1 /*- 2 * Copyright (c) 1993, David Greenman 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 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD$"); 29 30 #include <sys/param.h> 31 #include <sys/exec.h> 32 #include <sys/imgact.h> 33 #include <sys/imgact_aout.h> 34 #include <sys/kernel.h> 35 #include <sys/lock.h> 36 #include <sys/malloc.h> 37 #include <sys/mutex.h> 38 #include <sys/proc.h> 39 #include <sys/resourcevar.h> 40 #include <sys/signalvar.h> 41 #include <sys/syscall.h> 42 #include <sys/sysent.h> 43 #include <sys/systm.h> 44 #include <sys/vnode.h> 45 46 #include <machine/frame.h> 47 #include <machine/md_var.h> 48 49 #include <vm/vm.h> 50 #include <vm/pmap.h> 51 #include <vm/vm_map.h> 52 #include <vm/vm_object.h> 53 #include <vm/vm_param.h> 54 55 static int exec_aout_imgact(struct image_params *imgp); 56 static int aout_fixup(register_t **stack_base, struct image_params *imgp); 57 58 struct sysentvec aout_sysvec = { 59 .sv_size = SYS_MAXSYSCALL, 60 .sv_table = sysent, 61 .sv_mask = 0, 62 .sv_sigsize = 0, 63 .sv_sigtbl = NULL, 64 .sv_errsize = 0, 65 .sv_errtbl = NULL, 66 .sv_transtrap = NULL, 67 .sv_fixup = aout_fixup, 68 .sv_sendsig = sendsig, 69 .sv_sigcode = sigcode, 70 .sv_szsigcode = &szsigcode, 71 .sv_prepsyscall = NULL, 72 .sv_name = "FreeBSD a.out", 73 .sv_coredump = NULL, 74 .sv_imgact_try = NULL, 75 .sv_minsigstksz = MINSIGSTKSZ, 76 .sv_pagesize = PAGE_SIZE, 77 .sv_minuser = VM_MIN_ADDRESS, 78 .sv_maxuser = VM_MAXUSER_ADDRESS, 79 .sv_usrstack = USRSTACK, 80 .sv_psstrings = PS_STRINGS, 81 .sv_stackprot = VM_PROT_ALL, 82 .sv_copyout_strings = exec_copyout_strings, 83 .sv_setregs = exec_setregs, 84 .sv_fixlimit = NULL, 85 .sv_maxssiz = NULL, 86 .sv_flags = SV_ABI_FREEBSD | SV_AOUT | 87 #if defined(__i386__) 88 SV_IA32 | SV_ILP32 89 #else 90 #error Choose SV_XXX flags for the platform 91 #endif 92 }; 93 94 static int 95 aout_fixup(stack_base, imgp) 96 register_t **stack_base; 97 struct image_params *imgp; 98 { 99 100 return (suword(--(*stack_base), imgp->args->argc)); 101 } 102 103 static int 104 exec_aout_imgact(imgp) 105 struct image_params *imgp; 106 { 107 const struct exec *a_out = (const struct exec *) imgp->image_header; 108 struct vmspace *vmspace; 109 vm_map_t map; 110 vm_object_t object; 111 vm_offset_t text_end, data_end; 112 unsigned long virtual_offset; 113 unsigned long file_offset; 114 unsigned long bss_size; 115 int error; 116 117 /* 118 * Linux and *BSD binaries look very much alike, 119 * only the machine id is different: 120 * 0x64 for Linux, 0x86 for *BSD, 0x00 for BSDI. 121 * NetBSD is in network byte order.. ugh. 122 */ 123 if (((a_out->a_magic >> 16) & 0xff) != 0x86 && 124 ((a_out->a_magic >> 16) & 0xff) != 0 && 125 ((((int)ntohl(a_out->a_magic)) >> 16) & 0xff) != 0x86) 126 return -1; 127 128 /* 129 * Set file/virtual offset based on a.out variant. 130 * We do two cases: host byte order and network byte order 131 * (for NetBSD compatibility) 132 */ 133 switch ((int)(a_out->a_magic & 0xffff)) { 134 case ZMAGIC: 135 virtual_offset = 0; 136 if (a_out->a_text) { 137 file_offset = PAGE_SIZE; 138 } else { 139 /* Bill's "screwball mode" */ 140 file_offset = 0; 141 } 142 break; 143 case QMAGIC: 144 virtual_offset = PAGE_SIZE; 145 file_offset = 0; 146 /* Pass PS_STRINGS for BSD/OS binaries only. */ 147 if (N_GETMID(*a_out) == MID_ZERO) 148 imgp->ps_strings = aout_sysvec.sv_psstrings; 149 break; 150 default: 151 /* NetBSD compatibility */ 152 switch ((int)(ntohl(a_out->a_magic) & 0xffff)) { 153 case ZMAGIC: 154 case QMAGIC: 155 virtual_offset = PAGE_SIZE; 156 file_offset = 0; 157 break; 158 default: 159 return (-1); 160 } 161 } 162 163 bss_size = roundup(a_out->a_bss, PAGE_SIZE); 164 165 /* 166 * Check various fields in header for validity/bounds. 167 */ 168 if (/* entry point must lay with text region */ 169 a_out->a_entry < virtual_offset || 170 a_out->a_entry >= virtual_offset + a_out->a_text || 171 172 /* text and data size must each be page rounded */ 173 a_out->a_text & PAGE_MASK || a_out->a_data & PAGE_MASK) 174 return (-1); 175 176 /* text + data can't exceed file size */ 177 if (a_out->a_data + a_out->a_text > imgp->attr->va_size) 178 return (EFAULT); 179 180 /* 181 * text/data/bss must not exceed limits 182 */ 183 PROC_LOCK(imgp->proc); 184 if (/* text can't exceed maximum text size */ 185 a_out->a_text > maxtsiz || 186 187 /* data + bss can't exceed rlimit */ 188 a_out->a_data + bss_size > lim_cur(imgp->proc, RLIMIT_DATA)) { 189 PROC_UNLOCK(imgp->proc); 190 return (ENOMEM); 191 } 192 PROC_UNLOCK(imgp->proc); 193 194 /* 195 * Avoid a possible deadlock if the current address space is destroyed 196 * and that address space maps the locked vnode. In the common case, 197 * the locked vnode's v_usecount is decremented but remains greater 198 * than zero. Consequently, the vnode lock is not needed by vrele(). 199 * However, in cases where the vnode lock is external, such as nullfs, 200 * v_usecount may become zero. 201 */ 202 VOP_UNLOCK(imgp->vp, 0); 203 204 /* 205 * Destroy old process VM and create a new one (with a new stack) 206 */ 207 error = exec_new_vmspace(imgp, &aout_sysvec); 208 209 vn_lock(imgp->vp, LK_EXCLUSIVE | LK_RETRY); 210 if (error) 211 return (error); 212 213 /* 214 * The vm space can be changed by exec_new_vmspace 215 */ 216 vmspace = imgp->proc->p_vmspace; 217 218 object = imgp->object; 219 map = &vmspace->vm_map; 220 vm_map_lock(map); 221 vm_object_reference(object); 222 223 text_end = virtual_offset + a_out->a_text; 224 error = vm_map_insert(map, object, 225 file_offset, 226 virtual_offset, text_end, 227 VM_PROT_READ | VM_PROT_EXECUTE, VM_PROT_ALL, 228 MAP_COPY_ON_WRITE | MAP_PREFAULT); 229 if (error) { 230 vm_map_unlock(map); 231 vm_object_deallocate(object); 232 return (error); 233 } 234 data_end = text_end + a_out->a_data; 235 if (a_out->a_data) { 236 vm_object_reference(object); 237 error = vm_map_insert(map, object, 238 file_offset + a_out->a_text, 239 text_end, data_end, 240 VM_PROT_ALL, VM_PROT_ALL, 241 MAP_COPY_ON_WRITE | MAP_PREFAULT); 242 if (error) { 243 vm_map_unlock(map); 244 vm_object_deallocate(object); 245 return (error); 246 } 247 } 248 249 if (bss_size) { 250 error = vm_map_insert(map, NULL, 0, 251 data_end, data_end + bss_size, 252 VM_PROT_ALL, VM_PROT_ALL, 0); 253 if (error) { 254 vm_map_unlock(map); 255 return (error); 256 } 257 } 258 vm_map_unlock(map); 259 260 /* Fill in process VM information */ 261 vmspace->vm_tsize = a_out->a_text >> PAGE_SHIFT; 262 vmspace->vm_dsize = (a_out->a_data + bss_size) >> PAGE_SHIFT; 263 vmspace->vm_taddr = (caddr_t) (uintptr_t) virtual_offset; 264 vmspace->vm_daddr = (caddr_t) (uintptr_t) 265 (virtual_offset + a_out->a_text); 266 267 /* Fill in image_params */ 268 imgp->interpreted = 0; 269 imgp->entry_addr = a_out->a_entry; 270 271 imgp->proc->p_sysent = &aout_sysvec; 272 273 return (0); 274 } 275 276 /* 277 * Tell kern_execve.c about it, with a little help from the linker. 278 */ 279 static struct execsw aout_execsw = { exec_aout_imgact, "a.out" }; 280 EXEC_SET(aout, aout_execsw); 281