Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/fs/binfmt_aout.c | |
3 | * | |
4 | * Copyright (C) 1991, 1992, 1996 Linus Torvalds | |
5 | */ | |
6 | ||
7 | #include <linux/module.h> | |
8 | ||
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> | |
1da177e4 LT |
23 | #include <linux/binfmts.h> |
24 | #include <linux/personality.h> | |
25 | #include <linux/init.h> | |
088e7af7 | 26 | #include <linux/coredump.h> |
5a0e3ad6 | 27 | #include <linux/slab.h> |
1da177e4 | 28 | |
1da177e4 LT |
29 | #include <asm/uaccess.h> |
30 | #include <asm/cacheflush.h> | |
7fa30315 | 31 | #include <asm/a.out-core.h> |
1da177e4 LT |
32 | |
33 | static int load_aout_binary(struct linux_binprm *, struct pt_regs * regs); | |
34 | static int load_aout_library(struct file*); | |
f6151dfe | 35 | static int aout_core_dump(struct coredump_params *cprm); |
1da177e4 | 36 | |
1da177e4 LT |
37 | static struct linux_binfmt aout_format = { |
38 | .module = THIS_MODULE, | |
39 | .load_binary = load_aout_binary, | |
40 | .load_shlib = load_aout_library, | |
41 | .core_dump = aout_core_dump, | |
42 | .min_coredump = PAGE_SIZE | |
43 | }; | |
44 | ||
45 | #define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE) | |
46 | ||
47 | static int set_brk(unsigned long start, unsigned long end) | |
48 | { | |
49 | start = PAGE_ALIGN(start); | |
50 | end = PAGE_ALIGN(end); | |
51 | if (end > start) { | |
52 | unsigned long addr; | |
53 | down_write(¤t->mm->mmap_sem); | |
54 | addr = do_brk(start, end - start); | |
55 | up_write(¤t->mm->mmap_sem); | |
56 | if (BAD_ADDR(addr)) | |
57 | return addr; | |
58 | } | |
59 | return 0; | |
60 | } | |
61 | ||
1da177e4 LT |
62 | /* |
63 | * Routine writes a core dump image in the current directory. | |
64 | * Currently only a stub-function. | |
65 | * | |
66 | * Note that setuid/setgid files won't make a core-dump if the uid/gid | |
67 | * changed due to the set[u|g]id. It's enforced by the "current->mm->dumpable" | |
68 | * field, which also makes sure the core-dumps won't be recursive if the | |
69 | * dumping of the process results in another error.. | |
70 | */ | |
71 | ||
f6151dfe | 72 | static int aout_core_dump(struct coredump_params *cprm) |
1da177e4 | 73 | { |
f6151dfe | 74 | struct file *file = cprm->file; |
1da177e4 LT |
75 | mm_segment_t fs; |
76 | int has_dumped = 0; | |
7731d9a5 BP |
77 | void __user *dump_start; |
78 | int dump_size; | |
1da177e4 | 79 | struct user dump; |
17580d7f | 80 | #ifdef __alpha__ |
7731d9a5 | 81 | # define START_DATA(u) ((void __user *)u.start_data) |
17580d7f | 82 | #else |
7731d9a5 BP |
83 | # define START_DATA(u) ((void __user *)((u.u_tsize << PAGE_SHIFT) + \ |
84 | u.start_code)) | |
1da177e4 | 85 | #endif |
7731d9a5 | 86 | # define START_STACK(u) ((void __user *)u.start_stack) |
1da177e4 LT |
87 | |
88 | fs = get_fs(); | |
89 | set_fs(KERNEL_DS); | |
90 | has_dumped = 1; | |
91 | current->flags |= PF_DUMPCORE; | |
92 | strncpy(dump.u_comm, current->comm, sizeof(dump.u_comm)); | |
6e16d89b | 93 | dump.u_ar0 = offsetof(struct user, regs); |
f6151dfe MH |
94 | dump.signal = cprm->signr; |
95 | aout_dump_thread(cprm->regs, &dump); | |
1da177e4 LT |
96 | |
97 | /* If the size of the dump file exceeds the rlimit, then see what would happen | |
98 | if we wrote the stack, but not the data area. */ | |
f6151dfe | 99 | if ((dump.u_dsize + dump.u_ssize+1) * PAGE_SIZE > cprm->limit) |
1da177e4 | 100 | dump.u_dsize = 0; |
1da177e4 LT |
101 | |
102 | /* Make sure we have enough room to write the stack and data areas. */ | |
f6151dfe | 103 | if ((dump.u_ssize + 1) * PAGE_SIZE > cprm->limit) |
1da177e4 | 104 | dump.u_ssize = 0; |
1da177e4 LT |
105 | |
106 | /* make sure we actually have a data and stack area to dump */ | |
107 | set_fs(USER_DS); | |
7731d9a5 | 108 | if (!access_ok(VERIFY_READ, START_DATA(dump), dump.u_dsize << PAGE_SHIFT)) |
1da177e4 | 109 | dump.u_dsize = 0; |
7731d9a5 | 110 | if (!access_ok(VERIFY_READ, START_STACK(dump), dump.u_ssize << PAGE_SHIFT)) |
1da177e4 | 111 | dump.u_ssize = 0; |
1da177e4 LT |
112 | |
113 | set_fs(KERNEL_DS); | |
114 | /* struct user */ | |
088e7af7 DH |
115 | if (!dump_write(file, &dump, sizeof(dump))) |
116 | goto end_coredump; | |
1da177e4 | 117 | /* Now dump all of the user data. Include malloced stuff as well */ |
05f47fda DH |
118 | if (!dump_seek(cprm->file, PAGE_SIZE - sizeof(dump))) |
119 | goto end_coredump; | |
1da177e4 LT |
120 | /* now we start writing out the user space info */ |
121 | set_fs(USER_DS); | |
122 | /* Dump the data area */ | |
123 | if (dump.u_dsize != 0) { | |
124 | dump_start = START_DATA(dump); | |
1da177e4 | 125 | dump_size = dump.u_dsize << PAGE_SHIFT; |
088e7af7 DH |
126 | if (!dump_write(file, dump_start, dump_size)) |
127 | goto end_coredump; | |
1da177e4 LT |
128 | } |
129 | /* Now prepare to dump the stack area */ | |
130 | if (dump.u_ssize != 0) { | |
131 | dump_start = START_STACK(dump); | |
1da177e4 | 132 | dump_size = dump.u_ssize << PAGE_SHIFT; |
088e7af7 DH |
133 | if (!dump_write(file, dump_start, dump_size)) |
134 | goto end_coredump; | |
1da177e4 | 135 | } |
1da177e4 LT |
136 | end_coredump: |
137 | set_fs(fs); | |
138 | return has_dumped; | |
139 | } | |
140 | ||
141 | /* | |
142 | * create_aout_tables() parses the env- and arg-strings in new user | |
143 | * memory and creates the pointer tables from them, and puts their | |
144 | * addresses on the "stack", returning the new stack pointer value. | |
145 | */ | |
146 | static unsigned long __user *create_aout_tables(char __user *p, struct linux_binprm * bprm) | |
147 | { | |
148 | char __user * __user *argv; | |
149 | char __user * __user *envp; | |
150 | unsigned long __user *sp; | |
151 | int argc = bprm->argc; | |
152 | int envc = bprm->envc; | |
153 | ||
154 | sp = (void __user *)((-(unsigned long)sizeof(char *)) & (unsigned long) p); | |
1da177e4 LT |
155 | #ifdef __alpha__ |
156 | /* whee.. test-programs are so much fun. */ | |
157 | put_user(0, --sp); | |
158 | put_user(0, --sp); | |
159 | if (bprm->loader) { | |
160 | put_user(0, --sp); | |
17580d7f | 161 | put_user(1003, --sp); |
1da177e4 | 162 | put_user(bprm->loader, --sp); |
17580d7f | 163 | put_user(1002, --sp); |
1da177e4 LT |
164 | } |
165 | put_user(bprm->exec, --sp); | |
17580d7f | 166 | put_user(1001, --sp); |
1da177e4 LT |
167 | #endif |
168 | sp -= envc+1; | |
169 | envp = (char __user * __user *) sp; | |
170 | sp -= argc+1; | |
171 | argv = (char __user * __user *) sp; | |
17580d7f | 172 | #ifndef __alpha__ |
1da177e4 LT |
173 | put_user((unsigned long) envp,--sp); |
174 | put_user((unsigned long) argv,--sp); | |
175 | #endif | |
176 | put_user(argc,--sp); | |
177 | current->mm->arg_start = (unsigned long) p; | |
178 | while (argc-->0) { | |
179 | char c; | |
180 | put_user(p,argv++); | |
181 | do { | |
182 | get_user(c,p++); | |
183 | } while (c); | |
184 | } | |
185 | put_user(NULL,argv); | |
186 | current->mm->arg_end = current->mm->env_start = (unsigned long) p; | |
187 | while (envc-->0) { | |
188 | char c; | |
189 | put_user(p,envp++); | |
190 | do { | |
191 | get_user(c,p++); | |
192 | } while (c); | |
193 | } | |
194 | put_user(NULL,envp); | |
195 | current->mm->env_end = (unsigned long) p; | |
196 | return sp; | |
197 | } | |
198 | ||
199 | /* | |
200 | * These are the functions used to load a.out style executables and shared | |
201 | * libraries. There is no binary dependent code anywhere else. | |
202 | */ | |
203 | ||
204 | static int load_aout_binary(struct linux_binprm * bprm, struct pt_regs * regs) | |
205 | { | |
206 | struct exec ex; | |
207 | unsigned long error; | |
208 | unsigned long fd_offset; | |
209 | unsigned long rlim; | |
210 | int retval; | |
211 | ||
212 | ex = *((struct exec *) bprm->buf); /* exec-header */ | |
213 | if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != OMAGIC && | |
214 | N_MAGIC(ex) != QMAGIC && N_MAGIC(ex) != NMAGIC) || | |
215 | N_TRSIZE(ex) || N_DRSIZE(ex) || | |
0f7fc9e4 | 216 | i_size_read(bprm->file->f_path.dentry->d_inode) < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) { |
1da177e4 LT |
217 | return -ENOEXEC; |
218 | } | |
219 | ||
8454aeef ET |
220 | /* |
221 | * Requires a mmap handler. This prevents people from using a.out | |
222 | * as part of an exploit attack against /proc-related vulnerabilities. | |
223 | */ | |
224 | if (!bprm->file->f_op || !bprm->file->f_op->mmap) | |
225 | return -ENOEXEC; | |
226 | ||
1da177e4 LT |
227 | fd_offset = N_TXTOFF(ex); |
228 | ||
229 | /* Check initial limits. This avoids letting people circumvent | |
230 | * size limits imposed on them by creating programs with large | |
231 | * arrays in the data or bss. | |
232 | */ | |
d554ed89 | 233 | rlim = rlimit(RLIMIT_DATA); |
1da177e4 LT |
234 | if (rlim >= RLIM_INFINITY) |
235 | rlim = ~0; | |
236 | if (ex.a_data + ex.a_bss > rlim) | |
237 | return -ENOMEM; | |
238 | ||
239 | /* Flush all traces of the currently running executable */ | |
240 | retval = flush_old_exec(bprm); | |
241 | if (retval) | |
242 | return retval; | |
243 | ||
244 | /* OK, This is the point of no return */ | |
17580d7f | 245 | #ifdef __alpha__ |
1da177e4 | 246 | SET_AOUT_PERSONALITY(bprm, ex); |
1da177e4 LT |
247 | #else |
248 | set_personality(PER_LINUX); | |
249 | #endif | |
221af7f8 | 250 | setup_new_exec(bprm); |
1da177e4 LT |
251 | |
252 | current->mm->end_code = ex.a_text + | |
253 | (current->mm->start_code = N_TXTADDR(ex)); | |
254 | current->mm->end_data = ex.a_data + | |
255 | (current->mm->start_data = N_DATADDR(ex)); | |
256 | current->mm->brk = ex.a_bss + | |
257 | (current->mm->start_brk = N_BSSADDR(ex)); | |
258 | current->mm->free_area_cache = current->mm->mmap_base; | |
1363c3cd | 259 | current->mm->cached_hole_size = 0; |
1da177e4 | 260 | |
6414fa6a AV |
261 | retval = setup_arg_pages(bprm, STACK_TOP, EXSTACK_DEFAULT); |
262 | if (retval < 0) { | |
263 | /* Someone check-me: is this error path enough? */ | |
264 | send_sig(SIGKILL, current, 0); | |
265 | return retval; | |
266 | } | |
267 | ||
a6f76f23 | 268 | install_exec_creds(bprm); |
1da177e4 LT |
269 | |
270 | if (N_MAGIC(ex) == OMAGIC) { | |
271 | unsigned long text_addr, map_size; | |
272 | loff_t pos; | |
273 | ||
274 | text_addr = N_TXTADDR(ex); | |
275 | ||
fe30af97 | 276 | #ifdef __alpha__ |
1da177e4 LT |
277 | pos = fd_offset; |
278 | map_size = ex.a_text+ex.a_data + PAGE_SIZE - 1; | |
279 | #else | |
280 | pos = 32; | |
281 | map_size = ex.a_text+ex.a_data; | |
282 | #endif | |
283 | down_write(¤t->mm->mmap_sem); | |
284 | error = do_brk(text_addr & PAGE_MASK, map_size); | |
285 | up_write(¤t->mm->mmap_sem); | |
286 | if (error != (text_addr & PAGE_MASK)) { | |
287 | send_sig(SIGKILL, current, 0); | |
288 | return error; | |
289 | } | |
290 | ||
291 | error = bprm->file->f_op->read(bprm->file, | |
292 | (char __user *)text_addr, | |
293 | ex.a_text+ex.a_data, &pos); | |
294 | if ((signed long)error < 0) { | |
295 | send_sig(SIGKILL, current, 0); | |
296 | return error; | |
297 | } | |
298 | ||
299 | flush_icache_range(text_addr, text_addr+ex.a_text+ex.a_data); | |
300 | } else { | |
1da177e4 | 301 | if ((ex.a_text & 0xfff || ex.a_data & 0xfff) && |
2e50b6cc | 302 | (N_MAGIC(ex) != NMAGIC) && printk_ratelimit()) |
1da177e4 LT |
303 | { |
304 | printk(KERN_NOTICE "executable not page aligned\n"); | |
1da177e4 LT |
305 | } |
306 | ||
2e50b6cc | 307 | if ((fd_offset & ~PAGE_MASK) != 0 && printk_ratelimit()) |
1da177e4 LT |
308 | { |
309 | printk(KERN_WARNING | |
310 | "fd_offset is not page aligned. Please convert program: %s\n", | |
0f7fc9e4 | 311 | bprm->file->f_path.dentry->d_name.name); |
1da177e4 LT |
312 | } |
313 | ||
314 | if (!bprm->file->f_op->mmap||((fd_offset & ~PAGE_MASK) != 0)) { | |
315 | loff_t pos = fd_offset; | |
316 | down_write(¤t->mm->mmap_sem); | |
317 | do_brk(N_TXTADDR(ex), ex.a_text+ex.a_data); | |
318 | up_write(¤t->mm->mmap_sem); | |
319 | bprm->file->f_op->read(bprm->file, | |
320 | (char __user *)N_TXTADDR(ex), | |
321 | ex.a_text+ex.a_data, &pos); | |
322 | flush_icache_range((unsigned long) N_TXTADDR(ex), | |
323 | (unsigned long) N_TXTADDR(ex) + | |
324 | ex.a_text+ex.a_data); | |
325 | goto beyond_if; | |
326 | } | |
327 | ||
328 | down_write(¤t->mm->mmap_sem); | |
329 | error = do_mmap(bprm->file, N_TXTADDR(ex), ex.a_text, | |
330 | PROT_READ | PROT_EXEC, | |
331 | MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE, | |
332 | fd_offset); | |
333 | up_write(¤t->mm->mmap_sem); | |
334 | ||
335 | if (error != N_TXTADDR(ex)) { | |
336 | send_sig(SIGKILL, current, 0); | |
337 | return error; | |
338 | } | |
339 | ||
340 | down_write(¤t->mm->mmap_sem); | |
341 | error = do_mmap(bprm->file, N_DATADDR(ex), ex.a_data, | |
342 | PROT_READ | PROT_WRITE | PROT_EXEC, | |
343 | MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE, | |
344 | fd_offset + ex.a_text); | |
345 | up_write(¤t->mm->mmap_sem); | |
346 | if (error != N_DATADDR(ex)) { | |
347 | send_sig(SIGKILL, current, 0); | |
348 | return error; | |
349 | } | |
350 | } | |
351 | beyond_if: | |
352 | set_binfmt(&aout_format); | |
353 | ||
354 | retval = set_brk(current->mm->start_brk, current->mm->brk); | |
355 | if (retval < 0) { | |
356 | send_sig(SIGKILL, current, 0); | |
357 | return retval; | |
358 | } | |
359 | ||
1da177e4 LT |
360 | current->mm->start_stack = |
361 | (unsigned long) create_aout_tables((char __user *) bprm->p, bprm); | |
362 | #ifdef __alpha__ | |
363 | regs->gp = ex.a_gpvalue; | |
364 | #endif | |
365 | start_thread(regs, ex.a_entry, current->mm->start_stack); | |
1da177e4 LT |
366 | return 0; |
367 | } | |
368 | ||
369 | static int load_aout_library(struct file *file) | |
370 | { | |
371 | struct inode * inode; | |
372 | unsigned long bss, start_addr, len; | |
373 | unsigned long error; | |
374 | int retval; | |
375 | struct exec ex; | |
376 | ||
0f7fc9e4 | 377 | inode = file->f_path.dentry->d_inode; |
1da177e4 LT |
378 | |
379 | retval = -ENOEXEC; | |
380 | error = kernel_read(file, 0, (char *) &ex, sizeof(ex)); | |
381 | if (error != sizeof(ex)) | |
382 | goto out; | |
383 | ||
384 | /* We come in here for the regular a.out style of shared libraries */ | |
385 | if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != QMAGIC) || N_TRSIZE(ex) || | |
386 | N_DRSIZE(ex) || ((ex.a_entry & 0xfff) && N_MAGIC(ex) == ZMAGIC) || | |
387 | i_size_read(inode) < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) { | |
388 | goto out; | |
389 | } | |
390 | ||
8454aeef ET |
391 | /* |
392 | * Requires a mmap handler. This prevents people from using a.out | |
393 | * as part of an exploit attack against /proc-related vulnerabilities. | |
394 | */ | |
395 | if (!file->f_op || !file->f_op->mmap) | |
396 | goto out; | |
397 | ||
1da177e4 LT |
398 | if (N_FLAGS(ex)) |
399 | goto out; | |
400 | ||
401 | /* For QMAGIC, the starting address is 0x20 into the page. We mask | |
402 | this off to get the starting address for the page */ | |
403 | ||
404 | start_addr = ex.a_entry & 0xfffff000; | |
405 | ||
406 | if ((N_TXTOFF(ex) & ~PAGE_MASK) != 0) { | |
1da177e4 LT |
407 | loff_t pos = N_TXTOFF(ex); |
408 | ||
2e50b6cc | 409 | if (printk_ratelimit()) |
1da177e4 LT |
410 | { |
411 | printk(KERN_WARNING | |
412 | "N_TXTOFF is not page aligned. Please convert library: %s\n", | |
0f7fc9e4 | 413 | file->f_path.dentry->d_name.name); |
1da177e4 LT |
414 | } |
415 | down_write(¤t->mm->mmap_sem); | |
416 | do_brk(start_addr, ex.a_text + ex.a_data + ex.a_bss); | |
417 | up_write(¤t->mm->mmap_sem); | |
418 | ||
419 | file->f_op->read(file, (char __user *)start_addr, | |
420 | ex.a_text + ex.a_data, &pos); | |
421 | flush_icache_range((unsigned long) start_addr, | |
422 | (unsigned long) start_addr + ex.a_text + ex.a_data); | |
423 | ||
424 | retval = 0; | |
425 | goto out; | |
426 | } | |
427 | /* Now use mmap to map the library into memory. */ | |
428 | down_write(¤t->mm->mmap_sem); | |
429 | error = do_mmap(file, start_addr, ex.a_text + ex.a_data, | |
430 | PROT_READ | PROT_WRITE | PROT_EXEC, | |
431 | MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE, | |
432 | N_TXTOFF(ex)); | |
433 | up_write(¤t->mm->mmap_sem); | |
434 | retval = error; | |
435 | if (error != start_addr) | |
436 | goto out; | |
437 | ||
438 | len = PAGE_ALIGN(ex.a_text + ex.a_data); | |
439 | bss = ex.a_text + ex.a_data + ex.a_bss; | |
440 | if (bss > len) { | |
441 | down_write(¤t->mm->mmap_sem); | |
442 | error = do_brk(start_addr + len, bss - len); | |
443 | up_write(¤t->mm->mmap_sem); | |
444 | retval = error; | |
445 | if (error != start_addr + len) | |
446 | goto out; | |
447 | } | |
448 | retval = 0; | |
449 | out: | |
450 | return retval; | |
451 | } | |
452 | ||
453 | static int __init init_aout_binfmt(void) | |
454 | { | |
8fc3dc5a AV |
455 | register_binfmt(&aout_format); |
456 | return 0; | |
1da177e4 LT |
457 | } |
458 | ||
459 | static void __exit exit_aout_binfmt(void) | |
460 | { | |
461 | unregister_binfmt(&aout_format); | |
462 | } | |
463 | ||
464 | core_initcall(init_aout_binfmt); | |
465 | module_exit(exit_aout_binfmt); | |
466 | MODULE_LICENSE("GPL"); |