imgact_linux.c revision 105441
1/*- 2 * Copyright (c) 1994-1996 S�ren 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 * $FreeBSD: head/sys/i386/linux/imgact_linux.c 105441 2002-10-19 11:57:38Z markm $ 32 */ 33 34#include <sys/param.h> 35#include <sys/systm.h> 36#include <sys/exec.h> 37#include <sys/imgact.h> 38#include <sys/imgact_aout.h> 39#include <sys/kernel.h> 40#include <sys/lock.h> 41#include <sys/mman.h> 42#include <sys/mutex.h> 43#include <sys/proc.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 56static int exec_linux_imgact(struct image_params *iparams); 57 58static int 59exec_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 vm_offset_t buffer; 66 unsigned long bss_size; 67 struct thread *td = curthread; 68 int error; 69 70 if (((a_out->a_magic >> 16) & 0xff) != 0x64) 71 return -1; 72 73 /* 74 * Set file/virtual offset based on a.out variant. 75 */ 76 switch ((int)(a_out->a_magic & 0xffff)) { 77 case 0413: 78 virtual_offset = 0; 79 file_offset = 1024; 80 break; 81 case 0314: 82 virtual_offset = 4096; 83 file_offset = 0; 84 break; 85 default: 86 return (-1); 87 } 88 bss_size = round_page(a_out->a_bss); 89#ifdef DEBUG 90 printf("imgact: text: %08lx, data: %08lx, bss: %08lx\n", 91 (u_long)a_out->a_text, (u_long)a_out->a_data, bss_size); 92#endif 93 94 /* 95 * Check various fields in header for validity/bounds. 96 */ 97 if (a_out->a_entry < virtual_offset || 98 a_out->a_entry >= virtual_offset + a_out->a_text || 99 a_out->a_text & PAGE_MASK || a_out->a_data & PAGE_MASK) 100 return (-1); 101 102 /* text + data can't exceed file size */ 103 if (a_out->a_data + a_out->a_text > imgp->attr->va_size) 104 return (EFAULT); 105 /* 106 * text/data/bss must not exceed limits 107 */ 108 mtx_assert(&Giant, MA_OWNED); 109 if (a_out->a_text > maxtsiz || 110 a_out->a_data + bss_size > imgp->proc->p_rlimit[RLIMIT_DATA].rlim_cur) 111 return (ENOMEM); 112 113 VOP_UNLOCK(imgp->vp, 0, td); 114 115 /* copy in arguments and/or environment from old process */ 116 error = exec_extract_strings(imgp); 117 if (error) 118 goto fail; 119 120 /* 121 * Destroy old process VM and create a new one (with a new stack) 122 */ 123 exec_new_vmspace(imgp, &linux_sysvec); 124 vmspace = imgp->proc->p_vmspace; 125 126 /* 127 * Check if file_offset page aligned,. 128 * Currently we cannot handle misalinged 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, FALSE, 141 VM_PROT_ALL, VM_PROT_ALL, 0); 142 if (error) 143 goto fail; 144 145 error = vm_mmap(kernel_map, &buffer, 146 round_page(a_out->a_text + a_out->a_data + file_offset), 147 VM_PROT_READ, VM_PROT_READ, 0, 148 (caddr_t) imgp->vp, trunc_page(file_offset)); 149 if (error) 150 goto fail; 151 152 error = copyout((caddr_t)(void *)(uintptr_t)(buffer + file_offset), 153 (caddr_t)vmaddr, a_out->a_text + a_out->a_data); 154 155 vm_map_remove(kernel_map, buffer, 156 buffer + round_page(a_out->a_text + a_out->a_data + file_offset)); 157 158 if (error) 159 goto fail; 160 161 /* 162 * remove write enable on the 'text' part 163 */ 164 error = vm_map_protect(&vmspace->vm_map, 165 vmaddr, 166 vmaddr + a_out->a_text, 167 VM_PROT_EXECUTE|VM_PROT_READ, 168 TRUE); 169 if (error) 170 goto fail; 171 } 172 else { 173#ifdef DEBUG 174 printf("imgact: Page aligned binary %lu\n", file_offset); 175#endif 176 /* 177 * Map text+data read/execute 178 */ 179 vmaddr = virtual_offset; 180 error = vm_mmap(&vmspace->vm_map, &vmaddr, 181 a_out->a_text + a_out->a_data, 182 VM_PROT_READ | VM_PROT_EXECUTE, 183 VM_PROT_ALL, 184 MAP_PRIVATE | MAP_FIXED, 185 (caddr_t)imgp->vp, file_offset); 186 if (error) 187 goto fail; 188 189#ifdef DEBUG 190 printf("imgact: startaddr=%08lx, length=%08lx\n", 191 (u_long)vmaddr, a_out->a_text + a_out->a_data); 192#endif 193 /* 194 * allow read/write of data 195 */ 196 error = vm_map_protect(&vmspace->vm_map, 197 vmaddr + a_out->a_text, 198 vmaddr + a_out->a_text + a_out->a_data, 199 VM_PROT_ALL, 200 FALSE); 201 if (error) 202 goto fail; 203 204 /* 205 * Allocate anon demand-zeroed area for uninitialized data 206 */ 207 if (bss_size != 0) { 208 vmaddr = virtual_offset + a_out->a_text + a_out->a_data; 209 error = vm_map_find(&vmspace->vm_map, NULL, 0, &vmaddr, 210 bss_size, FALSE, VM_PROT_ALL, VM_PROT_ALL, 0); 211 if (error) 212 goto fail; 213#ifdef DEBUG 214 printf("imgact: bssaddr=%08lx, length=%08lx\n", 215 (u_long)vmaddr, bss_size); 216#endif 217 218 } 219 /* Indicate that this file should not be modified */ 220 mp_fixme("Unlocked v_flag access"); 221 imgp->vp->v_vflag |= VV_TEXT; 222 } 223 /* Fill in process VM information */ 224 vmspace->vm_tsize = round_page(a_out->a_text) >> PAGE_SHIFT; 225 vmspace->vm_dsize = round_page(a_out->a_data + bss_size) >> PAGE_SHIFT; 226 vmspace->vm_taddr = (caddr_t)(void *)(uintptr_t)virtual_offset; 227 vmspace->vm_daddr = (caddr_t)(void *)(uintptr_t) 228 (virtual_offset + a_out->a_text); 229 230 /* Fill in image_params */ 231 imgp->interpreted = 0; 232 imgp->entry_addr = a_out->a_entry; 233 234 imgp->proc->p_sysent = &linux_sysvec; 235 236fail: 237 vn_lock(imgp->vp, LK_EXCLUSIVE | LK_RETRY, td); 238 return (error); 239} 240 241/* 242 * Tell kern_execve.c about it, with a little help from the linker. 243 */ 244static struct execsw linux_execsw = { exec_linux_imgact, "linux a.out" }; 245EXEC_SET(linuxaout, linux_execsw); 246