imgact_linux.c revision 330897
1/*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1994-1996 S��ren 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 * in this position and unchanged. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. The name of the author may not be used to endorse or promote products 20 * derived from this software without specific prior written permission 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 25 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 26 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 27 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 31 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 32 */ 33 34#include <sys/cdefs.h> 35__FBSDID("$FreeBSD: stable/11/sys/i386/linux/imgact_linux.c 330897 2018-03-14 03:19:51Z eadler $"); 36 37#include <sys/param.h> 38#include <sys/systm.h> 39#include <sys/exec.h> 40#include <sys/imgact.h> 41#include <sys/imgact_aout.h> 42#include <sys/kernel.h> 43#include <sys/lock.h> 44#include <sys/mman.h> 45#include <sys/mutex.h> 46#include <sys/proc.h> 47#include <sys/racct.h> 48#include <sys/resourcevar.h> 49#include <sys/vnode.h> 50 51#include <vm/vm.h> 52#include <vm/vm_kern.h> 53#include <vm/vm_param.h> 54#include <vm/pmap.h> 55#include <vm/vm_map.h> 56#include <vm/vm_extern.h> 57 58#include <i386/linux/linux.h> 59 60static int exec_linux_imgact(struct image_params *iparams); 61 62static int 63exec_linux_imgact(struct image_params *imgp) 64{ 65 const struct exec *a_out = (const struct exec *) imgp->image_header; 66 struct vmspace *vmspace; 67 vm_offset_t vmaddr; 68 unsigned long virtual_offset, file_offset; 69 unsigned long bss_size; 70 ssize_t aresid; 71 int error; 72 73 if (((a_out->a_magic >> 16) & 0xff) != 0x64) 74 return -1; 75 76 /* 77 * Set file/virtual offset based on a.out variant. 78 */ 79 switch ((int)(a_out->a_magic & 0xffff)) { 80 case 0413: 81 virtual_offset = 0; 82 file_offset = 1024; 83 break; 84 case 0314: 85 virtual_offset = 4096; 86 file_offset = 0; 87 break; 88 default: 89 return (-1); 90 } 91 bss_size = round_page(a_out->a_bss); 92#ifdef DEBUG 93 printf("imgact: text: %08lx, data: %08lx, bss: %08lx\n", 94 (u_long)a_out->a_text, (u_long)a_out->a_data, bss_size); 95#endif 96 97 /* 98 * Check various fields in header for validity/bounds. 99 */ 100 if (a_out->a_entry < virtual_offset || 101 a_out->a_entry >= virtual_offset + a_out->a_text || 102 a_out->a_text & PAGE_MASK || a_out->a_data & PAGE_MASK) 103 return (-1); 104 105 /* text + data can't exceed file size */ 106 if (a_out->a_data + a_out->a_text > imgp->attr->va_size) 107 return (EFAULT); 108 /* 109 * text/data/bss must not exceed limits 110 */ 111 PROC_LOCK(imgp->proc); 112 if (a_out->a_text > maxtsiz || 113 a_out->a_data + bss_size > lim_cur_proc(imgp->proc, RLIMIT_DATA) || 114 racct_set(imgp->proc, RACCT_DATA, a_out->a_data + bss_size) != 0) { 115 PROC_UNLOCK(imgp->proc); 116 return (ENOMEM); 117 } 118 PROC_UNLOCK(imgp->proc); 119 120 VOP_UNLOCK(imgp->vp, 0); 121 122 /* 123 * Destroy old process VM and create a new one (with a new stack) 124 */ 125 error = exec_new_vmspace(imgp, &linux_sysvec); 126 if (error) 127 goto fail; 128 vmspace = imgp->proc->p_vmspace; 129 130 /* 131 * Check if file_offset page aligned,. 132 * Currently we cannot handle misaligned file offsets, 133 * and so we read in the entire image (what a waste). 134 */ 135 if (file_offset & PAGE_MASK) { 136#ifdef DEBUG 137 printf("imgact: Non page aligned binary %lu\n", file_offset); 138#endif 139 /* 140 * Map text+data+bss read/write/execute 141 */ 142 vmaddr = virtual_offset; 143 error = vm_map_find(&vmspace->vm_map, NULL, 0, &vmaddr, 144 a_out->a_text + a_out->a_data + bss_size, 0, VMFS_NO_SPACE, 145 VM_PROT_ALL, VM_PROT_ALL, 0); 146 if (error) 147 goto fail; 148 149 error = vn_rdwr(UIO_READ, imgp->vp, (void *)vmaddr, file_offset, 150 a_out->a_text + a_out->a_data, UIO_USERSPACE, 0, 151 curthread->td_ucred, NOCRED, &aresid, curthread); 152 if (error != 0) 153 goto fail; 154 if (aresid != 0) { 155 error = ENOEXEC; 156 goto fail; 157 } 158 159 /* 160 * remove write enable on the 'text' part 161 */ 162 error = vm_map_protect(&vmspace->vm_map, 163 vmaddr, 164 vmaddr + a_out->a_text, 165 VM_PROT_EXECUTE|VM_PROT_READ, 166 TRUE); 167 if (error) 168 goto fail; 169 } 170 else { 171#ifdef DEBUG 172 printf("imgact: Page aligned binary %lu\n", file_offset); 173#endif 174 /* 175 * Map text+data read/execute 176 */ 177 vmaddr = virtual_offset; 178 error = vm_mmap(&vmspace->vm_map, &vmaddr, 179 a_out->a_text + a_out->a_data, 180 VM_PROT_READ | VM_PROT_EXECUTE, 181 VM_PROT_ALL, 182 MAP_PRIVATE | MAP_FIXED, 183 OBJT_VNODE, 184 imgp->vp, file_offset); 185 if (error) 186 goto fail; 187 188#ifdef DEBUG 189 printf("imgact: startaddr=%08lx, length=%08lx\n", 190 (u_long)vmaddr, (u_long)a_out->a_text + (u_long)a_out->a_data); 191#endif 192 /* 193 * allow read/write of data 194 */ 195 error = vm_map_protect(&vmspace->vm_map, 196 vmaddr + a_out->a_text, 197 vmaddr + a_out->a_text + a_out->a_data, 198 VM_PROT_ALL, 199 FALSE); 200 if (error) 201 goto fail; 202 203 /* 204 * Allocate anon demand-zeroed area for uninitialized data 205 */ 206 if (bss_size != 0) { 207 vmaddr = virtual_offset + a_out->a_text + a_out->a_data; 208 error = vm_map_find(&vmspace->vm_map, NULL, 0, &vmaddr, 209 bss_size, 0, VMFS_NO_SPACE, VM_PROT_ALL, VM_PROT_ALL, 0); 210 if (error) 211 goto fail; 212#ifdef DEBUG 213 printf("imgact: bssaddr=%08lx, length=%08lx\n", 214 (u_long)vmaddr, bss_size); 215#endif 216 217 } 218 } 219 /* Fill in process VM information */ 220 vmspace->vm_tsize = round_page(a_out->a_text) >> PAGE_SHIFT; 221 vmspace->vm_dsize = round_page(a_out->a_data + bss_size) >> PAGE_SHIFT; 222 vmspace->vm_taddr = (caddr_t)(void *)(uintptr_t)virtual_offset; 223 vmspace->vm_daddr = (caddr_t)(void *)(uintptr_t) 224 (virtual_offset + a_out->a_text); 225 226 /* Fill in image_params */ 227 imgp->interpreted = 0; 228 imgp->entry_addr = a_out->a_entry; 229 230 imgp->proc->p_sysent = &linux_sysvec; 231 232fail: 233 vn_lock(imgp->vp, LK_EXCLUSIVE | LK_RETRY); 234 return (error); 235} 236 237/* 238 * Tell kern_execve.c about it, with a little help from the linker. 239 */ 240static struct execsw linux_execsw = { exec_linux_imgact, "linux a.out" }; 241EXEC_SET(linuxaout, linux_execsw); 242