/*      $NetBSD: coff_exec.c,v 1.36 2024/09/08 09:36:49 rillig Exp $    */

/*
 * Copyright (c) 1994, 1995 Scott Bartram
 * Copyright (c) 1994 Adam Glass
 * Copyright (c) 1993, 1994 Christopher G. Demetriou
 * All rights reserved.
 *
 * originally from kern/exec_ecoff.c
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Scott Bartram.
 * 4. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: coff_exec.c,v 1.36 2024/09/08 09:36:49 rillig Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/exec.h>
#include <sys/vnode.h>
#include <sys/resourcevar.h>
#include <sys/namei.h>
#include <sys/exec_coff.h>
#include <sys/module.h>

#include <uvm/uvm_extern.h>

MODULE(MODULE_CLASS_MISC, exec_coff, NULL);

static int coff_find_section(struct lwp *, struct vnode *,
    struct coff_filehdr *, struct coff_scnhdr *, int);

static struct execsw exec_coff_execsw[] = {
        { COFF_HDR_SIZE,
          exec_coff_makecmds,
          { NULL },
          &emul_netbsd,
          EXECSW_PRIO_ANY,
          0,
          copyargs,
          NULL,
          coredump_netbsd,
          exec_setup_stack },
};

static int
exec_coff_modcmd(modcmd_t cmd, void *arg)
{

        switch (cmd) {
        case MODULE_CMD_INIT:
                return exec_add(exec_coff_execsw,
                    __arraycount(exec_coff_execsw));

        case MODULE_CMD_FINI:
                return exec_remove(exec_coff_execsw,
                    __arraycount(exec_coff_execsw));

        default:
                return ENOTTY;
        }
}

/*
 * exec_coff_makecmds(): Check if it's a coff-format executable.
 *
 * Given a lwp pointer and an exec package pointer, see if the referent
 * of the epp is in coff format.  Check 'standard' magic numbers for
 * this architecture.  If that fails, return failure.
 *
 * This function is  responsible for creating a set of vmcmds which can be
 * used to build the process's vm space and inserting them into the exec
 * package.
 */

int
exec_coff_makecmds(struct lwp *l, struct exec_package *epp)
{
        int error;
        struct coff_filehdr *fp = epp->ep_hdr;
        struct coff_aouthdr *ap;

        if (epp->ep_hdrvalid < COFF_HDR_SIZE)
                return ENOEXEC;

        if (COFF_BADMAG(fp))
                return ENOEXEC;

        ap = (void *)((char *)epp->ep_hdr + sizeof(struct coff_filehdr));
        switch (ap->a_magic) {
        case COFF_OMAGIC:
                error = exec_coff_prep_omagic(l, epp, fp, ap);
                break;
        case COFF_NMAGIC:
                error = exec_coff_prep_nmagic(l, epp, fp, ap);
                break;
        case COFF_ZMAGIC:
                error = exec_coff_prep_zmagic(l, epp, fp, ap);
                break;
        default:
                return ENOEXEC;
        }

#ifdef  TODO
        if (error == 0)
                error = cpu_exec_coff_hook(p, epp);
#endif

        if (error)
                kill_vmcmds(&epp->ep_vmcmds);

        return error;
}

/*
 * exec_coff_prep_omagic(): Prepare a COFF OMAGIC binary's exec package
 */

int
exec_coff_prep_omagic(struct lwp *l, struct exec_package *epp,
    struct coff_filehdr *fp, struct coff_aouthdr *ap)
{
        epp->ep_taddr = COFF_SEGMENT_ALIGN(fp, ap, ap->a_tstart);
        epp->ep_tsize = ap->a_tsize;
        epp->ep_daddr = COFF_SEGMENT_ALIGN(fp, ap, ap->a_dstart);
        epp->ep_dsize = ap->a_dsize;
        epp->ep_entry = ap->a_entry;

        /* set up command for text and data segments */
        NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn,
            ap->a_tsize + ap->a_dsize, epp->ep_taddr, epp->ep_vp,
            COFF_TXTOFF(fp, ap),
            VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);

        /* set up command for bss segment */
#ifdef  __sh__
        if (ap->a_bsize > 0)
                NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, ap->a_bsize,
                    COFF_ROUND(ap->a_dstart + ap->a_dsize, COFF_LDPGSZ),
                    NULLVP, 0,
                    VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
#else
        if (ap->a_bsize > 0)
                NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, ap->a_bsize,
                    COFF_SEGMENT_ALIGN(fp, ap,
                        ap->a_dstart + ap->a_dsize),
                    NULLVP, 0,
                    VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
#endif

        return (*epp->ep_esch->es_setup_stack)(l, epp);
}

/*
 * exec_coff_prep_nmagic(): Prepare a 'native' NMAGIC COFF binary's exec
 *                          package.
 */

int
exec_coff_prep_nmagic(struct lwp *l, struct exec_package *epp, struct coff_filehdr *fp, struct coff_aouthdr *ap)
{
        epp->ep_taddr = COFF_SEGMENT_ALIGN(fp, ap, ap->a_tstart);
        epp->ep_tsize = ap->a_tsize;
        epp->ep_daddr = COFF_ROUND(ap->a_dstart, COFF_LDPGSZ);
        epp->ep_dsize = ap->a_dsize;
        epp->ep_entry = ap->a_entry;

        /* set up command for text segment */
        NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, epp->ep_tsize,
            epp->ep_taddr, epp->ep_vp, COFF_TXTOFF(fp, ap),
            VM_PROT_READ|VM_PROT_EXECUTE);

        /* set up command for data segment */
        NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, epp->ep_dsize,
            epp->ep_daddr, epp->ep_vp, COFF_DATOFF(fp, ap),
            VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);

        /* set up command for bss segment */
        if (ap->a_bsize > 0)
                NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, ap->a_bsize,
                    COFF_SEGMENT_ALIGN(fp, ap,
                        ap->a_dstart + ap->a_dsize),
                    NULLVP, 0,
                    VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);

        return (*epp->ep_esch->es_setup_stack)(l, epp);
}

/*
 * coff_find_section - load specified section header
 *
 * TODO - optimize by reading all section headers in at once
 */

static int
coff_find_section(struct lwp *l, struct vnode *vp, struct coff_filehdr *fp,
    struct coff_scnhdr *sh, int s_type)
{
        int i, pos, error;
        size_t siz, resid;

        pos = COFF_HDR_SIZE;
        for (i = 0; i < fp->f_nscns; i++, pos += sizeof(struct coff_scnhdr)) {
                siz = sizeof(struct coff_scnhdr);
                error = vn_rdwr(UIO_READ, vp, (void *) sh,
                    siz, pos, UIO_SYSSPACE, IO_NODELOCKED, l->l_cred,
                    &resid, NULL);
                if (error) {
                        DPRINTF(("section hdr %d read error %d\n", i, error));
                        return error;
                }
                siz -= resid;
                if (siz != sizeof(struct coff_scnhdr)) {
                        DPRINTF(("incomplete read: hdr %d ask=%d, rem=%zu got %zu\n",
                            s_type, sizeof(struct coff_scnhdr),
                            resid, siz));
                        return ENOEXEC;
                }
                DPRINTF(("found section: %lu\n", sh->s_flags));
                if (sh->s_flags == s_type)
                        return 0;
        }
        return ENOEXEC;
}

/*
 * exec_coff_prep_zmagic(): Prepare a COFF ZMAGIC binary's exec package
 *
 * First, set the various offsets/lengths in the exec package.
 *
 * Then, mark the text image busy (so it can be demand paged) or error
 * out if this is not possible.  Finally, set up vmcmds for the
 * text, data, bss, and stack segments.
 */

int
exec_coff_prep_zmagic(struct lwp *l, struct exec_package *epp,
    struct coff_filehdr *fp, struct coff_aouthdr *ap)
{
        int error;
        u_long offset;
        long dsize;
#ifndef __sh__
        long  baddr, bsize;
#endif
        struct coff_scnhdr sh;

        DPRINTF(("enter exec_coff_prep_zmagic\n"));

        /* set up command for text segment */
        error = coff_find_section(l, epp->ep_vp, fp, &sh, COFF_STYP_TEXT);
        if (error) {
                DPRINTF(("can't find text section: %d\n", error));
                return error;
        }
        DPRINTF(("COFF text addr %lu size %ld offset %ld\n", sh.s_vaddr,
            sh.s_size, sh.s_scnptr));
        epp->ep_taddr = COFF_ALIGN(sh.s_vaddr);
        offset = sh.s_scnptr - (sh.s_vaddr - epp->ep_taddr);
        epp->ep_tsize = sh.s_size + (sh.s_vaddr - epp->ep_taddr);

        error = vn_marktext(epp->ep_vp);
        if (error)
                return (error);

        DPRINTF(("VMCMD: addr %lx size %lx offset %lx\n", epp->ep_taddr,
            epp->ep_tsize, offset));
        if (!(offset & PAGE_MASK) && !(epp->ep_taddr & PAGE_MASK)) {
                epp->ep_tsize = round_page(epp->ep_tsize);
                NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, epp->ep_tsize,
                    epp->ep_taddr, epp->ep_vp, offset,
                    VM_PROT_READ|VM_PROT_EXECUTE);
        } else {
                NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, epp->ep_tsize,
                    epp->ep_taddr, epp->ep_vp, offset,
                    VM_PROT_READ|VM_PROT_EXECUTE);
        }

        /* set up command for data segment */
        error = coff_find_section(l, epp->ep_vp, fp, &sh, COFF_STYP_DATA);
        if (error) {
                DPRINTF(("can't find data section: %d\n", error));
                return error;
        }
        DPRINTF(("COFF data addr %lx size %ld offset %ld\n", sh.s_vaddr,
            sh.s_size, sh.s_scnptr));
        epp->ep_daddr = COFF_ALIGN(sh.s_vaddr);
        offset = sh.s_scnptr - (sh.s_vaddr - epp->ep_daddr);
        dsize = sh.s_size + (sh.s_vaddr - epp->ep_daddr);
#ifdef __sh__
        epp->ep_dsize = round_page(dsize) + ap->a_bsize;
#else
        epp->ep_dsize = dsize + ap->a_bsize;
#endif

        DPRINTF(("VMCMD: addr %lx size %lx offset %lx\n", epp->ep_daddr,
            dsize, offset));
        if (!(offset & PAGE_MASK) && !(epp->ep_daddr & PAGE_MASK)) {
                dsize = round_page(dsize);
                NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, dsize,
                    epp->ep_daddr, epp->ep_vp, offset,
                    VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
        } else {
                NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn,
                    dsize, epp->ep_daddr, epp->ep_vp, offset,
                    VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
        }

#ifdef  __sh__
        if (ap->a_bsize > 0) {
                NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, ap->a_bsize,
                    COFF_ROUND(ap->a_dstart + ap->a_dsize, COFF_LDPGSZ),
                    NULLVP, 0,
                    VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
        }
#else
        /* set up command for bss segment */
        baddr = round_page(epp->ep_daddr + dsize);
        bsize = epp->ep_daddr + epp->ep_dsize - baddr;
        if (bsize > 0) {
                DPRINTF(("VMCMD: addr %x size %x offset %x\n",
                    baddr, bsize, 0));
                NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero,
                    bsize, baddr, NULLVP, 0,
                    VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
        }
#endif

#ifdef  TODO
        /* load any shared libraries */
        error = coff_find_section(l, epp->ep_vp, fp, &sh, COFF_STYP_SHLIB);
        if (!error) {
                size_t resid;
                struct coff_slhdr *slhdr;
                char buf[128], *bufp;   /* FIXME */
                int len = sh.s_size, path_index, entry_len;

                DPRINTF(("COFF shlib size %d offset %d\n",
                    sh.s_size, sh.s_scnptr));

                error = vn_rdwr(UIO_READ, epp->ep_vp, (void *) buf,
                    len, sh.s_scnptr,
                    UIO_SYSSPACE, IO_NODELOCKED, l->l_cred,
                    &resid, NULL);
                if (error) {
                        DPRINTF(("shlib section read error %d\n", error));
                        return ENOEXEC;
                }
                bufp = buf;
                while (len) {
                        slhdr = (struct coff_slhdr *)bufp;
                        path_index = slhdr->path_index * sizeof(long);
                        entry_len = slhdr->entry_len * sizeof(long);

                        DPRINTF(("path_index: %d entry_len: %d name: %s\n",
                            path_index, entry_len, slhdr->sl_name));

                        error = coff_load_shlib(p, slhdr->sl_name, epp);
                        if (error)
                                return ENOEXEC;
                        bufp += entry_len;
                        len -= entry_len;
                }
        }
#endif
        /* set up entry point */
        epp->ep_entry = ap->a_entry;

#if 1
        DPRINTF(("text addr: %lx size: %ld data addr: %lx size: %ld entry: %lx\n",
            epp->ep_taddr, epp->ep_tsize,
            epp->ep_daddr, epp->ep_dsize,
            epp->ep_entry));
#endif
        return (*epp->ep_esch->es_setup_stack)(l, epp);
}

#if 0
int
coff_load_shlib(struct lwp *l, char *path, struct exec_package *epp)
{
        int error;
        size_t siz, resid;
        int taddr, tsize, daddr, dsize, offset;
        struct vnode *vp;
        struct coff_filehdr fh, *fhp = &fh;
        struct coff_scnhdr sh, *shp = &sh;

        /*
         * 1. open shlib file
         * 2. read filehdr
         * 3. map text, data, and bss out of it using VM_*
         */
        /* first get the vnode */
        error = namei_simple_kernel(path, NSM_FOLLOW_TRYEMULROOT, &vp);
        if (error != 0) {
                DPRINTF(("coff_load_shlib: can't find library %s\n", path));
                return error;
        }

        siz = sizeof(struct coff_filehdr);
        error = vn_rdwr(UIO_READ, vp, (void *) fhp, siz, 0,
            UIO_SYSSPACE, IO_NODELOCKED, l->l_cred, &resid, NULL);
        if (error) {
                DPRINTF(("filehdr read error %d\n", error));
                vrele(vp);
                return error;
        }
        siz -= resid;
        if (siz != sizeof(struct coff_filehdr)) {
                DPRINTF(("coff_load_shlib: incomplete read: ask=%d, rem=%zu got %zu\n",
                    sizeof(struct coff_filehdr), resid, siz));
                vrele(vp);
                return ENOEXEC;
        }

        /* load text */
        error = coff_find_section(l, vp, fhp, shp, COFF_STYP_TEXT);
        if (error) {
                DPRINTF(("can't find shlib text section\n"));
                vrele(vp);
                return error;
        }
        DPRINTF(("COFF text addr %x size %d offset %d\n", sh.s_vaddr,
            sh.s_size, sh.s_scnptr));
        taddr = COFF_ALIGN(shp->s_vaddr);
        offset = shp->s_scnptr - (shp->s_vaddr - taddr);
        tsize = shp->s_size + (shp->s_vaddr - taddr);
        DPRINTF(("VMCMD: addr %x size %x offset %x\n", taddr, tsize, offset));
        NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, tsize, taddr,
            vp, offset,
            VM_PROT_READ|VM_PROT_EXECUTE);

        /* load data */
        error = coff_find_section(l, vp, fhp, shp, COFF_STYP_DATA);
        if (error) {
                DPRINTF(("can't find shlib data section\n"));
                vrele(vp);
                return error;
        }
        DPRINTF(("COFF data addr %x size %d offset %d\n", shp->s_vaddr,
            shp->s_size, shp->s_scnptr));
        daddr = COFF_ALIGN(shp->s_vaddr);
        offset = shp->s_scnptr - (shp->s_vaddr - daddr);
        dsize = shp->s_size + (shp->s_vaddr - daddr);
        /* epp->ep_dsize = dsize + ap->a_bsize; */

        DPRINTF(("VMCMD: addr %x size %x offset %x\n", daddr, dsize, offset));
        NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn,
            dsize, daddr, vp, offset,
            VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);

        /* load bss */
        error = coff_find_section(l, vp, fhp, shp, COFF_STYP_BSS);
        if (!error) {
                int baddr = round_page(daddr + dsize);
                int bsize = daddr + dsize + shp->s_size - baddr;
                if (bsize > 0) {
                        DPRINTF(("VMCMD: addr %x size %x offset %x\n",
                            baddr, bsize, 0));
                        NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero,
                            bsize, baddr, NULLVP, 0,
                            VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
                }
        }
        vrele(vp);

        return 0;
}
#endif