1 /*- 2 * Copyright (c) 1994-1996 Søren Schmidt 3 * All rights reserved. 4 * 5 * Based heavily on /sys/kern/imgact_aout.c which is: 6 * Copyright (c) 1993, David Greenman 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer 13 * in this position and unchanged. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. The name of the author may not be used to endorse or promote products 18 * derived from this software without specific prior written permission 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 21 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 22 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 23 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 24 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 25 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 26 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 27 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 28 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 29 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 __FBSDID("$FreeBSD$"); 34 35 #include <sys/param.h> 36 #include <sys/systm.h> 37 #include <sys/exec.h> 38 #include <sys/imgact.h> 39 #include <sys/imgact_aout.h> 40 #include <sys/kernel.h> 41 #include <sys/lock.h> 42 #include <sys/mman.h> 43 #include <sys/mutex.h> 44 #include <sys/proc.h> 45 #include <sys/racct.h> 46 #include <sys/resourcevar.h> 47 #include <sys/vnode.h> 48 49 #include <vm/vm.h> 50 #include <vm/vm_kern.h> 51 #include <vm/vm_param.h> 52 #include <vm/pmap.h> 53 #include <vm/vm_map.h> 54 #include <vm/vm_extern.h> 55 56 #include <i386/linux/linux.h> 57 58 static int exec_linux_imgact(struct image_params *iparams); 59 60 static int 61 exec_linux_imgact(struct image_params *imgp) 62 { 63 const struct exec *a_out = (const struct exec *) imgp->image_header; 64 struct vmspace *vmspace; 65 vm_offset_t vmaddr; 66 unsigned long virtual_offset, file_offset; 67 unsigned long bss_size; 68 ssize_t aresid; 69 int error; 70 71 if (((a_out->a_magic >> 16) & 0xff) != 0x64) 72 return -1; 73 74 /* 75 * Set file/virtual offset based on a.out variant. 76 */ 77 switch ((int)(a_out->a_magic & 0xffff)) { 78 case 0413: 79 virtual_offset = 0; 80 file_offset = 1024; 81 break; 82 case 0314: 83 virtual_offset = 4096; 84 file_offset = 0; 85 break; 86 default: 87 return (-1); 88 } 89 bss_size = round_page(a_out->a_bss); 90 #ifdef DEBUG 91 printf("imgact: text: %08lx, data: %08lx, bss: %08lx\n", 92 (u_long)a_out->a_text, (u_long)a_out->a_data, bss_size); 93 #endif 94 95 /* 96 * Check various fields in header for validity/bounds. 97 */ 98 if (a_out->a_entry < virtual_offset || 99 a_out->a_entry >= virtual_offset + a_out->a_text || 100 a_out->a_text & PAGE_MASK || a_out->a_data & PAGE_MASK) 101 return (-1); 102 103 /* text + data can't exceed file size */ 104 if (a_out->a_data + a_out->a_text > imgp->attr->va_size) 105 return (EFAULT); 106 /* 107 * text/data/bss must not exceed limits 108 */ 109 PROC_LOCK(imgp->proc); 110 if (a_out->a_text > maxtsiz || 111 a_out->a_data + bss_size > lim_cur(imgp->proc, RLIMIT_DATA) || 112 racct_set(imgp->proc, RACCT_DATA, a_out->a_data + bss_size) != 0) { 113 PROC_UNLOCK(imgp->proc); 114 return (ENOMEM); 115 } 116 PROC_UNLOCK(imgp->proc); 117 118 VOP_UNLOCK(imgp->vp, 0); 119 120 /* 121 * Destroy old process VM and create a new one (with a new stack) 122 */ 123 error = exec_new_vmspace(imgp, &linux_sysvec); 124 if (error) 125 goto fail; 126 vmspace = imgp->proc->p_vmspace; 127 128 /* 129 * Check if file_offset page aligned,. 130 * Currently we cannot handle misaligned file offsets, 131 * and so we read in the entire image (what a waste). 132 */ 133 if (file_offset & PAGE_MASK) { 134 #ifdef DEBUG 135 printf("imgact: Non page aligned binary %lu\n", file_offset); 136 #endif 137 /* 138 * Map text+data+bss read/write/execute 139 */ 140 vmaddr = virtual_offset; 141 error = vm_map_find(&vmspace->vm_map, NULL, 0, &vmaddr, 142 a_out->a_text + a_out->a_data + bss_size, FALSE, 143 VM_PROT_ALL, VM_PROT_ALL, 0); 144 if (error) 145 goto fail; 146 147 error = vn_rdwr(UIO_READ, imgp->vp, (void *)vmaddr, file_offset, 148 a_out->a_text + a_out->a_data, UIO_USERSPACE, 0, 149 curthread->td_ucred, NOCRED, &aresid, curthread); 150 if (error != 0) 151 goto fail; 152 if (aresid != 0) { 153 error = ENOEXEC; 154 goto fail; 155 } 156 157 /* 158 * remove write enable on the 'text' part 159 */ 160 error = vm_map_protect(&vmspace->vm_map, 161 vmaddr, 162 vmaddr + a_out->a_text, 163 VM_PROT_EXECUTE|VM_PROT_READ, 164 TRUE); 165 if (error) 166 goto fail; 167 } 168 else { 169 #ifdef DEBUG 170 printf("imgact: Page aligned binary %lu\n", file_offset); 171 #endif 172 /* 173 * Map text+data read/execute 174 */ 175 vmaddr = virtual_offset; 176 error = vm_mmap(&vmspace->vm_map, &vmaddr, 177 a_out->a_text + a_out->a_data, 178 VM_PROT_READ | VM_PROT_EXECUTE, 179 VM_PROT_ALL, 180 MAP_PRIVATE | MAP_FIXED, 181 OBJT_VNODE, 182 imgp->vp, file_offset); 183 if (error) 184 goto fail; 185 186 #ifdef DEBUG 187 printf("imgact: startaddr=%08lx, length=%08lx\n", 188 (u_long)vmaddr, (u_long)a_out->a_text + (u_long)a_out->a_data); 189 #endif 190 /* 191 * allow read/write of data 192 */ 193 error = vm_map_protect(&vmspace->vm_map, 194 vmaddr + a_out->a_text, 195 vmaddr + a_out->a_text + a_out->a_data, 196 VM_PROT_ALL, 197 FALSE); 198 if (error) 199 goto fail; 200 201 /* 202 * Allocate anon demand-zeroed area for uninitialized data 203 */ 204 if (bss_size != 0) { 205 vmaddr = virtual_offset + a_out->a_text + a_out->a_data; 206 error = vm_map_find(&vmspace->vm_map, NULL, 0, &vmaddr, 207 bss_size, FALSE, VM_PROT_ALL, VM_PROT_ALL, 0); 208 if (error) 209 goto fail; 210 #ifdef DEBUG 211 printf("imgact: bssaddr=%08lx, length=%08lx\n", 212 (u_long)vmaddr, bss_size); 213 #endif 214 215 } 216 } 217 /* Fill in process VM information */ 218 vmspace->vm_tsize = round_page(a_out->a_text) >> PAGE_SHIFT; 219 vmspace->vm_dsize = round_page(a_out->a_data + bss_size) >> PAGE_SHIFT; 220 vmspace->vm_taddr = (caddr_t)(void *)(uintptr_t)virtual_offset; 221 vmspace->vm_daddr = (caddr_t)(void *)(uintptr_t) 222 (virtual_offset + a_out->a_text); 223 224 /* Fill in image_params */ 225 imgp->interpreted = 0; 226 imgp->entry_addr = a_out->a_entry; 227 228 imgp->proc->p_sysent = &linux_sysvec; 229 230 fail: 231 vn_lock(imgp->vp, LK_EXCLUSIVE | LK_RETRY); 232 return (error); 233 } 234 235 /* 236 * Tell kern_execve.c about it, with a little help from the linker. 237 */ 238 static struct execsw linux_execsw = { exec_linux_imgact, "linux a.out" }; 239 EXEC_SET(linuxaout, linux_execsw); 240