sys/kern/exec_aout.c

   1 /*      $NetBSD: exec_aout.c,v 1.33 2005/12/11 12:24:29 christos 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 #include <sys/cdefs.h>
  34 __KERNEL_RCSID(0, "$NetBSD: exec_aout.c,v 1.33 2005/12/11 12:24:29 christos Exp $");
  35
  36 #ifdef _KERNEL_OPT
  37 #include "opt_coredump.h"
  38 #endif
  39
  40 #include <sys/param.h>
  41 #include <sys/systm.h>
  42 #include <sys/proc.h>
  43 #include <sys/malloc.h>
  44 #include <sys/vnode.h>
  45 #include <sys/exec.h>
  46 #include <sys/exec_aout.h>
  47 #include <sys/resourcevar.h>
  48 #include <sys/module.h>
  49
  50 #include <uvm/uvm_extern.h>
  51
  52 #ifdef COREDUMP
  53 #define DEP     "coredump"
  54 #else
  55 #define DEP     NULL
  56 #endif
  57
  58 MODULE(MODULE_CLASS_MISC, exec_aout, DEP);
  59
  60 static struct execsw exec_aout_execsw[] = {
  61         { sizeof(struct exec),
  62           exec_aout_makecmds,
  63           { NULL },
  64           &emul_netbsd,
  65           EXECSW_PRIO_ANY,
  66           0,
  67           copyargs,
  68           NULL,
  69           coredump_netbsd,
  70           exec_setup_stack },
  71 };
  72
  73 static int
  74 exec_aout_modcmd(modcmd_t cmd, void *arg)
  75 {
  76
  77         switch (cmd) {
  78         case MODULE_CMD_INIT:
  79                 return exec_add(exec_aout_execsw,
  80                     __arraycount(exec_aout_execsw));
  81
  82         case MODULE_CMD_FINI:
  83                 return exec_remove(exec_aout_execsw,
  84                     __arraycount(exec_aout_execsw));
  85
  86         default:
  87                 return ENOTTY;
  88         }
  89 }
  90
  91 /*
  92  * exec_aout_makecmds(): Check if it's an a.out-format executable.
  93  *
  94  * Given a lwp pointer and an exec package pointer, see if the referent
  95  * of the epp is in a.out format.  First check 'standard' magic numbers for
  96  * this architecture.  If that fails, try a CPU-dependent hook.
  97  *
  98  * This function, in the former case, or the hook, in the latter, is
  99  * responsible for creating a set of vmcmds which can be used to build
 100  * the process's vm space and inserting them into the exec package.
 101  */
 102
 103 int
 104 exec_aout_makecmds(struct lwp *l, struct exec_package *epp)
 105 {
 106         u_long midmag, magic;
 107         u_short mid;
 108         int error;
 109         struct exec *execp = epp->ep_hdr;
 110
 111         if (epp->ep_hdrvalid < sizeof(struct exec))
 112                 return ENOEXEC;
 113
 114         midmag = ntohl(execp->a_midmag);
 115         mid = (midmag >> 16) & 0x3ff;
 116         magic = midmag & 0xffff;
 117
 118         midmag = mid << 16 | magic;
 119
 120         switch (midmag) {
 121         case (MID_MACHINE << 16) | ZMAGIC:
 122                 error = exec_aout_prep_zmagic(l, epp);
 123                 break;
 124         case (MID_MACHINE << 16) | NMAGIC:
 125                 error = exec_aout_prep_nmagic(l, epp);
 126                 break;
 127         case (MID_MACHINE << 16) | OMAGIC:
 128                 error = exec_aout_prep_omagic(l, epp);
 129                 break;
 130         default:
 131                 error = cpu_exec_aout_makecmds(l, epp);
 132         }
 133
 134         if (error)
 135                 kill_vmcmds(&epp->ep_vmcmds);
 136
 137         return error;
 138 }
 139
 140 /*
 141  * exec_aout_prep_zmagic(): Prepare a 'native' ZMAGIC binary's exec package
 142  *
 143  * First, set of the various offsets/lengths in the exec package.
 144  *
 145  * Then, mark the text image busy (so it can be demand paged) or error
 146  * out if this is not possible.  Finally, set up vmcmds for the
 147  * text, data, bss, and stack segments.
 148  */
 149
 150 int
 151 exec_aout_prep_zmagic(struct lwp *l, struct exec_package *epp)
 152 {
 153         struct exec *execp = epp->ep_hdr;
 154         int error;
 155
 156         epp->ep_taddr = AOUT_LDPGSZ;
 157         epp->ep_tsize = execp->a_text;
 158         epp->ep_daddr = epp->ep_taddr + execp->a_text;
 159         epp->ep_dsize = execp->a_data + execp->a_bss;
 160         epp->ep_entry = execp->a_entry;
 161
 162         error = vn_marktext(epp->ep_vp);
 163         if (error)
 164                 return (error);
 165
 166         /* set up command for text segment */
 167         NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, round_page(execp->a_text),
 168             epp->ep_taddr, epp->ep_vp, 0, VM_PROT_READ|VM_PROT_EXECUTE);
 169
 170         /* set up command for data segment */
 171         NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, round_page(execp->a_data),
 172             epp->ep_daddr, epp->ep_vp, execp->a_text,
 173             VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
 174
 175         /* set up command for bss segment */
 176         if (execp->a_bss > 0)
 177                 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, execp->a_bss,
 178                     epp->ep_daddr + execp->a_data, NULLVP, 0,
 179                     VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
 180
 181         return (*epp->ep_esch->es_setup_stack)(l, epp);
 182 }
 183
 184 /*
 185  * exec_aout_prep_nmagic(): Prepare a 'native' NMAGIC binary's exec package
 186  */
 187
 188 int
 189 exec_aout_prep_nmagic(struct lwp *l, struct exec_package *epp)
 190 {
 191         struct exec *execp = epp->ep_hdr;
 192         long bsize, baddr;
 193
 194         epp->ep_taddr = AOUT_LDPGSZ;
 195         epp->ep_tsize = execp->a_text;
 196         epp->ep_daddr = roundup(epp->ep_taddr + execp->a_text, AOUT_LDPGSZ);
 197         epp->ep_dsize = execp->a_data + execp->a_bss;
 198         epp->ep_entry = execp->a_entry;
 199
 200         /* set up command for text segment */
 201         NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_text,
 202             epp->ep_taddr, epp->ep_vp, sizeof(struct exec),
 203             VM_PROT_READ|VM_PROT_EXECUTE);
 204
 205         /* set up command for data segment */
 206         NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_data,
 207             epp->ep_daddr, epp->ep_vp, execp->a_text + sizeof(struct exec),
 208             VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
 209
 210         /* set up command for bss segment */
 211         baddr = round_page(epp->ep_daddr + execp->a_data);
 212         bsize = epp->ep_daddr + epp->ep_dsize - baddr;
 213         if (bsize > 0)
 214                 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, bsize, baddr,
 215                     NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
 216
 217         return (*epp->ep_esch->es_setup_stack)(l, epp);
 218 }
 219
 220 /*
 221  * exec_aout_prep_omagic(): Prepare a 'native' OMAGIC binary's exec package
 222  */
 223
 224 int
 225 exec_aout_prep_omagic(struct lwp *l, struct exec_package *epp)
 226 {
 227         struct exec *execp = epp->ep_hdr;
 228         long dsize, bsize, baddr;
 229
 230         epp->ep_taddr = AOUT_LDPGSZ;
 231         epp->ep_tsize = execp->a_text;
 232         epp->ep_daddr = epp->ep_taddr + execp->a_text;
 233         epp->ep_dsize = execp->a_data + execp->a_bss;
 234         epp->ep_entry = execp->a_entry;
 235
 236         /* set up command for text and data segments */
 237         NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn,
 238             execp->a_text + execp->a_data, epp->ep_taddr, epp->ep_vp,
 239             sizeof(struct exec), VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
 240
 241         /* set up command for bss segment */
 242         baddr = round_page(epp->ep_daddr + execp->a_data);
 243         bsize = epp->ep_daddr + epp->ep_dsize - baddr;
 244         if (bsize > 0)
 245                 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, bsize, baddr,
 246                     NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
 247
 248         /*
 249          * Make sure (# of pages) mapped above equals (vm_tsize + vm_dsize);
 250          * obreak(2) relies on this fact. Both `vm_tsize' and `vm_dsize' are
 251          * computed (in execve(2)) by rounding *up* `ep_tsize' and `ep_dsize'
 252          * respectively to page boundaries.
 253          * Compensate `ep_dsize' for the amount of data covered by the last
 254          * text page.
 255          */
 256         dsize = epp->ep_dsize + execp->a_text - round_page(execp->a_text);
 257         epp->ep_dsize = (dsize > 0) ? dsize : 0;
 258         return (*epp->ep_esch->es_setup_stack)(l, epp);
 259 }