exec_aout.c revision 1.11
1 /* $NetBSD: exec_aout.c,v 1.11 1994/07/01 02:57:52 deraadt 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/param.h> 34 #include <sys/systm.h> 35 #include <sys/proc.h> 36 #include <sys/malloc.h> 37 #include <sys/vnode.h> 38 #include <sys/exec.h> 39 #include <sys/resourcevar.h> 40 #include <vm/vm.h> 41 42 #include <machine/exec.h> 43 44 /* 45 * exec_aout_makecmds(): Check if it's an a.out-format executable. 46 * 47 * Given a proc pointer and an exec package pointer, see if the referent 48 * of the epp is in a.out format. First check 'standard' magic numbers for 49 * this architecture. If that fails, try a cpu-dependent hook. 50 * 51 * This function, in the former case, or the hook, in the latter, is 52 * responsible for creating a set of vmcmds which can be used to build 53 * the process's vm space and inserting them into the exec package. 54 */ 55 56 int 57 exec_aout_makecmds(p, epp) 58 struct proc *p; 59 struct exec_package *epp; 60 { 61 u_long midmag, magic; 62 u_short mid; 63 int error; 64 struct exec *execp = epp->ep_hdr; 65 66 if (epp->ep_hdrvalid < sizeof(struct exec)) 67 return ENOEXEC; 68 69 midmag = ntohl(execp->a_midmag); 70 mid = (midmag >> 16) & 0x3ff; 71 magic = midmag & 0xffff; 72 73 midmag = mid << 16 | magic; 74 75 switch (midmag) { 76 case (MID_MACHINE << 16) | ZMAGIC: 77 error = exec_aout_prep_zmagic(p, epp); 78 break; 79 case (MID_MACHINE << 16) | NMAGIC: 80 error = exec_aout_prep_nmagic(p, epp); 81 break; 82 case (MID_MACHINE << 16) | OMAGIC: 83 error = exec_aout_prep_omagic(p, epp); 84 break; 85 default: 86 error = cpu_exec_aout_makecmds(p, epp); 87 } 88 89 if (error) 90 kill_vmcmds(&epp->ep_vmcmds); 91 92 bad: 93 return error; 94 } 95 96 /* 97 * exec_aout_prep_zmagic(): Prepare a 'native' ZMAGIC binary's exec package 98 * 99 * First, set of the various offsets/lengths in the exec package. 100 * 101 * Then, mark the text image busy (so it can be demand paged) or error 102 * out if this is not possible. Finally, set up vmcmds for the 103 * text, data, bss, and stack segments. 104 */ 105 106 int 107 exec_aout_prep_zmagic(p, epp) 108 struct proc *p; 109 struct exec_package *epp; 110 { 111 struct exec *execp = epp->ep_hdr; 112 113 epp->ep_taddr = USRTEXT; 114 epp->ep_tsize = execp->a_text; 115 epp->ep_daddr = epp->ep_taddr + execp->a_text; 116 epp->ep_dsize = execp->a_data + execp->a_bss; 117 epp->ep_entry = execp->a_entry; 118 119 /* 120 * check if vnode is in open for writing, because we want to 121 * demand-page out of it. if it is, don't do it, for various 122 * reasons 123 */ 124 if ((execp->a_text != 0 || execp->a_data != 0) && 125 epp->ep_vp->v_writecount != 0) { 126 #ifdef DIAGNOSTIC 127 if (epp->ep_vp->v_flag & VTEXT) 128 panic("exec: a VTEXT vnode has writecount != 0\n"); 129 #endif 130 return ETXTBSY; 131 } 132 epp->ep_vp->v_flag |= VTEXT; 133 134 /* set up command for text segment */ 135 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, execp->a_text, 136 epp->ep_taddr, epp->ep_vp, 0, VM_PROT_READ|VM_PROT_EXECUTE); 137 138 /* set up command for data segment */ 139 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, execp->a_data, 140 epp->ep_daddr, epp->ep_vp, execp->a_text, 141 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 142 143 /* set up command for bss segment */ 144 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, execp->a_bss, 145 epp->ep_daddr + execp->a_data, NULLVP, 0, 146 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 147 148 return exec_aout_setup_stack(p, epp); 149 } 150 151 /* 152 * exec_aout_prep_nmagic(): Prepare a 'native' NMAGIC binary's exec package 153 */ 154 155 int 156 exec_aout_prep_nmagic(p, epp) 157 struct proc *p; 158 struct exec_package *epp; 159 { 160 struct exec *execp = epp->ep_hdr; 161 long bsize, baddr; 162 163 epp->ep_taddr = USRTEXT; 164 epp->ep_tsize = execp->a_text; 165 epp->ep_daddr = roundup(epp->ep_taddr + execp->a_text, __LDPGSZ); 166 epp->ep_dsize = execp->a_data + execp->a_bss; 167 epp->ep_entry = execp->a_entry; 168 169 /* set up command for text segment */ 170 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_text, 171 epp->ep_taddr, epp->ep_vp, sizeof(struct exec), 172 VM_PROT_READ|VM_PROT_EXECUTE); 173 174 /* set up command for data segment */ 175 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_data, 176 epp->ep_daddr, epp->ep_vp, execp->a_text + sizeof(struct exec), 177 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 178 179 /* set up command for bss segment */ 180 baddr = roundup(epp->ep_daddr + execp->a_data, NBPG); 181 bsize = epp->ep_daddr + epp->ep_dsize - baddr; 182 if (bsize > 0) 183 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, bsize, baddr, 184 NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 185 186 return exec_aout_setup_stack(p, epp); 187 } 188 189 /* 190 * exec_aout_prep_omagic(): Prepare a 'native' OMAGIC binary's exec package 191 */ 192 193 int 194 exec_aout_prep_omagic(p, epp) 195 struct proc *p; 196 struct exec_package *epp; 197 { 198 struct exec *execp = epp->ep_hdr; 199 long bsize, baddr; 200 201 epp->ep_taddr = USRTEXT; 202 epp->ep_tsize = execp->a_text; 203 epp->ep_daddr = epp->ep_taddr + execp->a_text; 204 epp->ep_dsize = execp->a_data + execp->a_bss; 205 epp->ep_entry = execp->a_entry; 206 207 /* set up command for text and data segments */ 208 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, 209 execp->a_text + execp->a_data, epp->ep_taddr, epp->ep_vp, 210 sizeof(struct exec), VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 211 212 /* set up command for bss segment */ 213 baddr = roundup(epp->ep_daddr + execp->a_data, NBPG); 214 bsize = epp->ep_daddr + epp->ep_dsize - baddr; 215 if (bsize > 0) 216 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, bsize, baddr, 217 NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 218 219 return exec_aout_setup_stack(p, epp); 220 } 221 222 /* 223 * exec_aout_setup_stack(): Set up the stack segment for an a.out 224 * executable. 225 * 226 * Note that the ep_ssize parameter must be set to be the current stack 227 * limit; this is adjusted in the body of execve() to yield the 228 * appropriate stack segment usage once the argument length is 229 * calculated. 230 * 231 * This function returns an int for uniformity with other (future) formats' 232 * stack setup functions. They might have errors to return. 233 */ 234 235 int 236 exec_aout_setup_stack(p, epp) 237 struct proc *p; 238 struct exec_package *epp; 239 { 240 241 epp->ep_maxsaddr = USRSTACK - MAXSSIZ; 242 epp->ep_minsaddr = USRSTACK; 243 epp->ep_ssize = p->p_rlimit[RLIMIT_STACK].rlim_cur; 244 245 /* 246 * set up commands for stack. note that this takes *two*, one to 247 * map the part of the stack which we can access, and one to map 248 * the part which we can't. 249 * 250 * arguably, it could be made into one, but that would require the 251 * addition of another mapping proc, which is unnecessary 252 * 253 * note that in memory, things assumed to be: 0 ....... ep_maxsaddr 254 * <stack> ep_minsaddr 255 */ 256 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, 257 ((epp->ep_minsaddr - epp->ep_ssize) - epp->ep_maxsaddr), 258 epp->ep_maxsaddr, NULLVP, 0, VM_PROT_NONE); 259 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, epp->ep_ssize, 260 (epp->ep_minsaddr - epp->ep_ssize), NULLVP, 0, 261 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 262 263 return 0; 264 } 265
Indexes created Tue Sep 30 20:09:53 GMT 2025