xref: /src/sys/compat/common/compat_exec.c

/*	$NetBSD: compat_exec.c,v 1.18 2019/01/27 02:08:39 pgoyette Exp $	*/

/*
 * Copyright (c) 1993, 1994 Christopher G. Demetriou
 * 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Christopher G. Demetriou.
 * 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: compat_exec.c,v 1.18 2019/01/27 02:08:39 pgoyette Exp $");

#ifdef _KERNEL_OPT
#include "opt_compat_netbsd.h"
#include "opt_execfmt.h"
#endif

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

#ifdef EXEC_AOUT
#include <sys/exec_aout.h>

/*
 * exec_aout_prep_oldzmagic():
 *	Prepare the vmcmds to build a vmspace for an old ZMAGIC
 *	binary. [386BSD/BSDI/4.4BSD/NetBSD0.8]
 *
 * Cloned from exec_aout_prep_zmagic() in kern/exec_aout.c; a more verbose
 * description of operation is there.
 * There were copies of this in the mac68k, hp300, and i386 ports.
 */
int
exec_aout_prep_oldzmagic(struct lwp *l, struct exec_package *epp)
{
	struct exec *execp = epp->ep_hdr;
	int error;

	epp->ep_taddr = 0;
	epp->ep_tsize = execp->a_text;
	epp->ep_daddr = epp->ep_taddr + execp->a_text;
	epp->ep_dsize = execp->a_data + execp->a_bss;
	epp->ep_entry = execp->a_entry;

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

	/* set up command for text segment */
	NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, execp->a_text,
	    epp->ep_taddr, epp->ep_vp, PAGE_SIZE, /* XXX CLBYTES? */
	    VM_PROT_READ|VM_PROT_EXECUTE);

	/* set up command for data segment */
	NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, execp->a_data,
	    epp->ep_daddr, epp->ep_vp,
	    execp->a_text + PAGE_SIZE, /* XXX CLBYTES? */
	    VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);

	/* set up command for bss segment */
	if (execp->a_bss)
	    NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, execp->a_bss,
		epp->ep_daddr + execp->a_data, NULLVP, 0,
		VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);

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


/*
 * exec_aout_prep_oldnmagic():
 *	Prepare the vmcmds to build a vmspace for an old NMAGIC
 *	binary. [BSDI]
 *
 * Cloned from exec_aout_prep_nmagic() in kern/exec_aout.c; with text starting
 * at 0.
 * XXX: There must be a better way to share this code.
 */
int
exec_aout_prep_oldnmagic(struct lwp *l, struct exec_package *epp)
{
	struct exec *execp = epp->ep_hdr;
	long bsize, baddr;

	epp->ep_taddr = 0;
	epp->ep_tsize = execp->a_text;
	epp->ep_daddr = roundup(epp->ep_taddr + execp->a_text, AOUT_LDPGSZ);
	epp->ep_dsize = execp->a_data + execp->a_bss;
	epp->ep_entry = execp->a_entry;

	/* set up command for text segment */
	NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_text,
	    epp->ep_taddr, epp->ep_vp, sizeof(struct exec),
	    VM_PROT_READ|VM_PROT_EXECUTE);

	/* set up command for data segment */
	NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_data,
	    epp->ep_daddr, epp->ep_vp, execp->a_text + sizeof(struct exec),
	    VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);

	/* set up command for bss segment */
	baddr = roundup(epp->ep_daddr + execp->a_data, PAGE_SIZE);
	bsize = epp->ep_daddr + epp->ep_dsize - baddr;
	if (bsize > 0)
		NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, bsize, baddr,
		    NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);

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


/*
 * exec_aout_prep_oldomagic():
 *	Prepare the vmcmds to build a vmspace for an old OMAGIC
 *	binary. [BSDI]
 *
 * Cloned from exec_aout_prep_omagic() in kern/exec_aout.c; with text starting
 * at 0.
 * XXX: There must be a better way to share this code.
 */
int
exec_aout_prep_oldomagic(struct lwp *l, struct exec_package *epp)
{
	struct exec *execp = epp->ep_hdr;
	long dsize, bsize, baddr;

	epp->ep_taddr = 0;
	epp->ep_tsize = execp->a_text;
	epp->ep_daddr = epp->ep_taddr + execp->a_text;
	epp->ep_dsize = execp->a_data + execp->a_bss;
	epp->ep_entry = execp->a_entry;

	/* set up command for text and data segments */
	NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn,
	    execp->a_text + execp->a_data, epp->ep_taddr, epp->ep_vp,
	    sizeof(struct exec), VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);

	/* set up command for bss segment */
	baddr = roundup(epp->ep_daddr + execp->a_data, PAGE_SIZE);
	bsize = epp->ep_daddr + epp->ep_dsize - baddr;
	if (bsize > 0)
		NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, bsize, baddr,
		    NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);

	/*
	 * Make sure (# of pages) mapped above equals (vm_tsize + vm_dsize);
	 * obreak(2) relies on this fact. Both `vm_tsize' and `vm_dsize' are
	 * computed (in execve(2)) by rounding *up* `ep_tsize' and `ep_dsize'
	 * respectively to page boundaries.
	 * Compensate `ep_dsize' for the amount of data covered by the last
	 * text page.
	 */
	dsize = epp->ep_dsize + execp->a_text - roundup(execp->a_text,
							PAGE_SIZE);
	epp->ep_dsize = (dsize > 0) ? dsize : 0;
	return (*epp->ep_esch->es_setup_stack)(l, epp);
}
#endif /* EXEC_AOUT */