1 | /* |
2 | Copyright (C) 2002 Richard Henderson |
3 | Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM. |
4 | |
5 | This program is free software; you can redistribute it and/or modify |
6 | it under the terms of the GNU General Public License as published by |
7 | the Free Software Foundation; either version 2 of the License, or |
8 | (at your option) any later version. |
9 | |
10 | This program is distributed in the hope that it will be useful, |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
13 | GNU General Public License for more details. |
14 | |
15 | You should have received a copy of the GNU General Public License |
16 | along with this program; if not, write to the Free Software |
17 | Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
18 | */ |
19 | #include <linux/export.h> |
20 | #include <linux/extable.h> |
21 | #include <linux/moduleloader.h> |
22 | #include <linux/trace_events.h> |
23 | #include <linux/init.h> |
24 | #include <linux/kallsyms.h> |
25 | #include <linux/file.h> |
26 | #include <linux/fs.h> |
27 | #include <linux/sysfs.h> |
28 | #include <linux/kernel.h> |
29 | #include <linux/slab.h> |
30 | #include <linux/vmalloc.h> |
31 | #include <linux/elf.h> |
32 | #include <linux/proc_fs.h> |
33 | #include <linux/security.h> |
34 | #include <linux/seq_file.h> |
35 | #include <linux/syscalls.h> |
36 | #include <linux/fcntl.h> |
37 | #include <linux/rcupdate.h> |
38 | #include <linux/capability.h> |
39 | #include <linux/cpu.h> |
40 | #include <linux/moduleparam.h> |
41 | #include <linux/errno.h> |
42 | #include <linux/err.h> |
43 | #include <linux/vermagic.h> |
44 | #include <linux/notifier.h> |
45 | #include <linux/sched.h> |
46 | #include <linux/device.h> |
47 | #include <linux/string.h> |
48 | #include <linux/mutex.h> |
49 | #include <linux/rculist.h> |
50 | #include <linux/uaccess.h> |
51 | #include <asm/cacheflush.h> |
52 | #include <linux/set_memory.h> |
53 | #include <asm/mmu_context.h> |
54 | #include <linux/license.h> |
55 | #include <asm/sections.h> |
56 | #include <linux/tracepoint.h> |
57 | #include <linux/ftrace.h> |
58 | #include <linux/livepatch.h> |
59 | #include <linux/async.h> |
60 | #include <linux/percpu.h> |
61 | #include <linux/kmemleak.h> |
62 | #include <linux/jump_label.h> |
63 | #include <linux/pfn.h> |
64 | #include <linux/bsearch.h> |
65 | #include <linux/dynamic_debug.h> |
66 | #include <linux/audit.h> |
67 | #include <uapi/linux/module.h> |
68 | #include "module-internal.h" |
69 | |
70 | #define CREATE_TRACE_POINTS |
71 | #include <trace/events/module.h> |
72 | |
73 | #ifndef ARCH_SHF_SMALL |
74 | #define ARCH_SHF_SMALL 0 |
75 | #endif |
76 | |
77 | /* |
78 | * Modules' sections will be aligned on page boundaries |
79 | * to ensure complete separation of code and data, but |
80 | * only when CONFIG_STRICT_MODULE_RWX=y |
81 | */ |
82 | #ifdef CONFIG_STRICT_MODULE_RWX |
83 | # define debug_align(X) ALIGN(X, PAGE_SIZE) |
84 | #else |
85 | # define debug_align(X) (X) |
86 | #endif |
87 | |
88 | /* If this is set, the section belongs in the init part of the module */ |
89 | #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1)) |
90 | |
91 | /* |
92 | * Mutex protects: |
93 | * 1) List of modules (also safely readable with preempt_disable), |
94 | * 2) module_use links, |
95 | * 3) module_addr_min/module_addr_max. |
96 | * (delete and add uses RCU list operations). */ |
97 | DEFINE_MUTEX(module_mutex); |
98 | EXPORT_SYMBOL_GPL(module_mutex); |
99 | static LIST_HEAD(modules); |
100 | |
101 | #ifdef CONFIG_MODULES_TREE_LOOKUP |
102 | |
103 | /* |
104 | * Use a latched RB-tree for __module_address(); this allows us to use |
105 | * RCU-sched lookups of the address from any context. |
106 | * |
107 | * This is conditional on PERF_EVENTS || TRACING because those can really hit |
108 | * __module_address() hard by doing a lot of stack unwinding; potentially from |
109 | * NMI context. |
110 | */ |
111 | |
112 | static __always_inline unsigned long __mod_tree_val(struct latch_tree_node *n) |
113 | { |
114 | struct module_layout *layout = container_of(n, struct module_layout, mtn.node); |
115 | |
116 | return (unsigned long)layout->base; |
117 | } |
118 | |
119 | static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n) |
120 | { |
121 | struct module_layout *layout = container_of(n, struct module_layout, mtn.node); |
122 | |
123 | return (unsigned long)layout->size; |
124 | } |
125 | |
126 | static __always_inline bool |
127 | mod_tree_less(struct latch_tree_node *a, struct latch_tree_node *b) |
128 | { |
129 | return __mod_tree_val(a) < __mod_tree_val(b); |
130 | } |
131 | |
132 | static __always_inline int |
133 | mod_tree_comp(void *key, struct latch_tree_node *n) |
134 | { |
135 | unsigned long val = (unsigned long)key; |
136 | unsigned long start, end; |
137 | |
138 | start = __mod_tree_val(n); |
139 | if (val < start) |
140 | return -1; |
141 | |
142 | end = start + __mod_tree_size(n); |
143 | if (val >= end) |
144 | return 1; |
145 | |
146 | return 0; |
147 | } |
148 | |
149 | static const struct latch_tree_ops mod_tree_ops = { |
150 | .less = mod_tree_less, |
151 | .comp = mod_tree_comp, |
152 | }; |
153 | |
154 | static struct mod_tree_root { |
155 | struct latch_tree_root root; |
156 | unsigned long addr_min; |
157 | unsigned long addr_max; |
158 | } mod_tree __cacheline_aligned = { |
159 | .addr_min = -1UL, |
160 | }; |
161 | |
162 | #define module_addr_min mod_tree.addr_min |
163 | #define module_addr_max mod_tree.addr_max |
164 | |
165 | static noinline void __mod_tree_insert(struct mod_tree_node *node) |
166 | { |
167 | latch_tree_insert(&node->node, &mod_tree.root, &mod_tree_ops); |
168 | } |
169 | |
170 | static void __mod_tree_remove(struct mod_tree_node *node) |
171 | { |
172 | latch_tree_erase(&node->node, &mod_tree.root, &mod_tree_ops); |
173 | } |
174 | |
175 | /* |
176 | * These modifications: insert, remove_init and remove; are serialized by the |
177 | * module_mutex. |
178 | */ |
179 | static void mod_tree_insert(struct module *mod) |
180 | { |
181 | mod->core_layout.mtn.mod = mod; |
182 | mod->init_layout.mtn.mod = mod; |
183 | |
184 | __mod_tree_insert(&mod->core_layout.mtn); |
185 | if (mod->init_layout.size) |
186 | __mod_tree_insert(&mod->init_layout.mtn); |
187 | } |
188 | |
189 | static void mod_tree_remove_init(struct module *mod) |
190 | { |
191 | if (mod->init_layout.size) |
192 | __mod_tree_remove(&mod->init_layout.mtn); |
193 | } |
194 | |
195 | static void mod_tree_remove(struct module *mod) |
196 | { |
197 | __mod_tree_remove(&mod->core_layout.mtn); |
198 | mod_tree_remove_init(mod); |
199 | } |
200 | |
201 | static struct module *mod_find(unsigned long addr) |
202 | { |
203 | struct latch_tree_node *ltn; |
204 | |
205 | ltn = latch_tree_find((void *)addr, &mod_tree.root, &mod_tree_ops); |
206 | if (!ltn) |
207 | return NULL; |
208 | |
209 | return container_of(ltn, struct mod_tree_node, node)->mod; |
210 | } |
211 | |
212 | #else /* MODULES_TREE_LOOKUP */ |
213 | |
214 | static unsigned long module_addr_min = -1UL, module_addr_max = 0; |
215 | |
216 | static void mod_tree_insert(struct module *mod) { } |
217 | static void mod_tree_remove_init(struct module *mod) { } |
218 | static void mod_tree_remove(struct module *mod) { } |
219 | |
220 | static struct module *mod_find(unsigned long addr) |
221 | { |
222 | struct module *mod; |
223 | |
224 | list_for_each_entry_rcu(mod, &modules, list) { |
225 | if (within_module(addr, mod)) |
226 | return mod; |
227 | } |
228 | |
229 | return NULL; |
230 | } |
231 | |
232 | #endif /* MODULES_TREE_LOOKUP */ |
233 | |
234 | /* |
235 | * Bounds of module text, for speeding up __module_address. |
236 | * Protected by module_mutex. |
237 | */ |
238 | static void __mod_update_bounds(void *base, unsigned int size) |
239 | { |
240 | unsigned long min = (unsigned long)base; |
241 | unsigned long max = min + size; |
242 | |
243 | if (min < module_addr_min) |
244 | module_addr_min = min; |
245 | if (max > module_addr_max) |
246 | module_addr_max = max; |
247 | } |
248 | |
249 | static void mod_update_bounds(struct module *mod) |
250 | { |
251 | __mod_update_bounds(mod->core_layout.base, mod->core_layout.size); |
252 | if (mod->init_layout.size) |
253 | __mod_update_bounds(mod->init_layout.base, mod->init_layout.size); |
254 | } |
255 | |
256 | #ifdef CONFIG_KGDB_KDB |
257 | struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */ |
258 | #endif /* CONFIG_KGDB_KDB */ |
259 | |
260 | static void module_assert_mutex(void) |
261 | { |
262 | lockdep_assert_held(&module_mutex); |
263 | } |
264 | |
265 | static void module_assert_mutex_or_preempt(void) |
266 | { |
267 | #ifdef CONFIG_LOCKDEP |
268 | if (unlikely(!debug_locks)) |
269 | return; |
270 | |
271 | WARN_ON_ONCE(!rcu_read_lock_sched_held() && |
272 | !lockdep_is_held(&module_mutex)); |
273 | #endif |
274 | } |
275 | |
276 | static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE); |
277 | module_param(sig_enforce, bool_enable_only, 0644); |
278 | |
279 | /* |
280 | * Export sig_enforce kernel cmdline parameter to allow other subsystems rely |
281 | * on that instead of directly to CONFIG_MODULE_SIG_FORCE config. |
282 | */ |
283 | bool is_module_sig_enforced(void) |
284 | { |
285 | return sig_enforce; |
286 | } |
287 | EXPORT_SYMBOL(is_module_sig_enforced); |
288 | |
289 | /* Block module loading/unloading? */ |
290 | int modules_disabled = 0; |
291 | core_param(nomodule, modules_disabled, bint, 0); |
292 | |
293 | /* Waiting for a module to finish initializing? */ |
294 | static DECLARE_WAIT_QUEUE_HEAD(module_wq); |
295 | |
296 | static BLOCKING_NOTIFIER_HEAD(module_notify_list); |
297 | |
298 | int register_module_notifier(struct notifier_block *nb) |
299 | { |
300 | return blocking_notifier_chain_register(&module_notify_list, nb); |
301 | } |
302 | EXPORT_SYMBOL(register_module_notifier); |
303 | |
304 | int unregister_module_notifier(struct notifier_block *nb) |
305 | { |
306 | return blocking_notifier_chain_unregister(&module_notify_list, nb); |
307 | } |
308 | EXPORT_SYMBOL(unregister_module_notifier); |
309 | |
310 | /* |
311 | * We require a truly strong try_module_get(): 0 means success. |
312 | * Otherwise an error is returned due to ongoing or failed |
313 | * initialization etc. |
314 | */ |
315 | static inline int strong_try_module_get(struct module *mod) |
316 | { |
317 | BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED); |
318 | if (mod && mod->state == MODULE_STATE_COMING) |
319 | return -EBUSY; |
320 | if (try_module_get(mod)) |
321 | return 0; |
322 | else |
323 | return -ENOENT; |
324 | } |
325 | |
326 | static inline void add_taint_module(struct module *mod, unsigned flag, |
327 | enum lockdep_ok lockdep_ok) |
328 | { |
329 | add_taint(flag, lockdep_ok); |
330 | set_bit(flag, &mod->taints); |
331 | } |
332 | |
333 | /* |
334 | * A thread that wants to hold a reference to a module only while it |
335 | * is running can call this to safely exit. nfsd and lockd use this. |
336 | */ |
337 | void __noreturn __module_put_and_exit(struct module *mod, long code) |
338 | { |
339 | module_put(mod); |
340 | do_exit(code); |
341 | } |
342 | EXPORT_SYMBOL(__module_put_and_exit); |
343 | |
344 | /* Find a module section: 0 means not found. */ |
345 | static unsigned int find_sec(const struct load_info *info, const char *name) |
346 | { |
347 | unsigned int i; |
348 | |
349 | for (i = 1; i < info->hdr->e_shnum; i++) { |
350 | Elf_Shdr *shdr = &info->sechdrs[i]; |
351 | /* Alloc bit cleared means "ignore it." */ |
352 | if ((shdr->sh_flags & SHF_ALLOC) |
353 | && strcmp(info->secstrings + shdr->sh_name, name) == 0) |
354 | return i; |
355 | } |
356 | return 0; |
357 | } |
358 | |
359 | /* Find a module section, or NULL. */ |
360 | static void *section_addr(const struct load_info *info, const char *name) |
361 | { |
362 | /* Section 0 has sh_addr 0. */ |
363 | return (void *)info->sechdrs[find_sec(info, name)].sh_addr; |
364 | } |
365 | |
366 | /* Find a module section, or NULL. Fill in number of "objects" in section. */ |
367 | static void *section_objs(const struct load_info *info, |
368 | const char *name, |
369 | size_t object_size, |
370 | unsigned int *num) |
371 | { |
372 | unsigned int sec = find_sec(info, name); |
373 | |
374 | /* Section 0 has sh_addr 0 and sh_size 0. */ |
375 | *num = info->sechdrs[sec].sh_size / object_size; |
376 | return (void *)info->sechdrs[sec].sh_addr; |
377 | } |
378 | |
379 | /* Provided by the linker */ |
380 | extern const struct kernel_symbol __start___ksymtab[]; |
381 | extern const struct kernel_symbol __stop___ksymtab[]; |
382 | extern const struct kernel_symbol __start___ksymtab_gpl[]; |
383 | extern const struct kernel_symbol __stop___ksymtab_gpl[]; |
384 | extern const struct kernel_symbol __start___ksymtab_gpl_future[]; |
385 | extern const struct kernel_symbol __stop___ksymtab_gpl_future[]; |
386 | extern const s32 __start___kcrctab[]; |
387 | extern const s32 __start___kcrctab_gpl[]; |
388 | extern const s32 __start___kcrctab_gpl_future[]; |
389 | #ifdef CONFIG_UNUSED_SYMBOLS |
390 | extern const struct kernel_symbol __start___ksymtab_unused[]; |
391 | extern const struct kernel_symbol __stop___ksymtab_unused[]; |
392 | extern const struct kernel_symbol __start___ksymtab_unused_gpl[]; |
393 | extern const struct kernel_symbol __stop___ksymtab_unused_gpl[]; |
394 | extern const s32 __start___kcrctab_unused[]; |
395 | extern const s32 __start___kcrctab_unused_gpl[]; |
396 | #endif |
397 | |
398 | #ifndef CONFIG_MODVERSIONS |
399 | #define symversion(base, idx) NULL |
400 | #else |
401 | #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL) |
402 | #endif |
403 | |
404 | static bool each_symbol_in_section(const struct symsearch *arr, |
405 | unsigned int arrsize, |
406 | struct module *owner, |
407 | bool (*fn)(const struct symsearch *syms, |
408 | struct module *owner, |
409 | void *data), |
410 | void *data) |
411 | { |
412 | unsigned int j; |
413 | |
414 | for (j = 0; j < arrsize; j++) { |
415 | if (fn(&arr[j], owner, data)) |
416 | return true; |
417 | } |
418 | |
419 | return false; |
420 | } |
421 | |
422 | /* Returns true as soon as fn returns true, otherwise false. */ |
423 | bool each_symbol_section(bool (*fn)(const struct symsearch *arr, |
424 | struct module *owner, |
425 | void *data), |
426 | void *data) |
427 | { |
428 | struct module *mod; |
429 | static const struct symsearch arr[] = { |
430 | { __start___ksymtab, __stop___ksymtab, __start___kcrctab, |
431 | NOT_GPL_ONLY, false }, |
432 | { __start___ksymtab_gpl, __stop___ksymtab_gpl, |
433 | __start___kcrctab_gpl, |
434 | GPL_ONLY, false }, |
435 | { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future, |
436 | __start___kcrctab_gpl_future, |
437 | WILL_BE_GPL_ONLY, false }, |
438 | #ifdef CONFIG_UNUSED_SYMBOLS |
439 | { __start___ksymtab_unused, __stop___ksymtab_unused, |
440 | __start___kcrctab_unused, |
441 | NOT_GPL_ONLY, true }, |
442 | { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl, |
443 | __start___kcrctab_unused_gpl, |
444 | GPL_ONLY, true }, |
445 | #endif |
446 | }; |
447 | |
448 | module_assert_mutex_or_preempt(); |
449 | |
450 | if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data)) |
451 | return true; |
452 | |
453 | list_for_each_entry_rcu(mod, &modules, list) { |
454 | struct symsearch arr[] = { |
455 | { mod->syms, mod->syms + mod->num_syms, mod->crcs, |
456 | NOT_GPL_ONLY, false }, |
457 | { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms, |
458 | mod->gpl_crcs, |
459 | GPL_ONLY, false }, |
460 | { mod->gpl_future_syms, |
461 | mod->gpl_future_syms + mod->num_gpl_future_syms, |
462 | mod->gpl_future_crcs, |
463 | WILL_BE_GPL_ONLY, false }, |
464 | #ifdef CONFIG_UNUSED_SYMBOLS |
465 | { mod->unused_syms, |
466 | mod->unused_syms + mod->num_unused_syms, |
467 | mod->unused_crcs, |
468 | NOT_GPL_ONLY, true }, |
469 | { mod->unused_gpl_syms, |
470 | mod->unused_gpl_syms + mod->num_unused_gpl_syms, |
471 | mod->unused_gpl_crcs, |
472 | GPL_ONLY, true }, |
473 | #endif |
474 | }; |
475 | |
476 | if (mod->state == MODULE_STATE_UNFORMED) |
477 | continue; |
478 | |
479 | if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data)) |
480 | return true; |
481 | } |
482 | return false; |
483 | } |
484 | EXPORT_SYMBOL_GPL(each_symbol_section); |
485 | |
486 | struct find_symbol_arg { |
487 | /* Input */ |
488 | const char *name; |
489 | bool gplok; |
490 | bool warn; |
491 | |
492 | /* Output */ |
493 | struct module *owner; |
494 | const s32 *crc; |
495 | const struct kernel_symbol *sym; |
496 | }; |
497 | |
498 | static bool check_exported_symbol(const struct symsearch *syms, |
499 | struct module *owner, |
500 | unsigned int symnum, void *data) |
501 | { |
502 | struct find_symbol_arg *fsa = data; |
503 | |
504 | if (!fsa->gplok) { |
505 | if (syms->licence == GPL_ONLY) |
506 | return false; |
507 | if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) { |
508 | pr_warn("Symbol %s is being used by a non-GPL module, " |
509 | "which will not be allowed in the future\n" , |
510 | fsa->name); |
511 | } |
512 | } |
513 | |
514 | #ifdef CONFIG_UNUSED_SYMBOLS |
515 | if (syms->unused && fsa->warn) { |
516 | pr_warn("Symbol %s is marked as UNUSED, however this module is " |
517 | "using it.\n" , fsa->name); |
518 | pr_warn("This symbol will go away in the future.\n" ); |
519 | pr_warn("Please evaluate if this is the right api to use and " |
520 | "if it really is, submit a report to the linux kernel " |
521 | "mailing list together with submitting your code for " |
522 | "inclusion.\n" ); |
523 | } |
524 | #endif |
525 | |
526 | fsa->owner = owner; |
527 | fsa->crc = symversion(syms->crcs, symnum); |
528 | fsa->sym = &syms->start[symnum]; |
529 | return true; |
530 | } |
531 | |
532 | static unsigned long kernel_symbol_value(const struct kernel_symbol *sym) |
533 | { |
534 | #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS |
535 | return (unsigned long)offset_to_ptr(&sym->value_offset); |
536 | #else |
537 | return sym->value; |
538 | #endif |
539 | } |
540 | |
541 | static const char *kernel_symbol_name(const struct kernel_symbol *sym) |
542 | { |
543 | #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS |
544 | return offset_to_ptr(&sym->name_offset); |
545 | #else |
546 | return sym->name; |
547 | #endif |
548 | } |
549 | |
550 | static int cmp_name(const void *va, const void *vb) |
551 | { |
552 | const char *a; |
553 | const struct kernel_symbol *b; |
554 | a = va; b = vb; |
555 | return strcmp(a, kernel_symbol_name(b)); |
556 | } |
557 | |
558 | static bool find_exported_symbol_in_section(const struct symsearch *syms, |
559 | struct module *owner, |
560 | void *data) |
561 | { |
562 | struct find_symbol_arg *fsa = data; |
563 | struct kernel_symbol *sym; |
564 | |
565 | sym = bsearch(fsa->name, syms->start, syms->stop - syms->start, |
566 | sizeof(struct kernel_symbol), cmp_name); |
567 | |
568 | if (sym != NULL && check_exported_symbol(syms, owner, |
569 | sym - syms->start, data)) |
570 | return true; |
571 | |
572 | return false; |
573 | } |
574 | |
575 | /* Find an exported symbol and return it, along with, (optional) crc and |
576 | * (optional) module which owns it. Needs preempt disabled or module_mutex. */ |
577 | const struct kernel_symbol *find_symbol(const char *name, |
578 | struct module **owner, |
579 | const s32 **crc, |
580 | bool gplok, |
581 | bool warn) |
582 | { |
583 | struct find_symbol_arg fsa; |
584 | |
585 | fsa.name = name; |
586 | fsa.gplok = gplok; |
587 | fsa.warn = warn; |
588 | |
589 | if (each_symbol_section(find_exported_symbol_in_section, &fsa)) { |
590 | if (owner) |
591 | *owner = fsa.owner; |
592 | if (crc) |
593 | *crc = fsa.crc; |
594 | return fsa.sym; |
595 | } |
596 | |
597 | pr_debug("Failed to find symbol %s\n" , name); |
598 | return NULL; |
599 | } |
600 | EXPORT_SYMBOL_GPL(find_symbol); |
601 | |
602 | /* |
603 | * Search for module by name: must hold module_mutex (or preempt disabled |
604 | * for read-only access). |
605 | */ |
606 | static struct module *find_module_all(const char *name, size_t len, |
607 | bool even_unformed) |
608 | { |
609 | struct module *mod; |
610 | |
611 | module_assert_mutex_or_preempt(); |
612 | |
613 | list_for_each_entry_rcu(mod, &modules, list) { |
614 | if (!even_unformed && mod->state == MODULE_STATE_UNFORMED) |
615 | continue; |
616 | if (strlen(mod->name) == len && !memcmp(mod->name, name, len)) |
617 | return mod; |
618 | } |
619 | return NULL; |
620 | } |
621 | |
622 | struct module *find_module(const char *name) |
623 | { |
624 | module_assert_mutex(); |
625 | return find_module_all(name, strlen(name), false); |
626 | } |
627 | EXPORT_SYMBOL_GPL(find_module); |
628 | |
629 | #ifdef CONFIG_SMP |
630 | |
631 | static inline void __percpu *mod_percpu(struct module *mod) |
632 | { |
633 | return mod->percpu; |
634 | } |
635 | |
636 | static int percpu_modalloc(struct module *mod, struct load_info *info) |
637 | { |
638 | Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu]; |
639 | unsigned long align = pcpusec->sh_addralign; |
640 | |
641 | if (!pcpusec->sh_size) |
642 | return 0; |
643 | |
644 | if (align > PAGE_SIZE) { |
645 | pr_warn("%s: per-cpu alignment %li > %li\n" , |
646 | mod->name, align, PAGE_SIZE); |
647 | align = PAGE_SIZE; |
648 | } |
649 | |
650 | mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align); |
651 | if (!mod->percpu) { |
652 | pr_warn("%s: Could not allocate %lu bytes percpu data\n" , |
653 | mod->name, (unsigned long)pcpusec->sh_size); |
654 | return -ENOMEM; |
655 | } |
656 | mod->percpu_size = pcpusec->sh_size; |
657 | return 0; |
658 | } |
659 | |
660 | static void percpu_modfree(struct module *mod) |
661 | { |
662 | free_percpu(mod->percpu); |
663 | } |
664 | |
665 | static unsigned int find_pcpusec(struct load_info *info) |
666 | { |
667 | return find_sec(info, ".data..percpu" ); |
668 | } |
669 | |
670 | static void percpu_modcopy(struct module *mod, |
671 | const void *from, unsigned long size) |
672 | { |
673 | int cpu; |
674 | |
675 | for_each_possible_cpu(cpu) |
676 | memcpy(per_cpu_ptr(mod->percpu, cpu), from, size); |
677 | } |
678 | |
679 | bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr) |
680 | { |
681 | struct module *mod; |
682 | unsigned int cpu; |
683 | |
684 | preempt_disable(); |
685 | |
686 | list_for_each_entry_rcu(mod, &modules, list) { |
687 | if (mod->state == MODULE_STATE_UNFORMED) |
688 | continue; |
689 | if (!mod->percpu_size) |
690 | continue; |
691 | for_each_possible_cpu(cpu) { |
692 | void *start = per_cpu_ptr(mod->percpu, cpu); |
693 | void *va = (void *)addr; |
694 | |
695 | if (va >= start && va < start + mod->percpu_size) { |
696 | if (can_addr) { |
697 | *can_addr = (unsigned long) (va - start); |
698 | *can_addr += (unsigned long) |
699 | per_cpu_ptr(mod->percpu, |
700 | get_boot_cpu_id()); |
701 | } |
702 | preempt_enable(); |
703 | return true; |
704 | } |
705 | } |
706 | } |
707 | |
708 | preempt_enable(); |
709 | return false; |
710 | } |
711 | |
712 | /** |
713 | * is_module_percpu_address - test whether address is from module static percpu |
714 | * @addr: address to test |
715 | * |
716 | * Test whether @addr belongs to module static percpu area. |
717 | * |
718 | * RETURNS: |
719 | * %true if @addr is from module static percpu area |
720 | */ |
721 | bool is_module_percpu_address(unsigned long addr) |
722 | { |
723 | return __is_module_percpu_address(addr, NULL); |
724 | } |
725 | |
726 | #else /* ... !CONFIG_SMP */ |
727 | |
728 | static inline void __percpu *mod_percpu(struct module *mod) |
729 | { |
730 | return NULL; |
731 | } |
732 | static int percpu_modalloc(struct module *mod, struct load_info *info) |
733 | { |
734 | /* UP modules shouldn't have this section: ENOMEM isn't quite right */ |
735 | if (info->sechdrs[info->index.pcpu].sh_size != 0) |
736 | return -ENOMEM; |
737 | return 0; |
738 | } |
739 | static inline void percpu_modfree(struct module *mod) |
740 | { |
741 | } |
742 | static unsigned int find_pcpusec(struct load_info *info) |
743 | { |
744 | return 0; |
745 | } |
746 | static inline void percpu_modcopy(struct module *mod, |
747 | const void *from, unsigned long size) |
748 | { |
749 | /* pcpusec should be 0, and size of that section should be 0. */ |
750 | BUG_ON(size != 0); |
751 | } |
752 | bool is_module_percpu_address(unsigned long addr) |
753 | { |
754 | return false; |
755 | } |
756 | |
757 | bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr) |
758 | { |
759 | return false; |
760 | } |
761 | |
762 | #endif /* CONFIG_SMP */ |
763 | |
764 | #define MODINFO_ATTR(field) \ |
765 | static void setup_modinfo_##field(struct module *mod, const char *s) \ |
766 | { \ |
767 | mod->field = kstrdup(s, GFP_KERNEL); \ |
768 | } \ |
769 | static ssize_t show_modinfo_##field(struct module_attribute *mattr, \ |
770 | struct module_kobject *mk, char *buffer) \ |
771 | { \ |
772 | return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \ |
773 | } \ |
774 | static int modinfo_##field##_exists(struct module *mod) \ |
775 | { \ |
776 | return mod->field != NULL; \ |
777 | } \ |
778 | static void free_modinfo_##field(struct module *mod) \ |
779 | { \ |
780 | kfree(mod->field); \ |
781 | mod->field = NULL; \ |
782 | } \ |
783 | static struct module_attribute modinfo_##field = { \ |
784 | .attr = { .name = __stringify(field), .mode = 0444 }, \ |
785 | .show = show_modinfo_##field, \ |
786 | .setup = setup_modinfo_##field, \ |
787 | .test = modinfo_##field##_exists, \ |
788 | .free = free_modinfo_##field, \ |
789 | }; |
790 | |
791 | MODINFO_ATTR(version); |
792 | MODINFO_ATTR(srcversion); |
793 | |
794 | static char last_unloaded_module[MODULE_NAME_LEN+1]; |
795 | |
796 | #ifdef CONFIG_MODULE_UNLOAD |
797 | |
798 | EXPORT_TRACEPOINT_SYMBOL(module_get); |
799 | |
800 | /* MODULE_REF_BASE is the base reference count by kmodule loader. */ |
801 | #define MODULE_REF_BASE 1 |
802 | |
803 | /* Init the unload section of the module. */ |
804 | static int module_unload_init(struct module *mod) |
805 | { |
806 | /* |
807 | * Initialize reference counter to MODULE_REF_BASE. |
808 | * refcnt == 0 means module is going. |
809 | */ |
810 | atomic_set(&mod->refcnt, MODULE_REF_BASE); |
811 | |
812 | INIT_LIST_HEAD(&mod->source_list); |
813 | INIT_LIST_HEAD(&mod->target_list); |
814 | |
815 | /* Hold reference count during initialization. */ |
816 | atomic_inc(&mod->refcnt); |
817 | |
818 | return 0; |
819 | } |
820 | |
821 | /* Does a already use b? */ |
822 | static int already_uses(struct module *a, struct module *b) |
823 | { |
824 | struct module_use *use; |
825 | |
826 | list_for_each_entry(use, &b->source_list, source_list) { |
827 | if (use->source == a) { |
828 | pr_debug("%s uses %s!\n" , a->name, b->name); |
829 | return 1; |
830 | } |
831 | } |
832 | pr_debug("%s does not use %s!\n" , a->name, b->name); |
833 | return 0; |
834 | } |
835 | |
836 | /* |
837 | * Module a uses b |
838 | * - we add 'a' as a "source", 'b' as a "target" of module use |
839 | * - the module_use is added to the list of 'b' sources (so |
840 | * 'b' can walk the list to see who sourced them), and of 'a' |
841 | * targets (so 'a' can see what modules it targets). |
842 | */ |
843 | static int add_module_usage(struct module *a, struct module *b) |
844 | { |
845 | struct module_use *use; |
846 | |
847 | pr_debug("Allocating new usage for %s.\n" , a->name); |
848 | use = kmalloc(sizeof(*use), GFP_ATOMIC); |
849 | if (!use) |
850 | return -ENOMEM; |
851 | |
852 | use->source = a; |
853 | use->target = b; |
854 | list_add(&use->source_list, &b->source_list); |
855 | list_add(&use->target_list, &a->target_list); |
856 | return 0; |
857 | } |
858 | |
859 | /* Module a uses b: caller needs module_mutex() */ |
860 | int ref_module(struct module *a, struct module *b) |
861 | { |
862 | int err; |
863 | |
864 | if (b == NULL || already_uses(a, b)) |
865 | return 0; |
866 | |
867 | /* If module isn't available, we fail. */ |
868 | err = strong_try_module_get(b); |
869 | if (err) |
870 | return err; |
871 | |
872 | err = add_module_usage(a, b); |
873 | if (err) { |
874 | module_put(b); |
875 | return err; |
876 | } |
877 | return 0; |
878 | } |
879 | EXPORT_SYMBOL_GPL(ref_module); |
880 | |
881 | /* Clear the unload stuff of the module. */ |
882 | static void module_unload_free(struct module *mod) |
883 | { |
884 | struct module_use *use, *tmp; |
885 | |
886 | mutex_lock(&module_mutex); |
887 | list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) { |
888 | struct module *i = use->target; |
889 | pr_debug("%s unusing %s\n" , mod->name, i->name); |
890 | module_put(i); |
891 | list_del(&use->source_list); |
892 | list_del(&use->target_list); |
893 | kfree(use); |
894 | } |
895 | mutex_unlock(&module_mutex); |
896 | } |
897 | |
898 | #ifdef CONFIG_MODULE_FORCE_UNLOAD |
899 | static inline int try_force_unload(unsigned int flags) |
900 | { |
901 | int ret = (flags & O_TRUNC); |
902 | if (ret) |
903 | add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE); |
904 | return ret; |
905 | } |
906 | #else |
907 | static inline int try_force_unload(unsigned int flags) |
908 | { |
909 | return 0; |
910 | } |
911 | #endif /* CONFIG_MODULE_FORCE_UNLOAD */ |
912 | |
913 | /* Try to release refcount of module, 0 means success. */ |
914 | static int try_release_module_ref(struct module *mod) |
915 | { |
916 | int ret; |
917 | |
918 | /* Try to decrement refcnt which we set at loading */ |
919 | ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt); |
920 | BUG_ON(ret < 0); |
921 | if (ret) |
922 | /* Someone can put this right now, recover with checking */ |
923 | ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0); |
924 | |
925 | return ret; |
926 | } |
927 | |
928 | static int try_stop_module(struct module *mod, int flags, int *forced) |
929 | { |
930 | /* If it's not unused, quit unless we're forcing. */ |
931 | if (try_release_module_ref(mod) != 0) { |
932 | *forced = try_force_unload(flags); |
933 | if (!(*forced)) |
934 | return -EWOULDBLOCK; |
935 | } |
936 | |
937 | /* Mark it as dying. */ |
938 | mod->state = MODULE_STATE_GOING; |
939 | |
940 | return 0; |
941 | } |
942 | |
943 | /** |
944 | * module_refcount - return the refcount or -1 if unloading |
945 | * |
946 | * @mod: the module we're checking |
947 | * |
948 | * Returns: |
949 | * -1 if the module is in the process of unloading |
950 | * otherwise the number of references in the kernel to the module |
951 | */ |
952 | int module_refcount(struct module *mod) |
953 | { |
954 | return atomic_read(&mod->refcnt) - MODULE_REF_BASE; |
955 | } |
956 | EXPORT_SYMBOL(module_refcount); |
957 | |
958 | /* This exists whether we can unload or not */ |
959 | static void free_module(struct module *mod); |
960 | |
961 | SYSCALL_DEFINE2(delete_module, const char __user *, name_user, |
962 | unsigned int, flags) |
963 | { |
964 | struct module *mod; |
965 | char name[MODULE_NAME_LEN]; |
966 | int ret, forced = 0; |
967 | |
968 | if (!capable(CAP_SYS_MODULE) || modules_disabled) |
969 | return -EPERM; |
970 | |
971 | if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0) |
972 | return -EFAULT; |
973 | name[MODULE_NAME_LEN-1] = '\0'; |
974 | |
975 | audit_log_kern_module(name); |
976 | |
977 | if (mutex_lock_interruptible(&module_mutex) != 0) |
978 | return -EINTR; |
979 | |
980 | mod = find_module(name); |
981 | if (!mod) { |
982 | ret = -ENOENT; |
983 | goto out; |
984 | } |
985 | |
986 | if (!list_empty(&mod->source_list)) { |
987 | /* Other modules depend on us: get rid of them first. */ |
988 | ret = -EWOULDBLOCK; |
989 | goto out; |
990 | } |
991 | |
992 | /* Doing init or already dying? */ |
993 | if (mod->state != MODULE_STATE_LIVE) { |
994 | /* FIXME: if (force), slam module count damn the torpedoes */ |
995 | pr_debug("%s already dying\n" , mod->name); |
996 | ret = -EBUSY; |
997 | goto out; |
998 | } |
999 | |
1000 | /* If it has an init func, it must have an exit func to unload */ |
1001 | if (mod->init && !mod->exit) { |
1002 | forced = try_force_unload(flags); |
1003 | if (!forced) { |
1004 | /* This module can't be removed */ |
1005 | ret = -EBUSY; |
1006 | goto out; |
1007 | } |
1008 | } |
1009 | |
1010 | /* Stop the machine so refcounts can't move and disable module. */ |
1011 | ret = try_stop_module(mod, flags, &forced); |
1012 | if (ret != 0) |
1013 | goto out; |
1014 | |
1015 | mutex_unlock(&module_mutex); |
1016 | /* Final destruction now no one is using it. */ |
1017 | if (mod->exit != NULL) |
1018 | mod->exit(); |
1019 | blocking_notifier_call_chain(&module_notify_list, |
1020 | MODULE_STATE_GOING, mod); |
1021 | klp_module_going(mod); |
1022 | ftrace_release_mod(mod); |
1023 | |
1024 | async_synchronize_full(); |
1025 | |
1026 | /* Store the name of the last unloaded module for diagnostic purposes */ |
1027 | strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module)); |
1028 | |
1029 | free_module(mod); |
1030 | return 0; |
1031 | out: |
1032 | mutex_unlock(&module_mutex); |
1033 | return ret; |
1034 | } |
1035 | |
1036 | static inline void print_unload_info(struct seq_file *m, struct module *mod) |
1037 | { |
1038 | struct module_use *use; |
1039 | int printed_something = 0; |
1040 | |
1041 | seq_printf(m, " %i " , module_refcount(mod)); |
1042 | |
1043 | /* |
1044 | * Always include a trailing , so userspace can differentiate |
1045 | * between this and the old multi-field proc format. |
1046 | */ |
1047 | list_for_each_entry(use, &mod->source_list, source_list) { |
1048 | printed_something = 1; |
1049 | seq_printf(m, "%s," , use->source->name); |
1050 | } |
1051 | |
1052 | if (mod->init != NULL && mod->exit == NULL) { |
1053 | printed_something = 1; |
1054 | seq_puts(m, "[permanent]," ); |
1055 | } |
1056 | |
1057 | if (!printed_something) |
1058 | seq_puts(m, "-" ); |
1059 | } |
1060 | |
1061 | void __symbol_put(const char *symbol) |
1062 | { |
1063 | struct module *owner; |
1064 | |
1065 | preempt_disable(); |
1066 | if (!find_symbol(symbol, &owner, NULL, true, false)) |
1067 | BUG(); |
1068 | module_put(owner); |
1069 | preempt_enable(); |
1070 | } |
1071 | EXPORT_SYMBOL(__symbol_put); |
1072 | |
1073 | /* Note this assumes addr is a function, which it currently always is. */ |
1074 | void symbol_put_addr(void *addr) |
1075 | { |
1076 | struct module *modaddr; |
1077 | unsigned long a = (unsigned long)dereference_function_descriptor(addr); |
1078 | |
1079 | if (core_kernel_text(a)) |
1080 | return; |
1081 | |
1082 | /* |
1083 | * Even though we hold a reference on the module; we still need to |
1084 | * disable preemption in order to safely traverse the data structure. |
1085 | */ |
1086 | preempt_disable(); |
1087 | modaddr = __module_text_address(a); |
1088 | BUG_ON(!modaddr); |
1089 | module_put(modaddr); |
1090 | preempt_enable(); |
1091 | } |
1092 | EXPORT_SYMBOL_GPL(symbol_put_addr); |
1093 | |
1094 | static ssize_t show_refcnt(struct module_attribute *mattr, |
1095 | struct module_kobject *mk, char *buffer) |
1096 | { |
1097 | return sprintf(buffer, "%i\n" , module_refcount(mk->mod)); |
1098 | } |
1099 | |
1100 | static struct module_attribute modinfo_refcnt = |
1101 | __ATTR(refcnt, 0444, show_refcnt, NULL); |
1102 | |
1103 | void __module_get(struct module *module) |
1104 | { |
1105 | if (module) { |
1106 | preempt_disable(); |
1107 | atomic_inc(&module->refcnt); |
1108 | trace_module_get(module, _RET_IP_); |
1109 | preempt_enable(); |
1110 | } |
1111 | } |
1112 | EXPORT_SYMBOL(__module_get); |
1113 | |
1114 | bool try_module_get(struct module *module) |
1115 | { |
1116 | bool ret = true; |
1117 | |
1118 | if (module) { |
1119 | preempt_disable(); |
1120 | /* Note: here, we can fail to get a reference */ |
1121 | if (likely(module_is_live(module) && |
1122 | atomic_inc_not_zero(&module->refcnt) != 0)) |
1123 | trace_module_get(module, _RET_IP_); |
1124 | else |
1125 | ret = false; |
1126 | |
1127 | preempt_enable(); |
1128 | } |
1129 | return ret; |
1130 | } |
1131 | EXPORT_SYMBOL(try_module_get); |
1132 | |
1133 | void module_put(struct module *module) |
1134 | { |
1135 | int ret; |
1136 | |
1137 | if (module) { |
1138 | preempt_disable(); |
1139 | ret = atomic_dec_if_positive(&module->refcnt); |
1140 | WARN_ON(ret < 0); /* Failed to put refcount */ |
1141 | trace_module_put(module, _RET_IP_); |
1142 | preempt_enable(); |
1143 | } |
1144 | } |
1145 | EXPORT_SYMBOL(module_put); |
1146 | |
1147 | #else /* !CONFIG_MODULE_UNLOAD */ |
1148 | static inline void print_unload_info(struct seq_file *m, struct module *mod) |
1149 | { |
1150 | /* We don't know the usage count, or what modules are using. */ |
1151 | seq_puts(m, " - -" ); |
1152 | } |
1153 | |
1154 | static inline void module_unload_free(struct module *mod) |
1155 | { |
1156 | } |
1157 | |
1158 | int ref_module(struct module *a, struct module *b) |
1159 | { |
1160 | return strong_try_module_get(b); |
1161 | } |
1162 | EXPORT_SYMBOL_GPL(ref_module); |
1163 | |
1164 | static inline int module_unload_init(struct module *mod) |
1165 | { |
1166 | return 0; |
1167 | } |
1168 | #endif /* CONFIG_MODULE_UNLOAD */ |
1169 | |
1170 | static size_t module_flags_taint(struct module *mod, char *buf) |
1171 | { |
1172 | size_t l = 0; |
1173 | int i; |
1174 | |
1175 | for (i = 0; i < TAINT_FLAGS_COUNT; i++) { |
1176 | if (taint_flags[i].module && test_bit(i, &mod->taints)) |
1177 | buf[l++] = taint_flags[i].c_true; |
1178 | } |
1179 | |
1180 | return l; |
1181 | } |
1182 | |
1183 | static ssize_t show_initstate(struct module_attribute *mattr, |
1184 | struct module_kobject *mk, char *buffer) |
1185 | { |
1186 | const char *state = "unknown" ; |
1187 | |
1188 | switch (mk->mod->state) { |
1189 | case MODULE_STATE_LIVE: |
1190 | state = "live" ; |
1191 | break; |
1192 | case MODULE_STATE_COMING: |
1193 | state = "coming" ; |
1194 | break; |
1195 | case MODULE_STATE_GOING: |
1196 | state = "going" ; |
1197 | break; |
1198 | default: |
1199 | BUG(); |
1200 | } |
1201 | return sprintf(buffer, "%s\n" , state); |
1202 | } |
1203 | |
1204 | static struct module_attribute modinfo_initstate = |
1205 | __ATTR(initstate, 0444, show_initstate, NULL); |
1206 | |
1207 | static ssize_t store_uevent(struct module_attribute *mattr, |
1208 | struct module_kobject *mk, |
1209 | const char *buffer, size_t count) |
1210 | { |
1211 | int rc; |
1212 | |
1213 | rc = kobject_synth_uevent(&mk->kobj, buffer, count); |
1214 | return rc ? rc : count; |
1215 | } |
1216 | |
1217 | struct module_attribute module_uevent = |
1218 | __ATTR(uevent, 0200, NULL, store_uevent); |
1219 | |
1220 | static ssize_t show_coresize(struct module_attribute *mattr, |
1221 | struct module_kobject *mk, char *buffer) |
1222 | { |
1223 | return sprintf(buffer, "%u\n" , mk->mod->core_layout.size); |
1224 | } |
1225 | |
1226 | static struct module_attribute modinfo_coresize = |
1227 | __ATTR(coresize, 0444, show_coresize, NULL); |
1228 | |
1229 | static ssize_t show_initsize(struct module_attribute *mattr, |
1230 | struct module_kobject *mk, char *buffer) |
1231 | { |
1232 | return sprintf(buffer, "%u\n" , mk->mod->init_layout.size); |
1233 | } |
1234 | |
1235 | static struct module_attribute modinfo_initsize = |
1236 | __ATTR(initsize, 0444, show_initsize, NULL); |
1237 | |
1238 | static ssize_t show_taint(struct module_attribute *mattr, |
1239 | struct module_kobject *mk, char *buffer) |
1240 | { |
1241 | size_t l; |
1242 | |
1243 | l = module_flags_taint(mk->mod, buffer); |
1244 | buffer[l++] = '\n'; |
1245 | return l; |
1246 | } |
1247 | |
1248 | static struct module_attribute modinfo_taint = |
1249 | __ATTR(taint, 0444, show_taint, NULL); |
1250 | |
1251 | static struct module_attribute *modinfo_attrs[] = { |
1252 | &module_uevent, |
1253 | &modinfo_version, |
1254 | &modinfo_srcversion, |
1255 | &modinfo_initstate, |
1256 | &modinfo_coresize, |
1257 | &modinfo_initsize, |
1258 | &modinfo_taint, |
1259 | #ifdef CONFIG_MODULE_UNLOAD |
1260 | &modinfo_refcnt, |
1261 | #endif |
1262 | NULL, |
1263 | }; |
1264 | |
1265 | static const char vermagic[] = VERMAGIC_STRING; |
1266 | |
1267 | static int try_to_force_load(struct module *mod, const char *reason) |
1268 | { |
1269 | #ifdef CONFIG_MODULE_FORCE_LOAD |
1270 | if (!test_taint(TAINT_FORCED_MODULE)) |
1271 | pr_warn("%s: %s: kernel tainted.\n" , mod->name, reason); |
1272 | add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE); |
1273 | return 0; |
1274 | #else |
1275 | return -ENOEXEC; |
1276 | #endif |
1277 | } |
1278 | |
1279 | #ifdef CONFIG_MODVERSIONS |
1280 | |
1281 | static u32 resolve_rel_crc(const s32 *crc) |
1282 | { |
1283 | return *(u32 *)((void *)crc + *crc); |
1284 | } |
1285 | |
1286 | static int check_version(const struct load_info *info, |
1287 | const char *symname, |
1288 | struct module *mod, |
1289 | const s32 *crc) |
1290 | { |
1291 | Elf_Shdr *sechdrs = info->sechdrs; |
1292 | unsigned int versindex = info->index.vers; |
1293 | unsigned int i, num_versions; |
1294 | struct modversion_info *versions; |
1295 | |
1296 | /* Exporting module didn't supply crcs? OK, we're already tainted. */ |
1297 | if (!crc) |
1298 | return 1; |
1299 | |
1300 | /* No versions at all? modprobe --force does this. */ |
1301 | if (versindex == 0) |
1302 | return try_to_force_load(mod, symname) == 0; |
1303 | |
1304 | versions = (void *) sechdrs[versindex].sh_addr; |
1305 | num_versions = sechdrs[versindex].sh_size |
1306 | / sizeof(struct modversion_info); |
1307 | |
1308 | for (i = 0; i < num_versions; i++) { |
1309 | u32 crcval; |
1310 | |
1311 | if (strcmp(versions[i].name, symname) != 0) |
1312 | continue; |
1313 | |
1314 | if (IS_ENABLED(CONFIG_MODULE_REL_CRCS)) |
1315 | crcval = resolve_rel_crc(crc); |
1316 | else |
1317 | crcval = *crc; |
1318 | if (versions[i].crc == crcval) |
1319 | return 1; |
1320 | pr_debug("Found checksum %X vs module %lX\n" , |
1321 | crcval, versions[i].crc); |
1322 | goto bad_version; |
1323 | } |
1324 | |
1325 | /* Broken toolchain. Warn once, then let it go.. */ |
1326 | pr_warn_once("%s: no symbol version for %s\n" , info->name, symname); |
1327 | return 1; |
1328 | |
1329 | bad_version: |
1330 | pr_warn("%s: disagrees about version of symbol %s\n" , |
1331 | info->name, symname); |
1332 | return 0; |
1333 | } |
1334 | |
1335 | static inline int check_modstruct_version(const struct load_info *info, |
1336 | struct module *mod) |
1337 | { |
1338 | const s32 *crc; |
1339 | |
1340 | /* |
1341 | * Since this should be found in kernel (which can't be removed), no |
1342 | * locking is necessary -- use preempt_disable() to placate lockdep. |
1343 | */ |
1344 | preempt_disable(); |
1345 | if (!find_symbol("module_layout" , NULL, &crc, true, false)) { |
1346 | preempt_enable(); |
1347 | BUG(); |
1348 | } |
1349 | preempt_enable(); |
1350 | return check_version(info, "module_layout" , mod, crc); |
1351 | } |
1352 | |
1353 | /* First part is kernel version, which we ignore if module has crcs. */ |
1354 | static inline int same_magic(const char *amagic, const char *bmagic, |
1355 | bool has_crcs) |
1356 | { |
1357 | if (has_crcs) { |
1358 | amagic += strcspn(amagic, " " ); |
1359 | bmagic += strcspn(bmagic, " " ); |
1360 | } |
1361 | return strcmp(amagic, bmagic) == 0; |
1362 | } |
1363 | #else |
1364 | static inline int check_version(const struct load_info *info, |
1365 | const char *symname, |
1366 | struct module *mod, |
1367 | const s32 *crc) |
1368 | { |
1369 | return 1; |
1370 | } |
1371 | |
1372 | static inline int check_modstruct_version(const struct load_info *info, |
1373 | struct module *mod) |
1374 | { |
1375 | return 1; |
1376 | } |
1377 | |
1378 | static inline int same_magic(const char *amagic, const char *bmagic, |
1379 | bool has_crcs) |
1380 | { |
1381 | return strcmp(amagic, bmagic) == 0; |
1382 | } |
1383 | #endif /* CONFIG_MODVERSIONS */ |
1384 | |
1385 | /* Resolve a symbol for this module. I.e. if we find one, record usage. */ |
1386 | static const struct kernel_symbol *resolve_symbol(struct module *mod, |
1387 | const struct load_info *info, |
1388 | const char *name, |
1389 | char ownername[]) |
1390 | { |
1391 | struct module *owner; |
1392 | const struct kernel_symbol *sym; |
1393 | const s32 *crc; |
1394 | int err; |
1395 | |
1396 | /* |
1397 | * The module_mutex should not be a heavily contended lock; |
1398 | * if we get the occasional sleep here, we'll go an extra iteration |
1399 | * in the wait_event_interruptible(), which is harmless. |
1400 | */ |
1401 | sched_annotate_sleep(); |
1402 | mutex_lock(&module_mutex); |
1403 | sym = find_symbol(name, &owner, &crc, |
1404 | !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true); |
1405 | if (!sym) |
1406 | goto unlock; |
1407 | |
1408 | if (!check_version(info, name, mod, crc)) { |
1409 | sym = ERR_PTR(-EINVAL); |
1410 | goto getname; |
1411 | } |
1412 | |
1413 | err = ref_module(mod, owner); |
1414 | if (err) { |
1415 | sym = ERR_PTR(err); |
1416 | goto getname; |
1417 | } |
1418 | |
1419 | getname: |
1420 | /* We must make copy under the lock if we failed to get ref. */ |
1421 | strncpy(ownername, module_name(owner), MODULE_NAME_LEN); |
1422 | unlock: |
1423 | mutex_unlock(&module_mutex); |
1424 | return sym; |
1425 | } |
1426 | |
1427 | static const struct kernel_symbol * |
1428 | resolve_symbol_wait(struct module *mod, |
1429 | const struct load_info *info, |
1430 | const char *name) |
1431 | { |
1432 | const struct kernel_symbol *ksym; |
1433 | char owner[MODULE_NAME_LEN]; |
1434 | |
1435 | if (wait_event_interruptible_timeout(module_wq, |
1436 | !IS_ERR(ksym = resolve_symbol(mod, info, name, owner)) |
1437 | || PTR_ERR(ksym) != -EBUSY, |
1438 | 30 * HZ) <= 0) { |
1439 | pr_warn("%s: gave up waiting for init of module %s.\n" , |
1440 | mod->name, owner); |
1441 | } |
1442 | return ksym; |
1443 | } |
1444 | |
1445 | /* |
1446 | * /sys/module/foo/sections stuff |
1447 | * J. Corbet <corbet@lwn.net> |
1448 | */ |
1449 | #ifdef CONFIG_SYSFS |
1450 | |
1451 | #ifdef CONFIG_KALLSYMS |
1452 | static inline bool sect_empty(const Elf_Shdr *sect) |
1453 | { |
1454 | return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0; |
1455 | } |
1456 | |
1457 | struct module_sect_attr { |
1458 | struct module_attribute mattr; |
1459 | char *name; |
1460 | unsigned long address; |
1461 | }; |
1462 | |
1463 | struct module_sect_attrs { |
1464 | struct attribute_group grp; |
1465 | unsigned int nsections; |
1466 | struct module_sect_attr attrs[0]; |
1467 | }; |
1468 | |
1469 | static ssize_t module_sect_show(struct module_attribute *mattr, |
1470 | struct module_kobject *mk, char *buf) |
1471 | { |
1472 | struct module_sect_attr *sattr = |
1473 | container_of(mattr, struct module_sect_attr, mattr); |
1474 | return sprintf(buf, "0x%px\n" , kptr_restrict < 2 ? |
1475 | (void *)sattr->address : NULL); |
1476 | } |
1477 | |
1478 | static void free_sect_attrs(struct module_sect_attrs *sect_attrs) |
1479 | { |
1480 | unsigned int section; |
1481 | |
1482 | for (section = 0; section < sect_attrs->nsections; section++) |
1483 | kfree(sect_attrs->attrs[section].name); |
1484 | kfree(sect_attrs); |
1485 | } |
1486 | |
1487 | static void add_sect_attrs(struct module *mod, const struct load_info *info) |
1488 | { |
1489 | unsigned int nloaded = 0, i, size[2]; |
1490 | struct module_sect_attrs *sect_attrs; |
1491 | struct module_sect_attr *sattr; |
1492 | struct attribute **gattr; |
1493 | |
1494 | /* Count loaded sections and allocate structures */ |
1495 | for (i = 0; i < info->hdr->e_shnum; i++) |
1496 | if (!sect_empty(&info->sechdrs[i])) |
1497 | nloaded++; |
1498 | size[0] = ALIGN(sizeof(*sect_attrs) |
1499 | + nloaded * sizeof(sect_attrs->attrs[0]), |
1500 | sizeof(sect_attrs->grp.attrs[0])); |
1501 | size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]); |
1502 | sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL); |
1503 | if (sect_attrs == NULL) |
1504 | return; |
1505 | |
1506 | /* Setup section attributes. */ |
1507 | sect_attrs->grp.name = "sections" ; |
1508 | sect_attrs->grp.attrs = (void *)sect_attrs + size[0]; |
1509 | |
1510 | sect_attrs->nsections = 0; |
1511 | sattr = §_attrs->attrs[0]; |
1512 | gattr = §_attrs->grp.attrs[0]; |
1513 | for (i = 0; i < info->hdr->e_shnum; i++) { |
1514 | Elf_Shdr *sec = &info->sechdrs[i]; |
1515 | if (sect_empty(sec)) |
1516 | continue; |
1517 | sattr->address = sec->sh_addr; |
1518 | sattr->name = kstrdup(info->secstrings + sec->sh_name, |
1519 | GFP_KERNEL); |
1520 | if (sattr->name == NULL) |
1521 | goto out; |
1522 | sect_attrs->nsections++; |
1523 | sysfs_attr_init(&sattr->mattr.attr); |
1524 | sattr->mattr.show = module_sect_show; |
1525 | sattr->mattr.store = NULL; |
1526 | sattr->mattr.attr.name = sattr->name; |
1527 | sattr->mattr.attr.mode = S_IRUSR; |
1528 | *(gattr++) = &(sattr++)->mattr.attr; |
1529 | } |
1530 | *gattr = NULL; |
1531 | |
1532 | if (sysfs_create_group(&mod->mkobj.kobj, §_attrs->grp)) |
1533 | goto out; |
1534 | |
1535 | mod->sect_attrs = sect_attrs; |
1536 | return; |
1537 | out: |
1538 | free_sect_attrs(sect_attrs); |
1539 | } |
1540 | |
1541 | static void remove_sect_attrs(struct module *mod) |
1542 | { |
1543 | if (mod->sect_attrs) { |
1544 | sysfs_remove_group(&mod->mkobj.kobj, |
1545 | &mod->sect_attrs->grp); |
1546 | /* We are positive that no one is using any sect attrs |
1547 | * at this point. Deallocate immediately. */ |
1548 | free_sect_attrs(mod->sect_attrs); |
1549 | mod->sect_attrs = NULL; |
1550 | } |
1551 | } |
1552 | |
1553 | /* |
1554 | * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections. |
1555 | */ |
1556 | |
1557 | struct module_notes_attrs { |
1558 | struct kobject *dir; |
1559 | unsigned int notes; |
1560 | struct bin_attribute attrs[0]; |
1561 | }; |
1562 | |
1563 | static ssize_t module_notes_read(struct file *filp, struct kobject *kobj, |
1564 | struct bin_attribute *bin_attr, |
1565 | char *buf, loff_t pos, size_t count) |
1566 | { |
1567 | /* |
1568 | * The caller checked the pos and count against our size. |
1569 | */ |
1570 | memcpy(buf, bin_attr->private + pos, count); |
1571 | return count; |
1572 | } |
1573 | |
1574 | static void free_notes_attrs(struct module_notes_attrs *notes_attrs, |
1575 | unsigned int i) |
1576 | { |
1577 | if (notes_attrs->dir) { |
1578 | while (i-- > 0) |
1579 | sysfs_remove_bin_file(notes_attrs->dir, |
1580 | ¬es_attrs->attrs[i]); |
1581 | kobject_put(notes_attrs->dir); |
1582 | } |
1583 | kfree(notes_attrs); |
1584 | } |
1585 | |
1586 | static void add_notes_attrs(struct module *mod, const struct load_info *info) |
1587 | { |
1588 | unsigned int notes, loaded, i; |
1589 | struct module_notes_attrs *notes_attrs; |
1590 | struct bin_attribute *nattr; |
1591 | |
1592 | /* failed to create section attributes, so can't create notes */ |
1593 | if (!mod->sect_attrs) |
1594 | return; |
1595 | |
1596 | /* Count notes sections and allocate structures. */ |
1597 | notes = 0; |
1598 | for (i = 0; i < info->hdr->e_shnum; i++) |
1599 | if (!sect_empty(&info->sechdrs[i]) && |
1600 | (info->sechdrs[i].sh_type == SHT_NOTE)) |
1601 | ++notes; |
1602 | |
1603 | if (notes == 0) |
1604 | return; |
1605 | |
1606 | notes_attrs = kzalloc(struct_size(notes_attrs, attrs, notes), |
1607 | GFP_KERNEL); |
1608 | if (notes_attrs == NULL) |
1609 | return; |
1610 | |
1611 | notes_attrs->notes = notes; |
1612 | nattr = ¬es_attrs->attrs[0]; |
1613 | for (loaded = i = 0; i < info->hdr->e_shnum; ++i) { |
1614 | if (sect_empty(&info->sechdrs[i])) |
1615 | continue; |
1616 | if (info->sechdrs[i].sh_type == SHT_NOTE) { |
1617 | sysfs_bin_attr_init(nattr); |
1618 | nattr->attr.name = mod->sect_attrs->attrs[loaded].name; |
1619 | nattr->attr.mode = S_IRUGO; |
1620 | nattr->size = info->sechdrs[i].sh_size; |
1621 | nattr->private = (void *) info->sechdrs[i].sh_addr; |
1622 | nattr->read = module_notes_read; |
1623 | ++nattr; |
1624 | } |
1625 | ++loaded; |
1626 | } |
1627 | |
1628 | notes_attrs->dir = kobject_create_and_add("notes" , &mod->mkobj.kobj); |
1629 | if (!notes_attrs->dir) |
1630 | goto out; |
1631 | |
1632 | for (i = 0; i < notes; ++i) |
1633 | if (sysfs_create_bin_file(notes_attrs->dir, |
1634 | ¬es_attrs->attrs[i])) |
1635 | goto out; |
1636 | |
1637 | mod->notes_attrs = notes_attrs; |
1638 | return; |
1639 | |
1640 | out: |
1641 | free_notes_attrs(notes_attrs, i); |
1642 | } |
1643 | |
1644 | static void remove_notes_attrs(struct module *mod) |
1645 | { |
1646 | if (mod->notes_attrs) |
1647 | free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes); |
1648 | } |
1649 | |
1650 | #else |
1651 | |
1652 | static inline void add_sect_attrs(struct module *mod, |
1653 | const struct load_info *info) |
1654 | { |
1655 | } |
1656 | |
1657 | static inline void remove_sect_attrs(struct module *mod) |
1658 | { |
1659 | } |
1660 | |
1661 | static inline void add_notes_attrs(struct module *mod, |
1662 | const struct load_info *info) |
1663 | { |
1664 | } |
1665 | |
1666 | static inline void remove_notes_attrs(struct module *mod) |
1667 | { |
1668 | } |
1669 | #endif /* CONFIG_KALLSYMS */ |
1670 | |
1671 | static void del_usage_links(struct module *mod) |
1672 | { |
1673 | #ifdef CONFIG_MODULE_UNLOAD |
1674 | struct module_use *use; |
1675 | |
1676 | mutex_lock(&module_mutex); |
1677 | list_for_each_entry(use, &mod->target_list, target_list) |
1678 | sysfs_remove_link(use->target->holders_dir, mod->name); |
1679 | mutex_unlock(&module_mutex); |
1680 | #endif |
1681 | } |
1682 | |
1683 | static int add_usage_links(struct module *mod) |
1684 | { |
1685 | int ret = 0; |
1686 | #ifdef CONFIG_MODULE_UNLOAD |
1687 | struct module_use *use; |
1688 | |
1689 | mutex_lock(&module_mutex); |
1690 | list_for_each_entry(use, &mod->target_list, target_list) { |
1691 | ret = sysfs_create_link(use->target->holders_dir, |
1692 | &mod->mkobj.kobj, mod->name); |
1693 | if (ret) |
1694 | break; |
1695 | } |
1696 | mutex_unlock(&module_mutex); |
1697 | if (ret) |
1698 | del_usage_links(mod); |
1699 | #endif |
1700 | return ret; |
1701 | } |
1702 | |
1703 | static int module_add_modinfo_attrs(struct module *mod) |
1704 | { |
1705 | struct module_attribute *attr; |
1706 | struct module_attribute *temp_attr; |
1707 | int error = 0; |
1708 | int i; |
1709 | |
1710 | mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) * |
1711 | (ARRAY_SIZE(modinfo_attrs) + 1)), |
1712 | GFP_KERNEL); |
1713 | if (!mod->modinfo_attrs) |
1714 | return -ENOMEM; |
1715 | |
1716 | temp_attr = mod->modinfo_attrs; |
1717 | for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) { |
1718 | if (!attr->test || attr->test(mod)) { |
1719 | memcpy(temp_attr, attr, sizeof(*temp_attr)); |
1720 | sysfs_attr_init(&temp_attr->attr); |
1721 | error = sysfs_create_file(&mod->mkobj.kobj, |
1722 | &temp_attr->attr); |
1723 | ++temp_attr; |
1724 | } |
1725 | } |
1726 | return error; |
1727 | } |
1728 | |
1729 | static void module_remove_modinfo_attrs(struct module *mod) |
1730 | { |
1731 | struct module_attribute *attr; |
1732 | int i; |
1733 | |
1734 | for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) { |
1735 | /* pick a field to test for end of list */ |
1736 | if (!attr->attr.name) |
1737 | break; |
1738 | sysfs_remove_file(&mod->mkobj.kobj, &attr->attr); |
1739 | if (attr->free) |
1740 | attr->free(mod); |
1741 | } |
1742 | kfree(mod->modinfo_attrs); |
1743 | } |
1744 | |
1745 | static void mod_kobject_put(struct module *mod) |
1746 | { |
1747 | DECLARE_COMPLETION_ONSTACK(c); |
1748 | mod->mkobj.kobj_completion = &c; |
1749 | kobject_put(&mod->mkobj.kobj); |
1750 | wait_for_completion(&c); |
1751 | } |
1752 | |
1753 | static int mod_sysfs_init(struct module *mod) |
1754 | { |
1755 | int err; |
1756 | struct kobject *kobj; |
1757 | |
1758 | if (!module_sysfs_initialized) { |
1759 | pr_err("%s: module sysfs not initialized\n" , mod->name); |
1760 | err = -EINVAL; |
1761 | goto out; |
1762 | } |
1763 | |
1764 | kobj = kset_find_obj(module_kset, mod->name); |
1765 | if (kobj) { |
1766 | pr_err("%s: module is already loaded\n" , mod->name); |
1767 | kobject_put(kobj); |
1768 | err = -EINVAL; |
1769 | goto out; |
1770 | } |
1771 | |
1772 | mod->mkobj.mod = mod; |
1773 | |
1774 | memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj)); |
1775 | mod->mkobj.kobj.kset = module_kset; |
1776 | err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL, |
1777 | "%s" , mod->name); |
1778 | if (err) |
1779 | mod_kobject_put(mod); |
1780 | |
1781 | /* delay uevent until full sysfs population */ |
1782 | out: |
1783 | return err; |
1784 | } |
1785 | |
1786 | static int mod_sysfs_setup(struct module *mod, |
1787 | const struct load_info *info, |
1788 | struct kernel_param *kparam, |
1789 | unsigned int num_params) |
1790 | { |
1791 | int err; |
1792 | |
1793 | err = mod_sysfs_init(mod); |
1794 | if (err) |
1795 | goto out; |
1796 | |
1797 | mod->holders_dir = kobject_create_and_add("holders" , &mod->mkobj.kobj); |
1798 | if (!mod->holders_dir) { |
1799 | err = -ENOMEM; |
1800 | goto out_unreg; |
1801 | } |
1802 | |
1803 | err = module_param_sysfs_setup(mod, kparam, num_params); |
1804 | if (err) |
1805 | goto out_unreg_holders; |
1806 | |
1807 | err = module_add_modinfo_attrs(mod); |
1808 | if (err) |
1809 | goto out_unreg_param; |
1810 | |
1811 | err = add_usage_links(mod); |
1812 | if (err) |
1813 | goto out_unreg_modinfo_attrs; |
1814 | |
1815 | add_sect_attrs(mod, info); |
1816 | add_notes_attrs(mod, info); |
1817 | |
1818 | kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD); |
1819 | return 0; |
1820 | |
1821 | out_unreg_modinfo_attrs: |
1822 | module_remove_modinfo_attrs(mod); |
1823 | out_unreg_param: |
1824 | module_param_sysfs_remove(mod); |
1825 | out_unreg_holders: |
1826 | kobject_put(mod->holders_dir); |
1827 | out_unreg: |
1828 | mod_kobject_put(mod); |
1829 | out: |
1830 | return err; |
1831 | } |
1832 | |
1833 | static void mod_sysfs_fini(struct module *mod) |
1834 | { |
1835 | remove_notes_attrs(mod); |
1836 | remove_sect_attrs(mod); |
1837 | mod_kobject_put(mod); |
1838 | } |
1839 | |
1840 | static void init_param_lock(struct module *mod) |
1841 | { |
1842 | mutex_init(&mod->param_lock); |
1843 | } |
1844 | #else /* !CONFIG_SYSFS */ |
1845 | |
1846 | static int mod_sysfs_setup(struct module *mod, |
1847 | const struct load_info *info, |
1848 | struct kernel_param *kparam, |
1849 | unsigned int num_params) |
1850 | { |
1851 | return 0; |
1852 | } |
1853 | |
1854 | static void mod_sysfs_fini(struct module *mod) |
1855 | { |
1856 | } |
1857 | |
1858 | static void module_remove_modinfo_attrs(struct module *mod) |
1859 | { |
1860 | } |
1861 | |
1862 | static void del_usage_links(struct module *mod) |
1863 | { |
1864 | } |
1865 | |
1866 | static void init_param_lock(struct module *mod) |
1867 | { |
1868 | } |
1869 | #endif /* CONFIG_SYSFS */ |
1870 | |
1871 | static void mod_sysfs_teardown(struct module *mod) |
1872 | { |
1873 | del_usage_links(mod); |
1874 | module_remove_modinfo_attrs(mod); |
1875 | module_param_sysfs_remove(mod); |
1876 | kobject_put(mod->mkobj.drivers_dir); |
1877 | kobject_put(mod->holders_dir); |
1878 | mod_sysfs_fini(mod); |
1879 | } |
1880 | |
1881 | #ifdef CONFIG_STRICT_MODULE_RWX |
1882 | /* |
1883 | * LKM RO/NX protection: protect module's text/ro-data |
1884 | * from modification and any data from execution. |
1885 | * |
1886 | * General layout of module is: |
1887 | * [text] [read-only-data] [ro-after-init] [writable data] |
1888 | * text_size -----^ ^ ^ ^ |
1889 | * ro_size ------------------------| | | |
1890 | * ro_after_init_size -----------------------------| | |
1891 | * size -----------------------------------------------------------| |
1892 | * |
1893 | * These values are always page-aligned (as is base) |
1894 | */ |
1895 | static void frob_text(const struct module_layout *layout, |
1896 | int (*set_memory)(unsigned long start, int num_pages)) |
1897 | { |
1898 | BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1)); |
1899 | BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1)); |
1900 | set_memory((unsigned long)layout->base, |
1901 | layout->text_size >> PAGE_SHIFT); |
1902 | } |
1903 | |
1904 | static void frob_rodata(const struct module_layout *layout, |
1905 | int (*set_memory)(unsigned long start, int num_pages)) |
1906 | { |
1907 | BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1)); |
1908 | BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1)); |
1909 | BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1)); |
1910 | set_memory((unsigned long)layout->base + layout->text_size, |
1911 | (layout->ro_size - layout->text_size) >> PAGE_SHIFT); |
1912 | } |
1913 | |
1914 | static void frob_ro_after_init(const struct module_layout *layout, |
1915 | int (*set_memory)(unsigned long start, int num_pages)) |
1916 | { |
1917 | BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1)); |
1918 | BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1)); |
1919 | BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1)); |
1920 | set_memory((unsigned long)layout->base + layout->ro_size, |
1921 | (layout->ro_after_init_size - layout->ro_size) >> PAGE_SHIFT); |
1922 | } |
1923 | |
1924 | static void frob_writable_data(const struct module_layout *layout, |
1925 | int (*set_memory)(unsigned long start, int num_pages)) |
1926 | { |
1927 | BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1)); |
1928 | BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1)); |
1929 | BUG_ON((unsigned long)layout->size & (PAGE_SIZE-1)); |
1930 | set_memory((unsigned long)layout->base + layout->ro_after_init_size, |
1931 | (layout->size - layout->ro_after_init_size) >> PAGE_SHIFT); |
1932 | } |
1933 | |
1934 | /* livepatching wants to disable read-only so it can frob module. */ |
1935 | void module_disable_ro(const struct module *mod) |
1936 | { |
1937 | if (!rodata_enabled) |
1938 | return; |
1939 | |
1940 | frob_text(&mod->core_layout, set_memory_rw); |
1941 | frob_rodata(&mod->core_layout, set_memory_rw); |
1942 | frob_ro_after_init(&mod->core_layout, set_memory_rw); |
1943 | frob_text(&mod->init_layout, set_memory_rw); |
1944 | frob_rodata(&mod->init_layout, set_memory_rw); |
1945 | } |
1946 | |
1947 | void module_enable_ro(const struct module *mod, bool after_init) |
1948 | { |
1949 | if (!rodata_enabled) |
1950 | return; |
1951 | |
1952 | frob_text(&mod->core_layout, set_memory_ro); |
1953 | frob_rodata(&mod->core_layout, set_memory_ro); |
1954 | frob_text(&mod->init_layout, set_memory_ro); |
1955 | frob_rodata(&mod->init_layout, set_memory_ro); |
1956 | |
1957 | if (after_init) |
1958 | frob_ro_after_init(&mod->core_layout, set_memory_ro); |
1959 | } |
1960 | |
1961 | static void module_enable_nx(const struct module *mod) |
1962 | { |
1963 | frob_rodata(&mod->core_layout, set_memory_nx); |
1964 | frob_ro_after_init(&mod->core_layout, set_memory_nx); |
1965 | frob_writable_data(&mod->core_layout, set_memory_nx); |
1966 | frob_rodata(&mod->init_layout, set_memory_nx); |
1967 | frob_writable_data(&mod->init_layout, set_memory_nx); |
1968 | } |
1969 | |
1970 | static void module_disable_nx(const struct module *mod) |
1971 | { |
1972 | frob_rodata(&mod->core_layout, set_memory_x); |
1973 | frob_ro_after_init(&mod->core_layout, set_memory_x); |
1974 | frob_writable_data(&mod->core_layout, set_memory_x); |
1975 | frob_rodata(&mod->init_layout, set_memory_x); |
1976 | frob_writable_data(&mod->init_layout, set_memory_x); |
1977 | } |
1978 | |
1979 | /* Iterate through all modules and set each module's text as RW */ |
1980 | void set_all_modules_text_rw(void) |
1981 | { |
1982 | struct module *mod; |
1983 | |
1984 | if (!rodata_enabled) |
1985 | return; |
1986 | |
1987 | mutex_lock(&module_mutex); |
1988 | list_for_each_entry_rcu(mod, &modules, list) { |
1989 | if (mod->state == MODULE_STATE_UNFORMED) |
1990 | continue; |
1991 | |
1992 | frob_text(&mod->core_layout, set_memory_rw); |
1993 | frob_text(&mod->init_layout, set_memory_rw); |
1994 | } |
1995 | mutex_unlock(&module_mutex); |
1996 | } |
1997 | |
1998 | /* Iterate through all modules and set each module's text as RO */ |
1999 | void set_all_modules_text_ro(void) |
2000 | { |
2001 | struct module *mod; |
2002 | |
2003 | if (!rodata_enabled) |
2004 | return; |
2005 | |
2006 | mutex_lock(&module_mutex); |
2007 | list_for_each_entry_rcu(mod, &modules, list) { |
2008 | /* |
2009 | * Ignore going modules since it's possible that ro |
2010 | * protection has already been disabled, otherwise we'll |
2011 | * run into protection faults at module deallocation. |
2012 | */ |
2013 | if (mod->state == MODULE_STATE_UNFORMED || |
2014 | mod->state == MODULE_STATE_GOING) |
2015 | continue; |
2016 | |
2017 | frob_text(&mod->core_layout, set_memory_ro); |
2018 | frob_text(&mod->init_layout, set_memory_ro); |
2019 | } |
2020 | mutex_unlock(&module_mutex); |
2021 | } |
2022 | |
2023 | static void disable_ro_nx(const struct module_layout *layout) |
2024 | { |
2025 | if (rodata_enabled) { |
2026 | frob_text(layout, set_memory_rw); |
2027 | frob_rodata(layout, set_memory_rw); |
2028 | frob_ro_after_init(layout, set_memory_rw); |
2029 | } |
2030 | frob_rodata(layout, set_memory_x); |
2031 | frob_ro_after_init(layout, set_memory_x); |
2032 | frob_writable_data(layout, set_memory_x); |
2033 | } |
2034 | |
2035 | #else |
2036 | static void disable_ro_nx(const struct module_layout *layout) { } |
2037 | static void module_enable_nx(const struct module *mod) { } |
2038 | static void module_disable_nx(const struct module *mod) { } |
2039 | #endif |
2040 | |
2041 | #ifdef CONFIG_LIVEPATCH |
2042 | /* |
2043 | * Persist Elf information about a module. Copy the Elf header, |
2044 | * section header table, section string table, and symtab section |
2045 | * index from info to mod->klp_info. |
2046 | */ |
2047 | static int copy_module_elf(struct module *mod, struct load_info *info) |
2048 | { |
2049 | unsigned int size, symndx; |
2050 | int ret; |
2051 | |
2052 | size = sizeof(*mod->klp_info); |
2053 | mod->klp_info = kmalloc(size, GFP_KERNEL); |
2054 | if (mod->klp_info == NULL) |
2055 | return -ENOMEM; |
2056 | |
2057 | /* Elf header */ |
2058 | size = sizeof(mod->klp_info->hdr); |
2059 | memcpy(&mod->klp_info->hdr, info->hdr, size); |
2060 | |
2061 | /* Elf section header table */ |
2062 | size = sizeof(*info->sechdrs) * info->hdr->e_shnum; |
2063 | mod->klp_info->sechdrs = kmemdup(info->sechdrs, size, GFP_KERNEL); |
2064 | if (mod->klp_info->sechdrs == NULL) { |
2065 | ret = -ENOMEM; |
2066 | goto free_info; |
2067 | } |
2068 | |
2069 | /* Elf section name string table */ |
2070 | size = info->sechdrs[info->hdr->e_shstrndx].sh_size; |
2071 | mod->klp_info->secstrings = kmemdup(info->secstrings, size, GFP_KERNEL); |
2072 | if (mod->klp_info->secstrings == NULL) { |
2073 | ret = -ENOMEM; |
2074 | goto free_sechdrs; |
2075 | } |
2076 | |
2077 | /* Elf symbol section index */ |
2078 | symndx = info->index.sym; |
2079 | mod->klp_info->symndx = symndx; |
2080 | |
2081 | /* |
2082 | * For livepatch modules, core_kallsyms.symtab is a complete |
2083 | * copy of the original symbol table. Adjust sh_addr to point |
2084 | * to core_kallsyms.symtab since the copy of the symtab in module |
2085 | * init memory is freed at the end of do_init_module(). |
2086 | */ |
2087 | mod->klp_info->sechdrs[symndx].sh_addr = \ |
2088 | (unsigned long) mod->core_kallsyms.symtab; |
2089 | |
2090 | return 0; |
2091 | |
2092 | free_sechdrs: |
2093 | kfree(mod->klp_info->sechdrs); |
2094 | free_info: |
2095 | kfree(mod->klp_info); |
2096 | return ret; |
2097 | } |
2098 | |
2099 | static void free_module_elf(struct module *mod) |
2100 | { |
2101 | kfree(mod->klp_info->sechdrs); |
2102 | kfree(mod->klp_info->secstrings); |
2103 | kfree(mod->klp_info); |
2104 | } |
2105 | #else /* !CONFIG_LIVEPATCH */ |
2106 | static int copy_module_elf(struct module *mod, struct load_info *info) |
2107 | { |
2108 | return 0; |
2109 | } |
2110 | |
2111 | static void free_module_elf(struct module *mod) |
2112 | { |
2113 | } |
2114 | #endif /* CONFIG_LIVEPATCH */ |
2115 | |
2116 | void __weak module_memfree(void *module_region) |
2117 | { |
2118 | vfree(module_region); |
2119 | } |
2120 | |
2121 | void __weak module_arch_cleanup(struct module *mod) |
2122 | { |
2123 | } |
2124 | |
2125 | void __weak module_arch_freeing_init(struct module *mod) |
2126 | { |
2127 | } |
2128 | |
2129 | /* Free a module, remove from lists, etc. */ |
2130 | static void free_module(struct module *mod) |
2131 | { |
2132 | trace_module_free(mod); |
2133 | |
2134 | mod_sysfs_teardown(mod); |
2135 | |
2136 | /* We leave it in list to prevent duplicate loads, but make sure |
2137 | * that noone uses it while it's being deconstructed. */ |
2138 | mutex_lock(&module_mutex); |
2139 | mod->state = MODULE_STATE_UNFORMED; |
2140 | mutex_unlock(&module_mutex); |
2141 | |
2142 | /* Remove dynamic debug info */ |
2143 | ddebug_remove_module(mod->name); |
2144 | |
2145 | /* Arch-specific cleanup. */ |
2146 | module_arch_cleanup(mod); |
2147 | |
2148 | /* Module unload stuff */ |
2149 | module_unload_free(mod); |
2150 | |
2151 | /* Free any allocated parameters. */ |
2152 | destroy_params(mod->kp, mod->num_kp); |
2153 | |
2154 | if (is_livepatch_module(mod)) |
2155 | free_module_elf(mod); |
2156 | |
2157 | /* Now we can delete it from the lists */ |
2158 | mutex_lock(&module_mutex); |
2159 | /* Unlink carefully: kallsyms could be walking list. */ |
2160 | list_del_rcu(&mod->list); |
2161 | mod_tree_remove(mod); |
2162 | /* Remove this module from bug list, this uses list_del_rcu */ |
2163 | module_bug_cleanup(mod); |
2164 | /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */ |
2165 | synchronize_rcu(); |
2166 | mutex_unlock(&module_mutex); |
2167 | |
2168 | /* This may be empty, but that's OK */ |
2169 | disable_ro_nx(&mod->init_layout); |
2170 | module_arch_freeing_init(mod); |
2171 | module_memfree(mod->init_layout.base); |
2172 | kfree(mod->args); |
2173 | percpu_modfree(mod); |
2174 | |
2175 | /* Free lock-classes; relies on the preceding sync_rcu(). */ |
2176 | lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size); |
2177 | |
2178 | /* Finally, free the core (containing the module structure) */ |
2179 | disable_ro_nx(&mod->core_layout); |
2180 | module_memfree(mod->core_layout.base); |
2181 | } |
2182 | |
2183 | void *__symbol_get(const char *symbol) |
2184 | { |
2185 | struct module *owner; |
2186 | const struct kernel_symbol *sym; |
2187 | |
2188 | preempt_disable(); |
2189 | sym = find_symbol(symbol, &owner, NULL, true, true); |
2190 | if (sym && strong_try_module_get(owner)) |
2191 | sym = NULL; |
2192 | preempt_enable(); |
2193 | |
2194 | return sym ? (void *)kernel_symbol_value(sym) : NULL; |
2195 | } |
2196 | EXPORT_SYMBOL_GPL(__symbol_get); |
2197 | |
2198 | /* |
2199 | * Ensure that an exported symbol [global namespace] does not already exist |
2200 | * in the kernel or in some other module's exported symbol table. |
2201 | * |
2202 | * You must hold the module_mutex. |
2203 | */ |
2204 | static int verify_exported_symbols(struct module *mod) |
2205 | { |
2206 | unsigned int i; |
2207 | struct module *owner; |
2208 | const struct kernel_symbol *s; |
2209 | struct { |
2210 | const struct kernel_symbol *sym; |
2211 | unsigned int num; |
2212 | } arr[] = { |
2213 | { mod->syms, mod->num_syms }, |
2214 | { mod->gpl_syms, mod->num_gpl_syms }, |
2215 | { mod->gpl_future_syms, mod->num_gpl_future_syms }, |
2216 | #ifdef CONFIG_UNUSED_SYMBOLS |
2217 | { mod->unused_syms, mod->num_unused_syms }, |
2218 | { mod->unused_gpl_syms, mod->num_unused_gpl_syms }, |
2219 | #endif |
2220 | }; |
2221 | |
2222 | for (i = 0; i < ARRAY_SIZE(arr); i++) { |
2223 | for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) { |
2224 | if (find_symbol(kernel_symbol_name(s), &owner, NULL, |
2225 | true, false)) { |
2226 | pr_err("%s: exports duplicate symbol %s" |
2227 | " (owned by %s)\n" , |
2228 | mod->name, kernel_symbol_name(s), |
2229 | module_name(owner)); |
2230 | return -ENOEXEC; |
2231 | } |
2232 | } |
2233 | } |
2234 | return 0; |
2235 | } |
2236 | |
2237 | /* Change all symbols so that st_value encodes the pointer directly. */ |
2238 | static int simplify_symbols(struct module *mod, const struct load_info *info) |
2239 | { |
2240 | Elf_Shdr *symsec = &info->sechdrs[info->index.sym]; |
2241 | Elf_Sym *sym = (void *)symsec->sh_addr; |
2242 | unsigned long secbase; |
2243 | unsigned int i; |
2244 | int ret = 0; |
2245 | const struct kernel_symbol *ksym; |
2246 | |
2247 | for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) { |
2248 | const char *name = info->strtab + sym[i].st_name; |
2249 | |
2250 | switch (sym[i].st_shndx) { |
2251 | case SHN_COMMON: |
2252 | /* Ignore common symbols */ |
2253 | if (!strncmp(name, "__gnu_lto" , 9)) |
2254 | break; |
2255 | |
2256 | /* We compiled with -fno-common. These are not |
2257 | supposed to happen. */ |
2258 | pr_debug("Common symbol: %s\n" , name); |
2259 | pr_warn("%s: please compile with -fno-common\n" , |
2260 | mod->name); |
2261 | ret = -ENOEXEC; |
2262 | break; |
2263 | |
2264 | case SHN_ABS: |
2265 | /* Don't need to do anything */ |
2266 | pr_debug("Absolute symbol: 0x%08lx\n" , |
2267 | (long)sym[i].st_value); |
2268 | break; |
2269 | |
2270 | case SHN_LIVEPATCH: |
2271 | /* Livepatch symbols are resolved by livepatch */ |
2272 | break; |
2273 | |
2274 | case SHN_UNDEF: |
2275 | ksym = resolve_symbol_wait(mod, info, name); |
2276 | /* Ok if resolved. */ |
2277 | if (ksym && !IS_ERR(ksym)) { |
2278 | sym[i].st_value = kernel_symbol_value(ksym); |
2279 | break; |
2280 | } |
2281 | |
2282 | /* Ok if weak. */ |
2283 | if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK) |
2284 | break; |
2285 | |
2286 | ret = PTR_ERR(ksym) ?: -ENOENT; |
2287 | pr_warn("%s: Unknown symbol %s (err %d)\n" , |
2288 | mod->name, name, ret); |
2289 | break; |
2290 | |
2291 | default: |
2292 | /* Divert to percpu allocation if a percpu var. */ |
2293 | if (sym[i].st_shndx == info->index.pcpu) |
2294 | secbase = (unsigned long)mod_percpu(mod); |
2295 | else |
2296 | secbase = info->sechdrs[sym[i].st_shndx].sh_addr; |
2297 | sym[i].st_value += secbase; |
2298 | break; |
2299 | } |
2300 | } |
2301 | |
2302 | return ret; |
2303 | } |
2304 | |
2305 | static int apply_relocations(struct module *mod, const struct load_info *info) |
2306 | { |
2307 | unsigned int i; |
2308 | int err = 0; |
2309 | |
2310 | /* Now do relocations. */ |
2311 | for (i = 1; i < info->hdr->e_shnum; i++) { |
2312 | unsigned int infosec = info->sechdrs[i].sh_info; |
2313 | |
2314 | /* Not a valid relocation section? */ |
2315 | if (infosec >= info->hdr->e_shnum) |
2316 | continue; |
2317 | |
2318 | /* Don't bother with non-allocated sections */ |
2319 | if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC)) |
2320 | continue; |
2321 | |
2322 | /* Livepatch relocation sections are applied by livepatch */ |
2323 | if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH) |
2324 | continue; |
2325 | |
2326 | if (info->sechdrs[i].sh_type == SHT_REL) |
2327 | err = apply_relocate(info->sechdrs, info->strtab, |
2328 | info->index.sym, i, mod); |
2329 | else if (info->sechdrs[i].sh_type == SHT_RELA) |
2330 | err = apply_relocate_add(info->sechdrs, info->strtab, |
2331 | info->index.sym, i, mod); |
2332 | if (err < 0) |
2333 | break; |
2334 | } |
2335 | return err; |
2336 | } |
2337 | |
2338 | /* Additional bytes needed by arch in front of individual sections */ |
2339 | unsigned int __weak arch_mod_section_prepend(struct module *mod, |
2340 | unsigned int section) |
2341 | { |
2342 | /* default implementation just returns zero */ |
2343 | return 0; |
2344 | } |
2345 | |
2346 | /* Update size with this section: return offset. */ |
2347 | static long get_offset(struct module *mod, unsigned int *size, |
2348 | Elf_Shdr *sechdr, unsigned int section) |
2349 | { |
2350 | long ret; |
2351 | |
2352 | *size += arch_mod_section_prepend(mod, section); |
2353 | ret = ALIGN(*size, sechdr->sh_addralign ?: 1); |
2354 | *size = ret + sechdr->sh_size; |
2355 | return ret; |
2356 | } |
2357 | |
2358 | /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld |
2359 | might -- code, read-only data, read-write data, small data. Tally |
2360 | sizes, and place the offsets into sh_entsize fields: high bit means it |
2361 | belongs in init. */ |
2362 | static void layout_sections(struct module *mod, struct load_info *info) |
2363 | { |
2364 | static unsigned long const masks[][2] = { |
2365 | /* NOTE: all executable code must be the first section |
2366 | * in this array; otherwise modify the text_size |
2367 | * finder in the two loops below */ |
2368 | { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL }, |
2369 | { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL }, |
2370 | { SHF_RO_AFTER_INIT | SHF_ALLOC, ARCH_SHF_SMALL }, |
2371 | { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL }, |
2372 | { ARCH_SHF_SMALL | SHF_ALLOC, 0 } |
2373 | }; |
2374 | unsigned int m, i; |
2375 | |
2376 | for (i = 0; i < info->hdr->e_shnum; i++) |
2377 | info->sechdrs[i].sh_entsize = ~0UL; |
2378 | |
2379 | pr_debug("Core section allocation order:\n" ); |
2380 | for (m = 0; m < ARRAY_SIZE(masks); ++m) { |
2381 | for (i = 0; i < info->hdr->e_shnum; ++i) { |
2382 | Elf_Shdr *s = &info->sechdrs[i]; |
2383 | const char *sname = info->secstrings + s->sh_name; |
2384 | |
2385 | if ((s->sh_flags & masks[m][0]) != masks[m][0] |
2386 | || (s->sh_flags & masks[m][1]) |
2387 | || s->sh_entsize != ~0UL |
2388 | || strstarts(sname, ".init" )) |
2389 | continue; |
2390 | s->sh_entsize = get_offset(mod, &mod->core_layout.size, s, i); |
2391 | pr_debug("\t%s\n" , sname); |
2392 | } |
2393 | switch (m) { |
2394 | case 0: /* executable */ |
2395 | mod->core_layout.size = debug_align(mod->core_layout.size); |
2396 | mod->core_layout.text_size = mod->core_layout.size; |
2397 | break; |
2398 | case 1: /* RO: text and ro-data */ |
2399 | mod->core_layout.size = debug_align(mod->core_layout.size); |
2400 | mod->core_layout.ro_size = mod->core_layout.size; |
2401 | break; |
2402 | case 2: /* RO after init */ |
2403 | mod->core_layout.size = debug_align(mod->core_layout.size); |
2404 | mod->core_layout.ro_after_init_size = mod->core_layout.size; |
2405 | break; |
2406 | case 4: /* whole core */ |
2407 | mod->core_layout.size = debug_align(mod->core_layout.size); |
2408 | break; |
2409 | } |
2410 | } |
2411 | |
2412 | pr_debug("Init section allocation order:\n" ); |
2413 | for (m = 0; m < ARRAY_SIZE(masks); ++m) { |
2414 | for (i = 0; i < info->hdr->e_shnum; ++i) { |
2415 | Elf_Shdr *s = &info->sechdrs[i]; |
2416 | const char *sname = info->secstrings + s->sh_name; |
2417 | |
2418 | if ((s->sh_flags & masks[m][0]) != masks[m][0] |
2419 | || (s->sh_flags & masks[m][1]) |
2420 | || s->sh_entsize != ~0UL |
2421 | || !strstarts(sname, ".init" )) |
2422 | continue; |
2423 | s->sh_entsize = (get_offset(mod, &mod->init_layout.size, s, i) |
2424 | | INIT_OFFSET_MASK); |
2425 | pr_debug("\t%s\n" , sname); |
2426 | } |
2427 | switch (m) { |
2428 | case 0: /* executable */ |
2429 | mod->init_layout.size = debug_align(mod->init_layout.size); |
2430 | mod->init_layout.text_size = mod->init_layout.size; |
2431 | break; |
2432 | case 1: /* RO: text and ro-data */ |
2433 | mod->init_layout.size = debug_align(mod->init_layout.size); |
2434 | mod->init_layout.ro_size = mod->init_layout.size; |
2435 | break; |
2436 | case 2: |
2437 | /* |
2438 | * RO after init doesn't apply to init_layout (only |
2439 | * core_layout), so it just takes the value of ro_size. |
2440 | */ |
2441 | mod->init_layout.ro_after_init_size = mod->init_layout.ro_size; |
2442 | break; |
2443 | case 4: /* whole init */ |
2444 | mod->init_layout.size = debug_align(mod->init_layout.size); |
2445 | break; |
2446 | } |
2447 | } |
2448 | } |
2449 | |
2450 | static void set_license(struct module *mod, const char *license) |
2451 | { |
2452 | if (!license) |
2453 | license = "unspecified" ; |
2454 | |
2455 | if (!license_is_gpl_compatible(license)) { |
2456 | if (!test_taint(TAINT_PROPRIETARY_MODULE)) |
2457 | pr_warn("%s: module license '%s' taints kernel.\n" , |
2458 | mod->name, license); |
2459 | add_taint_module(mod, TAINT_PROPRIETARY_MODULE, |
2460 | LOCKDEP_NOW_UNRELIABLE); |
2461 | } |
2462 | } |
2463 | |
2464 | /* Parse tag=value strings from .modinfo section */ |
2465 | static char *next_string(char *string, unsigned long *secsize) |
2466 | { |
2467 | /* Skip non-zero chars */ |
2468 | while (string[0]) { |
2469 | string++; |
2470 | if ((*secsize)-- <= 1) |
2471 | return NULL; |
2472 | } |
2473 | |
2474 | /* Skip any zero padding. */ |
2475 | while (!string[0]) { |
2476 | string++; |
2477 | if ((*secsize)-- <= 1) |
2478 | return NULL; |
2479 | } |
2480 | return string; |
2481 | } |
2482 | |
2483 | static char *get_modinfo(struct load_info *info, const char *tag) |
2484 | { |
2485 | char *p; |
2486 | unsigned int taglen = strlen(tag); |
2487 | Elf_Shdr *infosec = &info->sechdrs[info->index.info]; |
2488 | unsigned long size = infosec->sh_size; |
2489 | |
2490 | /* |
2491 | * get_modinfo() calls made before rewrite_section_headers() |
2492 | * must use sh_offset, as sh_addr isn't set! |
2493 | */ |
2494 | for (p = (char *)info->hdr + infosec->sh_offset; p; p = next_string(p, &size)) { |
2495 | if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=') |
2496 | return p + taglen + 1; |
2497 | } |
2498 | return NULL; |
2499 | } |
2500 | |
2501 | static void setup_modinfo(struct module *mod, struct load_info *info) |
2502 | { |
2503 | struct module_attribute *attr; |
2504 | int i; |
2505 | |
2506 | for (i = 0; (attr = modinfo_attrs[i]); i++) { |
2507 | if (attr->setup) |
2508 | attr->setup(mod, get_modinfo(info, attr->attr.name)); |
2509 | } |
2510 | } |
2511 | |
2512 | static void free_modinfo(struct module *mod) |
2513 | { |
2514 | struct module_attribute *attr; |
2515 | int i; |
2516 | |
2517 | for (i = 0; (attr = modinfo_attrs[i]); i++) { |
2518 | if (attr->free) |
2519 | attr->free(mod); |
2520 | } |
2521 | } |
2522 | |
2523 | #ifdef CONFIG_KALLSYMS |
2524 | |
2525 | /* Lookup exported symbol in given range of kernel_symbols */ |
2526 | static const struct kernel_symbol *lookup_exported_symbol(const char *name, |
2527 | const struct kernel_symbol *start, |
2528 | const struct kernel_symbol *stop) |
2529 | { |
2530 | return bsearch(name, start, stop - start, |
2531 | sizeof(struct kernel_symbol), cmp_name); |
2532 | } |
2533 | |
2534 | static int is_exported(const char *name, unsigned long value, |
2535 | const struct module *mod) |
2536 | { |
2537 | const struct kernel_symbol *ks; |
2538 | if (!mod) |
2539 | ks = lookup_exported_symbol(name, __start___ksymtab, __stop___ksymtab); |
2540 | else |
2541 | ks = lookup_exported_symbol(name, mod->syms, mod->syms + mod->num_syms); |
2542 | |
2543 | return ks != NULL && kernel_symbol_value(ks) == value; |
2544 | } |
2545 | |
2546 | /* As per nm */ |
2547 | static char elf_type(const Elf_Sym *sym, const struct load_info *info) |
2548 | { |
2549 | const Elf_Shdr *sechdrs = info->sechdrs; |
2550 | |
2551 | if (ELF_ST_BIND(sym->st_info) == STB_WEAK) { |
2552 | if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT) |
2553 | return 'v'; |
2554 | else |
2555 | return 'w'; |
2556 | } |
2557 | if (sym->st_shndx == SHN_UNDEF) |
2558 | return 'U'; |
2559 | if (sym->st_shndx == SHN_ABS || sym->st_shndx == info->index.pcpu) |
2560 | return 'a'; |
2561 | if (sym->st_shndx >= SHN_LORESERVE) |
2562 | return '?'; |
2563 | if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR) |
2564 | return 't'; |
2565 | if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC |
2566 | && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) { |
2567 | if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE)) |
2568 | return 'r'; |
2569 | else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL) |
2570 | return 'g'; |
2571 | else |
2572 | return 'd'; |
2573 | } |
2574 | if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) { |
2575 | if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL) |
2576 | return 's'; |
2577 | else |
2578 | return 'b'; |
2579 | } |
2580 | if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name, |
2581 | ".debug" )) { |
2582 | return 'n'; |
2583 | } |
2584 | return '?'; |
2585 | } |
2586 | |
2587 | static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs, |
2588 | unsigned int shnum, unsigned int pcpundx) |
2589 | { |
2590 | const Elf_Shdr *sec; |
2591 | |
2592 | if (src->st_shndx == SHN_UNDEF |
2593 | || src->st_shndx >= shnum |
2594 | || !src->st_name) |
2595 | return false; |
2596 | |
2597 | #ifdef CONFIG_KALLSYMS_ALL |
2598 | if (src->st_shndx == pcpundx) |
2599 | return true; |
2600 | #endif |
2601 | |
2602 | sec = sechdrs + src->st_shndx; |
2603 | if (!(sec->sh_flags & SHF_ALLOC) |
2604 | #ifndef CONFIG_KALLSYMS_ALL |
2605 | || !(sec->sh_flags & SHF_EXECINSTR) |
2606 | #endif |
2607 | || (sec->sh_entsize & INIT_OFFSET_MASK)) |
2608 | return false; |
2609 | |
2610 | return true; |
2611 | } |
2612 | |
2613 | /* |
2614 | * We only allocate and copy the strings needed by the parts of symtab |
2615 | * we keep. This is simple, but has the effect of making multiple |
2616 | * copies of duplicates. We could be more sophisticated, see |
2617 | * linux-kernel thread starting with |
2618 | * <73defb5e4bca04a6431392cc341112b1@localhost>. |
2619 | */ |
2620 | static void layout_symtab(struct module *mod, struct load_info *info) |
2621 | { |
2622 | Elf_Shdr *symsect = info->sechdrs + info->index.sym; |
2623 | Elf_Shdr *strsect = info->sechdrs + info->index.str; |
2624 | const Elf_Sym *src; |
2625 | unsigned int i, nsrc, ndst, strtab_size = 0; |
2626 | |
2627 | /* Put symbol section at end of init part of module. */ |
2628 | symsect->sh_flags |= SHF_ALLOC; |
2629 | symsect->sh_entsize = get_offset(mod, &mod->init_layout.size, symsect, |
2630 | info->index.sym) | INIT_OFFSET_MASK; |
2631 | pr_debug("\t%s\n" , info->secstrings + symsect->sh_name); |
2632 | |
2633 | src = (void *)info->hdr + symsect->sh_offset; |
2634 | nsrc = symsect->sh_size / sizeof(*src); |
2635 | |
2636 | /* Compute total space required for the core symbols' strtab. */ |
2637 | for (ndst = i = 0; i < nsrc; i++) { |
2638 | if (i == 0 || is_livepatch_module(mod) || |
2639 | is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum, |
2640 | info->index.pcpu)) { |
2641 | strtab_size += strlen(&info->strtab[src[i].st_name])+1; |
2642 | ndst++; |
2643 | } |
2644 | } |
2645 | |
2646 | /* Append room for core symbols at end of core part. */ |
2647 | info->symoffs = ALIGN(mod->core_layout.size, symsect->sh_addralign ?: 1); |
2648 | info->stroffs = mod->core_layout.size = info->symoffs + ndst * sizeof(Elf_Sym); |
2649 | mod->core_layout.size += strtab_size; |
2650 | mod->core_layout.size = debug_align(mod->core_layout.size); |
2651 | |
2652 | /* Put string table section at end of init part of module. */ |
2653 | strsect->sh_flags |= SHF_ALLOC; |
2654 | strsect->sh_entsize = get_offset(mod, &mod->init_layout.size, strsect, |
2655 | info->index.str) | INIT_OFFSET_MASK; |
2656 | pr_debug("\t%s\n" , info->secstrings + strsect->sh_name); |
2657 | |
2658 | /* We'll tack temporary mod_kallsyms on the end. */ |
2659 | mod->init_layout.size = ALIGN(mod->init_layout.size, |
2660 | __alignof__(struct mod_kallsyms)); |
2661 | info->mod_kallsyms_init_off = mod->init_layout.size; |
2662 | mod->init_layout.size += sizeof(struct mod_kallsyms); |
2663 | mod->init_layout.size = debug_align(mod->init_layout.size); |
2664 | } |
2665 | |
2666 | /* |
2667 | * We use the full symtab and strtab which layout_symtab arranged to |
2668 | * be appended to the init section. Later we switch to the cut-down |
2669 | * core-only ones. |
2670 | */ |
2671 | static void add_kallsyms(struct module *mod, const struct load_info *info) |
2672 | { |
2673 | unsigned int i, ndst; |
2674 | const Elf_Sym *src; |
2675 | Elf_Sym *dst; |
2676 | char *s; |
2677 | Elf_Shdr *symsec = &info->sechdrs[info->index.sym]; |
2678 | |
2679 | /* Set up to point into init section. */ |
2680 | mod->kallsyms = mod->init_layout.base + info->mod_kallsyms_init_off; |
2681 | |
2682 | mod->kallsyms->symtab = (void *)symsec->sh_addr; |
2683 | mod->kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym); |
2684 | /* Make sure we get permanent strtab: don't use info->strtab. */ |
2685 | mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr; |
2686 | |
2687 | /* Set types up while we still have access to sections. */ |
2688 | for (i = 0; i < mod->kallsyms->num_symtab; i++) |
2689 | mod->kallsyms->symtab[i].st_size |
2690 | = elf_type(&mod->kallsyms->symtab[i], info); |
2691 | |
2692 | /* Now populate the cut down core kallsyms for after init. */ |
2693 | mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs; |
2694 | mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs; |
2695 | src = mod->kallsyms->symtab; |
2696 | for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) { |
2697 | if (i == 0 || is_livepatch_module(mod) || |
2698 | is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum, |
2699 | info->index.pcpu)) { |
2700 | dst[ndst] = src[i]; |
2701 | dst[ndst++].st_name = s - mod->core_kallsyms.strtab; |
2702 | s += strlcpy(s, &mod->kallsyms->strtab[src[i].st_name], |
2703 | KSYM_NAME_LEN) + 1; |
2704 | } |
2705 | } |
2706 | mod->core_kallsyms.num_symtab = ndst; |
2707 | } |
2708 | #else |
2709 | static inline void layout_symtab(struct module *mod, struct load_info *info) |
2710 | { |
2711 | } |
2712 | |
2713 | static void add_kallsyms(struct module *mod, const struct load_info *info) |
2714 | { |
2715 | } |
2716 | #endif /* CONFIG_KALLSYMS */ |
2717 | |
2718 | static void dynamic_debug_setup(struct module *mod, struct _ddebug *debug, unsigned int num) |
2719 | { |
2720 | if (!debug) |
2721 | return; |
2722 | ddebug_add_module(debug, num, mod->name); |
2723 | } |
2724 | |
2725 | static void dynamic_debug_remove(struct module *mod, struct _ddebug *debug) |
2726 | { |
2727 | if (debug) |
2728 | ddebug_remove_module(mod->name); |
2729 | } |
2730 | |
2731 | void * __weak module_alloc(unsigned long size) |
2732 | { |
2733 | return vmalloc_exec(size); |
2734 | } |
2735 | |
2736 | #ifdef CONFIG_DEBUG_KMEMLEAK |
2737 | static void kmemleak_load_module(const struct module *mod, |
2738 | const struct load_info *info) |
2739 | { |
2740 | unsigned int i; |
2741 | |
2742 | /* only scan the sections containing data */ |
2743 | kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL); |
2744 | |
2745 | for (i = 1; i < info->hdr->e_shnum; i++) { |
2746 | /* Scan all writable sections that's not executable */ |
2747 | if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) || |
2748 | !(info->sechdrs[i].sh_flags & SHF_WRITE) || |
2749 | (info->sechdrs[i].sh_flags & SHF_EXECINSTR)) |
2750 | continue; |
2751 | |
2752 | kmemleak_scan_area((void *)info->sechdrs[i].sh_addr, |
2753 | info->sechdrs[i].sh_size, GFP_KERNEL); |
2754 | } |
2755 | } |
2756 | #else |
2757 | static inline void kmemleak_load_module(const struct module *mod, |
2758 | const struct load_info *info) |
2759 | { |
2760 | } |
2761 | #endif |
2762 | |
2763 | #ifdef CONFIG_MODULE_SIG |
2764 | static int module_sig_check(struct load_info *info, int flags) |
2765 | { |
2766 | int err = -ENOKEY; |
2767 | const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1; |
2768 | const void *mod = info->hdr; |
2769 | |
2770 | /* |
2771 | * Require flags == 0, as a module with version information |
2772 | * removed is no longer the module that was signed |
2773 | */ |
2774 | if (flags == 0 && |
2775 | info->len > markerlen && |
2776 | memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) { |
2777 | /* We truncate the module to discard the signature */ |
2778 | info->len -= markerlen; |
2779 | err = mod_verify_sig(mod, info); |
2780 | } |
2781 | |
2782 | if (!err) { |
2783 | info->sig_ok = true; |
2784 | return 0; |
2785 | } |
2786 | |
2787 | /* Not having a signature is only an error if we're strict. */ |
2788 | if (err == -ENOKEY && !is_module_sig_enforced()) |
2789 | err = 0; |
2790 | |
2791 | return err; |
2792 | } |
2793 | #else /* !CONFIG_MODULE_SIG */ |
2794 | static int module_sig_check(struct load_info *info, int flags) |
2795 | { |
2796 | return 0; |
2797 | } |
2798 | #endif /* !CONFIG_MODULE_SIG */ |
2799 | |
2800 | /* Sanity checks against invalid binaries, wrong arch, weird elf version. */ |
2801 | static int (struct load_info *info) |
2802 | { |
2803 | if (info->len < sizeof(*(info->hdr))) |
2804 | return -ENOEXEC; |
2805 | |
2806 | if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0 |
2807 | || info->hdr->e_type != ET_REL |
2808 | || !elf_check_arch(info->hdr) |
2809 | || info->hdr->e_shentsize != sizeof(Elf_Shdr)) |
2810 | return -ENOEXEC; |
2811 | |
2812 | if (info->hdr->e_shoff >= info->len |
2813 | || (info->hdr->e_shnum * sizeof(Elf_Shdr) > |
2814 | info->len - info->hdr->e_shoff)) |
2815 | return -ENOEXEC; |
2816 | |
2817 | return 0; |
2818 | } |
2819 | |
2820 | #define COPY_CHUNK_SIZE (16*PAGE_SIZE) |
2821 | |
2822 | static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len) |
2823 | { |
2824 | do { |
2825 | unsigned long n = min(len, COPY_CHUNK_SIZE); |
2826 | |
2827 | if (copy_from_user(dst, usrc, n) != 0) |
2828 | return -EFAULT; |
2829 | cond_resched(); |
2830 | dst += n; |
2831 | usrc += n; |
2832 | len -= n; |
2833 | } while (len); |
2834 | return 0; |
2835 | } |
2836 | |
2837 | #ifdef CONFIG_LIVEPATCH |
2838 | static int check_modinfo_livepatch(struct module *mod, struct load_info *info) |
2839 | { |
2840 | if (get_modinfo(info, "livepatch" )) { |
2841 | mod->klp = true; |
2842 | add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK); |
2843 | pr_notice_once("%s: tainting kernel with TAINT_LIVEPATCH\n" , |
2844 | mod->name); |
2845 | } |
2846 | |
2847 | return 0; |
2848 | } |
2849 | #else /* !CONFIG_LIVEPATCH */ |
2850 | static int check_modinfo_livepatch(struct module *mod, struct load_info *info) |
2851 | { |
2852 | if (get_modinfo(info, "livepatch" )) { |
2853 | pr_err("%s: module is marked as livepatch module, but livepatch support is disabled" , |
2854 | mod->name); |
2855 | return -ENOEXEC; |
2856 | } |
2857 | |
2858 | return 0; |
2859 | } |
2860 | #endif /* CONFIG_LIVEPATCH */ |
2861 | |
2862 | static void check_modinfo_retpoline(struct module *mod, struct load_info *info) |
2863 | { |
2864 | if (retpoline_module_ok(get_modinfo(info, "retpoline" ))) |
2865 | return; |
2866 | |
2867 | pr_warn("%s: loading module not compiled with retpoline compiler.\n" , |
2868 | mod->name); |
2869 | } |
2870 | |
2871 | /* Sets info->hdr and info->len. */ |
2872 | static int copy_module_from_user(const void __user *umod, unsigned long len, |
2873 | struct load_info *info) |
2874 | { |
2875 | int err; |
2876 | |
2877 | info->len = len; |
2878 | if (info->len < sizeof(*(info->hdr))) |
2879 | return -ENOEXEC; |
2880 | |
2881 | err = security_kernel_load_data(LOADING_MODULE); |
2882 | if (err) |
2883 | return err; |
2884 | |
2885 | /* Suck in entire file: we'll want most of it. */ |
2886 | info->hdr = __vmalloc(info->len, |
2887 | GFP_KERNEL | __GFP_NOWARN, PAGE_KERNEL); |
2888 | if (!info->hdr) |
2889 | return -ENOMEM; |
2890 | |
2891 | if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) { |
2892 | vfree(info->hdr); |
2893 | return -EFAULT; |
2894 | } |
2895 | |
2896 | return 0; |
2897 | } |
2898 | |
2899 | static void free_copy(struct load_info *info) |
2900 | { |
2901 | vfree(info->hdr); |
2902 | } |
2903 | |
2904 | static int (struct load_info *info, int flags) |
2905 | { |
2906 | unsigned int i; |
2907 | |
2908 | /* This should always be true, but let's be sure. */ |
2909 | info->sechdrs[0].sh_addr = 0; |
2910 | |
2911 | for (i = 1; i < info->hdr->e_shnum; i++) { |
2912 | Elf_Shdr *shdr = &info->sechdrs[i]; |
2913 | if (shdr->sh_type != SHT_NOBITS |
2914 | && info->len < shdr->sh_offset + shdr->sh_size) { |
2915 | pr_err("Module len %lu truncated\n" , info->len); |
2916 | return -ENOEXEC; |
2917 | } |
2918 | |
2919 | /* Mark all sections sh_addr with their address in the |
2920 | temporary image. */ |
2921 | shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset; |
2922 | |
2923 | #ifndef CONFIG_MODULE_UNLOAD |
2924 | /* Don't load .exit sections */ |
2925 | if (strstarts(info->secstrings+shdr->sh_name, ".exit" )) |
2926 | shdr->sh_flags &= ~(unsigned long)SHF_ALLOC; |
2927 | #endif |
2928 | } |
2929 | |
2930 | /* Track but don't keep modinfo and version sections. */ |
2931 | info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC; |
2932 | info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC; |
2933 | |
2934 | return 0; |
2935 | } |
2936 | |
2937 | /* |
2938 | * Set up our basic convenience variables (pointers to section headers, |
2939 | * search for module section index etc), and do some basic section |
2940 | * verification. |
2941 | * |
2942 | * Set info->mod to the temporary copy of the module in info->hdr. The final one |
2943 | * will be allocated in move_module(). |
2944 | */ |
2945 | static int setup_load_info(struct load_info *info, int flags) |
2946 | { |
2947 | unsigned int i; |
2948 | |
2949 | /* Set up the convenience variables */ |
2950 | info->sechdrs = (void *)info->hdr + info->hdr->e_shoff; |
2951 | info->secstrings = (void *)info->hdr |
2952 | + info->sechdrs[info->hdr->e_shstrndx].sh_offset; |
2953 | |
2954 | /* Try to find a name early so we can log errors with a module name */ |
2955 | info->index.info = find_sec(info, ".modinfo" ); |
2956 | if (!info->index.info) |
2957 | info->name = "(missing .modinfo section)" ; |
2958 | else |
2959 | info->name = get_modinfo(info, "name" ); |
2960 | |
2961 | /* Find internal symbols and strings. */ |
2962 | for (i = 1; i < info->hdr->e_shnum; i++) { |
2963 | if (info->sechdrs[i].sh_type == SHT_SYMTAB) { |
2964 | info->index.sym = i; |
2965 | info->index.str = info->sechdrs[i].sh_link; |
2966 | info->strtab = (char *)info->hdr |
2967 | + info->sechdrs[info->index.str].sh_offset; |
2968 | break; |
2969 | } |
2970 | } |
2971 | |
2972 | if (info->index.sym == 0) { |
2973 | pr_warn("%s: module has no symbols (stripped?)\n" , info->name); |
2974 | return -ENOEXEC; |
2975 | } |
2976 | |
2977 | info->index.mod = find_sec(info, ".gnu.linkonce.this_module" ); |
2978 | if (!info->index.mod) { |
2979 | pr_warn("%s: No module found in object\n" , |
2980 | info->name ?: "(missing .modinfo name field)" ); |
2981 | return -ENOEXEC; |
2982 | } |
2983 | /* This is temporary: point mod into copy of data. */ |
2984 | info->mod = (void *)info->hdr + info->sechdrs[info->index.mod].sh_offset; |
2985 | |
2986 | /* |
2987 | * If we didn't load the .modinfo 'name' field earlier, fall back to |
2988 | * on-disk struct mod 'name' field. |
2989 | */ |
2990 | if (!info->name) |
2991 | info->name = info->mod->name; |
2992 | |
2993 | if (flags & MODULE_INIT_IGNORE_MODVERSIONS) |
2994 | info->index.vers = 0; /* Pretend no __versions section! */ |
2995 | else |
2996 | info->index.vers = find_sec(info, "__versions" ); |
2997 | |
2998 | info->index.pcpu = find_pcpusec(info); |
2999 | |
3000 | return 0; |
3001 | } |
3002 | |
3003 | static int check_modinfo(struct module *mod, struct load_info *info, int flags) |
3004 | { |
3005 | const char *modmagic = get_modinfo(info, "vermagic" ); |
3006 | int err; |
3007 | |
3008 | if (flags & MODULE_INIT_IGNORE_VERMAGIC) |
3009 | modmagic = NULL; |
3010 | |
3011 | /* This is allowed: modprobe --force will invalidate it. */ |
3012 | if (!modmagic) { |
3013 | err = try_to_force_load(mod, "bad vermagic" ); |
3014 | if (err) |
3015 | return err; |
3016 | } else if (!same_magic(modmagic, vermagic, info->index.vers)) { |
3017 | pr_err("%s: version magic '%s' should be '%s'\n" , |
3018 | info->name, modmagic, vermagic); |
3019 | return -ENOEXEC; |
3020 | } |
3021 | |
3022 | if (!get_modinfo(info, "intree" )) { |
3023 | if (!test_taint(TAINT_OOT_MODULE)) |
3024 | pr_warn("%s: loading out-of-tree module taints kernel.\n" , |
3025 | mod->name); |
3026 | add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK); |
3027 | } |
3028 | |
3029 | check_modinfo_retpoline(mod, info); |
3030 | |
3031 | if (get_modinfo(info, "staging" )) { |
3032 | add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK); |
3033 | pr_warn("%s: module is from the staging directory, the quality " |
3034 | "is unknown, you have been warned.\n" , mod->name); |
3035 | } |
3036 | |
3037 | err = check_modinfo_livepatch(mod, info); |
3038 | if (err) |
3039 | return err; |
3040 | |
3041 | /* Set up license info based on the info section */ |
3042 | set_license(mod, get_modinfo(info, "license" )); |
3043 | |
3044 | return 0; |
3045 | } |
3046 | |
3047 | static int find_module_sections(struct module *mod, struct load_info *info) |
3048 | { |
3049 | mod->kp = section_objs(info, "__param" , |
3050 | sizeof(*mod->kp), &mod->num_kp); |
3051 | mod->syms = section_objs(info, "__ksymtab" , |
3052 | sizeof(*mod->syms), &mod->num_syms); |
3053 | mod->crcs = section_addr(info, "__kcrctab" ); |
3054 | mod->gpl_syms = section_objs(info, "__ksymtab_gpl" , |
3055 | sizeof(*mod->gpl_syms), |
3056 | &mod->num_gpl_syms); |
3057 | mod->gpl_crcs = section_addr(info, "__kcrctab_gpl" ); |
3058 | mod->gpl_future_syms = section_objs(info, |
3059 | "__ksymtab_gpl_future" , |
3060 | sizeof(*mod->gpl_future_syms), |
3061 | &mod->num_gpl_future_syms); |
3062 | mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future" ); |
3063 | |
3064 | #ifdef CONFIG_UNUSED_SYMBOLS |
3065 | mod->unused_syms = section_objs(info, "__ksymtab_unused" , |
3066 | sizeof(*mod->unused_syms), |
3067 | &mod->num_unused_syms); |
3068 | mod->unused_crcs = section_addr(info, "__kcrctab_unused" ); |
3069 | mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl" , |
3070 | sizeof(*mod->unused_gpl_syms), |
3071 | &mod->num_unused_gpl_syms); |
3072 | mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl" ); |
3073 | #endif |
3074 | #ifdef CONFIG_CONSTRUCTORS |
3075 | mod->ctors = section_objs(info, ".ctors" , |
3076 | sizeof(*mod->ctors), &mod->num_ctors); |
3077 | if (!mod->ctors) |
3078 | mod->ctors = section_objs(info, ".init_array" , |
3079 | sizeof(*mod->ctors), &mod->num_ctors); |
3080 | else if (find_sec(info, ".init_array" )) { |
3081 | /* |
3082 | * This shouldn't happen with same compiler and binutils |
3083 | * building all parts of the module. |
3084 | */ |
3085 | pr_warn("%s: has both .ctors and .init_array.\n" , |
3086 | mod->name); |
3087 | return -EINVAL; |
3088 | } |
3089 | #endif |
3090 | |
3091 | #ifdef CONFIG_TRACEPOINTS |
3092 | mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs" , |
3093 | sizeof(*mod->tracepoints_ptrs), |
3094 | &mod->num_tracepoints); |
3095 | #endif |
3096 | #ifdef CONFIG_BPF_EVENTS |
3097 | mod->bpf_raw_events = section_objs(info, "__bpf_raw_tp_map" , |
3098 | sizeof(*mod->bpf_raw_events), |
3099 | &mod->num_bpf_raw_events); |
3100 | #endif |
3101 | #ifdef CONFIG_JUMP_LABEL |
3102 | mod->jump_entries = section_objs(info, "__jump_table" , |
3103 | sizeof(*mod->jump_entries), |
3104 | &mod->num_jump_entries); |
3105 | #endif |
3106 | #ifdef CONFIG_EVENT_TRACING |
3107 | mod->trace_events = section_objs(info, "_ftrace_events" , |
3108 | sizeof(*mod->trace_events), |
3109 | &mod->num_trace_events); |
3110 | mod->trace_evals = section_objs(info, "_ftrace_eval_map" , |
3111 | sizeof(*mod->trace_evals), |
3112 | &mod->num_trace_evals); |
3113 | #endif |
3114 | #ifdef CONFIG_TRACING |
3115 | mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt" , |
3116 | sizeof(*mod->trace_bprintk_fmt_start), |
3117 | &mod->num_trace_bprintk_fmt); |
3118 | #endif |
3119 | #ifdef CONFIG_FTRACE_MCOUNT_RECORD |
3120 | /* sechdrs[0].sh_size is always zero */ |
3121 | mod->ftrace_callsites = section_objs(info, "__mcount_loc" , |
3122 | sizeof(*mod->ftrace_callsites), |
3123 | &mod->num_ftrace_callsites); |
3124 | #endif |
3125 | #ifdef CONFIG_FUNCTION_ERROR_INJECTION |
3126 | mod->ei_funcs = section_objs(info, "_error_injection_whitelist" , |
3127 | sizeof(*mod->ei_funcs), |
3128 | &mod->num_ei_funcs); |
3129 | #endif |
3130 | mod->extable = section_objs(info, "__ex_table" , |
3131 | sizeof(*mod->extable), &mod->num_exentries); |
3132 | |
3133 | if (section_addr(info, "__obsparm" )) |
3134 | pr_warn("%s: Ignoring obsolete parameters\n" , mod->name); |
3135 | |
3136 | info->debug = section_objs(info, "__verbose" , |
3137 | sizeof(*info->debug), &info->num_debug); |
3138 | |
3139 | return 0; |
3140 | } |
3141 | |
3142 | static int move_module(struct module *mod, struct load_info *info) |
3143 | { |
3144 | int i; |
3145 | void *ptr; |
3146 | |
3147 | /* Do the allocs. */ |
3148 | ptr = module_alloc(mod->core_layout.size); |
3149 | /* |
3150 | * The pointer to this block is stored in the module structure |
3151 | * which is inside the block. Just mark it as not being a |
3152 | * leak. |
3153 | */ |
3154 | kmemleak_not_leak(ptr); |
3155 | if (!ptr) |
3156 | return -ENOMEM; |
3157 | |
3158 | memset(ptr, 0, mod->core_layout.size); |
3159 | mod->core_layout.base = ptr; |
3160 | |
3161 | if (mod->init_layout.size) { |
3162 | ptr = module_alloc(mod->init_layout.size); |
3163 | /* |
3164 | * The pointer to this block is stored in the module structure |
3165 | * which is inside the block. This block doesn't need to be |
3166 | * scanned as it contains data and code that will be freed |
3167 | * after the module is initialized. |
3168 | */ |
3169 | kmemleak_ignore(ptr); |
3170 | if (!ptr) { |
3171 | module_memfree(mod->core_layout.base); |
3172 | return -ENOMEM; |
3173 | } |
3174 | memset(ptr, 0, mod->init_layout.size); |
3175 | mod->init_layout.base = ptr; |
3176 | } else |
3177 | mod->init_layout.base = NULL; |
3178 | |
3179 | /* Transfer each section which specifies SHF_ALLOC */ |
3180 | pr_debug("final section addresses:\n" ); |
3181 | for (i = 0; i < info->hdr->e_shnum; i++) { |
3182 | void *dest; |
3183 | Elf_Shdr *shdr = &info->sechdrs[i]; |
3184 | |
3185 | if (!(shdr->sh_flags & SHF_ALLOC)) |
3186 | continue; |
3187 | |
3188 | if (shdr->sh_entsize & INIT_OFFSET_MASK) |
3189 | dest = mod->init_layout.base |
3190 | + (shdr->sh_entsize & ~INIT_OFFSET_MASK); |
3191 | else |
3192 | dest = mod->core_layout.base + shdr->sh_entsize; |
3193 | |
3194 | if (shdr->sh_type != SHT_NOBITS) |
3195 | memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size); |
3196 | /* Update sh_addr to point to copy in image. */ |
3197 | shdr->sh_addr = (unsigned long)dest; |
3198 | pr_debug("\t0x%lx %s\n" , |
3199 | (long)shdr->sh_addr, info->secstrings + shdr->sh_name); |
3200 | } |
3201 | |
3202 | return 0; |
3203 | } |
3204 | |
3205 | static int check_module_license_and_versions(struct module *mod) |
3206 | { |
3207 | int prev_taint = test_taint(TAINT_PROPRIETARY_MODULE); |
3208 | |
3209 | /* |
3210 | * ndiswrapper is under GPL by itself, but loads proprietary modules. |
3211 | * Don't use add_taint_module(), as it would prevent ndiswrapper from |
3212 | * using GPL-only symbols it needs. |
3213 | */ |
3214 | if (strcmp(mod->name, "ndiswrapper" ) == 0) |
3215 | add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE); |
3216 | |
3217 | /* driverloader was caught wrongly pretending to be under GPL */ |
3218 | if (strcmp(mod->name, "driverloader" ) == 0) |
3219 | add_taint_module(mod, TAINT_PROPRIETARY_MODULE, |
3220 | LOCKDEP_NOW_UNRELIABLE); |
3221 | |
3222 | /* lve claims to be GPL but upstream won't provide source */ |
3223 | if (strcmp(mod->name, "lve" ) == 0) |
3224 | add_taint_module(mod, TAINT_PROPRIETARY_MODULE, |
3225 | LOCKDEP_NOW_UNRELIABLE); |
3226 | |
3227 | if (!prev_taint && test_taint(TAINT_PROPRIETARY_MODULE)) |
3228 | pr_warn("%s: module license taints kernel.\n" , mod->name); |
3229 | |
3230 | #ifdef CONFIG_MODVERSIONS |
3231 | if ((mod->num_syms && !mod->crcs) |
3232 | || (mod->num_gpl_syms && !mod->gpl_crcs) |
3233 | || (mod->num_gpl_future_syms && !mod->gpl_future_crcs) |
3234 | #ifdef CONFIG_UNUSED_SYMBOLS |
3235 | || (mod->num_unused_syms && !mod->unused_crcs) |
3236 | || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs) |
3237 | #endif |
3238 | ) { |
3239 | return try_to_force_load(mod, |
3240 | "no versions for exported symbols" ); |
3241 | } |
3242 | #endif |
3243 | return 0; |
3244 | } |
3245 | |
3246 | static void flush_module_icache(const struct module *mod) |
3247 | { |
3248 | mm_segment_t old_fs; |
3249 | |
3250 | /* flush the icache in correct context */ |
3251 | old_fs = get_fs(); |
3252 | set_fs(KERNEL_DS); |
3253 | |
3254 | /* |
3255 | * Flush the instruction cache, since we've played with text. |
3256 | * Do it before processing of module parameters, so the module |
3257 | * can provide parameter accessor functions of its own. |
3258 | */ |
3259 | if (mod->init_layout.base) |
3260 | flush_icache_range((unsigned long)mod->init_layout.base, |
3261 | (unsigned long)mod->init_layout.base |
3262 | + mod->init_layout.size); |
3263 | flush_icache_range((unsigned long)mod->core_layout.base, |
3264 | (unsigned long)mod->core_layout.base + mod->core_layout.size); |
3265 | |
3266 | set_fs(old_fs); |
3267 | } |
3268 | |
3269 | int __weak module_frob_arch_sections(Elf_Ehdr *hdr, |
3270 | Elf_Shdr *sechdrs, |
3271 | char *secstrings, |
3272 | struct module *mod) |
3273 | { |
3274 | return 0; |
3275 | } |
3276 | |
3277 | /* module_blacklist is a comma-separated list of module names */ |
3278 | static char *module_blacklist; |
3279 | static bool blacklisted(const char *module_name) |
3280 | { |
3281 | const char *p; |
3282 | size_t len; |
3283 | |
3284 | if (!module_blacklist) |
3285 | return false; |
3286 | |
3287 | for (p = module_blacklist; *p; p += len) { |
3288 | len = strcspn(p, "," ); |
3289 | if (strlen(module_name) == len && !memcmp(module_name, p, len)) |
3290 | return true; |
3291 | if (p[len] == ',') |
3292 | len++; |
3293 | } |
3294 | return false; |
3295 | } |
3296 | core_param(module_blacklist, module_blacklist, charp, 0400); |
3297 | |
3298 | static struct module *layout_and_allocate(struct load_info *info, int flags) |
3299 | { |
3300 | struct module *mod; |
3301 | unsigned int ndx; |
3302 | int err; |
3303 | |
3304 | err = check_modinfo(info->mod, info, flags); |
3305 | if (err) |
3306 | return ERR_PTR(err); |
3307 | |
3308 | /* Allow arches to frob section contents and sizes. */ |
3309 | err = module_frob_arch_sections(info->hdr, info->sechdrs, |
3310 | info->secstrings, info->mod); |
3311 | if (err < 0) |
3312 | return ERR_PTR(err); |
3313 | |
3314 | /* We will do a special allocation for per-cpu sections later. */ |
3315 | info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC; |
3316 | |
3317 | /* |
3318 | * Mark ro_after_init section with SHF_RO_AFTER_INIT so that |
3319 | * layout_sections() can put it in the right place. |
3320 | * Note: ro_after_init sections also have SHF_{WRITE,ALLOC} set. |
3321 | */ |
3322 | ndx = find_sec(info, ".data..ro_after_init" ); |
3323 | if (ndx) |
3324 | info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT; |
3325 | /* |
3326 | * Mark the __jump_table section as ro_after_init as well: these data |
3327 | * structures are never modified, with the exception of entries that |
3328 | * refer to code in the __init section, which are annotated as such |
3329 | * at module load time. |
3330 | */ |
3331 | ndx = find_sec(info, "__jump_table" ); |
3332 | if (ndx) |
3333 | info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT; |
3334 | |
3335 | /* Determine total sizes, and put offsets in sh_entsize. For now |
3336 | this is done generically; there doesn't appear to be any |
3337 | special cases for the architectures. */ |
3338 | layout_sections(info->mod, info); |
3339 | layout_symtab(info->mod, info); |
3340 | |
3341 | /* Allocate and move to the final place */ |
3342 | err = move_module(info->mod, info); |
3343 | if (err) |
3344 | return ERR_PTR(err); |
3345 | |
3346 | /* Module has been copied to its final place now: return it. */ |
3347 | mod = (void *)info->sechdrs[info->index.mod].sh_addr; |
3348 | kmemleak_load_module(mod, info); |
3349 | return mod; |
3350 | } |
3351 | |
3352 | /* mod is no longer valid after this! */ |
3353 | static void module_deallocate(struct module *mod, struct load_info *info) |
3354 | { |
3355 | percpu_modfree(mod); |
3356 | module_arch_freeing_init(mod); |
3357 | module_memfree(mod->init_layout.base); |
3358 | module_memfree(mod->core_layout.base); |
3359 | } |
3360 | |
3361 | int __weak module_finalize(const Elf_Ehdr *hdr, |
3362 | const Elf_Shdr *sechdrs, |
3363 | struct module *me) |
3364 | { |
3365 | return 0; |
3366 | } |
3367 | |
3368 | static int post_relocation(struct module *mod, const struct load_info *info) |
3369 | { |
3370 | /* Sort exception table now relocations are done. */ |
3371 | sort_extable(mod->extable, mod->extable + mod->num_exentries); |
3372 | |
3373 | /* Copy relocated percpu area over. */ |
3374 | percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr, |
3375 | info->sechdrs[info->index.pcpu].sh_size); |
3376 | |
3377 | /* Setup kallsyms-specific fields. */ |
3378 | add_kallsyms(mod, info); |
3379 | |
3380 | /* Arch-specific module finalizing. */ |
3381 | return module_finalize(info->hdr, info->sechdrs, mod); |
3382 | } |
3383 | |
3384 | /* Is this module of this name done loading? No locks held. */ |
3385 | static bool finished_loading(const char *name) |
3386 | { |
3387 | struct module *mod; |
3388 | bool ret; |
3389 | |
3390 | /* |
3391 | * The module_mutex should not be a heavily contended lock; |
3392 | * if we get the occasional sleep here, we'll go an extra iteration |
3393 | * in the wait_event_interruptible(), which is harmless. |
3394 | */ |
3395 | |
---|