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