exec_aout.c revision 1.28
1 /* $NetBSD: exec_aout.c,v 1.28 2003/06/28 14:21:51 darrenr 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 1.28 2003/06/28 14:21:51 darrenr 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 lwp *l, struct exec_package *epp) 61 { 62 u_long midmag, magic; 63 u_short mid; 64 int error; 65 struct proc *p = l->l_proc; 66 struct exec *execp = epp->ep_hdr; 67 68 if (epp->ep_hdrvalid < sizeof(struct exec)) 69 return ENOEXEC; 70 71 midmag = ntohl(execp->a_midmag); 72 mid = (midmag >> 16) & 0x3ff; 73 magic = midmag & 0xffff; 74 75 midmag = mid << 16 | magic; 76 77 switch (midmag) { 78 case (MID_MACHINE << 16) | ZMAGIC: 79 error = exec_aout_prep_zmagic(p, epp); 80 break; 81 case (MID_MACHINE << 16) | NMAGIC: 82 error = exec_aout_prep_nmagic(p, epp); 83 break; 84 case (MID_MACHINE << 16) | OMAGIC: 85 error = exec_aout_prep_omagic(p, epp); 86 break; 87 default: 88 error = cpu_exec_aout_makecmds(l, epp); 89 } 90 91 if (error) 92 kill_vmcmds(&epp->ep_vmcmds); 93 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(struct proc *p, struct exec_package *epp) 109 { 110 struct exec *execp = epp->ep_hdr; 111 int error; 112 113 epp->ep_taddr = AOUT_LDPGSZ; 114 epp->ep_tsize = execp->a_text; 115 epp->ep_daddr = epp->ep_taddr + execp->a_text; 116 epp->ep_dsize = execp->a_data + execp->a_bss; 117 epp->ep_entry = execp->a_entry; 118 119 error = vn_marktext(epp->ep_vp); 120 if (error) 121 return (error); 122 123 /* set up command for text segment */ 124 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, round_page(execp->a_text), 125 epp->ep_taddr, epp->ep_vp, 0, VM_PROT_READ|VM_PROT_EXECUTE); 126 127 /* set up command for data segment */ 128 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, round_page(execp->a_data), 129 epp->ep_daddr, epp->ep_vp, execp->a_text, 130 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 131 132 /* set up command for bss segment */ 133 if (execp->a_bss > 0) 134 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, execp->a_bss, 135 epp->ep_daddr + execp->a_data, NULLVP, 0, 136 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 137 138 return exec_aout_setup_stack(p, epp); 139 } 140 141 /* 142 * exec_aout_prep_nmagic(): Prepare a 'native' NMAGIC binary's exec package 143 */ 144 145 int 146 exec_aout_prep_nmagic(struct proc *p, struct exec_package *epp) 147 { 148 struct exec *execp = epp->ep_hdr; 149 long bsize, baddr; 150 151 epp->ep_taddr = AOUT_LDPGSZ; 152 epp->ep_tsize = execp->a_text; 153 epp->ep_daddr = roundup(epp->ep_taddr + execp->a_text, AOUT_LDPGSZ); 154 epp->ep_dsize = execp->a_data + execp->a_bss; 155 epp->ep_entry = execp->a_entry; 156 157 /* set up command for text segment */ 158 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_text, 159 epp->ep_taddr, epp->ep_vp, sizeof(struct exec), 160 VM_PROT_READ|VM_PROT_EXECUTE); 161 162 /* set up command for data segment */ 163 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_data, 164 epp->ep_daddr, epp->ep_vp, execp->a_text + sizeof(struct exec), 165 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 166 167 /* set up command for bss segment */ 168 baddr = round_page(epp->ep_daddr + execp->a_data); 169 bsize = epp->ep_daddr + epp->ep_dsize - baddr; 170 if (bsize > 0) 171 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, bsize, baddr, 172 NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 173 174 return exec_aout_setup_stack(p, epp); 175 } 176 177 /* 178 * exec_aout_prep_omagic(): Prepare a 'native' OMAGIC binary's exec package 179 */ 180 181 int 182 exec_aout_prep_omagic(struct proc *p, struct exec_package *epp) 183 { 184 struct exec *execp = epp->ep_hdr; 185 long dsize, bsize, baddr; 186 187 epp->ep_taddr = AOUT_LDPGSZ; 188 epp->ep_tsize = execp->a_text; 189 epp->ep_daddr = epp->ep_taddr + execp->a_text; 190 epp->ep_dsize = execp->a_data + execp->a_bss; 191 epp->ep_entry = execp->a_entry; 192 193 /* set up command for text and data segments */ 194 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, 195 execp->a_text + execp->a_data, epp->ep_taddr, epp->ep_vp, 196 sizeof(struct exec), VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 197 198 /* set up command for bss segment */ 199 baddr = round_page(epp->ep_daddr + execp->a_data); 200 bsize = epp->ep_daddr + epp->ep_dsize - baddr; 201 if (bsize > 0) 202 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, bsize, baddr, 203 NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 204 205 /* 206 * Make sure (# of pages) mapped above equals (vm_tsize + vm_dsize); 207 * obreak(2) relies on this fact. Both `vm_tsize' and `vm_dsize' are 208 * computed (in execve(2)) by rounding *up* `ep_tsize' and `ep_dsize' 209 * respectively to page boundaries. 210 * Compensate `ep_dsize' for the amount of data covered by the last 211 * text page. 212 */ 213 dsize = epp->ep_dsize + execp->a_text - round_page(execp->a_text); 214 epp->ep_dsize = (dsize > 0) ? dsize : 0; 215 return exec_aout_setup_stack(p, epp); 216 } 217 218 /* 219 * exec_aout_setup_stack(): Set up the stack segment for an a.out 220 * executable. 221 * 222 * Note that the ep_ssize parameter must be set to be the current stack 223 * limit; this is adjusted in the body of execve() to yield the 224 * appropriate stack segment usage once the argument length is 225 * calculated. 226 * 227 * This function returns an int for uniformity with other (future) formats' 228 * stack setup functions. They might have errors to return. 229 */ 230 231 int 232 exec_aout_setup_stack(struct proc *p, struct exec_package *epp) 233 { 234 235 epp->ep_maxsaddr = USRSTACK - MAXSSIZ; 236 epp->ep_minsaddr = USRSTACK; 237 epp->ep_ssize = p->p_rlimit[RLIMIT_STACK].rlim_cur; 238 239 /* 240 * set up commands for stack. note that this takes *two*, one to 241 * map the part of the stack which we can access, and one to map 242 * the part which we can't. 243 * 244 * arguably, it could be made into one, but that would require the 245 * addition of another mapping proc, which is unnecessary 246 * 247 * note that in memory, things assumed to be: 0 ... ep_maxsaddr 248 * <stack> ep_minsaddr 249 */ 250 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, 251 ((epp->ep_minsaddr - epp->ep_ssize) - epp->ep_maxsaddr), 252 epp->ep_maxsaddr, NULLVP, 0, VM_PROT_NONE); 253 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, epp->ep_ssize, 254 (epp->ep_minsaddr - epp->ep_ssize), NULLVP, 0, 255 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 256 257 return 0; 258 } 259
Indexes created Wed Sep 24 15:09:51 GMT 2025