exec_aout.c revision 1.2
1 /* 2 * Copyright (c) 1993 Christopher G. Demetriou 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by Christopher G. Demetriou. 16 * 4. The name of the author may not be used to endorse or promote products 17 * derived from this software withough specific prior written permission 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 * 30 * $Id: exec_aout.c,v 1.2 1993/12/12 19:26:18 deraadt Exp $ 31 */ 32 33 #include <sys/param.h> 34 #include <sys/systm.h> 35 #include <sys/filedesc.h> 36 #include <sys/kernel.h> 37 #include <sys/proc.h> 38 #include <sys/mount.h> 39 #include <sys/malloc.h> 40 #include <sys/namei.h> 41 #include <sys/vnode.h> 42 #include <sys/file.h> 43 #include <sys/exec.h> 44 #include <sys/resourcevar.h> 45 #include <sys/wait.h> 46 #include <sys/mman.h> 47 48 #include <vm/vm.h> 49 #include <vm/vm_param.h> 50 #include <vm/vm_map.h> 51 #include <vm/vm_kern.h> 52 #include <vm/vm_pager.h> 53 54 #include <machine/cpu.h> 55 #include <machine/reg.h> 56 #include <machine/exec.h> 57 58 /* 59 * exec_aout_makecmds(): Check if it's an a.out-format executable. 60 * 61 * Given a proc pointer and an exec package pointer, see if the referent 62 * of the epp is in a.out format. First check 'standard' magic numbers for 63 * this architecture. If that fails, try a cpu-dependent hook. 64 * 65 * This function, in the former case, or the hook, in the latter, is 66 * responsible for creating a set of vmcmds which can be used to build 67 * the process's vm space and inserting them into the exec package. 68 */ 69 70 int 71 exec_aout_makecmds(p, epp) 72 struct proc *p; 73 struct exec_package *epp; 74 { 75 u_long midmag, magic; 76 u_short mid; 77 int error; 78 79 midmag = ntohl(epp->ep_execp->a_midmag); 80 mid = (midmag >> 16) & 0x3ff; 81 magic = midmag & 0xffff; 82 83 #ifdef EXEC_DEBUG 84 printf("exec_makecmds: a_midmag is %x, magic=%x mid=%x\n", 85 epp->ep_execp->a_midmag, magic, mid); 86 #endif 87 88 midmag = mid << 16 | magic; 89 90 switch (midmag) { 91 case (MID_MACHINE << 16) | ZMAGIC: 92 error = exec_aout_prep_zmagic(p, epp); 93 break; 94 case (MID_MACHINE << 16) | NMAGIC: 95 error = exec_aout_prep_nmagic(p, epp); 96 break; 97 case (MID_MACHINE << 16) | OMAGIC: 98 error = exec_aout_prep_omagic(p, epp); 99 break; 100 default: 101 error = cpu_exec_aout_makecmds(p, epp); 102 } 103 104 if (error && epp->ep_vcp) 105 kill_vmcmd(&epp->ep_vcp); 106 107 bad: 108 109 #ifdef EXEC_DEBUG 110 printf("exec_makecmds returning with error = %d\n", error); 111 #endif 112 return error; 113 } 114 115 /* 116 * exec_aout_prep_zmagic(): Prepare a 'native' ZMAGIC binary's exec package 117 * 118 * First, set of the various offsets/lengths in the exec package. 119 * 120 * Then, mark the text image busy (so it can be demand paged) or error 121 * out if this is not possible. Finally, set up vmcmds for the 122 * text, data, bss, and stack segments. 123 */ 124 125 int 126 exec_aout_prep_zmagic(p, epp) 127 struct proc *p; 128 struct exec_package *epp; 129 { 130 struct exec *execp = epp->ep_execp; 131 struct exec_vmcmd *ccmdp; 132 133 epp->ep_taddr = USRTEXT; 134 epp->ep_tsize = execp->a_text; 135 epp->ep_daddr = epp->ep_taddr + execp->a_text; 136 epp->ep_dsize = execp->a_data + execp->a_bss; 137 epp->ep_entry = execp->a_entry; 138 139 /* 140 * check if vnode is in open for writing, because we want to 141 * demand-page out of it. if it is, don't do it, for various 142 * reasons 143 */ 144 if ((execp->a_text != 0 || execp->a_data != 0) && 145 epp->ep_vp->v_writecount != 0) { 146 #ifdef DIAGNOSTIC 147 if (epp->ep_vp->v_flag & VTEXT) 148 panic("exec: a VTEXT vnode has writecount != 0\n"); 149 #endif 150 epp->ep_vcp = NULL; 151 return ETXTBSY; 152 } 153 epp->ep_vp->v_flag |= VTEXT; 154 155 /* set up command for text segment */ 156 epp->ep_vcp = new_vmcmd(vmcmd_map_pagedvn, 157 execp->a_text, 158 epp->ep_taddr, 159 epp->ep_vp, 160 0, 161 VM_PROT_READ | VM_PROT_EXECUTE); 162 ccmdp = epp->ep_vcp; 163 164 /* set up command for data segment */ 165 ccmdp->ev_next = new_vmcmd(vmcmd_map_pagedvn, 166 execp->a_data, 167 epp->ep_daddr, 168 epp->ep_vp, 169 execp->a_text, 170 VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE); 171 ccmdp = ccmdp->ev_next; 172 173 /* set up command for bss segment */ 174 ccmdp->ev_next = new_vmcmd(vmcmd_map_zero, 175 execp->a_bss, 176 epp->ep_daddr + execp->a_data, 177 0, 178 0, 179 VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE); 180 ccmdp = ccmdp->ev_next; 181 182 return exec_aout_setup_stack(p, epp, ccmdp); 183 } 184 185 /* 186 * exec_aout_prep_nmagic(): Prepare a 'native' NMAGIC binary's exec package 187 */ 188 189 int 190 exec_aout_prep_nmagic(p, epp) 191 struct proc *p; 192 struct exec_package *epp; 193 { 194 struct exec *execp = epp->ep_execp; 195 struct exec_vmcmd *ccmdp; 196 long bsize, baddr; 197 198 epp->ep_taddr = USRTEXT; 199 epp->ep_tsize = execp->a_text; 200 epp->ep_daddr = roundup(epp->ep_taddr + execp->a_text, __LDPGSZ); 201 epp->ep_dsize = execp->a_data + execp->a_bss; 202 epp->ep_entry = execp->a_entry; 203 204 /* set up command for text segment */ 205 epp->ep_vcp = new_vmcmd(vmcmd_map_readvn, 206 execp->a_text, 207 epp->ep_taddr, 208 epp->ep_vp, 209 sizeof(struct exec), 210 VM_PROT_READ | VM_PROT_EXECUTE); 211 ccmdp = epp->ep_vcp; 212 213 /* set up command for data segment */ 214 ccmdp->ev_next = new_vmcmd(vmcmd_map_readvn, 215 execp->a_data, 216 epp->ep_daddr, 217 epp->ep_vp, 218 execp->a_text + sizeof(struct exec), 219 VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE); 220 ccmdp = ccmdp->ev_next; 221 222 /* set up command for bss segment */ 223 baddr = roundup(epp->ep_daddr + execp->a_data, NBPG); 224 bsize = epp->ep_daddr + epp->ep_dsize - baddr; 225 if (bsize > 0) { 226 ccmdp->ev_next = new_vmcmd(vmcmd_map_zero, bsize, baddr, 227 0, 0, VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE); 228 ccmdp = ccmdp->ev_next; 229 } 230 231 return exec_aout_setup_stack(p, epp, ccmdp); 232 } 233 234 /* 235 * exec_aout_prep_omagic(): Prepare a 'native' OMAGIC binary's exec package 236 */ 237 238 int 239 exec_aout_prep_omagic(p, epp) 240 struct proc *p; 241 struct exec_package *epp; 242 { 243 struct exec *execp = epp->ep_execp; 244 struct exec_vmcmd *ccmdp; 245 long bsize, baddr; 246 247 epp->ep_taddr = USRTEXT; 248 epp->ep_tsize = execp->a_text; 249 epp->ep_daddr = epp->ep_taddr + execp->a_text; 250 epp->ep_dsize = execp->a_data + execp->a_bss; 251 epp->ep_entry = execp->a_entry; 252 253 /* set up command for text and data segments */ 254 epp->ep_vcp = new_vmcmd(vmcmd_map_readvn, 255 execp->a_text + execp->a_data, 256 epp->ep_taddr, 257 epp->ep_vp, 258 sizeof(struct exec), 259 VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE); 260 ccmdp = epp->ep_vcp; 261 262 /* set up command for bss segment */ 263 baddr = roundup(epp->ep_daddr + execp->a_data, NBPG); 264 bsize = epp->ep_daddr + epp->ep_dsize - baddr; 265 if (bsize > 0) { 266 ccmdp->ev_next = new_vmcmd(vmcmd_map_zero, bsize, baddr, 267 0, 0, VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE); 268 ccmdp = ccmdp->ev_next; 269 } 270 271 return exec_aout_setup_stack(p, epp, ccmdp); 272 } 273 274 /* 275 * exec_aout_setup_stack(): Set up the stack segment for an a.out 276 * executable. 277 * 278 * Note that the ep_ssize parameter must be set to be the current stack 279 * limit; this is adjusted in the body of execve() to yield the 280 * appropriate stack segment usage once the argument length is 281 * calculated. 282 */ 283 284 int 285 exec_aout_setup_stack(p, epp, ccmdp) 286 struct proc *p; 287 struct exec_package *epp; 288 struct exec_vmcmd *ccmdp; 289 { 290 291 epp->ep_maxsaddr = USRSTACK - MAXSSIZ; 292 epp->ep_minsaddr = USRSTACK; 293 epp->ep_ssize = p->p_rlimit[RLIMIT_STACK].rlim_cur; 294 295 /* 296 * set up commands for stack. note that this takes *two*, one to 297 * map the part of the stack which we can access, and one to map 298 * the part which we can't. 299 * 300 * arguably, it could be made into one, but that would require the 301 * addition of another mapping proc, which is unnecessary 302 * 303 * note that in memory, things assumed to be: 0 ....... ep_maxsaddr 304 * <stack> ep_minsaddr 305 */ 306 ccmdp->ev_next = new_vmcmd(vmcmd_map_zero, 307 ((epp->ep_minsaddr - epp->ep_ssize) - epp->ep_maxsaddr), 308 epp->ep_maxsaddr, 309 0, 310 0, 311 VM_PROT_NONE); 312 ccmdp = ccmdp->ev_next; 313 ccmdp->ev_next = new_vmcmd(vmcmd_map_zero, 314 epp->ep_ssize, 315 (epp->ep_minsaddr - epp->ep_ssize), 316 0, 317 0, 318 VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE); 319 320 return 0; 321 } 322
Indexes created Tue Sep 23 02:09:52 GMT 2025