat32bit/compat32bit.h>

typedef struct prstatus32 elf_prstatus_t;
typedef struct prpsinfo32 elf_prpsinfo_t;
typedef struct fpreg32 elf_prfpregset_t;
typedef struct fpreg32 elf_fpregset_t;
typedef struct reg32 elf_gregset_t;
typedef struct thrmisc32 elf_thrmisc_t;
#define ELF_KERN_PROC_MASK      KERN_PROC_MASK32
typedef struct kinfo_proc32 elf_kinfo_proc_t;
typedef uint32_t elf_ps_strings_t;
#else
typedef prstatus_t elf_prstatus_t;
typedef prpsinfo_t elf_prpsinfo_t;
typedef prfpregset_t elf_prfpregset_t;
typedef prfpregset_t elf_fpregset_t;
typedef gregset_t elf_gregset_t;
typedef thrmisc_t elf_thrmisc_t;
#define ELF_KERN_PROC_MASK      0
typedef struct kinfo_proc elf_kinfo_proc_t;
typedef vm_offset_t elf_ps_strings_t;
#endif

static void
__elfN(note_prpsinfo)(void *arg, struct sbuf *sb, size_t *sizep)
{
        struct proc *p;
        elf_prpsinfo_t *psinfo;

        p = (struct proc *)arg;
        if (sb != NULL) {
                KASSERT(*sizep == sizeof(*psinfo), ("invalid size"));
                psinfo = malloc(sizeof(*psinfo), M_TEMP, M_ZERO | M_WAITOK);
                psinfo->pr_version = PRPSINFO_VERSION;
                psinfo->pr_psinfosz = sizeof(elf_prpsinfo_t);
                strlcpy(psinfo->pr_fname, p->p_comm, sizeof(psinfo->pr_fname));
                /*
                 * XXX - We don't fill in the command line arguments properly
                 * yet.
                 */
                strlcpy(psinfo->pr_psargs, p->p_comm,
                    sizeof(psinfo->pr_psargs));

                sbuf_bcat(sb, psinfo, sizeof(*psinfo));
                free(psinfo, M_TEMP);
        }
        *sizep = sizeof(*psinfo);
}

static void
__elfN(note_prstatus)(void *arg, struct sbuf *sb, size_t *sizep)
{
        struct thread *td;
        elf_prstatus_t *status;

        td = (struct thread *)arg;
        if (sb != NULL) {
                KASSERT(*sizep == sizeof(*status), ("invalid size"));
                status = malloc(sizeof(*status), M_TEMP, M_ZERO | M_WAITOK);
                status->pr_version = PRSTATUS_VERSION;
                status->pr_statussz = sizeof(elf_prstatus_t);
                status->pr_gregsetsz = sizeof(elf_gregset_t);
                status->pr_fpregsetsz = sizeof(elf_fpregset_t);
                status->pr_osreldate = osreldate;
                status->pr_cursig = td->td_proc->p_sig;
                status->pr_pid = td->td_tid;
#if defined(COMPAT_32BIT) && __ELF_WORD_SIZE == 32
                fill_regs32(td, &status->pr_reg);
#else
                fill_regs(td, &status->pr_reg);
#endif
                sbuf_bcat(sb, status, sizeof(*status));
                free(status, M_TEMP);
        }
        *sizep = sizeof(*status);
}

static void
__elfN(note_fpregset)(void *arg, struct sbuf *sb, size_t *sizep)
{
        struct thread *td;
        elf_prfpregset_t *fpregset;

        td = (struct thread *)arg;
        if (sb != NULL) {
                KASSERT(*sizep == sizeof(*fpregset), ("invalid size"));
                fpregset = malloc(sizeof(*fpregset), M_TEMP, M_ZERO | M_WAITOK);
#if defined(COMPAT_32BIT) && __ELF_WORD_SIZE == 32
                fill_fpregs32(td, fpregset);
#else
                fill_fpregs(td, fpregset);
#endif
                sbuf_bcat(sb, fpregset, sizeof(*fpregset));
                free(fpregset, M_TEMP);
        }
        *sizep = sizeof(*fpregset);
}

static void
__elfN(note_thrmisc)(void *arg, struct sbuf *sb, size_t *sizep)
{
        struct thread *td;
        elf_thrmisc_t thrmisc;

        td = (struct thread *)arg;
        if (sb != NULL) {
                KASSERT(*sizep == sizeof(thrmisc), ("invalid size"));
                bzero(&thrmisc._pad, sizeof(thrmisc._pad));
                strcpy(thrmisc.pr_tname, td->td_name);
                sbuf_bcat(sb, &thrmisc, sizeof(thrmisc));
        }
        *sizep = sizeof(thrmisc);
}

/*
 * Allow for MD specific notes, as well as any MD
 * specific preparations for writing MI notes.
 */
static void
__elfN(note_threadmd)(void *arg, struct sbuf *sb, size_t *sizep)
{
        struct thread *td;
        void *buf;
        size_t size;

        td = (struct thread *)arg;
        size = *sizep;
        if (size != 0 && sb != NULL)
                buf = malloc(size, M_TEMP, M_ZERO | M_WAITOK);
        else
                buf = NULL;
        size = 0;
        __elfN(dump_thread)(td, buf, &size);
        KASSERT(*sizep == size, ("invalid size"));
        if (size != 0 && sb != NULL)
                sbuf_bcat(sb, buf, size);
        free(buf, M_TEMP);
        *sizep = size;
}

#ifdef KINFO_PROC_SIZE
CTASSERT(sizeof(struct kinfo_proc) == KINFO_PROC_SIZE);
#endif

static void
__elfN(note_procstat_proc)(void *arg, struct sbuf *sb, size_t *sizep)
{
        struct proc *p;
        size_t size;
        int structsize;

        p = (struct proc *)arg;
        size = sizeof(structsize) + p->p_numthreads *
            sizeof(elf_kinfo_proc_t);

        if (sb != NULL) {
                KASSERT(*sizep == size, ("invalid size"));
                structsize = sizeof(elf_kinfo_proc_t);
                sbuf_bcat(sb, &structsize, sizeof(structsize));
                PROC_LOCK(p);
                kern_proc_out(p, sb, ELF_KERN_PROC_MASK);
        }
        *sizep = size;
}

#ifdef KINFO_FILE_SIZE
CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE);
#endif

static void
note_procstat_files(void *arg, struct sbuf *sb, size_t *sizep)
{
        struct proc *p;
        size_t size;
        int structsize;

        p = (struct proc *)arg;
        if (sb == NULL) {
                size = 0;
                sb = sbuf_new(NULL, NULL, 128, SBUF_FIXEDLEN);
                sbuf_set_drain(sb, sbuf_drain_count, &size);
                sbuf_bcat(sb, &structsize, sizeof(structsize));
                PROC_LOCK(p);
                kern_proc_filedesc_out(p, sb, -1);
                sbuf_finish(sb);
                sbuf_delete(sb);
                *sizep = size;
        } else {
                structsize = sizeof(struct kinfo_file);
                sbuf_bcat(sb, &structsize, sizeof(structsize));
                PROC_LOCK(p);
                kern_proc_filedesc_out(p, sb, -1);
        }
}

#ifdef KINFO_VMENTRY_SIZE
CTASSERT(sizeof(struct kinfo_vmentry) == KINFO_VMENTRY_SIZE);
#endif

static void
note_procstat_vmmap(void *arg, struct sbuf *sb, size_t *sizep)
{
        struct proc *p;
        size_t size;
        int structsize;

        p = (struct proc *)arg;
        if (sb == NULL) {
                size = 0;
                sb = sbuf_new(NULL, NULL, 128, SBUF_FIXEDLEN);
                sbuf_set_drain(sb, sbuf_drain_count, &size);
                sbuf_bcat(sb, &structsize, sizeof(structsize));
                PROC_LOCK(p);
                kern_proc_vmmap_out(p, sb);
                sbuf_finish(sb);
                sbuf_delete(sb);
                *sizep = size;
        } else {
                structsize = sizeof(struct kinfo_vmentry);
                sbuf_bcat(sb, &structsize, sizeof(structsize));
                PROC_LOCK(p);
                kern_proc_vmmap_out(p, sb);
        }
}

static void
note_procstat_groups(void *arg, struct sbuf *sb, size_t *sizep)
{
        struct proc *p;
        size_t size;
        int structsize;

        p = (struct proc *)arg;
        size = sizeof(structsize) + p->p_ucred->cr_ngroups * sizeof(gid_t);
        if (sb != NULL) {
                KASSERT(*sizep == size, ("invalid size"));
                structsize = sizeof(gid_t);
                sbuf_bcat(sb, &structsize, sizeof(structsize));
                sbuf_bcat(sb, p->p_ucred->cr_groups, p->p_ucred->cr_ngroups *
                    sizeof(gid_t));
        }
        *sizep = size;
}

static void
note_procstat_umask(void *arg, struct sbuf *sb, size_t *sizep)
{
        struct proc *p;
        size_t size;
        int structsize;

        p = (struct proc *)arg;
        size = sizeof(structsize) + sizeof(p->p_fd->fd_cmask);
        if (sb != NULL) {
                KASSERT(*sizep == size, ("invalid size"));
                structsize = sizeof(p->p_fd->fd_cmask);
                sbuf_bcat(sb, &structsize, sizeof(structsize));
                sbuf_bcat(sb, &p->p_fd->fd_cmask, sizeof(p->p_fd->fd_cmask));
        }
        *sizep = size;
}

static void
note_procstat_rlimit(void *arg, struct sbuf *sb, size_t *sizep)
{
        struct proc *p;
        struct rlimit rlim[RLIM_NLIMITS];
        size_t size;
        int structsize, i;

        p = (struct proc *)arg;
        size = sizeof(structsize) + sizeof(rlim);
        if (sb != NULL) {
                KASSERT(*sizep == size, ("invalid size"));
                structsize = sizeof(rlim);
                sbuf_bcat(sb, &structsize, sizeof(structsize));
                PROC_LOCK(p);
                for (i = 0; i < RLIM_NLIMITS; i++)
                        lim_rlimit(p, i, &rlim[i]);
                PROC_UNLOCK(p);
                sbuf_bcat(sb, rlim, sizeof(rlim));
        }
        *sizep = size;
}

static void
note_procstat_osrel(void *arg, struct sbuf *sb, size_t *sizep)
{
        struct proc *p;
        size_t size;
        int structsize;

        p = (struct proc *)arg;
        size = sizeof(structsize) + sizeof(p->p_osrel);
        if (sb != NULL) {
                KASSERT(*sizep == size, ("invalid size"));
                structsize = sizeof(p->p_osrel);
                sbuf_bcat(sb, &structsize, sizeof(structsize));
                sbuf_bcat(sb, &p->p_osrel, sizeof(p->p_osrel));
        }
        *sizep = size;
}

static void
__elfN(note_procstat_psstrings)(void *arg, struct sbuf *sb, size_t *sizep)
{
        struct proc *p;
        elf_ps_strings_t ps_strings;
        size_t size;
        int structsize;

        p = (struct proc *)arg;
        size = sizeof(structsize) + sizeof(ps_strings);
        if (sb != NULL) {
                KASSERT(*sizep == size, ("invalid size"));
                structsize = sizeof(ps_strings);
#if defined(COMPAT_32BIT) && __ELF_WORD_SIZE == 32
                ps_strings = PTROUT(p->p_sysent->sv_psstrings);
#else
                ps_strings = p->p_sysent->sv_psstrings;
#endif
                sbuf_bcat(sb, &structsize, sizeof(structsize));
                sbuf_bcat(sb, &ps_strings, sizeof(ps_strings));
        }
        *sizep = size;
}

static void
__elfN(note_procstat_auxv)(void *arg, struct sbuf *sb, size_t *sizep)
{
        struct proc *p;
        size_t size;
        int structsize;

        p = (struct proc *)arg;
        if (sb == NULL) {
                size = 0;
                sb = sbuf_new(NULL, NULL, 128, SBUF_FIXEDLEN);
                sbuf_set_drain(sb, sbuf_drain_count, &size);
                sbuf_bcat(sb, &structsize, sizeof(structsize));
                PHOLD(p);
                proc_getauxv(curthread, p, sb);
                PRELE(p);
                sbuf_finish(sb);
                sbuf_delete(sb);
                *sizep = size;
        } else {
                structsize = sizeof(Elf_Auxinfo);
                sbuf_bcat(sb, &structsize, sizeof(structsize));
                PHOLD(p);
                proc_getauxv(curthread, p, sb);
                PRELE(p);
        }
}

static boolean_t
__elfN(parse_notes)(struct image_params *imgp, Elf_Brandnote *checknote,
    int32_t *osrel, const Elf_Phdr *pnote)
{
        const Elf_Note *note, *note0, *note_end;
        const char *note_name;
        int i;

        if (pnote == NULL || pnote->p_offset > PAGE_SIZE ||
            pnote->p_filesz > PAGE_SIZE - pnote->p_offset)
                return (FALSE);

        note = note0 = (const Elf_Note *)(imgp->image_header + pnote->p_offset);
        note_end = (const Elf_Note *)(imgp->image_header +
            pnote->p_offset + pnote->p_filesz);
        for (i = 0; i < 100 && note >= note0 && note < note_end; i++) {
                if (!aligned(note, Elf32_Addr) || (const char *)note_end -
                    (const char *)note < sizeof(Elf_Note))
                        return (FALSE);
                if (note->n_namesz != checknote->hdr.n_namesz ||
                    note->n_descsz != checknote->hdr.n_descsz ||
                    note->n_type != checknote->hdr.n_type)
                        goto nextnote;
                note_name = (const char *)(note + 1);
                if (note_name + checknote->hdr.n_namesz >=
                    (const char *)note_end || strncmp(checknote->vendor,
                    note_name, checknote->hdr.n_namesz) != 0)
                        goto nextnote;

                /*
                 * Fetch the osreldate for binary
                 * from the ELF OSABI-note if necessary.
                 */
                if ((checknote->flags & BN_TRANSLATE_OSREL) != 0 &&
                    checknote->trans_osrel != NULL)
                        return (checknote->trans_osrel(note, osrel));
                return (TRUE);

nextnote:
                note = (const Elf_Note *)((const char *)(note + 1) +
                    roundup2(note->n_namesz, ELF_NOTE_ROUNDSIZE) +
                    roundup2(note->n_descsz, ELF_NOTE_ROUNDSIZE));
        }

        return (FALSE);
}

/*
 * Try to find the appropriate ABI-note section for checknote,
 * fetch the osreldate for binary from the ELF OSABI-note. Only the
 * first page of the image is searched, the same as for headers.
 */
static boolean_t
__elfN(check_note)(struct image_params *imgp, Elf_Brandnote *checknote,
    int32_t *osrel)
{
        const Elf_Phdr *phdr;
        const Elf_Ehdr *hdr;
        int i;

        hdr = (const Elf_Ehdr *)imgp->image_header;
        phdr = (const Elf_Phdr *)(imgp->image_header + hdr->e_phoff);

        for (i = 0; i < hdr->e_phnum; i++) {
                if (phdr[i].p_type == PT_NOTE &&
                    __elfN(parse_notes)(imgp, checknote, osrel, &phdr[i]))
                        return (TRUE);
        }
        return (FALSE);

}

/*
 * Tell kern_execve.c about it, with a little help from the linker.
 */
static struct execsw __elfN(execsw) = {
        __CONCAT(exec_, __elfN(imgact)),
        __XSTRING(__CONCAT(ELF, __ELF_WORD_SIZE))
};
EXEC_SET(__CONCAT(elf, __ELF_WORD_SIZE), __elfN(execsw));

#ifdef COMPRESS_USER_CORES
/*
 * Compress and write out a core segment for a user process.
 *
 * 'inbuf' is the starting address of a VM segment in the process' address
 * space that is to be compressed and written out to the core file.  'dest_buf'
 * is a buffer in the kernel's address space.  The segment is copied from 
 * 'inbuf' to 'dest_buf' first before being processed by the compression
 * routine gzwrite().  This copying is necessary because the content of the VM
 * segment may change between the compression pass and the crc-computation pass
 * in gzwrite().  This is because realtime threads may preempt the UNIX kernel.
 *
 * If inbuf is NULL it is assumed that data is already copied to 'dest_buf'.
 */
static int
compress_core (gzFile file, char *inbuf, char *dest_buf, unsigned int len,
    struct thread *td)
{
        int len_compressed;
        int error = 0;
        unsigned int chunk_len;

        while (len) {
                if (inbuf != NULL) {
                        chunk_len = (len > CORE_BUF_SIZE) ? CORE_BUF_SIZE : len;
                        copyin(inbuf, dest_buf, chunk_len);
                        inbuf += chunk_len;
                } else {
                        chunk_len = len;
                }
                len_compressed = gzwrite(file, dest_buf, chunk_len);

                EVENTHANDLER_INVOKE(app_coredump_progress, td, len_compressed);

                if ((unsigned int)len_compressed != chunk_len) {
                        log(LOG_WARNING,
                            "compress_core: length mismatch (0x%x returned, "
                            "0x%x expected)\n", len_compressed, chunk_len);
                        EVENTHANDLER_INVOKE(app_coredump_error, td,
                            "compress_core: length mismatch %x -> %x",
                            chunk_len, len_compressed);
                        error = EFAULT;
                        break;
                }
                len -= chunk_len;
                maybe_yield();
        }

        return (error);
}
#endif /* COMPRESS_USER_CORES */

static vm_prot_t
__elfN(trans_prot)(Elf_Word flags)
{
        vm_prot_t prot;

        prot = 0;
        if (flags & PF_X)
                prot |= VM_PROT_EXECUTE;
        if (flags & PF_W)
                prot |= VM_PROT_WRITE;
        if (flags & PF_R)
                prot |= VM_PROT_READ;
#if __ELF_WORD_SIZE == 32
#if defined(__amd64__) || defined(__ia64__)
        if (i386_read_exec && (flags & PF_R))
                prot |= VM_PROT_EXECUTE;
#endif
#endif
        return (prot);
}

static Elf_Word
__elfN(untrans_prot)(vm_prot_t prot)
{
        Elf_Word flags;

        flags = 0;
        if (prot & VM_PROT_EXECUTE)
                flags |= PF_X;
        if (prot & VM_PROT_READ)
                flags |= PF_R;
        if (prot & VM_PROT_WRITE)
                flags |= PF_W;
        return (flags);
}