1/* 2 * linux/fs/binfmt_aout.c 3 * 4 * Copyright (C) 1991, 1992, 1996 Linus Torvalds 5 * 6 * Hacked a bit by DaveM to make it work with 32-bit SunOS 7 * binaries on the sparc64 port. 8 */ 9 10#include <linux/module.h> 11 12#include <linux/sched.h> 13#include <linux/kernel.h> 14#include <linux/mm.h> 15#include <linux/mman.h> 16#include <linux/a.out.h> 17#include <linux/errno.h> 18#include <linux/signal.h> 19#include <linux/string.h> 20#include <linux/fs.h> 21#include <linux/file.h> 22#include <linux/stat.h> 23#include <linux/fcntl.h> 24#include <linux/ptrace.h> 25#include <linux/user.h> 26#include <linux/slab.h> 27#include <linux/binfmts.h> 28#include <linux/personality.h> 29#include <linux/init.h> 30 31#include <asm/system.h> 32#include <asm/uaccess.h> 33#include <asm/pgalloc.h> 34#include <asm/mmu_context.h> 35 36static int load_aout32_binary(struct linux_binprm *, struct pt_regs * regs); 37static int load_aout32_library(struct file*); 38static int aout32_core_dump(long signr, struct pt_regs * regs, struct file *file); 39 40static struct linux_binfmt aout32_format = { 41 NULL, THIS_MODULE, load_aout32_binary, load_aout32_library, aout32_core_dump, 42 PAGE_SIZE 43}; 44 45static void set_brk(unsigned long start, unsigned long end) 46{ 47 start = PAGE_ALIGN(start); 48 end = PAGE_ALIGN(end); 49 if (end <= start) 50 return; 51 down_write(¤t->mm->mmap_sem); 52 do_brk(start, end - start); 53 up_write(¤t->mm->mmap_sem); 54} 55 56/* 57 * These are the only things you should do on a core-file: use only these 58 * macros to write out all the necessary info. 59 */ 60 61static int dump_write(struct file *file, const void *addr, int nr) 62{ 63 return file->f_op->write(file, addr, nr, &file->f_pos) == nr; 64} 65 66#define DUMP_WRITE(addr, nr) \ 67 if (!dump_write(file, (void *)(addr), (nr))) \ 68 goto end_coredump; 69 70#define DUMP_SEEK(offset) \ 71if (file->f_op->llseek) { \ 72 if (file->f_op->llseek(file,(offset),0) != (offset)) \ 73 goto end_coredump; \ 74} else file->f_pos = (offset) 75 76/* 77 * Routine writes a core dump image in the current directory. 78 * Currently only a stub-function. 79 * 80 * Note that setuid/setgid files won't make a core-dump if the uid/gid 81 * changed due to the set[u|g]id. It's enforced by the "current->mm->dumpable" 82 * field, which also makes sure the core-dumps won't be recursive if the 83 * dumping of the process results in another error.. 84 */ 85 86static int aout32_core_dump(long signr, struct pt_regs *regs, struct file *file) 87{ 88 mm_segment_t fs; 89 int has_dumped = 0; 90 unsigned long dump_start, dump_size; 91 struct user dump; 92# define START_DATA(u) (u.u_tsize) 93# define START_STACK(u) ((regs->u_regs[UREG_FP]) & ~(PAGE_SIZE - 1)) 94 95 fs = get_fs(); 96 set_fs(KERNEL_DS); 97 has_dumped = 1; 98 current->flags |= PF_DUMPCORE; 99 strncpy(dump.u_comm, current->comm, sizeof(dump.u_comm)); 100 dump.signal = signr; 101 dump_thread(regs, &dump); 102 103/* If the size of the dump file exceeds the rlimit, then see what would happen 104 if we wrote the stack, but not the data area. */ 105 if ((dump.u_dsize+dump.u_ssize) > 106 current->signal->rlim[RLIMIT_CORE].rlim_cur) 107 dump.u_dsize = 0; 108 109/* Make sure we have enough room to write the stack and data areas. */ 110 if ((dump.u_ssize) > 111 current->signal->rlim[RLIMIT_CORE].rlim_cur) 112 dump.u_ssize = 0; 113 114/* make sure we actually have a data and stack area to dump */ 115 set_fs(USER_DS); 116 if (!access_ok(VERIFY_READ, (void __user *) START_DATA(dump), dump.u_dsize)) 117 dump.u_dsize = 0; 118 if (!access_ok(VERIFY_READ, (void __user *) START_STACK(dump), dump.u_ssize)) 119 dump.u_ssize = 0; 120 121 set_fs(KERNEL_DS); 122/* struct user */ 123 DUMP_WRITE(&dump,sizeof(dump)); 124/* now we start writing out the user space info */ 125 set_fs(USER_DS); 126/* Dump the data area */ 127 if (dump.u_dsize != 0) { 128 dump_start = START_DATA(dump); 129 dump_size = dump.u_dsize; 130 DUMP_WRITE(dump_start,dump_size); 131 } 132/* Now prepare to dump the stack area */ 133 if (dump.u_ssize != 0) { 134 dump_start = START_STACK(dump); 135 dump_size = dump.u_ssize; 136 DUMP_WRITE(dump_start,dump_size); 137 } 138/* Finally dump the task struct. Not be used by gdb, but could be useful */ 139 set_fs(KERNEL_DS); 140 DUMP_WRITE(current,sizeof(*current)); 141end_coredump: 142 set_fs(fs); 143 return has_dumped; 144} 145 146/* 147 * create_aout32_tables() parses the env- and arg-strings in new user 148 * memory and creates the pointer tables from them, and puts their 149 * addresses on the "stack", returning the new stack pointer value. 150 */ 151 152static u32 __user *create_aout32_tables(char __user *p, struct linux_binprm *bprm) 153{ 154 u32 __user *argv; 155 u32 __user *envp; 156 u32 __user *sp; 157 int argc = bprm->argc; 158 int envc = bprm->envc; 159 160 sp = (u32 __user *)((-(unsigned long)sizeof(char *))&(unsigned long)p); 161 162 /* This imposes the proper stack alignment for a new process. */ 163 sp = (u32 __user *) (((unsigned long) sp) & ~7); 164 if ((envc+argc+3)&1) 165 --sp; 166 167 sp -= envc+1; 168 envp = sp; 169 sp -= argc+1; 170 argv = sp; 171 put_user(argc,--sp); 172 current->mm->arg_start = (unsigned long) p; 173 while (argc-->0) { 174 char c; 175 put_user(((u32)(unsigned long)(p)),argv++); 176 do { 177 get_user(c,p++); 178 } while (c); 179 } 180 put_user(NULL,argv); 181 current->mm->arg_end = current->mm->env_start = (unsigned long) p; 182 while (envc-->0) { 183 char c; 184 put_user(((u32)(unsigned long)(p)),envp++); 185 do { 186 get_user(c,p++); 187 } while (c); 188 } 189 put_user(NULL,envp); 190 current->mm->env_end = (unsigned long) p; 191 return sp; 192} 193 194/* 195 * These are the functions used to load a.out style executables and shared 196 * libraries. There is no binary dependent code anywhere else. 197 */ 198 199static int load_aout32_binary(struct linux_binprm * bprm, struct pt_regs * regs) 200{ 201 struct exec ex; 202 unsigned long error; 203 unsigned long fd_offset; 204 unsigned long rlim; 205 unsigned long orig_thr_flags; 206 int retval; 207 208 ex = *((struct exec *) bprm->buf); /* exec-header */ 209 if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != OMAGIC && 210 N_MAGIC(ex) != QMAGIC && N_MAGIC(ex) != NMAGIC) || 211 N_TRSIZE(ex) || N_DRSIZE(ex) || 212 bprm->file->f_path.dentry->d_inode->i_size < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) { 213 return -ENOEXEC; 214 } 215 216 fd_offset = N_TXTOFF(ex); 217 218 /* Check initial limits. This avoids letting people circumvent 219 * size limits imposed on them by creating programs with large 220 * arrays in the data or bss. 221 */ 222 rlim = current->signal->rlim[RLIMIT_DATA].rlim_cur; 223 if (rlim >= RLIM_INFINITY) 224 rlim = ~0; 225 if (ex.a_data + ex.a_bss > rlim) 226 return -ENOMEM; 227 228 /* Flush all traces of the currently running executable */ 229 retval = flush_old_exec(bprm); 230 if (retval) 231 return retval; 232 233 /* OK, This is the point of no return */ 234 set_personality(PER_SUNOS); 235 236 current->mm->end_code = ex.a_text + 237 (current->mm->start_code = N_TXTADDR(ex)); 238 current->mm->end_data = ex.a_data + 239 (current->mm->start_data = N_DATADDR(ex)); 240 current->mm->brk = ex.a_bss + 241 (current->mm->start_brk = N_BSSADDR(ex)); 242 current->mm->free_area_cache = current->mm->mmap_base; 243 current->mm->cached_hole_size = 0; 244 245 current->mm->mmap = NULL; 246 compute_creds(bprm); 247 current->flags &= ~PF_FORKNOEXEC; 248 if (N_MAGIC(ex) == NMAGIC) { 249 loff_t pos = fd_offset; 250 /* Fuck me plenty... */ 251 down_write(¤t->mm->mmap_sem); 252 error = do_brk(N_TXTADDR(ex), ex.a_text); 253 up_write(¤t->mm->mmap_sem); 254 bprm->file->f_op->read(bprm->file, (char __user *)N_TXTADDR(ex), 255 ex.a_text, &pos); 256 down_write(¤t->mm->mmap_sem); 257 error = do_brk(N_DATADDR(ex), ex.a_data); 258 up_write(¤t->mm->mmap_sem); 259 bprm->file->f_op->read(bprm->file, (char __user *)N_DATADDR(ex), 260 ex.a_data, &pos); 261 goto beyond_if; 262 } 263 264 if (N_MAGIC(ex) == OMAGIC) { 265 loff_t pos = fd_offset; 266 down_write(¤t->mm->mmap_sem); 267 do_brk(N_TXTADDR(ex) & PAGE_MASK, 268 ex.a_text+ex.a_data + PAGE_SIZE - 1); 269 up_write(¤t->mm->mmap_sem); 270 bprm->file->f_op->read(bprm->file, (char __user *)N_TXTADDR(ex), 271 ex.a_text+ex.a_data, &pos); 272 } else { 273 static unsigned long error_time; 274 if ((ex.a_text & 0xfff || ex.a_data & 0xfff) && 275 (N_MAGIC(ex) != NMAGIC) && (jiffies-error_time) > 5*HZ) 276 { 277 printk(KERN_NOTICE "executable not page aligned\n"); 278 error_time = jiffies; 279 } 280 281 if (!bprm->file->f_op->mmap) { 282 loff_t pos = fd_offset; 283 down_write(¤t->mm->mmap_sem); 284 do_brk(0, ex.a_text+ex.a_data); 285 up_write(¤t->mm->mmap_sem); 286 bprm->file->f_op->read(bprm->file, 287 (char __user *)N_TXTADDR(ex), 288 ex.a_text+ex.a_data, &pos); 289 goto beyond_if; 290 } 291 292 down_write(¤t->mm->mmap_sem); 293 error = do_mmap(bprm->file, N_TXTADDR(ex), ex.a_text, 294 PROT_READ | PROT_EXEC, 295 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE, 296 fd_offset); 297 up_write(¤t->mm->mmap_sem); 298 299 if (error != N_TXTADDR(ex)) { 300 send_sig(SIGKILL, current, 0); 301 return error; 302 } 303 304 down_write(¤t->mm->mmap_sem); 305 error = do_mmap(bprm->file, N_DATADDR(ex), ex.a_data, 306 PROT_READ | PROT_WRITE | PROT_EXEC, 307 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE, 308 fd_offset + ex.a_text); 309 up_write(¤t->mm->mmap_sem); 310 if (error != N_DATADDR(ex)) { 311 send_sig(SIGKILL, current, 0); 312 return error; 313 } 314 } 315beyond_if: 316 set_binfmt(&aout32_format); 317 318 set_brk(current->mm->start_brk, current->mm->brk); 319 320 /* Make sure STACK_TOP returns the right thing. */ 321 orig_thr_flags = current_thread_info()->flags; 322 current_thread_info()->flags |= _TIF_32BIT; 323 324 retval = setup_arg_pages(bprm, STACK_TOP, EXSTACK_DEFAULT); 325 if (retval < 0) { 326 current_thread_info()->flags = orig_thr_flags; 327 328 /* Someone check-me: is this error path enough? */ 329 send_sig(SIGKILL, current, 0); 330 return retval; 331 } 332 333 current->mm->start_stack = 334 (unsigned long) create_aout32_tables((char __user *)bprm->p, bprm); 335 tsb_context_switch(current->mm); 336 337 start_thread32(regs, ex.a_entry, current->mm->start_stack); 338 if (current->ptrace & PT_PTRACED) 339 send_sig(SIGTRAP, current, 0); 340 return 0; 341} 342 343/* N.B. Move to .h file and use code in fs/binfmt_aout.c? */ 344static int load_aout32_library(struct file *file) 345{ 346 struct inode * inode; 347 unsigned long bss, start_addr, len; 348 unsigned long error; 349 int retval; 350 struct exec ex; 351 352 inode = file->f_path.dentry->d_inode; 353 354 retval = -ENOEXEC; 355 error = kernel_read(file, 0, (char *) &ex, sizeof(ex)); 356 if (error != sizeof(ex)) 357 goto out; 358 359 /* We come in here for the regular a.out style of shared libraries */ 360 if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != QMAGIC) || N_TRSIZE(ex) || 361 N_DRSIZE(ex) || ((ex.a_entry & 0xfff) && N_MAGIC(ex) == ZMAGIC) || 362 inode->i_size < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) { 363 goto out; 364 } 365 366 if (N_MAGIC(ex) == ZMAGIC && N_TXTOFF(ex) && 367 (N_TXTOFF(ex) < inode->i_sb->s_blocksize)) { 368 printk("N_TXTOFF < BLOCK_SIZE. Please convert library\n"); 369 goto out; 370 } 371 372 if (N_FLAGS(ex)) 373 goto out; 374 375 /* For QMAGIC, the starting address is 0x20 into the page. We mask 376 this off to get the starting address for the page */ 377 378 start_addr = ex.a_entry & 0xfffff000; 379 380 /* Now use mmap to map the library into memory. */ 381 down_write(¤t->mm->mmap_sem); 382 error = do_mmap(file, start_addr, ex.a_text + ex.a_data, 383 PROT_READ | PROT_WRITE | PROT_EXEC, 384 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE, 385 N_TXTOFF(ex)); 386 up_write(¤t->mm->mmap_sem); 387 retval = error; 388 if (error != start_addr) 389 goto out; 390 391 len = PAGE_ALIGN(ex.a_text + ex.a_data); 392 bss = ex.a_text + ex.a_data + ex.a_bss; 393 if (bss > len) { 394 down_write(¤t->mm->mmap_sem); 395 error = do_brk(start_addr + len, bss - len); 396 up_write(¤t->mm->mmap_sem); 397 retval = error; 398 if (error != start_addr + len) 399 goto out; 400 } 401 retval = 0; 402out: 403 return retval; 404} 405 406static int __init init_aout32_binfmt(void) 407{ 408 return register_binfmt(&aout32_format); 409} 410 411static void __exit exit_aout32_binfmt(void) 412{ 413 unregister_binfmt(&aout32_format); 414} 415 416module_init(init_aout32_binfmt); 417module_exit(exit_aout32_binfmt); 418