exec_aout.c revision 1.19
1 /* $NetBSD: exec_aout.c,v 1.19 2000/08/01 04:57:28 thorpej 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 41 /* 42 * exec_aout_makecmds(): Check if it's an a.out-format executable. 43 * 44 * Given a proc pointer and an exec package pointer, see if the referent 45 * of the epp is in a.out format. First check 'standard' magic numbers for 46 * this architecture. If that fails, try a cpu-dependent hook. 47 * 48 * This function, in the former case, or the hook, in the latter, is 49 * responsible for creating a set of vmcmds which can be used to build 50 * the process's vm space and inserting them into the exec package. 51 */ 52 53 int 54 exec_aout_makecmds(struct proc *p, struct exec_package *epp) 55 { 56 u_long midmag, magic; 57 u_short mid; 58 int error; 59 struct exec *execp = epp->ep_hdr; 60 61 if (epp->ep_hdrvalid < sizeof(struct exec)) 62 return ENOEXEC; 63 64 midmag = ntohl(execp->a_midmag); 65 mid = (midmag >> 16) & 0x3ff; 66 magic = midmag & 0xffff; 67 68 midmag = mid << 16 | magic; 69 70 switch (midmag) { 71 case (MID_MACHINE << 16) | ZMAGIC: 72 error = exec_aout_prep_zmagic(p, epp); 73 break; 74 case (MID_MACHINE << 16) | NMAGIC: 75 error = exec_aout_prep_nmagic(p, epp); 76 break; 77 case (MID_MACHINE << 16) | OMAGIC: 78 error = exec_aout_prep_omagic(p, epp); 79 break; 80 default: 81 error = cpu_exec_aout_makecmds(p, epp); 82 } 83 84 if (error) 85 kill_vmcmds(&epp->ep_vmcmds); 86 87 return error; 88 } 89 90 /* 91 * exec_aout_prep_zmagic(): Prepare a 'native' ZMAGIC binary's exec package 92 * 93 * First, set of the various offsets/lengths in the exec package. 94 * 95 * Then, mark the text image busy (so it can be demand paged) or error 96 * out if this is not possible. Finally, set up vmcmds for the 97 * text, data, bss, and stack segments. 98 */ 99 100 int 101 exec_aout_prep_zmagic(struct proc *p, struct exec_package *epp) 102 { 103 struct exec *execp = epp->ep_hdr; 104 105 epp->ep_taddr = USRTEXT; 106 epp->ep_tsize = execp->a_text; 107 epp->ep_daddr = epp->ep_taddr + execp->a_text; 108 epp->ep_dsize = execp->a_data + execp->a_bss; 109 epp->ep_entry = execp->a_entry; 110 111 /* 112 * check if vnode is in open for writing, because we want to 113 * demand-page out of it. if it is, don't do it, for various 114 * reasons 115 */ 116 if ((execp->a_text != 0 || execp->a_data != 0) && 117 epp->ep_vp->v_writecount != 0) { 118 #ifdef DIAGNOSTIC 119 if (epp->ep_vp->v_flag & VTEXT) 120 panic("exec: a VTEXT vnode has writecount != 0\n"); 121 #endif 122 return ETXTBSY; 123 } 124 vn_marktext(epp->ep_vp); 125 126 /* set up command for text segment */ 127 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, round_page(execp->a_text), 128 epp->ep_taddr, epp->ep_vp, 0, VM_PROT_READ|VM_PROT_EXECUTE); 129 130 /* set up command for data segment */ 131 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, round_page(execp->a_data), 132 epp->ep_daddr, epp->ep_vp, execp->a_text, 133 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 134 135 /* set up command for bss segment */ 136 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, execp->a_bss, 137 epp->ep_daddr + execp->a_data, NULLVP, 0, 138 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 139 140 return exec_aout_setup_stack(p, epp); 141 } 142 143 /* 144 * exec_aout_prep_nmagic(): Prepare a 'native' NMAGIC binary's exec package 145 */ 146 147 int 148 exec_aout_prep_nmagic(struct proc *p, struct exec_package *epp) 149 { 150 struct exec *execp = epp->ep_hdr; 151 long bsize, baddr; 152 153 epp->ep_taddr = USRTEXT; 154 epp->ep_tsize = execp->a_text; 155 epp->ep_daddr = roundup(epp->ep_taddr + execp->a_text, __LDPGSZ); 156 epp->ep_dsize = execp->a_data + execp->a_bss; 157 epp->ep_entry = execp->a_entry; 158 159 /* set up command for text segment */ 160 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_text, 161 epp->ep_taddr, epp->ep_vp, sizeof(struct exec), 162 VM_PROT_READ|VM_PROT_EXECUTE); 163 164 /* set up command for data segment */ 165 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_data, 166 epp->ep_daddr, epp->ep_vp, execp->a_text + sizeof(struct exec), 167 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 168 169 /* set up command for bss segment */ 170 baddr = roundup(epp->ep_daddr + execp->a_data, NBPG); 171 bsize = epp->ep_daddr + epp->ep_dsize - baddr; 172 if (bsize > 0) 173 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, bsize, baddr, 174 NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 175 176 return exec_aout_setup_stack(p, epp); 177 } 178 179 /* 180 * exec_aout_prep_omagic(): Prepare a 'native' OMAGIC binary's exec package 181 */ 182 183 int 184 exec_aout_prep_omagic(struct proc *p, struct exec_package *epp) 185 { 186 struct exec *execp = epp->ep_hdr; 187 long dsize, bsize, baddr; 188 189 epp->ep_taddr = USRTEXT; 190 epp->ep_tsize = execp->a_text; 191 epp->ep_daddr = epp->ep_taddr + execp->a_text; 192 epp->ep_dsize = execp->a_data + execp->a_bss; 193 epp->ep_entry = execp->a_entry; 194 195 /* set up command for text and data segments */ 196 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, 197 execp->a_text + execp->a_data, epp->ep_taddr, epp->ep_vp, 198 sizeof(struct exec), VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 199 200 /* set up command for bss segment */ 201 baddr = roundup(epp->ep_daddr + execp->a_data, NBPG); 202 bsize = epp->ep_daddr + epp->ep_dsize - baddr; 203 if (bsize > 0) 204 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, bsize, baddr, 205 NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 206 207 /* 208 * Make sure (# of pages) mapped above equals (vm_tsize + vm_dsize); 209 * obreak(2) relies on this fact. Both `vm_tsize' and `vm_dsize' are 210 * computed (in execve(2)) by rounding *up* `ep_tsize' and `ep_dsize' 211 * respectively to page boundaries. 212 * Compensate `ep_dsize' for the amount of data covered by the last 213 * text page. 214 */ 215 dsize = epp->ep_dsize + execp->a_text - roundup(execp->a_text, NBPG); 216 epp->ep_dsize = (dsize > 0) ? dsize : 0; 217 return exec_aout_setup_stack(p, epp); 218 } 219 220 /* 221 * exec_aout_setup_stack(): Set up the stack segment for an a.out 222 * executable. 223 * 224 * Note that the ep_ssize parameter must be set to be the current stack 225 * limit; this is adjusted in the body of execve() to yield the 226 * appropriate stack segment usage once the argument length is 227 * calculated. 228 * 229 * This function returns an int for uniformity with other (future) formats' 230 * stack setup functions. They might have errors to return. 231 */ 232 233 int 234 exec_aout_setup_stack(struct proc *p, struct exec_package *epp) 235 { 236 237 epp->ep_maxsaddr = USRSTACK - MAXSSIZ; 238 epp->ep_minsaddr = USRSTACK; 239 epp->ep_ssize = p->p_rlimit[RLIMIT_STACK].rlim_cur; 240 241 /* 242 * set up commands for stack. note that this takes *two*, one to 243 * map the part of the stack which we can access, and one to map 244 * the part which we can't. 245 * 246 * arguably, it could be made into one, but that would require the 247 * addition of another mapping proc, which is unnecessary 248 * 249 * note that in memory, things assumed to be: 0 ... ep_maxsaddr 250 * <stack> ep_minsaddr 251 */ 252 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, 253 ((epp->ep_minsaddr - epp->ep_ssize) - epp->ep_maxsaddr), 254 epp->ep_maxsaddr, NULLVP, 0, VM_PROT_NONE); 255 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, epp->ep_ssize, 256 (epp->ep_minsaddr - epp->ep_ssize), NULLVP, 0, 257 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 258 259 return 0; 260 } 261
Indexes created Tue Sep 30 20:09:53 GMT 2025