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Commit | Line | Data |
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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> |
68db0cf1 | 28 | #include <linux/sched/task_stack.h> |
1da177e4 | 29 | |
7c0f6ba6 | 30 | #include <linux/uaccess.h> |
1da177e4 | 31 | #include <asm/cacheflush.h> |
7fa30315 | 32 | #include <asm/a.out-core.h> |
1da177e4 | 33 | |
71613c3b | 34 | static int load_aout_binary(struct linux_binprm *); |
1da177e4 | 35 | static int load_aout_library(struct file*); |
1da177e4 | 36 | |
046d662f | 37 | #ifdef CONFIG_COREDUMP |
1da177e4 LT |
38 | /* |
39 | * Routine writes a core dump image in the current directory. | |
40 | * Currently only a stub-function. | |
41 | * | |
42 | * Note that setuid/setgid files won't make a core-dump if the uid/gid | |
43 | * changed due to the set[u|g]id. It's enforced by the "current->mm->dumpable" | |
44 | * field, which also makes sure the core-dumps won't be recursive if the | |
45 | * dumping of the process results in another error.. | |
46 | */ | |
f6151dfe | 47 | static int aout_core_dump(struct coredump_params *cprm) |
1da177e4 LT |
48 | { |
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; | |
1da177e4 | 65 | strncpy(dump.u_comm, current->comm, sizeof(dump.u_comm)); |
6e16d89b | 66 | dump.u_ar0 = offsetof(struct user, regs); |
5ab1c309 | 67 | dump.signal = cprm->siginfo->si_signo; |
f6151dfe | 68 | aout_dump_thread(cprm->regs, &dump); |
1da177e4 LT |
69 | |
70 | /* If the size of the dump file exceeds the rlimit, then see what would happen | |
71 | if we wrote the stack, but not the data area. */ | |
f6151dfe | 72 | if ((dump.u_dsize + dump.u_ssize+1) * PAGE_SIZE > cprm->limit) |
1da177e4 | 73 | dump.u_dsize = 0; |
1da177e4 LT |
74 | |
75 | /* Make sure we have enough room to write the stack and data areas. */ | |
f6151dfe | 76 | if ((dump.u_ssize + 1) * PAGE_SIZE > cprm->limit) |
1da177e4 | 77 | dump.u_ssize = 0; |
1da177e4 LT |
78 | |
79 | /* make sure we actually have a data and stack area to dump */ | |
80 | set_fs(USER_DS); | |
7731d9a5 | 81 | if (!access_ok(VERIFY_READ, START_DATA(dump), dump.u_dsize << PAGE_SHIFT)) |
1da177e4 | 82 | dump.u_dsize = 0; |
7731d9a5 | 83 | if (!access_ok(VERIFY_READ, START_STACK(dump), dump.u_ssize << PAGE_SHIFT)) |
1da177e4 | 84 | dump.u_ssize = 0; |
1da177e4 LT |
85 | |
86 | set_fs(KERNEL_DS); | |
87 | /* struct user */ | |
43a5d548 | 88 | if (!dump_emit(cprm, &dump, sizeof(dump))) |
088e7af7 | 89 | goto end_coredump; |
1da177e4 | 90 | /* Now dump all of the user data. Include malloced stuff as well */ |
9b56d543 | 91 | if (!dump_skip(cprm, PAGE_SIZE - sizeof(dump))) |
05f47fda | 92 | goto end_coredump; |
1da177e4 LT |
93 | /* now we start writing out the user space info */ |
94 | set_fs(USER_DS); | |
95 | /* Dump the data area */ | |
96 | if (dump.u_dsize != 0) { | |
97 | dump_start = START_DATA(dump); | |
1da177e4 | 98 | dump_size = dump.u_dsize << PAGE_SHIFT; |
43a5d548 | 99 | if (!dump_emit(cprm, dump_start, dump_size)) |
088e7af7 | 100 | goto end_coredump; |
1da177e4 LT |
101 | } |
102 | /* Now prepare to dump the stack area */ | |
103 | if (dump.u_ssize != 0) { | |
104 | dump_start = START_STACK(dump); | |
1da177e4 | 105 | dump_size = dump.u_ssize << PAGE_SHIFT; |
43a5d548 | 106 | if (!dump_emit(cprm, dump_start, dump_size)) |
088e7af7 | 107 | goto end_coredump; |
1da177e4 | 108 | } |
1da177e4 LT |
109 | end_coredump: |
110 | set_fs(fs); | |
111 | return has_dumped; | |
112 | } | |
046d662f AK |
113 | #else |
114 | #define aout_core_dump NULL | |
115 | #endif | |
116 | ||
117 | static struct linux_binfmt aout_format = { | |
118 | .module = THIS_MODULE, | |
119 | .load_binary = load_aout_binary, | |
120 | .load_shlib = load_aout_library, | |
121 | .core_dump = aout_core_dump, | |
122 | .min_coredump = PAGE_SIZE | |
123 | }; | |
124 | ||
125 | #define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE) | |
126 | ||
127 | static int set_brk(unsigned long start, unsigned long end) | |
128 | { | |
129 | start = PAGE_ALIGN(start); | |
130 | end = PAGE_ALIGN(end); | |
5d22fc25 LT |
131 | if (end > start) |
132 | return vm_brk(start, end - start); | |
046d662f AK |
133 | return 0; |
134 | } | |
1da177e4 LT |
135 | |
136 | /* | |
137 | * create_aout_tables() parses the env- and arg-strings in new user | |
138 | * memory and creates the pointer tables from them, and puts their | |
139 | * addresses on the "stack", returning the new stack pointer value. | |
140 | */ | |
141 | static unsigned long __user *create_aout_tables(char __user *p, struct linux_binprm * bprm) | |
142 | { | |
143 | char __user * __user *argv; | |
144 | char __user * __user *envp; | |
145 | unsigned long __user *sp; | |
146 | int argc = bprm->argc; | |
147 | int envc = bprm->envc; | |
148 | ||
149 | sp = (void __user *)((-(unsigned long)sizeof(char *)) & (unsigned long) p); | |
1da177e4 LT |
150 | #ifdef __alpha__ |
151 | /* whee.. test-programs are so much fun. */ | |
152 | put_user(0, --sp); | |
153 | put_user(0, --sp); | |
154 | if (bprm->loader) { | |
155 | put_user(0, --sp); | |
17580d7f | 156 | put_user(1003, --sp); |
1da177e4 | 157 | put_user(bprm->loader, --sp); |
17580d7f | 158 | put_user(1002, --sp); |
1da177e4 LT |
159 | } |
160 | put_user(bprm->exec, --sp); | |
17580d7f | 161 | put_user(1001, --sp); |
1da177e4 LT |
162 | #endif |
163 | sp -= envc+1; | |
164 | envp = (char __user * __user *) sp; | |
165 | sp -= argc+1; | |
166 | argv = (char __user * __user *) sp; | |
17580d7f | 167 | #ifndef __alpha__ |
1da177e4 LT |
168 | put_user((unsigned long) envp,--sp); |
169 | put_user((unsigned long) argv,--sp); | |
170 | #endif | |
171 | put_user(argc,--sp); | |
172 | current->mm->arg_start = (unsigned long) p; | |
173 | while (argc-->0) { | |
174 | char c; | |
175 | put_user(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(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 | ||
71613c3b | 199 | static int load_aout_binary(struct linux_binprm * bprm) |
1da177e4 | 200 | { |
71613c3b | 201 | struct pt_regs *regs = current_pt_regs(); |
1da177e4 LT |
202 | struct exec ex; |
203 | unsigned long error; | |
204 | unsigned long fd_offset; | |
205 | unsigned long rlim; | |
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) || | |
496ad9aa | 212 | i_size_read(file_inode(bprm->file)) < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) { |
1da177e4 LT |
213 | return -ENOEXEC; |
214 | } | |
215 | ||
8454aeef ET |
216 | /* |
217 | * Requires a mmap handler. This prevents people from using a.out | |
218 | * as part of an exploit attack against /proc-related vulnerabilities. | |
219 | */ | |
72c2d531 | 220 | if (!bprm->file->f_op->mmap) |
8454aeef ET |
221 | return -ENOEXEC; |
222 | ||
1da177e4 LT |
223 | fd_offset = N_TXTOFF(ex); |
224 | ||
225 | /* Check initial limits. This avoids letting people circumvent | |
226 | * size limits imposed on them by creating programs with large | |
227 | * arrays in the data or bss. | |
228 | */ | |
d554ed89 | 229 | rlim = rlimit(RLIMIT_DATA); |
1da177e4 LT |
230 | if (rlim >= RLIM_INFINITY) |
231 | rlim = ~0; | |
232 | if (ex.a_data + ex.a_bss > rlim) | |
233 | return -ENOMEM; | |
234 | ||
235 | /* Flush all traces of the currently running executable */ | |
236 | retval = flush_old_exec(bprm); | |
237 | if (retval) | |
238 | return retval; | |
239 | ||
240 | /* OK, This is the point of no return */ | |
17580d7f | 241 | #ifdef __alpha__ |
1da177e4 | 242 | SET_AOUT_PERSONALITY(bprm, ex); |
1da177e4 LT |
243 | #else |
244 | set_personality(PER_LINUX); | |
245 | #endif | |
221af7f8 | 246 | setup_new_exec(bprm); |
1da177e4 LT |
247 | |
248 | current->mm->end_code = ex.a_text + | |
249 | (current->mm->start_code = N_TXTADDR(ex)); | |
250 | current->mm->end_data = ex.a_data + | |
251 | (current->mm->start_data = N_DATADDR(ex)); | |
252 | current->mm->brk = ex.a_bss + | |
253 | (current->mm->start_brk = N_BSSADDR(ex)); | |
1da177e4 | 254 | |
6414fa6a | 255 | retval = setup_arg_pages(bprm, STACK_TOP, EXSTACK_DEFAULT); |
19d860a1 | 256 | if (retval < 0) |
6414fa6a | 257 | return retval; |
6414fa6a | 258 | |
a6f76f23 | 259 | install_exec_creds(bprm); |
1da177e4 LT |
260 | |
261 | if (N_MAGIC(ex) == OMAGIC) { | |
262 | unsigned long text_addr, map_size; | |
263 | loff_t pos; | |
264 | ||
265 | text_addr = N_TXTADDR(ex); | |
266 | ||
fe30af97 | 267 | #ifdef __alpha__ |
1da177e4 LT |
268 | pos = fd_offset; |
269 | map_size = ex.a_text+ex.a_data + PAGE_SIZE - 1; | |
270 | #else | |
271 | pos = 32; | |
272 | map_size = ex.a_text+ex.a_data; | |
273 | #endif | |
e4eb1ff6 | 274 | error = vm_brk(text_addr & PAGE_MASK, map_size); |
5d22fc25 | 275 | if (error) |
1da177e4 | 276 | return error; |
1da177e4 | 277 | |
3dc20cb2 AV |
278 | error = read_code(bprm->file, text_addr, pos, |
279 | ex.a_text+ex.a_data); | |
19d860a1 | 280 | if ((signed long)error < 0) |
1da177e4 | 281 | return error; |
1da177e4 | 282 | } else { |
1da177e4 | 283 | if ((ex.a_text & 0xfff || ex.a_data & 0xfff) && |
2e50b6cc | 284 | (N_MAGIC(ex) != NMAGIC) && printk_ratelimit()) |
1da177e4 LT |
285 | { |
286 | printk(KERN_NOTICE "executable not page aligned\n"); | |
1da177e4 LT |
287 | } |
288 | ||
2e50b6cc | 289 | if ((fd_offset & ~PAGE_MASK) != 0 && printk_ratelimit()) |
1da177e4 LT |
290 | { |
291 | printk(KERN_WARNING | |
a455589f AV |
292 | "fd_offset is not page aligned. Please convert program: %pD\n", |
293 | bprm->file); | |
1da177e4 LT |
294 | } |
295 | ||
296 | if (!bprm->file->f_op->mmap||((fd_offset & ~PAGE_MASK) != 0)) { | |
864778b1 | 297 | error = vm_brk(N_TXTADDR(ex), ex.a_text+ex.a_data); |
5d22fc25 | 298 | if (error) |
864778b1 MH |
299 | return error; |
300 | ||
3dc20cb2 AV |
301 | read_code(bprm->file, N_TXTADDR(ex), fd_offset, |
302 | ex.a_text + ex.a_data); | |
1da177e4 LT |
303 | goto beyond_if; |
304 | } | |
305 | ||
6be5ceb0 | 306 | error = vm_mmap(bprm->file, N_TXTADDR(ex), ex.a_text, |
1da177e4 LT |
307 | PROT_READ | PROT_EXEC, |
308 | MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE, | |
309 | fd_offset); | |
1da177e4 | 310 | |
19d860a1 | 311 | if (error != N_TXTADDR(ex)) |
1da177e4 | 312 | return error; |
1da177e4 | 313 | |
6be5ceb0 | 314 | error = vm_mmap(bprm->file, N_DATADDR(ex), ex.a_data, |
1da177e4 LT |
315 | PROT_READ | PROT_WRITE | PROT_EXEC, |
316 | MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE, | |
317 | fd_offset + ex.a_text); | |
19d860a1 | 318 | if (error != N_DATADDR(ex)) |
1da177e4 | 319 | return error; |
1da177e4 LT |
320 | } |
321 | beyond_if: | |
322 | set_binfmt(&aout_format); | |
323 | ||
324 | retval = set_brk(current->mm->start_brk, current->mm->brk); | |
19d860a1 | 325 | if (retval < 0) |
1da177e4 | 326 | return retval; |
1da177e4 | 327 | |
1da177e4 LT |
328 | current->mm->start_stack = |
329 | (unsigned long) create_aout_tables((char __user *) bprm->p, bprm); | |
330 | #ifdef __alpha__ | |
331 | regs->gp = ex.a_gpvalue; | |
332 | #endif | |
b8383831 | 333 | finalize_exec(bprm); |
1da177e4 | 334 | start_thread(regs, ex.a_entry, current->mm->start_stack); |
1da177e4 LT |
335 | return 0; |
336 | } | |
337 | ||
338 | static int load_aout_library(struct file *file) | |
339 | { | |
340 | struct inode * inode; | |
341 | unsigned long bss, start_addr, len; | |
342 | unsigned long error; | |
343 | int retval; | |
344 | struct exec ex; | |
bdd1d2d3 | 345 | loff_t pos = 0; |
1da177e4 | 346 | |
496ad9aa | 347 | inode = file_inode(file); |
1da177e4 LT |
348 | |
349 | retval = -ENOEXEC; | |
bdd1d2d3 | 350 | error = kernel_read(file, &ex, sizeof(ex), &pos); |
1da177e4 LT |
351 | if (error != sizeof(ex)) |
352 | goto out; | |
353 | ||
354 | /* We come in here for the regular a.out style of shared libraries */ | |
355 | if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != QMAGIC) || N_TRSIZE(ex) || | |
356 | N_DRSIZE(ex) || ((ex.a_entry & 0xfff) && N_MAGIC(ex) == ZMAGIC) || | |
357 | i_size_read(inode) < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) { | |
358 | goto out; | |
359 | } | |
360 | ||
8454aeef ET |
361 | /* |
362 | * Requires a mmap handler. This prevents people from using a.out | |
363 | * as part of an exploit attack against /proc-related vulnerabilities. | |
364 | */ | |
72c2d531 | 365 | if (!file->f_op->mmap) |
8454aeef ET |
366 | goto out; |
367 | ||
1da177e4 LT |
368 | if (N_FLAGS(ex)) |
369 | goto out; | |
370 | ||
371 | /* For QMAGIC, the starting address is 0x20 into the page. We mask | |
372 | this off to get the starting address for the page */ | |
373 | ||
374 | start_addr = ex.a_entry & 0xfffff000; | |
375 | ||
376 | if ((N_TXTOFF(ex) & ~PAGE_MASK) != 0) { | |
2e50b6cc | 377 | if (printk_ratelimit()) |
1da177e4 LT |
378 | { |
379 | printk(KERN_WARNING | |
a455589f AV |
380 | "N_TXTOFF is not page aligned. Please convert library: %pD\n", |
381 | file); | |
1da177e4 | 382 | } |
864778b1 | 383 | retval = vm_brk(start_addr, ex.a_text + ex.a_data + ex.a_bss); |
5d22fc25 | 384 | if (retval) |
864778b1 MH |
385 | goto out; |
386 | ||
3dc20cb2 AV |
387 | read_code(file, start_addr, N_TXTOFF(ex), |
388 | ex.a_text + ex.a_data); | |
1da177e4 LT |
389 | retval = 0; |
390 | goto out; | |
391 | } | |
392 | /* Now use mmap to map the library into memory. */ | |
6be5ceb0 | 393 | error = vm_mmap(file, start_addr, ex.a_text + ex.a_data, |
1da177e4 LT |
394 | PROT_READ | PROT_WRITE | PROT_EXEC, |
395 | MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE, | |
396 | N_TXTOFF(ex)); | |
1da177e4 LT |
397 | retval = error; |
398 | if (error != start_addr) | |
399 | goto out; | |
400 | ||
401 | len = PAGE_ALIGN(ex.a_text + ex.a_data); | |
402 | bss = ex.a_text + ex.a_data + ex.a_bss; | |
403 | if (bss > len) { | |
5d22fc25 LT |
404 | retval = vm_brk(start_addr + len, bss - len); |
405 | if (retval) | |
1da177e4 LT |
406 | goto out; |
407 | } | |
408 | retval = 0; | |
409 | out: | |
410 | return retval; | |
411 | } | |
412 | ||
413 | static int __init init_aout_binfmt(void) | |
414 | { | |
8fc3dc5a AV |
415 | register_binfmt(&aout_format); |
416 | return 0; | |
1da177e4 LT |
417 | } |
418 | ||
419 | static void __exit exit_aout_binfmt(void) | |
420 | { | |
421 | unregister_binfmt(&aout_format); | |
422 | } | |
423 | ||
424 | core_initcall(init_aout_binfmt); | |
425 | module_exit(exit_aout_binfmt); | |
426 | MODULE_LICENSE("GPL"); |