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