/*-
 * 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.
 *
 * $FreeBSD: src/sys/kern/imgact_elf.c,v 1.73.2.13 2002/12/28 19:49:41 dillon Exp $
 */

#include <sys/param.h>
#include <sys/exec.h>
#include <sys/fcntl.h>
#include <sys/file.h>
#include <sys/imgact.h>
#include <sys/imgact_elf.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mman.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/nlookup.h>
#include <sys/pioctl.h>
#include <sys/procfs.h>
#include <sys/resourcevar.h>
#include <sys/signalvar.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/sysctl.h>
#include <sys/sysent.h>
#include <sys/vnode.h>
#include <sys/eventhandler.h>

#include <cpu/lwbuf.h>

#include <vm/vm.h>
#include <vm/vm_kern.h>
#include <vm/vm_param.h>
#include <vm/pmap.h>
#include <sys/lock.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>
#include <sys/mount.h>
#include <sys/ckpt.h>

#define OLD_EI_BRAND    8
#define truncps(va,ps)  rounddown2(va, ps)
#define aligned(a,t)    (truncps((u_long)(a), sizeof(t)) == (u_long)(a))

static int __elfN(check_header)(const Elf_Ehdr *hdr);
static Elf_Brandinfo *__elfN(get_brandinfo)(struct image_params *imgp,
    const char *interp, int32_t *osrel);
static int __elfN(load_file)(struct proc *p, const char *file, u_long *addr,
    u_long *entry);
static int __elfN(load_section)(struct proc *p,
    struct vmspace *vmspace, struct vnode *vp,
    vm_offset_t offset, caddr_t vmaddr, size_t memsz, size_t filsz,
    vm_prot_t prot);
static int __CONCAT(exec_, __elfN(imgact))(struct image_params *imgp);
static boolean_t __elfN(bsd_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);
static boolean_t check_PT_NOTE(struct image_params *imgp,
    Elf_Brandnote *checknote, int32_t *osrel, const Elf_Phdr * pnote);
static boolean_t extract_interpreter(struct image_params *imgp,
    const Elf_Phdr *pinterpreter, char *data);
static u_long pie_base_hint(struct proc *p);

static int elf_legacy_coredump = 0;
static int __elfN(fallback_brand) = -1;
static int elf_pie_base_mmap = 0;
#if defined(__x86_64__)
SYSCTL_NODE(_kern, OID_AUTO, elf64, CTLFLAG_RW, 0, "");
SYSCTL_INT(_debug, OID_AUTO, elf64_legacy_coredump, CTLFLAG_RW,
    &elf_legacy_coredump, 0, "legacy coredump mode");
SYSCTL_INT(_kern_elf64, OID_AUTO, fallback_brand, CTLFLAG_RW,
    &elf64_fallback_brand, 0, "ELF64 brand of last resort");
TUNABLE_INT("kern.elf64.fallback_brand", &elf64_fallback_brand);
SYSCTL_INT(_kern_elf64, OID_AUTO, pie_base_mmap, CTLFLAG_RW,
    &elf_pie_base_mmap, 0,
    "choose a base address for PIE as if it is mapped with mmap()");
TUNABLE_INT("kern.elf64.pie_base_mmap", &elf_pie_base_mmap);
#else /* i386 assumed */
SYSCTL_NODE(_kern, OID_AUTO, elf32, CTLFLAG_RW, 0, "");
SYSCTL_INT(_debug, OID_AUTO, elf32_legacy_coredump, CTLFLAG_RW,
    &elf_legacy_coredump, 0, "legacy coredump mode");
SYSCTL_INT(_kern_elf32, OID_AUTO, fallback_brand, CTLFLAG_RW,
    &elf32_fallback_brand, 0, "ELF32 brand of last resort");
TUNABLE_INT("kern.elf32.fallback_brand", &elf32_fallback_brand);
SYSCTL_INT(_kern_elf32, OID_AUTO, pie_base_mmap, CTLFLAG_RW,
    &elf_pie_base_mmap, 0,
    "choose a base address for PIE as if it is mapped with mmap()");
TUNABLE_INT("kern.elf32.pie_base_mmap", &elf_pie_base_mmap);
#endif

static Elf_Brandinfo *elf_brand_list[MAX_BRANDS];

static const char DRAGONFLY_ABI_VENDOR[] = "DragonFly";

Elf_Brandnote __elfN(dragonfly_brandnote) = {
        .hdr.n_namesz   = sizeof(DRAGONFLY_ABI_VENDOR),
        .hdr.n_descsz   = sizeof(int32_t),
        .hdr.n_type     = 1,
        .vendor         = DRAGONFLY_ABI_VENDOR,
        .flags          = BN_TRANSLATE_OSREL,
        .trans_osrel    = __elfN(bsd_trans_osrel),
};

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) {
                uprintf("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);
}

/*
 * Check if an elf brand is being used anywhere in the system.
 *
 * Used by the linux emulation module unloader.  This isn't safe from
 * races.
 */
struct elf_brand_inuse_info {
        int rval;
        Elf_Brandinfo *entry;
};

static int elf_brand_inuse_callback(struct proc *p, void *data);

int
__elfN(brand_inuse)(Elf_Brandinfo *entry)
{
        struct elf_brand_inuse_info info;

        info.rval = FALSE;
        info.entry = entry;
        allproc_scan(elf_brand_inuse_callback, &info, 0);
        return (info.rval);
}

static
int
elf_brand_inuse_callback(struct proc *p, void *data)
{
        struct elf_brand_inuse_info *info = data;

        if (p->p_sysent == info->entry->sysvec) {
                info->rval = TRUE;
                return (-1);
        }
        return (0);
}

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_ehsize != sizeof(Elf_Ehdr) ||
            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(load_section)(struct proc *p, struct vmspace *vmspace, struct vnode *vp,
                 vm_offset_t offset, caddr_t vmaddr, size_t memsz,
                 size_t filsz, vm_prot_t prot)
{
        size_t map_len;
        vm_offset_t map_addr;
        int error, rv, cow;
        int count;
        int shared;
        size_t copy_len;
        vm_object_t object;
        vm_offset_t file_addr;

        object = vp->v_object;
        error = 0;

        /*
         * In most cases we will be able to use a shared lock on the
         * object we are inserting into the map.  The lock will be
         * upgraded in situations where new VM pages must be allocated.
         */
        vm_object_hold_shared(object);
        shared = 1;

        /*
         * 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 > vp->v_filesize || filsz > memsz) {
                uprintf("elf_load_section: truncated ELF file\n");
                vm_object_drop(object);
                return (ENOEXEC);
        }

        map_addr = trunc_page((vm_offset_t)vmaddr);
        file_addr = trunc_page(offset);

        /*
         * 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(offset+filsz) - file_addr;
        else
                map_len = round_page(offset+filsz) - file_addr;

        if (map_len != 0) {
                vm_object_reference_locked(object);

                /* cow flags: don't dump readonly sections in core */
                cow = COWF_COPY_ON_WRITE | COWF_PREFAULT;
                if ((prot & VM_PROT_WRITE) == 0)
                        cow |= COWF_DISABLE_COREDUMP;
                if (shared == 0)
                        cow |= COWF_PREFAULT_RELOCK;

                count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
                vm_map_lock(&vmspace->vm_map);
                rv = vm_map_insert(&vmspace->vm_map, &count,
                                      object, NULL,
                                      file_addr, NULL,  /* file offset */
                                      map_addr,         /* virtual start */
                                      map_addr + map_len,/* virtual end */
                                      VM_MAPTYPE_NORMAL,
                                      VM_SUBSYS_IMGACT,
                                      prot, VM_PROT_ALL, cow);
                vm_map_unlock(&vmspace->vm_map);
                vm_map_entry_release(count);

                /*
                 * NOTE: Object must have a hold ref when calling
                 * vm_object_deallocate().
                 */
                if (rv != KERN_SUCCESS) {
                        vm_object_deallocate_locked(object);
                        vm_object_drop(object);
                        return (EINVAL);
                }

                /* we can stop now if we've covered it all */
                if (memsz == filsz) {
                        vm_object_drop(object);
                        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(offset + filsz);
        map_addr = trunc_page((vm_offset_t)vmaddr + filsz);
        map_len = round_page((vm_offset_t)vmaddr + memsz) - map_addr;

        /* This had damn well better be true! */
        if (map_len != 0) {
                count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
                vm_map_lock(&vmspace->vm_map);
                rv = vm_map_insert(&vmspace->vm_map, &count,
                                        NULL, NULL,
                                        0, NULL,
                                        map_addr,
                                        map_addr + map_len,
                                        VM_MAPTYPE_NORMAL,
                                        VM_SUBSYS_IMGACT,
                                        VM_PROT_ALL, VM_PROT_ALL, 0);
                vm_map_unlock(&vmspace->vm_map);
                vm_map_entry_release(count);
                if (rv != KERN_SUCCESS) {
                        vm_object_drop(object);
                        return (EINVAL);
                }
        }

        if (copy_len != 0) {
                struct lwbuf *lwb;
                struct lwbuf lwb_cache;
                vm_page_t m;

                m = vm_fault_object_page(object, trunc_page(offset + filsz),
                                         VM_PROT_READ, 0, &shared, &error);
                vm_object_drop(object);
                if (m) {
                        lwb = lwbuf_alloc(m, &lwb_cache);
                        error = copyout((caddr_t)lwbuf_kva(lwb),
                                        (caddr_t)map_addr, copy_len);
                        lwbuf_free(lwb);
                        vm_page_unhold(m);
                }
        } else {
                vm_object_drop(object);
        }

        /*
         * set it to the specified protection
         */
        if (error == 0) {
                vm_map_protect(&vmspace->vm_map,
                               map_addr, map_addr + map_len,
                               prot, FALSE);
        }
        return (error);
}

/*
 * 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)
{
        struct {
                struct nlookupdata nd;
                struct vattr_lite lva;
                struct image_params image_params;
        } *tempdata;
        const Elf_Ehdr *hdr = NULL;
        const Elf_Phdr *phdr = NULL;
        struct nlookupdata *nd;
        struct vmspace *vmspace = p->p_vmspace;
        struct vattr_lite *lvap;
        struct image_params *imgp;
        struct mount *topmnt;
        vm_prot_t prot;
        u_long rbase;
        u_long base_addr = 0;
        int error, i, numsegs;

        tempdata = kmalloc(sizeof(*tempdata), M_TEMP, M_WAITOK);
        nd = &tempdata->nd;
        lvap = &tempdata->lva;
        imgp = &tempdata->image_params;

        /*
         * Initialize part of the common data
         */
        imgp->proc = p;
        imgp->lvap = lvap;
        imgp->firstpage = NULL;
        imgp->image_header = NULL;
        imgp->vp = NULL;

        error = nlookup_init(nd, file, UIO_SYSSPACE, NLC_FOLLOW);
        if (error == 0)
                error = nlookup(nd);
        if (error == 0)
                error = cache_vget(&nd->nl_nch, nd->nl_cred,
                                   LK_SHARED, &imgp->vp);
        topmnt = nd->nl_nch.mount;
        nlookup_done(nd);
        if (error)
                goto fail;

        /*
         * Check permissions, modes, uid, etc on the file, and "open" it.
         */
        error = exec_check_permissions(imgp, topmnt);
        if (error) {
                vn_unlock(imgp->vp);
                goto fail;
        }

        error = exec_map_first_page(imgp);
        /*
         * Also make certain that the interpreter stays the same, so set
         * its VTEXT flag, too.
         */
        if (error == 0)
                vsetflags(imgp->vp, VTEXT);
        vn_unlock(imgp->vp);
        if (error)
                goto fail;

        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      */
        /*    (multiplication of two Elf_Half fields will not overflow) */
        if ((hdr->e_phoff > PAGE_SIZE) ||
            (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);
                        error = __elfN(load_section)(
                                    p, vmspace, imgp->vp,
                                    phdr[i].p_offset,
                                    (caddr_t)phdr[i].p_vaddr +
                                    rbase,
                                    phdr[i].p_memsz,
                                    phdr[i].p_filesz, prot);
                        if (error != 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 (imgp->vp) {
                vrele(imgp->vp);
                imgp->vp = NULL;
        }
        kfree(tempdata, M_TEMP);

        return (error);
}

static Elf_Brandinfo *
__elfN(get_brandinfo)(struct image_params *imgp, const char *interp,
    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 within 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 &&
                            strcmp(interp, bi->interp_path) == 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
__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 = 0, entry = 0, proghdr = 0;
        int32_t osrel = 0;
        int error = 0, i, n;
        boolean_t failure;
        char *interp = NULL;
        const char *newinterp = NULL;
        Elf_Brandinfo *brand_info;
        char *path;

        /*
         * Do we have a valid ELF header ?
         *
         * Only allow ET_EXEC & ET_DYN here, reject ET_DYN later if a particular
         * brand doesn't support it.  Both DragonFly platforms do by default.
         */
        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) ||
            (hdr->e_phoff + hdr->e_phentsize * hdr->e_phnum) > PAGE_SIZE) {
                /* 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++) {
                if (phdr[i].p_type == PT_LOAD) {
                        if (n == 0)
                                baddr = phdr[i].p_vaddr;
                        n++;
                        continue;
                }
                if (phdr[i].p_type == PT_INTERP) {
                        /*
                         * If interp is already defined there are more than
                         * one PT_INTERP program headers present.  Take only
                         * the first one and ignore the rest.
                         */
                        if (interp != NULL)
                                continue;

                        if (phdr[i].p_filesz == 0 ||
                            phdr[i].p_filesz > PAGE_SIZE ||
                            phdr[i].p_filesz > MAXPATHLEN)
                                return (ENOEXEC);

                        interp = kmalloc(phdr[i].p_filesz, M_TEMP, M_WAITOK);
                        failure = extract_interpreter(imgp, &phdr[i], interp);
                        if (failure) {
                                kfree(interp, M_TEMP);
                                return (ENOEXEC);
                        }
                        continue;
                }
        }
        
        brand_info = __elfN(get_brandinfo)(imgp, interp, &osrel);
        if (brand_info == NULL) {
                uprintf("ELF binary type \"%u\" not known.\n",
                    hdr->e_ident[EI_OSABI]);
                if (interp != NULL)
                        kfree(interp, M_TEMP);
                return (ENOEXEC);
        }
        if (hdr->e_type == ET_DYN) {
                if ((brand_info->flags & BI_CAN_EXEC_DYN) == 0) {
                        if (interp != NULL)
                                kfree(interp, M_TEMP);
                        return (ENOEXEC);
                }
                /*
                 * If p_vaddr field of PT_LOAD program header is zero and type of an
                 * executale is ET_DYN, then it must be a position independent
                 * executable (PIE). In this case the system needs to pick a base
                 * address for us. Set et_dyn_addr to non-zero and choose the actual
                 * address when we are ready.
                 */
                if (baddr == 0)
                        et_dyn_addr = 1;
        }

        if (interp != NULL && brand_info->interp_newpath != NULL)
                newinterp = brand_info->interp_newpath;

        exec_new_vmspace(imgp, NULL);

        /*
         * Yeah, I'm paranoid.  There is every reason in the world to get
         * VTEXT now since from here on out, there are places we can have
         * a context switch.  Better safe than sorry; I really don't want
         * the file to change while it's being loaded.
         */
        vsetflags(imgp->vp, VTEXT);

        vmspace = imgp->proc->p_vmspace;
        /* Choose the base address for dynamic executables if we need to. */
        if (et_dyn_addr)
                et_dyn_addr = pie_base_hint(imgp->proc);

        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)(
                                        imgp->proc,
                                        vmspace,
                                        imgp->vp,
                                        phdr[i].p_offset,
                                        (caddr_t)phdr[i].p_vaddr + et_dyn_addr,
                                        phdr[i].p_memsz,
                                        phdr[i].p_filesz,
                                        prot)) != 0) {
                                if (interp != NULL)
                                        kfree (interp, M_TEMP);
                                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);

                        /*
                         * Is this .text or .data?  We can't use
                         * VM_PROT_WRITE or VM_PROT_EXEC, it breaks the
                         * alpha terribly and possibly does other bad
                         * things so we stick to the old way of figuring
                         * it out:  If the segment contains the program
                         * entry point, it's a text segment, otherwise it
                         * is a data segment.
                         *
                         * 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 (hdr->e_entry >= phdr[i].p_vaddr &&
                            hdr->e_entry < (phdr[i].p_vaddr +
                            phdr[i].p_memsz)) {
                                text_size = seg_size;
                                text_addr = seg_addr;
                                entry = (u_long)hdr->e_entry + et_dyn_addr;
                        } else {
                                data_size = seg_size;
                                data_addr = seg_addr;
                        }
                        total_size += seg_size;

                        /*
                         * Check limits.  It should be safe to check the
                         * limits after loading the segment since we do
                         * not actually fault in all the segment's pages.
                         */
                        if (data_size >
                            imgp->proc->p_rlimit[RLIMIT_DATA].rlim_cur ||
                            text_size > maxtsiz ||
                            total_size >
                            imgp->proc->p_rlimit[RLIMIT_VMEM].rlim_cur) {
                                if (interp != NULL)
                                        kfree(interp, M_TEMP);
                                error = ENOMEM;
                                return (error);
                        }
                        break;
                case PT_PHDR:   /* Program header table info */
                        proghdr = phdr[i].p_vaddr + et_dyn_addr;
                        break;
                default:
                        break;
                }
        }

        vmspace->vm_tsize = text_size;          /* in bytes */
        vmspace->vm_taddr = (caddr_t)(uintptr_t)text_addr;
        vmspace->vm_dsize = data_size;          /* in bytes */
        vmspace->vm_daddr = (caddr_t)(uintptr_t)data_addr;

        addr = ELF_RTLD_ADDR(vmspace);

        imgp->entry_addr = entry;

        imgp->proc->p_sysent = brand_info->sysvec;

        if (interp != NULL) {
                int have_interp = FALSE;
                if (brand_info->emul_path != NULL &&
                    brand_info->emul_path[0] != '\0') {
                        path = kmalloc(MAXPATHLEN, M_TEMP, M_WAITOK);
                        ksnprintf(path, MAXPATHLEN, "%s%s",
                            brand_info->emul_path, interp);
                        error = __elfN(load_file)(imgp->proc, path, &addr,
                            &imgp->entry_addr);
                        kfree(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);
                        if (error == 0)
                                have_interp = TRUE;
                }
                if (!have_interp) {
                        error = __elfN(load_file)(imgp->proc, interp, &addr,
                            &imgp->entry_addr);
                }
                if (error != 0) {
                        uprintf("ELF interpreter %s not found\n", interp);
                        kfree(interp, M_TEMP);
                        return (error);
                }
                kfree(interp, M_TEMP);
        } else
                addr = et_dyn_addr;

        /*
         * Construct auxargs table (used by the fixup routine)
         */
        elf_auxargs = kmalloc(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->proc->p_osrel = osrel;

        return (error);
}

int
__elfN(dragonfly_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);
        AUXARGS_ENTRY(pos, AT_NULL, 0);

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

        base--;
        suword64(base, (long)imgp->args->argc);
        *stack_base = (register_t *)base;
        return (0);
}

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

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

/* Closure for cb_put_phdr(). */
struct phdr_closure {
        Elf_Phdr *phdr;         /* Program header to fill in (incremented) */
        Elf_Phdr *phdr_max;     /* Pointer bound for error check */
        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 vsize;           /* Total size of all writable segments. */
};

/* Closure for cb_put_fp(). */
struct fp_closure {
        struct vn_hdr *vnh;
        struct vn_hdr *vnh_max;
        int count;
        struct stat *sb;
};

typedef struct elf_buf {
        char    *buf;
        size_t  off;
        size_t  off_max;
} *elf_buf_t;

static void *target_reserve(elf_buf_t target, size_t bytes, int *error);

static int cb_put_phdr (vm_map_entry_t, void *);
static int cb_size_segment (vm_map_entry_t, void *);
static int cb_fpcount_segment(vm_map_entry_t, void *);
static int cb_put_fp(vm_map_entry_t, void *);


static int each_segment (struct proc *, segment_callback, void *, int);
static int __elfN(corehdr)(struct lwp *, int, struct file *, struct ucred *,
                        int, elf_buf_t);
enum putmode { WRITE, DRYRUN };
static int __elfN(puthdr)(struct lwp *, elf_buf_t, int sig, enum putmode,
                        int, struct file *);
static int elf_putallnotes(struct lwp *, elf_buf_t, int, enum putmode);
static int __elfN(putnote)(elf_buf_t, const char *, int, const void *, size_t);

static int elf_putsigs(struct lwp *, elf_buf_t);
static int elf_puttextvp(struct proc *, elf_buf_t);
static int elf_putfiles(struct proc *, elf_buf_t, struct file *);

int
__elfN(coredump)(struct lwp *lp, int sig, struct vnode *vp, off_t limit)
{
        struct file *fp; 
        int error;

        if ((error = falloc(NULL, &fp, NULL)) != 0)
                return (error);
        fsetcred(fp, lp->lwp_proc->p_ucred);

        /*
         * XXX fixme.
         */
        fp->f_type = DTYPE_VNODE;
        fp->f_flag = O_CREAT|O_WRONLY|O_NOFOLLOW;
        fp->f_ops = &vnode_fileops;
        fp->f_data = vp;
        
        error = generic_elf_coredump(lp, sig, fp, limit);

        fp->f_type = 0;
        fp->f_flag = 0;
        fp->f_ops = &badfileops;
        fp->f_data = NULL;
        fdrop(fp);
        return (error);
}

int
generic_elf_coredump(struct lwp *lp, int sig, struct file *fp, off_t limit)
{
        struct proc *p = lp->lwp_proc;
        struct ucred *cred = p->p_ucred;
        int error = 0;
        struct sseg_closure seginfo;
        struct elf_buf target;

        if (!fp)
                kprintf("can't dump core - null fp\n");

        /*
         * Size the program segments
         */
        seginfo.count = 0;
        seginfo.vsize = 0;
        each_segment(p, cb_size_segment, &seginfo, 1);

        /*
         * Calculate the size of the core file header area by making
         * a dry run of generating it.  Nothing is written, but the
         * size is calculated.
         */
        bzero(&target, sizeof(target));
        __elfN(puthdr)(lp, &target, sig, DRYRUN, seginfo.count, fp);

        if (target.off + seginfo.vsize >= limit)
                return (EFAULT);

        /*
         * Allocate memory for building the header, fill it up,
         * and write it out.
         */
        target.off_max = target.off;
        target.off = 0;
        target.buf = kmalloc(target.off_max, M_TEMP, M_WAITOK|M_ZERO);

        error = __elfN(corehdr)(lp, sig, fp, cred, seginfo.count, &target);

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

                php = (Elf_Phdr *)(target.buf + sizeof(Elf_Ehdr)) + 1;
                for (i = 0; i < seginfo.count; i++) {
                        error = fp_write(fp, (caddr_t)php->p_vaddr,
                                        php->p_filesz, &nbytes, UIO_USERSPACE);
                        if (error != 0)
                                break;
                        if (p->p_flags & P_MUSTKILL) {
                                error = EIO;
                                break;
                        }
                        php++;
                }
        }
        kfree(target.buf, M_TEMP);
        
        return (error);
}

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

        if (phc->phdr == phc->phdr_max)
                return (EINVAL);

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

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

        phc->offset += phdr->p_filesz;
        ++phc->phdr;
        return (0);
}

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

        ++ssc->count;
        ssc->vsize += entry->ba.end - entry->ba.start;
        return (0);
}

/*
 * A callback for each_segment() to gather information about
 * the number of text segments.
 */
static int
cb_fpcount_segment(vm_map_entry_t entry, void *closure)
{
        int *count = closure;
        struct vnode *vp;

        if (entry->ba.object && entry->ba.object->type == OBJT_VNODE) {
                vp = (struct vnode *)entry->ba.object->handle;
                if ((vp->v_flag & VCKPT) && curproc->p_textvp == vp)
                        return (0);
                ++*count;
        }
        return (0);
}

static int
cb_put_fp(vm_map_entry_t entry, void *closure) 
{
        struct fp_closure *fpc = closure;
        struct vn_hdr *vnh = fpc->vnh;
        Elf_Phdr *phdr = &vnh->vnh_phdr;
        struct vnode *vp;
        int error;

        /*
         * If an entry represents a vnode then write out a file handle.
         *
         * If we are checkpointing a checkpoint-restored program we do
         * NOT record the filehandle for the old checkpoint vnode (which
         * is mapped all over the place).  Instead we rely on the fact
         * that a checkpoint-restored program does not mmap() the checkpt
         * vnode NOCORE, so its contents will be written out to the
         * new checkpoint file.  This is necessary because the 'old'
         * checkpoint file is typically destroyed when a new one is created
         * and thus cannot be used to restore the new checkpoint.
         *
         * Theoretically we could create a chain of checkpoint files and
         * operate the checkpointing operation kinda like an incremental
         * checkpoint, but a checkpoint restore would then likely wind up
         * referencing many prior checkpoint files and that is a bit over
         * the top for the purpose of the checkpoint API.
         */
        if (entry->ba.object && entry->ba.object->type == OBJT_VNODE) {
                vp = (struct vnode *)entry->ba.object->handle;
                if ((vp->v_flag & VCKPT) && curproc->p_textvp == vp)
                        return (0);
                if (vnh == fpc->vnh_max)
                        return (EINVAL);

                if (vp->v_mount)
                        vnh->vnh_fh.fh_fsid = vp->v_mount->mnt_stat.f_fsid;
                error = VFS_VPTOFH(vp, &vnh->vnh_fh.fh_fid);
                if (error) {
                        char *freepath, *fullpath;

                        /*
                         * This is actually a relatively common occurance,
                         * so don't spew on the console by default.
                         */
                        if (vn_fullpath(curproc, vp, &fullpath, &freepath, 0)) {
                                if (bootverbose)
                                        kprintf("Warning: coredump, error %d: cannot store file handle for vnode %p\n", error, vp);
                        } else {
                                if (bootverbose)
                                        kprintf("Warning: coredump, error %d: cannot store file handle for %s\n", error, fullpath);
                                kfree(freepath, M_TEMP);
                        }
                        error = 0;
                }

                phdr->p_type = PT_LOAD;
                phdr->p_offset = 0;        /* not written to core */
                phdr->p_vaddr = entry->ba.start;
                phdr->p_paddr = 0;
                phdr->p_filesz = phdr->p_memsz =
                        entry->ba.end - entry->ba.start;
                phdr->p_align = PAGE_SIZE;
                phdr->p_flags = 0;
                if (entry->protection & VM_PROT_READ)
                        phdr->p_flags |= PF_R;
                if (entry->protection & VM_PROT_WRITE)
                        phdr->p_flags |= PF_W;
                if (entry->protection & VM_PROT_EXECUTE)
                        phdr->p_flags |= PF_X;
                ++fpc->vnh;
                ++fpc->count;
        }
        return (0);
}

/*
 * 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 int
each_segment(struct proc *p, segment_callback func, void *closure, int writable)
{
        int error = 0;
        vm_map_t map = &p->p_vmspace->vm_map;
        vm_map_entry_t entry;

        RB_FOREACH(entry, vm_map_rb_tree, &map->rb_root) {
                vm_map_backing_t ba;
                vm_object_t obj;

                /*
                 * 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 (writable && (entry->protection & VM_PROT_RW) != VM_PROT_RW)
                                continue;
                } else {
                        if (writable && (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).
                 *
                 * Currently we only dump normal VM object maps.  We do
                 * not dump submaps or virtual page tables.
                 */
                if (writable && (entry->eflags & MAP_ENTRY_NOCOREDUMP))
                        continue;
                if (entry->maptype != VM_MAPTYPE_NORMAL)
                        continue;

                /*
                 * Find the bottom-most object, leaving the base object
                 * and the bottom-most object held (but only one hold
                 * if they happen to be the same).
                 */
                ba = &entry->ba;
                while (ba->backing_ba)
                        ba = ba->backing_ba;
                obj = ba->object;

                /*
                 * The callback only applies to default, swap, or vnode
                 * objects.  Other types of objects such as memory-mapped
                 * devices are ignored.
                 */
                if (obj) {
                        vm_object_hold_shared(obj);

                        if (obj->type == OBJT_DEFAULT ||
                            obj->type == OBJT_SWAP ||
                            obj->type == OBJT_VNODE) {
                                error = (*func)(entry, closure);
                        }
                        vm_object_drop(obj);
                }
        }
        return (error);
}

static
void *
target_reserve(elf_buf_t target, size_t bytes, int *error)
{
    void *res = NULL;

    if (target->buf) {
            if (target->off + bytes > target->off_max)
                    *error = EINVAL;
            else
                    res = target->buf + target->off;
    }
    target->off += bytes;
    return (res);
}

/*
 * Write the core file header to the file, including padding up to
 * the page boundary.
 */
static int
__elfN(corehdr)(struct lwp *lp, int sig, struct file *fp, struct ucred *cred,
            int numsegs, elf_buf_t target)
{
        int error;
        ssize_t nbytes;

        /*
         * Fill in the header.  The fp is passed so we can detect and flag
         * a checkpoint file pointer within the core file itself, because
         * it may not be restored from the same file handle.
         */
        error = __elfN(puthdr)(lp, target, sig, WRITE, numsegs, fp);

        /* Write it to the core file. */
        if (error == 0) {
                error = fp_write(fp, target->buf, target->off, &nbytes,
                                 UIO_SYSSPACE);
        }
        return (error);
}

static int
__elfN(puthdr)(struct lwp *lp, elf_buf_t target, int sig, enum putmode mode,
    int numsegs, struct file *fp)
{
        struct proc *p = lp->lwp_proc;
        int error = 0;
        size_t phoff;
        size_t noteoff;
        size_t notesz;
        Elf_Ehdr *ehdr;
        Elf_Phdr *phdr;

        ehdr = target_reserve(target, sizeof(Elf_Ehdr), &error);

        phoff = target->off;
        phdr = target_reserve(target, (numsegs + 1) * sizeof(Elf_Phdr), &error);

        noteoff = target->off;
        if (error == 0)
                elf_putallnotes(lp, target, sig, mode);
        notesz = target->off - noteoff;

        /*
         * put extra cruft for dumping process state here 
         *  - we really want it be before all the program 
         *    mappings
         *  - we just need to update the offset accordingly
         *    and GDB will be none the wiser.
         */
        if (error == 0)
                error = elf_puttextvp(p, target);
        if (error == 0)
                error = elf_putsigs(lp, target);
        if (error == 0)
                error = elf_putfiles(p, target, fp);

        /*
         * Align up to a page boundary for the program segments.  The
         * actual data will be written to the outptu file, not to elf_buf_t,
         * so we do not have to do any further bounds checking.
         */
        target->off = round_page(target->off);
        if (error == 0 && ehdr != NULL) {
                /*
                 * Fill in the ELF header.
                 */
                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_NONE;
                ehdr->e_ident[EI_ABIVERSION] = 0;
                ehdr->e_ident[EI_PAD] = 0;
                ehdr->e_type = ET_CORE;
                ehdr->e_machine = ELF_ARCH;
                ehdr->e_version = EV_CURRENT;
                ehdr->e_entry = 0;
                ehdr->e_phoff = phoff;
                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;
        }
        if (error == 0 && phdr != NULL) {
                /*
                 * Fill in the program header entries.
                 */
                struct phdr_closure phc;

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

                /* All the writable segments from the program. */
                phc.phdr = phdr;
                phc.phdr_max = phdr + numsegs;
                phc.offset = target->off;
                each_segment(p, cb_put_phdr, &phc, 1);
        }
        return (error);
}

/*
 * Append core dump notes to target ELF buffer or simply update target size
 * if dryrun selected.
 */
static int
elf_putallnotes(struct lwp *corelp, elf_buf_t target, int sig,
    enum putmode mode)
{
        struct proc *p = corelp->lwp_proc;
        int error;
        struct {
                prstatus_t status;
                prfpregset_t fpregs;
                prpsinfo_t psinfo;
        } *tmpdata;
        prstatus_t *status;
        prfpregset_t *fpregs;
        prpsinfo_t *psinfo;
        struct lwp *lp;

        /*
         * Allocate temporary storage for notes on heap to avoid stack overflow.
         */
        if (mode != DRYRUN) {
                tmpdata = kmalloc(sizeof(*tmpdata), M_TEMP, M_ZERO | M_WAITOK);
                status = &tmpdata->status;
                fpregs = &tmpdata->fpregs;
                psinfo = &tmpdata->psinfo;
        } else {
                tmpdata = NULL;
                status = NULL;
                fpregs = NULL;
                psinfo = NULL;
        }

        /*
         * Append LWP-agnostic note.
         */
        if (mode != DRYRUN) {
                psinfo->pr_version = PRPSINFO_VERSION;
                psinfo->pr_psinfosz = sizeof(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));
        }
        error =
            __elfN(putnote)(target, "CORE", NT_PRPSINFO, psinfo, sizeof *psinfo);
        if (error)
                goto exit;

        /*
         * Append first note for LWP that triggered core so that it is
         * the selected one when the debugger starts.
         */
        if (mode != DRYRUN) {
                status->pr_version = PRSTATUS_VERSION;
                status->pr_statussz = sizeof(prstatus_t);
                status->pr_gregsetsz = sizeof(gregset_t);
                status->pr_fpregsetsz = sizeof(fpregset_t);
                status->pr_osreldate = osreldate;
                status->pr_cursig = sig;
                status->pr_pid = corelp->lwp_tid;
                fill_regs(corelp, &status->pr_reg);
                fill_fpregs(corelp, fpregs);
        }
        error =
            __elfN(putnote)(target, "CORE", NT_PRSTATUS, status, sizeof *status);
        if (error)
                goto exit;
        error =
            __elfN(putnote)(target, "CORE", NT_FPREGSET, fpregs, sizeof *fpregs);
        if (error)
                goto exit;

        /*
         * Then append notes for other LWPs.
         */
        FOREACH_LWP_IN_PROC(lp, p) {
                if (lp == corelp)
                        continue;
                /* skip lwps being created */
                if (lp->lwp_thread == NULL)
                        continue;
                if (mode != DRYRUN) {
                        status->pr_pid = lp->lwp_tid;
                        fill_regs(lp, &status->pr_reg);
                        fill_fpregs(lp, fpregs);
                }
                error = __elfN(putnote)(target, "CORE", NT_PRSTATUS,
                                        status, sizeof *status);
                if (error)
                        goto exit;
                error = __elfN(putnote)(target, "CORE", NT_FPREGSET,
                                        fpregs, sizeof *fpregs);
                if (error)
                        goto exit;
        }

exit:
        if (tmpdata != NULL)
                kfree(tmpdata, M_TEMP);
        return (error);
}

/*
 * Generate a note sub-structure.
 *
 * NOTE: 4-byte alignment.
 */
static int
__elfN(putnote)(elf_buf_t target, const char *name, int type,
            const void *desc, size_t descsz)
{
        int error = 0;
        char *dst;
        Elf_Note note;

        note.n_namesz = strlen(name) + 1;
        note.n_descsz = descsz;
        note.n_type = type;
        dst = target_reserve(target, sizeof(note), &error);
        if (dst != NULL)
                bcopy(&note, dst, sizeof note);
        dst = target_reserve(target, note.n_namesz, &error);
        if (dst != NULL)
                bcopy(name, dst, note.n_namesz);
        target->off = roundup2(target->off, sizeof(Elf_Word));
        dst = target_reserve(target, note.n_descsz, &error);
        if (dst != NULL)
                bcopy(desc, dst, note.n_descsz);
        target->off = roundup2(target->off, sizeof(Elf_Word));
        return (error);
}


static int
elf_putsigs(struct lwp *lp, elf_buf_t target)
{
        /* XXX lwp handle more than one lwp */
        struct proc *p = lp->lwp_proc;
        int error = 0;
        struct ckpt_siginfo *csi;

        csi = target_reserve(target, sizeof(struct ckpt_siginfo), &error);
        if (csi) {
                csi->csi_ckptpisz = sizeof(struct ckpt_siginfo);
                bcopy(p->p_sigacts, &csi->csi_sigacts, sizeof(*p->p_sigacts));
                bcopy(&p->p_realtimer, &csi->csi_itimerval, sizeof(struct itimerval));
                bcopy(&lp->lwp_sigmask, &csi->csi_sigmask,
                        sizeof(sigset_t));
                csi->csi_sigparent = p->p_sigparent;
        }
        return (error);
}

static int
elf_putfiles(struct proc *p, elf_buf_t target, struct file *ckfp)
{
        thread_t td = curthread;
        int error = 0;
        int i;
        struct ckpt_filehdr *cfh = NULL;
        struct ckpt_fileinfo *cfi;
        struct file *fp;        
        struct vnode *vp;

        /*
         * the duplicated loop is gross, but it was the only way
         * to eliminate uninitialized variable warnings 
         */
        cfh = target_reserve(target, sizeof(struct ckpt_filehdr), &error);
        if (cfh) {
                cfh->cfh_nfiles = 0;            
        }

        /*
         * ignore STDIN/STDERR/STDOUT.
         */
        KKASSERT(td->td_proc == p);
        for (i = 3; error == 0 && i < p->p_fd->fd_nfiles; i++) {
                fp = holdfp(td, i, -1);
                if (fp == NULL)
                        continue;
                /* 
                 * XXX Only checkpoint vnodes for now.
                 */
                if (fp->f_type != DTYPE_VNODE) {
                        fdrop(fp);
                        continue;
                }
                cfi = target_reserve(target, sizeof(struct ckpt_fileinfo),
                                        &error);
                if (cfi == NULL) {
                        fdrop(fp);
                        continue;
                }
                cfi->cfi_index = -1;
                cfi->cfi_type = fp->f_type;
                cfi->cfi_flags = fp->f_flag;
                cfi->cfi_offset = fp->f_offset;
                cfi->cfi_ckflags = 0;

                if (fp == ckfp)
                        cfi->cfi_ckflags |= CKFIF_ISCKPTFD;
                /* f_count and f_msgcount should not be saved/restored */
                /* XXX save cred info */

                switch(fp->f_type) {
                case DTYPE_VNODE:
                        vp = (struct vnode *)fp->f_data;
                        /*
                         * it looks like a bug in ptrace is marking 
                         * a non-vnode as a vnode - until we find the 
                         * root cause this will at least prevent
                         * further panics from truss
                         */
                        if (vp == NULL || vp->v_mount == NULL)
                                break;
                        cfh->cfh_nfiles++;
                        cfi->cfi_index = i;
                        cfi->cfi_fh.fh_fsid = vp->v_mount->mnt_stat.f_fsid;
                        error = VFS_VPTOFH(vp, &cfi->cfi_fh.fh_fid);
                        break;
                default:
                        break;
                }
                fdrop(fp);
        }
        return (error);
}

static int
elf_puttextvp(struct proc *p, elf_buf_t target)
{
        int error = 0;
        int *vn_count;
        struct fp_closure fpc;
        struct ckpt_vminfo *vminfo;

        vminfo = target_reserve(target, sizeof(struct ckpt_vminfo), &error);
        if (vminfo != NULL) {
                vminfo->cvm_dsize = btoc(p->p_vmspace->vm_dsize); /* pages */
                vminfo->cvm_tsize = btoc(p->p_vmspace->vm_tsize); /* pages */
                vminfo->cvm_daddr = p->p_vmspace->vm_daddr;
                vminfo->cvm_taddr = p->p_vmspace->vm_taddr;
        }

        fpc.count = 0;
        vn_count = target_reserve(target, sizeof(int), &error);
        if (target->buf != NULL) {
                fpc.vnh = (struct vn_hdr *)(target->buf + target->off);
                fpc.vnh_max = fpc.vnh + 
                        (target->off_max - target->off) / sizeof(struct vn_hdr);
                error = each_segment(p, cb_put_fp, &fpc, 0);
                if (vn_count)
                        *vn_count = fpc.count;
        } else {
                error = each_segment(p, cb_fpcount_segment, &fpc.count, 0);
        }
        target->off += fpc.count * sizeof(struct vn_hdr);
        return (error);
}

/*
 * Try to find the appropriate ABI-note section for checknote,
 * The entire image is searched if necessary, not only the first page.
 */
static boolean_t
__elfN(check_note)(struct image_params *imgp, Elf_Brandnote *checknote,
    int32_t *osrel)
{
        boolean_t valid_note_found;
        const Elf_Phdr *phdr, *pnote;
        const Elf_Ehdr *hdr;
        int i;

        valid_note_found = FALSE;
        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) {
                        pnote = &phdr[i];
                        valid_note_found = check_PT_NOTE (imgp, checknote,
                                osrel, pnote);
                        if (valid_note_found)
                                break;
                }
        }
        return valid_note_found;
}

/*
 * Be careful not to create new overflow conditions when checking
 * for overflow.
 */
static boolean_t
note_overflow(const Elf_Note *note, size_t maxsize)
{
        if (sizeof(*note) > maxsize)
                return TRUE;
        if (note->n_namesz > maxsize - sizeof(*note))
                return TRUE;
        return FALSE;
}

static boolean_t
hdr_overflow(__ElfN(Off) off_beg, __ElfN(Size) size)
{
        __ElfN(Off) off_end;

        off_end = off_beg + size;
        if (off_end < off_beg)
                return TRUE;
        return FALSE;
}

static boolean_t
check_PT_NOTE(struct image_params *imgp, Elf_Brandnote *checknote,
              int32_t *osrel, const Elf_Phdr * pnote)
{
        boolean_t limited_to_first_page;
        boolean_t found = FALSE;
        const Elf_Note *note, *note0, *note_end;
        const char *note_name;
        __ElfN(Off) noteloc, firstloc;
        __ElfN(Size) notesz, firstlen, endbyte;
        struct lwbuf *lwb;
        struct lwbuf lwb_cache;
        const char *page;
        char *data = NULL;
        int n;

        if (hdr_overflow(pnote->p_offset, pnote->p_filesz))
                return (FALSE);
        notesz = pnote->p_filesz;
        noteloc = pnote->p_offset;
        endbyte = noteloc + notesz;
        limited_to_first_page = noteloc < PAGE_SIZE && endbyte < PAGE_SIZE;

        if (limited_to_first_page) {
                note = (const Elf_Note *)(imgp->image_header + noteloc);
                note_end = (const Elf_Note *)(imgp->image_header + endbyte);
                note0 = note;
        } else {
                firstloc = noteloc & PAGE_MASK;
                firstlen = PAGE_SIZE - firstloc;
                if (notesz < sizeof(Elf_Note) || notesz > PAGE_SIZE)
                        return (FALSE);

                lwb = &lwb_cache;
                if (exec_map_page(imgp, noteloc >> PAGE_SHIFT, &lwb, &page))
                        return (FALSE);
                if (firstlen < notesz) {         /* crosses page boundary */
                        data = kmalloc(notesz, M_TEMP, M_WAITOK);
                        bcopy(page + firstloc, data, firstlen);

                        exec_unmap_page(lwb);
                        lwb = &lwb_cache;
                        if (exec_map_page(imgp, (noteloc >> PAGE_SHIFT) + 1,
                                &lwb, &page)) {
                                kfree(data, M_TEMP);
                                return (FALSE);
                        }
                        bcopy(page, data + firstlen, notesz - firstlen);
                        note = note0 = (const Elf_Note *)(data);
                        note_end = (const Elf_Note *)(data + notesz);
                } else {
                        note = note0 = (const Elf_Note *)(page + firstloc);
                        note_end = (const Elf_Note *)(page + firstloc +
                                firstlen);
                }
        }

        for (n = 0; n < 100 && note >= note0 && note < note_end; n++) {
                if (!aligned(note, Elf32_Addr))
                        break;
                if (note_overflow(note, (const char *)note_end -
                                        (const char *)note)) {
                        break;
                }
                note_name = (const char *)(note + 1);

                if (note->n_namesz == checknote->hdr.n_namesz
                    && note->n_descsz == checknote->hdr.n_descsz
                    && note->n_type == checknote->hdr.n_type
                    && (strncmp(checknote->vendor, note_name,
                        checknote->hdr.n_namesz) == 0)) {
                        /* Fetch osreldata from ABI.note-tag */
                        if ((checknote->flags & BN_TRANSLATE_OSREL) != 0 &&
                            checknote->trans_osrel != NULL)
                                checknote->trans_osrel(note, osrel);
                        found = TRUE;
                        break;
                }
                note = (const Elf_Note *)((const char *)(note + 1) +
                    roundup2(note->n_namesz, sizeof(Elf32_Addr)) +
                    roundup2(note->n_descsz, sizeof(Elf32_Addr)));
        }

        if (!limited_to_first_page) {
                if (data != NULL)
                        kfree(data, M_TEMP);
                exec_unmap_page(lwb);
        }
        return (found);
}

/*
 * The interpreter program header may be located beyond the first page, so
 * regardless of its location, a copy of the interpreter path is created so
 * that it may be safely referenced by the calling function in all case.  The
 * memory is allocated by calling function, and the copying is done here.
 */
static boolean_t
extract_interpreter(struct image_params *imgp, const Elf_Phdr *pinterpreter,
                    char *data)
{
        boolean_t limited_to_first_page;
        const boolean_t result_success = FALSE;
        const boolean_t result_failure = TRUE;
        __ElfN(Off) pathloc, firstloc;
        __ElfN(Size) pathsz, firstlen, endbyte;
        struct lwbuf *lwb;
        struct lwbuf lwb_cache;
        const char *page;

        if (hdr_overflow(pinterpreter->p_offset, pinterpreter->p_filesz))
                return (result_failure);
        pathsz  = pinterpreter->p_filesz;
        pathloc = pinterpreter->p_offset;
        endbyte = pathloc + pathsz;

        limited_to_first_page = pathloc < PAGE_SIZE && endbyte < PAGE_SIZE;
        if (limited_to_first_page) {
                bcopy(imgp->image_header + pathloc, data, pathsz);
                return (result_success);
        }

        firstloc = pathloc & PAGE_MASK;
        firstlen = PAGE_SIZE - firstloc;

        lwb = &lwb_cache;
        if (exec_map_page(imgp, pathloc >> PAGE_SHIFT, &lwb, &page))
                return (result_failure);

        if (firstlen < pathsz) {         /* crosses page boundary */
                bcopy(page + firstloc, data, firstlen);

                exec_unmap_page(lwb);
                lwb = &lwb_cache;
                if (exec_map_page(imgp, (pathloc >> PAGE_SHIFT) + 1, &lwb,
                        &page))
                        return (result_failure);
                bcopy(page, data + firstlen, pathsz - firstlen);
        } else
                bcopy(page + firstloc, data, pathsz);

        exec_unmap_page(lwb);
        return (result_success);
}

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

        p = (uintptr_t)(note + 1);
        p += roundup2(note->n_namesz, sizeof(Elf32_Addr));
        *osrel = *(const int32_t *)(p);

        return (TRUE);
}

/*
 * Tell kern_execve.c about it, with a little help from the linker.
 */
#if defined(__x86_64__)
static struct execsw elf_execsw = {exec_elf64_imgact, "ELF64"};
EXEC_SET_ORDERED(elf64, elf_execsw, SI_ORDER_FIRST);
#else /* i386 assumed */
static struct execsw elf_execsw = {exec_elf32_imgact, "ELF32"};
EXEC_SET_ORDERED(elf32, elf_execsw, SI_ORDER_FIRST);
#endif

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;
        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);
}

static u_long
pie_base_hint(struct proc *p)
{
        u_long base;

        if (elf_pie_base_mmap)
                base = vm_map_hint(p, 0, VM_PROT_READ | VM_PROT_EXECUTE, 0);
        else
                base = ET_DYN_LOAD_ADDR;
        return base;
}