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 .sv_set_syscall_retval = cpu_set_syscall_retval, 94 .sv_fetch_syscall_args = cpu_fetch_syscall_args, 95 .sv_syscallnames = syscallnames, 96 }; 97 98 static int 99 aout_fixup(stack_base, imgp) 100 register_t **stack_base; 101 struct image_params *imgp; 102 { 103 104 return (suword(--(*stack_base), imgp->args->argc)); 105 } 106 107 static int 108 exec_aout_imgact(imgp) 109 struct image_params *imgp; 110 { 111 const struct exec *a_out = (const struct exec *) imgp->image_header; 112 struct vmspace *vmspace; 113 vm_map_t map; 114 vm_object_t object; 115 vm_offset_t text_end, data_end; 116 unsigned long virtual_offset; 117 unsigned long file_offset; 118 unsigned long bss_size; 119 int error; 120 121 /* 122 * Linux and *BSD binaries look very much alike, 123 * only the machine id is different: 124 * 0x64 for Linux, 0x86 for *BSD, 0x00 for BSDI. 125 * NetBSD is in network byte order.. ugh. 126 */ 127 if (((a_out->a_magic >> 16) & 0xff) != 0x86 && 128 ((a_out->a_magic >> 16) & 0xff) != 0 && 129 ((((int)ntohl(a_out->a_magic)) >> 16) & 0xff) != 0x86) 130 return -1; 131 132 /* 133 * Set file/virtual offset based on a.out variant. 134 * We do two cases: host byte order and network byte order 135 * (for NetBSD compatibility) 136 */ 137 switch ((int)(a_out->a_magic & 0xffff)) { 138 case ZMAGIC: 139 virtual_offset = 0; 140 if (a_out->a_text) { 141 file_offset = PAGE_SIZE; 142 } else { 143 /* Bill's "screwball mode" */ 144 file_offset = 0; 145 } 146 break; 147 case QMAGIC: 148 virtual_offset = PAGE_SIZE; 149 file_offset = 0; 150 /* Pass PS_STRINGS for BSD/OS binaries only. */ 151 if (N_GETMID(*a_out) == MID_ZERO) 152 imgp->ps_strings = aout_sysvec.sv_psstrings; 153 break; 154 default: 155 /* NetBSD compatibility */ 156 switch ((int)(ntohl(a_out->a_magic) & 0xffff)) { 157 case ZMAGIC: 158 case QMAGIC: 159 virtual_offset = PAGE_SIZE; 160 file_offset = 0; 161 break; 162 default: 163 return (-1); 164 } 165 } 166 167 bss_size = roundup(a_out->a_bss, PAGE_SIZE); 168 169 /* 170 * Check various fields in header for validity/bounds. 171 */ 172 if (/* entry point must lay with text region */ 173 a_out->a_entry < virtual_offset || 174 a_out->a_entry >= virtual_offset + a_out->a_text || 175 176 /* text and data size must each be page rounded */ 177 a_out->a_text & PAGE_MASK || a_out->a_data & PAGE_MASK) 178 return (-1); 179 180 /* text + data can't exceed file size */ 181 if (a_out->a_data + a_out->a_text > imgp->attr->va_size) 182 return (EFAULT); 183 184 /* 185 * text/data/bss must not exceed limits 186 */ 187 PROC_LOCK(imgp->proc); 188 if (/* text can't exceed maximum text size */ 189 a_out->a_text > maxtsiz || 190 191 /* data + bss can't exceed rlimit */ 192 a_out->a_data + bss_size > lim_cur(imgp->proc, RLIMIT_DATA)) { 193 PROC_UNLOCK(imgp->proc); 194 return (ENOMEM); 195 } 196 PROC_UNLOCK(imgp->proc); 197 198 /* 199 * Avoid a possible deadlock if the current address space is destroyed 200 * and that address space maps the locked vnode. In the common case, 201 * the locked vnode's v_usecount is decremented but remains greater 202 * than zero. Consequently, the vnode lock is not needed by vrele(). 203 * However, in cases where the vnode lock is external, such as nullfs, 204 * v_usecount may become zero. 205 */ 206 VOP_UNLOCK(imgp->vp, 0); 207 208 /* 209 * Destroy old process VM and create a new one (with a new stack) 210 */ 211 error = exec_new_vmspace(imgp, &aout_sysvec); 212 213 vn_lock(imgp->vp, LK_EXCLUSIVE | LK_RETRY); 214 if (error) 215 return (error); 216 217 /* 218 * The vm space can be changed by exec_new_vmspace 219 */ 220 vmspace = imgp->proc->p_vmspace; 221 222 object = imgp->object; 223 map = &vmspace->vm_map; 224 vm_map_lock(map); 225 vm_object_reference(object); 226 227 text_end = virtual_offset + a_out->a_text; 228 error = vm_map_insert(map, object, 229 file_offset, 230 virtual_offset, text_end, 231 VM_PROT_READ | VM_PROT_EXECUTE, VM_PROT_ALL, 232 MAP_COPY_ON_WRITE | MAP_PREFAULT); 233 if (error) { 234 vm_map_unlock(map); 235 vm_object_deallocate(object); 236 return (error); 237 } 238 data_end = text_end + a_out->a_data; 239 if (a_out->a_data) { 240 vm_object_reference(object); 241 error = vm_map_insert(map, object, 242 file_offset + a_out->a_text, 243 text_end, data_end, 244 VM_PROT_ALL, VM_PROT_ALL, 245 MAP_COPY_ON_WRITE | MAP_PREFAULT); 246 if (error) { 247 vm_map_unlock(map); 248 vm_object_deallocate(object); 249 return (error); 250 } 251 } 252 253 if (bss_size) { 254 error = vm_map_insert(map, NULL, 0, 255 data_end, data_end + bss_size, 256 VM_PROT_ALL, VM_PROT_ALL, 0); 257 if (error) { 258 vm_map_unlock(map); 259 return (error); 260 } 261 } 262 vm_map_unlock(map); 263 264 /* Fill in process VM information */ 265 vmspace->vm_tsize = a_out->a_text >> PAGE_SHIFT; 266 vmspace->vm_dsize = (a_out->a_data + bss_size) >> PAGE_SHIFT; 267 vmspace->vm_taddr = (caddr_t) (uintptr_t) virtual_offset; 268 vmspace->vm_daddr = (caddr_t) (uintptr_t) 269 (virtual_offset + a_out->a_text); 270 271 /* Fill in image_params */ 272 imgp->interpreted = 0; 273 imgp->entry_addr = a_out->a_entry; 274 275 imgp->proc->p_sysent = &aout_sysvec; 276 277 return (0); 278 } 279 280 /* 281 * Tell kern_execve.c about it, with a little help from the linker. 282 */ 283 static struct execsw aout_execsw = { exec_aout_imgact, "a.out" }; 284 EXEC_SET(aout, aout_execsw); 285