1 /*
2 * a.out loader for x86-64
3 *
4 * Copyright (C) 1991, 1992, 1996 Linus Torvalds
5 * Hacked together by Andi Kleen
6 */
7
8 #include <linux/module.h>
9
10 #include <linux/time.h>
11 #include <linux/kernel.h>
12 #include <linux/mm.h>
13 #include <linux/mman.h>
14 #include <linux/a.out.h>
15 #include <linux/errno.h>
16 #include <linux/signal.h>
17 #include <linux/string.h>
18 #include <linux/fs.h>
19 #include <linux/file.h>
20 #include <linux/stat.h>
21 #include <linux/fcntl.h>
22 #include <linux/ptrace.h>
23 #include <linux/user.h>
24 #include <linux/slab.h>
25 #include <linux/binfmts.h>
26 #include <linux/personality.h>
27 #include <linux/init.h>
28 #include <linux/jiffies.h>
29
30 #include <asm/system.h>
31 #include <asm/uaccess.h>
32 #include <asm/pgalloc.h>
33 #include <asm/cacheflush.h>
34 #include <asm/user32.h>
35 #include <asm/ia32.h>
36
37 #undef WARN_OLD
38 #undef CORE_DUMP /* probably broken */
39
40 static int load_aout_binary(struct linux_binprm *, struct pt_regs *regs);
41 static int load_aout_library(struct file *);
42
43 #ifdef CORE_DUMP
44 static int aout_core_dump(long signr, struct pt_regs *regs, struct file *file,
45 unsigned long limit);
46
47 /*
48 * fill in the user structure for a core dump..
49 */
50 static void dump_thread32(struct pt_regs *regs, struct user32 *dump)
51 {
52 u32 fs, gs;
53
54 /* changed the size calculations - should hopefully work better. lbt */
55 dump->magic = CMAGIC;
56 dump->start_code = 0;
57 dump->start_stack = regs->sp & ~(PAGE_SIZE - 1);
58 dump->u_tsize = ((unsigned long) current->mm->end_code) >> PAGE_SHIFT;
59 dump->u_dsize = ((unsigned long)
60 (current->mm->brk + (PAGE_SIZE-1))) >> PAGE_SHIFT;
61 dump->u_dsize -= dump->u_tsize;
62 dump->u_ssize = 0;
63 dump->u_debugreg[0] = current->thread.debugreg0;
64 dump->u_debugreg[1] = current->thread.debugreg1;
65 dump->u_debugreg[2] = current->thread.debugreg2;
66 dump->u_debugreg[3] = current->thread.debugreg3;
67 dump->u_debugreg[4] = 0;
68 dump->u_debugreg[5] = 0;
69 dump->u_debugreg[6] = current->thread.debugreg6;
70 dump->u_debugreg[7] = current->thread.debugreg7;
71
72 if (dump->start_stack < 0xc0000000) {
73 unsigned long tmp;
74
75 tmp = (unsigned long) (0xc0000000 - dump->start_stack);
76 dump->u_ssize = tmp >> PAGE_SHIFT;
77 }
78
79 dump->regs.bx = regs->bx;
80 dump->regs.cx = regs->cx;
81 dump->regs.dx = regs->dx;
82 dump->regs.si = regs->si;
83 dump->regs.di = regs->di;
84 dump->regs.bp = regs->bp;
85 dump->regs.ax = regs->ax;
86 dump->regs.ds = current->thread.ds;
87 dump->regs.es = current->thread.es;
88 asm("movl %%fs,%0" : "=r" (fs)); dump->regs.fs = fs;
89 asm("movl %%gs,%0" : "=r" (gs)); dump->regs.gs = gs;
90 dump->regs.orig_ax = regs->orig_ax;
91 dump->regs.ip = regs->ip;
92 dump->regs.cs = regs->cs;
93 dump->regs.flags = regs->flags;
94 dump->regs.sp = regs->sp;
95 dump->regs.ss = regs->ss;
96
97 #if 1 /* FIXME */
98 dump->u_fpvalid = 0;
99 #else
100 dump->u_fpvalid = dump_fpu(regs, &dump->i387);
101 #endif
102 }
103
104 #endif
105
106 static struct linux_binfmt aout_format = {
107 .module = THIS_MODULE,
108 .load_binary = load_aout_binary,
109 .load_shlib = load_aout_library,
110 #ifdef CORE_DUMP
111 .core_dump = aout_core_dump,
112 #endif
113 .min_coredump = PAGE_SIZE
114 };
115
116 static void set_brk(unsigned long start, unsigned long end)
117 {
118 start = PAGE_ALIGN(start);
119 end = PAGE_ALIGN(end);
120 if (end <= start)
121 return;
122 down_write(¤t->mm->mmap_sem);
123 do_brk(start, end - start);
124 up_write(¤t->mm->mmap_sem);
125 }
126
127 #ifdef CORE_DUMP
128 /*
129 * These are the only things you should do on a core-file: use only these
130 * macros to write out all the necessary info.
131 */
132
133 static int dump_write(struct file *file, const void *addr, int nr)
134 {
135 return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
136 }
137
138 #define DUMP_WRITE(addr, nr) \
139 if (!dump_write(file, (void *)(addr), (nr))) \
140 goto end_coredump;
141
142 #define DUMP_SEEK(offset) \
143 if (file->f_op->llseek) { \
144 if (file->f_op->llseek(file, (offset), 0) != (offset)) \
145 goto end_coredump; \
146 } else \
147 file->f_pos = (offset)
148
149 #define START_DATA() (u.u_tsize << PAGE_SHIFT)
150 #define START_STACK(u) (u.start_stack)
151
152 /*
153 * Routine writes a core dump image in the current directory.
154 * Currently only a stub-function.
155 *
156 * Note that setuid/setgid files won't make a core-dump if the uid/gid
157 * changed due to the set[u|g]id. It's enforced by the "current->mm->dumpable"
158 * field, which also makes sure the core-dumps won't be recursive if the
159 * dumping of the process results in another error..
160 */
161
162 static int aout_core_dump(long signr, struct pt_regs *regs, struct file *file,
163 unsigned long limit)
164 {
165 mm_segment_t fs;
166 int has_dumped = 0;
167 unsigned long dump_start, dump_size;
168 struct user32 dump;
169
170 fs = get_fs();
171 set_fs(KERNEL_DS);
172 has_dumped = 1;
173 current->flags |= PF_DUMPCORE;
174 strncpy(dump.u_comm, current->comm, sizeof(current->comm));
175 dump.u_ar0 = offsetof(struct user32, regs);
176 dump.signal = signr;
177 dump_thread32(regs, &dump);
178
179 /*
180 * If the size of the dump file exceeds the rlimit, then see
181 * what would happen if we wrote the stack, but not the data
182 * area.
183 */
184 if ((dump.u_dsize + dump.u_ssize + 1) * PAGE_SIZE > limit)
185 dump.u_dsize = 0;
186
187 /* Make sure we have enough room to write the stack and data areas. */
188 if ((dump.u_ssize + 1) * PAGE_SIZE > limit)
189 dump.u_ssize = 0;
190
191 /* make sure we actually have a data and stack area to dump */
192 set_fs(USER_DS);
193 if (!access_ok(VERIFY_READ, (void *) (unsigned long)START_DATA(dump),
194 dump.u_dsize << PAGE_SHIFT))
195 dump.u_dsize = 0;
196 if (!access_ok(VERIFY_READ, (void *) (unsigned long)START_STACK(dump),
197 dump.u_ssize << PAGE_SHIFT))
198 dump.u_ssize = 0;
199
200 set_fs(KERNEL_DS);
201 /* struct user */
202 DUMP_WRITE(&dump, sizeof(dump));
203 /* Now dump all of the user data. Include malloced stuff as well */
204 DUMP_SEEK(PAGE_SIZE);
205 /* now we start writing out the user space info */
206 set_fs(USER_DS);
207 /* Dump the data area */
208 if (dump.u_dsize != 0) {
209 dump_start = START_DATA(dump);
210 dump_size = dump.u_dsize << PAGE_SHIFT;
211 DUMP_WRITE(dump_start, dump_size);
212 }
213 /* Now prepare to dump the stack area */
214 if (dump.u_ssize != 0) {
215 dump_start = START_STACK(dump);
216 dump_size = dump.u_ssize << PAGE_SHIFT;
217 DUMP_WRITE(dump_start, dump_size);
218 }
219 /*
220 * Finally dump the task struct. Not be used by gdb, but
221 * could be useful
222 */
223 set_fs(KERNEL_DS);
224 DUMP_WRITE(current, sizeof(*current));
225 end_coredump:
226 set_fs(fs);
227 return has_dumped;
228 }
229 #endif
230
231 /*
232 * create_aout_tables() parses the env- and arg-strings in new user
233 * memory and creates the pointer tables from them, and puts their
234 * addresses on the "stack", returning the new stack pointer value.
235 */
236 static u32 __user *create_aout_tables(char __user *p, struct linux_binprm *bprm)
237 {
238 u32 __user *argv, *envp, *sp;
239 int argc = bprm->argc, envc = bprm->envc;
240
241 sp = (u32 __user *) ((-(unsigned long)sizeof(u32)) & (unsigned long) p);
242 sp -= envc+1;
243 envp = sp;
244 sp -= argc+1;
245 argv = sp;
246 put_user((unsigned long) envp, --sp);
247 put_user((unsigned long) argv, --sp);
248 put_user(argc, --sp);
249 current->mm->arg_start = (unsigned long) p;
250 while (argc-- > 0) {
251 char c;
252
253 put_user((u32)(unsigned long)p, argv++);
254 do {
255 get_user(c, p++);
256 } while (c);
257 }
258 put_user(0, argv);
259 current->mm->arg_end = current->mm->env_start = (unsigned long) p;
260 while (envc-- > 0) {
261 char c;
262
263 put_user((u32)(unsigned long)p, envp++);
264 do {
265 get_user(c, p++);
266 } while (c);
267 }
268 put_user(0, envp);
269 current->mm->env_end = (unsigned long) p;
270 return sp;
271 }
272
273 /*
274 * These are the functions used to load a.out style executables and shared
275 * libraries. There is no binary dependent code anywhere else.
276 */
277 static int load_aout_binary(struct linux_binprm *bprm, struct pt_regs *regs)
278 {
279 unsigned long error, fd_offset, rlim;
280 struct exec ex;
281 int retval;
282
283 ex = *((struct exec *) bprm->buf); /* exec-header */
284 if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != OMAGIC &&
285 N_MAGIC(ex) != QMAGIC && N_MAGIC(ex) != NMAGIC) ||
286 N_TRSIZE(ex) || N_DRSIZE(ex) ||
287 i_size_read(bprm->file->f_path.dentry->d_inode) <
288 ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
289 return -ENOEXEC;
290 }
291
292 fd_offset = N_TXTOFF(ex);
293
294 /* Check initial limits. This avoids letting people circumvent
295 * size limits imposed on them by creating programs with large
296 * arrays in the data or bss.
297 */
298 rlim = current->signal->rlim[RLIMIT_DATA].rlim_cur;
299 if (rlim >= RLIM_INFINITY)
300 rlim = ~0;
301 if (ex.a_data + ex.a_bss > rlim)
302 return -ENOMEM;
303
304 /* Flush all traces of the currently running executable */
305 retval = flush_old_exec(bprm);
306 if (retval)
307 return retval;
308
309 regs->cs = __USER32_CS;
310 regs->r8 = regs->r9 = regs->r10 = regs->r11 = regs->r12 =
311 regs->r13 = regs->r14 = regs->r15 = 0;
312
313 /* OK, This is the point of no return */
314 set_personality(PER_LINUX);
315 set_thread_flag(TIF_IA32);
316 clear_thread_flag(TIF_ABI_PENDING);
317
318 current->mm->end_code = ex.a_text +
319 (current->mm->start_code = N_TXTADDR(ex));
320 current->mm->end_data = ex.a_data +
321 (current->mm->start_data = N_DATADDR(ex));
322 current->mm->brk = ex.a_bss +
323 (current->mm->start_brk = N_BSSADDR(ex));
324 current->mm->free_area_cache = TASK_UNMAPPED_BASE;
325 current->mm->cached_hole_size = 0;
326
327 current->mm->mmap = NULL;
328 compute_creds(bprm);
329 current->flags &= ~PF_FORKNOEXEC;
330
331 if (N_MAGIC(ex) == OMAGIC) {
332 unsigned long text_addr, map_size;
333 loff_t pos;
334
335 text_addr = N_TXTADDR(ex);
336
337 pos = 32;
338 map_size = ex.a_text+ex.a_data;
339
340 down_write(¤t->mm->mmap_sem);
341 error = do_brk(text_addr & PAGE_MASK, map_size);
342 up_write(¤t->mm->mmap_sem);
343
344 if (error != (text_addr & PAGE_MASK)) {
345 send_sig(SIGKILL, current, 0);
346 return error;
347 }
348
349 error = bprm->file->f_op->read(bprm->file,
350 (char __user *)text_addr,
351 ex.a_text+ex.a_data, &pos);
352 if ((signed long)error < 0) {
353 send_sig(SIGKILL, current, 0);
354 return error;
355 }
356
357 flush_icache_range(text_addr, text_addr+ex.a_text+ex.a_data);
358 } else {
359 #ifdef WARN_OLD
360 static unsigned long error_time, error_time2;
361 if ((ex.a_text & 0xfff || ex.a_data & 0xfff) &&
362 (N_MAGIC(ex) != NMAGIC) &&
363 time_after(jiffies, error_time2 + 5*HZ)) {
364 printk(KERN_NOTICE "executable not page aligned\n");
365 error_time2 = jiffies;
366 }
367
368 if ((fd_offset & ~PAGE_MASK) != 0 &&
369 time_after(jiffies, error_time + 5*HZ)) {
370 printk(KERN_WARNING
371 "fd_offset is not page aligned. Please convert "
372 "program: %s\n",
373 bprm->file->f_path.dentry->d_name.name);
374 error_time = jiffies;
375 }
376 #endif
377
378 if (!bprm->file->f_op->mmap || (fd_offset & ~PAGE_MASK) != 0) {
379 loff_t pos = fd_offset;
380
381 down_write(¤t->mm->mmap_sem);
382 do_brk(N_TXTADDR(ex), ex.a_text+ex.a_data);
383 up_write(¤t->mm->mmap_sem);
384 bprm->file->f_op->read(bprm->file,
385 (char __user *)N_TXTADDR(ex),
386 ex.a_text+ex.a_data, &pos);
387 flush_icache_range((unsigned long) N_TXTADDR(ex),
388 (unsigned long) N_TXTADDR(ex) +
389 ex.a_text+ex.a_data);
390 goto beyond_if;
391 }
392
393 down_write(¤t->mm->mmap_sem);
394 error = do_mmap(bprm->file, N_TXTADDR(ex), ex.a_text,
395 PROT_READ | PROT_EXEC,
396 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE |
397 MAP_EXECUTABLE | MAP_32BIT,
398 fd_offset);
399 up_write(¤t->mm->mmap_sem);
400
401 if (error != N_TXTADDR(ex)) {
402 send_sig(SIGKILL, current, 0);
403 return error;
404 }
405
406 down_write(¤t->mm->mmap_sem);
407 error = do_mmap(bprm->file, N_DATADDR(ex), ex.a_data,
408 PROT_READ | PROT_WRITE | PROT_EXEC,
409 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE |
410 MAP_EXECUTABLE | MAP_32BIT,
411 fd_offset + ex.a_text);
412 up_write(¤t->mm->mmap_sem);
413 if (error != N_DATADDR(ex)) {
414 send_sig(SIGKILL, current, 0);
415 return error;
416 }
417 }
418 beyond_if:
419 set_binfmt(&aout_format);
420
421 set_brk(current->mm->start_brk, current->mm->brk);
422
423 retval = setup_arg_pages(bprm, IA32_STACK_TOP, EXSTACK_DEFAULT);
424 if (retval < 0) {
425 /* Someone check-me: is this error path enough? */
426 send_sig(SIGKILL, current, 0);
427 return retval;
428 }
429
430 current->mm->start_stack =
431 (unsigned long)create_aout_tables((char __user *)bprm->p, bprm);
432 /* start thread */
433 asm volatile("movl %0,%%fs" :: "r" (0)); \
434 asm volatile("movl %0,%%es; movl %0,%%ds": :"r" (__USER32_DS));
435 load_gs_index(0);
436 (regs)->ip = ex.a_entry;
437 (regs)->sp = current->mm->start_stack;
438 (regs)->flags = 0x200;
439 (regs)->cs = __USER32_CS;
440 (regs)->ss = __USER32_DS;
441 regs->r8 = regs->r9 = regs->r10 = regs->r11 =
442 regs->r12 = regs->r13 = regs->r14 = regs->r15 = 0;
443 set_fs(USER_DS);
444 if (unlikely(current->ptrace & PT_PTRACED)) {
445 if (current->ptrace & PT_TRACE_EXEC)
446 ptrace_notify((PTRACE_EVENT_EXEC << 8) | SIGTRAP);
447 else
448 send_sig(SIGTRAP, current, 0);
449 }
450 return 0;
451 }
452
453 static int load_aout_library(struct file *file)
454 {
455 struct inode *inode;
456 unsigned long bss, start_addr, len, error;
457 int retval;
458 struct exec ex;
459
460 inode = file->f_path.dentry->d_inode;
461
462 retval = -ENOEXEC;
463 error = kernel_read(file, 0, (char *) &ex, sizeof(ex));
464 if (error != sizeof(ex))
465 goto out;
466
467 /* We come in here for the regular a.out style of shared libraries */
468 if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != QMAGIC) || N_TRSIZE(ex) ||
469 N_DRSIZE(ex) || ((ex.a_entry & 0xfff) && N_MAGIC(ex) == ZMAGIC) ||
470 i_size_read(inode) <
471 ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
472 goto out;
473 }
474
475 if (N_FLAGS(ex))
476 goto out;
477
478 /* For QMAGIC, the starting address is 0x20 into the page. We mask
479 this off to get the starting address for the page */
480
481 start_addr = ex.a_entry & 0xfffff000;
482
483 if ((N_TXTOFF(ex) & ~PAGE_MASK) != 0) {
484 loff_t pos = N_TXTOFF(ex);
485
486 #ifdef WARN_OLD
487 static unsigned long error_time;
488 if (time_after(jiffies, error_time + 5*HZ)) {
489 printk(KERN_WARNING
490 "N_TXTOFF is not page aligned. Please convert "
491 "library: %s\n",
492 file->f_path.dentry->d_name.name);
493 error_time = jiffies;
494 }
495 #endif
496 down_write(¤t->mm->mmap_sem);
497 do_brk(start_addr, ex.a_text + ex.a_data + ex.a_bss);
498 up_write(¤t->mm->mmap_sem);
499
500 file->f_op->read(file, (char __user *)start_addr,
501 ex.a_text + ex.a_data, &pos);
502 flush_icache_range((unsigned long) start_addr,
503 (unsigned long) start_addr + ex.a_text +
504 ex.a_data);
505
506 retval = 0;
507 goto out;
508 }
509 /* Now use mmap to map the library into memory. */
510 down_write(¤t->mm->mmap_sem);
511 error = do_mmap(file, start_addr, ex.a_text + ex.a_data,
512 PROT_READ | PROT_WRITE | PROT_EXEC,
513 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_32BIT,
514 N_TXTOFF(ex));
515 up_write(¤t->mm->mmap_sem);
516 retval = error;
517 if (error != start_addr)
518 goto out;
519
520 len = PAGE_ALIGN(ex.a_text + ex.a_data);
521 bss = ex.a_text + ex.a_data + ex.a_bss;
522 if (bss > len) {
523 down_write(¤t->mm->mmap_sem);
524 error = do_brk(start_addr + len, bss - len);
525 up_write(¤t->mm->mmap_sem);
526 retval = error;
527 if (error != start_addr + len)
528 goto out;
529 }
530 retval = 0;
531 out:
532 return retval;
533 }
534
535 static int __init init_aout_binfmt(void)
536 {
537 return register_binfmt(&aout_format);
538 }
539
540 static void __exit exit_aout_binfmt(void)
541 {
542 unregister_binfmt(&aout_format);
543 }
544
545 module_init(init_aout_binfmt);
546 module_exit(exit_aout_binfmt);
547 MODULE_LICENSE("GPL");
548
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