ia64/linux-2.6.18-xen.hg

view fs/binfmt_aout.c @ 524:7f8b544237bf

netfront: Allow netfront in domain 0.

This is useful if your physical network device is in a utility domain.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
author Keir Fraser <keir.fraser@citrix.com>
date Tue Apr 15 15:18:58 2008 +0100 (2008-04-15)
parents 831230e53067
children
line source
1 /*
2 * linux/fs/binfmt_aout.c
3 *
4 * Copyright (C) 1991, 1992, 1996 Linus Torvalds
5 */
7 #include <linux/module.h>
9 #include <linux/time.h>
10 #include <linux/kernel.h>
11 #include <linux/mm.h>
12 #include <linux/mman.h>
13 #include <linux/a.out.h>
14 #include <linux/errno.h>
15 #include <linux/signal.h>
16 #include <linux/string.h>
17 #include <linux/fs.h>
18 #include <linux/file.h>
19 #include <linux/stat.h>
20 #include <linux/fcntl.h>
21 #include <linux/ptrace.h>
22 #include <linux/user.h>
23 #include <linux/slab.h>
24 #include <linux/binfmts.h>
25 #include <linux/personality.h>
26 #include <linux/init.h>
28 #include <asm/system.h>
29 #include <asm/uaccess.h>
30 #include <asm/cacheflush.h>
32 static int load_aout_binary(struct linux_binprm *, struct pt_regs * regs);
33 static int load_aout_library(struct file*);
34 static int aout_core_dump(long signr, struct pt_regs * regs, struct file *file);
36 static struct linux_binfmt aout_format = {
37 .module = THIS_MODULE,
38 .load_binary = load_aout_binary,
39 .load_shlib = load_aout_library,
40 .core_dump = aout_core_dump,
41 .min_coredump = PAGE_SIZE
42 };
44 #define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE)
46 static int set_brk(unsigned long start, unsigned long end)
47 {
48 start = PAGE_ALIGN(start);
49 end = PAGE_ALIGN(end);
50 if (end > start) {
51 unsigned long addr;
52 down_write(&current->mm->mmap_sem);
53 addr = do_brk(start, end - start);
54 up_write(&current->mm->mmap_sem);
55 if (BAD_ADDR(addr))
56 return addr;
57 }
58 return 0;
59 }
61 /*
62 * These are the only things you should do on a core-file: use only these
63 * macros to write out all the necessary info.
64 */
66 static int dump_write(struct file *file, const void *addr, int nr)
67 {
68 return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
69 }
71 #define DUMP_WRITE(addr, nr) \
72 if (!dump_write(file, (void *)(addr), (nr))) \
73 goto end_coredump;
75 #define DUMP_SEEK(offset) \
76 if (file->f_op->llseek) { \
77 if (file->f_op->llseek(file,(offset),0) != (offset)) \
78 goto end_coredump; \
79 } else file->f_pos = (offset)
81 /*
82 * Routine writes a core dump image in the current directory.
83 * Currently only a stub-function.
84 *
85 * Note that setuid/setgid files won't make a core-dump if the uid/gid
86 * changed due to the set[u|g]id. It's enforced by the "current->mm->dumpable"
87 * field, which also makes sure the core-dumps won't be recursive if the
88 * dumping of the process results in another error..
89 */
91 static int aout_core_dump(long signr, struct pt_regs * regs, struct file *file)
92 {
93 mm_segment_t fs;
94 int has_dumped = 0;
95 unsigned long dump_start, dump_size;
96 struct user dump;
97 #if defined(__alpha__)
98 # define START_DATA(u) (u.start_data)
99 #elif defined(__arm__)
100 # define START_DATA(u) ((u.u_tsize << PAGE_SHIFT) + u.start_code)
101 #elif defined(__sparc__)
102 # define START_DATA(u) (u.u_tsize)
103 #elif defined(__i386__) || defined(__mc68000__) || defined(__arch_um__)
104 # define START_DATA(u) (u.u_tsize << PAGE_SHIFT)
105 #endif
106 #ifdef __sparc__
107 # define START_STACK(u) ((regs->u_regs[UREG_FP]) & ~(PAGE_SIZE - 1))
108 #else
109 # define START_STACK(u) (u.start_stack)
110 #endif
112 fs = get_fs();
113 set_fs(KERNEL_DS);
114 has_dumped = 1;
115 current->flags |= PF_DUMPCORE;
116 strncpy(dump.u_comm, current->comm, sizeof(dump.u_comm));
117 #ifndef __sparc__
118 dump.u_ar0 = (void *)(((unsigned long)(&dump.regs)) - ((unsigned long)(&dump)));
119 #endif
120 dump.signal = signr;
121 dump_thread(regs, &dump);
123 /* If the size of the dump file exceeds the rlimit, then see what would happen
124 if we wrote the stack, but not the data area. */
125 #ifdef __sparc__
126 if ((dump.u_dsize+dump.u_ssize) >
127 current->signal->rlim[RLIMIT_CORE].rlim_cur)
128 dump.u_dsize = 0;
129 #else
130 if ((dump.u_dsize+dump.u_ssize+1) * PAGE_SIZE >
131 current->signal->rlim[RLIMIT_CORE].rlim_cur)
132 dump.u_dsize = 0;
133 #endif
135 /* Make sure we have enough room to write the stack and data areas. */
136 #ifdef __sparc__
137 if ((dump.u_ssize) >
138 current->signal->rlim[RLIMIT_CORE].rlim_cur)
139 dump.u_ssize = 0;
140 #else
141 if ((dump.u_ssize+1) * PAGE_SIZE >
142 current->signal->rlim[RLIMIT_CORE].rlim_cur)
143 dump.u_ssize = 0;
144 #endif
146 /* make sure we actually have a data and stack area to dump */
147 set_fs(USER_DS);
148 #ifdef __sparc__
149 if (!access_ok(VERIFY_READ, (void __user *)START_DATA(dump), dump.u_dsize))
150 dump.u_dsize = 0;
151 if (!access_ok(VERIFY_READ, (void __user *)START_STACK(dump), dump.u_ssize))
152 dump.u_ssize = 0;
153 #else
154 if (!access_ok(VERIFY_READ, (void __user *)START_DATA(dump), dump.u_dsize << PAGE_SHIFT))
155 dump.u_dsize = 0;
156 if (!access_ok(VERIFY_READ, (void __user *)START_STACK(dump), dump.u_ssize << PAGE_SHIFT))
157 dump.u_ssize = 0;
158 #endif
160 set_fs(KERNEL_DS);
161 /* struct user */
162 DUMP_WRITE(&dump,sizeof(dump));
163 /* Now dump all of the user data. Include malloced stuff as well */
164 #ifndef __sparc__
165 DUMP_SEEK(PAGE_SIZE);
166 #endif
167 /* now we start writing out the user space info */
168 set_fs(USER_DS);
169 /* Dump the data area */
170 if (dump.u_dsize != 0) {
171 dump_start = START_DATA(dump);
172 #ifdef __sparc__
173 dump_size = dump.u_dsize;
174 #else
175 dump_size = dump.u_dsize << PAGE_SHIFT;
176 #endif
177 DUMP_WRITE(dump_start,dump_size);
178 }
179 /* Now prepare to dump the stack area */
180 if (dump.u_ssize != 0) {
181 dump_start = START_STACK(dump);
182 #ifdef __sparc__
183 dump_size = dump.u_ssize;
184 #else
185 dump_size = dump.u_ssize << PAGE_SHIFT;
186 #endif
187 DUMP_WRITE(dump_start,dump_size);
188 }
189 /* Finally dump the task struct. Not be used by gdb, but could be useful */
190 set_fs(KERNEL_DS);
191 DUMP_WRITE(current,sizeof(*current));
192 end_coredump:
193 set_fs(fs);
194 return has_dumped;
195 }
197 /*
198 * create_aout_tables() parses the env- and arg-strings in new user
199 * memory and creates the pointer tables from them, and puts their
200 * addresses on the "stack", returning the new stack pointer value.
201 */
202 static unsigned long __user *create_aout_tables(char __user *p, struct linux_binprm * bprm)
203 {
204 char __user * __user *argv;
205 char __user * __user *envp;
206 unsigned long __user *sp;
207 int argc = bprm->argc;
208 int envc = bprm->envc;
210 sp = (void __user *)((-(unsigned long)sizeof(char *)) & (unsigned long) p);
211 #ifdef __sparc__
212 /* This imposes the proper stack alignment for a new process. */
213 sp = (void __user *) (((unsigned long) sp) & ~7);
214 if ((envc+argc+3)&1) --sp;
215 #endif
216 #ifdef __alpha__
217 /* whee.. test-programs are so much fun. */
218 put_user(0, --sp);
219 put_user(0, --sp);
220 if (bprm->loader) {
221 put_user(0, --sp);
222 put_user(0x3eb, --sp);
223 put_user(bprm->loader, --sp);
224 put_user(0x3ea, --sp);
225 }
226 put_user(bprm->exec, --sp);
227 put_user(0x3e9, --sp);
228 #endif
229 sp -= envc+1;
230 envp = (char __user * __user *) sp;
231 sp -= argc+1;
232 argv = (char __user * __user *) sp;
233 #if defined(__i386__) || defined(__mc68000__) || defined(__arm__) || defined(__arch_um__)
234 put_user((unsigned long) envp,--sp);
235 put_user((unsigned long) argv,--sp);
236 #endif
237 put_user(argc,--sp);
238 current->mm->arg_start = (unsigned long) p;
239 while (argc-->0) {
240 char c;
241 put_user(p,argv++);
242 do {
243 get_user(c,p++);
244 } while (c);
245 }
246 put_user(NULL,argv);
247 current->mm->arg_end = current->mm->env_start = (unsigned long) p;
248 while (envc-->0) {
249 char c;
250 put_user(p,envp++);
251 do {
252 get_user(c,p++);
253 } while (c);
254 }
255 put_user(NULL,envp);
256 current->mm->env_end = (unsigned long) p;
257 return sp;
258 }
260 /*
261 * These are the functions used to load a.out style executables and shared
262 * libraries. There is no binary dependent code anywhere else.
263 */
265 static int load_aout_binary(struct linux_binprm * bprm, struct pt_regs * regs)
266 {
267 struct exec ex;
268 unsigned long error;
269 unsigned long fd_offset;
270 unsigned long rlim;
271 int retval;
273 ex = *((struct exec *) bprm->buf); /* exec-header */
274 if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != OMAGIC &&
275 N_MAGIC(ex) != QMAGIC && N_MAGIC(ex) != NMAGIC) ||
276 N_TRSIZE(ex) || N_DRSIZE(ex) ||
277 i_size_read(bprm->file->f_dentry->d_inode) < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
278 return -ENOEXEC;
279 }
281 fd_offset = N_TXTOFF(ex);
283 /* Check initial limits. This avoids letting people circumvent
284 * size limits imposed on them by creating programs with large
285 * arrays in the data or bss.
286 */
287 rlim = current->signal->rlim[RLIMIT_DATA].rlim_cur;
288 if (rlim >= RLIM_INFINITY)
289 rlim = ~0;
290 if (ex.a_data + ex.a_bss > rlim)
291 return -ENOMEM;
293 /* Flush all traces of the currently running executable */
294 retval = flush_old_exec(bprm);
295 if (retval)
296 return retval;
298 /* OK, This is the point of no return */
299 #if defined(__alpha__)
300 SET_AOUT_PERSONALITY(bprm, ex);
301 #elif defined(__sparc__)
302 set_personality(PER_SUNOS);
303 #if !defined(__sparc_v9__)
304 memcpy(&current->thread.core_exec, &ex, sizeof(struct exec));
305 #endif
306 #else
307 set_personality(PER_LINUX);
308 #endif
310 current->mm->end_code = ex.a_text +
311 (current->mm->start_code = N_TXTADDR(ex));
312 current->mm->end_data = ex.a_data +
313 (current->mm->start_data = N_DATADDR(ex));
314 current->mm->brk = ex.a_bss +
315 (current->mm->start_brk = N_BSSADDR(ex));
316 current->mm->free_area_cache = current->mm->mmap_base;
317 current->mm->cached_hole_size = 0;
319 current->mm->mmap = NULL;
320 compute_creds(bprm);
321 current->flags &= ~PF_FORKNOEXEC;
322 #ifdef __sparc__
323 if (N_MAGIC(ex) == NMAGIC) {
324 loff_t pos = fd_offset;
325 /* Fuck me plenty... */
326 /* <AOL></AOL> */
327 down_write(&current->mm->mmap_sem);
328 error = do_brk(N_TXTADDR(ex), ex.a_text);
329 up_write(&current->mm->mmap_sem);
330 bprm->file->f_op->read(bprm->file, (char *) N_TXTADDR(ex),
331 ex.a_text, &pos);
332 down_write(&current->mm->mmap_sem);
333 error = do_brk(N_DATADDR(ex), ex.a_data);
334 up_write(&current->mm->mmap_sem);
335 bprm->file->f_op->read(bprm->file, (char *) N_DATADDR(ex),
336 ex.a_data, &pos);
337 goto beyond_if;
338 }
339 #endif
341 if (N_MAGIC(ex) == OMAGIC) {
342 unsigned long text_addr, map_size;
343 loff_t pos;
345 text_addr = N_TXTADDR(ex);
347 #if defined(__alpha__) || defined(__sparc__)
348 pos = fd_offset;
349 map_size = ex.a_text+ex.a_data + PAGE_SIZE - 1;
350 #else
351 pos = 32;
352 map_size = ex.a_text+ex.a_data;
353 #endif
354 down_write(&current->mm->mmap_sem);
355 error = do_brk(text_addr & PAGE_MASK, map_size);
356 up_write(&current->mm->mmap_sem);
357 if (error != (text_addr & PAGE_MASK)) {
358 send_sig(SIGKILL, current, 0);
359 return error;
360 }
362 error = bprm->file->f_op->read(bprm->file,
363 (char __user *)text_addr,
364 ex.a_text+ex.a_data, &pos);
365 if ((signed long)error < 0) {
366 send_sig(SIGKILL, current, 0);
367 return error;
368 }
370 flush_icache_range(text_addr, text_addr+ex.a_text+ex.a_data);
371 } else {
372 static unsigned long error_time, error_time2;
373 if ((ex.a_text & 0xfff || ex.a_data & 0xfff) &&
374 (N_MAGIC(ex) != NMAGIC) && (jiffies-error_time2) > 5*HZ)
375 {
376 printk(KERN_NOTICE "executable not page aligned\n");
377 error_time2 = jiffies;
378 }
380 if ((fd_offset & ~PAGE_MASK) != 0 &&
381 (jiffies-error_time) > 5*HZ)
382 {
383 printk(KERN_WARNING
384 "fd_offset is not page aligned. Please convert program: %s\n",
385 bprm->file->f_dentry->d_name.name);
386 error_time = jiffies;
387 }
389 if (!bprm->file->f_op->mmap||((fd_offset & ~PAGE_MASK) != 0)) {
390 loff_t pos = fd_offset;
391 down_write(&current->mm->mmap_sem);
392 do_brk(N_TXTADDR(ex), ex.a_text+ex.a_data);
393 up_write(&current->mm->mmap_sem);
394 bprm->file->f_op->read(bprm->file,
395 (char __user *)N_TXTADDR(ex),
396 ex.a_text+ex.a_data, &pos);
397 flush_icache_range((unsigned long) N_TXTADDR(ex),
398 (unsigned long) N_TXTADDR(ex) +
399 ex.a_text+ex.a_data);
400 goto beyond_if;
401 }
403 down_write(&current->mm->mmap_sem);
404 error = do_mmap(bprm->file, N_TXTADDR(ex), ex.a_text,
405 PROT_READ | PROT_EXEC,
406 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE,
407 fd_offset);
408 up_write(&current->mm->mmap_sem);
410 if (error != N_TXTADDR(ex)) {
411 send_sig(SIGKILL, current, 0);
412 return error;
413 }
415 down_write(&current->mm->mmap_sem);
416 error = do_mmap(bprm->file, N_DATADDR(ex), ex.a_data,
417 PROT_READ | PROT_WRITE | PROT_EXEC,
418 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE,
419 fd_offset + ex.a_text);
420 up_write(&current->mm->mmap_sem);
421 if (error != N_DATADDR(ex)) {
422 send_sig(SIGKILL, current, 0);
423 return error;
424 }
425 }
426 beyond_if:
427 set_binfmt(&aout_format);
429 retval = set_brk(current->mm->start_brk, current->mm->brk);
430 if (retval < 0) {
431 send_sig(SIGKILL, current, 0);
432 return retval;
433 }
435 retval = setup_arg_pages(bprm, STACK_TOP, EXSTACK_DEFAULT);
436 if (retval < 0) {
437 /* Someone check-me: is this error path enough? */
438 send_sig(SIGKILL, current, 0);
439 return retval;
440 }
442 current->mm->start_stack =
443 (unsigned long) create_aout_tables((char __user *) bprm->p, bprm);
444 #ifdef __alpha__
445 regs->gp = ex.a_gpvalue;
446 #endif
447 start_thread(regs, ex.a_entry, current->mm->start_stack);
448 if (unlikely(current->ptrace & PT_PTRACED)) {
449 if (current->ptrace & PT_TRACE_EXEC)
450 ptrace_notify ((PTRACE_EVENT_EXEC << 8) | SIGTRAP);
451 else
452 send_sig(SIGTRAP, current, 0);
453 }
454 return 0;
455 }
457 static int load_aout_library(struct file *file)
458 {
459 struct inode * inode;
460 unsigned long bss, start_addr, len;
461 unsigned long error;
462 int retval;
463 struct exec ex;
465 inode = file->f_dentry->d_inode;
467 retval = -ENOEXEC;
468 error = kernel_read(file, 0, (char *) &ex, sizeof(ex));
469 if (error != sizeof(ex))
470 goto out;
472 /* We come in here for the regular a.out style of shared libraries */
473 if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != QMAGIC) || N_TRSIZE(ex) ||
474 N_DRSIZE(ex) || ((ex.a_entry & 0xfff) && N_MAGIC(ex) == ZMAGIC) ||
475 i_size_read(inode) < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
476 goto out;
477 }
479 if (N_FLAGS(ex))
480 goto out;
482 /* For QMAGIC, the starting address is 0x20 into the page. We mask
483 this off to get the starting address for the page */
485 start_addr = ex.a_entry & 0xfffff000;
487 if ((N_TXTOFF(ex) & ~PAGE_MASK) != 0) {
488 static unsigned long error_time;
489 loff_t pos = N_TXTOFF(ex);
491 if ((jiffies-error_time) > 5*HZ)
492 {
493 printk(KERN_WARNING
494 "N_TXTOFF is not page aligned. Please convert library: %s\n",
495 file->f_dentry->d_name.name);
496 error_time = jiffies;
497 }
498 down_write(&current->mm->mmap_sem);
499 do_brk(start_addr, ex.a_text + ex.a_data + ex.a_bss);
500 up_write(&current->mm->mmap_sem);
502 file->f_op->read(file, (char __user *)start_addr,
503 ex.a_text + ex.a_data, &pos);
504 flush_icache_range((unsigned long) start_addr,
505 (unsigned long) start_addr + ex.a_text + ex.a_data);
507 retval = 0;
508 goto out;
509 }
510 /* Now use mmap to map the library into memory. */
511 down_write(&current->mm->mmap_sem);
512 error = do_mmap(file, start_addr, ex.a_text + ex.a_data,
513 PROT_READ | PROT_WRITE | PROT_EXEC,
514 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
515 N_TXTOFF(ex));
516 up_write(&current->mm->mmap_sem);
517 retval = error;
518 if (error != start_addr)
519 goto out;
521 len = PAGE_ALIGN(ex.a_text + ex.a_data);
522 bss = ex.a_text + ex.a_data + ex.a_bss;
523 if (bss > len) {
524 down_write(&current->mm->mmap_sem);
525 error = do_brk(start_addr + len, bss - len);
526 up_write(&current->mm->mmap_sem);
527 retval = error;
528 if (error != start_addr + len)
529 goto out;
530 }
531 retval = 0;
532 out:
533 return retval;
534 }
536 static int __init init_aout_binfmt(void)
537 {
538 return register_binfmt(&aout_format);
539 }
541 static void __exit exit_aout_binfmt(void)
542 {
543 unregister_binfmt(&aout_format);
544 }
546 core_initcall(init_aout_binfmt);
547 module_exit(exit_aout_binfmt);
548 MODULE_LICENSE("GPL");