exec_aout.c revision 1.15.24.1
1 /* $NetBSD: exec_aout.c,v 1.15.24.1 1999/07/04 01:33:35 chs 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 /* 43 * exec_aout_makecmds(): Check if it's an a.out-format executable. 44 * 45 * Given a proc pointer and an exec package pointer, see if the referent 46 * of the epp is in a.out format. First check 'standard' magic numbers for 47 * this architecture. If that fails, try a cpu-dependent hook. 48 * 49 * This function, in the former case, or the hook, in the latter, is 50 * responsible for creating a set of vmcmds which can be used to build 51 * the process's vm space and inserting them into the exec package. 52 */ 53 54 int 55 exec_aout_makecmds(p, epp) 56 struct proc *p; 57 struct exec_package *epp; 58 { 59 u_long midmag, magic; 60 u_short mid; 61 int error; 62 struct exec *execp = epp->ep_hdr; 63 64 if (epp->ep_hdrvalid < sizeof(struct exec)) 65 return ENOEXEC; 66 67 midmag = ntohl(execp->a_midmag); 68 mid = (midmag >> 16) & 0x3ff; 69 magic = midmag & 0xffff; 70 71 midmag = mid << 16 | magic; 72 73 switch (midmag) { 74 case (MID_MACHINE << 16) | ZMAGIC: 75 error = exec_aout_prep_zmagic(p, epp); 76 break; 77 case (MID_MACHINE << 16) | NMAGIC: 78 error = exec_aout_prep_nmagic(p, epp); 79 break; 80 case (MID_MACHINE << 16) | OMAGIC: 81 error = exec_aout_prep_omagic(p, epp); 82 break; 83 default: 84 error = cpu_exec_aout_makecmds(p, epp); 85 } 86 87 if (error) 88 kill_vmcmds(&epp->ep_vmcmds); 89 90 return error; 91 } 92 93 /* 94 * exec_aout_prep_zmagic(): Prepare a 'native' ZMAGIC binary's exec package 95 * 96 * First, set of the various offsets/lengths in the exec package. 97 * 98 * Then, mark the text image busy (so it can be demand paged) or error 99 * out if this is not possible. Finally, set up vmcmds for the 100 * text, data, bss, and stack segments. 101 */ 102 103 int 104 exec_aout_prep_zmagic(p, epp) 105 struct proc *p; 106 struct exec_package *epp; 107 { 108 struct exec *execp = epp->ep_hdr; 109 110 epp->ep_taddr = USRTEXT; 111 epp->ep_tsize = execp->a_text; 112 epp->ep_daddr = epp->ep_taddr + execp->a_text; 113 epp->ep_dsize = execp->a_data + execp->a_bss; 114 epp->ep_entry = execp->a_entry; 115 116 /* 117 * check if vnode is in open for writing, because we want to 118 * demand-page out of it. if it is, don't do it, for various 119 * reasons 120 */ 121 if ((execp->a_text != 0 || execp->a_data != 0) && 122 epp->ep_vp->v_writecount != 0) { 123 #ifdef DIAGNOSTIC 124 if (epp->ep_vp->v_flag & VTEXT) 125 panic("exec: a VTEXT vnode has writecount != 0\n"); 126 #endif 127 return ETXTBSY; 128 } 129 130 /* 131 * mark this vnode as being the image of a running process. 132 * also flush any cached file mappings now so the process will 133 * have a better chance of being able to use the cache. 134 */ 135 136 epp->ep_vp->v_flag |= VTEXT; 137 ubc_flush(&epp->ep_vp->v_uvm.u_obj, 0, 0); 138 139 /* set up command for text segment */ 140 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, execp->a_text, 141 epp->ep_taddr, epp->ep_vp, 0, VM_PROT_READ|VM_PROT_EXECUTE); 142 143 /* set up command for data segment */ 144 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, execp->a_data, 145 epp->ep_daddr, epp->ep_vp, execp->a_text, 146 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 147 148 /* set up command for bss segment */ 149 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, execp->a_bss, 150 epp->ep_daddr + execp->a_data, NULLVP, 0, 151 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 152 153 return exec_aout_setup_stack(p, epp); 154 } 155 156 /* 157 * exec_aout_prep_nmagic(): Prepare a 'native' NMAGIC binary's exec package 158 */ 159 160 int 161 exec_aout_prep_nmagic(p, epp) 162 struct proc *p; 163 struct exec_package *epp; 164 { 165 struct exec *execp = epp->ep_hdr; 166 long bsize, baddr; 167 168 epp->ep_taddr = USRTEXT; 169 epp->ep_tsize = execp->a_text; 170 epp->ep_daddr = roundup(epp->ep_taddr + execp->a_text, __LDPGSZ); 171 epp->ep_dsize = execp->a_data + execp->a_bss; 172 epp->ep_entry = execp->a_entry; 173 174 /* set up command for text segment */ 175 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_text, 176 epp->ep_taddr, epp->ep_vp, sizeof(struct exec), 177 VM_PROT_READ|VM_PROT_EXECUTE); 178 179 /* set up command for data segment */ 180 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_data, 181 epp->ep_daddr, epp->ep_vp, execp->a_text + sizeof(struct exec), 182 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 183 184 /* set up command for bss segment */ 185 baddr = roundup(epp->ep_daddr + execp->a_data, NBPG); 186 bsize = epp->ep_daddr + epp->ep_dsize - baddr; 187 if (bsize > 0) 188 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, bsize, baddr, 189 NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 190 191 return exec_aout_setup_stack(p, epp); 192 } 193 194 /* 195 * exec_aout_prep_omagic(): Prepare a 'native' OMAGIC binary's exec package 196 */ 197 198 int 199 exec_aout_prep_omagic(p, epp) 200 struct proc *p; 201 struct exec_package *epp; 202 { 203 struct exec *execp = epp->ep_hdr; 204 long dsize, bsize, baddr; 205 206 epp->ep_taddr = USRTEXT; 207 epp->ep_tsize = execp->a_text; 208 epp->ep_daddr = epp->ep_taddr + execp->a_text; 209 epp->ep_dsize = execp->a_data + execp->a_bss; 210 epp->ep_entry = execp->a_entry; 211 212 /* set up command for text and data segments */ 213 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, 214 execp->a_text + execp->a_data, epp->ep_taddr, epp->ep_vp, 215 sizeof(struct exec), VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 216 217 /* set up command for bss segment */ 218 baddr = roundup(epp->ep_daddr + execp->a_data, NBPG); 219 bsize = epp->ep_daddr + epp->ep_dsize - baddr; 220 if (bsize > 0) 221 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, bsize, baddr, 222 NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 223 224 /* 225 * Make sure (# of pages) mapped above equals (vm_tsize + vm_dsize); 226 * obreak(2) relies on this fact. Both `vm_tsize' and `vm_dsize' are 227 * computed (in execve(2)) by rounding *up* `ep_tsize' and `ep_dsize' 228 * respectively to page boundaries. 229 * Compensate `ep_dsize' for the amount of data covered by the last 230 * text page. 231 */ 232 dsize = epp->ep_dsize + execp->a_text - roundup(execp->a_text, NBPG); 233 epp->ep_dsize = (dsize > 0) ? dsize : 0; 234 return exec_aout_setup_stack(p, epp); 235 } 236 237 /* 238 * exec_aout_setup_stack(): Set up the stack segment for an a.out 239 * executable. 240 * 241 * Note that the ep_ssize parameter must be set to be the current stack 242 * limit; this is adjusted in the body of execve() to yield the 243 * appropriate stack segment usage once the argument length is 244 * calculated. 245 * 246 * This function returns an int for uniformity with other (future) formats' 247 * stack setup functions. They might have errors to return. 248 */ 249 250 int 251 exec_aout_setup_stack(p, epp) 252 struct proc *p; 253 struct exec_package *epp; 254 { 255 256 epp->ep_maxsaddr = USRSTACK - MAXSSIZ; 257 epp->ep_minsaddr = USRSTACK; 258 epp->ep_ssize = p->p_rlimit[RLIMIT_STACK].rlim_cur; 259 260 /* 261 * set up commands for stack. note that this takes *two*, one to 262 * map the part of the stack which we can access, and one to map 263 * the part which we can't. 264 * 265 * arguably, it could be made into one, but that would require the 266 * addition of another mapping proc, which is unnecessary 267 * 268 * note that in memory, things assumed to be: 0 ... ep_maxsaddr 269 * <stack> ep_minsaddr 270 */ 271 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, 272 ((epp->ep_minsaddr - epp->ep_ssize) - epp->ep_maxsaddr), 273 epp->ep_maxsaddr, NULLVP, 0, VM_PROT_NONE); 274 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, epp->ep_ssize, 275 (epp->ep_minsaddr - epp->ep_ssize), NULLVP, 0, 276 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 277 278 return 0; 279 } 280
Indexes created Tue Sep 30 17:09:57 GMT 2025