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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/module.h> |
20 | #include <linux/moduleloader.h> |
21 | #include <linux/ftrace_event.h> |
22 | #include <linux/init.h> |
23 | #include <linux/kallsyms.h> |
24 | #include <linux/fs.h> |
25 | #include <linux/sysfs.h> |
26 | #include <linux/kernel.h> |
27 | #include <linux/slab.h> |
28 | #include <linux/vmalloc.h> |
29 | #include <linux/elf.h> |
30 | #include <linux/proc_fs.h> |
31 | #include <linux/seq_file.h> |
32 | #include <linux/syscalls.h> |
33 | #include <linux/fcntl.h> |
34 | #include <linux/rcupdate.h> |
35 | #include <linux/capability.h> |
36 | #include <linux/cpu.h> |
37 | #include <linux/moduleparam.h> |
38 | #include <linux/errno.h> |
39 | #include <linux/err.h> |
40 | #include <linux/vermagic.h> |
41 | #include <linux/notifier.h> |
42 | #include <linux/sched.h> |
43 | #include <linux/stop_machine.h> |
44 | #include <linux/device.h> |
45 | #include <linux/string.h> |
46 | #include <linux/mutex.h> |
47 | #include <linux/rculist.h> |
48 | #include <asm/uaccess.h> |
49 | #include <asm/cacheflush.h> |
50 | #include <asm/mmu_context.h> |
51 | #include <linux/license.h> |
52 | #include <asm/sections.h> |
53 | #include <linux/tracepoint.h> |
54 | #include <linux/ftrace.h> |
55 | #include <linux/async.h> |
56 | #include <linux/percpu.h> |
57 | #include <linux/kmemleak.h> |
58 | #include <linux/jump_label.h> |
59 | #include <linux/pfn.h> |
60 | #include <linux/bsearch.h> |
61 | |
62 | #define CREATE_TRACE_POINTS |
63 | #include <trace/events/module.h> |
64 | |
65 | #if 0 |
66 | #define DEBUGP printk |
67 | #else |
68 | #define DEBUGP(fmt , a...) |
69 | #endif |
70 | |
71 | #ifndef ARCH_SHF_SMALL |
72 | #define ARCH_SHF_SMALL 0 |
73 | #endif |
74 | |
75 | /* |
76 | * Modules' sections will be aligned on page boundaries |
77 | * to ensure complete separation of code and data, but |
78 | * only when CONFIG_DEBUG_SET_MODULE_RONX=y |
79 | */ |
80 | #ifdef CONFIG_DEBUG_SET_MODULE_RONX |
81 | # define debug_align(X) ALIGN(X, PAGE_SIZE) |
82 | #else |
83 | # define debug_align(X) (X) |
84 | #endif |
85 | |
86 | /* |
87 | * Given BASE and SIZE this macro calculates the number of pages the |
88 | * memory regions occupies |
89 | */ |
90 | #define MOD_NUMBER_OF_PAGES(BASE, SIZE) (((SIZE) > 0) ? \ |
91 | (PFN_DOWN((unsigned long)(BASE) + (SIZE) - 1) - \ |
92 | PFN_DOWN((unsigned long)BASE) + 1) \ |
93 | : (0UL)) |
94 | |
95 | /* If this is set, the section belongs in the init part of the module */ |
96 | #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1)) |
97 | |
98 | /* |
99 | * Mutex protects: |
100 | * 1) List of modules (also safely readable with preempt_disable), |
101 | * 2) module_use links, |
102 | * 3) module_addr_min/module_addr_max. |
103 | * (delete uses stop_machine/add uses RCU list operations). */ |
104 | DEFINE_MUTEX(module_mutex); |
105 | EXPORT_SYMBOL_GPL(module_mutex); |
106 | static LIST_HEAD(modules); |
107 | #ifdef CONFIG_KGDB_KDB |
108 | struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */ |
109 | #endif /* CONFIG_KGDB_KDB */ |
110 | |
111 | |
112 | /* Block module loading/unloading? */ |
113 | int modules_disabled = 0; |
114 | |
115 | /* Waiting for a module to finish initializing? */ |
116 | static DECLARE_WAIT_QUEUE_HEAD(module_wq); |
117 | |
118 | static BLOCKING_NOTIFIER_HEAD(module_notify_list); |
119 | |
120 | /* Bounds of module allocation, for speeding __module_address. |
121 | * Protected by module_mutex. */ |
122 | static unsigned long module_addr_min = -1UL, module_addr_max = 0; |
123 | |
124 | int register_module_notifier(struct notifier_block * nb) |
125 | { |
126 | return blocking_notifier_chain_register(&module_notify_list, nb); |
127 | } |
128 | EXPORT_SYMBOL(register_module_notifier); |
129 | |
130 | int unregister_module_notifier(struct notifier_block * nb) |
131 | { |
132 | return blocking_notifier_chain_unregister(&module_notify_list, nb); |
133 | } |
134 | EXPORT_SYMBOL(unregister_module_notifier); |
135 | |
136 | struct load_info { |
137 | Elf_Ehdr *hdr; |
138 | unsigned long len; |
139 | Elf_Shdr *sechdrs; |
140 | char *secstrings, *strtab; |
141 | unsigned long *strmap; |
142 | unsigned long symoffs, stroffs; |
143 | struct _ddebug *debug; |
144 | unsigned int num_debug; |
145 | struct { |
146 | unsigned int sym, str, mod, vers, info, pcpu; |
147 | } index; |
148 | }; |
149 | |
150 | /* We require a truly strong try_module_get(): 0 means failure due to |
151 | ongoing or failed initialization etc. */ |
152 | static inline int strong_try_module_get(struct module *mod) |
153 | { |
154 | if (mod && mod->state == MODULE_STATE_COMING) |
155 | return -EBUSY; |
156 | if (try_module_get(mod)) |
157 | return 0; |
158 | else |
159 | return -ENOENT; |
160 | } |
161 | |
162 | static inline void add_taint_module(struct module *mod, unsigned flag) |
163 | { |
164 | add_taint(flag); |
165 | mod->taints |= (1U << flag); |
166 | } |
167 | |
168 | /* |
169 | * A thread that wants to hold a reference to a module only while it |
170 | * is running can call this to safely exit. nfsd and lockd use this. |
171 | */ |
172 | void __module_put_and_exit(struct module *mod, long code) |
173 | { |
174 | module_put(mod); |
175 | do_exit(code); |
176 | } |
177 | EXPORT_SYMBOL(__module_put_and_exit); |
178 | |
179 | /* Find a module section: 0 means not found. */ |
180 | static unsigned int find_sec(const struct load_info *info, const char *name) |
181 | { |
182 | unsigned int i; |
183 | |
184 | for (i = 1; i < info->hdr->e_shnum; i++) { |
185 | Elf_Shdr *shdr = &info->sechdrs[i]; |
186 | /* Alloc bit cleared means "ignore it." */ |
187 | if ((shdr->sh_flags & SHF_ALLOC) |
188 | && strcmp(info->secstrings + shdr->sh_name, name) == 0) |
189 | return i; |
190 | } |
191 | return 0; |
192 | } |
193 | |
194 | /* Find a module section, or NULL. */ |
195 | static void *section_addr(const struct load_info *info, const char *name) |
196 | { |
197 | /* Section 0 has sh_addr 0. */ |
198 | return (void *)info->sechdrs[find_sec(info, name)].sh_addr; |
199 | } |
200 | |
201 | /* Find a module section, or NULL. Fill in number of "objects" in section. */ |
202 | static void *section_objs(const struct load_info *info, |
203 | const char *name, |
204 | size_t object_size, |
205 | unsigned int *num) |
206 | { |
207 | unsigned int sec = find_sec(info, name); |
208 | |
209 | /* Section 0 has sh_addr 0 and sh_size 0. */ |
210 | *num = info->sechdrs[sec].sh_size / object_size; |
211 | return (void *)info->sechdrs[sec].sh_addr; |
212 | } |
213 | |
214 | /* Provided by the linker */ |
215 | extern const struct kernel_symbol __start___ksymtab[]; |
216 | extern const struct kernel_symbol __stop___ksymtab[]; |
217 | extern const struct kernel_symbol __start___ksymtab_gpl[]; |
218 | extern const struct kernel_symbol __stop___ksymtab_gpl[]; |
219 | extern const struct kernel_symbol __start___ksymtab_gpl_future[]; |
220 | extern const struct kernel_symbol __stop___ksymtab_gpl_future[]; |
221 | extern const unsigned long __start___kcrctab[]; |
222 | extern const unsigned long __start___kcrctab_gpl[]; |
223 | extern const unsigned long __start___kcrctab_gpl_future[]; |
224 | #ifdef CONFIG_UNUSED_SYMBOLS |
225 | extern const struct kernel_symbol __start___ksymtab_unused[]; |
226 | extern const struct kernel_symbol __stop___ksymtab_unused[]; |
227 | extern const struct kernel_symbol __start___ksymtab_unused_gpl[]; |
228 | extern const struct kernel_symbol __stop___ksymtab_unused_gpl[]; |
229 | extern const unsigned long __start___kcrctab_unused[]; |
230 | extern const unsigned long __start___kcrctab_unused_gpl[]; |
231 | #endif |
232 | |
233 | #ifndef CONFIG_MODVERSIONS |
234 | #define symversion(base, idx) NULL |
235 | #else |
236 | #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL) |
237 | #endif |
238 | |
239 | static bool each_symbol_in_section(const struct symsearch *arr, |
240 | unsigned int arrsize, |
241 | struct module *owner, |
242 | bool (*fn)(const struct symsearch *syms, |
243 | struct module *owner, |
244 | void *data), |
245 | void *data) |
246 | { |
247 | unsigned int j; |
248 | |
249 | for (j = 0; j < arrsize; j++) { |
250 | if (fn(&arr[j], owner, data)) |
251 | return true; |
252 | } |
253 | |
254 | return false; |
255 | } |
256 | |
257 | /* Returns true as soon as fn returns true, otherwise false. */ |
258 | bool each_symbol_section(bool (*fn)(const struct symsearch *arr, |
259 | struct module *owner, |
260 | void *data), |
261 | void *data) |
262 | { |
263 | struct module *mod; |
264 | static const struct symsearch arr[] = { |
265 | { __start___ksymtab, __stop___ksymtab, __start___kcrctab, |
266 | NOT_GPL_ONLY, false }, |
267 | { __start___ksymtab_gpl, __stop___ksymtab_gpl, |
268 | __start___kcrctab_gpl, |
269 | GPL_ONLY, false }, |
270 | { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future, |
271 | __start___kcrctab_gpl_future, |
272 | WILL_BE_GPL_ONLY, false }, |
273 | #ifdef CONFIG_UNUSED_SYMBOLS |
274 | { __start___ksymtab_unused, __stop___ksymtab_unused, |
275 | __start___kcrctab_unused, |
276 | NOT_GPL_ONLY, true }, |
277 | { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl, |
278 | __start___kcrctab_unused_gpl, |
279 | GPL_ONLY, true }, |
280 | #endif |
281 | }; |
282 | |
283 | if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data)) |
284 | return true; |
285 | |
286 | list_for_each_entry_rcu(mod, &modules, list) { |
287 | struct symsearch arr[] = { |
288 | { mod->syms, mod->syms + mod->num_syms, mod->crcs, |
289 | NOT_GPL_ONLY, false }, |
290 | { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms, |
291 | mod->gpl_crcs, |
292 | GPL_ONLY, false }, |
293 | { mod->gpl_future_syms, |
294 | mod->gpl_future_syms + mod->num_gpl_future_syms, |
295 | mod->gpl_future_crcs, |
296 | WILL_BE_GPL_ONLY, false }, |
297 | #ifdef CONFIG_UNUSED_SYMBOLS |
298 | { mod->unused_syms, |
299 | mod->unused_syms + mod->num_unused_syms, |
300 | mod->unused_crcs, |
301 | NOT_GPL_ONLY, true }, |
302 | { mod->unused_gpl_syms, |
303 | mod->unused_gpl_syms + mod->num_unused_gpl_syms, |
304 | mod->unused_gpl_crcs, |
305 | GPL_ONLY, true }, |
306 | #endif |
307 | }; |
308 | |
309 | if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data)) |
310 | return true; |
311 | } |
312 | return false; |
313 | } |
314 | EXPORT_SYMBOL_GPL(each_symbol_section); |
315 | |
316 | struct find_symbol_arg { |
317 | /* Input */ |
318 | const char *name; |
319 | bool gplok; |
320 | bool warn; |
321 | |
322 | /* Output */ |
323 | struct module *owner; |
324 | const unsigned long *crc; |
325 | const struct kernel_symbol *sym; |
326 | }; |
327 | |
328 | static bool check_symbol(const struct symsearch *syms, |
329 | struct module *owner, |
330 | unsigned int symnum, void *data) |
331 | { |
332 | struct find_symbol_arg *fsa = data; |
333 | |
334 | if (!fsa->gplok) { |
335 | if (syms->licence == GPL_ONLY) |
336 | return false; |
337 | if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) { |
338 | printk(KERN_WARNING "Symbol %s is being used " |
339 | "by a non-GPL module, which will not " |
340 | "be allowed in the future\n", fsa->name); |
341 | printk(KERN_WARNING "Please see the file " |
342 | "Documentation/feature-removal-schedule.txt " |
343 | "in the kernel source tree for more details.\n"); |
344 | } |
345 | } |
346 | |
347 | #ifdef CONFIG_UNUSED_SYMBOLS |
348 | if (syms->unused && fsa->warn) { |
349 | printk(KERN_WARNING "Symbol %s is marked as UNUSED, " |
350 | "however this module is using it.\n", fsa->name); |
351 | printk(KERN_WARNING |
352 | "This symbol will go away in the future.\n"); |
353 | printk(KERN_WARNING |
354 | "Please evalute if this is the right api to use and if " |
355 | "it really is, submit a report the linux kernel " |
356 | "mailinglist together with submitting your code for " |
357 | "inclusion.\n"); |
358 | } |
359 | #endif |
360 | |
361 | fsa->owner = owner; |
362 | fsa->crc = symversion(syms->crcs, symnum); |
363 | fsa->sym = &syms->start[symnum]; |
364 | return true; |
365 | } |
366 | |
367 | static int cmp_name(const void *va, const void *vb) |
368 | { |
369 | const char *a; |
370 | const struct kernel_symbol *b; |
371 | a = va; b = vb; |
372 | return strcmp(a, b->name); |
373 | } |
374 | |
375 | static bool find_symbol_in_section(const struct symsearch *syms, |
376 | struct module *owner, |
377 | void *data) |
378 | { |
379 | struct find_symbol_arg *fsa = data; |
380 | struct kernel_symbol *sym; |
381 | |
382 | sym = bsearch(fsa->name, syms->start, syms->stop - syms->start, |
383 | sizeof(struct kernel_symbol), cmp_name); |
384 | |
385 | if (sym != NULL && check_symbol(syms, owner, sym - syms->start, data)) |
386 | return true; |
387 | |
388 | return false; |
389 | } |
390 | |
391 | /* Find a symbol and return it, along with, (optional) crc and |
392 | * (optional) module which owns it. Needs preempt disabled or module_mutex. */ |
393 | const struct kernel_symbol *find_symbol(const char *name, |
394 | struct module **owner, |
395 | const unsigned long **crc, |
396 | bool gplok, |
397 | bool warn) |
398 | { |
399 | struct find_symbol_arg fsa; |
400 | |
401 | fsa.name = name; |
402 | fsa.gplok = gplok; |
403 | fsa.warn = warn; |
404 | |
405 | if (each_symbol_section(find_symbol_in_section, &fsa)) { |
406 | if (owner) |
407 | *owner = fsa.owner; |
408 | if (crc) |
409 | *crc = fsa.crc; |
410 | return fsa.sym; |
411 | } |
412 | |
413 | DEBUGP("Failed to find symbol %s\n", name); |
414 | return NULL; |
415 | } |
416 | EXPORT_SYMBOL_GPL(find_symbol); |
417 | |
418 | /* Search for module by name: must hold module_mutex. */ |
419 | struct module *find_module(const char *name) |
420 | { |
421 | struct module *mod; |
422 | |
423 | list_for_each_entry(mod, &modules, list) { |
424 | if (strcmp(mod->name, name) == 0) |
425 | return mod; |
426 | } |
427 | return NULL; |
428 | } |
429 | EXPORT_SYMBOL_GPL(find_module); |
430 | |
431 | #ifdef CONFIG_SMP |
432 | |
433 | static inline void __percpu *mod_percpu(struct module *mod) |
434 | { |
435 | return mod->percpu; |
436 | } |
437 | |
438 | static int percpu_modalloc(struct module *mod, |
439 | unsigned long size, unsigned long align) |
440 | { |
441 | if (align > PAGE_SIZE) { |
442 | printk(KERN_WARNING "%s: per-cpu alignment %li > %li\n", |
443 | mod->name, align, PAGE_SIZE); |
444 | align = PAGE_SIZE; |
445 | } |
446 | |
447 | mod->percpu = __alloc_reserved_percpu(size, align); |
448 | if (!mod->percpu) { |
449 | printk(KERN_WARNING |
450 | "%s: Could not allocate %lu bytes percpu data\n", |
451 | mod->name, size); |
452 | return -ENOMEM; |
453 | } |
454 | mod->percpu_size = size; |
455 | return 0; |
456 | } |
457 | |
458 | static void percpu_modfree(struct module *mod) |
459 | { |
460 | free_percpu(mod->percpu); |
461 | } |
462 | |
463 | static unsigned int find_pcpusec(struct load_info *info) |
464 | { |
465 | return find_sec(info, ".data..percpu"); |
466 | } |
467 | |
468 | static void percpu_modcopy(struct module *mod, |
469 | const void *from, unsigned long size) |
470 | { |
471 | int cpu; |
472 | |
473 | for_each_possible_cpu(cpu) |
474 | memcpy(per_cpu_ptr(mod->percpu, cpu), from, size); |
475 | } |
476 | |
477 | /** |
478 | * is_module_percpu_address - test whether address is from module static percpu |
479 | * @addr: address to test |
480 | * |
481 | * Test whether @addr belongs to module static percpu area. |
482 | * |
483 | * RETURNS: |
484 | * %true if @addr is from module static percpu area |
485 | */ |
486 | bool is_module_percpu_address(unsigned long addr) |
487 | { |
488 | struct module *mod; |
489 | unsigned int cpu; |
490 | |
491 | preempt_disable(); |
492 | |
493 | list_for_each_entry_rcu(mod, &modules, list) { |
494 | if (!mod->percpu_size) |
495 | continue; |
496 | for_each_possible_cpu(cpu) { |
497 | void *start = per_cpu_ptr(mod->percpu, cpu); |
498 | |
499 | if ((void *)addr >= start && |
500 | (void *)addr < start + mod->percpu_size) { |
501 | preempt_enable(); |
502 | return true; |
503 | } |
504 | } |
505 | } |
506 | |
507 | preempt_enable(); |
508 | return false; |
509 | } |
510 | |
511 | #else /* ... !CONFIG_SMP */ |
512 | |
513 | static inline void __percpu *mod_percpu(struct module *mod) |
514 | { |
515 | return NULL; |
516 | } |
517 | static inline int percpu_modalloc(struct module *mod, |
518 | unsigned long size, unsigned long align) |
519 | { |
520 | return -ENOMEM; |
521 | } |
522 | static inline void percpu_modfree(struct module *mod) |
523 | { |
524 | } |
525 | static unsigned int find_pcpusec(struct load_info *info) |
526 | { |
527 | return 0; |
528 | } |
529 | static inline void percpu_modcopy(struct module *mod, |
530 | const void *from, unsigned long size) |
531 | { |
532 | /* pcpusec should be 0, and size of that section should be 0. */ |
533 | BUG_ON(size != 0); |
534 | } |
535 | bool is_module_percpu_address(unsigned long addr) |
536 | { |
537 | return false; |
538 | } |
539 | |
540 | #endif /* CONFIG_SMP */ |
541 | |
542 | #define MODINFO_ATTR(field) \ |
543 | static void setup_modinfo_##field(struct module *mod, const char *s) \ |
544 | { \ |
545 | mod->field = kstrdup(s, GFP_KERNEL); \ |
546 | } \ |
547 | static ssize_t show_modinfo_##field(struct module_attribute *mattr, \ |
548 | struct module *mod, char *buffer) \ |
549 | { \ |
550 | return sprintf(buffer, "%s\n", mod->field); \ |
551 | } \ |
552 | static int modinfo_##field##_exists(struct module *mod) \ |
553 | { \ |
554 | return mod->field != NULL; \ |
555 | } \ |
556 | static void free_modinfo_##field(struct module *mod) \ |
557 | { \ |
558 | kfree(mod->field); \ |
559 | mod->field = NULL; \ |
560 | } \ |
561 | static struct module_attribute modinfo_##field = { \ |
562 | .attr = { .name = __stringify(field), .mode = 0444 }, \ |
563 | .show = show_modinfo_##field, \ |
564 | .setup = setup_modinfo_##field, \ |
565 | .test = modinfo_##field##_exists, \ |
566 | .free = free_modinfo_##field, \ |
567 | }; |
568 | |
569 | MODINFO_ATTR(version); |
570 | MODINFO_ATTR(srcversion); |
571 | |
572 | static char last_unloaded_module[MODULE_NAME_LEN+1]; |
573 | |
574 | #ifdef CONFIG_MODULE_UNLOAD |
575 | |
576 | EXPORT_TRACEPOINT_SYMBOL(module_get); |
577 | |
578 | /* Init the unload section of the module. */ |
579 | static int module_unload_init(struct module *mod) |
580 | { |
581 | mod->refptr = alloc_percpu(struct module_ref); |
582 | if (!mod->refptr) |
583 | return -ENOMEM; |
584 | |
585 | INIT_LIST_HEAD(&mod->source_list); |
586 | INIT_LIST_HEAD(&mod->target_list); |
587 | |
588 | /* Hold reference count during initialization. */ |
589 | __this_cpu_write(mod->refptr->incs, 1); |
590 | /* Backwards compatibility macros put refcount during init. */ |
591 | mod->waiter = current; |
592 | |
593 | return 0; |
594 | } |
595 | |
596 | /* Does a already use b? */ |
597 | static int already_uses(struct module *a, struct module *b) |
598 | { |
599 | struct module_use *use; |
600 | |
601 | list_for_each_entry(use, &b->source_list, source_list) { |
602 | if (use->source == a) { |
603 | DEBUGP("%s uses %s!\n", a->name, b->name); |
604 | return 1; |
605 | } |
606 | } |
607 | DEBUGP("%s does not use %s!\n", a->name, b->name); |
608 | return 0; |
609 | } |
610 | |
611 | /* |
612 | * Module a uses b |
613 | * - we add 'a' as a "source", 'b' as a "target" of module use |
614 | * - the module_use is added to the list of 'b' sources (so |
615 | * 'b' can walk the list to see who sourced them), and of 'a' |
616 | * targets (so 'a' can see what modules it targets). |
617 | */ |
618 | static int add_module_usage(struct module *a, struct module *b) |
619 | { |
620 | struct module_use *use; |
621 | |
622 | DEBUGP("Allocating new usage for %s.\n", a->name); |
623 | use = kmalloc(sizeof(*use), GFP_ATOMIC); |
624 | if (!use) { |
625 | printk(KERN_WARNING "%s: out of memory loading\n", a->name); |
626 | return -ENOMEM; |
627 | } |
628 | |
629 | use->source = a; |
630 | use->target = b; |
631 | list_add(&use->source_list, &b->source_list); |
632 | list_add(&use->target_list, &a->target_list); |
633 | return 0; |
634 | } |
635 | |
636 | /* Module a uses b: caller needs module_mutex() */ |
637 | int ref_module(struct module *a, struct module *b) |
638 | { |
639 | int err; |
640 | |
641 | if (b == NULL || already_uses(a, b)) |
642 | return 0; |
643 | |
644 | /* If module isn't available, we fail. */ |
645 | err = strong_try_module_get(b); |
646 | if (err) |
647 | return err; |
648 | |
649 | err = add_module_usage(a, b); |
650 | if (err) { |
651 | module_put(b); |
652 | return err; |
653 | } |
654 | return 0; |
655 | } |
656 | EXPORT_SYMBOL_GPL(ref_module); |
657 | |
658 | /* Clear the unload stuff of the module. */ |
659 | static void module_unload_free(struct module *mod) |
660 | { |
661 | struct module_use *use, *tmp; |
662 | |
663 | mutex_lock(&module_mutex); |
664 | list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) { |
665 | struct module *i = use->target; |
666 | DEBUGP("%s unusing %s\n", mod->name, i->name); |
667 | module_put(i); |
668 | list_del(&use->source_list); |
669 | list_del(&use->target_list); |
670 | kfree(use); |
671 | } |
672 | mutex_unlock(&module_mutex); |
673 | |
674 | free_percpu(mod->refptr); |
675 | } |
676 | |
677 | #ifdef CONFIG_MODULE_FORCE_UNLOAD |
678 | static inline int try_force_unload(unsigned int flags) |
679 | { |
680 | int ret = (flags & O_TRUNC); |
681 | if (ret) |
682 | add_taint(TAINT_FORCED_RMMOD); |
683 | return ret; |
684 | } |
685 | #else |
686 | static inline int try_force_unload(unsigned int flags) |
687 | { |
688 | return 0; |
689 | } |
690 | #endif /* CONFIG_MODULE_FORCE_UNLOAD */ |
691 | |
692 | struct stopref |
693 | { |
694 | struct module *mod; |
695 | int flags; |
696 | int *forced; |
697 | }; |
698 | |
699 | /* Whole machine is stopped with interrupts off when this runs. */ |
700 | static int __try_stop_module(void *_sref) |
701 | { |
702 | struct stopref *sref = _sref; |
703 | |
704 | /* If it's not unused, quit unless we're forcing. */ |
705 | if (module_refcount(sref->mod) != 0) { |
706 | if (!(*sref->forced = try_force_unload(sref->flags))) |
707 | return -EWOULDBLOCK; |
708 | } |
709 | |
710 | /* Mark it as dying. */ |
711 | sref->mod->state = MODULE_STATE_GOING; |
712 | return 0; |
713 | } |
714 | |
715 | static int try_stop_module(struct module *mod, int flags, int *forced) |
716 | { |
717 | if (flags & O_NONBLOCK) { |
718 | struct stopref sref = { mod, flags, forced }; |
719 | |
720 | return stop_machine(__try_stop_module, &sref, NULL); |
721 | } else { |
722 | /* We don't need to stop the machine for this. */ |
723 | mod->state = MODULE_STATE_GOING; |
724 | synchronize_sched(); |
725 | return 0; |
726 | } |
727 | } |
728 | |
729 | unsigned int module_refcount(struct module *mod) |
730 | { |
731 | unsigned int incs = 0, decs = 0; |
732 | int cpu; |
733 | |
734 | for_each_possible_cpu(cpu) |
735 | decs += per_cpu_ptr(mod->refptr, cpu)->decs; |
736 | /* |
737 | * ensure the incs are added up after the decs. |
738 | * module_put ensures incs are visible before decs with smp_wmb. |
739 | * |
740 | * This 2-count scheme avoids the situation where the refcount |
741 | * for CPU0 is read, then CPU0 increments the module refcount, |
742 | * then CPU1 drops that refcount, then the refcount for CPU1 is |
743 | * read. We would record a decrement but not its corresponding |
744 | * increment so we would see a low count (disaster). |
745 | * |
746 | * Rare situation? But module_refcount can be preempted, and we |
747 | * might be tallying up 4096+ CPUs. So it is not impossible. |
748 | */ |
749 | smp_rmb(); |
750 | for_each_possible_cpu(cpu) |
751 | incs += per_cpu_ptr(mod->refptr, cpu)->incs; |
752 | return incs - decs; |
753 | } |
754 | EXPORT_SYMBOL(module_refcount); |
755 | |
756 | /* This exists whether we can unload or not */ |
757 | static void free_module(struct module *mod); |
758 | |
759 | static void wait_for_zero_refcount(struct module *mod) |
760 | { |
761 | /* Since we might sleep for some time, release the mutex first */ |
762 | mutex_unlock(&module_mutex); |
763 | for (;;) { |
764 | DEBUGP("Looking at refcount...\n"); |
765 | set_current_state(TASK_UNINTERRUPTIBLE); |
766 | if (module_refcount(mod) == 0) |
767 | break; |
768 | schedule(); |
769 | } |
770 | current->state = TASK_RUNNING; |
771 | mutex_lock(&module_mutex); |
772 | } |
773 | |
774 | SYSCALL_DEFINE2(delete_module, const char __user *, name_user, |
775 | unsigned int, flags) |
776 | { |
777 | struct module *mod; |
778 | char name[MODULE_NAME_LEN]; |
779 | int ret, forced = 0; |
780 | |
781 | if (!capable(CAP_SYS_MODULE) || modules_disabled) |
782 | return -EPERM; |
783 | |
784 | if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0) |
785 | return -EFAULT; |
786 | name[MODULE_NAME_LEN-1] = '\0'; |
787 | |
788 | if (mutex_lock_interruptible(&module_mutex) != 0) |
789 | return -EINTR; |
790 | |
791 | mod = find_module(name); |
792 | if (!mod) { |
793 | ret = -ENOENT; |
794 | goto out; |
795 | } |
796 | |
797 | if (!list_empty(&mod->source_list)) { |
798 | /* Other modules depend on us: get rid of them first. */ |
799 | ret = -EWOULDBLOCK; |
800 | goto out; |
801 | } |
802 | |
803 | /* Doing init or already dying? */ |
804 | if (mod->state != MODULE_STATE_LIVE) { |
805 | /* FIXME: if (force), slam module count and wake up |
806 | waiter --RR */ |
807 | DEBUGP("%s already dying\n", mod->name); |
808 | ret = -EBUSY; |
809 | goto out; |
810 | } |
811 | |
812 | /* If it has an init func, it must have an exit func to unload */ |
813 | if (mod->init && !mod->exit) { |
814 | forced = try_force_unload(flags); |
815 | if (!forced) { |
816 | /* This module can't be removed */ |
817 | ret = -EBUSY; |
818 | goto out; |
819 | } |
820 | } |
821 | |
822 | /* Set this up before setting mod->state */ |
823 | mod->waiter = current; |
824 | |
825 | /* Stop the machine so refcounts can't move and disable module. */ |
826 | ret = try_stop_module(mod, flags, &forced); |
827 | if (ret != 0) |
828 | goto out; |
829 | |
830 | /* Never wait if forced. */ |
831 | if (!forced && module_refcount(mod) != 0) |
832 | wait_for_zero_refcount(mod); |
833 | |
834 | mutex_unlock(&module_mutex); |
835 | /* Final destruction now no one is using it. */ |
836 | if (mod->exit != NULL) |
837 | mod->exit(); |
838 | blocking_notifier_call_chain(&module_notify_list, |
839 | MODULE_STATE_GOING, mod); |
840 | async_synchronize_full(); |
841 | |
842 | /* Store the name of the last unloaded module for diagnostic purposes */ |
843 | strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module)); |
844 | |
845 | free_module(mod); |
846 | return 0; |
847 | out: |
848 | mutex_unlock(&module_mutex); |
849 | return ret; |
850 | } |
851 | |
852 | static inline void print_unload_info(struct seq_file *m, struct module *mod) |
853 | { |
854 | struct module_use *use; |
855 | int printed_something = 0; |
856 | |
857 | seq_printf(m, " %u ", module_refcount(mod)); |
858 | |
859 | /* Always include a trailing , so userspace can differentiate |
860 | between this and the old multi-field proc format. */ |
861 | list_for_each_entry(use, &mod->source_list, source_list) { |
862 | printed_something = 1; |
863 | seq_printf(m, "%s,", use->source->name); |
864 | } |
865 | |
866 | if (mod->init != NULL && mod->exit == NULL) { |
867 | printed_something = 1; |
868 | seq_printf(m, "[permanent],"); |
869 | } |
870 | |
871 | if (!printed_something) |
872 | seq_printf(m, "-"); |
873 | } |
874 | |
875 | void __symbol_put(const char *symbol) |
876 | { |
877 | struct module *owner; |
878 | |
879 | preempt_disable(); |
880 | if (!find_symbol(symbol, &owner, NULL, true, false)) |
881 | BUG(); |
882 | module_put(owner); |
883 | preempt_enable(); |
884 | } |
885 | EXPORT_SYMBOL(__symbol_put); |
886 | |
887 | /* Note this assumes addr is a function, which it currently always is. */ |
888 | void symbol_put_addr(void *addr) |
889 | { |
890 | struct module *modaddr; |
891 | unsigned long a = (unsigned long)dereference_function_descriptor(addr); |
892 | |
893 | if (core_kernel_text(a)) |
894 | return; |
895 | |
896 | /* module_text_address is safe here: we're supposed to have reference |
897 | * to module from symbol_get, so it can't go away. */ |
898 | modaddr = __module_text_address(a); |
899 | BUG_ON(!modaddr); |
900 | module_put(modaddr); |
901 | } |
902 | EXPORT_SYMBOL_GPL(symbol_put_addr); |
903 | |
904 | static ssize_t show_refcnt(struct module_attribute *mattr, |
905 | struct module *mod, char *buffer) |
906 | { |
907 | return sprintf(buffer, "%u\n", module_refcount(mod)); |
908 | } |
909 | |
910 | static struct module_attribute refcnt = { |
911 | .attr = { .name = "refcnt", .mode = 0444 }, |
912 | .show = show_refcnt, |
913 | }; |
914 | |
915 | void module_put(struct module *module) |
916 | { |
917 | if (module) { |
918 | preempt_disable(); |
919 | smp_wmb(); /* see comment in module_refcount */ |
920 | __this_cpu_inc(module->refptr->decs); |
921 | |
922 | trace_module_put(module, _RET_IP_); |
923 | /* Maybe they're waiting for us to drop reference? */ |
924 | if (unlikely(!module_is_live(module))) |
925 | wake_up_process(module->waiter); |
926 | preempt_enable(); |
927 | } |
928 | } |
929 | EXPORT_SYMBOL(module_put); |
930 | |
931 | #else /* !CONFIG_MODULE_UNLOAD */ |
932 | static inline void print_unload_info(struct seq_file *m, struct module *mod) |
933 | { |
934 | /* We don't know the usage count, or what modules are using. */ |
935 | seq_printf(m, " - -"); |
936 | } |
937 | |
938 | static inline void module_unload_free(struct module *mod) |
939 | { |
940 | } |
941 | |
942 | int ref_module(struct module *a, struct module *b) |
943 | { |
944 | return strong_try_module_get(b); |
945 | } |
946 | EXPORT_SYMBOL_GPL(ref_module); |
947 | |
948 | static inline int module_unload_init(struct module *mod) |
949 | { |
950 | return 0; |
951 | } |
952 | #endif /* CONFIG_MODULE_UNLOAD */ |
953 | |
954 | static ssize_t show_initstate(struct module_attribute *mattr, |
955 | struct module *mod, char *buffer) |
956 | { |
957 | const char *state = "unknown"; |
958 | |
959 | switch (mod->state) { |
960 | case MODULE_STATE_LIVE: |
961 | state = "live"; |
962 | break; |
963 | case MODULE_STATE_COMING: |
964 | state = "coming"; |
965 | break; |
966 | case MODULE_STATE_GOING: |
967 | state = "going"; |
968 | break; |
969 | } |
970 | return sprintf(buffer, "%s\n", state); |
971 | } |
972 | |
973 | static struct module_attribute initstate = { |
974 | .attr = { .name = "initstate", .mode = 0444 }, |
975 | .show = show_initstate, |
976 | }; |
977 | |
978 | static struct module_attribute *modinfo_attrs[] = { |
979 | &modinfo_version, |
980 | &modinfo_srcversion, |
981 | &initstate, |
982 | #ifdef CONFIG_MODULE_UNLOAD |
983 | &refcnt, |
984 | #endif |
985 | NULL, |
986 | }; |
987 | |
988 | static const char vermagic[] = VERMAGIC_STRING; |
989 | |
990 | static int try_to_force_load(struct module *mod, const char *reason) |
991 | { |
992 | #ifdef CONFIG_MODULE_FORCE_LOAD |
993 | if (!test_taint(TAINT_FORCED_MODULE)) |
994 | printk(KERN_WARNING "%s: %s: kernel tainted.\n", |
995 | mod->name, reason); |
996 | add_taint_module(mod, TAINT_FORCED_MODULE); |
997 | return 0; |
998 | #else |
999 | return -ENOEXEC; |
1000 | #endif |
1001 | } |
1002 | |
1003 | #ifdef CONFIG_MODVERSIONS |
1004 | /* If the arch applies (non-zero) relocations to kernel kcrctab, unapply it. */ |
1005 | static unsigned long maybe_relocated(unsigned long crc, |
1006 | const struct module *crc_owner) |
1007 | { |
1008 | #ifdef ARCH_RELOCATES_KCRCTAB |
1009 | if (crc_owner == NULL) |
1010 | return crc - (unsigned long)reloc_start; |
1011 | #endif |
1012 | return crc; |
1013 | } |
1014 | |
1015 | static int check_version(Elf_Shdr *sechdrs, |
1016 | unsigned int versindex, |
1017 | const char *symname, |
1018 | struct module *mod, |
1019 | const unsigned long *crc, |
1020 | const struct module *crc_owner) |
1021 | { |
1022 | unsigned int i, num_versions; |
1023 | struct modversion_info *versions; |
1024 | |
1025 | /* Exporting module didn't supply crcs? OK, we're already tainted. */ |
1026 | if (!crc) |
1027 | return 1; |
1028 | |
1029 | /* No versions at all? modprobe --force does this. */ |
1030 | if (versindex == 0) |
1031 | return try_to_force_load(mod, symname) == 0; |
1032 | |
1033 | versions = (void *) sechdrs[versindex].sh_addr; |
1034 | num_versions = sechdrs[versindex].sh_size |
1035 | / sizeof(struct modversion_info); |
1036 | |
1037 | for (i = 0; i < num_versions; i++) { |
1038 | if (strcmp(versions[i].name, symname) != 0) |
1039 | continue; |
1040 | |
1041 | if (versions[i].crc == maybe_relocated(*crc, crc_owner)) |
1042 | return 1; |
1043 | DEBUGP("Found checksum %lX vs module %lX\n", |
1044 | maybe_relocated(*crc, crc_owner), versions[i].crc); |
1045 | goto bad_version; |
1046 | } |
1047 | |
1048 | printk(KERN_WARNING "%s: no symbol version for %s\n", |
1049 | mod->name, symname); |
1050 | return 0; |
1051 | |
1052 | bad_version: |
1053 | printk("%s: disagrees about version of symbol %s\n", |
1054 | mod->name, symname); |
1055 | return 0; |
1056 | } |
1057 | |
1058 | static inline int check_modstruct_version(Elf_Shdr *sechdrs, |
1059 | unsigned int versindex, |
1060 | struct module *mod) |
1061 | { |
1062 | const unsigned long *crc; |
1063 | |
1064 | /* Since this should be found in kernel (which can't be removed), |
1065 | * no locking is necessary. */ |
1066 | if (!find_symbol(MODULE_SYMBOL_PREFIX "module_layout", NULL, |
1067 | &crc, true, false)) |
1068 | BUG(); |
1069 | return check_version(sechdrs, versindex, "module_layout", mod, crc, |
1070 | NULL); |
1071 | } |
1072 | |
1073 | /* First part is kernel version, which we ignore if module has crcs. */ |
1074 | static inline int same_magic(const char *amagic, const char *bmagic, |
1075 | bool has_crcs) |
1076 | { |
1077 | if (has_crcs) { |
1078 | amagic += strcspn(amagic, " "); |
1079 | bmagic += strcspn(bmagic, " "); |
1080 | } |
1081 | return strcmp(amagic, bmagic) == 0; |
1082 | } |
1083 | #else |
1084 | static inline int check_version(Elf_Shdr *sechdrs, |
1085 | unsigned int versindex, |
1086 | const char *symname, |
1087 | struct module *mod, |
1088 | const unsigned long *crc, |
1089 | const struct module *crc_owner) |
1090 | { |
1091 | return 1; |
1092 | } |
1093 | |
1094 | static inline int check_modstruct_version(Elf_Shdr *sechdrs, |
1095 | unsigned int versindex, |
1096 | struct module *mod) |
1097 | { |
1098 | return 1; |
1099 | } |
1100 | |
1101 | static inline int same_magic(const char *amagic, const char *bmagic, |
1102 | bool has_crcs) |
1103 | { |
1104 | return strcmp(amagic, bmagic) == 0; |
1105 | } |
1106 | #endif /* CONFIG_MODVERSIONS */ |
1107 | |
1108 | /* Resolve a symbol for this module. I.e. if we find one, record usage. */ |
1109 | static const struct kernel_symbol *resolve_symbol(struct module *mod, |
1110 | const struct load_info *info, |
1111 | const char *name, |
1112 | char ownername[]) |
1113 | { |
1114 | struct module *owner; |
1115 | const struct kernel_symbol *sym; |
1116 | const unsigned long *crc; |
1117 | int err; |
1118 | |
1119 | mutex_lock(&module_mutex); |
1120 | sym = find_symbol(name, &owner, &crc, |
1121 | !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true); |
1122 | if (!sym) |
1123 | goto unlock; |
1124 | |
1125 | if (!check_version(info->sechdrs, info->index.vers, name, mod, crc, |
1126 | owner)) { |
1127 | sym = ERR_PTR(-EINVAL); |
1128 | goto getname; |
1129 | } |
1130 | |
1131 | err = ref_module(mod, owner); |
1132 | if (err) { |
1133 | sym = ERR_PTR(err); |
1134 | goto getname; |
1135 | } |
1136 | |
1137 | getname: |
1138 | /* We must make copy under the lock if we failed to get ref. */ |
1139 | strncpy(ownername, module_name(owner), MODULE_NAME_LEN); |
1140 | unlock: |
1141 | mutex_unlock(&module_mutex); |
1142 | return sym; |
1143 | } |
1144 | |
1145 | static const struct kernel_symbol * |
1146 | resolve_symbol_wait(struct module *mod, |
1147 | const struct load_info *info, |
1148 | const char *name) |
1149 | { |
1150 | const struct kernel_symbol *ksym; |
1151 | char owner[MODULE_NAME_LEN]; |
1152 | |
1153 | if (wait_event_interruptible_timeout(module_wq, |
1154 | !IS_ERR(ksym = resolve_symbol(mod, info, name, owner)) |
1155 | || PTR_ERR(ksym) != -EBUSY, |
1156 | 30 * HZ) <= 0) { |
1157 | printk(KERN_WARNING "%s: gave up waiting for init of module %s.\n", |
1158 | mod->name, owner); |
1159 | } |
1160 | return ksym; |
1161 | } |
1162 | |
1163 | /* |
1164 | * /sys/module/foo/sections stuff |
1165 | * J. Corbet <corbet@lwn.net> |
1166 | */ |
1167 | #ifdef CONFIG_SYSFS |
1168 | |
1169 | #ifdef CONFIG_KALLSYMS |
1170 | static inline bool sect_empty(const Elf_Shdr *sect) |
1171 | { |
1172 | return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0; |
1173 | } |
1174 | |
1175 | struct module_sect_attr |
1176 | { |
1177 | struct module_attribute mattr; |
1178 | char *name; |
1179 | unsigned long address; |
1180 | }; |
1181 | |
1182 | struct module_sect_attrs |
1183 | { |
1184 | struct attribute_group grp; |
1185 | unsigned int nsections; |
1186 | struct module_sect_attr attrs[0]; |
1187 | }; |
1188 | |
1189 | static ssize_t module_sect_show(struct module_attribute *mattr, |
1190 | struct module *mod, char *buf) |
1191 | { |
1192 | struct module_sect_attr *sattr = |
1193 | container_of(mattr, struct module_sect_attr, mattr); |
1194 | return sprintf(buf, "0x%pK\n", (void *)sattr->address); |
1195 | } |
1196 | |
1197 | static void free_sect_attrs(struct module_sect_attrs *sect_attrs) |
1198 | { |
1199 | unsigned int section; |
1200 | |
1201 | for (section = 0; section < sect_attrs->nsections; section++) |
1202 | kfree(sect_attrs->attrs[section].name); |
1203 | kfree(sect_attrs); |
1204 | } |
1205 | |
1206 | static void add_sect_attrs(struct module *mod, const struct load_info *info) |
1207 | { |
1208 | unsigned int nloaded = 0, i, size[2]; |
1209 | struct module_sect_attrs *sect_attrs; |
1210 | struct module_sect_attr *sattr; |
1211 | struct attribute **gattr; |
1212 | |
1213 | /* Count loaded sections and allocate structures */ |
1214 | for (i = 0; i < info->hdr->e_shnum; i++) |
1215 | if (!sect_empty(&info->sechdrs[i])) |
1216 | nloaded++; |
1217 | size[0] = ALIGN(sizeof(*sect_attrs) |
1218 | + nloaded * sizeof(sect_attrs->attrs[0]), |
1219 | sizeof(sect_attrs->grp.attrs[0])); |
1220 | size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]); |
1221 | sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL); |
1222 | if (sect_attrs == NULL) |
1223 | return; |
1224 | |
1225 | /* Setup section attributes. */ |
1226 | sect_attrs->grp.name = "sections"; |
1227 | sect_attrs->grp.attrs = (void *)sect_attrs + size[0]; |
1228 | |
1229 | sect_attrs->nsections = 0; |
1230 | sattr = §_attrs->attrs[0]; |
1231 | gattr = §_attrs->grp.attrs[0]; |
1232 | for (i = 0; i < info->hdr->e_shnum; i++) { |
1233 | Elf_Shdr *sec = &info->sechdrs[i]; |
1234 | if (sect_empty(sec)) |
1235 | continue; |
1236 | sattr->address = sec->sh_addr; |
1237 | sattr->name = kstrdup(info->secstrings + sec->sh_name, |
1238 | GFP_KERNEL); |
1239 | if (sattr->name == NULL) |
1240 | goto out; |
1241 | sect_attrs->nsections++; |
1242 | sysfs_attr_init(&sattr->mattr.attr); |
1243 | sattr->mattr.show = module_sect_show; |
1244 | sattr->mattr.store = NULL; |
1245 | sattr->mattr.attr.name = sattr->name; |
1246 | sattr->mattr.attr.mode = S_IRUGO; |
1247 | *(gattr++) = &(sattr++)->mattr.attr; |
1248 | } |
1249 | *gattr = NULL; |
1250 | |
1251 | if (sysfs_create_group(&mod->mkobj.kobj, §_attrs->grp)) |
1252 | goto out; |
1253 | |
1254 | mod->sect_attrs = sect_attrs; |
1255 | return; |
1256 | out: |
1257 | free_sect_attrs(sect_attrs); |
1258 | } |
1259 | |
1260 | static void remove_sect_attrs(struct module *mod) |
1261 | { |
1262 | if (mod->sect_attrs) { |
1263 | sysfs_remove_group(&mod->mkobj.kobj, |
1264 | &mod->sect_attrs->grp); |
1265 | /* We are positive that no one is using any sect attrs |
1266 | * at this point. Deallocate immediately. */ |
1267 | free_sect_attrs(mod->sect_attrs); |
1268 | mod->sect_attrs = NULL; |
1269 | } |
1270 | } |
1271 | |
1272 | /* |
1273 | * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections. |
1274 | */ |
1275 | |
1276 | struct module_notes_attrs { |
1277 | struct kobject *dir; |
1278 | unsigned int notes; |
1279 | struct bin_attribute attrs[0]; |
1280 | }; |
1281 | |
1282 | static ssize_t module_notes_read(struct file *filp, struct kobject *kobj, |
1283 | struct bin_attribute *bin_attr, |
1284 | char *buf, loff_t pos, size_t count) |
1285 | { |
1286 | /* |
1287 | * The caller checked the pos and count against our size. |
1288 | */ |
1289 | memcpy(buf, bin_attr->private + pos, count); |
1290 | return count; |
1291 | } |
1292 | |
1293 | static void free_notes_attrs(struct module_notes_attrs *notes_attrs, |
1294 | unsigned int i) |
1295 | { |
1296 | if (notes_attrs->dir) { |
1297 | while (i-- > 0) |
1298 | sysfs_remove_bin_file(notes_attrs->dir, |
1299 | ¬es_attrs->attrs[i]); |
1300 | kobject_put(notes_attrs->dir); |
1301 | } |
1302 | kfree(notes_attrs); |
1303 | } |
1304 | |
1305 | static void add_notes_attrs(struct module *mod, const struct load_info *info) |
1306 | { |
1307 | unsigned int notes, loaded, i; |
1308 | struct module_notes_attrs *notes_attrs; |
1309 | struct bin_attribute *nattr; |
1310 | |
1311 | /* failed to create section attributes, so can't create notes */ |
1312 | if (!mod->sect_attrs) |
1313 | return; |
1314 | |
1315 | /* Count notes sections and allocate structures. */ |
1316 | notes = 0; |
1317 | for (i = 0; i < info->hdr->e_shnum; i++) |
1318 | if (!sect_empty(&info->sechdrs[i]) && |
1319 | (info->sechdrs[i].sh_type == SHT_NOTE)) |
1320 | ++notes; |
1321 | |
1322 | if (notes == 0) |
1323 | return; |
1324 | |
1325 | notes_attrs = kzalloc(sizeof(*notes_attrs) |
1326 | + notes * sizeof(notes_attrs->attrs[0]), |
1327 | GFP_KERNEL); |
1328 | if (notes_attrs == NULL) |
1329 | return; |
1330 | |
1331 | notes_attrs->notes = notes; |
1332 | nattr = ¬es_attrs->attrs[0]; |
1333 | for (loaded = i = 0; i < info->hdr->e_shnum; ++i) { |
1334 | if (sect_empty(&info->sechdrs[i])) |
1335 | continue; |
1336 | if (info->sechdrs[i].sh_type == SHT_NOTE) { |
1337 | sysfs_bin_attr_init(nattr); |
1338 | nattr->attr.name = mod->sect_attrs->attrs[loaded].name; |
1339 | nattr->attr.mode = S_IRUGO; |
1340 | nattr->size = info->sechdrs[i].sh_size; |
1341 | nattr->private = (void *) info->sechdrs[i].sh_addr; |
1342 | nattr->read = module_notes_read; |
1343 | ++nattr; |
1344 | } |
1345 | ++loaded; |
1346 | } |
1347 | |
1348 | notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj); |
1349 | if (!notes_attrs->dir) |
1350 | goto out; |
1351 | |
1352 | for (i = 0; i < notes; ++i) |
1353 | if (sysfs_create_bin_file(notes_attrs->dir, |
1354 | ¬es_attrs->attrs[i])) |
1355 | goto out; |
1356 | |
1357 | mod->notes_attrs = notes_attrs; |
1358 | return; |
1359 | |
1360 | out: |
1361 | free_notes_attrs(notes_attrs, i); |
1362 | } |
1363 | |
1364 | static void remove_notes_attrs(struct module *mod) |
1365 | { |
1366 | if (mod->notes_attrs) |
1367 | free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes); |
1368 | } |
1369 | |
1370 | #else |
1371 | |
1372 | static inline void add_sect_attrs(struct module *mod, |
1373 | const struct load_info *info) |
1374 | { |
1375 | } |
1376 | |
1377 | static inline void remove_sect_attrs(struct module *mod) |
1378 | { |
1379 | } |
1380 | |
1381 | static inline void add_notes_attrs(struct module *mod, |
1382 | const struct load_info *info) |
1383 | { |
1384 | } |
1385 | |
1386 | static inline void remove_notes_attrs(struct module *mod) |
1387 | { |
1388 | } |
1389 | #endif /* CONFIG_KALLSYMS */ |
1390 | |
1391 | static void add_usage_links(struct module *mod) |
1392 | { |
1393 | #ifdef CONFIG_MODULE_UNLOAD |
1394 | struct module_use *use; |
1395 | int nowarn; |
1396 | |
1397 | mutex_lock(&module_mutex); |
1398 | list_for_each_entry(use, &mod->target_list, target_list) { |
1399 | nowarn = sysfs_create_link(use->target->holders_dir, |
1400 | &mod->mkobj.kobj, mod->name); |
1401 | } |
1402 | mutex_unlock(&module_mutex); |
1403 | #endif |
1404 | } |
1405 | |
1406 | static void del_usage_links(struct module *mod) |
1407 | { |
1408 | #ifdef CONFIG_MODULE_UNLOAD |
1409 | struct module_use *use; |
1410 | |
1411 | mutex_lock(&module_mutex); |
1412 | list_for_each_entry(use, &mod->target_list, target_list) |
1413 | sysfs_remove_link(use->target->holders_dir, mod->name); |
1414 | mutex_unlock(&module_mutex); |
1415 | #endif |
1416 | } |
1417 | |
1418 | static int module_add_modinfo_attrs(struct module *mod) |
1419 | { |
1420 | struct module_attribute *attr; |
1421 | struct module_attribute *temp_attr; |
1422 | int error = 0; |
1423 | int i; |
1424 | |
1425 | mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) * |
1426 | (ARRAY_SIZE(modinfo_attrs) + 1)), |
1427 | GFP_KERNEL); |
1428 | if (!mod->modinfo_attrs) |
1429 | return -ENOMEM; |
1430 | |
1431 | temp_attr = mod->modinfo_attrs; |
1432 | for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) { |
1433 | if (!attr->test || |
1434 | (attr->test && attr->test(mod))) { |
1435 | memcpy(temp_attr, attr, sizeof(*temp_attr)); |
1436 | sysfs_attr_init(&temp_attr->attr); |
1437 | error = sysfs_create_file(&mod->mkobj.kobj,&temp_attr->attr); |
1438 | ++temp_attr; |
1439 | } |
1440 | } |
1441 | return error; |
1442 | } |
1443 | |
1444 | static void module_remove_modinfo_attrs(struct module *mod) |
1445 | { |
1446 | struct module_attribute *attr; |
1447 | int i; |
1448 | |
1449 | for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) { |
1450 | /* pick a field to test for end of list */ |
1451 | if (!attr->attr.name) |
1452 | break; |
1453 | sysfs_remove_file(&mod->mkobj.kobj,&attr->attr); |
1454 | if (attr->free) |
1455 | attr->free(mod); |
1456 | } |
1457 | kfree(mod->modinfo_attrs); |
1458 | } |
1459 | |
1460 | static int mod_sysfs_init(struct module *mod) |
1461 | { |
1462 | int err; |
1463 | struct kobject *kobj; |
1464 | |
1465 | if (!module_sysfs_initialized) { |
1466 | printk(KERN_ERR "%s: module sysfs not initialized\n", |
1467 | mod->name); |
1468 | err = -EINVAL; |
1469 | goto out; |
1470 | } |
1471 | |
1472 | kobj = kset_find_obj(module_kset, mod->name); |
1473 | if (kobj) { |
1474 | printk(KERN_ERR "%s: module is already loaded\n", mod->name); |
1475 | kobject_put(kobj); |
1476 | err = -EINVAL; |
1477 | goto out; |
1478 | } |
1479 | |
1480 | mod->mkobj.mod = mod; |
1481 | |
1482 | memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj)); |
1483 | mod->mkobj.kobj.kset = module_kset; |
1484 | err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL, |
1485 | "%s", mod->name); |
1486 | if (err) |
1487 | kobject_put(&mod->mkobj.kobj); |
1488 | |
1489 | /* delay uevent until full sysfs population */ |
1490 | out: |
1491 | return err; |
1492 | } |
1493 | |
1494 | static int mod_sysfs_setup(struct module *mod, |
1495 | const struct load_info *info, |
1496 | struct kernel_param *kparam, |
1497 | unsigned int num_params) |
1498 | { |
1499 | int err; |
1500 | |
1501 | err = mod_sysfs_init(mod); |
1502 | if (err) |
1503 | goto out; |
1504 | |
1505 | mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj); |
1506 | if (!mod->holders_dir) { |
1507 | err = -ENOMEM; |
1508 | goto out_unreg; |
1509 | } |
1510 | |
1511 | err = module_param_sysfs_setup(mod, kparam, num_params); |
1512 | if (err) |
1513 | goto out_unreg_holders; |
1514 | |
1515 | err = module_add_modinfo_attrs(mod); |
1516 | if (err) |
1517 | goto out_unreg_param; |
1518 | |
1519 | add_usage_links(mod); |
1520 | add_sect_attrs(mod, info); |
1521 | add_notes_attrs(mod, info); |
1522 | |
1523 | kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD); |
1524 | return 0; |
1525 | |
1526 | out_unreg_param: |
1527 | module_param_sysfs_remove(mod); |
1528 | out_unreg_holders: |
1529 | kobject_put(mod->holders_dir); |
1530 | out_unreg: |
1531 | kobject_put(&mod->mkobj.kobj); |
1532 | out: |
1533 | return err; |
1534 | } |
1535 | |
1536 | static void mod_sysfs_fini(struct module *mod) |
1537 | { |
1538 | remove_notes_attrs(mod); |
1539 | remove_sect_attrs(mod); |
1540 | kobject_put(&mod->mkobj.kobj); |
1541 | } |
1542 | |
1543 | #else /* !CONFIG_SYSFS */ |
1544 | |
1545 | static int mod_sysfs_setup(struct module *mod, |
1546 | const struct load_info *info, |
1547 | struct kernel_param *kparam, |
1548 | unsigned int num_params) |
1549 | { |
1550 | return 0; |
1551 | } |
1552 | |
1553 | static void mod_sysfs_fini(struct module *mod) |
1554 | { |
1555 | } |
1556 | |
1557 | static void module_remove_modinfo_attrs(struct module *mod) |
1558 | { |
1559 | } |
1560 | |
1561 | static void del_usage_links(struct module *mod) |
1562 | { |
1563 | } |
1564 | |
1565 | #endif /* CONFIG_SYSFS */ |
1566 | |
1567 | static void mod_sysfs_teardown(struct module *mod) |
1568 | { |
1569 | del_usage_links(mod); |
1570 | module_remove_modinfo_attrs(mod); |
1571 | module_param_sysfs_remove(mod); |
1572 | kobject_put(mod->mkobj.drivers_dir); |
1573 | kobject_put(mod->holders_dir); |
1574 | mod_sysfs_fini(mod); |
1575 | } |
1576 | |
1577 | /* |
1578 | * unlink the module with the whole machine is stopped with interrupts off |
1579 | * - this defends against kallsyms not taking locks |
1580 | */ |
1581 | static int __unlink_module(void *_mod) |
1582 | { |
1583 | struct module *mod = _mod; |
1584 | list_del(&mod->list); |
1585 | module_bug_cleanup(mod); |
1586 | return 0; |
1587 | } |
1588 | |
1589 | #ifdef CONFIG_DEBUG_SET_MODULE_RONX |
1590 | /* |
1591 | * LKM RO/NX protection: protect module's text/ro-data |
1592 | * from modification and any data from execution. |
1593 | */ |
1594 | void set_page_attributes(void *start, void *end, int (*set)(unsigned long start, int num_pages)) |
1595 | { |
1596 | unsigned long begin_pfn = PFN_DOWN((unsigned long)start); |
1597 | unsigned long end_pfn = PFN_DOWN((unsigned long)end); |
1598 | |
1599 | if (end_pfn > begin_pfn) |
1600 | set(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn); |
1601 | } |
1602 | |
1603 | static void set_section_ro_nx(void *base, |
1604 | unsigned long text_size, |
1605 | unsigned long ro_size, |
1606 | unsigned long total_size) |
1607 | { |
1608 | /* begin and end PFNs of the current subsection */ |
1609 | unsigned long begin_pfn; |
1610 | unsigned long end_pfn; |
1611 | |
1612 | /* |
1613 | * Set RO for module text and RO-data: |
1614 | * - Always protect first page. |
1615 | * - Do not protect last partial page. |
1616 | */ |
1617 | if (ro_size > 0) |
1618 | set_page_attributes(base, base + ro_size, set_memory_ro); |
1619 | |
1620 | /* |
1621 | * Set NX permissions for module data: |
1622 | * - Do not protect first partial page. |
1623 | * - Always protect last page. |
1624 | */ |
1625 | if (total_size > text_size) { |
1626 | begin_pfn = PFN_UP((unsigned long)base + text_size); |
1627 | end_pfn = PFN_UP((unsigned long)base + total_size); |
1628 | if (end_pfn > begin_pfn) |
1629 | set_memory_nx(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn); |
1630 | } |
1631 | } |
1632 | |
1633 | static void unset_module_core_ro_nx(struct module *mod) |
1634 | { |
1635 | set_page_attributes(mod->module_core + mod->core_text_size, |
1636 | mod->module_core + mod->core_size, |
1637 | set_memory_x); |
1638 | set_page_attributes(mod->module_core, |
1639 | mod->module_core + mod->core_ro_size, |
1640 | set_memory_rw); |
1641 | } |
1642 | |
1643 | static void unset_module_init_ro_nx(struct module *mod) |
1644 | { |
1645 | set_page_attributes(mod->module_init + mod->init_text_size, |
1646 | mod->module_init + mod->init_size, |
1647 | set_memory_x); |
1648 | set_page_attributes(mod->module_init, |
1649 | mod->module_init + mod->init_ro_size, |
1650 | set_memory_rw); |
1651 | } |
1652 | |
1653 | /* Iterate through all modules and set each module's text as RW */ |
1654 | void set_all_modules_text_rw(void) |
1655 | { |
1656 | struct module *mod; |
1657 | |
1658 | mutex_lock(&module_mutex); |
1659 | list_for_each_entry_rcu(mod, &modules, list) { |
1660 | if ((mod->module_core) && (mod->core_text_size)) { |
1661 | set_page_attributes(mod->module_core, |
1662 | mod->module_core + mod->core_text_size, |
1663 | set_memory_rw); |
1664 | } |
1665 | if ((mod->module_init) && (mod->init_text_size)) { |
1666 | set_page_attributes(mod->module_init, |
1667 | mod->module_init + mod->init_text_size, |
1668 | set_memory_rw); |
1669 | } |
1670 | } |
1671 | mutex_unlock(&module_mutex); |
1672 | } |
1673 | |
1674 | /* Iterate through all modules and set each module's text as RO */ |
1675 | void set_all_modules_text_ro(void) |
1676 | { |
1677 | struct module *mod; |
1678 | |
1679 | mutex_lock(&module_mutex); |
1680 | list_for_each_entry_rcu(mod, &modules, list) { |
1681 | if ((mod->module_core) && (mod->core_text_size)) { |
1682 | set_page_attributes(mod->module_core, |
1683 | mod->module_core + mod->core_text_size, |
1684 | set_memory_ro); |
1685 | } |
1686 | if ((mod->module_init) && (mod->init_text_size)) { |
1687 | set_page_attributes(mod->module_init, |
1688 | mod->module_init + mod->init_text_size, |
1689 | set_memory_ro); |
1690 | } |
1691 | } |
1692 | mutex_unlock(&module_mutex); |
1693 | } |
1694 | #else |
1695 | static inline void set_section_ro_nx(void *base, unsigned long text_size, unsigned long ro_size, unsigned long total_size) { } |
1696 | static void unset_module_core_ro_nx(struct module *mod) { } |
1697 | static void unset_module_init_ro_nx(struct module *mod) { } |
1698 | #endif |
1699 | |
1700 | /* Free a module, remove from lists, etc. */ |
1701 | static void free_module(struct module *mod) |
1702 | { |
1703 | trace_module_free(mod); |
1704 | |
1705 | /* Delete from various lists */ |
1706 | mutex_lock(&module_mutex); |
1707 | stop_machine(__unlink_module, mod, NULL); |
1708 | mutex_unlock(&module_mutex); |
1709 | mod_sysfs_teardown(mod); |
1710 | |
1711 | /* Remove dynamic debug info */ |
1712 | ddebug_remove_module(mod->name); |
1713 | |
1714 | /* Arch-specific cleanup. */ |
1715 | module_arch_cleanup(mod); |
1716 | |
1717 | /* Module unload stuff */ |
1718 | module_unload_free(mod); |
1719 | |
1720 | /* Free any allocated parameters. */ |
1721 | destroy_params(mod->kp, mod->num_kp); |
1722 | |
1723 | /* This may be NULL, but that's OK */ |
1724 | unset_module_init_ro_nx(mod); |
1725 | module_free(mod, mod->module_init); |
1726 | kfree(mod->args); |
1727 | percpu_modfree(mod); |
1728 | |
1729 | /* Free lock-classes: */ |
1730 | lockdep_free_key_range(mod->module_core, mod->core_size); |
1731 | |
1732 | /* Finally, free the core (containing the module structure) */ |
1733 | unset_module_core_ro_nx(mod); |
1734 | module_free(mod, mod->module_core); |
1735 | |
1736 | #ifdef CONFIG_MPU |
1737 | update_protections(current->mm); |
1738 | #endif |
1739 | } |
1740 | |
1741 | void *__symbol_get(const char *symbol) |
1742 | { |
1743 | struct module *owner; |
1744 | const struct kernel_symbol *sym; |
1745 | |
1746 | preempt_disable(); |
1747 | sym = find_symbol(symbol, &owner, NULL, true, true); |
1748 | if (sym && strong_try_module_get(owner)) |
1749 | sym = NULL; |
1750 | preempt_enable(); |
1751 | |
1752 | return sym ? (void *)sym->value : NULL; |
1753 | } |
1754 | EXPORT_SYMBOL_GPL(__symbol_get); |
1755 | |
1756 | /* |
1757 | * Ensure that an exported symbol [global namespace] does not already exist |
1758 | * in the kernel or in some other module's exported symbol table. |
1759 | * |
1760 | * You must hold the module_mutex. |
1761 | */ |
1762 | static int verify_export_symbols(struct module *mod) |
1763 | { |
1764 | unsigned int i; |
1765 | struct module *owner; |
1766 | const struct kernel_symbol *s; |
1767 | struct { |
1768 | const struct kernel_symbol *sym; |
1769 | unsigned int num; |
1770 | } arr[] = { |
1771 | { mod->syms, mod->num_syms }, |
1772 | { mod->gpl_syms, mod->num_gpl_syms }, |
1773 | { mod->gpl_future_syms, mod->num_gpl_future_syms }, |
1774 | #ifdef CONFIG_UNUSED_SYMBOLS |
1775 | { mod->unused_syms, mod->num_unused_syms }, |
1776 | { mod->unused_gpl_syms, mod->num_unused_gpl_syms }, |
1777 | #endif |
1778 | }; |
1779 | |
1780 | for (i = 0; i < ARRAY_SIZE(arr); i++) { |
1781 | for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) { |
1782 | if (find_symbol(s->name, &owner, NULL, true, false)) { |
1783 | printk(KERN_ERR |
1784 | "%s: exports duplicate symbol %s" |
1785 | " (owned by %s)\n", |
1786 | mod->name, s->name, module_name(owner)); |
1787 | return -ENOEXEC; |
1788 | } |
1789 | } |
1790 | } |
1791 | return 0; |
1792 | } |
1793 | |
1794 | /* Change all symbols so that st_value encodes the pointer directly. */ |
1795 | static int simplify_symbols(struct module *mod, const struct load_info *info) |
1796 | { |
1797 | Elf_Shdr *symsec = &info->sechdrs[info->index.sym]; |
1798 | Elf_Sym *sym = (void *)symsec->sh_addr; |
1799 | unsigned long secbase; |
1800 | unsigned int i; |
1801 | int ret = 0; |
1802 | const struct kernel_symbol *ksym; |
1803 | |
1804 | for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) { |
1805 | const char *name = info->strtab + sym[i].st_name; |
1806 | |
1807 | switch (sym[i].st_shndx) { |
1808 | case SHN_COMMON: |
1809 | /* We compiled with -fno-common. These are not |
1810 | supposed to happen. */ |
1811 | DEBUGP("Common symbol: %s\n", name); |
1812 | printk("%s: please compile with -fno-common\n", |
1813 | mod->name); |
1814 | ret = -ENOEXEC; |
1815 | break; |
1816 | |
1817 | case SHN_ABS: |
1818 | /* Don't need to do anything */ |
1819 | DEBUGP("Absolute symbol: 0x%08lx\n", |
1820 | (long)sym[i].st_value); |
1821 | break; |
1822 | |
1823 | case SHN_UNDEF: |
1824 | ksym = resolve_symbol_wait(mod, info, name); |
1825 | /* Ok if resolved. */ |
1826 | if (ksym && !IS_ERR(ksym)) { |
1827 | sym[i].st_value = ksym->value; |
1828 | break; |
1829 | } |
1830 | |
1831 | /* Ok if weak. */ |
1832 | if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK) |
1833 | break; |
1834 | |
1835 | printk(KERN_WARNING "%s: Unknown symbol %s (err %li)\n", |
1836 | mod->name, name, PTR_ERR(ksym)); |
1837 | ret = PTR_ERR(ksym) ?: -ENOENT; |
1838 | break; |
1839 | |
1840 | default: |
1841 | /* Divert to percpu allocation if a percpu var. */ |
1842 | if (sym[i].st_shndx == info->index.pcpu) |
1843 | secbase = (unsigned long)mod_percpu(mod); |
1844 | else |
1845 | secbase = info->sechdrs[sym[i].st_shndx].sh_addr; |
1846 | sym[i].st_value += secbase; |
1847 | break; |
1848 | } |
1849 | } |
1850 | |
1851 | return ret; |
1852 | } |
1853 | |
1854 | static int apply_relocations(struct module *mod, const struct load_info *info) |
1855 | { |
1856 | unsigned int i; |
1857 | int err = 0; |
1858 | |
1859 | /* Now do relocations. */ |
1860 | for (i = 1; i < info->hdr->e_shnum; i++) { |
1861 | unsigned int infosec = info->sechdrs[i].sh_info; |
1862 | |
1863 | /* Not a valid relocation section? */ |
1864 | if (infosec >= info->hdr->e_shnum) |
1865 | continue; |
1866 | |
1867 | /* Don't bother with non-allocated sections */ |
1868 | if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC)) |
1869 | continue; |
1870 | |
1871 | if (info->sechdrs[i].sh_type == SHT_REL) |
1872 | err = apply_relocate(info->sechdrs, info->strtab, |
1873 | info->index.sym, i, mod); |
1874 | else if (info->sechdrs[i].sh_type == SHT_RELA) |
1875 | err = apply_relocate_add(info->sechdrs, info->strtab, |
1876 | info->index.sym, i, mod); |
1877 | if (err < 0) |
1878 | break; |
1879 | } |
1880 | return err; |
1881 | } |
1882 | |
1883 | /* Additional bytes needed by arch in front of individual sections */ |
1884 | unsigned int __weak arch_mod_section_prepend(struct module *mod, |
1885 | unsigned int section) |
1886 | { |
1887 | /* default implementation just returns zero */ |
1888 | return 0; |
1889 | } |
1890 | |
1891 | /* Update size with this section: return offset. */ |
1892 | static long get_offset(struct module *mod, unsigned int *size, |
1893 | Elf_Shdr *sechdr, unsigned int section) |
1894 | { |
1895 | long ret; |
1896 | |
1897 | *size += arch_mod_section_prepend(mod, section); |
1898 | ret = ALIGN(*size, sechdr->sh_addralign ?: 1); |
1899 | *size = ret + sechdr->sh_size; |
1900 | return ret; |
1901 | } |
1902 | |
1903 | /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld |
1904 | might -- code, read-only data, read-write data, small data. Tally |
1905 | sizes, and place the offsets into sh_entsize fields: high bit means it |
1906 | belongs in init. */ |
1907 | static void layout_sections(struct module *mod, struct load_info *info) |
1908 | { |
1909 | static unsigned long const masks[][2] = { |
1910 | /* NOTE: all executable code must be the first section |
1911 | * in this array; otherwise modify the text_size |
1912 | * finder in the two loops below */ |
1913 | { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL }, |
1914 | { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL }, |
1915 | { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL }, |
1916 | { ARCH_SHF_SMALL | SHF_ALLOC, 0 } |
1917 | }; |
1918 | unsigned int m, i; |
1919 | |
1920 | for (i = 0; i < info->hdr->e_shnum; i++) |
1921 | info->sechdrs[i].sh_entsize = ~0UL; |
1922 | |
1923 | DEBUGP("Core section allocation order:\n"); |
1924 | for (m = 0; m < ARRAY_SIZE(masks); ++m) { |
1925 | for (i = 0; i < info->hdr->e_shnum; ++i) { |
1926 | Elf_Shdr *s = &info->sechdrs[i]; |
1927 | const char *sname = info->secstrings + s->sh_name; |
1928 | |
1929 | if ((s->sh_flags & masks[m][0]) != masks[m][0] |
1930 | || (s->sh_flags & masks[m][1]) |
1931 | || s->sh_entsize != ~0UL |
1932 | || strstarts(sname, ".init")) |
1933 | continue; |
1934 | s->sh_entsize = get_offset(mod, &mod->core_size, s, i); |
1935 | DEBUGP("\t%s\n", name); |
1936 | } |
1937 | switch (m) { |
1938 | case 0: /* executable */ |
1939 | mod->core_size = debug_align(mod->core_size); |
1940 | mod->core_text_size = mod->core_size; |
1941 | break; |
1942 | case 1: /* RO: text and ro-data */ |
1943 | mod->core_size = debug_align(mod->core_size); |
1944 | mod->core_ro_size = mod->core_size; |
1945 | break; |
1946 | case 3: /* whole core */ |
1947 | mod->core_size = debug_align(mod->core_size); |
1948 | break; |
1949 | } |
1950 | } |
1951 | |
1952 | DEBUGP("Init section allocation order:\n"); |
1953 | for (m = 0; m < ARRAY_SIZE(masks); ++m) { |
1954 | for (i = 0; i < info->hdr->e_shnum; ++i) { |
1955 | Elf_Shdr *s = &info->sechdrs[i]; |
1956 | const char *sname = info->secstrings + s->sh_name; |
1957 | |
1958 | if ((s->sh_flags & masks[m][0]) != masks[m][0] |
1959 | || (s->sh_flags & masks[m][1]) |
1960 | || s->sh_entsize != ~0UL |
1961 | || !strstarts(sname, ".init")) |
1962 | continue; |
1963 | s->sh_entsize = (get_offset(mod, &mod->init_size, s, i) |
1964 | | INIT_OFFSET_MASK); |
1965 | DEBUGP("\t%s\n", sname); |
1966 | } |
1967 | switch (m) { |
1968 | case 0: /* executable */ |
1969 | mod->init_size = debug_align(mod->init_size); |
1970 | mod->init_text_size = mod->init_size; |
1971 | break; |
1972 | case 1: /* RO: text and ro-data */ |
1973 | mod->init_size = debug_align(mod->init_size); |
1974 | mod->init_ro_size = mod->init_size; |
1975 | break; |
1976 | case 3: /* whole init */ |
1977 | mod->init_size = debug_align(mod->init_size); |
1978 | break; |
1979 | } |
1980 | } |
1981 | } |
1982 | |
1983 | static void set_license(struct module *mod, const char *license) |
1984 | { |
1985 | if (!license) |
1986 | license = "unspecified"; |
1987 | |
1988 | if (!license_is_gpl_compatible(license)) { |
1989 | if (!test_taint(TAINT_PROPRIETARY_MODULE)) |
1990 | printk(KERN_WARNING "%s: module license '%s' taints " |
1991 | "kernel.\n", mod->name, license); |
1992 | add_taint_module(mod, TAINT_PROPRIETARY_MODULE); |
1993 | } |
1994 | } |
1995 | |
1996 | /* Parse tag=value strings from .modinfo section */ |
1997 | static char *next_string(char *string, unsigned long *secsize) |
1998 | { |
1999 | /* Skip non-zero chars */ |
2000 | while (string[0]) { |
2001 | string++; |
2002 | if ((*secsize)-- <= 1) |
2003 | return NULL; |
2004 | } |
2005 | |
2006 | /* Skip any zero padding. */ |
2007 | while (!string[0]) { |
2008 | string++; |
2009 | if ((*secsize)-- <= 1) |
2010 | return NULL; |
2011 | } |
2012 | return string; |
2013 | } |
2014 | |
2015 | static char *get_modinfo(struct load_info *info, const char *tag) |
2016 | { |
2017 | char *p; |
2018 | unsigned int taglen = strlen(tag); |
2019 | Elf_Shdr *infosec = &info->sechdrs[info->index.info]; |
2020 | unsigned long size = infosec->sh_size; |
2021 | |
2022 | for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) { |
2023 | if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=') |
2024 | return p + taglen + 1; |
2025 | } |
2026 | return NULL; |
2027 | } |
2028 | |
2029 | static void setup_modinfo(struct module *mod, struct load_info *info) |
2030 | { |
2031 | struct module_attribute *attr; |
2032 | int i; |
2033 | |
2034 | for (i = 0; (attr = modinfo_attrs[i]); i++) { |
2035 | if (attr->setup) |
2036 | attr->setup(mod, get_modinfo(info, attr->attr.name)); |
2037 | } |
2038 | } |
2039 | |
2040 | static void free_modinfo(struct module *mod) |
2041 | { |
2042 | struct module_attribute *attr; |
2043 | int i; |
2044 | |
2045 | for (i = 0; (attr = modinfo_attrs[i]); i++) { |
2046 | if (attr->free) |
2047 | attr->free(mod); |
2048 | } |
2049 | } |
2050 | |
2051 | #ifdef CONFIG_KALLSYMS |
2052 | |
2053 | /* lookup symbol in given range of kernel_symbols */ |
2054 | static const struct kernel_symbol *lookup_symbol(const char *name, |
2055 | const struct kernel_symbol *start, |
2056 | const struct kernel_symbol *stop) |
2057 | { |
2058 | return bsearch(name, start, stop - start, |
2059 | sizeof(struct kernel_symbol), cmp_name); |
2060 | } |
2061 | |
2062 | static int is_exported(const char *name, unsigned long value, |
2063 | const struct module *mod) |
2064 | { |
2065 | const struct kernel_symbol *ks; |
2066 | if (!mod) |
2067 | ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab); |
2068 | else |
2069 | ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms); |
2070 | return ks != NULL && ks->value == value; |
2071 | } |
2072 | |
2073 | /* As per nm */ |
2074 | static char elf_type(const Elf_Sym *sym, const struct load_info *info) |
2075 | { |
2076 | const Elf_Shdr *sechdrs = info->sechdrs; |
2077 | |
2078 | if (ELF_ST_BIND(sym->st_info) == STB_WEAK) { |
2079 | if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT) |
2080 | return 'v'; |
2081 | else |
2082 | return 'w'; |
2083 | } |
2084 | if (sym->st_shndx == SHN_UNDEF) |
2085 | return 'U'; |
2086 | if (sym->st_shndx == SHN_ABS) |
2087 | return 'a'; |
2088 | if (sym->st_shndx >= SHN_LORESERVE) |
2089 | return '?'; |
2090 | if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR) |
2091 | return 't'; |
2092 | if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC |
2093 | && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) { |
2094 | if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE)) |
2095 | return 'r'; |
2096 | else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL) |
2097 | return 'g'; |
2098 | else |
2099 | return 'd'; |
2100 | } |
2101 | if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) { |
2102 | if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL) |
2103 | return 's'; |
2104 | else |
2105 | return 'b'; |
2106 | } |
2107 | if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name, |
2108 | ".debug")) { |
2109 | return 'n'; |
2110 | } |
2111 | return '?'; |
2112 | } |
2113 | |
2114 | static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs, |
2115 | unsigned int shnum) |
2116 | { |
2117 | const Elf_Shdr *sec; |
2118 | |
2119 | if (src->st_shndx == SHN_UNDEF |
2120 | || src->st_shndx >= shnum |
2121 | || !src->st_name) |
2122 | return false; |
2123 | |
2124 | sec = sechdrs + src->st_shndx; |
2125 | if (!(sec->sh_flags & SHF_ALLOC) |
2126 | #ifndef CONFIG_KALLSYMS_ALL |
2127 | || !(sec->sh_flags & SHF_EXECINSTR) |
2128 | #endif |
2129 | || (sec->sh_entsize & INIT_OFFSET_MASK)) |
2130 | return false; |
2131 | |
2132 | return true; |
2133 | } |
2134 | |
2135 | static void layout_symtab(struct module *mod, struct load_info *info) |
2136 | { |
2137 | Elf_Shdr *symsect = info->sechdrs + info->index.sym; |
2138 | Elf_Shdr *strsect = info->sechdrs + info->index.str; |
2139 | const Elf_Sym *src; |
2140 | unsigned int i, nsrc, ndst; |
2141 | |
2142 | /* Put symbol section at end of init part of module. */ |
2143 | symsect->sh_flags |= SHF_ALLOC; |
2144 | symsect->sh_entsize = get_offset(mod, &mod->init_size, symsect, |
2145 | info->index.sym) | INIT_OFFSET_MASK; |
2146 | DEBUGP("\t%s\n", info->secstrings + symsect->sh_name); |
2147 | |
2148 | src = (void *)info->hdr + symsect->sh_offset; |
2149 | nsrc = symsect->sh_size / sizeof(*src); |
2150 | for (ndst = i = 1; i < nsrc; ++i, ++src) |
2151 | if (is_core_symbol(src, info->sechdrs, info->hdr->e_shnum)) { |
2152 | unsigned int j = src->st_name; |
2153 | |
2154 | while (!__test_and_set_bit(j, info->strmap) |
2155 | && info->strtab[j]) |
2156 | ++j; |
2157 | ++ndst; |
2158 | } |
2159 | |
2160 | /* Append room for core symbols at end of core part. */ |
2161 | info->symoffs = ALIGN(mod->core_size, symsect->sh_addralign ?: 1); |
2162 | mod->core_size = info->symoffs + ndst * sizeof(Elf_Sym); |
2163 | |
2164 | /* Put string table section at end of init part of module. */ |
2165 | strsect->sh_flags |= SHF_ALLOC; |
2166 | strsect->sh_entsize = get_offset(mod, &mod->init_size, strsect, |
2167 | info->index.str) | INIT_OFFSET_MASK; |
2168 | DEBUGP("\t%s\n", info->secstrings + strsect->sh_name); |
2169 | |
2170 | /* Append room for core symbols' strings at end of core part. */ |
2171 | info->stroffs = mod->core_size; |
2172 | __set_bit(0, info->strmap); |
2173 | mod->core_size += bitmap_weight(info->strmap, strsect->sh_size); |
2174 | } |
2175 | |
2176 | static void add_kallsyms(struct module *mod, const struct load_info *info) |
2177 | { |
2178 | unsigned int i, ndst; |
2179 | const Elf_Sym *src; |
2180 | Elf_Sym *dst; |
2181 | char *s; |
2182 | Elf_Shdr *symsec = &info->sechdrs[info->index.sym]; |
2183 | |
2184 | mod->symtab = (void *)symsec->sh_addr; |
2185 | mod->num_symtab = symsec->sh_size / sizeof(Elf_Sym); |
2186 | /* Make sure we get permanent strtab: don't use info->strtab. */ |
2187 | mod->strtab = (void *)info->sechdrs[info->index.str].sh_addr; |
2188 | |
2189 | /* Set types up while we still have access to sections. */ |
2190 | for (i = 0; i < mod->num_symtab; i++) |
2191 | mod->symtab[i].st_info = elf_type(&mod->symtab[i], info); |
2192 | |
2193 | mod->core_symtab = dst = mod->module_core + info->symoffs; |
2194 | src = mod->symtab; |
2195 | *dst = *src; |
2196 | for (ndst = i = 1; i < mod->num_symtab; ++i, ++src) { |
2197 | if (!is_core_symbol(src, info->sechdrs, info->hdr->e_shnum)) |
2198 | continue; |
2199 | dst[ndst] = *src; |
2200 | dst[ndst].st_name = bitmap_weight(info->strmap, |
2201 | dst[ndst].st_name); |
2202 | ++ndst; |
2203 | } |
2204 | mod->core_num_syms = ndst; |
2205 | |
2206 | mod->core_strtab = s = mod->module_core + info->stroffs; |
2207 | for (*s = 0, i = 1; i < info->sechdrs[info->index.str].sh_size; ++i) |
2208 | if (test_bit(i, info->strmap)) |
2209 | *++s = mod->strtab[i]; |
2210 | } |
2211 | #else |
2212 | static inline void layout_symtab(struct module *mod, struct load_info *info) |
2213 | { |
2214 | } |
2215 | |
2216 | static void add_kallsyms(struct module *mod, const struct load_info *info) |
2217 | { |
2218 | } |
2219 | #endif /* CONFIG_KALLSYMS */ |
2220 | |
2221 | static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num) |
2222 | { |
2223 | if (!debug) |
2224 | return; |
2225 | #ifdef CONFIG_DYNAMIC_DEBUG |
2226 | if (ddebug_add_module(debug, num, debug->modname)) |
2227 | printk(KERN_ERR "dynamic debug error adding module: %s\n", |
2228 | debug->modname); |
2229 | #endif |
2230 | } |
2231 | |
2232 | static void dynamic_debug_remove(struct _ddebug *debug) |
2233 | { |
2234 | if (debug) |
2235 | ddebug_remove_module(debug->modname); |
2236 | } |
2237 | |
2238 | static void *module_alloc_update_bounds(unsigned long size) |
2239 | { |
2240 | void *ret = module_alloc(size); |
2241 | |
2242 | if (ret) { |
2243 | mutex_lock(&module_mutex); |
2244 | /* Update module bounds. */ |
2245 | if ((unsigned long)ret < module_addr_min) |
2246 | module_addr_min = (unsigned long)ret; |
2247 | if ((unsigned long)ret + size > module_addr_max) |
2248 | module_addr_max = (unsigned long)ret + size; |
2249 | mutex_unlock(&module_mutex); |
2250 | } |
2251 | return ret; |
2252 | } |
2253 | |
2254 | #ifdef CONFIG_DEBUG_KMEMLEAK |
2255 | static void kmemleak_load_module(const struct module *mod, |
2256 | const struct load_info *info) |
2257 | { |
2258 | unsigned int i; |
2259 | |
2260 | /* only scan the sections containing data */ |
2261 | kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL); |
2262 | |
2263 | for (i = 1; i < info->hdr->e_shnum; i++) { |
2264 | const char *name = info->secstrings + info->sechdrs[i].sh_name; |
2265 | if (!(info->sechdrs[i].sh_flags & SHF_ALLOC)) |
2266 | continue; |
2267 | if (!strstarts(name, ".data") && !strstarts(name, ".bss")) |
2268 | continue; |
2269 | |
2270 | kmemleak_scan_area((void *)info->sechdrs[i].sh_addr, |
2271 | info->sechdrs[i].sh_size, GFP_KERNEL); |
2272 | } |
2273 | } |
2274 | #else |
2275 | static inline void kmemleak_load_module(const struct module *mod, |
2276 | const struct load_info *info) |
2277 | { |
2278 | } |
2279 | #endif |
2280 | |
2281 | /* Sets info->hdr and info->len. */ |
2282 | static int copy_and_check(struct load_info *info, |
2283 | const void __user *umod, unsigned long len, |
2284 | const char __user *uargs) |
2285 | { |
2286 | int err; |
2287 | Elf_Ehdr *hdr; |
2288 | |
2289 | if (len < sizeof(*hdr)) |
2290 | return -ENOEXEC; |
2291 | |
2292 | /* Suck in entire file: we'll want most of it. */ |
2293 | /* vmalloc barfs on "unusual" numbers. Check here */ |
2294 | if (len > 64 * 1024 * 1024 || (hdr = vmalloc(len)) == NULL) |
2295 | return -ENOMEM; |
2296 | |
2297 | if (copy_from_user(hdr, umod, len) != 0) { |
2298 | err = -EFAULT; |
2299 | goto free_hdr; |
2300 | } |
2301 | |
2302 | /* Sanity checks against insmoding binaries or wrong arch, |
2303 | weird elf version */ |
2304 | if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0 |
2305 | || hdr->e_type != ET_REL |
2306 | || !elf_check_arch(hdr) |
2307 | || hdr->e_shentsize != sizeof(Elf_Shdr)) { |
2308 | err = -ENOEXEC; |
2309 | goto free_hdr; |
2310 | } |
2311 | |
2312 | if (len < hdr->e_shoff + hdr->e_shnum * sizeof(Elf_Shdr)) { |
2313 | err = -ENOEXEC; |
2314 | goto free_hdr; |
2315 | } |
2316 | |
2317 | info->hdr = hdr; |
2318 | info->len = len; |
2319 | return 0; |
2320 | |
2321 | free_hdr: |
2322 | vfree(hdr); |
2323 | return err; |
2324 | } |
2325 | |
2326 | static void free_copy(struct load_info *info) |
2327 | { |
2328 | vfree(info->hdr); |
2329 | } |
2330 | |
2331 | static int rewrite_section_headers(struct load_info *info) |
2332 | { |
2333 | unsigned int i; |
2334 | |
2335 | /* This should always be true, but let's be sure. */ |
2336 | info->sechdrs[0].sh_addr = 0; |
2337 | |
2338 | for (i = 1; i < info->hdr->e_shnum; i++) { |
2339 | Elf_Shdr *shdr = &info->sechdrs[i]; |
2340 | if (shdr->sh_type != SHT_NOBITS |
2341 | && info->len < shdr->sh_offset + shdr->sh_size) { |
2342 | printk(KERN_ERR "Module len %lu truncated\n", |
2343 | info->len); |
2344 | return -ENOEXEC; |
2345 | } |
2346 | |
2347 | /* Mark all sections sh_addr with their address in the |
2348 | temporary image. */ |
2349 | shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset; |
2350 | |
2351 | #ifndef CONFIG_MODULE_UNLOAD |
2352 | /* Don't load .exit sections */ |
2353 | if (strstarts(info->secstrings+shdr->sh_name, ".exit")) |
2354 | shdr->sh_flags &= ~(unsigned long)SHF_ALLOC; |
2355 | #endif |
2356 | } |
2357 | |
2358 | /* Track but don't keep modinfo and version sections. */ |
2359 | info->index.vers = find_sec(info, "__versions"); |
2360 | info->index.info = find_sec(info, ".modinfo"); |
2361 | info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC; |
2362 | info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC; |
2363 | return 0; |
2364 | } |
2365 | |
2366 | /* |
2367 | * Set up our basic convenience variables (pointers to section headers, |
2368 | * search for module section index etc), and do some basic section |
2369 | * verification. |
2370 | * |
2371 | * Return the temporary module pointer (we'll replace it with the final |
2372 | * one when we move the module sections around). |
2373 | */ |
2374 | static struct module *setup_load_info(struct load_info *info) |
2375 | { |
2376 | unsigned int i; |
2377 | int err; |
2378 | struct module *mod; |
2379 | |
2380 | /* Set up the convenience variables */ |
2381 | info->sechdrs = (void *)info->hdr + info->hdr->e_shoff; |
2382 | info->secstrings = (void *)info->hdr |
2383 | + info->sechdrs[info->hdr->e_shstrndx].sh_offset; |
2384 | |
2385 | err = rewrite_section_headers(info); |
2386 | if (err) |
2387 | return ERR_PTR(err); |
2388 | |
2389 | /* Find internal symbols and strings. */ |
2390 | for (i = 1; i < info->hdr->e_shnum; i++) { |
2391 | if (info->sechdrs[i].sh_type == SHT_SYMTAB) { |
2392 | info->index.sym = i; |
2393 | info->index.str = info->sechdrs[i].sh_link; |
2394 | info->strtab = (char *)info->hdr |
2395 | + info->sechdrs[info->index.str].sh_offset; |
2396 | break; |
2397 | } |
2398 | } |
2399 | |
2400 | info->index.mod = find_sec(info, ".gnu.linkonce.this_module"); |
2401 | if (!info->index.mod) { |
2402 | printk(KERN_WARNING "No module found in object\n"); |
2403 | return ERR_PTR(-ENOEXEC); |
2404 | } |
2405 | /* This is temporary: point mod into copy of data. */ |
2406 | mod = (void *)info->sechdrs[info->index.mod].sh_addr; |
2407 | |
2408 | if (info->index.sym == 0) { |
2409 | printk(KERN_WARNING "%s: module has no symbols (stripped?)\n", |
2410 | mod->name); |
2411 | return ERR_PTR(-ENOEXEC); |
2412 | } |
2413 | |
2414 | info->index.pcpu = find_pcpusec(info); |
2415 | |
2416 | /* Check module struct version now, before we try to use module. */ |
2417 | if (!check_modstruct_version(info->sechdrs, info->index.vers, mod)) |
2418 | return ERR_PTR(-ENOEXEC); |
2419 | |
2420 | return mod; |
2421 | } |
2422 | |
2423 | static int check_modinfo(struct module *mod, struct load_info *info) |
2424 | { |
2425 | const char *modmagic = get_modinfo(info, "vermagic"); |
2426 | int err; |
2427 | |
2428 | /* This is allowed: modprobe --force will invalidate it. */ |
2429 | if (!modmagic) { |
2430 | err = try_to_force_load(mod, "bad vermagic"); |
2431 | if (err) |
2432 | return err; |
2433 | } else if (!same_magic(modmagic, vermagic, info->index.vers)) { |
2434 | printk(KERN_ERR "%s: version magic '%s' should be '%s'\n", |
2435 | mod->name, modmagic, vermagic); |
2436 | return -ENOEXEC; |
2437 | } |
2438 | |
2439 | if (get_modinfo(info, "staging")) { |
2440 | add_taint_module(mod, TAINT_CRAP); |
2441 | printk(KERN_WARNING "%s: module is from the staging directory," |
2442 | " the quality is unknown, you have been warned.\n", |
2443 | mod->name); |
2444 | } |
2445 | |
2446 | /* Set up license info based on the info section */ |
2447 | set_license(mod, get_modinfo(info, "license")); |
2448 | |
2449 | return 0; |
2450 | } |
2451 | |
2452 | static void find_module_sections(struct module *mod, struct load_info *info) |
2453 | { |
2454 | mod->kp = section_objs(info, "__param", |
2455 | sizeof(*mod->kp), &mod->num_kp); |
2456 | mod->syms = section_objs(info, "__ksymtab", |
2457 | sizeof(*mod->syms), &mod->num_syms); |
2458 | mod->crcs = section_addr(info, "__kcrctab"); |
2459 | mod->gpl_syms = section_objs(info, "__ksymtab_gpl", |
2460 | sizeof(*mod->gpl_syms), |
2461 | &mod->num_gpl_syms); |
2462 | mod->gpl_crcs = section_addr(info, "__kcrctab_gpl"); |
2463 | mod->gpl_future_syms = section_objs(info, |
2464 | "__ksymtab_gpl_future", |
2465 | sizeof(*mod->gpl_future_syms), |
2466 | &mod->num_gpl_future_syms); |
2467 | mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future"); |
2468 | |
2469 | #ifdef CONFIG_UNUSED_SYMBOLS |
2470 | mod->unused_syms = section_objs(info, "__ksymtab_unused", |
2471 | sizeof(*mod->unused_syms), |
2472 | &mod->num_unused_syms); |
2473 | mod->unused_crcs = section_addr(info, "__kcrctab_unused"); |
2474 | mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl", |
2475 | sizeof(*mod->unused_gpl_syms), |
2476 | &mod->num_unused_gpl_syms); |
2477 | mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl"); |
2478 | #endif |
2479 | #ifdef CONFIG_CONSTRUCTORS |
2480 | mod->ctors = section_objs(info, ".ctors", |
2481 | sizeof(*mod->ctors), &mod->num_ctors); |
2482 | #endif |
2483 | |
2484 | #ifdef CONFIG_TRACEPOINTS |
2485 | mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs", |
2486 | sizeof(*mod->tracepoints_ptrs), |
2487 | &mod->num_tracepoints); |
2488 | #endif |
2489 | #ifdef HAVE_JUMP_LABEL |
2490 | mod->jump_entries = section_objs(info, "__jump_table", |
2491 | sizeof(*mod->jump_entries), |
2492 | &mod->num_jump_entries); |
2493 | #endif |
2494 | #ifdef CONFIG_EVENT_TRACING |
2495 | mod->trace_events = section_objs(info, "_ftrace_events", |
2496 | sizeof(*mod->trace_events), |
2497 | &mod->num_trace_events); |
2498 | /* |
2499 | * This section contains pointers to allocated objects in the trace |
2500 | * code and not scanning it leads to false positives. |
2501 | */ |
2502 | kmemleak_scan_area(mod->trace_events, sizeof(*mod->trace_events) * |
2503 | mod->num_trace_events, GFP_KERNEL); |
2504 | #endif |
2505 | #ifdef CONFIG_TRACING |
2506 | mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt", |
2507 | sizeof(*mod->trace_bprintk_fmt_start), |
2508 | &mod->num_trace_bprintk_fmt); |
2509 | /* |
2510 | * This section contains pointers to allocated objects in the trace |
2511 | * code and not scanning it leads to false positives. |
2512 | */ |
2513 | kmemleak_scan_area(mod->trace_bprintk_fmt_start, |
2514 | sizeof(*mod->trace_bprintk_fmt_start) * |
2515 | mod->num_trace_bprintk_fmt, GFP_KERNEL); |
2516 | #endif |
2517 | #ifdef CONFIG_FTRACE_MCOUNT_RECORD |
2518 | /* sechdrs[0].sh_size is always zero */ |
2519 | mod->ftrace_callsites = section_objs(info, "__mcount_loc", |
2520 | sizeof(*mod->ftrace_callsites), |
2521 | &mod->num_ftrace_callsites); |
2522 | #endif |
2523 | |
2524 | mod->extable = section_objs(info, "__ex_table", |
2525 | sizeof(*mod->extable), &mod->num_exentries); |
2526 | |
2527 | if (section_addr(info, "__obsparm")) |
2528 | printk(KERN_WARNING "%s: Ignoring obsolete parameters\n", |
2529 | mod->name); |
2530 | |
2531 | info->debug = section_objs(info, "__verbose", |
2532 | sizeof(*info->debug), &info->num_debug); |
2533 | } |
2534 | |
2535 | static int move_module(struct module *mod, struct load_info *info) |
2536 | { |
2537 | int i; |
2538 | void *ptr; |
2539 | |
2540 | /* Do the allocs. */ |
2541 | ptr = module_alloc_update_bounds(mod->core_size); |
2542 | /* |
2543 | * The pointer to this block is stored in the module structure |
2544 | * which is inside the block. Just mark it as not being a |
2545 | * leak. |
2546 | */ |
2547 | kmemleak_not_leak(ptr); |
2548 | if (!ptr) |
2549 | return -ENOMEM; |
2550 | |
2551 | memset(ptr, 0, mod->core_size); |
2552 | mod->module_core = ptr; |
2553 | |
2554 | ptr = module_alloc_update_bounds(mod->init_size); |
2555 | /* |
2556 | * The pointer to this block is stored in the module structure |
2557 | * which is inside the block. This block doesn't need to be |
2558 | * scanned as it contains data and code that will be freed |
2559 | * after the module is initialized. |
2560 | */ |
2561 | kmemleak_ignore(ptr); |
2562 | if (!ptr && mod->init_size) { |
2563 | module_free(mod, mod->module_core); |
2564 | return -ENOMEM; |
2565 | } |
2566 | memset(ptr, 0, mod->init_size); |
2567 | mod->module_init = ptr; |
2568 | |
2569 | /* Transfer each section which specifies SHF_ALLOC */ |
2570 | DEBUGP("final section addresses:\n"); |
2571 | for (i = 0; i < info->hdr->e_shnum; i++) { |
2572 | void *dest; |
2573 | Elf_Shdr *shdr = &info->sechdrs[i]; |
2574 | |
2575 | if (!(shdr->sh_flags & SHF_ALLOC)) |
2576 | continue; |
2577 | |
2578 | if (shdr->sh_entsize & INIT_OFFSET_MASK) |
2579 | dest = mod->module_init |
2580 | + (shdr->sh_entsize & ~INIT_OFFSET_MASK); |
2581 | else |
2582 | dest = mod->module_core + shdr->sh_entsize; |
2583 | |
2584 | if (shdr->sh_type != SHT_NOBITS) |
2585 | memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size); |
2586 | /* Update sh_addr to point to copy in image. */ |
2587 | shdr->sh_addr = (unsigned long)dest; |
2588 | DEBUGP("\t0x%lx %s\n", |
2589 | shdr->sh_addr, info->secstrings + shdr->sh_name); |
2590 | } |
2591 | |
2592 | return 0; |
2593 | } |
2594 | |
2595 | static int check_module_license_and_versions(struct module *mod) |
2596 | { |
2597 | /* |
2598 | * ndiswrapper is under GPL by itself, but loads proprietary modules. |
2599 | * Don't use add_taint_module(), as it would prevent ndiswrapper from |
2600 | * using GPL-only symbols it needs. |
2601 | */ |
2602 | if (strcmp(mod->name, "ndiswrapper") == 0) |
2603 | add_taint(TAINT_PROPRIETARY_MODULE); |
2604 | |
2605 | /* driverloader was caught wrongly pretending to be under GPL */ |
2606 | if (strcmp(mod->name, "driverloader") == 0) |
2607 | add_taint_module(mod, TAINT_PROPRIETARY_MODULE); |
2608 | |
2609 | #ifdef CONFIG_MODVERSIONS |
2610 | if ((mod->num_syms && !mod->crcs) |
2611 | || (mod->num_gpl_syms && !mod->gpl_crcs) |
2612 | || (mod->num_gpl_future_syms && !mod->gpl_future_crcs) |
2613 | #ifdef CONFIG_UNUSED_SYMBOLS |
2614 | || (mod->num_unused_syms && !mod->unused_crcs) |
2615 | || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs) |
2616 | #endif |
2617 | ) { |
2618 | return try_to_force_load(mod, |
2619 | "no versions for exported symbols"); |
2620 | } |
2621 | #endif |
2622 | return 0; |
2623 | } |
2624 | |
2625 | static void flush_module_icache(const struct module *mod) |
2626 | { |
2627 | mm_segment_t old_fs; |
2628 | |
2629 | /* flush the icache in correct context */ |
2630 | old_fs = get_fs(); |
2631 | set_fs(KERNEL_DS); |
2632 | |
2633 | /* |
2634 | * Flush the instruction cache, since we've played with text. |
2635 | * Do it before processing of module parameters, so the module |
2636 | * can provide parameter accessor functions of its own. |
2637 | */ |
2638 | if (mod->module_init) |
2639 | flush_icache_range((unsigned long)mod->module_init, |
2640 | (unsigned long)mod->module_init |
2641 | + mod->init_size); |
2642 | flush_icache_range((unsigned long)mod->module_core, |
2643 | (unsigned long)mod->module_core + mod->core_size); |
2644 | |
2645 | set_fs(old_fs); |
2646 | } |
2647 | |
2648 | static struct module *layout_and_allocate(struct load_info *info) |
2649 | { |
2650 | /* Module within temporary copy. */ |
2651 | struct module *mod; |
2652 | Elf_Shdr *pcpusec; |
2653 | int err; |
2654 | |
2655 | mod = setup_load_info(info); |
2656 | if (IS_ERR(mod)) |
2657 | return mod; |
2658 | |
2659 | err = check_modinfo(mod, info); |
2660 | if (err) |
2661 | return ERR_PTR(err); |
2662 | |
2663 | /* Allow arches to frob section contents and sizes. */ |
2664 | err = module_frob_arch_sections(info->hdr, info->sechdrs, |
2665 | info->secstrings, mod); |
2666 | if (err < 0) |
2667 | goto out; |
2668 | |
2669 | pcpusec = &info->sechdrs[info->index.pcpu]; |
2670 | if (pcpusec->sh_size) { |
2671 | /* We have a special allocation for this section. */ |
2672 | err = percpu_modalloc(mod, |
2673 | pcpusec->sh_size, pcpusec->sh_addralign); |
2674 | if (err) |
2675 | goto out; |
2676 | pcpusec->sh_flags &= ~(unsigned long)SHF_ALLOC; |
2677 | } |
2678 | |
2679 | /* Determine total sizes, and put offsets in sh_entsize. For now |
2680 | this is done generically; there doesn't appear to be any |
2681 | special cases for the architectures. */ |
2682 | layout_sections(mod, info); |
2683 | |
2684 | info->strmap = kzalloc(BITS_TO_LONGS(info->sechdrs[info->index.str].sh_size) |
2685 | * sizeof(long), GFP_KERNEL); |
2686 | if (!info->strmap) { |
2687 | err = -ENOMEM; |
2688 | goto free_percpu; |
2689 | } |
2690 | layout_symtab(mod, info); |
2691 | |
2692 | /* Allocate and move to the final place */ |
2693 | err = move_module(mod, info); |
2694 | if (err) |
2695 | goto free_strmap; |
2696 | |
2697 | /* Module has been copied to its final place now: return it. */ |
2698 | mod = (void *)info->sechdrs[info->index.mod].sh_addr; |
2699 | kmemleak_load_module(mod, info); |
2700 | return mod; |
2701 | |
2702 | free_strmap: |
2703 | kfree(info->strmap); |
2704 | free_percpu: |
2705 | percpu_modfree(mod); |
2706 | out: |
2707 | return ERR_PTR(err); |
2708 | } |
2709 | |
2710 | /* mod is no longer valid after this! */ |
2711 | static void module_deallocate(struct module *mod, struct load_info *info) |
2712 | { |
2713 | kfree(info->strmap); |
2714 | percpu_modfree(mod); |
2715 | module_free(mod, mod->module_init); |
2716 | module_free(mod, mod->module_core); |
2717 | } |
2718 | |
2719 | static int post_relocation(struct module *mod, const struct load_info *info) |
2720 | { |
2721 | /* Sort exception table now relocations are done. */ |
2722 | sort_extable(mod->extable, mod->extable + mod->num_exentries); |
2723 | |
2724 | /* Copy relocated percpu area over. */ |
2725 | percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr, |
2726 | info->sechdrs[info->index.pcpu].sh_size); |
2727 | |
2728 | /* Setup kallsyms-specific fields. */ |
2729 | add_kallsyms(mod, info); |
2730 | |
2731 | /* Arch-specific module finalizing. */ |
2732 | return module_finalize(info->hdr, info->sechdrs, mod); |
2733 | } |
2734 | |
2735 | /* Allocate and load the module: note that size of section 0 is always |
2736 | zero, and we rely on this for optional sections. */ |
2737 | static struct module *load_module(void __user *umod, |
2738 | unsigned long len, |
2739 | const char __user *uargs) |
2740 | { |
2741 | struct load_info info = { NULL, }; |
2742 | struct module *mod; |
2743 | long err; |
2744 | |
2745 | DEBUGP("load_module: umod=%p, len=%lu, uargs=%p\n", |
2746 | umod, len, uargs); |
2747 | |
2748 | /* Copy in the blobs from userspace, check they are vaguely sane. */ |
2749 | err = copy_and_check(&info, umod, len, uargs); |
2750 | if (err) |
2751 | return ERR_PTR(err); |
2752 | |
2753 | /* Figure out module layout, and allocate all the memory. */ |
2754 | mod = layout_and_allocate(&info); |
2755 | if (IS_ERR(mod)) { |
2756 | err = PTR_ERR(mod); |
2757 | goto free_copy; |
2758 | } |
2759 | |
2760 | /* Now module is in final location, initialize linked lists, etc. */ |
2761 | err = module_unload_init(mod); |
2762 | if (err) |
2763 | goto free_module; |
2764 | |
2765 | /* Now we've got everything in the final locations, we can |
2766 | * find optional sections. */ |
2767 | find_module_sections(mod, &info); |
2768 | |
2769 | err = check_module_license_and_versions(mod); |
2770 | if (err) |
2771 | goto free_unload; |
2772 | |
2773 | /* Set up MODINFO_ATTR fields */ |
2774 | setup_modinfo(mod, &info); |
2775 | |
2776 | /* Fix up syms, so that st_value is a pointer to location. */ |
2777 | err = simplify_symbols(mod, &info); |
2778 | if (err < 0) |
2779 | goto free_modinfo; |
2780 | |
2781 | err = apply_relocations(mod, &info); |
2782 | if (err < 0) |
2783 | goto free_modinfo; |
2784 | |
2785 | err = post_relocation(mod, &info); |
2786 | if (err < 0) |
2787 | goto free_modinfo; |
2788 | |
2789 | flush_module_icache(mod); |
2790 | |
2791 | /* Now copy in args */ |
2792 | mod->args = strndup_user(uargs, ~0UL >> 1); |
2793 | if (IS_ERR(mod->args)) { |
2794 | err = PTR_ERR(mod->args); |
2795 | goto free_arch_cleanup; |
2796 | } |
2797 | |
2798 | /* Mark state as coming so strong_try_module_get() ignores us. */ |
2799 | mod->state = MODULE_STATE_COMING; |
2800 | |
2801 | /* Now sew it into the lists so we can get lockdep and oops |
2802 | * info during argument parsing. No one should access us, since |
2803 | * strong_try_module_get() will fail. |
2804 | * lockdep/oops can run asynchronous, so use the RCU list insertion |
2805 | * function to insert in a way safe to concurrent readers. |
2806 | * The mutex protects against concurrent writers. |
2807 | */ |
2808 | mutex_lock(&module_mutex); |
2809 | if (find_module(mod->name)) { |
2810 | err = -EEXIST; |
2811 | goto unlock; |
2812 | } |
2813 | |
2814 | /* This has to be done once we're sure module name is unique. */ |
2815 | if (!mod->taints || mod->taints == (1U<<TAINT_CRAP)) |
2816 | dynamic_debug_setup(info.debug, info.num_debug); |
2817 | |
2818 | /* Find duplicate symbols */ |
2819 | err = verify_export_symbols(mod); |
2820 | if (err < 0) |
2821 | goto ddebug; |
2822 | |
2823 | module_bug_finalize(info.hdr, info.sechdrs, mod); |
2824 | list_add_rcu(&mod->list, &modules); |
2825 | mutex_unlock(&module_mutex); |
2826 | |
2827 | /* Module is ready to execute: parsing args may do that. */ |
2828 | err = parse_args(mod->name, mod->args, mod->kp, mod->num_kp, NULL); |
2829 | if (err < 0) |
2830 | goto unlink; |
2831 | |
2832 | /* Link in to syfs. */ |
2833 | err = mod_sysfs_setup(mod, &info, mod->kp, mod->num_kp); |
2834 | if (err < 0) |
2835 | goto unlink; |
2836 | |
2837 | /* Get rid of temporary copy and strmap. */ |
2838 | kfree(info.strmap); |
2839 | free_copy(&info); |
2840 | |
2841 | /* Done! */ |
2842 | trace_module_load(mod); |
2843 | return mod; |
2844 | |
2845 | unlink: |
2846 | mutex_lock(&module_mutex); |
2847 | /* Unlink carefully: kallsyms could be walking list. */ |
2848 | list_del_rcu(&mod->list); |
2849 | module_bug_cleanup(mod); |
2850 | |
2851 | ddebug: |
2852 | if (!mod->taints || mod->taints == (1U<<TAINT_CRAP)) |
2853 | dynamic_debug_remove(info.debug); |
2854 | unlock: |
2855 | mutex_unlock(&module_mutex); |
2856 | synchronize_sched(); |
2857 | kfree(mod->args); |
2858 | free_arch_cleanup: |
2859 | module_arch_cleanup(mod); |
2860 | free_modinfo: |
2861 | free_modinfo(mod); |
2862 | free_unload: |
2863 | module_unload_free(mod); |
2864 | free_module: |
2865 | module_deallocate(mod, &info); |
2866 | free_copy: |
2867 | free_copy(&info); |
2868 | return ERR_PTR(err); |
2869 | } |
2870 | |
2871 | /* Call module constructors. */ |
2872 | static void do_mod_ctors(struct module *mod) |
2873 | { |
2874 | #ifdef CONFIG_CONSTRUCTORS |
2875 | unsigned long i; |
2876 | |
2877 | for (i = 0; i < mod->num_ctors; i++) |
2878 | mod->ctors[i](); |
2879 | #endif |
2880 | } |
2881 | |
2882 | /* This is where the real work happens */ |
2883 | SYSCALL_DEFINE3(init_module, void __user *, umod, |
2884 | unsigned long, len, const char __user *, uargs) |
2885 | { |
2886 | struct module *mod; |
2887 | int ret = 0; |
2888 | |
2889 | /* Must have permission */ |
2890 | if (!capable(CAP_SYS_MODULE) || modules_disabled) |
2891 | return -EPERM; |
2892 | |
2893 | /* Do all the hard work */ |
2894 | mod = load_module(umod, len, uargs); |
2895 | if (IS_ERR(mod)) |
2896 | return PTR_ERR(mod); |
2897 | |
2898 | blocking_notifier_call_chain(&module_notify_list, |
2899 | MODULE_STATE_COMING, mod); |
2900 | |
2901 | /* Set RO and NX regions for core */ |
2902 | set_section_ro_nx(mod->module_core, |
2903 | mod->core_text_size, |
2904 | mod->core_ro_size, |
2905 | mod->core_size); |
2906 | |
2907 | /* Set RO and NX regions for init */ |
2908 | set_section_ro_nx(mod->module_init, |
2909 | mod->init_text_size, |
2910 | mod->init_ro_size, |
2911 | mod->init_size); |
2912 | |
2913 | do_mod_ctors(mod); |
2914 | /* Start the module */ |
2915 | if (mod->init != NULL) |
2916 | ret = do_one_initcall(mod->init); |
2917 | if (ret < 0) { |
2918 | /* Init routine failed: abort. Try to protect us from |
2919 | buggy refcounters. */ |
2920 | mod->state = MODULE_STATE_GOING; |
2921 | synchronize_sched(); |
2922 | module_put(mod); |
2923 | blocking_notifier_call_chain(&module_notify_list, |
2924 | MODULE_STATE_GOING, mod); |
2925 | free_module(mod); |
2926 | wake_up(&module_wq); |
2927 | return ret; |
2928 | } |
2929 | if (ret > 0) { |
2930 | printk(KERN_WARNING |
2931 | "%s: '%s'->init suspiciously returned %d, it should follow 0/-E convention\n" |
2932 | "%s: loading module anyway...\n", |
2933 | __func__, mod->name, ret, |
2934 | __func__); |
2935 | dump_stack(); |
2936 | } |
2937 | |
2938 | /* Now it's a first class citizen! Wake up anyone waiting for it. */ |
2939 | mod->state = MODULE_STATE_LIVE; |
2940 | wake_up(&module_wq); |
2941 | blocking_notifier_call_chain(&module_notify_list, |
2942 | MODULE_STATE_LIVE, mod); |
2943 | |
2944 | /* We need to finish all async code before the module init sequence is done */ |
2945 | async_synchronize_full(); |
2946 | |
2947 | mutex_lock(&module_mutex); |
2948 | /* Drop initial reference. */ |
2949 | module_put(mod); |
2950 | trim_init_extable(mod); |
2951 | #ifdef CONFIG_KALLSYMS |
2952 | mod->num_symtab = mod->core_num_syms; |
2953 | mod->symtab = mod->core_symtab; |
2954 | mod->strtab = mod->core_strtab; |
2955 | #endif |
2956 | unset_module_init_ro_nx(mod); |
2957 | module_free(mod, mod->module_init); |
2958 | mod->module_init = NULL; |
2959 | mod->init_size = 0; |
2960 | mod->init_ro_size = 0; |
2961 | mod->init_text_size = 0; |
2962 | mutex_unlock(&module_mutex); |
2963 | |
2964 | return 0; |
2965 | } |
2966 | |
2967 | static inline int within(unsigned long addr, void *start, unsigned long size) |
2968 | { |
2969 | return ((void *)addr >= start && (void *)addr < start + size); |
2970 | } |
2971 | |
2972 | #ifdef CONFIG_KALLSYMS |
2973 | /* |
2974 | * This ignores the intensely annoying "mapping symbols" found |
2975 | * in ARM ELF files: $a, $t and $d. |
2976 | */ |
2977 | static inline int is_arm_mapping_symbol(const char *str) |
2978 | { |
2979 | return str[0] == '$' && strchr("atd", str[1]) |
2980 | && (str[2] == '\0' || str[2] == '.'); |
2981 | } |
2982 | |
2983 | static const char *get_ksymbol(struct module *mod, |
2984 | unsigned long addr, |
2985 | unsigned long *size, |
2986 | unsigned long *offset) |
2987 | { |
2988 | unsigned int i, best = 0; |
2989 | unsigned long nextval; |
2990 | |
2991 | /* At worse, next value is at end of module */ |
2992 | if (within_module_init(addr, mod)) |
2993 | nextval = (unsigned long)mod->module_init+mod->init_text_size; |
2994 | else |
2995 | nextval = (unsigned long)mod->module_core+mod->core_text_size; |
2996 | |
2997 | /* Scan for closest preceding symbol, and next symbol. (ELF |
2998 | starts real symbols at 1). */ |
2999 | for (i = 1; i < mod->num_symtab; i++) { |
3000 | if (mod->symtab[i].st_shndx == SHN_UNDEF) |
3001 | continue; |
3002 | |
3003 | /* We ignore unnamed symbols: they're uninformative |
3004 | * and inserted at a whim. */ |
3005 | if (mod->symtab[i].st_value <= addr |
3006 | && mod->symtab[i].st_value > mod->symtab[best].st_value |
3007 | && *(mod->strtab + mod->symtab[i].st_name) != '\0' |
3008 | && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name)) |
3009 | best = i; |
3010 | if (mod->symtab[i].st_value > addr |
3011 | && mod->symtab[i].st_value < nextval |
3012 | && *(mod->strtab + mod->symtab[i].st_name) != '\0' |
3013 | && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name)) |
3014 | nextval = mod->symtab[i].st_value; |
3015 | } |
3016 | |
3017 | if (!best) |
3018 | return NULL; |
3019 | |
3020 | if (size) |
3021 | *size = nextval - mod->symtab[best].st_value; |
3022 | if (offset) |
3023 | *offset = addr - mod->symtab[best].st_value; |
3024 | return mod->strtab + mod->symtab[best].st_name; |
3025 | } |
3026 | |
3027 | /* For kallsyms to ask for address resolution. NULL means not found. Careful |
3028 | * not to lock to avoid deadlock on oopses, simply disable preemption. */ |
3029 | const char *module_address_lookup(unsigned long addr, |
3030 | unsigned long *size, |
3031 | unsigned long *offset, |
3032 | char **modname, |
3033 | char *namebuf) |
3034 | { |
3035 | struct module *mod; |
3036 | const char *ret = NULL; |
3037 | |
3038 | preempt_disable(); |
3039 | list_for_each_entry_rcu(mod, &modules, list) { |
3040 | if (within_module_init(addr, mod) || |
3041 | within_module_core(addr, mod)) { |
3042 | if (modname) |
3043 | *modname = mod->name; |
3044 | ret = get_ksymbol(mod, addr, size, offset); |
3045 | break; |
3046 | } |
3047 | } |
3048 | /* Make a copy in here where it's safe */ |
3049 | if (ret) { |
3050 | strncpy(namebuf, ret, KSYM_NAME_LEN - 1); |
3051 | ret = namebuf; |
3052 | } |
3053 | preempt_enable(); |
3054 | return ret; |
3055 | } |
3056 | |
3057 | int lookup_module_symbol_name(unsigned long addr, char *symname) |
3058 | { |
3059 | struct module *mod; |
3060 | |
3061 | preempt_disable(); |
3062 | list_for_each_entry_rcu(mod, &modules, list) { |
3063 | if (within_module_init(addr, mod) || |
3064 | within_module_core(addr, mod)) { |
3065 | const char *sym; |
3066 | |
3067 | sym = get_ksymbol(mod, addr, NULL, NULL); |
3068 | if (!sym) |
3069 | goto out; |
3070 | strlcpy(symname, sym, KSYM_NAME_LEN); |
3071 | preempt_enable(); |
3072 | return 0; |
3073 | } |
3074 | } |
3075 | out: |
3076 | preempt_enable(); |
3077 | return -ERANGE; |
3078 | } |
3079 | |
3080 | int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, |
3081 | unsigned long *offset, char *modname, char *name) |
3082 | { |
3083 | struct module *mod; |
3084 | |
3085 | preempt_disable(); |
3086 | list_for_each_entry_rcu(mod, &modules, list) { |
3087 | if (within_module_init(addr, mod) || |
3088 | within_module_core(addr, mod)) { |
3089 | const char *sym; |
3090 | |
3091 | sym = get_ksymbol(mod, addr, size, offset); |
3092 | if (!sym) |
3093 | goto out; |
3094 | if (modname) |
3095 | strlcpy(modname, mod->name, MODULE_NAME_LEN); |
3096 | if (name) |
3097 | strlcpy(name, sym, KSYM_NAME_LEN); |
3098 | preempt_enable(); |
3099 | return 0; |
3100 | } |
3101 | } |
3102 | out: |
3103 | preempt_enable(); |
3104 | return -ERANGE; |
3105 | } |
3106 | |
3107 | int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type, |
3108 | char *name, char *module_name, int *exported) |
3109 | { |
3110 | struct module *mod; |
3111 | |
3112 | preempt_disable(); |
3113 | list_for_each_entry_rcu(mod, &modules, list) { |
3114 | if (symnum < mod->num_symtab) { |
3115 | *value = mod->symtab[symnum].st_value; |
3116 | *type = mod->symtab[symnum].st_info; |
3117 | strlcpy(name, mod->strtab + mod->symtab[symnum].st_name, |
3118 | KSYM_NAME_LEN); |
3119 | strlcpy(module_name, mod->name, MODULE_NAME_LEN); |
3120 | *exported = is_exported(name, *value, mod); |
3121 | preempt_enable(); |
3122 | return 0; |
3123 | } |
3124 | symnum -= mod->num_symtab; |
3125 | } |
3126 | preempt_enable(); |
3127 | return -ERANGE; |
3128 | } |
3129 | |
3130 | static unsigned long mod_find_symname(struct module *mod, const char *name) |
3131 | { |
3132 | unsigned int i; |
3133 | |
3134 | for (i = 0; i < mod->num_symtab; i++) |
3135 | if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 && |
3136 | mod->symtab[i].st_info != 'U') |
3137 | return mod->symtab[i].st_value; |
3138 | return 0; |
3139 | } |
3140 | |
3141 | /* Look for this name: can be of form module:name. */ |
3142 | unsigned long module_kallsyms_lookup_name(const char *name) |
3143 | { |
3144 | struct module *mod; |
3145 | char *colon; |
3146 | unsigned long ret = 0; |
3147 | |
3148 | /* Don't lock: we're in enough trouble already. */ |
3149 | preempt_disable(); |
3150 | if ((colon = strchr(name, ':')) != NULL) { |
3151 | *colon = '\0'; |
3152 | if ((mod = find_module(name)) != NULL) |
3153 | ret = mod_find_symname(mod, colon+1); |
3154 | *colon = ':'; |
3155 | } else { |
3156 | list_for_each_entry_rcu(mod, &modules, list) |
3157 | if ((ret = mod_find_symname(mod, name)) != 0) |
3158 | break; |
3159 | } |
3160 | preempt_enable(); |
3161 | return ret; |
3162 | } |
3163 | |
3164 | int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *, |
3165 | struct module *, unsigned long), |
3166 | void *data) |
3167 | { |
3168 | struct module *mod; |
3169 | unsigned int i; |
3170 | int ret; |
3171 | |
3172 | list_for_each_entry(mod, &modules, list) { |
3173 | for (i = 0; i < mod->num_symtab; i++) { |
3174 | ret = fn(data, mod->strtab + mod->symtab[i].st_name, |
3175 | mod, mod->symtab[i].st_value); |
3176 | if (ret != 0) |
3177 | return ret; |
3178 | } |
3179 | } |
3180 | return 0; |
3181 | } |
3182 | #endif /* CONFIG_KALLSYMS */ |
3183 | |
3184 | static char *module_flags(struct module *mod, char *buf) |
3185 | { |
3186 | int bx = 0; |
3187 | |
3188 | if (mod->taints || |
3189 | mod->state == MODULE_STATE_GOING || |
3190 | mod->state == MODULE_STATE_COMING) { |
3191 | buf[bx++] = '('; |
3192 | if (mod->taints & (1 << TAINT_PROPRIETARY_MODULE)) |
3193 | buf[bx++] = 'P'; |
3194 | if (mod->taints & (1 << TAINT_FORCED_MODULE)) |
3195 | buf[bx++] = 'F'; |
3196 | if (mod->taints & (1 << TAINT_CRAP)) |
3197 | buf[bx++] = 'C'; |
3198 | /* |
3199 | * TAINT_FORCED_RMMOD: could be added. |
3200 | * TAINT_UNSAFE_SMP, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't |
3201 | * apply to modules. |
3202 | */ |
3203 | |
3204 | /* Show a - for module-is-being-unloaded */ |
3205 | if (mod->state == MODULE_STATE_GOING) |
3206 | buf[bx++] = '-'; |
3207 | /* Show a + for module-is-being-loaded */ |
3208 | if (mod->state == MODULE_STATE_COMING) |
3209 | buf[bx++] = '+'; |
3210 | buf[bx++] = ')'; |
3211 | } |
3212 | buf[bx] = '\0'; |
3213 | |
3214 | return buf; |
3215 | } |
3216 | |
3217 | #ifdef CONFIG_PROC_FS |
3218 | /* Called by the /proc file system to return a list of modules. */ |
3219 | static void *m_start(struct seq_file *m, loff_t *pos) |
3220 | { |
3221 | mutex_lock(&module_mutex); |
3222 | return seq_list_start(&modules, *pos); |
3223 | } |
3224 | |
3225 | static void *m_next(struct seq_file *m, void *p, loff_t *pos) |
3226 | { |
3227 | return seq_list_next(p, &modules, pos); |
3228 | } |
3229 | |
3230 | static void m_stop(struct seq_file *m, void *p) |
3231 | { |
3232 | mutex_unlock(&module_mutex); |
3233 | } |
3234 | |
3235 | static int m_show(struct seq_file *m, void *p) |
3236 | { |
3237 | struct module *mod = list_entry(p, struct module, list); |
3238 | char buf[8]; |
3239 | |
3240 | seq_printf(m, "%s %u", |
3241 | mod->name, mod->init_size + mod->core_size); |
3242 | print_unload_info(m, mod); |
3243 | |
3244 | /* Informative for users. */ |
3245 | seq_printf(m, " %s", |
3246 | mod->state == MODULE_STATE_GOING ? "Unloading": |
3247 | mod->state == MODULE_STATE_COMING ? "Loading": |
3248 | "Live"); |
3249 | /* Used by oprofile and other similar tools. */ |
3250 | seq_printf(m, " 0x%pK", mod->module_core); |
3251 | |
3252 | /* Taints info */ |
3253 | if (mod->taints) |
3254 | seq_printf(m, " %s", module_flags(mod, buf)); |
3255 | |
3256 | seq_printf(m, "\n"); |
3257 | return 0; |
3258 | } |
3259 | |
3260 | /* Format: modulename size refcount deps address |
3261 | |
3262 | Where refcount is a number or -, and deps is a comma-separated list |
3263 | of depends or -. |
3264 | */ |
3265 | static const struct seq_operations modules_op = { |
3266 | .start = m_start, |
3267 | .next = m_next, |
3268 | .stop = m_stop, |
3269 | .show = m_show |
3270 | }; |
3271 | |
3272 | static int modules_open(struct inode *inode, struct file *file) |
3273 | { |
3274 | return seq_open(file, &modules_op); |
3275 | } |
3276 | |
3277 | static const struct file_operations proc_modules_operations = { |
3278 | .open = modules_open, |
3279 | .read = seq_read, |
3280 | .llseek = seq_lseek, |
3281 | .release = seq_release, |
3282 | }; |
3283 | |
3284 | static int __init proc_modules_init(void) |
3285 | { |
3286 | proc_create("modules", 0, NULL, &proc_modules_operations); |
3287 | return 0; |
3288 | } |
3289 | module_init(proc_modules_init); |
3290 | #endif |
3291 | |
3292 | /* Given an address, look for it in the module exception tables. */ |
3293 | const struct exception_table_entry *search_module_extables(unsigned long addr) |
3294 | { |
3295 | const struct exception_table_entry *e = NULL; |
3296 | struct module *mod; |
3297 | |
3298 | preempt_disable(); |
3299 | list_for_each_entry_rcu(mod, &modules, list) { |
3300 | if (mod->num_exentries == 0) |
3301 | continue; |
3302 | |
3303 | e = search_extable(mod->extable, |
3304 | mod->extable + mod->num_exentries - 1, |
3305 | addr); |
3306 | if (e) |
3307 | break; |
3308 | } |
3309 | preempt_enable(); |
3310 | |
3311 | /* Now, if we found one, we are running inside it now, hence |
3312 | we cannot unload the module, hence no refcnt needed. */ |
3313 | return e; |
3314 | } |
3315 | |
3316 | /* |
3317 | * is_module_address - is this address inside a module? |
3318 | * @addr: the address to check. |
3319 | * |
3320 | * See is_module_text_address() if you simply want to see if the address |
3321 | * is code (not data). |
3322 | */ |
3323 | bool is_module_address(unsigned long addr) |
3324 | { |
3325 | bool ret; |
3326 | |
3327 | preempt_disable(); |
3328 | ret = __module_address(addr) != NULL; |
3329 | preempt_enable(); |
3330 | |
3331 | return ret; |
3332 | } |
3333 | |
3334 | /* |
3335 | * __module_address - get the module which contains an address. |
3336 | * @addr: the address. |
3337 | * |
3338 | * Must be called with preempt disabled or module mutex held so that |
3339 | * module doesn't get freed during this. |
3340 | */ |
3341 | struct module *__module_address(unsigned long addr) |
3342 | { |
3343 | struct module *mod; |
3344 | |
3345 | if (addr < module_addr_min || addr > module_addr_max) |
3346 | return NULL; |
3347 | |
3348 | list_for_each_entry_rcu(mod, &modules, list) |
3349 | if (within_module_core(addr, mod) |
3350 | || within_module_init(addr, mod)) |
3351 | return mod; |
3352 | return NULL; |
3353 | } |
3354 | EXPORT_SYMBOL_GPL(__module_address); |
3355 | |
3356 | /* |
3357 | * is_module_text_address - is this address inside module code? |
3358 | * @addr: the address to check. |
3359 | * |
3360 | * See is_module_address() if you simply want to see if the address is |
3361 | * anywhere in a module. See kernel_text_address() for testing if an |
3362 | * address corresponds to kernel or module code. |
3363 | */ |
3364 | bool is_module_text_address(unsigned long addr) |
3365 | { |
3366 | bool ret; |
3367 | |
3368 | preempt_disable(); |
3369 | ret = __module_text_address(addr) != NULL; |
3370 | preempt_enable(); |
3371 | |
3372 | return ret; |
3373 | } |
3374 | |
3375 | /* |
3376 | * __module_text_address - get the module whose code contains an address. |
3377 | * @addr: the address. |
3378 | * |
3379 | * Must be called with preempt disabled or module mutex held so that |
3380 | * module doesn't get freed during this. |
3381 | */ |
3382 | struct module *__module_text_address(unsigned long addr) |
3383 | { |
3384 | struct module *mod = __module_address(addr); |
3385 | if (mod) { |
3386 | /* Make sure it's within the text section. */ |
3387 | if (!within(addr, mod->module_init, mod->init_text_size) |
3388 | && !within(addr, mod->module_core, mod->core_text_size)) |
3389 | mod = NULL; |
3390 | } |
3391 | return mod; |
3392 | } |
3393 | EXPORT_SYMBOL_GPL(__module_text_address); |
3394 | |
3395 | /* Don't grab lock, we're oopsing. */ |
3396 | void print_modules(void) |
3397 | { |
3398 | struct module *mod; |
3399 | char buf[8]; |
3400 | |
3401 | printk(KERN_DEFAULT "Modules linked in:"); |
3402 | /* Most callers should already have preempt disabled, but make sure */ |
3403 | preempt_disable(); |
3404 | list_for_each_entry_rcu(mod, &modules, list) |
3405 | printk(" %s%s", mod->name, module_flags(mod, buf)); |
3406 | preempt_enable(); |
3407 | if (last_unloaded_module[0]) |
3408 | printk(" [last unloaded: %s]", last_unloaded_module); |
3409 | printk("\n"); |
3410 | } |
3411 | |
3412 | #ifdef CONFIG_MODVERSIONS |
3413 | /* Generate the signature for all relevant module structures here. |
3414 | * If these change, we don't want to try to parse the module. */ |
3415 | void module_layout(struct module *mod, |
3416 | struct modversion_info *ver, |
3417 | struct kernel_param *kp, |
3418 | struct kernel_symbol *ks, |
3419 | struct tracepoint * const *tp) |
3420 | { |
3421 | } |
3422 | EXPORT_SYMBOL(module_layout); |
3423 | #endif |
3424 | |
3425 | #ifdef CONFIG_TRACEPOINTS |
3426 | void module_update_tracepoints(void) |
3427 | { |
3428 | struct module *mod; |
3429 | |
3430 | mutex_lock(&module_mutex); |
3431 | list_for_each_entry(mod, &modules, list) |
3432 | if (!mod->taints) |
3433 | tracepoint_update_probe_range(mod->tracepoints_ptrs, |
3434 | mod->tracepoints_ptrs + mod->num_tracepoints); |
3435 | mutex_unlock(&module_mutex); |
3436 | } |
3437 | |
3438 | /* |
3439 | * Returns 0 if current not found. |
3440 | * Returns 1 if current found. |
3441 | */ |
3442 | int module_get_iter_tracepoints(struct tracepoint_iter *iter) |
3443 | { |
3444 | struct module *iter_mod; |
3445 | int found = 0; |
3446 | |
3447 | mutex_lock(&module_mutex); |
3448 | list_for_each_entry(iter_mod, &modules, list) { |
3449 | if (!iter_mod->taints) { |
3450 | /* |
3451 | * Sorted module list |
3452 | */ |
3453 | if (iter_mod < iter->module) |
3454 | continue; |
3455 | else if (iter_mod > iter->module) |
3456 | iter->tracepoint = NULL; |
3457 | found = tracepoint_get_iter_range(&iter->tracepoint, |
3458 | iter_mod->tracepoints_ptrs, |
3459 | iter_mod->tracepoints_ptrs |
3460 | + iter_mod->num_tracepoints); |
3461 | if (found) { |
3462 | iter->module = iter_mod; |
3463 | break; |
3464 | } |
3465 | } |
3466 | } |
3467 | mutex_unlock(&module_mutex); |
3468 | return found; |
3469 | } |
3470 | #endif |
3471 |
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