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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/moduleloader.h> | |
21 | #include <linux/trace_events.h> | |
22 | #include <linux/init.h> | |
23 | #include <linux/kallsyms.h> | |
24 | #include <linux/file.h> | |
25 | #include <linux/fs.h> | |
26 | #include <linux/sysfs.h> | |
27 | #include <linux/kernel.h> | |
28 | #include <linux/slab.h> | |
29 | #include <linux/vmalloc.h> | |
30 | #include <linux/elf.h> | |
31 | #include <linux/proc_fs.h> | |
32 | #include <linux/security.h> | |
33 | #include <linux/seq_file.h> | |
34 | #include <linux/syscalls.h> | |
35 | #include <linux/fcntl.h> | |
36 | #include <linux/rcupdate.h> | |
37 | #include <linux/capability.h> | |
38 | #include <linux/cpu.h> | |
39 | #include <linux/moduleparam.h> | |
40 | #include <linux/errno.h> | |
41 | #include <linux/err.h> | |
42 | #include <linux/vermagic.h> | |
43 | #include <linux/notifier.h> | |
44 | #include <linux/sched.h> | |
45 | #include <linux/device.h> | |
46 | #include <linux/string.h> | |
47 | #include <linux/mutex.h> | |
48 | #include <linux/rculist.h> | |
49 | #include <linux/uaccess.h> | |
50 | #include <asm/cacheflush.h> | |
51 | #include <asm/mmu_context.h> | |
52 | #include <linux/license.h> | |
53 | #include <asm/sections.h> | |
54 | #include <linux/tracepoint.h> | |
55 | #include <linux/ftrace.h> | |
56 | #include <linux/livepatch.h> | |
57 | #include <linux/async.h> | |
58 | #include <linux/percpu.h> | |
59 | #include <linux/kmemleak.h> | |
60 | #include <linux/jump_label.h> | |
61 | #include <linux/pfn.h> | |
62 | #include <linux/bsearch.h> | |
63 | #include <linux/dynamic_debug.h> | |
64 | #include <uapi/linux/module.h> | |
65 | #include "module-internal.h" | |
66 | ||
67 | #define CREATE_TRACE_POINTS | |
68 | #include <trace/events/module.h> | |
69 | ||
70 | #ifndef ARCH_SHF_SMALL | |
71 | #define ARCH_SHF_SMALL 0 | |
72 | #endif | |
73 | ||
74 | /* | |
75 | * Modules' sections will be aligned on page boundaries | |
76 | * to ensure complete separation of code and data, but | |
77 | * only when CONFIG_DEBUG_SET_MODULE_RONX=y | |
78 | */ | |
79 | #ifdef CONFIG_DEBUG_SET_MODULE_RONX | |
80 | # define debug_align(X) ALIGN(X, PAGE_SIZE) | |
81 | #else | |
82 | # define debug_align(X) (X) | |
83 | #endif | |
84 | ||
85 | /* If this is set, the section belongs in the init part of the module */ | |
86 | #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1)) | |
87 | ||
88 | /* | |
89 | * Mutex protects: | |
90 | * 1) List of modules (also safely readable with preempt_disable), | |
91 | * 2) module_use links, | |
92 | * 3) module_addr_min/module_addr_max. | |
93 | * (delete and add uses RCU list operations). */ | |
94 | DEFINE_MUTEX(module_mutex); | |
95 | EXPORT_SYMBOL_GPL(module_mutex); | |
96 | static LIST_HEAD(modules); | |
97 | ||
98 | #ifdef CONFIG_MODULES_TREE_LOOKUP | |
99 | ||
100 | /* | |
101 | * Use a latched RB-tree for __module_address(); this allows us to use | |
102 | * RCU-sched lookups of the address from any context. | |
103 | * | |
104 | * This is conditional on PERF_EVENTS || TRACING because those can really hit | |
105 | * __module_address() hard by doing a lot of stack unwinding; potentially from | |
106 | * NMI context. | |
107 | */ | |
108 | ||
109 | static __always_inline unsigned long __mod_tree_val(struct latch_tree_node *n) | |
110 | { | |
111 | struct module_layout *layout = container_of(n, struct module_layout, mtn.node); | |
112 | ||
113 | return (unsigned long)layout->base; | |
114 | } | |
115 | ||
116 | static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n) | |
117 | { | |
118 | struct module_layout *layout = container_of(n, struct module_layout, mtn.node); | |
119 | ||
120 | return (unsigned long)layout->size; | |
121 | } | |
122 | ||
123 | static __always_inline bool | |
124 | mod_tree_less(struct latch_tree_node *a, struct latch_tree_node *b) | |
125 | { | |
126 | return __mod_tree_val(a) < __mod_tree_val(b); | |
127 | } | |
128 | ||
129 | static __always_inline int | |
130 | mod_tree_comp(void *key, struct latch_tree_node *n) | |
131 | { | |
132 | unsigned long val = (unsigned long)key; | |
133 | unsigned long start, end; | |
134 | ||
135 | start = __mod_tree_val(n); | |
136 | if (val < start) | |
137 | return -1; | |
138 | ||
139 | end = start + __mod_tree_size(n); | |
140 | if (val >= end) | |
141 | return 1; | |
142 | ||
143 | return 0; | |
144 | } | |
145 | ||
146 | static const struct latch_tree_ops mod_tree_ops = { | |
147 | .less = mod_tree_less, | |
148 | .comp = mod_tree_comp, | |
149 | }; | |
150 | ||
151 | static struct mod_tree_root { | |
152 | struct latch_tree_root root; | |
153 | unsigned long addr_min; | |
154 | unsigned long addr_max; | |
155 | } mod_tree __cacheline_aligned = { | |
156 | .addr_min = -1UL, | |
157 | }; | |
158 | ||
159 | #define module_addr_min mod_tree.addr_min | |
160 | #define module_addr_max mod_tree.addr_max | |
161 | ||
162 | static noinline void __mod_tree_insert(struct mod_tree_node *node) | |
163 | { | |
164 | latch_tree_insert(&node->node, &mod_tree.root, &mod_tree_ops); | |
165 | } | |
166 | ||
167 | static void __mod_tree_remove(struct mod_tree_node *node) | |
168 | { | |
169 | latch_tree_erase(&node->node, &mod_tree.root, &mod_tree_ops); | |
170 | } | |
171 | ||
172 | /* | |
173 | * These modifications: insert, remove_init and remove; are serialized by the | |
174 | * module_mutex. | |
175 | */ | |
176 | static void mod_tree_insert(struct module *mod) | |
177 | { | |
178 | mod->core_layout.mtn.mod = mod; | |
179 | mod->init_layout.mtn.mod = mod; | |
180 | ||
181 | __mod_tree_insert(&mod->core_layout.mtn); | |
182 | if (mod->init_layout.size) | |
183 | __mod_tree_insert(&mod->init_layout.mtn); | |
184 | } | |
185 | ||
186 | static void mod_tree_remove_init(struct module *mod) | |
187 | { | |
188 | if (mod->init_layout.size) | |
189 | __mod_tree_remove(&mod->init_layout.mtn); | |
190 | } | |
191 | ||
192 | static void mod_tree_remove(struct module *mod) | |
193 | { | |
194 | __mod_tree_remove(&mod->core_layout.mtn); | |
195 | mod_tree_remove_init(mod); | |
196 | } | |
197 | ||
198 | static struct module *mod_find(unsigned long addr) | |
199 | { | |
200 | struct latch_tree_node *ltn; | |
201 | ||
202 | ltn = latch_tree_find((void *)addr, &mod_tree.root, &mod_tree_ops); | |
203 | if (!ltn) | |
204 | return NULL; | |
205 | ||
206 | return container_of(ltn, struct mod_tree_node, node)->mod; | |
207 | } | |
208 | ||
209 | #else /* MODULES_TREE_LOOKUP */ | |
210 | ||
211 | static unsigned long module_addr_min = -1UL, module_addr_max = 0; | |
212 | ||
213 | static void mod_tree_insert(struct module *mod) { } | |
214 | static void mod_tree_remove_init(struct module *mod) { } | |
215 | static void mod_tree_remove(struct module *mod) { } | |
216 | ||
217 | static struct module *mod_find(unsigned long addr) | |
218 | { | |
219 | struct module *mod; | |
220 | ||
221 | list_for_each_entry_rcu(mod, &modules, list) { | |
222 | if (within_module(addr, mod)) | |
223 | return mod; | |
224 | } | |
225 | ||
226 | return NULL; | |
227 | } | |
228 | ||
229 | #endif /* MODULES_TREE_LOOKUP */ | |
230 | ||
231 | /* | |
232 | * Bounds of module text, for speeding up __module_address. | |
233 | * Protected by module_mutex. | |
234 | */ | |
235 | static void __mod_update_bounds(void *base, unsigned int size) | |
236 | { | |
237 | unsigned long min = (unsigned long)base; | |
238 | unsigned long max = min + size; | |
239 | ||
240 | if (min < module_addr_min) | |
241 | module_addr_min = min; | |
242 | if (max > module_addr_max) | |
243 | module_addr_max = max; | |
244 | } | |
245 | ||
246 | static void mod_update_bounds(struct module *mod) | |
247 | { | |
248 | __mod_update_bounds(mod->core_layout.base, mod->core_layout.size); | |
249 | if (mod->init_layout.size) | |
250 | __mod_update_bounds(mod->init_layout.base, mod->init_layout.size); | |
251 | } | |
252 | ||
253 | #ifdef CONFIG_KGDB_KDB | |
254 | struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */ | |
255 | #endif /* CONFIG_KGDB_KDB */ | |
256 | ||
257 | static void module_assert_mutex(void) | |
258 | { | |
259 | lockdep_assert_held(&module_mutex); | |
260 | } | |
261 | ||
262 | static void module_assert_mutex_or_preempt(void) | |
263 | { | |
264 | #ifdef CONFIG_LOCKDEP | |
265 | if (unlikely(!debug_locks)) | |
266 | return; | |
267 | ||
268 | WARN_ON_ONCE(!rcu_read_lock_sched_held() && | |
269 | !lockdep_is_held(&module_mutex)); | |
270 | #endif | |
271 | } | |
272 | ||
273 | static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE); | |
274 | #ifndef CONFIG_MODULE_SIG_FORCE | |
275 | module_param(sig_enforce, bool_enable_only, 0644); | |
276 | #endif /* !CONFIG_MODULE_SIG_FORCE */ | |
277 | ||
278 | /* Block module loading/unloading? */ | |
279 | int modules_disabled = 0; | |
280 | core_param(nomodule, modules_disabled, bint, 0); | |
281 | ||
282 | /* Waiting for a module to finish initializing? */ | |
283 | static DECLARE_WAIT_QUEUE_HEAD(module_wq); | |
284 | ||
285 | static BLOCKING_NOTIFIER_HEAD(module_notify_list); | |
286 | ||
287 | int register_module_notifier(struct notifier_block *nb) | |
288 | { | |
289 | return blocking_notifier_chain_register(&module_notify_list, nb); | |
290 | } | |
291 | EXPORT_SYMBOL(register_module_notifier); | |
292 | ||
293 | int unregister_module_notifier(struct notifier_block *nb) | |
294 | { | |
295 | return blocking_notifier_chain_unregister(&module_notify_list, nb); | |
296 | } | |
297 | EXPORT_SYMBOL(unregister_module_notifier); | |
298 | ||
299 | struct load_info { | |
300 | Elf_Ehdr *hdr; | |
301 | unsigned long len; | |
302 | Elf_Shdr *sechdrs; | |
303 | char *secstrings, *strtab; | |
304 | unsigned long symoffs, stroffs; | |
305 | struct _ddebug *debug; | |
306 | unsigned int num_debug; | |
307 | bool sig_ok; | |
308 | #ifdef CONFIG_KALLSYMS | |
309 | unsigned long mod_kallsyms_init_off; | |
310 | #endif | |
311 | struct { | |
312 | unsigned int sym, str, mod, vers, info, pcpu; | |
313 | } index; | |
314 | }; | |
315 | ||
316 | /* | |
317 | * We require a truly strong try_module_get(): 0 means success. | |
318 | * Otherwise an error is returned due to ongoing or failed | |
319 | * initialization etc. | |
320 | */ | |
321 | static inline int strong_try_module_get(struct module *mod) | |
322 | { | |
323 | BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED); | |
324 | if (mod && mod->state == MODULE_STATE_COMING) | |
325 | return -EBUSY; | |
326 | if (try_module_get(mod)) | |
327 | return 0; | |
328 | else | |
329 | return -ENOENT; | |
330 | } | |
331 | ||
332 | static inline void add_taint_module(struct module *mod, unsigned flag, | |
333 | enum lockdep_ok lockdep_ok) | |
334 | { | |
335 | add_taint(flag, lockdep_ok); | |
336 | set_bit(flag, &mod->taints); | |
337 | } | |
338 | ||
339 | /* | |
340 | * A thread that wants to hold a reference to a module only while it | |
341 | * is running can call this to safely exit. nfsd and lockd use this. | |
342 | */ | |
343 | void __noreturn __module_put_and_exit(struct module *mod, long code) | |
344 | { | |
345 | module_put(mod); | |
346 | do_exit(code); | |
347 | } | |
348 | EXPORT_SYMBOL(__module_put_and_exit); | |
349 | ||
350 | /* Find a module section: 0 means not found. */ | |
351 | static unsigned int find_sec(const struct load_info *info, const char *name) | |
352 | { | |
353 | unsigned int i; | |
354 | ||
355 | for (i = 1; i < info->hdr->e_shnum; i++) { | |
356 | Elf_Shdr *shdr = &info->sechdrs[i]; | |
357 | /* Alloc bit cleared means "ignore it." */ | |
358 | if ((shdr->sh_flags & SHF_ALLOC) | |
359 | && strcmp(info->secstrings + shdr->sh_name, name) == 0) | |
360 | return i; | |
361 | } | |
362 | return 0; | |
363 | } | |
364 | ||
365 | /* Find a module section, or NULL. */ | |
366 | static void *section_addr(const struct load_info *info, const char *name) | |
367 | { | |
368 | /* Section 0 has sh_addr 0. */ | |
369 | return (void *)info->sechdrs[find_sec(info, name)].sh_addr; | |
370 | } | |
371 | ||
372 | /* Find a module section, or NULL. Fill in number of "objects" in section. */ | |
373 | static void *section_objs(const struct load_info *info, | |
374 | const char *name, | |
375 | size_t object_size, | |
376 | unsigned int *num) | |
377 | { | |
378 | unsigned int sec = find_sec(info, name); | |
379 | ||
380 | /* Section 0 has sh_addr 0 and sh_size 0. */ | |
381 | *num = info->sechdrs[sec].sh_size / object_size; | |
382 | return (void *)info->sechdrs[sec].sh_addr; | |
383 | } | |
384 | ||
385 | /* Provided by the linker */ | |
386 | extern const struct kernel_symbol __start___ksymtab[]; | |
387 | extern const struct kernel_symbol __stop___ksymtab[]; | |
388 | extern const struct kernel_symbol __start___ksymtab_gpl[]; | |
389 | extern const struct kernel_symbol __stop___ksymtab_gpl[]; | |
390 | extern const struct kernel_symbol __start___ksymtab_gpl_future[]; | |
391 | extern const struct kernel_symbol __stop___ksymtab_gpl_future[]; | |
392 | extern const s32 __start___kcrctab[]; | |
393 | extern const s32 __start___kcrctab_gpl[]; | |
394 | extern const s32 __start___kcrctab_gpl_future[]; | |
395 | #ifdef CONFIG_UNUSED_SYMBOLS | |
396 | extern const struct kernel_symbol __start___ksymtab_unused[]; | |
397 | extern const struct kernel_symbol __stop___ksymtab_unused[]; | |
398 | extern const struct kernel_symbol __start___ksymtab_unused_gpl[]; | |
399 | extern const struct kernel_symbol __stop___ksymtab_unused_gpl[]; | |
400 | extern const s32 __start___kcrctab_unused[]; | |
401 | extern const s32 __start___kcrctab_unused_gpl[]; | |
402 | #endif | |
403 | ||
404 | #ifndef CONFIG_MODVERSIONS | |
405 | #define symversion(base, idx) NULL | |
406 | #else | |
407 | #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL) | |
408 | #endif | |
409 | ||
410 | static bool each_symbol_in_section(const struct symsearch *arr, | |
411 | unsigned int arrsize, | |
412 | struct module *owner, | |
413 | bool (*fn)(const struct symsearch *syms, | |
414 | struct module *owner, | |
415 | void *data), | |
416 | void *data) | |
417 | { | |
418 | unsigned int j; | |
419 | ||
420 | for (j = 0; j < arrsize; j++) { | |
421 | if (fn(&arr[j], owner, data)) | |
422 | return true; | |
423 | } | |
424 | ||
425 | return false; | |
426 | } | |
427 | ||
428 | /* Returns true as soon as fn returns true, otherwise false. */ | |
429 | bool each_symbol_section(bool (*fn)(const struct symsearch *arr, | |
430 | struct module *owner, | |
431 | void *data), | |
432 | void *data) | |
433 | { | |
434 | struct module *mod; | |
435 | static const struct symsearch arr[] = { | |
436 | { __start___ksymtab, __stop___ksymtab, __start___kcrctab, | |
437 | NOT_GPL_ONLY, false }, | |
438 | { __start___ksymtab_gpl, __stop___ksymtab_gpl, | |
439 | __start___kcrctab_gpl, | |
440 | GPL_ONLY, false }, | |
441 | { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future, | |
442 | __start___kcrctab_gpl_future, | |
443 | WILL_BE_GPL_ONLY, false }, | |
444 | #ifdef CONFIG_UNUSED_SYMBOLS | |
445 | { __start___ksymtab_unused, __stop___ksymtab_unused, | |
446 | __start___kcrctab_unused, | |
447 | NOT_GPL_ONLY, true }, | |
448 | { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl, | |
449 | __start___kcrctab_unused_gpl, | |
450 | GPL_ONLY, true }, | |
451 | #endif | |
452 | }; | |
453 | ||
454 | module_assert_mutex_or_preempt(); | |
455 | ||
456 | if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data)) | |
457 | return true; | |
458 | ||
459 | list_for_each_entry_rcu(mod, &modules, list) { | |
460 | struct symsearch arr[] = { | |
461 | { mod->syms, mod->syms + mod->num_syms, mod->crcs, | |
462 | NOT_GPL_ONLY, false }, | |
463 | { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms, | |
464 | mod->gpl_crcs, | |
465 | GPL_ONLY, false }, | |
466 | { mod->gpl_future_syms, | |
467 | mod->gpl_future_syms + mod->num_gpl_future_syms, | |
468 | mod->gpl_future_crcs, | |
469 | WILL_BE_GPL_ONLY, false }, | |
470 | #ifdef CONFIG_UNUSED_SYMBOLS | |
471 | { mod->unused_syms, | |
472 | mod->unused_syms + mod->num_unused_syms, | |
473 | mod->unused_crcs, | |
474 | NOT_GPL_ONLY, true }, | |
475 | { mod->unused_gpl_syms, | |
476 | mod->unused_gpl_syms + mod->num_unused_gpl_syms, | |
477 | mod->unused_gpl_crcs, | |
478 | GPL_ONLY, true }, | |
479 | #endif | |
480 | }; | |
481 | ||
482 | if (mod->state == MODULE_STATE_UNFORMED) | |
483 | continue; | |
484 | ||
485 | if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data)) | |
486 | return true; | |
487 | } | |
488 | return false; | |
489 | } | |
490 | EXPORT_SYMBOL_GPL(each_symbol_section); | |
491 | ||
492 | struct find_symbol_arg { | |
493 | /* Input */ | |
494 | const char *name; | |
495 | bool gplok; | |
496 | bool warn; | |
497 | ||
498 | /* Output */ | |
499 | struct module *owner; | |
500 | const s32 *crc; | |
501 | const struct kernel_symbol *sym; | |
502 | }; | |
503 | ||
504 | static bool check_symbol(const struct symsearch *syms, | |
505 | struct module *owner, | |
506 | unsigned int symnum, void *data) | |
507 | { | |
508 | struct find_symbol_arg *fsa = data; | |
509 | ||
510 | if (!fsa->gplok) { | |
511 | if (syms->licence == GPL_ONLY) | |
512 | return false; | |
513 | if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) { | |
514 | pr_warn("Symbol %s is being used by a non-GPL module, " | |
515 | "which will not be allowed in the future\n", | |
516 | fsa->name); | |
517 | } | |
518 | } | |
519 | ||
520 | #ifdef CONFIG_UNUSED_SYMBOLS | |
521 | if (syms->unused && fsa->warn) { | |
522 | pr_warn("Symbol %s is marked as UNUSED, however this module is " | |
523 | "using it.\n", fsa->name); | |
524 | pr_warn("This symbol will go away in the future.\n"); | |
525 | pr_warn("Please evaluate if this is the right api to use and " | |
526 | "if it really is, submit a report to the linux kernel " | |
527 | "mailing list together with submitting your code for " | |
528 | "inclusion.\n"); | |
529 | } | |
530 | #endif | |
531 | ||
532 | fsa->owner = owner; | |
533 | fsa->crc = symversion(syms->crcs, symnum); | |
534 | fsa->sym = &syms->start[symnum]; | |
535 | return true; | |
536 | } | |
537 | ||
538 | static int cmp_name(const void *va, const void *vb) | |
539 | { | |
540 | const char *a; | |
541 | const struct kernel_symbol *b; | |
542 | a = va; b = vb; | |
543 | return strcmp(a, b->name); | |
544 | } | |
545 | ||
546 | static bool find_symbol_in_section(const struct symsearch *syms, | |
547 | struct module *owner, | |
548 | void *data) | |
549 | { | |
550 | struct find_symbol_arg *fsa = data; | |
551 | struct kernel_symbol *sym; | |
552 | ||
553 | sym = bsearch(fsa->name, syms->start, syms->stop - syms->start, | |
554 | sizeof(struct kernel_symbol), cmp_name); | |
555 | ||
556 | if (sym != NULL && check_symbol(syms, owner, sym - syms->start, data)) | |
557 | return true; | |
558 | ||
559 | return false; | |
560 | } | |
561 | ||
562 | /* Find a symbol and return it, along with, (optional) crc and | |
563 | * (optional) module which owns it. Needs preempt disabled or module_mutex. */ | |
564 | const struct kernel_symbol *find_symbol(const char *name, | |
565 | struct module **owner, | |
566 | const s32 **crc, | |
567 | bool gplok, | |
568 | bool warn) | |
569 | { | |
570 | struct find_symbol_arg fsa; | |
571 | ||
572 | fsa.name = name; | |
573 | fsa.gplok = gplok; | |
574 | fsa.warn = warn; | |
575 | ||
576 | if (each_symbol_section(find_symbol_in_section, &fsa)) { | |
577 | if (owner) | |
578 | *owner = fsa.owner; | |
579 | if (crc) | |
580 | *crc = fsa.crc; | |
581 | return fsa.sym; | |
582 | } | |
583 | ||
584 | pr_debug("Failed to find symbol %s\n", name); | |
585 | return NULL; | |
586 | } | |
587 | EXPORT_SYMBOL_GPL(find_symbol); | |
588 | ||
589 | /* | |
590 | * Search for module by name: must hold module_mutex (or preempt disabled | |
591 | * for read-only access). | |
592 | */ | |
593 | static struct module *find_module_all(const char *name, size_t len, | |
594 | bool even_unformed) | |
595 | { | |
596 | struct module *mod; | |
597 | ||
598 | module_assert_mutex_or_preempt(); | |
599 | ||
600 | list_for_each_entry(mod, &modules, list) { | |
601 | if (!even_unformed && mod->state == MODULE_STATE_UNFORMED) | |
602 | continue; | |
603 | if (strlen(mod->name) == len && !memcmp(mod->name, name, len)) | |
604 | return mod; | |
605 | } | |
606 | return NULL; | |
607 | } | |
608 | ||
609 | struct module *find_module(const char *name) | |
610 | { | |
611 | module_assert_mutex(); | |
612 | return find_module_all(name, strlen(name), false); | |
613 | } | |
614 | EXPORT_SYMBOL_GPL(find_module); | |
615 | ||
616 | #ifdef CONFIG_SMP | |
617 | ||
618 | static inline void __percpu *mod_percpu(struct module *mod) | |
619 | { | |
620 | return mod->percpu; | |
621 | } | |
622 | ||
623 | static int percpu_modalloc(struct module *mod, struct load_info *info) | |
624 | { | |
625 | Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu]; | |
626 | unsigned long align = pcpusec->sh_addralign; | |
627 | ||
628 | if (!pcpusec->sh_size) | |
629 | return 0; | |
630 | ||
631 | if (align > PAGE_SIZE) { | |
632 | pr_warn("%s: per-cpu alignment %li > %li\n", | |
633 | mod->name, align, PAGE_SIZE); | |
634 | align = PAGE_SIZE; | |
635 | } | |
636 | ||
637 | mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align); | |
638 | if (!mod->percpu) { | |
639 | pr_warn("%s: Could not allocate %lu bytes percpu data\n", | |
640 | mod->name, (unsigned long)pcpusec->sh_size); | |
641 | return -ENOMEM; | |
642 | } | |
643 | mod->percpu_size = pcpusec->sh_size; | |
644 | return 0; | |
645 | } | |
646 | ||
647 | static void percpu_modfree(struct module *mod) | |
648 | { | |
649 | free_percpu(mod->percpu); | |
650 | } | |
651 | ||
652 | static unsigned int find_pcpusec(struct load_info *info) | |
653 | { | |
654 | return find_sec(info, ".data..percpu"); | |
655 | } | |
656 | ||
657 | static void percpu_modcopy(struct module *mod, | |
658 | const void *from, unsigned long size) | |
659 | { | |
660 | int cpu; | |
661 | ||
662 | for_each_possible_cpu(cpu) | |
663 | memcpy(per_cpu_ptr(mod->percpu, cpu), from, size); | |
664 | } | |
665 | ||
666 | /** | |
667 | * is_module_percpu_address - test whether address is from module static percpu | |
668 | * @addr: address to test | |
669 | * | |
670 | * Test whether @addr belongs to module static percpu area. | |
671 | * | |
672 | * RETURNS: | |
673 | * %true if @addr is from module static percpu area | |
674 | */ | |
675 | bool is_module_percpu_address(unsigned long addr) | |
676 | { | |
677 | struct module *mod; | |
678 | unsigned int cpu; | |
679 | ||
680 | preempt_disable(); | |
681 | ||
682 | list_for_each_entry_rcu(mod, &modules, list) { | |
683 | if (mod->state == MODULE_STATE_UNFORMED) | |
684 | continue; | |
685 | if (!mod->percpu_size) | |
686 | continue; | |
687 | for_each_possible_cpu(cpu) { | |
688 | void *start = per_cpu_ptr(mod->percpu, cpu); | |
689 | ||
690 | if ((void *)addr >= start && | |
691 | (void *)addr < start + mod->percpu_size) { | |
692 | preempt_enable(); | |
693 | return true; | |
694 | } | |
695 | } | |
696 | } | |
697 | ||
698 | preempt_enable(); | |
699 | return false; | |
700 | } | |
701 | ||
702 | #else /* ... !CONFIG_SMP */ | |
703 | ||
704 | static inline void __percpu *mod_percpu(struct module *mod) | |
705 | { | |
706 | return NULL; | |
707 | } | |
708 | static int percpu_modalloc(struct module *mod, struct load_info *info) | |
709 | { | |
710 | /* UP modules shouldn't have this section: ENOMEM isn't quite right */ | |
711 | if (info->sechdrs[info->index.pcpu].sh_size != 0) | |
712 | return -ENOMEM; | |
713 | return 0; | |
714 | } | |
715 | static inline void percpu_modfree(struct module *mod) | |
716 | { | |
717 | } | |
718 | static unsigned int find_pcpusec(struct load_info *info) | |
719 | { | |
720 | return 0; | |
721 | } | |
722 | static inline void percpu_modcopy(struct module *mod, | |
723 | const void *from, unsigned long size) | |
724 | { | |
725 | /* pcpusec should be 0, and size of that section should be 0. */ | |
726 | BUG_ON(size != 0); | |
727 | } | |
728 | bool is_module_percpu_address(unsigned long addr) | |
729 | { | |
730 | return false; | |
731 | } | |
732 | ||
733 | #endif /* CONFIG_SMP */ | |
734 | ||
735 | #define MODINFO_ATTR(field) \ | |
736 | static void setup_modinfo_##field(struct module *mod, const char *s) \ | |
737 | { \ | |
738 | mod->field = kstrdup(s, GFP_KERNEL); \ | |
739 | } \ | |
740 | static ssize_t show_modinfo_##field(struct module_attribute *mattr, \ | |
741 | struct module_kobject *mk, char *buffer) \ | |
742 | { \ | |
743 | return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \ | |
744 | } \ | |
745 | static int modinfo_##field##_exists(struct module *mod) \ | |
746 | { \ | |
747 | return mod->field != NULL; \ | |
748 | } \ | |
749 | static void free_modinfo_##field(struct module *mod) \ | |
750 | { \ | |
751 | kfree(mod->field); \ | |
752 | mod->field = NULL; \ | |
753 | } \ | |
754 | static struct module_attribute modinfo_##field = { \ | |
755 | .attr = { .name = __stringify(field), .mode = 0444 }, \ | |
756 | .show = show_modinfo_##field, \ | |
757 | .setup = setup_modinfo_##field, \ | |
758 | .test = modinfo_##field##_exists, \ | |
759 | .free = free_modinfo_##field, \ | |
760 | }; | |
761 | ||
762 | MODINFO_ATTR(version); | |
763 | MODINFO_ATTR(srcversion); | |
764 | ||
765 | static char last_unloaded_module[MODULE_NAME_LEN+1]; | |
766 | ||
767 | #ifdef CONFIG_MODULE_UNLOAD | |
768 | ||
769 | EXPORT_TRACEPOINT_SYMBOL(module_get); | |
770 | ||
771 | /* MODULE_REF_BASE is the base reference count by kmodule loader. */ | |
772 | #define MODULE_REF_BASE 1 | |
773 | ||
774 | /* Init the unload section of the module. */ | |
775 | static int module_unload_init(struct module *mod) | |
776 | { | |
777 | /* | |
778 | * Initialize reference counter to MODULE_REF_BASE. | |
779 | * refcnt == 0 means module is going. | |
780 | */ | |
781 | atomic_set(&mod->refcnt, MODULE_REF_BASE); | |
782 | ||
783 | INIT_LIST_HEAD(&mod->source_list); | |
784 | INIT_LIST_HEAD(&mod->target_list); | |
785 | ||
786 | /* Hold reference count during initialization. */ | |
787 | atomic_inc(&mod->refcnt); | |
788 | ||
789 | return 0; | |
790 | } | |
791 | ||
792 | /* Does a already use b? */ | |
793 | static int already_uses(struct module *a, struct module *b) | |
794 | { | |
795 | struct module_use *use; | |
796 | ||
797 | list_for_each_entry(use, &b->source_list, source_list) { | |
798 | if (use->source == a) { | |
799 | pr_debug("%s uses %s!\n", a->name, b->name); | |
800 | return 1; | |
801 | } | |
802 | } | |
803 | pr_debug("%s does not use %s!\n", a->name, b->name); | |
804 | return 0; | |
805 | } | |
806 | ||
807 | /* | |
808 | * Module a uses b | |
809 | * - we add 'a' as a "source", 'b' as a "target" of module use | |
810 | * - the module_use is added to the list of 'b' sources (so | |
811 | * 'b' can walk the list to see who sourced them), and of 'a' | |
812 | * targets (so 'a' can see what modules it targets). | |
813 | */ | |
814 | static int add_module_usage(struct module *a, struct module *b) | |
815 | { | |
816 | struct module_use *use; | |
817 | ||
818 | pr_debug("Allocating new usage for %s.\n", a->name); | |
819 | use = kmalloc(sizeof(*use), GFP_ATOMIC); | |
820 | if (!use) { | |
821 | pr_warn("%s: out of memory loading\n", a->name); | |
822 | return -ENOMEM; | |
823 | } | |
824 | ||
825 | use->source = a; | |
826 | use->target = b; | |
827 | list_add(&use->source_list, &b->source_list); | |
828 | list_add(&use->target_list, &a->target_list); | |
829 | return 0; | |
830 | } | |
831 | ||
832 | /* Module a uses b: caller needs module_mutex() */ | |
833 | int ref_module(struct module *a, struct module *b) | |
834 | { | |
835 | int err; | |
836 | ||
837 | if (b == NULL || already_uses(a, b)) | |
838 | return 0; | |
839 | ||
840 | /* If module isn't available, we fail. */ | |
841 | err = strong_try_module_get(b); | |
842 | if (err) | |
843 | return err; | |
844 | ||
845 | err = add_module_usage(a, b); | |
846 | if (err) { | |
847 | module_put(b); | |
848 | return err; | |
849 | } | |
850 | return 0; | |
851 | } | |
852 | EXPORT_SYMBOL_GPL(ref_module); | |
853 | ||
854 | /* Clear the unload stuff of the module. */ | |
855 | static void module_unload_free(struct module *mod) | |
856 | { | |
857 | struct module_use *use, *tmp; | |
858 | ||
859 | mutex_lock(&module_mutex); | |
860 | list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) { | |
861 | struct module *i = use->target; | |
862 | pr_debug("%s unusing %s\n", mod->name, i->name); | |
863 | module_put(i); | |
864 | list_del(&use->source_list); | |
865 | list_del(&use->target_list); | |
866 | kfree(use); | |
867 | } | |
868 | mutex_unlock(&module_mutex); | |
869 | } | |
870 | ||
871 | #ifdef CONFIG_MODULE_FORCE_UNLOAD | |
872 | static inline int try_force_unload(unsigned int flags) | |
873 | { | |
874 | int ret = (flags & O_TRUNC); | |
875 | if (ret) | |
876 | add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE); | |
877 | return ret; | |
878 | } | |
879 | #else | |
880 | static inline int try_force_unload(unsigned int flags) | |
881 | { | |
882 | return 0; | |
883 | } | |
884 | #endif /* CONFIG_MODULE_FORCE_UNLOAD */ | |
885 | ||
886 | /* Try to release refcount of module, 0 means success. */ | |
887 | static int try_release_module_ref(struct module *mod) | |
888 | { | |
889 | int ret; | |
890 | ||
891 | /* Try to decrement refcnt which we set at loading */ | |
892 | ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt); | |
893 | BUG_ON(ret < 0); | |
894 | if (ret) | |
895 | /* Someone can put this right now, recover with checking */ | |
896 | ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0); | |
897 | ||
898 | return ret; | |
899 | } | |
900 | ||
901 | static int try_stop_module(struct module *mod, int flags, int *forced) | |
902 | { | |
903 | /* If it's not unused, quit unless we're forcing. */ | |
904 | if (try_release_module_ref(mod) != 0) { | |
905 | *forced = try_force_unload(flags); | |
906 | if (!(*forced)) | |
907 | return -EWOULDBLOCK; | |
908 | } | |
909 | ||
910 | /* Mark it as dying. */ | |
911 | mod->state = MODULE_STATE_GOING; | |
912 | ||
913 | return 0; | |
914 | } | |
915 | ||
916 | /** | |
917 | * module_refcount - return the refcount or -1 if unloading | |
918 | * | |
919 | * @mod: the module we're checking | |
920 | * | |
921 | * Returns: | |
922 | * -1 if the module is in the process of unloading | |
923 | * otherwise the number of references in the kernel to the module | |
924 | */ | |
925 | int module_refcount(struct module *mod) | |
926 | { | |
927 | return atomic_read(&mod->refcnt) - MODULE_REF_BASE; | |
928 | } | |
929 | EXPORT_SYMBOL(module_refcount); | |
930 | ||
931 | /* This exists whether we can unload or not */ | |
932 | static void free_module(struct module *mod); | |
933 | ||
934 | SYSCALL_DEFINE2(delete_module, const char __user *, name_user, | |
935 | unsigned int, flags) | |
936 | { | |
937 | struct module *mod; | |
938 | char name[MODULE_NAME_LEN]; | |
939 | int ret, forced = 0; | |
940 | ||
941 | if (!capable(CAP_SYS_MODULE) || modules_disabled) | |
942 | return -EPERM; | |
943 | ||
944 | if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0) | |
945 | return -EFAULT; | |
946 | name[MODULE_NAME_LEN-1] = '\0'; | |
947 | ||
948 | if (mutex_lock_interruptible(&module_mutex) != 0) | |
949 | return -EINTR; | |
950 | ||
951 | mod = find_module(name); | |
952 | if (!mod) { | |
953 | ret = -ENOENT; | |
954 | goto out; | |
955 | } | |
956 | ||
957 | if (!list_empty(&mod->source_list)) { | |
958 | /* Other modules depend on us: get rid of them first. */ | |
959 | ret = -EWOULDBLOCK; | |
960 | goto out; | |
961 | } | |
962 | ||
963 | /* Doing init or already dying? */ | |
964 | if (mod->state != MODULE_STATE_LIVE) { | |
965 | /* FIXME: if (force), slam module count damn the torpedoes */ | |
966 | pr_debug("%s already dying\n", mod->name); | |
967 | ret = -EBUSY; | |
968 | goto out; | |
969 | } | |
970 | ||
971 | /* If it has an init func, it must have an exit func to unload */ | |
972 | if (mod->init && !mod->exit) { | |
973 | forced = try_force_unload(flags); | |
974 | if (!forced) { | |
975 | /* This module can't be removed */ | |
976 | ret = -EBUSY; | |
977 | goto out; | |
978 | } | |
979 | } | |
980 | ||
981 | /* Stop the machine so refcounts can't move and disable module. */ | |
982 | ret = try_stop_module(mod, flags, &forced); | |
983 | if (ret != 0) | |
984 | goto out; | |
985 | ||
986 | mutex_unlock(&module_mutex); | |
987 | /* Final destruction now no one is using it. */ | |
988 | if (mod->exit != NULL) | |
989 | mod->exit(); | |
990 | blocking_notifier_call_chain(&module_notify_list, | |
991 | MODULE_STATE_GOING, mod); | |
992 | klp_module_going(mod); | |
993 | ftrace_release_mod(mod); | |
994 | ||
995 | async_synchronize_full(); | |
996 | ||
997 | /* Store the name of the last unloaded module for diagnostic purposes */ | |
998 | strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module)); | |
999 | ||
1000 | free_module(mod); | |
1001 | return 0; | |
1002 | out: | |
1003 | mutex_unlock(&module_mutex); | |
1004 | return ret; | |
1005 | } | |
1006 | ||
1007 | static inline void print_unload_info(struct seq_file *m, struct module *mod) | |
1008 | { | |
1009 | struct module_use *use; | |
1010 | int printed_something = 0; | |
1011 | ||
1012 | seq_printf(m, " %i ", module_refcount(mod)); | |
1013 | ||
1014 | /* | |
1015 | * Always include a trailing , so userspace can differentiate | |
1016 | * between this and the old multi-field proc format. | |
1017 | */ | |
1018 | list_for_each_entry(use, &mod->source_list, source_list) { | |
1019 | printed_something = 1; | |
1020 | seq_printf(m, "%s,", use->source->name); | |
1021 | } | |
1022 | ||
1023 | if (mod->init != NULL && mod->exit == NULL) { | |
1024 | printed_something = 1; | |
1025 | seq_puts(m, "[permanent],"); | |
1026 | } | |
1027 | ||
1028 | if (!printed_something) | |
1029 | seq_puts(m, "-"); | |
1030 | } | |
1031 | ||
1032 | void __symbol_put(const char *symbol) | |
1033 | { | |
1034 | struct module *owner; | |
1035 | ||
1036 | preempt_disable(); | |
1037 | if (!find_symbol(symbol, &owner, NULL, true, false)) | |
1038 | BUG(); | |
1039 | module_put(owner); | |
1040 | preempt_enable(); | |
1041 | } | |
1042 | EXPORT_SYMBOL(__symbol_put); | |
1043 | ||
1044 | /* Note this assumes addr is a function, which it currently always is. */ | |
1045 | void symbol_put_addr(void *addr) | |
1046 | { | |
1047 | struct module *modaddr; | |
1048 | unsigned long a = (unsigned long)dereference_function_descriptor(addr); | |
1049 | ||
1050 | if (core_kernel_text(a)) | |
1051 | return; | |
1052 | ||
1053 | /* | |
1054 | * Even though we hold a reference on the module; we still need to | |
1055 | * disable preemption in order to safely traverse the data structure. | |
1056 | */ | |
1057 | preempt_disable(); | |
1058 | modaddr = __module_text_address(a); | |
1059 | BUG_ON(!modaddr); | |
1060 | module_put(modaddr); | |
1061 | preempt_enable(); | |
1062 | } | |
1063 | EXPORT_SYMBOL_GPL(symbol_put_addr); | |
1064 | ||
1065 | static ssize_t show_refcnt(struct module_attribute *mattr, | |
1066 | struct module_kobject *mk, char *buffer) | |
1067 | { | |
1068 | return sprintf(buffer, "%i\n", module_refcount(mk->mod)); | |
1069 | } | |
1070 | ||
1071 | static struct module_attribute modinfo_refcnt = | |
1072 | __ATTR(refcnt, 0444, show_refcnt, NULL); | |
1073 | ||
1074 | void __module_get(struct module *module) | |
1075 | { | |
1076 | if (module) { | |
1077 | preempt_disable(); | |
1078 | atomic_inc(&module->refcnt); | |
1079 | trace_module_get(module, _RET_IP_); | |
1080 | preempt_enable(); | |
1081 | } | |
1082 | } | |
1083 | EXPORT_SYMBOL(__module_get); | |
1084 | ||
1085 | bool try_module_get(struct module *module) | |
1086 | { | |
1087 | bool ret = true; | |
1088 | ||
1089 | if (module) { | |
1090 | preempt_disable(); | |
1091 | /* Note: here, we can fail to get a reference */ | |
1092 | if (likely(module_is_live(module) && | |
1093 | atomic_inc_not_zero(&module->refcnt) != 0)) | |
1094 | trace_module_get(module, _RET_IP_); | |
1095 | else | |
1096 | ret = false; | |
1097 | ||
1098 | preempt_enable(); | |
1099 | } | |
1100 | return ret; | |
1101 | } | |
1102 | EXPORT_SYMBOL(try_module_get); | |
1103 | ||
1104 | void module_put(struct module *module) | |
1105 | { | |
1106 | int ret; | |
1107 | ||
1108 | if (module) { | |
1109 | preempt_disable(); | |
1110 | ret = atomic_dec_if_positive(&module->refcnt); | |
1111 | WARN_ON(ret < 0); /* Failed to put refcount */ | |
1112 | trace_module_put(module, _RET_IP_); | |
1113 | preempt_enable(); | |
1114 | } | |
1115 | } | |
1116 | EXPORT_SYMBOL(module_put); | |
1117 | ||
1118 | #else /* !CONFIG_MODULE_UNLOAD */ | |
1119 | static inline void print_unload_info(struct seq_file *m, struct module *mod) | |
1120 | { | |
1121 | /* We don't know the usage count, or what modules are using. */ | |
1122 | seq_puts(m, " - -"); | |
1123 | } | |
1124 | ||
1125 | static inline void module_unload_free(struct module *mod) | |
1126 | { | |
1127 | } | |
1128 | ||
1129 | int ref_module(struct module *a, struct module *b) | |
1130 | { | |
1131 | return strong_try_module_get(b); | |
1132 | } | |
1133 | EXPORT_SYMBOL_GPL(ref_module); | |
1134 | ||
1135 | static inline int module_unload_init(struct module *mod) | |
1136 | { | |
1137 | return 0; | |
1138 | } | |
1139 | #endif /* CONFIG_MODULE_UNLOAD */ | |
1140 | ||
1141 | static size_t module_flags_taint(struct module *mod, char *buf) | |
1142 | { | |
1143 | size_t l = 0; | |
1144 | int i; | |
1145 | ||
1146 | for (i = 0; i < TAINT_FLAGS_COUNT; i++) { | |
1147 | if (taint_flags[i].module && test_bit(i, &mod->taints)) | |
1148 | buf[l++] = taint_flags[i].c_true; | |
1149 | } | |
1150 | ||
1151 | return l; | |
1152 | } | |
1153 | ||
1154 | static ssize_t show_initstate(struct module_attribute *mattr, | |
1155 | struct module_kobject *mk, char *buffer) | |
1156 | { | |
1157 | const char *state = "unknown"; | |
1158 | ||
1159 | switch (mk->mod->state) { | |
1160 | case MODULE_STATE_LIVE: | |
1161 | state = "live"; | |
1162 | break; | |
1163 | case MODULE_STATE_COMING: | |
1164 | state = "coming"; | |
1165 | break; | |
1166 | case MODULE_STATE_GOING: | |
1167 | state = "going"; | |
1168 | break; | |
1169 | default: | |
1170 | BUG(); | |
1171 | } | |
1172 | return sprintf(buffer, "%s\n", state); | |
1173 | } | |
1174 | ||
1175 | static struct module_attribute modinfo_initstate = | |
1176 | __ATTR(initstate, 0444, show_initstate, NULL); | |
1177 | ||
1178 | static ssize_t store_uevent(struct module_attribute *mattr, | |
1179 | struct module_kobject *mk, | |
1180 | const char *buffer, size_t count) | |
1181 | { | |
1182 | enum kobject_action action; | |
1183 | ||
1184 | if (kobject_action_type(buffer, count, &action) == 0) | |
1185 | kobject_uevent(&mk->kobj, action); | |
1186 | return count; | |
1187 | } | |
1188 | ||
1189 | struct module_attribute module_uevent = | |
1190 | __ATTR(uevent, 0200, NULL, store_uevent); | |
1191 | ||
1192 | static ssize_t show_coresize(struct module_attribute *mattr, | |
1193 | struct module_kobject *mk, char *buffer) | |
1194 | { | |
1195 | return sprintf(buffer, "%u\n", mk->mod->core_layout.size); | |
1196 | } | |
1197 | ||
1198 | static struct module_attribute modinfo_coresize = | |
1199 | __ATTR(coresize, 0444, show_coresize, NULL); | |
1200 | ||
1201 | static ssize_t show_initsize(struct module_attribute *mattr, | |
1202 | struct module_kobject *mk, char *buffer) | |
1203 | { | |
1204 | return sprintf(buffer, "%u\n", mk->mod->init_layout.size); | |
1205 | } | |
1206 | ||
1207 | static struct module_attribute modinfo_initsize = | |
1208 | __ATTR(initsize, 0444, show_initsize, NULL); | |
1209 | ||
1210 | static ssize_t show_taint(struct module_attribute *mattr, | |
1211 | struct module_kobject *mk, char *buffer) | |
1212 | { | |
1213 | size_t l; | |
1214 | ||
1215 | l = module_flags_taint(mk->mod, buffer); | |
1216 | buffer[l++] = '\n'; | |
1217 | return l; | |
1218 | } | |
1219 | ||
1220 | static struct module_attribute modinfo_taint = | |
1221 | __ATTR(taint, 0444, show_taint, NULL); | |
1222 | ||
1223 | static struct module_attribute *modinfo_attrs[] = { | |
1224 | &module_uevent, | |
1225 | &modinfo_version, | |
1226 | &modinfo_srcversion, | |
1227 | &modinfo_initstate, | |
1228 | &modinfo_coresize, | |
1229 | &modinfo_initsize, | |
1230 | &modinfo_taint, | |
1231 | #ifdef CONFIG_MODULE_UNLOAD | |
1232 | &modinfo_refcnt, | |
1233 | #endif | |
1234 | NULL, | |
1235 | }; | |
1236 | ||
1237 | static const char vermagic[] = VERMAGIC_STRING; | |
1238 | ||
1239 | static int try_to_force_load(struct module *mod, const char *reason) | |
1240 | { | |
1241 | #ifdef CONFIG_MODULE_FORCE_LOAD | |
1242 | if (!test_taint(TAINT_FORCED_MODULE)) | |
1243 | pr_warn("%s: %s: kernel tainted.\n", mod->name, reason); | |
1244 | add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE); | |
1245 | return 0; | |
1246 | #else | |
1247 | return -ENOEXEC; | |
1248 | #endif | |
1249 | } | |
1250 | ||
1251 | #ifdef CONFIG_MODVERSIONS | |
1252 | ||
1253 | static u32 resolve_rel_crc(const s32 *crc) | |
1254 | { | |
1255 | return *(u32 *)((void *)crc + *crc); | |
1256 | } | |
1257 | ||
1258 | static int check_version(Elf_Shdr *sechdrs, | |
1259 | unsigned int versindex, | |
1260 | const char *symname, | |
1261 | struct module *mod, | |
1262 | const s32 *crc) | |
1263 | { | |
1264 | unsigned int i, num_versions; | |
1265 | struct modversion_info *versions; | |
1266 | ||
1267 | /* Exporting module didn't supply crcs? OK, we're already tainted. */ | |
1268 | if (!crc) | |
1269 | return 1; | |
1270 | ||
1271 | /* No versions at all? modprobe --force does this. */ | |
1272 | if (versindex == 0) | |
1273 | return try_to_force_load(mod, symname) == 0; | |
1274 | ||
1275 | versions = (void *) sechdrs[versindex].sh_addr; | |
1276 | num_versions = sechdrs[versindex].sh_size | |
1277 | / sizeof(struct modversion_info); | |
1278 | ||
1279 | for (i = 0; i < num_versions; i++) { | |
1280 | u32 crcval; | |
1281 | ||
1282 | if (strcmp(versions[i].name, symname) != 0) | |
1283 | continue; | |
1284 | ||
1285 | if (IS_ENABLED(CONFIG_MODULE_REL_CRCS)) | |
1286 | crcval = resolve_rel_crc(crc); | |
1287 | else | |
1288 | crcval = *crc; | |
1289 | if (versions[i].crc == crcval) | |
1290 | return 1; | |
1291 | pr_debug("Found checksum %X vs module %lX\n", | |
1292 | crcval, versions[i].crc); | |
1293 | goto bad_version; | |
1294 | } | |
1295 | ||
1296 | /* Broken toolchain. Warn once, then let it go.. */ | |
1297 | pr_warn_once("%s: no symbol version for %s\n", mod->name, symname); | |
1298 | return 1; | |
1299 | ||
1300 | bad_version: | |
1301 | pr_warn("%s: disagrees about version of symbol %s\n", | |
1302 | mod->name, symname); | |
1303 | return 0; | |
1304 | } | |
1305 | ||
1306 | static inline int check_modstruct_version(Elf_Shdr *sechdrs, | |
1307 | unsigned int versindex, | |
1308 | struct module *mod) | |
1309 | { | |
1310 | const s32 *crc; | |
1311 | ||
1312 | /* | |
1313 | * Since this should be found in kernel (which can't be removed), no | |
1314 | * locking is necessary -- use preempt_disable() to placate lockdep. | |
1315 | */ | |
1316 | preempt_disable(); | |
1317 | if (!find_symbol(VMLINUX_SYMBOL_STR(module_layout), NULL, | |
1318 | &crc, true, false)) { | |
1319 | preempt_enable(); | |
1320 | BUG(); | |
1321 | } | |
1322 | preempt_enable(); | |
1323 | return check_version(sechdrs, versindex, | |
1324 | VMLINUX_SYMBOL_STR(module_layout), mod, crc); | |
1325 | } | |
1326 | ||
1327 | /* First part is kernel version, which we ignore if module has crcs. */ | |
1328 | static inline int same_magic(const char *amagic, const char *bmagic, | |
1329 | bool has_crcs) | |
1330 | { | |
1331 | if (has_crcs) { | |
1332 | amagic += strcspn(amagic, " "); | |
1333 | bmagic += strcspn(bmagic, " "); | |
1334 | } | |
1335 | return strcmp(amagic, bmagic) == 0; | |
1336 | } | |
1337 | #else | |
1338 | static inline int check_version(Elf_Shdr *sechdrs, | |
1339 | unsigned int versindex, | |
1340 | const char *symname, | |
1341 | struct module *mod, | |
1342 | const s32 *crc) | |
1343 | { | |
1344 | return 1; | |
1345 | } | |
1346 | ||
1347 | static inline int check_modstruct_version(Elf_Shdr *sechdrs, | |
1348 | unsigned int versindex, | |
1349 | struct module *mod) | |
1350 | { | |
1351 | return 1; | |
1352 | } | |
1353 | ||
1354 | static inline int same_magic(const char *amagic, const char *bmagic, | |
1355 | bool has_crcs) | |
1356 | { | |
1357 | return strcmp(amagic, bmagic) == 0; | |
1358 | } | |
1359 | #endif /* CONFIG_MODVERSIONS */ | |
1360 | ||
1361 | /* Resolve a symbol for this module. I.e. if we find one, record usage. */ | |
1362 | static const struct kernel_symbol *resolve_symbol(struct module *mod, | |
1363 | const struct load_info *info, | |
1364 | const char *name, | |
1365 | char ownername[]) | |
1366 | { | |
1367 | struct module *owner; | |
1368 | const struct kernel_symbol *sym; | |
1369 | const s32 *crc; | |
1370 | int err; | |
1371 | ||
1372 | /* | |
1373 | * The module_mutex should not be a heavily contended lock; | |
1374 | * if we get the occasional sleep here, we'll go an extra iteration | |
1375 | * in the wait_event_interruptible(), which is harmless. | |
1376 | */ | |
1377 | sched_annotate_sleep(); | |
1378 | mutex_lock(&module_mutex); | |
1379 | sym = find_symbol(name, &owner, &crc, | |
1380 | !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true); | |
1381 | if (!sym) | |
1382 | goto unlock; | |
1383 | ||
1384 | if (!check_version(info->sechdrs, info->index.vers, name, mod, crc)) { | |
1385 | sym = ERR_PTR(-EINVAL); | |
1386 | goto getname; | |
1387 | } | |
1388 | ||
1389 | err = ref_module(mod, owner); | |
1390 | if (err) { | |
1391 | sym = ERR_PTR(err); | |
1392 | goto getname; | |
1393 | } | |
1394 | ||
1395 | getname: | |
1396 | /* We must make copy under the lock if we failed to get ref. */ | |
1397 | strncpy(ownername, module_name(owner), MODULE_NAME_LEN); | |
1398 | unlock: | |
1399 | mutex_unlock(&module_mutex); | |
1400 | return sym; | |
1401 | } | |
1402 | ||
1403 | static const struct kernel_symbol * | |
1404 | resolve_symbol_wait(struct module *mod, | |
1405 | const struct load_info *info, | |
1406 | const char *name) | |
1407 | { | |
1408 | const struct kernel_symbol *ksym; | |
1409 | char owner[MODULE_NAME_LEN]; | |
1410 | ||
1411 | if (wait_event_interruptible_timeout(module_wq, | |
1412 | !IS_ERR(ksym = resolve_symbol(mod, info, name, owner)) | |
1413 | || PTR_ERR(ksym) != -EBUSY, | |
1414 | 30 * HZ) <= 0) { | |
1415 | pr_warn("%s: gave up waiting for init of module %s.\n", | |
1416 | mod->name, owner); | |
1417 | } | |
1418 | return ksym; | |
1419 | } | |
1420 | ||
1421 | /* | |
1422 | * /sys/module/foo/sections stuff | |
1423 | * J. Corbet <corbet@lwn.net> | |
1424 | */ | |
1425 | #ifdef CONFIG_SYSFS | |
1426 | ||
1427 | #ifdef CONFIG_KALLSYMS | |
1428 | static inline bool sect_empty(const Elf_Shdr *sect) | |
1429 | { | |
1430 | return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0; | |
1431 | } | |
1432 | ||
1433 | struct module_sect_attr { | |
1434 | struct module_attribute mattr; | |
1435 | char *name; | |
1436 | unsigned long address; | |
1437 | }; | |
1438 | ||
1439 | struct module_sect_attrs { | |
1440 | struct attribute_group grp; | |
1441 | unsigned int nsections; | |
1442 | struct module_sect_attr attrs[0]; | |
1443 | }; | |
1444 | ||
1445 | static ssize_t module_sect_show(struct module_attribute *mattr, | |
1446 | struct module_kobject *mk, char *buf) | |
1447 | { | |
1448 | struct module_sect_attr *sattr = | |
1449 | container_of(mattr, struct module_sect_attr, mattr); | |
1450 | return sprintf(buf, "0x%pK\n", (void *)sattr->address); | |
1451 | } | |
1452 | ||
1453 | static void free_sect_attrs(struct module_sect_attrs *sect_attrs) | |
1454 | { | |
1455 | unsigned int section; | |
1456 | ||
1457 | for (section = 0; section < sect_attrs->nsections; section++) | |
1458 | kfree(sect_attrs->attrs[section].name); | |
1459 | kfree(sect_attrs); | |
1460 | } | |
1461 | ||
1462 | static void add_sect_attrs(struct module *mod, const struct load_info *info) | |
1463 | { | |
1464 | unsigned int nloaded = 0, i, size[2]; | |
1465 | struct module_sect_attrs *sect_attrs; | |
1466 | struct module_sect_attr *sattr; | |
1467 | struct attribute **gattr; | |
1468 | ||
1469 | /* Count loaded sections and allocate structures */ | |
1470 | for (i = 0; i < info->hdr->e_shnum; i++) | |
1471 | if (!sect_empty(&info->sechdrs[i])) | |
1472 | nloaded++; | |
1473 | size[0] = ALIGN(sizeof(*sect_attrs) | |
1474 | + nloaded * sizeof(sect_attrs->attrs[0]), | |
1475 | sizeof(sect_attrs->grp.attrs[0])); | |
1476 | size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]); | |
1477 | sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL); | |
1478 | if (sect_attrs == NULL) | |
1479 | return; | |
1480 | ||
1481 | /* Setup section attributes. */ | |
1482 | sect_attrs->grp.name = "sections"; | |
1483 | sect_attrs->grp.attrs = (void *)sect_attrs + size[0]; | |
1484 | ||
1485 | sect_attrs->nsections = 0; | |
1486 | sattr = §_attrs->attrs[0]; | |
1487 | gattr = §_attrs->grp.attrs[0]; | |
1488 | for (i = 0; i < info->hdr->e_shnum; i++) { | |
1489 | Elf_Shdr *sec = &info->sechdrs[i]; | |
1490 | if (sect_empty(sec)) | |
1491 | continue; | |
1492 | sattr->address = sec->sh_addr; | |
1493 | sattr->name = kstrdup(info->secstrings + sec->sh_name, | |
1494 | GFP_KERNEL); | |
1495 | if (sattr->name == NULL) | |
1496 | goto out; | |
1497 | sect_attrs->nsections++; | |
1498 | sysfs_attr_init(&sattr->mattr.attr); | |
1499 | sattr->mattr.show = module_sect_show; | |
1500 | sattr->mattr.store = NULL; | |
1501 | sattr->mattr.attr.name = sattr->name; | |
1502 | sattr->mattr.attr.mode = S_IRUGO; | |
1503 | *(gattr++) = &(sattr++)->mattr.attr; | |
1504 | } | |
1505 | *gattr = NULL; | |
1506 | ||
1507 | if (sysfs_create_group(&mod->mkobj.kobj, §_attrs->grp)) | |
1508 | goto out; | |
1509 | ||
1510 | mod->sect_attrs = sect_attrs; | |
1511 | return; | |
1512 | out: | |
1513 | free_sect_attrs(sect_attrs); | |
1514 | } | |
1515 | ||
1516 | static void remove_sect_attrs(struct module *mod) | |
1517 | { | |
1518 | if (mod->sect_attrs) { | |
1519 | sysfs_remove_group(&mod->mkobj.kobj, | |
1520 | &mod->sect_attrs->grp); | |
1521 | /* We are positive that no one is using any sect attrs | |
1522 | * at this point. Deallocate immediately. */ | |
1523 | free_sect_attrs(mod->sect_attrs); | |
1524 | mod->sect_attrs = NULL; | |
1525 | } | |
1526 | } | |
1527 | ||
1528 | /* | |
1529 | * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections. | |
1530 | */ | |
1531 | ||
1532 | struct module_notes_attrs { | |
1533 | struct kobject *dir; | |
1534 | unsigned int notes; | |
1535 | struct bin_attribute attrs[0]; | |
1536 | }; | |
1537 | ||
1538 | static ssize_t module_notes_read(struct file *filp, struct kobject *kobj, | |
1539 | struct bin_attribute *bin_attr, | |
1540 | char *buf, loff_t pos, size_t count) | |
1541 | { | |
1542 | /* | |
1543 | * The caller checked the pos and count against our size. | |
1544 | */ | |
1545 | memcpy(buf, bin_attr->private + pos, count); | |
1546 | return count; | |
1547 | } | |
1548 | ||
1549 | static void free_notes_attrs(struct module_notes_attrs *notes_attrs, | |
1550 | unsigned int i) | |
1551 | { | |
1552 | if (notes_attrs->dir) { | |
1553 | while (i-- > 0) | |
1554 | sysfs_remove_bin_file(notes_attrs->dir, | |
1555 | ¬es_attrs->attrs[i]); | |
1556 | kobject_put(notes_attrs->dir); | |
1557 | } | |
1558 | kfree(notes_attrs); | |
1559 | } | |
1560 | ||
1561 | static void add_notes_attrs(struct module *mod, const struct load_info *info) | |
1562 | { | |
1563 | unsigned int notes, loaded, i; | |
1564 | struct module_notes_attrs *notes_attrs; | |
1565 | struct bin_attribute *nattr; | |
1566 | ||
1567 | /* failed to create section attributes, so can't create notes */ | |
1568 | if (!mod->sect_attrs) | |
1569 | return; | |
1570 | ||
1571 | /* Count notes sections and allocate structures. */ | |
1572 | notes = 0; | |
1573 | for (i = 0; i < info->hdr->e_shnum; i++) | |
1574 | if (!sect_empty(&info->sechdrs[i]) && | |
1575 | (info->sechdrs[i].sh_type == SHT_NOTE)) | |
1576 | ++notes; | |
1577 | ||
1578 | if (notes == 0) | |
1579 | return; | |
1580 | ||
1581 | notes_attrs = kzalloc(sizeof(*notes_attrs) | |
1582 | + notes * sizeof(notes_attrs->attrs[0]), | |
1583 | GFP_KERNEL); | |
1584 | if (notes_attrs == NULL) | |
1585 | return; | |
1586 | ||
1587 | notes_attrs->notes = notes; | |
1588 | nattr = ¬es_attrs->attrs[0]; | |
1589 | for (loaded = i = 0; i < info->hdr->e_shnum; ++i) { | |
1590 | if (sect_empty(&info->sechdrs[i])) | |
1591 | continue; | |
1592 | if (info->sechdrs[i].sh_type == SHT_NOTE) { | |
1593 | sysfs_bin_attr_init(nattr); | |
1594 | nattr->attr.name = mod->sect_attrs->attrs[loaded].name; | |
1595 | nattr->attr.mode = S_IRUGO; | |
1596 | nattr->size = info->sechdrs[i].sh_size; | |
1597 | nattr->private = (void *) info->sechdrs[i].sh_addr; | |
1598 | nattr->read = module_notes_read; | |
1599 | ++nattr; | |
1600 | } | |
1601 | ++loaded; | |
1602 | } | |
1603 | ||
1604 | notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj); | |
1605 | if (!notes_attrs->dir) | |
1606 | goto out; | |
1607 | ||
1608 | for (i = 0; i < notes; ++i) | |
1609 | if (sysfs_create_bin_file(notes_attrs->dir, | |
1610 | ¬es_attrs->attrs[i])) | |
1611 | goto out; | |
1612 | ||
1613 | mod->notes_attrs = notes_attrs; | |
1614 | return; | |
1615 | ||
1616 | out: | |
1617 | free_notes_attrs(notes_attrs, i); | |
1618 | } | |
1619 | ||
1620 | static void remove_notes_attrs(struct module *mod) | |
1621 | { | |
1622 | if (mod->notes_attrs) | |
1623 | free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes); | |
1624 | } | |
1625 | ||
1626 | #else | |
1627 | ||
1628 | static inline void add_sect_attrs(struct module *mod, | |
1629 | const struct load_info *info) | |
1630 | { | |
1631 | } | |
1632 | ||
1633 | static inline void remove_sect_attrs(struct module *mod) | |
1634 | { | |
1635 | } | |
1636 | ||
1637 | static inline void add_notes_attrs(struct module *mod, | |
1638 | const struct load_info *info) | |
1639 | { | |
1640 | } | |
1641 | ||
1642 | static inline void remove_notes_attrs(struct module *mod) | |
1643 | { | |
1644 | } | |
1645 | #endif /* CONFIG_KALLSYMS */ | |
1646 | ||
1647 | static void add_usage_links(struct module *mod) | |
1648 | { | |
1649 | #ifdef CONFIG_MODULE_UNLOAD | |
1650 | struct module_use *use; | |
1651 | int nowarn; | |
1652 | ||
1653 | mutex_lock(&module_mutex); | |
1654 | list_for_each_entry(use, &mod->target_list, target_list) { | |
1655 | nowarn = sysfs_create_link(use->target->holders_dir, | |
1656 | &mod->mkobj.kobj, mod->name); | |
1657 | } | |
1658 | mutex_unlock(&module_mutex); | |
1659 | #endif | |
1660 | } | |
1661 | ||
1662 | static void del_usage_links(struct module *mod) | |
1663 | { | |
1664 | #ifdef CONFIG_MODULE_UNLOAD | |
1665 | struct module_use *use; | |
1666 | ||
1667 | mutex_lock(&module_mutex); | |
1668 | list_for_each_entry(use, &mod->target_list, target_list) | |
1669 | sysfs_remove_link(use->target->holders_dir, mod->name); | |
1670 | mutex_unlock(&module_mutex); | |
1671 | #endif | |
1672 | } | |
1673 | ||
1674 | static int module_add_modinfo_attrs(struct module *mod) | |
1675 | { | |
1676 | struct module_attribute *attr; | |
1677 | struct module_attribute *temp_attr; | |
1678 | int error = 0; | |
1679 | int i; | |
1680 | ||
1681 | mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) * | |
1682 | (ARRAY_SIZE(modinfo_attrs) + 1)), | |
1683 | GFP_KERNEL); | |
1684 | if (!mod->modinfo_attrs) | |
1685 | return -ENOMEM; | |
1686 | ||
1687 | temp_attr = mod->modinfo_attrs; | |
1688 | for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) { | |
1689 | if (!attr->test || attr->test(mod)) { | |
1690 | memcpy(temp_attr, attr, sizeof(*temp_attr)); | |
1691 | sysfs_attr_init(&temp_attr->attr); | |
1692 | error = sysfs_create_file(&mod->mkobj.kobj, | |
1693 | &temp_attr->attr); | |
1694 | ++temp_attr; | |
1695 | } | |
1696 | } | |
1697 | return error; | |
1698 | } | |
1699 | ||
1700 | static void module_remove_modinfo_attrs(struct module *mod) | |
1701 | { | |
1702 | struct module_attribute *attr; | |
1703 | int i; | |
1704 | ||
1705 | for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) { | |
1706 | /* pick a field to test for end of list */ | |
1707 | if (!attr->attr.name) | |
1708 | break; | |
1709 | sysfs_remove_file(&mod->mkobj.kobj, &attr->attr); | |
1710 | if (attr->free) | |
1711 | attr->free(mod); | |
1712 | } | |
1713 | kfree(mod->modinfo_attrs); | |
1714 | } | |
1715 | ||
1716 | static void mod_kobject_put(struct module *mod) | |
1717 | { | |
1718 | DECLARE_COMPLETION_ONSTACK(c); | |
1719 | mod->mkobj.kobj_completion = &c; | |
1720 | kobject_put(&mod->mkobj.kobj); | |
1721 | wait_for_completion(&c); | |
1722 | } | |
1723 | ||
1724 | static int mod_sysfs_init(struct module *mod) | |
1725 | { | |
1726 | int err; | |
1727 | struct kobject *kobj; | |
1728 | ||
1729 | if (!module_sysfs_initialized) { | |
1730 | pr_err("%s: module sysfs not initialized\n", mod->name); | |
1731 | err = -EINVAL; | |
1732 | goto out; | |
1733 | } | |
1734 | ||
1735 | kobj = kset_find_obj(module_kset, mod->name); | |
1736 | if (kobj) { | |
1737 | pr_err("%s: module is already loaded\n", mod->name); | |
1738 | kobject_put(kobj); | |
1739 | err = -EINVAL; | |
1740 | goto out; | |
1741 | } | |
1742 | ||
1743 | mod->mkobj.mod = mod; | |
1744 | ||
1745 | memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj)); | |
1746 | mod->mkobj.kobj.kset = module_kset; | |
1747 | err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL, | |
1748 | "%s", mod->name); | |
1749 | if (err) | |
1750 | mod_kobject_put(mod); | |
1751 | ||
1752 | /* delay uevent until full sysfs population */ | |
1753 | out: | |
1754 | return err; | |
1755 | } | |
1756 | ||
1757 | static int mod_sysfs_setup(struct module *mod, | |
1758 | const struct load_info *info, | |
1759 | struct kernel_param *kparam, | |
1760 | unsigned int num_params) | |
1761 | { | |
1762 | int err; | |
1763 | ||
1764 | err = mod_sysfs_init(mod); | |
1765 | if (err) | |
1766 | goto out; | |
1767 | ||
1768 | mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj); | |
1769 | if (!mod->holders_dir) { | |
1770 | err = -ENOMEM; | |
1771 | goto out_unreg; | |
1772 | } | |
1773 | ||
1774 | err = module_param_sysfs_setup(mod, kparam, num_params); | |
1775 | if (err) | |
1776 | goto out_unreg_holders; | |
1777 | ||
1778 | err = module_add_modinfo_attrs(mod); | |
1779 | if (err) | |
1780 | goto out_unreg_param; | |
1781 | ||
1782 | add_usage_links(mod); | |
1783 | add_sect_attrs(mod, info); | |
1784 | add_notes_attrs(mod, info); | |
1785 | ||
1786 | kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD); | |
1787 | return 0; | |
1788 | ||
1789 | out_unreg_param: | |
1790 | module_param_sysfs_remove(mod); | |
1791 | out_unreg_holders: | |
1792 | kobject_put(mod->holders_dir); | |
1793 | out_unreg: | |
1794 | mod_kobject_put(mod); | |
1795 | out: | |
1796 | return err; | |
1797 | } | |
1798 | ||
1799 | static void mod_sysfs_fini(struct module *mod) | |
1800 | { | |
1801 | remove_notes_attrs(mod); | |
1802 | remove_sect_attrs(mod); | |
1803 | mod_kobject_put(mod); | |
1804 | } | |
1805 | ||
1806 | static void init_param_lock(struct module *mod) | |
1807 | { | |
1808 | mutex_init(&mod->param_lock); | |
1809 | } | |
1810 | #else /* !CONFIG_SYSFS */ | |
1811 | ||
1812 | static int mod_sysfs_setup(struct module *mod, | |
1813 | const struct load_info *info, | |
1814 | struct kernel_param *kparam, | |
1815 | unsigned int num_params) | |
1816 | { | |
1817 | return 0; | |
1818 | } | |
1819 | ||
1820 | static void mod_sysfs_fini(struct module *mod) | |
1821 | { | |
1822 | } | |
1823 | ||
1824 | static void module_remove_modinfo_attrs(struct module *mod) | |
1825 | { | |
1826 | } | |
1827 | ||
1828 | static void del_usage_links(struct module *mod) | |
1829 | { | |
1830 | } | |
1831 | ||
1832 | static void init_param_lock(struct module *mod) | |
1833 | { | |
1834 | } | |
1835 | #endif /* CONFIG_SYSFS */ | |
1836 | ||
1837 | static void mod_sysfs_teardown(struct module *mod) | |
1838 | { | |
1839 | del_usage_links(mod); | |
1840 | module_remove_modinfo_attrs(mod); | |
1841 | module_param_sysfs_remove(mod); | |
1842 | kobject_put(mod->mkobj.drivers_dir); | |
1843 | kobject_put(mod->holders_dir); | |
1844 | mod_sysfs_fini(mod); | |
1845 | } | |
1846 | ||
1847 | #ifdef CONFIG_DEBUG_SET_MODULE_RONX | |
1848 | /* | |
1849 | * LKM RO/NX protection: protect module's text/ro-data | |
1850 | * from modification and any data from execution. | |
1851 | * | |
1852 | * General layout of module is: | |
1853 | * [text] [read-only-data] [ro-after-init] [writable data] | |
1854 | * text_size -----^ ^ ^ ^ | |
1855 | * ro_size ------------------------| | | | |
1856 | * ro_after_init_size -----------------------------| | | |
1857 | * size -----------------------------------------------------------| | |
1858 | * | |
1859 | * These values are always page-aligned (as is base) | |
1860 | */ | |
1861 | static void frob_text(const struct module_layout *layout, | |
1862 | int (*set_memory)(unsigned long start, int num_pages)) | |
1863 | { | |
1864 | BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1)); | |
1865 | BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1)); | |
1866 | set_memory((unsigned long)layout->base, | |
1867 | layout->text_size >> PAGE_SHIFT); | |
1868 | } | |
1869 | ||
1870 | static void frob_rodata(const struct module_layout *layout, | |
1871 | int (*set_memory)(unsigned long start, int num_pages)) | |
1872 | { | |
1873 | BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1)); | |
1874 | BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1)); | |
1875 | BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1)); | |
1876 | set_memory((unsigned long)layout->base + layout->text_size, | |
1877 | (layout->ro_size - layout->text_size) >> PAGE_SHIFT); | |
1878 | } | |
1879 | ||
1880 | static void frob_ro_after_init(const struct module_layout *layout, | |
1881 | int (*set_memory)(unsigned long start, int num_pages)) | |
1882 | { | |
1883 | BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1)); | |
1884 | BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1)); | |
1885 | BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1)); | |
1886 | set_memory((unsigned long)layout->base + layout->ro_size, | |
1887 | (layout->ro_after_init_size - layout->ro_size) >> PAGE_SHIFT); | |
1888 | } | |
1889 | ||
1890 | static void frob_writable_data(const struct module_layout *layout, | |
1891 | int (*set_memory)(unsigned long start, int num_pages)) | |
1892 | { | |
1893 | BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1)); | |
1894 | BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1)); | |
1895 | BUG_ON((unsigned long)layout->size & (PAGE_SIZE-1)); | |
1896 | set_memory((unsigned long)layout->base + layout->ro_after_init_size, | |
1897 | (layout->size - layout->ro_after_init_size) >> PAGE_SHIFT); | |
1898 | } | |
1899 | ||
1900 | /* livepatching wants to disable read-only so it can frob module. */ | |
1901 | void module_disable_ro(const struct module *mod) | |
1902 | { | |
1903 | if (!rodata_enabled) | |
1904 | return; | |
1905 | ||
1906 | frob_text(&mod->core_layout, set_memory_rw); | |
1907 | frob_rodata(&mod->core_layout, set_memory_rw); | |
1908 | frob_ro_after_init(&mod->core_layout, set_memory_rw); | |
1909 | frob_text(&mod->init_layout, set_memory_rw); | |
1910 | frob_rodata(&mod->init_layout, set_memory_rw); | |
1911 | } | |
1912 | ||
1913 | void module_enable_ro(const struct module *mod, bool after_init) | |
1914 | { | |
1915 | if (!rodata_enabled) | |
1916 | return; | |
1917 | ||
1918 | frob_text(&mod->core_layout, set_memory_ro); | |
1919 | frob_rodata(&mod->core_layout, set_memory_ro); | |
1920 | frob_text(&mod->init_layout, set_memory_ro); | |
1921 | frob_rodata(&mod->init_layout, set_memory_ro); | |
1922 | ||
1923 | if (after_init) | |
1924 | frob_ro_after_init(&mod->core_layout, set_memory_ro); | |
1925 | } | |
1926 | ||
1927 | static void module_enable_nx(const struct module *mod) | |
1928 | { | |
1929 | frob_rodata(&mod->core_layout, set_memory_nx); | |
1930 | frob_ro_after_init(&mod->core_layout, set_memory_nx); | |
1931 | frob_writable_data(&mod->core_layout, set_memory_nx); | |
1932 | frob_rodata(&mod->init_layout, set_memory_nx); | |
1933 | frob_writable_data(&mod->init_layout, set_memory_nx); | |
1934 | } | |
1935 | ||
1936 | static void module_disable_nx(const struct module *mod) | |
1937 | { | |
1938 | frob_rodata(&mod->core_layout, set_memory_x); | |
1939 | frob_ro_after_init(&mod->core_layout, set_memory_x); | |
1940 | frob_writable_data(&mod->core_layout, set_memory_x); | |
1941 | frob_rodata(&mod->init_layout, set_memory_x); | |
1942 | frob_writable_data(&mod->init_layout, set_memory_x); | |
1943 | } | |
1944 | ||
1945 | /* Iterate through all modules and set each module's text as RW */ | |
1946 | void set_all_modules_text_rw(void) | |
1947 | { | |
1948 | struct module *mod; | |
1949 | ||
1950 | if (!rodata_enabled) | |
1951 | return; | |
1952 | ||
1953 | mutex_lock(&module_mutex); | |
1954 | list_for_each_entry_rcu(mod, &modules, list) { | |
1955 | if (mod->state == MODULE_STATE_UNFORMED) | |
1956 | continue; | |
1957 | ||
1958 | frob_text(&mod->core_layout, set_memory_rw); | |
1959 | frob_text(&mod->init_layout, set_memory_rw); | |
1960 | } | |
1961 | mutex_unlock(&module_mutex); | |
1962 | } | |
1963 | ||
1964 | /* Iterate through all modules and set each module's text as RO */ | |
1965 | void set_all_modules_text_ro(void) | |
1966 | { | |
1967 | struct module *mod; | |
1968 | ||
1969 | if (!rodata_enabled) | |
1970 | return; | |
1971 | ||
1972 | mutex_lock(&module_mutex); | |
1973 | list_for_each_entry_rcu(mod, &modules, list) { | |
1974 | /* | |
1975 | * Ignore going modules since it's possible that ro | |
1976 | * protection has already been disabled, otherwise we'll | |
1977 | * run into protection faults at module deallocation. | |
1978 | */ | |
1979 | if (mod->state == MODULE_STATE_UNFORMED || | |
1980 | mod->state == MODULE_STATE_GOING) | |
1981 | continue; | |
1982 | ||
1983 | frob_text(&mod->core_layout, set_memory_ro); | |
1984 | frob_text(&mod->init_layout, set_memory_ro); | |
1985 | } | |
1986 | mutex_unlock(&module_mutex); | |
1987 | } | |
1988 | ||
1989 | static void disable_ro_nx(const struct module_layout *layout) | |
1990 | { | |
1991 | if (rodata_enabled) { | |
1992 | frob_text(layout, set_memory_rw); | |
1993 | frob_rodata(layout, set_memory_rw); | |
1994 | frob_ro_after_init(layout, set_memory_rw); | |
1995 | } | |
1996 | frob_rodata(layout, set_memory_x); | |
1997 | frob_ro_after_init(layout, set_memory_x); | |
1998 | frob_writable_data(layout, set_memory_x); | |
1999 | } | |
2000 | ||
2001 | #else | |
2002 | static void disable_ro_nx(const struct module_layout *layout) { } | |
2003 | static void module_enable_nx(const struct module *mod) { } | |
2004 | static void module_disable_nx(const struct module *mod) { } | |
2005 | #endif | |
2006 | ||
2007 | #ifdef CONFIG_LIVEPATCH | |
2008 | /* | |
2009 | * Persist Elf information about a module. Copy the Elf header, | |
2010 | * section header table, section string table, and symtab section | |
2011 | * index from info to mod->klp_info. | |
2012 | */ | |
2013 | static int copy_module_elf(struct module *mod, struct load_info *info) | |
2014 | { | |
2015 | unsigned int size, symndx; | |
2016 | int ret; | |
2017 | ||
2018 | size = sizeof(*mod->klp_info); | |
2019 | mod->klp_info = kmalloc(size, GFP_KERNEL); | |
2020 | if (mod->klp_info == NULL) | |
2021 | return -ENOMEM; | |
2022 | ||
2023 | /* Elf header */ | |
2024 | size = sizeof(mod->klp_info->hdr); | |
2025 | memcpy(&mod->klp_info->hdr, info->hdr, size); | |
2026 | ||
2027 | /* Elf section header table */ | |
2028 | size = sizeof(*info->sechdrs) * info->hdr->e_shnum; | |
2029 | mod->klp_info->sechdrs = kmalloc(size, GFP_KERNEL); | |
2030 | if (mod->klp_info->sechdrs == NULL) { | |
2031 | ret = -ENOMEM; | |
2032 | goto free_info; | |
2033 | } | |
2034 | memcpy(mod->klp_info->sechdrs, info->sechdrs, size); | |
2035 | ||
2036 | /* Elf section name string table */ | |
2037 | size = info->sechdrs[info->hdr->e_shstrndx].sh_size; | |
2038 | mod->klp_info->secstrings = kmalloc(size, GFP_KERNEL); | |
2039 | if (mod->klp_info->secstrings == NULL) { | |
2040 | ret = -ENOMEM; | |
2041 | goto free_sechdrs; | |
2042 | } | |
2043 | memcpy(mod->klp_info->secstrings, info->secstrings, size); | |
2044 | ||
2045 | /* Elf symbol section index */ | |
2046 | symndx = info->index.sym; | |
2047 | mod->klp_info->symndx = symndx; | |
2048 | ||
2049 | /* | |
2050 | * For livepatch modules, core_kallsyms.symtab is a complete | |
2051 | * copy of the original symbol table. Adjust sh_addr to point | |
2052 | * to core_kallsyms.symtab since the copy of the symtab in module | |
2053 | * init memory is freed at the end of do_init_module(). | |
2054 | */ | |
2055 | mod->klp_info->sechdrs[symndx].sh_addr = \ | |
2056 | (unsigned long) mod->core_kallsyms.symtab; | |
2057 | ||
2058 | return 0; | |
2059 | ||
2060 | free_sechdrs: | |
2061 | kfree(mod->klp_info->sechdrs); | |
2062 | free_info: | |
2063 | kfree(mod->klp_info); | |
2064 | return ret; | |
2065 | } | |
2066 | ||
2067 | static void free_module_elf(struct module *mod) | |
2068 | { | |
2069 | kfree(mod->klp_info->sechdrs); | |
2070 | kfree(mod->klp_info->secstrings); | |
2071 | kfree(mod->klp_info); | |
2072 | } | |
2073 | #else /* !CONFIG_LIVEPATCH */ | |
2074 | static int copy_module_elf(struct module *mod, struct load_info *info) | |
2075 | { | |
2076 | return 0; | |
2077 | } | |
2078 | ||
2079 | static void free_module_elf(struct module *mod) | |
2080 | { | |
2081 | } | |
2082 | #endif /* CONFIG_LIVEPATCH */ | |
2083 | ||
2084 | void __weak module_memfree(void *module_region) | |
2085 | { | |
2086 | vfree(module_region); | |
2087 | } | |
2088 | ||
2089 | void __weak module_arch_cleanup(struct module *mod) | |
2090 | { | |
2091 | } | |
2092 | ||
2093 | void __weak module_arch_freeing_init(struct module *mod) | |
2094 | { | |
2095 | } | |
2096 | ||
2097 | /* Free a module, remove from lists, etc. */ | |
2098 | static void free_module(struct module *mod) | |
2099 | { | |
2100 | trace_module_free(mod); | |
2101 | ||
2102 | mod_sysfs_teardown(mod); | |
2103 | ||
2104 | /* We leave it in list to prevent duplicate loads, but make sure | |
2105 | * that noone uses it while it's being deconstructed. */ | |
2106 | mutex_lock(&module_mutex); | |
2107 | mod->state = MODULE_STATE_UNFORMED; | |
2108 | mutex_unlock(&module_mutex); | |
2109 | ||
2110 | /* Remove dynamic debug info */ | |
2111 | ddebug_remove_module(mod->name); | |
2112 | ||
2113 | /* Arch-specific cleanup. */ | |
2114 | module_arch_cleanup(mod); | |
2115 | ||
2116 | /* Module unload stuff */ | |
2117 | module_unload_free(mod); | |
2118 | ||
2119 | /* Free any allocated parameters. */ | |
2120 | destroy_params(mod->kp, mod->num_kp); | |
2121 | ||
2122 | if (is_livepatch_module(mod)) | |
2123 | free_module_elf(mod); | |
2124 | ||
2125 | /* Now we can delete it from the lists */ | |
2126 | mutex_lock(&module_mutex); | |
2127 | /* Unlink carefully: kallsyms could be walking list. */ | |
2128 | list_del_rcu(&mod->list); | |
2129 | mod_tree_remove(mod); | |
2130 | /* Remove this module from bug list, this uses list_del_rcu */ | |
2131 | module_bug_cleanup(mod); | |
2132 | /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */ | |
2133 | synchronize_sched(); | |
2134 | mutex_unlock(&module_mutex); | |
2135 | ||
2136 | /* This may be empty, but that's OK */ | |
2137 | disable_ro_nx(&mod->init_layout); | |
2138 | module_arch_freeing_init(mod); | |
2139 | module_memfree(mod->init_layout.base); | |
2140 | kfree(mod->args); | |
2141 | percpu_modfree(mod); | |
2142 | ||
2143 | /* Free lock-classes; relies on the preceding sync_rcu(). */ | |
2144 | lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size); | |
2145 | ||
2146 | /* Finally, free the core (containing the module structure) */ | |
2147 | disable_ro_nx(&mod->core_layout); | |
2148 | module_memfree(mod->core_layout.base); | |
2149 | ||
2150 | #ifdef CONFIG_MPU | |
2151 | update_protections(current->mm); | |
2152 | #endif | |
2153 | } | |
2154 | ||
2155 | void *__symbol_get(const char *symbol) | |
2156 | { | |
2157 | struct module *owner; | |
2158 | const struct kernel_symbol *sym; | |
2159 | ||
2160 | preempt_disable(); | |
2161 | sym = find_symbol(symbol, &owner, NULL, true, true); | |
2162 | if (sym && strong_try_module_get(owner)) | |
2163 | sym = NULL; | |
2164 | preempt_enable(); | |
2165 | ||
2166 | return sym ? (void *)sym->value : NULL; | |
2167 | } | |
2168 | EXPORT_SYMBOL_GPL(__symbol_get); | |
2169 | ||
2170 | /* | |
2171 | * Ensure that an exported symbol [global namespace] does not already exist | |
2172 | * in the kernel or in some other module's exported symbol table. | |
2173 | * | |
2174 | * You must hold the module_mutex. | |
2175 | */ | |
2176 | static int verify_export_symbols(struct module *mod) | |
2177 | { | |
2178 | unsigned int i; | |
2179 | struct module *owner; | |
2180 | const struct kernel_symbol *s; | |
2181 | struct { | |
2182 | const struct kernel_symbol *sym; | |
2183 | unsigned int num; | |
2184 | } arr[] = { | |
2185 | { mod->syms, mod->num_syms }, | |
2186 | { mod->gpl_syms, mod->num_gpl_syms }, | |
2187 | { mod->gpl_future_syms, mod->num_gpl_future_syms }, | |
2188 | #ifdef CONFIG_UNUSED_SYMBOLS | |
2189 | { mod->unused_syms, mod->num_unused_syms }, | |
2190 | { mod->unused_gpl_syms, mod->num_unused_gpl_syms }, | |
2191 | #endif | |
2192 | }; | |
2193 | ||
2194 | for (i = 0; i < ARRAY_SIZE(arr); i++) { | |
2195 | for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) { | |
2196 | if (find_symbol(s->name, &owner, NULL, true, false)) { | |
2197 | pr_err("%s: exports duplicate symbol %s" | |
2198 | " (owned by %s)\n", | |
2199 | mod->name, s->name, module_name(owner)); | |
2200 | return -ENOEXEC; | |
2201 | } | |
2202 | } | |
2203 | } | |
2204 | return 0; | |
2205 | } | |
2206 | ||
2207 | /* Change all symbols so that st_value encodes the pointer directly. */ | |
2208 | static int simplify_symbols(struct module *mod, const struct load_info *info) | |
2209 | { | |
2210 | Elf_Shdr *symsec = &info->sechdrs[info->index.sym]; | |
2211 | Elf_Sym *sym = (void *)symsec->sh_addr; | |
2212 | unsigned long secbase; | |
2213 | unsigned int i; | |
2214 | int ret = 0; | |
2215 | const struct kernel_symbol *ksym; | |
2216 | ||
2217 | for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) { | |
2218 | const char *name = info->strtab + sym[i].st_name; | |
2219 | ||
2220 | switch (sym[i].st_shndx) { | |
2221 | case SHN_COMMON: | |
2222 | /* Ignore common symbols */ | |
2223 | if (!strncmp(name, "__gnu_lto", 9)) | |
2224 | break; | |
2225 | ||
2226 | /* We compiled with -fno-common. These are not | |
2227 | supposed to happen. */ | |
2228 | pr_debug("Common symbol: %s\n", name); | |
2229 | pr_warn("%s: please compile with -fno-common\n", | |
2230 | mod->name); | |
2231 | ret = -ENOEXEC; | |
2232 | break; | |
2233 | ||
2234 | case SHN_ABS: | |
2235 | /* Don't need to do anything */ | |
2236 | pr_debug("Absolute symbol: 0x%08lx\n", | |
2237 | (long)sym[i].st_value); | |
2238 | break; | |
2239 | ||
2240 | case SHN_LIVEPATCH: | |
2241 | /* Livepatch symbols are resolved by livepatch */ | |
2242 | break; | |
2243 | ||
2244 | case SHN_UNDEF: | |
2245 | ksym = resolve_symbol_wait(mod, info, name); | |
2246 | /* Ok if resolved. */ | |
2247 | if (ksym && !IS_ERR(ksym)) { | |
2248 | sym[i].st_value = ksym->value; | |
2249 | break; | |
2250 | } | |
2251 | ||
2252 | /* Ok if weak. */ | |
2253 | if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK) | |
2254 | break; | |
2255 | ||
2256 | pr_warn("%s: Unknown symbol %s (err %li)\n", | |
2257 | mod->name, name, PTR_ERR(ksym)); | |
2258 | ret = PTR_ERR(ksym) ?: -ENOENT; | |
2259 | break; | |
2260 | ||
2261 | default: | |
2262 | /* Divert to percpu allocation if a percpu var. */ | |
2263 | if (sym[i].st_shndx == info->index.pcpu) | |
2264 | secbase = (unsigned long)mod_percpu(mod); | |
2265 | else | |
2266 | secbase = info->sechdrs[sym[i].st_shndx].sh_addr; | |
2267 | sym[i].st_value += secbase; | |
2268 | break; | |
2269 | } | |
2270 | } | |
2271 | ||
2272 | return ret; | |
2273 | } | |
2274 | ||
2275 | static int apply_relocations(struct module *mod, const struct load_info *info) | |
2276 | { | |
2277 | unsigned int i; | |
2278 | int err = 0; | |
2279 | ||
2280 | /* Now do relocations. */ | |
2281 | for (i = 1; i < info->hdr->e_shnum; i++) { | |
2282 | unsigned int infosec = info->sechdrs[i].sh_info; | |
2283 | ||
2284 | /* Not a valid relocation section? */ | |
2285 | if (infosec >= info->hdr->e_shnum) | |
2286 | continue; | |
2287 | ||
2288 | /* Don't bother with non-allocated sections */ | |
2289 | if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC)) | |
2290 | continue; | |
2291 | ||
2292 | /* Livepatch relocation sections are applied by livepatch */ | |
2293 | if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH) | |
2294 | continue; | |
2295 | ||
2296 | if (info->sechdrs[i].sh_type == SHT_REL) | |
2297 | err = apply_relocate(info->sechdrs, info->strtab, | |
2298 | info->index.sym, i, mod); | |
2299 | else if (info->sechdrs[i].sh_type == SHT_RELA) | |
2300 | err = apply_relocate_add(info->sechdrs, info->strtab, | |
2301 | info->index.sym, i, mod); | |
2302 | if (err < 0) | |
2303 | break; | |
2304 | } | |
2305 | return err; | |
2306 | } | |
2307 | ||
2308 | /* Additional bytes needed by arch in front of individual sections */ | |
2309 | unsigned int __weak arch_mod_section_prepend(struct module *mod, | |
2310 | unsigned int section) | |
2311 | { | |
2312 | /* default implementation just returns zero */ | |
2313 | return 0; | |
2314 | } | |
2315 | ||
2316 | /* Update size with this section: return offset. */ | |
2317 | static long get_offset(struct module *mod, unsigned int *size, | |
2318 | Elf_Shdr *sechdr, unsigned int section) | |
2319 | { | |
2320 | long ret; | |
2321 | ||
2322 | *size += arch_mod_section_prepend(mod, section); | |
2323 | ret = ALIGN(*size, sechdr->sh_addralign ?: 1); | |
2324 | *size = ret + sechdr->sh_size; | |
2325 | return ret; | |
2326 | } | |
2327 | ||
2328 | /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld | |
2329 | might -- code, read-only data, read-write data, small data. Tally | |
2330 | sizes, and place the offsets into sh_entsize fields: high bit means it | |
2331 | belongs in init. */ | |
2332 | static void layout_sections(struct module *mod, struct load_info *info) | |
2333 | { | |
2334 | static unsigned long const masks[][2] = { | |
2335 | /* NOTE: all executable code must be the first section | |
2336 | * in this array; otherwise modify the text_size | |
2337 | * finder in the two loops below */ | |
2338 | { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL }, | |
2339 | { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL }, | |
2340 | { SHF_RO_AFTER_INIT | SHF_ALLOC, ARCH_SHF_SMALL }, | |
2341 | { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL }, | |
2342 | { ARCH_SHF_SMALL | SHF_ALLOC, 0 } | |
2343 | }; | |
2344 | unsigned int m, i; | |
2345 | ||
2346 | for (i = 0; i < info->hdr->e_shnum; i++) | |
2347 | info->sechdrs[i].sh_entsize = ~0UL; | |
2348 | ||
2349 | pr_debug("Core section allocation order:\n"); | |
2350 | for (m = 0; m < ARRAY_SIZE(masks); ++m) { | |
2351 | for (i = 0; i < info->hdr->e_shnum; ++i) { | |
2352 | Elf_Shdr *s = &info->sechdrs[i]; | |
2353 | const char *sname = info->secstrings + s->sh_name; | |
2354 | ||
2355 | if ((s->sh_flags & masks[m][0]) != masks[m][0] | |
2356 | || (s->sh_flags & masks[m][1]) | |
2357 | || s->sh_entsize != ~0UL | |
2358 | || strstarts(sname, ".init")) | |
2359 | continue; | |
2360 | s->sh_entsize = get_offset(mod, &mod->core_layout.size, s, i); | |
2361 | pr_debug("\t%s\n", sname); | |
2362 | } | |
2363 | switch (m) { | |
2364 | case 0: /* executable */ | |
2365 | mod->core_layout.size = debug_align(mod->core_layout.size); | |
2366 | mod->core_layout.text_size = mod->core_layout.size; | |
2367 | break; | |
2368 | case 1: /* RO: text and ro-data */ | |
2369 | mod->core_layout.size = debug_align(mod->core_layout.size); | |
2370 | mod->core_layout.ro_size = mod->core_layout.size; | |
2371 | break; | |
2372 | case 2: /* RO after init */ | |
2373 | mod->core_layout.size = debug_align(mod->core_layout.size); | |
2374 | mod->core_layout.ro_after_init_size = mod->core_layout.size; | |
2375 | break; | |
2376 | case 4: /* whole core */ | |
2377 | mod->core_layout.size = debug_align(mod->core_layout.size); | |
2378 | break; | |
2379 | } | |
2380 | } | |
2381 | ||
2382 | pr_debug("Init section allocation order:\n"); | |
2383 | for (m = 0; m < ARRAY_SIZE(masks); ++m) { | |
2384 | for (i = 0; i < info->hdr->e_shnum; ++i) { | |
2385 | Elf_Shdr *s = &info->sechdrs[i]; | |
2386 | const char *sname = info->secstrings + s->sh_name; | |
2387 | ||
2388 | if ((s->sh_flags & masks[m][0]) != masks[m][0] | |
2389 | || (s->sh_flags & masks[m][1]) | |
2390 | || s->sh_entsize != ~0UL | |
2391 | || !strstarts(sname, ".init")) | |
2392 | continue; | |
2393 | s->sh_entsize = (get_offset(mod, &mod->init_layout.size, s, i) | |
2394 | | INIT_OFFSET_MASK); | |
2395 | pr_debug("\t%s\n", sname); | |
2396 | } | |
2397 | switch (m) { | |
2398 | case 0: /* executable */ | |
2399 | mod->init_layout.size = debug_align(mod->init_layout.size); | |
2400 | mod->init_layout.text_size = mod->init_layout.size; | |
2401 | break; | |
2402 | case 1: /* RO: text and ro-data */ | |
2403 | mod->init_layout.size = debug_align(mod->init_layout.size); | |
2404 | mod->init_layout.ro_size = mod->init_layout.size; | |
2405 | break; | |
2406 | case 2: | |
2407 | /* | |
2408 | * RO after init doesn't apply to init_layout (only | |
2409 | * core_layout), so it just takes the value of ro_size. | |
2410 | */ | |
2411 | mod->init_layout.ro_after_init_size = mod->init_layout.ro_size; | |
2412 | break; | |
2413 | case 4: /* whole init */ | |
2414 | mod->init_layout.size = debug_align(mod->init_layout.size); | |
2415 | break; | |
2416 | } | |
2417 | } | |
2418 | } | |
2419 | ||
2420 | static void set_license(struct module *mod, const char *license) | |
2421 | { | |
2422 | if (!license) | |
2423 | license = "unspecified"; | |
2424 | ||
2425 | if (!license_is_gpl_compatible(license)) { | |
2426 | if (!test_taint(TAINT_PROPRIETARY_MODULE)) | |
2427 | pr_warn("%s: module license '%s' taints kernel.\n", | |
2428 | mod->name, license); | |
2429 | add_taint_module(mod, TAINT_PROPRIETARY_MODULE, | |
2430 | LOCKDEP_NOW_UNRELIABLE); | |
2431 | } | |
2432 | } | |
2433 | ||
2434 | /* Parse tag=value strings from .modinfo section */ | |
2435 | static char *next_string(char *string, unsigned long *secsize) | |
2436 | { | |
2437 | /* Skip non-zero chars */ | |
2438 | while (string[0]) { | |
2439 | string++; | |
2440 | if ((*secsize)-- <= 1) | |
2441 | return NULL; | |
2442 | } | |
2443 | ||
2444 | /* Skip any zero padding. */ | |
2445 | while (!string[0]) { | |
2446 | string++; | |
2447 | if ((*secsize)-- <= 1) | |
2448 | return NULL; | |
2449 | } | |
2450 | return string; | |
2451 | } | |
2452 | ||
2453 | static char *get_modinfo(struct load_info *info, const char *tag) | |
2454 | { | |
2455 | char *p; | |
2456 | unsigned int taglen = strlen(tag); | |
2457 | Elf_Shdr *infosec = &info->sechdrs[info->index.info]; | |
2458 | unsigned long size = infosec->sh_size; | |
2459 | ||
2460 | for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) { | |
2461 | if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=') | |
2462 | return p + taglen + 1; | |
2463 | } | |
2464 | return NULL; | |
2465 | } | |
2466 | ||
2467 | static void setup_modinfo(struct module *mod, struct load_info *info) | |
2468 | { | |
2469 | struct module_attribute *attr; | |
2470 | int i; | |
2471 | ||
2472 | for (i = 0; (attr = modinfo_attrs[i]); i++) { | |
2473 | if (attr->setup) | |
2474 | attr->setup(mod, get_modinfo(info, attr->attr.name)); | |
2475 | } | |
2476 | } | |
2477 | ||
2478 | static void free_modinfo(struct module *mod) | |
2479 | { | |
2480 | struct module_attribute *attr; | |
2481 | int i; | |
2482 | ||
2483 | for (i = 0; (attr = modinfo_attrs[i]); i++) { | |
2484 | if (attr->free) | |
2485 | attr->free(mod); | |
2486 | } | |
2487 | } | |
2488 | ||
2489 | #ifdef CONFIG_KALLSYMS | |
2490 | ||
2491 | /* lookup symbol in given range of kernel_symbols */ | |
2492 | static const struct kernel_symbol *lookup_symbol(const char *name, | |
2493 | const struct kernel_symbol *start, | |
2494 | const struct kernel_symbol *stop) | |
2495 | { | |
2496 | return bsearch(name, start, stop - start, | |
2497 | sizeof(struct kernel_symbol), cmp_name); | |
2498 | } | |
2499 | ||
2500 | static int is_exported(const char *name, unsigned long value, | |
2501 | const struct module *mod) | |
2502 | { | |
2503 | const struct kernel_symbol *ks; | |
2504 | if (!mod) | |
2505 | ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab); | |
2506 | else | |
2507 | ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms); | |
2508 | return ks != NULL && ks->value == value; | |
2509 | } | |
2510 | ||
2511 | /* As per nm */ | |
2512 | static char elf_type(const Elf_Sym *sym, const struct load_info *info) | |
2513 | { | |
2514 | const Elf_Shdr *sechdrs = info->sechdrs; | |
2515 | ||
2516 | if (ELF_ST_BIND(sym->st_info) == STB_WEAK) { | |
2517 | if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT) | |
2518 | return 'v'; | |
2519 | else | |
2520 | return 'w'; | |
2521 | } | |
2522 | if (sym->st_shndx == SHN_UNDEF) | |
2523 | return 'U'; | |
2524 | if (sym->st_shndx == SHN_ABS || sym->st_shndx == info->index.pcpu) | |
2525 | return 'a'; | |
2526 | if (sym->st_shndx >= SHN_LORESERVE) | |
2527 | return '?'; | |
2528 | if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR) | |
2529 | return 't'; | |
2530 | if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC | |
2531 | && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) { | |
2532 | if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE)) | |
2533 | return 'r'; | |
2534 | else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL) | |
2535 | return 'g'; | |
2536 | else | |
2537 | return 'd'; | |
2538 | } | |
2539 | if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) { | |
2540 | if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL) | |
2541 | return 's'; | |
2542 | else | |
2543 | return 'b'; | |
2544 | } | |
2545 | if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name, | |
2546 | ".debug")) { | |
2547 | return 'n'; | |
2548 | } | |
2549 | return '?'; | |
2550 | } | |
2551 | ||
2552 | static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs, | |
2553 | unsigned int shnum, unsigned int pcpundx) | |
2554 | { | |
2555 | const Elf_Shdr *sec; | |
2556 | ||
2557 | if (src->st_shndx == SHN_UNDEF | |
2558 | || src->st_shndx >= shnum | |
2559 | || !src->st_name) | |
2560 | return false; | |
2561 | ||
2562 | #ifdef CONFIG_KALLSYMS_ALL | |
2563 | if (src->st_shndx == pcpundx) | |
2564 | return true; | |
2565 | #endif | |
2566 | ||
2567 | sec = sechdrs + src->st_shndx; | |
2568 | if (!(sec->sh_flags & SHF_ALLOC) | |
2569 | #ifndef CONFIG_KALLSYMS_ALL | |
2570 | || !(sec->sh_flags & SHF_EXECINSTR) | |
2571 | #endif | |
2572 | || (sec->sh_entsize & INIT_OFFSET_MASK)) | |
2573 | return false; | |
2574 | ||
2575 | return true; | |
2576 | } | |
2577 | ||
2578 | /* | |
2579 | * We only allocate and copy the strings needed by the parts of symtab | |
2580 | * we keep. This is simple, but has the effect of making multiple | |
2581 | * copies of duplicates. We could be more sophisticated, see | |
2582 | * linux-kernel thread starting with | |
2583 | * <73defb5e4bca04a6431392cc341112b1@localhost>. | |
2584 | */ | |
2585 | static void layout_symtab(struct module *mod, struct load_info *info) | |
2586 | { | |
2587 | Elf_Shdr *symsect = info->sechdrs + info->index.sym; | |
2588 | Elf_Shdr *strsect = info->sechdrs + info->index.str; | |
2589 | const Elf_Sym *src; | |
2590 | unsigned int i, nsrc, ndst, strtab_size = 0; | |
2591 | ||
2592 | /* Put symbol section at end of init part of module. */ | |
2593 | symsect->sh_flags |= SHF_ALLOC; | |
2594 | symsect->sh_entsize = get_offset(mod, &mod->init_layout.size, symsect, | |
2595 | info->index.sym) | INIT_OFFSET_MASK; | |
2596 | pr_debug("\t%s\n", info->secstrings + symsect->sh_name); | |
2597 | ||
2598 | src = (void *)info->hdr + symsect->sh_offset; | |
2599 | nsrc = symsect->sh_size / sizeof(*src); | |
2600 | ||
2601 | /* Compute total space required for the core symbols' strtab. */ | |
2602 | for (ndst = i = 0; i < nsrc; i++) { | |
2603 | if (i == 0 || is_livepatch_module(mod) || | |
2604 | is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum, | |
2605 | info->index.pcpu)) { | |
2606 | strtab_size += strlen(&info->strtab[src[i].st_name])+1; | |
2607 | ndst++; | |
2608 | } | |
2609 | } | |
2610 | ||
2611 | /* Append room for core symbols at end of core part. */ | |
2612 | info->symoffs = ALIGN(mod->core_layout.size, symsect->sh_addralign ?: 1); | |
2613 | info->stroffs = mod->core_layout.size = info->symoffs + ndst * sizeof(Elf_Sym); | |
2614 | mod->core_layout.size += strtab_size; | |
2615 | mod->core_layout.size = debug_align(mod->core_layout.size); | |
2616 | ||
2617 | /* Put string table section at end of init part of module. */ | |
2618 | strsect->sh_flags |= SHF_ALLOC; | |
2619 | strsect->sh_entsize = get_offset(mod, &mod->init_layout.size, strsect, | |
2620 | info->index.str) | INIT_OFFSET_MASK; | |
2621 | pr_debug("\t%s\n", info->secstrings + strsect->sh_name); | |
2622 | ||
2623 | /* We'll tack temporary mod_kallsyms on the end. */ | |
2624 | mod->init_layout.size = ALIGN(mod->init_layout.size, | |
2625 | __alignof__(struct mod_kallsyms)); | |
2626 | info->mod_kallsyms_init_off = mod->init_layout.size; | |
2627 | mod->init_layout.size += sizeof(struct mod_kallsyms); | |
2628 | mod->init_layout.size = debug_align(mod->init_layout.size); | |
2629 | } | |
2630 | ||
2631 | /* | |
2632 | * We use the full symtab and strtab which layout_symtab arranged to | |
2633 | * be appended to the init section. Later we switch to the cut-down | |
2634 | * core-only ones. | |
2635 | */ | |
2636 | static void add_kallsyms(struct module *mod, const struct load_info *info) | |
2637 | { | |
2638 | unsigned int i, ndst; | |
2639 | const Elf_Sym *src; | |
2640 | Elf_Sym *dst; | |
2641 | char *s; | |
2642 | Elf_Shdr *symsec = &info->sechdrs[info->index.sym]; | |
2643 | ||
2644 | /* Set up to point into init section. */ | |
2645 | mod->kallsyms = mod->init_layout.base + info->mod_kallsyms_init_off; | |
2646 | ||
2647 | mod->kallsyms->symtab = (void *)symsec->sh_addr; | |
2648 | mod->kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym); | |
2649 | /* Make sure we get permanent strtab: don't use info->strtab. */ | |
2650 | mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr; | |
2651 | ||
2652 | /* Set types up while we still have access to sections. */ | |
2653 | for (i = 0; i < mod->kallsyms->num_symtab; i++) | |
2654 | mod->kallsyms->symtab[i].st_info | |
2655 | = elf_type(&mod->kallsyms->symtab[i], info); | |
2656 | ||
2657 | /* Now populate the cut down core kallsyms for after init. */ | |
2658 | mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs; | |
2659 | mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs; | |
2660 | src = mod->kallsyms->symtab; | |
2661 | for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) { | |
2662 | if (i == 0 || is_livepatch_module(mod) || | |
2663 | is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum, | |
2664 | info->index.pcpu)) { | |
2665 | dst[ndst] = src[i]; | |
2666 | dst[ndst++].st_name = s - mod->core_kallsyms.strtab; | |
2667 | s += strlcpy(s, &mod->kallsyms->strtab[src[i].st_name], | |
2668 | KSYM_NAME_LEN) + 1; | |
2669 | } | |
2670 | } | |
2671 | mod->core_kallsyms.num_symtab = ndst; | |
2672 | } | |
2673 | #else | |
2674 | static inline void layout_symtab(struct module *mod, struct load_info *info) | |
2675 | { | |
2676 | } | |
2677 | ||
2678 | static void add_kallsyms(struct module *mod, const struct load_info *info) | |
2679 | { | |
2680 | } | |
2681 | #endif /* CONFIG_KALLSYMS */ | |
2682 | ||
2683 | static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num) | |
2684 | { | |
2685 | if (!debug) | |
2686 | return; | |
2687 | #ifdef CONFIG_DYNAMIC_DEBUG | |
2688 | if (ddebug_add_module(debug, num, debug->modname)) | |
2689 | pr_err("dynamic debug error adding module: %s\n", | |
2690 | debug->modname); | |
2691 | #endif | |
2692 | } | |
2693 | ||
2694 | static void dynamic_debug_remove(struct _ddebug *debug) | |
2695 | { | |
2696 | if (debug) | |
2697 | ddebug_remove_module(debug->modname); | |
2698 | } | |
2699 | ||
2700 | void * __weak module_alloc(unsigned long size) | |
2701 | { | |
2702 | return vmalloc_exec(size); | |
2703 | } | |
2704 | ||
2705 | #ifdef CONFIG_DEBUG_KMEMLEAK | |
2706 | static void kmemleak_load_module(const struct module *mod, | |
2707 | const struct load_info *info) | |
2708 | { | |
2709 | unsigned int i; | |
2710 | ||
2711 | /* only scan the sections containing data */ | |
2712 | kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL); | |
2713 | ||
2714 | for (i = 1; i < info->hdr->e_shnum; i++) { | |
2715 | /* Scan all writable sections that's not executable */ | |
2716 | if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) || | |
2717 | !(info->sechdrs[i].sh_flags & SHF_WRITE) || | |
2718 | (info->sechdrs[i].sh_flags & SHF_EXECINSTR)) | |
2719 | continue; | |
2720 | ||
2721 | kmemleak_scan_area((void *)info->sechdrs[i].sh_addr, | |
2722 | info->sechdrs[i].sh_size, GFP_KERNEL); | |
2723 | } | |
2724 | } | |
2725 | #else | |
2726 | static inline void kmemleak_load_module(const struct module *mod, | |
2727 | const struct load_info *info) | |
2728 | { | |
2729 | } | |
2730 | #endif | |
2731 | ||
2732 | #ifdef CONFIG_MODULE_SIG | |
2733 | static int module_sig_check(struct load_info *info, int flags) | |
2734 | { | |
2735 | int err = -ENOKEY; | |
2736 | const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1; | |
2737 | const void *mod = info->hdr; | |
2738 | ||
2739 | /* | |
2740 | * Require flags == 0, as a module with version information | |
2741 | * removed is no longer the module that was signed | |
2742 | */ | |
2743 | if (flags == 0 && | |
2744 | info->len > markerlen && | |
2745 | memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) { | |
2746 | /* We truncate the module to discard the signature */ | |
2747 | info->len -= markerlen; | |
2748 | err = mod_verify_sig(mod, &info->len); | |
2749 | } | |
2750 | ||
2751 | if (!err) { | |
2752 | info->sig_ok = true; | |
2753 | return 0; | |
2754 | } | |
2755 | ||
2756 | /* Not having a signature is only an error if we're strict. */ | |
2757 | if (err == -ENOKEY && !sig_enforce) | |
2758 | err = 0; | |
2759 | ||
2760 | return err; | |
2761 | } | |
2762 | #else /* !CONFIG_MODULE_SIG */ | |
2763 | static int module_sig_check(struct load_info *info, int flags) | |
2764 | { | |
2765 | return 0; | |
2766 | } | |
2767 | #endif /* !CONFIG_MODULE_SIG */ | |
2768 | ||
2769 | /* Sanity checks against invalid binaries, wrong arch, weird elf version. */ | |
2770 | static int elf_header_check(struct load_info *info) | |
2771 | { | |
2772 | if (info->len < sizeof(*(info->hdr))) | |
2773 | return -ENOEXEC; | |
2774 | ||
2775 | if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0 | |
2776 | || info->hdr->e_type != ET_REL | |
2777 | || !elf_check_arch(info->hdr) | |
2778 | || info->hdr->e_shentsize != sizeof(Elf_Shdr)) | |
2779 | return -ENOEXEC; | |
2780 | ||
2781 | if (info->hdr->e_shoff >= info->len | |
2782 | || (info->hdr->e_shnum * sizeof(Elf_Shdr) > | |
2783 | info->len - info->hdr->e_shoff)) | |
2784 | return -ENOEXEC; | |
2785 | ||
2786 | return 0; | |
2787 | } | |
2788 | ||
2789 | #define COPY_CHUNK_SIZE (16*PAGE_SIZE) | |
2790 | ||
2791 | static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len) | |
2792 | { | |
2793 | do { | |
2794 | unsigned long n = min(len, COPY_CHUNK_SIZE); | |
2795 | ||
2796 | if (copy_from_user(dst, usrc, n) != 0) | |
2797 | return -EFAULT; | |
2798 | cond_resched(); | |
2799 | dst += n; | |
2800 | usrc += n; | |
2801 | len -= n; | |
2802 | } while (len); | |
2803 | return 0; | |
2804 | } | |
2805 | ||
2806 | #ifdef CONFIG_LIVEPATCH | |
2807 | static int check_modinfo_livepatch(struct module *mod, struct load_info *info) | |
2808 | { | |
2809 | if (get_modinfo(info, "livepatch")) { | |
2810 | mod->klp = true; | |
2811 | add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK); | |
2812 | } | |
2813 | ||
2814 | return 0; | |
2815 | } | |
2816 | #else /* !CONFIG_LIVEPATCH */ | |
2817 | static int check_modinfo_livepatch(struct module *mod, struct load_info *info) | |
2818 | { | |
2819 | if (get_modinfo(info, "livepatch")) { | |
2820 | pr_err("%s: module is marked as livepatch module, but livepatch support is disabled", | |
2821 | mod->name); | |
2822 | return -ENOEXEC; | |
2823 | } | |
2824 | ||
2825 | return 0; | |
2826 | } | |
2827 | #endif /* CONFIG_LIVEPATCH */ | |
2828 | ||
2829 | /* Sets info->hdr and info->len. */ | |
2830 | static int copy_module_from_user(const void __user *umod, unsigned long len, | |
2831 | struct load_info *info) | |
2832 | { | |
2833 | int err; | |
2834 | ||
2835 | info->len = len; | |
2836 | if (info->len < sizeof(*(info->hdr))) | |
2837 | return -ENOEXEC; | |
2838 | ||
2839 | err = security_kernel_read_file(NULL, READING_MODULE); | |
2840 | if (err) | |
2841 | return err; | |
2842 | ||
2843 | /* Suck in entire file: we'll want most of it. */ | |
2844 | info->hdr = __vmalloc(info->len, | |
2845 | GFP_KERNEL | __GFP_HIGHMEM | __GFP_NOWARN, PAGE_KERNEL); | |
2846 | if (!info->hdr) | |
2847 | return -ENOMEM; | |
2848 | ||
2849 | if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) { | |
2850 | vfree(info->hdr); | |
2851 | return -EFAULT; | |
2852 | } | |
2853 | ||
2854 | return 0; | |
2855 | } | |
2856 | ||
2857 | static void free_copy(struct load_info *info) | |
2858 | { | |
2859 | vfree(info->hdr); | |
2860 | } | |
2861 | ||
2862 | static int rewrite_section_headers(struct load_info *info, int flags) | |
2863 | { | |
2864 | unsigned int i; | |
2865 | ||
2866 | /* This should always be true, but let's be sure. */ | |
2867 | info->sechdrs[0].sh_addr = 0; | |
2868 | ||
2869 | for (i = 1; i < info->hdr->e_shnum; i++) { | |
2870 | Elf_Shdr *shdr = &info->sechdrs[i]; | |
2871 | if (shdr->sh_type != SHT_NOBITS | |
2872 | && info->len < shdr->sh_offset + shdr->sh_size) { | |
2873 | pr_err("Module len %lu truncated\n", info->len); | |
2874 | return -ENOEXEC; | |
2875 | } | |
2876 | ||
2877 | /* Mark all sections sh_addr with their address in the | |
2878 | temporary image. */ | |
2879 | shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset; | |
2880 | ||
2881 | #ifndef CONFIG_MODULE_UNLOAD | |
2882 | /* Don't load .exit sections */ | |
2883 | if (strstarts(info->secstrings+shdr->sh_name, ".exit")) | |
2884 | shdr->sh_flags &= ~(unsigned long)SHF_ALLOC; | |
2885 | #endif | |
2886 | } | |
2887 | ||
2888 | /* Track but don't keep modinfo and version sections. */ | |
2889 | if (flags & MODULE_INIT_IGNORE_MODVERSIONS) | |
2890 | info->index.vers = 0; /* Pretend no __versions section! */ | |
2891 | else | |
2892 | info->index.vers = find_sec(info, "__versions"); | |
2893 | info->index.info = find_sec(info, ".modinfo"); | |
2894 | info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC; | |
2895 | info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC; | |
2896 | return 0; | |
2897 | } | |
2898 | ||
2899 | /* | |
2900 | * Set up our basic convenience variables (pointers to section headers, | |
2901 | * search for module section index etc), and do some basic section | |
2902 | * verification. | |
2903 | * | |
2904 | * Return the temporary module pointer (we'll replace it with the final | |
2905 | * one when we move the module sections around). | |
2906 | */ | |
2907 | static struct module *setup_load_info(struct load_info *info, int flags) | |
2908 | { | |
2909 | unsigned int i; | |
2910 | int err; | |
2911 | struct module *mod; | |
2912 | ||
2913 | /* Set up the convenience variables */ | |
2914 | info->sechdrs = (void *)info->hdr + info->hdr->e_shoff; | |
2915 | info->secstrings = (void *)info->hdr | |
2916 | + info->sechdrs[info->hdr->e_shstrndx].sh_offset; | |
2917 | ||
2918 | err = rewrite_section_headers(info, flags); | |
2919 | if (err) | |
2920 | return ERR_PTR(err); | |
2921 | ||
2922 | /* Find internal symbols and strings. */ | |
2923 | for (i = 1; i < info->hdr->e_shnum; i++) { | |
2924 | if (info->sechdrs[i].sh_type == SHT_SYMTAB) { | |
2925 | info->index.sym = i; | |
2926 | info->index.str = info->sechdrs[i].sh_link; | |
2927 | info->strtab = (char *)info->hdr | |
2928 | + info->sechdrs[info->index.str].sh_offset; | |
2929 | break; | |
2930 | } | |
2931 | } | |
2932 | ||
2933 | info->index.mod = find_sec(info, ".gnu.linkonce.this_module"); | |
2934 | if (!info->index.mod) { | |
2935 | pr_warn("No module found in object\n"); | |
2936 | return ERR_PTR(-ENOEXEC); | |
2937 | } | |
2938 | /* This is temporary: point mod into copy of data. */ | |
2939 | mod = (void *)info->sechdrs[info->index.mod].sh_addr; | |
2940 | ||
2941 | if (info->index.sym == 0) { | |
2942 | pr_warn("%s: module has no symbols (stripped?)\n", mod->name); | |
2943 | return ERR_PTR(-ENOEXEC); | |
2944 | } | |
2945 | ||
2946 | info->index.pcpu = find_pcpusec(info); | |
2947 | ||
2948 | /* Check module struct version now, before we try to use module. */ | |
2949 | if (!check_modstruct_version(info->sechdrs, info->index.vers, mod)) | |
2950 | return ERR_PTR(-ENOEXEC); | |
2951 | ||
2952 | return mod; | |
2953 | } | |
2954 | ||
2955 | static int check_modinfo(struct module *mod, struct load_info *info, int flags) | |
2956 | { | |
2957 | const char *modmagic = get_modinfo(info, "vermagic"); | |
2958 | int err; | |
2959 | ||
2960 | if (flags & MODULE_INIT_IGNORE_VERMAGIC) | |
2961 | modmagic = NULL; | |
2962 | ||
2963 | /* This is allowed: modprobe --force will invalidate it. */ | |
2964 | if (!modmagic) { | |
2965 | err = try_to_force_load(mod, "bad vermagic"); | |
2966 | if (err) | |
2967 | return err; | |
2968 | } else if (!same_magic(modmagic, vermagic, info->index.vers)) { | |
2969 | pr_err("%s: version magic '%s' should be '%s'\n", | |
2970 | mod->name, modmagic, vermagic); | |
2971 | return -ENOEXEC; | |
2972 | } | |
2973 | ||
2974 | if (!get_modinfo(info, "intree")) { | |
2975 | if (!test_taint(TAINT_OOT_MODULE)) | |
2976 | pr_warn("%s: loading out-of-tree module taints kernel.\n", | |
2977 | mod->name); | |
2978 | add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK); | |
2979 | } | |
2980 | ||
2981 | if (get_modinfo(info, "staging")) { | |
2982 | add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK); | |
2983 | pr_warn("%s: module is from the staging directory, the quality " | |
2984 | "is unknown, you have been warned.\n", mod->name); | |
2985 | } | |
2986 | ||
2987 | err = check_modinfo_livepatch(mod, info); | |
2988 | if (err) | |
2989 | return err; | |
2990 | ||
2991 | /* Set up license info based on the info section */ | |
2992 | set_license(mod, get_modinfo(info, "license")); | |
2993 | ||
2994 | return 0; | |
2995 | } | |
2996 | ||
2997 | static int find_module_sections(struct module *mod, struct load_info *info) | |
2998 | { | |
2999 | mod->kp = section_objs(info, "__param", | |
3000 | sizeof(*mod->kp), &mod->num_kp); | |
3001 | mod->syms = section_objs(info, "__ksymtab", | |
3002 | sizeof(*mod->syms), &mod->num_syms); | |
3003 | mod->crcs = section_addr(info, "__kcrctab"); | |
3004 | mod->gpl_syms = section_objs(info, "__ksymtab_gpl", | |
3005 | sizeof(*mod->gpl_syms), | |
3006 | &mod->num_gpl_syms); | |
3007 | mod->gpl_crcs = section_addr(info, "__kcrctab_gpl"); | |
3008 | mod->gpl_future_syms = section_objs(info, | |
3009 | "__ksymtab_gpl_future", | |
3010 | sizeof(*mod->gpl_future_syms), | |
3011 | &mod->num_gpl_future_syms); | |
3012 | mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future"); | |
3013 | ||
3014 | #ifdef CONFIG_UNUSED_SYMBOLS | |
3015 | mod->unused_syms = section_objs(info, "__ksymtab_unused", | |
3016 | sizeof(*mod->unused_syms), | |
3017 | &mod->num_unused_syms); | |
3018 | mod->unused_crcs = section_addr(info, "__kcrctab_unused"); | |
3019 | mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl", | |
3020 | sizeof(*mod->unused_gpl_syms), | |
3021 | &mod->num_unused_gpl_syms); | |
3022 | mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl"); | |
3023 | #endif | |
3024 | #ifdef CONFIG_CONSTRUCTORS | |
3025 | mod->ctors = section_objs(info, ".ctors", | |
3026 | sizeof(*mod->ctors), &mod->num_ctors); | |
3027 | if (!mod->ctors) | |
3028 | mod->ctors = section_objs(info, ".init_array", | |
3029 | sizeof(*mod->ctors), &mod->num_ctors); | |
3030 | else if (find_sec(info, ".init_array")) { | |
3031 | /* | |
3032 | * This shouldn't happen with same compiler and binutils | |
3033 | * building all parts of the module. | |
3034 | */ | |
3035 | pr_warn("%s: has both .ctors and .init_array.\n", | |
3036 | mod->name); | |
3037 | return -EINVAL; | |
3038 | } | |
3039 | #endif | |
3040 | ||
3041 | #ifdef CONFIG_TRACEPOINTS | |
3042 | mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs", | |
3043 | sizeof(*mod->tracepoints_ptrs), | |
3044 | &mod->num_tracepoints); | |
3045 | #endif | |
3046 | #ifdef HAVE_JUMP_LABEL | |
3047 | mod->jump_entries = section_objs(info, "__jump_table", | |
3048 | sizeof(*mod->jump_entries), | |
3049 | &mod->num_jump_entries); | |
3050 | #endif | |
3051 | #ifdef CONFIG_EVENT_TRACING | |
3052 | mod->trace_events = section_objs(info, "_ftrace_events", | |
3053 | sizeof(*mod->trace_events), | |
3054 | &mod->num_trace_events); | |
3055 | mod->trace_enums = section_objs(info, "_ftrace_enum_map", | |
3056 | sizeof(*mod->trace_enums), | |
3057 | &mod->num_trace_enums); | |
3058 | #endif | |
3059 | #ifdef CONFIG_TRACING | |
3060 | mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt", | |
3061 | sizeof(*mod->trace_bprintk_fmt_start), | |
3062 | &mod->num_trace_bprintk_fmt); | |
3063 | #endif | |
3064 | #ifdef CONFIG_FTRACE_MCOUNT_RECORD | |
3065 | /* sechdrs[0].sh_size is always zero */ | |
3066 | mod->ftrace_callsites = section_objs(info, "__mcount_loc", | |
3067 | sizeof(*mod->ftrace_callsites), | |
3068 | &mod->num_ftrace_callsites); | |
3069 | #endif | |
3070 | ||
3071 | mod->extable = section_objs(info, "__ex_table", | |
3072 | sizeof(*mod->extable), &mod->num_exentries); | |
3073 | ||
3074 | if (section_addr(info, "__obsparm")) | |
3075 | pr_warn("%s: Ignoring obsolete parameters\n", mod->name); | |
3076 | ||
3077 | info->debug = section_objs(info, "__verbose", | |
3078 | sizeof(*info->debug), &info->num_debug); | |
3079 | ||
3080 | return 0; | |
3081 | } | |
3082 | ||
3083 | static int move_module(struct module *mod, struct load_info *info) | |
3084 | { | |
3085 | int i; | |
3086 | void *ptr; | |
3087 | ||
3088 | /* Do the allocs. */ | |
3089 | ptr = module_alloc(mod->core_layout.size); | |
3090 | /* | |
3091 | * The pointer to this block is stored in the module structure | |
3092 | * which is inside the block. Just mark it as not being a | |
3093 | * leak. | |
3094 | */ | |
3095 | kmemleak_not_leak(ptr); | |
3096 | if (!ptr) | |
3097 | return -ENOMEM; | |
3098 | ||
3099 | memset(ptr, 0, mod->core_layout.size); | |
3100 | mod->core_layout.base = ptr; | |
3101 | ||
3102 | if (mod->init_layout.size) { | |
3103 | ptr = module_alloc(mod->init_layout.size); | |
3104 | /* | |
3105 | * The pointer to this block is stored in the module structure | |
3106 | * which is inside the block. This block doesn't need to be | |
3107 | * scanned as it contains data and code that will be freed | |
3108 | * after the module is initialized. | |
3109 | */ | |
3110 | kmemleak_ignore(ptr); | |
3111 | if (!ptr) { | |
3112 | module_memfree(mod->core_layout.base); | |
3113 | return -ENOMEM; | |
3114 | } | |
3115 | memset(ptr, 0, mod->init_layout.size); | |
3116 | mod->init_layout.base = ptr; | |
3117 | } else | |
3118 | mod->init_layout.base = NULL; | |
3119 | ||
3120 | /* Transfer each section which specifies SHF_ALLOC */ | |
3121 | pr_debug("final section addresses:\n"); | |
3122 | for (i = 0; i < info->hdr->e_shnum; i++) { | |
3123 | void *dest; | |
3124 | Elf_Shdr *shdr = &info->sechdrs[i]; | |
3125 | ||
3126 | if (!(shdr->sh_flags & SHF_ALLOC)) | |
3127 | continue; | |
3128 | ||
3129 | if (shdr->sh_entsize & INIT_OFFSET_MASK) | |
3130 | dest = mod->init_layout.base | |
3131 | + (shdr->sh_entsize & ~INIT_OFFSET_MASK); | |
3132 | else | |
3133 | dest = mod->core_layout.base + shdr->sh_entsize; | |
3134 | ||
3135 | if (shdr->sh_type != SHT_NOBITS) | |
3136 | memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size); | |
3137 | /* Update sh_addr to point to copy in image. */ | |
3138 | shdr->sh_addr = (unsigned long)dest; | |
3139 | pr_debug("\t0x%lx %s\n", | |
3140 | (long)shdr->sh_addr, info->secstrings + shdr->sh_name); | |
3141 | } | |
3142 | ||
3143 | return 0; | |
3144 | } | |
3145 | ||
3146 | static int check_module_license_and_versions(struct module *mod) | |
3147 | { | |
3148 | int prev_taint = test_taint(TAINT_PROPRIETARY_MODULE); | |
3149 | ||
3150 | /* | |
3151 | * ndiswrapper is under GPL by itself, but loads proprietary modules. | |
3152 | * Don't use add_taint_module(), as it would prevent ndiswrapper from | |
3153 | * using GPL-only symbols it needs. | |
3154 | */ | |
3155 | if (strcmp(mod->name, "ndiswrapper") == 0) | |
3156 | add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE); | |
3157 | ||
3158 | /* driverloader was caught wrongly pretending to be under GPL */ | |
3159 | if (strcmp(mod->name, "driverloader") == 0) | |
3160 | add_taint_module(mod, TAINT_PROPRIETARY_MODULE, | |
3161 | LOCKDEP_NOW_UNRELIABLE); | |
3162 | ||
3163 | /* lve claims to be GPL but upstream won't provide source */ | |
3164 | if (strcmp(mod->name, "lve") == 0) | |
3165 | add_taint_module(mod, TAINT_PROPRIETARY_MODULE, | |
3166 | LOCKDEP_NOW_UNRELIABLE); | |
3167 | ||
3168 | if (!prev_taint && test_taint(TAINT_PROPRIETARY_MODULE)) | |
3169 | pr_warn("%s: module license taints kernel.\n", mod->name); | |
3170 | ||
3171 | #ifdef CONFIG_MODVERSIONS | |
3172 | if ((mod->num_syms && !mod->crcs) | |
3173 | || (mod->num_gpl_syms && !mod->gpl_crcs) | |
3174 | || (mod->num_gpl_future_syms && !mod->gpl_future_crcs) | |
3175 | #ifdef CONFIG_UNUSED_SYMBOLS | |
3176 | || (mod->num_unused_syms && !mod->unused_crcs) | |
3177 | || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs) | |
3178 | #endif | |
3179 | ) { | |
3180 | return try_to_force_load(mod, | |
3181 | "no versions for exported symbols"); | |
3182 | } | |
3183 | #endif | |
3184 | return 0; | |
3185 | } | |
3186 | ||
3187 | static void flush_module_icache(const struct module *mod) | |
3188 | { | |
3189 | mm_segment_t old_fs; | |
3190 | ||
3191 | /* flush the icache in correct context */ | |
3192 | old_fs = get_fs(); | |
3193 | set_fs(KERNEL_DS); | |
3194 | ||
3195 | /* | |
3196 | * Flush the instruction cache, since we've played with text. | |
3197 | * Do it before processing of module parameters, so the module | |
3198 | * can provide parameter accessor functions of its own. | |
3199 | */ | |
3200 | if (mod->init_layout.base) | |
3201 | flush_icache_range((unsigned long)mod->init_layout.base, | |
3202 | (unsigned long)mod->init_layout.base | |
3203 | + mod->init_layout.size); | |
3204 | flush_icache_range((unsigned long)mod->core_layout.base, | |
3205 | (unsigned long)mod->core_layout.base + mod->core_layout.size); | |
3206 | ||
3207 | set_fs(old_fs); | |
3208 | } | |
3209 | ||
3210 | int __weak module_frob_arch_sections(Elf_Ehdr *hdr, | |
3211 | Elf_Shdr *sechdrs, | |
3212 | char *secstrings, | |
3213 | struct module *mod) | |
3214 | { | |
3215 | return 0; | |
3216 | } | |
3217 | ||
3218 | /* module_blacklist is a comma-separated list of module names */ | |
3219 | static char *module_blacklist; | |
3220 | static bool blacklisted(char *module_name) | |
3221 | { | |
3222 | const char *p; | |
3223 | size_t len; | |
3224 | ||
3225 | if (!module_blacklist) | |
3226 | return false; | |
3227 | ||
3228 | for (p = module_blacklist; *p; p += len) { | |
3229 | len = strcspn(p, ","); | |
3230 | if (strlen(module_name) == len && !memcmp(module_name, p, len)) | |
3231 | return true; | |
3232 | if (p[len] == ',') | |
3233 | len++; | |
3234 | } | |
3235 | return false; | |
3236 | } | |
3237 | core_param(module_blacklist, module_blacklist, charp, 0400); | |
3238 | ||
3239 | static struct module *layout_and_allocate(struct load_info *info, int flags) | |
3240 | { | |
3241 | /* Module within temporary copy. */ | |
3242 | struct module *mod; | |
3243 | unsigned int ndx; | |
3244 | int err; | |
3245 | ||
3246 | mod = setup_load_info(info, flags); | |
3247 | if (IS_ERR(mod)) | |
3248 | return mod; | |
3249 | ||
3250 | if (blacklisted(mod->name)) | |
3251 | return ERR_PTR(-EPERM); | |
3252 | ||
3253 | err = check_modinfo(mod, info, flags); | |
3254 | if (err) | |
3255 | return ERR_PTR(err); | |
3256 | ||
3257 | /* Allow arches to frob section contents and sizes. */ | |
3258 | err = module_frob_arch_sections(info->hdr, info->sechdrs, | |
3259 | info->secstrings, mod); | |
3260 | if (err < 0) | |
3261 | return ERR_PTR(err); | |
3262 | ||
3263 | /* We will do a special allocation for per-cpu sections later. */ | |
3264 | info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC; | |
3265 | ||
3266 | /* | |
3267 | * Mark ro_after_init section with SHF_RO_AFTER_INIT so that | |
3268 | * layout_sections() can put it in the right place. | |
3269 | * Note: ro_after_init sections also have SHF_{WRITE,ALLOC} set. | |
3270 | */ | |
3271 | ndx = find_sec(info, ".data..ro_after_init"); | |
3272 | if (ndx) | |
3273 | info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT; | |
3274 | ||
3275 | /* Determine total sizes, and put offsets in sh_entsize. For now | |
3276 | this is done generically; there doesn't appear to be any | |
3277 | special cases for the architectures. */ | |
3278 | layout_sections(mod, info); | |
3279 | layout_symtab(mod, info); | |
3280 | ||
3281 | /* Allocate and move to the final place */ | |
3282 | err = move_module(mod, info); | |
3283 | if (err) | |
3284 | return ERR_PTR(err); | |
3285 | ||
3286 | /* Module has been copied to its final place now: return it. */ | |
3287 | mod = (void *)info->sechdrs[info->index.mod].sh_addr; | |
3288 | kmemleak_load_module(mod, info); | |
3289 | return mod; | |
3290 | } | |
3291 | ||
3292 | /* mod is no longer valid after this! */ | |
3293 | static void module_deallocate(struct module *mod, struct load_info *info) | |
3294 | { | |
3295 | percpu_modfree(mod); | |
3296 | module_arch_freeing_init(mod); | |
3297 | module_memfree(mod->init_layout.base); | |
3298 | module_memfree(mod->core_layout.base); | |
3299 | } | |
3300 | ||
3301 | int __weak module_finalize(const Elf_Ehdr *hdr, | |
3302 | const Elf_Shdr *sechdrs, | |
3303 | struct module *me) | |
3304 | { | |
3305 | return 0; | |
3306 | } | |
3307 | ||
3308 | static int post_relocation(struct module *mod, const struct load_info *info) | |
3309 | { | |
3310 | /* Sort exception table now relocations are done. */ | |
3311 | sort_extable(mod->extable, mod->extable + mod->num_exentries); | |
3312 | ||
3313 | /* Copy relocated percpu area over. */ | |
3314 | percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr, | |
3315 | info->sechdrs[info->index.pcpu].sh_size); | |
3316 | ||
3317 | /* Setup kallsyms-specific fields. */ | |
3318 | add_kallsyms(mod, info); | |
3319 | ||
3320 | /* Arch-specific module finalizing. */ | |
3321 | return module_finalize(info->hdr, info->sechdrs, mod); | |
3322 | } | |
3323 | ||
3324 | /* Is this module of this name done loading? No locks held. */ | |
3325 | static bool finished_loading(const char *name) | |
3326 | { | |
3327 | struct module *mod; | |
3328 | bool ret; | |
3329 | ||
3330 | /* | |
3331 | * The module_mutex should not be a heavily contended lock; | |
3332 | * if we get the occasional sleep here, we'll go an extra iteration | |
3333 | * in the wait_event_interruptible(), which is harmless. | |
3334 | */ | |
3335 | sched_annotate_sleep(); | |
3336 | mutex_lock(&module_mutex); | |
3337 | mod = find_module_all(name, strlen(name), true); | |
3338 | ret = !mod || mod->state == MODULE_STATE_LIVE | |
3339 | || mod->state == MODULE_STATE_GOING; | |
3340 | mutex_unlock(&module_mutex); | |
3341 | ||
3342 | return ret; | |
3343 | } | |
3344 | ||
3345 | /* Call module constructors. */ | |
3346 | static void do_mod_ctors(struct module *mod) | |
3347 | { | |
3348 | #ifdef CONFIG_CONSTRUCTORS | |
3349 | unsigned long i; | |
3350 | ||
3351 | for (i = 0; i < mod->num_ctors; i++) | |
3352 | mod->ctors[i](); | |
3353 | #endif | |
3354 | } | |
3355 | ||
3356 | /* For freeing module_init on success, in case kallsyms traversing */ | |
3357 | struct mod_initfree { | |
3358 | struct rcu_head rcu; | |
3359 | void *module_init; | |
3360 | }; | |
3361 | ||
3362 | static void do_free_init(struct rcu_head *head) | |
3363 | { | |
3364 | struct mod_initfree *m = container_of(head, struct mod_initfree, rcu); | |
3365 | module_memfree(m->module_init); | |
3366 | kfree(m); | |
3367 | } | |
3368 | ||
3369 | /* | |
3370 | * This is where the real work happens. | |
3371 | * | |
3372 | * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb | |
3373 | * helper command 'lx-symbols'. | |
3374 | */ | |
3375 | static noinline int do_init_module(struct module *mod) | |
3376 | { | |
3377 | int ret = 0; | |
3378 | struct mod_initfree *freeinit; | |
3379 | ||
3380 | freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL); | |
3381 | if (!freeinit) { | |
3382 | ret = -ENOMEM; | |
3383 | goto fail; | |
3384 | } | |
3385 | freeinit->module_init = mod->init_layout.base; | |
3386 | ||
3387 | /* | |
3388 | * We want to find out whether @mod uses async during init. Clear | |
3389 | * PF_USED_ASYNC. async_schedule*() will set it. | |
3390 | */ | |
3391 | current->flags &= ~PF_USED_ASYNC; | |
3392 | ||
3393 | do_mod_ctors(mod); | |
3394 | /* Start the module */ | |
3395 | if (mod->init != NULL) | |
3396 | ret = do_one_initcall(mod->init); | |
3397 | if (ret < 0) { | |
3398 | goto fail_free_freeinit; | |
3399 | } | |
3400 | if (ret > 0) { | |
3401 | pr_warn("%s: '%s'->init suspiciously returned %d, it should " | |
3402 | "follow 0/-E convention\n" | |
3403 | "%s: loading module anyway...\n", | |
3404 | __func__, mod->name, ret, __func__); | |
3405 | dump_stack(); | |
3406 | } | |
3407 | ||
3408 | /* Now it's a first class citizen! */ | |
3409 | mod->state = MODULE_STATE_LIVE; | |
3410 | blocking_notifier_call_chain(&module_notify_list, | |
3411 | MODULE_STATE_LIVE, mod); | |
3412 | ||
3413 | /* | |
3414 | * We need to finish all async code before the module init sequence | |
3415 | * is done. This has potential to deadlock. For example, a newly | |
3416 | * detected block device can trigger request_module() of the | |
3417 | * default iosched from async probing task. Once userland helper | |
3418 | * reaches here, async_synchronize_full() will wait on the async | |
3419 | * task waiting on request_module() and deadlock. | |
3420 | * | |
3421 | * This deadlock is avoided by perfomring async_synchronize_full() | |
3422 | * iff module init queued any async jobs. This isn't a full | |
3423 | * solution as it will deadlock the same if module loading from | |
3424 | * async jobs nests more than once; however, due to the various | |
3425 | * constraints, this hack seems to be the best option for now. | |
3426 | * Please refer to the following thread for details. | |
3427 | * | |
3428 | * http://thread.gmane.org/gmane.linux.kernel/1420814 | |
3429 | */ | |
3430 | if (!mod->async_probe_requested && (current->flags & PF_USED_ASYNC)) | |
3431 | async_synchronize_full(); | |
3432 | ||
3433 | mutex_lock(&module_mutex); | |
3434 | /* Drop initial reference. */ | |
3435 | module_put(mod); | |
3436 | trim_init_extable(mod); | |
3437 | #ifdef CONFIG_KALLSYMS | |
3438 | /* Switch to core kallsyms now init is done: kallsyms may be walking! */ | |
3439 | rcu_assign_pointer(mod->kallsyms, &mod->core_kallsyms); | |
3440 | #endif | |
3441 | module_enable_ro(mod, true); | |
3442 | mod_tree_remove_init(mod); | |
3443 | disable_ro_nx(&mod->init_layout); | |
3444 | module_arch_freeing_init(mod); | |
3445 | mod->init_layout.base = NULL; | |
3446 | mod->init_layout.size = 0; | |
3447 | mod->init_layout.ro_size = 0; | |
3448 | mod->init_layout.ro_after_init_size = 0; | |
3449 | mod->init_layout.text_size = 0; | |
3450 | /* | |
3451 | * We want to free module_init, but be aware that kallsyms may be | |
3452 | * walking this with preempt disabled. In all the failure paths, we | |
3453 | * call synchronize_sched(), but we don't want to slow down the success | |
3454 | * path, so use actual RCU here. | |
3455 | */ | |
3456 | call_rcu_sched(&freeinit->rcu, do_free_init); | |
3457 | mutex_unlock(&module_mutex); | |
3458 | wake_up_all(&module_wq); | |
3459 | ||
3460 | return 0; | |
3461 | ||
3462 | fail_free_freeinit: | |
3463 | kfree(freeinit); | |
3464 | fail: | |
3465 | /* Try to protect us from buggy refcounters. */ | |
3466 | mod->state = MODULE_STATE_GOING; | |
3467 | synchronize_sched(); | |
3468 | module_put(mod); | |
3469 | blocking_notifier_call_chain(&module_notify_list, | |
3470 | MODULE_STATE_GOING, mod); | |
3471 | klp_module_going(mod); | |
3472 | ftrace_release_mod(mod); | |
3473 | free_module(mod); | |
3474 | wake_up_all(&module_wq); | |
3475 | return ret; | |
3476 | } | |
3477 | ||
3478 | static int may_init_module(void) | |
3479 | { | |
3480 | if (!capable(CAP_SYS_MODULE) || modules_disabled) | |
3481 | return -EPERM; | |
3482 | ||
3483 | return 0; | |
3484 | } | |
3485 | ||
3486 | /* | |
3487 | * We try to place it in the list now to make sure it's unique before | |
3488 | * we dedicate too many resources. In particular, temporary percpu | |
3489 | * memory exhaustion. | |
3490 | */ | |
3491 | static int add_unformed_module(struct module *mod) | |
3492 | { | |
3493 | int err; | |
3494 | struct module *old; | |
3495 | ||
3496 | mod->state = MODULE_STATE_UNFORMED; | |
3497 | ||
3498 | again: | |
3499 | mutex_lock(&module_mutex); | |
3500 | old = find_module_all(mod->name, strlen(mod->name), true); | |
3501 | if (old != NULL) { | |
3502 | if (old->state == MODULE_STATE_COMING | |
3503 | || old->state == MODULE_STATE_UNFORMED) { | |
3504 | /* Wait in case it fails to load. */ | |
3505 | mutex_unlock(&module_mutex); | |
3506 | err = wait_event_interruptible(module_wq, | |
3507 | finished_loading(mod->name)); | |
3508 | if (err) | |
3509 | goto out_unlocked; | |
3510 | goto again; | |
3511 | } | |
3512 | err = -EEXIST; | |
3513 | goto out; | |
3514 | } | |
3515 | mod_update_bounds(mod); | |
3516 | list_add_rcu(&mod->list, &modules); | |
3517 | mod_tree_insert(mod); | |
3518 | err = 0; | |
3519 | ||
3520 | out: | |
3521 | mutex_unlock(&module_mutex); | |
3522 | out_unlocked: | |
3523 | return err; | |
3524 | } | |
3525 | ||
3526 | static int complete_formation(struct module *mod, struct load_info *info) | |
3527 | { | |
3528 | int err; | |
3529 | ||
3530 | mutex_lock(&module_mutex); | |
3531 | ||
3532 | /* Find duplicate symbols (must be called under lock). */ | |
3533 | err = verify_export_symbols(mod); | |
3534 | if (err < 0) | |
3535 | goto out; | |
3536 | ||
3537 | /* This relies on module_mutex for list integrity. */ | |
3538 | module_bug_finalize(info->hdr, info->sechdrs, mod); | |
3539 | ||
3540 | module_enable_ro(mod, false); | |
3541 | module_enable_nx(mod); | |
3542 | ||
3543 | /* Mark state as coming so strong_try_module_get() ignores us, | |
3544 | * but kallsyms etc. can see us. */ | |
3545 | mod->state = MODULE_STATE_COMING; | |
3546 | mutex_unlock(&module_mutex); | |
3547 | ||
3548 | return 0; | |
3549 | ||
3550 | out: | |
3551 | mutex_unlock(&module_mutex); | |
3552 | return err; | |
3553 | } | |
3554 | ||
3555 | static int prepare_coming_module(struct module *mod) | |
3556 | { | |
3557 | int err; | |
3558 | ||
3559 | ftrace_module_enable(mod); | |
3560 | err = klp_module_coming(mod); | |
3561 | if (err) | |
3562 | return err; | |
3563 | ||
3564 | blocking_notifier_call_chain(&module_notify_list, | |
3565 | MODULE_STATE_COMING, mod); | |
3566 | return 0; | |
3567 | } | |
3568 | ||
3569 | static int unknown_module_param_cb(char *param, char *val, const char *modname, | |
3570 | void *arg) | |
3571 | { | |
3572 | struct module *mod = arg; | |
3573 | int ret; | |
3574 | ||
3575 | if (strcmp(param, "async_probe") == 0) { | |
3576 | mod->async_probe_requested = true; | |
3577 | return 0; | |
3578 | } | |
3579 | ||
3580 | /* Check for magic 'dyndbg' arg */ | |
3581 | ret = ddebug_dyndbg_module_param_cb(param, val, modname); | |
3582 | if (ret != 0) | |
3583 | pr_warn("%s: unknown parameter '%s' ignored\n", modname, param); | |
3584 | return 0; | |
3585 | } | |
3586 | ||
3587 | /* Allocate and load the module: note that size of section 0 is always | |
3588 | zero, and we rely on this for optional sections. */ | |
3589 | static int load_module(struct load_info *info, const char __user *uargs, | |
3590 | int flags) | |
3591 | { | |
3592 | struct module *mod; | |
3593 | long err; | |
3594 | char *after_dashes; | |
3595 | ||
3596 | err = module_sig_check(info, flags); | |
3597 | if (err) | |
3598 | goto free_copy; | |
3599 | ||
3600 | err = elf_header_check(info); | |
3601 | if (err) | |
3602 | goto free_copy; | |
3603 | ||
3604 | /* Figure out module layout, and allocate all the memory. */ | |
3605 | mod = layout_and_allocate(info, flags); | |
3606 | if (IS_ERR(mod)) { | |
3607 | err = PTR_ERR(mod); | |
3608 | goto free_copy; | |
3609 | } | |
3610 | ||
3611 | /* Reserve our place in the list. */ | |
3612 | err = add_unformed_module(mod); | |
3613 | if (err) | |
3614 | goto free_module; | |
3615 | ||
3616 | #ifdef CONFIG_MODULE_SIG | |
3617 | mod->sig_ok = info->sig_ok; | |
3618 | if (!mod->sig_ok) { | |
3619 | pr_notice_once("%s: module verification failed: signature " | |
3620 | "and/or required key missing - tainting " | |
3621 | "kernel\n", mod->name); | |
3622 | add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK); | |
3623 | } | |
3624 | #endif | |
3625 | ||
3626 | /* To avoid stressing percpu allocator, do this once we're unique. */ | |
3627 | err = percpu_modalloc(mod, info); | |
3628 | if (err) | |
3629 | goto unlink_mod; | |
3630 | ||
3631 | /* Now module is in final location, initialize linked lists, etc. */ | |
3632 | err = module_unload_init(mod); | |
3633 | if (err) | |
3634 | goto unlink_mod; | |
3635 | ||
3636 | init_param_lock(mod); | |
3637 | ||
3638 | /* Now we've got everything in the final locations, we can | |
3639 | * find optional sections. */ | |
3640 | err = find_module_sections(mod, info); | |
3641 | if (err) | |
3642 | goto free_unload; | |
3643 | ||
3644 | err = check_module_license_and_versions(mod); | |
3645 | if (err) | |
3646 | goto free_unload; | |
3647 | ||
3648 | /* Set up MODINFO_ATTR fields */ | |
3649 | setup_modinfo(mod, info); | |
3650 | ||
3651 | /* Fix up syms, so that st_value is a pointer to location. */ | |
3652 | err = simplify_symbols(mod, info); | |
3653 | if (err < 0) | |
3654 | goto free_modinfo; | |
3655 | ||
3656 | err = apply_relocations(mod, info); | |
3657 | if (err < 0) | |
3658 | goto free_modinfo; | |
3659 | ||
3660 | err = post_relocation(mod, info); | |
3661 | if (err < 0) | |
3662 | goto free_modinfo; | |
3663 | ||
3664 | flush_module_icache(mod); | |
3665 | ||
3666 | /* Now copy in args */ | |
3667 | mod->args = strndup_user(uargs, ~0UL >> 1); | |
3668 | if (IS_ERR(mod->args)) { | |
3669 | err = PTR_ERR(mod->args); | |
3670 | goto free_arch_cleanup; | |
3671 | } | |
3672 | ||
3673 | dynamic_debug_setup(info->debug, info->num_debug); | |
3674 | ||
3675 | /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */ | |
3676 | ftrace_module_init(mod); | |
3677 | ||
3678 | /* Finally it's fully formed, ready to start executing. */ | |
3679 | err = complete_formation(mod, info); | |
3680 | if (err) | |
3681 | goto ddebug_cleanup; | |
3682 | ||
3683 | err = prepare_coming_module(mod); | |
3684 | if (err) | |
3685 | goto bug_cleanup; | |
3686 | ||
3687 | /* Module is ready to execute: parsing args may do that. */ | |
3688 | after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp, | |
3689 | -32768, 32767, mod, | |
3690 | unknown_module_param_cb); | |
3691 | if (IS_ERR(after_dashes)) { | |
3692 | err = PTR_ERR(after_dashes); | |
3693 | goto coming_cleanup; | |
3694 | } else if (after_dashes) { | |
3695 | pr_warn("%s: parameters '%s' after `--' ignored\n", | |
3696 | mod->name, after_dashes); | |
3697 | } | |
3698 | ||
3699 | /* Link in to syfs. */ | |
3700 | err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp); | |
3701 | if (err < 0) | |
3702 | goto coming_cleanup; | |
3703 | ||
3704 | if (is_livepatch_module(mod)) { | |
3705 | err = copy_module_elf(mod, info); | |
3706 | if (err < 0) | |
3707 | goto sysfs_cleanup; | |
3708 | } | |
3709 | ||
3710 | /* Get rid of temporary copy. */ | |
3711 | free_copy(info); | |
3712 | ||
3713 | /* Done! */ | |
3714 | trace_module_load(mod); | |
3715 | ||
3716 | return do_init_module(mod); | |
3717 | ||
3718 | sysfs_cleanup: | |
3719 | mod_sysfs_teardown(mod); | |
3720 | coming_cleanup: | |
3721 | mod->state = MODULE_STATE_GOING; | |
3722 | destroy_params(mod->kp, mod->num_kp); | |
3723 | blocking_notifier_call_chain(&module_notify_list, | |
3724 | MODULE_STATE_GOING, mod); | |
3725 | klp_module_going(mod); | |
3726 | bug_cleanup: | |
3727 | /* module_bug_cleanup needs module_mutex protection */ | |
3728 | mutex_lock(&module_mutex); | |
3729 | module_bug_cleanup(mod); | |
3730 | mutex_unlock(&module_mutex); | |
3731 | ||
3732 | /* we can't deallocate the module until we clear memory protection */ | |
3733 | module_disable_ro(mod); | |
3734 | module_disable_nx(mod); | |
3735 | ||
3736 | ddebug_cleanup: | |
3737 | dynamic_debug_remove(info->debug); | |
3738 | synchronize_sched(); | |
3739 | kfree(mod->args); | |
3740 | free_arch_cleanup: | |
3741 | module_arch_cleanup(mod); | |
3742 | free_modinfo: | |
3743 | free_modinfo(mod); | |
3744 | free_unload: | |
3745 | module_unload_free(mod); | |
3746 | unlink_mod: | |
3747 | mutex_lock(&module_mutex); | |
3748 | /* Unlink carefully: kallsyms could be walking list. */ | |
3749 | list_del_rcu(&mod->list); | |
3750 | mod_tree_remove(mod); | |
3751 | wake_up_all(&module_wq); | |
3752 | /* Wait for RCU-sched synchronizing before releasing mod->list. */ | |
3753 | synchronize_sched(); | |
3754 | mutex_unlock(&module_mutex); | |
3755 | free_module: | |
3756 | /* | |
3757 | * Ftrace needs to clean up what it initialized. | |
3758 | * This does nothing if ftrace_module_init() wasn't called, | |
3759 | * but it must be called outside of module_mutex. | |
3760 | */ | |
3761 | ftrace_release_mod(mod); | |
3762 | /* Free lock-classes; relies on the preceding sync_rcu() */ | |
3763 | lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size); | |
3764 | ||
3765 | module_deallocate(mod, info); | |
3766 | free_copy: | |
3767 | free_copy(info); | |
3768 | return err; | |
3769 | } | |
3770 | ||
3771 | SYSCALL_DEFINE3(init_module, void __user *, umod, | |
3772 | unsigned long, len, const char __user *, uargs) | |
3773 | { | |
3774 | int err; | |
3775 | struct load_info info = { }; | |
3776 | ||
3777 | err = may_init_module(); | |
3778 | if (err) | |
3779 | return err; | |
3780 | ||
3781 | pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n", | |
3782 | umod, len, uargs); | |
3783 | ||
3784 | err = copy_module_from_user(umod, len, &info); | |
3785 | if (err) | |
3786 | return err; | |
3787 | ||
3788 | return load_module(&info, uargs, 0); | |
3789 | } | |
3790 | ||
3791 | SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags) | |
3792 | { | |
3793 | struct load_info info = { }; | |
3794 | loff_t size; | |
3795 | void *hdr; | |
3796 | int err; | |
3797 | ||
3798 | err = may_init_module(); | |
3799 | if (err) | |
3800 | return err; | |
3801 | ||
3802 | pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags); | |
3803 | ||
3804 | if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS | |
3805 | |MODULE_INIT_IGNORE_VERMAGIC)) | |
3806 | return -EINVAL; | |
3807 | ||
3808 | err = kernel_read_file_from_fd(fd, &hdr, &size, INT_MAX, | |
3809 | READING_MODULE); | |
3810 | if (err) | |
3811 | return err; | |
3812 | info.hdr = hdr; | |
3813 | info.len = size; | |
3814 | ||
3815 | return load_module(&info, uargs, flags); | |
3816 | } | |
3817 | ||
3818 | static inline int within(unsigned long addr, void *start, unsigned long size) | |
3819 | { | |
3820 | return ((void *)addr >= start && (void *)addr < start + size); | |
3821 | } | |
3822 | ||
3823 | #ifdef CONFIG_KALLSYMS | |
3824 | /* | |
3825 | * This ignores the intensely annoying "mapping symbols" found | |
3826 | * in ARM ELF files: $a, $t and $d. | |
3827 | */ | |
3828 | static inline int is_arm_mapping_symbol(const char *str) | |
3829 | { | |
3830 | if (str[0] == '.' && str[1] == 'L') | |
3831 | return true; | |
3832 | return str[0] == '$' && strchr("axtd", str[1]) | |
3833 | && (str[2] == '\0' || str[2] == '.'); | |
3834 | } | |
3835 | ||
3836 | static const char *symname(struct mod_kallsyms *kallsyms, unsigned int symnum) | |
3837 | { | |
3838 | return kallsyms->strtab + kallsyms->symtab[symnum].st_name; | |
3839 | } | |
3840 | ||
3841 | static const char *get_ksymbol(struct module *mod, | |
3842 | unsigned long addr, | |
3843 | unsigned long *size, | |
3844 | unsigned long *offset) | |
3845 | { | |
3846 | unsigned int i, best = 0; | |
3847 | unsigned long nextval; | |
3848 | struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms); | |
3849 | ||
3850 | /* At worse, next value is at end of module */ | |
3851 | if (within_module_init(addr, mod)) | |
3852 | nextval = (unsigned long)mod->init_layout.base+mod->init_layout.text_size; | |
3853 | else | |
3854 | nextval = (unsigned long)mod->core_layout.base+mod->core_layout.text_size; | |
3855 | ||
3856 | /* Scan for closest preceding symbol, and next symbol. (ELF | |
3857 | starts real symbols at 1). */ | |
3858 | for (i = 1; i < kallsyms->num_symtab; i++) { | |
3859 | if (kallsyms->symtab[i].st_shndx == SHN_UNDEF) | |
3860 | continue; | |
3861 | ||
3862 | /* We ignore unnamed symbols: they're uninformative | |
3863 | * and inserted at a whim. */ | |
3864 | if (*symname(kallsyms, i) == '\0' | |
3865 | || is_arm_mapping_symbol(symname(kallsyms, i))) | |
3866 | continue; | |
3867 | ||
3868 | if (kallsyms->symtab[i].st_value <= addr | |
3869 | && kallsyms->symtab[i].st_value > kallsyms->symtab[best].st_value) | |
3870 | best = i; | |
3871 | if (kallsyms->symtab[i].st_value > addr | |
3872 | && kallsyms->symtab[i].st_value < nextval) | |
3873 | nextval = kallsyms->symtab[i].st_value; | |
3874 | } | |
3875 | ||
3876 | if (!best) | |
3877 | return NULL; | |
3878 | ||
3879 | if (size) | |
3880 | *size = nextval - kallsyms->symtab[best].st_value; | |
3881 | if (offset) | |
3882 | *offset = addr - kallsyms->symtab[best].st_value; | |
3883 | return symname(kallsyms, best); | |
3884 | } | |
3885 | ||
3886 | /* For kallsyms to ask for address resolution. NULL means not found. Careful | |
3887 | * not to lock to avoid deadlock on oopses, simply disable preemption. */ | |
3888 | const char *module_address_lookup(unsigned long addr, | |
3889 | unsigned long *size, | |
3890 | unsigned long *offset, | |
3891 | char **modname, | |
3892 | char *namebuf) | |
3893 | { | |
3894 | const char *ret = NULL; | |
3895 | struct module *mod; | |
3896 | ||
3897 | preempt_disable(); | |
3898 | mod = __module_address(addr); | |
3899 | if (mod) { | |
3900 | if (modname) | |
3901 | *modname = mod->name; | |
3902 | ret = get_ksymbol(mod, addr, size, offset); | |
3903 | } | |
3904 | /* Make a copy in here where it's safe */ | |
3905 | if (ret) { | |
3906 | strncpy(namebuf, ret, KSYM_NAME_LEN - 1); | |
3907 | ret = namebuf; | |
3908 | } | |
3909 | preempt_enable(); | |
3910 | ||
3911 | return ret; | |
3912 | } | |
3913 | ||
3914 | int lookup_module_symbol_name(unsigned long addr, char *symname) | |
3915 | { | |
3916 | struct module *mod; | |
3917 | ||
3918 | preempt_disable(); | |
3919 | list_for_each_entry_rcu(mod, &modules, list) { | |
3920 | if (mod->state == MODULE_STATE_UNFORMED) | |
3921 | continue; | |
3922 | if (within_module(addr, mod)) { | |
3923 | const char *sym; | |
3924 | ||
3925 | sym = get_ksymbol(mod, addr, NULL, NULL); | |
3926 | if (!sym) | |
3927 | goto out; | |
3928 | strlcpy(symname, sym, KSYM_NAME_LEN); | |
3929 | preempt_enable(); | |
3930 | return 0; | |
3931 | } | |
3932 | } | |
3933 | out: | |
3934 | preempt_enable(); | |
3935 | return -ERANGE; | |
3936 | } | |
3937 | ||
3938 | int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, | |
3939 | unsigned long *offset, char *modname, char *name) | |
3940 | { | |
3941 | struct module *mod; | |
3942 | ||
3943 | preempt_disable(); | |
3944 | list_for_each_entry_rcu(mod, &modules, list) { | |
3945 | if (mod->state == MODULE_STATE_UNFORMED) | |
3946 | continue; | |
3947 | if (within_module(addr, mod)) { | |
3948 | const char *sym; | |
3949 | ||
3950 | sym = get_ksymbol(mod, addr, size, offset); | |
3951 | if (!sym) | |
3952 | goto out; | |
3953 | if (modname) | |
3954 | strlcpy(modname, mod->name, MODULE_NAME_LEN); | |
3955 | if (name) | |
3956 | strlcpy(name, sym, KSYM_NAME_LEN); | |
3957 | preempt_enable(); | |
3958 | return 0; | |
3959 | } | |
3960 | } | |
3961 | out: | |
3962 | preempt_enable(); | |
3963 | return -ERANGE; | |
3964 | } | |
3965 | ||
3966 | int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type, | |
3967 | char *name, char *module_name, int *exported) | |
3968 | { | |
3969 | struct module *mod; | |
3970 | ||
3971 | preempt_disable(); | |
3972 | list_for_each_entry_rcu(mod, &modules, list) { | |
3973 | struct mod_kallsyms *kallsyms; | |
3974 | ||
3975 | if (mod->state == MODULE_STATE_UNFORMED) | |
3976 | continue; | |
3977 | kallsyms = rcu_dereference_sched(mod->kallsyms); | |
3978 | if (symnum < kallsyms->num_symtab) { | |
3979 | *value = kallsyms->symtab[symnum].st_value; | |
3980 | *type = kallsyms->symtab[symnum].st_info; | |
3981 | strlcpy(name, symname(kallsyms, symnum), KSYM_NAME_LEN); | |
3982 | strlcpy(module_name, mod->name, MODULE_NAME_LEN); | |
3983 | *exported = is_exported(name, *value, mod); | |
3984 | preempt_enable(); | |
3985 | return 0; | |
3986 | } | |
3987 | symnum -= kallsyms->num_symtab; | |
3988 | } | |
3989 | preempt_enable(); | |
3990 | return -ERANGE; | |
3991 | } | |
3992 | ||
3993 | static unsigned long mod_find_symname(struct module *mod, const char *name) | |
3994 | { | |
3995 | unsigned int i; | |
3996 | struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms); | |
3997 | ||
3998 | for (i = 0; i < kallsyms->num_symtab; i++) | |
3999 | if (strcmp(name, symname(kallsyms, i)) == 0 && | |
4000 | kallsyms->symtab[i].st_info != 'U') | |
4001 | return kallsyms->symtab[i].st_value; | |
4002 | return 0; | |
4003 | } | |
4004 | ||
4005 | /* Look for this name: can be of form module:name. */ | |
4006 | unsigned long module_kallsyms_lookup_name(const char *name) | |
4007 | { | |
4008 | struct module *mod; | |
4009 | char *colon; | |
4010 | unsigned long ret = 0; | |
4011 | ||
4012 | /* Don't lock: we're in enough trouble already. */ | |
4013 | preempt_disable(); | |
4014 | if ((colon = strchr(name, ':')) != NULL) { | |
4015 | if ((mod = find_module_all(name, colon - name, false)) != NULL) | |
4016 | ret = mod_find_symname(mod, colon+1); | |
4017 | } else { | |
4018 | list_for_each_entry_rcu(mod, &modules, list) { | |
4019 | if (mod->state == MODULE_STATE_UNFORMED) | |
4020 | continue; | |
4021 | if ((ret = mod_find_symname(mod, name)) != 0) | |
4022 | break; | |
4023 | } | |
4024 | } | |
4025 | preempt_enable(); | |
4026 | return ret; | |
4027 | } | |
4028 | ||
4029 | int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *, | |
4030 | struct module *, unsigned long), | |
4031 | void *data) | |
4032 | { | |
4033 | struct module *mod; | |
4034 | unsigned int i; | |
4035 | int ret; | |
4036 | ||
4037 | module_assert_mutex(); | |
4038 | ||
4039 | list_for_each_entry(mod, &modules, list) { | |
4040 | /* We hold module_mutex: no need for rcu_dereference_sched */ | |
4041 | struct mod_kallsyms *kallsyms = mod->kallsyms; | |
4042 | ||
4043 | if (mod->state == MODULE_STATE_UNFORMED) | |
4044 | continue; | |
4045 | for (i = 0; i < kallsyms->num_symtab; i++) { | |
4046 | ret = fn(data, symname(kallsyms, i), | |
4047 | mod, kallsyms->symtab[i].st_value); | |
4048 | if (ret != 0) | |
4049 | return ret; | |
4050 | } | |
4051 | } | |
4052 | return 0; | |
4053 | } | |
4054 | #endif /* CONFIG_KALLSYMS */ | |
4055 | ||
4056 | /* Maximum number of characters written by module_flags() */ | |
4057 | #define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4) | |
4058 | ||
4059 | /* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */ | |
4060 | static char *module_flags(struct module *mod, char *buf) | |
4061 | { | |
4062 | int bx = 0; | |
4063 | ||
4064 | BUG_ON(mod->state == MODULE_STATE_UNFORMED); | |
4065 | if (mod->taints || | |
4066 | mod->state == MODULE_STATE_GOING || | |
4067 | mod->state == MODULE_STATE_COMING) { | |
4068 | buf[bx++] = '('; | |
4069 | bx += module_flags_taint(mod, buf + bx); | |
4070 | /* Show a - for module-is-being-unloaded */ | |
4071 | if (mod->state == MODULE_STATE_GOING) | |
4072 | buf[bx++] = '-'; | |
4073 | /* Show a + for module-is-being-loaded */ | |
4074 | if (mod->state == MODULE_STATE_COMING) | |
4075 | buf[bx++] = '+'; | |
4076 | buf[bx++] = ')'; | |
4077 | } | |
4078 | buf[bx] = '\0'; | |
4079 | ||
4080 | return buf; | |
4081 | } | |
4082 | ||
4083 | #ifdef CONFIG_PROC_FS | |
4084 | /* Called by the /proc file system to return a list of modules. */ | |
4085 | static void *m_start(struct seq_file *m, loff_t *pos) | |
4086 | { | |
4087 | mutex_lock(&module_mutex); | |
4088 | return seq_list_start(&modules, *pos); | |
4089 | } | |
4090 | ||
4091 | static void *m_next(struct seq_file *m, void *p, loff_t *pos) | |
4092 | { | |
4093 | return seq_list_next(p, &modules, pos); | |
4094 | } | |
4095 | ||
4096 | static void m_stop(struct seq_file *m, void *p) | |
4097 | { | |
4098 | mutex_unlock(&module_mutex); | |
4099 | } | |
4100 | ||
4101 | static int m_show(struct seq_file *m, void *p) | |
4102 | { | |
4103 | struct module *mod = list_entry(p, struct module, list); | |
4104 | char buf[MODULE_FLAGS_BUF_SIZE]; | |
4105 | ||
4106 | /* We always ignore unformed modules. */ | |
4107 | if (mod->state == MODULE_STATE_UNFORMED) | |
4108 | return 0; | |
4109 | ||
4110 | seq_printf(m, "%s %u", | |
4111 | mod->name, mod->init_layout.size + mod->core_layout.size); | |
4112 | print_unload_info(m, mod); | |
4113 | ||
4114 | /* Informative for users. */ | |
4115 | seq_printf(m, " %s", | |
4116 | mod->state == MODULE_STATE_GOING ? "Unloading" : | |
4117 | mod->state == MODULE_STATE_COMING ? "Loading" : | |
4118 | "Live"); | |
4119 | /* Used by oprofile and other similar tools. */ | |
4120 | seq_printf(m, " 0x%pK", mod->core_layout.base); | |
4121 | ||
4122 | /* Taints info */ | |
4123 | if (mod->taints) | |
4124 | seq_printf(m, " %s", module_flags(mod, buf)); | |
4125 | ||
4126 | seq_puts(m, "\n"); | |
4127 | return 0; | |
4128 | } | |
4129 | ||
4130 | /* Format: modulename size refcount deps address | |
4131 | ||
4132 | Where refcount is a number or -, and deps is a comma-separated list | |
4133 | of depends or -. | |
4134 | */ | |
4135 | static const struct seq_operations modules_op = { | |
4136 | .start = m_start, | |
4137 | .next = m_next, | |
4138 | .stop = m_stop, | |
4139 | .show = m_show | |
4140 | }; | |
4141 | ||
4142 | static int modules_open(struct inode *inode, struct file *file) | |
4143 | { | |
4144 | return seq_open(file, &modules_op); | |
4145 | } | |
4146 | ||
4147 | static const struct file_operations proc_modules_operations = { | |
4148 | .open = modules_open, | |
4149 | .read = seq_read, | |
4150 | .llseek = seq_lseek, | |
4151 | .release = seq_release, | |
4152 | }; | |
4153 | ||
4154 | static int __init proc_modules_init(void) | |
4155 | { | |
4156 | proc_create("modules", 0, NULL, &proc_modules_operations); | |
4157 | return 0; | |
4158 | } | |
4159 | module_init(proc_modules_init); | |
4160 | #endif | |
4161 | ||
4162 | /* Given an address, look for it in the module exception tables. */ | |
4163 | const struct exception_table_entry *search_module_extables(unsigned long addr) | |
4164 | { | |
4165 | const struct exception_table_entry *e = NULL; | |
4166 | struct module *mod; | |
4167 | ||
4168 | preempt_disable(); | |
4169 | list_for_each_entry_rcu(mod, &modules, list) { | |
4170 | if (mod->state == MODULE_STATE_UNFORMED) | |
4171 | continue; | |
4172 | if (mod->num_exentries == 0) | |
4173 | continue; | |
4174 | ||
4175 | e = search_extable(mod->extable, | |
4176 | mod->extable + mod->num_exentries - 1, | |
4177 | addr); | |
4178 | if (e) | |
4179 | break; | |
4180 | } | |
4181 | preempt_enable(); | |
4182 | ||
4183 | /* Now, if we found one, we are running inside it now, hence | |
4184 | we cannot unload the module, hence no refcnt needed. */ | |
4185 | return e; | |
4186 | } | |
4187 | ||
4188 | /* | |
4189 | * is_module_address - is this address inside a module? | |
4190 | * @addr: the address to check. | |
4191 | * | |
4192 | * See is_module_text_address() if you simply want to see if the address | |
4193 | * is code (not data). | |
4194 | */ | |
4195 | bool is_module_address(unsigned long addr) | |
4196 | { | |
4197 | bool ret; | |
4198 | ||
4199 | preempt_disable(); | |
4200 | ret = __module_address(addr) != NULL; | |
4201 | preempt_enable(); | |
4202 | ||
4203 | return ret; | |
4204 | } | |
4205 | ||
4206 | /* | |
4207 | * __module_address - get the module which contains an address. | |
4208 | * @addr: the address. | |
4209 | * | |
4210 | * Must be called with preempt disabled or module mutex held so that | |
4211 | * module doesn't get freed during this. | |
4212 | */ | |
4213 | struct module *__module_address(unsigned long addr) | |
4214 | { | |
4215 | struct module *mod; | |
4216 | ||
4217 | if (addr < module_addr_min || addr > module_addr_max) | |
4218 | return NULL; | |
4219 | ||
4220 | module_assert_mutex_or_preempt(); | |
4221 | ||
4222 | mod = mod_find(addr); | |
4223 | if (mod) { | |
4224 | BUG_ON(!within_module(addr, mod)); | |
4225 | if (mod->state == MODULE_STATE_UNFORMED) | |
4226 | mod = NULL; | |
4227 | } | |
4228 | return mod; | |
4229 | } | |
4230 | EXPORT_SYMBOL_GPL(__module_address); | |
4231 | ||
4232 | /* | |
4233 | * is_module_text_address - is this address inside module code? | |
4234 | * @addr: the address to check. | |
4235 | * | |
4236 | * See is_module_address() if you simply want to see if the address is | |
4237 | * anywhere in a module. See kernel_text_address() for testing if an | |
4238 | * address corresponds to kernel or module code. | |
4239 | */ | |
4240 | bool is_module_text_address(unsigned long addr) | |
4241 | { | |
4242 | bool ret; | |
4243 | ||
4244 | preempt_disable(); | |
4245 | ret = __module_text_address(addr) != NULL; | |
4246 | preempt_enable(); | |
4247 | ||
4248 | return ret; | |
4249 | } | |
4250 | ||
4251 | /* | |
4252 | * __module_text_address - get the module whose code contains an address. | |
4253 | * @addr: the address. | |
4254 | * | |
4255 | * Must be called with preempt disabled or module mutex held so that | |
4256 | * module doesn't get freed during this. | |
4257 | */ | |
4258 | struct module *__module_text_address(unsigned long addr) | |
4259 | { | |
4260 | struct module *mod = __module_address(addr); | |
4261 | if (mod) { | |
4262 | /* Make sure it's within the text section. */ | |
4263 | if (!within(addr, mod->init_layout.base, mod->init_layout.text_size) | |
4264 | && !within(addr, mod->core_layout.base, mod->core_layout.text_size)) | |
4265 | mod = NULL; | |
4266 | } | |
4267 | return mod; | |
4268 | } | |
4269 | EXPORT_SYMBOL_GPL(__module_text_address); | |
4270 | ||
4271 | /* Don't grab lock, we're oopsing. */ | |
4272 | void print_modules(void) | |
4273 | { | |
4274 | struct module *mod; | |
4275 | char buf[MODULE_FLAGS_BUF_SIZE]; | |
4276 | ||
4277 | printk(KERN_DEFAULT "Modules linked in:"); | |
4278 | /* Most callers should already have preempt disabled, but make sure */ | |
4279 | preempt_disable(); | |
4280 | list_for_each_entry_rcu(mod, &modules, list) { | |
4281 | if (mod->state == MODULE_STATE_UNFORMED) | |
4282 | continue; | |
4283 | pr_cont(" %s%s", mod->name, module_flags(mod, buf)); | |
4284 | } | |
4285 | preempt_enable(); | |
4286 | if (last_unloaded_module[0]) | |
4287 | pr_cont(" [last unloaded: %s]", last_unloaded_module); | |
4288 | pr_cont("\n"); | |
4289 | } | |
4290 | ||
4291 | #ifdef CONFIG_MODVERSIONS | |
4292 | /* Generate the signature for all relevant module structures here. | |
4293 | * If these change, we don't want to try to parse the module. */ | |
4294 | void module_layout(struct module *mod, | |
4295 | struct modversion_info *ver, | |
4296 | struct kernel_param *kp, | |
4297 | struct kernel_symbol *ks, | |
4298 | struct tracepoint * const *tp) | |
4299 | { | |
4300 | } | |
4301 | EXPORT_SYMBOL(module_layout); | |
4302 | #endif | |
4303 | ||
4304 | #ifdef CONFIG_MODULE_SIG | |
4305 | void enforce_signed_modules(void) | |
4306 | { | |
4307 | sig_enforce = true; | |
4308 | } | |
4309 | #endif | |
4310 | ||
4311 | bool secure_modules(void) | |
4312 | { | |
4313 | #ifdef CONFIG_MODULE_SIG | |
4314 | return (sig_enforce || modules_disabled); | |
4315 | #else | |
4316 | return modules_disabled; | |
4317 | #endif | |
4318 | } | |
4319 | EXPORT_SYMBOL(secure_modules); |