1 /* $NetBSD: exec_aout.c,v 1.35 2011/04/24 18:46:22 rmind 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 1.35 2011/04/24 18:46:22 rmind Exp $"); 35 36 #ifdef _KERNEL_OPT 37 #include "opt_coredump.h" 38 #endif 39 40 #include <sys/param.h> 41 #include <sys/systm.h> 42 #include <sys/proc.h> 43 #include <sys/vnode.h> 44 #include <sys/exec.h> 45 #include <sys/exec_aout.h> 46 #include <sys/resourcevar.h> 47 #include <sys/module.h> 48 49 #include <uvm/uvm_extern.h> 50 51 #ifdef COREDUMP 52 #define DEP "coredump" 53 #else 54 #define DEP NULL 55 #endif 56 57 MODULE(MODULE_CLASS_MISC, exec_aout, DEP); 58 59 static struct execsw exec_aout_execsw[] = { 60 { sizeof(struct exec), 61 exec_aout_makecmds, 62 { NULL }, 63 &emul_netbsd, 64 EXECSW_PRIO_ANY, 65 0, 66 copyargs, 67 NULL, 68 coredump_netbsd, 69 exec_setup_stack }, 70 }; 71 72 static int 73 exec_aout_modcmd(modcmd_t cmd, void *arg) 74 { 75 76 switch (cmd) { 77 case MODULE_CMD_INIT: 78 return exec_add(exec_aout_execsw, 79 __arraycount(exec_aout_execsw)); 80 81 case MODULE_CMD_FINI: 82 return exec_remove(exec_aout_execsw, 83 __arraycount(exec_aout_execsw)); 84 85 default: 86 return ENOTTY; 87 } 88 } 89 90 /* 91 * exec_aout_makecmds(): Check if it's an a.out-format executable. 92 * 93 * Given a lwp pointer and an exec package pointer, see if the referent 94 * of the epp is in a.out format. First check 'standard' magic numbers for 95 * this architecture. If that fails, try a CPU-dependent hook. 96 * 97 * This function, in the former case, or the hook, in the latter, is 98 * responsible for creating a set of vmcmds which can be used to build 99 * the process's vm space and inserting them into the exec package. 100 */ 101 102 int 103 exec_aout_makecmds(struct lwp *l, struct exec_package *epp) 104 { 105 u_long midmag, magic; 106 u_short mid; 107 int error; 108 struct exec *execp = epp->ep_hdr; 109 110 if (epp->ep_hdrvalid < sizeof(struct exec)) 111 return ENOEXEC; 112 113 midmag = ntohl(execp->a_midmag); 114 mid = (midmag >> 16) & 0x3ff; 115 magic = midmag & 0xffff; 116 117 midmag = mid << 16 | magic; 118 119 switch (midmag) { 120 case (MID_MACHINE << 16) | ZMAGIC: 121 error = exec_aout_prep_zmagic(l, epp); 122 break; 123 case (MID_MACHINE << 16) | NMAGIC: 124 error = exec_aout_prep_nmagic(l, epp); 125 break; 126 case (MID_MACHINE << 16) | OMAGIC: 127 error = exec_aout_prep_omagic(l, epp); 128 break; 129 default: 130 error = cpu_exec_aout_makecmds(l, epp); 131 } 132 133 if (error) 134 kill_vmcmds(&epp->ep_vmcmds); 135 136 return error; 137 } 138 139 /* 140 * exec_aout_prep_zmagic(): Prepare a 'native' ZMAGIC binary's exec package 141 * 142 * First, set of the various offsets/lengths in the exec package. 143 * 144 * Then, mark the text image busy (so it can be demand paged) or error 145 * out if this is not possible. Finally, set up vmcmds for the 146 * text, data, bss, and stack segments. 147 */ 148 149 int 150 exec_aout_prep_zmagic(struct lwp *l, struct exec_package *epp) 151 { 152 struct exec *execp = epp->ep_hdr; 153 int error; 154 155 epp->ep_taddr = AOUT_LDPGSZ; 156 epp->ep_tsize = execp->a_text; 157 epp->ep_daddr = epp->ep_taddr + execp->a_text; 158 epp->ep_dsize = execp->a_data + execp->a_bss; 159 epp->ep_entry = execp->a_entry; 160 161 error = vn_marktext(epp->ep_vp); 162 if (error) 163 return (error); 164 165 /* set up command for text segment */ 166 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, round_page(execp->a_text), 167 epp->ep_taddr, epp->ep_vp, 0, VM_PROT_READ|VM_PROT_EXECUTE); 168 169 /* set up command for data segment */ 170 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, round_page(execp->a_data), 171 epp->ep_daddr, epp->ep_vp, execp->a_text, 172 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 173 174 /* set up command for bss segment */ 175 if (execp->a_bss > 0) 176 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, execp->a_bss, 177 epp->ep_daddr + execp->a_data, NULLVP, 0, 178 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 179 180 return (*epp->ep_esch->es_setup_stack)(l, epp); 181 } 182 183 /* 184 * exec_aout_prep_nmagic(): Prepare a 'native' NMAGIC binary's exec package 185 */ 186 187 int 188 exec_aout_prep_nmagic(struct lwp *l, struct exec_package *epp) 189 { 190 struct exec *execp = epp->ep_hdr; 191 long bsize, baddr; 192 193 epp->ep_taddr = AOUT_LDPGSZ; 194 epp->ep_tsize = execp->a_text; 195 epp->ep_daddr = roundup(epp->ep_taddr + execp->a_text, AOUT_LDPGSZ); 196 epp->ep_dsize = execp->a_data + execp->a_bss; 197 epp->ep_entry = execp->a_entry; 198 199 /* set up command for text segment */ 200 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_text, 201 epp->ep_taddr, epp->ep_vp, sizeof(struct exec), 202 VM_PROT_READ|VM_PROT_EXECUTE); 203 204 /* set up command for data segment */ 205 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_data, 206 epp->ep_daddr, epp->ep_vp, execp->a_text + sizeof(struct exec), 207 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 208 209 /* set up command for bss segment */ 210 baddr = round_page(epp->ep_daddr + execp->a_data); 211 bsize = epp->ep_daddr + epp->ep_dsize - baddr; 212 if (bsize > 0) 213 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, bsize, baddr, 214 NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 215 216 return (*epp->ep_esch->es_setup_stack)(l, epp); 217 } 218 219 /* 220 * exec_aout_prep_omagic(): Prepare a 'native' OMAGIC binary's exec package 221 */ 222 223 int 224 exec_aout_prep_omagic(struct lwp *l, struct exec_package *epp) 225 { 226 struct exec *execp = epp->ep_hdr; 227 long dsize, bsize, baddr; 228 229 epp->ep_taddr = AOUT_LDPGSZ; 230 epp->ep_tsize = execp->a_text; 231 epp->ep_daddr = epp->ep_taddr + execp->a_text; 232 epp->ep_dsize = execp->a_data + execp->a_bss; 233 epp->ep_entry = execp->a_entry; 234 235 /* set up command for text and data segments */ 236 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, 237 execp->a_text + execp->a_data, epp->ep_taddr, epp->ep_vp, 238 sizeof(struct exec), VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 239 240 /* set up command for bss segment */ 241 baddr = round_page(epp->ep_daddr + execp->a_data); 242 bsize = epp->ep_daddr + epp->ep_dsize - baddr; 243 if (bsize > 0) 244 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, bsize, baddr, 245 NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 246 247 /* 248 * Make sure (# of pages) mapped above equals (vm_tsize + vm_dsize); 249 * obreak(2) relies on this fact. Both `vm_tsize' and `vm_dsize' are 250 * computed (in execve(2)) by rounding *up* `ep_tsize' and `ep_dsize' 251 * respectively to page boundaries. 252 * Compensate `ep_dsize' for the amount of data covered by the last 253 * text page. 254 */ 255 dsize = epp->ep_dsize + execp->a_text - round_page(execp->a_text); 256 epp->ep_dsize = (dsize > 0) ? dsize : 0; 257 return (*epp->ep_esch->es_setup_stack)(l, epp); 258 } 259