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 | 32 | |
71613c3b | 33 | static int load_aout_binary(struct linux_binprm *); |
1da177e4 | 34 | static int load_aout_library(struct file*); |
1da177e4 | 35 | |
046d662f | 36 | #ifdef CONFIG_COREDUMP |
1da177e4 LT |
37 | /* |
38 | * Routine writes a core dump image in the current directory. | |
39 | * Currently only a stub-function. | |
40 | * | |
41 | * Note that setuid/setgid files won't make a core-dump if the uid/gid | |
42 | * changed due to the set[u|g]id. It's enforced by the "current->mm->dumpable" | |
43 | * field, which also makes sure the core-dumps won't be recursive if the | |
44 | * dumping of the process results in another error.. | |
45 | */ | |
f6151dfe | 46 | static int aout_core_dump(struct coredump_params *cprm) |
1da177e4 | 47 | { |
f6151dfe | 48 | struct file *file = cprm->file; |
1da177e4 LT |
49 | mm_segment_t fs; |
50 | int has_dumped = 0; | |
7731d9a5 BP |
51 | void __user *dump_start; |
52 | int dump_size; | |
1da177e4 | 53 | struct user dump; |
17580d7f | 54 | #ifdef __alpha__ |
7731d9a5 | 55 | # define START_DATA(u) ((void __user *)u.start_data) |
17580d7f | 56 | #else |
7731d9a5 BP |
57 | # define START_DATA(u) ((void __user *)((u.u_tsize << PAGE_SHIFT) + \ |
58 | u.start_code)) | |
1da177e4 | 59 | #endif |
7731d9a5 | 60 | # define START_STACK(u) ((void __user *)u.start_stack) |
1da177e4 LT |
61 | |
62 | fs = get_fs(); | |
63 | set_fs(KERNEL_DS); | |
64 | has_dumped = 1; | |
65 | current->flags |= PF_DUMPCORE; | |
66 | strncpy(dump.u_comm, current->comm, sizeof(dump.u_comm)); | |
6e16d89b | 67 | dump.u_ar0 = offsetof(struct user, regs); |
5ab1c309 | 68 | dump.signal = cprm->siginfo->si_signo; |
f6151dfe | 69 | aout_dump_thread(cprm->regs, &dump); |
1da177e4 LT |
70 | |
71 | /* If the size of the dump file exceeds the rlimit, then see what would happen | |
72 | if we wrote the stack, but not the data area. */ | |
f6151dfe | 73 | if ((dump.u_dsize + dump.u_ssize+1) * PAGE_SIZE > cprm->limit) |
1da177e4 | 74 | dump.u_dsize = 0; |
1da177e4 LT |
75 | |
76 | /* Make sure we have enough room to write the stack and data areas. */ | |
f6151dfe | 77 | if ((dump.u_ssize + 1) * PAGE_SIZE > cprm->limit) |
1da177e4 | 78 | dump.u_ssize = 0; |
1da177e4 LT |
79 | |
80 | /* make sure we actually have a data and stack area to dump */ | |
81 | set_fs(USER_DS); | |
7731d9a5 | 82 | if (!access_ok(VERIFY_READ, START_DATA(dump), dump.u_dsize << PAGE_SHIFT)) |
1da177e4 | 83 | dump.u_dsize = 0; |
7731d9a5 | 84 | if (!access_ok(VERIFY_READ, START_STACK(dump), dump.u_ssize << PAGE_SHIFT)) |
1da177e4 | 85 | dump.u_ssize = 0; |
1da177e4 LT |
86 | |
87 | set_fs(KERNEL_DS); | |
88 | /* struct user */ | |
088e7af7 DH |
89 | if (!dump_write(file, &dump, sizeof(dump))) |
90 | goto end_coredump; | |
1da177e4 | 91 | /* Now dump all of the user data. Include malloced stuff as well */ |
05f47fda DH |
92 | if (!dump_seek(cprm->file, PAGE_SIZE - sizeof(dump))) |
93 | goto end_coredump; | |
1da177e4 LT |
94 | /* now we start writing out the user space info */ |
95 | set_fs(USER_DS); | |
96 | /* Dump the data area */ | |
97 | if (dump.u_dsize != 0) { | |
98 | dump_start = START_DATA(dump); | |
1da177e4 | 99 | dump_size = dump.u_dsize << PAGE_SHIFT; |
088e7af7 DH |
100 | if (!dump_write(file, dump_start, dump_size)) |
101 | goto end_coredump; | |
1da177e4 LT |
102 | } |
103 | /* Now prepare to dump the stack area */ | |
104 | if (dump.u_ssize != 0) { | |
105 | dump_start = START_STACK(dump); | |
1da177e4 | 106 | dump_size = dump.u_ssize << PAGE_SHIFT; |
088e7af7 DH |
107 | if (!dump_write(file, dump_start, dump_size)) |
108 | goto end_coredump; | |
1da177e4 | 109 | } |
1da177e4 LT |
110 | end_coredump: |
111 | set_fs(fs); | |
112 | return has_dumped; | |
113 | } | |
046d662f AK |
114 | #else |
115 | #define aout_core_dump NULL | |
116 | #endif | |
117 | ||
118 | static struct linux_binfmt aout_format = { | |
119 | .module = THIS_MODULE, | |
120 | .load_binary = load_aout_binary, | |
121 | .load_shlib = load_aout_library, | |
122 | .core_dump = aout_core_dump, | |
123 | .min_coredump = PAGE_SIZE | |
124 | }; | |
125 | ||
126 | #define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE) | |
127 | ||
128 | static int set_brk(unsigned long start, unsigned long end) | |
129 | { | |
130 | start = PAGE_ALIGN(start); | |
131 | end = PAGE_ALIGN(end); | |
132 | if (end > start) { | |
133 | unsigned long addr; | |
134 | addr = vm_brk(start, end - start); | |
135 | if (BAD_ADDR(addr)) | |
136 | return addr; | |
137 | } | |
138 | return 0; | |
139 | } | |
1da177e4 LT |
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 | ||
71613c3b | 204 | static int load_aout_binary(struct linux_binprm * bprm) |
1da177e4 | 205 | { |
71613c3b | 206 | struct pt_regs *regs = current_pt_regs(); |
1da177e4 LT |
207 | struct exec ex; |
208 | unsigned long error; | |
209 | unsigned long fd_offset; | |
210 | unsigned long rlim; | |
211 | int retval; | |
212 | ||
213 | ex = *((struct exec *) bprm->buf); /* exec-header */ | |
214 | if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != OMAGIC && | |
215 | N_MAGIC(ex) != QMAGIC && N_MAGIC(ex) != NMAGIC) || | |
216 | N_TRSIZE(ex) || N_DRSIZE(ex) || | |
0f7fc9e4 | 217 | i_size_read(bprm->file->f_path.dentry->d_inode) < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) { |
1da177e4 LT |
218 | return -ENOEXEC; |
219 | } | |
220 | ||
8454aeef ET |
221 | /* |
222 | * Requires a mmap handler. This prevents people from using a.out | |
223 | * as part of an exploit attack against /proc-related vulnerabilities. | |
224 | */ | |
225 | if (!bprm->file->f_op || !bprm->file->f_op->mmap) | |
226 | return -ENOEXEC; | |
227 | ||
1da177e4 LT |
228 | fd_offset = N_TXTOFF(ex); |
229 | ||
230 | /* Check initial limits. This avoids letting people circumvent | |
231 | * size limits imposed on them by creating programs with large | |
232 | * arrays in the data or bss. | |
233 | */ | |
d554ed89 | 234 | rlim = rlimit(RLIMIT_DATA); |
1da177e4 LT |
235 | if (rlim >= RLIM_INFINITY) |
236 | rlim = ~0; | |
237 | if (ex.a_data + ex.a_bss > rlim) | |
238 | return -ENOMEM; | |
239 | ||
240 | /* Flush all traces of the currently running executable */ | |
241 | retval = flush_old_exec(bprm); | |
242 | if (retval) | |
243 | return retval; | |
244 | ||
245 | /* OK, This is the point of no return */ | |
17580d7f | 246 | #ifdef __alpha__ |
1da177e4 | 247 | SET_AOUT_PERSONALITY(bprm, ex); |
1da177e4 LT |
248 | #else |
249 | set_personality(PER_LINUX); | |
250 | #endif | |
221af7f8 | 251 | setup_new_exec(bprm); |
1da177e4 LT |
252 | |
253 | current->mm->end_code = ex.a_text + | |
254 | (current->mm->start_code = N_TXTADDR(ex)); | |
255 | current->mm->end_data = ex.a_data + | |
256 | (current->mm->start_data = N_DATADDR(ex)); | |
257 | current->mm->brk = ex.a_bss + | |
258 | (current->mm->start_brk = N_BSSADDR(ex)); | |
259 | current->mm->free_area_cache = current->mm->mmap_base; | |
1363c3cd | 260 | current->mm->cached_hole_size = 0; |
1da177e4 | 261 | |
6414fa6a AV |
262 | retval = setup_arg_pages(bprm, STACK_TOP, EXSTACK_DEFAULT); |
263 | if (retval < 0) { | |
264 | /* Someone check-me: is this error path enough? */ | |
265 | send_sig(SIGKILL, current, 0); | |
266 | return retval; | |
267 | } | |
268 | ||
a6f76f23 | 269 | install_exec_creds(bprm); |
1da177e4 LT |
270 | |
271 | if (N_MAGIC(ex) == OMAGIC) { | |
272 | unsigned long text_addr, map_size; | |
273 | loff_t pos; | |
274 | ||
275 | text_addr = N_TXTADDR(ex); | |
276 | ||
fe30af97 | 277 | #ifdef __alpha__ |
1da177e4 LT |
278 | pos = fd_offset; |
279 | map_size = ex.a_text+ex.a_data + PAGE_SIZE - 1; | |
280 | #else | |
281 | pos = 32; | |
282 | map_size = ex.a_text+ex.a_data; | |
283 | #endif | |
e4eb1ff6 | 284 | error = vm_brk(text_addr & PAGE_MASK, map_size); |
1da177e4 LT |
285 | if (error != (text_addr & PAGE_MASK)) { |
286 | send_sig(SIGKILL, current, 0); | |
287 | return error; | |
288 | } | |
289 | ||
290 | error = bprm->file->f_op->read(bprm->file, | |
291 | (char __user *)text_addr, | |
292 | ex.a_text+ex.a_data, &pos); | |
293 | if ((signed long)error < 0) { | |
294 | send_sig(SIGKILL, current, 0); | |
295 | return error; | |
296 | } | |
297 | ||
298 | flush_icache_range(text_addr, text_addr+ex.a_text+ex.a_data); | |
299 | } else { | |
1da177e4 | 300 | if ((ex.a_text & 0xfff || ex.a_data & 0xfff) && |
2e50b6cc | 301 | (N_MAGIC(ex) != NMAGIC) && printk_ratelimit()) |
1da177e4 LT |
302 | { |
303 | printk(KERN_NOTICE "executable not page aligned\n"); | |
1da177e4 LT |
304 | } |
305 | ||
2e50b6cc | 306 | if ((fd_offset & ~PAGE_MASK) != 0 && printk_ratelimit()) |
1da177e4 LT |
307 | { |
308 | printk(KERN_WARNING | |
309 | "fd_offset is not page aligned. Please convert program: %s\n", | |
0f7fc9e4 | 310 | bprm->file->f_path.dentry->d_name.name); |
1da177e4 LT |
311 | } |
312 | ||
313 | if (!bprm->file->f_op->mmap||((fd_offset & ~PAGE_MASK) != 0)) { | |
314 | loff_t pos = fd_offset; | |
e4eb1ff6 | 315 | vm_brk(N_TXTADDR(ex), ex.a_text+ex.a_data); |
1da177e4 LT |
316 | bprm->file->f_op->read(bprm->file, |
317 | (char __user *)N_TXTADDR(ex), | |
318 | ex.a_text+ex.a_data, &pos); | |
319 | flush_icache_range((unsigned long) N_TXTADDR(ex), | |
320 | (unsigned long) N_TXTADDR(ex) + | |
321 | ex.a_text+ex.a_data); | |
322 | goto beyond_if; | |
323 | } | |
324 | ||
6be5ceb0 | 325 | error = vm_mmap(bprm->file, N_TXTADDR(ex), ex.a_text, |
1da177e4 LT |
326 | PROT_READ | PROT_EXEC, |
327 | MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE, | |
328 | fd_offset); | |
1da177e4 LT |
329 | |
330 | if (error != N_TXTADDR(ex)) { | |
331 | send_sig(SIGKILL, current, 0); | |
332 | return error; | |
333 | } | |
334 | ||
6be5ceb0 | 335 | error = vm_mmap(bprm->file, N_DATADDR(ex), ex.a_data, |
1da177e4 LT |
336 | PROT_READ | PROT_WRITE | PROT_EXEC, |
337 | MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE, | |
338 | fd_offset + ex.a_text); | |
1da177e4 LT |
339 | if (error != N_DATADDR(ex)) { |
340 | send_sig(SIGKILL, current, 0); | |
341 | return error; | |
342 | } | |
343 | } | |
344 | beyond_if: | |
345 | set_binfmt(&aout_format); | |
346 | ||
347 | retval = set_brk(current->mm->start_brk, current->mm->brk); | |
348 | if (retval < 0) { | |
349 | send_sig(SIGKILL, current, 0); | |
350 | return retval; | |
351 | } | |
352 | ||
1da177e4 LT |
353 | current->mm->start_stack = |
354 | (unsigned long) create_aout_tables((char __user *) bprm->p, bprm); | |
355 | #ifdef __alpha__ | |
356 | regs->gp = ex.a_gpvalue; | |
357 | #endif | |
358 | start_thread(regs, ex.a_entry, current->mm->start_stack); | |
1da177e4 LT |
359 | return 0; |
360 | } | |
361 | ||
362 | static int load_aout_library(struct file *file) | |
363 | { | |
364 | struct inode * inode; | |
365 | unsigned long bss, start_addr, len; | |
366 | unsigned long error; | |
367 | int retval; | |
368 | struct exec ex; | |
369 | ||
0f7fc9e4 | 370 | inode = file->f_path.dentry->d_inode; |
1da177e4 LT |
371 | |
372 | retval = -ENOEXEC; | |
373 | error = kernel_read(file, 0, (char *) &ex, sizeof(ex)); | |
374 | if (error != sizeof(ex)) | |
375 | goto out; | |
376 | ||
377 | /* We come in here for the regular a.out style of shared libraries */ | |
378 | if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != QMAGIC) || N_TRSIZE(ex) || | |
379 | N_DRSIZE(ex) || ((ex.a_entry & 0xfff) && N_MAGIC(ex) == ZMAGIC) || | |
380 | i_size_read(inode) < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) { | |
381 | goto out; | |
382 | } | |
383 | ||
8454aeef ET |
384 | /* |
385 | * Requires a mmap handler. This prevents people from using a.out | |
386 | * as part of an exploit attack against /proc-related vulnerabilities. | |
387 | */ | |
388 | if (!file->f_op || !file->f_op->mmap) | |
389 | goto out; | |
390 | ||
1da177e4 LT |
391 | if (N_FLAGS(ex)) |
392 | goto out; | |
393 | ||
394 | /* For QMAGIC, the starting address is 0x20 into the page. We mask | |
395 | this off to get the starting address for the page */ | |
396 | ||
397 | start_addr = ex.a_entry & 0xfffff000; | |
398 | ||
399 | if ((N_TXTOFF(ex) & ~PAGE_MASK) != 0) { | |
1da177e4 LT |
400 | loff_t pos = N_TXTOFF(ex); |
401 | ||
2e50b6cc | 402 | if (printk_ratelimit()) |
1da177e4 LT |
403 | { |
404 | printk(KERN_WARNING | |
405 | "N_TXTOFF is not page aligned. Please convert library: %s\n", | |
0f7fc9e4 | 406 | file->f_path.dentry->d_name.name); |
1da177e4 | 407 | } |
e4eb1ff6 | 408 | vm_brk(start_addr, ex.a_text + ex.a_data + ex.a_bss); |
1da177e4 LT |
409 | |
410 | file->f_op->read(file, (char __user *)start_addr, | |
411 | ex.a_text + ex.a_data, &pos); | |
412 | flush_icache_range((unsigned long) start_addr, | |
413 | (unsigned long) start_addr + ex.a_text + ex.a_data); | |
414 | ||
415 | retval = 0; | |
416 | goto out; | |
417 | } | |
418 | /* Now use mmap to map the library into memory. */ | |
6be5ceb0 | 419 | error = vm_mmap(file, start_addr, ex.a_text + ex.a_data, |
1da177e4 LT |
420 | PROT_READ | PROT_WRITE | PROT_EXEC, |
421 | MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE, | |
422 | N_TXTOFF(ex)); | |
1da177e4 LT |
423 | retval = error; |
424 | if (error != start_addr) | |
425 | goto out; | |
426 | ||
427 | len = PAGE_ALIGN(ex.a_text + ex.a_data); | |
428 | bss = ex.a_text + ex.a_data + ex.a_bss; | |
429 | if (bss > len) { | |
e4eb1ff6 | 430 | error = vm_brk(start_addr + len, bss - len); |
1da177e4 LT |
431 | retval = error; |
432 | if (error != start_addr + len) | |
433 | goto out; | |
434 | } | |
435 | retval = 0; | |
436 | out: | |
437 | return retval; | |
438 | } | |
439 | ||
440 | static int __init init_aout_binfmt(void) | |
441 | { | |
8fc3dc5a AV |
442 | register_binfmt(&aout_format); |
443 | return 0; | |
1da177e4 LT |
444 | } |
445 | ||
446 | static void __exit exit_aout_binfmt(void) | |
447 | { | |
448 | unregister_binfmt(&aout_format); | |
449 | } | |
450 | ||
451 | core_initcall(init_aout_binfmt); | |
452 | module_exit(exit_aout_binfmt); | |
453 | MODULE_LICENSE("GPL"); |