exec_aout.c revision 1.9
1 /* 2 * Copyright (c) 1993, 1994 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 without 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 1.9 1994/01/28 23:46:59 jtc Exp $ 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 <sys/exec_aout.h> 43 #include <machine/exec.h> 44 45 /* 46 * exec_aout_makecmds(): Check if it's an a.out-format executable. 47 * 48 * Given a proc pointer and an exec package pointer, see if the referent 49 * of the epp is in a.out format. First check 'standard' magic numbers for 50 * this architecture. If that fails, try a cpu-dependent hook. 51 * 52 * This function, in the former case, or the hook, in the latter, is 53 * responsible for creating a set of vmcmds which can be used to build 54 * the process's vm space and inserting them into the exec package. 55 */ 56 57 int 58 exec_aout_makecmds(p, epp) 59 struct proc *p; 60 struct exec_package *epp; 61 { 62 u_long midmag, magic; 63 u_short mid; 64 int error; 65 struct exec *execp = epp->ep_hdr; 66 67 if (epp->ep_hdrvalid < sizeof(struct exec)) 68 return ENOEXEC; 69 70 midmag = ntohl(execp->a_midmag); 71 mid = (midmag >> 16) & 0x3ff; 72 magic = midmag & 0xffff; 73 74 midmag = mid << 16 | magic; 75 76 switch (midmag) { 77 case (MID_MACHINE << 16) | ZMAGIC: 78 error = exec_aout_prep_zmagic(p, epp); 79 break; 80 case (MID_MACHINE << 16) | NMAGIC: 81 error = exec_aout_prep_nmagic(p, epp); 82 break; 83 case (MID_MACHINE << 16) | OMAGIC: 84 error = exec_aout_prep_omagic(p, epp); 85 break; 86 default: 87 error = cpu_exec_aout_makecmds(p, epp); 88 } 89 90 if (error) 91 kill_vmcmds(&epp->ep_vmcmds); 92 93 bad: 94 return error; 95 } 96 97 /* 98 * exec_aout_prep_zmagic(): Prepare a 'native' ZMAGIC binary's exec package 99 * 100 * First, set of the various offsets/lengths in the exec package. 101 * 102 * Then, mark the text image busy (so it can be demand paged) or error 103 * out if this is not possible. Finally, set up vmcmds for the 104 * text, data, bss, and stack segments. 105 */ 106 107 int 108 exec_aout_prep_zmagic(p, epp) 109 struct proc *p; 110 struct exec_package *epp; 111 { 112 struct exec *execp = epp->ep_hdr; 113 114 epp->ep_taddr = USRTEXT; 115 epp->ep_tsize = execp->a_text; 116 epp->ep_daddr = epp->ep_taddr + execp->a_text; 117 epp->ep_dsize = execp->a_data + execp->a_bss; 118 epp->ep_entry = execp->a_entry; 119 120 /* 121 * check if vnode is in open for writing, because we want to 122 * demand-page out of it. if it is, don't do it, for various 123 * reasons 124 */ 125 if ((execp->a_text != 0 || execp->a_data != 0) && 126 epp->ep_vp->v_writecount != 0) { 127 #ifdef DIAGNOSTIC 128 if (epp->ep_vp->v_flag & VTEXT) 129 panic("exec: a VTEXT vnode has writecount != 0\n"); 130 #endif 131 return ETXTBSY; 132 } 133 epp->ep_vp->v_flag |= VTEXT; 134 135 /* set up command for text segment */ 136 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, execp->a_text, 137 epp->ep_taddr, epp->ep_vp, 0, VM_PROT_READ|VM_PROT_EXECUTE); 138 139 /* set up command for data segment */ 140 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, execp->a_data, 141 epp->ep_daddr, epp->ep_vp, execp->a_text, 142 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 143 144 /* set up command for bss segment */ 145 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, execp->a_bss, 146 epp->ep_daddr + execp->a_data, NULLVP, 0, 147 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 148 149 return exec_aout_setup_stack(p, epp); 150 } 151 152 /* 153 * exec_aout_prep_nmagic(): Prepare a 'native' NMAGIC binary's exec package 154 */ 155 156 int 157 exec_aout_prep_nmagic(p, epp) 158 struct proc *p; 159 struct exec_package *epp; 160 { 161 struct exec *execp = epp->ep_hdr; 162 long bsize, baddr; 163 164 epp->ep_taddr = USRTEXT; 165 epp->ep_tsize = execp->a_text; 166 epp->ep_daddr = roundup(epp->ep_taddr + execp->a_text, __LDPGSZ); 167 epp->ep_dsize = execp->a_data + execp->a_bss; 168 epp->ep_entry = execp->a_entry; 169 170 /* set up command for text segment */ 171 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_text, 172 epp->ep_taddr, epp->ep_vp, sizeof(struct exec), 173 VM_PROT_READ|VM_PROT_EXECUTE); 174 175 /* set up command for data segment */ 176 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_data, 177 epp->ep_daddr, epp->ep_vp, execp->a_text + sizeof(struct exec), 178 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 179 180 /* set up command for bss segment */ 181 baddr = roundup(epp->ep_daddr + execp->a_data, NBPG); 182 bsize = epp->ep_daddr + epp->ep_dsize - baddr; 183 if (bsize > 0) 184 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, bsize, baddr, 185 NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 186 187 return exec_aout_setup_stack(p, epp); 188 } 189 190 /* 191 * exec_aout_prep_omagic(): Prepare a 'native' OMAGIC binary's exec package 192 */ 193 194 int 195 exec_aout_prep_omagic(p, epp) 196 struct proc *p; 197 struct exec_package *epp; 198 { 199 struct exec *execp = epp->ep_hdr; 200 long bsize, baddr; 201 202 epp->ep_taddr = USRTEXT; 203 epp->ep_tsize = execp->a_text; 204 epp->ep_daddr = epp->ep_taddr + execp->a_text; 205 epp->ep_dsize = execp->a_data + execp->a_bss; 206 epp->ep_entry = execp->a_entry; 207 208 /* set up command for text and data segments */ 209 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, 210 execp->a_text + execp->a_data, epp->ep_taddr, epp->ep_vp, 211 sizeof(struct exec), VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 212 213 /* set up command for bss segment */ 214 baddr = roundup(epp->ep_daddr + execp->a_data, NBPG); 215 bsize = epp->ep_daddr + epp->ep_dsize - baddr; 216 if (bsize > 0) 217 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, bsize, baddr, 218 NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 219 220 return exec_aout_setup_stack(p, epp); 221 } 222 223 /* 224 * exec_aout_setup_stack(): Set up the stack segment for an a.out 225 * executable. 226 * 227 * Note that the ep_ssize parameter must be set to be the current stack 228 * limit; this is adjusted in the body of execve() to yield the 229 * appropriate stack segment usage once the argument length is 230 * calculated. 231 * 232 * This function returns an int for uniformity with other (future) formats' 233 * stack setup functions. They might have errors to return. 234 */ 235 236 int 237 exec_aout_setup_stack(p, epp) 238 struct proc *p; 239 struct exec_package *epp; 240 { 241 242 epp->ep_maxsaddr = USRSTACK - MAXSSIZ; 243 epp->ep_minsaddr = USRSTACK; 244 epp->ep_ssize = p->p_rlimit[RLIMIT_STACK].rlim_cur; 245 246 /* 247 * set up commands for stack. note that this takes *two*, one to 248 * map the part of the stack which we can access, and one to map 249 * the part which we can't. 250 * 251 * arguably, it could be made into one, but that would require the 252 * addition of another mapping proc, which is unnecessary 253 * 254 * note that in memory, things assumed to be: 0 ....... ep_maxsaddr 255 * <stack> ep_minsaddr 256 */ 257 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, 258 ((epp->ep_minsaddr - epp->ep_ssize) - epp->ep_maxsaddr), 259 epp->ep_maxsaddr, NULLVP, 0, VM_PROT_NONE); 260 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, epp->ep_ssize, 261 (epp->ep_minsaddr - epp->ep_ssize), NULLVP, 0, 262 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 263 264 return 0; 265 } 266
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