1 /* $NetBSD: exec_aout.c,v 1.40 2014/03/07 01:55:01 matt 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 1.40 2014/03/07 01:55:01 matt 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_EXEC, exec_aout, DEP); 58 59 static struct execsw exec_aout_execsw = { 60 .es_hdrsz = sizeof(struct exec), 61 .es_makecmds = exec_aout_makecmds, 62 .u = { 63 .elf_probe_func = NULL, 64 }, 65 .es_emul = &emul_netbsd, 66 .es_prio = EXECSW_PRIO_ANY, 67 .es_arglen = 0, 68 .es_copyargs = copyargs, 69 .es_setregs = NULL, 70 .es_coredump = coredump_netbsd, 71 .es_setup_stack = exec_setup_stack, 72 }; 73 74 static int 75 exec_aout_modcmd(modcmd_t cmd, void *arg) 76 { 77 78 switch (cmd) { 79 case MODULE_CMD_INIT: 80 return exec_add(&exec_aout_execsw, 1); 81 82 case MODULE_CMD_FINI: 83 return exec_remove(&exec_aout_execsw, 1); 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 else 136 epp->ep_flags &= ~EXEC_TOPDOWN_VM; 137 138 return error; 139 } 140 141 /* 142 * exec_aout_prep_zmagic(): Prepare a 'native' ZMAGIC binary's exec package 143 * 144 * First, set of the various offsets/lengths in the exec package. 145 * 146 * Then, mark the text image busy (so it can be demand paged) or error 147 * out if this is not possible. Finally, set up vmcmds for the 148 * text, data, bss, and stack segments. 149 */ 150 151 int 152 exec_aout_prep_zmagic(struct lwp *l, struct exec_package *epp) 153 { 154 struct exec *execp = epp->ep_hdr; 155 int error; 156 157 epp->ep_taddr = AOUT_LDPGSZ; 158 epp->ep_tsize = execp->a_text; 159 epp->ep_daddr = epp->ep_taddr + execp->a_text; 160 epp->ep_dsize = execp->a_data + execp->a_bss; 161 epp->ep_entry = execp->a_entry; 162 163 error = vn_marktext(epp->ep_vp); 164 if (error) 165 return (error); 166 167 /* set up command for text segment */ 168 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, round_page(execp->a_text), 169 epp->ep_taddr, epp->ep_vp, 0, VM_PROT_READ|VM_PROT_EXECUTE); 170 171 /* set up command for data segment */ 172 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, round_page(execp->a_data), 173 epp->ep_daddr, epp->ep_vp, execp->a_text, 174 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 175 176 /* set up command for bss segment */ 177 if (execp->a_bss > 0) 178 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, execp->a_bss, 179 epp->ep_daddr + execp->a_data, NULLVP, 0, 180 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 181 182 return (*epp->ep_esch->es_setup_stack)(l, epp); 183 } 184 185 /* 186 * exec_aout_prep_nmagic(): Prepare a 'native' NMAGIC binary's exec package 187 */ 188 189 int 190 exec_aout_prep_nmagic(struct lwp *l, struct exec_package *epp) 191 { 192 struct exec *execp = epp->ep_hdr; 193 long bsize, baddr; 194 195 epp->ep_taddr = AOUT_LDPGSZ; 196 epp->ep_tsize = execp->a_text; 197 epp->ep_daddr = roundup(epp->ep_taddr + execp->a_text, AOUT_LDPGSZ); 198 epp->ep_dsize = execp->a_data + execp->a_bss; 199 epp->ep_entry = execp->a_entry; 200 201 /* set up command for text segment */ 202 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_text, 203 epp->ep_taddr, epp->ep_vp, sizeof(struct exec), 204 VM_PROT_READ|VM_PROT_EXECUTE); 205 206 /* set up command for data segment */ 207 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_data, 208 epp->ep_daddr, epp->ep_vp, execp->a_text + sizeof(struct exec), 209 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 210 211 /* set up command for bss segment */ 212 baddr = round_page(epp->ep_daddr + execp->a_data); 213 bsize = epp->ep_daddr + epp->ep_dsize - baddr; 214 if (bsize > 0) 215 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, bsize, baddr, 216 NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 217 218 return (*epp->ep_esch->es_setup_stack)(l, epp); 219 } 220 221 /* 222 * exec_aout_prep_omagic(): Prepare a 'native' OMAGIC binary's exec package 223 */ 224 225 int 226 exec_aout_prep_omagic(struct lwp *l, struct exec_package *epp) 227 { 228 struct exec *execp = epp->ep_hdr; 229 long dsize, bsize, baddr; 230 231 epp->ep_taddr = AOUT_LDPGSZ; 232 epp->ep_tsize = execp->a_text; 233 epp->ep_daddr = epp->ep_taddr + execp->a_text; 234 epp->ep_dsize = execp->a_data + execp->a_bss; 235 epp->ep_entry = execp->a_entry; 236 237 /* set up command for text and data segments */ 238 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, 239 execp->a_text + execp->a_data, epp->ep_taddr, epp->ep_vp, 240 sizeof(struct exec), VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 241 242 /* set up command for bss segment */ 243 baddr = round_page(epp->ep_daddr + execp->a_data); 244 bsize = epp->ep_daddr + epp->ep_dsize - baddr; 245 if (bsize > 0) 246 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, bsize, baddr, 247 NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 248 249 /* 250 * Make sure (# of pages) mapped above equals (vm_tsize + vm_dsize); 251 * obreak(2) relies on this fact. Both `vm_tsize' and `vm_dsize' are 252 * computed (in execve(2)) by rounding *up* `ep_tsize' and `ep_dsize' 253 * respectively to page boundaries. 254 * Compensate `ep_dsize' for the amount of data covered by the last 255 * text page. 256 */ 257 dsize = epp->ep_dsize + execp->a_text - round_page(execp->a_text); 258 epp->ep_dsize = (dsize > 0) ? dsize : 0; 259 return (*epp->ep_esch->es_setup_stack)(l, epp); 260 } 261