Version:  2.0.40 2.2.26 2.4.37 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7

Linux/kernel/module.c

  1 /*
  2    Copyright (C) 2002 Richard Henderson
  3    Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM.
  4 
  5     This program is free software; you can redistribute it and/or modify
  6     it under the terms of the GNU General Public License as published by
  7     the Free Software Foundation; either version 2 of the License, or
  8     (at your option) any later version.
  9 
 10     This program is distributed in the hope that it will be useful,
 11     but WITHOUT ANY WARRANTY; without even the implied warranty of
 12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 13     GNU General Public License for more details.
 14 
 15     You should have received a copy of the GNU General Public License
 16     along with this program; if not, write to the Free Software
 17     Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 18 */
 19 #include <linux/export.h>
 20 #include <linux/moduleloader.h>
 21 #include <linux/trace_events.h>
 22 #include <linux/init.h>
 23 #include <linux/kallsyms.h>
 24 #include <linux/file.h>
 25 #include <linux/fs.h>
 26 #include <linux/sysfs.h>
 27 #include <linux/kernel.h>
 28 #include <linux/slab.h>
 29 #include <linux/vmalloc.h>
 30 #include <linux/elf.h>
 31 #include <linux/proc_fs.h>
 32 #include <linux/security.h>
 33 #include <linux/seq_file.h>
 34 #include <linux/syscalls.h>
 35 #include <linux/fcntl.h>
 36 #include <linux/rcupdate.h>
 37 #include <linux/capability.h>
 38 #include <linux/cpu.h>
 39 #include <linux/moduleparam.h>
 40 #include <linux/errno.h>
 41 #include <linux/err.h>
 42 #include <linux/vermagic.h>
 43 #include <linux/notifier.h>
 44 #include <linux/sched.h>
 45 #include <linux/device.h>
 46 #include <linux/string.h>
 47 #include <linux/mutex.h>
 48 #include <linux/rculist.h>
 49 #include <asm/uaccess.h>
 50 #include <asm/cacheflush.h>
 51 #include <asm/mmu_context.h>
 52 #include <linux/license.h>
 53 #include <asm/sections.h>
 54 #include <linux/tracepoint.h>
 55 #include <linux/ftrace.h>
 56 #include <linux/livepatch.h>
 57 #include <linux/async.h>
 58 #include <linux/percpu.h>
 59 #include <linux/kmemleak.h>
 60 #include <linux/jump_label.h>
 61 #include <linux/pfn.h>
 62 #include <linux/bsearch.h>
 63 #include <uapi/linux/module.h>
 64 #include "module-internal.h"
 65 
 66 #define CREATE_TRACE_POINTS
 67 #include <trace/events/module.h>
 68 
 69 #ifndef ARCH_SHF_SMALL
 70 #define ARCH_SHF_SMALL 0
 71 #endif
 72 
 73 /*
 74  * Modules' sections will be aligned on page boundaries
 75  * to ensure complete separation of code and data, but
 76  * only when CONFIG_DEBUG_SET_MODULE_RONX=y
 77  */
 78 #ifdef CONFIG_DEBUG_SET_MODULE_RONX
 79 # define debug_align(X) ALIGN(X, PAGE_SIZE)
 80 #else
 81 # define debug_align(X) (X)
 82 #endif
 83 
 84 /* If this is set, the section belongs in the init part of the module */
 85 #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
 86 
 87 /*
 88  * Mutex protects:
 89  * 1) List of modules (also safely readable with preempt_disable),
 90  * 2) module_use links,
 91  * 3) module_addr_min/module_addr_max.
 92  * (delete and add uses RCU list operations). */
 93 DEFINE_MUTEX(module_mutex);
 94 EXPORT_SYMBOL_GPL(module_mutex);
 95 static LIST_HEAD(modules);
 96 
 97 #ifdef CONFIG_MODULES_TREE_LOOKUP
 98 
 99 /*
100  * Use a latched RB-tree for __module_address(); this allows us to use
101  * RCU-sched lookups of the address from any context.
102  *
103  * This is conditional on PERF_EVENTS || TRACING because those can really hit
104  * __module_address() hard by doing a lot of stack unwinding; potentially from
105  * NMI context.
106  */
107 
108 static __always_inline unsigned long __mod_tree_val(struct latch_tree_node *n)
109 {
110         struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
111 
112         return (unsigned long)layout->base;
113 }
114 
115 static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n)
116 {
117         struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
118 
119         return (unsigned long)layout->size;
120 }
121 
122 static __always_inline bool
123 mod_tree_less(struct latch_tree_node *a, struct latch_tree_node *b)
124 {
125         return __mod_tree_val(a) < __mod_tree_val(b);
126 }
127 
128 static __always_inline int
129 mod_tree_comp(void *key, struct latch_tree_node *n)
130 {
131         unsigned long val = (unsigned long)key;
132         unsigned long start, end;
133 
134         start = __mod_tree_val(n);
135         if (val < start)
136                 return -1;
137 
138         end = start + __mod_tree_size(n);
139         if (val >= end)
140                 return 1;
141 
142         return 0;
143 }
144 
145 static const struct latch_tree_ops mod_tree_ops = {
146         .less = mod_tree_less,
147         .comp = mod_tree_comp,
148 };
149 
150 static struct mod_tree_root {
151         struct latch_tree_root root;
152         unsigned long addr_min;
153         unsigned long addr_max;
154 } mod_tree __cacheline_aligned = {
155         .addr_min = -1UL,
156 };
157 
158 #define module_addr_min mod_tree.addr_min
159 #define module_addr_max mod_tree.addr_max
160 
161 static noinline void __mod_tree_insert(struct mod_tree_node *node)
162 {
163         latch_tree_insert(&node->node, &mod_tree.root, &mod_tree_ops);
164 }
165 
166 static void __mod_tree_remove(struct mod_tree_node *node)
167 {
168         latch_tree_erase(&node->node, &mod_tree.root, &mod_tree_ops);
169 }
170 
171 /*
172  * These modifications: insert, remove_init and remove; are serialized by the
173  * module_mutex.
174  */
175 static void mod_tree_insert(struct module *mod)
176 {
177         mod->core_layout.mtn.mod = mod;
178         mod->init_layout.mtn.mod = mod;
179 
180         __mod_tree_insert(&mod->core_layout.mtn);
181         if (mod->init_layout.size)
182                 __mod_tree_insert(&mod->init_layout.mtn);
183 }
184 
185 static void mod_tree_remove_init(struct module *mod)
186 {
187         if (mod->init_layout.size)
188                 __mod_tree_remove(&mod->init_layout.mtn);
189 }
190 
191 static void mod_tree_remove(struct module *mod)
192 {
193         __mod_tree_remove(&mod->core_layout.mtn);
194         mod_tree_remove_init(mod);
195 }
196 
197 static struct module *mod_find(unsigned long addr)
198 {
199         struct latch_tree_node *ltn;
200 
201         ltn = latch_tree_find((void *)addr, &mod_tree.root, &mod_tree_ops);
202         if (!ltn)
203                 return NULL;
204 
205         return container_of(ltn, struct mod_tree_node, node)->mod;
206 }
207 
208 #else /* MODULES_TREE_LOOKUP */
209 
210 static unsigned long module_addr_min = -1UL, module_addr_max = 0;
211 
212 static void mod_tree_insert(struct module *mod) { }
213 static void mod_tree_remove_init(struct module *mod) { }
214 static void mod_tree_remove(struct module *mod) { }
215 
216 static struct module *mod_find(unsigned long addr)
217 {
218         struct module *mod;
219 
220         list_for_each_entry_rcu(mod, &modules, list) {
221                 if (within_module(addr, mod))
222                         return mod;
223         }
224 
225         return NULL;
226 }
227 
228 #endif /* MODULES_TREE_LOOKUP */
229 
230 /*
231  * Bounds of module text, for speeding up __module_address.
232  * Protected by module_mutex.
233  */
234 static void __mod_update_bounds(void *base, unsigned int size)
235 {
236         unsigned long min = (unsigned long)base;
237         unsigned long max = min + size;
238 
239         if (min < module_addr_min)
240                 module_addr_min = min;
241         if (max > module_addr_max)
242                 module_addr_max = max;
243 }
244 
245 static void mod_update_bounds(struct module *mod)
246 {
247         __mod_update_bounds(mod->core_layout.base, mod->core_layout.size);
248         if (mod->init_layout.size)
249                 __mod_update_bounds(mod->init_layout.base, mod->init_layout.size);
250 }
251 
252 #ifdef CONFIG_KGDB_KDB
253 struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
254 #endif /* CONFIG_KGDB_KDB */
255 
256 static void module_assert_mutex(void)
257 {
258         lockdep_assert_held(&module_mutex);
259 }
260 
261 static void module_assert_mutex_or_preempt(void)
262 {
263 #ifdef CONFIG_LOCKDEP
264         if (unlikely(!debug_locks))
265                 return;
266 
267         WARN_ON(!rcu_read_lock_sched_held() &&
268                 !lockdep_is_held(&module_mutex));
269 #endif
270 }
271 
272 static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE);
273 #ifndef CONFIG_MODULE_SIG_FORCE
274 module_param(sig_enforce, bool_enable_only, 0644);
275 #endif /* !CONFIG_MODULE_SIG_FORCE */
276 
277 /* Block module loading/unloading? */
278 int modules_disabled = 0;
279 core_param(nomodule, modules_disabled, bint, 0);
280 
281 /* Waiting for a module to finish initializing? */
282 static DECLARE_WAIT_QUEUE_HEAD(module_wq);
283 
284 static BLOCKING_NOTIFIER_HEAD(module_notify_list);
285 
286 int register_module_notifier(struct notifier_block *nb)
287 {
288         return blocking_notifier_chain_register(&module_notify_list, nb);
289 }
290 EXPORT_SYMBOL(register_module_notifier);
291 
292 int unregister_module_notifier(struct notifier_block *nb)
293 {
294         return blocking_notifier_chain_unregister(&module_notify_list, nb);
295 }
296 EXPORT_SYMBOL(unregister_module_notifier);
297 
298 struct load_info {
299         Elf_Ehdr *hdr;
300         unsigned long len;
301         Elf_Shdr *sechdrs;
302         char *secstrings, *strtab;
303         unsigned long symoffs, stroffs;
304         struct _ddebug *debug;
305         unsigned int num_debug;
306         bool sig_ok;
307 #ifdef CONFIG_KALLSYMS
308         unsigned long mod_kallsyms_init_off;
309 #endif
310         struct {
311                 unsigned int sym, str, mod, vers, info, pcpu;
312         } index;
313 };
314 
315 /* We require a truly strong try_module_get(): 0 means failure due to
316    ongoing or failed initialization etc. */
317 static inline int strong_try_module_get(struct module *mod)
318 {
319         BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
320         if (mod && mod->state == MODULE_STATE_COMING)
321                 return -EBUSY;
322         if (try_module_get(mod))
323                 return 0;
324         else
325                 return -ENOENT;
326 }
327 
328 static inline void add_taint_module(struct module *mod, unsigned flag,
329                                     enum lockdep_ok lockdep_ok)
330 {
331         add_taint(flag, lockdep_ok);
332         mod->taints |= (1U << flag);
333 }
334 
335 /*
336  * A thread that wants to hold a reference to a module only while it
337  * is running can call this to safely exit.  nfsd and lockd use this.
338  */
339 void __module_put_and_exit(struct module *mod, long code)
340 {
341         module_put(mod);
342         do_exit(code);
343 }
344 EXPORT_SYMBOL(__module_put_and_exit);
345 
346 /* Find a module section: 0 means not found. */
347 static unsigned int find_sec(const struct load_info *info, const char *name)
348 {
349         unsigned int i;
350 
351         for (i = 1; i < info->hdr->e_shnum; i++) {
352                 Elf_Shdr *shdr = &info->sechdrs[i];
353                 /* Alloc bit cleared means "ignore it." */
354                 if ((shdr->sh_flags & SHF_ALLOC)
355                     && strcmp(info->secstrings + shdr->sh_name, name) == 0)
356                         return i;
357         }
358         return 0;
359 }
360 
361 /* Find a module section, or NULL. */
362 static void *section_addr(const struct load_info *info, const char *name)
363 {
364         /* Section 0 has sh_addr 0. */
365         return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
366 }
367 
368 /* Find a module section, or NULL.  Fill in number of "objects" in section. */
369 static void *section_objs(const struct load_info *info,
370                           const char *name,
371                           size_t object_size,
372                           unsigned int *num)
373 {
374         unsigned int sec = find_sec(info, name);
375 
376         /* Section 0 has sh_addr 0 and sh_size 0. */
377         *num = info->sechdrs[sec].sh_size / object_size;
378         return (void *)info->sechdrs[sec].sh_addr;
379 }
380 
381 /* Provided by the linker */
382 extern const struct kernel_symbol __start___ksymtab[];
383 extern const struct kernel_symbol __stop___ksymtab[];
384 extern const struct kernel_symbol __start___ksymtab_gpl[];
385 extern const struct kernel_symbol __stop___ksymtab_gpl[];
386 extern const struct kernel_symbol __start___ksymtab_gpl_future[];
387 extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
388 extern const unsigned long __start___kcrctab[];
389 extern const unsigned long __start___kcrctab_gpl[];
390 extern const unsigned long __start___kcrctab_gpl_future[];
391 #ifdef CONFIG_UNUSED_SYMBOLS
392 extern const struct kernel_symbol __start___ksymtab_unused[];
393 extern const struct kernel_symbol __stop___ksymtab_unused[];
394 extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
395 extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
396 extern const unsigned long __start___kcrctab_unused[];
397 extern const unsigned long __start___kcrctab_unused_gpl[];
398 #endif
399 
400 #ifndef CONFIG_MODVERSIONS
401 #define symversion(base, idx) NULL
402 #else
403 #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
404 #endif
405 
406 static bool each_symbol_in_section(const struct symsearch *arr,
407                                    unsigned int arrsize,
408                                    struct module *owner,
409                                    bool (*fn)(const struct symsearch *syms,
410                                               struct module *owner,
411                                               void *data),
412                                    void *data)
413 {
414         unsigned int j;
415 
416         for (j = 0; j < arrsize; j++) {
417                 if (fn(&arr[j], owner, data))
418                         return true;
419         }
420 
421         return false;
422 }
423 
424 /* Returns true as soon as fn returns true, otherwise false. */
425 bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
426                                     struct module *owner,
427                                     void *data),
428                          void *data)
429 {
430         struct module *mod;
431         static const struct symsearch arr[] = {
432                 { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
433                   NOT_GPL_ONLY, false },
434                 { __start___ksymtab_gpl, __stop___ksymtab_gpl,
435                   __start___kcrctab_gpl,
436                   GPL_ONLY, false },
437                 { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
438                   __start___kcrctab_gpl_future,
439                   WILL_BE_GPL_ONLY, false },
440 #ifdef CONFIG_UNUSED_SYMBOLS
441                 { __start___ksymtab_unused, __stop___ksymtab_unused,
442                   __start___kcrctab_unused,
443                   NOT_GPL_ONLY, true },
444                 { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
445                   __start___kcrctab_unused_gpl,
446                   GPL_ONLY, true },
447 #endif
448         };
449 
450         module_assert_mutex_or_preempt();
451 
452         if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
453                 return true;
454 
455         list_for_each_entry_rcu(mod, &modules, list) {
456                 struct symsearch arr[] = {
457                         { mod->syms, mod->syms + mod->num_syms, mod->crcs,
458                           NOT_GPL_ONLY, false },
459                         { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
460                           mod->gpl_crcs,
461                           GPL_ONLY, false },
462                         { mod->gpl_future_syms,
463                           mod->gpl_future_syms + mod->num_gpl_future_syms,
464                           mod->gpl_future_crcs,
465                           WILL_BE_GPL_ONLY, false },
466 #ifdef CONFIG_UNUSED_SYMBOLS
467                         { mod->unused_syms,
468                           mod->unused_syms + mod->num_unused_syms,
469                           mod->unused_crcs,
470                           NOT_GPL_ONLY, true },
471                         { mod->unused_gpl_syms,
472                           mod->unused_gpl_syms + mod->num_unused_gpl_syms,
473                           mod->unused_gpl_crcs,
474                           GPL_ONLY, true },
475 #endif
476                 };
477 
478                 if (mod->state == MODULE_STATE_UNFORMED)
479                         continue;
480 
481                 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
482                         return true;
483         }
484         return false;
485 }
486 EXPORT_SYMBOL_GPL(each_symbol_section);
487 
488 struct find_symbol_arg {
489         /* Input */
490         const char *name;
491         bool gplok;
492         bool warn;
493 
494         /* Output */
495         struct module *owner;
496         const unsigned long *crc;
497         const struct kernel_symbol *sym;
498 };
499 
500 static bool check_symbol(const struct symsearch *syms,
501                                  struct module *owner,
502                                  unsigned int symnum, void *data)
503 {
504         struct find_symbol_arg *fsa = data;
505 
506         if (!fsa->gplok) {
507                 if (syms->licence == GPL_ONLY)
508                         return false;
509                 if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) {
510                         pr_warn("Symbol %s is being used by a non-GPL module, "
511                                 "which will not be allowed in the future\n",
512                                 fsa->name);
513                 }
514         }
515 
516 #ifdef CONFIG_UNUSED_SYMBOLS
517         if (syms->unused && fsa->warn) {
518                 pr_warn("Symbol %s is marked as UNUSED, however this module is "
519                         "using it.\n", fsa->name);
520                 pr_warn("This symbol will go away in the future.\n");
521                 pr_warn("Please evaluate if this is the right api to use and "
522                         "if it really is, submit a report to the linux kernel "
523                         "mailing list together with submitting your code for "
524                         "inclusion.\n");
525         }
526 #endif
527 
528         fsa->owner = owner;
529         fsa->crc = symversion(syms->crcs, symnum);
530         fsa->sym = &syms->start[symnum];
531         return true;
532 }
533 
534 static int cmp_name(const void *va, const void *vb)
535 {
536         const char *a;
537         const struct kernel_symbol *b;
538         a = va; b = vb;
539         return strcmp(a, b->name);
540 }
541 
542 static bool find_symbol_in_section(const struct symsearch *syms,
543                                    struct module *owner,
544                                    void *data)
545 {
546         struct find_symbol_arg *fsa = data;
547         struct kernel_symbol *sym;
548 
549         sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
550                         sizeof(struct kernel_symbol), cmp_name);
551 
552         if (sym != NULL && check_symbol(syms, owner, sym - syms->start, data))
553                 return true;
554 
555         return false;
556 }
557 
558 /* Find a symbol and return it, along with, (optional) crc and
559  * (optional) module which owns it.  Needs preempt disabled or module_mutex. */
560 const struct kernel_symbol *find_symbol(const char *name,
561                                         struct module **owner,
562                                         const unsigned long **crc,
563                                         bool gplok,
564                                         bool warn)
565 {
566         struct find_symbol_arg fsa;
567 
568         fsa.name = name;
569         fsa.gplok = gplok;
570         fsa.warn = warn;
571 
572         if (each_symbol_section(find_symbol_in_section, &fsa)) {
573                 if (owner)
574                         *owner = fsa.owner;
575                 if (crc)
576                         *crc = fsa.crc;
577                 return fsa.sym;
578         }
579 
580         pr_debug("Failed to find symbol %s\n", name);
581         return NULL;
582 }
583 EXPORT_SYMBOL_GPL(find_symbol);
584 
585 /*
586  * Search for module by name: must hold module_mutex (or preempt disabled
587  * for read-only access).
588  */
589 static struct module *find_module_all(const char *name, size_t len,
590                                       bool even_unformed)
591 {
592         struct module *mod;
593 
594         module_assert_mutex_or_preempt();
595 
596         list_for_each_entry(mod, &modules, list) {
597                 if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
598                         continue;
599                 if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
600                         return mod;
601         }
602         return NULL;
603 }
604 
605 struct module *find_module(const char *name)
606 {
607         module_assert_mutex();
608         return find_module_all(name, strlen(name), false);
609 }
610 EXPORT_SYMBOL_GPL(find_module);
611 
612 #ifdef CONFIG_SMP
613 
614 static inline void __percpu *mod_percpu(struct module *mod)
615 {
616         return mod->percpu;
617 }
618 
619 static int percpu_modalloc(struct module *mod, struct load_info *info)
620 {
621         Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
622         unsigned long align = pcpusec->sh_addralign;
623 
624         if (!pcpusec->sh_size)
625                 return 0;
626 
627         if (align > PAGE_SIZE) {
628                 pr_warn("%s: per-cpu alignment %li > %li\n",
629                         mod->name, align, PAGE_SIZE);
630                 align = PAGE_SIZE;
631         }
632 
633         mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
634         if (!mod->percpu) {
635                 pr_warn("%s: Could not allocate %lu bytes percpu data\n",
636                         mod->name, (unsigned long)pcpusec->sh_size);
637                 return -ENOMEM;
638         }
639         mod->percpu_size = pcpusec->sh_size;
640         return 0;
641 }
642 
643 static void percpu_modfree(struct module *mod)
644 {
645         free_percpu(mod->percpu);
646 }
647 
648 static unsigned int find_pcpusec(struct load_info *info)
649 {
650         return find_sec(info, ".data..percpu");
651 }
652 
653 static void percpu_modcopy(struct module *mod,
654                            const void *from, unsigned long size)
655 {
656         int cpu;
657 
658         for_each_possible_cpu(cpu)
659                 memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
660 }
661 
662 /**
663  * is_module_percpu_address - test whether address is from module static percpu
664  * @addr: address to test
665  *
666  * Test whether @addr belongs to module static percpu area.
667  *
668  * RETURNS:
669  * %true if @addr is from module static percpu area
670  */
671 bool is_module_percpu_address(unsigned long addr)
672 {
673         struct module *mod;
674         unsigned int cpu;
675 
676         preempt_disable();
677 
678         list_for_each_entry_rcu(mod, &modules, list) {
679                 if (mod->state == MODULE_STATE_UNFORMED)
680                         continue;
681                 if (!mod->percpu_size)
682                         continue;
683                 for_each_possible_cpu(cpu) {
684                         void *start = per_cpu_ptr(mod->percpu, cpu);
685 
686                         if ((void *)addr >= start &&
687                             (void *)addr < start + mod->percpu_size) {
688                                 preempt_enable();
689                                 return true;
690                         }
691                 }
692         }
693 
694         preempt_enable();
695         return false;
696 }
697 
698 #else /* ... !CONFIG_SMP */
699 
700 static inline void __percpu *mod_percpu(struct module *mod)
701 {
702         return NULL;
703 }
704 static int percpu_modalloc(struct module *mod, struct load_info *info)
705 {
706         /* UP modules shouldn't have this section: ENOMEM isn't quite right */
707         if (info->sechdrs[info->index.pcpu].sh_size != 0)
708                 return -ENOMEM;
709         return 0;
710 }
711 static inline void percpu_modfree(struct module *mod)
712 {
713 }
714 static unsigned int find_pcpusec(struct load_info *info)
715 {
716         return 0;
717 }
718 static inline void percpu_modcopy(struct module *mod,
719                                   const void *from, unsigned long size)
720 {
721         /* pcpusec should be 0, and size of that section should be 0. */
722         BUG_ON(size != 0);
723 }
724 bool is_module_percpu_address(unsigned long addr)
725 {
726         return false;
727 }
728 
729 #endif /* CONFIG_SMP */
730 
731 #define MODINFO_ATTR(field)     \
732 static void setup_modinfo_##field(struct module *mod, const char *s)  \
733 {                                                                     \
734         mod->field = kstrdup(s, GFP_KERNEL);                          \
735 }                                                                     \
736 static ssize_t show_modinfo_##field(struct module_attribute *mattr,   \
737                         struct module_kobject *mk, char *buffer)      \
738 {                                                                     \
739         return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field);  \
740 }                                                                     \
741 static int modinfo_##field##_exists(struct module *mod)               \
742 {                                                                     \
743         return mod->field != NULL;                                    \
744 }                                                                     \
745 static void free_modinfo_##field(struct module *mod)                  \
746 {                                                                     \
747         kfree(mod->field);                                            \
748         mod->field = NULL;                                            \
749 }                                                                     \
750 static struct module_attribute modinfo_##field = {                    \
751         .attr = { .name = __stringify(field), .mode = 0444 },         \
752         .show = show_modinfo_##field,                                 \
753         .setup = setup_modinfo_##field,                               \
754         .test = modinfo_##field##_exists,                             \
755         .free = free_modinfo_##field,                                 \
756 };
757 
758 MODINFO_ATTR(version);
759 MODINFO_ATTR(srcversion);
760 
761 static char last_unloaded_module[MODULE_NAME_LEN+1];
762 
763 #ifdef CONFIG_MODULE_UNLOAD
764 
765 EXPORT_TRACEPOINT_SYMBOL(module_get);
766 
767 /* MODULE_REF_BASE is the base reference count by kmodule loader. */
768 #define MODULE_REF_BASE 1
769 
770 /* Init the unload section of the module. */
771 static int module_unload_init(struct module *mod)
772 {
773         /*
774          * Initialize reference counter to MODULE_REF_BASE.
775          * refcnt == 0 means module is going.
776          */
777         atomic_set(&mod->refcnt, MODULE_REF_BASE);
778 
779         INIT_LIST_HEAD(&mod->source_list);
780         INIT_LIST_HEAD(&mod->target_list);
781 
782         /* Hold reference count during initialization. */
783         atomic_inc(&mod->refcnt);
784 
785         return 0;
786 }
787 
788 /* Does a already use b? */
789 static int already_uses(struct module *a, struct module *b)
790 {
791         struct module_use *use;
792 
793         list_for_each_entry(use, &b->source_list, source_list) {
794                 if (use->source == a) {
795                         pr_debug("%s uses %s!\n", a->name, b->name);
796                         return 1;
797                 }
798         }
799         pr_debug("%s does not use %s!\n", a->name, b->name);
800         return 0;
801 }
802 
803 /*
804  * Module a uses b
805  *  - we add 'a' as a "source", 'b' as a "target" of module use
806  *  - the module_use is added to the list of 'b' sources (so
807  *    'b' can walk the list to see who sourced them), and of 'a'
808  *    targets (so 'a' can see what modules it targets).
809  */
810 static int add_module_usage(struct module *a, struct module *b)
811 {
812         struct module_use *use;
813 
814         pr_debug("Allocating new usage for %s.\n", a->name);
815         use = kmalloc(sizeof(*use), GFP_ATOMIC);
816         if (!use) {
817                 pr_warn("%s: out of memory loading\n", a->name);
818                 return -ENOMEM;
819         }
820 
821         use->source = a;
822         use->target = b;
823         list_add(&use->source_list, &b->source_list);
824         list_add(&use->target_list, &a->target_list);
825         return 0;
826 }
827 
828 /* Module a uses b: caller needs module_mutex() */
829 int ref_module(struct module *a, struct module *b)
830 {
831         int err;
832 
833         if (b == NULL || already_uses(a, b))
834                 return 0;
835 
836         /* If module isn't available, we fail. */
837         err = strong_try_module_get(b);
838         if (err)
839                 return err;
840 
841         err = add_module_usage(a, b);
842         if (err) {
843                 module_put(b);
844                 return err;
845         }
846         return 0;
847 }
848 EXPORT_SYMBOL_GPL(ref_module);
849 
850 /* Clear the unload stuff of the module. */
851 static void module_unload_free(struct module *mod)
852 {
853         struct module_use *use, *tmp;
854 
855         mutex_lock(&module_mutex);
856         list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
857                 struct module *i = use->target;
858                 pr_debug("%s unusing %s\n", mod->name, i->name);
859                 module_put(i);
860                 list_del(&use->source_list);
861                 list_del(&use->target_list);
862                 kfree(use);
863         }
864         mutex_unlock(&module_mutex);
865 }
866 
867 #ifdef CONFIG_MODULE_FORCE_UNLOAD
868 static inline int try_force_unload(unsigned int flags)
869 {
870         int ret = (flags & O_TRUNC);
871         if (ret)
872                 add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
873         return ret;
874 }
875 #else
876 static inline int try_force_unload(unsigned int flags)
877 {
878         return 0;
879 }
880 #endif /* CONFIG_MODULE_FORCE_UNLOAD */
881 
882 /* Try to release refcount of module, 0 means success. */
883 static int try_release_module_ref(struct module *mod)
884 {
885         int ret;
886 
887         /* Try to decrement refcnt which we set at loading */
888         ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt);
889         BUG_ON(ret < 0);
890         if (ret)
891                 /* Someone can put this right now, recover with checking */
892                 ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0);
893 
894         return ret;
895 }
896 
897 static int try_stop_module(struct module *mod, int flags, int *forced)
898 {
899         /* If it's not unused, quit unless we're forcing. */
900         if (try_release_module_ref(mod) != 0) {
901                 *forced = try_force_unload(flags);
902                 if (!(*forced))
903                         return -EWOULDBLOCK;
904         }
905 
906         /* Mark it as dying. */
907         mod->state = MODULE_STATE_GOING;
908 
909         return 0;
910 }
911 
912 /**
913  * module_refcount - return the refcount or -1 if unloading
914  *
915  * @mod:        the module we're checking
916  *
917  * Returns:
918  *      -1 if the module is in the process of unloading
919  *      otherwise the number of references in the kernel to the module
920  */
921 int module_refcount(struct module *mod)
922 {
923         return atomic_read(&mod->refcnt) - MODULE_REF_BASE;
924 }
925 EXPORT_SYMBOL(module_refcount);
926 
927 /* This exists whether we can unload or not */
928 static void free_module(struct module *mod);
929 
930 SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
931                 unsigned int, flags)
932 {
933         struct module *mod;
934         char name[MODULE_NAME_LEN];
935         int ret, forced = 0;
936 
937         if (!capable(CAP_SYS_MODULE) || modules_disabled)
938                 return -EPERM;
939 
940         if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
941                 return -EFAULT;
942         name[MODULE_NAME_LEN-1] = '\0';
943 
944         if (mutex_lock_interruptible(&module_mutex) != 0)
945                 return -EINTR;
946 
947         mod = find_module(name);
948         if (!mod) {
949                 ret = -ENOENT;
950                 goto out;
951         }
952 
953         if (!list_empty(&mod->source_list)) {
954                 /* Other modules depend on us: get rid of them first. */
955                 ret = -EWOULDBLOCK;
956                 goto out;
957         }
958 
959         /* Doing init or already dying? */
960         if (mod->state != MODULE_STATE_LIVE) {
961                 /* FIXME: if (force), slam module count damn the torpedoes */
962                 pr_debug("%s already dying\n", mod->name);
963                 ret = -EBUSY;
964                 goto out;
965         }
966 
967         /* If it has an init func, it must have an exit func to unload */
968         if (mod->init && !mod->exit) {
969                 forced = try_force_unload(flags);
970                 if (!forced) {
971                         /* This module can't be removed */
972                         ret = -EBUSY;
973                         goto out;
974                 }
975         }
976 
977         /* Stop the machine so refcounts can't move and disable module. */
978         ret = try_stop_module(mod, flags, &forced);
979         if (ret != 0)
980                 goto out;
981 
982         mutex_unlock(&module_mutex);
983         /* Final destruction now no one is using it. */
984         if (mod->exit != NULL)
985                 mod->exit();
986         blocking_notifier_call_chain(&module_notify_list,
987                                      MODULE_STATE_GOING, mod);
988         klp_module_going(mod);
989         ftrace_release_mod(mod);
990 
991         async_synchronize_full();
992 
993         /* Store the name of the last unloaded module for diagnostic purposes */
994         strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
995 
996         free_module(mod);
997         return 0;
998 out:
999         mutex_unlock(&module_mutex);
1000         return ret;
1001 }
1002 
1003 static inline void print_unload_info(struct seq_file *m, struct module *mod)
1004 {
1005         struct module_use *use;
1006         int printed_something = 0;
1007 
1008         seq_printf(m, " %i ", module_refcount(mod));
1009 
1010         /*
1011          * Always include a trailing , so userspace can differentiate
1012          * between this and the old multi-field proc format.
1013          */
1014         list_for_each_entry(use, &mod->source_list, source_list) {
1015                 printed_something = 1;
1016                 seq_printf(m, "%s,", use->source->name);
1017         }
1018 
1019         if (mod->init != NULL && mod->exit == NULL) {
1020                 printed_something = 1;
1021                 seq_puts(m, "[permanent],");
1022         }
1023 
1024         if (!printed_something)
1025                 seq_puts(m, "-");
1026 }
1027 
1028 void __symbol_put(const char *symbol)
1029 {
1030         struct module *owner;
1031 
1032         preempt_disable();
1033         if (!find_symbol(symbol, &owner, NULL, true, false))
1034                 BUG();
1035         module_put(owner);
1036         preempt_enable();
1037 }
1038 EXPORT_SYMBOL(__symbol_put);
1039 
1040 /* Note this assumes addr is a function, which it currently always is. */
1041 void symbol_put_addr(void *addr)
1042 {
1043         struct module *modaddr;
1044         unsigned long a = (unsigned long)dereference_function_descriptor(addr);
1045 
1046         if (core_kernel_text(a))
1047                 return;
1048 
1049         /*
1050          * Even though we hold a reference on the module; we still need to
1051          * disable preemption in order to safely traverse the data structure.
1052          */
1053         preempt_disable();
1054         modaddr = __module_text_address(a);
1055         BUG_ON(!modaddr);
1056         module_put(modaddr);
1057         preempt_enable();
1058 }
1059 EXPORT_SYMBOL_GPL(symbol_put_addr);
1060 
1061 static ssize_t show_refcnt(struct module_attribute *mattr,
1062                            struct module_kobject *mk, char *buffer)
1063 {
1064         return sprintf(buffer, "%i\n", module_refcount(mk->mod));
1065 }
1066 
1067 static struct module_attribute modinfo_refcnt =
1068         __ATTR(refcnt, 0444, show_refcnt, NULL);
1069 
1070 void __module_get(struct module *module)
1071 {
1072         if (module) {
1073                 preempt_disable();
1074                 atomic_inc(&module->refcnt);
1075                 trace_module_get(module, _RET_IP_);
1076                 preempt_enable();
1077         }
1078 }
1079 EXPORT_SYMBOL(__module_get);
1080 
1081 bool try_module_get(struct module *module)
1082 {
1083         bool ret = true;
1084 
1085         if (module) {
1086                 preempt_disable();
1087                 /* Note: here, we can fail to get a reference */
1088                 if (likely(module_is_live(module) &&
1089                            atomic_inc_not_zero(&module->refcnt) != 0))
1090                         trace_module_get(module, _RET_IP_);
1091                 else
1092                         ret = false;
1093 
1094                 preempt_enable();
1095         }
1096         return ret;
1097 }
1098 EXPORT_SYMBOL(try_module_get);
1099 
1100 void module_put(struct module *module)
1101 {
1102         int ret;
1103 
1104         if (module) {
1105                 preempt_disable();
1106                 ret = atomic_dec_if_positive(&module->refcnt);
1107                 WARN_ON(ret < 0);       /* Failed to put refcount */
1108                 trace_module_put(module, _RET_IP_);
1109                 preempt_enable();
1110         }
1111 }
1112 EXPORT_SYMBOL(module_put);
1113 
1114 #else /* !CONFIG_MODULE_UNLOAD */
1115 static inline void print_unload_info(struct seq_file *m, struct module *mod)
1116 {
1117         /* We don't know the usage count, or what modules are using. */
1118         seq_puts(m, " - -");
1119 }
1120 
1121 static inline void module_unload_free(struct module *mod)
1122 {
1123 }
1124 
1125 int ref_module(struct module *a, struct module *b)
1126 {
1127         return strong_try_module_get(b);
1128 }
1129 EXPORT_SYMBOL_GPL(ref_module);
1130 
1131 static inline int module_unload_init(struct module *mod)
1132 {
1133         return 0;
1134 }
1135 #endif /* CONFIG_MODULE_UNLOAD */
1136 
1137 static size_t module_flags_taint(struct module *mod, char *buf)
1138 {
1139         size_t l = 0;
1140 
1141         if (mod->taints & (1 << TAINT_PROPRIETARY_MODULE))
1142                 buf[l++] = 'P';
1143         if (mod->taints & (1 << TAINT_OOT_MODULE))
1144                 buf[l++] = 'O';
1145         if (mod->taints & (1 << TAINT_FORCED_MODULE))
1146                 buf[l++] = 'F';
1147         if (mod->taints & (1 << TAINT_CRAP))
1148                 buf[l++] = 'C';
1149         if (mod->taints & (1 << TAINT_UNSIGNED_MODULE))
1150                 buf[l++] = 'E';
1151         /*
1152          * TAINT_FORCED_RMMOD: could be added.
1153          * TAINT_CPU_OUT_OF_SPEC, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
1154          * apply to modules.
1155          */
1156         return l;
1157 }
1158 
1159 static ssize_t show_initstate(struct module_attribute *mattr,
1160                               struct module_kobject *mk, char *buffer)
1161 {
1162         const char *state = "unknown";
1163 
1164         switch (mk->mod->state) {
1165         case MODULE_STATE_LIVE:
1166                 state = "live";
1167                 break;
1168         case MODULE_STATE_COMING:
1169                 state = "coming";
1170                 break;
1171         case MODULE_STATE_GOING:
1172                 state = "going";
1173                 break;
1174         default:
1175                 BUG();
1176         }
1177         return sprintf(buffer, "%s\n", state);
1178 }
1179 
1180 static struct module_attribute modinfo_initstate =
1181         __ATTR(initstate, 0444, show_initstate, NULL);
1182 
1183 static ssize_t store_uevent(struct module_attribute *mattr,
1184                             struct module_kobject *mk,
1185                             const char *buffer, size_t count)
1186 {
1187         enum kobject_action action;
1188 
1189         if (kobject_action_type(buffer, count, &action) == 0)
1190                 kobject_uevent(&mk->kobj, action);
1191         return count;
1192 }
1193 
1194 struct module_attribute module_uevent =
1195         __ATTR(uevent, 0200, NULL, store_uevent);
1196 
1197 static ssize_t show_coresize(struct module_attribute *mattr,
1198                              struct module_kobject *mk, char *buffer)
1199 {
1200         return sprintf(buffer, "%u\n", mk->mod->core_layout.size);
1201 }
1202 
1203 static struct module_attribute modinfo_coresize =
1204         __ATTR(coresize, 0444, show_coresize, NULL);
1205 
1206 static ssize_t show_initsize(struct module_attribute *mattr,
1207                              struct module_kobject *mk, char *buffer)
1208 {
1209         return sprintf(buffer, "%u\n", mk->mod->init_layout.size);
1210 }
1211 
1212 static struct module_attribute modinfo_initsize =
1213         __ATTR(initsize, 0444, show_initsize, NULL);
1214 
1215 static ssize_t show_taint(struct module_attribute *mattr,
1216                           struct module_kobject *mk, char *buffer)
1217 {
1218         size_t l;
1219 
1220         l = module_flags_taint(mk->mod, buffer);
1221         buffer[l++] = '\n';
1222         return l;
1223 }
1224 
1225 static struct module_attribute modinfo_taint =
1226         __ATTR(taint, 0444, show_taint, NULL);
1227 
1228 static struct module_attribute *modinfo_attrs[] = {
1229         &module_uevent,
1230         &modinfo_version,
1231         &modinfo_srcversion,
1232         &modinfo_initstate,
1233         &modinfo_coresize,
1234         &modinfo_initsize,
1235         &modinfo_taint,
1236 #ifdef CONFIG_MODULE_UNLOAD
1237         &modinfo_refcnt,
1238 #endif
1239         NULL,
1240 };
1241 
1242 static const char vermagic[] = VERMAGIC_STRING;
1243 
1244 static int try_to_force_load(struct module *mod, const char *reason)
1245 {
1246 #ifdef CONFIG_MODULE_FORCE_LOAD
1247         if (!test_taint(TAINT_FORCED_MODULE))
1248                 pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
1249         add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1250         return 0;
1251 #else
1252         return -ENOEXEC;
1253 #endif
1254 }
1255 
1256 #ifdef CONFIG_MODVERSIONS
1257 /* If the arch applies (non-zero) relocations to kernel kcrctab, unapply it. */
1258 static unsigned long maybe_relocated(unsigned long crc,
1259                                      const struct module *crc_owner)
1260 {
1261 #ifdef ARCH_RELOCATES_KCRCTAB
1262         if (crc_owner == NULL)
1263                 return crc - (unsigned long)reloc_start;
1264 #endif
1265         return crc;
1266 }
1267 
1268 static int check_version(Elf_Shdr *sechdrs,
1269                          unsigned int versindex,
1270                          const char *symname,
1271                          struct module *mod,
1272                          const unsigned long *crc,
1273                          const struct module *crc_owner)
1274 {
1275         unsigned int i, num_versions;
1276         struct modversion_info *versions;
1277 
1278         /* Exporting module didn't supply crcs?  OK, we're already tainted. */
1279         if (!crc)
1280                 return 1;
1281 
1282         /* No versions at all?  modprobe --force does this. */
1283         if (versindex == 0)
1284                 return try_to_force_load(mod, symname) == 0;
1285 
1286         versions = (void *) sechdrs[versindex].sh_addr;
1287         num_versions = sechdrs[versindex].sh_size
1288                 / sizeof(struct modversion_info);
1289 
1290         for (i = 0; i < num_versions; i++) {
1291                 if (strcmp(versions[i].name, symname) != 0)
1292                         continue;
1293 
1294                 if (versions[i].crc == maybe_relocated(*crc, crc_owner))
1295                         return 1;
1296                 pr_debug("Found checksum %lX vs module %lX\n",
1297                        maybe_relocated(*crc, crc_owner), versions[i].crc);
1298                 goto bad_version;
1299         }
1300 
1301         pr_warn("%s: no symbol version for %s\n", mod->name, symname);
1302         return 0;
1303 
1304 bad_version:
1305         pr_warn("%s: disagrees about version of symbol %s\n",
1306                mod->name, symname);
1307         return 0;
1308 }
1309 
1310 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1311                                           unsigned int versindex,
1312                                           struct module *mod)
1313 {
1314         const unsigned long *crc;
1315 
1316         /*
1317          * Since this should be found in kernel (which can't be removed), no
1318          * locking is necessary -- use preempt_disable() to placate lockdep.
1319          */
1320         preempt_disable();
1321         if (!find_symbol(VMLINUX_SYMBOL_STR(module_layout), NULL,
1322                          &crc, true, false)) {
1323                 preempt_enable();
1324                 BUG();
1325         }
1326         preempt_enable();
1327         return check_version(sechdrs, versindex,
1328                              VMLINUX_SYMBOL_STR(module_layout), mod, crc,
1329                              NULL);
1330 }
1331 
1332 /* First part is kernel version, which we ignore if module has crcs. */
1333 static inline int same_magic(const char *amagic, const char *bmagic,
1334                              bool has_crcs)
1335 {
1336         if (has_crcs) {
1337                 amagic += strcspn(amagic, " ");
1338                 bmagic += strcspn(bmagic, " ");
1339         }
1340         return strcmp(amagic, bmagic) == 0;
1341 }
1342 #else
1343 static inline int check_version(Elf_Shdr *sechdrs,
1344                                 unsigned int versindex,
1345                                 const char *symname,
1346                                 struct module *mod,
1347                                 const unsigned long *crc,
1348                                 const struct module *crc_owner)
1349 {
1350         return 1;
1351 }
1352 
1353 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1354                                           unsigned int versindex,
1355                                           struct module *mod)
1356 {
1357         return 1;
1358 }
1359 
1360 static inline int same_magic(const char *amagic, const char *bmagic,
1361                              bool has_crcs)
1362 {
1363         return strcmp(amagic, bmagic) == 0;
1364 }
1365 #endif /* CONFIG_MODVERSIONS */
1366 
1367 /* Resolve a symbol for this module.  I.e. if we find one, record usage. */
1368 static const struct kernel_symbol *resolve_symbol(struct module *mod,
1369                                                   const struct load_info *info,
1370                                                   const char *name,
1371                                                   char ownername[])
1372 {
1373         struct module *owner;
1374         const struct kernel_symbol *sym;
1375         const unsigned long *crc;
1376         int err;
1377 
1378         /*
1379          * The module_mutex should not be a heavily contended lock;
1380          * if we get the occasional sleep here, we'll go an extra iteration
1381          * in the wait_event_interruptible(), which is harmless.
1382          */
1383         sched_annotate_sleep();
1384         mutex_lock(&module_mutex);
1385         sym = find_symbol(name, &owner, &crc,
1386                           !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1387         if (!sym)
1388                 goto unlock;
1389 
1390         if (!check_version(info->sechdrs, info->index.vers, name, mod, crc,
1391                            owner)) {
1392                 sym = ERR_PTR(-EINVAL);
1393                 goto getname;
1394         }
1395 
1396         err = ref_module(mod, owner);
1397         if (err) {
1398                 sym = ERR_PTR(err);
1399                 goto getname;
1400         }
1401 
1402 getname:
1403         /* We must make copy under the lock if we failed to get ref. */
1404         strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
1405 unlock:
1406         mutex_unlock(&module_mutex);
1407         return sym;
1408 }
1409 
1410 static const struct kernel_symbol *
1411 resolve_symbol_wait(struct module *mod,
1412                     const struct load_info *info,
1413                     const char *name)
1414 {
1415         const struct kernel_symbol *ksym;
1416         char owner[MODULE_NAME_LEN];
1417 
1418         if (wait_event_interruptible_timeout(module_wq,
1419                         !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1420                         || PTR_ERR(ksym) != -EBUSY,
1421                                              30 * HZ) <= 0) {
1422                 pr_warn("%s: gave up waiting for init of module %s.\n",
1423                         mod->name, owner);
1424         }
1425         return ksym;
1426 }
1427 
1428 /*
1429  * /sys/module/foo/sections stuff
1430  * J. Corbet <corbet@lwn.net>
1431  */
1432 #ifdef CONFIG_SYSFS
1433 
1434 #ifdef CONFIG_KALLSYMS
1435 static inline bool sect_empty(const Elf_Shdr *sect)
1436 {
1437         return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1438 }
1439 
1440 struct module_sect_attr {
1441         struct module_attribute mattr;
1442         char *name;
1443         unsigned long address;
1444 };
1445 
1446 struct module_sect_attrs {
1447         struct attribute_group grp;
1448         unsigned int nsections;
1449         struct module_sect_attr attrs[0];
1450 };
1451 
1452 static ssize_t module_sect_show(struct module_attribute *mattr,
1453                                 struct module_kobject *mk, char *buf)
1454 {
1455         struct module_sect_attr *sattr =
1456                 container_of(mattr, struct module_sect_attr, mattr);
1457         return sprintf(buf, "0x%pK\n", (void *)sattr->address);
1458 }
1459 
1460 static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1461 {
1462         unsigned int section;
1463 
1464         for (section = 0; section < sect_attrs->nsections; section++)
1465                 kfree(sect_attrs->attrs[section].name);
1466         kfree(sect_attrs);
1467 }
1468 
1469 static void add_sect_attrs(struct module *mod, const struct load_info *info)
1470 {
1471         unsigned int nloaded = 0, i, size[2];
1472         struct module_sect_attrs *sect_attrs;
1473         struct module_sect_attr *sattr;
1474         struct attribute **gattr;
1475 
1476         /* Count loaded sections and allocate structures */
1477         for (i = 0; i < info->hdr->e_shnum; i++)
1478                 if (!sect_empty(&info->sechdrs[i]))
1479                         nloaded++;
1480         size[0] = ALIGN(sizeof(*sect_attrs)
1481                         + nloaded * sizeof(sect_attrs->attrs[0]),
1482                         sizeof(sect_attrs->grp.attrs[0]));
1483         size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1484         sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1485         if (sect_attrs == NULL)
1486                 return;
1487 
1488         /* Setup section attributes. */
1489         sect_attrs->grp.name = "sections";
1490         sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1491 
1492         sect_attrs->nsections = 0;
1493         sattr = &sect_attrs->attrs[0];
1494         gattr = &sect_attrs->grp.attrs[0];
1495         for (i = 0; i < info->hdr->e_shnum; i++) {
1496                 Elf_Shdr *sec = &info->sechdrs[i];
1497                 if (sect_empty(sec))
1498                         continue;
1499                 sattr->address = sec->sh_addr;
1500                 sattr->name = kstrdup(info->secstrings + sec->sh_name,
1501                                         GFP_KERNEL);
1502                 if (sattr->name == NULL)
1503                         goto out;
1504                 sect_attrs->nsections++;
1505                 sysfs_attr_init(&sattr->mattr.attr);
1506                 sattr->mattr.show = module_sect_show;
1507                 sattr->mattr.store = NULL;
1508                 sattr->mattr.attr.name = sattr->name;
1509                 sattr->mattr.attr.mode = S_IRUGO;
1510                 *(gattr++) = &(sattr++)->mattr.attr;
1511         }
1512         *gattr = NULL;
1513 
1514         if (sysfs_create_group(&mod->mkobj.kobj, &sect_attrs->grp))
1515                 goto out;
1516 
1517         mod->sect_attrs = sect_attrs;
1518         return;
1519   out:
1520         free_sect_attrs(sect_attrs);
1521 }
1522 
1523 static void remove_sect_attrs(struct module *mod)
1524 {
1525         if (mod->sect_attrs) {
1526                 sysfs_remove_group(&mod->mkobj.kobj,
1527                                    &mod->sect_attrs->grp);
1528                 /* We are positive that no one is using any sect attrs
1529                  * at this point.  Deallocate immediately. */
1530                 free_sect_attrs(mod->sect_attrs);
1531                 mod->sect_attrs = NULL;
1532         }
1533 }
1534 
1535 /*
1536  * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1537  */
1538 
1539 struct module_notes_attrs {
1540         struct kobject *dir;
1541         unsigned int notes;
1542         struct bin_attribute attrs[0];
1543 };
1544 
1545 static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1546                                  struct bin_attribute *bin_attr,
1547                                  char *buf, loff_t pos, size_t count)
1548 {
1549         /*
1550          * The caller checked the pos and count against our size.
1551          */
1552         memcpy(buf, bin_attr->private + pos, count);
1553         return count;
1554 }
1555 
1556 static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1557                              unsigned int i)
1558 {
1559         if (notes_attrs->dir) {
1560                 while (i-- > 0)
1561                         sysfs_remove_bin_file(notes_attrs->dir,
1562                                               &notes_attrs->attrs[i]);
1563                 kobject_put(notes_attrs->dir);
1564         }
1565         kfree(notes_attrs);
1566 }
1567 
1568 static void add_notes_attrs(struct module *mod, const struct load_info *info)
1569 {
1570         unsigned int notes, loaded, i;
1571         struct module_notes_attrs *notes_attrs;
1572         struct bin_attribute *nattr;
1573 
1574         /* failed to create section attributes, so can't create notes */
1575         if (!mod->sect_attrs)
1576                 return;
1577 
1578         /* Count notes sections and allocate structures.  */
1579         notes = 0;
1580         for (i = 0; i < info->hdr->e_shnum; i++)
1581                 if (!sect_empty(&info->sechdrs[i]) &&
1582                     (info->sechdrs[i].sh_type == SHT_NOTE))
1583                         ++notes;
1584 
1585         if (notes == 0)
1586                 return;
1587 
1588         notes_attrs = kzalloc(sizeof(*notes_attrs)
1589                               + notes * sizeof(notes_attrs->attrs[0]),
1590                               GFP_KERNEL);
1591         if (notes_attrs == NULL)
1592                 return;
1593 
1594         notes_attrs->notes = notes;
1595         nattr = &notes_attrs->attrs[0];
1596         for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1597                 if (sect_empty(&info->sechdrs[i]))
1598                         continue;
1599                 if (info->sechdrs[i].sh_type == SHT_NOTE) {
1600                         sysfs_bin_attr_init(nattr);
1601                         nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
1602                         nattr->attr.mode = S_IRUGO;
1603                         nattr->size = info->sechdrs[i].sh_size;
1604                         nattr->private = (void *) info->sechdrs[i].sh_addr;
1605                         nattr->read = module_notes_read;
1606                         ++nattr;
1607                 }
1608                 ++loaded;
1609         }
1610 
1611         notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1612         if (!notes_attrs->dir)
1613                 goto out;
1614 
1615         for (i = 0; i < notes; ++i)
1616                 if (sysfs_create_bin_file(notes_attrs->dir,
1617                                           &notes_attrs->attrs[i]))
1618                         goto out;
1619 
1620         mod->notes_attrs = notes_attrs;
1621         return;
1622 
1623   out:
1624         free_notes_attrs(notes_attrs, i);
1625 }
1626 
1627 static void remove_notes_attrs(struct module *mod)
1628 {
1629         if (mod->notes_attrs)
1630                 free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1631 }
1632 
1633 #else
1634 
1635 static inline void add_sect_attrs(struct module *mod,
1636                                   const struct load_info *info)
1637 {
1638 }
1639 
1640 static inline void remove_sect_attrs(struct module *mod)
1641 {
1642 }
1643 
1644 static inline void add_notes_attrs(struct module *mod,
1645                                    const struct load_info *info)
1646 {
1647 }
1648 
1649 static inline void remove_notes_attrs(struct module *mod)
1650 {
1651 }
1652 #endif /* CONFIG_KALLSYMS */
1653 
1654 static void add_usage_links(struct module *mod)
1655 {
1656 #ifdef CONFIG_MODULE_UNLOAD
1657         struct module_use *use;
1658         int nowarn;
1659 
1660         mutex_lock(&module_mutex);
1661         list_for_each_entry(use, &mod->target_list, target_list) {
1662                 nowarn = sysfs_create_link(use->target->holders_dir,
1663                                            &mod->mkobj.kobj, mod->name);
1664         }
1665         mutex_unlock(&module_mutex);
1666 #endif
1667 }
1668 
1669 static void del_usage_links(struct module *mod)
1670 {
1671 #ifdef CONFIG_MODULE_UNLOAD
1672         struct module_use *use;
1673 
1674         mutex_lock(&module_mutex);
1675         list_for_each_entry(use, &mod->target_list, target_list)
1676                 sysfs_remove_link(use->target->holders_dir, mod->name);
1677         mutex_unlock(&module_mutex);
1678 #endif
1679 }
1680 
1681 static int module_add_modinfo_attrs(struct module *mod)
1682 {
1683         struct module_attribute *attr;
1684         struct module_attribute *temp_attr;
1685         int error = 0;
1686         int i;
1687 
1688         mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1689                                         (ARRAY_SIZE(modinfo_attrs) + 1)),
1690                                         GFP_KERNEL);
1691         if (!mod->modinfo_attrs)
1692                 return -ENOMEM;
1693 
1694         temp_attr = mod->modinfo_attrs;
1695         for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
1696                 if (!attr->test ||
1697                     (attr->test && attr->test(mod))) {
1698                         memcpy(temp_attr, attr, sizeof(*temp_attr));
1699                         sysfs_attr_init(&temp_attr->attr);
1700                         error = sysfs_create_file(&mod->mkobj.kobj,
1701                                         &temp_attr->attr);
1702                         ++temp_attr;
1703                 }
1704         }
1705         return error;
1706 }
1707 
1708 static void module_remove_modinfo_attrs(struct module *mod)
1709 {
1710         struct module_attribute *attr;
1711         int i;
1712 
1713         for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1714                 /* pick a field to test for end of list */
1715                 if (!attr->attr.name)
1716                         break;
1717                 sysfs_remove_file(&mod->mkobj.kobj, &attr->attr);
1718                 if (attr->free)
1719                         attr->free(mod);
1720         }
1721         kfree(mod->modinfo_attrs);
1722 }
1723 
1724 static void mod_kobject_put(struct module *mod)
1725 {
1726         DECLARE_COMPLETION_ONSTACK(c);
1727         mod->mkobj.kobj_completion = &c;
1728         kobject_put(&mod->mkobj.kobj);
1729         wait_for_completion(&c);
1730 }
1731 
1732 static int mod_sysfs_init(struct module *mod)
1733 {
1734         int err;
1735         struct kobject *kobj;
1736 
1737         if (!module_sysfs_initialized) {
1738                 pr_err("%s: module sysfs not initialized\n", mod->name);
1739                 err = -EINVAL;
1740                 goto out;
1741         }
1742 
1743         kobj = kset_find_obj(module_kset, mod->name);
1744         if (kobj) {
1745                 pr_err("%s: module is already loaded\n", mod->name);
1746                 kobject_put(kobj);
1747                 err = -EINVAL;
1748                 goto out;
1749         }
1750 
1751         mod->mkobj.mod = mod;
1752 
1753         memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1754         mod->mkobj.kobj.kset = module_kset;
1755         err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1756                                    "%s", mod->name);
1757         if (err)
1758                 mod_kobject_put(mod);
1759 
1760         /* delay uevent until full sysfs population */
1761 out:
1762         return err;
1763 }
1764 
1765 static int mod_sysfs_setup(struct module *mod,
1766                            const struct load_info *info,
1767                            struct kernel_param *kparam,
1768                            unsigned int num_params)
1769 {
1770         int err;
1771 
1772         err = mod_sysfs_init(mod);
1773         if (err)
1774                 goto out;
1775 
1776         mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1777         if (!mod->holders_dir) {
1778                 err = -ENOMEM;
1779                 goto out_unreg;
1780         }
1781 
1782         err = module_param_sysfs_setup(mod, kparam, num_params);
1783         if (err)
1784                 goto out_unreg_holders;
1785 
1786         err = module_add_modinfo_attrs(mod);
1787         if (err)
1788                 goto out_unreg_param;
1789 
1790         add_usage_links(mod);
1791         add_sect_attrs(mod, info);
1792         add_notes_attrs(mod, info);
1793 
1794         kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1795         return 0;
1796 
1797 out_unreg_param:
1798         module_param_sysfs_remove(mod);
1799 out_unreg_holders:
1800         kobject_put(mod->holders_dir);
1801 out_unreg:
1802         mod_kobject_put(mod);
1803 out:
1804         return err;
1805 }
1806 
1807 static void mod_sysfs_fini(struct module *mod)
1808 {
1809         remove_notes_attrs(mod);
1810         remove_sect_attrs(mod);
1811         mod_kobject_put(mod);
1812 }
1813 
1814 static void init_param_lock(struct module *mod)
1815 {
1816         mutex_init(&mod->param_lock);
1817 }
1818 #else /* !CONFIG_SYSFS */
1819 
1820 static int mod_sysfs_setup(struct module *mod,
1821                            const struct load_info *info,
1822                            struct kernel_param *kparam,
1823                            unsigned int num_params)
1824 {
1825         return 0;
1826 }
1827 
1828 static void mod_sysfs_fini(struct module *mod)
1829 {
1830 }
1831 
1832 static void module_remove_modinfo_attrs(struct module *mod)
1833 {
1834 }
1835 
1836 static void del_usage_links(struct module *mod)
1837 {
1838 }
1839 
1840 static void init_param_lock(struct module *mod)
1841 {
1842 }
1843 #endif /* CONFIG_SYSFS */
1844 
1845 static void mod_sysfs_teardown(struct module *mod)
1846 {
1847         del_usage_links(mod);
1848         module_remove_modinfo_attrs(mod);
1849         module_param_sysfs_remove(mod);
1850         kobject_put(mod->mkobj.drivers_dir);
1851         kobject_put(mod->holders_dir);
1852         mod_sysfs_fini(mod);
1853 }
1854 
1855 #ifdef CONFIG_DEBUG_SET_MODULE_RONX
1856 /*
1857  * LKM RO/NX protection: protect module's text/ro-data
1858  * from modification and any data from execution.
1859  *
1860  * General layout of module is:
1861  *          [text] [read-only-data] [writable data]
1862  * text_size -----^                ^               ^
1863  * ro_size ------------------------|               |
1864  * size -------------------------------------------|
1865  *
1866  * These values are always page-aligned (as is base)
1867  */
1868 static void frob_text(const struct module_layout *layout,
1869                       int (*set_memory)(unsigned long start, int num_pages))
1870 {
1871         BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1872         BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1873         set_memory((unsigned long)layout->base,
1874                    layout->text_size >> PAGE_SHIFT);
1875 }
1876 
1877 static void frob_rodata(const struct module_layout *layout,
1878                         int (*set_memory)(unsigned long start, int num_pages))
1879 {
1880         BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1881         BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1882         BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
1883         set_memory((unsigned long)layout->base + layout->text_size,
1884                    (layout->ro_size - layout->text_size) >> PAGE_SHIFT);
1885 }
1886 
1887 static void frob_writable_data(const struct module_layout *layout,
1888                                int (*set_memory)(unsigned long start, int num_pages))
1889 {
1890         BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1891         BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
1892         BUG_ON((unsigned long)layout->size & (PAGE_SIZE-1));
1893         set_memory((unsigned long)layout->base + layout->ro_size,
1894                    (layout->size - layout->ro_size) >> PAGE_SHIFT);
1895 }
1896 
1897 /* livepatching wants to disable read-only so it can frob module. */
1898 void module_disable_ro(const struct module *mod)
1899 {
1900         frob_text(&mod->core_layout, set_memory_rw);
1901         frob_rodata(&mod->core_layout, set_memory_rw);
1902         frob_text(&mod->init_layout, set_memory_rw);
1903         frob_rodata(&mod->init_layout, set_memory_rw);
1904 }
1905 
1906 void module_enable_ro(const struct module *mod)
1907 {
1908         frob_text(&mod->core_layout, set_memory_ro);
1909         frob_rodata(&mod->core_layout, set_memory_ro);
1910         frob_text(&mod->init_layout, set_memory_ro);
1911         frob_rodata(&mod->init_layout, set_memory_ro);
1912 }
1913 
1914 static void module_enable_nx(const struct module *mod)
1915 {
1916         frob_rodata(&mod->core_layout, set_memory_nx);
1917         frob_writable_data(&mod->core_layout, set_memory_nx);
1918         frob_rodata(&mod->init_layout, set_memory_nx);
1919         frob_writable_data(&mod->init_layout, set_memory_nx);
1920 }
1921 
1922 static void module_disable_nx(const struct module *mod)
1923 {
1924         frob_rodata(&mod->core_layout, set_memory_x);
1925         frob_writable_data(&mod->core_layout, set_memory_x);
1926         frob_rodata(&mod->init_layout, set_memory_x);
1927         frob_writable_data(&mod->init_layout, set_memory_x);
1928 }
1929 
1930 /* Iterate through all modules and set each module's text as RW */
1931 void set_all_modules_text_rw(void)
1932 {
1933         struct module *mod;
1934 
1935         mutex_lock(&module_mutex);
1936         list_for_each_entry_rcu(mod, &modules, list) {
1937                 if (mod->state == MODULE_STATE_UNFORMED)
1938                         continue;
1939 
1940                 frob_text(&mod->core_layout, set_memory_rw);
1941                 frob_text(&mod->init_layout, set_memory_rw);
1942         }
1943         mutex_unlock(&module_mutex);
1944 }
1945 
1946 /* Iterate through all modules and set each module's text as RO */
1947 void set_all_modules_text_ro(void)
1948 {
1949         struct module *mod;
1950 
1951         mutex_lock(&module_mutex);
1952         list_for_each_entry_rcu(mod, &modules, list) {
1953                 if (mod->state == MODULE_STATE_UNFORMED)
1954                         continue;
1955 
1956                 frob_text(&mod->core_layout, set_memory_ro);
1957                 frob_text(&mod->init_layout, set_memory_ro);
1958         }
1959         mutex_unlock(&module_mutex);
1960 }
1961 
1962 static void disable_ro_nx(const struct module_layout *layout)
1963 {
1964         frob_text(layout, set_memory_rw);
1965         frob_rodata(layout, set_memory_rw);
1966         frob_rodata(layout, set_memory_x);
1967         frob_writable_data(layout, set_memory_x);
1968 }
1969 
1970 #else
1971 static void disable_ro_nx(const struct module_layout *layout) { }
1972 static void module_enable_nx(const struct module *mod) { }
1973 static void module_disable_nx(const struct module *mod) { }
1974 #endif
1975 
1976 #ifdef CONFIG_LIVEPATCH
1977 /*
1978  * Persist Elf information about a module. Copy the Elf header,
1979  * section header table, section string table, and symtab section
1980  * index from info to mod->klp_info.
1981  */
1982 static int copy_module_elf(struct module *mod, struct load_info *info)
1983 {
1984         unsigned int size, symndx;
1985         int ret;
1986 
1987         size = sizeof(*mod->klp_info);
1988         mod->klp_info = kmalloc(size, GFP_KERNEL);
1989         if (mod->klp_info == NULL)
1990                 return -ENOMEM;
1991 
1992         /* Elf header */
1993         size = sizeof(mod->klp_info->hdr);
1994         memcpy(&mod->klp_info->hdr, info->hdr, size);
1995 
1996         /* Elf section header table */
1997         size = sizeof(*info->sechdrs) * info->hdr->e_shnum;
1998         mod->klp_info->sechdrs = kmalloc(size, GFP_KERNEL);
1999         if (mod->klp_info->sechdrs == NULL) {
2000                 ret = -ENOMEM;
2001                 goto free_info;
2002         }
2003         memcpy(mod->klp_info->sechdrs, info->sechdrs, size);
2004 
2005         /* Elf section name string table */
2006         size = info->sechdrs[info->hdr->e_shstrndx].sh_size;
2007         mod->klp_info->secstrings = kmalloc(size, GFP_KERNEL);
2008         if (mod->klp_info->secstrings == NULL) {
2009                 ret = -ENOMEM;
2010                 goto free_sechdrs;
2011         }
2012         memcpy(mod->klp_info->secstrings, info->secstrings, size);
2013 
2014         /* Elf symbol section index */
2015         symndx = info->index.sym;
2016         mod->klp_info->symndx = symndx;
2017 
2018         /*
2019          * For livepatch modules, core_kallsyms.symtab is a complete
2020          * copy of the original symbol table. Adjust sh_addr to point
2021          * to core_kallsyms.symtab since the copy of the symtab in module
2022          * init memory is freed at the end of do_init_module().
2023          */
2024         mod->klp_info->sechdrs[symndx].sh_addr = \
2025                 (unsigned long) mod->core_kallsyms.symtab;
2026 
2027         return 0;
2028 
2029 free_sechdrs:
2030         kfree(mod->klp_info->sechdrs);
2031 free_info:
2032         kfree(mod->klp_info);
2033         return ret;
2034 }
2035 
2036 static void free_module_elf(struct module *mod)
2037 {
2038         kfree(mod->klp_info->sechdrs);
2039         kfree(mod->klp_info->secstrings);
2040         kfree(mod->klp_info);
2041 }
2042 #else /* !CONFIG_LIVEPATCH */
2043 static int copy_module_elf(struct module *mod, struct load_info *info)
2044 {
2045         return 0;
2046 }
2047 
2048 static void free_module_elf(struct module *mod)
2049 {
2050 }
2051 #endif /* CONFIG_LIVEPATCH */
2052 
2053 void __weak module_memfree(void *module_region)
2054 {
2055         vfree(module_region);
2056 }
2057 
2058 void __weak module_arch_cleanup(struct module *mod)
2059 {
2060 }
2061 
2062 void __weak module_arch_freeing_init(struct module *mod)
2063 {
2064 }
2065 
2066 /* Free a module, remove from lists, etc. */
2067 static void free_module(struct module *mod)
2068 {
2069         trace_module_free(mod);
2070 
2071         mod_sysfs_teardown(mod);
2072 
2073         /* We leave it in list to prevent duplicate loads, but make sure
2074          * that noone uses it while it's being deconstructed. */
2075         mutex_lock(&module_mutex);
2076         mod->state = MODULE_STATE_UNFORMED;
2077         mutex_unlock(&module_mutex);
2078 
2079         /* Remove dynamic debug info */
2080         ddebug_remove_module(mod->name);
2081 
2082         /* Arch-specific cleanup. */
2083         module_arch_cleanup(mod);
2084 
2085         /* Module unload stuff */
2086         module_unload_free(mod);
2087 
2088         /* Free any allocated parameters. */
2089         destroy_params(mod->kp, mod->num_kp);
2090 
2091         if (is_livepatch_module(mod))
2092                 free_module_elf(mod);
2093 
2094         /* Now we can delete it from the lists */
2095         mutex_lock(&module_mutex);
2096         /* Unlink carefully: kallsyms could be walking list. */
2097         list_del_rcu(&mod->list);
2098         mod_tree_remove(mod);
2099         /* Remove this module from bug list, this uses list_del_rcu */
2100         module_bug_cleanup(mod);
2101         /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
2102         synchronize_sched();
2103         mutex_unlock(&module_mutex);
2104 
2105         /* This may be empty, but that's OK */
2106         disable_ro_nx(&mod->init_layout);
2107         module_arch_freeing_init(mod);
2108         module_memfree(mod->init_layout.base);
2109         kfree(mod->args);
2110         percpu_modfree(mod);
2111 
2112         /* Free lock-classes; relies on the preceding sync_rcu(). */
2113         lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
2114 
2115         /* Finally, free the core (containing the module structure) */
2116         disable_ro_nx(&mod->core_layout);
2117         module_memfree(mod->core_layout.base);
2118 
2119 #ifdef CONFIG_MPU
2120         update_protections(current->mm);
2121 #endif
2122 }
2123 
2124 void *__symbol_get(const char *symbol)
2125 {
2126         struct module *owner;
2127         const struct kernel_symbol *sym;
2128 
2129         preempt_disable();
2130         sym = find_symbol(symbol, &owner, NULL, true, true);
2131         if (sym && strong_try_module_get(owner))
2132                 sym = NULL;
2133         preempt_enable();
2134 
2135         return sym ? (void *)sym->value : NULL;
2136 }
2137 EXPORT_SYMBOL_GPL(__symbol_get);
2138 
2139 /*
2140  * Ensure that an exported symbol [global namespace] does not already exist
2141  * in the kernel or in some other module's exported symbol table.
2142  *
2143  * You must hold the module_mutex.
2144  */
2145 static int verify_export_symbols(struct module *mod)
2146 {
2147         unsigned int i;
2148         struct module *owner;
2149         const struct kernel_symbol *s;
2150         struct {
2151                 const struct kernel_symbol *sym;
2152                 unsigned int num;
2153         } arr[] = {
2154                 { mod->syms, mod->num_syms },
2155                 { mod->gpl_syms, mod->num_gpl_syms },
2156                 { mod->gpl_future_syms, mod->num_gpl_future_syms },
2157 #ifdef CONFIG_UNUSED_SYMBOLS
2158                 { mod->unused_syms, mod->num_unused_syms },
2159                 { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
2160 #endif
2161         };
2162 
2163         for (i = 0; i < ARRAY_SIZE(arr); i++) {
2164                 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
2165                         if (find_symbol(s->name, &owner, NULL, true, false)) {
2166                                 pr_err("%s: exports duplicate symbol %s"
2167                                        " (owned by %s)\n",
2168                                        mod->name, s->name, module_name(owner));
2169                                 return -ENOEXEC;
2170                         }
2171                 }
2172         }
2173         return 0;
2174 }
2175 
2176 /* Change all symbols so that st_value encodes the pointer directly. */
2177 static int simplify_symbols(struct module *mod, const struct load_info *info)
2178 {
2179         Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2180         Elf_Sym *sym = (void *)symsec->sh_addr;
2181         unsigned long secbase;
2182         unsigned int i;
2183         int ret = 0;
2184         const struct kernel_symbol *ksym;
2185 
2186         for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
2187                 const char *name = info->strtab + sym[i].st_name;
2188 
2189                 switch (sym[i].st_shndx) {
2190                 case SHN_COMMON:
2191                         /* Ignore common symbols */
2192                         if (!strncmp(name, "__gnu_lto", 9))
2193                                 break;
2194 
2195                         /* We compiled with -fno-common.  These are not
2196                            supposed to happen.  */
2197                         pr_debug("Common symbol: %s\n", name);
2198                         pr_warn("%s: please compile with -fno-common\n",
2199                                mod->name);
2200                         ret = -ENOEXEC;
2201                         break;
2202 
2203                 case SHN_ABS:
2204                         /* Don't need to do anything */
2205                         pr_debug("Absolute symbol: 0x%08lx\n",
2206                                (long)sym[i].st_value);
2207                         break;
2208 
2209                 case SHN_LIVEPATCH:
2210                         /* Livepatch symbols are resolved by livepatch */
2211                         break;
2212 
2213                 case SHN_UNDEF:
2214                         ksym = resolve_symbol_wait(mod, info, name);
2215                         /* Ok if resolved.  */
2216                         if (ksym && !IS_ERR(ksym)) {
2217                                 sym[i].st_value = ksym->value;
2218                                 break;
2219                         }
2220 
2221                         /* Ok if weak.  */
2222                         if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
2223                                 break;
2224 
2225                         pr_warn("%s: Unknown symbol %s (err %li)\n",
2226                                 mod->name, name, PTR_ERR(ksym));
2227                         ret = PTR_ERR(ksym) ?: -ENOENT;
2228                         break;
2229 
2230                 default:
2231                         /* Divert to percpu allocation if a percpu var. */
2232                         if (sym[i].st_shndx == info->index.pcpu)
2233                                 secbase = (unsigned long)mod_percpu(mod);
2234                         else
2235                                 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
2236                         sym[i].st_value += secbase;
2237                         break;
2238                 }
2239         }
2240 
2241         return ret;
2242 }
2243 
2244 static int apply_relocations(struct module *mod, const struct load_info *info)
2245 {
2246         unsigned int i;
2247         int err = 0;
2248 
2249         /* Now do relocations. */
2250         for (i = 1; i < info->hdr->e_shnum; i++) {
2251                 unsigned int infosec = info->sechdrs[i].sh_info;
2252 
2253                 /* Not a valid relocation section? */
2254                 if (infosec >= info->hdr->e_shnum)
2255                         continue;
2256 
2257                 /* Don't bother with non-allocated sections */
2258                 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
2259                         continue;
2260 
2261                 /* Livepatch relocation sections are applied by livepatch */
2262                 if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH)
2263                         continue;
2264 
2265                 if (info->sechdrs[i].sh_type == SHT_REL)
2266                         err = apply_relocate(info->sechdrs, info->strtab,
2267                                              info->index.sym, i, mod);
2268                 else if (info->sechdrs[i].sh_type == SHT_RELA)
2269                         err = apply_relocate_add(info->sechdrs, info->strtab,
2270                                                  info->index.sym, i, mod);
2271                 if (err < 0)
2272                         break;
2273         }
2274         return err;
2275 }
2276 
2277 /* Additional bytes needed by arch in front of individual sections */
2278 unsigned int __weak arch_mod_section_prepend(struct module *mod,
2279                                              unsigned int section)
2280 {
2281         /* default implementation just returns zero */
2282         return 0;
2283 }
2284 
2285 /* Update size with this section: return offset. */
2286 static long get_offset(struct module *mod, unsigned int *size,
2287                        Elf_Shdr *sechdr, unsigned int section)
2288 {
2289         long ret;
2290 
2291         *size += arch_mod_section_prepend(mod, section);
2292         ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
2293         *size = ret + sechdr->sh_size;
2294         return ret;
2295 }
2296 
2297 /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2298    might -- code, read-only data, read-write data, small data.  Tally
2299    sizes, and place the offsets into sh_entsize fields: high bit means it
2300    belongs in init. */
2301 static void layout_sections(struct module *mod, struct load_info *info)
2302 {
2303         static unsigned long const masks[][2] = {
2304                 /* NOTE: all executable code must be the first section
2305                  * in this array; otherwise modify the text_size
2306                  * finder in the two loops below */
2307                 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
2308                 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
2309                 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
2310                 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
2311         };
2312         unsigned int m, i;
2313 
2314         for (i = 0; i < info->hdr->e_shnum; i++)
2315                 info->sechdrs[i].sh_entsize = ~0UL;
2316 
2317         pr_debug("Core section allocation order:\n");
2318         for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2319                 for (i = 0; i < info->hdr->e_shnum; ++i) {
2320                         Elf_Shdr *s = &info->sechdrs[i];
2321                         const char *sname = info->secstrings + s->sh_name;
2322 
2323                         if ((s->sh_flags & masks[m][0]) != masks[m][0]
2324                             || (s->sh_flags & masks[m][1])
2325                             || s->sh_entsize != ~0UL
2326                             || strstarts(sname, ".init"))
2327                                 continue;
2328                         s->sh_entsize = get_offset(mod, &mod->core_layout.size, s, i);
2329                         pr_debug("\t%s\n", sname);
2330                 }
2331                 switch (m) {
2332                 case 0: /* executable */
2333                         mod->core_layout.size = debug_align(mod->core_layout.size);
2334                         mod->core_layout.text_size = mod->core_layout.size;
2335                         break;
2336                 case 1: /* RO: text and ro-data */
2337                         mod->core_layout.size = debug_align(mod->core_layout.size);
2338                         mod->core_layout.ro_size = mod->core_layout.size;
2339                         break;
2340                 case 3: /* whole core */
2341                         mod->core_layout.size = debug_align(mod->core_layout.size);
2342                         break;
2343                 }
2344         }
2345 
2346         pr_debug("Init section allocation order:\n");
2347         for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2348                 for (i = 0; i < info->hdr->e_shnum; ++i) {
2349                         Elf_Shdr *s = &info->sechdrs[i];
2350                         const char *sname = info->secstrings + s->sh_name;
2351 
2352                         if ((s->sh_flags & masks[m][0]) != masks[m][0]
2353                             || (s->sh_flags & masks[m][1])
2354                             || s->sh_entsize != ~0UL
2355                             || !strstarts(sname, ".init"))
2356                                 continue;
2357                         s->sh_entsize = (get_offset(mod, &mod->init_layout.size, s, i)
2358                                          | INIT_OFFSET_MASK);
2359                         pr_debug("\t%s\n", sname);
2360                 }
2361                 switch (m) {
2362                 case 0: /* executable */
2363                         mod->init_layout.size = debug_align(mod->init_layout.size);
2364                         mod->init_layout.text_size = mod->init_layout.size;
2365                         break;
2366                 case 1: /* RO: text and ro-data */
2367                         mod->init_layout.size = debug_align(mod->init_layout.size);
2368                         mod->init_layout.ro_size = mod->init_layout.size;
2369                         break;
2370                 case 3: /* whole init */
2371                         mod->init_layout.size = debug_align(mod->init_layout.size);
2372                         break;
2373                 }
2374         }
2375 }
2376 
2377 static void set_license(struct module *mod, const char *license)
2378 {
2379         if (!license)
2380                 license = "unspecified";
2381 
2382         if (!license_is_gpl_compatible(license)) {
2383                 if (!test_taint(TAINT_PROPRIETARY_MODULE))
2384                         pr_warn("%s: module license '%s' taints kernel.\n",
2385                                 mod->name, license);
2386                 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2387                                  LOCKDEP_NOW_UNRELIABLE);
2388         }
2389 }
2390 
2391 /* Parse tag=value strings from .modinfo section */
2392 static char *next_string(char *string, unsigned long *secsize)
2393 {
2394         /* Skip non-zero chars */
2395         while (string[0]) {
2396                 string++;
2397                 if ((*secsize)-- <= 1)
2398                         return NULL;
2399         }
2400 
2401         /* Skip any zero padding. */
2402         while (!string[0]) {
2403                 string++;
2404                 if ((*secsize)-- <= 1)
2405                         return NULL;
2406         }
2407         return string;
2408 }
2409 
2410 static char *get_modinfo(struct load_info *info, const char *tag)
2411 {
2412         char *p;
2413         unsigned int taglen = strlen(tag);
2414         Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2415         unsigned long size = infosec->sh_size;
2416 
2417         for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) {
2418                 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2419                         return p + taglen + 1;
2420         }
2421         return NULL;
2422 }
2423 
2424 static void setup_modinfo(struct module *mod, struct load_info *info)
2425 {
2426         struct module_attribute *attr;
2427         int i;
2428 
2429         for (i = 0; (attr = modinfo_attrs[i]); i++) {
2430                 if (attr->setup)
2431                         attr->setup(mod, get_modinfo(info, attr->attr.name));
2432         }
2433 }
2434 
2435 static void free_modinfo(struct module *mod)
2436 {
2437         struct module_attribute *attr;
2438         int i;
2439 
2440         for (i = 0; (attr = modinfo_attrs[i]); i++) {
2441                 if (attr->free)
2442                         attr->free(mod);
2443         }
2444 }
2445 
2446 #ifdef CONFIG_KALLSYMS
2447 
2448 /* lookup symbol in given range of kernel_symbols */
2449 static const struct kernel_symbol *lookup_symbol(const char *name,
2450         const struct kernel_symbol *start,
2451         const struct kernel_symbol *stop)
2452 {
2453         return bsearch(name, start, stop - start,
2454                         sizeof(struct kernel_symbol), cmp_name);
2455 }
2456 
2457 static int is_exported(const char *name, unsigned long value,
2458                        const struct module *mod)
2459 {
2460         const struct kernel_symbol *ks;
2461         if (!mod)
2462                 ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
2463         else
2464                 ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
2465         return ks != NULL && ks->value == value;
2466 }
2467 
2468 /* As per nm */
2469 static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2470 {
2471         const Elf_Shdr *sechdrs = info->sechdrs;
2472 
2473         if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2474                 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2475                         return 'v';
2476                 else
2477                         return 'w';
2478         }
2479         if (sym->st_shndx == SHN_UNDEF)
2480                 return 'U';
2481         if (sym->st_shndx == SHN_ABS || sym->st_shndx == info->index.pcpu)
2482                 return 'a';
2483         if (sym->st_shndx >= SHN_LORESERVE)
2484                 return '?';
2485         if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2486                 return 't';
2487         if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2488             && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2489                 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2490                         return 'r';
2491                 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2492                         return 'g';
2493                 else
2494                         return 'd';
2495         }
2496         if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2497                 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2498                         return 's';
2499                 else
2500                         return 'b';
2501         }
2502         if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2503                       ".debug")) {
2504                 return 'n';
2505         }
2506         return '?';
2507 }
2508 
2509 static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2510                         unsigned int shnum, unsigned int pcpundx)
2511 {
2512         const Elf_Shdr *sec;
2513 
2514         if (src->st_shndx == SHN_UNDEF
2515             || src->st_shndx >= shnum
2516             || !src->st_name)
2517                 return false;
2518 
2519 #ifdef CONFIG_KALLSYMS_ALL
2520         if (src->st_shndx == pcpundx)
2521                 return true;
2522 #endif
2523 
2524         sec = sechdrs + src->st_shndx;
2525         if (!(sec->sh_flags & SHF_ALLOC)
2526 #ifndef CONFIG_KALLSYMS_ALL
2527             || !(sec->sh_flags & SHF_EXECINSTR)
2528 #endif
2529             || (sec->sh_entsize & INIT_OFFSET_MASK))
2530                 return false;
2531 
2532         return true;
2533 }
2534 
2535 /*
2536  * We only allocate and copy the strings needed by the parts of symtab
2537  * we keep.  This is simple, but has the effect of making multiple
2538  * copies of duplicates.  We could be more sophisticated, see
2539  * linux-kernel thread starting with
2540  * <73defb5e4bca04a6431392cc341112b1@localhost>.
2541  */
2542 static void layout_symtab(struct module *mod, struct load_info *info)
2543 {
2544         Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2545         Elf_Shdr *strsect = info->sechdrs + info->index.str;
2546         const Elf_Sym *src;
2547         unsigned int i, nsrc, ndst, strtab_size = 0;
2548 
2549         /* Put symbol section at end of init part of module. */
2550         symsect->sh_flags |= SHF_ALLOC;
2551         symsect->sh_entsize = get_offset(mod, &mod->init_layout.size, symsect,
2552                                          info->index.sym) | INIT_OFFSET_MASK;
2553         pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2554 
2555         src = (void *)info->hdr + symsect->sh_offset;
2556         nsrc = symsect->sh_size / sizeof(*src);
2557 
2558         /* Compute total space required for the core symbols' strtab. */
2559         for (ndst = i = 0; i < nsrc; i++) {
2560                 if (i == 0 || is_livepatch_module(mod) ||
2561                     is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2562                                    info->index.pcpu)) {
2563                         strtab_size += strlen(&info->strtab[src[i].st_name])+1;
2564                         ndst++;
2565                 }
2566         }
2567 
2568         /* Append room for core symbols at end of core part. */
2569         info->symoffs = ALIGN(mod->core_layout.size, symsect->sh_addralign ?: 1);
2570         info->stroffs = mod->core_layout.size = info->symoffs + ndst * sizeof(Elf_Sym);
2571         mod->core_layout.size += strtab_size;
2572         mod->core_layout.size = debug_align(mod->core_layout.size);
2573 
2574         /* Put string table section at end of init part of module. */
2575         strsect->sh_flags |= SHF_ALLOC;
2576         strsect->sh_entsize = get_offset(mod, &mod->init_layout.size, strsect,
2577                                          info->index.str) | INIT_OFFSET_MASK;
2578         pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2579 
2580         /* We'll tack temporary mod_kallsyms on the end. */
2581         mod->init_layout.size = ALIGN(mod->init_layout.size,
2582                                       __alignof__(struct mod_kallsyms));
2583         info->mod_kallsyms_init_off = mod->init_layout.size;
2584         mod->init_layout.size += sizeof(struct mod_kallsyms);
2585         mod->init_layout.size = debug_align(mod->init_layout.size);
2586 }
2587 
2588 /*
2589  * We use the full symtab and strtab which layout_symtab arranged to
2590  * be appended to the init section.  Later we switch to the cut-down
2591  * core-only ones.
2592  */
2593 static void add_kallsyms(struct module *mod, const struct load_info *info)
2594 {
2595         unsigned int i, ndst;
2596         const Elf_Sym *src;
2597         Elf_Sym *dst;
2598         char *s;
2599         Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2600 
2601         /* Set up to point into init section. */
2602         mod->kallsyms = mod->init_layout.base + info->mod_kallsyms_init_off;
2603 
2604         mod->kallsyms->symtab = (void *)symsec->sh_addr;
2605         mod->kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2606         /* Make sure we get permanent strtab: don't use info->strtab. */
2607         mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2608 
2609         /* Set types up while we still have access to sections. */
2610         for (i = 0; i < mod->kallsyms->num_symtab; i++)
2611                 mod->kallsyms->symtab[i].st_info
2612                         = elf_type(&mod->kallsyms->symtab[i], info);
2613 
2614         /* Now populate the cut down core kallsyms for after init. */
2615         mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs;
2616         mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs;
2617         src = mod->kallsyms->symtab;
2618         for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) {
2619                 if (i == 0 || is_livepatch_module(mod) ||
2620                     is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2621                                    info->index.pcpu)) {
2622                         dst[ndst] = src[i];
2623                         dst[ndst++].st_name = s - mod->core_kallsyms.strtab;
2624                         s += strlcpy(s, &mod->kallsyms->strtab[src[i].st_name],
2625                                      KSYM_NAME_LEN) + 1;
2626                 }
2627         }
2628         mod->core_kallsyms.num_symtab = ndst;
2629 }
2630 #else
2631 static inline void layout_symtab(struct module *mod, struct load_info *info)
2632 {
2633 }
2634 
2635 static void add_kallsyms(struct module *mod, const struct load_info *info)
2636 {
2637 }
2638 #endif /* CONFIG_KALLSYMS */
2639 
2640 static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num)
2641 {
2642         if (!debug)
2643                 return;
2644 #ifdef CONFIG_DYNAMIC_DEBUG
2645         if (ddebug_add_module(debug, num, debug->modname))
2646                 pr_err("dynamic debug error adding module: %s\n",
2647                         debug->modname);
2648 #endif
2649 }
2650 
2651 static void dynamic_debug_remove(struct _ddebug *debug)
2652 {
2653         if (debug)
2654                 ddebug_remove_module(debug->modname);
2655 }
2656 
2657 void * __weak module_alloc(unsigned long size)
2658 {
2659         return vmalloc_exec(size);
2660 }
2661 
2662 #ifdef CONFIG_DEBUG_KMEMLEAK
2663 static void kmemleak_load_module(const struct module *mod,
2664                                  const struct load_info *info)
2665 {
2666         unsigned int i;
2667 
2668         /* only scan the sections containing data */
2669         kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2670 
2671         for (i = 1; i < info->hdr->e_shnum; i++) {
2672                 /* Scan all writable sections that's not executable */
2673                 if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
2674                     !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
2675                     (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
2676                         continue;
2677 
2678                 kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2679                                    info->sechdrs[i].sh_size, GFP_KERNEL);
2680         }
2681 }
2682 #else
2683 static inline void kmemleak_load_module(const struct module *mod,
2684                                         const struct load_info *info)
2685 {
2686 }
2687 #endif
2688 
2689 #ifdef CONFIG_MODULE_SIG
2690 static int module_sig_check(struct load_info *info)
2691 {
2692         int err = -ENOKEY;
2693         const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
2694         const void *mod = info->hdr;
2695 
2696         if (info->len > markerlen &&
2697             memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2698                 /* We truncate the module to discard the signature */
2699                 info->len -= markerlen;
2700                 err = mod_verify_sig(mod, &info->len);
2701         }
2702 
2703         if (!err) {
2704                 info->sig_ok = true;
2705                 return 0;
2706         }
2707 
2708         /* Not having a signature is only an error if we're strict. */
2709         if (err == -ENOKEY && !sig_enforce)
2710                 err = 0;
2711 
2712         return err;
2713 }
2714 #else /* !CONFIG_MODULE_SIG */
2715 static int module_sig_check(struct load_info *info)
2716 {
2717         return 0;
2718 }
2719 #endif /* !CONFIG_MODULE_SIG */
2720 
2721 /* Sanity checks against invalid binaries, wrong arch, weird elf version. */
2722 static int elf_header_check(struct load_info *info)
2723 {
2724         if (info->len < sizeof(*(info->hdr)))
2725                 return -ENOEXEC;
2726 
2727         if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0
2728             || info->hdr->e_type != ET_REL
2729             || !elf_check_arch(info->hdr)
2730             || info->hdr->e_shentsize != sizeof(Elf_Shdr))
2731                 return -ENOEXEC;
2732 
2733         if (info->hdr->e_shoff >= info->len
2734             || (info->hdr->e_shnum * sizeof(Elf_Shdr) >
2735                 info->len - info->hdr->e_shoff))
2736                 return -ENOEXEC;
2737 
2738         return 0;
2739 }
2740 
2741 #define COPY_CHUNK_SIZE (16*PAGE_SIZE)
2742 
2743 static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len)
2744 {
2745         do {
2746                 unsigned long n = min(len, COPY_CHUNK_SIZE);
2747 
2748                 if (copy_from_user(dst, usrc, n) != 0)
2749                         return -EFAULT;
2750                 cond_resched();
2751                 dst += n;
2752                 usrc += n;
2753                 len -= n;
2754         } while (len);
2755         return 0;
2756 }
2757 
2758 #ifdef CONFIG_LIVEPATCH
2759 static int find_livepatch_modinfo(struct module *mod, struct load_info *info)
2760 {
2761         mod->klp = get_modinfo(info, "livepatch") ? true : false;
2762 
2763         return 0;
2764 }
2765 #else /* !CONFIG_LIVEPATCH */
2766 static int find_livepatch_modinfo(struct module *mod, struct load_info *info)
2767 {
2768         if (get_modinfo(info, "livepatch")) {
2769                 pr_err("%s: module is marked as livepatch module, but livepatch support is disabled",
2770                        mod->name);
2771                 return -ENOEXEC;
2772         }
2773 
2774         return 0;
2775 }
2776 #endif /* CONFIG_LIVEPATCH */
2777 
2778 /* Sets info->hdr and info->len. */
2779 static int copy_module_from_user(const void __user *umod, unsigned long len,
2780                                   struct load_info *info)
2781 {
2782         int err;
2783 
2784         info->len = len;
2785         if (info->len < sizeof(*(info->hdr)))
2786                 return -ENOEXEC;
2787 
2788         err = security_kernel_read_file(NULL, READING_MODULE);
2789         if (err)
2790                 return err;
2791 
2792         /* Suck in entire file: we'll want most of it. */
2793         info->hdr = __vmalloc(info->len,
2794                         GFP_KERNEL | __GFP_HIGHMEM | __GFP_NOWARN, PAGE_KERNEL);
2795         if (!info->hdr)
2796                 return -ENOMEM;
2797 
2798         if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) {
2799                 vfree(info->hdr);
2800                 return -EFAULT;
2801         }
2802 
2803         return 0;
2804 }
2805 
2806 static void free_copy(struct load_info *info)
2807 {
2808         vfree(info->hdr);
2809 }
2810 
2811 static int rewrite_section_headers(struct load_info *info, int flags)
2812 {
2813         unsigned int i;
2814 
2815         /* This should always be true, but let's be sure. */
2816         info->sechdrs[0].sh_addr = 0;
2817 
2818         for (i = 1; i < info->hdr->e_shnum; i++) {
2819                 Elf_Shdr *shdr = &info->sechdrs[i];
2820                 if (shdr->sh_type != SHT_NOBITS
2821                     && info->len < shdr->sh_offset + shdr->sh_size) {
2822                         pr_err("Module len %lu truncated\n", info->len);
2823                         return -ENOEXEC;
2824                 }
2825 
2826                 /* Mark all sections sh_addr with their address in the
2827                    temporary image. */
2828                 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
2829 
2830 #ifndef CONFIG_MODULE_UNLOAD
2831                 /* Don't load .exit sections */
2832                 if (strstarts(info->secstrings+shdr->sh_name, ".exit"))
2833                         shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
2834 #endif
2835         }
2836 
2837         /* Track but don't keep modinfo and version sections. */
2838         if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
2839                 info->index.vers = 0; /* Pretend no __versions section! */
2840         else
2841                 info->index.vers = find_sec(info, "__versions");
2842         info->index.info = find_sec(info, ".modinfo");
2843         info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
2844         info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2845         return 0;
2846 }
2847 
2848 /*
2849  * Set up our basic convenience variables (pointers to section headers,
2850  * search for module section index etc), and do some basic section
2851  * verification.
2852  *
2853  * Return the temporary module pointer (we'll replace it with the final
2854  * one when we move the module sections around).
2855  */
2856 static struct module *setup_load_info(struct load_info *info, int flags)
2857 {
2858         unsigned int i;
2859         int err;
2860         struct module *mod;
2861 
2862         /* Set up the convenience variables */
2863         info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2864         info->secstrings = (void *)info->hdr
2865                 + info->sechdrs[info->hdr->e_shstrndx].sh_offset;
2866 
2867         err = rewrite_section_headers(info, flags);
2868         if (err)
2869                 return ERR_PTR(err);
2870 
2871         /* Find internal symbols and strings. */
2872         for (i = 1; i < info->hdr->e_shnum; i++) {
2873                 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
2874                         info->index.sym = i;
2875                         info->index.str = info->sechdrs[i].sh_link;
2876                         info->strtab = (char *)info->hdr
2877                                 + info->sechdrs[info->index.str].sh_offset;
2878                         break;
2879                 }
2880         }
2881 
2882         info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
2883         if (!info->index.mod) {
2884                 pr_warn("No module found in object\n");
2885                 return ERR_PTR(-ENOEXEC);
2886         }
2887         /* This is temporary: point mod into copy of data. */
2888         mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2889 
2890         if (info->index.sym == 0) {
2891                 pr_warn("%s: module has no symbols (stripped?)\n", mod->name);
2892                 return ERR_PTR(-ENOEXEC);
2893         }
2894 
2895         info->index.pcpu = find_pcpusec(info);
2896 
2897         /* Check module struct version now, before we try to use module. */
2898         if (!check_modstruct_version(info->sechdrs, info->index.vers, mod))
2899                 return ERR_PTR(-ENOEXEC);
2900 
2901         return mod;
2902 }
2903 
2904 static int check_modinfo(struct module *mod, struct load_info *info, int flags)
2905 {
2906         const char *modmagic = get_modinfo(info, "vermagic");
2907         int err;
2908 
2909         if (flags & MODULE_INIT_IGNORE_VERMAGIC)
2910                 modmagic = NULL;
2911 
2912         /* This is allowed: modprobe --force will invalidate it. */
2913         if (!modmagic) {
2914                 err = try_to_force_load(mod, "bad vermagic");
2915                 if (err)
2916                         return err;
2917         } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
2918                 pr_err("%s: version magic '%s' should be '%s'\n",
2919                        mod->name, modmagic, vermagic);
2920                 return -ENOEXEC;
2921         }
2922 
2923         if (!get_modinfo(info, "intree"))
2924                 add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
2925 
2926         if (get_modinfo(info, "staging")) {
2927                 add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
2928                 pr_warn("%s: module is from the staging directory, the quality "
2929                         "is unknown, you have been warned.\n", mod->name);
2930         }
2931 
2932         err = find_livepatch_modinfo(mod, info);
2933         if (err)
2934                 return err;
2935 
2936         /* Set up license info based on the info section */
2937         set_license(mod, get_modinfo(info, "license"));
2938 
2939         return 0;
2940 }
2941 
2942 static int find_module_sections(struct module *mod, struct load_info *info)
2943 {
2944         mod->kp = section_objs(info, "__param",
2945                                sizeof(*mod->kp), &mod->num_kp);
2946         mod->syms = section_objs(info, "__ksymtab",
2947                                  sizeof(*mod->syms), &mod->num_syms);
2948         mod->crcs = section_addr(info, "__kcrctab");
2949         mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
2950                                      sizeof(*mod->gpl_syms),
2951                                      &mod->num_gpl_syms);
2952         mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
2953         mod->gpl_future_syms = section_objs(info,
2954                                             "__ksymtab_gpl_future",
2955                                             sizeof(*mod->gpl_future_syms),
2956                                             &mod->num_gpl_future_syms);
2957         mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
2958 
2959 #ifdef CONFIG_UNUSED_SYMBOLS
2960         mod->unused_syms = section_objs(info, "__ksymtab_unused",
2961                                         sizeof(*mod->unused_syms),
2962                                         &mod->num_unused_syms);
2963         mod->unused_crcs = section_addr(info, "__kcrctab_unused");
2964         mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
2965                                             sizeof(*mod->unused_gpl_syms),
2966                                             &mod->num_unused_gpl_syms);
2967         mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
2968 #endif
2969 #ifdef CONFIG_CONSTRUCTORS
2970         mod->ctors = section_objs(info, ".ctors",
2971                                   sizeof(*mod->ctors), &mod->num_ctors);
2972         if (!mod->ctors)
2973                 mod->ctors = section_objs(info, ".init_array",
2974                                 sizeof(*mod->ctors), &mod->num_ctors);
2975         else if (find_sec(info, ".init_array")) {
2976                 /*
2977                  * This shouldn't happen with same compiler and binutils
2978                  * building all parts of the module.
2979                  */
2980                 pr_warn("%s: has both .ctors and .init_array.\n",
2981                        mod->name);
2982                 return -EINVAL;
2983         }
2984 #endif
2985 
2986 #ifdef CONFIG_TRACEPOINTS
2987         mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
2988                                              sizeof(*mod->tracepoints_ptrs),
2989                                              &mod->num_tracepoints);
2990 #endif
2991 #ifdef HAVE_JUMP_LABEL
2992         mod->jump_entries = section_objs(info, "__jump_table",
2993                                         sizeof(*mod->jump_entries),
2994                                         &mod->num_jump_entries);
2995 #endif
2996 #ifdef CONFIG_EVENT_TRACING
2997         mod->trace_events = section_objs(info, "_ftrace_events",
2998                                          sizeof(*mod->trace_events),
2999                                          &mod->num_trace_events);
3000         mod->trace_enums = section_objs(info, "_ftrace_enum_map",
3001                                         sizeof(*mod->trace_enums),
3002                                         &mod->num_trace_enums);
3003 #endif
3004 #ifdef CONFIG_TRACING
3005         mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
3006                                          sizeof(*mod->trace_bprintk_fmt_start),
3007                                          &mod->num_trace_bprintk_fmt);
3008 #endif
3009 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
3010         /* sechdrs[0].sh_size is always zero */
3011         mod->ftrace_callsites = section_objs(info, "__mcount_loc",
3012                                              sizeof(*mod->ftrace_callsites),
3013                                              &mod->num_ftrace_callsites);
3014 #endif
3015 
3016         mod->extable = section_objs(info, "__ex_table",
3017                                     sizeof(*mod->extable), &mod->num_exentries);
3018 
3019         if (section_addr(info, "__obsparm"))
3020                 pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
3021 
3022         info->debug = section_objs(info, "__verbose",
3023                                    sizeof(*info->debug), &info->num_debug);
3024 
3025         return 0;
3026 }
3027 
3028 static int move_module(struct module *mod, struct load_info *info)
3029 {
3030         int i;
3031         void *ptr;
3032 
3033         /* Do the allocs. */
3034         ptr = module_alloc(mod->core_layout.size);
3035         /*
3036          * The pointer to this block is stored in the module structure
3037          * which is inside the block. Just mark it as not being a
3038          * leak.
3039          */
3040         kmemleak_not_leak(ptr);
3041         if (!ptr)
3042                 return -ENOMEM;
3043 
3044         memset(ptr, 0, mod->core_layout.size);
3045         mod->core_layout.base = ptr;
3046 
3047         if (mod->init_layout.size) {
3048                 ptr = module_alloc(mod->init_layout.size);
3049                 /*
3050                  * The pointer to this block is stored in the module structure
3051                  * which is inside the block. This block doesn't need to be
3052                  * scanned as it contains data and code that will be freed
3053                  * after the module is initialized.
3054                  */
3055                 kmemleak_ignore(ptr);
3056                 if (!ptr) {
3057                         module_memfree(mod->core_layout.base);
3058                         return -ENOMEM;
3059                 }
3060                 memset(ptr, 0, mod->init_layout.size);
3061                 mod->init_layout.base = ptr;
3062         } else
3063                 mod->init_layout.base = NULL;
3064 
3065         /* Transfer each section which specifies SHF_ALLOC */
3066         pr_debug("final section addresses:\n");
3067         for (i = 0; i < info->hdr->e_shnum; i++) {
3068                 void *dest;
3069                 Elf_Shdr *shdr = &info->sechdrs[i];
3070 
3071                 if (!(shdr->sh_flags & SHF_ALLOC))
3072                         continue;
3073 
3074                 if (shdr->sh_entsize & INIT_OFFSET_MASK)
3075                         dest = mod->init_layout.base
3076                                 + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
3077                 else
3078                         dest = mod->core_layout.base + shdr->sh_entsize;
3079 
3080                 if (shdr->sh_type != SHT_NOBITS)
3081                         memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
3082                 /* Update sh_addr to point to copy in image. */
3083                 shdr->sh_addr = (unsigned long)dest;
3084                 pr_debug("\t0x%lx %s\n",
3085                          (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
3086         }
3087 
3088         return 0;
3089 }
3090 
3091 static int check_module_license_and_versions(struct module *mod)
3092 {
3093         /*
3094          * ndiswrapper is under GPL by itself, but loads proprietary modules.
3095          * Don't use add_taint_module(), as it would prevent ndiswrapper from
3096          * using GPL-only symbols it needs.
3097          */
3098         if (strcmp(mod->name, "ndiswrapper") == 0)
3099                 add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
3100 
3101         /* driverloader was caught wrongly pretending to be under GPL */
3102         if (strcmp(mod->name, "driverloader") == 0)
3103                 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3104                                  LOCKDEP_NOW_UNRELIABLE);
3105 
3106         /* lve claims to be GPL but upstream won't provide source */
3107         if (strcmp(mod->name, "lve") == 0)
3108                 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3109                                  LOCKDEP_NOW_UNRELIABLE);
3110 
3111 #ifdef CONFIG_MODVERSIONS
3112         if ((mod->num_syms && !mod->crcs)
3113             || (mod->num_gpl_syms && !mod->gpl_crcs)
3114             || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
3115 #ifdef CONFIG_UNUSED_SYMBOLS
3116             || (mod->num_unused_syms && !mod->unused_crcs)
3117             || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
3118 #endif
3119                 ) {
3120                 return try_to_force_load(mod,
3121                                          "no versions for exported symbols");
3122         }
3123 #endif
3124         return 0;
3125 }
3126 
3127 static void flush_module_icache(const struct module *mod)
3128 {
3129         mm_segment_t old_fs;
3130 
3131         /* flush the icache in correct context */
3132         old_fs = get_fs();
3133         set_fs(KERNEL_DS);
3134 
3135         /*
3136          * Flush the instruction cache, since we've played with text.
3137          * Do it before processing of module parameters, so the module
3138          * can provide parameter accessor functions of its own.
3139          */
3140         if (mod->init_layout.base)
3141                 flush_icache_range((unsigned long)mod->init_layout.base,
3142                                    (unsigned long)mod->init_layout.base
3143                                    + mod->init_layout.size);
3144         flush_icache_range((unsigned long)mod->core_layout.base,
3145                            (unsigned long)mod->core_layout.base + mod->core_layout.size);
3146 
3147         set_fs(old_fs);
3148 }
3149 
3150 int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
3151                                      Elf_Shdr *sechdrs,
3152                                      char *secstrings,
3153                                      struct module *mod)
3154 {
3155         return 0;
3156 }
3157 
3158 static struct module *layout_and_allocate(struct load_info *info, int flags)
3159 {
3160         /* Module within temporary copy. */
3161         struct module *mod;
3162         int err;
3163 
3164         mod = setup_load_info(info, flags);
3165         if (IS_ERR(mod))
3166                 return mod;
3167 
3168         err = check_modinfo(mod, info, flags);
3169         if (err)
3170                 return ERR_PTR(err);
3171 
3172         /* Allow arches to frob section contents and sizes.  */
3173         err = module_frob_arch_sections(info->hdr, info->sechdrs,
3174                                         info->secstrings, mod);
3175         if (err < 0)
3176                 return ERR_PTR(err);
3177 
3178         /* We will do a special allocation for per-cpu sections later. */
3179         info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
3180 
3181         /* Determine total sizes, and put offsets in sh_entsize.  For now
3182            this is done generically; there doesn't appear to be any
3183            special cases for the architectures. */
3184         layout_sections(mod, info);
3185         layout_symtab(mod, info);
3186 
3187         /* Allocate and move to the final place */
3188         err = move_module(mod, info);
3189         if (err)
3190                 return ERR_PTR(err);
3191 
3192         /* Module has been copied to its final place now: return it. */
3193         mod = (void *)info->sechdrs[info->index.mod].sh_addr;
3194         kmemleak_load_module(mod, info);
3195         return mod;
3196 }
3197 
3198 /* mod is no longer valid after this! */
3199 static void module_deallocate(struct module *mod, struct load_info *info)
3200 {
3201         percpu_modfree(mod);
3202         module_arch_freeing_init(mod);
3203         module_memfree(mod->init_layout.base);
3204         module_memfree(mod->core_layout.base);
3205 }
3206 
3207 int __weak module_finalize(const Elf_Ehdr *hdr,
3208                            const Elf_Shdr *sechdrs,
3209                            struct module *me)
3210 {
3211         return 0;
3212 }
3213 
3214 static int post_relocation(struct module *mod, const struct load_info *info)
3215 {
3216         /* Sort exception table now relocations are done. */
3217         sort_extable(mod->extable, mod->extable + mod->num_exentries);
3218 
3219         /* Copy relocated percpu area over. */
3220         percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
3221                        info->sechdrs[info->index.pcpu].sh_size);
3222 
3223         /* Setup kallsyms-specific fields. */
3224         add_kallsyms(mod, info);
3225 
3226         /* Arch-specific module finalizing. */
3227         return module_finalize(info->hdr, info->sechdrs, mod);
3228 }
3229 
3230 /* Is this module of this name done loading?  No locks held. */
3231 static bool finished_loading(const char *name)
3232 {
3233         struct module *mod;
3234         bool ret;
3235 
3236         /*
3237          * The module_mutex should not be a heavily contended lock;
3238          * if we get the occasional sleep here, we'll go an extra iteration
3239          * in the wait_event_interruptible(), which is harmless.
3240          */
3241         sched_annotate_sleep();
3242         mutex_lock(&module_mutex);
3243         mod = find_module_all(name, strlen(name), true);
3244         ret = !mod || mod->state == MODULE_STATE_LIVE
3245                 || mod->state == MODULE_STATE_GOING;
3246         mutex_unlock(&module_mutex);
3247 
3248         return ret;
3249 }
3250 
3251 /* Call module constructors. */
3252 static void do_mod_ctors(struct module *mod)
3253 {
3254 #ifdef CONFIG_CONSTRUCTORS
3255         unsigned long i;
3256 
3257         for (i = 0; i < mod->num_ctors; i++)
3258                 mod->ctors[i]();
3259 #endif
3260 }
3261 
3262 /* For freeing module_init on success, in case kallsyms traversing */
3263 struct mod_initfree {
3264         struct rcu_head rcu;
3265         void *module_init;
3266 };
3267 
3268 static void do_free_init(struct rcu_head *head)
3269 {
3270         struct mod_initfree *m = container_of(head, struct mod_initfree, rcu);
3271         module_memfree(m->module_init);
3272         kfree(m);
3273 }
3274 
3275 /*
3276  * This is where the real work happens.
3277  *
3278  * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb
3279  * helper command 'lx-symbols'.
3280  */
3281 static noinline int do_init_module(struct module *mod)
3282 {
3283         int ret = 0;
3284         struct mod_initfree *freeinit;
3285 
3286         freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
3287         if (!freeinit) {
3288                 ret = -ENOMEM;
3289                 goto fail;
3290         }
3291         freeinit->module_init = mod->init_layout.base;
3292 
3293         /*
3294          * We want to find out whether @mod uses async during init.  Clear
3295          * PF_USED_ASYNC.  async_schedule*() will set it.
3296          */
3297         current->flags &= ~PF_USED_ASYNC;
3298 
3299         do_mod_ctors(mod);
3300         /* Start the module */
3301         if (mod->init != NULL)
3302                 ret = do_one_initcall(mod->init);
3303         if (ret < 0) {
3304                 goto fail_free_freeinit;
3305         }
3306         if (ret > 0) {
3307                 pr_warn("%s: '%s'->init suspiciously returned %d, it should "
3308                         "follow 0/-E convention\n"
3309                         "%s: loading module anyway...\n",
3310                         __func__, mod->name, ret, __func__);
3311                 dump_stack();
3312         }
3313 
3314         /* Now it's a first class citizen! */
3315         mod->state = MODULE_STATE_LIVE;
3316         blocking_notifier_call_chain(&module_notify_list,
3317                                      MODULE_STATE_LIVE, mod);
3318 
3319         /*
3320          * We need to finish all async code before the module init sequence
3321          * is done.  This has potential to deadlock.  For example, a newly
3322          * detected block device can trigger request_module() of the
3323          * default iosched from async probing task.  Once userland helper
3324          * reaches here, async_synchronize_full() will wait on the async
3325          * task waiting on request_module() and deadlock.
3326          *
3327          * This deadlock is avoided by perfomring async_synchronize_full()
3328          * iff module init queued any async jobs.  This isn't a full
3329          * solution as it will deadlock the same if module loading from
3330          * async jobs nests more than once; however, due to the various
3331          * constraints, this hack seems to be the best option for now.
3332          * Please refer to the following thread for details.
3333          *
3334          * http://thread.gmane.org/gmane.linux.kernel/1420814
3335          */
3336         if (!mod->async_probe_requested && (current->flags & PF_USED_ASYNC))
3337                 async_synchronize_full();
3338 
3339         mutex_lock(&module_mutex);
3340         /* Drop initial reference. */
3341         module_put(mod);
3342         trim_init_extable(mod);
3343 #ifdef CONFIG_KALLSYMS
3344         /* Switch to core kallsyms now init is done: kallsyms may be walking! */
3345         rcu_assign_pointer(mod->kallsyms, &mod->core_kallsyms);
3346 #endif
3347         mod_tree_remove_init(mod);
3348         disable_ro_nx(&mod->init_layout);
3349         module_arch_freeing_init(mod);
3350         mod->init_layout.base = NULL;
3351         mod->init_layout.size = 0;
3352         mod->init_layout.ro_size = 0;
3353         mod->init_layout.text_size = 0;
3354         /*
3355          * We want to free module_init, but be aware that kallsyms may be
3356          * walking this with preempt disabled.  In all the failure paths, we
3357          * call synchronize_sched(), but we don't want to slow down the success
3358          * path, so use actual RCU here.
3359          */
3360         call_rcu_sched(&freeinit->rcu, do_free_init);
3361         mutex_unlock(&module_mutex);
3362         wake_up_all(&module_wq);
3363 
3364         return 0;
3365 
3366 fail_free_freeinit:
3367         kfree(freeinit);
3368 fail:
3369         /* Try to protect us from buggy refcounters. */
3370         mod->state = MODULE_STATE_GOING;
3371         synchronize_sched();
3372         module_put(mod);
3373         blocking_notifier_call_chain(&module_notify_list,
3374                                      MODULE_STATE_GOING, mod);
3375         klp_module_going(mod);
3376         ftrace_release_mod(mod);
3377         free_module(mod);
3378         wake_up_all(&module_wq);
3379         return ret;
3380 }
3381 
3382 static int may_init_module(void)
3383 {
3384         if (!capable(CAP_SYS_MODULE) || modules_disabled)
3385                 return -EPERM;
3386 
3387         return 0;
3388 }
3389 
3390 /*
3391  * We try to place it in the list now to make sure it's unique before
3392  * we dedicate too many resources.  In particular, temporary percpu
3393  * memory exhaustion.
3394  */
3395 static int add_unformed_module(struct module *mod)
3396 {
3397         int err;
3398         struct module *old;
3399 
3400         mod->state = MODULE_STATE_UNFORMED;
3401 
3402 again:
3403         mutex_lock(&module_mutex);
3404         old = find_module_all(mod->name, strlen(mod->name), true);
3405         if (old != NULL) {
3406                 if (old->state == MODULE_STATE_COMING
3407                     || old->state == MODULE_STATE_UNFORMED) {
3408                         /* Wait in case it fails to load. */
3409                         mutex_unlock(&module_mutex);
3410                         err = wait_event_interruptible(module_wq,
3411                                                finished_loading(mod->name));
3412                         if (err)
3413                                 goto out_unlocked;
3414                         goto again;
3415                 }
3416                 err = -EEXIST;
3417                 goto out;
3418         }
3419         mod_update_bounds(mod);
3420         list_add_rcu(&mod->list, &modules);
3421         mod_tree_insert(mod);
3422         err = 0;
3423 
3424 out:
3425         mutex_unlock(&module_mutex);
3426 out_unlocked:
3427         return err;
3428 }
3429 
3430 static int complete_formation(struct module *mod, struct load_info *info)
3431 {
3432         int err;
3433 
3434         mutex_lock(&module_mutex);
3435 
3436         /* Find duplicate symbols (must be called under lock). */
3437         err = verify_export_symbols(mod);
3438         if (err < 0)
3439                 goto out;
3440 
3441         /* This relies on module_mutex for list integrity. */
3442         module_bug_finalize(info->hdr, info->sechdrs, mod);
3443 
3444         /* Set RO and NX regions */
3445         module_enable_ro(mod);
3446         module_enable_nx(mod);
3447 
3448         /* Mark state as coming so strong_try_module_get() ignores us,
3449          * but kallsyms etc. can see us. */
3450         mod->state = MODULE_STATE_COMING;
3451         mutex_unlock(&module_mutex);
3452 
3453         return 0;
3454 
3455 out:
3456         mutex_unlock(&module_mutex);
3457         return err;
3458 }
3459 
3460 static int prepare_coming_module(struct module *mod)
3461 {
3462         int err;
3463 
3464         ftrace_module_enable(mod);
3465         err = klp_module_coming(mod);
3466         if (err)
3467                 return err;
3468 
3469         blocking_notifier_call_chain(&module_notify_list,
3470                                      MODULE_STATE_COMING, mod);
3471         return 0;
3472 }
3473 
3474 static int unknown_module_param_cb(char *param, char *val, const char *modname,
3475                                    void *arg)
3476 {
3477         struct module *mod = arg;
3478         int ret;
3479 
3480         if (strcmp(param, "async_probe") == 0) {
3481                 mod->async_probe_requested = true;
3482                 return 0;
3483         }
3484 
3485         /* Check for magic 'dyndbg' arg */
3486         ret = ddebug_dyndbg_module_param_cb(param, val, modname);
3487         if (ret != 0)
3488                 pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
3489         return 0;
3490 }
3491 
3492 /* Allocate and load the module: note that size of section 0 is always
3493    zero, and we rely on this for optional sections. */
3494 static int load_module(struct load_info *info, const char __user *uargs,
3495                        int flags)
3496 {
3497         struct module *mod;
3498         long err;
3499         char *after_dashes;
3500 
3501         err = module_sig_check(info);
3502         if (err)
3503                 goto free_copy;
3504 
3505         err = elf_header_check(info);
3506         if (err)
3507                 goto free_copy;
3508 
3509         /* Figure out module layout, and allocate all the memory. */
3510         mod = layout_and_allocate(info, flags);
3511         if (IS_ERR(mod)) {
3512                 err = PTR_ERR(mod);
3513                 goto free_copy;
3514         }
3515 
3516         /* Reserve our place in the list. */
3517         err = add_unformed_module(mod);
3518         if (err)
3519                 goto free_module;
3520 
3521 #ifdef CONFIG_MODULE_SIG
3522         mod->sig_ok = info->sig_ok;
3523         if (!mod->sig_ok) {
3524                 pr_notice_once("%s: module verification failed: signature "
3525                                "and/or required key missing - tainting "
3526                                "kernel\n", mod->name);
3527                 add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
3528         }
3529 #endif
3530 
3531         /* To avoid stressing percpu allocator, do this once we're unique. */
3532         err = percpu_modalloc(mod, info);
3533         if (err)
3534                 goto unlink_mod;
3535 
3536         /* Now module is in final location, initialize linked lists, etc. */
3537         err = module_unload_init(mod);
3538         if (err)
3539                 goto unlink_mod;
3540 
3541         init_param_lock(mod);
3542 
3543         /* Now we've got everything in the final locations, we can
3544          * find optional sections. */
3545         err = find_module_sections(mod, info);
3546         if (err)
3547                 goto free_unload;
3548 
3549         err = check_module_license_and_versions(mod);
3550         if (err)
3551                 goto free_unload;
3552 
3553         /* Set up MODINFO_ATTR fields */
3554         setup_modinfo(mod, info);
3555 
3556         /* Fix up syms, so that st_value is a pointer to location. */
3557         err = simplify_symbols(mod, info);
3558         if (err < 0)
3559                 goto free_modinfo;
3560 
3561         err = apply_relocations(mod, info);
3562         if (err < 0)
3563                 goto free_modinfo;
3564 
3565         err = post_relocation(mod, info);
3566         if (err < 0)
3567                 goto free_modinfo;
3568 
3569         flush_module_icache(mod);
3570 
3571         /* Now copy in args */
3572         mod->args = strndup_user(uargs, ~0UL >> 1);
3573         if (IS_ERR(mod->args)) {
3574                 err = PTR_ERR(mod->args);
3575                 goto free_arch_cleanup;
3576         }
3577 
3578         dynamic_debug_setup(info->debug, info->num_debug);
3579 
3580         /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
3581         ftrace_module_init(mod);
3582 
3583         /* Finally it's fully formed, ready to start executing. */
3584         err = complete_formation(mod, info);
3585         if (err)
3586                 goto ddebug_cleanup;
3587 
3588         err = prepare_coming_module(mod);
3589         if (err)
3590                 goto bug_cleanup;
3591 
3592         /* Module is ready to execute: parsing args may do that. */
3593         after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
3594                                   -32768, 32767, mod,
3595                                   unknown_module_param_cb);
3596         if (IS_ERR(after_dashes)) {
3597                 err = PTR_ERR(after_dashes);
3598                 goto coming_cleanup;
3599         } else if (after_dashes) {
3600                 pr_warn("%s: parameters '%s' after `--' ignored\n",
3601                        mod->name, after_dashes);
3602         }
3603 
3604         /* Link in to syfs. */
3605         err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
3606         if (err < 0)
3607                 goto coming_cleanup;
3608 
3609         if (is_livepatch_module(mod)) {
3610                 err = copy_module_elf(mod, info);
3611                 if (err < 0)
3612                         goto sysfs_cleanup;
3613         }
3614 
3615         /* Get rid of temporary copy. */
3616         free_copy(info);
3617 
3618         /* Done! */
3619         trace_module_load(mod);
3620 
3621         return do_init_module(mod);
3622 
3623  sysfs_cleanup:
3624         mod_sysfs_teardown(mod);
3625  coming_cleanup:
3626         blocking_notifier_call_chain(&module_notify_list,
3627                                      MODULE_STATE_GOING, mod);
3628         klp_module_going(mod);
3629  bug_cleanup:
3630         /* module_bug_cleanup needs module_mutex protection */
3631         mutex_lock(&module_mutex);
3632         module_bug_cleanup(mod);
3633         mutex_unlock(&module_mutex);
3634 
3635         /* we can't deallocate the module until we clear memory protection */
3636         module_disable_ro(mod);
3637         module_disable_nx(mod);
3638 
3639  ddebug_cleanup:
3640         dynamic_debug_remove(info->debug);
3641         synchronize_sched();
3642         kfree(mod->args);
3643  free_arch_cleanup:
3644         module_arch_cleanup(mod);
3645  free_modinfo:
3646         free_modinfo(mod);
3647  free_unload:
3648         module_unload_free(mod);
3649  unlink_mod:
3650         mutex_lock(&module_mutex);
3651         /* Unlink carefully: kallsyms could be walking list. */
3652         list_del_rcu(&mod->list);
3653         mod_tree_remove(mod);
3654         wake_up_all(&module_wq);
3655         /* Wait for RCU-sched synchronizing before releasing mod->list. */
3656         synchronize_sched();
3657         mutex_unlock(&module_mutex);
3658  free_module:
3659         /*
3660          * Ftrace needs to clean up what it initialized.
3661          * This does nothing if ftrace_module_init() wasn't called,
3662          * but it must be called outside of module_mutex.
3663          */
3664         ftrace_release_mod(mod);
3665         /* Free lock-classes; relies on the preceding sync_rcu() */
3666         lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
3667 
3668         module_deallocate(mod, info);
3669  free_copy:
3670         free_copy(info);
3671         return err;
3672 }
3673 
3674 SYSCALL_DEFINE3(init_module, void __user *, umod,
3675                 unsigned long, len, const char __user *, uargs)
3676 {
3677         int err;
3678         struct load_info info = { };
3679 
3680         err = may_init_module();
3681         if (err)
3682                 return err;
3683 
3684         pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
3685                umod, len, uargs);
3686 
3687         err = copy_module_from_user(umod, len, &info);
3688         if (err)
3689                 return err;
3690 
3691         return load_module(&info, uargs, 0);
3692 }
3693 
3694 SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
3695 {
3696         struct load_info info = { };
3697         loff_t size;
3698         void *hdr;
3699         int err;
3700 
3701         err = may_init_module();
3702         if (err)
3703                 return err;
3704 
3705         pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
3706 
3707         if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
3708                       |MODULE_INIT_IGNORE_VERMAGIC))
3709                 return -EINVAL;
3710 
3711         err = kernel_read_file_from_fd(fd, &hdr, &size, INT_MAX,
3712                                        READING_MODULE);
3713         if (err)
3714                 return err;
3715         info.hdr = hdr;
3716         info.len = size;
3717 
3718         return load_module(&info, uargs, flags);
3719 }
3720 
3721 static inline int within(unsigned long addr, void *start, unsigned long size)
3722 {
3723         return ((void *)addr >= start && (void *)addr < start + size);
3724 }
3725 
3726 #ifdef CONFIG_KALLSYMS
3727 /*
3728  * This ignores the intensely annoying "mapping symbols" found
3729  * in ARM ELF files: $a, $t and $d.
3730  */
3731 static inline int is_arm_mapping_symbol(const char *str)
3732 {
3733         if (str[0] == '.' && str[1] == 'L')
3734                 return true;
3735         return str[0] == '$' && strchr("axtd", str[1])
3736                && (str[2] == '\0' || str[2] == '.');
3737 }
3738 
3739 static const char *symname(struct mod_kallsyms *kallsyms, unsigned int symnum)
3740 {
3741         return kallsyms->strtab + kallsyms->symtab[symnum].st_name;
3742 }
3743 
3744 static const char *get_ksymbol(struct module *mod,
3745                                unsigned long addr,
3746                                unsigned long *size,
3747                                unsigned long *offset)
3748 {
3749         unsigned int i, best = 0;
3750         unsigned long nextval;
3751         struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
3752 
3753         /* At worse, next value is at end of module */
3754         if (within_module_init(addr, mod))
3755                 nextval = (unsigned long)mod->init_layout.base+mod->init_layout.text_size;
3756         else
3757                 nextval = (unsigned long)mod->core_layout.base+mod->core_layout.text_size;
3758 
3759         /* Scan for closest preceding symbol, and next symbol. (ELF
3760            starts real symbols at 1). */
3761         for (i = 1; i < kallsyms->num_symtab; i++) {
3762                 if (kallsyms->symtab[i].st_shndx == SHN_UNDEF)
3763                         continue;
3764 
3765                 /* We ignore unnamed symbols: they're uninformative
3766                  * and inserted at a whim. */
3767                 if (*symname(kallsyms, i) == '\0'
3768                     || is_arm_mapping_symbol(symname(kallsyms, i)))
3769                         continue;
3770 
3771                 if (kallsyms->symtab[i].st_value <= addr
3772                     && kallsyms->symtab[i].st_value > kallsyms->symtab[best].st_value)
3773                         best = i;
3774                 if (kallsyms->symtab[i].st_value > addr
3775                     && kallsyms->symtab[i].st_value < nextval)
3776                         nextval = kallsyms->symtab[i].st_value;
3777         }
3778 
3779         if (!best)
3780                 return NULL;
3781 
3782         if (size)
3783                 *size = nextval - kallsyms->symtab[best].st_value;
3784         if (offset)
3785                 *offset = addr - kallsyms->symtab[best].st_value;
3786         return symname(kallsyms, best);
3787 }
3788 
3789 /* For kallsyms to ask for address resolution.  NULL means not found.  Careful
3790  * not to lock to avoid deadlock on oopses, simply disable preemption. */
3791 const char *module_address_lookup(unsigned long addr,
3792                             unsigned long *size,
3793                             unsigned long *offset,
3794                             char **modname,
3795                             char *namebuf)
3796 {
3797         const char *ret = NULL;
3798         struct module *mod;
3799 
3800         preempt_disable();
3801         mod = __module_address(addr);
3802         if (mod) {
3803                 if (modname)
3804                         *modname = mod->name;
3805                 ret = get_ksymbol(mod, addr, size, offset);
3806         }
3807         /* Make a copy in here where it's safe */
3808         if (ret) {
3809                 strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
3810                 ret = namebuf;
3811         }
3812         preempt_enable();
3813 
3814         return ret;
3815 }
3816 
3817 int lookup_module_symbol_name(unsigned long addr, char *symname)
3818 {
3819         struct module *mod;
3820 
3821         preempt_disable();
3822         list_for_each_entry_rcu(mod, &modules, list) {
3823                 if (mod->state == MODULE_STATE_UNFORMED)
3824                         continue;
3825                 if (within_module(addr, mod)) {
3826                         const char *sym;
3827 
3828                         sym = get_ksymbol(mod, addr, NULL, NULL);
3829                         if (!sym)
3830                                 goto out;
3831                         strlcpy(symname, sym, KSYM_NAME_LEN);
3832                         preempt_enable();
3833                         return 0;
3834                 }
3835         }
3836 out:
3837         preempt_enable();
3838         return -ERANGE;
3839 }
3840 
3841 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
3842                         unsigned long *offset, char *modname, char *name)
3843 {
3844         struct module *mod;
3845 
3846         preempt_disable();
3847         list_for_each_entry_rcu(mod, &modules, list) {
3848                 if (mod->state == MODULE_STATE_UNFORMED)
3849                         continue;
3850                 if (within_module(addr, mod)) {
3851                         const char *sym;
3852 
3853                         sym = get_ksymbol(mod, addr, size, offset);
3854                         if (!sym)
3855                                 goto out;
3856                         if (modname)
3857                                 strlcpy(modname, mod->name, MODULE_NAME_LEN);
3858                         if (name)
3859                                 strlcpy(name, sym, KSYM_NAME_LEN);
3860                         preempt_enable();
3861                         return 0;
3862                 }
3863         }
3864 out:
3865         preempt_enable();
3866         return -ERANGE;
3867 }
3868 
3869 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
3870                         char *name, char *module_name, int *exported)
3871 {
3872         struct module *mod;
3873 
3874         preempt_disable();
3875         list_for_each_entry_rcu(mod, &modules, list) {
3876                 struct mod_kallsyms *kallsyms;
3877 
3878                 if (mod->state == MODULE_STATE_UNFORMED)
3879                         continue;
3880                 kallsyms = rcu_dereference_sched(mod->kallsyms);
3881                 if (symnum < kallsyms->num_symtab) {
3882                         *value = kallsyms->symtab[symnum].st_value;
3883                         *type = kallsyms->symtab[symnum].st_info;
3884                         strlcpy(name, symname(kallsyms, symnum), KSYM_NAME_LEN);
3885                         strlcpy(module_name, mod->name, MODULE_NAME_LEN);
3886                         *exported = is_exported(name, *value, mod);
3887                         preempt_enable();
3888                         return 0;
3889                 }
3890                 symnum -= kallsyms->num_symtab;
3891         }
3892         preempt_enable();
3893         return -ERANGE;
3894 }
3895 
3896 static unsigned long mod_find_symname(struct module *mod, const char *name)
3897 {
3898         unsigned int i;
3899         struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
3900 
3901         for (i = 0; i < kallsyms->num_symtab; i++)
3902                 if (strcmp(name, symname(kallsyms, i)) == 0 &&
3903                     kallsyms->symtab[i].st_info != 'U')
3904                         return kallsyms->symtab[i].st_value;
3905         return 0;
3906 }
3907 
3908 /* Look for this name: can be of form module:name. */
3909 unsigned long module_kallsyms_lookup_name(const char *name)
3910 {
3911         struct module *mod;
3912         char *colon;
3913         unsigned long ret = 0;
3914 
3915         /* Don't lock: we're in enough trouble already. */
3916         preempt_disable();
3917         if ((colon = strchr(name, ':')) != NULL) {
3918                 if ((mod = find_module_all(name, colon - name, false)) != NULL)
3919                         ret = mod_find_symname(mod, colon+1);
3920         } else {
3921                 list_for_each_entry_rcu(mod, &modules, list) {
3922                         if (mod->state == MODULE_STATE_UNFORMED)
3923                                 continue;
3924                         if ((ret = mod_find_symname(mod, name)) != 0)
3925                                 break;
3926                 }
3927         }
3928         preempt_enable();
3929         return ret;
3930 }
3931 
3932 int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
3933                                              struct module *, unsigned long),
3934                                    void *data)
3935 {
3936         struct module *mod;
3937         unsigned int i;
3938         int ret;
3939 
3940         module_assert_mutex();
3941 
3942         list_for_each_entry(mod, &modules, list) {
3943                 /* We hold module_mutex: no need for rcu_dereference_sched */
3944                 struct mod_kallsyms *kallsyms = mod->kallsyms;
3945 
3946                 if (mod->state == MODULE_STATE_UNFORMED)
3947                         continue;
3948                 for (i = 0; i < kallsyms->num_symtab; i++) {
3949                         ret = fn(data, symname(kallsyms, i),
3950                                  mod, kallsyms->symtab[i].st_value);
3951                         if (ret != 0)
3952                                 return ret;
3953                 }
3954         }
3955         return 0;
3956 }
3957 #endif /* CONFIG_KALLSYMS */
3958 
3959 static char *module_flags(struct module *mod, char *buf)
3960 {
3961         int bx = 0;
3962 
3963         BUG_ON(mod->state == MODULE_STATE_UNFORMED);
3964         if (mod->taints ||
3965             mod->state == MODULE_STATE_GOING ||
3966             mod->state == MODULE_STATE_COMING) {
3967                 buf[bx++] = '(';
3968                 bx += module_flags_taint(mod, buf + bx);
3969                 /* Show a - for module-is-being-unloaded */
3970                 if (mod->state == MODULE_STATE_GOING)
3971                         buf[bx++] = '-';
3972                 /* Show a + for module-is-being-loaded */
3973                 if (mod->state == MODULE_STATE_COMING)
3974                         buf[bx++] = '+';
3975                 buf[bx++] = ')';
3976         }
3977         buf[bx] = '\0';
3978 
3979         return buf;
3980 }
3981 
3982 #ifdef CONFIG_PROC_FS
3983 /* Called by the /proc file system to return a list of modules. */
3984 static void *m_start(struct seq_file *m, loff_t *pos)
3985 {
3986         mutex_lock(&module_mutex);
3987         return seq_list_start(&modules, *pos);
3988 }
3989 
3990 static void *m_next(struct seq_file *m, void *p, loff_t *pos)
3991 {
3992         return seq_list_next(p, &modules, pos);
3993 }
3994 
3995 static void m_stop(struct seq_file *m, void *p)
3996 {
3997         mutex_unlock(&module_mutex);
3998 }
3999 
4000 static int m_show(struct seq_file *m, void *p)
4001 {
4002         struct module *mod = list_entry(p, struct module, list);
4003         char buf[8];
4004 
4005         /* We always ignore unformed modules. */
4006         if (mod->state == MODULE_STATE_UNFORMED)
4007                 return 0;
4008 
4009         seq_printf(m, "%s %u",
4010                    mod->name, mod->init_layout.size + mod->core_layout.size);
4011         print_unload_info(m, mod);
4012 
4013         /* Informative for users. */
4014         seq_printf(m, " %s",
4015                    mod->state == MODULE_STATE_GOING ? "Unloading" :
4016                    mod->state == MODULE_STATE_COMING ? "Loading" :
4017                    "Live");
4018         /* Used by oprofile and other similar tools. */
4019         seq_printf(m, " 0x%pK", mod->core_layout.base);
4020 
4021         /* Taints info */
4022         if (mod->taints)
4023                 seq_printf(m, " %s", module_flags(mod, buf));
4024 
4025         seq_puts(m, "\n");
4026         return 0;
4027 }
4028 
4029 /* Format: modulename size refcount deps address
4030 
4031    Where refcount is a number or -, and deps is a comma-separated list
4032    of depends or -.
4033 */
4034 static const struct seq_operations modules_op = {
4035         .start  = m_start,
4036         .next   = m_next,
4037         .stop   = m_stop,
4038         .show   = m_show
4039 };
4040 
4041 static int modules_open(struct inode *inode, struct file *file)
4042 {
4043         return seq_open(file, &modules_op);
4044 }
4045 
4046 static const struct file_operations proc_modules_operations = {
4047         .open           = modules_open,
4048         .read           = seq_read,
4049         .llseek         = seq_lseek,
4050         .release        = seq_release,
4051 };
4052 
4053 static int __init proc_modules_init(void)
4054 {
4055         proc_create("modules", 0, NULL, &proc_modules_operations);
4056         return 0;
4057 }
4058 module_init(proc_modules_init);
4059 #endif
4060 
4061 /* Given an address, look for it in the module exception tables. */
4062 const struct exception_table_entry *search_module_extables(unsigned long addr)
4063 {
4064         const struct exception_table_entry *e = NULL;
4065         struct module *mod;
4066 
4067         preempt_disable();
4068         list_for_each_entry_rcu(mod, &modules, list) {
4069                 if (mod->state == MODULE_STATE_UNFORMED)
4070                         continue;
4071                 if (mod->num_exentries == 0)
4072                         continue;
4073 
4074                 e = search_extable(mod->extable,
4075                                    mod->extable + mod->num_exentries - 1,
4076                                    addr);
4077                 if (e)
4078                         break;
4079         }
4080         preempt_enable();
4081 
4082         /* Now, if we found one, we are running inside it now, hence
4083            we cannot unload the module, hence no refcnt needed. */
4084         return e;
4085 }
4086 
4087 /*
4088  * is_module_address - is this address inside a module?
4089  * @addr: the address to check.
4090  *
4091  * See is_module_text_address() if you simply want to see if the address
4092  * is code (not data).
4093  */
4094 bool is_module_address(unsigned long addr)
4095 {
4096         bool ret;
4097 
4098         preempt_disable();
4099         ret = __module_address(addr) != NULL;
4100         preempt_enable();
4101 
4102         return ret;
4103 }
4104 
4105 /*
4106  * __module_address - get the module which contains an address.
4107  * @addr: the address.
4108  *
4109  * Must be called with preempt disabled or module mutex held so that
4110  * module doesn't get freed during this.
4111  */
4112 struct module *__module_address(unsigned long addr)
4113 {
4114         struct module *mod;
4115 
4116         if (addr < module_addr_min || addr > module_addr_max)
4117                 return NULL;
4118 
4119         module_assert_mutex_or_preempt();
4120 
4121         mod = mod_find(addr);
4122         if (mod) {
4123                 BUG_ON(!within_module(addr, mod));
4124                 if (mod->state == MODULE_STATE_UNFORMED)
4125                         mod = NULL;
4126         }
4127         return mod;
4128 }
4129 EXPORT_SYMBOL_GPL(__module_address);
4130 
4131 /*
4132  * is_module_text_address - is this address inside module code?
4133  * @addr: the address to check.
4134  *
4135  * See is_module_address() if you simply want to see if the address is
4136  * anywhere in a module.  See kernel_text_address() for testing if an
4137  * address corresponds to kernel or module code.
4138  */
4139 bool is_module_text_address(unsigned long addr)
4140 {
4141         bool ret;
4142 
4143         preempt_disable();
4144         ret = __module_text_address(addr) != NULL;
4145         preempt_enable();
4146 
4147         return ret;
4148 }
4149 
4150 /*
4151  * __module_text_address - get the module whose code contains an address.
4152  * @addr: the address.
4153  *
4154  * Must be called with preempt disabled or module mutex held so that
4155  * module doesn't get freed during this.
4156  */
4157 struct module *__module_text_address(unsigned long addr)
4158 {
4159         struct module *mod = __module_address(addr);
4160         if (mod) {
4161                 /* Make sure it's within the text section. */
4162                 if (!within(addr, mod->init_layout.base, mod->init_layout.text_size)
4163                     && !within(addr, mod->core_layout.base, mod->core_layout.text_size))
4164                         mod = NULL;
4165         }
4166         return mod;
4167 }
4168 EXPORT_SYMBOL_GPL(__module_text_address);
4169 
4170 /* Don't grab lock, we're oopsing. */
4171 void print_modules(void)
4172 {
4173         struct module *mod;
4174         char buf[8];
4175 
4176         printk(KERN_DEFAULT "Modules linked in:");
4177         /* Most callers should already have preempt disabled, but make sure */
4178         preempt_disable();
4179         list_for_each_entry_rcu(mod, &modules, list) {
4180                 if (mod->state == MODULE_STATE_UNFORMED)
4181                         continue;
4182                 pr_cont(" %s%s", mod->name, module_flags(mod, buf));
4183         }
4184         preempt_enable();
4185         if (last_unloaded_module[0])
4186                 pr_cont(" [last unloaded: %s]", last_unloaded_module);
4187         pr_cont("\n");
4188 }
4189 
4190 #ifdef CONFIG_MODVERSIONS
4191 /* Generate the signature for all relevant module structures here.
4192  * If these change, we don't want to try to parse the module. */
4193 void module_layout(struct module *mod,
4194                    struct modversion_info *ver,
4195                    struct kernel_param *kp,
4196                    struct kernel_symbol *ks,
4197                    struct tracepoint * const *tp)
4198 {
4199 }
4200 EXPORT_SYMBOL(module_layout);
4201 #endif
4202 

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