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/param.h> 33 #include <sys/systm.h> 34 #include <sys/exec.h> 35 #include <sys/imgact.h> 36 #include <sys/imgact_aout.h> 37 #include <sys/kernel.h> 38 #include <sys/lock.h> 39 #include <sys/mman.h> 40 #include <sys/mutex.h> 41 #include <sys/proc.h> 42 #include <sys/racct.h> 43 #include <sys/resourcevar.h> 44 #include <sys/vnode.h> 45 46 #include <vm/vm.h> 47 #include <vm/vm_kern.h> 48 #include <vm/vm_param.h> 49 #include <vm/pmap.h> 50 #include <vm/vm_map.h> 51 #include <vm/vm_extern.h> 52 53 #include <i386/linux/linux.h> 54 55 static int exec_linux_imgact(struct image_params *iparams); 56 57 static int 58 exec_linux_imgact(struct image_params *imgp) 59 { 60 const struct exec *a_out = (const struct exec *) imgp->image_header; 61 struct vmspace *vmspace; 62 vm_offset_t vmaddr; 63 unsigned long virtual_offset, file_offset; 64 unsigned long bss_size; 65 ssize_t aresid; 66 int error; 67 68 if (((a_out->a_magic >> 16) & 0xff) != 0x64) 69 return (-1); 70 71 /* 72 * Set file/virtual offset based on a.out variant. 73 */ 74 switch ((int)(a_out->a_magic & 0xffff)) { 75 case 0413: 76 virtual_offset = 0; 77 file_offset = 1024; 78 break; 79 case 0314: 80 virtual_offset = 4096; 81 file_offset = 0; 82 break; 83 default: 84 return (-1); 85 } 86 bss_size = round_page(a_out->a_bss); 87 #ifdef DEBUG 88 printf("imgact: text: %08lx, data: %08lx, bss: %08lx\n", 89 (u_long)a_out->a_text, (u_long)a_out->a_data, bss_size); 90 #endif 91 92 /* 93 * Check various fields in header for validity/bounds. 94 */ 95 if (a_out->a_entry < virtual_offset || 96 a_out->a_entry >= virtual_offset + a_out->a_text || 97 a_out->a_text & PAGE_MASK || a_out->a_data & PAGE_MASK) 98 return (-1); 99 100 /* text + data can't exceed file size */ 101 if (a_out->a_data + a_out->a_text > imgp->attr->va_size) 102 return (EFAULT); 103 /* 104 * text/data/bss must not exceed limits 105 */ 106 PROC_LOCK(imgp->proc); 107 if (a_out->a_text > maxtsiz || 108 a_out->a_data + bss_size > lim_cur_proc(imgp->proc, RLIMIT_DATA) || 109 racct_set(imgp->proc, RACCT_DATA, a_out->a_data + bss_size) != 0) { 110 PROC_UNLOCK(imgp->proc); 111 return (ENOMEM); 112 } 113 PROC_UNLOCK(imgp->proc); 114 115 VOP_UNLOCK(imgp->vp); 116 117 /* 118 * Destroy old process VM and create a new one (with a new stack) 119 */ 120 error = exec_new_vmspace(imgp, &linux_sysvec); 121 if (error) 122 goto fail; 123 vmspace = imgp->proc->p_vmspace; 124 125 /* 126 * Check if file_offset page aligned,. 127 * Currently we cannot handle misaligned file offsets, 128 * and so we read in the entire image (what a waste). 129 */ 130 if (file_offset & PAGE_MASK) { 131 #ifdef DEBUG 132 printf("imgact: Non page aligned binary %lu\n", file_offset); 133 #endif 134 /* 135 * Map text+data+bss read/write/execute 136 */ 137 vmaddr = virtual_offset; 138 error = vm_map_find(&vmspace->vm_map, NULL, 0, &vmaddr, 139 a_out->a_text + a_out->a_data + bss_size, 0, VMFS_NO_SPACE, 140 VM_PROT_ALL, VM_PROT_ALL, 0); 141 if (error) 142 goto fail; 143 144 error = vn_rdwr(UIO_READ, imgp->vp, (void *)vmaddr, file_offset, 145 a_out->a_text + a_out->a_data, UIO_USERSPACE, 0, 146 curthread->td_ucred, NOCRED, &aresid, curthread); 147 if (error != 0) 148 goto fail; 149 if (aresid != 0) { 150 error = ENOEXEC; 151 goto fail; 152 } 153 154 /* 155 * remove write enable on the 'text' part 156 */ 157 error = vm_map_protect(&vmspace->vm_map, vmaddr, 158 vmaddr + a_out->a_text, 0, VM_PROT_EXECUTE | VM_PROT_READ, 159 VM_MAP_PROTECT_SET_MAXPROT); 160 if (error) 161 goto fail; 162 } else { 163 #ifdef DEBUG 164 printf("imgact: Page aligned binary %lu\n", file_offset); 165 #endif 166 /* 167 * Map text+data read/execute 168 */ 169 vmaddr = virtual_offset; 170 error = vm_mmap(&vmspace->vm_map, &vmaddr, 171 a_out->a_text + a_out->a_data, 172 VM_PROT_READ | VM_PROT_EXECUTE, VM_PROT_ALL, 173 MAP_PRIVATE | MAP_FIXED, OBJT_VNODE, imgp->vp, file_offset); 174 if (error) 175 goto fail; 176 177 #ifdef DEBUG 178 printf("imgact: startaddr=%08lx, length=%08lx\n", 179 (u_long)vmaddr, 180 (u_long)a_out->a_text + (u_long)a_out->a_data); 181 #endif 182 /* 183 * allow read/write of data 184 */ 185 error = vm_map_protect(&vmspace->vm_map, vmaddr + a_out->a_text, 186 vmaddr + a_out->a_text + a_out->a_data, VM_PROT_ALL, 0, 187 VM_MAP_PROTECT_SET_PROT); 188 if (error) 189 goto fail; 190 191 /* 192 * Allocate anon demand-zeroed area for uninitialized data 193 */ 194 if (bss_size != 0) { 195 vmaddr = virtual_offset + a_out->a_text + a_out->a_data; 196 error = vm_map_find(&vmspace->vm_map, NULL, 0, &vmaddr, 197 bss_size, 0, VMFS_NO_SPACE, VM_PROT_ALL, VM_PROT_ALL, 0); 198 if (error) 199 goto fail; 200 #ifdef DEBUG 201 printf("imgact: bssaddr=%08lx, length=%08lx\n", (u_long)vmaddr, 202 bss_size); 203 #endif 204 } 205 } 206 /* Fill in process VM information */ 207 vmspace->vm_tsize = round_page(a_out->a_text) >> PAGE_SHIFT; 208 vmspace->vm_dsize = round_page(a_out->a_data + bss_size) >> PAGE_SHIFT; 209 vmspace->vm_taddr = (caddr_t)(void *)(uintptr_t)virtual_offset; 210 vmspace->vm_daddr = 211 (caddr_t)(void *)(uintptr_t)(virtual_offset + a_out->a_text); 212 213 error = exec_map_stack(imgp); 214 if (error != 0) 215 goto fail; 216 217 /* Fill in image_params */ 218 imgp->interpreted = 0; 219 imgp->entry_addr = a_out->a_entry; 220 221 imgp->proc->p_sysent = &linux_sysvec; 222 223 fail: 224 vn_lock(imgp->vp, LK_EXCLUSIVE | LK_RETRY); 225 return (error); 226 } 227 228 /* 229 * Tell kern_execve.c about it, with a little help from the linker. 230 */ 231 static struct execsw linux_execsw = { exec_linux_imgact, "Linux a.out" }; 232 EXEC_SET(linuxaout, linux_execsw); 233