exec_aout.c revision 1.27
1 /* $NetBSD: exec_aout.c,v 1.27 2002/12/10 17:14:29 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/cdefs.h> 34 __KERNEL_RCSID(0, "$NetBSD: exec_aout.c,v 1.27 2002/12/10 17:14:29 thorpej Exp $"); 35 36 #include <sys/param.h> 37 #include <sys/systm.h> 38 #include <sys/proc.h> 39 #include <sys/malloc.h> 40 #include <sys/vnode.h> 41 #include <sys/exec.h> 42 #include <sys/exec_aout.h> 43 #include <sys/resourcevar.h> 44 45 #include <uvm/uvm_extern.h> 46 47 /* 48 * exec_aout_makecmds(): Check if it's an a.out-format executable. 49 * 50 * Given a proc pointer and an exec package pointer, see if the referent 51 * of the epp is in a.out format. First check 'standard' magic numbers for 52 * this architecture. If that fails, try a cpu-dependent hook. 53 * 54 * This function, in the former case, or the hook, in the latter, is 55 * responsible for creating a set of vmcmds which can be used to build 56 * the process's vm space and inserting them into the exec package. 57 */ 58 59 int 60 exec_aout_makecmds(struct proc *p, 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 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(struct proc *p, struct exec_package *epp) 108 { 109 struct exec *execp = epp->ep_hdr; 110 int error; 111 112 epp->ep_taddr = AOUT_LDPGSZ; 113 epp->ep_tsize = execp->a_text; 114 epp->ep_daddr = epp->ep_taddr + execp->a_text; 115 epp->ep_dsize = execp->a_data + execp->a_bss; 116 epp->ep_entry = execp->a_entry; 117 118 error = vn_marktext(epp->ep_vp); 119 if (error) 120 return (error); 121 122 /* set up command for text segment */ 123 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, round_page(execp->a_text), 124 epp->ep_taddr, epp->ep_vp, 0, VM_PROT_READ|VM_PROT_EXECUTE); 125 126 /* set up command for data segment */ 127 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, round_page(execp->a_data), 128 epp->ep_daddr, epp->ep_vp, execp->a_text, 129 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 130 131 /* set up command for bss segment */ 132 if (execp->a_bss > 0) 133 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, execp->a_bss, 134 epp->ep_daddr + execp->a_data, NULLVP, 0, 135 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 136 137 return exec_aout_setup_stack(p, epp); 138 } 139 140 /* 141 * exec_aout_prep_nmagic(): Prepare a 'native' NMAGIC binary's exec package 142 */ 143 144 int 145 exec_aout_prep_nmagic(struct proc *p, struct exec_package *epp) 146 { 147 struct exec *execp = epp->ep_hdr; 148 long bsize, baddr; 149 150 epp->ep_taddr = AOUT_LDPGSZ; 151 epp->ep_tsize = execp->a_text; 152 epp->ep_daddr = roundup(epp->ep_taddr + execp->a_text, AOUT_LDPGSZ); 153 epp->ep_dsize = execp->a_data + execp->a_bss; 154 epp->ep_entry = execp->a_entry; 155 156 /* set up command for text segment */ 157 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_text, 158 epp->ep_taddr, epp->ep_vp, sizeof(struct exec), 159 VM_PROT_READ|VM_PROT_EXECUTE); 160 161 /* set up command for data segment */ 162 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_data, 163 epp->ep_daddr, epp->ep_vp, execp->a_text + sizeof(struct exec), 164 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 165 166 /* set up command for bss segment */ 167 baddr = round_page(epp->ep_daddr + execp->a_data); 168 bsize = epp->ep_daddr + epp->ep_dsize - baddr; 169 if (bsize > 0) 170 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, bsize, baddr, 171 NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 172 173 return exec_aout_setup_stack(p, epp); 174 } 175 176 /* 177 * exec_aout_prep_omagic(): Prepare a 'native' OMAGIC binary's exec package 178 */ 179 180 int 181 exec_aout_prep_omagic(struct proc *p, struct exec_package *epp) 182 { 183 struct exec *execp = epp->ep_hdr; 184 long dsize, bsize, baddr; 185 186 epp->ep_taddr = AOUT_LDPGSZ; 187 epp->ep_tsize = execp->a_text; 188 epp->ep_daddr = epp->ep_taddr + execp->a_text; 189 epp->ep_dsize = execp->a_data + execp->a_bss; 190 epp->ep_entry = execp->a_entry; 191 192 /* set up command for text and data segments */ 193 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, 194 execp->a_text + execp->a_data, epp->ep_taddr, epp->ep_vp, 195 sizeof(struct exec), VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 196 197 /* set up command for bss segment */ 198 baddr = round_page(epp->ep_daddr + execp->a_data); 199 bsize = epp->ep_daddr + epp->ep_dsize - baddr; 200 if (bsize > 0) 201 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, bsize, baddr, 202 NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 203 204 /* 205 * Make sure (# of pages) mapped above equals (vm_tsize + vm_dsize); 206 * obreak(2) relies on this fact. Both `vm_tsize' and `vm_dsize' are 207 * computed (in execve(2)) by rounding *up* `ep_tsize' and `ep_dsize' 208 * respectively to page boundaries. 209 * Compensate `ep_dsize' for the amount of data covered by the last 210 * text page. 211 */ 212 dsize = epp->ep_dsize + execp->a_text - round_page(execp->a_text); 213 epp->ep_dsize = (dsize > 0) ? dsize : 0; 214 return exec_aout_setup_stack(p, epp); 215 } 216 217 /* 218 * exec_aout_setup_stack(): Set up the stack segment for an a.out 219 * executable. 220 * 221 * Note that the ep_ssize parameter must be set to be the current stack 222 * limit; this is adjusted in the body of execve() to yield the 223 * appropriate stack segment usage once the argument length is 224 * calculated. 225 * 226 * This function returns an int for uniformity with other (future) formats' 227 * stack setup functions. They might have errors to return. 228 */ 229 230 int 231 exec_aout_setup_stack(struct proc *p, struct exec_package *epp) 232 { 233 234 epp->ep_maxsaddr = USRSTACK - MAXSSIZ; 235 epp->ep_minsaddr = USRSTACK; 236 epp->ep_ssize = p->p_rlimit[RLIMIT_STACK].rlim_cur; 237 238 /* 239 * set up commands for stack. note that this takes *two*, one to 240 * map the part of the stack which we can access, and one to map 241 * the part which we can't. 242 * 243 * arguably, it could be made into one, but that would require the 244 * addition of another mapping proc, which is unnecessary 245 * 246 * note that in memory, things assumed to be: 0 ... ep_maxsaddr 247 * <stack> ep_minsaddr 248 */ 249 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, 250 ((epp->ep_minsaddr - epp->ep_ssize) - epp->ep_maxsaddr), 251 epp->ep_maxsaddr, NULLVP, 0, VM_PROT_NONE); 252 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, epp->ep_ssize, 253 (epp->ep_minsaddr - epp->ep_ssize), NULLVP, 0, 254 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 255 256 return 0; 257 } 258
Indexes created Sun Sep 21 20:09:37 GMT 2025