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m68k4k_exec.c revision 1.17.44.1
      1 /*	$NetBSD: m68k4k_exec.c,v 1.17.44.1 2007/12/09 19:37:11 jmcneill Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1993, 1994 Christopher G. Demetriou
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *      This product includes software developed by Christopher G. Demetriou.
     18  * 4. The name of the author may not be used to endorse or promote products
     19  *    derived from this software without specific prior written permission
     20  *
     21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     22  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     23  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     24  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     26  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     27  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     28  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     29  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     30  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     31  */
     32 
     33 /*
     34  * Exec glue to provide compatibility with older NetBSD m68k4k exectuables.
     35  *
     36  * Taken directly from kern/exec_aout.c and frobbed to map text and
     37  * data as m68k4k executables expect.
     38  *
     39  * This module only works on machines with PAGE_SIZE == 4096.  It's not clear
     40  * that making it work on other machines is worth the trouble.
     41  */
     42 
     43 #include <sys/cdefs.h>
     44 __KERNEL_RCSID(0, "$NetBSD: m68k4k_exec.c,v 1.17.44.1 2007/12/09 19:37:11 jmcneill Exp $");
     45 
     46 #if !defined(__m68k__)
     47 #error YOU GOTTA BE KIDDING!
     48 #endif
     49 
     50 #include <sys/param.h>
     51 #include <sys/systm.h>
     52 #include <sys/proc.h>
     53 #include <sys/malloc.h>
     54 #include <sys/vnode.h>
     55 #include <sys/exec.h>
     56 #include <sys/resourcevar.h>
     57 
     58 #include <compat/m68k4k/m68k4k_exec.h>
     59 
     60 int	exec_m68k4k_prep_zmagic(struct lwp *, struct exec_package *);
     61 int	exec_m68k4k_prep_nmagic(struct lwp *, struct exec_package *);
     62 int	exec_m68k4k_prep_omagic(struct lwp *, struct exec_package *);
     63 
     64 /*
     65  * exec_m68k4k_makecmds(): Check if it's an a.out-format executable
     66  * with an m68k4k magic number.
     67  *
     68  * Given a proc pointer and an exec package pointer, see if the referent
     69  * of the epp is in a.out format.  Just check 'standard' magic numbers for
     70  * this architecture.
     71  *
     72  * This function, in the former case, or the hook, in the latter, is
     73  * responsible for creating a set of vmcmds which can be used to build
     74  * the process's vm space and inserting them into the exec package.
     75  */
     76 
     77 int
     78 exec_m68k4k_makecmds(struct lwp *l, struct exec_package *epp)
     79 {
     80 	u_long midmag, magic;
     81 	u_short mid;
     82 	int error;
     83 	struct exec *execp = epp->ep_hdr;
     84 
     85 	/* See note above... */
     86 	if (M68K4K_LDPGSZ != PAGE_SIZE)
     87 		return ENOEXEC;
     88 
     89 	if (epp->ep_hdrvalid < sizeof(struct exec))
     90 		return ENOEXEC;
     91 
     92 	midmag = ntohl(execp->a_midmag);
     93 	mid = (midmag >> 16) & 0x3ff;
     94 	magic = midmag & 0xffff;
     95 
     96 	midmag = mid << 16 | magic;
     97 
     98 	switch (midmag) {
     99 	case (MID_M68K4K << 16) | ZMAGIC:
    100 		error = exec_m68k4k_prep_zmagic(l, epp);
    101 		break;
    102 	case (MID_M68K4K << 16) | NMAGIC:
    103 		error = exec_m68k4k_prep_nmagic(l, epp);
    104 		break;
    105 	case (MID_M68K4K << 16) | OMAGIC:
    106 		error = exec_m68k4k_prep_omagic(l, epp);
    107 		break;
    108 	default:
    109 		error = ENOEXEC;
    110 	}
    111 
    112 	if (error)
    113 		kill_vmcmds(&epp->ep_vmcmds);
    114 
    115 	return error;
    116 }
    117 
    118 /*
    119  * exec_m68k4k_prep_zmagic(): Prepare an m68k4k ZMAGIC binary's exec package
    120  *
    121  * First, set of the various offsets/lengths in the exec package.
    122  *
    123  * Then, mark the text image busy (so it can be demand paged) or error
    124  * out if this is not possible.  Finally, set up vmcmds for the
    125  * text, data, bss, and stack segments.
    126  */
    127 
    128 int
    129 exec_m68k4k_prep_zmagic(struct lwp *l, struct exec_package *epp)
    130 {
    131 	struct exec *execp = epp->ep_hdr;
    132 	int error;
    133 
    134 	epp->ep_taddr = M68K4K_USRTEXT;
    135 	epp->ep_tsize = execp->a_text;
    136 	epp->ep_daddr = epp->ep_taddr + execp->a_text;
    137 	epp->ep_dsize = execp->a_data + execp->a_bss;
    138 	epp->ep_entry = execp->a_entry;
    139 
    140 	error = vn_marktext(epp->ep_vp);
    141 	if (error)
    142 		return (error);
    143 
    144 	/* set up command for text segment */
    145 	NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, execp->a_text,
    146 	    epp->ep_taddr, epp->ep_vp, 0, VM_PROT_READ|VM_PROT_EXECUTE);
    147 
    148 	/* set up command for data segment */
    149 	NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, execp->a_data,
    150 	    epp->ep_daddr, epp->ep_vp, execp->a_text,
    151 	    VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
    152 
    153 	/* set up command for bss segment */
    154 	if (execp->a_bss)
    155 		NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, execp->a_bss,
    156 		    epp->ep_daddr + execp->a_data, NULLVP, 0,
    157 		    VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
    158 
    159 	return (*epp->ep_esch->es_setup_stack)(l, epp);
    160 }
    161 
    162 /*
    163  * exec_m68k4k_prep_nmagic(): Prepare a m68k4k NMAGIC binary's exec package
    164  */
    165 
    166 int
    167 exec_m68k4k_prep_nmagic(struct lwp *l, struct exec_package *epp)
    168 {
    169 	struct exec *execp = epp->ep_hdr;
    170 	long bsize, baddr;
    171 
    172 	epp->ep_taddr = M68K4K_USRTEXT;
    173 	epp->ep_tsize = execp->a_text;
    174 	epp->ep_daddr = roundup(epp->ep_taddr + execp->a_text,
    175 	    M68K4K_LDPGSZ);
    176 	epp->ep_dsize = execp->a_data + execp->a_bss;
    177 	epp->ep_entry = execp->a_entry;
    178 
    179 	/* set up command for text segment */
    180 	NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_text,
    181 	    epp->ep_taddr, epp->ep_vp, sizeof(struct exec),
    182 	    VM_PROT_READ|VM_PROT_EXECUTE);
    183 
    184 	/* set up command for data segment */
    185 	NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_data,
    186 	    epp->ep_daddr, epp->ep_vp, execp->a_text + sizeof(struct exec),
    187 	    VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
    188 
    189 	/* set up command for bss segment */
    190 	baddr = roundup(epp->ep_daddr + execp->a_data, PAGE_SIZE);
    191 	bsize = epp->ep_daddr + epp->ep_dsize - baddr;
    192 	if (bsize > 0)
    193 		NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, bsize, baddr,
    194 		    NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
    195 
    196 	return (*epp->ep_esch->es_setup_stack)(l, epp);
    197 }
    198 
    199 /*
    200  * exec_m68k4k_prep_omagic(): Prepare a m68k4k OMAGIC binary's exec package
    201  */
    202 
    203 int
    204 exec_m68k4k_prep_omagic(struct lwp *l, struct exec_package *epp)
    205 {
    206 	struct exec *execp = epp->ep_hdr;
    207 	long dsize, bsize, baddr;
    208 
    209 	epp->ep_taddr = M68K4K_USRTEXT;
    210 	epp->ep_tsize = execp->a_text;
    211 	epp->ep_daddr = epp->ep_taddr + execp->a_text;
    212 	epp->ep_dsize = execp->a_data + execp->a_bss;
    213 	epp->ep_entry = execp->a_entry;
    214 
    215 	/* set up command for text and data segments */
    216 	NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn,
    217 	    execp->a_text + execp->a_data, epp->ep_taddr, epp->ep_vp,
    218 	    sizeof(struct exec), VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
    219 
    220 	/* set up command for bss segment */
    221 	baddr = roundup(epp->ep_daddr + execp->a_data, PAGE_SIZE);
    222 	bsize = epp->ep_daddr + epp->ep_dsize - baddr;
    223 	if (bsize > 0)
    224 		NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, bsize, baddr,
    225 		    NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
    226 
    227 	/*
    228 	 * Make sure (# of pages) mapped above equals (vm_tsize + vm_dsize);
    229 	 * obreak(2) relies on this fact. Both `vm_tsize' and `vm_dsize' are
    230 	 * computed (in execve(2)) by rounding *up* `ep_tsize' and `ep_dsize'
    231 	 * respectively to page boundaries.
    232 	 * Compensate `ep_dsize' for the amount of data covered by the last
    233 	 * text page.
    234 	 */
    235 	dsize = epp->ep_dsize + execp->a_text - roundup(execp->a_text,
    236 							PAGE_SIZE);
    237 	epp->ep_dsize = (dsize > 0) ? dsize : 0;
    238 	return (*epp->ep_esch->es_setup_stack)(l, epp);
    239 }
    240