/*-
 * Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
 * Copyright (c) 1998 Peter Wemm <peter@freebsd.org>
 * 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.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/param.h>
#include <sys/endian.h>
#include <sys/exec.h>
#include <sys/linker.h>
#include <sys/module.h>
#include <machine/elf.h>
#include <stand.h>

#include "bootstrap.h"
#include "modinfo.h"

#define COPYOUT(s,d,l)  archsw.arch_copyout((vm_offset_t)(s), d, l)

#if defined(__i386__) && __ELF_WORD_SIZE == 64
#undef ELF_TARG_CLASS
#undef ELF_TARG_MACH
#define ELF_TARG_CLASS  ELFCLASS64
#define ELF_TARG_MACH   EM_X86_64
#endif

typedef struct elf_file {
        Elf_Phdr        *ph;
        Elf_Ehdr        *ehdr;
        Elf_Sym         *symtab;
        Elf_Hashelt     *hashtab;
        Elf_Hashelt     nbuckets;
        Elf_Hashelt     nchains;
        Elf_Hashelt     *buckets;
        Elf_Hashelt     *chains;
        Elf_Rel *rel;
        size_t  relsz;
        Elf_Rela        *rela;
        size_t  relasz;
        char    *strtab;
        size_t  strsz;
        int             fd;
        caddr_t firstpage;
        size_t  firstlen;
        int             kernel;
        uint64_t        off;
#ifdef LOADER_VERIEXEC_VECTX
        struct vectx    *vctx;
#endif
} *elf_file_t;

#ifdef LOADER_VERIEXEC_VECTX
#define VECTX_HANDLE(ef) (ef)->vctx
#else
#define VECTX_HANDLE(ef) (ef)->fd
#endif

static int __elfN(loadimage)(struct preloaded_file *mp, elf_file_t ef,
    uint64_t loadaddr);
static int __elfN(lookup_symbol)(elf_file_t ef, const char* name,
    Elf_Sym *sym, unsigned char type);
static int __elfN(reloc_ptr)(struct preloaded_file *mp, elf_file_t ef,
    Elf_Addr p, void *val, size_t len);
static int __elfN(parse_modmetadata)(struct preloaded_file *mp, elf_file_t ef,
    Elf_Addr p_start, Elf_Addr p_end);
static symaddr_fn __elfN(symaddr);
static char     *fake_modname(const char *name);

uint64_t        __elfN(relocation_offset) = 0;

#ifdef __powerpc__
extern void elf_wrong_field_size(void);
#define CONVERT_FIELD(b, f, e)                  \
        switch (sizeof((b)->f)) {               \
        case 2:                                 \
                (b)->f = e ## 16toh((b)->f);    \
                break;                          \
        case 4:                                 \
                (b)->f = e ## 32toh((b)->f);    \
                break;                          \
        case 8:                                 \
                (b)->f = e ## 64toh((b)->f);    \
                break;                          \
        default:                                \
                /* Force a link time error. */  \
                elf_wrong_field_size();         \
                break;                          \
        }

#define CONVERT_SWITCH(h, d, f)                 \
        switch ((h)->e_ident[EI_DATA]) {        \
        case ELFDATA2MSB:                       \
                f(d, be);                       \
                break;                          \
        case ELFDATA2LSB:                       \
                f(d, le);                       \
                break;                          \
        default:                                \
                return (EINVAL);                \
        }


static int elf_header_convert(Elf_Ehdr *ehdr)
{
        /*
         * Fixup ELF header endianness.
         *
         * The Xhdr structure was loaded using block read call to optimize file
         * accesses. It might happen, that the endianness of the system memory
         * is different that endianness of the ELF header.  Swap fields here to
         * guarantee that Xhdr always contain valid data regardless of
         * architecture.
         */
#define HEADER_FIELDS(b, e)                     \
        CONVERT_FIELD(b, e_type, e);            \
        CONVERT_FIELD(b, e_machine, e);         \
        CONVERT_FIELD(b, e_version, e);         \
        CONVERT_FIELD(b, e_entry, e);           \
        CONVERT_FIELD(b, e_phoff, e);           \
        CONVERT_FIELD(b, e_shoff, e);           \
        CONVERT_FIELD(b, e_flags, e);           \
        CONVERT_FIELD(b, e_ehsize, e);          \
        CONVERT_FIELD(b, e_phentsize, e);       \
        CONVERT_FIELD(b, e_phnum, e);           \
        CONVERT_FIELD(b, e_shentsize, e);       \
        CONVERT_FIELD(b, e_shnum, e);           \
        CONVERT_FIELD(b, e_shstrndx, e)

        CONVERT_SWITCH(ehdr, ehdr, HEADER_FIELDS);

#undef HEADER_FIELDS

        return (0);
}

static int elf_program_header_convert(const Elf_Ehdr *ehdr, Elf_Phdr *phdr)
{
#define PROGRAM_HEADER_FIELDS(b, e)             \
        CONVERT_FIELD(b, p_type, e);            \
        CONVERT_FIELD(b, p_flags, e);           \
        CONVERT_FIELD(b, p_offset, e);          \
        CONVERT_FIELD(b, p_vaddr, e);           \
        CONVERT_FIELD(b, p_paddr, e);           \
        CONVERT_FIELD(b, p_filesz, e);          \
        CONVERT_FIELD(b, p_memsz, e);           \
        CONVERT_FIELD(b, p_align, e)

        CONVERT_SWITCH(ehdr, phdr, PROGRAM_HEADER_FIELDS);

#undef PROGRAM_HEADER_FIELDS

        return (0);
}

static int elf_section_header_convert(const Elf_Ehdr *ehdr, Elf_Shdr *shdr)
{
#define SECTION_HEADER_FIELDS(b, e)             \
        CONVERT_FIELD(b, sh_name, e);           \
        CONVERT_FIELD(b, sh_type, e);           \
        CONVERT_FIELD(b, sh_link, e);           \
        CONVERT_FIELD(b, sh_info, e);           \
        CONVERT_FIELD(b, sh_flags, e);          \
        CONVERT_FIELD(b, sh_addr, e);           \
        CONVERT_FIELD(b, sh_offset, e);         \
        CONVERT_FIELD(b, sh_size, e);           \
        CONVERT_FIELD(b, sh_addralign, e);      \
        CONVERT_FIELD(b, sh_entsize, e)

        CONVERT_SWITCH(ehdr, shdr, SECTION_HEADER_FIELDS);

#undef SECTION_HEADER_FIELDS

        return (0);
}
#undef CONVERT_SWITCH
#undef CONVERT_FIELD
#else
static int elf_header_convert(Elf_Ehdr *ehdr)
{
        return (0);
}

static int elf_program_header_convert(const Elf_Ehdr *ehdr, Elf_Phdr *phdr)
{
        return (0);
}

static int elf_section_header_convert(const Elf_Ehdr *ehdr, Elf_Shdr *shdr)
{
        return (0);
}
#endif

#if defined(__amd64__) || (defined(__i386__) && defined(EFI))
static bool
is_kernphys_relocatable(elf_file_t ef)
{
        Elf_Sym sym;

        return (__elfN(lookup_symbol)(ef, "kernphys", &sym, STT_OBJECT) == 0);
}
#endif

#ifdef __i386__
static bool
is_tg_kernel_support(struct preloaded_file *fp, elf_file_t ef)
{
        Elf_Sym         sym;
        Elf_Addr        p_start, p_end, v, p;
        char            vd_name[16];
        int             error;

        if (__elfN(lookup_symbol)(ef, "__start_set_vt_drv_set", &sym, STT_NOTYPE) != 0)
                return (false);
        p_start = sym.st_value + ef->off;
        if (__elfN(lookup_symbol)(ef, "__stop_set_vt_drv_set", &sym, STT_NOTYPE) != 0)
                return (false);
        p_end = sym.st_value + ef->off;

        /*
         * Walk through vt_drv_set, each vt driver structure starts with
         * static 16 chars for driver name. If we have "vbefb", return true.
         */
        for (p = p_start; p < p_end; p += sizeof(Elf_Addr)) {
                COPYOUT(p, &v, sizeof(v));

                error = __elfN(reloc_ptr)(fp, ef, p, &v, sizeof(v));
                if (error == EOPNOTSUPP)
                        v += ef->off;
                else if (error != 0)
                        return (false);
                COPYOUT(v, &vd_name, sizeof(vd_name));
                if (strncmp(vd_name, "vbefb", sizeof(vd_name)) == 0)
                        return (true);
        }

        return (false);
}
#endif

static int
__elfN(load_elf_header)(char *filename, elf_file_t ef)
{
        ssize_t                  bytes_read;
        Elf_Ehdr                *ehdr;
        int                      err;

        /*
         * Open the image, read and validate the ELF header
         */
        if (filename == NULL)   /* can't handle nameless */
                return (EFTYPE);
        if ((ef->fd = open(filename, O_RDONLY)) == -1)
                return (errno);
        ef->firstpage = malloc(PAGE_SIZE);
        if (ef->firstpage == NULL) {
                close(ef->fd);
                return (ENOMEM);
        }
        preload(ef->fd);
#ifdef LOADER_VERIEXEC_VECTX
        {
                int verror;

                ef->vctx = vectx_open(ef->fd, filename, 0L, NULL, &verror, __func__);
                if (verror) {
                        printf("Unverified %s: %s\n", filename, ve_error_get());
                        close(ef->fd);
                        free(ef->vctx);
                        return (EAUTH);
                }
        }
#endif
        bytes_read = VECTX_READ(VECTX_HANDLE(ef), ef->firstpage, PAGE_SIZE);
        ef->firstlen = (size_t)bytes_read;
        if (bytes_read < 0 || ef->firstlen <= sizeof(Elf_Ehdr)) {
                err = EFTYPE; /* could be EIO, but may be small file */
                goto error;
        }
        ehdr = ef->ehdr = (Elf_Ehdr *)ef->firstpage;

        /* Is it ELF? */
        if (!IS_ELF(*ehdr)) {
                err = EFTYPE;
                goto error;
        }

        if (ehdr->e_ident[EI_CLASS] != ELF_TARG_CLASS || /* Layout ? */
            ehdr->e_ident[EI_DATA] != ELF_TARG_DATA ||
            ehdr->e_ident[EI_VERSION] != EV_CURRENT) /* Version ? */ {
                err = EFTYPE;
                goto error;
        }

        err = elf_header_convert(ehdr);
        if (err)
                goto error;

        if (ehdr->e_version != EV_CURRENT || ehdr->e_machine != ELF_TARG_MACH) {
                /* Machine ? */
                err = EFTYPE;
                goto error;
        }

#if defined(LOADER_VERIEXEC) && !defined(LOADER_VERIEXEC_VECTX)
        if (verify_file(ef->fd, filename, bytes_read, VE_MUST, __func__) < 0) {
                err = EAUTH;
                goto error;
        }
#endif
        return (0);

error:
        if (ef->firstpage != NULL) {
                free(ef->firstpage);
                ef->firstpage = NULL;
        }
        if (ef->fd != -1) {
#ifdef LOADER_VERIEXEC_VECTX
                free(ef->vctx);
#endif
                close(ef->fd);
                ef->fd = -1;
        }
        return (err);
}

/*
 * Attempt to load the file (file) as an ELF module.  It will be stored at
 * (dest), and a pointer to a module structure describing the loaded object
 * will be saved in (result).
 */
int
__elfN(loadfile)(char *filename, uint64_t dest, struct preloaded_file **result)
{
        return (__elfN(loadfile_raw)(filename, dest, result, 0));
}

int
__elfN(loadfile_raw)(char *filename, uint64_t dest,
    struct preloaded_file **result, int multiboot)
{
        struct preloaded_file   *fp, *kfp;
        struct elf_file         ef;
        Elf_Ehdr                *ehdr;
        int                     err;

        fp = NULL;
        bzero(&ef, sizeof(struct elf_file));
        ef.fd = -1;

        err = __elfN(load_elf_header)(filename, &ef);
        if (err != 0)
                return (err);

        ehdr = ef.ehdr;

        /*
         * Check to see what sort of module we are.
         */
        kfp = file_findfile(NULL, md_kerntype);
#ifdef __powerpc__
        /*
         * Kernels can be ET_DYN, so just assume the first loaded object is the
         * kernel. This assumption will be checked later.
         */
        if (kfp == NULL)
                ef.kernel = 1;
#endif
        if (ef.kernel || ehdr->e_type == ET_EXEC) {
                /* Looks like a kernel */
                if (kfp != NULL) {
                        printf("elf" __XSTRING(__ELF_WORD_SIZE)
                            "_loadfile: kernel already loaded\n");
                        err = EPERM;
                        goto oerr;
                }
                /*
                 * Calculate destination address based on kernel entrypoint.
                 *
                 * For ARM, the destination address is independent of any values
                 * in the elf header (an ARM kernel can be loaded at any 2MB
                 * boundary), so we leave dest set to the value calculated by
                 * archsw.arch_loadaddr() and passed in to this function.
                 * XXX This comment is obsolete, but it still seems to work
                 */
#ifndef __arm__
                if (ehdr->e_type == ET_EXEC)
                        dest = (ehdr->e_entry & ~PAGE_MASK);
#endif
                if ((ehdr->e_entry & ~PAGE_MASK) == 0) {
                        printf("elf" __XSTRING(__ELF_WORD_SIZE)
                            "_loadfile: not a kernel (maybe static binary?)\n");
                        err = EPERM;
                        goto oerr;
                }
                ef.kernel = 1;

        } else if (ehdr->e_type == ET_DYN) {
                /* Looks like a kld module */
                if (multiboot != 0) {
                        printf("elf" __XSTRING(__ELF_WORD_SIZE)
                            "_loadfile: can't load module as multiboot\n");
                        err = EPERM;
                        goto oerr;
                }
                if (kfp == NULL) {
                        printf("elf" __XSTRING(__ELF_WORD_SIZE)
                            "_loadfile: can't load module before kernel\n");
                        err = EPERM;
                        goto oerr;
                }
                if (strcmp(md_kerntype, kfp->f_type)) {
                        printf("elf" __XSTRING(__ELF_WORD_SIZE)
                         "_loadfile: can't load module with kernel type '%s'\n",
                            kfp->f_type);
                        err = EPERM;
                        goto oerr;
                }
                /* Looks OK, got ahead */
                ef.kernel = 0;
        
        } else {
                err = EFTYPE;
                goto oerr;
        }

        dest = md_align(dest);

        /*
         * Ok, we think we should handle this.
         */
        fp = file_alloc();
        if (fp == NULL) {
                printf("elf" __XSTRING(__ELF_WORD_SIZE)
                    "_loadfile: cannot allocate module info\n");
                err = EPERM;
                goto out;
        }
        if (ef.kernel == 1 && multiboot == 0)
                setenv("kernelname", filename, 1);
        fp->f_name = strdup(filename);
        if (multiboot == 0)
                fp->f_type = strdup(ef.kernel ?
                    md_kerntype : md_modtype);
        else
                fp->f_type = strdup(md_kerntype_mb);

        if (module_verbose >= MODULE_VERBOSE_FULL) {
                if (ef.kernel)
                        printf("%s entry at 0x%jx\n", filename,
                            (uintmax_t)ehdr->e_entry);
        } else if (module_verbose > MODULE_VERBOSE_SILENT)
                printf("%s ", filename);

        fp->f_size = __elfN(loadimage)(fp, &ef, dest);
        if (fp->f_size == 0 || fp->f_addr == 0)
                goto ioerr;

        /* save exec header as metadata */
        file_addmetadata(fp, MODINFOMD_ELFHDR, sizeof(*ehdr), ehdr);

        /* Load OK, return module pointer */
        *result = (struct preloaded_file *)fp;
        err = 0;
#if defined(__amd64__) || (defined(__i386__) && defined(EFI))
        fp->f_kernphys_relocatable = multiboot || is_kernphys_relocatable(&ef);
#endif
#if defined(__i386__) && !defined(EFI)
        fp->f_tg_kernel_support = is_tg_kernel_support(fp, &ef);
#endif
        goto out;

ioerr:
        err = EIO;
oerr:
        file_discard(fp);
out:
        if (ef.firstpage)
                free(ef.firstpage);
        if (ef.fd != -1) {
#ifdef LOADER_VERIEXEC_VECTX
                if (!err && ef.vctx) {
                        int verror;

                        verror = vectx_close(ef.vctx, VE_MUST, __func__);
                        if (verror) {
                                err = EAUTH;
                                file_discard(fp);
                        }
                }
#endif
                close(ef.fd);
        }
        return (err);
}

/*
 * With the file (fd) open on the image, and (ehdr) containing
 * the Elf header, load the image at (off)
 */
static int
__elfN(loadimage)(struct preloaded_file *fp, elf_file_t ef, uint64_t off)
{
        int             i;
        u_int           j;
        Elf_Ehdr        *ehdr;
        Elf_Phdr        *phdr, *php;
        Elf_Shdr        *shdr;
        char            *shstr;
        int             ret;
        vm_offset_t     firstaddr;
        vm_offset_t     lastaddr;
        size_t          chunk;
        ssize_t         result;
        Elf_Addr        ssym, esym;
        Elf_Dyn         *dp;
        Elf_Addr        adp;
        Elf_Addr        ctors;
        int             ndp;
        int             symstrindex;
        int             symtabindex;
        Elf_Size        size;
        u_int           fpcopy;
        Elf_Sym         sym;
        Elf_Addr        p_start, p_end;

        dp = NULL;
        shdr = NULL;
        ret = 0;
        firstaddr = lastaddr = 0;
        ehdr = ef->ehdr;
#ifdef __powerpc__
        if (ef->kernel) {
#else
        if (ehdr->e_type == ET_EXEC) {
#endif
#if defined(__i386__) || defined(__amd64__)
#if __ELF_WORD_SIZE == 64
                /* x86_64 relocates after locore */
                off = - (off & 0xffffffffff000000ull);
#else
                /* i386 relocates after locore */
                off = - (off & 0xff000000u);
#endif
#elif defined(__powerpc__)
                /*
                 * On the purely virtual memory machines like e500, the kernel
                 * is linked against its final VA range, which is most often
                 * not available at the loader stage, but only after kernel
                 * initializes and completes its VM settings. In such cases we
                 * cannot use p_vaddr field directly to load ELF segments, but
                 * put them at some 'load-time' locations.
                 */
                if (off & 0xf0000000u) {
                        off = -(off & 0xf0000000u);
                        /*
                         * XXX the physical load address should not be
                         * hardcoded. Note that the Book-E kernel assumes that
                         * it's loaded at a 16MB boundary for now...
                         */
                        off += 0x01000000;
                }
                ehdr->e_entry += off;
                if (module_verbose >= MODULE_VERBOSE_FULL)
                        printf("Converted entry 0x%jx\n",
                            (uintmax_t)ehdr->e_entry);

#elif defined(__arm__) && !defined(EFI)
                /*
                 * The elf headers in arm kernels specify virtual addresses in
                 * all header fields, even the ones that should be physical
                 * addresses.  We assume the entry point is in the first page,
                 * and masking the page offset will leave us with the virtual
                 * address the kernel was linked at.  We subtract that from the
                 * load offset, making 'off' into the value which, when added
                 * to a virtual address in an elf header, translates it to a
                 * physical address.  We do the va->pa conversion on the entry
                 * point address in the header now, so that later we can launch
                 * the kernel by just jumping to that address.
                 *
                 * When booting from UEFI the copyin and copyout functions
                 * handle adjusting the location relative to the first virtual
                 * address.  Because of this there is no need to adjust the
                 * offset or entry point address as these will both be handled
                 * by the efi code.
                 */
                off -= ehdr->e_entry & ~PAGE_MASK;
                ehdr->e_entry += off;
                if (module_verbose >= MODULE_VERBOSE_FULL)
                        printf("ehdr->e_entry 0x%jx, va<->pa off %llx\n",
                            (uintmax_t)ehdr->e_entry, off);
#else
                off = 0;        /* other archs use direct mapped kernels */
#endif
        }
        ef->off = off;

        if (ef->kernel)
                __elfN(relocation_offset) = off;

        if ((ehdr->e_phoff + ehdr->e_phnum * sizeof(*phdr)) > ef->firstlen) {
                printf("elf" __XSTRING(__ELF_WORD_SIZE)
                    "_loadimage: program header not within first page\n");
                goto out;
        }
        phdr = (Elf_Phdr *)(ef->firstpage + ehdr->e_phoff);

        for (i = 0; i < ehdr->e_phnum; i++) {
                if (elf_program_header_convert(ehdr, phdr))
                        continue;

                /* We want to load PT_LOAD segments only.. */
                if (phdr[i].p_type != PT_LOAD)
                        continue;

                if (module_verbose >= MODULE_VERBOSE_FULL) {
                        printf("Segment: 0x%lx@0x%lx -> 0x%lx-0x%lx",
                            (long)phdr[i].p_filesz, (long)phdr[i].p_offset,
                            (long)(phdr[i].p_vaddr + off),
                            (long)(phdr[i].p_vaddr + off + phdr[i].p_memsz - 1));
                } else if (module_verbose > MODULE_VERBOSE_SILENT) {
                        if ((phdr[i].p_flags & PF_W) == 0) {
                                printf("text=0x%lx ", (long)phdr[i].p_filesz);
                        } else {
                                printf("data=0x%lx", (long)phdr[i].p_filesz);
                                if (phdr[i].p_filesz < phdr[i].p_memsz)
                                        printf("+0x%lx", (long)(phdr[i].p_memsz -
                                                phdr[i].p_filesz));
                                printf(" ");
                        }
                }
                fpcopy = 0;
                if (ef->firstlen > phdr[i].p_offset) {
                        fpcopy = ef->firstlen - phdr[i].p_offset;
                        archsw.arch_copyin(ef->firstpage + phdr[i].p_offset,
                            phdr[i].p_vaddr + off, fpcopy);
                }
                if (phdr[i].p_filesz > fpcopy) {
                        if (kern_pread(VECTX_HANDLE(ef),
                            phdr[i].p_vaddr + off + fpcopy,
                            phdr[i].p_filesz - fpcopy,
                            phdr[i].p_offset + fpcopy) != 0) {
                                printf("\nelf" __XSTRING(__ELF_WORD_SIZE)
                                    "_loadimage: read failed\n");
                                goto out;
                        }
                }
                /* clear space from oversized segments; eg: bss */
                if (phdr[i].p_filesz < phdr[i].p_memsz) {
                        if (module_verbose >= MODULE_VERBOSE_FULL) {
                                printf(" (bss: 0x%lx-0x%lx)",
                                    (long)(phdr[i].p_vaddr + off + phdr[i].p_filesz),
                                    (long)(phdr[i].p_vaddr + off + phdr[i].p_memsz -1));
                        }       
                        kern_bzero(phdr[i].p_vaddr + off + phdr[i].p_filesz,
                            phdr[i].p_memsz - phdr[i].p_filesz);
                }
                if (module_verbose >= MODULE_VERBOSE_FULL)
                        printf("\n");

                if (archsw.arch_loadseg != NULL)
                        archsw.arch_loadseg(ehdr, phdr + i, off);

                if (firstaddr == 0 || firstaddr > (phdr[i].p_vaddr + off))
                        firstaddr = phdr[i].p_vaddr + off;
                if (lastaddr == 0 || lastaddr <
                    (phdr[i].p_vaddr + off + phdr[i].p_memsz))
                        lastaddr = phdr[i].p_vaddr + off + phdr[i].p_memsz;
        }
        lastaddr = roundup(lastaddr, sizeof(long));

        /*
         * Get the section headers.  We need this for finding the .ctors
         * section as well as for loading any symbols.  Both may be hard
         * to do if reading from a .gz file as it involves seeking.  I
         * think the rule is going to have to be that you must strip a
         * file to remove symbols before gzipping it.
         */
        chunk = (size_t)ehdr->e_shnum * (size_t)ehdr->e_shentsize;
        if (chunk == 0 || ehdr->e_shoff == 0)
                goto nosyms;
        shdr = alloc_pread(VECTX_HANDLE(ef), ehdr->e_shoff, chunk);
        if (shdr == NULL) {
                printf("\nelf" __XSTRING(__ELF_WORD_SIZE)
                    "_loadimage: failed to read section headers");
                goto nosyms;
        }

        for (i = 0; i < ehdr->e_shnum; i++)
                elf_section_header_convert(ehdr, &shdr[i]);

        file_addmetadata(fp, MODINFOMD_SHDR, chunk, shdr);

        /*
         * Read the section string table and look for the .ctors section.
         * We need to tell the kernel where it is so that it can call the
         * ctors.
         */
        chunk = shdr[ehdr->e_shstrndx].sh_size;
        if (chunk) {
                shstr = alloc_pread(VECTX_HANDLE(ef),
                    shdr[ehdr->e_shstrndx].sh_offset, chunk);
                if (shstr) {
                        for (i = 0; i < ehdr->e_shnum; i++) {
                                if (strcmp(shstr + shdr[i].sh_name,
                                    ".ctors") != 0)
                                        continue;
                                ctors = shdr[i].sh_addr;
                                file_addmetadata(fp, MODINFOMD_CTORS_ADDR,
                                    sizeof(ctors), &ctors);
                                size = shdr[i].sh_size;
                                file_addmetadata(fp, MODINFOMD_CTORS_SIZE,
                                    sizeof(size), &size);
                                break;
                        }
                        free(shstr);
                }
        }

        /*
         * Now load any symbols.
         */
        symtabindex = -1;
        symstrindex = -1;
        for (i = 0; i < ehdr->e_shnum; i++) {
                if (shdr[i].sh_type != SHT_SYMTAB)
                        continue;
                for (j = 0; j < ehdr->e_phnum; j++) {
                        if (phdr[j].p_type != PT_LOAD)
                                continue;
                        if (shdr[i].sh_offset >= phdr[j].p_offset &&
                            (shdr[i].sh_offset + shdr[i].sh_size <=
                            phdr[j].p_offset + phdr[j].p_filesz)) {
                                shdr[i].sh_offset = 0;
                                shdr[i].sh_size = 0;
                                break;
                        }
                }
                if (shdr[i].sh_offset == 0 || shdr[i].sh_size == 0)
                        continue;       /* alread loaded in a PT_LOAD above */
                /* Save it for loading below */
                symtabindex = i;
                symstrindex = shdr[i].sh_link;
        }
        if (symtabindex < 0 || symstrindex < 0)
                goto nosyms;

        /* Ok, committed to a load. */
        if (module_verbose >= MODULE_VERBOSE_FULL)
                printf("syms=[");
        ssym = lastaddr;
        for (i = symtabindex; i >= 0; i = symstrindex) {
                char    *secname;

                switch(shdr[i].sh_type) {
                case SHT_SYMTAB:                /* Symbol table */
                        secname = "symtab";
                        break;
                case SHT_STRTAB:                /* String table */
                        secname = "strtab";
                        break;
                default:
                        secname = "WHOA!!";
                        break;
                }
                size = shdr[i].sh_size;

                archsw.arch_copyin(&size, lastaddr, sizeof(size));
                lastaddr += sizeof(size);

                if (module_verbose >= MODULE_VERBOSE_FULL) {
                        printf("\n%s: 0x%jx@0x%jx -> 0x%jx-0x%jx", secname,
                            (uintmax_t)shdr[i].sh_size, (uintmax_t)shdr[i].sh_offset,
                            (uintmax_t)lastaddr,
                            (uintmax_t)(lastaddr + shdr[i].sh_size));
                } else if (module_verbose > MODULE_VERBOSE_SILENT) {
                        if (i == symstrindex)
                                printf("+");
                        printf("0x%lx+0x%lx", (long)sizeof(size), (long)size);
                }
                if (VECTX_LSEEK(VECTX_HANDLE(ef), (off_t)shdr[i].sh_offset, SEEK_SET) == -1) {
                        printf("\nelf" __XSTRING(__ELF_WORD_SIZE)
                           "_loadimage: could not seek for symbols - skipped!");
                        lastaddr = ssym;
                        ssym = 0;
                        goto nosyms;
                }
                result = archsw.arch_readin(VECTX_HANDLE(ef), lastaddr, shdr[i].sh_size);
                if (result < 0 || (size_t)result != shdr[i].sh_size) {
                        printf("\nelf" __XSTRING(__ELF_WORD_SIZE)
                            "_loadimage: could not read symbols - skipped! "
                            "(%ju != %ju)", (uintmax_t)result,
                            (uintmax_t)shdr[i].sh_size);
                        lastaddr = ssym;
                        ssym = 0;
                        goto nosyms;
                }
                /* Reset offsets relative to ssym */
                lastaddr += shdr[i].sh_size;
                lastaddr = roundup(lastaddr, sizeof(size));
                if (i == symtabindex)
                        symtabindex = -1;
                else if (i == symstrindex)
                        symstrindex = -1;
        }
        esym = lastaddr;
        if (module_verbose >= MODULE_VERBOSE_FULL)
                printf("]");

        file_addmetadata(fp, MODINFOMD_SSYM, sizeof(ssym), &ssym);
        file_addmetadata(fp, MODINFOMD_ESYM, sizeof(esym), &esym);

nosyms:
        if (module_verbose > MODULE_VERBOSE_SILENT)
                printf("\n");

        ret = lastaddr - firstaddr;
        fp->f_addr = firstaddr;

        php = NULL;
        for (i = 0; i < ehdr->e_phnum; i++) {
                if (phdr[i].p_type == PT_DYNAMIC) {
                        php = phdr + i;
                        adp = php->p_vaddr;
                        file_addmetadata(fp, MODINFOMD_DYNAMIC, sizeof(adp),
                            &adp);
                        break;
                }
        }

        if (php == NULL) /* this is bad, we cannot get to symbols or _DYNAMIC */
                goto out;

        ndp = php->p_filesz / sizeof(Elf_Dyn);
        if (ndp == 0)
                goto out;
        dp = malloc(php->p_filesz);
        if (dp == NULL)
                goto out;
        archsw.arch_copyout(php->p_vaddr + off, dp, php->p_filesz);

        ef->strsz = 0;
        for (i = 0; i < ndp; i++) {
                if (dp[i].d_tag == 0)
                        break;
                switch (dp[i].d_tag) {
                case DT_HASH:
                        ef->hashtab =
                            (Elf_Hashelt*)(uintptr_t)(dp[i].d_un.d_ptr + off);
                        break;
                case DT_STRTAB:
                        ef->strtab =
                            (char *)(uintptr_t)(dp[i].d_un.d_ptr + off);
                        break;
                case DT_STRSZ:
                        ef->strsz = dp[i].d_un.d_val;
                        break;
                case DT_SYMTAB:
                        ef->symtab =
                            (Elf_Sym *)(uintptr_t)(dp[i].d_un.d_ptr + off);
                        break;
                case DT_REL:
                        ef->rel =
                            (Elf_Rel *)(uintptr_t)(dp[i].d_un.d_ptr + off);
                        break;
                case DT_RELSZ:
                        ef->relsz = dp[i].d_un.d_val;
                        break;
                case DT_RELA:
                        ef->rela =
                            (Elf_Rela *)(uintptr_t)(dp[i].d_un.d_ptr + off);
                        break;
                case DT_RELASZ:
                        ef->relasz = dp[i].d_un.d_val;
                        break;
                default:
                        break;
                }
        }
        if (ef->hashtab == NULL || ef->symtab == NULL ||
            ef->strtab == NULL || ef->strsz == 0)
                goto out;
        COPYOUT(ef->hashtab, &ef->nbuckets, sizeof(ef->nbuckets));
        COPYOUT(ef->hashtab + 1, &ef->nchains, sizeof(ef->nchains));
        ef->buckets = ef->hashtab + 2;
        ef->chains = ef->buckets + ef->nbuckets;

        if (__elfN(lookup_symbol)(ef, "__start_set_modmetadata_set", &sym,
            STT_NOTYPE) != 0)
                return 0;
        p_start = sym.st_value + ef->off;
        if (__elfN(lookup_symbol)(ef, "__stop_set_modmetadata_set", &sym,
            STT_NOTYPE) != 0)
                return 0;
        p_end = sym.st_value + ef->off;

        if (__elfN(parse_modmetadata)(fp, ef, p_start, p_end) == 0)
                goto out;

        if (ef->kernel)         /* kernel must not depend on anything */
                goto out;

out:
        if (dp)
                free(dp);
        if (shdr)
                free(shdr);
        return ret;
}

static char invalid_name[] = "bad";

char *
fake_modname(const char *name)
{
        const char *sp, *ep;
        char *fp;
        size_t len;

        sp = strrchr(name, '/');
        if (sp)
                sp++;
        else
                sp = name;

        ep = strrchr(sp, '.');
        if (ep == NULL) {
                ep = sp + strlen(sp);
        }
        if (ep == sp) {
                sp = invalid_name;
                ep = invalid_name + sizeof(invalid_name) - 1;
        }

        len = ep - sp;
        fp = malloc(len + 1);
        if (fp == NULL)
                return NULL;
        memcpy(fp, sp, len);
        fp[len] = '\0';
        return fp;
}

#if (defined(__i386__) || defined(__powerpc__)) && __ELF_WORD_SIZE == 64
struct mod_metadata64 {
        int             md_version;     /* structure version MDTV_* */
        int             md_type;        /* type of entry MDT_* */
        uint64_t        md_data;        /* specific data */
        uint64_t        md_cval;        /* common string label */
};
#endif
#if defined(__amd64__) && __ELF_WORD_SIZE == 32
struct mod_metadata32 {
        int             md_version;     /* structure version MDTV_* */
        int             md_type;        /* type of entry MDT_* */
        uint32_t        md_data;        /* specific data */
        uint32_t        md_cval;        /* common string label */
};
#endif

int
__elfN(load_modmetadata)(struct preloaded_file *fp, uint64_t dest)
{
        struct elf_file          ef;
        int                      err, i, j;
        Elf_Shdr                *sh_meta, *shdr = NULL;
        Elf_Shdr                *sh_data[2];
        char                    *shstrtab = NULL;
        size_t                   size;
        Elf_Addr                 p_start, p_end;

        bzero(&ef, sizeof(struct elf_file));
        ef.fd = -1;

        err = __elfN(load_elf_header)(fp->f_name, &ef);
        if (err != 0)
                goto out;

        if (ef.kernel == 1 || ef.ehdr->e_type == ET_EXEC) {
                ef.kernel = 1;
        } else if (ef.ehdr->e_type != ET_DYN) {
                err = EFTYPE;
                goto out;
        }

        size = (size_t)ef.ehdr->e_shnum * (size_t)ef.ehdr->e_shentsize;
        shdr = alloc_pread(VECTX_HANDLE(&ef), ef.ehdr->e_shoff, size);
        if (shdr == NULL) {
                err = ENOMEM;
                goto out;
        }

        /* Load shstrtab. */
        shstrtab = alloc_pread(VECTX_HANDLE(&ef), shdr[ef.ehdr->e_shstrndx].sh_offset,
            shdr[ef.ehdr->e_shstrndx].sh_size);
        if (shstrtab == NULL) {
                printf("\nelf" __XSTRING(__ELF_WORD_SIZE)
                    "load_modmetadata: unable to load shstrtab\n");
                err = EFTYPE;
                goto out;
        }

        /* Find set_modmetadata_set and data sections. */
        sh_data[0] = sh_data[1] = sh_meta = NULL;
        for (i = 0, j = 0; i < ef.ehdr->e_shnum; i++) {
                if (strcmp(&shstrtab[shdr[i].sh_name],
                    "set_modmetadata_set") == 0) {
                        sh_meta = &shdr[i];
                }
                if ((strcmp(&shstrtab[shdr[i].sh_name], ".data") == 0) ||
                    (strcmp(&shstrtab[shdr[i].sh_name], ".rodata") == 0)) {
                        sh_data[j++] = &shdr[i];
                }
        }
        if (sh_meta == NULL || sh_data[0] == NULL || sh_data[1] == NULL) {
                printf("\nelf" __XSTRING(__ELF_WORD_SIZE)
    "load_modmetadata: unable to find set_modmetadata_set or data sections\n");
                err = EFTYPE;
                goto out;
        }

        /* Load set_modmetadata_set into memory */
        err = kern_pread(VECTX_HANDLE(&ef), dest, sh_meta->sh_size, sh_meta->sh_offset);
        if (err != 0) {
                printf("\nelf" __XSTRING(__ELF_WORD_SIZE)
    "load_modmetadata: unable to load set_modmetadata_set: %d\n", err);
                goto out;
        }
        p_start = dest;
        p_end = dest + sh_meta->sh_size;
        dest += sh_meta->sh_size;

        /* Load data sections into memory. */
        err = kern_pread(VECTX_HANDLE(&ef), dest, sh_data[0]->sh_size,
            sh_data[0]->sh_offset);
        if (err != 0) {
                printf("\nelf" __XSTRING(__ELF_WORD_SIZE)
                    "load_modmetadata: unable to load data: %d\n", err);
                goto out;
        }

        /*
         * We have to increment the dest, so that the offset is the same into
         * both the .rodata and .data sections.
         */
        ef.off = -(sh_data[0]->sh_addr - dest);
        dest += (sh_data[1]->sh_addr - sh_data[0]->sh_addr);

        err = kern_pread(VECTX_HANDLE(&ef), dest, sh_data[1]->sh_size,
            sh_data[1]->sh_offset);
        if (err != 0) {
                printf("\nelf" __XSTRING(__ELF_WORD_SIZE)
                    "load_modmetadata: unable to load data: %d\n", err);
                goto out;
        }

        err = __elfN(parse_modmetadata)(fp, &ef, p_start, p_end);
        if (err != 0) {
                printf("\nelf" __XSTRING(__ELF_WORD_SIZE)
                    "load_modmetadata: unable to parse metadata: %d\n", err);
                goto out;
        }

out:
        if (shstrtab != NULL)
                free(shstrtab);
        if (shdr != NULL)
                free(shdr);
        if (ef.firstpage != NULL)
                free(ef.firstpage);
        if (ef.fd != -1) {
#ifdef LOADER_VERIEXEC_VECTX
                if (!err && ef.vctx) {
                        int verror;

                        verror = vectx_close(ef.vctx, VE_MUST, __func__);
                        if (verror) {
                                err = EAUTH;
                                file_discard(fp);
                        }
                }
#endif
                close(ef.fd);
        }
        return (err);
}

int
__elfN(parse_modmetadata)(struct preloaded_file *fp, elf_file_t ef,
    Elf_Addr p_start, Elf_Addr p_end)
{
        struct mod_metadata md;
#if (defined(__i386__) || defined(__powerpc__)) && __ELF_WORD_SIZE == 64
        struct mod_metadata64 md64;
#elif defined(__amd64__) && __ELF_WORD_SIZE == 32
        struct mod_metadata32 md32;
#endif
        struct mod_depend *mdepend;
        struct mod_version mver;
        char *s;
        int error, modcnt, minfolen;
        Elf_Addr v, p;

        modcnt = 0;
        p = p_start;
        while (p < p_end) {
                COPYOUT(p, &v, sizeof(v));
                error = __elfN(reloc_ptr)(fp, ef, p, &v, sizeof(v));
                if (error == EOPNOTSUPP)
                        v += ef->off;
                else if (error != 0)
                        return (error);
#if (defined(__i386__) || defined(__powerpc__)) && __ELF_WORD_SIZE == 64
                COPYOUT(v, &md64, sizeof(md64));
                error = __elfN(reloc_ptr)(fp, ef, v, &md64, sizeof(md64));
                if (error == EOPNOTSUPP) {
                        md64.md_cval += ef->off;
                        md64.md_data += ef->off;
                } else if (error != 0)
                        return (error);
                md.md_version = md64.md_version;
                md.md_type = md64.md_type;
                md.md_cval = (const char *)(uintptr_t)md64.md_cval;
                md.md_data = (void *)(uintptr_t)md64.md_data;
#elif defined(__amd64__) && __ELF_WORD_SIZE == 32
                COPYOUT(v, &md32, sizeof(md32));
                error = __elfN(reloc_ptr)(fp, ef, v, &md32, sizeof(md32));
                if (error == EOPNOTSUPP) {
                        md32.md_cval += ef->off;
                        md32.md_data += ef->off;
                } else if (error != 0)
                        return (error);
                md.md_version = md32.md_version;
                md.md_type = md32.md_type;
                md.md_cval = (const char *)(uintptr_t)md32.md_cval;
                md.md_data = (void *)(uintptr_t)md32.md_data;
#else
                COPYOUT(v, &md, sizeof(md));
                error = __elfN(reloc_ptr)(fp, ef, v, &md, sizeof(md));
                if (error == EOPNOTSUPP) {
                        md.md_cval += ef->off;
                        md.md_data = (void *)((uintptr_t)md.md_data +
                            (uintptr_t)ef->off);
                } else if (error != 0)
                        return (error);
#endif
                p += sizeof(Elf_Addr);
                switch(md.md_type) {
                case MDT_DEPEND:
                        if (ef->kernel) /* kernel must not depend on anything */
                                break;
                        s = strdupout((vm_offset_t)md.md_cval);
                        minfolen = sizeof(*mdepend) + strlen(s) + 1;
                        mdepend = malloc(minfolen);
                        if (mdepend == NULL)
                                return ENOMEM;
                        COPYOUT((vm_offset_t)md.md_data, mdepend,
                            sizeof(*mdepend));
                        strcpy((char*)(mdepend + 1), s);
                        free(s);
                        file_addmetadata(fp, MODINFOMD_DEPLIST, minfolen,
                            mdepend);
                        free(mdepend);
                        break;
                case MDT_VERSION:
                        s = strdupout((vm_offset_t)md.md_cval);
                        COPYOUT((vm_offset_t)md.md_data, &mver, sizeof(mver));
                        file_addmodule(fp, s, mver.mv_version, NULL);
                        free(s);
                        modcnt++;
                        break;
                }
        }
        if (modcnt == 0) {
                s = fake_modname(fp->f_name);
                file_addmodule(fp, s, 1, NULL);
                free(s);
        }
        return 0;
}

static unsigned long
elf_hash(const char *name)
{
        const unsigned char *p = (const unsigned char *) name;
        unsigned long h = 0;
        unsigned long g;

        while (*p != '\0') {
                h = (h << 4) + *p++;
                if ((g = h & 0xf0000000) != 0)
                        h ^= g >> 24;
                h &= ~g;
        }
        return h;
}

static const char __elfN(bad_symtable)[] = "elf" __XSTRING(__ELF_WORD_SIZE)
    "_lookup_symbol: corrupt symbol table\n";
int
__elfN(lookup_symbol)(elf_file_t ef, const char* name, Elf_Sym *symp,
    unsigned char type)
{
        Elf_Hashelt symnum;
        Elf_Sym sym;
        char *strp;
        unsigned long hash;

        if (ef->nbuckets == 0) {
                printf(__elfN(bad_symtable));
                return ENOENT;
        }

        hash = elf_hash(name);
        COPYOUT(&ef->buckets[hash % ef->nbuckets], &symnum, sizeof(symnum));

        while (symnum != STN_UNDEF) {
                if (symnum >= ef->nchains) {
                        printf(__elfN(bad_symtable));
                        return ENOENT;
                }

                COPYOUT(ef->symtab + symnum, &sym, sizeof(sym));
                if (sym.st_name == 0) {
                        printf(__elfN(bad_symtable));
                        return ENOENT;
                }

                strp = strdupout((vm_offset_t)(ef->strtab + sym.st_name));
                if (strcmp(name, strp) == 0) {
                        free(strp);
                        if (sym.st_shndx != SHN_UNDEF && sym.st_value != 0 &&
                            ELF_ST_TYPE(sym.st_info) == type) {
                                *symp = sym;
                                return 0;
                        }
                        return ENOENT;
                }
                free(strp);
                COPYOUT(&ef->chains[symnum], &symnum, sizeof(symnum));
        }
        return ENOENT;
}

/*
 * Apply any intra-module relocations to the value. p is the load address
 * of the value and val/len is the value to be modified. This does NOT modify
 * the image in-place, because this is done by kern_linker later on.
 *
 * Returns EOPNOTSUPP if no relocation method is supplied.
 */
static int
__elfN(reloc_ptr)(struct preloaded_file *mp, elf_file_t ef,
    Elf_Addr p, void *val, size_t len)
{
        size_t n;
        Elf_Rela a;
        Elf_Rel r;
        int error;

        /*
         * The kernel is already relocated, but we still want to apply
         * offset adjustments.
         */
        if (ef->kernel)
                return (EOPNOTSUPP);

        for (n = 0; n < ef->relsz / sizeof(r); n++) {
                COPYOUT(ef->rel + n, &r, sizeof(r));

                error = __elfN(reloc)(ef, __elfN(symaddr), &r, ELF_RELOC_REL,
                    ef->off, p, val, len);
                if (error != 0)
                        return (error);
        }
        for (n = 0; n < ef->relasz / sizeof(a); n++) {
                COPYOUT(ef->rela + n, &a, sizeof(a));

                error = __elfN(reloc)(ef, __elfN(symaddr), &a, ELF_RELOC_RELA,
                    ef->off, p, val, len);
                if (error != 0)
                        return (error);
        }

        return (0);
}

static Elf_Addr
__elfN(symaddr)(struct elf_file *ef, Elf_Size symidx)
{

        /* Symbol lookup by index not required here. */
        return (0);
}